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Published online before print July 6, 2005, 10.1148/radiol.2362040766
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(Radiology 2005;236:725-729.)
© RSNA, 2005

Vascular and Interventional Radiology

Dacron-covered Stent-Grafts in Transjugular Intrahepatic Portosystemic Shunts: Initial Experience1

Charles T. Lau, MD, Mark Scott, DO, S. William Stavropoulos, MD, Michael C. Soulen, MD, Jeffery A. Solomon, MD and Timothy W. I. Clark, MD, MSc

1 From the Section of Interventional Radiology, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA, 19104 (C.T.L., S.W.S., M.C.S., J.A.S., T.W.I.C.); and Department of Radiology, Lankenau Hospital, Wynnewood, Pa (M.S.). Received April 28, 2004; revision requested July 12; revision received September 3; accepted October 4. Address correspondence to T.W.I.C. (e-mail: timothy.clark{at}uphs.upenn.edu).


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 
PURPOSE: To retrospectively review the authors' experience with use of a Dacron-covered stent-graft in transjugular intrahepatic postosystemic shunts (TIPS).

MATERIALS AND METHODS: The need for internal review board approval was waived. Informed consent was obtained from all patients. The study was compliant with the Health Insurance Portability and Accountability Act. A retrospective analysis was performed of 16 patients who received a Dacron-covered stent-graft during revision or de novo creation of TIPS. There were 13 men and three women aged 44–80 years (mean age, 61 years). Primary unassisted and assisted patency rates and secondary patency rates were estimated. The primary unassisted patency of patients who underwent de novo placement of stent-grafts (n = 10) was compared with that of patients with stent-grafts placed during shunt revision (n = 6); in all patients, stent-grafts were placed within stents. Primary unassisted patency was also compared between patients in whom the covered stent was confined to the parenchymal tract (n = 7) and those in whom the stent extended 1 cm or more into the portal vein (n = 9). Patency was estimated with the Kaplan-Meier method, and group comparisons were performed with the log-rank test.

RESULTS: Primary unassisted patency rates following stent-graft placement at 4, 12, and 24 months (± standard error) were 64% ± 14, 54% ± 15, and 40% ± 16, respectively. The rates for primary assisted patency were 78% ± 12, 67% ± 14, and 67% ± 14 and those for secondary patency were 91% ± 9, 81% ± 12, and 54% ± 23. At 12 months, primary unassisted patency with de novo stent-graft placement was 90% ± 9, whereas that with stent-grafts placed during TIPS revision was 17% ± 15 (P = .005). At 12 months, the primary unassisted patency in patients with stent-grafts confined to the parenchymal tract was 75% ± 22, and that of patients with stent-grafts extending at least 1 cm into the portal vein was 40% ± 17 (P = .21).

CONCLUSION: In this small series, satisfactory long-term patency was observed among patients in whom Dacron-covered stent-grafts were placed during revision or de novo creation of TIPS. More favorable outcomes were observed when the stent-graft was placed during de novo TIPS creation and when the device was confined to the parenchymal tract.

© RSNA, 2005


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 
Since its inception for the treatment of recurrent variceal bleeding more than 15 years ago (1,2), the transjugular intrahepatic portosystemic shunt (TIPS) has proved valuable in the management of refractory ascites (3,4), hepatic hydrothorax (5,6), Budd-Chiari syndrome (7,8), and hepatorenal syndrome (9). Shunt failure following TIPS creation remains a common and burdensome problem, necessitating continued imaging surveillance and shunt revision. Shunt failure in the 1st year following TIPS creation occurs in 50%–70% of patients (10). Because the creation of TIPS involves the establishment of a raw tract of hepatic tissue between the portal and hepatic veins supported by a bare stent, the use of stent-grafts has been postulated as a way of improving patency by providing a more biocompatible shunt lining.

In case series to date, favorable patency outcomes have been observed in studies in which polytetrafluoroethylene (PTFE)-covered stents have been used in TIPS (8,11,12). Dacron (polyethylene terephthalate)-covered stents have been used in a porcine model of TIPS (13,14); however, clinical experience is limited. The Wallgraft (Boston Scientific, Natick, Mass) is a Dacron-covered self-expanding stent (Wallstent; Boston Scientific) with an additional highly radiopaque marker woven into the stent to increase fluoroscopic conspicuity. The purpose of our study was to retrospectively review our experience with use of a Dacron-covered stent-graft in TIPS.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 References
 
Patients
For both institutions involved in this study, internal review board exemption was received for this retrospective study. Our study was compliant with the Health Insurance Portability and Accountability Act. Sixteen patients who received a single stent-graft during revision or de novo creation of TIPS were identified during a 3-year period from 2000 to 2003 at two tertiary care teaching hospitals. In the United States, this device is approved by the U.S. Food and Drug Administration for tracheobronchial stent placement, and its use in TIPS constitutes off-label use. The off-label nature of the use of the stent-graft in this setting had been discussed with patients and their families before shunt creation, and informed consent was obtained. At the time of Wallgraft placement, this was the only covered self-expanding stent available. At no time was this stent used for research purposes; instead, it was placed solely for medical reasons given the concern for bile leak and/or shunt thrombosis following conventional bare-stent TIPS.

Of the 16 patients, 13 were men, and three were women. The mean patient age was 61 years (range, 44–80 years) (Table). The indication for TIPS was refractory ascites in seven patients, refractory variceal bleeding in seven, and both refractory ascites and variceal bleeding in two. The median model of end-stage liver disease score (15) for the patient cohort was 12 (range, 9–21), and the median Child-Pugh score was 7 (range, 4–10), which corresponds to Child-Pugh class B disease. Stent-grafts were placed during de novo TIPS creation in 10 patients and during TIPS revision in six.


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  		Baseline Characteristics of 16 Patients who Underwent Placement of a Dacron-covered Stent for TIPS

 
TIPS Procedure
Initially, TIPS were created by using previously described techniques (16). All TIPS procedures were performed by fellowship-trained interventional radiologists (M.S., S.W.S., M.C.S., J.A.S., T.W.I.C.) with 2–12 years of experience. Shunt tracts were dilated with 10-mm-diameter angioplasty balloons and lined with 10-mm-diameter stents. The shunts were dilated to reach a target portosystemic gradient of less than 12 mm Hg. In one patient, a large duodenal varix that was actively bleeding at TIPS creation was embolized with coils because the portosystemic gradient remained at 15 mm Hg despite dilation of the shunt to a diameter of 10 mm.

In all patients, TIPS were initially created with one or two stents to create a bare-stent conduit from the portal vein to the junction of the hepatic vein and inferior vena cava. This was done to provide continued portal blood flow through the interstices of the bare stent and to enable precise portography before stent-graft placement to enable appropriate stent-graft sizing. Stent-grafts were then placed within this bare-stented TIPS. Stent-grafts were placed immediately after TIPS creation with stents (Fig 1) or at shunt revision in patients with TIPS created with stents. The stent-grafts were 10 mm in diameter in 14 of the 16 patients (88%) and 12 mm in diameter in two (12%); 12-mm-diameter stent-grafts were placed at the discretion of the operator when there was concern about adequate apposition of the stent-graft within the course of the shunt tract. The length of the stent-graft ranged from 30 to 70 mm and varied according to the length of the parenchymal tract.



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  		Figure 1. Anteroposterior venogram of TIPS obtained after placement of a 10 x 50-mm stent-graft. The stent-graft (arrows) is confined to the parenchymal tract of the TIPS and was placed within a 10 x 68 mm stent placed immediately before stent-graft insertion. Note the filling of intrahepatic portal branches distal to the shunt origin.

 
TIPS revision was performed when a hemodynamically significant shunt stenosis (≥50%) was present at venography and the portosystemic gradient was more than 12 mm Hg.

Image Review
In our practice, we obtain a baseline duplex ultrasonographic (US) scan the day after TIPS creation or TIPS revision; subsequent shunt velocities measured at follow-up clinical visits are then compared with this baseline study during follow-up. This evaluation is performed by a sonologist and includes assessment of intrashunt velocities, main portal vein velocities, and US criteria of shunt dysfunction. These criteria include shunt occlusion, midshunt velocities of less than 60 cm/sec, main portal vein velocities of less than 40 cm/sec, decrease in peak shunt or main portal vein velocities more than 30% from initial baseline postprocedural values, or a focal area of high shunt velocity (>200 cm/sec) (17,18). TIPS venography was performed when at least one of these duplex US criteria was suggestive of shunt dysfunction. TIPS venography was also performed in patients with repeat bleeding or reaccumulation of ascites due to suspected shunt dysfunction. TIPS venograms were reviewed by three authors (C.T.L., M.S., T.W.I.C.) for the presence of shunt patency, areas and degrees of stenosis (if present), and position of the leading edge of the stent-graft in relation to the portal vein entry site. Venography performed after stent-graft placement was used to classify patients into two groups (Table): those in whom the stent-graft was confined within the parenchymal tract (n = 7) and those in whom the stent-graft extended 1 cm or more into the portal vein (n = 9).

Follow-up and Definitions
Rates of technical and hemodynamic success were calculated. Technical success, as defined previously (19), is the successful creation of a shunt between an intrahepatic portal vein branch and the hepatic vein. Hemodynamic success was defined as a reduction of the portosystemic gradient to a target of 12 mm Hg or less. Shunt status was determined by several authors (C.T.L., T.W.I.C., M.S.) by means of interventional radiology clinic records, telephone patient contact, and contact with referring physicians. In our practice, patients are seen in the interventional radiology clinic 1, 3, 6, 9, and 12 months after TIPS creation and at 6-month intervals thereafter. Shunts were considered patent on the basis of absence of shunt occlusion and/or thrombosis at US and/or shunt venography (19). Primary unassisted patency, primary assisted patency, and secondary patency were estimated for all patients. Primary unassisted patency was defined as the interval of time without intervention. Primary assisted patency was defined as the interval until thrombosis of the TIPS, even if repeat interventions had occurred during this interval to treat stenosis. Secondary patency was defined as the total time that the TIPS remained patent, regardless of primary interventions and/or thrombectomies.

Statistical Analysis
Patency estimates were performed with the Kaplan-Meier technique for all patients. Primary unassisted patency was compared between patients with stent-grafts placed during initial TIPS creation and those with stent-grafts placed during TIPS revision. Primary assisted patency was also compared for patients in whom the stent-graft extended more than 1 cm into the portal vein and those in whom the stent-graft extended 1 cm or less into the portal vein (ie, confined to the parenchymal tract). These intergroup comparisons were performed with the log-rank test. Censoring criteria included death unrelated to shunt failure or hepatic transplantation. A P value of .05 was used as the threshold for statistical significance. All analyses were performed by using GraphPad Prism 3.02 for Windows (GraphPad Software, San Diego, Calif).


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 References
 
Technical Success and Follow-up
Technical success of stent-graft insertion was achieved in all 16 patients (100%). After the procedure, the mean portosystemic pressure gradient was 8 mm Hg (range, 5–15 mm Hg) and the mean portal pressure was 20 mm Hg (range, 10–28 mm Hg). Before the procedure, the mean portosystemic pressure gradient was 21 mm Hg (range, 17–23 mm Hg) and the mean portal pressure was 28 mm Hg (range, 20–50 mm Hg). Hemodynamic success was achieved in 15 of the 16 patients (94%). The 30-day mortality rate was 0%.

Total observation time of the patient cohort was 150 months, during which time seven patients died and two underwent liver transplantation. TIPS were abandoned in two patients. The remaining five patients continue to have functioning shunts. Encephalopathy developed in two patients (13%) after TIPS placement, and it was managed with protein restriction and lactulose administration.

In the seven patients who died during the study period, death occurred a mean of 266 days (range, 31–788 days) after stent-graft placement. The cause of death included hepatic failure, congestive heart failure, and metastatic colon cancer. Six patients had a patent TIPS at the time of death, and although no documentation of shunt failure was available in the other patient who died, the patient's symptoms of recurrent ascites were suggestive of shunt failure. In patients who underwent liver transplantation, transplantation occurred a mean of 81 days (range, 52–111 days) after stent-graft placement. In both patients, the TIPS was deemed patent at explantation by the pathologist reviewing the explanted specimen; however, a detailed histopathologic analysis of the shunt tract was not performed. In patients in whom the TIPS was abandoned, US evidence of shunt occlusion occurred a mean of 381 days (range, 146–615 days) after stent-graft placement. Recanalization was not attempted in either patient. One patient with polycythemia rubra vera remained free of ascites despite TIPS occlusion, and no attempt was made to recanalize the TIPS. In the second patient, living donor transplantation was scheduled within the next 2 weeks and recanalization was deemed unnecessary.

The remaining five patients continue to have functioning shunts at a mean of 11.8 months (range, 1.0–30.5 months) after stent-graft placement.

Kaplan-Meier Estimates
Kaplan-Meier estimates (± standard error) of the primary unassisted patency of TIPS after stent-graft placement were 64% ± 14, 54% ± 15, and 40% ± 16 at 4, 12, and 24 months, respectively. Estimates of primary assisted patency were 78% ± 12, 67% ± 14, and 67% ± 14 at 4, 12, and 24 months, respectively. Estimates of secondary patency were 91% ± 9, 81% ± 12, and 54% ± 23 at 4, 12, and 24 months, respectively (Fig 2).



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  		Figure 2. Graph shows the Kaplan-Meier estimates of primary and secondary patency of TIPS after placement of a Dacron-covered stent-graft in 16 patients. Vertical bars represent censored observations. Median shunt patency was approximately doubled by the repeated interventions reflected in the secondary patency rates.

 
The Kaplan-Meier estimate of primary unassisted patency 12 months after TIPS placement in patients undergoing stent-graft placement during de novo TIPS creation was 90% ± 9, whereas that in patients undergoing stent-graft placement during TIPS revision was 17% ± 15 (P = .005, Fig 3). Kaplan-Meier estimates of primary unassisted patency of TIPS at 12 months for patients with stent-grafts confined to the parenchymal tract was 75% ± 22, and that of patients with stent-grafts extending at least 1 cm into the portal vein was 40% ± 17 (P = .21).



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  		Figure 3. Graph shows the Kaplan-Meier estimates of primary unassisted patency of TIPS after placement of a Dacron-covered stent-graft in patients with de novo (n = 10) versus revised (n = 6) TIPS. Vertical bars represent censored observations. Shunts created with de novo placement of stent-grafts remained patent significantly longer than did shunts with stent-grafts placed during TIPS revision (P = .005).

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
References
 
The presence of a TIPS stent within the liver produces local responses that can lead to the development of areas of narrowing with shunt dysfunction. Studies of explanted TIPS (20–22) in animal models and in patients after liver transplantation have helped elucidate possible mechanisms by which these areas of shunt stenosis develop. These responses include formation of an intense cellular response of myofibroblasts and collagen that encroach on the lumen of the shunt (pseudointimal proliferation), leakage of bile into the shunt tract with subsequent narrowing or blockage of the shunt (biliary fistula), and proliferation of smooth muscle cells and fibroblasts at the junction of the stent with the hepatic vein (intimal hyperplasia). This cellular proliferation appears to be stimulated by ingrowth from hepatic sinusoids of endothelial cells, which differ from vascular endothelial cells. Efforts to prevent these effects have been directed toward a synthetic covering of the stent used in TIPS. These coverings are intended to serve as a barrier to bile and as a biocompatible interface with the adjacent liver, which does not incite an inflammatory or proliferative cellular response. Lack of thrombogenicity of the synthetic covering is another major attribute. Ideally, the material would also serve as a matrix for the formation of an endothelial lining of the shunt.

To date, a variety of TIPS stent coverings have been studied, including silicone (23), polyesters (polyethylene terephthalate) (13,14), polycarbonate urethane (24), and PTFE (11,25–31). The Wallgraft (Boston Scientific) is a Dacron-covered stent with a strut design similar to that of the Wallstent (Boston Scientific).

We observed favorable long-term patency among patients who received a stent-graft during de novo creation or revision of TIPS, particularly among patients who underwent stent-graft placement during de novo TIPS creation. Whereas primary patency rates of 25%–66% at 1 year have been observed following TIPS creation (10), we observed an unassisted primary patency rate of 90% at 1 year in patients who received a stent-graft during de novo TIPS creation.

When we compared shunt patency between patients who received a stent-graft at TIPS creation and those who received a stent-graft during TIPS revision, we found a significantly shorter duration of primary unassisted patency in the group that underwent revision (12-month primary patency, 90% and 17%, respectively; P = .005). Patients who require early shunt revision are a selected population of patients who harbor at least one factor leading to shunt failure, one of which is bile leak. The Dacron covering in Wallgrafts (Boston Scientific) has been described as being porous to bile (14). This assumption, however, has been challenged in more recent in vitro experiments in which the stent-graft was shown to be significantly less permeable to bile than commercially available PTFE-covered stent-grafts (32). Although fluoroscopic evidence of a bile leak was not observed in the six patients in whom stent-grafts were placed owing to TIPS failure, subclinical bile leaks may have been present and contributed to reduced patency after stent-graft placement.

With the anticipated availability of U.S. Food and Drug Administration–approved stent-grafts for TIPS, it is expected that a greater proportion of TIPS will be created with these devices. Although stent-grafts may overcome many problems of shunt failure from restenosis, the complex flow patterns from covered stent segments within the portal vein remain to be systematically studied. It has been shown that insufficient stent coverage in the hepatic venous outflow is a risk factor for early TIPS failure (33). It would appear that in an era of stent-grafts for TIPS, the position of the leading edge of the covered stent relative to the portal vein may become an equally important determinant of shunt patency. We observed a trend of improved shunt patency among patients in whom the stent-graft was confined to the parenchymal tract. Patients with stent-grafts that were confined to the parenchymal tract had a 75% 12-month primary patency, whereas those with stent-grafts extending at least 1 cm into the portal vein had a 12-month patency of 40%. Although this difference did not reach the threshold for statistical significance (P = .21), until further data become available we suggest care should be taken to ensure that the covered segment of a stent-graft does not extend into the portal venous system. This observation would seem to be supported by Haskal et al (34), who reported three cases of early TIPS failure in patients with stent-grafts; in two of these patients, the stent-grafts extended several centimeters into the portal vein.

Despite this small series, our patency outcomes are similar to those obtained with PTFE-covered stents for TIPS. In one of the largest series to date, Hausegger et al (30) observed a 12-month primary patency rate of 81% in 71 patients after de novo TIPS placement of a PTFE-covered stent-graft (Viatorr; Gore, Flagstaff, Ariz); in our series, we had a 12-month patency rate of 90%.

This study is limited by the small patient population, lack of a contemporaneous control group, variable follow-up, and retrospective design. Despite these limitations, we found that TIPS creation with a Dacron-covered stent-graft, when placed within a bare stent to limit the covered segment to the parenchymal portion of the tract, achieves favorable long-term primary patency rates. Confining the leading edge of the covered segment of the stent-graft to the junction of the hepatic parenchyma and the portal vein may be an important determinant of shunt patency.


   FOOTNOTES
 

Abbreviations: PTFE = polytetrafluoroethylene • TIPS = transjugular intrahepatic portosystemic shunt

Author contributions: Guarantor of integrity of entire study, T.W.I.C.; study concepts, T.W.I.C., M.S., M.C.S.; study design, T.W.I.C., M.S., C.T.L.; literature research, T.W.I.C.; clinical studies, T.W.I.C.; data acquisition, T.W.I.C., C.T.L., M.S., J.A.S., S.W.S.; data analysis/interpretation, T.W.I.C., C.T.L.; statistical analysis, T.W.I.C.; manuscript preparation, all authors; manuscript definition of intellectual content, editing, and revision/review, T.W.I.C.; manuscript final version approval, all authors


   References
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 References
 

  1. Colapinto RF, Stronell RD, Gildiner M, et al. Formation of intrahepatic portosystemic shunts using a balloon dilatation catheter: preliminary clinical experience. AJR Am J Roentgenol 1983; 140:709–714.[Abstract/Free Full Text]
  2. Richter GM, Noeldge G, Palmaz JC, et al. Transjugular intrahepatic portacaval stent shunt: preliminary clinical results. Radiology 1990; 174:1027–1030.[Abstract]
  3. Rossle M, Ochs A, Gulberg V, et al. A comparison of paracentesis and transjugular intrahepatic portosystemic shunting in patients with ascites. N Engl J Med 2000; 342:1701–1707.[Abstract/Free Full Text]
  4. Sanyal AJ, Genning C, Reddy KR, et al. The North American Study for the Treatment of Refractory Ascites. Gastroenterology 2003; 124:634–641.[CrossRef][Medline]
  5. Haskal ZJ, Zuckerman J. Resolution of hepatic hydrothorax after transjugular intrahepatic portosystemic shunt (TIPS) placement. Chest 1994; 106:1293–1295.[Abstract/Free Full Text]
  6. Siegerstetter V, Deibert P, Ochs A, Olschewski M, Blum HE, Rossle M. Treatment of refractory hepatic hydrothorax with transjugular intrahepatic portosystemic shunt: long-term results in 40 patients. Eur J Gastroenterol Hepatol 2001; 13:529–534.[CrossRef][Medline]
  7. Ochs A, Sellinger M, Haag K, et al. Transjugular intrahepatic portosystemic stent-shunt (TIPS) in the treatment of Budd-Chiari syndrome. J Hepatol 1993; 18:217–225.[CrossRef][Medline]
  8. Cejna M, Peck-Radosavljevic M, Schoder M, et al. Repeat interventions for maintenance of transjugular intrahepatic portosystemic shunt function in patients with Budd-Chiari syndrome. J Vasc Interv Radiol 2002; 13:193–199.[Medline]
  9. Brensing KA, Textor J, Perz J, et al. Long-term outcome after transjugular intrahepatic portosystemic stent-shunt in non-transplant cirrhotics with hepatorenal syndrome: a phase II study. Gut 2000; 47:288–295.[Abstract/Free Full Text]
  10. LaBerge JM, Somberg KA, Lake JR, et al. Two-year outcome following transjugular intrahepatic portosystemic shunt for variceal bleeding: results in 90 patients. Gastroenterology 1995; 108:1143–1151.[CrossRef][Medline]
  11. Saxon RR, Timmermans HA, Uchida BT, et al. Stent-grafts for revision of TIPS stenoses and occlusions: a clinical pilot study. J Vasc Interv Radiol 1997; 8:539–548.[Medline]
  12. Haskal ZJ. Improved patency of transjugular intrahepatic portosystemic shunts in humans: creation and revision with PTFE stent-grafts. Radiology 1999; 213:759–766.[Abstract/Free Full Text]
  13. Otal P, Rousseau H, Vinel JP, Ducoin H, Hassissene S, Joffre F. High occlusion rate in experimental transjugular intrahepatic portosystemic shunt created with a Dacron-covered nitinol stent. J Vasc Interv Radiol 1999; 10:183–188.[Medline]
  14. Haskal ZJ, Brennecke LH. Transjugular intrahepatic portosystemic shunts formed with polyethylene terephthalate–covered stents: experimental evaluation in pigs. Radiology 1999; 213:853–859.[Abstract/Free Full Text]
  15. Kamath PS, Wiesner RH, Malinchoc M, et al. A model to predict survival in patients with end-stage liver disease. Hepatology 2001; 33:464–470.[CrossRef][Medline]
  16. LaBerge JM, Ring EJ, Gordon RL, et al. Creation of transjugular intrahepatic portosystemic shunts with the wallstent endoprosthesis: results in 100 patients. Radiology 1993; 187:413–420.[Abstract/Free Full Text]
  17. Haskal ZJ, Rees CR, Ring EJ, Saxon R, Sacks D. Reporting standards for transjugular intrahepatic portosystemic shunts. J Vasc Interv Radiol 2003; 14(9 Pt 2):S419–S426.[Medline]
  18. Kanterman RY, Darcy MD, Middleton WD, Sterling KM, Teefey SA, Pilgram TK. Doppler sonography findings associated with transjugular intrahepatic portosystemic shunt malfunction. AJR Am J Roentgenol 1997; 168:467–472.[Abstract/Free Full Text]
  19. Haskal ZJ, Martin L, Cardella JF, et al. Quality improvement guidelines for transjugular intrahepatic portosystemic shunts. J Vasc Interv Radiol 2003; 14(9 Pt 2):S265–S270.[Medline]
  20. LaBerge JM, Ferrell LD, Ring EJ, Gordon RL. Histopathologic study of stenotic and occluded transjugular intrahepatic portosystemic shunts. J Vasc Interv Radiol 1993; 4:779–786.[Medline]
  21. Sanyal AJ, Contos MJ, Yager D, Zhu YN, Willey A, Graham MF. Development of pseudointima and stenosis after transjugular intrahepatic portasystemic shunts: characterization of cell phenotype and function. Hepatology 1998; 28:22–32.[CrossRef][Medline]
  22. Sanyal AJ, Mirshahi F. Endothelial cells lining transjugular intrahepatic portasystemic shunts originate in hepatic sinusoids: implications for pseudointimal hyperplasia. Hepatology 1999; 29:710–718.[CrossRef][Medline]
  23. Tanihata H, Saxon RR, Kubota Y, et al. Transjugular intrahepatic portosystemic shunt with silicone-covered Wallstents: results in a swine model. Radiology 1997; 205:181–184.[Abstract/Free Full Text]
  24. Haskal ZJ, Brennecke LJ. Porous and nonporous polycarbonate urethane stent-grafts for TIPS formation: biologic responses. J Vasc Interv Radiol 1999; 10:1255–1263.[Medline]
  25. Nishimine K, Saxon RR, Kichikawa K, et al. Improved transjugular intrahepatic portosystemic shunt patency with PTFE-covered stent-grafts: experimental results in swine. Radiology 1995; 196:341–347.[Abstract/Free Full Text]
  26. Andrews RT, Saxon RR, Bloch RD, et al. Stent-grafts for de novo TIPS: technique and early results. J Vasc Interv Radiol 1999; 10:1371–1378.[Medline]
  27. Cejna M, Peck-Radosavljevic M, Thurnher SA, Hittmair K, Schoder M, Lammer J. Creation of transjugular intrahepatic portosystemic shunts with stent-grafts: initial experiences with a polytetrafluoroethylene-covered nitinol endoprosthesis. Radiology 2001; 221:437–446.[Abstract/Free Full Text]
  28. Cejna M, Peck-Radosavljevic M, Thurnher S, et al. ePTFE-covered stent-grafts for revision of obstructed transjugular intrahepatic portosystemic shunt. Cardiovasc Intervent Radiol 2002; 25:365–372.[CrossRef][Medline]
  29. Angermayr B, Cejna M, Koenig F, et al. Survival in patients undergoing transjugular intrahepatic portosystemic shunt: ePTFE-covered stent-grafts versus bare stents. Hepatology 2003; 38:1043–1050.[CrossRef][Medline]
  30. Hausegger KA, Karnel F, Georgieva B, et al. Transjugular intrahepatic portosystemic shunt creation with the Viatorr expanded polytetrafluoroethylene-covered stent-graft. J Vasc Interv Radiol 2004; 15:239–248.[Medline]
  31. Rossi P, Salvatori FM, Fanelli F, et al. Polytetrafluoroethylene-covered nitinol stent-graft for transjugular intrahepatic portosystemic shunt creation: 3-year experience. Radiology 2004; 231:820–830.[Abstract/Free Full Text]
  32. Wittkugel O, Koops A, Habermann CR, Weiss F, Adam G, Krupski G. Bile resistance of coated transjugular intrahepatic portosystemic shunt stents in a flow-model. Invest Radiol 2004; 39:717–722.[CrossRef][Medline]
  33. Clark TW, Agarwal R, Haskal ZJ, Stavropoulos SW. The effect of initial shunt outflow position on patency of transjugular intrahepatic portosystemic shunts. J Vasc Interv Radiol 2004; 15:147–152.[Medline]
  34. Haskal ZJ, Weintraub JL, Susman J. Recurrent TIPS thrombosis after polyethylene stent-graft use and salvage with polytetrafluoroethylene stent-grafts. J Vasc Interv Radiol 2002; 13:1255–1259.[Medline]




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