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1 oktober 2010, Item does not contain fulltext, BACKGROUND: Laparoscopic surgery involves the establishment of a pneumoperitoneum, mostly using carbon dioxide. Cooling of the peritoneum, due to insufflation, may traumatize the peritoneum and disturb local biological processes. The current study was performed to assess the effect of the temperature of carbon dioxide on peritoneal transforming growth factor beta1 (TGF-beta1) expression. DESIGN: Patients were randomized into 2 groups. In one group, a pneumoperitoneum was created with carbon dioxide at room temperature; in the other, with carbon dioxide at body temperature. Peritoneal biopsy specimens were taken at the start and end of surgery. SETTING: Community hospital. PATIENTS: Thirty patients scheduled for laparoscopic cholecystectomy. MAIN OUTCOME MEASURES: Tissue concentrations of total and active TGF-beta1 were measured using enzyme-linked immunosorbent assays. Results : At the start of surgery, there were no significant differences between groups in the total and active fractions of TGF-beta1. At the end of the procedure, the peritoneal active TGF-beta1 concentrations were significantly lower (P = .03) in patients receiving carbon dioxide at body temperature. In contrast, the concentrations of total TGF-beta1 did not differ between groups. A slight, nonsignificant increase in total and active TGF-beta1 levels was observed in patients receiving unheated carbon dioxide. The ratio of active to total TGF-beta1 did not change during procedures, and there were no differences between groups. CONCLUSIONS: Heating of carbon dioxide, used for insufflation, to body temperature decreases the expression of active TGF-beta1 in the peritoneum. Considering the broad biological effects of TGF-beta1, including the regulation of peritoneal healing and oncological processes, this observation might have clinical repercussions.

Item does not contain fulltext, BACKGROUND: Laparoscopic surgery may affect peritoneal physiology. Short-term laparoscopic surgery does not affect peritoneal transforming growth factor beta (TGF-b1) expression. The current study was conducted to evaluate the hypothesis that prolonged laparoscopic surgery may affect peritoneal TGF-b1 expression. STUDY DESIGN: In the first study, 24 patients scheduled for a right colonic resection were enrolled in the trial. Twelve underwent conventional surgery (CCR) and 12 were operated on laparoscopically (LCR). In the second study, 12 patients undergoing laparoscopic gastric bypass (LGB) surgery for morbid obesity were included. Biopsies of the parietal peritoneum were taken at standardized moments during the procedures. Tissue concentrations of active and total TGF-b1 were measured by using enzyme-linked immunosorbent assays. Results : During the LCR, there was a significant increase in peritoneal active TGF-b1 levels (P < 0.05). A similar, but not significant, trend was observed during the CCR. A similar pattern was seen in the total TGF-b1 concentrations during both procedures. The LGB procedure did not affect peritoneal active or total TGF-b1 concentrations. During the procedure, both the active and total TGF-b1 levels were significantly higher in the LCR, when compared to the LGB, group (P < 0.05). CONCLUSIONS: Prolonged laparoscopic surgery may affect peritoneal TGF-b1 expression, depending on the procedure performed. Considering the role of TGF-b1 in various biologic processes, including adhesiogenesis and oncology, these results may have clinical consequences.

1 juni 2010, Item does not contain fulltext, OBJECTIVES: Recurrences of varicosities of the small saphenous vein (SSV) are common. Surgical reintervention is associated with increased complication rates. The aim of the study was to assess the feasibility of endovenous laser ablation (EVLA) in recurrent varicose veins of the SSV and to compare this technique with surgical reintervention. METHODS: All case files of patients treated for SSV varicosities between May 2006 and October 2008 were evaluated and recurrences were selected. Demographics, duplex findings, clinical, aetiological, anatomical and pathological classification, perioperative and follow-up data were all registered. Additionally, a questionnaire focusing on patient satisfaction was taken. RESULTS: Two hundred and eighty-one patients were treated for varicosities of the SSV, of which 42 were for recurrences. Twenty-six of these were treated with EVLA, all under local anaesthesia, and 16 were surgically treated. Most surgically treated patients were treated under regional anaesthesia (88%). Technical success was achieved in 94% of surgically treated patients and in all EVLA-treated patients. Complications in both groups were mostly minor and self-limiting. Sural nerve neuralgia appeared to be more frequent in the surgically treated group (20% versus 9%). After correction for length of follow-up, the incidence of rerecurrences was not statistically significant between groups. CONCLUSION: EVLA is feasible in patients with recurrent varicose veins of the SSV with possibly a lower incidence of sural nerve injury. Patient satisfaction is high for both treatment modalities. Studies with larger samples are indicated to confirm these observations.

Contains fulltext : 81067.pdf (publisher's version ) (Closed access), OBJECTIVE: Varicose vein recurrence of the great saphenous vein (GSV) is a common, costly, and complex problem. The aim of the study was to assess feasibility of endovenous laser ablation (EVLA) in recurrent varicose veins of the GSV and to compare this technique with conventional surgical reintervention. METHODS: Case files of all patients treated for GSV varicosities were evaluated and recurrences selected. Demographics, duplex scan findings, CEAP classification, perioperative data, and follow-up examinations were all registered. A questionnaire focusing on patient satisfaction was administered. RESULTS: Sixty-seven limbs were treated with EVLA and 149 were surgically treated. General and regional anesthesia were used more in the surgery group (P < .001). Most complications were minor and self-limiting. Wound infections (8% vs 0%; P < .05) and parasthesia (27% vs 13%; P < .05) were more abundant in the surgery group, whereas the EVLA-treated patients reported more delayed tightness (17% vs 31%; P < .05). Surgically-treated patients suffered less postoperative pain (P < .05) but reported a higher use of analgesics (P < .05). Hospital stay in the surgery group was longer (P < .05) and they reported a longer delay before resuming work (7 vs 2 days; P < .0001). Patient satisfaction was equally high in both groups. At 25 weeks of follow-up, re-recurrences occurred in 29% of the surgically-treated patients and in 19% of the EVLA-treated patients (P = .511). CONCLUSION: EVLA is feasible in patients with recurrent varicose veins of the GSV. Complication rates are lower and socioeconomic outcome is better compared to surgical reintervention.

Contains fulltext : 80135.pdf (publisher's version ) (Closed access), Mesothelial cells are involved in a variety of biological processes, which include the formation of peritoneal adhesions. The cultures of human peritoneal mesothelial cells comprise an important tool to investigate the behavior and functions of mesothelial cells. Very little is known about the differences among mesothelial cells isolated from different sources and about the changes in specific functions as caused by cell propagation in vitro or that result from storage of cells at low temperatures. This study aims to characterize 2 particular cellular activities relevant for tissue repair, which include the expression of intercellular adhesion molecule-1 (ICAM-1) and the gelatinase activity; in addition, this study will assess the effect of hyaluronan, which is an antiadhesive agent, on these cellular activities. Viable cell lines were established from both omentum and peritoneal lavage fluid from 7 patients. Both ICAM-1 expression, which was measured by enzyme-linked immunosorbent assay (ELISA), and matrix metalloproteinase (MMP) bioactivity, which was measured by zymography, were measured in the 2nd and 4th passage; the latter also was measured after freezing and storing of cells in liquid nitrogen. The effects of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), phorbol myristate acetate (PMA), and hyaluronan were analyzed. ICAM-1 was constitutively expressed and stimulated by IL-1beta, TNF-alpha, and PMA. All cell lines produced both MMP-2 and MMP-9. Only the latter activity was affected by TNF-alpha and, especially so, PMA. Differences were found between the 2nd and 4th passage, as well as between cells of different lineage, mostly so if the relative stimulation by the various agents was compared. The addition of sodium hyaluronate either to control cultures or to cultures together with any of the 3 stimuli examined did not significantly change either ICAM-1 expression or gelatinase activity. The freezing and storage of cells did not affect

Contains fulltext : 81407.pdf (publisher's version ) (Closed access), BACKGROUND: Abdominal adhesions and abscesses are a major source of morbidity and mortality after abdominal surgery and peritonitis. Adhesions are hard to detect with standard imaging techniques. Liposomes, coated with polyethylene glycol (PEG), represent an agent developed for infection imaging. This study investigated the capacity of 99mTc-PEG-liposomes to localize early adhesion formation after peritonitis. Additionally, the value of 99mTc-PEG-liposomes for therapy evaluation of hyaluronan solution, which reduces adhesion and abscess formation in experimental peritonitis, was assessed. METHODS: In 24 rats, a bacterial peritonitis was induced by performing a cecal ligation and puncture procedure. The animals were treated with sodium chloride solution or 0.4% hyaluronan solution intra-abdominally. One week later, scintigraphy was performed using 99mTc-PEG-liposomes, and abnormal focal uptake in the abdomen was scored. Thereafter, autopsy was performed and adhesions and abscesses were scored. RESULTS: A significant correlation was found between the total adhesion score and the scintigraphic score (P < 0.01, r = 0.65). Treatment with hyaluronan significantly reduced the total adhesion score (P = 0.01). The size of abscesses significantly correlated with the scintigraphic score (P < 0.01, r = 0.65). Treatment with hyaluronan reduced the size of abscesses (P < 0.05). CONCLUSION: 99mTc-PEG-liposomes are able to detect early adhesions and abscesses and may be used for therapy evaluation of agents that reduce adhesions and abscesses.

Contains fulltext : 69944.pdf (publisher's version ) (Closed access), PURPOSE: The development of endovascular repair of popliteal aneurysms has provided an alternative, minimally invasive way of treatment. We present a case of a late type-I endoleak, after previous exclusion of a popliteal pseudoaneurysm, leading to rupture and massive hematoma, which was excluded in a hybrid procedure. CASE REPORT: A 95-year-old woman presented with progressive swelling with skin ulceration and necrosis cranial to the medial side of her left knee. Four years earlier, a left popliteal pseudoaneurysm was excluded with a stent-graft. Rupture of the popliteal artery with massive hematoma was demonstrated by ultrasound examination and a spiral computed tomography scan, with high suspicion of a type-I endoleak. Endovascular repair of the endoleak with a polytetrafluoroethylene-covered stent-graft was followed by surgical resection of the damaged skin and evacuation of the hematoma. CONCLUSION: Type-I endoleaks after endovascular exclusion of popliteal pseudoaneurysms do occur and may lead to rupture. A symptomatic pseudoaneurysm may be successfully treated by a hybrid procedure.

Contains fulltext : 70358.pdf (publisher's version ) (Closed access), Infections of abdominal aortic endografts are rare. There are no reports on the association with spondylodiscitis. We report a case of a 74-year-old man who underwent endovascular aneurysm repair (EVAR) and subsequently femorofemoral bypass placement due to occlusion of the right limb of the endograft. Six months later, he presented with rectal bleeding, weight loss, back pain, and low abdominal pain. Computed tomography revealed extensive abscess formation with air in and around the endograft and psoas muscles, in continuity with destructive spondylodiscitis L3-4. There was a small bowel loop in close proximity to the occluded right leg of the endograft, which was filled with air bubbles. An axillofemoral bypass was created followed by a laparotomy. Intra-operatively, an iliaco-enteral fistula was found. The small bowel defect was sutured, the endograft completely removed, and the infrarenal aorta and both common iliac arteries were closed. Necrotic fragments of the former L3-4 disk were removed. The postoperative course was uneventful. Seven months postoperatively, the patient had recovered well. Iliaco-enteric fistula and spondylodiscitis are rare complications of aortic aneurysm repair. This is the first report of spondylodiscitis after EVAR.

Contains fulltext : 48024.pdf (publisher's version ) (Closed access), OBJECTIVE: To determine whether the presence of cells of the monocyte-macrophage system affects the fibrinolytic response of peritoneal mesothelial cells to lipopolysaccharide (LPS) in the presence and absence of sodium hyaluronate. DESIGN: Controlled laboratory experiment. SETTING: Cell cultures in an academic laboratory research environment. PATIENT(S): Human peritoneal mesothelial cells were harvested from patients undergoing a laparotomy for noninfectious reasons and were cultured in vitro. Co-cultures were formed by adding U-937 human monocyte-like cells to a monolayer of mesothelial cells. INTERVENTION(S): After 24 hours, cultures were treated with 10 ng/mL of LPS, and sodium hyaluronate was added in a final concentration of 0.2%. Controls received medium without sodium hyaluronate. MAIN OUTCOME MEASURE(S): After 24 hours' incubation, tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor-1 (PAI-1) levels were determined in medium and cell lysates by using ELISA techniques. RESULT(S): In medium of co-cultures, tPA and PAI-1 concentrations were statistically significantly increased compared with the case of monocultures, whereas uPA concentration was statistically significantly decreased. In cell lysates of co-cultures, PAI-1 concentration was statistically significantly increased compared with the case of monocultures, whereas tPA and uPA were unaffected. Treatment with sodium hyaluronate statistically significantly decreased PAI-1 and uPA concentrations in medium of monocultures but decreased uPA concentration only in medium of co-cultures, compared with the case of controls. CONCLUSION(S): Cells of the monocyte-macrophage system modulate the fibrinolytic capacity of LPS treated human peritoneal mesothelial cells and interfere in the hyaluronan-associated changes in mesothelial fibrinolytic capacity.

Item does not contain fulltext, BACKGROUND: A relationship between post-surgical adhesion formation and peritoneal tumour implantation has been proposed. Hyaluronan (HA)-based agents reduce adhesion formation, but the effect on peritoneal tumour is not established. This study investigated the influence of a HA-containing agent on intraperitoneal tumour in an experimental model. METHODS: 66 Balb/c mice underwent laparotomy and damage was inflicted to the parietal peritoneum. The animals were randomized into five groups. Groups 1 and 2 received HA-carboxymethylcellulose bioresorbable membrane and no treatment, respectively. Mice in groups 3-5 were injected intraperitoneally with 10(5) colon 26-B cells after the laparotomy. Treatment consisted of HA membrane, no HA agent and placement of HA membrane on the non-traumatized peritoneal wall, respectively. Animals were killed after 14 days; adhesions were scored in groups 1 and 2, and the tumour mass in groups 3-5. 45 Wag/Rij rats underwent the same procedures and treatment as mice in groups 3-5. In rats, 10(6) CC-531 cells were injected. Rats were killed after 3 weeks and the tumour mass was scored. Results: HA membrane resulted in a significant reduction of adhesions, but had no major effect on the intraperitoneal tumour mass in mice and rats. CONCLUSION: HA-carboxymethylcellulose bioresorbable membrane has no major effect on intraperitoneal tumour implantation and growth in an experimental model.

Item does not contain fulltext, BACKGROUND: Intra-abdominal adhesions and abscesses cause significant morbidity and mortality. The formation of fibrin in the abdominal cavity is a common pathophysiological pathway for both. The aim of this review was to investigate the pathophysiology of intra-abdominal adhesions and abscesses, and to explore the possible sites of action of hyaluronan. METHODS: Data were reviewed from the literature using the Medline database. RESULTS: Both surgery and peritonitis disturb the equilibrium between coagulation and fibrinolysis in the abdominal cavity in favour of the coagulation system. Hyaluronan-based agents reduce adhesion formation after surgery. Moreover, hyaluronan solution reduces abscess formation in experimental peritonitis. Possible mechanisms of action include mechanical separation of wound surfaces, improvement of peritoneal healing, modulation of the inflammatory response and enhanced fibrinolysis. CONCLUSION: Diminished fibrin degradation is a common pathway for the formation of adhesions and abscesses. The potential of hyaluronan-based agents to reduce intra-abdominal adhesions and abscesses in abdominal surgery and sepsis is a promising new concept. Elucidating the mechanisms involved and the clinical application of hyaluronan in peritonitis are challenges for future research.

Background: This study assessed the peritoneal fibrinolytic response during the first week after colonic surgery in rats with and without bacterial peritonitis, and possible modulation of the response by two hyaluronan-based antiadhesive agents. Methods: A colonic anastomosis was constructed in 90 male Wistar rats. Peritonitis was induced in another 108 rats and a colonic anastomosis was constructed after 24 h. Rats in both groups were randomized into an untreated group or one of two groups treated with hyaluronan-based agents. One-third of each group was killed at each of days 1, 3 and 7 after operation, and tissue plasminogen activator (tPA) antigen and activity were measured in peritoneal biopsies. Results: One day after colonic surgery in normal rats, tPA antigen concentration was significantly (P < 0.005) increased, whereas tPA activity levels were normal. By day 3 after operation tPA antigen had returned to baseline values while tPA activity was significantly increased (P < 0.05). One day after inducing peritonitis tPA antigen was significantly increased (P < 0.001), while tPA activity was significantly reduced (P < 0.05). Three and seven days after colonic surgery in rats with peritonitis tPA activity was increased (P < 0.001) while tPA antigen had returned to baseline values. Neither of the hyaluronan-based agents affected peritoneal tPA antigen levels or activity after colonic surgery. Conclusion: Both abdominal surgery and infection caused an early increase in peritoneal tPA antigen levels, followed by an increase in tPA activity. Peritonitis severely depressed early tPA activity. Application of hyaluronan-based agents did not affect the peritoneal fibrinolytic response to surgery and/or infection. Chemicals/CAS: Hyaluronic Acid, 9004-61-9; Tissue Plasminogen Activator, EC 3.4.21.68

KUN, 22 februari 2002, Promotores : Bleichrodt, R.P., Goris, R.J.A. Co-promotores : Goor, H. van, Holmdahl, L., Item does not contain fulltext

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Item does not contain fulltext, HYPOTHESIS: Sodium hyaluronate interferes with the fibrin degrading capacity of human peritoneal mesothelial cells exposed to tumor necrosis factor (TNF) alpha. DESIGN: Controlled laboratory experiment. INTERVENTION: Human peritoneal mesothelial cells were harvested from 5 patients undergoing laparotomy and cultured in vitro. Cells were treated with TNF-alpha, a cytokine typically involved in peritoneal inflammation, and sodium hyaluronate was added in a final concentration of 0.1%, 0.2%, or 0.4%. Controls received medium only. After 24 hours' incubation, tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI-1) were measured in the medium and cell lysates using enzyme-linked immunosorbent assay techniques. Specific gene transcripts in cells treated with 0.4% sodium hyaluronate and controls were determined using a quantitative reverse transcription polymerase chain reaction. MAIN OUTCOME MEASURES: Concentrations of tPA, uPA, and PAI-1, and their specific gene transcripts. RESULTS: Sodium hyaluronate significantly increased tPA concentration in cell lysates without affecting its gene expression as determined after 24 hours (P =.02). The uPA concentration was significantly decreased by sodium hyaluronate in the medium but not in cell lysates (P<.0001). The uPA messenger RNA expression was 1000-fold increased compared with control. Sodium hyaluronate significantly decreased PAI-1 concentration in the medium and reduced its gene expression 500-fold (P =.04), while PAI-1 concentration in cell lysates did not change. CONCLUSION: Sodium hyaluronate affected the fibrinolytic response of TNF-alpha-stimulated human peritoneal mesothelial cells, most notably by decreasing PAI-1 transcription and release. This observation indicates that sodium hyaluronate counteracts the fibrinolytic decline induced by TNF-alpha and suggests a biological mechanism of action for sodium hyaluronate intra-abdominally.

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