Wireless Surveillance for Transjugular Intrahepatic Portosystemic Shunts (TIPS)

Rationale and Objectives

Shunt surveillance is a critical component of follow-up for patients with cirrhosis with transjugular intrahepatic portosystemic shunts (TIPS). Transabdominal Doppler ultrasound analysis of the shunt has been used as a noninvasive means of assessing shunt function. Doppler ultrasound analysis of the shunt is less sensitive than direct transjugular portosystemic pressure gradient measurement for detecting shunt failure. A wireless, noninvasive means of measuring the portosystemic pressure gradient in the clinic may facilitate follow-up in this group of patients. The aim of this study was to determine if two implanted wireless pressure sensors could accurately transmit a portosystemic pressure gradient across a TIPS.

Materials and Methods

Two wireless microelectromechanical system pressure sensors were placed in a swine model for measuring the portosystemic pressure gradient across a TIPS. Catheter-based pressure transducers were also placed and used as the gold standard. Pressures from both systems were measured concurrently.

Results

Wireless microelectromechanical system portal and systemic pressure measurements were accurate within ±2 mm Hg (mean, 0.86 mm Hg) of the gold standard.

Conclusion

The use of wireless sensors may facilitate the surveillance of shunt function in patients with portal hypertension who have undergone placement of TIPS.

Key Words: TIPS, portal hypertension, transjugular intrahepatic portosystemic shunt, cirrhosis, interventional radiology, biomedical microdevices