J Extra Corpor Technol 2024 , 56 , 77 – 81 Ó The Author ( s ), published by EDP Sciences , 2024 https :// doi . org / 10.1051 / ject / 2024005
Available online at : ject . edpsciences . org
TECHNIQUE or APPLICATION
Venovenous bypass in liver transplantation : Exploring the benefits , efficacy , and safety
Salman Pervaiz Butt ( MBA MSc MPHYS ACCP FCCP CES-A ) 1 ,* , Arun Kumar ( MD ) 2 , Fazil Ashiq ( MD ) 3 , Andrei Minou ( MD ) 4 , Giuseppe Iuppa ( MD ) 5 , and Cristiano Quintini ( MD ) 6
1 Perfusionist & ECMO Specialist , Heart Vascular and Thoracic Institute , Cleveland Clinic , PO Box : 112412 , Abu Dhabi , United Arab Emirates 2 Department Chair , Cardiothoracic Aesthesia , Anesthesiology Institute , Cleveland Clinic , Abu Dhabi , United Arab Emirates 3 Anesthesiology Physician , Anesthesiology Institute , Cleveland Clinic , Abu Dhabi , United Arab Emirates 4 Anesthesiology Institute , Cleveland Clinic , Abu Dhabi , United Arab Emirates 5 Digestive Disease Institute , Cleveland Clinic , Abu Dhabi , United Arab Emirates 6 Institute Chair , Digestive Disease Institute , Cleveland Clinic , Abu Dhabi , United Arab Emirates
Received 26 October 2023 , Accepted 4 March 2024
Abstract – Venovenous bypass ( VVB ) is a technique used in liver transplantation ( LT ) to maintain hemodynamic stability and abdominal organ perfusion and thereby improve patient outcomes . Despite its perceived benefits , VVB utilization has declined globally due to concerns related to heparinization , major bleeding and the need for expertise . Recent advancements , such as percutaneous cannulation techniques and improved extracorporeal technology have improved the safety of VVB in LT . This paper presents a modified VVB circuit with enhanced safety features . Cannulation plays a pivotal role in VVB establishment , with percutaneous methods increasingly favored . Studies demonstrate VVB ’ s efficacy in improving patient outcomes with lower incidence of acute kidney injury and reduced operative time and blood loss , with no added morbidity or mortality . However , its routine use faces challenges , with alternative techniques gaining traction . Our experience highlights VVB ’ s role in various clinical scenarios , including patients with high Model for End-Stage Liver Disease ( MELD ) scores , challenging surgical anatomy , portal vein thrombosis and pre-existing cardiovascular disease , emphasizing its safety and efficacy . Continued research is needed to optimize VVB techniques and ensure better outcomes for liver transplant recipients .
Key words : Liver transplant , Venovenous bypass , Benefits .
Introduction
Venovenous bypass ( VVB ) is a technique employed during liver transplantation ( LT ) to redirect blood flow from Inferior vena cava ( IVC ) and portal circulation . This technique brings multiple advantages , notably minimizing the necessity for using the classic technique of IVC clamping . By diverting venous blood away from the liver , VVB maintains hemodynamic stability , prevents complications associated with prolonged clamping , and enhances recipient outcomes . Additionally , VVB shortens the anhepatic phase , reducing the risk of ischemia-reperfusion injury . Although the adoption of VVB requires ECC and specialized equipment , its integration into routine liver transplants holds great promise for improving outcomes and accessibility of this procedure [ 1 – 3 ].
The introduction of VVB in LT has a long history marked by significant milestones . Dating back to the early 1960s , initial
* Corresponding author : buttsab9 @ hotmail . com attempts at employing ECC techniques during LT were made by Dr . Thomas Starzl . However , these early efforts , including heparinization and venoarterial bypass , were soon abandoned due to unsatisfactory outcomes . A breakthrough came in the early 1980s when the Pittsburgh group introduced the VVB method , which utilized specialized equipment and techniques . This innovative approach , characterized by heparin-bonded tubing and blood propulsion via a low-pressure vortex principle , offered improved perfusion of the venous system with reduced trauma to blood . Over time , advancements have been made in bypass systems , such as the utilization of Biomedicus centrifugal pumps and the introduction of the Griffith TDMAC Veno-venous Shunt . These milestones in the evolution of VVB techniques have significantly contributed to addressing challenges associated with heparinisation and major bleeding during LT . Additionally , the development of rapid transfusion systems , pioneered by the Pittsburgh group , has further improved the management of rapid blood loss during surgical procedures [ 4 ].
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