Wireless Surveillance for Transjugular Intrahepatic Portosystemic Shunts (TIPS) A Feasibility Study

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.