Portal Venous Pressure Variation during Hepatectomy: A Prospective Study.

INTRODUCTION: Excessive portal venous pressure in the liver remnant is an independent factor in the occurrence of posthepatectomy liver failure and small-for-size syndrome. The baseline portal pressure prior to hepatectomy was not considered previously. The aim of this study is to assess the impact of portal pressure change during hepatectomy on the patient outcome. MATERIAL AND METHODS: Prospective observational study including 30 patients subjected to intraoperative measurement of portal pressure before and after hepatectomy. This variation was related to the patient outcome. Control group evaluation was assessed. Patient, disease and procedure features were considered. The optimal cut-off of portal pressure variation was determined. Linear regression or logistic regression was applied to identify predictors of the outcome. RESULTS: The univariate analysis showed that portal pressure increase after hepatectomy was associated with coagulation impairment in the first 30 postoperative days (p < 0.05), and with the occurrence of major complications (p = 0.01), namely hepatic failure (p = 0.041). The multivariate analysis showed that portal venous pressure increase ≥ 2 mmHg is an independent factor for worse outcomes. DISCUSSION: As in previous studies, this study concludes that, after hepatectomy, in addition to the functional liver remnant, other factors are responsible for deterioration of liver function and patient outcome, such as the portal pressure increase and the exposure to chemotherapy prior to hepatectomy. This work may influence the definition of future indications for portal influx modulation. CONCLUSION: Patient outcomes are influenced by the portal venous pressure increase: an increment ≥ 2 mmHg after hepatectomy seems to increase the risk of major complications.

Introdução: O aumento da pressão venosa portal para o remanescente hepático é um fator independente para falência hepática após hepatectomia e síndrome small-for-size. Estudos anteriores não consideram o valor de pressão portal prévio à hepatectomia. O objetivo deste estudo é analisar o impacto da variação da pressão portal durante a hepatectomia na evolução clínica pós-operatória. Material e Métodos: Estudo observacional prospetivo, incluindo 30 doentes submetidos a medição intraoperatória da pressão portal antes e após hepatectomia, relacionando esta variação com a evolução clínica pós-operatória. Avaliação similar foi efetuada num grupo de controlo. Fatores relacionados com o doente, doença e procedimento foram considerados. Determinou-se o valor ideal de variação da pressão portal. Regressão linear ou logística foram aplicadas para identificar fatores preditores de evolução clínica. Resultados: A análise univariada mostrou que um aumento de pressão portal após hepatectomia associa-se a deterioração da coagulação nos primeiros 30 dias após hepatectomia (p < 0,05), a complicações major (p = 0,01) como a falência hepática após hepatectomia (p = 0,041). A análise multivariada mostrou que um aumento de pressão portal ≥ 2 mmHg é um fator independente para a evolução clínica pós-operatória desfavorável. Discussão: Após hepatectomia, para além do remanescente hepático funcional, outros fatores são responsáveis pela deterioração da função hepática e pela morbimortalidade, como o aumento da pressão portal e a exposição prévia a quimioterapia. Este trabalho contribui para a definição futura das indicações para modulação do influxo portal. Conclusão: Um aumento de pressão portal ≥ 2 mmHg após hepatectomia parece agravar o risco de complicações major.

Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viability.

It was reported that prevention of acute portal overpressure in small-for-size livers by inflow modulation results in a better postoperative outcome. The aim is to investigate the impact of portal blood flow reduction by splenic artery ligation after major hepatectomy in a murine model. Forty-eight rats were subjected to an 85% hepatectomy or 85% hepatectomy and splenic artery ligation. Both groups were evaluated at 24, 48, 72 and 120 post-operative hours: liver function, regeneration and viability. All methods and experiments were carried out in accordance with Coimbra University guidelines. Splenic artery ligation produces viability increase after 24 h, induces a relative decrease in oxidative stress during the first 48 hours, allows antioxidant capacity increment after 24 h, which is reflected in a decrease of half-time normalized liver curve at 48 h and at 72 h and in an increase of mitotic index between 48 h and 72 h. Splenic artery ligation combined with 85% hepatectomy in a murine model, allows portal inflow modulation, promoting an increase in hepatocellular viability and regeneration, without impairing the function, probably by inducing a less marked elevation of oxidative stress at first 48 hours.