Role of ultrasound surveillance of transjugular intrahepatic portosystemic shunts in the covered stent era

Abdominal Vascular Evaluation

The vascular lab (VL) is instrumental in diagnosing vascular diseases such as renal artery stenosis and mesenteric ischemia or following a patient after transjugular intrahepatic portal systemic shunt (TIPS) creation. This article discusses indications, protocol, and diagnostic criteria for abdominal vascular ultrasound. The vascular lab can be used to investigate pathology in the abdomen either as a preliminary screening tool to evaluate for a pathology such as mesenteric artery stenosis in a patient with food fear and weight loss, renal artery stenosis in a patient with refractory hypertension or renal failure, or as a diagnostic tool in follow up after a patient has undergone a transjugular intrahepatic portal systemic shunt (TIPS) for portal hypertension. The technical success of duplex ultrasonography of the abdomen can be compromised by respiratory motion, obesity, and intestinal gas. Therefore, duplex scanning is performed in the fasting state particularly in elective outpatient cases. In emergent cases when pathology such as acute mesenteric ischemia is suspected evaluation with CT angiography may be best.

4D Flow MRI in the portal venous system: imaging and analysis methods, and clinical applications

Thus far, ultrasound, CT, and 2D cine phase-contrast MRI has been adopted to evaluate blood flow and vascular morphology in the portal venous system; however, all these techniques have some shortcomings, such as limited field of view and difficulty in accurately evaluating blood flow. A new imaging technique, namely 3D cine phase-contrast (4D Flow) MRI, can acquire blood flow data of the entire abdomen at once and in a time-resolved manner, allowing visual, quantitative, and comprehensive assessment of blood flow in the portal venous system. In addition, a retrospective blood flow analysis, i.e., "retrospective flowmetry," is possible. Although the development of 4D Flow MRI for the portal system has been delayed compared to that for the arterial system owing to the lower flow velocity of the portal venous system and the presence of respiratory artifacts, several useful reports have recently been published as the technology has advanced. In the first part of this narrative review article, technical considerations of image acquisition and analysis methods of 4D Flow MRI for the portal venous system and the validations of their results are described. In the second part, the current clinical application of 4D Flow MRI for the portal venous system is reviewed.

Retrospective evaluation of early thrombosis in transjugular intrahepatic portosystemic polytetrafluoroethylene-coated shunts under 2-day postinterventional heparinization

The development of acute thrombosis within the TIPS tract may be prevented by prophylactic anticoagulation; however, there is no evidence of the correct anticoagulation regimen after TIPS placement. The purpose of this single-center retrospective study was to evaluate the short-term occlusion rate of transjugular intrahepatic portosystemic shunts (TIPSs) with polytetrafluorethylene (PTFE)-coated stents under consequent periprocedural full heparinization (target partial thromboplastin time [PTT]: 60–80 s). We analyzed TIPS placements that were followed up over a six-month period by Doppler ultrasound in 94 patients and compared the study group of 54 patients who received intravenous periprocedural full heparinization (target PTT: 60–80 s) without any other anticoagulation to patients with prolonged anticoagulation medication. The primary endpoint was TIPS patency after six months. The primary patency rate was 88.3% overall, and in the study group, 90.7%, with an early thrombosis rate of 3.2% (study group: 1.9%) and a primary assisted patency rate of 95.7% (study group: 96.3%). In the study group, one case of TIPS thrombosis occurred on the 23rd day after TIPS placement. Two patients underwent reintervention because of stenosis or buckling. Moreover, the target PTT was not attained in 8 of the 54 patent TIPSs. Four patients had an increased portosystemic pressure gradient, without stenosis, and the flow rate was corrected by increasing the TIPS diameter by dilation. Two-day heparinization seems sufficient to avoid early TIPS thrombosis over a six-month period.

Diagnostic Value of Contrast-Enhanced Ultrasound for Evaluation of Transjugular Intrahepatic Portosystemic Shunt Perfusion

BACKGROUND

In patients with liver cirrhosis, transjugular intrahepatic portosystemic shunt (TIPS) displays an effective method for treating portal hypertension. Main indications include refractory ascites and secondary prevention of esophageal bleeding. Color Doppler ultrasound (CDUS) plays a leading role in the follow-up management, whereas contrast-enhanced ultrasound (CEUS) is not routinely considered. We compared the efficacy of CEUS to CDUS and highlighted differences compared to findings of corresponding computed tomography (CT) and magnetic resonance imaging (MRI). (2) Methods: On a retrospective basis, 106 patients with CEUS examination after TIPS were included. The enrollment period was 12 years (between 2008 and 2020) and the age group ranged from 23.3 to 82.1 years. In addition, 92 CDUS, 43 CT and 58 MRI scans were evaluated for intermodal comparison. (3) Results: Intermodal analysis and comparison revealed a high level of concordance between CDUS, CT and MRI in the vast majority of cases. In comparison to CDUS, the correlation of the relevant findings was 92.5%, 95.3% for CT and 87.9% for MRI. In some cases, however, additional information was provided by CEUS (4) Conclusions: CEUS depicts a safe and effective imaging modality for follow-up after TIPS. In addition to CDUS, CEUS enables specific assessment of stent pathologies and stent dysfunction due to its capacity to dynamically visualize single microbubbles at high spatial and temporal resolution. Due to the low number of adverse events regarding the application of contrast agents, CEUS can be administered to a very broad patient population, thus avoiding additional radiation exposure compared to CT angiography in cases with divergent findings during follow-up.

Transjugular intrahepatic portosystemic shunt creation may be associated with hyperplastic hepatic nodular lesions in the long term: an analysis of 18 pediatric and young adult patients

BACKGROUND

Retrospective studies have demonstrated the efficacy and safety of pediatric and adolescent transjugular intrahepatic portosystemic shunt (TIPS), but long-term outcomes warrant further investigation.

OBJECTIVE

To report on the development of hyperplastic hepatic nodular lesion development in children and young adults (<21 years) with TIPS patency >3 years.

MATERIALS AND METHODS

Eighteen children and young adults, including 10 (55.6%) females and 8 (44.4%) males, underwent TIPS creation with >3 years' patency and follow-up evaluation at a tertiary children's hospital. The mean age at the time of TIPS creation was 12.5±5.1 years (range: 1.5-20.0 years). The mean model for end-stage liver disease (MELD) at the time of TIPS creation was 8.1±1.6 (range: 6-11). Indications for TIPS creation included acute variceal bleeding (8/18, 44.4%), primary (1/18, 5.6%) or secondary (7/18, 38.9%) prevention of varices, portal vein thrombosis (1/18, 5.6%), and splenic sequestration (1/18, 5.6%). Technical successes, intra-procedural parameters, hemodynamic and clinical successes, TIPS patencies, adverse events, imaging evaluations, and follow-ups were recorded.

RESULTS

All (100%) TIPS placements were successful; however, a direct intrahepatic portosystemic shunt was created in one (5.6%) patient. Mean reduction of the portosystemic shunt gradient was 9.1±3.3 mmHg (range: 4-16 mmHg). Seventeen (94.4%) patients demonstrated clinical success with resolution of their initial clinical indication for TIPS placement. The 3-year TIPS primary, primary-assisted, and secondary patencies were 83.3% (15/18), 94.4% (17/18), and 100% (18/18), respectively. Two (11.1%) patients developed mild, medically controlled hepatic encephalopathy. One (5.6%) patient developed hepatopulmonary syndrome. Nine (50%) patients developed single or multiple hepatic nodules at a mean imaging surveillance time after TIPS of 4.4±3.0 years (range: 1.5-10.2 years). Six (33.3%) patients developed nodules >1 cm with imaging features most consistent with focal nodular hyperplasia or focal nodular hyperplasia-like nodules. The mean follow-up duration was 5.7±2.9 years (range: 3.0-13.1 years).

CONCLUSION

Long-term (>3 years) portosystemic shunting via TIPS is associated with the development of hepatic nodular lesions in children. Consequently, children with TIPS may need gray-scale assessment of hepatic parenchyma as part of routine ultrasound exams and extended imaging surveillance until more is understood regarding the natural history of induced nodularity.

Role of Doppler Ultrasound Combined With Clinical Features in the Diagnosis of Transjugular Intrahepatic Portosystemic Shunt Dysfunction in the Era of Covered Stents

OBJECTIVES

Our goal was to discuss the role of Doppler ultrasound (US), combined with clinical features, in the diagnosis of transjugular intrahepatic portosystemic shunt (TIPS) dysfunction in the era of covered stents. In light of the lack of research regarding the accuracy of Doppler US in TIPS dysfunction evaluations when using covered stents and a recent major meta-analysis, which primarily reviewed studies with bare metal stents but few with covered stents, we aimed to provide our single-center case study for further investigation.

METHODS

All patients from 2010 to 2019 who underwent angiography for a covered stent preceded by a Doppler US examination in our institution were retrospectively reviewed.

RESULTS

All of the Doppler US and angiographic examination results showed complete agreement, and 11 of 12 were positive for TIPS dysfunction.

CONCLUSIONS

Combining the presence of positive clinical signs for TIPS dysfunction with Doppler US may increase its accuracy. Considering our results, there may be a need to reinvestigate Doppler US as a noninvasive, inexpensive, and available tool for the diagnosis of TIPS dysfunction in the era of covered stents, despite recent publications depicting Doppler US as inadequate for evaluating a TIPS.

Predictive Value of Abnormal Findings on Covered Transjugular Intrahepatic Portosystemic Shunt Baseline Doppler Sonography

Doppler ultrasound (DUS) is frequently performed as a screening and diagnostic modality to evaluate the transjugular intrahepatic portosystemic shunt (TIPS) for short- and intermediate-term complications of the procedure. However, the clinical significance of initial frequently observed abnormalities in flow velocities, gradient, and direction in patients with covered TIPS is less studied. A retrospective study was performed between January 2005 and December 2014, and all patients undergoing covered TIPS procedure for the management of portal hypertension were included. Abnormal DUS findings were defined as intrashunt peak systolic velocities (PSVs) less than 90 or greater than 190 cm/s, intrashunt gradient greater than 50 cm/s, and abnormal flow direction in the main, right, and/or left portal veins. A total of 283 patients with adequate clinical follow-up and baseline TIPS DUS were included in the study. Median follow-up was 18.2 months. During the follow-up period, portal hypertension symptoms recurred in 83 patients who underwent TIPS angiography and/or revision. Of the 83, 57 had an elevated portosystemic gradient (>12 mm Hg) requiring angioplasty/stenting. With regard to baseline ultrasound, low PSVs were present in 88 patients (31.1%), high PSVs in 44 patients (15.5%), and elevated gradient in 98 patients (34.6%). The rate of developing TIPS stenosis in the future was not higher in patients with abnormal DUS parameters. For example, 26 (19.7%) of 132 patients with abnormal TIPS velocities developed stenosis compared with 31 (20.5%) of 151 patients with normal velocities (P = 0.9). Based on these results, abnormal DUS findings observed on baseline TIPS ultrasound examination have low predictive value for future covered TIPS dysfunction and failure.

The Feasibility of Using Volumetric Phase-Contrast MR Imaging (4D Flow) to Assess for Transjugular Intrahepatic Portosystemic Shunt Dysfunction

PURPOSE

To demonstrate the feasibility of detecting patency, stenosis, or occlusion of transjugular intrahepatic portosystemic shunt (TIPS) with four-dimensional (4D) flow MR imaging.

MATERIALS AND METHODS

Sequential adult patients with TIPS were eligible for enrollment. Volumetric phase-contrast sequence was used to image TIPS. Particle tracing cine images were used for qualitative assessment of stenosis. TIPS was segmented to generate quantitative data sets of peak velocity. Segmentation and quantitative measurement of flow throughout an entire TIPS defined technical success. Doppler US was used for comparison. Venography, when available, and 6-month clinical follow-up were used as reference standards.

RESULTS

4D flow MR imaging was performed in 23 patient encounters and was technically successful in 16/23 (69.6%) encounters. Three cases demonstrated both focal turbulence and abnormal velocities (> 190 cm/s or < 90 cm/s) on 4D flow and had venography-confirmed stenosis (true-positive cases). Seven cases had normal velocities and no turbulence on 4D flow, and all were confirmed negative with clinical follow-up or venography (true-negative cases). Six cases had discordant 4D flow results, with abnormal velocities but no turbulence or focal turbulence but normal velocities. All 6 discordant cases had no evidence of dysfunction during 6-month follow-up.

CONCLUSION

4D flow MR imaging can detect TIPS patency and stenosis, but further investigation is required before it can be used to assess for TIPS dysfunction.

Transjugular Intrahepatic Portosystemic Shunt: A Literature Review

Transjugular intrahepatic portosystemic shunt, or TIPS, is a procedure used to decompress the portal system resulting from portal hypertension. The technique was inadvertently discovered during a transjugular cholangiography procedure around 1969. Technological advances in the 1980s and 1990s have resulted in more positive outcomes for the TIPS procedure since its inception. There are several indications for performing the procedure, including refractory ascites, variceal bleeding, and portal hypertension. Liver disease can lead to portal hypertension, and few treatments are available; however, with TIPS, many patients obtain favorable results. The goal of placing an intrahepatic portosystemic shunt is to bypass the vascular resistance in the cirrhotic liver by creating a channel between the portal and hepatic veins, thereby reducing portal venous pressure and portal hypertension. Normal and diseased liver function is explained as well as the TIPS procedure process, materials, complications, and long-term outcomes.

Consensus conference on TIPS management: Techniques, indications, contraindications

The trans jugular intrahepatic Porto systemic shunt (TIPS) is no longer viewed as a salvage therapy or a bridge to liver transplantation and is currently indicated for a number of conditions related to portal hypertension with positive results in survival. Moreover, the availability of self-expandable polytetrafluoroethylene (PTFE)-covered endoprostheses has dramatically improved the long-term patency of TIPS. However, since the last updated International guidelines have been published (year 2009) new evidence have come, which have open the field to new indications and solved areas of uncertainty. On this basis, the Italian Association of the Study of the Liver (AISF), the Italian College of Interventional Radiology-Italian Society of Medical Radiology (ICIR-SIRM), and the Italian Society of Anesthesia, Analgesia and Intensive Care (SIAARTI) promoted a Consensus Conference on TIPS. Under the auspices of the three scientific societies, the consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Bergamo on June 4th and 5th, 2015. The final statements presented here were graded according to quality of evidence and strength of recommendations and were approved by an independent jury. By highlighting strengths and weaknesses of current indications to TIPS, the recommendations of AISF-ICIR-SIRM-SIAARTI may represent the starting point for further studies.

Transjugular Intrahepatic Portosystemic Shunt Dysfunction: Concordance of Clinical Findings, Doppler Ultrasound Examination, and Shunt Venography

Objectives:

The objective of this study was to evaluate the concordance between clinical symptoms, Doppler ultrasound (US), and shunt venography for the detection of stent-graft transjugular intrahepatic portosystemic shunt (TIPS) dysfunction.

Materials and Methods:

Forty-one patients (M:F 30:11, median age 55 years) who underwent contemporaneous clinical exam, Doppler US, and TIPS venography between 2003 and 2014 were retrospectively studied. Clinical symptoms (recurrent ascites or variceal bleeding) were dichotomously classified as present/absent, and US and TIPS venograms were categorized in a binary fashion as normal/abnormal. US abnormalities included high/low (>190 or <90 cm/s) TIPS velocity, significant velocity rise/fall (>50 cm/s), absent flow, and return of antegrade intra-hepatic portal flow. Venographic abnormalities included shunt stenosis/occlusion and/or pressure gradient elevation. Clinical and imaging concordance rates were calculated.

Results:

Fifty-two corresponding US examinations and venograms were assessed. The median time between studies was 3 days. Forty of 52 (77%) patients were symptomatic, 33/52 (64%) US examinations were abnormal, and 20/52 (38%) TIPS venograms were abnormal. Concordance between clinical symptoms and TIPS venography was 48% (25/52), while the agreement between US and shunt venography was 65% (34/52). Clinical symptoms and the US concurred in 60% (31/52) of the patients. The sensitivity of clinical symptoms and US for the detection of venographically abnormal shunts was 80% (16/20) and 85% (17/20), respectively. Both clinical symptoms and the US had low specificity (25%, 8/32 and 50%, 16/32) for venographically abnormal shunts.

Conclusion:

Clinical findings and the US had low concordance rates with TIPS venography, with acceptable sensitivity but poor specificity. These findings suggest the need for improved noninvasive imaging methods for stent-graft TIPS surveillance.

The Evolution of Transjugular Intrahepatic Portosystemic Shunt: Tips

Since Richter's description in the literature in 1989 of the first procedure on human patients, transjugular intrahepatic portosystemic shunt (TIPS) has been worldwide considered as a noninvasive technique to manage portal hypertension complications. TIPS succeeds in lowering the hepatic sinusoidal pressure and in increasing the circulatory flow, thus reducing sodium retention, ascites recurrence, and variceal bleeding. Required several revisions of the shunt TIPS can be performed in case of different conditions such as hepatorenal syndrome, hepatichydrothorax, portal vein thrombosis, and Budd-Chiari syndrome. Most of the previous studies on TIPS procedure were based on the use of bare stents and most patients chose TIPS 2-3 years after traditional treatment, thus making TIPS appear to be not superior to endoscopy in survival rates. Bare stents were associated with higher incidence of shunt failure and consequently patients required several revisions during the follow-up. With the introduction of a dedicated e-PTFE covered stent-graft, these problems were completely solved, No more reinterventions are required with a tremendous improvement of patient's quality of life. One of the main drawbacks of the use of e-PTFE covered stent-graft is higher incidence of hepatic encephalopathy. In those cases refractory to the conventional medical therapy, a shunt reduction must be performed.

Diagnostic radiology of transjugular intrahepatic portosystemic shunts

Transjugular intrahepatic portosystemic shunts (TIPS) are an effective method for treating the complications of portal hypertension. Specific indications for TIPS include secondary prevention of variceal bleeding and refractory ascites. The purpose of this review is to summarize the role of diagnostic radiology in the creation and assessment of TIPS, to highlight the complications that can occur post-TIPS, and to critically evaluate the literature regarding ultrasound evaluation of TIPS.

Long-term follow-up of TIPS created with expanded poly-tetrafluoroethylene covered stents

BACKGROUND

Transjugular intrahepatic portosystemic shunts (TIPS) created with expanded poly-tetrafluoroethylene-covered stents have largely replaced bare metal stents. Short-term shunt patency is typically assessed with protocol Doppler ultrasound (US), while little information exists with regard to long-term patency.

AIM

We investigated the value of Doppler US in assessing TIPS patency as well as long-term clinical outcomes.

METHODS

A retrospective analysis of 59 patients with covered stents used for TIPS between January 2001 and December 2011 was performed.

RESULTS

Fifty-four patients had early (median 9 days) Doppler US follow-up. Seven of eight patients with an abnormal baseline US required stent revisions. None of the 46 patients with normal baseline Doppler US required revisions within the first 6 months; six of these patients subsequently had a portogram because of symptoms, but all TIPS were patent. Fifty-two patients survived for long-term (>6 months) follow-up, averaging 654 days and three Doppler US exams. Five of six patients with abnormal follow-up Doppler US required revisions, whereas none of the 46 patients with normal follow-up US had revisions. The recurrence of symptoms of portal hypertension and/or hepatic encephalopathy (HE) was low (4/52 patients). No significant predictors of long-term stenosis were identified. Post-TIPS HE was independent of pre-TIPS HE or Child-Pugh score.

CONCLUSIONS

Short-term patency and that at approximately 2 years after TIPS placement was 87 and 77 %, respectively. We conclude that Doppler US at least 1 week after TIPS is warranted, but repeated Doppler US follow-up is probably not necessary in the absence of clinical symptoms.

Covered transjugular intrahepatic portosystemic shunts: accuracy of ultrasound in detecting shunt malfunction

OBJECTIVE

The purpose of this study was to determine the accuracy of ultrasound for detecting transjugular intrahepatic portosystemic shunt (TIPS) malfunction in covered stents in comparison with bare metal stents.

MATERIALS AND METHODS

During a 6-year period, 126 TIPS angiography examinations were performed in 78 patients who had undergone a recent TIPS ultrasound examination. Radiology reports and images were retrospectively reviewed, and the sensitivity and specificity of sonographic parameters for detecting TIPS dysfunction were calculated using TIPS angiography and portosystemic gradient as the reference standards.

RESULTS

Of 126 paired studies, 43 were in bare metal TIPS and 83 were in covered TIPS. Peak shunt velocity of covered and bare metal TIPS measured by ultrasound showed comparable sensitivities for detection of shunt dysfunction, using both depressed (< 90 cm/s) and elevated (> 200 cm/s) peak shunt velocity criteria. However, a depressed velocity was more specific in covered TIPS (0.939 vs 0.550, p < 0.001) whereas elevated velocity was more specific in bare TIPS (0.485 vs 0.800, p = 0.041). An interval change in peak TIPS velocity greater than 25% was significantly more sensitive in detection of dysfunction in covered TIPS (0.815 vs 0.400, p = 0.015) whereas detection based on main portal vein velocities (≤ 30 cm/s) was not statistically different in the two groups.

CONCLUSION

Our data suggest that the accuracy of ultrasound for detection of TIPS shunt malfunction is at least as high in covered stents as in bare metal stents. Diagnostic performance for several sonographic parameters varied significantly between bare and covered stents, suggesting the need for optimization of sonographic criteria for covered stents.

Evaluation and management of transjugular intrahepatic portosystemic shunts

OBJECTIVE

The purpose of this article is to describe the evaluation of transjugular intrahepatic portosystemic shunts (TIPS) and the management of dysfunctional shunts.

CONCLUSION

TIPS can become dysfunctional if stenosis develops in the shunt or the hepatic vein above the shunt. Screening allows detection of stenoses before portal hypertensive-related complications recur. Revision of stenotic shunts can be easily accomplished in most cases. Techniques for screening and revision will be discussed.

Patency and clinical outcomes of transjugular intrahepatic portosystemic shunt with polytetrafluoroethylene-covered stents versus bare stents: a meta-analysis

BACKGROUND AND AIM

 Transjugular intrahepatic portosystemic shunt (TIPS) with polytetrafluoroethylene-(PTFE)-covered stent has been increasingly used for patients with complications of portal hypertension. It is still debated whether the new endoprostheses will improve some clinical outcomes (except for shunt patency) compared to the bare stents. The aims of our meta-analysis were to explore the patency and clinical outcomes of TIPS with PTFE-covered stent-grafts versus bare stents.

METHODS

Pertinent studies were retrieved through PubMed (1950-2010), MEDLINE (1950-2010), and reference lists of key articles. Outcome measures were primary patency, risk of encephalopathy and survival. Time-to-event data analysis was used to calculate the overall hazard ratios (HR).

RESULTS

Six studies were identified including a total of 1275 patients (346 TIPS with PTFE-covered stent-grafts and 929 TIPS with bare stents). Pooled shunt patency data from four eligible studies suggested a significant improvement of primary patency in patients who were treated with PTFE-covered stent-grafts (HR = 0.28, 95% confidence interval [CI] 0.20-0.35). Pooled encephalopathy data from three eligible studies suggested a significant reduction of risk in the PTFE-covered group (HR = 0.65, 95%CI 0.45-0.86). Pooled survival data from four eligible studies also suggested a significant decrease of mortality in the PTFE-covered group (HR = 0.76, 95%CI 0.58-0.94). No statistical heterogeneity was observed between studies for either outcome.

CONCLUSIONS

This meta-analysis shows that the use of PTFE-covered stent-grafts clearly improves shunt patency without increasing the risk of hepatic encephalopathy and with a trend towards better survival.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

The transjugular intrahepatic portosystemic shunt (TIPS)

The creation of an intrahepatic portosystemic shunt via a transjugular approach (TIPS) is an interventional radiological procedure used to treat the complications of portal hypertension. TIPS insertion is principally indicated to prevent or arrest variceal bleeding when medical or endoscopic treatments fail, and in the management refractory ascites. This review discusses the development and execution of the technique, with focus on its clinical efficacy. Patient selection, imaging surveillance, revision techniques, and complications are also discussed.

Causes of TIPS dysfunction

OBJECTIVE

Transjugular intrahepatic portosystemic shunt (TIPS) creation is an effective method to control portal hypertension. TIPS creations with bare stents have shown limited and unpredictable patency. In nearly all cases of rebleeding or recurrent ascites after TIPS creation, there is shunt stenosis or occlusion. The purpose of this article is to review the biologic and technical factors that predispose to TIPS failure and how the use of an expandable polytetrafluoroethylene (PTFE)-covered-stent has significantly improved TIPS patency.

CONCLUSION

Biologic and technical factors may predispose to shunt failure. The combination of improved technique and expandable PTFE has significantly improved TIPS patency. The need for follow-up venography and secondary interventions has been reduced significantly as a result of improved shunt patency.

Is sonographic surveillance of polytetrafluoroethylene-covered transjugular intrahepatic portosystemic shunts (TIPS) necessary? A single centre experience comparing both types of stents

AIM

To investigate whether sonographic (US) surveillance of polytetrafluoroethylene covered transjugular intrahepatic portosystemic shunts (TIPS) is necessary.

MATERIALS AND METHODS

We identified 128 patients who underwent TIPS for complications of portal hypertension between January 2001 and December 2005 at a large tertiary centre. Procedural data were retrospectively analysed. US surveillance of the TIPS was performed at baseline with scheduled follow-up or whenever shunt dysfunction was suspected. Clinical and radiology reports were compared to assess US surveillance of the TIPS.

RESULTS

Four hundred and twenty-six US studies were performed, with a median of three per patient (range 1-5). The median follow-up period was 378 days (range 1-1749 days). Twenty-three patients (18%) had baseline US studies performed only whereas 105 (82%) also had follow-up studies. Forty-one (32%) of 128 patients [32 (78%) Wallstent, nine (22%) Viatorr] had Doppler ultrasound abnormalities noted. Venography was performed in all 41 patients. Abnormal venography and elevated hepatic venous pressure gradient (HVPG) was seen in 34 (82.9%) of the 41 patients [29 (85.3%) Wallstent, five (14.7%) Viatorr]. Among the 34 patients, 17 (50%) [13 (76.5%) Wallstent, four (23.5%) Viatorr] had venographic abnormalities noted at the hepatic venous end accompanied by increased HVPG. All four of the Viatorr patients had minor narrowing at the hepatic venous end and HVPG measurements that ranged 3-4 mm Hg above 12 mm Hg.

CONCLUSION

Considering the improved patency of covered stents in TIPS, US surveillance may be superfluous after the baseline study.