2Īn ideal method of treating CEPSSs would be a single, quick, inexpensive procedure that resulted in gradual PSS attenuation without the risk of portal venous hypertension. 2,6 For those patients, a second surgical procedure for further attenuation of the PSS has been recommended. The long-term prognosis associated with partial shunt ligation is less favorable, with 41% to 50% of dogs experiencing clinical recurrence. 3–5 The result of acute overattenuation is development of life-threatening portal hypertension. However, only 16% to 68% of dogs with CEPSSs tolerate complete intraoperative ligation of the shunt. 2,3 In 1 study, 2 100% of patients that underwent complete surgical ligation of the shunt were clinically normal at long-term follow-up. Fatal liver failure develops by 3 years of age in most dogs that receive only medical treatment, 1 whereas surgical attenuation of shunts is associated with a more favorable long-term prognosis. In small-breed dogs, approximately 80% of shunts are CEPSSs. Portosystemic shunts are anomalous vessels that join the portal and systemic venous circulations, allowing blood from splanchnic organs to bypass the liver. Intraoperative attenuation of CEPSSs to a diameter < 3.0 mm is not necessary and may result in a less favorable outcome. The technique may facilitate minimally invasive treatment of CEPSSs in dogs. In the prospectively enrolled dogs, mean PPSBA concentrations increased over time in dogs in the partial attenuation group, but not in dogs in the no-attenuation group.Ĭonclusions and Clinical Relevance-Cellophane banding may be used to occlude larger CEPSSs and may decrease the need for intraoperative monitoring of portal vein blood pressure. Shunts were occluded to a diameter 6 months after surgery (22 dogs). Procedures-Gradual occlusion of CEPSSs was performed via cellophane banding. Study Design-Retrospective case series and prospective study.Īnimals-18 cases evaluated retrospectively and 14 dogs evaluated prospectively. AU - Sharma,HS AU - Wünsch,M AU - Brand,T AU - Verdouw,PD AU - Schaper,W EP - 31 PY - 1992/// SN - 0160-2446 SP - 23 TI - Molecular biology of the coronary vascular and myocardial responses to ischemia.Objective-To evaluate the effect of intraoperative attenuation of congenital extrahepatic portosystemic shunts (CEPSSs) during cellophane banding procedures in dogs. Our results clearly indicate that myocardial stunning stimulates the expression of transcription factors which might be involved in regulation of certain growth factors like HBGF-1 and TGF-beta 1 which may play a significant role in the development of a collateral circulation. In situ techniques revealed the localization of HBGF-1 transcripts in the blood vessel wall, and TGF-beta 1 in cardiac myocytes and Purkinje cells. Using polymerase chain reaction (PCR) and Northern hybridization techniques, we observed significantly enhanced expression of HBGF-1 and TGF-beta 1 in collateralized myocardium as compared with normal. Progredient stenosis of the circumflex coronary artery was induced by implanting a hygroscopic ameroid constrictor ring around it and occlusion was verified by in vivo angiography. In the second model, we examined the expression of the peptide mitogens heparin-binding growth factor 1 (HBGF-1) and transforming growth factor beta 1 (TGF-beta 1) after a chronic coronary artery occlusion leading to myocardial collateralization. We observed several-fold enhanced expression of c-fos and HSP-70 mRNA in the stunned myocardium as compared with the control, whereas c-myc mRNA levels remained almost unchanged. Myocardial stunning was achieved by two cycles of 10-min left anterior descending coronary artery (LAD) occlusion and 30 min reperfusion. In a "stunning" model of repetitive ischemia and reperfusion, we studied the mRNA expression of immediate early genes like c-fos, c-myc and heat shock protein-70 (HSP-70). Download RIS format (EndNote, RefMan) TY - JOUR AB - To understand the complex mechanism(s) involved in molecular responses to ischemia, we developed two experimental models in pigs.
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