1 2 n  n  Description of Procedures Embolization of Portal Vein Collaterals n  n  n  n  1 2 Fig. 1 Portal venous angiogram in a 53-year-old patient referred for TIPS creation because of recurrent variceal bleeding not controlled by medication plus multiple treatments with endoscopic band ligation and sclerotherapy. The varices are supplied by a single coronary vein  Fig. 2 a b  Whenever AVP embolization preceded TIPS placement, the guiding catheter for AVP delivery was introduced transhepatically into the right portal vein. At our institution the portal vein is routinely catheterized prior to TIPS with a 3- or 4-Fr catheter to visualize the portal vein as a fluoroscopic target for transjugular transhepatic puncture. For transhepatic AVP placement this catheter was exchanged for a 6- to 8-Fr hepatic introducer sheath. After AVP embolization and initial creation of the hepatic-to-portal vein shunt tract for TIPS, the hepatic introducer sheath was withdrawn in multiple small successive steps over the course of the remainder of the procedure, so that a solid sealing clot could form in the hepatic parenchymal tract. No additional embolization of the tract was performed. Whenever vein embolization was performed after the creation of a TIPS, AVP placement was done via the transjugular route. In all patients, the large-diameter coronary/gastric vein supplying extensive esophageal/gastric varices was embolized using a single AVP plug 10, 12, or 14 mm in diameter. For placement, a 6- to 8-Fr guiding catheter was first negotiated into the proximal part of the coronary vein. Then the AVP device was advanced through the guiding catheter and initially deployed by retracting the guiding catheter but without detaching the device. A control injection was made, and if needed, the AVP was retrieved into the guiding catheter and repositioned. When in a satisfactory position, the AVP was detached by anticlockwise rotation of the AVP guide wire to unscrew it from the AVP device proper. Within minutes of deployment, the collateral flow through the coronary vein had completely stopped. TIPS creation was done by placement of e-PTFE-covered stent-grafts (Viatorr; Gore, Flagstaff, AZ) 8–10 mm in diameter and 6 ± 2 cm long, resulting in a postprocedural portosystemic pressure difference of 5–10 mm Hg. All patients were hemodynamically stable immediately after the procedure. During follow-up there were no recorded episodes of rebleeding with a follow-up of 1 year maximum. The patient who was treated for bleeding rectal hemorrhoids died after 3 days because of combined liver and respiratory failure. Another patient who received emergency TIPS while in hypovolemic shock due to massive unstoppable bleeding from esophageal varices died 46 days after the procedure because of liver and kidney failure complicated by ileus. TIPS Occlusion 3 Fig. 3 a b c  Another patient, a 65-year-old male, had been referred for TIPS placement for refractory ascites following liver transplantation, which required weekly paracentesis. In the days following placement of a 10-mm-diameter e-PTFE-covered stent-graft TIPS, liver failure developed, necessitating its closure. Closure of the TIPS was technically successfully achieved using a 16-mm-diameter AVP but did not substantially improve the clinical status. Because of liver failure and refractory ascites, the patient underwent a second liver transplantation 2 days after TIPS occlusion. Discussion In this report we have described the use of AVP embolization in the context of TIPS. For closure of collateral veins supplying bleeding varices, we consider the AVP a useful device in a defined subset of patients. The AVP’s relative advantages are its efficiency to occlude large-diameter vessels in a single-step procedure and its reliability of placement. Unlike standard embolization coils, the AVP can be positioned precisely, its position can be checked with contrast injections before actual detachment, and it can be repositioned if required. Migration of the AVP during or after deployment is unlikely. Disadvantages of the AVP include the higher cost of the device itself and of the additionally required guiding catheter. Furthermore, the 6- to 8-Fr guiding catheter markedly increases the bulk of the introducer system relative to the 4- to 5-Fr catheter alternatively used for coil embolization. In our practice we are inclined to use the AVP whenever there is a single, large-diameter collateral vein which would otherwise require the insertions of multiple embolization coils and/or whenever accurate placement of the embolic device close to the portal vein may be critical. 3 4 Another potential use for the AVP device is for closure of the TIPS itself, in circumstances where hepatic encephalopathy and/or liver failure because of the shunt may prove to be life-incapacitating. Here, the effectiveness of the AVP in occluding large-diameter high-flow vessels, its resistance to migration, and its ease of placement are particularly helpful. 5 As mentioned, we routinely place a transhepatic catheter into the portal vein as a target for puncturing the portal vein during TIPS creation. In our experience, this increases the control over the exact entrance point into the portal vein and also reduces the number of puncture attempts while creating the TIPS tract. We have found that the reduced procedure time for the TIPS procedure proper more than makes up for the extra time it takes to insert this initial transhepatic catheter into the portal vein. We have encountered no complications because of this approach in more than 100 TIPS procedures. 6