Patient demographics
The study group included 44 males (72%) and 17 females with mean ages of 68.5±10.0 years (ranging 39-86 years). Background liver diseases included normal liver in four patients (7%), chemotherapy-associated liver dysfunction in nine (15%), chronic viral hepatitis in 17 (29%; cirrhosis in nil) and obstructive jaundiced liver in 31 (51%). Diseases included hepatocellular carcinoma in 17 patients (29%), intrahepatic cholangiocarcinoma in 13 (21%), chronic liver metastasis in 9 (15%), biliary cancers in 18 (30%) and others in four. Right hepatectomy was performed in 16 patients (25%), right hepatectomy with bile duct resection in eight (13%), right trisectionectomy in one (2%), left hepatectomy in 12 (20%), left hepatectomy with bile duct resection in 14 (23%), left trisectionectomy in one (2%), left hepatectomy with pancreaticoduodenectomy in four (7%) and central hepatectomy (segment 4, 5 and 8) in five (8%). In-hospital morbidity and morbidity over CD III was 37 (61%) and 17 (28%), respectively. The 30-day mortality and in-hospital mortality was nil and two (3%), respectively. The 30-day mortality rate and in-hospital mortality rate calculated by NCD-RC in the present series were 2.25±2.21% (ranging 0.1-10.5%) and 2.37±3.05% (ranging 0.3-15.9%), respectively.
Relationship with the estimated mortality by NCD-RC
The age was significantly correlated with the 30-day mortality (r=0.377, p=0.003) and, tended to be correlated with in-hospital mortality but not significant (r=0.240, p=0.062), respectively. Table 1 summarized the relationship between patient demographics and results by NCD-RC. Male patient showed significantly higher in-hospital mortality rate in compared to female (p<0.01). Age was divided into 3 groups and elderly patients significantly showed higher the 30-day mortality (p<0.05) and the in-hospital mortality also tended to be higher in elderly patients but no significant difference. Existence of systemic circulatory, cerebral, renal and respiratory diseases tended to show higher 30-day mortality rate without significance, and significantly showed higher in-hospital mortality rate (p<0.01). Existence of chronic respiratory diseases significantly showed higher in-hospital mortality rate (P<0.01). Background liver diseases were not significantly associated with 30-day or in-hospital mortality rate, either. The 30-day and in-hospital mortality rate was not significantly different in each type of major hepatectomy, respectively.
The 37 patients (61%) without severe morbidity (CD>II) or mortality who had low predictive 30-day or in-hospital mortality rate by NCD-RC (group woML) were examined. Age was 67.8±8.7 with ranging 45 and 84 years old (y.o.). Elderly patients of 70-79 and over 80 y.o. was 18 (49%) and two (5%). Table 2 showed the relationship between preoperative patient demographics, co-morbidity, operation or postoperative results, and predictive mortality rate by NCD-RC. The cut-off percent for high risk mortality before hepatectomy was set at 5%.
Patient features of highly estimated mortality by NCD-RC
Table 2, 3 and 4 showed preoperative parameters including age, gender, main hepatobiliary diseases, type of hepatectomy, CD-high (over III), postoperative major complications, mortality and the preoperative predictive mortality rates by NCD-RC were indicated in each situation with severe morbidity or with high risk mortality rates, except no morbidity, mortality nor high risk rates in 37 patients as above. These were divided in three groups as follows; A) with severe complications or mortality in whom low mortality rate by NCD-RC (group wML, n=13 (21%)), B) without severe complications neither mortality in whom high mortality rate (group woMH, n=7 (11%)), and C) with severe complications or mortality in whom high mortality rate (group wMH, n=4 (6.5%)) as Table 2-4. Patient age were not significantly different as 67.8±8.7 y.o., 66.4±13.7, 72±7.6 and 75.3±10.9, respectively, and the number of elderly patients (divided by <70, 70-79 and >79 y.o.) was not significantly different between groups (p=0.48). Prevalence of male was not significantly different between groups (p=0.99). Prevalence of the background liver injury and the main hepatobiliary diseases were not significantly different between groups, respectively (p=0.47 and 0.76). Although the preoperative co-morbidity rates in patients without postoperative severe complications (27% in the group woML and 23% in the group woMH) tended to be lower in comparison with that with complications (57% in the group wML and 50% in the group wMH), the prevalence of preoperative co-morbidity were not significantly different between groups (p=0.31).
In the group wML, type of hepatectomy was various and the bile leakage and the in-hospital death was not observed. In the group woMH, type of hepatectomy was various and organ failures or in-hospital death was not observed. In the group wMH, all operations were right hepatectomy with bile duct resection (RH-BDR) for biliary malignancy. Two patients died of hepatic failure over 30 days. Other two patients had hepatectomy-unrelated complications were occurred after hepatectomy and recovered. The prevalence of RH-BDR tended to be higher (p=0.089) but not significantly different. The predictive 30-day mortality rate before hepatectomy by NCD-RC was 1.4±1.1% in the group woML, 1.6±1.1% in the group wML, 5.5±2.6% and 6.6±2.0% in the group wMH, respectively and the latter two groups significantly showed higher percent (p<0.01). The predictive in-hospital mortality rate before hepatectomy by NCD-RC was 1.6±1.0% in the group woML, 1.2±0.6% in the group wML, 8.1±6.3% and 3.4±1.1% in the group wMH, respectively and the latter two groups significantly showed higher percent (p<0.01).