68 results on '"Yim AP"'
Search Results
2. Solitary nasopharyngeal metastasis from lung primary: a long-term survivor after radiotherapy.
- Author
-
Wong RH, Tse GM, Ng CS, Wan IY, Underwood MJ, and Yim AP
- Subjects
- Adenocarcinoma surgery, Biopsy, Needle, Endoscopy methods, Follow-Up Studies, Humans, Immunohistochemistry, Lung Neoplasms surgery, Magnetic Resonance Imaging methods, Male, Middle Aged, Neoplasm Staging, Pneumonectomy methods, Radiotherapy Dosage, Time Factors, Treatment Outcome, Adenocarcinoma secondary, Lung Neoplasms pathology, Nasopharyngeal Neoplasms radiotherapy, Nasopharyngeal Neoplasms secondary
- Abstract
Isolated nasopharyngeal metastasis from lung primary is a rare condition. We report a patient with stage 1B adenocarcinoma of the lung who underwent anatomical lung resection and was subsequently found to have solitary nasopharyngeal metastasis. The patient received radiotherapy to nasopharynx and remained disease-free for 10 years from the date of diagnosis of nasopharyngeal metastasis. We postulate that solitary nasopharyngeal metastasis from lung primary might be a separate entity that responded well to radiotherapy., (Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
3. Invited commentary.
- Author
-
Yim AP
- Subjects
- Humans, Length of Stay, Thoracotomy, Treatment Outcome, Bronchiectasis surgery, Pneumonectomy, Thoracic Surgery, Video-Assisted
- Published
- 2011
- Full Text
- View/download PDF
4. Synchronous primary lung cancer and epidermal growth factor receptor mutation.
- Author
-
Ma ES, Cheng PN, Wong CL, and Yim AP
- Subjects
- Aged, Humans, Male, Carcinoma, Non-Small-Cell Lung genetics, Genes, erbB-1 genetics, Lung Neoplasms genetics, Mutation
- Abstract
We describe a 75-year-old Chinese man who presented with three separate tumors in three different lobes of the lung, without evidence of mediastinal or systemic involvement. All three tumors were surgically resected by minimal invasive approach. Based on a differing epidermal growth factor receptor (EGFR) mutation status, the tumors were characterized as synchronous triple primary rather than intrapulmonary metastases. This report highlights the clinical usefulness of molecular cancer biomarkers to determine prognosis and to guide management decision in multiple lung tumors., (2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
5. Video-assisted thoracic lung surgery: is there a barrier to widespread adoption?
- Author
-
Yim AP
- Subjects
- Humans, Lung Neoplasms surgery, Pneumonectomy methods, Thoracic Surgery, Video-Assisted
- Published
- 2010
- Full Text
- View/download PDF
6. Video-assisted thoracic surgery thymectomy: the better approach.
- Author
-
Ng CS, Wan IY, and Yim AP
- Subjects
- Humans, Myasthenia Gravis surgery, Thoracic Surgery, Video-Assisted, Thymectomy methods
- Abstract
Minimally invasive video-assisted thoracic surgery (VATS) thymectomy has evolved significantly over the last decade. The most common indication for VATS thymectomy is the treatment of myasthenia gravis (MG). Video-assisted thoracic surgery thymectomy results in less postoperative pain, better preserved pulmonary function, and improved cosmesis, which can be particularly important to many young female MG patients. Results of VATS thymectomy, in terms of complete stable remission from MG and symptomatic improvement, as well as safety, are comparable with conventional surgical techniques. This more patient-friendly approach would lead to wider acceptance by MG patients and their neurologists for earlier thymectomies and improved outcomes., (2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
7. Invited commentary.
- Author
-
Wan S and Yim AP
- Subjects
- Humans, Severity of Illness Index, Hemoptysis surgery, Pneumonectomy
- Published
- 2009
- Full Text
- View/download PDF
8. Multidisciplinary management of life-threatening massive hemoptysis: a 10-year experience.
- Author
-
Shigemura N, Wan IY, Yu SC, Wong RH, Hsin MK, Thung HK, Lee TW, Wan S, Underwood MJ, and Yim AP
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Algorithms, Female, Hemoptysis etiology, Humans, Male, Middle Aged, Retrospective Studies, Severity of Illness Index, Time Factors, Young Adult, Bronchial Arteries, Embolization, Therapeutic, Emergency Treatment, Hemoptysis therapy, Patient Care Team
- Abstract
Background: Life-threatening massive hemoptysis requires prompt action and thoracic surgical input. Although there are a number of reports regarding each therapeutic modality for medical or surgical treatment, the significance of a multidisciplinary strategy remains undetermined., Methods: From January 1995 to December 2005, 120 patients were referred to our cardiothoracic center with massive hemoptysis. We retrospectively reviewed and compared the outcomes of a recent 5-year period (2000 to 2005) with those from the previous 5 years (1995 to 1999), as we made major changes in our practice in 2000. We currently try to avoid surgery within 48 hours after onset of active hemoptysis and adopt bronchial artery embolization as a first-line therapy. Treatment decisions are made after discussions among intensive care unit physicians, thoracic surgeons, and interventional radiologists., Results: The former group had 49 patients (57.9 +/- 14.1 years old, 41 males), and the recent group, 71 (62.2 +/- 23.5 years old, 52 males). There were no significant differences for any characteristics studied between the groups. In analyses of short-term complications after surgery, the former had a higher in-hospital mortality rate than the recent group (15% versus 0%). Furthermore, postoperative complications were seen in 8 patients (30%) in the former, whereas those occurred in 3 patients (18%) in the recent group., Conclusion: Bronchial artery embolization is an effective therapeutic tool and plays a pivotal role in management of life-threatening massive hemoptysis. Surgery is indicated when bronchial artery embolization is not suitable and can be safely performed in combination with a rigid bronchoscopy or bronchial artery embolization procedure. Our results indicate that a multidisciplinary approach should be adopted for management of life-threatening massive hemoptysis.
- Published
- 2009
- Full Text
- View/download PDF
9. Video-assisted thoracic surgery major lung resection can be safely taught to trainees.
- Author
-
Wan IY, Thung KH, Hsin MK, Underwood MJ, and Yim AP
- Subjects
- Aged, Biopsy, Needle, Cohort Studies, Education, Medical, Graduate methods, Female, Follow-Up Studies, Humans, Immunohistochemistry, Internship and Residency, Lung Neoplasms mortality, Male, Middle Aged, Minimally Invasive Surgical Procedures adverse effects, Minimally Invasive Surgical Procedures education, Minimally Invasive Surgical Procedures methods, Neoplasm Staging, Postoperative Complications epidemiology, Postoperative Complications pathology, Probability, Retrospective Studies, Risk Assessment, Survival Rate, Thoracic Surgery, Video-Assisted adverse effects, Thoracic Surgery, Video-Assisted methods, Treatment Outcome, Clinical Competence, Lung Neoplasms pathology, Lung Neoplasms surgery, Pneumonectomy methods, Thoracic Surgery, Video-Assisted education
- Abstract
Background: Video-assisted thoracoscopic surgery (VATS) major lung resection for lung cancer has been an important part of thoracic surgical training program in our institution. In this study, we compared the results of VATS major lung resection performed by surgical trainees with those performed by experienced thoracic surgeons with specialist interest in VATS., Methods: From January 2002 to October 2006, the clinical data of 111 consecutive patients scheduled for VATS major lung resection were prospectively entered into the computerized clinical management system of the local health authority; these include patient demographics, comorbidity, operating time, postoperative complications, and outcome. We retrospectively compared the data of patients who were operated on by trainees with those who were operated on by experienced VATS surgeons., Results: One hundred and eleven patients with clinical stage I and II lung cancer underwent VATS major lung resection. Fifty-one (46%) of the procedures were performed by consultant surgeons and 60 VATS lung resections (54%) were performed by supervised trainees. Patients' demography and risk factors were comparable between the two groups. Trainees spent more time in performing the operation as compared with experienced VATS surgeons (mean operating time 162 minutes, p = 0.01). There was no significant difference in intraoperative or postoperative complications and outcomes between the two groups., Conclusions: Video-assisted thoracic surgery major lung resection for early stage nonsmall-cell lung cancer can be taught to residents who work under the supervision of experienced VATS surgeons. Video-assisted thoracic surgery major lung resection for lung cancer should be an integral part of thoracic surgical training program.
- Published
- 2008
- Full Text
- View/download PDF
10. Ventilation during cardiopulmonary bypass: impact on cytokine response and cardiopulmonary function.
- Author
-
Ng CS, Arifi AA, Wan S, Ho AM, Wan IY, Wong EM, and Yim AP
- Subjects
- Cardiopulmonary Bypass adverse effects, Coronary Angiography, Coronary Artery Bypass methods, Coronary Artery Bypass mortality, Coronary Stenosis blood, Coronary Stenosis diagnostic imaging, Coronary Stenosis mortality, Female, Follow-Up Studies, Heart Function Tests, Hemodynamics physiology, Humans, Inflammation Mediators blood, Male, Monitoring, Intraoperative methods, Multivariate Analysis, Oxygen therapeutic use, Probability, Prospective Studies, Reference Values, Respiratory Function Tests, Risk Assessment, Survival Rate, Treatment Outcome, Cardiopulmonary Bypass methods, Coronary Stenosis surgery, Cytokines blood, Intraoperative Care methods, Respiration, Artificial methods
- Abstract
Background: A complex inflammatory response associated with the use of cardiopulmonary bypass may ultimately lead to organ dysfunction. We investigate the effect of continuing ventilation during cardiopulmonary bypass on inflammatory reactions and cardiopulmonary function., Methods: Fifty patients undergoing cardiopulmonary bypass were prospectively randomized to continuous ventilation and nonventilation groups. Plasma interleukin-8, interleukin-10, matrix metalloproteinase-9, tissue inhibitor metalloproteinase-1, and thromboxane B2 levels were measured preoperatively, at 1, 4, and 6 hours after aortic declamping. Levels of these mediators were also determined in bronchoalveolar lavage preoperatively and four hours after declamping. Seven parameters of cardiopulmonary function, including dynamic compliance and systemic vascular resistance, were recorded during the same time points., Results: Plasma interleukin-10 levels were higher at 6 hours and tissue inhibitor metalloproteinase-1 levels were higher at 1 hour after aortic declamping in the continuous ventilation compared with the nonventilation group (p = 0.04 and 0.002, respectively), while bronchoalveolar lavage levels of tissue inhibitor metalloproteinase-1 were also higher in the continuous ventilation group 4 hours after declamping (p = 0.02). Plasma interleukin-8 levels were higher at 4 hours after declamping in the nonventilation group (p = 0.04). Postoperative dynamic compliance was better preserved in continuous ventilation patients than nonventilation patients at 6 hours after declamping (p = 0.0008)., Conclusions: Continued ventilation during cardiopulmonary bypass results in lesser inflammatory and proteolytic responses, and may better preserve pulmonary function than cardiopulmonary bypass without ventilation.
- Published
- 2008
- Full Text
- View/download PDF
11. Role of endothelin-1 receptor antagonists in vasoconstriction mediated by endothelin and other vasoconstrictors in human internal mammary artery.
- Author
-
He GW, Liu MH, Yang Q, Furnary A, and Yim AP
- Subjects
- Aged, Endothelin B Receptor Antagonists, Humans, In Vitro Techniques, Mammary Arteries physiology, Middle Aged, Oligopeptides pharmacology, Peptides, Cyclic pharmacology, Piperidines pharmacology, Receptor, Endothelin A physiology, Endothelin A Receptor Antagonists, Endothelin-1 physiology, Mammary Arteries drug effects, Vasoconstriction drug effects, Vasoconstrictor Agents pharmacology
- Abstract
Background: The action of antagonists for endothelin type A (ET(A)) and type B (ET(B)) on the vasoconstriction mediated by various vasoconstrictors in the human bypass grafts have not been well-defined. We studied the role of antagonists for both ET(A) and ET(B) receptors in vasoconstriction mediated by endothelin-1 and other vasoconstrictors in the human internal mammary artery (IMA)., Methods: Isolated IMA rings (n = 192, taken from 49 patients) were studied in organ bath for the interaction between endothelin-1, angiotensin II, U46619, and potassium chloride and the antagonist for ET(A) (BQ-123) or ET(B) (BQ-788)., Results: Significant relaxations were observed by BQ-123 (agonist: endothelin-1, 84.9 +/- 7.9%; angiotensin II, 45.5 +/- 5.1%; and U46619, 30.7 +/- 5.7%) or BQ-788 (agonist: endothelin-1, 66.5 +/- 11.3%; angiotensin II, 38.9 +/- 4.2%; and U46619, 30.8 +/- 4.0%), but not to potassium chloride-induced precontraction. Incubation of IMA with BQ-123 or BQ-123 + BQ-788 significantly shifted the concentration-contraction curve to endothelin-1 rightward (p < 0.05 vs control) with effective concentration causing 50% of maximal response (EC50) (-7.59 +/- 0.04 or -7.81 +/- 0.05 vs -8.47 +/- 0.05 log M in the control, p < 0.001), whereas BQ-788 alone did not affect the contraction curve (p = 1.0 vs control). In contrast, none of the endothelin-1 inhibitors and the combination demonstrated significant depression effects on angiotensin II, U46619, or potassium chloride-induced contraction., Conclusions: The present study demonstrates the role of ET(A) and ET(B) antagonists in the endothelin-1-mediated contraction in the human IMA and indicates the dominant role of ET(A) receptors. Although these effects are specific to endothelin-1, cross-action between endothelin-1 and angiotensin II exists. These findings provide useful knowledge for the future development of the clinical antispastic protocol in coronary bypass surgery.
- Published
- 2007
- Full Text
- View/download PDF
12. A case of endobronchial and cutaneous metastases.
- Author
-
Hsin MK and Yim AP
- Subjects
- Humans, Male, Middle Aged, Radiography, Thoracic, Tomography, X-Ray Computed, Adenocarcinoma secondary, Bronchial Neoplasms secondary, Skin Neoplasms secondary
- Published
- 2007
- Full Text
- View/download PDF
13. Giant metastatic endometrial sarcoma to the right lung.
- Author
-
Hsin MK and Yim AP
- Subjects
- Endometrial Neoplasms surgery, Female, Gynecologic Surgical Procedures, Humans, Lung Neoplasms surgery, Middle Aged, Pneumonectomy, Sarcoma surgery, Endometrial Neoplasms pathology, Lung Neoplasms secondary, Sarcoma secondary
- Published
- 2006
- Full Text
- View/download PDF
14. Invited commentary.
- Author
-
Ng EK and Yim AP
- Subjects
- Esophagectomy adverse effects, Humans, Surgical Wound Dehiscence etiology, Suture Techniques, Esophagectomy methods, Omentum surgery, Surgical Flaps, Surgical Wound Dehiscence prevention & control
- Published
- 2006
- Full Text
- View/download PDF
15. Jia-Si Huang: "A surgeon and something more".
- Author
-
Wan S and Yim AP
- Subjects
- China, History, 20th Century, Humans, International Cooperation, Military Medicine history, Societies, Medical history, Thoracic Surgery education, Thoracic Surgery history
- Abstract
In contrast to many industrialized countries, the growth of thoracic surgery in China was much more difficult over the first 5 decades under the ever-changing political and harsh socioeconomic conditions. As a matter of fact, the struggle to establish this specialty in a developing country with more than one fifth of the world population was certainly one of the most crucial challenges in the last century. The unique story of a pioneering Chinese thoracic surgeon--Dr Jia-Si Huang (1906-1984) was a glorious example of heroic leadership and self sacrifice. His fundamental role in developing cardiothoracic surgery in China was clearly reflected not only by some first-in-China operations he personally performed, but also by his continued contributions in educating younger generations of Chinese surgeons.
- Published
- 2006
- Full Text
- View/download PDF
16. Video-assisted thoracic surgery pulmonary resection for lung cancer in patients with poor lung function.
- Author
-
Garzon JC, Ng CS, Sihoe AD, Manlulu AV, Wong RH, Lee TW, and Yim AP
- Subjects
- Aged, Aged, 80 and over, Carcinoma, Non-Small-Cell Lung mortality, Carcinoma, Non-Small-Cell Lung physiopathology, Carcinoma, Non-Small-Cell Lung therapy, Combined Modality Therapy, Comorbidity, Female, Follow-Up Studies, Humans, Life Tables, Lung Neoplasms mortality, Lung Neoplasms physiopathology, Lung Neoplasms therapy, Male, Neoadjuvant Therapy, Neoplasm Metastasis, Pneumonectomy statistics & numerical data, Postoperative Complications epidemiology, Pulmonary Disease, Chronic Obstructive epidemiology, Retrospective Studies, Risk Factors, Severity of Illness Index, Smoking epidemiology, Survival Analysis, Survival Rate, Treatment Outcome, Carcinoma, Non-Small-Cell Lung surgery, Forced Expiratory Volume, Lung Neoplasms surgery, Pneumonectomy methods, Thoracic Surgery, Video-Assisted statistics & numerical data
- Abstract
Background: The aim of this study is to evaluate the early outcome of patients with poor lung function who underwent video-assisted thoracic surgery (VATS) pulmonary resection for primary non-small cell lung carcinoma., Methods: We reviewed retrospectively the records of patients with lung cancer undergoing VATS lung resection over a period of 5 years. Twenty-five patients with preoperative poor lung function defined as forced expiratory volume in 1 second less than 0.8 L or the percentage predicted value for forced expiratory volume in 1 second less than 50% were identified. Thirteen patients underwent VATS lobectomies and 12 VATS wedge resections. Data were analyzed with respect to demographics, risk factors, and early postoperative outcome and survival., Results: There were 8 cases of morbidities (29%) and no surgical mortality. Five of these 8 patients had respiratory-related complications after surgery. A deterioration in pulmonary performance as indicated by the Eastern Cooperative Oncology Group (ECOG) score was seen in 7 patients (28%), with only 1 patient having an ECOG score greater than 2. No patient required home oxygen supplementation beyond the third month postoperatively. After a median follow-up period of 15.1 months (range, 1 to 24), 5 patients died. Only 1 patient (4%) died of a respiratory complication (pneumonia 6 weeks after surgery). The other 4 deaths were due to recurrent or metastatic disease. The actuarial survival rates at 1 and 2 years were 80% and 69%, respectively., Conclusions: Video-assisted thoracic surgery pulmonary resection for cancer in patients with poor lung function can achieve acceptable functional and oncologic outcome.
- Published
- 2006
- Full Text
- View/download PDF
17. Analgesic effect of electroacupuncture in postthoracotomy pain: a prospective randomized trial.
- Author
-
Wong RH, Lee TW, Sihoe AD, Wan IY, Ng CS, Chan SK, Wong WW, Liang YM, and Yim AP
- Subjects
- Acetaminophen administration & dosage, Acetaminophen therapeutic use, Administration, Oral, Aged, Analgesia, Patient-Controlled, Analgesics, Non-Narcotic administration & dosage, Analgesics, Non-Narcotic therapeutic use, Carcinoma, Non-Small-Cell Lung surgery, Dextropropoxyphene administration & dosage, Dextropropoxyphene therapeutic use, Double-Blind Method, Equipment Design, Female, Humans, Lung Neoplasms surgery, Male, Middle Aged, Morphine administration & dosage, Morphine therapeutic use, Narcotics administration & dosage, Narcotics therapeutic use, Pain Measurement, Pain, Postoperative drug therapy, Pilot Projects, Placebos, Pneumonectomy methods, Prospective Studies, Electroacupuncture, Pain, Postoperative therapy, Thoracotomy, Transcutaneous Electric Nerve Stimulation
- Abstract
Background: The role of electroacupuncture in postthoracotomy pain control is uncertain. We conducted a pilot study to evaluate the role of electroacupuncture in the management of early postthoracotomy wound pain., Methods: A total of 27 patients with operable non-small cell lung carcinoma who received thoracotomy were recruited and randomized to receive either electroacupuncture or sham acupuncture in addition to routine oral analgesics and patient-controlled intravenous analgesia for postoperative pain control. All patients received acupuncture twice daily with visual analog pain score recorded for the first 7 postoperative days. Specific chest acupoints (LI 4, GB 34, GB 36, and TE 8) were targeted. Patient-controlled analgesia was used for the first 3 postoperative days in all patients, and the cumulative dosage used was recorded., Results: Two patients were excluded after randomization because of complications unrelated to acupuncture. Interventions and data collection were completed for the remaining 25 patients (13 in the electroacupuncture group; 12 in the sham acupuncture group). There was a trend for lower visual analog scale pain scores in the electro-acupuncture group between postoperative days 2 and 6, although this did not reach statistical significance. The cumulative dose of patient-controlled analgesia morphine used on postoperative day 2 was significantly lower in the electroacupuncture group (7.5 +/- 5 mg versus 15.6 +/- 12 mg; p < 0.05). Such delay of onset of pain control may be related to the frequency of electroacupuncture used., Conclusions: Electroacupuncture may reduce narcotic analgesic usage in the early postoperative period. A prospective randomized controlled trial using different electroacupuncture frequency is warranted to verify this benefit.
- Published
- 2006
- Full Text
- View/download PDF
18. Invited commentary.
- Author
-
Yim AP
- Subjects
- Humans, Prosthesis Design, Radiography, Interventional, Bronchial Fistula therapy, Pleural Diseases therapy, Respiratory Tract Fistula therapy, Stents
- Published
- 2006
- Full Text
- View/download PDF
19. Effect of hypoxia-reoxygenation on endothelial function in porcine cardiac microveins.
- Author
-
Dong YY, Wu M, Yim AP, and He GW
- Subjects
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid pharmacology, Animals, Bicarbonates, Biological Factors pharmacology, Bradykinin pharmacology, Calcium Chloride, Cardioplegic Solutions, Coronary Vessels, Endothelium, Vascular drug effects, In Vitro Techniques, Isotonic Solutions, Magnesium, Myocardial Contraction drug effects, Nitric Oxide physiology, Partial Pressure, Potassium Chloride, Sodium Chloride, Swine, Vasodilation drug effects, Endothelium, Vascular physiopathology, Myocardial Reperfusion Injury physiopathology
- Abstract
Background: The cardiac venous system possesses up to 30% of total coronary vascular resistance and the effect of hypoxia-reoxygenation (H-R) and St Thomas (ST) cardioplegic solution on the vein is unknown. We investigated the effects of H-R, with or without ST, on endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation in porcine cardiac microveins under clinically relevant temperatures., Methods: The microveins (diameter 200 to 450 microM) mounted in a myograph were subjected to hypoxia (Po2 < 5 mm Hg) for 30 minutes in Krebs solution (n = 8) or for 60 minutes in Krebs (n = 8) or in ST at 37 degrees C (n = 8) or 4 degrees C (n = 8), followed by 30-minute reoxygenation. The microvein was precontracted with thromboxane A2 mimetic U46619 (-7 log M) and the EDHF-mediated relaxation was induced by bradykinin (-10 to -6 log M) in the presence of indomethacin, NG-nitro-L-arginine, and oxyhemoglobin before and after H-R., Results: The maximal EDHF-mediated relaxation was significantly reduced after 30-minute hypoxia (38.7 +/- 2.0% vs 61.1 +/- 2.3%, n = 8, p < 0.001) or 60-minute hypoxia in either Krebs or ST at 37 degrees C (Krebs: 27.8 +/- 1.2% vs 56.6 +/- 2.5%, n = 8, p < 0.001; ST: 23.8 +/- 4.1% vs 57.1 +/- 1.5%, n = 8, p < 0.001). The relaxation was significantly less after prolonged H-R in Krebs (p < 0.001). Incubation in Krebs or ST at 4 degrees C also reduced the EDHF-mediated relaxation (Krebs: 25.3 +/- 3.3%, n = 8, p < 0.001; ST: 29.1 +/- 4.4%, n = 8, p < 0.001) and there were no significant differences between Krebs and ST regarding the relaxation at either 37 degrees C or 4 degrees C (p > 0.05)., Conclusions: We conclude that (1) H-R impairs EDHF-mediated relaxation in the coronary microveins with more severe injury during prolonged H-R and (2) ST does not provide protection to the EDHF-mediated relaxation impaired by H-R at either 37 degrees C or 4 degrees C.
- Published
- 2006
- Full Text
- View/download PDF
20. Hypoxia-reoxygenation, St. Thomas cardioplegic solution, and nicorandil on endothelium-derived hyperpolarizing factor in coronary microarteries.
- Author
-
Dong YY, Wu M, Yim AP, and He GW
- Subjects
- Animals, Bicarbonates pharmacology, Calcium Chloride pharmacology, Cell Hypoxia drug effects, Drug Interactions, Magnesium pharmacology, Potassium Chloride pharmacology, Sodium Chloride pharmacology, Swine, Biological Factors antagonists & inhibitors, Muscle, Smooth, Vascular drug effects, Nicorandil pharmacology, Vasodilation drug effects, Vasodilator Agents pharmacology
- Abstract
Background: We investigated effects of hypoxia-reoxygenation (H-R) with and without St. Thomas solution under clinically relevant temperatures and effects of nicorandil on endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation in porcine coronary microarteries., Methods: In a myograph, rings of porcine microarteries (diameter 200 to 450 microm) were subjected to hypoxia (PO2 < 5 mm Hg) for 30 minutes in Krebs at 37 degrees C, or for 60 minutes in Krebs and St. Thomas solution with or without nicorandil (0.1 microM) at 37 degrees C or 4 degrees C, followed by 30-minute reoxygenation. The EDHF-mediated relaxation by bradykinin (-10 to approximately -6 logM) with inhibitors of nitric oxide and prostacyclin was studied., Results: The maximal EDHF-mediated relaxation was reduced after hypoxia for 30 minutes (59.9%% +/- 1.6% versus 81.2%% +/- 3.5%, p < 0.05) or 60 minutes (44.4% +/- 6.0% versus 82.7% +/- 7.4%, p < 0.001) in Krebs or St. Thomas (28.9% +/- 1.8% versus 78.1% +/- 3.0%, p < 0.001) at 37 degrees C and at 4 degrees C (Krebs: 49.3% +/- 3.0%, p < 0.001; ST: 43.1% +/- 2.6%, p < 0.001) and it was less in St. Thomas solution at 37 degrees C than at 4 degrees C (p < 0.001). The reduced relaxation was recovered by nicorandil (Krebs at 37 degrees C: 81.7% +/- 3.4%, p < 0.001; St. Thomas at 37 degrees C: 71.0% +/- 7.9%, p <0.001; St. Thomas at 4 degrees C: 85.3% +/- 3.3%, p < 0.001)., Conclusions: We conclude that (1) H-R impairs EDHF-mediated relaxation in the coronary microarteries with more injury during prolonged H-R, and this can be partially eliminated by St. Thomas at 4 degrees C but not at 37 degrees C; and (2) as an additive, nicorandil may fully restore EDHF-mediated endothelial function after prolonged H-R.
- Published
- 2005
- Full Text
- View/download PDF
21. Release of nitric oxide and endothelium-derived hyperpolarizing factor (EDHF) in porcine coronary arteries exposed to hyperkalemia: effect of nicorandil.
- Author
-
Yang Q, Zhang RZ, Yim AP, and He GW
- Subjects
- Animals, Bradykinin physiology, Endothelium, Vascular physiopathology, Heart Arrest, Induced, Swine, Antihypertensive Agents pharmacology, Biological Factors physiology, Coronary Circulation drug effects, Coronary Vessels metabolism, Hyperkalemia physiopathology, Nicorandil pharmacology, Nitric Oxide metabolism
- Abstract
Background: Although the detrimental effect of hyperkalemia on coronary endothelium has been reported, there is no direct evidence regarding the effect of hyperkalemic exposure on nitric oxide (NO) release from the coronary endothelium. In addition, it is unclear whether nicorandil, a KATP channel opener, used as hyperpolarizing cardioplegia or added in hyperkalemic cardioplegic solution may protect endothelial function during cardiac surgery. The present study was designed to clarify NO release and the function of endothelium-derived hyperpolarizing factor (EDHF) in coronary circulation with respect to the effect of hyperkalemia and nicorandil., Methods: Nitric oxide was measured by using a NO-specific electrode, and EDHF-mediated relaxation was investigated in a myograph. Substance P- and calcium ionophore A23187-induced NO release was compared in porcine left circumflex coronary arteries before and after 1-hour exposure to 20 mM potassium (K+) at 37 degrees C. In coronary microarteries (diameter 200 to 450 microm), precontracted with U46619, in the presence of indomethacin (7 microM), NG-nitro-L-arginine (300 microM), and oxyhemoglobin (20 microM), EDHF-mediated relaxation was induced by bradykinin (-10 to -6.5 log M) after incubation with Krebs (control) or 20 mM K+ with or without 10 microM nicorandil at 37 degrees C for 1 hour., Results: Neither substance P (58.8 +/- 5.0 versus 66.2 +/- 7.2 nmol/L) nor A23187 (86.6 +/- 9.0 versus 82.4 +/- 9.2 nmol/L in control) induced NO release was altered by hyperkalemic exposure (p > 0.05). In contrast, EDHF-mediated relaxation was decreased from 84.2% +/- 3.8% to 42.3% +/- 6.0% (p < 0.001) that was partially restored by nicorandil (50.7% +/- 5.5%, p < 0.05)., Conclusions: Exposure to potassium at 20 mM does not affect NO release but impairs EDHF-mediated relaxation in coronary arteries. Supplementation of nicorandil in hyperkalemic cardioplegia may provide a protective effect on EDHF-related endothelial function.
- Published
- 2005
- Full Text
- View/download PDF
22. Rupture of a giant coronary artery aneurysm due to Kawasaki disease.
- Author
-
Hwong TM, Arifi AA, Wan IY, Thung KH, Wan S, Sung RY, and Yim AP
- Subjects
- Anticoagulants therapeutic use, Aspirin therapeutic use, Cardiac Tamponade etiology, Child, Preschool, Combined Modality Therapy, Coronary Aneurysm diagnostic imaging, Coronary Aneurysm surgery, Disease Progression, Emergencies, Heart Arrest etiology, Heart Diseases etiology, Heparin therapeutic use, Humans, Immunoglobulins, Intravenous therapeutic use, Male, Mucocutaneous Lymph Node Syndrome drug therapy, Mucocutaneous Lymph Node Syndrome therapy, Platelet Aggregation Inhibitors therapeutic use, Remission Induction, Rupture, Spontaneous, Thrombectomy, Thrombosis etiology, Ultrasonography, Coronary Aneurysm etiology, Coronary Artery Bypass, Mucocutaneous Lymph Node Syndrome etiology
- Abstract
Coronary artery aneurysm requiring surgery is rare. We report a case of a ruptured giant coronary artery aneurysm due to Kawasaki vasculitis which presented with cardiac arrest and was successfully treated by emergency coronary artery bypass grafting. The controversies surrounding the management of this disease are also discussed.
- Published
- 2004
- Full Text
- View/download PDF
23. Alteration of cellular electrophysiologic properties in porcine pulmonary microcirculation after preservation with University of Wisconsin and Euro-Collins solutions.
- Author
-
Zhang RZ, Yang Q, Yim AP, and He GW
- Subjects
- Animals, Arterioles cytology, Arterioles drug effects, Bradykinin pharmacology, Electrophysiology, Endothelium, Vascular cytology, Endothelium, Vascular drug effects, Endothelium, Vascular physiology, Enzyme Inhibitors pharmacology, In Vitro Techniques, Indomethacin pharmacology, Membrane Potentials, Microcirculation, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular physiology, Nitroarginine pharmacology, Oxyhemoglobins pharmacology, Swine, Venules cytology, Venules drug effects, Adenosine pharmacology, Allopurinol pharmacology, Arterioles physiology, Glutathione pharmacology, Hypertonic Solutions pharmacology, Insulin pharmacology, Lung blood supply, Organ Preservation, Organ Preservation Solutions, Raffinose pharmacology, Venules physiology
- Abstract
Background: The effect of cold storage of porcine pulmonary microvessels in University of Wisconsin (UW) and Euro-Collins (EC) solutions on the cellular electrophysiologic properties remains unknown., Methods: The pulmonary microarteries (PA, 381.6 +/- 62.8 microm; n = 60) and microveins (PV, 360.8 +/- 54.5 microm; n = 60) were incubated with Krebs (control), UW, or EC solution at 4 degrees C for 4 hours in a myograph. The resting membrane potential and the endothelium-derived hyperpolarizing factor-mediated hyperpolarization to bradykinin (0.1 micromol/L) in the presence of inhibitors of nitric oxide and prostacyclin, N(omega)-nitro-l-arginine, hemoglobin, and indomethacin, in a single smooth muscle cell were directly measured., Results: The resting membrane potential (-60.8 +/- 1.3 mV in PA and -48.1 +/- 0.7 mV in PV, n = 6) was depolarized after exposure to UW solution (to -18.4 +/- 0.7 mV in PA and -13.6 +/- 0.8 mV in PV; n = 8; p < 0.001). The amplitude of endothelium-derived hyperpolarizing factor-mediated hyperpolarization to bradykinin was also decreased (from 7.4 +/- 0.7 mV to 2.6 +/- 0.7 mV in PA and from 4.6 +/- 0.5 mV to 0.9 +/- 0.4 mV in PV; p < 0.001). In comparison, EC depolarized the membrane potential to a lesser extent (to -28.3 +/- 0.9 mV in PA and to -21.3 +/- 0.8 mV in PV; n = 8; p < 0.001) and almost abolished the hyperpolarization to bradykinin. After washout, hyperpolarization was partially restored (UW, 4.9 +/- 0.7 mV in PA and 2.0 +/- 0.3 mV in PV. p < 0.01; EC, 2.3 +/- 0.5 mV in PA and 1.0 +/- 0.3 mV in PV. p < 0.01)., Conclusions: Cold storage of porcine PA and PV with UW or EC solution impairs the electrophysiologic properties (hyperpolarization) related to endothelium-smooth muscle interaction. The alteration is more profound with EC than UW solution and in veins than in arteries. The findings urge further studies on lung preservation solutions.
- Published
- 2004
- Full Text
- View/download PDF
24. Selective lobar collapse for video-assisted thoracic surgery.
- Author
-
Sihoe AD, Ho KM, Sze TS, Lee TW, and Yim AP
- Subjects
- Adult, Aged, Feasibility Studies, Female, Humans, Lung, Male, Middle Aged, Thoracic Surgery, Video-Assisted methods
- Abstract
Background: Video-assisted thoracic surgery (VATS) is conventionally performed under single-lung ventilation. A small proportion of patients are often excluded from undergoing VATS because of their inability to tolerate single-lung ventilation. We describe a simple technique of selective lobar lung collapse that may help to recruit additional, selected patients for VATS., Methods: We use a standard suction catheter placed under bronchoscopic guidance to the target lobar bronchus through a single-lumen endotracheal tube. The catheter is left open to air, or suction can be applied to facilitate lobar collapse. The remaining lobe of the same lung can be ventilated throughout surgery. Surgery is performed using standard VATS techniques., Results: Using this technique we have successfully performed VATS on 63 chest sides in 35 patients. The procedures performed included thoracodorsal sympathectomies (n = 28), mechanical pleurodesis procedures (n = 3), mediastinal and pleural biopsies (n = 2), and lung wedge resections (n = 2). We encountered no mortality or morbidity in all cases., Conclusions: This technique is simple and safe and requires no expensive disposable devices. Although not essential for most patients undergoing VATS, it deserves to be in the armamentarium of the thoracic surgeon. Further studies will be required to better define its application in clinical practice.
- Published
- 2004
- Full Text
- View/download PDF
25. The evolution of cardiovascular surgery in China.
- Author
-
Wan S and Yim AP
- Subjects
- Cardiopulmonary Bypass history, China, History, 20th Century, Humans, Cardiovascular Surgical Procedures history
- Abstract
The history of the development of cardiovascular surgery in China was little known to the West not only because the majority of the earlier reports were published almost exclusively in the Chinese language but also because China was essentially closed to the West before the 1980s. We present here an account of how some Chinese surgeons struggled to establish a new specialty in a country that makes up more than one fifth of the world population.
- Published
- 2003
- Full Text
- View/download PDF
26. Effect of 11,12-epoxyeicosatrienoic acid as an additive to St. Thomas' cardioplegia and University of Wisconsin solutions on endothelium-derived hyperpolarizing factor-mediated function in coronary microarteries: influence of temperature and time.
- Author
-
Yang Q, Zhang RZ, Yim AP, and He GW
- Subjects
- Analysis of Variance, Animals, Capillaries drug effects, Capillaries physiology, Cardioplegic Solutions pharmacology, Coronary Vessels physiology, Culture Techniques, Endothelium, Vascular drug effects, Heart Arrest, Induced, Probability, Sensitivity and Specificity, Swine, Temperature, Time Factors, Vasodilation physiology, 8,11,14-Eicosatrienoic Acid analogs & derivatives, 8,11,14-Eicosatrienoic Acid pharmacology, Adenosine pharmacology, Allopurinol pharmacology, Biological Factors pharmacology, Coronary Vessels drug effects, Glutathione pharmacology, Insulin pharmacology, Organ Preservation Solutions, Raffinose pharmacology, Vasodilation drug effects
- Abstract
Background: We examined the effect of 11,12-epoxyeicosatrienoic acid (EET(11,12)) added to St. Thomas' Hospital (ST) solution or University of Wisconsin (UW) solution on endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation under clinically relevant temperature and exposure time., Methods: Porcine coronary microarteries (200 to 450 microm) were incubated with Krebs' solution (control), ST with or without EET(11,12) (300 nmol/L) at 22 degrees C for 1 hour as well as at 4 degrees C for 1 or 4 hours, and UW with or without EET(11,12) at 4 degrees C for 4 hours. The EDHF-mediated relaxation was induced by bradykinin (-10 to approximately -6.5 log M) in the precontraction evoked by U(46619) (10 nmol/L) or U(46619) (1 nmol/L) plus endothelin-1 (6 nmol/L)., Results: The EDHF-mediated relaxation was reduced after exposure to UW (79.7% +/- 4.6% versus 93.6% +/- 2.8%, p = 0.01) at 4 degrees C for 4 hours. One-hour exposure to ST under 22 degrees C or 4 degrees C decreased the relaxation (75.2% +/- 7.6% versus 96.7% +/- 1.6%, p < 0.05) or the sensitivity to bradykinin (-8.04 +/- 0.15 versus -8.50 +/- 0.20 log M, p < 0.05). The relaxation increased to 86.8% +/- 5.3% by addition of EET(11,12) to ST (1 hour at 22 degrees C, p < 0.05) but was unchanged when added to either ST or UW at 4 degrees C for 1 or 4 hours., Conclusions: As an additive to ST solution, EET(11,12) may partially restore EDHF-mediated endothelial function under moderate hypothermia but had no significant effect under profound hypothermia when added to either ST or UW solution. Further investigation is necessary to improve the effect.
- Published
- 2003
- Full Text
- View/download PDF
27. Hemoptysis from an unusual pulmonary arteriovenous malformation.
- Author
-
Thung KH, Sihoe AD, Wan IY, Lee TW, Wong R, and Yim AP
- Subjects
- Angiography methods, Arteriovenous Malformations complications, Arteriovenous Malformations diagnostic imaging, Biopsy, Needle, Female, Follow-Up Studies, Humans, Immunohistochemistry, Lung Diseases complications, Lung Diseases diagnostic imaging, Middle Aged, Pneumonectomy methods, Pulmonary Artery pathology, Pulmonary Veins pathology, Radiography, Thoracic, Risk Assessment, Severity of Illness Index, Thoracic Surgery, Video-Assisted methods, Treatment Outcome, Arteriovenous Malformations surgery, Hemoptysis etiology, Lung Diseases surgery, Pulmonary Artery abnormalities, Pulmonary Veins abnormalities
- Abstract
We report the case of a 64-year-old woman who presented with massive hemoptysis. She was found to be bleeding from a pulmonary arteriovenous malformation in the right middle lobe, which had a peculiar blood supply from the right internal mammary artery. Video-assisted thoracic surgery lobectomy was successfully performed for this condition. Limitations of embolization as a treatment modality for this condition are discussed.
- Published
- 2003
- Full Text
- View/download PDF
28. Cystic pulmonary metastases from epithelioid cell sarcoma.
- Author
-
Chan DP, Griffith JF, Lee TW, Chow LT, and Yim AP
- Subjects
- Adult, Cysts pathology, Humans, Lung Neoplasms diagnostic imaging, Lung Neoplasms pathology, Male, Sarcoma diagnostic imaging, Sarcoma pathology, Thigh, Tomography, X-Ray Computed, Lung Neoplasms secondary, Sarcoma secondary
- Abstract
A patient with cystic pulmonary metastases, from epithelioid sarcoma of the thigh, resulting in bilateral pneumothoraces is presented. The pulmonary metastases superficially resembled pneumomatoceles and were not visible on radiography. Computed tomography examinations over a 10-month period showed no change in the size or number of the cystic metastases, though air fluid levels and pericystic nodular consolidation (probably due to pulmonary hemorrhage) did occur and regress. This case report serves to emphasize that bullous type lesions on thoracic computed tomography in patients with a known sarcoma should be interpreted with particular caution.
- Published
- 2003
- Full Text
- View/download PDF
29. A new technological approach to nonanatomical pulmonary resection: saline enhanced thermal sealing.
- Author
-
Yim AP, Rendina EA, Hazelrigg SR, Chow LT, Lee TW, Wan S, and Arifi AA
- Subjects
- Adult, Aged, Equipment Design, Female, Humans, Lung Neoplasms pathology, Lung Neoplasms surgery, Male, Middle Aged, Postoperative Complications etiology, Pulmonary Embolism etiology, Sodium Chloride, Solitary Pulmonary Nodule pathology, Treatment Outcome, Electrocoagulation instrumentation, Lung Neoplasms secondary, Pneumonectomy instrumentation, Solitary Pulmonary Nodule surgery, Surgical Instruments, Thoracic Surgery, Video-Assisted instrumentation
- Abstract
Background: This is the first clinical report on the feasibility study of two new devices (monopolar Floating Ball and bipolar Sealing Forceps; TissueLink Medical Inc, Dover NH) that incorporated the novel technology of saline enhanced thermal sealing., Methods: From December 2000 to December 2001, 25 patients (mean age, 54.8 years) with peripheral lung nodules planned for either diagnostic or therapeutic wedge resection were recruited for the study. When the nodule lay deep to a flat lung surface, video-assisted thoracic surgical resection using the modified Perelman technique with the Floating Ball (TissueLink Medical Inc) was preferred. In other patients, the Sealing Forceps (TissueLink Medical Inc) were used for video-assisted thoracic surgical wedge resection., Results: There were no mortality or major intraoperative complications. The Floating Ball was used exclusively in 11 patients; the Sealing Forceps were used in 9 patients; and a combination of the two devices was used in 5 patients. The mean operation time was 70.3 minutes. Average chest drain duration was 3.9 days, and postoperative hospital stay was 5.2 days. There were 2 patients with persistent air leak more than 1 week, one who resolved spontaneously, and the other who required reoperation for control. One patient had pulmonary embolism after a technically uneventful procedure. There have been no late complications after an average follow-up of 10 months., Conclusions: The devices appear to be technically safe. The Floating Ball has definite advantages over the conventional diathermy and can be adapted to the Perelman procedure using the video-assisted thoracic surgical approach. The Sealing Forceps hold promise to reduce overall consumable costs compared with conventional staplers. These devices should complement the surgeon's existing armamentarium. Comparative studies with conventional instruments are warranted to further define the role of these new devices in thoracic operations.
- Published
- 2002
- Full Text
- View/download PDF
30. VATS major pulmonary resection revisited--controversies, techniques, and results.
- Author
-
Yim AP
- Subjects
- Contraindications, Humans, Patient Selection, Pneumonectomy adverse effects, Pneumonectomy instrumentation, Postoperative Complications epidemiology, Survival Rate, Treatment Outcome, Pneumonectomy methods, Thoracic Surgery, Video-Assisted adverse effects, Thoracic Surgery, Video-Assisted instrumentation, Thoracic Surgery, Video-Assisted methods
- Abstract
The application of video-assisted thoracoscopic surgery (VATS) in major pulmonary resections has remained infrequent, despite earlier demonstration of its technical feasibility. The early postoperative benefits of this approach to patients are now well documented. The intermediate to long-term clinical results of VATS major resections for primary cancer are now available and appear extremely encouraging. There are few, detailed descriptions of this technique in the literature. This article reviews the current status of VATS major resection with emphasis on its controversies, techniques, and results.
- Published
- 2002
- Full Text
- View/download PDF
31. Images in cardiothoracic surgery. Pleuroperitoneal fistula.
- Author
-
Yim AP, Lee TW, Wan IY, and Ng C
- Subjects
- Aged, Digestive System Fistula complications, Digestive System Fistula surgery, Female, Humans, Hydropneumothorax etiology, Peritoneal Dialysis adverse effects, Peritoneal Diseases complications, Peritoneal Diseases surgery, Pleural Diseases complications, Pleural Diseases surgery, Radiography, Respiratory Tract Fistula complications, Respiratory Tract Fistula surgery, Digestive System Fistula diagnostic imaging, Peritoneal Diseases diagnostic imaging, Pleural Diseases diagnostic imaging, Respiratory Tract Fistula diagnostic imaging
- Published
- 2002
- Full Text
- View/download PDF
32. Vascular endothelial growth factor-mediated, endothelium-dependent relaxation in human internal mammary artery.
- Author
-
Liu MH, Jin H, Floten HS, Ren Z, Yim AP, and He GW
- Subjects
- Aged, Female, Humans, Male, Middle Aged, Nitric Oxide physiology, Nitroglycerin pharmacology, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factors, Endothelial Growth Factors physiology, Endothelium, Vascular physiology, Lymphokines physiology, Mammary Arteries, Vasodilation physiology
- Abstract
Background: Vascular endothelial growth factor (VEGF) has been shown to have potential to treat ischemic diseases. Moreover, its vasorelaxing or vasodilatory effect might be favorable for relieving graft spasm. In this study, we examined the vasorelaxing effects of recombinant VEGF in isolated human internal mammary artery (IMA) and compared the responses to acetylcholine and nitroglycerin., Methods: Isometric tension of IMA ring segments was measured with an organ bath technique. With an optimal resting tension determined from its individual length-tension curve, precontraction was induced by 10(-8) M U46619 and cumulative concentration-relaxation was measured by application of VEGF (10(-12) to 10(-15) M), acetylcholine (10(-10) to 10(-5) M), and then nitroglycerin (10(-4.5) M)., Results: Vascular endothelial growth factor induced concentration-dependent relaxation (EC50: -9.89+/-0.05 log M; Emax: 63.2%+/-7.3%) in IMA with intact endothelium. The relaxant responses to VEGF were significantly attenuated by pretreatment with Nomega-nitro-L-arginine (L-NNA) alone and indomethacin + L-NNA, and totally abolished by removal of the endothelium or pretreatment with indomethacin + L-NNA + oxyhemoglobin. Internal mammary arteries became more sensitive to VEGF in the presence of indomethacin alone. However, acetylcholine-induced relaxation was not abolished by treatment with indomethacin + L-NNA + oxyhemoglobin (Emax: 16.9%+/-2.7%). The endothelium-independent relaxations induced by nitroglycerin were also significantly inhibited by administration of oxyhemoglobin., Conclusions: The results demonstrate that VEGF-induced endothelium-dependent relaxation in the human IMA is mainly due to nitric oxide release. Although the vasorelaxing effect is not the primary advantage of this drug when it is used for angiogenesis, such effect may be advantageous in patients who also need a coronary artery bypass operation.
- Published
- 2002
- Full Text
- View/download PDF
33. Video-assisted thoracic surgery lobectomy for pulmonary sequestration.
- Author
-
Wan IY, Lee TW, Sihoe AD, Ng CS, and Yim AP
- Subjects
- Adult, Bronchopulmonary Sequestration diagnosis, Female, Humans, Magnetic Resonance Angiography, Pulmonary Artery pathology, Pulmonary Artery surgery, Pulmonary Veins pathology, Pulmonary Veins surgery, Surgical Staplers, Suture Techniques, Bronchopulmonary Sequestration surgery, Pneumonectomy, Thoracic Surgery, Video-Assisted
- Abstract
Pulmonary sequestration is a rare developmental abnormality, and the patients usually present with recurrent pneumonia. We report a case of video-assisted thoracic surgery lobectomy in a 32-year-old woman with an intrapulmonary sequestration in the left lower lobe.
- Published
- 2002
- Full Text
- View/download PDF
34. Epoxyeicosatrienoic acids (EET(11,12)) may partially restore endothelium-derived hyperpolarizing factor-mediated function in coronary microarteries.
- Author
-
Zou W, Yang Q, Yim AP, and He GW
- Subjects
- Animals, Coronary Vessels physiology, Culture Techniques, Endothelium, Vascular physiology, Potassium pharmacology, Swine, 8,11,14-Eicosatrienoic Acid analogs & derivatives, 8,11,14-Eicosatrienoic Acid pharmacology, Biological Factors physiology, Coronary Vessels drug effects, Endothelium, Vascular drug effects, Vasodilator Agents pharmacology
- Abstract
Background: Endothelial cells derive nitric oxide, prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF). The cytochrome P-450-monooxygenase metabolites of arachidonic acid (epoxyeicosatrienoic acids [EETs]) have been suggested to be EDHF. This study was designed to examine the effect of EET(11,12) with regard to the possibility of restoring EDHF function when added into hyperkalemic cardioplegic solution., Methods: Porcine coronary microartery rings were studied in a myograph. In groups 1 and 2, paired arteries were incubated in either hyperkalemic solution (K+ 20 mmol/L) or Krebs' solution (control). In group 3, the paired arteries were incubated in hyperkalemia plus EET(11,12) (1 x 10(-6.5) mol/L) or hyperkalemia alone (control) at 37 degrees C for 1 hour, followed by Krebs' washout and then precontracted with 1 x 10(-8.5) mol/L U46619. The EDHF-mediated relaxation to EET(11,12) (group 1) or bradykinin (groups 2 and 3) was studied in the presence of N(G)-nitro-L-arginine, indomethacin, and oxyhemoglobin., Results: After exposure to hyperkalemia, the EDHF-mediated maximal relaxation by bradykinin (72.5% +/- 7.8% versus 41.6% +/- 10.6%; p < 0.05), but not by EET(11,12) (18.4% +/- 3.3% versus 25.1% +/- 4.9%; p > 0.05) was significantly reduced. Incubation with EET(11,12) partially restored EDHF function (33.3% +/- 9.5% versus 62.0% +/- 8.5%; p < 0.05)., Conclusions: In coronary microarteries, hyperkalemia impairs EDHF-mediated relaxation, and EET(11,12) may partially mimic the EDHF function. Addition of EET(11,12) into cardioplegic solution may partially restore EDHF-mediated function reduced by exposure to hyperkalemia.
- Published
- 2001
- Full Text
- View/download PDF
35. Effects of potassium channel opener aprikalim on the receptor-mediated vasoconstriction in the human internal mammary artery.
- Author
-
Liu MH, Floten HS, Furnary AP, Yim AP, and He GW
- Subjects
- Angiotensin II pharmacology, Culture Techniques, Dose-Response Relationship, Drug, Endothelin-1 pharmacology, Humans, Norepinephrine pharmacology, Serotonin pharmacology, Mammary Arteries drug effects, Picolines pharmacology, Potassium Channels drug effects, Pyrans pharmacology, Receptors, Neurotransmitter drug effects, Vasoconstriction drug effects, Vasodilator Agents pharmacology
- Abstract
Background: Arterial grafts for coronary artery bypass grafting such as the internal mammary artery (IMA) may develop spasm perioperatively. The purpose of this study was to investigate the effects of the potassium channel opener, aprikalim, on the receptor-mediated vasoconstriction in the human IMA in vitro., Methods: We studied 160 IMA rings taken from coronary artery surgery in organ baths. The interaction between aprikalim and four vasoconstrictors 5-hydroxytryptamine (5-HT), norepinephrine (NE), endothelin-1 (ET-1), and angiotensin II (AII) was investigated in two ways., Results: Aprikalim relaxed IMA rings precontracted by the vasoconstrictors to 66.40 +/- 5.9% for 5-HT (EC50: -6.78 +/- 0.26 LogM), 57.40 +/- 5.5% for NE (-6.54 +/- 0.39 LogM), 81.00 +/- 6.7% for ET-1 (-6.58 +/- 0.26 LogM), and 93.90 +/- 2.5% for AII (-7.80 +/- 0.23 LogM). The relaxation in endothelium-denuded rings contracted by AII was similar to that in the endothelium-intact rings. The relaxation was attenuated by glibenclamide (3 microM) in 5-HT or NE-precontracted IMA. Pretreatment with aprikalim at 1 microM depressed AII-induced contraction (33.20 +/- 7.5% versus 59.70 +/- 7.3%, p < 0.01) but only shifted the curves rightward for 5-HT or NE (EC50 3.1 or 4.3-folds higher, p < 0.05), whereas at 30 microM it also significantly depressed the maximal contraction for 5-HT (35.70 +/- 4.9% versus 103.30 +/- 9.8%, p < 0.001) and NE (90.60 +/- 15.6% versus 125.60 +/- 7.9%, p < 0.05). In contrast, aprikalim did not significantly depress the contraction induced by ET-1 (p > 0.05)., Conclusions: We conclude that aprikalim has vasorelaxant effects on IMA and the effect is vasoconstrictor-selective and endothelium-independent. Aprikalim may provide clinically useful vasorelaxant effects in coronary bypass surgery.
- Published
- 2001
- Full Text
- View/download PDF
36. ATP-sensitive potassium channel openers may mimic the effects of hypoxic preconditioning on the coronary artery.
- Author
-
Ren Z, Yang Q, Floten HS, Furnary AP, Yim AP, and He GW
- Subjects
- Animals, Biological Factors physiology, Coronary Vessels drug effects, Culture Techniques, Potassium Channels drug effects, Pyridines pharmacology, Swine, Vasodilation drug effects, Vasodilation physiology, Vasodilator Agents pharmacology, Adenosine Triphosphate physiology, Coronary Vessels physiology, Ischemic Preconditioning, Myocardial, Potassium Channels physiology
- Abstract
Background: This study was designed to investigate the effects of the potassium channel opener KRN4884 in mimicking hypoxic preconditioning on coronary arteries and to explore the possible mechanisms., Methods: In the organ chamber, porcine coronary artery rings (n = 96) were studied in 6 groups (n = 16 in each group): I., Control: normoxia (pO2 > 200 mmHg); II. Hypoxia-reoxygenation: 60-minute hypoxia (pO2 < 15 mmHg) followed by 30-minute reoxygenation; III. Preconditioning: 5-minute hypoxia followed by 10-minute reoxygenation prior to hypoxia-reoxygenation; IV. KRN4884-pretreatment: KRN4884 (30 microM) was added into the chamber 20 minutes before hypoxia-reoxygenation; V. 5-HD-pretreatment: sodium 5-hydroxydecanoate (5-HD, 10 microM) was given 20 minutes prior to KRN4884-pretreatment; and VI. GBC-pretreatment: glibenclamide (GBC, 3 microM) was added 20 minutes prior to KRN4884-pretreatment. Concentration-contraction curves for U46619 (n = 8 in each group) were constructed. Concentration-relaxation curves for bradykinin (n = 8 in each group) related to endothelium-derived hyperpolarizing factor (EDHF) were established in the rings precontracted with U46619 (30 microM) in the presence of Nomega-nitro-L-arginine (L-NNA, 300 microM) and indomethacin (7 microM)., Results: The maximal relaxation induced by bradykinin was reduced in hypoxia-reoxygenation (54.6 +/- 4.3% versus 85.2 +/- 5.7% in control, p = 0.001). This reduced relaxation was recovered in KRN4884-pretreatment (78.9 +/- 3.7%, p = 0.014) or preconditioning (79.9 +/- 3.7%, p = 0.009). 5-HD- but not GBC-pretreatment abolished the effect of KRN4884-pretreatment (78.9 +/- 3.7% versus 53.5 +/- 4.7%, p = 0.009)., Conclusions: Hypoxia-reoxygenation reduces the relaxation mediated by EDHF in the coronary artery. This function can be restored by either hypoxic preconditioning or the potassium channel opener KRN4884. The mechanism of such effect is mainly related to the mitochondrial ATP-sensitive K+ channels.
- Published
- 2001
- Full Text
- View/download PDF
37. Direct measurement of nitric oxide release from saphenous vein: abolishment by surgical preparation.
- Author
-
Liu ZG, Liu XC, Yim AP, and He GW
- Subjects
- Humans, In Vitro Techniques, Endothelium, Vascular metabolism, Nitric Oxide metabolism, Saphenous Vein metabolism, Tissue and Organ Harvesting
- Abstract
Background: Surgical preparation (distension) of the saphenous vein (SV) is applied routinely during harvesting in coronary artery bypass grafting (CABG). However, mechanical distension may impair the endothelium, which plays an important role in long-term patency. The present study investigated the effect of surgical preparation of the SV on nitric oxide (NO) release from the endothelium by direct measurement of NO., Methods: Saphenous vein segments taken from CABG patients were cut open longitudinally and placed in an organ chamber. An NO-sensitive electrode and NO meter were used to directly measure NO release induced by acetylcholine (ACh) and bradykinin (BK) from the surgically prepared veins (PV) compared with the control (nondistended) veins., Results: The basal release of NO in the PV group was significantly lower than that in the control group (3.4 +/- 1.4 nM, n = 9 versus 9.9 +/- 2.8 nM, n = 13, p = 0.002). The maximum concentrations of NO release induced by ACh and BK in the PV group were also significantly lower than those in the control veins (for ACh 10(-6) mol/L: 9.6 +/- 3.1 nM, n = 8 versus 41.9 +/- 11.2 nM, n = 12, p = 0.005; for BK 10(-8) mol/L: 8.3 +/- 3.7 nM, n = 7 versus 37.9 +/- 6.1 nM, n = 9, p = 0.003). Further, the duration of NO release in the PV group was significantly shorter than that in control veins (1.5 +/- 1.3 minutes, n = 8 versus 8.1 +/- 1.9 minutes, n = 8, p < 0.001)., Conclusions: Surgical preparation almost abolishes NO release by the SV and this may significantly contribute to the low long-term patency rate of the vein graft.
- Published
- 2001
- Full Text
- View/download PDF
38. Inhibition of vasoconstriction by angiotensin receptor antagonist GR117289C in arterial grafts.
- Author
-
Liu MH, Floten HS, Furnary AP, Yim AP, and He GW
- Subjects
- Aged, Angiotensin II pharmacology, Culture Techniques, Dose-Response Relationship, Drug, Female, Humans, Male, Middle Aged, Vasoconstrictor Agents pharmacology, Coronary Artery Bypass, Internal Mammary-Coronary Artery Anastomosis, Mammary Arteries drug effects, Nicotinic Acids pharmacology, Receptors, Angiotensin drug effects, Tetrazoles pharmacology, Vasoconstriction drug effects
- Abstract
Background: Angiotensin II (AII) has been suggested to be one of the important factors for genesis of graft spasm in coronary artery bypass surgery. The aim of this work was to investigate the effects of the nonpeptide angiotensin receptor AT1 antagonist GR117289C on the contraction induced by AII and other vasoconstrictors in isolated human internal mammary artery (IMA) preparations., Methods: Two hundred eight IMA rings taken from 64 patients undergoing coronary artery bypass grafting were studied in organ baths. The interaction between GR117289C and AII or the other vasoconstrictors (U46619, norepinephrine, endothelin-1, and potassium chloride) was investigated in two ways., Results: GR117289C induced near-maximal relaxation (94.5% +/- 2.9%) in IMA rings precontracted by AII. In IMA rings incubated with 1 or 10 nmol/L GR117289C, contractile responses to AII were attenuated in a concentration-related manner, whereas the dose-response curve did not shift to the right when higher doses of AII were administered, suggesting that the AT1 receptor blockade was noncompetitive in nature. Moreover, GR117289C also induced significant relaxation (82.9% +/- 8.1%) in IMA rings precontracted by U46619, but no inhibitory responses to U46619 could be observed when IMA rings were incubated with GR117289C. GR117289C did not alter responses to potassium chloride, norepinephrine, and endothelin-1., Conclusions: These results indicate that GR117289C is a potent, selective, noncompetitive AT1 receptor antagonist that may have a possible antagonistic effect on the thromboxane A2 receptor. Because AII and thromboxane A2 are important vasoconstrictors in the genesis of graft spasm, GR117289C may become an alternative treatment to relieve graft spasm.
- Published
- 2000
- Full Text
- View/download PDF
39. VATS lobectomy reduces cytokine responses compared with conventional surgery.
- Author
-
Yim AP, Wan S, Lee TW, and Arifi AA
- Subjects
- Aged, Aged, 80 and over, Carcinoma, Non-Small-Cell Lung pathology, Female, Humans, Lung Neoplasms pathology, Male, Middle Aged, Neoplasm Staging, Carcinoma, Non-Small-Cell Lung surgery, Interleukins blood, Lung Neoplasms surgery, Pneumonectomy methods, Thoracic Surgery, Video-Assisted, Tumor Necrosis Factor-alpha analysis
- Abstract
Background: Video-assisted thoracic surgery (VATS) lobectomy for early lung cancer has been shown to be technically feasible. Comparative studies on laparoscopic versus open procedures indicate that laparoscopy may reduce inflammatory reactions as reflected by the lesser release of cytokines. We investigated the cytokine responses following VATS and conventional lobectomy for clinical stage I lung cancer., Methods: Thirty-six patients with clinical stage I nonsmall cell lung cancer were studied. 18 patients underwent VATS lobectomy and the other 18 by conventional thoracotomy. There were no differences between the two groups with respect to age, gender, pulmonary function, smoking history, comorbidity, tumor size, and pathology. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, IL-8, and an antiinflammatory cytokine IL-10 were measured before surgery, at the end of the procedure, and 4, 8, 24, and 48 hours thereafter in all patients., Results: There was no mortality or major complication in either group. Analgesic requirement was significantly less in the VATS group. Although the release of TNF-alpha and IL-1beta were minimal after surgery in both groups, the levels of IL-6, IL-8, and IL-10 were elevated. IL-6 and IL-8 levels were significantly lower in the VATS group at the end of surgery than in the open group. In addition, reduced release of IL-10 was also observed in the VATS group shortly after surgery., Conclusions: VATS lobectomy is associated with reduced postoperative release of both proinflammatory and antiinflammatory cytokines compared with the open approach. The clinical significance of these findings remains to be fully elucidated.
- Published
- 2000
- Full Text
- View/download PDF
40. Ruptured aneurysm of an aberrant artery from the descending thoracic aorta.
- Author
-
Arifi AA, Yim AP, and Wan S
- Subjects
- Aneurysm, Ruptured surgery, Arteries abnormalities, Humans, Male, Middle Aged, Radiography, Aneurysm, Ruptured diagnostic imaging, Aorta, Thoracic diagnostic imaging
- Published
- 1999
41. Heparin-coated circuits reduce myocardial injury in heart or heart-lung transplantation: a prospective, randomized study.
- Author
-
Wan S, LeClerc JL, Antoine M, DeSmet JM, Yim AP, and Vincent JL
- Subjects
- Adolescent, Adult, Aged, Child, Endotoxins blood, Female, Humans, Interleukins blood, Male, Middle Aged, Postoperative Complications immunology, Prospective Studies, Systemic Inflammatory Response Syndrome immunology, Troponin I blood, Cardiopulmonary Bypass instrumentation, Coated Materials, Biocompatible, Heart-Lung Transplantation physiology, Heparin, Postoperative Complications diagnosis, Systemic Inflammatory Response Syndrome diagnosis
- Abstract
Background: The effects of heparin-coated (HC) circuits have been primarily investigated in routine cardiac operations with limited duration of cardiopulmonary bypass (CPB) and ischemia. Their benefits have not been conclusively proven but could be more significant when CPB and ischemic times are longer, such as during heart transplantation (HTx) or heart-lung transplantation (HLTx)., Methods: In a 22-month period, 29 patients undergoing HTx and HLTx were randomly divided into two groups using HC (Duraflo II, n = 14, 10 HTx and 4 HLTx) or uncoated but identical circuits (NHC group, n = 15, 10 HTx and 5 HLTx). All patients received full systemic heparinization (3 mg/kg) during CPB. Plasma endotoxin, interleukin (IL)-6, IL-8, IL-10, IL-12, and cardiac troponin-I were measured before heparin administration, immediately after aortic cross-clamping, 5, 30, 60, 90, 120 minutes, and 12 and 24 hours after aortic declamping. The intensive care unit (ICU) staff and the laboratory technologists were blinded as to the use of HC circuits., Results: No statistically significant differences between groups were found with respect to all baseline values, duration of CPB and aortic cross-clamping, graft ischemic time, doses of heparin, postoperative blood loss and transfusion, peak lactate and creatine kinase-MB isoenzyme values, duration of mechanical ventilation, or length of ICU stay. One patient in each group died during the hospital stay. Patients in the HC group needed more protamine sulfate after CPB. Although endotoxin levels were similar in the two groups, significantly lower IL-6, IL-8, and IL-10 levels were observed 1 hour after aortic declamping in the HC group. The release of cardiac troponin-I was also significantly reduced in the HC group 12 and 24 hours after reperfusion., Conclusions: The use of HC circuit limits both pro- and anti-inflammatory responses to CPB. It may also reduce myocardial injury after prolonged duration of CPB and ischemia.
- Published
- 1999
- Full Text
- View/download PDF
42. Avoiding cardiopulmonary bypass in multivessel CABG reduces cytokine response and myocardial injury.
- Author
-
Wan S, Izzat MB, Lee TW, Wan IY, Tang NL, and Yim AP
- Subjects
- Creatine Kinase blood, Female, Humans, Interleukin-10 blood, Interleukin-6 blood, Interleukin-8 blood, Isoenzymes, Male, Middle Aged, Prospective Studies, Troponin I blood, Tumor Necrosis Factor-alpha analysis, Cardiopulmonary Bypass adverse effects, Coronary Artery Bypass, Cytokines blood, Myocardium metabolism
- Abstract
Background: Proinflammatory cytokines play a key role in the inflammatory cascade after cardiopulmonary bypass and may induce cardiac dysfunction. We compared the production of cytokines and the degree of postoperative myocardial injury in patients with multivessel coronary artery disease undergoing coronary artery bypass grafting through median sternotomy with or without cardiopulmonary bypass., Methods: Forty-four consecutive patients were studied. Patients were selected for off-pump coronary artery bypass grafting whenever complete revascularization was technically feasible. There were no differences between the two groups with respect to age, sex, symptoms, or functional class. Plasma levels of tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 were measured before the operation, at the end of the procedure, and 2, 4, 8, 24, and 48 hours thereafter. Levels of the MB isoenzyme of creatine kinase and cardiac troponin-I were also measured after the operation., Results: The number of grafts was 2+/-0.7 in the off-pump group (n = 18) and 3+/-0.8 in the cardiopulmonary bypass group (n = 26). There were no deaths or major complications in either group. Levels of tumor necrosis factor-alpha were low in both groups. No significant intergroup differences were noted regarding serial IL-6 measurements. However, IL-8 and IL-10 levels after the operation were lower in the off-pump group (IL-8, 4+/-1 versus 38+/-12 pg/mL, p < 0.01; IL-10, 5+/-2 versus 191+/-33 pg/mL, p < 0.001). Whereas postoperative creatine kinase-MB values were similar in the two groups, cardiac troponin-I levels were significantly lower in the off-pump group (8 hours, p < 0.005; 24 hours, p < 0.02, respectively). Moreover, cardiac troponin-I values 24 hours after operation correlated strongly with IL-8 levels (r = 0.61, p < 0.005), indicating that the degree of myocardial injury may be related to IL-8 production., Conclusions: Compared with conventional coronary artery bypass grafting, coronary revascularization without cardiopulmonary bypass is associated with reduced cytokine responses and less myocardial injury.
- Published
- 1999
- Full Text
- View/download PDF
43. Early experience with partial left ventriculectomy in the Asia-Pacific region.
- Author
-
Izzat MB, Kabbani SS, Suma H, Pandey K, Morishita K, and Yim AP
- Subjects
- Adolescent, Adult, Aged, Asia, Cardiomyopathies physiopathology, Cardiomyopathies surgery, Child, Child, Preschool, Female, Heart Failure physiopathology, Humans, Male, Middle Aged, Treatment Outcome, Ventricular Function, Left, Heart Failure surgery, Heart Ventricles surgery
- Abstract
Background: We report our early experience with partial left ventriculectomy done by a group of cardiac surgeons in the Asia-Pacific region., Methods: Partial left ventriculectomy was done in 48 patients (mean age, 43 years) with advanced symptomatic cardiomyopathy. The origin of cardiomyopathy was idiopathic in 30 patients, valvular in 10, ischemic in 3, peripartum in 3, sarcoidosis in 1, and viral myocarditis in 1. Procedures performed on the mitral valve were repair with Alfieri method in 8 patients, ring annuloplasty in 2, and replacement in 25., Results: Seventy-seven percent of patients required myocardial support for weaning from cardiopulmonary bypass, and the overall in-hospital mortality rate was 27%. Mean follow up was 6.5 months (range, 1 to 18 months), and patient survival at 1, 3, and 6 months after discharge was 91%, 88%, and 84%, respectively. Sixty-five percent of survivors with idiopathic and valvular disease achieved significant and sustained improvement in ventricular contractility and symptoms, but there were no clear symptomatic benefits from partial left ventriculectomy in patients with cardiomyopathy from other causes. Most cases of late recurrence of heart failure symptoms (90%) appeared to be related to the development of progressive mitral incompetence., Conclusions: After partial left ventriculectomy left ventricular function improved in patients with idiopathic and valve related cardiomyopathies. Late deterioration was related to the development of significant mitral valve incompetence postoperatively, hence definitive mitral valve repair or replacement at the time of the partial left ventriculectomy procedure is advised.
- Published
- 1999
- Full Text
- View/download PDF
44. Ministernotomy for aortic valve replacement in a patient with osteogenesis imperfecta.
- Author
-
Izzat MB, Wan S, Wan IY, Khaw KS, and Yim AP
- Subjects
- Adult, Humans, Male, Methods, Aortic Valve Insufficiency surgery, Heart Valve Prosthesis Implantation, Osteogenesis Imperfecta complications, Sternum surgery
- Abstract
Open heart operations in patients with osteogenesis imperfecta are associated with increased morbidity and mortality resulting from tissue friability and bone brittleness. We used a ministernotomy approach for aortic valve replacement in a patient with osteogenesis imperfecta, with clear benefits and a satisfactory outcome.
- Published
- 1999
- Full Text
- View/download PDF
45. A Chinese thoracic surgeon and his two decisions.
- Author
-
Wan S and Yim AP
- Subjects
- China, History, 20th Century, Thoracic Surgery history
- Abstract
Doctor Wu Ying-Kai is known to many in the thoracic surgical academia worldwide. This article focuses on the two decisions he made at the ages of 33 and 70 that profoundly influenced the development of thoracic and cardiovascular medicine in a country with one quarter of the world population. His successful career was gauged not so much by the position he achieved, but by the obstacles he had to overcome to achieve it.
- Published
- 1999
- Full Text
- View/download PDF
46. A survey on partial left ventriculectomy in the Asia-Pacific region.
- Author
-
Izzat MB, Yim AP, Wan S, and Atassi W
- Subjects
- Cardiac Volume physiology, Asia, Eastern, Heart Failure mortality, Heart Transplantation, Hospital Mortality, Humans, Postoperative Complications mortality, Survival Rate, Heart Failure surgery, Heart Ventricles surgery
- Abstract
Background: There has been increasing interest in partial left ventriculectomy as a new therapy for end-stage heart failure. Because the most significant impact of this development is likely to be in regions where heart transplantation is largely unavailable, we conducted a survey among a group of cardiac surgeons based in the Asia-Pacific region to evaluate their overall views on partial left ventriculectomy procedures., Methods: A questionnaire was sent to surgeons from 65 major institutions in 17 countries and regions in the Asia-Pacific. Questions examined current demographics and opinions regarding potential application and future prospects of this operation., Results: Surveyed surgeons were based in equal proportions in academic, government, and private practice institutions. One third of respondents have already performed partial left ventriculectomy operations, largely in small numbers. In total, 86 procedures were performed with 75% hospital survival rate. Failures were thought to be caused by limited knowledge about patient selection criteria and lack of experience with operative technique and perioperative care. The majority of respondents believe that partial left ventriculectomy is potentially a valuable intervention and intend to perform more cases. Nevertheless, most surgeons identified the need to have larger clinical experience, to perform randomized trials against other therapeutic modalities, and to improve perioperative care., Conclusions: Although all surgeons recognize that more knowledge is needed before partial left ventriculectomy becomes a standard procedure, it is clear from this survey that the procedure has rapidly gained interest, with more surgeons seeking to learn it.
- Published
- 1999
- Full Text
- View/download PDF
47. Favorable scanning electron microscopic findings of stapled saphenous vein-carotid artery anastomoses.
- Author
-
Izzat MB, Yim AP, Ho KC, Chan CS, Yew D, and Chow LT
- Subjects
- Animals, Carotid Arteries ultrastructure, Endothelium, Vascular ultrastructure, Microscopy, Electron, Scanning, Saphenous Vein ultrastructure, Suture Techniques, Swine, Vascular Patency, Anastomosis, Surgical methods, Carotid Arteries surgery, Saphenous Vein surgery, Surgical Stapling
- Abstract
Background: In the progress toward "off-pump" endoscopic coronary artery surgical procedures, new techniques for coronary artery anastomoses are being developed. One such approach is the use of nonpenetrating titanium clips. We evaluated the quality of anastomoses achieved using this technique in a porcine model of saphenous vein-carotid artery grafting using scanning electron microscopy., Methods: Bilateral saphenous vein-carotid artery interposition grafts were implanted in 10 "white race" pigs, using the nonpenetrating clips in one side of the neck and conventional hand suturing on the opposite side. One week after operation, the grafts were harvested., Results: All grafts were patent 7 days after operation, and 40 anastomoses underwent scanning electron microscopic study. In all samples, the luminal surfaces of both the carotid artery and vein graft were covered by a continuous layer of endothelial cells up to the anastomosis. Anastomotic sites in all clipped samples and most of the sutured anastomoses were completely endothelialized, and anastomotic clefts were indistinguishable. However, in 25% of sutured specimens, the suture material remained clearly visible inside the lumen of the vessel, and the subendothelial matrix remained exposed, with extensive fibrin, red blood cells, and platelet deposition on its surface., Conclusions: Because the endothelial coverage consistently appeared to be complete and the subendothelial matrix was not exposed, it is likely that the risk of early anastomotic thrombosis is reduced by using the nonpenetrating titanium clips.
- Published
- 1999
- Full Text
- View/download PDF
48. Reducing inflammatory reactions by heparin-coated circuit.
- Author
-
Wan S, Izzat MB, and Yim AP
- Subjects
- Child, Heparin administration & dosage, Humans, Inflammation Mediators physiology, Cardiopulmonary Bypass instrumentation, Heparin pharmacology, Inflammation prevention & control
- Published
- 1998
49. Snaring of a coronary artery causing distal atheroma embolization.
- Author
-
Izzat MB, Yim AP, and El-Zufari MH
- Subjects
- Aged, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease prevention & control, Humans, Male, Methods, Myocardial Revascularization, Postoperative Complications prevention & control, Recurrence, Coronary Artery Disease surgery
- Abstract
We report a case of total occlusion of the left anterior descending coronary artery with atheromatous debris after "off-pump" grafting. Atheroma break-off and distal embolization probably occurred from proximal snare occlusion of the target coronary artery, and this was recognized by intraoperative angiography. Alternatives to suture snaring should be considered whenever an atherosclerotic artery is to be grafted without cardiopulmonary bypass.
- Published
- 1998
- Full Text
- View/download PDF
50. Intraoperative "direct" LIMA angiography for beating heart operations.
- Author
-
Izzat MB, El-Zufari MH, and Yim AP
- Subjects
- Contrast Media, Humans, Intraoperative Care methods, Iopamidol, Coronary Angiography methods, Internal Mammary-Coronary Artery Anastomosis methods
- Abstract
The importance of the angiographic assessment of coronary bypass grafts performed on the beating heart has been recognized. We describe a simple technique for intraoperative angiography of left internal mammary artery to left anterior descending coronary artery grafts that does not require selective left internal mammary artery catheterization. This method allows immediate appraisal of the graft, hence enabling the surgeon to revise any graft or anastomosis abnormality immediately and to verify optimal results of beating heart operations.
- Published
- 1998
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.