The value of residual liver volume as a predictor of hepatic dysfunction and infection after major liver resection

Abstract

Background and aims: Major liver resection incurs a risk of postoperative liver dysfunction and infection and there is a lack of objective evidence relating residual liver volume to these complications.

Patients and methods: Liver volumetry was performed on computer models derived from computed tomography (CT) angioportograms of 104 patients with normal synthetic liver function scheduled for liver resection. Relative residual liver volume (%RLV) was calculated as the relation of residual to total functional liver volume and related to postoperative hepatic dysfunction and infection. Receiver operator characteristic curve analysis was undertaken to determine the critical %RLV predicting severe hepatic dysfunction and infection. Univariate analysis and multivariate logistic regression analysis were performed to delineate perioperative predictors of severe hepatic dysfunction and infection.

Results: The incidence of severe hepatic dysfunction and infection following liver resection increased significantly with smaller %RLV. A critical %RLV of 26.6% was identified as associated with severe hepatic dysfunction (p<0.0001). Additionally, body mass index (BMI), operating time, and intraoperative blood loss were significant prognostic indicators for severe hepatic dysfunction. It was not possible to predict the individual risk of postoperative infection precisely by %RLV. However, in patients undergoing major liver resection, infection was significantly more common in those who developed postoperative severe hepatic dysfunction compared with those who did not (p=0.030).

Conclusions: The likelihood of severe hepatic dysfunction following liver resection can be predicted by a small %RLV and a high BMI whereas postoperative infection is more related to liver dysfunction than precise residual liver volume. Understanding the relationship between liver volume and synthetic and immune function is the key to improving the safety of major liver resection.

Figure 1

(A–C) Three dimensional liver volumetry of an extended right hepatectomy with caudate excision. (A) Total liver volume (TLV = 1133 ml; red colour); tumour volume (TuV = 34 ml; green colour); and total functional liver volume (TFLV = 1099 ml). (B) Residual liver volume (RLV = 293 ml yellow colour) from three dimensional liver model after virtual resection; relative residual liver volume (%RLV = 26.7%). (C) Intraoperative view of the residual liver following resection.

Figure 2

Mean (SD) relative residual liver volume (%RLV) of different types of extended (Ext R Hep, extended right hepatectomy; Ext L Hep, extended left hepatectomy), standard (R Hep, right hepatectomy; Centr Trisegm, central trisegmentectomy; L Hep, left hepatectomy), and minor (R Post Sect, right posterior sectionectomy; L Lat Sect, left lateral sectionectomy; Segment, segmentectomy) liver resection. Reference line indicates 33% RLV.

Figure 3

Mean (SD) relative residual liver volume (%RLV) in patients with no, mild, moderate, and severe hepatic dysfunction following liver resection (one way between group ANOVA; **p = 0.005, ***p<0.0001). Reference line indicates 33% RLV.

Figure 4

(A) Receiver operator characteristic (ROC) curve analysis of relative residual liver volume (%RLV) to predict postoperative severe hepatic dysfunction. A critical %RLV value of 26.6% was identified (area under the curve = 0.918 (95% confidence interval 0.854–0.983); p<0.0001). (B) Incidence of severe hepatic dysfunction following liver resection according to %RLV. Reference line indicates the critical %RLV of 26.6% associated with a significant risk of postoperative severe hepatic dysfunction (Fisher’s exact test; p<0.0001).

Figure 5

(A) Receiver operator characteristic (ROC) curve analysis of relative residual liver volume (%RLV) to predict postoperative infection. No critical %RLV was identified in predicting infection with precision (area under the curve = 0.641 (95% confidence interval 0.528–0.755); p = 0.021). (B) Incidence of infection following liver resection according to %RLV (Fisher’s exact test, p = 0.069). Reference line indicates 26.6% RLV.

Figure 6

Incidence of severe hepatic dysfunction following liver resection in relation to relative residual liver volume (%RLV) and the presence of the additional risk factors body mass index >30 (BMI), operating time >240 minutes and/or blood loss >2000 ml (Intraop), or both (BMI+Intraop). Reference line indicates the critical %RLV of 26.6%.