Subject(s)
Immunosuppressive Agents/therapeutic use , Liver Transplantation/psychology , Treatment Refusal , Adolescent , Age Factors , Child , Child, Preschool , Cyclosporine/therapeutic use , Female , Follow-Up Studies , Graft Rejection/epidemiology , Graft Rejection/prevention & control , Humans , Immunosuppression Therapy/psychology , Liver Transplantation/immunology , Male , Psychology, Adolescent , Retrospective Studies , Tacrolimus/therapeutic use , Time FactorsABSTRACT
BACKGROUND: Splanchnic artery occlusion shock is caused by increased capillary permeability and cellular injury precipitated by oxygen derived free radicals following ischemia and reperfusion of splanchnic organs. The purpose of this study was to assess the role of several well-known oxygen-derived free radical scavengers in ameliorating or preventing this syndrome. STUDY DESIGN: Anesthetized rats were subjected to periods of occlusion of the visceral arteries and reperfusion. Tocopherol, taurine, selenium or a 'cocktail' of these three agents was injected subcutaneously for 4 consecutive days prior to operation. Mean arterial blood pressure was measured throughout the experimental period. Fluorometry and technetium-99m pyrophosphate counting of the visceral organs were performed as well as a histologic grading system for intestinal viability. RESULTS: Final mean arterial blood pressure associated with the 'cocktail' and selenium groups was 79.1 +/- 27.4 mmHg and 83.6 +/- 17.8 mmHg, respectively. These values were significantly higher than the control group, 40.8 +/- 11.4 mmHg (P < 0.05). Similar patterns of the benefit of selenium in contrast with the other groups were obtained with fluorescein perfusion, radioisotopic activity and histologic analysis. CONCLUSION: Pretreatment with selenium of splanchnic ischemia and reperfusion in the rat improves mean arterial blood pressure and microcirculatory visceral perfusion. Further analysis of the precise protective mechanism of selenium for reperfusion injury will enable visceral organs to withstand the consequences of increased capillary leakage and oxidant injury.
Subject(s)
Reperfusion Injury/prevention & control , Selenium/administration & dosage , Splanchnic Circulation/drug effects , Taurine/administration & dosage , Vitamin E/administration & dosage , Animals , Cecum/blood supply , Cecum/drug effects , Disease Models, Animal , Duodenum/blood supply , Duodenum/drug effects , Ileum/blood supply , Ileum/drug effects , Jejunum/blood supply , Jejunum/drug effects , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Reference Values , Regional Blood Flow/drug effects , Stomach/blood supply , Stomach/drug effects , Viscera/blood supplyABSTRACT
PURPOSE: Successful use of the distal adjunctive arteriovenous fistula (dAVF) for the enhancement of prosthetic graft patency rates in the crural position is critically dependent on the qualitative and quantitative aspects of the arterial and venous runoff. Precise technical performance of the fistula is equally vital to secure optimal results. The purpose of this study was to determine current prosthetic graft patency and limb salvage rates using a modified version of the common ostium dAVF. METHODS: The standard method to create the common ostium variant of dAVF has been modified to improve apposition of the "otomy" sites of the artery and vein, avoid twisting and stenosis by terminating the fistula suture line at the artery-vein junctures, reshaping the ovoid ostium to a rectangular shape, and finally, use of multiple interrupted heel-toe sutures. RESULTS: Since 1979 we have created 290 fistulas in 281 patients who required leg revascularization procedures. In different time periods we have documented improving graft patency and limb salvage rates. Fistula patency, reflected by annual attrition rates of 13% to 26% per year, continues as a challenge for long-term results. Current 3-year secondary cumulative graft patency and limb salvage rates by life table analysis are 61% and 74%, respectively. The conduit material may play a role with regard to steal phenomena and the need for banding techniques. CONCLUSION: Configuration of the adjunctive dAVF may impact on prosthetic graft patency in the crural position. In addition, the type of graft material used for bypass may be instrumental in preventing or precipitating the steal phenomenon. These issues require further study to better understand flow dynamics, patterns of intimal hyperplasia, and blood distribution as a function of conduit material and impedance of the arterial and venous runoff.
