vv Archives of Organ Transplantation CC By 001 Clinical Group Citation: Lozano P, Martín L, Orue-Echebarria MI, Asencio JM, Sharma H, et al. (2019) Purpose of the measurement of intraoperative hepatic hemodynamics in liver transplant surgery. Arch Organ Transplant 4(1): 001-004. DOI: http://doi.org/10.17352/2640-7973.000011 DOI: http://dx.doi.org/10.17352/aot ISSN: 2640-7973 Case Study Purpose of the measurement of intraoperative hepatic hemodynamics in liver transplant surgery Pablo Lozano*, Lorena Martín, Maitane Igone Orue-Echebarria, José Manuel Asencio, Hemant Sharma and Jose Ángel López Baena Department of Transplant, Hospital Universitario Gregorio Maranon, C/ Doctor Esquerdo 44.28007, Madrid, Spain Dates: Received: 11 March, 2019; Accepted: 21 March, 2019; Published: 22 March, 2019 *Corresponding author: Pablo Lozano, MD,PhD, Hospital Universitario Gregorio Maranon. Dr. Esquer- do st 44 28007, Madrid, Spain, Tel: 0034639011522; E-mail: Keywords: Hepatic artery flow; Portal vein flow; Liver transplant https://www.peertechz.com Abbreviation EAD: Early Allograft Dysfunction; HAF: Hepatic Artery Flow; LDLT: Living Donor Liver Transplantation; PH: Portal hypertension; PVF: Portal Vein Flow; PVP: Portal Venous Pressure; TACE: Transarterial Embolization; THF: Total Hepatic Flow Case Study The intraoperative measurement of coronary flow began to be clinically relevant [1,2], when it demonstrated its short and long term predictive value in the functional evaluation of the revascularizations in patients undergoing revascularization surgery , especially with the advent of minimally invasive revascularization surgery over the heart, in which the quality control of the anastomosis is paramount [3]. In the field of liver transplantation, experimental studies have shown the importance of adequate perfusion of the liver graft to ensure its correct function. However, the relevance of the hepatic artery and portal vein flows in that function are still unknown. Abstract Liver graft function depends on different biological factors that are related to the donor, the recipient and the potential damage arising from the organ preservation technique. However, adequate hepatic artery flow and portal vein flow rates ensure a sufficient flow of oxygen and nutrients in order to ensure a suitable cellular graft function after the extreme metabolic decrease condition induced by hypothermia and the preservation solution. Liver inflow is a highly complex system due to its double irrigation system. These two systems are connected by the well-known “hepatic arterial buffer response” concept. This mechanism explains changes in hepatic arterial flow (HAF) as a compensation for changes in the portal vein flow (PVF), so that the hepatic artery adjusts total flow in relation to alterations in the portal blood flow. At the moment, the minimum HAF and PVF required for an adequate regeneration and functional recovery of the liver graft have not been yet established. The hyperdynamic circulation state observed in cirrhosis could influence liver hemodynamics during liver transplantation; with this situation can be modified intraoperative surgical maneuvers if necessary. A decrease in the HAF could lead to hepatic artery thrombosis. The changes in microcirculation also play an important role in the damage caused by the ischemia reperfusion injury; for instance, sinusoidal diameter narrowing and vascular flow are the first changes to occur after damage by ischemia reperfusion. The damage produced in the sinusoidal endothelium manifests itself as alterations in the early stages of intraoperative hemodynamics. Therefore, and in conclusion, early intraoperative detection of alterations in liver hemodynamics during liver transplantation could be used to prevent worse outcomes in the postoperative time. Measurement of intraoperative vascular flows The measurement of the intraoperative flows is made with a VeriQ™ flowmeter (Medistin, Norway), VeriQ™ offers both proven transit time flow measurement (TTFM) and Doppler velocity measurements that are specifically designed for intraoperative blood flow and graft patency verification. The Doppler effect uses the transmission of a continuous wave and the MFTT employs the transmission of pulses. By applying the Doppler concept on the components of the blood, we can measure the vessel blood flow velocity. If the sound is directed in the direction of flow, the received signal will be different depending on whether the blood components are near or far from the transducer. The sensor used by the MFTT contains two transducers and a reflector. The two transducers are located on one side of the vessel and the reflector on the opposite side, this arrangement causes a double ultrasound passage through the vessel. The crystal located in the direction of flow generates a pulse of ultrasound that is captured by the glass of the opposite