Transjugular intrahepatic portosystemic shunt: Techniques for portal localization

Method for Calculating the Bending Angle of Puncture Needle in Preoperative Planning for Transjugular Intrahepatic Portal Systemic Shunt (TIPS)

Transjugular Intrahepatic Portal Systemic Shunt is a comprehensive interventional therapy for portal hypertension. During this intervention, puncturing from hepatic vein into portal vein is a difficult step. Selecting puncture needle with a proper bending angle is vital to accurate puncture. Thus, this prospective study provides a method to calculate the angle of the puncture needle using preinterventional contrast-enhanced CT imaging. According to the geometrical characteristics of puncture needle, Bezier curve equation was adopted to describe its bending part. By testing whether each point in a specific region satisfied the equation set of Bezier curves, the possible position of needle tip was obtained. Then, the bending angle of puncture needle was obtained by calculating curvature. The method was evaluated in 13 patients from 2 centers showing now a success rate of 100% and a duration of the procedure of 141 and 161 minutes. The method based on Bezier curve equation for calculating a proper bending angle of puncture needle was proven to be effective. And the clinical study is preliminary and additional work for clinical evaluation is necessary.

TIPS in patients with cranial porta hepatis: ultrasound-guided transhepatic portohepatic-portocaval puncture in single needle pass

OBJECTIVE

The purpose of this study was to describe our technique of transhepatic serial puncture of the portal vein and hepatic vein-inferior vena cava in one needle pass under ultrasound guidance to place a transjugular intrahepatic portosystemic shunt (TIPS) in patients with a porta hepatis cranial to the usual location.

MATERIALS AND METHODS

Six patients (five men, one woman) underwent transhepatic TIPS procedures at our institution. The indications for portal decompression were recurrent variceal bleeding in four patients and refractory ascites and hydrothorax in one patient each. In five patients initial attempts at a classic transjugular approach failed because of an unusual angle between the hepatic vein and the portal vein; in the other patient, revision of an occluded shunt had failed. Two patients had main portal vein thrombosis.

RESULTS

Technical success was achieved in all six patients. Two patients received a portohepatic venous shunt and four a portocaval shunt (inferior vena cava to right portal vein in three patients and inferior vena cava to left portal vein in one patient).The portosystemic pressure gradient before TIPS was 17-35 mm Hg and after TIPS was 6-10 mm Hg. No procedure-related complications occurred. One patient had severe hepatic encephalopathy. Two patients had shunt occlusion, which was successfully revised 17 and 10 months after the procedure.

CONCLUSION

Our technique is a safe, effective, and universally applicable method for establishment of a TIPS in patients with either normal venous anatomy or severely distorted liver parenchyma.

Portal anatomic variants relevant to transjugular intrahepatic portosystemic shunt

Transjugular intrahepatic portosystemic shunt (TIPS) creation is an accepted treatment for portal hypertension. TIPS creation remains a challenging procedure because it involves the successful passage of a needle from a point of origin (hepatic vein) to a target point (portal vein) through the liver substance. An understanding of the anatomy of these two vascular beds facilitates overcoming the challenge of the spatial relationship between these two points. In this article the authors review the vascular and parenchymal anatomic variations, both congenital and acquired that impact the success of TIPS creation.