Volumetric Gain of the Liver after Major Hepatectomy in Obese Patients A Case-Matched Study in 84 Patients

Objective: The objective was to determine the liver volumetric recovering capacity and postoperative course after major hepatectomy in obese patients through a case-matched study. Background: In literature, the impact of obesity on liver recovering has been analyzed only indirectly in terms of morbimortality but never through volumetric assessment. Patients and Method: Between 2005 and 2011, 42 patients with body mass index (BMI) 30 or higher (Ob group) underwent major hepatectomy and were matched with 42 patients with BMI 25 or lower (NonOb group) on the magnitude of resection (number of resected segments +/-1, remnant liver volume to total liver volume, RLV/TLV, +/-5%). The RLV was measured on computed tomographic slices preoperatively and postoperatively at 1 month (RLV-1M) for all patients and within 3 to 12 months in 42 paired patients (median = 6 months, RLV-6M). Considering hepatomegaly in Ob group, RLV was also normalized to body weight (RLVBWR). The liver volumetric gain was expressed as a relative increase [(RLV-1M - RLV)/RLV] or increase in RLVBWR. Results: The Ob and NonOb groups were comparable regarding clinicopathological data, except for arterial hypertension (48% vs 19%; P = 0.005), mean steatosis (24% vs 10%; P = 0.03), and fibrosis incidence (33% vs 10%; P = 0.008). Ob group showed longer operative time and higher blood losses. There were no intergroup differences in liver failure (both 7.1%) and 90-day morbimortality. Despite comparable RLV/TLV (38.1% vs 37.7%; P = 0.13), the relative liver volumetric gain at 1 month was significantly lower in Ob group (+ 93% vs + 115%; P = 0.002), as well as RLVBWR increase (+ 0.59% vs + 0.79%; P < 0.001). The RLV-1M represented 66.2% of initial TLV in Ob group compared with 73.8% (P = 0.005) in NonOb group. This delay in relative volumetric gain persisted at 6 months (+ 105.4% vs + 137.6%; P = 0.009), the RLV-6M representing 71.2% vs 82.4% of initial TLV (P = 0.014). Conclusions: In a methodologically robust trial in the first cohort reported up to date, the regenerative response in obese patients was comparatively slower based on their initial TLV or body weight.