Improved patency of transjugular intrahepatic portosystemic shunts in humans: creation and revision with PTFE stent-grafts

PURPOSE: To determine whether polytetrafluoroethylene (PTFE) stent-grafts yield longer patency for creation or revision of transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS: Fourteen PTFE-covered Wallstents were placed in 13 patients with TIPS: seven at shunt creation and seven during revision of TIPS with one to five prior thromboses at 1 day to 1 year after initial TIPS formation. In six cases, prior to stent-graft placement persistent biliary-TIPS fistulas were demonstrated despite repeated shunt revisions with additional metallic stents. RESULTS: All but one graft-lined TIPS were widely patent at a mean duration of venographic follow-up of 19 months (median, 17 months; range, 5-32 months). The limiting percentage of stenosis within the grafted shunts was 0%-10%. One patient developed stent-graft thrombosis; the prior biliary-TIPS fistula was seen despite the graft. A second, parallel PTFE-lined transcaval shunt was created in this patient; it was widely patent at 11-month follow-up. In two asymptomatic patients, stenoses developed in the short, nongrafted portions of the outflow hepatic veins. CONCLUSION: PTFE stent-grafts can markedly prolong TIPS patency, potentially reducing the need for shunt follow-up and revision and the risk of recurrent symptoms associated with shunt stenosis or occlusion.     

Dacron-covered stent-grafts in transjugular intrahepatic portosystemic shunts: initial experience

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.     

Results of a retrospective multicenter trial of the Viatorr expanded polytetrafluoroethylene-covered stent-graft for transjugular intrahepatic portosystemic shunt creation

PURPOSE: To report the results of a multicenter experience with the Viatorr expanded polytetrafluoroethylene-covered stent-graft for transjugular intrahepatic portosystemic shunt (TIPS) creation in which patency and clinical outcome were evaluated. MATERIALS AND METHODS: One hundred consecutive patients with portal hypertension, with a mean age of 52 years (range, 22-86 years), underwent implantation of the Viatorr TIPS stent-graft at one of three hospital centers. The indications for TIPS creation were variceal bleeding (n = 81) and refractory ascites (n = 19). Twenty patients had Child-Pugh class A disease, 46 had class B disease, and 34 had class C disease. Eighty-seven patients underwent de novo TIPS placements, with 13 treated for recurrent TIPS stenosis. Sixty-two patients were available for follow-up portal venography and portosystemic pressure gradient (PSG) measurement commencing 6 months after Viatorr stent-graft placement. RESULTS: The technical success rate was 100%. TIPS creation resulted in an immediate decrease in mean PSG (+/-SD) from 21 mm Hg +/- 6 to 7 mm Hg +/- 3. Acute repeat intervention (within 30 days) was required for portal vein thrombosis (n = 1), continued bleeding (n = 3), and encephalopathy (n = 1). The all-cause 30-day mortality rate was 12%. Two patients developed acute severe refractory encephalopathy, which led to death in one case. New or worsening encephalopathy was identified in 14% of patients. The incidence of recurrent bleeding was 8%. The cumulative survival rate at 1 year was 65%. Sixty-two patients available for venographic follow-up had a mean PSG of 9 mm Hg +/- 5 at a mean interval of 343 days (range, 56-967 days). There were four stent-graft occlusions (6%) and seven hemodynamically significant stenoses (11%), four within the stent-graft and three in the non-stent-implanted hepatic vein. The primary patency rate at 1 year by Kaplan-Meier analysis was 84%. CONCLUSIONS: This retrospective multicenter experience with the Viatorr stent-graft confirms the preliminary findings of other investigators of good technical results and improved patency compared with bare stents. Early mortality and symptomatic recurrence rates are low by historical standards. The theoretical increase in TIPS-related encephalopathy was not demonstrated. Longer-term follow-up will be required to determine whether the additional cost of the Viatorr stent-graft will be offset by reduced surveillance and repeat intervention.     

Recurrent TIPS thrombosis after polyethylene stent-graft use and salvage with polytetrafluoroethylene stent-grafts

Increasing data support the use of polytetrafluoroethylene (PTFE) stent-grafts for de novo and revision transjugular intrahepatic portosystemic shunt (TIPS) applications. Animal experiments have indicated that polyethylene terephthalate (PET) stent-grafts provide no improvement or actually worsen TIPS patency compared with controls, but human TIPS experience with PET grafts is more limited. Herein we describe three patients who underwent de novo creation of TIPS with PET-covered stent-grafts at outside institutions, which resulted in immediate and recurring TIPS thromboses despite repeated thrombectomies. After the failed TIPS were revised with PTFE stent-grafts, the presenting symptoms resolved and uninterrupted patency was achieved.     

Use of the Viatorr expanded polytetrafluoroethylene-covered stent-graft for transjugular intrahepatic portosystemic shunt creation in children: initial clinical experience

Four children, three boys and one girl, with a median age of 9 years 8 months, underwent transjugular intrahepatic portosystemic shunt creation with an expanded polytetrafluoroethylene (e-PTFE)-covered nitinol stent. The stent-graft was successfully placed in all four patients without any complication. Clinical and biochemical improvement was noted in all four patients during follow-up. Radiological follow-up with use of duplex ultrasound showed a recurrent stenosis of the shunt 180 days after stent-graft implantation in one patient. This was treated with placement of an additional stent-graft, re-expanding completely the recurrent stenosis. In the other three patients, the stent-graft remained fully patent until the end of the study or until orthotopic liver transplantation. These preliminary results suggest that use of the Viatorr ePTFE-covered stent-graft in children is safe and feasible, with potentially the same high patency rate and improved clinical outcome as reported in adult patients.     

Transjugular intrahepatic portosystemic shunt creation with the Viatorr expanded polytetrafluoroethylene-covered stent-graft

PURPOSE: To evaluate the midterm clinical results and patency of transjugular portosystemic shunts (TIPS) created with a commercially available expanded polytetrafluoroethylene (ePTFE)-covered stent-graft based on angiographic and ultrasonographic (US) criteria in a series of 71 patients. MATERIALS AND METHODS: Seventy-one patients (61 men, 10 women; mean age, 58.6 years, range, 25-78 years) were included in this series, which was performed in two centers. Indications for TIPS creation were refractory ascites (n = 44) and recurrent esophageal bleeding (n = 27). Ten patients had Child-Pugh class A liver cirrhosis, 43 had class B disease, and 18 had class C disease. Underlying liver diseases were alcoholic cirrhosis (n = 58), cirrhosis resulting from hepatitis (n = 9), cryptogenic cirrhosis (n = 3), and Budd-Chiari syndrome (n = 1). TIPS were created with commercially available ePTFE-covered stent-grafts in all patients. The diameters of the stent-grafts were 10 mm in 58 patients and 8 mm in the remaining 13 patients. Follow-up included clinical examination and color-coded US after 5 days, 1, 3, and 6 months, and every 6 months thereafter. Shunt angiograms were obtained every 6 months. Median follow-up was 16.3 months (range, 3.8-26.6 months). RESULTS: TIPS creation was successful in all patients without complications, and effective portal decompression was observed with a reduction of the mean portal gradient from 19 mm Hg to 6 mm Hg before and after TIPS creation. Four shunt occlusions were observed after 5 days, 2 months, 3 months, and 6 months. Shunt stenosis was observed in three patients at the hepatic vein, which was not fully covered by the stent-graft, after 6 months (n = 2) and 12 months, and at the portal side after 1 month in a patient who initially had portal vein thrombosis. The repeat intervention rate was 11.3%. The primary patency rates were 87.4% (95% CI, 77.7%-97.1%) after 6 months and 80.8% (95% CI, 68.2%-93.4%) after 12 months. The rate of de novo or deteriorated hepatic encephalopathy was 31%. The recurrent bleeding rate was 3.7% (one of 27), and ascites improved or resolved in 64% of patients after 1 month. CONCLUSION: TIPS patency can be significantly increased if the ePTFE-covered stent-graft is used for shunt creation. The increased shunt patency contributes to low repeat intervention and recurrent bleeding rates. The rate of hepatic encephalopathy is within the range of previously reported rates.     

Intravascular ultrasound-guided direct intrahepatic portacaval shunt: midterm follow-up

PURPOSE: To describe the midterm patency and clinical results of the intravascular ultrasound (US)-guided direct intrahepatic portacaval shunt (DIPS) procedure for the treatment of intractable ascites and variceal bleeding. MATERIALS AND METHODS: From February 23, 1999, to December 18, 2002, inferior vena cava (IVC)-to-portal vein (PV) shunts were created in 40 patients for ascites (n = 35) and bleeding (n = 5). Intravascular US was used to guide direct puncture from the IVC to the PV. The shunts were completed with the use of single (n = 15) or overlapping (n = 25) polytetrafluoroethylene (PTFE)-covered Palmaz stents. These stent-grafts were deployed primarily at diameters of 8 mm. The diameter of the shunt was increased in three cases to achieve a target portosystemic gradient (PSG) of 15 mm Hg or lower. All patients were followed clinically and with portography with manometry. RESULTS: All DIPSs were created successfully. Mean PSGs were reduced from 23 mm Hg before DIPS creation to 9 mm afterward. During the follow-up period of a maximum of 38 months, 22 of 40 patients died or underwent liver transplantation (mean follow-up, 9 months; median, 6 months). At the time of this report, 18 of 40 patients remain living after follow-up ranging in duration from 8 to 38 months (mean, 22 months; median, 16.5 months). During the follow-up period, there was one stent-graft occlusion and three stenoses. These four patients were successfully treated by additional stent-graft placement. In addition, two patients developed IVC stenosis cephalad to the DIPS, which required IVC stent placement. The primary patency rates by Kaplan-Meier analysis were 100% at 6 months and 75% (95% CI, 53%-97%) at 12 months. CONCLUSION: Intravascular US-guided direct IVC-to-PV shunts may be created successfully with minimal complications. Primary patency of the shunt is greater than that with conventional TIPS with a bare wire stent and appears equal to that with TIPS with a PTFE-covered stent-graft.     

Polytetrafluoroethylene-covered nitinol stent-graft for transjugular intrahepatic portosystemic shunt creation: 3-year experience

PURPOSE: To prospectively evaluate the use of a recently developed expanded polytetrafluoroethylene (PTFE)-covered nitinol stent-graft in preventing the need for repeated intervention after transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS: Fifty-three consecutive patients underwent TIPS procedures between January 2000 and February 2002. Minimum patient follow-up was 9 months (mean, 16.3 months). Fifty-six stent-grafts were implanted in 53 patients; eight of the devices were 8 mm in diameter and 48 were 10 mm in diameter. The stent length varied from 4 to 7 cm. Indications for the procedure included recurrence of bleeding after sclerotherapy (28 patients with cirrhosis, one patient without), refractory ascites or hydrothorax (21 patients with cirrhosis, one patient without), and Budd-Chiari syndrome (two patients). RESULTS: A technical success rate of 100% was obtained, with an early clinical success rate of 96.2%. During the follow-up period, the recurrence rate was 3.4% (one of 29 patients) for bleeding and 9.0% (two of 22 patients) for ascites. Shunt malfunction occurred in nine of 53 patients (16.9%); in one of these nine patients, shunt occlusion was evident after revision, and a parallel shunt was created. The 1-year primary and secondary patency rates were 83.8% and 98.1%, respectively. In this series, the incidence of encephalopathy (included even as a single short-lived episode) was 47.1% (25 of 53 patients). The 30-day mortality rate was 3.8% (two of 53), and the late mortality rate was 17.3% (eight of 46), excluding seven patients who underwent transplantation. CONCLUSION: The new PTFE-covered nitinol stent-graft used appears to be excellent in preventing the need for repeated interventions. A primary patency rate of 83.8% and a secondary patency rate of 98.1% were achieved.     

ePTFE-Covered Stent-Grafts for Revision of Obstructed Transjugular Intrahepatic Portosystemic Shunt

Purpose: To determine whether transjugular intrahepatic portosystemic shunt (TIPS) revisions with the Hemobahn stent-graft or the Viatorr endoprosthesis increase secondary patency rates. Methods: Between 1998 and June 1999, Hemobahn endoprostheses (W.L. Gore, Flagstaff, AZ, USA) were used for the revision of obstructed TIPS in seven patients, 51–67 years of age (mean 59 years). From June 1999 to 2000, the Viatorr endoprosthesis (W.L. Gore, Flagstaff, AZ, USA) was used for revision of obstructed TIPS in nine patients, 33–64 years of age (mean 49 years). Follow-up included duplex ultrasound, clinical assessment and venous portography. Results: The technical success rate of TIPS revision with the Hemobahn stent-graft was 100%. The pressure gradient decreased from a mean of 20 mmHg to 10 mmHg. The mean follow-up was 407 days (range 81–868 days). In two patients TIPS occlusion occurred at 62 and 529 days after stent-graft placement, respectively; in another two patients outflow tract stenosis occurred at 275 and 393 days, respectively. The technical success rate of TIPS revision with the Viatorr endoprosthesis was also 100%. The pressure gradient decreased from a mean of 27 mmHg to 11 mmHg. At a mean follow-up of 201 days (range 9–426 days), all Viatorr endoprostheses are still patent without in-graft stenosis, but angioplasty was required in two patients to treat a portosystemic pressure gradient > 15 mmHg. Four of the nine patients in the Viatorr group suffered from new encephalopathy after TIPS revision. Conclusion: The Viatorr endoprosthesis yielded optimal results with 100% in-graft patency rates at follow-up but had a high incidence of new encephalopathy, whereas the use of Hemobahn stent-graft for TIPS revision did not appear to improve the secondary patency rates in our series.     

Creation of transjugular intrahepatic portosystemic shunts with stent-grafts: initial experiences with a polytetrafluoroethylene-covered nitinol endoprosthesis.

PURPOSE: To evaluate the safety and performance of a recently developed expanded polytetrafluoroethylene (ePTFE)-covered nitinol stent-graft to create transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension and related complications. MATERIALS AND METHODS: The ePTFE-covered nitinol stent-graft was used to create TIPS in 16 patients with recurrent variceal bleeding (n = 13) or refractory ascites (n = 3). Follow-up was performed with duplex ultrasonography, clinical assessment, and venography at 6 months. Technical success and portosystemic pressure gradients (PPGs) before and after stent-graft implantation and at follow-up were assessed. Two patients died during follow-up. Histopathologic follow-up data were available for one patient at autopsy and for the other after liver transplantation. RESULTS: The implantation technical success rate was 100%. Mean (+/- SD) PPG was reduced from 24 mm Hg +/- 5 to 9 mm Hg +/- 2. Histopathologic analysis of the explanted endoprostheses revealed no inflammatory response or neointima formation. The venographic follow-up data available for 10 patients demonstrated 100% in-graft patency (mean follow-up, 289 days +/- 26). Revisions with implantation of a new ePTFE-covered nitinol stent-graft or another commercially available stent in 10 patients were necessary because of hepatic vein stenosis above the grafted portion and/or relative diameter mismatch causing TIPS dysfunction. CONCLUSION: The ePTFE-covered nitinol stent-graft was used successfully to create TIPS and has the potential to prolong TIPS patency upon complete coverage to the hepatocaval junction.     

TIPS中8mm直径覆膜支架直用的临床研究

目的评价在TIPS中应用8mm直径覆膜支架的临床效果。方法对19例伴有食管胃底静脉曲张破裂出血和(或)难治性腹水的门脉高压症患者行TIPS术,术中应用8mm直径的覆膜支架,术后观察临床症状改善程度,并进行定期影像学和实验室检查,以评价疗效。结果所有患者均成功完成TIPS术,技术成功率100%,术中未出现并发症。术后平均随访13.5个月(2.7～28个月),1例(1/19,5.3%)原有肝性脑病加重;2例(10.5%)再次出血;腹水改善及治愈率为66.7%(12/18);16例患者进行了6个月的随访,初次开通率100%,8例患者随访12个月,初次开通率87.5%。结论在TIPS术中应用8mm直径覆膜支架在保证有效分流量,提高术后分流道开通率的同时,可以降低肝性脑病的发生率。     

Viatorr支架行TIPS术治疗门静脉高压性静脉曲张消化道出血效果评估

目的评价应用Viatorr支架行经颈静脉肝内门体分流术(TIPS)术治疗门静脉高压性静脉曲张消化道出血的可行性、安全性和临床效果。方法回顾性分析2015年10月至2018年11月收治的42例肝硬化门静脉高压性静脉曲张消化道出血患者临床资料,所有患者符合TIPS治疗指征,均接受Viatorr支架行TIPS术治疗。术中检测门静脉压力梯度(PPG)。术后1、3、6、12个月,之后每年随访超声或增强CT检查,评价分流道通畅情况,并通过电子病历、临床或电话随访患者肝功能、凝血4项、再出血、肝性脑病发生和生存时间。配对t检验分析术前、术后PPG、总胆红素、血清白蛋白和凝血酶原时间变化,Kaplan-Meier法分析分流道通畅率和生存率。结果 42例均成功施行TIPS术,技术成功率为100%。共植入直径8 mm Viatorr支架42枚。PPG均值由术前(26.85±6.00) mmHg(1 mmHg=0.133 kPa)降低为(11.62±4.54) mmHg(t=11.359,P<0.05),平均降低(55.63±16.77)%。与术前相比,术后3 d总胆红素浓度升高(P<0.05),血清白蛋白降低(P<0.05),凝血酶原时间延长(P<0.05)。术后1个月总胆红素、血清白蛋白和凝血酶原时间与术前水平差异均无统计学意义(P>0.05)。术后中位随访14.5(2~39)个月,再出血发生率为9.5%(4/42),其中1例接受分流道再通;肝性脑病发生率为19.1%(8/42)。术后1、2、3年分流道通畅率分别为91.9%、83.9%、77.4%,生存率分别为94.7%、89.4%、82.0%。肝硬化相关死亡率为9.5%(4/42),均于术后2~30个月死于终末期肝病伴多脏器功能衰竭。结论 Viatorr支架行TIPS术治疗肝硬化门静脉高压性静脉曲张消化道出血具有较高的技术成功率,术后分流道通畅率高,肝性脑病发生率低。     

Dr. Gary J. Becker young investigator award: comparison of small-diameter type 1 collagen stent-grafts and PTFE stent-grafts in a canine model--work in progress

PURPOSE: To report an in-progress experiment in a canine model in which two types of small-diameter stent-grafts-one constructed of polytetrafluoroethylene (PTFE) and the other of a new, type 1 collagen material-were compared regarding vessel patency, intimal hyperplasia formation, and tissue reaction. MATERIALS AND METHODS: Six mongrel dogs weighing 30-35 kg were used. Stent-grafts of 4-mm diameter and 20-mm length were constructed with use of balloon-expandable stainless-steel stents wrapped with either PTFE or a new type 1 collagen graft. Stent-grafts were placed in deep femoral arteries bilaterally (PTFE on one side, collagen on the other). Animals were followed for 2 weeks (n = 2), 6 weeks (n = 2), or 12 weeks (n = 2). Percent stenosis based on angiographic findings as well as thickness and area of neointimal hyperplasia were compared at each time point and compared with use of the Student t test. RESULTS: All devices were patent in the immediate postimplantation period. Five of six collagen stent-grafts and five of six PTFE implants were patent at follow-up. In-stent stenosis was undetectable angiographically in all five patent collagen stent-grafts. All five patent PTFE stent-grafts showed demonstrable in-stent stenosis (10%-60%), indicating a trend toward improved patency in collagen stent-grafts versus PTFE stent-grafts (P = .07). Neointimal hyperplasia was absent at 2 weeks in the collagen stent-grafts. Neointimal thickness increased to a maximum of 360 microm at 12 weeks in the collagen stent-grafts. For PTFE stent-grafts, neointimal hyperplasia was present in all samples and reached a maximum of 770 microm at 12 weeks (P = .03). CONCLUSIONS: Even in small-diameter vessels, type 1 collagen stent-grafts demonstrate excellent patency rates and favorable histologic findings. The type 1 collagen stent-graft technology merits further developmental efforts in preclinical models.     

Polyurethane-coated dacron-covered stent-grafts for TIPS: results in swine

Purpose: To evaluate shunt patency after placing a new polyurethane-coated Dacron-covered spiral Z stent-graft to create a transjugular intrahepatic portosystemic shunt (TIPS). Methods: TIPS stent-grafts were placed in six young swine, using polyurethane-coated, Dacron-covered spiral Z stent-grafts. Animals were followed weekly by transhepatic portal venography until shunt occlusion or up to 6 weeks, then were sacrificed for gross and histologic evaluation. Results: Five of six TIPS stent-grafts were found to be occluded by 3 weeks and none were patent at 6 weeks. Histologic evaluation demonstrated a marked foreign body reaction with superimposed thrombosis occluding the graft lumen. Conclusion: Polyurethane-coated Dacron-covered stent-grafts do not improve TIPS patency.     

Early and long-term clinical and radiological follow-up results of expanded-polytetrafluoroethylene-covered stent-grafts for transjugular intrahepatic portosystemic shunt procedures

The purpose of this study was to assess the therapeutic efficacy and immediate and long-term safety of expanded-tetrafluoroethylene covered stent-grafts for transjugular intrahepatic portosystemic shunts in patients with portal hypertension-related complications. A cohort of 56 patients suffering from severe portal hypertension-related complications underwent implantation of an expanded-polytetrafluoroethylene-covered stent-graft. All patients suffered from severe liver cirrhosis graded Child-Pugh A (n=8; 16%), B (n=13; 21%) or C (n=35; 63%). In 44 patients, the stent-graft was placed during the initial TIPS procedure (de novo TIPS); in the other 12 patients, the stent-graft was placed to repermeabilize the previously placed bare stent (TIPS revision). Follow-up was performed with clinical assessment, duplex ultrasound and, if abnormal or inconclusive, with invasive venography and pressure measurements. Per- en immediate post-procedural complications occurred in four patients (4/56, 7%). None of them was lethal. During follow-up, stent occlusion appeared in one patient and stenosis in two; no recurrence of bleeding was noted in all patients treated for variceal bleeding (n=28), and 24 of the 28 patients (86%) suffering from refractory ascites and/or hepatic hydrothorax were free of regular paracenteses and/or drainage of pleural effusion after shunt creation. The 30-day and global mortality for the total study population (n=56) was, respectively, 7% (n=4) and 28.5% (n=16). In the patient subgroup with variceal bleeding (n=28), 30-day mortality was 3.5% (n=1) and global mortality 14.2% (n=4). In the ascites and/or hydrothorax subgroup (n=28), 8.1% (n=3) mortality at 30 days was found and global mortality was 32.4% (n=12). In 10 patients of the 56 studied patients (18%), isolated hepatic encephalopathy occurred, which was lethal in 4 (Child C) patients (7%). Three of these four patients died within the 1st month after TIPS placement. A very high primary patency rate of TIPS can be obtained long-term after implantation of an e-PTFE-covered stent-graft, leading to a definitive resolution of portal hypertension-related complications. The incidence of TIPS-induced hepatic encephalopathy is acceptable.     

Transjugular intrahepatic portosystemic shunts formed with polyethylene terephthalate-covered stents: experimental evaluation in pigs

PURPOSE: To evaluate the safety, efficacy, and tissue response associated with Wallstents covered with polyethylene terephthalate (PETP) compared with those associated with uncovered Wallstents for creation of transjugular intrahepatic portosystemic shunts (TIPS) in a porcine model. MATERIALS AND METHODS: Thirteen TIPS were created in 13 minipigs: eight with PETP-covered Wallstents, five with standard Wallstents. Shunt venography was performed at 5-8 weeks, and necropsy was performed at 7-8 weeks. Histopathologic, immunohistochemical, and scanning electron microscopic examinations were performed. RESULTS: Mean shunt stenoses of the control and graft groups were 45% and 53%, respectively. Graft stenoses involved the entire graft-bearing segment, whereas bare stent stenoses were localized within the liver tract. Myofibroblast and extracellular collagen matrix proliferation encompassed both control and graft-covered stents. There was one graft TIPS occlusion. One control TIPS stenosis was due to transstent proliferation of normal porcine hepatic tissue. A small focus of bile staining was seen on the abluminal surface of one TIPS, which was a patent PETP-lined shunt. CONCLUSION: PETP graft TIPS provided equal, but not superior, patency to that of bare stent TIPS. The pattern of PETP TIPS graft healing differed from that of bare stents but was similar to that reported with other polyester graft vascular implants and consisted of diffuse transmural penetration and paving of the graft surface by extracellular collagen matrix and myofibroblasts.     

Stent graft in TIPS: technical and procedural aspects

Transjugular intrahepatic portosystemic shunt (TIPS) is a nonoperative therapeutic option for the management of portal hypertension, variceal bleeding, recurrent ascites, Budd-Chiari syndrome. In view of the many issues surrounding the use of TIPS, in 1994 the US National Digestive Diseases Advisory Board convened a scientific conference to review the current data available and to establish the indications and controindications for this procedure. However there are still unsolved problems especially short primary patency of the shunt due to intimal hyperplasia, which causes a reduction of the shunt lumen thus favoring a return of the portal hypertension with recurrent variceal bleeding. Several study were performed in the last years to evaluate the efficacy of covered stent in order to reduce shunt disfunction secondary to intimal hyperplasia. PTFE seems to be more efficient in the prevention of restenoses. In our experience more then 100 patients were treated with the Viatorr stent-graft. After a follow-up ranging from 1 to 50 months we reported a 1- year primary patency rate of 83.8%. However the use of the stentgraft is correlate with a high rate of hepatic hencefalopathy (46.6 %). In case of hepatic hencefalopathy refractory to the conventional medical therapy, TIPS reduction should be performed.     

Use of balloon-expandable stents in transjugular intrahepatic portosystemic shunts in cases of Wallstent endoprosthesis technical failure and revision of shunt stenosis

Thirteen patients underwent placement of a balloon-expandable stent either at initial transjugular intrahepatic portosystemic shunt (TIPS) creation (n = 3) because of immediate technical failure of the Wallstent or at shunt revision because of failure of the Wallstent to reduce the portosystemic gradient 相似文献   

Intravascular US-guided direct intrahepatic portacaval shunt with a PTFE-covered stent-graft: feasibility study in swine and initial clinical results

PURPOSE: To determine the feasibility of the creation of a direct intrahepatic inferior vena cava (IVC)-to-portal-vein shunt with puncture guided by a transfemorally placed intravascular ultrasound (IVUS) probe and use of a polytetrafluoroethylene (PTFE)-covered stent-graft. MATERIALS AND METHODS: In five swine, transjugular access was used to perform a direct puncture from the IVC to the portal vein with use of a modified Rosch-Uchida Portal Access set directed with real-time IVUS (9 MHz) introduced from a transfemoral venous approach. The direct intrahepatic portocaval shunt (DIPS) was then created with single or overlapping PTFE-covered Palmaz stents placed through a 10-F sheath and dilated to a diameter of 8 mm. Follow-up was performed with transhepatic portography at 2, 4, and 8 weeks. Animals were killed when shunts occluded or at the termination of the study at 8 weeks. Gross and microscopic histologic study was performed on sacrificed animals. A similar technique was used to create DIPS in five patients with intractable ascites, with follow-up by US and venography. RESULTS: All experimental DIPS created in swine were created without complications. Portal vein punctures were achieved in four of five swine on the first or second pass of the needle. Follow-up transhepatic portography at 2 weeks demonstrated occlusion of two shunts, both explained by technical reasons at sacrifice. At 4 and 8 weeks, the remaining three shunts were patent on portography. Histology showed a thin neointimal lining with no significant tissue ingrowth or hyperplasia. Clinically, in five patients, successful puncture of the portal vein from the IVC was achieved in one to three passes. Creation of DIPS led to a reduction of mean portosystemic gradient from 18-29 mm Hg (mean, 24 mm Hg) to 9-10 mm Hg (mean, 9 mm Hg). One patient died of liver failure 2 days after creation of DIPS. The other four patients were doing well 2-15 months (mean, 8 months) after the procedure, with patency confirmed by US and venography. CONCLUSION: Creation of DIPS is technically feasible, and the direct IVC-to-portal-vein puncture can be done accurately with real-time IVUS guidance. Further studies and longer follow-up are necessary to determine if the short length of the PTFE-covered stent-graft and avoidance of the hepatic vein will increase the long-term patency compared to standard transjugular intrahepatic portosystemic shunt creation.     

Efficacy of Doppler ultrasonography for assessment of transjugular intrahepatic portosystemic shunt patency

Purpose To assess the efficacy of Doppler ultrasonography (US) as a noninvasive method for monitoring patency of the transjugular intrahepatic portosystemic shunt (TIPS). Methods Twenty-nine patients who had received TIPS for bleeding esophagogastric varices and/or refractory ascites with portal hypertension underwent Doppler US studies within 2 weeks after TIPS. Further studies were performed in 15 of them at 6 months, in 9 at 1 year, and in 4 at 2 years for a total of 57 US studies. The US findings were compared with the angiographic findings obtained at the same time. Results In 45 of the 57 studies, shunt patency was found by Doppler US, correlating to 44 patencies and one occlusion on angiography. Doppler signal in the shunt could not be detected in 12 studies resulting in the diagnosis of shunt occlusion. This correlated with angiographic occlusion in 8 studies and patency in the remaining 4. All angiographically patent shunts that were occluded by Doppler US had various degrees of stenosis. A number of technical factors were found to be responsible for Doppler US false-positive or false-negative diagnoses, some related to the type of stent used. The Doppler US sensitivity was therefore 92%, the specificity 89%. Conclusion Doppler US is a reliable noninvasive method to evaluate patency of TIPS.