346. Die bedeutung von stenosen an gefä\verzweigungen. eine experimentelle untersuchung an der femoralisgabel unter besonderer berücksichtigung der indikation zur profundaplastik

Zusammenfassung In einem pulsatil mit Kochsalz durchströmten Modell der Femoralisgabel wurden Flussmessungen und Druckgradienten für Flussmengen von 170 bis 860 ml/min bei peripheren Widerständen von 232 bis 25 792 dyn s cm^–5 über dem Superficialis- und Profundaabgang bei Stenosen von 1 cm Länge und Querschnittsverminderungen von 0% bis 100% gemessen. Bei grossen Flussmengen (800–860 ml/min) und kleinem peripheren Widerstand (<640 dyn s cm^–5) lag die kritische Stenose am Profundaabgang bei 4,1 mm Durchmesser, für hohe periphere Widerstände (> 5 072 dyn s cm^–5) bei 2,6 mm; bei kleinen Flussmengen (<400 ml/min) betrug der kritische Durchmesser 1,8 mm. Der nicht stenosierte Profundaabgang stellte für keine der Versuchsbedingungen ein strömungsdynamisches Hindernis dar.     

Veränderungen des operativen Krankenguts

Die Anaesthesiologie - Die Veränderung der Altersstruktur der Bevölkerung der Industrieländer führte zu einer Verschiebung der zu behandelnden (Alters-)Erkrankungen gleichzeitig...     

A new bioassay including a small scale hepatocyte bioreactor for hepato-mediated toxicity testing in a target cell line

New approaches for in vitro testing of hepato-mediated toxicity are undertaken to offer alternatives to in vivo animal testing. The described bioassay for hepato-mediated toxicity testing is based on a small scale hepatocyte-bioreactor with pig hepatocytes connected to a silicon sensor based microphysiometer system for monitoring of the extracellular acidification rate (EAR) of cells and the microphysiometer alone. EAR represents the metabolic activity of tested cells (hepatocytes and ZR 751 cells) under the influence of perfused media, compared to controls, which were set to 100%. Cyclophosphamide (CYCL), whose cytostatic effect is dependent on CYP 450 biotransformation was used as a model substrate. CYCL showed decrease of EAR in hepatocytes, but not in ZR 751 cells. Bioreactor supernatant including CYCL was pumped into the microphysiometer and EARs of the target ZR 751 cell line were recorded. After 7 h of bioreactor supernatant perfusion the ZR 751 cell line showed an EAR decrease of 18.68% +/- 10.18, as compared to controls (bioreactor supernatant from the identical set-up without CYCL). Thus the presented model of hepato-activated toxicity showed an EAR decrease in the ZR 751 cell line that reflected the toxic activation of CYCL by the bioreactor. This new bioassay serves as an example of future applications for hepatocyte bioreactors in automated toxicity testing devices, e.g. in preclinical drug studies or evaluation of hepato-mediated toxicity, not depending on cell destruction or further assays.     

Pulmonary graft function after long-term preservation of non-heart-beating donor lungs

BACKGROUND: Critical organ shortage in lung transplantation could be attenuated by the use of non-heart-beating donor (NHBD) lungs. In addition, prolonged ischemic tolerance of the organs would contribute to the alleviation of organ shortage. The aim of this study was to investigate pulmonary graft function of NHBD lungs after long-term hypothermic storage. METHODS: Twelve native-bred pigs (bodyweight 20 to 30 kg) underwent left lung allotransplantation. In the heart-beating donor (HBD) group, lungs were harvested immediately after cardiac arrest. In the NHBD group, lungs were subjected to a warm ischemic period of 90 minutes before harvesting. After a total ischemic time of 19 hours, pulmonary grafts in both groups were reperfused and pulmonary graft function was assessed. All values were compared with a sham-operated control group. RESULTS: Pulmonary graft function in the HBD group was excellent. In the NHBD group, pulmonary gas exchange was impaired, but still provided good graft function compared with the excellent graft function in the HBD group. Pulmonary vascular resistance was even lower in the NHBD group. In the NHBD group, calculated intrapulmonary shunt fraction (Qs/Qt) was significantly increased compared with the sham-group. Histologic alteration and wet-to-dry ratio did not differ significantly between the HBD and NHBD group. CONCLUSIONS: We conclude that NHBD lungs (90 minutes of warm ischemic time) have the potential to alleviate organ shortage in lung transplantation even after an extended total ischemic time.     

Characterization of synovial fluid from periprosthetic infection in revision total joint arthroplasty by single-molecule microscopy

Periprosthetic joint infection is among the most common and severe complications in total joint arthroplasty. Today, a combination of different methods is used for diagnosis because no single method with sufficient sensitivity and specificity is available. In this study, we explored the usability of single-molecule microscopy to characterize synovial fluid samples from periprosthetic joint infections. Patients (n = 27) that needed revision arthroplasty underwent the routine diagnostic procedures for periprosthetic joint infection of the University Hospital in Bonn. Additionally, the diffusion rate of two probes, dextran and hyaluronan, was measured in small volumes of periprosthetic synovial fluid samples using single-molecule microscopy. To evaluate the suitability of single-molecule microscopy to detect PJI the AUC for both markers was calculated. The diffusion rate of hyaluronan in periprosthetic synovial fluid from patients with septic loosening was faster than in samples from patients with aseptic loosening. Single-molecule microscopy showed excellent diagnostic performance, with an area under the receiver operating characteristic curve of 0.93, and allowed the detection of periprosthetic joint infection in patients that would be challenging to diagnose with current methods. For the first time, single-molecule microscopy was used to detect periprosthetic joint infection. Our results are encouraging to study the value of single-molecule microscopy in a larger patient cohort. The speed and accuracy of single-molecule microscopy can be used to further characterize synovial fluid, potentially allowing intraoperative diagnosis of periprosthetic joint infections in the future.     

Results of long-term follow-up after curative resection of Dukes A colorectal cancer

Patients with Dukes A (UICC I) colorectal cancer have a good prognosis after curative resection. It is not known, however, if the outcome is significantly different for UICC Ia and Ib patients or if patients with reduced risks of recurrences can be identified early after surgery. This is of interest, as it would permit a more cost-effective, patient-oriented, and tumor stage-oriented follow-up program. To study these questions, a prospective follow-up database, including 1375 patients after curative resection of colorectal cancer, was analyzed. A total of 296 patients with Dukes A colorectal cancer with a median follow-up of 44 months were studied. Perioperative and follow-up mortality rates were 3% and 14%, respectively. Recurrent disease developed in 10% of Dukes A patients after a disease-free interval of 16 months. Significantly more patients suffering from pT2 (UICC Ib) cancer had recurrent disease than patients with pT1 (UICC Ia) cancer (13% vs. 4%; p <0.05). Preoperative CEA levels in patients with recurrent disease were significantly higher than in long-term disease-free patients (5.3 +/- 1.8 vs. 3.5 +/- 0.6 ng/ml; p <0.05). Curative resection of recurrent disease was achieved in 38% of the patients with recurrences (4% of all patients). Survival analysis showed significantly better survival in patients with Dukes A cancer than in those at higher tumor stages (log rank, <0.0001), and only 39% of all Dukes A patients who died during follow-up had recurrent disease. Dukes A (UICC Ia and Ib) colorectal cancer was diagnosed in 22% of our patients treated for cure, and long-term survival was 86%. There were significantly fewer cases of recurrent disease after curative resection of UICC Ia (pT1N0M0) cancer, so we propose a novel, less intensive follow-up regimen for these patients, leading to a more cost-effective, patient-oriented, and tumor stage-oriented follow-up program.     

Laparoscopic repair of an extrahiatal hernia caused by congenital dysplasia: a case report

A 40-year-old woman with complaints of relapse in the upper abdomen and dysphagia was referred for laparascopic hiatal hernia repair. Chest radiograph, barium-swallow, and upper endoscopy revealed a paraesophageal hernia. Esophageal manometry and 24-h-pH study showed no pathological findings. A laparoscopic gastropexy was planned. Intraoperatively, in contradiction to the preoperative findings, an extrahiatal hernia containing most of the stomach was found. After resection of the hernia sac, the beating heart without covering pericardium was seen. These findings were confirmed by an additional thoracoscopy at the end of the operation. The defect was closed by direct suturing. The postoperative course and 2-month follow-up were uneventful. The resected parts of the hernia sac showed an embryonic and dysgenetic etiology. This rare malformation has been reported in combination with complex syndromes, which appear with serious clinical and morphological signs in the neonatal period. In adults, the pericardial aplasia can be observed during diagnostic or surgical interventions. In these patients, complaints are usually not caused by the malformation but may be due to the occasional herniation of abdominal organs. We consider laparoscopic repair to be a gentle and safe procedure for the treatment of extrahiatal hernias.     

Chronic left heart catheterization for microvascular blood flow determination in the rabbit: a minimally invasive technique using specially designed port devices.

BACKGROUND: This study describes a modified catheterization technique with subcutaneously implanted port catheters to be inserted in a retrograde manner across the aortic valve into the left heart ventricle through the right carotid artery to measure organ perfusion. MATERIALS AND METHODS: The specially designed arterial port catheters were implanted in New Zealand rabbits (n = 11, 3.7 +/- 0.1 kg [mean +/- SEM]) under iv anesthesia (medetomidine/ketamine) and single-shot perioperative antibiotic therapy. Hemodynamics were registered continuously during the operation via an ear artery catheter. RESULTS: Implantation of ports was performed in all animals (11/11) without major complications (mean operation time: 70 +/- 3 min). We did not observe catheter-associated arrhythmia, fall in mean arterial pressure (MAP before and post OP: 70 +/- 2 and 68 +/- 2 Torr, respectively), or change in arterial oxygen saturation (SaO2 before and post OP: 89 +/- 3 and 95 +/- 2%, respectively). With a specifically modified microsurgical insertion technique, cerebral blood supply was effectively preserved as evidenced from postmortem histological examinations, cerebral blood flow determination with fluorescent microspheres, and measurement of S-100b protein serum concentrations, a specific marker of neuronal damage. The positioning of the catheter tip in the left ventricle was found to be correct in 10/11 animals. CONCLUSIONS: Repeated and atraumatic microsphere injections into the left ventricle have become feasible by transcutaneous puncture of subcutaneous port systems over several weeks under light sedation. Hence, this new approach (i) avoids the necessity of repeated intracardiac injections and port insertions via thoracotomy, thus reducing the perioperative stress for the animals, and (ii) allows for the first time minimally invasive repetitive and chronic measurements of regional organ blood flow under various experimental settings.     

Management of common bile duct stones--Results of a nationwide survey with analysis of 8 433 common bile duct explorations in Germany

BACKGROUND: Aim of this study was the evaluation of the management of choledocholithiasis and outcome of laparoscopic as well as open cholecystectomy in Germany. METHODS: A written questionnaire was sent to 449 randomly selected German surgeons annually from 1991 to 1994 and additionally to all German university hospitals until 1998. RESULTS: A total of 98 482 operations for gallstone disease including 86 485 cholecystectomies (non-university hospitals 1991-1993: n = 60 246, university hospitals 1991-1996: n = 26 239) and 8 433 common bile duct (CBD) explorations (non-university hospitals: n = 6 919, university hospitals: n = 1 514) with or without cholecystectomy were reported. The overall complication rate for CBD explorations was 13.2 % (non-university hospitals) and 15.1 % (university hospitals), the overall hospital mortality rate was 0.64 % (non-university hospitals) and 0.58 % (university hospitals, n. s.). When choledocholithiasis was suspected, in 1998 all university hospitals used a two-stage management with preoperative ERC. In case of diagnosed isolated choledocholithiasis 93 % usually chose an endoscopic approach. When simultaneous cholecysto-choledocholithiasis was diagnosed preoperatively 86 % of the university hospitals used a two-stage management with preoperative ERC and stone extraction and secondary cholecystectomy (1991: 45 %). The percentage of CBD explorations decreased continuously from 7.4 % in 1991 to 3.8 % in 1996 (p < 0.01). CONCLUSION: These results allow for the estimation of frequency and overall risks in surgical therapy of CBD stones. At the moment, laparoscopic CBD exploration does not play a significant role in Germany. Data show a trend to the two-stage "therapeutical splitting" with lower complication rates.