A Method for Experimental Production of Gradual Occlusion of the Portal Vein.

Re‐Evaluation of a Portocaval Venograft Without an Ameroid Constrictor as a Method for Controlling Portal Hypertension After Occlusion of Intrahepatic Portocaval Shunts in Dogs

“…In neither of the 2 previously reported dogs could the portocaval venograft be identified on abdominal ultrasonography 10 . Necropsy of dog 4 showed severe intestinal mucosal and intraluminal hemorrhage consistent with previous reports of necropsy findings in research dogs with portal hypertension 38 …”

“…Three main lesions are responsible: gastro‐esophageal varices, hypertensive gastropathy, and antral vascular ectasia 37 . Experimentally, in dogs, acute severe portal hypertension causes sudden death, with engorged mesenteric vessels, congestion of the spleen and hemorrhagic areas in the mesentery and intestinal wall, 38 and extreme passive hyperemia of the stomach, often associated with gastrointestinal hemorrhage 31 . Sustained portal hypertension in research dogs can result in the formation of esophageal varices that can result in melena 31,39 …”

Experimental Evaluation of Four Methods of Progressive Venous Attenuation in Dogs

“…There is little objective information in the literature regarding the rate and degree of vascular occlusion in response to cellophane implantation. Occlusion of the canine portal vein within 40 to 60 days of polyethylene banding has been reported 21 . Virtually complete occlusion of the portal vein within 6 weeks of cellophane banding was observed in a further 12 dogs 22 .…”

“…Initial work in laboratory animals and dogs suggested that ameroid clay produced minimal foreign body reaction 9,20 . In another report, neutrophils appeared adjacent to the implant within 10 days 21 . Twenty to 30 days after implantation, inflammatory infiltrates had subsided; however, proliferation of the intimal cells, and edema produced luminal narrowing.…”

Short‐ and long‐term outcomes of polyethylene band attenuation of congenital extrahepatic portosystemic shunts in dogs: 60 cases (2010‐2020)

“…Use of polyethylene was reported in 1948 as a film for achieving gradual attenuation of large vessels in human patients (Yeager & Cowley 1948) and then for gradual occlusion of the portal vein dogs (Stone & Murphy 1949). Subsequently, this polymer has been widely used in surgery as sheets for hernia repair (Yeager & Cowley 1948, Collins 1965, tape for tendon augmentation (Leciejewski et al 2018) and as suture material for complete ligation of CEHPSSs (Bristow et al 2019).…”