Evaluation of implantable Doppler probe continuous monitoring of hepatic artery anastomosis after liver transplantation

Abstract

Background: Thrombosis of hepatic artery anastomosis (HAT) after liver transplantation is a catastrophic and dreaded complication. Early identification of HAT can salvage the situation. To monitor the anastomosis, conventional daily transcutaneous Doppler is performed. However, it has disadvantages of being noncontinuous, operator-dependent and technically difficult. Implantable Doppler probes wrapped around the anastomosed vessel giving continuous signal may be an important tool; however, very few studies are performed to study its efficacy after intra-abdominal vascular anastomosis, and its role is not clearly established.

Methods: Patients who underwent deceased donor liver transplant surgery were part of the study. On hepatic arterial anastomosis, implantable Doppler probe was fixed for monitoring. Conventional daily transcutaneous Doppler was also performed and the results were compared.

Results: A total of 40 hepatic arterial anastomoses were studied. The incidence of HAT was 10.53%. For the implantable Doppler probe monitoring, sensitivity and negative predictive value was 100%, whereas specificity was 94.44% and positive predictive value was 66.66% with an overall accuracy of 95%. A mean of 10 h of lead time was gained by implantable Doppler probe monitoring.

Conclusion: Our study showed that there was high sensitivity and negative predictive value of implantable Doppler probe monitoring system, which makes it ideal for post-operative vascular anastomoses surveillance monitoring; however, abnormal positive finding on implantable Doppler probe monitoring needs to be confirmed by conventional transcutaneous Doppler. The implantable Doppler probe monitoring, because of its round the clock and continuous nature gives us a good lead time in identifying vascular complication, which translates into graft salvage and reduction in morbidity and mortality.

Keywords: Hepatic arterial anastomosis; Hepatic artery thrombosis; Implantable Doppler probe; Liver transplantation.

Conflict of interest statement

The authors have none to declare.

© 2020 Director General, Armed Forces Medical Services. Published by Elsevier, a division of RELX India Pvt. Ltd.

Figures

Fig. 1

Doppler probe being implanted distal to the anastomosis.

Fig. 2

Cable of implanted Doppler being anchored to skin using metal staples.

Fig. 3

Position of implantable Doppler leaving skin in relation to main wound.

Fig. 4

Implantable Doppler monitor with continuous audio-visual signal.