The Use of Intraoperative Transit Time Flow Meter for the Early Detection and Prevention of Vascular Complications Following Adult Deceased Donor Liver Transplantation

Abstract

Purpose: This study aims to determine whether intraoperative analysis of arterial and portal venous flow using transit time flow measurement (TTFM) data is associated with a reduced incidence of vascular complications after orthotopic liver transplantation.

Methods: This is a retrospective chart review of all adult orthotopic liver transplant recipients at Saint Louis University Hospital from 2015-2020 (n = 188). We reviewed intraoperative flow probe use, as well as documentation of abnormal flow patterns detected during surgery. Normal graft flow measurements were defined as hepatic artery flow >100 ml/min and portal vein flow >0.5 ml/min/gram-liver. Postoperative imaging and ultrasonographic data were then reviewed for reports of vascular complications requiring intervention between the time of transplant and December 31, 2020. The incidence of VCs was compared between those who received intraoperative TTFM and those who did not. We then compared the demographic composition of these 2 groups to ensure similarity and screen for potential confounding factors.

Results: 188 liver transplant operative reports met the criteria for inclusion and were reviewed. TTFM use was documented in 78 (41.5%) cases and abnormal flow was detected in 8 (10.3%) of these cases, prompting intraoperative correction. Subsequently, no patients who received intraoperative TTFM developed vascular complications during the postoperative course. Conversely, of the 110 (58.5%) cases with no reported intraoperative flow data, 6 (5.5%, P = .042) patients later developed vascular complications. Reported vascular complications included hepatic artery stenosis, hepatic artery thrombosis, portal vein thrombosis, hepatic vein thrombosis, and IVC thrombosis. There was no significant difference in patient population between patients who received intraoperative TTFM and those who did not, apart from the type of liver implantation. There was a significantly higher prevalence of bicaval liver implantations in the group of patients who did not receive TTFM than those who did (P = .002).

Conclusions: Transit time flow measurement may be a useful tool for the detection of vascular flow abnormalities intraoperatively, allowing for early correction and prevention of vascular complications during the postoperative course. This could potentially result in enhanced graft survival and reduced recipient mortality following orthotopic liver transplantation.