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H Witzigmann

Publications and source records attributed to H Witzigmann.

53 records · Page 3Linked to original sources
PubMed1998

Exogenous L-arginine protects liver microcirculation from ischemia reperfusion injury.

UNLABELLED: Hepatic ischemia followed by reperfusion evokes an imbalance between the vasoregulatory compounds endothelin and nitric oxide (NO) followed by constriction of the vascular bed, leading to microcirculatory disturbances and reduced blood flow, thereby causing hypoxia and liver damage. The aim of this study was to protect the liver microcirculation by maintaining this delicate balance. MATERIAL AND METHODS: In an in vivo ischemia/reperfusion model with portal decompression by a splenocaval shunt, hepatic ischemia was induced for 30 min by Pringle's maneuver. The effect of the NO donor L-arginine (400 mg/kg b.w. i.v.) was assessed by in vivo microscopy. Microhemodynamic studies, including the sinusoidal perfusion rate, diameters of hepatic sinusoids and postsinusoidal venules, leukocyte endothelium interactions and leukocyte velocity were performed. Microcirculatory data were compared with local tissue pO2 and serum transaminase levels. RESULTS: After ischemia the diameters of sinusoids and postsinusoidal venules were significantly reduced to 76+/-7 and 86+/-10% respectively in the nontreatment group, but dilated to 102+/-3 and 105+/-7% in the group treated with L-arginine (p < 0.001). The percentage of permanently adherent leukocytes in sinusoids and venules was increased by ischemia, but L-arginine reversed this increase (p < 0.001). Perfusion rate was improved to 90+/-2 compared with 83+/-5% in the untreated group (p < 0.01). Systemic arterial blood pressure was not affected by administration of the NO donor. The postischemic increase in serum transaminase levels was diminished in the treatment group (ASAT: p < 0.05). Local postischemic hepatic tissue pO2 was significantly decreased to 45% of basal values after 30 min and to 55% after 60 min of reperfusion (p < 0.05). Administration of L-arginine results in a significant increase in local tissue pO2 to 86 and 106% of basal values respectively (p < 0.05). CONCLUSION: These data indicate that L-arginine improves hepatic microcirculation after warm ischemia by increasing sinusoidal perfusion rate and by diminishing leukocyte endothelium interactions. Maintained integrity of microcirculation is associated with sufficient oxygen supply and improved hepatocellular function.

Animals↗
PubMed1998

[Role of endothelin-nitrogen monoxide equilibrium in ischemia/reperfusion damage of the liver].

Elevated levels of endothelin (ET) are measured during ischemia and reperfusion, but no adequate increase of nitric oxide (NO) can be observed. Thus, the balance of both substances, which occurs under physiological conditions and regulates microcirculatory vessel widths, is disturbed. This leads to microcirculatory damages. As well ET receptor blocking using a mixed ET receptor antagonist as increase of NO production after L-arginine treatment influenced this pathomechanism. The preischemic sinusoidal diameters were maintained and leukocyte endothelial interactions reduced. Concomitantly, sinusoidal perfusion rate and local hepatic tissue pO2 were increased. Because of significant reduced hepatocellular damage in both therapy groups both therapeutical ways might exert beneficial effects to attenuate ischemia/reperfusion induced microvascular and tissue injury.

Animals↗
PubMed1998

[Laparoscopic implantation of catheters for continuous ambulatory peritoneal dialysis].

Continuous ambulatory peritoneal dialysis (CAPD) has become an established procedure and is an equal alternative to haemodialysis (HD) in the management of terminal renal failure. Nevertheless CAPD still plays a minor role compared with HD (10% of all dialyses). CAPD offers advantages in quality of live but is still associated with a significant number of complications. The improvement of surgical technique and development of new peritoneal dialysis catheters (PDK) improved the results of peritoneal dialysis. 3 methods for implantation of PDK are used: the open surgical technique, the blind percutaneous procedure and the laparoscopic method. The latter technique is currently an accepted practice. 10 patients were treated by the laparoscopic method. Additionally to the PDK-tunnel of the abdominal wall we used 2 trocars (1 x 5 mm, 1 x 12 mm). Advantages of this technique are avoiding of perforating lesions, possibility for further operations and a safe implantation of the PDK. Peritoneal dialysis was started 7 days after operation with initially low dialysate volumes. The observed incidence of complications and removed catheters are comparable to the reports in the literature.

Catheters, Indwelling↗
PubMed1998

[Effect of forced organ cooling on microperfusion of donor livers].

UNLABELLED: With regard to the factors of graft damage the role of rapid cooling during cold in situ perfusion should not be underestimated. The aim of this study was to analyse the effect of rapid cooling on microperfusion of rat livers in an in vitro model. MATERIAL AND METHODS: During harvest of 14 rat livers the organs' core temperature was monitored. Two groups were formed: (1) cold UW perfusion. (2) cold UW perfusion under additional graft cooling by iced water. Thereafter, isolated livers were perfused (4 degrees C. 1 h, 5 mmHg) monitoring the portocaval resistance, and liver enzyme release and pH levels in the perfusate. Finally, portal angiography of each liver was performed. RESULTS: Rapid in situ cooling resulted in a decrease of the plateau temperature of the organ by 6.5 degrees C (p < 0.01). The pH slope in the perfusate and the enzyme release were diminished obviously, but not significantly. On the other hand, the portocaval resistance was increased by more than 20% (p < 0.05). Portal angiographies assessed by a special score expressed a marked deterioration of microperfusion in peripheral and subcapsular regions. CONCLUSIONS: This study shows that rapid cooling results in worsened microperfusion of liver grafts. The effect of rapid cooling on function and histomorphology of transplanted livers should be analysed in further investigations.

Animals↗
PubMed1998

[Therapy and follow-up of injuries after laparoscopic operations].

From May 1993 to September 1997 we treated 22 patients with complications after laparoscopic surgery. We report on 18 patients after laparoscopic cholecystectomy, three patients after diagnostic laparoscopy and one after TAPP. Two patients died (hepatic failure and without any possibility of definitive therapy) and the injuries of the other 20 patients were repaired.

Biliary Fistula↗
PubMed1996

[The ultrasound scalpel in laparoscopic surgery].

The ultrasonically activated scalpel works by means of the longitudinally vibrating sharp blade. The most important advantages- compared with electrosurgery-are the lack of current flow through the patient and limited local heat generation. It can be used as an instrument for coagulation, dissection and preparation. There is no generation of smoke. It is easy to use. Disadvantages are the slow speed of cutting and the high costs. In the future it could be an alternative to preparation on with dissector, scissors, and electrosurgery.

Dermatologic Surgical Procedures↗
PubMed1995

[Leiomyosarcoma of the rectum].

The distinction between leiomyoma and high differentiated leiomyosarcoma can be difficult. The most important distinguishing feature is the number of mitoses. Additionally the tightness of the cells, the number of necroses and cell atypias and the size of the tumor are significant. The most common therapy for large and low differentiated leiomyosarcomas of the rectum are the abdomino-perineal resection or the low anterior resection. In high graded tumors of less than 2.5 cm the radicality of the surgical treatment is questioned. Some authors recommend a wide local excision, but in this case a high local recurrence rate has to be expected. This is the reason for a more radical treatment of all leiomyosarcomas of the rectum. Chemotherapy and radiotherapy are generally not effective. The prognosis is poor.

Adult↗
PubMed1994

[Therapy of anal cancer].

The primary non-invasive treatment of anal-carcinoma by radiochemotherapy (RCT) is generally accepted although prospective randomised trials have not been finished yet. Finally the complex interaction of the radiotherapy and the commonly used cytotoxic agents 5-FU and Mitomycin-C are unknown, besides the radiosensitization. In the radiotherapy quality assurance is warranted in different radiotherapy-techniques and the total and single doses are well established for primary tumor (50-55 Gy) and lymphatic pathways (40-50 Gy) with 1,8 Gy single dose per fraction. According to the slow tumor regression restaging is made three months after completion of RCT. Residual tumor needs abdomino-perineal-resection.

Anal Canal↗
PubMed1990

[Lactic acidosis--recognition and treatment of an important complication of perioperative parenteral nutrition].

We report 5 cases of acute vitamin B-1 induced lactic acidosis in surgical patients receiving parenteral nutrition. In all patients treatment with vitamin B-1 induced a dramatical improvement of clinical findings. 4 patients recovered completely, 1 patient died from already developed irreversible cardiocirculatory failure. These cases underline the need for regular vitamin B-1 substitution in patients with parenteral nutrition and preoperatively in alcoholics and in patients, in whom a sufficient food intake can not be assured.

Acidosis, Lactic↗