ePTFE-covered Stent Research Articles

Expanded polytetrafluoroethylene (ePTFE)-covered stents versus bare stents for transjugular intrahepatic portosystemic shunt in people with liver cirrhosis.

Expanded polytetrafluoroethylene (ePTFE)-covered stents versus bare stents for transjugular intrahepatic portosystemic shunt in people with liver cirrhosis.

Comparison of the curative effect of transjugular intrahepatic portosystemic shunt with expanded polytetrafluoroethylene-covered stent and drug combined with gastroscopy as the secondary prevention of esophageal -gastric variceal bleeding in portal hypertension

Objective: To compare the clinical efficacy of transjugular intrahepatic portosystemic shunt (TIPS) with expanded polytetrafluoroethylene (ePTFE)-covered stent and drug combined with gastroscopy as the secondary prevention of esophageal-gastric variceal bleeding in portal hypertension. Methods: Patients with esophageal-gastric variceal bleeding who received TIPS treatment (ePTFE covered stent) or gastroscopy for the first time as the secondary prevention for portal hypertension at Nanfang Hospital of Southern Medical University through March to July 2017 were selected. One year after the operation, liver function changes, ascites remission rates, incidence of hepatic encephalopathy, re-bleeding rate, average hospitalization frequency and expenses, survival time, as well as the TIPS patency conditions were analyzed in the two groups of patients. 2 test, Kaplan-Meier method and Mann-Whitney U test were used to analyze the data. Results: There were 74 and 66 cases in the TIPS and the drug combined gastroscopy group and the follow-up duration (14.57 ± 0.79) was 12-16 months. One year after surgery, the remission rate of ascites in the TIPS group was higher 57.1% (32/56) than that of the drug combined gastroscopy group (0), and the difference was statistically significant (χ(2) = 2 = 36.73, P < 0.01). The cumulative incidence of hepatic encephalopathy at 1, 3, 6, and 12 months after surgery in the TIPS group was 32.4% (24/74), 37.8% (28/74), 40.5% (30/74), and 40.5% (30/74), respectively. The cumulative incidence of hepatic encephalopathy in the drug combined gastroscopy group was 3.0% (2/66), 3.0% (2/66), 3.0% (2/66), and 6.1% (4/66), respectively. Kaplan-Meier analysis showed that the cumulative incidence of hepatic encephalopathy in the TIPS group was higher than that of the drug combined gastroscopy group (χ(2) = 11.29, P < 0.01). The incidence of severe hepatic encephalopathy ( grade III to IV) at 1, 3, 6, and 12 months after surgery in the TIPS group was 2.7% (2/74), 0, 0, and 0, respectively. The incidence of severe hepatic encephalopathy in drug combined gastroscopy group was 0, and there was no statistically significant difference in development of hepatic encephalopathy between the two groups (P > 0.05). The re-bleeding rates of TIPS group and drug combined gastroscopy group were 0 and 27.3% (18/66), respectively, and the difference was statistically significant (χ(2) = 22.42, P < 0.01). There was no death reported during the follow-up period between both groups. The hospitalization frequency times (1.45 ± 0.80) in TIPS group was lower than that of the drug combined gastroscopy group times (3.24 ± 1.80), and the difference was statistically significant (U = -4.52, P < 0.01). Conclusion: In the prevention of esophageal-gastric variceal bleeding, TIPS (ePTFE-covered stent) treatment has the advantages of reducing re-bleeding rate, high ascites remission rate and hospitalizations frequency. In addition, patients treated with TIPS have a higher incidence of hepatic encephalopathy than that of drugs combined with gastroscopy. However, TIPS did not exacerbate the incidence of hepatic encephalopathy, and there was no significant difference in the 1-year survival rate after TIPS and drugs combined with gastroscopy treatment.

Prognostic Factors for Acute Transjugular Intrahepatic Portosystemic Shunt Occlusion Using Expanded Polytetrafluoroethylene-Covered Stent.

The expanded polytetrafluoroethylene (ePTFE)-covered stent has been widely used in the transjugular intrahepatic portosystemic shunt (TIPS) procedure. However, the epidemiologic data of acute TIPS occlusion (ATO) and the underlying mechanisms are scarce. The purpose of this study was to evaluate the incidence and prognostic factors for ATO within 1week in TIPS recipients using ePTFE-covered stents. We identified 222 patients who underwent ePTFE-covered TIPS creation for complications of portal hypertension between June 2015 and June 2017 at a large tertiary center. Medical records and TIPS procedure data were retrospectively reviewed, and the influence of these variables on ATO was assessed by multivariate logistic regression analysis. TIPS technical success was achieved in 219 patients (98.6%). Two patients were excluded due to missing data, leaving 217 patients for final analysis. ATO occurred in nine patients (4.1%). Blood flow was restored by balloon angioplasty (n = 4), additional stent insertion (n = 4), and parallel TIPS (n = 1). In multivariable logistic regression, intrastent stenosis (HR 43.871; 95% CI 3.816, 504.373; P = 0.002), previous splenectomy (HR 26.843; 95% CI 2.106, 342.124; P = 0.011), and stent shortening in the hepatic vein (HR 11.54; 95% CI 1.021, 130.416; P = 0.048) were demonstrated as independent significant risk factors for ATO. These findings suggest that the intrastent stenosis, previous splenectomy, and stent shortening in the hepatic vein are vital prognostic factors for ATO in TIPS recipients. Individualized post-TIPS management strategy was required.

The Effect of Puncture Sites of Portal Vein in TIPS with ePTFE-Covered Stents on Postoperative Long-Term Clinical Efficacy

Purpose To evaluate the effect of puncture sites of the portal vein in transjugular intrahepatic portosystemic shunt (TIPS) on long-term clinical efficacy. Methods A retrospective review was performed, including consecutive 171 patients who underwent TIPS with ePTFE-covered stents. All patients were divided into 3 groups according to the puncture site of the portal vein: intrahepatic bifurcation of the portal vein (group A, n = 88), right branch of the portal vein (group B, n = 48), and left branch of the portal vein (group C, n = 35). The Kaplan-Meier analysis was performed to assess the effect of different puncture sites on primary patency, the incidence of hepatic encephalopathy (HE), and survival. Results The primary restenosis rate was 29.8% (51/171). The total HE rate was 31.6% (54/171). The cumulative death rate was 19.3% (33/171). The Kaplan-Meier analysis showed that group C versus group A, group C versus group B, and group A versus group B were significantly different on the primary restenosis rate, respectively (χ2 = 11.49, P = 0.001; χ2 = 4.54, P = 0.033; and χ2 = 4.12, P = 0.046), and group C is better than the other two groups. What is more, group C versus group A and group C versus group B were significantly different on the incidence of HE, respectively (χ2 = 8.07, P = 0.004; χ2 = 9.44, P = 0.002), and group C is better than the other two groups. There was no significant difference on survival. Conclusion Choosing the left branch of the portal vein as the puncture site to create the shunt in TIPS with ePTFE-covered stents may decrease the incident of primary restenosis and HE significantly.

Long-term outcome of transjugular intrahepatic portosystemic shunt for portal hypertension in autosomal recessive polycystic kidney disease

BackgroundAutosomal recessive polycystic kidney disease (ARPKD) with congenital hepatic fibrosis (CHF) causes portal hypertension and its complications. A transjugular intrahepatic portosystemic shunt (TIPSS) could serve as a symptomatic treatment for portal hypertension-related symptoms in these children. AimsTo study the effect of TIPSS on portal hypertension, liver and kidney function and the long term complications. Materials and methodsWe report on 5 children with CHF treated with a TIPSS to manage severe portal hypertension related symptoms. ResultsMean follow-up time was 7 years and 2 months. At the end of follow-up there was a reduction of spleen size (p = 0.715) and hypersplenism with a rise in platelet count (p = 0.465). Esophageal varices and ascites disappeared in all patients. Liver and kidney function remained stable. In two patients endotipsitis was suspected and two patients developed an in-stent stenosis. There was no sign of encephalopathy in our patients. ConclusionTIPSS using ePTFE-covered stent is a feasible and effective alternative for surgical portosystemic shunting in children with CHF, also on the long term. It can postpone the need of a liver transplantation but close monitoring remains important for early diagnosis of endotipsitis or stent dysfunction related to stenosis.

3:54 PMAbstract No. 387 - Persistence of varices on CT or MR imaging and risk of variceal hemorrhage after transjugular intrahepatic portosystemic shunt with embolotherapy

To determine whether the presence of visible varices on contrast-enhanced CT or MR imaging after TIPS with adjunctive procedures to occlude varices predicts future variceal bleeding. In this single-center, retrospective study, 121 patients underwent TIPS creation for variceal hemorrhage or ascites using ePTFE-covered stents with adjunctive variceal occlusion from Jan 2005 to Jun 2015. Patients without post-TIPS contrast-enhanced CT or MR imaging were excluded (n = 59). Patient demographics and post-TIPS outcomes were recorded, while visualization of varices ≥2mm on cross-sectional imaging was confirmed by two independent radiologists. ANOVA, Chi-squared, and Fisher’s exact tests were used to assess continuous and categorical data. 24 patients (38.7%) had persistent visible varices (VIS) on follow-up cross-sectional imaging, while 38 patients (61.3%) no longer had visible varices (NON-VIS). Except for age (57.5 yrs vs 50.9 yrs, p = 0.032), preoperative characteristics did not differ between VIS and NON-VIS groups, and mean time to follow-up imaging (VIS 183 days vs NON-VIS 215 days, p = 0.719) was similar. Variceal occlusion method (embolization vs embolization plus sclerotherapy) did not significantly affect the proportion of patients with visible varices (embolization 47.6% vs embolization plus sclerotherapy 36.6%, p = 0.654). In patients with persistent varices, 22 (91.7%) showed esophageal varices, of which 17 (77.3%) protruded intraluminally, while 15 (62.5%) had gastric varices, of which 6 (40%) protruded intraluminally. Mean size of esophageal vs gastric varices did not significantly differ (5.3 mm vs 6.1 mm, p = 0.381). The presence of visible varices did not increase the rate of rebleeding (VIS 0.0%, vs NON-VIS 7.9%, p = 0.16) or rate of repeat variceal occlusion interventions (VIS 0.0% vs NON-VIS 7.9%, p = 0.16). Despite procedures to occlude varices, 38.7% of patients had persistent variceal filling on cross-sectional imaging. The presence of visibly filling varices on cross-sectional imaging after TIPS with embolotherapy did not confer a higher risk for rebleeding. The study is limited by few rebleeding events.

Safety and Efficacy of Percutaneous Biliary Covered Stent Placement in Patients with Malignant Biliary Hilar Obstruction; Correlation with Liver Function.

To estimate the safety and efficacy of percutaneous ePTFE-covered biliary stent placement and the relationship between underlying liver function and stent patency in patients with malignant hilar obstruction. From March 2012 to June 2015, 41 patients [22 females, 19 males; mean age 69.8 (range 34-94) years] with malignant biliary obstruction underwent percutaneous biliary stent placement (31 patients with unilateral, 10 patients with bilateral side-by-side). Cumulative patient survival and stent patency rate curves were derived using the Kaplan-Meier method. A Cox model was used to explore the relationship between liver function and patient survival, and also biliary stent patency. Pearson correlation coefficient was used to analyze the relationship between patient survival and stent patency. Technical success rate was 100% and clinical success rate was 95%. During follow-up, four complications occurred (two bilomas and two cases of acute cholecystitis) and were treated successfully with percutaneous drainage. No other complication occurred. Mean serum bilirubin level was 11.34±7.35mg/dL before drainage and 5.00±4.83mg/dL 2 weeks after stent placement. The median patent survival duration was 147days (95% CI, 69.6-224.4days). The median stent patency duration was 101days (95% CI, 70.0-132.0days). The cumulative stent patency rates at 1, 3, 6, and 12months were 97, 57.6, 30.3, and 17.0%, respectively. Child-Pugh score was correlated significantly with patient survival (P=0.011) and stent patency (P=0.007). MELD score was correlated significantly with stent patency (P=0.044). There was a correlation between patient survival and stent patency (r=0.778, P<0.001). Percutaneous placement of ePTFE-covered biliary stent was a safe and an effective method for malignant biliary obstruction. Underlying liver function seemed to be one of the important factors affecting patient survival and stent patency, and stent patency showed statistically significant correlation with patient survival.

Long-Term Patency and Clinical Analysis of Expanded Polytetrafluoroethylene–Covered Transjugular Intrahepatic Portosystemic Shunt Stent Grafts

PurposeTo evaluate long-term patency and symptomatic recurrence rates following transjugular intrahepatic portosystemic shunt (TIPS) creation with expanded polytetrafluoroethylene (ePTFE)–covered stent grafts and to determine the necessity of extended clinical follow-up beyond 2 years after TIPS creation. Materials and MethodsA retrospective review including 262 TIPSs created with ePTFE-covered stent grafts between July 2002 and October 2012 was performed. Primary, primary assisted, and secondary patency rates were calculated. Assessment of clinical data included technical, hemodynamic, and clinical success rates, as well as mortality after TIPS creation. ResultsPrimary patency rates at 2, 4, and 6 years were 74%, 62%, and 50%, respectively. Primary assisted patency rates at 2, 4, and 6 years were 93%, 85%, and 78%, respectively. Secondary patency rates at 2, 4, and 6 years were 99%, 91%, and 84%, respectively. Technical and hemodynamic success rates were 99% and 93%, respectively. Clinical success rates for refractory ascites were 66% (complete response) and 90% (partial response); clinical success rate for bleeding/varices was 90%. Mortality rates at 2, 4, and 6 years after TIPS creation were 27%, 38%, and 46%, respectively. At the median wait time until transplantation, patients had an 84% chance of being alive. TIPS dysfunction developed in 21% of patients; 30% of revisions occurred later than 2 years during follow-up. ConclusionsBeyond 2 years after TIPS creation, patency rates gradually decrease, mortality rates continue to increase, and the chance of recurrent ascites or bleeding remains present. Together, these findings suggest that continued clinical follow-up beyond 2 years is necessary in patients with a TIPS created with an ePTFE-covered stent graft.

O23 DECREASED DEVELOPMENT OF DIABETES MELLITUS WITH IMPROVEMENT OF NONALCOHOLIC FATTY LIVER DISEASE: A 10-YEAR JAPANESE COHORT STUDY

in 10-mm group (43.3% vs. 5.4%; p < 0.01). After TIPS, the decrease in PPG was significantly higher in 10-mm group (10.4±4.2 vs. 8.7±3.5mmHg; p =0.004). The 3-months need of paracentesis was not statistically different (23% vs. 18%; p =0.36), however the longterm need of paracentesis was higher in 8-mm group (58% vs. 31%; p =0.003). Overall HE, severe HE (grade III-IV), new episodes or worsening of HE, acute HE, chronic HE, and cumulative probability of developing the first episode of HE were similar in both groups. Similarly, no significant differences were observed in new episodes of VB, SBP, TIPS dysfunction, Child–Pugh score, MELD, need of liver transplantation, overall survival and transplant-free survival. Conclusions: This study supports the use of 10-mm diameter ePTFE-covered stent in cirrhotic patients with refractory ascites.

Percutaneous Metallic Stent Placement in Patients with Cancer Recurrence at Bilioenterostomy Site

PurposeTo investigate the outcomes of percutaneous metallic stent placement in patients with malignant bilioenterostomy obstruction and to assess the risk factors influencing stent patency. Materials and MethodsFrom August 2008 to January 2012, 53 patients with malignant bilioenterostomy obstructions were treated with percutaneous placement of biliary metallic stents; this included expanded polytetrafluoroethylene (ePTFE)–covered stent placement in 36 patients and uncovered stent placement in 17 patients. ResultsA total of 75 stents were successfully placed in 53 patients. No major complications occurred in any patients, and minor complications occurred in nine patients (17%). The mean serum bilirubin level, which was 3.6 mg/dL ± 0.7 before drainage, decreased significantly to 2.5 mg/dL ± 0.4 at 1 month after stent placement (P = .041). Successful internal drainage was achieved in 44 of the 53 patients (83%). Kaplan–Meier analysis showed a median overall survival time of 145 days (95% confidence interval, 100–190 d), a median stent patency time of 313 days (95% confidence interval, 46–580 d), and cumulative stent patency rates at 1, 3, 6, 9, and 12 months of 91%, 75%, 64%, 56%, and 45%, respectively. Multivariate Cox regression analysis showed that the use of uncovered stents (odds ratio, 2.924; P = .033) was the only significant independent factor associated with stent occlusion. ConclusionsPercutaneous metallic stent placement is a safe and effective method for the treatment of patients with malignant bilioenterostomy obstruction. Moreover, as uncovered stent placement is the only significant independent factor associated with stent occlusion, ePTFE-covered stent placement is preferable in these patients.

Malignant Superior Vena Cava Syndrome: A Comparative Cohort Study of Treatment with Covered Stents versus Uncovered Stents

To evaluate outcomes of expanded polytetrafluoroethylene (ePTFE)-covered stents and compare them with outcomes of uncovered stents in patients with malignant superior vena cava (SVC) syndrome. This study was approved by the institutional review board and written informed consent was obtained. Thirty-seven consecutive patients (33 men, four women; mean age, 60.3 years; range, 35-81 years) who underwent ePTFE-covered stent placement for SVC syndrome were enrolled in a prospective study between January 2009 and September 2011. Their data were compared with retrospective data of 36 consecutive patients (31 men, five women; mean age, 62.3 years; range, 41-81 years) who underwent uncovered stent placement for SVC syndrome between January 2005 and December 2008. The causes of malignant SVC syndrome were squamous cell carcinoma (n = 27), adenocarcinoma (n = 25), small cell carcinoma (n = 15), thymic carcinoma (n = 3), invasive thymoma (n = 2), and breast cancer (n = 1). Stent patency and patient survival rates were calculated by using the Kaplan-Meier method, and groups were compared with the log-rank test. Stent placement was technically successful in all patients. Complications did not occur in either group. Kaplan-Meier analysis revealed that covered stents had higher cumulative patency (97%, 94%, 94%, and 94% at 1, 3, 6, and 12 months, respectively) than uncovered stents (97%, 79%, 67%, and 48% at 1, 3, 6, and 12 months, respectively; P = .038). Clinical success rates did not significantly differ (P = .674), nor did patient survival (P = .549). Median survival in the covered stent group was 141 days (95% confidence interval: 81, 201 days) and 100 days in the uncovered stent group (95% confidence interval: 60, 140 days). Endovascular placement of ePTFE-covered stents appeared to be a safe and effective method to treat patients with malignant SVC syndrome and seemed to be superior to uncovered stents in terms of stent patency.

Percutaneous unilateral placement of biliary covered metallic stent in patients with malignant hilar biliary obstruction and contralateral portal vein occlusion

Unilateral biliary metallic stent placement in the lobe with patent portal vein seemed to be a safe and effective palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancy, obviating bilateral stent placement in these patients, because the hepatic lobe with portal vein occlusion ceases to produce bile due to interruption of enterohepatic circulation. To investigate the safety and efficacy of percutaneous unilateral expanded polytetrafluoroethylene (ePTFE)-covered stent placement in malignant hilar biliary obstruction with contralateral portal vein occlusion. From February 2008 to March 2011, 24 consecutive patients with malignant hilar biliary obstruction and unilobar portal vein occlusion were enrolled in this prospective study. All patients were treated by percutaneous placement of ePTFE-covered stents. Stent deployment was technically successful in all patients. Two (8%) patients experienced minor self-limiting hemobilia. No major complication was noted. Successful internal drainage was achieved in 22 (91.6%) patients. Mean serum bilirubin level, which was 12.5 mg/dl ± 8.4 before drainage, decreased significantly to 2.7 mg/dl ± 3.4, 1 month after stent placement (P < 0.001). Median survival was 191 days (95% CI, 94-288 days) and cumulative stent patency rates at 1, 3, 6, 9, and 12 months were 100%, 95%, 95%, 95%, and 71%, respectively. Two (8%) patients presented with stent occlusion due to sludge incrustation. Aside from two patients who had died within 30 days after stent placement, the other 22 patients demonstrated slight decrease in diameter of undrained lobe and did not experience cholangitis nor jaundice. Unilateral placement of ePTFE-covered stent in the lobe with patent portal vein seems to be a safe and effective method for palliative treatment of patients with contralateral portal vein occlusion. In addition, ePTFE-covered stent placement can prevent tumor ingrowth without functional occlusion of segmental bile ducts.

Covered stents versus uncovered stents for the palliation of malignant extrahepatic biliary obstruction caused by direct tumor invasion: a cohort comparative study

Biliary stenting is a well-established palliative treatment in patients with unresectable malignant biliary strictures. The aim of the present study was to compare clinical outcomes of covered and uncovered stents in patients with malignant extrahepatic biliary obstruction caused by direct tumor invasion. Patients diagnosed with malignant extrahepatic biliary obstruction caused by direct tumor invasion were enrolled in this study. Of these patients, 37 received ePTFE-covered stent placement and were prospectively studied, and 47 received uncovered stent placement and were retrospectively studied. The technical success rate, tumor ingrowth rate, complication rate, stent patency, and patient survival were evaluated for both groups. Stent placement was successful in all cases except one in the covered group due to stent kinking. Tumor ingrowth occurred exclusively in the uncovered group. No significant differences were observed for the complication rate and patient survival between the two groups. Three patients in the covered group experienced stent migration, whereas no patients did in the uncovered group. A significant difference was found regarding stent patency, which was greater for the covered group compared to the uncovered group. The placement of ePTFE-covered stents for the treatment of malignant biliary obstruction caused by direct tumor invasion was a safe and an effective method characterized by greater stent patency.

Safety and Efficacy of Percutaneous Y-configured Covered Stent Placement for Malignant Hilar Biliary Obstruction: A Prospective, Pilot Study

PurposeTo investigate the technical and clinical safety and efficacy of percutaneous Y-configured covered stent placement in patients with malignant hilar biliary obstruction. Materials and MethodsThis prospective, pilot study enrolled 20 consecutive patients with malignant hilar biliary obstructions from October 2009 to December 2010. All patients were treated by percutaneous transhepatic placement of partially expanded polytetrafluoroethylene (ePTFE)–covered stents in a Y configuration. ResultsBilateral Y-configured covered stent deployment was technically successful in all 20 patients. Minor procedure-related complications occurred in four (20%) patients including self-limiting hemobilia in one patient and rapidly resolving cholangitis in three patients. Successful internal drainage was achieved in 18 (90%) of 20 patients. Mean serum bilirubin level, which was 12.6 mg/dL ± 5.1 before drainage, decreased significantly to 2.5 mg/dL ± 4.5 1 month after stent placement (P < .001). Median patient survival and stent patency times were 218 days (95% confidence interval [CI] 112–324 days) and 375 days (95% CI 55–695 days). Seven (35%) patients presented with stent occlusion, in six owing to sludge incrustation and in one owing to tumor overgrowth, and required repeat percutaneous transhepatic biliary drainage (PTBD). Tumor ingrowth, acute cholecystitis, or stent migration was not observed in any patient. ConclusionsPreliminary results suggest that percutaneous palliative treatment of malignant hilar biliary obstruction with Y-configured covered stents is safe and clinically effective in achieving internal biliary drainage. Y-configured, ePTFE-covered stents can also prevent tumor ingrowth without functional occlusion of hepatic segmental bile ducts.

Results of heparin-bonded ePTFE-covered stents for chronic occlusive superficial femoral artery disease

The purpose of this study was to assess the 1-year patency rates of heparin-bonded covered stents in the treatment of chronic occlusive disease of the superficial femoral artery (SFA). All patients treated with a heparin-bonded endograft between April 2009 and October 2010 for chronic occlusive disease of the SFA were prospectively gathered in a database and retrospectively analyzed. Primary, primary-assisted, and secondary patency rates, assessed by ultrasound scanning, were analyzed at 1-year, as were the complication rates and mortality. A total of 56 limbs were treated with a heparin-bonded covered stent in 53 patients for chronic ischemia Rutherford category 3 (n = 36), 4 (n = 5), 5 (n = 11), and 6 (n = 1). Lesions were classified as TransAtlantic Inter-Society Consensus (TASC)-2-B (n = 9), C (n = 14), and D (n = 33), and the mean treated lesion length was 18.5 ± 7.7 cm. Postoperative complications occurred in 7.5%, including hematoma (n = 1), edema (n = 1), pneumonia (n = 1), and urinary retention (n = 1), and the 30-day mortality rate was 0%. The mean follow-up was 413 ± 208 days. At 1 year, the primary patency was 76%, the primary-assisted patency 82%, and the secondary patency 89%. The limb salvage rate was 100%. Heparin-bonded covered stents seem to provide a valid alternative to surgical treatment of long occlusive lesions in the SFA. Randomized trials and long-term data are required before considering the technique as a new standard of care.

Influence of the Secondary Deployment of Expanded Polytetrafluoroethylene–covered Stent Grafts on Maintenance of Transjugular Intrahepatic Portosystemic Shunt Patency

To evaluate the effects of secondary deployment of expanded polytetrafluoroethylene (ePTFE)-covered stent grafts in the treatment of dysfunctional transjugular intrahepatic portosystemic shunts (TIPSs) in comparison with other common approaches (conventional angioplasty or implantation of bare metal stents). A retrospective review of 121 dysfunctional bare metal TIPS presenting between 2000 and 2004 was conducted. The group was divided into four subgroups according to the type of intervention: conventional angioplasty (52 cases; 43%), bare metal stent deployment (35 cases; 28.9%), nondedicated ePTFE-covered stent-graft deployment (15 cases; 12.4%), and dedicated ePTFE-covered stent-graft deployment (19 cases; 15.7%). In all four groups, the primary patency after the specific intervention was calculated and mutually compared. Primary patency rates after 12 and 24 months were 49.7% and 25.3%, respectively, in conventional angioplasty; 74.9% and 64.9%, respectively, with bare metal stents; 75.2% and 64.5%, respectively, with nondedicated ePTFE-covered stent grafts; and 88.1% and 80.8%, respectively, with dedicated ePTFE-covered stent grafts. In the treatment of dysfunctional TIPS, better patency after the intervention was obtained by deploying dedicated ePTFE-covered stent grafts in comparison with conventional angioplasty, bare metal stents, and nondedicated ePTFE-covered stents.

Comparison study of Doppler ultrasound surveillance of expanded polytetrafluoroethylene‐covered stent versus bare stent in transjugular intrahepatic portosystemic shunt

This prospectively randomized controlled study aimed to assess with Doppler ultrasound (US) the shunt function of expanded polytetrafluoroethylene (ePTFE)-covered transjugular intrahepatic portosystemic shunt (TIPS) stent versus bare stent and to evaluate the usefulness of routine TIPS follow-up of ePTFE-covered stents. Sixty consecutive patients were randomized for bare or covered transjugular TIPS stenting in our institution between April 2007 and April 2009. Data of follow-up Doppler US, angiography, and portosystemic pressure gradient measurements were collected and analyzed. The follow-up period was 8.34 + or - 4.42 months in the bare-stent group and 6.16 + or - 3.89 months in the covered-stent group. Baseline clinical characteristics were similar in both groups. Two hundred three US studies were performed in 60 patients, with a mean of 3.4 per patient, and demonstrated abnormalities in 28 patients (21 bare stents, 7 ePTFE-covered stents), 19 of them (13 in bare-stent group, 6 in covered-stent group) showing no clinical evidence of recurrence. Ten of 13 patients in the bare-stent group underwent balloon angioplasty or additional stent placement, whereas only one of six patients in the covered-stent group needed reintervention for intimal hyperplasia. The average peak velocity in the midshunt of ePTFE-covered stent was 139 + or - 26 cm/s after TIPS creation and 125 + or - 20 cm/s during follow-up, which was significantly higher than the bare-stent group (p < 0.05). The main portal vein and hepatic artery showed higher flow velocities in the ePTFE-covered stent group than in the bare-stent group. ePTFE-covered stents maintained lower portosystemic pressure gradient than bare stents (9.5 + or - 2.9 versus 13.2 + or - 1.5 mmHg, p < 0.05). ePTFE-covered stents resulted in higher patency rates and better hemodynamics than bare stents. Routine US surveillance may not be necessary in patients with ePTFE-covered TIPS stent.

Expanded Polytetrafluoroethylene–covered Stent Treatment of Angioplasty-related Extravasation during Hemodialysis Access Intervention: Technical and 180-day Patency

To review technical and patency results with expanded polytetrafluoroethylene (ePTFE)-covered stents for treatment of venous rupture encountered during percutaneous hemodialysis intervention. The Fluency covered stent is a tracheobronchial device that was used in an off-label manner to treat percutaneous transluminal angioplasty (PTA)-induced rupture in hemodialysis circuits. Data were retrospectively reviewed for all patients treated with the stent in 2004-2005 at two medical centers for PTA-related rupture. From a database of 106 procedures, 21 patients (21 procedures) were treated with the ePTFE-covered stent for PTA-related extravasation. Nine patients had arteriovenous (AV) grafts and 12 had AV fistulas. Five extravasations followed angioplasty as part of an AV graft declotting procedure. Location of extravasation was the outflow or cannulation venous segment (n = 11), cephalic arch (n = 3), AV graft venous anastomosis (n = 6), and intragraft (n = 1). All procedures were technically successful at halting extravasation and preserving vascular access. There were no known complications, and all patients underwent a successful first dialysis session. Twenty of the 21 circuits remained patent beyond the first week after intervention. The 180-day primary circuit patency rate was 20% and the 180-day cumulative circuit patency rate was 65%. In 21 patients, the ePTFE-covered stent successfully treated PTA-induced rupture with no need for acute secondary procedures such as thrombolysis or surgery. There was no instance of pseudoaneurysm formation or delayed bleeding. The ePTFE-covered stent offers advantages compared to prolonged PTA or bare stents when attempting to preserve hemodialysis access after PTA-induced rupture.

Comparison of Tissue Reaction with Three Different Endografts Used for Exclusion of Carotid Artery Aneurysm in a Dog Model

To assess the efficacy and biocompatibility of balloon-expandable stainless-steel stents covered with various membrane types. Stents covered with biomembrane (ie, piglet greater omentum vein), polyurethane, or expanded polytetrafluoroethylene (ePTFE; n = 12 each) were implanted into the 36 bilateral carotid arteries of 18 dogs to treat 36 surgically created saccular side wall aneurysms. Treated dogs were administered anticoagulation therapy after stent implantation. Angiography was performed immediately after the procedure and at 2, 4, and 12 weeks. Aneurysm isolation, primary parent artery patency, acute thrombosis in the stent, and endoleak were investigated. Two dogs in each group were killed at each follow-up interval, the stent-implanted arteries were removed for light and electron microscopy, and aneurysm thrombosis, stenosis rate, and endothelialization progress were observed. Thirty-six stents were successfully placed and 36 aneurysms completely isolated, with no endoleaks revealed by immediate or follow-up angiography. The primary patency rates of the biomembrane-, polyurethane-, and ePTFE-covered stents were 91.7%, 50%, and 66.7%, respectively. At 12 weeks, a luminal narrowing of 24.27% +/- 6.23% was seen in the biomembrane group, compared with 30.78% +/- 1.41% (P = .025) in the polyurethane group and 20.56% +/- 7.22% (P = .247) in the ePTFE group. All treated aneurysmal pouches had filled with thrombi and stent wires were encased by extended neointima. Endothelialization in the biomembrane group had begun by 2 weeks, which was earlier than in the polyurethane or ePTFE groups. All three stent-grafts successfully excluded carotid aneurysms. Biomembrane-covered stents showed better primary patency and less intimal hyperplasia than polyurethane- or ePTFE-covered stents.

Acute Hemobilia After Bilioplasty Due to Hepatic Artery Pseudoaneurysm: Treatment with an ePTFE-Covered Stent

A 61-year-old male underwent biliodigestive anastomosis (BDA) 7 years after orthotopic liver transplantation (OLT) due to intraand extrahepatic lithiasis. One month later he developed cholangitis and jaundice. Ultrasound examination revealed intrahepatic duct dilatation associated with the presence of stones. Percutaneous transhepatic cholangiography (PTC) and drainage were deemed necessary due to elevation of bilirubin levels and risk of sepsis. PTC revealed a stricture at the level of the previous BDA, with several filling defects in the common bile duct (CBD), which were attributed to the presence of stones. An 8-Fr internal/external drainage catheter (Flexima; Boston Scientific, Watertown, MA, USA) was initially used to decompress the biliary tree and gradually replaced with wider ones, up to 14 Fr, over the next 7 days. Lithotripsy was then decided on, and a 0.035-in. stiff guidewire (Amplatz; Boston Scientific Corp., Natick, MA, USA) was advanced into the drainage catheter. Upon advancement of the wire into the catheter it accidentally came out of one of the side holes into the liver parenchyma, and when the catheter was removed a jet of massive highpressure hemorrhage followed from the catheter tract. A new 14-Fr catheter was immediately inserted into the hepatic tract and angiography followed, but without the necessity for further intervention. The patient remained stable for the next 48 h and reintervention was decided on. Dilatation of the BDA was performed with a 10 9 20-mm balloon and stones were advanced toward the bowel loop with a biliary extraction balloon. Two days later cholangiography was repeated and the external catheter was removed by a new high-pressure hemorrhage episode from the catheter tract. The patient became hemodynamically unstable, angiography was repeated, and a small, saccular aneurysm was demonstrated at the right hepatic artery main branch, close to the bilioplasty region (Fig. 1). A 3.5 9 16-mm balloon-expandable coronary stentgraft (Graftmaster Jostent; Abbott Vascular, Ulestraten, Holland), covered eith expandable polytetrafluoroethylene (ePTFE), was advanced over a 0.014-in. stiff wire toward the aneurysm. Although the common hepatic artery had a stenosis, the stent was successfully advanced and deployed,