Analysis Of Pulmonary Arterial Pressure Changes And Related Factors In Neohepatic Stage Of Classical Orthotopic Liver Transplantation

Background:Classical orthotopic liver transplantation(OLT)is the most common type of liver transplantation in clinical practice at the present stage.Due to the complex pathophysiological status of patients before surgery and the particularity of surgical operation,perioperative hemodynamics fluctuates greatly.Especially after the opening of the portal vein and inferior vena cava,the systemic and pulmonary circulations will undergo drastic changes,resulting in a sharp increase in pulmonary arterial pressure in a short period,and even lead to pulmonary arterial hypertension crisis,poor perfusion of donor liver,right heart failure and even whole heart failure.Most of the relevant studies focus on the influence of postreperfusion syndrome on pulmonary arterial pressure.Based on the analysis of hemodynamic changes during liver transplantation,this study aimed to find other factors that may cause pulmonary arterial pressure elevation in neohepatic stage and provide evidences for clinical practice.Objective:To investigate the related factors of pulmonary artery elevation in the neohepatic stage in classical orthotopic liver transplantation,and to provide evidences for the prevention and treatment of pulmonary hypertension in liver transplantation.Method:Prospective data were collected from relevant patients.The clinical data of 80 patients who underwent classical orthotopic liver transplantation in The Affiliated Hospital of Qingdao University from May 2020 to December 2021 were collected.Heart rate(HR),mean arterial blood pressure(m ABP),mean pulmonary arterial pressure(m PAP),pulmonary artery wedge pressure(PAWP),central venous pressure(CVP),heart index(CI),system and pulmonary vascular resistance index(SVRI,PVRI)and stroke volume variation(SVV)were recorded at the time of before cuting skin(T0),pre-anhepatic(T1),immediate occlusion(T2),30 min after occlusion(T3),immediate reperfusion(T4),60 min after reperfusion(T5),and after operation(T6).The two groups were divided into pulmonary hypertension group(PAH group)and non-pah group(non-PAH group)according to whether m PAP was greater than 25 mm Hg in the neohepatic stage.Univariate analysis and Logistic multiple regression analysis were used to find the risk factors of pulmonary hypertension in the neohepatic stage.Results:1.Intraoperative hemodynamic changesAt each time point,there were no significant differences in HR,mABP and CI between PAH group and non-PAH group,while m PAP of PAH group were significantly higher than those in non-PAH group from T1 to T6(P<0.05).The SVV of PAH group always lower than PAH group.Compared with non-PAH group,PAWP and CVP in PAH group were higher at T1,T4 and T5(P<0.05),and there was no significant difference at other time points.SVRI and PVRI at T1 and T5 were higher than those in non-PAH group(P<0.05),and there was no significant difference at other time points.2.Univariate analysisA total of 32 patients developed pulmonary hypertension in the neohepatic stage,while the remaining 48 patients did not.Compared with non-PAH group,patients in PAH group had higher preoperative MELD score,higher CVP at immediate reperfusion,lower SVV at immediate reperfusion.And more colloidal fluid was injected in PAH group before reperfusion(P<0.05).3.Logistic regression analysisThe results showed that preoperative MELD score,SVV at immediate reperfusion,and the volume of colloidal fluid before reperfusion were independent risk factors for pulmonary hypertension in the neohepatic stage.4.Comparison of prognostic indicatorsCompared with non-PAH group,PAH group had higher incidence of cardiac arrest(P=0.035)and pulmonary hypertension crisis(P=0.026).And the postoperative mechanical ventilation time was longer(P=0.033).There was no significant difference in the incidence of PRS,re-intubation,AKI,CRRT and PNF between the two groups.Besides,the ICU stay,total stay and in-hospital mortality are similar between the two groups.Conclusion:Preoperative MELD score,CVP and SVV at immediate reperfusion and the volume of colloidal fluid before reperfusion were important risk factors for pulmonary hypertension in the neohepatic stage.Among which,preoperative MELD score,SVV at immediate reperfusion and the volume of colloidal fluid before reperfusion were the independent risk factors.Therefore,attention to the severity of liver disease before the operation and appropriate control of colloid input during the operation are the keys to prevent pulmonary hypertension in liver transplantation.