Hemolysis after transjugular intrahepatic portosystemic shunting: The naked stent syndrome

Abstract

SEE ARTICLE ON PAGE 32. venous pressure and the severity of PSE after TIPS are inversely related. 12 In 1992, Sanyal et al reported a post-TIPS patient with Naked we came into the world, and naked we shall depart hemolytic anemia and progressive hepatic encephalopathy from it.(HE), which they attributed to the stent, 13 although the Aesop, Fables relationship between the encephalopathy and the hemolyTransjugular intrahepatic portosystemic shunts sis was not clear. The patient, a Korean man with post-(TIPS) is an exciting new technique for the treatment HCV cirrhosis, received a Wallstent implant (Schneider, of portal hypertension. In the 8 years since it was first Inc., Minneapolis, MN) following an episode of hemordescribed, 1 it has been reported to be almost magical rhage from esophageal varices. Over the next 10 days, in its control of portal hypertension 2,3 and bleeding var-the serum bilirubin level increased and the hemoglobin ices 4 and semimagical in its treatment of refractory concentration decreased, in the absence of further bleedascites. 5,6 However, it is not free of problems. It has ing. Intravascular hemolysis was diagnosed, based on caused a broad spectrum of complications 7 and has these findings and the appearance of schistocytes in the been plagued by a variety of malfunctions. 8,9 The most peripheral blood smear, reticulocytosis, hypohaptoglobincommon of the complications are procedural, primarily emia, hemosiderinuria, and a negative Coomb's test. Worsperforations of the capsule of the liver or of abdominal ening HE required a liver transplantation, after which the organs that are associated with intra-abdominal hem-hemolysis promptly subsided. At the time of liver transorrhage. Infection, arrhythmias, thrombosis, misplaced plantation, they observed in the explanted liver that the or migrating stents, and nephrotoxicity are common Wallstent protruded into the portal and hepatic veins. The occurrences.intrahepatic portion of the stent was completely endotheliBased on the similarity of TIPS to portosystemic alized, but the extrahepatic, intravenous ends of the stent, anastomoses (PSA) it was predicted that portosystemic which consisted of bare wires, protruded into the portal encephalopathy (PSE) would be a common metabolic and hepatic veins (Fig. 1). They postulated that the hemocomplication. Indeed, 25% to 35% of patients who have lysis resulted from traumatic injury to erythrocytes flowundergone TIPS implantation have promptly devel-ing through the naked steel wires of the stent that prooped new or worsened PSE. 10 The frequency and sever-truded into the veins. In the absence of a positive Coomb's ity of PSE after PSA, whether spontaneous, surgical, test, which excludes antibodies to gamma globulins, macor interventional are proportional to the size of the roglobulins and complement, of spur cells, of sepsis, of shunt. 11 Most descriptions of post-TIPS PSE mention hepatocellular carcinoma or of disseminated intravascular that it tends to be mild, easily treatable, and of short hemo...

Hemolytic Anemia following Stent-Graft Transjugular Intrahepatic Portosystemic Shunt Creation

“…Injury occurs as red blood cells collide with the unendothelialized bare wire mesh of the stent, particularly along the free hepatic and portal venous ends. [7][8][9][10]14 Hemolytic anemia related to other implanted devices is a known phenomenon, and traumatic red cell damage from high-flow shear stress induced by heart valve prostheses and aortic bypass grafts has been previously reported. 11 Flow models have shown that hemolysis by shear stress is found in flow velocities greater than 2,000 cm/s.…”

Intravascular stents do not cause microangiopathic hemolysis or thrombotic microangiopathy

“…Sanyal et al first reported hemolytic anemia in a patient who underwent a TIPS procedure in 1992 [11]. A series of 9 case reports were reviewed by Conn in 1996 [12]. That same year, Sanyal et al described 7 instances of hemolytic anemia that developed in a group of 60 TIPS patients [4].…”

“…All of these patients had advanced liver cirrhosis and spur cell anemia. The onset of hemolysis was during the first 4 weeks after TIPS placement and as early as the second day [4,12]. Red blood cell abnormalities included anisocytosis, poikilocytosis, target cells, echinocytes, and acanthocytes, but schistocytes were not observed [4].…”

Intravascular stents do not cause microangiopathic hemolysis or thrombotic microangiopathy

“…That same year, Sanyal et al described 7 instances of hemolytic anemia that developed in a group of 60 TIPS patients [4]. The onset of hemolysis was during the first 4 weeks after TIPS placement and as early as the second day [4,12]. The onset of hemolysis was during the first 4 weeks after TIPS placement and as early as the second day [4,12].…”