A modified microsurgical model for end-to-side selective portacaval shunt in the rat: intraoperative microcirculatory investigations

PURPOSE: To investigate the intraoperative microcirculatory changes of the affected organs (small bowel, liver and kidney) during the making of a modified selective portacaval (PC) shunt. METHODS: On ten anaesthetized Sprague-Dawley rats the selective end-to-side mesocaval anastomosis was performed, where only the rostral mesenteric vein is utilized and the portal vein with the splenic vein are left intact. Morphometric and microcirculatory investigations using a LDF device determining flux units (BFU) were carried out. RESULTS: After completing the shunts the microcirculatory flux values did not recover in the same manner on the surface of the small intestine, the liver or the kidney. BFU values showed deterioration in the small intestine and in the liver (p<0.001). During the reperfusion the BFU values improved, but not in the same manner. The small intestine values left behind the kidney and liver data. CONCLUSIONS: Technically, the advantages of the models include the selective characteristic, the mesocaval localization and the relatively easy access to those vessels. However, its major disadvantage is the time needed for positioning the vessels without coiling or definitive stretching. Intraoperative LDF may provide useful data on the microcirculatory affection of the organs suffering from hypoperfusion or ischemia during creating the shunts.

Distal splenocaval shunt for rebleeding patients after periesophagastric devascularization / 中华普通外科杂志

Objective To evaluate the therapeutic effect of distal splenocaval shunt for portal hypertensive variceal rebleeding after periesophagastric devascularization.Method In this study 18 patients with recurrent bleeding after devascularization underwent distal splenocaval shunt.Clinical data and follow-up result were collected and analyzed.Result The free portal pressure decreased from (35.6 ±3.8) cm H2O before shunting to (26.9 ±2.7) cm H2O after shunting.The operative mortality was 0.Liver function after postoperative second day changed significantly comparing to preoperative levels and it recovered to pre-operative level after 7 days.The rate of rebleeding and ascites was 17％ and 44％ respectively.There were 2 patients suffering from postshunt hepatic encephalopathy and the 2-year survival rate was 94.4％.Conclusions Distal splenocaval shunt could still be performed in portal hypertensive patients with recurrent variceal bleeding after periesophagastric devascularization with a patent splenic vein.

The interventional treatment for shunt stenosis or occlusion after mesocaval shunts in portal hypertension / 中华普通外科杂志

Objective To evaluate interventional therapy in the treatment of interposition graft stenosis or occlusion after mesocaval shunts.Methods The clinical data of 19 cases of artificial vessel stenosis or occlusion after mesocaval shunts for portal hypertension at our department from march 2009 to march 2012 were retrospectively analyzed.Results In the 19 cases with artificial vessels stenosis or occlusion developed after mesocaval interposition shunts for portal hypertension,there were 5 cases in which acute thrombosis occurred within a week after the surgery.Catheter directed thrombolysis was successfully conducted.In 6 cases in which shunt stenosis developing 1 to 8 years after surgery were managed by balloon dilatation or stent angioplasty successfully.The shunt graft occlusion occurred in 8 cases after 1 to 4 years of surgery was successfully managed and the shunt was reopened by balloon dilatation or stent angioplasty in 6 cases,and in 2 the procedure was failed for the guide wire can't go through the anastomotic site of artificial vessel-superior mesenteric vein.In 11 cases embolization of the esophagogastric varices was successfully carried out for postoperative standard anticoagulation.During a period of 3 months to 3 years follow-up,stenosis recurred 1 year after balloon dilatation in one case,and stenosis was managed by angioplasty successfully.Conclusions Interventional radiological techniques by percutaneous puncture through femoral vein-inferior vena cava-artificial vessel-portal vein (including catheter directed thrombolysis,balloon dilatation,stent placement,etc) are less traumatic,highly successful in the treatment of shunt stenosis or occlusion after mesocaval shunts in portal hypertension.

Mesocaval shunt plus portaazygous disconnection for portal hypertensive variceal bleeding caused by cavernous transformation of the portal vein in adults / 中华普通外科杂志

Objective To investigate the clinical effect of mesocaval shunt and selective coronary vein ligation for portal hypertension caused by cavernous transformation of the portal vein in adults.Methods The clinical data of 26 adult patients with portal hypertensive variceal bleeding caused by cavernous transformation of the portal vein treated by mesocaval shunt plus splenic artery and coronary vein ligation were analyzed retrospectively from 2001 to 2011.Results There was no operative deaths,free portal vein pressure decreased postoperatively,differences were significant before and after shunt (34.4 ± 4.7) cm H2O vs.(24.8 ±2.7) cm H2O,t =12.30,P ＜0.01.Postoperative complications included slight hepatic encephalopathy in 1 case,stress ulcer bleeding in 1 case,which were cured by conservative treatment.23 cases were followed up from 6 months to 4.5 years,and there was no bleeding case.Conclusious Mesocaval shunt plus selective vascular ligation for portal hypertensive variceal bleeding caused by cavernous transformation of the portal vein in adults is safe and effective.

Portal vein arterialization by right renal artery in portacaval shunt rats / 中华普通外科杂志

Objective To estabhsh a rat portacaval shunt model of portal vein arterialization (PVA)by using right renal artery,andtoinvestigateitsinfluence on portal velnpressure,liver funciton and hepatic pathology.Method Forty-three Sprague-Dawley rats were assigned to PVA group(33 rats)and control group(10 rats).Portal pressure,liver function and pathological changes were evaluated at day 2,2 weeks and 2 months after surgery,respectively.Results The experimental model was successfully established in 30 out of 33(91%)rats.At day 2,2 weeks and 2 months after the operation,the portal pressure increased significanfly(P<0.05)compared with the control group,but no significant differences were found in the senrum level of alanine amlnotransferase,total bilirubin,total bile acid and creatinine.There were no patholgiccal changes from day 2 to 2 weeks after surgery,only postoperative expanslon of the sinusoidal snace was found on 2 months after surgery.Conclusion The rat model of PVA by renal artery was successfully established with the hand-suture mierosurgical techniques.The portal vein pressure maintained at a high level after PVA,meanwhile,no negative effect was found on the liver function and hepatic histological structure changes.

Experimental comparison study of the tissue characteristics in transjugular intrahepalic portosystemic shunt and vascular stent / 中华放射学杂志

Objective To investigate the tissue characteristics within vascular stent and transjugular intrahepatic portosystemic shunt(TIPS)on swine and to provide more information for the understanding and prevention of vascular stent and TIPS restenosis.Methods Animal models for TIPS were built in 6 swine and vascular stents were implanted in iliac veins simultaneouly.14-28 days after the operation.the 6 swine were killed to remove the TIPS and vascular stent and the pathological examinations were performed on the tissues within the shunt and stent.The similarities and difierences of the tissues within the shunt and stent were analvzed with Kruskal Wallis test. Results Restenosis of TIPS occurred in 4 models and complete occlusion were seen in 2,while all vascular stents were patent and coated with a thin layer of intimal tissueElectron micmscopic results showed that the tissues in restenotic TIPS were loose and with more extra matrix and fibers.and less smooth muscle,fibroblastic and myofibroblastic cells with different and irregular shape and rich secretory granules.The tissues in patent,TIPS contained more extra fibers,smooth muscle and fibmblastic cells with normal organdie.The intimal tissues in vascular stent contained more fibers and fibroblasts cells.less smooth muscle cells.On immunohistoehemical staining,the tissues in restenotlc and Datent TIPS as well as the intimal tissues in vascular stent had strong positive expression for anti-SMCactin-α.the expression were gradually weakened for PCNA,the intimal tissues in vascular stent had a strong positive expression for vimentin,while the expression of the tissues in restenotic and patent TIPS were weakened gradually.For myoglobulin,the tissues in restenotic TIPS had weakly positive expression,the expression in patent TIPS and vascular stent were almost negative. Western blot results for TGF-β showed that the absorbance ratios of the intima tissues in vascular stent,normal vascular tissues,normal liver tissues.the tissues in restenotic and patent TIPS were 0.23,0,0,0.57 and 0.30 respectively,and they were significantiy different (H=27.8,P＜0.01).Conclusions The tissues in restenotic TIPS mainly contain proliferated SMCs which have positive expression for anti-SMC-actin-α,strong proliferation and movement but unstability.The tissues in patent TIPS and intimal tissues in Vascular stent mainly contain fibroblastie cells which have positive expression for vimentin and stability.

The changes of plasma renin activity in cirrhotic patients with ascites undergoing portacaval shunt / 中国普通外科杂志

Objective To observe the changes of plasma renin activity (PRA)in cirrhotic patients with ascites after portacaval shunt. Method Portal vein, artery,and peripheral vein PRA levels were measured in 16 cirrhotic patients with ascites during perioperative period of portacaval shunt. Results were compared with that in 16 cases of GI tract carcinoma.Results Z] (1)Measured at postshunt day 7,the portal venous pressure (PVP) was significantly lower than that preoperatively〔(26?4)?cm?H 2O vs. (36?4)?cm?H 2O, P

Evaluation of portal vein pressure by radionuclide imaging in cirrhotic patients undergoing portacaval shunt or pericardial devascularization / 中国普通外科杂志

ObjectiveTo evaluate the changes of portal vein pressure by (PVP) radionuclide imaging in cirrhotic patients undergoing portacaval shunt or esophageal transection-splenectomy.MethodThe radionuclide imaging was used to calculate portal pressure perioperatively in 15 shunt and 20 esophageal transection-splenectomy patients of portal hypertension.Results were compared with direct portal vein manometry.ResultPVP by manometry in portal hypertension patients 〔(37?4)?cm?H 2O〕 was very close to that calculated by preoperative imaging 〔(36?4)?cm?H 2O〕r=0.81,P