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We investigated whether supra-aortic vessel (SAV)s dissection is a risk factor for neurological dysfunction (ND) after surgical repair for type A acute aortic dissection (TAAAD). A retrospective review was done in 178 patients with TAAAD undergoing aortic repair between 2015 and 2019, comparing those with SAV dissection to those without it. Preoperatively, 93 patients (54.4%) had SAV dissection. Postoperatively, ND occurred in 26 patients (14.6%), 17 of whom (65.4%) already had been present with preoperative ND. Patients with SAV dissection were more likely to have postoperative ND than those without it (21.5% vs 7.7%; p = 0.02). The severity of preoperative dissection-related stenosis in common carotid artery significantly related to postoperative ND (right; p =0.0071, left; p0.0001). Multivariable analysis showed dissection-related stenosis of75% in brachiocepharic and left common carotid arteries, and thrombosed false lumen in common carotid arteries were independent risk factors for postoperative ND. However, SAV dissection was not related to new onset of ND. Dissection with stenosis of75% in SAVs were significantly decreased after aortic repair and even after ascending aorta/hemiarch replacement. In conclusion, ND after surgical repair for TAAAD is closely related to SAV dissection, especially to stenosis of75% and thrombosed false lumen in common carotid arteries. Aortic repair significantly decreased SAV dissection and severity of stenosis.

Background Concerns of gastrointestinal (GI) bleeding after cardiac surgery are increasing with increased use of antiplatelets and anticoagulants. We investigated the roles of preoperative screening for fecal occult blood by fecal immunochemical test (FIT) widely used to detect GI bleeding and cancer. Methods A retrospective review was done in 1,663 consecutive patients undergoing FIT before cardiac surgery between years 2012 and 2020. One or two rounds of FIT were performed 2 to 3 weeks before surgery, when antiplatelets and anticoagulants were not suspended yet. Results Positive FIT (> 30 μg of hemoglobin/g of feces) was observed in 227 patients (13.7%). Preoperative risk factors for positive FIT included age > 70 years, anticoagulants, and chronic kidney disease. Of those with positive FIT, 180 patients (79%) received preoperative endoscopy, including gastroscopy (n = 139), colonoscopy (n = 9), and both (n = 32), with no findings of bleeding. The most common finding of gastroscopy was atrophic gastritis (36%) while early gastric cancer was detected in 2 patients. The most common finding of colonoscopy was colon polyps (42%) while colorectal cancer was detected in 5 patients. Of 180 FIT-positive patients receiving endoscopy, 8 (4.4%) underwent preoperative GI treatment, while postoperative GI events were documented in 28 (15.6%). Of 1,436 with negative FIT, 21 (1.5%) presented GI complications after surgery. Conclusion Preoperative FIT, which is influenced by anticoagulant use, has little impacts on identification of GI bleeding sites. However, it may be useful to detect GI malignant lesions, potentially impacting operative risks, surgical strategies, and postoperative management.

We report a case of surgically repaired symptomatic mitral valve regurgitation (MR) in a 61-year-old woman with anomalous unilateral single pulmonary vein. A two-staged surgery was scheduled; first a catheter embolization of anomalous vessel to avoid recirculation of the blood into the left atrium during cardiopulmonary bypass, and second a mitral valve repair via right lateral thoracotomy. LEARNING OBJECTIVE: Scimitar sign is a horn-like shape on plain chest radiograph. One of the possible diagnoses is partial anomalous pulmonary venous return (APVR), which often requires surgical interventions due to comorbidities of congenital heart disease and recurrent pneumonia [1–3]. Another is anomalous unilateral single pulmonary vein (AUSPV), which is generally asymptomatic, and therefore, requires no medical interventions. This case addresses the advantage of multidetector computed tomography (CT) and the safety of two-staged strategy.

Thermoreactive nitinol Flexigrip has been developed to ensure better fixation than conventional wire closure. To verify the advantage of Flexigrip over the conventional wiring, we compared early sternal bone healing on computed tomography (CT).A prospective cohort study enrolled the first consecutive 80 patients with wiring and the second consecutive 44 patients undergoing Flexigrip sternal closure. The primary endpoint was sternal healing evaluated quantitatively using a 6-point scale and measured gaps/offsets of the sternal halves at 6 levels on CT scans on the 14th postoperative day. Secondary endpoints included pain scores and sternal complications 1 month after surgery.Compared with the patients of wiring, those who received Flexigrips showed higher 6-point scores at most sternum levels, less frequent gaps (52% vs 70%, p = 0.04), lower offsets (3.3 ± 0.9 mm vs 4.3 ± 0.7 mm, p0.001) at the manubrium, and less frequent gaps (25% vs 43%, p = 0.04) and offsets (2.3% vs 24%, p = 0.002) at the middle of sternum. The pain scores and sternal complication rates were similar between both groups.CT evaluation 2 weeks after surgery revealed that Flexigrip sternal closure showed less gaps and offsets of the sternal halves, suggesting faster sternal bone union when compared to the wiring.

We report a case of mechanical prosthetic mitral valve thrombosis in a 52-year-old woman with previous diagnosis of dilated cardiomyopathy, who was supported with advanced mechanical circulatory support after urgent mechanical mitral valve replacement (MVR) and tricuspid annuloplasty. Difficult weaning from cardiopulmonary bypass needed support with veno-arterial extracorporeal membranous oxygenation and Impella (Abiomed Inc, Danvers, MA, USA), so-called ECPELLA. Temporary discontinuation of heparin and massive blood transfusion were necessary due to four times of reoperation for bleeding during ECPELLA support. Poor recovery of cardiac function needed escalation from ECPELLA to extracorporeal biventricular assist device (ex-BiVAD) using two centrifugal pumps on Day 12. After gradual decrease in the left ventricular assist device flow, transesophageal echocardiography and fluoroscopic images revealed the stuck leaflets of the mitral prosthesis. Therefore, the patient underwent re-MVR with a bioprosthesis on Day 18, followed by continued assistance with ex-BiVAD. The patient was finally weaned from ex-BiVAD on Day 28 and was transferred to the referral hospital for rehabilitation. She was alive in good general condition at 2-year follow-up. It is important to balance the effects of anticoagulation on advanced mechanical circulatory support with ECPELLA, against the side effects of bleeding, especially in post-cardiotomy patients with bleeding tendency.

ObjectiveThe purpose of this study is to describe recent mortality trends from aortic stenosis (AS) among eight high-income countries.MethodsWe analysed the WHO mortality database to determine trends in mortality from AS in the UK, Germany, France, Italy, Japan, Australia, the USA and Canada from 2000 to 2020. Crude and age-standardised mortality rates per 100 000 persons were calculated. We calculated age-specific mortality rates in three groups (ResultsDuring the observation period, the crude mortality rates per 100 000 persons increased in all the eight countries (from 3.47 to 5.87 in the UK, from 2.98 to 8.93 in Germany, from 3.84 to 5.52 in France, from 1.97 to 4.33 in Italy, from 1.12 to 5.49 in Japan, from 2.14 to 3.38 in Australia, from 3.58 to 4.22 in the USA and from 2.12 to 5.00 in Canada). In joinpoint regression of age-standardised mortality rates, trend changes towards a decrease were observed in Germany after 2012 (−1.2%, p=0.015), Australia after 2011 (−1.9%, p=0.005) and the USA after 2014 (−3.1%, pConclusionsWhile crude mortality rates increased in the eight countries, shifts towards decreasing trends were identified in age-standardised mortality rates in three countries and in the elderly aged ≥80 years in the eight countries. Further multidimensional observation is warranted to clarify the mortality trends.

We report wound management using a vacuum-assisted closure (VAC) system for the cannula sites of extracorporeal biventricular assist devices (BiVADs) for 295 days in a 23-year old Chinese female patient with fulminant giant cell myocarditis, who finally underwent heart transplantation. When the cannula sites appeared necrotic 3 months after BiVADs placement, she received negative pressure wound therapy prophylactically for four cannula sites, using a VAC system for 3 months, followed by no infections. Such prophylactic VAC therapy, using the skin barrier paste usually used for the ostomy pouching system to create a flatter surface and airtightness, may be useful to avoid cannula site infections, which is still a fatal complication causing sepsis, especially in patients with extracorporeal BiVADs.

OBJECTIVES Patients with cardiovascular disease are vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Although SARS-CoV2 vaccination may be effective, its impact on surgical patients is not well studied. We investigated the effects of cardiovascular surgery, especially under cardiopulmonary bypass (CPB), on the antibody titres after SARS-CoV2 vaccination. METHODS A prospective observational study was designed for patients undergoing surgery between July and November 2021. The immunoglobulin G against the receptor-binding domain was measured and antibody preserved rate (APR) was calculated from perioperative titres comparison. RESULTS Enrolled 63 study patients were divided into 39 undergoing surgery with CPB (Group CPB) and 24 without CPB (Group None). Preoperative vaccines were BNT162b2 (Pfizer/BioNTech) (n = 58, 92%) and mRNA-1273 (Moderna) (n = 5, 8%). While immunoglobulin G against the receptor-binding domain titres did not significantly decrease after surgery in Group None, they decreased significantly in Group CPB from 21.80 [11.15, 37.85] to 11.95 [6.80, 18.18] U/ml (P CONCLUSIONS The SARS-CoV2 antibody titres significantly decreased with lower APRs immediately after surgery under CPB. Based on our informative results, careful considerations of vaccination schedule might be required for surgery under CPB.

A 70-year-old patient who survived about 40 years after left pneumonectomy for tuberculosis visited emergency hospital, because of dyspnea. She received suitable medical therapy for atirial fibrillation and severe mitral regurgitation and hesitated heart surgery because of anxiety for surgical risk. The computed-tomography showed mediastinal shift to left and right lung compensatory expansion. Respiratory function test after treatment of heart failure showed only mild restrictive disorder. And the blood-gas examination in room air was 101 mmHg of Pao2 and 37 mmHg of Paco2. The mitral valve replacement was performed via median sternotomy and using normal cardiopulmonary bypass. And she fully recoverd without any respiratory complications. Mediastinal shift did not obstract the surgical view and establishment of cardiopulmonary bypass in this case. It seemed that the key of surgical successs is the preserved function of healthy residual lung.

Background Thoracic aortitis caused by Clostridium septicum is a rare infection with a strong association with malignancy and high mortality rate when left untreated. We report a case of surgical treatment for Stanford type A acute aortic dissection in a patient with C. septicum sepsis and thoracic aortitis. Case presentation A 63-year-old hypertensive man with rheumatoid arthritis presented with general malaise and diagnosed with C. septicum-infected aortitis with sepsis. On the 5th day of hospitalization, Stanford type A acute aortic dissection developed with severe aortic regurgitation. The patient underwent emergent surgical treatment successfully with excision of the infected ascending aorta and aortic root followed by replacement using a composite graft, followed by diagnosis of sigmoid colon cancer 7 months after aortic surgery. He was scheduled to undergo elective colon surgery. Conclusions C. septicum aortitis can progress quickly, causing aneurysm or dissection. Therefore, in a patient with C. septicum aortitis, prompt surgical in situ graft replacement should be performed to debride the infected vascular lesions. Further investigations for gastrointestinal and hematological malignancies as a source of C. septicum should be also conducted.

Kommerell diverticulum (KD) is an aneurysm of the orifice of an aberrant subclavian artery (SCA) from the descending aorta or aortic arch. We have performed two-staged surgical strategy for the treatment of KD with right aortic arch. The first step was the bypass grafting between the left common carotid artery and the aberrant left SCA with occlusion of the distal side of KD with the plug. The second step was the descending aorta replacement through the right thoracotomy. Four patients underwent these operations. No hospital deaths or major complications were observed. All four patients were discharged and have been alive for 1-6 years without any health problems. Two of four patients had symptoms of dysphagia preoperatively, and it resolved postoperatively in both patients. No hoarseness occurred after surgery, and 1-6 years of CT observation showed no recanalization of the vascular plug.

We report wound management using a vacuum-assisted closure (VAC) system for the cannula sites of long-term extracorporeal biventricular assist devices (BiVADs). A 23-year old Chinese female patient with a diagnosis of giant cell myocarditis needed extracorporeal BiVADs for more than 9 months. When the cannula sites appeared necrotic 3 months after BiVADs placement, she underwent negative pressure wound therapy prophylactically for four cannula sites, using a VAC system for 3 months, followed by no infections. Such prophylactic VAC therapy may be useful to avoid cannula site infections, which is still a fatal adverse event causing sepsis, especially in patients with extracorporeal BiVADs.

The frozen elephant trunk (FET) technique allows single-stage extended surgical repair of Stanford type A aortic dissection and has shown promotion of aortic remodeling by maintaining the true lumen flow and facilitating its expansion and by promoting false lumen thrombosis. However, few studies have compared the effectiveness of FET technique, in terms of the downstream aortic remodeling. Between 2005 and 2017, 50 patients underwent total arch replacement for Stanford type A aortic dissection, including that with (n = 22) and without FET technique (n = 28). We compared distal aortic remodeling in patients who underwent total arch replacement with (using a J-Graft open stent graft) or without the technique. The false lumen complete thrombosis rate and the ratio of true lumen area at three levels of the descending aorta were evaluated post operation. In FET group, the diameter and length of the stent graft were 29.0 ± 3.9 mm and 70.9 ± 17.4 mm, respectively. The in-hospital death with and without the FET technique was 0 and 3, respectively, with no late death in both groups. Eight patients (28.6%) only in the non-FET group required additional surgical treatment for downstream aorta. In the FET group, the ratio of true lumen area at the level of bronchial carina and false lumen complete thrombosis rate at the levels of bronchial carina and aortic valve were significantly higher than non-FET group. A more favorable remodeling in the descending aorta was observed in patients who underwent FET associated with a total arch replacement compared to those who underwent total arch replacement alone.

Transit-time flow measurement (TTFM) has been increasingly applied to detect graft failure during coronary artery bypass grafting (CABG), because TTFM is less invasive, more reproducible, and less time consuming. Many authors have attempted to validate TTFM and to gain the clear cutoff values and algorithm in TTFM to predict graft failure. The TTFM technology has also been shown to be a useful tool to investigate CABG graft flow characteristics and coronary circulation physiology. It is important to recognize the practical roles of TTFM in the cardiac operating room by review and summarize the literatures.

Aortic annular rupture is a potentially fatal complication after transcatheter aortic valve implantation with high mortality. Although it is quite rare and difficult to identify the mechanisms and predictors, prosthesis oversizing and massive calcification of the aortic annulus are thought to be a potential risk of this complication. A case presented here is an aortic annular rupture after transcatheter aortic valve implantation. Although the valve was not oversized, there were 2 severe calcifications of aortic annulus at nearby areas like "twin icicles," thought to be a trigger of this potentially fatal complication.

Background Transit-time flow measurement (TTFM) is frequently used for intraoperative graft flow analysis during coronary artery bypass grafting (CABG). Although the TTFM results may be influenced by fractional flow reserve (FFR) of the target coronary artery as a determinant of coronary lesion-specific ischemia, the data have been limited. Methods We retrospectively investigated the relationships between the intraoperative TTFM variables and preoperative FFR values of the target coronary arteries in 40 in situ left internal thoracic artery (LITA) grafts to the left anterior descending artery (LAD), which were revealed to be patent on postoperative computed tomographic angiography. Results The Spearman correlation coefficients of the TTFM variables with FFR were maximum flow, −0.12 (P = .301); minimum flow (Qmin), −0.43 (P = .004); mean flow (Qm), −0.30 (P = .036); pulsatility index, 0.37 (P = .012); diastolic filling, −0.36 (P = .012); percentage insufficiency, 0.45 (P = .002); and fast Fourier transform (FFT) ratio, −0.07 (P = .329). While Min and Qm showed significant negative correlation, the pulsatility index and percentage insufficiency showed significant positive correlation with FFR. Conclusions Most TTFM variables, including Qm, of the LITA graft to the LAD during CABG are strongly affected by preoperative FFR values. Because the FFT ratio is not influenced by FFR, FFT analysis of the TTFM may be recommend in the case of the in situ LITA graft to the LAD with moderate stenosis with a higher FFR exceeding 0.75.

OBJECTIVES Postoperative acute kidney injury (AKI) is known as a risk factor for death after surgery for Stanford type A acute aortic dissection under hypothermic circulatory arrest. It may also adversely affect long-term survival. We searched for modifiable risk factors for postoperative AKI, focusing on lower body ischaemic time. METHODS We reviewed 191 patients undergoing surgical repair for Stanford type A acute aortic dissection. The distal anastomosis depended on excluding the primary tear location, resulting in ascending/hemiarch (n = 119), partial arch (n = 18) and total arch replacement (n = 54). We defined an increase in the serum creatinine level to ≧2 times the baseline level as AKI. The incidence of AKI was investigated with multivariate analysis of its risk factors. RESULTS Postoperative AKI was observed in 49 patients (26%), 31% of whom required renal replacement therapy. The overall hospital mortality rate was 8.5%. Postoperative AKI, preoperative shock and organ malperfusion were predictors of hospital death. Multivariate stepwise logistic regression analysis identified age, body mass index, preoperative chronic kidney disease and lower body ischaemic time as risk factors for postoperative AKI. CONCLUSIONS Although surgical repair for Stanford type A acute aortic dissection showed favourable results, the incidence of postoperative AKI is still high, closely associated with hospital death. Lower body ischaemic time should be recognized specifically as a modifiable surgical risk factor for postoperative AKI.

We report a rare case of retrograde Stanford type A aortic dissection after endovascular repair for complicated Stanford type B aortic dissection. A 45-year-old man presented with a sudden onset of back pain and was transferred to our hospital. Computed tomography demonstrated acute Stanford type B aortic dissection with lower limb ischemia. Emergency endovascular surgery was planned for repair of the Stanford type B aortic dissection. The patient suddenly developed recurrent chest pain 10 days after the initial procedure. Computed tomography revealed retrograde Stanford type A aortic dissection involving the ascending aorta and aortic arch. The patient underwent a successful emergency total aortic arch replacement.

Background Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is technically demanding. We tried to identify the predictors for short- and long-term outcomes after PEA for CTEPH with aggressive use of pulmonary vasodilators, including epoprostenol sodium. Methods From 2005 to 2013, 122 CTEPH patients, whose preoperative mean pulmonary artery pressure (mPAP) was 47 ± 10 mm Hg and pulmonary vascular resistance was 847 ± 373 dynes/s/cm5, underwent PEA with hypothermic circulatory arrest. Before PEA, all patients underwent pulmonary vasodilator therapy, including epoprostenol sodium of 2 to 6 ng/kg/min. We collected the perioperative and follow-up data retrospectively to identify the predictors for early and late outcomes after PEA. Results In-hospital mortality was 7.4% (n = 9). Predictors for in-hospital death were age older than 65 years and New York Heart Association Functional Classification IV. Among the 113 PEA survivors, the mPAP and pulmonary vascular resistance significantly decreased. After the median follow-up of 6.8 years, the overall survival rates were 91.8%, 89.2%, 89.2%, 89.2%, and 86.1%, and the cardiac events-free rates were 100%, 98.1%, 95.8%, 85.5%, and 49.0%, at 1, 3, 5, 7, and 10 years, respectively, in the Kaplan-Meier model. A multivariate Cox proportional hazard model identified postoperative mPAP exceeding 30 mm Hg as the only predictor for late cardiac events. Conclusions Early and late outcomes of PEA for CTEPH with perioperative aggressive pulmonary vasodilator treatment seem satisfactory. However, residual pulmonary hypertension remains challenging to achieve further improvement of late outcomes.

Background Because increased age is a strong independent predictor of mortality and morbidity, surgery for octogenarians with Stanford type A aortic dissection (AAD) may be avoided.Methods and Results:From 2005 to 2015, 158 patients underwent surgical repair for AAD via a median sternotomy. We compared 24 (15.2%) octogenarians (83±3 years) with 134 (84.8%) patients aged ≤79 years (62±13 years), based on retrospectively collected clinical data. Octogenarians were predominantly female (79.2% vs. 44.8%, P=0.0033). Ascending aortic replacement was more frequently performed in the octogenarians (95.8% vs. 65.7%, P=0.0015) and total arch replacement in the younger patients (4.2% vs. 26.9%, P=0.0165). There were 14 hospital deaths among the younger patients, none among the octogenarians (0% vs. 10.4%, P=0.1303), and major morbidity rates were comparable. There were 3 late deaths among the octogenarians and 9 deaths among the younger patients. The respective 1-, 3-, and 5-year survival rates were 94.4%, 81.5%, and 81.5% in the octogenarians and 86.9%, 85.6%, and 83.9% in the younger patients, with no significant differences. Conclusions Surgical repair for AAD in octogenarians showed favorable results when compared with a younger patient cohort, with low hospital mortality rate and excellent late outcomes. Therefore, this technique should not be disregarded just because the patient is an octogenarian. (Circ J 2016; 80: 2468-2472).

Prosthetic valve selection in dialysis patients remains controversial because of the limited data available. This study aimed to clarify late clinical outcomes and discuss strategies for optimal valve selection in dialysis patients.We retrospectively analyzed the data obtained from 406 consecutive patients who underwent aortic valve replacement between 1995 and 2010. We compared valve-related outcomes among 89 dialysis and 317 nondialysis patients. We selected bioprostheses for all patients older than 65 to 70 years, irrespective of the renal function.Dialysis was found to be a significant risk factor for bleeding events (hazard ratio, 3.98; 95% confidence interval, 2.51 to 6.30; p0.001), however, no significant differences were observed according to the type of prosthesis. The overall survival was significantly worse in the dialysis patients (63% versus 85% at 5 years; p0.001), and freedom from structural valve deterioration was also lower in the dialysis patients (82% versus 100% at 5 years; p0.001). Among the dialysis patients, an advanced age (≥ 70 years; hazard ratio, 3.53; p = 0.011), diabetes mellitus (hazard ratio, 2.48; p = 0.041), and concomitant coronary artery bypass grafting (hazard ratio, 1.99; p = 0.071) were independent predictors for late death based on a multivariate analysis.Our valve selection criteria in dialysis patients, which are the same as the current practice guidelines for nondialysis patients, are acceptable. Bioprostheses can be considered in all dialysis patients with diabetes or coronary artery disease.

Since 1991, in our laboratory, a pivot bearing-supported, sealless, centrifugal pump has been developed as an implantable ventricular assist device (VAD). For this application, the configuration of the total pump system should be relatively small. The C1E3 pump developed for this purpose was anatomically compatible with the small-sized patient population. To evaluate an-tithrombogenicity, ex vivo 2-week screening studies were conducted instead of studies involving an intracorpore-ally implanted VADs using calves. Five paracorporeal LVAD studies were performed using calves for longer than 2 weeks. The activated clotting time (ACT) was maintained at approximately 250 s using heparin. All of the devices demonstrated trouble-free performances over 2 weeks. Among these 5 studies, 3 implantations were subjected to 1-month system validation studies. There were no device-induced thrombus formations inside the pump housing, and plasma-free hemoglobin levels in calves were within the normal range throughout the experiment (35, 34, and 31 days). There were no incidents of system malfunction. Subsequently, the mass production model was fabricated and yielded a normalized index of hemolysis of 0.0014, which was comparable to that of clinically available pumps. The wear life of the impeller bearings was estimated at longer than 8 years. In the next series of in vivo studies, an implantable model of the C1E3 pump will be fabricated for longer term implantation. The pump-actuator will be implanted inside the body; thus the design calls for substituting plastic for metallic parts.

The frozen elephant trunk (FET) technique allows single-stage extended surgical repair of Stanford type A aortic dissection and has shown promotion of aortic remodeling by maintaining the true lumen flow and facilitating its expansion and by promoting false lumen thrombosis. However, few studies have compared the effectiveness of FET technique, in terms of the downstream aortic remodeling. Between 2005 and 2017, 50 patients underwent total arch replacement for Stanford type A aortic dissection, including that with (n = 22) and without FET technique (n = 28). We compared distal aortic remodeling in patients who underwent total arch replacement with (using a J-Graft open stent graft) or without the technique. The false lumen complete thrombosis rate and the ratio of true lumen area at three levels of the descending aorta were evaluated post operation. In FET group, the diameter and length of the stent graft were 29.0 ± 3.9 mm and 70.9 ± 17.4 mm, respectively. The in-hospital death with and without the FET technique was 0 and 3, respectively, with no late death in both groups. Eight patients (28.6%) only in the non-FET group required additional surgical treatment for downstream aorta. In the FET group, the ratio of true lumen area at the level of bronchial carina and false lumen complete thrombosis rate at the levels of bronchial carina and aortic valve were significantly higher than non-FET group. A more favorable remodeling in the descending aorta was observed in patients who underwent FET associated with a total arch replacement compared to those who underwent total arch replacement alone.

Objective We investigated flow characteristics of right gastroepiploic arterial grafts, widely used to extend in situ arterial conduits in coronary artery bypass grafting. Methods Intraoperative transit-time measurements and postoperative angiographic findings were obtained for 111 patients undergoing coronary artery bypass grafting with gastroepiploic artery and bilateral internal thoracic arteries: mean, maximum, and minimum flows; pulsatility index; insufficiency rate; and differentiated index of early diastolic flow. Results Favored target for gastroepiploic artery was posterior descending artery (106 patients, 95%). Patency rates were 91.0% for gastroepiploic artery, 98.2% for left internal thoracic artery, and 97.5% for right internal thoracic artery. There were four flow profiles of gastroepiploic arteries: A (systolic protruded), B (trapezoidal), C (sine waved), and D (diastolic-dominant biphasic). Functional gastroepiploic arteries showed A in 16 cases, B in 6, C in 31, and D in 48, with prevalence according to severity of stenosis in target coronary artery. Two occluded gastroepiploic arteries showed type A, and reverse or competitive flows were types A in 1, B in 1, C in 4, and D in 2. Relative to functional internal thoracic arteries, functional gastroepiploic arteries showed significantly lower minimum flow, higher insufficiency rate, and lower differentiated index of early diastolic flow. Conclusion Intraoperative transit-time flow profiles of patent in situ gastroepiploic arterial grafts were classified into four types, closely associated with disease severity of target coronary artery. Patent in situ gastroepiploic arterial grafts show more regurgitant flow and lower differentiated index of early diastolic flow than in situ internal thoracic arterial grafts.

Preoperative autologous blood donation (PAD) is important for reducing exposure to allogenic blood in cardiac surgery. Unfortunately, even after PAD, allogenic blood transfusion is not always avoided. We investigated the predictors of blood component usage during elective cardiac surgery in patients prepared with PAD.Clinical data were collected for 143 consecutive patients (103 men and 40 women; mean age, 62 +/- 9 years) who underwent elective cardiac surgery after PAD (959 +/- 240 ml), often using iron supplement and recombinant human erythropoietin.Allogenic blood transfusion was avoided during and after surgery in 107 patients (75%), whereas 36 patients required an allogenic transfusion (4.1 +/- 3.8 U of packed red cells, 3.4 +/- 4.1 U of fresh frozen plasma, and 5.8 +/- 11.0 U of platelet concentrate). The independent factors for perioperative allogenic blood transfusion in these patients included the pre-donation hemoglobin value, the preoperative platelet count, and the lowest hemoglobin value during cardiopulmonary bypass.Even with PAD for elective cardiac surgery, patients whose pre-donation hemoglobin value and preoperative platelet count are low may require allogenic blood transfusion.

症例は39歳女性で，CT検査によって遠位弓部大動脈の形態異常を指摘されたため紹介された．患者は無症状で感染症および外傷の既往を認めなかった．3D-CT検査の結果，左鎖骨下動脈起始部を含めた特異な形の大動脈瘤と判明した．瘤の最大径は5 cmで患者年齢を考慮し早期手術を施行した．手術は左第4肋間開胸，FF部分体外循環下に，左総頸動脈直後と下行大動脈との単純遮断にて，大動脈峡部を20 mm，鎖骨下動脈を8 mmのダクロングラフトで置換した．本症例は，原始大動脈弓の発生異常によって生じる背側大動脈遺残，すなわちコメレル憩室と考えられた．病理所見上，高度のmedial layer atrophyを認めた．若年者の大動脈峡部の特発性大動脈瘤は，その破裂の危険性から，瘤径にかかわらず早期手術が望ましいと考えられた．文献的考察を加え報告する．

The blood contacting surface quality is an important pump parameter for blood compatibility and cell damage. This study investigates the surface roughness and the effect it has on hemolysis in a centrifugal blood pump. In vitro hemolysis tests were performed with a pivot bearing supported Gyro centrifugal pump (C1E3) simulating cardiopulmonary bypass (CPB; 5 L/min, 350 mm Hg) and left ventricular assist device (LVAD; 5 L/min, 100 mm Hg) conditions. To produce 4 different grades of surface roughness, the impellers and housings were subjected to vapor polishing, sand papering, fine sand blasting, or coarse sand blasting. Seven pumps were assembled with different impeller and housing surfaces. These surfaces were then examined by a surface profile instrument and a scanning electron microscope. The results of this study are as follows. First, the effect of surface roughness on hemolysis was significantly greater in the CPB condition than in the LVAD condition. Second, surface roughness, regardless of whether it is the impeller or pump housing, had little effect on hemolysis in the LVAD condition. Third, in the CPB condition, the surface roughness of the pump housing has a greater effect on hemolysis than does that of the impeller. From a hemolytic point of view, an extremely smooth pump housing is required for use of an impeller type centrifugal pump as a CPB device. In contrast, it is conceivable that a smooth surface is not always essential for an impeller type centrifugal pump that is used as an LVAD.

It is acknowledged that pulsatile flow enhances the gas exchange performance of membrane oxygenators. However, the data for currently developed oxygenators are limited. In this study, the effect of pulsatile flow was assessed utilizing the MENOX EL-4000 oxygenator. The in vitro test was performed following the Association for the Advancement of Medical Instrumentation (AAMI) standards. Pulsatile flow was produced by the Gyro C1-E3 centrifugal pump with periodical changing of the impeller speed. In Study 1, the following 3 groups were created and examined: nonpulsatile flow, pulsatile flow of 40 bpm, and pulsatile flow of 60 bpm. The blood flow rate was maintained at 3 L/min, and the V/Q ratio was 1. In Study 2, four groups were examined, nonpulsatile flow with V/Q = 1, nonpulsatile with V/Q = 2, pulsatile with V/Q = 1, and pulsatile with V/Q = 2. The blood flow rate was maintained at 4 L/min, and the pulse frequency was set at 40 bpm. In study 1, although O2 transfer was not enhanced, CO2 transfer was significantly improved (40-50%) by pulsatile flow, regardless of pulse frequency. Study 2 demonstrated that pulsatile flow resulted in improved CO2 transfer as did higher ventilation (V/Q = 2). Furthermore, even after applying higher ventilation, the pulsatile mode enhanced CO2 transfer more than the nonpulsatile mode. It was considered that the pulsatile mode induced an active secondary flow and enhanced mixing effects, and consequently CO2 transfer was improved. In conclusion, the pulsatile flow significantly enhanced the CO2 transfer of the MENOX oxygenator. It is indicated that applying the pulsatile mode is a unique and effective method to improve the gas exchange performance for a current membrane oxygenator.

An eccentric inlet port is a unique feature of the pivot bearing supported Gyro Compact-1 Eccentric Inlet Port Model 3 (ClE3) centrifugal pump, a completely seal-less centrifugal pump. The latest C1E3 has an eccentric inlet port with a 30 degree vertical angle. To investigate the adequacy of this 30 degree angle, flow visualization studies and in vitro hemolysis tests were performed, comparing 4 pumps, each with a different angle of the eccentric inlet port (0, 30, 60, and 90 degrees). The flow visualization study utilizing a tracer method focused on the flow pattern just distal to the inlet port of each pump, and each pump was operated at 5 L/min against 100 mm Hg and 5 L/min against 350 mm Hg. In the pumps with angles of 90 and 60 degrees, the flow direction changed horizontally, causing a vortex formation. In the pump with the 30 degree angle, the inflow did not change its course, resulting in minimal space for vortex formation. In the pump with the 0 degree angle, the inflow collided with the pump housing, resulting in a small vortex formation along the housing surface. The in vitro hemolysis tests at 5 L/min against 350 mm Hg revealed that the pump with the 30 degree angle was the least hemolytic and the pump with the 90 degree angle was the most hemolytic among the 4 pumps. These results suggest that the angle of the eccentric inlet port of the Gyro C1E3 pump should be 30 degrees to have less vortex formation and less red blood cell trauma.

Centrifugal pumps are generally employed as nonpulsatile blood flow pumps; however, these pumps can produce pulsatile flow by periodically alternating the impeller rotation speed. This study investigates blood trauma due to the effect of pulse frequency and various ranges of pump speed. The hemolysis tests were conducted using the Gyro C1E3 pump. The study was divided into the following categories: Group 1 in a nonpulsatile mode; Group 2 operated at 40 bpm with 30% of speed variance; Group 3, 60 bpm with 30% of speed variance; Group 4, 40 bpm with 70% of speed variance; and Group 5, 60 bpm with 70% of speed variance. A flow rate of 3 L/min and a total pressure head of 200 mm Hg were employed in all groups to simulate a percutaneous cardiopulmonary support condition. There were no significant differences in the hemolysis levels among Groups 1, 2, and 3. However, Groups 4 and 5 exhibited a significantly higher hemolysis rate compared to the other groups. These results indicate that a high rate of speed variance increases hemolysis; however, a range of less than 30% does not affect hemolysis. The pulse rate has no significant effect on hemolysis. In conclusion, the higher speed variance increases the hemolysis level when a pulsatile mode is applied with a centrifugal pump at the given test conditions. However, a speed variance of less than 30% or a pulse rate of less than 60 bpm does not affect hemolysis.

A miniaturized pivot bearing-supported centrifugal blood pump (Gyro PI) has been developed as a long-term biventricular assist system (BiVAS). In this study we determined the anatomical configuration of this system using a bovine model. Under general anesthesia, a left lateral thoracotomy was performed to open the chest. Two Gyro PI-601 pumps for left and right assists were placed in the preperitoneal pocket by a subcostal abdominal incision. The left pump could be placed along the dome of the diaphragm just beneath the apex of the left ventricle. The right pump could be placed next to the left pump. The inlet and outlet ports of both pumps penetrated the diaphragm. The inlet port of the left pump, with a length of 55 mm, was inserted directly into the apex of the left ventricle. A woven Dacron graft (150 mm long, 11 mm inner diameter) was placed between the outlet port of the left pump and the descending aorta. As for the right pump. a 100 mm long and 120 degree angled inflow conduit was placed between the inlet port and the right ventricular infundibulum. The outlet port of the right pump was connected to the main trunk of the pulmonary artery using a 90 mm long, 11 mm inner diameter Dacron graft. We could perform biventricular assistance to confirm the anatomical feasibility of the Gyro implantable centrifugal BiVAS.

Mechanical trauma of white blood cells (WBC) due to the operation of a rotary blood pump was examined, using a simple method of trypan blue dye exclusion test for a cell viability measurement. The degree of WBC trauma was investigated using a roller pump (RP) and 3 commercially available centrifugal pumps (Bio-Medicus [BP], Capiox [CP], Nikkiso [NK]), and compared with the red blood cell (RBC) trauma. Each pump was operated 3 times at a flow rate of 5 L/min against the total pressure head of 350 mm Hg for 6 h in a mock circuit with 400 ml of fresh bovine blood. Blood was sampled at 2 h intervals measuring plasma free hemoglobin concentration and the percentage of damaged WBC in the trypan blue dye exclusion test. Each pump demonstrated a linear increase in the degree of WBC trauma, and there were differences among the tested pumps (RP > BP > CP > NK). These findings were similar to those of the free hemoglobin measurements. To compare the degree of RBC and WBC trauma, the probability (gamma, omega) of RBC and WBC to be damaged was calculated, respectively. gamma = delta DRBC/delta N, omega = delta DWBC/delta N where DRBC and DWBC are the ratios of the damaged RBC and WBC, respectively, and N is the passing number defined as Qt/V (Q, flow rate; t, time; V, circulating volume). The data of this study demonstrated that the omega value was approximately 20 times or more greater than the gamma equally in all the tested pumps. This suggests that a WBC is more vulnerable to mechanical damage by a rotary blood pump than a RBC.

The conclusions remain controversial about whether the sternal blood flow is preserved or diminished after internal thoracic artery (ITA) harvesting for coronary artery bypass grafting (CABG), especially in diabetic patients. We investigated the blood supply of the chest wall noninvasively using near-infrared spectroscopy (NIRS) immediately after CABG.The study group comprised 30 patients who underwent CABG using a skeletonized left ITA through median sternotomy. As a control group, three nondiabetic patients undergoing valve surgery through median sternotomy were also included. On arrival of the patient in the intensive care unit immediately after surgery, two reflectance sensors were placed on the bilateral parasternal regions at the fourth intercostal space to record regional oxygen saturation (rSO(2)) and hemoglobin index (HbI) continuously approximately for 17 h.The differences in right and left values (R-L rSO(2) and R-L HbI) were significantly greater in the diabetic patients than in the nondiabetic patients (3.74% +/- 2.47% vs. 1.98% +/- 1.67 %, p = 0.036; and 0.28 +/- 0.19 vs. 0.13 +/- 0.13, p = 0.020). The R-L HbI was significantly greater in the on-pump patients than in the off-pump patients, although there was no significant difference in R-L rSO(2). Both R-L rSO(2) and R-L HbI were similar among the control, nondiabetic, and off-pump patients.The technique of NIRS enables noninvasive, continuous monitoring of chest wall perfusion immediately after ITA harvesting. Our study using NIRS showed a decrease in blood flow and oxygen metabolism of the hemisternum after LITA harvest in diabetic CABG patients.

Background Coronary artery bypass grafting (CABG) is best indicated for chronic total occlusion of the left anterior descending artery (LAD) with collaterals. We investigated angiographic changes in the collateral circulation after CABG. Methods Preoperative and postoperative angiograms were reviewed in 42 patients who underwent grafting onto occluded LADs. We described the type, location, and size of collaterals, the Rentrop grading, and collateral frame count (CFC). Regional wall motion of the LAD area was also evaluated with the centerline method. Postoperatively, we measured the lengths of LAD proximal (Lp) and distal (Ld) to the graft anastomotic site. Results Preoperative collaterals comprised 78 pathways (septal 42%, branch-branch 20%, atrial 19%, bridging 18%). After CABG, residual collaterals were identified, mainly through the septal pathways, in 6 patients (14%), most of whom were diabetic. The residual collaterals were a part of those which had been opacified in earlier phases of the preoperative angiograms (CFC: 17 ± 3 vs 25 ± 15, p = 0.01). Also, the Ld was shorter in these patients so that Lp/Ld was greater than in patients without residual collaterals (0.80 ± 0.24 vs 0.53 ± 0.28, p = 0.04). We found no association of residual collaterals with the improvement of LAD regional wall motion after CABG. Conclusions Even after successful CABG, some collaterals with earlier filling of the LAD remain, mainly through the septum. Although the clinical significance remains to be clarified, complex and diffuse atherosclerosis associated with more distal graft anastomoses may contribute to maintaining collaterals after CABG to the occluded LAD, especially in diabetic patients.

Liver cirrhosis is recognized as one of the risk factors for severe complications after cardiac surgery. However, there are no established methods for risk stratification of the patients with liver cirrhosis (LC) regarding cardiac surgery. We present our experience of preoperative evaluation of liver function using asialoscintigraphy.Between April 1999 and December 2005, we evaluated preoperative liver function using asialoscintigraphy with technetium-99m galactosyl human serum albumin in four cirrhotic patients undergoing coronary artery bypass grafting (n = 2) and valve replacement (n = 2), whose etiologies of LC were alcohol abuse (n = 1) and hepatitis C virus infection (n = 3). They also underwent other tests for preoperative evaluation of liver function, including the indocyanine green (ICG) test.Asialoscintigraphy revealed that the receptor index and the index of blood clearance in each patient were 0.81/0.73, 0.95/0.5, 0.82/0.62, and 0.97/0.57, respectively. These values closely correlated with the results of the ICG test. All patients were discharged alive from hospital after surgery. However, although one patient who underwent off-pump bypass had an uneventful course, three patients had major complications: pleural effusion (n = 1) and wound infection (n = 2).Asialoscintigraphy is a practical, reliable method that can replace the ICG test for estimating hepatic function for risk stratification of cirrhotic patients undergoing cardiac surgery, whose mortality and morbidity are still high.

We have been using magnetic resonance angiography (MRA) preoperatively to identify patients at increased risk of stroke in coronary artery bypass grafting (CABG). Based upon the intracranial MRA findings, either the off-pump or the on-pump procedure was selected. We report the results of our MRA-based strategy of CABG in 140 consecutive patients. Intracranial arterial lesions were found in 90 patients (64%). The most affected arteries were internal carotid (48%), followed by vertebral (18%) and middle cerebral (16%). Using the MRA score describing the severity of intracranial atherosclerosis, 35 patients with a score of > or = 5 underwent off-pump, while 105 patients with a score of < 5 underwent on-pump CABG. In the off-pump group, the patient age was older, the incidence of abnormal preoperative brain CT was higher, and the MRA score was higher (6.0+/-1.1 vs. 1.2+/-1.3 points) than in the on-pump groups. Even though the risk was higher in the off-pump group, the clinical outcomes were not significantly different, including the hospital mortality and the incidence of stroke and additional coronary intervention. In conclusion, the brain MRA-based selection of off-pump CABG can contribute to prevention of stroke in neurologically high-risk patients.

Centrifugal pumps have been increasingly used in clinical settings. Like roller pumps, centrifugal pumps can cause debris release due to mechanical stress. The objectives of this study were to evaluate in vitro the particle release from a centrifugal pump, Gyro Pump (Japan Medical Materials Co., Osaka, Japan), which is a pivot-bearing supported pump clinically used in Japan, and to identify the released particles. In the clean room Class 10,000, the pump was operated for 24 h at 4000 rpm and 6 L/min in a mock loop filled with lactated Ringer's solution. After 24 h, the sample fluid and a blank were filtered with a 0.45-microm membrane filter for microscopic counting, followed by observation with a scanning electron microscope and element analysis with an X-ray spectrometer. Microscopic countings were 128 +/- 42 in the test samples (n = 10) of the Gyro Pump and 98 +/- 42 in the blank samples (n = 10) (P = 0.12). The oxygen/carbon atomic ratio of the particles in the test samples was 0.32 +/- 0.06, which was similar to the ratio of the particles in the blank sample (0.34 +/- 0.06). The profiles of elements with an X-ray spectrometer showed that the released particles from the Gyro Pump were not derived from the pump materials. In conclusion, an in vitro test system has been established for estimation of particle release from a centrifugal pump. Based upon the results with the system, the Gyro Pump with a pivot-bearing system has little risk to release debris particles even in a severe condition.

Background Although it has been reported that coronary artery bypass grafting (CABG) for multivessel disease markedly improves several parameters of signal-averaged electrocardiography (SAECG), its beneficial effect on SAECG is variable. The hypothesis of the present study was that the presence of diabetes mellitus (DM) affects the improvement in SAECG after CABG. Methods and Results Pre- and post-operative SAECGs were recorded in 100 consecutive patients who underwent complete surgical revascularization. Changes in the following parameters were compared between the diabetic (n=43) and non-diabetic (n=57) patients: filtered QRS duration (dQRS), root mean square voltage in the terminal 40 s of the QRS complex (RMS40), and duration of the terminal low-amplitude signal lower than 40 μV (LAS40). Although baseline characteristics and the occurrence of late potentials were similar in both groups, quantitative improvements in the SAECG parameters after CABG were significantly greater in non-diabetic than in diabetic patients (dQRS: 109±22 ms vs 102±19 ms in diabetics and 106±21 ms vs 88±11 ms in non-diabetics; p=0.028, RMS40: 55±46 μV vs 65±38 μV in diabetics and 50 ±37 μV vs 76±37 μV in non-diabetics; p=0.037, LAS40: 31±20 ms vs 26±17 ms in diabetics and 32±12 ms vs 17±8 ms in non-diabetics; p=0.007, respectively). Conclusions The presence of DM limits the CABG-induced improvement in SAECG. In diabetic patients, therefore, perioperative changes of the SAECG must be interpreted with caution. (Circ J 2004; 68: 334 - 337)