Transjugular intrahepatic portosystemic shunt (TIPS) placement is a well-studied procedure for patients with variceal bleeding, refractory ascites, and hepatic hydrothorax on optimal medical therapy. Despite its efficacy, TIPS remains one of the more technically challenging procedures, particularly related to safely gaining access into the portal venous system.

A typical TIPS procedure involves internal jugular venous access, hepatic vein catheterization, venography, and wedged CO2 portography, and the most challenging step—retrograde portal vein access prior to tract dilatation and stent placement. When using CO2 portography as a landmark for portal venous access, usually several needle passes are required and each additional needle pass increases the risk of adverse events, such as hepatic artery injury, hemobilia, and damage to surrounding structures (kidney, colon, and lung parenchyma).

There have been multiple ways to mitigate this issue, such as biplanar angiography, percutaneous transhepatic guidewire placement within the portal venous system, and cone-beam CT guidance. These methods have had various successes but may require increased procedure time, increased radiation dose, or alternative access sites (for example when placing a microwire into the portal venous system via the transhepatic route).

In our opinion, the best solution for accessing the portal venous system during the TIPS procedure is using intravascular ultrasound guidance with a side-firing intracardiac echocardiographic tip (ICE). The benefit of having ICE guidance is intuitive: it allows for direct visualization of the portal venous target, proper selection of the closest hepatic vein to the respective portal vein, and needle guidance using real-time ultrasound visualization. Therefore, ICE guidance reduces the number of needle passes, the risk of hitting critical structures, and the length of the procedure. Previously, ICE guidance has proven its worth in managing complicated TIPS cases, such as portal vein thrombosis, distorted anatomy from prior surgery or neoplastic disease, as well as TIPS for Budd-Chiari syndrome (direct IVC to portal venous access in these cases).

There have been a few retrospective investigations comparing fluoroscopic guidance to ICE guidance for the TIPS procedure. In a study by Kao et al., the authors did a retrospective comparison between ICE and fluoroscopic guidance. It is interesting to note that the ICE operators were only 2 and 3 years out of fellowship versus 20+ years of experience in the conventional group. The data showed that ICE catheter guidance significantly decreased the number of needle passes, contrast volume, fluoroscopy time, procedure time, and radiation exposure. More importantly, ICE largely reduced the number of “outliers” —those occasional cases in which 30+ needle passes and a few hours of fluoroscopy times are required. It is likely in clinical practice that exactly these outlier cases drive up complication rates.

In a different study, by Ramaswamy et al., the authors did a propensity-matched retrospective review. The data showed the procedure time and outcomes were not significantly different between ICE and conventional techniques. However, there was a significant reduction in contrast volume and radiation in the ICE guidance group. The major caveat of the study was that the ICE operators were much earlier in their career than the conventional group, with an average experience of 4.2 years versus 11 years. The difference in operator experience probably indicates that ICE has the potential to decrease the procedure time when adjusted for operator experience.

Based on the available retrospective studies and our experience, a few points can be confirmed.

1. ICE decreases the number of needle passes, radiation exposure (to both the patient and operator), and contrast volume.
2. ICE most likely decreases the procedure time, accounting for differences in operator experience.
3. ICE will largely eliminate outlier cases that are more likely associated with complex anatomy/clinical scenario and have a higher potential to cause major complications.

In our experience, ICE catheter guidance makes the procedure safer in tough situations. Of course, ICE adds costs (~ $1,000/probe). The modality has a pretty steep learning curve, and it requires an additional venipuncture. In addition, the (more inexperienced) conventional operator can achieve excellent results in routine and/or complex scenarios without using ICE.

In our view, ICE guidance is most helpful in dealing with complex TIPS cases in which a large number of needle passes are expected and complications are frequent. Furthermore, it offers a back-up option when a conventional TIPS procedure runs into unexpected challenges. Instead of blindly sticking another 20 times, we should become familiar with using the available tool (ICE catheter guidance) in our procedural arsenal to provide a safer experience for our patients, ultimately improving outcome in the end-stage liver disease population.

All comments are welcomed; Sasan Partovi can be reached at partovs@ccf.org.

References:

Ramaswamy RS, Charalel R, Guevara CJ et al. Propensity-matched comparison of transjugular intrahepatic portosystemic shunt placement techniques: Intracardiac echocardiography (ICE) versus fluoroscopic guidance. Clin Imaging. 2019; 57:40–44.

Kao SD, Morshedi MM, Narsinh KH, Kinney TB et al. Intravascular Ultrasound in the Creation of Transhepatic Portosystemic Shunts Reduces Needle Passes, Radiation Dose, and Procedure Time: A Retrospective Study of a Single-Institution Experience. JVIR. 2016; 27:1148–1153.

Interested in learning more about POCUS? Check out the following posts from the Scan:

• Do It With Heart: Pre-Intubation Point-of-Care Echocardiography for Hemodynamic Optimization
• Ultrasound in Central Vein Assessment – The Importance of Knowing
• The Expanding Scope and Diagnostic Capabilities of Vascular Ultrasound