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UNLABELLED Native av-fistulas are the access of first choice for long-term hemodialysis. However, a large number of patients require an alternative vascular access, e. g. ePTFE grafts. Patency of ePTFE grafts is inferior to that of native av-fistulas. PURPOSE To analyse the effectiveness of surgical revisions of occluded straight ePTFE dialysis access grafts. METHODS Retrospective review of all upper arm dialysis access procedures from 1/94 to 8/99. RESULTS Redo surgery was performed in 67 patients. Av-fistula dysfunction was caused by venous anastomotic stenoses (22 %), outflow occlusion (9 %), arterial anastomotic stenoses/inflow occlusion (12 %), and intragraft stenoses (6 %). 9 grafts had to be revised due to infection or perigraft hematoma (14 %). In 37 % the cause of graft occlusion could not be identified. Neither the cause of occlusion nor the type of treatment correlated with patency after revision. 6- and 12-months primary patency after surgery were 29 % and 11 %. 59 shunts required up to 12 revisions to maintain patency. Thus, secondary 1 yr-patency after revision was 29 %. CONCLUSION Patency after redo surgery is disappointing. However, with repeated procedures ePTFE grafts remain open > 1 year in 29 % of the patients.

BACKGROUND—Capillary leakage with fluid loss into the third space contributes to many of the early systemic complications in severe acute pancreatitis. There has been increasing interest in endothelin as one of the factors affecting capillary permeability. AIM—To elucidate further the role of endothelin in the development of capillary leakage in acute pancreatitis by investigating the effect of exogenous endothelin administration and endothelin receptor blockade in sham operated animals and two models of acute pancreatitis. METHODS—Determination of capillary permeability in the pancreas and colonic mucosa by quantifying extravasation of fluorescein labelled dextran using a novel computer assisted video image analysis system. RESULTS—Pancreatic and colonic capillary permeability increased stepwise from mild to severe acute pancreatitis. Endothelin increased pancreatic and colonic capillary permeability in healthy animals and animals with mild acute pancreatitis but had no additional adverse effect in severe acute pancreatitis. Endothelin receptor blockade decreased pancreatic capillary permeability in sham operated rats but had no effect on the colon. In mild and severe acute pancreatitis, endothelin receptor blockade stabilised increased capillary permeability in both the pancreas and colon. CONCLUSIONS—Endothelin plays an important role in mediating capillary permeability in the pancreas. In severe pancreatitis, it increases capillary permeability even outside the pancreas, thereby contributing to capillary leakage. Endothelin receptor blockade significantly reduces capillary permeability in acute pancreatitis both in and outside the pancreas, suggesting a therapeutic approach to counteract capillary leakage in severe acute pancreatitis. Keywords: pancreatitis; endothelin; endothelin receptor antagonist; microcirculation; capillary permeability; fluid sequestration

Haemorrhage, penetration and perforation are common complications of peptic ulcers. Free intraabdominal air is seen in 80 % after perforation. Penetration into the retroperitoneum with pneumothorax and mediastinal emphysema are rarely observed. We report the case of a 85-year-old female patient with nausea, vomiting and little appetite. During endoscopy of the upper GI-tract she complained about progressive dyspnea. Chest X-ray revealed mediastinal emphysema and pneumothorax. When performing laparotomy, we found a duodenal ulcer, that had penetrated the retroperitoneal space. The patient underwent partial gastrectomy and reconstruction with Billroth-II anastomosis. The postoperative course was uneventful.

Background: Increased leukocyte-endothelium interaction occurs during the acute phase of human colitis. It may promote the endoscopically confirmed reduction of mucosal blood flow and thus the disease activity. There are indications that this interaction is influenced by selective COX-2 inhibitors. This study examines in a rat TNBS colitis model (1) whether increased leukocyte stickers can be detected beside these capillary blood flow restrictions, as reported in earlier studies, (2) whether this phenomenon can be positively influenced by selective administration of COX-2 inhibitors, and (3) whether this has any effect on the microcirculation and (4) disease activity. Methods: Induction of colitis in rats by intrarectal instillation of 0.25 ml trinitrobenzosulfonic acid (TNBS). After 12 hours, randomization into 2 groups: group A (placebo): 1 mmol/kg b.w./day 0.9% NaCl solution. Group B (verum): 10 mg/kg b.w./day a selective COX-2 inhibitor (NS-398; Alexis Deutschland GmbH, Grunberg, Germany). Healthy animals (intrarectal saline injection) served as controls. After 48 hours, laparotomy was performed in 8 animals per group for intravital microscopic determination of (1) capillary blood flow, (2) capillary permeability, (3) leukocyte sticking, and (4) functional capillary density. Additional target parameters: hematocrit, weight, etc. Results: A significant reduction of capillary blood flow (0.6 ± 0.02 nl/cap/min) and significant increase in leukocyte sticking (n= 16.3 ± 1.54) was observed in group A compared to controls (2.3 ± 0.02 nl/cap/min and n = 0.1 ± 0.06). On the other hand, the administration of selective COX-2 inhibitors (NS-398) in group B led to a significant improvement of both capillary blood flow (1.1 ±0.02 nl/cap/min) and leukocyte sticking (n = 6.7 ±0.52). Hematocrit and weight course as an indicator of disease activity were congruent (hematocrit in %: 45.8 ± 0.5 (control), 48.6 ± 0.5 (group A), 43.5 ± 0.7 (group B), weight course in g: +4.2 ± 1.1 (control), - 35.8 ± 2.2 (group A). - 26.5 ± 2.3 (group B). Conclusion: (1) The acute phase of TNBS colitis is characterized by reduced capillary blood flow as well as significantly increased leukocyte-endothelium interaction in conjunction with increased capillary permeability and decreased functional capillary density. (2) The administration of selective COX-2 inhibitors leads to a significant decrease of leukocyte sticking. (3) Moreover, there is a significant improvement of capillary blood flow, functional capillary density and capillary permeability. (4) The hematocrit and weight course are indicative of decreased disease activity in the treated animals.

Microcirculatory disorders (MCD) in severe acute pancreatitis (AP) are not confined to the pancreas but can also be found in other organs (e.g. colon, liver, lungs), where they contribute to AP-associated multiple organ dysfunction syndrome (MODS). Therapy aimed at enhancing microcirculation has been shown to ameliorate MODS even when therapy is delayed to a point at which pancreatic necrosis can no longer be influenced. Thus, research on novel methods for enhancing microcirculation is of particular interest in AP. The aim of this study was to evaluate the effect of a novel perfluorochemical oxygen carrier in AP and compare it with an established method for enhancing microcirculation, i.e. isovolemic hemodilution (HD). Six hours after induction of severe AP by intraductal bile salt infusion and i.v. cerulein, 18 rats were randomized into 3 groups (6 animals each) for therapy with [SAL]: 5 ml/kg normal saline i.v. (untreated controls); [HD]: isovolemic hemodilution by exchange of 8 ml/kg blood for hydroxyethylstarch, or [OXY]: 5 ml/kg perfluobron emulsion i.v. (3 g/kg Oxygent™, Alliance Pharmaceutical Corp. San Diego). At 24 hours intravital microscopic determination of pancreatic and colonic capillary blood flow (CBF). Additional monitoring included measurement of heart rate, arterial blood pressure and blood gases, hematocrit, and urine output. Hemodilution therapy significantly reduced hematocrit (33 ± 2 vs. 44 ± 2% in saline-treated controls) and improved CBF in the pancreas (1.8 ± 01 vs. 1.3 ± 0.1 nl/min) and colon (1.6 ± 0.1 vs. 1.3 ± 0.1 nl/min). This was associated with a stabilization of cardiorespiratory parameters (RRsys 112 ± 17 vs. 94 ± 8 mmHg; O2 saturation 95 ± 2 vs. 81 ± 9%). Therapy with Oxygent had comparable beneficial effects on microcirculation and cardiorespiratory parameters (pancreatic and colonic CBF 1.7 ± 0.1 nl/min; RRsys 115 ± 15 mmHg; O2 sat. 96 ± 2%) without reducing hematocrit (43 ± 2%). This suggests that perfluorochemical oxygen carriers may be an option for enhancing microcirculation and stabilizing organ function in severe acute pancreatitis. Further studies will evaluate whether they should be used instead of or in combination with hemodilution.

Sputum retention causing pulmonary atelectasis, secondary pneumonia, and respiratory failure is a frequent complication particularly in patients recovering from abdominal and thoracic surgery. Physiotherapy and conventional therapeutic means like blind tracheobronchial and bronchoscopic suction applied to prevent and treat postoperative respiratory complications have been shown to not be completely effective. Minitracheotomy is a new alternative method for the treatment of sputum retention. Endobronchial suction can be performed as often as required, using a thin uncuffed tube (ID 4.5 mm) which is inserted into the trachea through the cricothyroid membrane under local anaesthesia. Since respiration occurs normally through the nose, mouth, and larynx these patients retain speech and the ability to cough. Complications are rare. Endobronchial suction via minitracheostomy is minimally invasive, more comfortable, and at least as effective as conventional bronchoscopic suction. It therefore has become a routine method used in the treatment of postoperative sputum retention in high-risk patients in many intensive-care units.