Transjugular Intrahepatic Portosystemic Shunt Tract Research Articles

Thrombosis after transjugular intrahepatic portosystemic shunt: an ominous sign?

Transjugular intrahepatic portosystemic shunt (TIPS) is increasingly used for the treatment of complications of portal hypertension, especially variceal bleeding and ascites refractory to conventional therapy (1,2). Development of thrombosis after TIPS placement is an uncommon complication, which was reported to occur in only 3% to 10% of patients when bare stents were used in several large series (3-6). Thrombosis usually develops acutely either at the time the stent is being deployed or within several days of TIPS placement (2,6). The cause of the thrombosis may be leakage of bile into the shunt, hypercoagulable syndromes, stent mispositioning, suboptimal stent sites, or inadequate coverage of the TIPS tract with sufficient stent (2,7-12). The direct result of thrombosis development is occlusion of the TIPS device, blocking flow in the portal vein and directly resulting in the recurrence of the complication of portal hypertension in addition to potentially causing bowel ischemia as a result of venous congestion in cases of thrombosis extending into the splenic and mesenteric veins (7). Thrombosis can be identified by Doppler ultrasound and patency can be re-established by repeat catheterization (2,7). The development of acute thrombosis also can be effectively prevented by prophylaxis anticoagulation or using e-PTFE-coated stents (13,14). One randomized controlled trial (RCT) showed that use of phenprocoumon (an anticoagulant) was associated with a lower rate of complete occlusion within the first three months following TIPS placement (13). In the RCT by Bureau (14), no early thrombosis was observed in the e-PTFE covered stent-graft group (n=39) as compared with three cases in the covered stent-graft group (n=41). A recent RCT also showed that early thromboses were less frequent in patients receiving covered stent TIPS compared with those receiving bare stents (10/67 in bare stent group vs. 3/63 in the covered stent group) (15).

Postinterventional Passive Expansion of Partially Dilated Transjugular Intrahepatic Portosystemic Shunt Stents

PurposeTo investigate passive transjugular intrahepatic portosystemic shunt (TIPS) stent expansion in patients with intentional “underdilation” (eg, 10-mm stent, 8-mm balloon) during TIPS creation. Materials and MethodsCustom in-house software was developed for objective quantification of cross-sectional stent area from computed tomography (CT) data. The technique was validated by in vitro experiments. The study included 39 patients (22 men; mean age, 59.2 y) who underwent TIPS creation (VIATORR stent graft [W. L. Gore & Associates, Flagstaff, Arizona]; n = 29; WALLSTENT endoprosthesis [Boston Scientific, Marlborough, Massachusetts], n = 10) with stent underdilation. Follow-up CT data of the patients were used to quantify in vivo stent area changes. Data were analyzed by variance analysis and entered into a general linear model to test for interrelations between stent area changes and clinical (eg, cirrhosis grade) and procedural parameters. ResultsIn vitro validation of the in-house software showed good agreement and reproducibility without overestimation of stent area. Mean clinical follow-up time in patients was 787 days (range, 7–2,450 d). At the time of intervention, VIATORR stent grafts and WALLSTENT endoprostheses were dilated to an average of 64.4% ± 2.3% and 65.63% ± 8.52% of nominal area, respectively. At the last imaging follow-up evaluation, this value had increased in all stents to a mean of 87.8% ± 7.9% (VIATORR) and 82.34% ± 19.6% (WALLSTENT) in the TIPS tract (P < .05). Multivariate analysis revealed the time after intervention to be the only predictor of stent area in the TIPS tract. There was no significant association between stent expansion and clinical or procedure-related parameters. ConclusionsThe area of self-expanding stents implanted in the liver for TIPS creation with dilation to less than nominal diameter significantly increases over time. This increase has to be considered as an additional factor influencing the long-term portosystemic gradient.

Transcatheter embolotherapy with N-butyl cyanoacrylate for ectopic varices.

To address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices. The institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed. Preprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5-33.2 months). Transcatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices.

Duodenal variceal bleeding after balloon-occluded retrograde transverse obliteration: Treatment with transjugular intrahepatic portosystemic shunt

We report a case of duodenal varix bleeding as a long term complication of balloon occluded retrograde transvenous obliteration (BRTO), which was successfully treated with a transjugular intrahepatic portosystemic shunt (TIPS). A 57-year-old man was admitted to the emergency room suffering from melena. He had undergone BRTO to treat gastric varix bleeding 5 mo before admission. Endoscopy and a computed tomography (CT) scan showed complete obliteration of the gastric varix, but the nodular varices in the second portion of the duodenum expanded after BRTO, and spurting blood was seen. TIPS was performed for treatment of duodenal variceal bleeding, because attempts at endoscopic varix ligation were unsuccessful. The postoperative course was uneventful and the patient was discharged without complications. A follow up CT scan obtained 21 mo after TIPS revealed a patent TIPS tract and complete obliteration of duodenal varices, but multinodular hepatocellular carcinoma had developed. He died of hepatic failure 28 mo after TIPS.

Transjugular Intrahepatic Portosystemic Shunt with an Autologous Endothelial Progenitor Cell Seeded Stent:: A Porcine Model

To evaluate the efficacy of a self-expanding metal stent seeded with autologous endothelial progenitor cells (EPCs) for preventing in-stent stenoses in transjugular intrahepatic portosystemic shunt (TIPS) in a swine model. TIPS was performed in 18 young adult pigs, using a self-expanding nitinol stent (control, n = 8) and an autologous EPC-seeded stent (treatment, n = 10). All pigs were sacrificed at 2 weeks post-TIPS procedure. Portography was performed immediately before the euthanasia. Gross, microscopic, and immunohistochemistry of the TIPS tract specimens were examined. The proliferative response of the shunt was quantified histologically. TIPS was performed successfully in 16 swine, 2 animals died during the procedure. Another pig died of unknown causes 2 days post-procedure. At day 14 follow-up, portography and necropsy of the 15 remaining swine demonstrated that five shunts occluded and one shunt was stenotic (80%) in the control group (n = 6). Five shunts remained patent, two shunts were stenosed (50%, 70%), and the remaining two shunts were occluded in the treatment group (n = 9). The patency rate was significantly lower in the control group than in the treatment group, 0% versus 55.6% (P = .03). Histological analyses showed a significantly greater pseudointimal hyperplasia in the TIPS track of the control group than that of the treatment group (P < .05). Intact endothelium was documented in the lumina of all the EPC-implanted stent group. The EPC-seeded metal stent is feasibly fabricated in vitro and improves the patency in TIPS in a porcine model.

Inhibition of pseudointimal hyperplasia in swine TIPS models: the efficacy of local delivery of paclitaxel using a perforated balloon catheter

The aim of this study was to investigate the efficacy and feasibility of local delivery of paclitaxel to inhibit pseudointimal hyperplasia/intimal hyperplasia in swine transjugular intrahepatic portosystemic shunt (TIPS) models TIPS were created in seven healthy domestic swine (15-20 kg). Before TIPS stent insertion, we performed a short-term infusion of paclitaxel (treatment group: n = 4) and saline (control group: n = 3) into the TIPS tract using a balloon catheter in which two 0.010 inch holes were created on opposite sides of the balloon. Paclitaxel or saline was given to all animals via the hepatic parenchymal and venous outflow tract. The animals were followed for up to two weeks and then killed. Gross and histological evaluations of the shunts were performed, and the maximum pseudointimal/intimal hyperplasia thicknesses were calculated for each animal The average infusion time of paclitaxel or saline was 7.6 min (6-9 min). At gross and histological evaluation, considerable pseudointimal hyperplasia had formed in the control group and statistically significant differences were found upon microscopic evaluation in the maximum pseudointimal hyperplasia thickness between the control (2.41 mm, range 1.7-3.16 mm) and animals receiving paclitaxel (0.63 mm, range 0.42-0.98 mm, p<0.05) Local delivery of paclitaxel at the time of TIPS creation may have been effective in reducing pseudointimal/intimal hyperplasia in swine TIPS models.

A Technique for Controlled Partial Closure of a Transjugular Intrahepatic Portosystemic Shunt Tract in a Patient with Hepatic Encephalopathy

A novel endovascular technique to reduce flow through a transjugular intrahepatic portosystemic shunt (TIPS) is described in a patient with severe hepatic encephalopathy. This technique allows controlled and potentially adjustable partial closure of the TIPS without thromboembolic risk. The patient experienced a dramatic clinical improvement after the procedure.

MR-guided Transjugular Intrahepatic Portosystemic Shunt Creation with Use of a Hybrid Radiography/MR System

To evaluate the performance of a combined hybrid radiography/magnetic resonance (MR) unit to guide portal vein (PV) puncture during human transjugular intrahepatic portosystemic shunt (TIPS) creation. Fourteen patients undergoing TIPS creation were studied during standard clinical applications. Patients were anesthetized and then positioned in an open MR unit containing a flat-panel radiographic fluoroscopic unit. With use of a combination of fluoroscopy and MR imaging, the PV was accessed and the TIPS procedure was performed. A noncovered nitinol stent or a covered stent-graft was placed in the TIPS tract. Number of punctures required, total procedure time, fluoroscopy time, procedural success rate, complications, and ultrasonographic and clinical follow-up were recorded. Clinical success was obtained in 13 of 14 patients. In one patient, extrahepatic puncture of the PV occurred, resulting in hemorrhage and requiring placement of a covered stent to control the bleeding. The mean number of punctures required to access the PV was 2.6 +/- 1.7, and the total procedure time was 2.5 hours +/- 0.6. Mean fluoroscopy time was 22.3 minutes +/- 5.5. Results of clinical and ultrasonographic follow-up compare favorably to previously published reports. TIPS creation with a combination hybrid radiography/MR unit is feasible and may reduce the number of needle passes required and radiation exposure, with similar overall outcomes compared with studies reported in the literature.

Efficacy of a Dexamethasone-Eluting Nitinol Stent on the Inhibition of Pseudointimal Hyperplasia in a Transjugular Intrahepatic Portosystemic Shunt: An Experimental Study in a Swine Model

ObjectiveWe wanted to evaluate the feasibility and efficacy of using a dexamethasone (DM)-eluting nitinol stent to inhibit the pseudointimal hyperplasia following stent placement in the transjugular intrahepatic portosystemic shunt tract (TIPS) of a swine.Materials and MethodsFifteen stents were constructed using 0.15 mm-thick nitinol wire; they were 60 mm in length and 10 mm in diameter. The metallic stents were then classified into three types; type 1 and 2 was coated with the mixture of 12% and 20%, respectively, of DM solution and polyurethane (PU), while type 3 was a bare stent that was used for control study. In fifteen swine, each type of stent was implanted in the TIPS tract of 5 swine, and each animal was sacrificed 2 weeks after TIPS creation. The proliferation of the pseudointima was evaluated both on follow-up portogram and pathologic examination.ResultsOne TIPS case, using the type 1 stent, and two TIPS cases, using the type 2 stent, maintained their luminal patency while the others were all occluded. On the histopathologic analysis, the mean of the maximum pseudointimal hyperplasia was expressed as the percentage of the stent radius that was patent, and these values were 51.2%, 50% and 76% for the type 1, 2, and 3 stents, respectively.ConclusionThe DM-eluting stent showed a tendency to reduce the development of pseudointimal hyperplasia in the TIPS tract of a swine model with induced-portal hypertension.