MR angiographic guidance for transjugular intrahepatic portosystemic shunt procedures

Clinical Impact and Safety of Non-Target Punctures (NTP) during Portal Vein Access in TIPS Procedure

BACKGROUND

Although non-target puncture (NPT)-related complications are well known to clinicians performing TIPS, there is no NTP-focused study to assess the true clinical sequalae of NTP-related complications. In this study, the aim was to evaluate the incidence, safety, clinical outcomes and complications related to NTPs during the portal access of TIPS procedures.

METHODS

A retrospective review of 369 TIPS procedures from October 2007 to September 2019 was performed. We identified inadvertent NTPs, including biliary, hepatic artery, lymphatic and capsular punctures. Next, the medical records and images were reviewed and analyzed to assess the safety and clinical outcomes of these cohorts.

RESULTS

A total of 71 NTPs were identified in 56 patients (15.18% of 369 patients). Of 369 TIPS patients, there were (1) 28 biliary punctures (7.6%), (2) 16 extracapsular punctures (4.3%), (3) 15 lymphatic punctures (4.1%) and (4) 12 hepatic artery punctures (3.3%). The overall complication rate was 2.2% (8/369). Based on the Clavien-Dindo classification, three patients (0.8%) had a minor complication. In addition, five patients (1.4%) experienced grade II-V major complications, such as symptomatic hemoperitoneum, arterio-biliary fistula or hemorrhagic shock leading to death. Mortality (0.5%) was only caused by extracapsular puncture combined with other NTP.

CONCLUSIONS

NTPs during the portal access of TIPS procedures are associated with low complication risk. However, when extracapsular punctures are combined with other NTPs, a more severe complication, including mortality, can occur. Nevertheless, all patients with NTP should be closely monitored at a higher level of care after TIPS placement.

The difficult transjugular intrahepatic portosystemic shunt: alternative techniques and "tips" to successful shunt creation

The transjugular intrahepatic portosystemic shunt (TIPS) is one of the most complex procedures performed by interventional radiologists. Most of these procedures are straightforward and may be successfully completed within 2 hours. In some cases, TIPS creation may be extremely difficult, for example in situations such as: variant anatomy, portal vein thrombosis, hepatic vein thrombosis, or preexisting TIPS. In this article we describe some maneuvers that may be attempted in cases where creation of the shunt proves to be difficult.

Magnetic resonance imaging for disorders of liver vasculature

Magnetic resonance imaging (MRI) provides a noninvasive technique to evaluate the hepatic vasculature. Angiographic and flow-based techniques include intrinsic properties of MRI as well as those that use contrast media. Clinical and technical perspectives of a wide range of vascular disorders affecting the liver, particularly cirrhosis and portal hypertension, portal vein obstruction, as well as imaging of the vasculature prior to and postliver transplantation are presented in this article.

Magnetic resonance imaging and diseases of the liver and biliary tract. Part 2. Magnetic resonance cholangiography and angiography and conclusions

Magnetic resonance cholangiography (MRC) relies on the strong T2 signal from stationary liquids, in this case bile, to generate images. No contrast agents are required, and the failure rate and risk of serious complications is lower than with endoscopic retrograde cholangiopancreatography (ERCP). Data from MRC can be summated to produce an image much like the cholangiogram obtained by using ERCP. In addition, MRC and conventional MRI can provide information about the biliary and other anatomy above and below a biliary obstruction. This provides information for therapeutic intervention that is probably most useful for hilar and intrahepatic biliary obstruction. Magnetic resonance cholangiography appears to be similar to ERCP with respect to sensitivity and specificity in detecting lesions causing biliary obstruction, and in the diagnosis of choledocholithiasis. It is also suited to the assessment of biliary anatomy (including the assessment of surgical bile-duct injuries) and intrahepatic biliary pathology. However, ERCP can be therapeutic as well as diagnostic, and MRC should be limited to situations where intervention is unlikely, where intrahepatic or hilar pathology is suspected, to delineate the biliary anatomy prior to other interventions, or after failed or inadequate ERCP. Magnetic resonance angiography (MRA) relies on the properties of flowing liquids to generate images. It is particularly suited to assessment of the hepatic vasculature and appears as good as conventional angiography. It has been shown to be useful in delineating vascular anatomy prior to liver transplantation or insertion of a transjugular intrahepatic portasystemic shunt. Magnetic resonance angiography may also be useful in predicting subsequent variceal haemorrhage in patients with oesophageal varices.

Active intrahepatic gadolinium extravasation following TIPS

A 31-year-old male patient had a transjugular intrahepatic portal systemic shunt (TIPS) placed for acute Budd-Chiari syndrome secondary to paroxysmal nocturnal hemoglobinuria (PNH). Post-procedure, he was anticoagulated for his underlying paroxysmal nocturnal hemoglobinuria. After 11 days, he complained of upper abdominal pain and underwent magnetic resonance imaging (MRI). On immediate post-gadolinium spoiled-gradient-echo (SGE) images, active extravasation of gadolinium was depicted in one of two intrahepatic hematomas. Progression of layering of high signal gadolinium was shown from early to later phase post-gadolinium images. The active arterial bleeding was confirmed by conventional angiography performed immediately following the magnetic resonance imaging.

SPIO-enhanced 2D-TOF MR angiography of the portal venous system: results of an intraindividual comparison

The purpose of this study was to investigate whether MR angiography (MRA) of the portal venous system may be improved by means of superparamagnetic iron oxides (SPIOs) during accumulation phase imaging and to study the underlying contrast mechanisms. MRA of the portal venous system was performed on 48 patients before and after intravenous injection of a new SPIO (Resovist, Schering AG, Berlin, Germany). Resovist, as a predominantly liver parenchymal darkening agent on T2-weighted MR images with uptake into the reticuloendothelial cell system, was administered intravenously by bolus injection of 8 to 12 micromol Fe/kg body weight. Patients were scanned with breath-hold coronal and axial two-dimensional (2D) time of flight (TOF) MRA (TR = 31.0 msec, TE = 9.8 msec, flip angle (FA) = 50 degrees, and 6.9-second acquisition time per section) sequences. Signal intensity values of liver parenchyma, the portal venous system, and background were obtained for quantitative analysis. The clinical relevance of additional plain and contrast-enhanced MRA studies for surgical planning was assessed by independent reading of three readers. Liver signal-to-noise ratio (SNR) significantly decreased following iv injection of Resovist; however, SNR values of the portal veins or hepatic veins did not change significantly. Visibility of the portal venous system improved significantly (tertiary branches visible: pre in 15.2% versus post in 87.0% of patients). Resovist-enhanced 2D-TOF MRA may improve planning of liver resections by better demonstrating the relationship of central liver lesions and vessels on source images. The decrease in liver SNR at a constant vessel SNR after iv injection of Resovist improves MRA of the liver. SPIO-enhanced 2D-TOF MRA scans are superior to plain 2D-TOF MRA studies and may be added for the workup of preoperative patients.

Transjugular intrahepatic portosystemic shunting (TIPS) with balloon-expandable and self-expanding stents: technical and clinical aspects after 3 1/2 years' experience

PURPOSE

To evaluate prospectively our experience with transjugular intrahepatic portosystemic shunt (TIPS) using four different metallic stents.

METHODS

Between November 1991 and April 1995, 57 patients (41 men and 16 women; age 35-72 years, mean 54 years) underwent the TIPS procedure. Techniques for portal vein localization before and during TIPS were fluoroscopy, computed tomography (CT) studies, wedged hepatic venography, arterial portography, and ultrasound. After predilation we deployed balloon-expandable (n = 48) and self-expanding (n = 45) metallic stents. Fifteen patients underwent variceal embolization. Initial follow-up angiograms (mean 6.9 months, range 3-24 months) were obtained in 39 of these patients.

RESULTS

Fifty-three patients (93%) had successful TIPS placement. The mean decrease in portal pressure was 42.7%. Besides fluoroscopy, the most helpful techniques for portal vein localization were venography and CT. Residual stenosis (n = 1) and late shortening (n = 4) of Wallstents resulted in shunt dysfunction. The technical problems encountered with the Palmaz stent resulted from its lack of flexibility. We combined balloon-expandable and self-expanding stents in 12 patients. The 30-day and late follow-up (mean 11.9 months) percutaneous reintervention rates were 11.3% and 64.2%, respectively. There were no clinically significant complications related to the TIPS insertions.

CONCLUSION

An ideal stent does not exist for TIPS, and the authors recommend combining a Palmaz stent with a flexible self-expanding stent.

Transmesenteric-transfemoral method of intrahepatic portosystemic shunt placement with minilaparotomy

PURPOSE

To determine whether the transmesenteric-transfemoral method of intrahepatic portosystemic shunt (IPS) placement is safer and more efficient than the transjugular method.

PATIENTS AND METHODS

Sixty-six consecutive patients with cirrhosis and bleeding varices underwent 67 IPS procedures. Sixty-one of these procedures were performed using a combination of transfemoral access to the hepatic vein with transmesenteric access to the portal system provided by means of minilaparotomy. Follow-up days were collected periodically by means of clinical evaluation and duplex sonography of the shunt. Angiographic evaluation was performed when necessary.

RESULTS

No technical failures or periprocedural deaths occurred. The radiologic and surgical portions of the procedure were accomplished within 45 and 55 minutes, respectively. In cases without portal thrombosis, maximum fluoroscopy time was 12 minutes. During follow-up (mean, 16 months), eight shunt revisions including one additional shunt placement were necessary.

CONCLUSION

Transmesenteric-transfemoral IPS placement requires surgical participation but may offer improved efficiency and safety compared with regular transjugular IPS placement.

Hepatic laceration from wedged venography performed before transjugular intrahepatic portosystemic shunt placement

Transjugular intrahepatic portosystemic shunt (TIPS) placement is an increasingly used, nonoperative technique for treating variceal bleeding and refractory ascites secondary to portal hypertension. Since the first clinical TIPS case in 1989, the procedure has undergone significant technical refinement to improve the safety and efficacy of shunt placement. A major technical challenge of TIPS creation is passage of the transjugular needle from the hepatic vein into the portal vein. Perforation of the liver capsule from an errant needle pass can lead to massive intraperitoneal bleeding. To minimize the number of needle passes required to enter the portal vein, investigators have devised a variety of techniques to visualize the portal vein anatomy including direct transhepatic catheterization of the portal vein, superior mesenteric artery (SMA) angiography, real-time ultrasound (US) guidance and refluxing contrast medium into the portal vein with wedged hepatic venography. While these technical improvements have made TIPS a safe and attractive alternative to conventional surgical shunts, the procedure remains technically challenging and lethal hemorrhagic complications can occur when the liver capsule is perforated during the course of the procedure. To our knowledge, there are no reported major complications directly related to the wedged hepatic venogram prior to TIPS. We describe an unusual series of severe liver injuries from wedged hepatic venography during attempts to localize the portal vein.

Comparison of ultrasound, CT, and MR imaging in the evaluation of candidates for TIPS

To compare ultrasound (US), CT, and MRI in the evaluation of hepatic vascular anatomy, portal and splenic venous flow, and collateral pathways (varices and spontaneous shunts) in candidates for transjugular intrahepatic portosystemic shunting (TIPS), 17 patients with history of refractory variceal bleeding or intractable ascites underwent duplex US, contrast-enhanced CT, and MRI before TIPS. The appearance of portal and hepatic anatomy was graded from 1 (not visible) to 4 (excellent visualization) independently by four radiologists. Presence and direction of portal and splenic venous flow, and presence and location of varices and spontaneous portosystemic shunts were also assessed. Results and effects of interobserver variation were assessed for significance using Friedman's ANOVA and Wilcoxon's signed-rank test. MRI yielded higher scores than CT or US for hepatic veins (P < .0001) and inferior vena cava (P < .0001). MRI and CT scored better than US for portal vein branches (P = .012) and splenic vein (P = .0038). All tests demonstrated the main portal vein well, with no statistically significant difference. US and MRI were more sensitive than CT for detecting portal vein flow and direction (US 76%, CT 0%, MRI 82%). MRI was most sensitive for splenic vein flow and direction (US 41%, CT 0%, MRI 76%). CT and MRI were more sensitive than US in detecting varices (US 5%, CT 50%, MRI 58%) and spontaneous shunts (US 13%, CT 75%, MRI 75%). Interobserver variation did not influence results significantly P = .3691). MRI provides the most useful information and may be the preferred single imaging test prior to TIPS.