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

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.

Performance of ultrasound for detection of transjugular intrahepatic portosystemic shunt dysfunction: a meta-analysis

PURPOSE

Although ultrasound has been widely used to evaluate transjugular intrahepatic portosystemic shunts (TIPS) patency, several studies have reported conflicting data regarding its performance. Therefore, we aimed to evaluate performance of ultrasound for detection of TIPS dysfunction by performing a meta-analysis.

METHODS

Literature search was performed for studies evaluating ultrasound for TIPS dysfunction, stenosis, and occlusion using PubMed, EMBASE, Scopus, and Cochrane Library through February 2019. Pooled sensitivity, specificity, log diagnostic odds ratio (LDOR), and area under curve (AUC) of summary receiver-operating characteristic were calculated. Subgroup analyses were performed according to ultrasonographic criteria and type of stent.

RESULTS

In total, 21 studies were evaluated. Pooled sensitivity, specificity, and LDOR of ultrasound for detection of TIPS dysfunction were 0.82 (0.67, 0.93), 0.58 (0.46, 0.70), and 1.77 (1.20, 2.35). Pooled sensitivity, specificity, and LDOR for TIPS stenosis were 0.80 (0.69, 0.90), 0.80 (0.69, 0.91), and 2.83 (1.88, 3.78). Pooled sensitivity, specificity, and LDOR for TIPS occlusion were 0.96 (0.92, 0.99), 1 (0.99, 1.00), and 6.28 (4.96, 7.60). AUCs of ultrasound for TIPS dysfunction, stenosis, and occlusion were 0.77, 0.86, and 0.95, respectively.

CONCLUSIONS

Although ultrasound had excellent performance for TIPS occlusion and acceptable performance for TIP stenosis, most studies utilized bare metal stent, and therefore, application to current practice is limited. Ultrasound for TIPS dysfunction in the setting of covered metal stent appeared to have acceptable sensitivity of 0.82, but limited specificity of 0.58 and low LDOR of 1.77. A new noninvasive tool is needed for detection of TIPS dysfunction in the era of covered metal stent.

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.

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

PURPOSE

To assess ultrasound (US) surveillance of expanded polytetrafluoroethylene (ePTFE)-covered stents in transjugular intrahepatic portosystemic shunts (TIPS).

MATERIALS AND METHODS

Procedural data, including stent size and portosystemic gradients (PSG) before and after creation of TIPS, were obtained retrospectively in 55 patients (33 men, 22 women). Chart review provided clinical information, including etiology of liver disease, indication for TIPS creation, and Child-Pugh class. Radiology reports provided US venography data and pathology reports confirmed shunt status in transplant recipients. Patients had baseline US examinations 3-7 days after TIPS creation with scheduled follow-up at 1, 3, 6, and 12 months after the procedure. Clinical and radiology reports were compared to evaluate US surveillance of Viatorr stents.

RESULTS

One hundred fifty-nine US examinations were performed on 52 patients, for an average 3.1 studies per patient (range, 1-7) over a mean follow-up duration of 173 days (range, 0-1,013 d). Sixty-four US studies (40%) were baseline studies, 88 studies (55%) were routine follow-up studies, and seven (4%) were interval studies. US predicted TIPS abnormalities in 30 of 159 studies (19%); venography followed 15 of 30 abnormal US findings (50%) and clinical examinations complemented 10 of 15 venograms (67%). Venography and US were concordant in eight of 15 paired studies (53%); clinical examinations, when conducted, accurately predicted shunt status in all but one case. US findings changed management in six of 159 studies (4%): five of six (83%) were baseline evaluations and the other one (17%) was a routine follow-up examination. A total of five baseline US examinations (8%) and one surveillance examination (1%) altered patient management.

CONCLUSIONS

A single US examination after a TIPS procedure to confirm immediate function may be valuable, but routine US is not effective for long-term surveillance of ePTFE-covered stents.

Value of Doppler sonography in revealing transjugular intrahepatic portosystemic shunt malfunction: a 5-year experience in 216 patients

OBJECTIVE

The purpose of the study was to evaluate the long-term clinical efficacy of Doppler sonography in revealing failure of transjugular intrahepatic portosystemic shunts (TIPS).

SUBJECTS AND METHODS

During a 5-year period, 1192 Doppler examinations were performed in 216 patients with TIPS. No regular follow-up shunt venography was performed. Doppler examinations were retrospectively compared with the results of shunt revisions. Sonograms with negative findings were compared with the patients' clinical status so that the number of false-negative sonographic findings leading to an episode of shunt failure (recurrence of gastrointestinal bleeding or ascites) could be ascertained. Sonographic parameters assessed included diameter, velocity, flow volume, and congestion index of the portal vein; and shunt velocities.

RESULTS

Doppler sonography revealed shunt occlusion in 25 of 26 angiographically proven cases (sensitivity, 96%). The combination of velocity criteria (peak intrashunt velocity > or =250 cm/sec, maximum velocity in the portal third of the shunt < or =50 cm/sec, or maximum portal vein velocity less than or equal to two thirds of the baseline value) revealed shunt stenosis in 103 of 110 cases (sensitivity, 94%). Doppler sonography missed a significant shunt stenosis that led to an episode of gastrointestinal bleeding or ascites recurrence in only seven cases. The congestion index of the portal vein showed significant differences between patent and malfunctioning shunts (p < 0.001).

CONCLUSION

Doppler sonography is an effective primary imaging method for long-term follow-up of patients with TIPS.

Esophageal varices. II. TIPS (transjugular intrahepatic portosystemic shunt) and surgical therapy

The role of surgery in the prevention and treatment of variceal hemorrhage is reviewed. Types of available surgery, their physiologic basis, and literature supporting their use are discussed in the context of the natural history of variceal hemorrhage. The evolution of transjugular intrahepatic portosystemic shunt (TIPS) as a treatment modality for variceal hemorrhage is reviewed. The effects of TIPS on portal and systemic hemodynamics and clinical usefulness in the management of variceal hemorrhage are discussed. A treatment algorithm for the integrated use of the various treatments is provided.

The first decade of the transjugular intrahepatic portosystemic shunt (TIPS): state of the art

The transjugular intrahepatic portosystemic shunt (TIPS) is an interventional treatment resulting in decompression of the portal system by creation of a side-to-side portosystemic anastomosis. Since its introduction 10 years ago, more than 500 publications have appeared demonstrating rapid acceptance and increasing clinical use. This review summarizes the present knowledge of technical aspects and complications, follow-up of patients, and indications. With respect to the technique, the TIPS procedure is probably one of the most difficult interventions and, therefore, technical success and complications clearly depend on the skills of the operator. Thus, the number and kind of complications reported in this review do not necessarily relate to the procedural complications of an experienced center. The follow-up of the TIPS patient has to assess shunt patency, liver function and hepatic encephalopathy. Shunt patency can best be monitored by duplex-sonography. Routine radiological revision seems not to be helpful and does not improve results, i.e., rebleeding and survival. Short term patency may be improved by anticoagulation, while such a treatment does not influence long-term patency. With respect to the indications of TIPS, much is known about treatment of variceal bleeding. The nine randomized studies that are available to date show that survival is comparable between patients receiving TIPS or endoscopic treatment. The second group of patients is the group with refractory ascites and related complications, such as hepatorenal syndrome and hepatic hydrothorax. It has been demonstrated that TIPS improves these complications, but randomized studies are still lacking. In addition, TIPS has been applied successfully to patients with Budd-Chiari syndrome, portal vein thrombosis, before liver transplantation, and for the treatment of ectopic portal hypertensive bleeding.