To construct a risk factor model for postoperative skeletal muscle reduction in patients undergoing extensive hepatectomy for liver cancer and verify its application effect.

A retrospective analysis was conducted on the clinical data of 260 patients with extensive resection of liver cancer admitted to Shandong Provincial Third Hospital from March 2019 to March 2021, using the random number table method, all patients were included in the training group (n=182) and the validation group (n=78) in a ratio of 7∶3 respectively. CT imaging was used to evaluate the reduction of skeletal muscle, and the differences in clinical data between patients with and without skeletal muscle reduction in the training group (n=182) were compared. Logistic multivariate regression analysis was used to summarize the risk factors of postoperative skeletal muscle reduction in patients with extensive resection of liver cancer, and the risk factors were incorporated into the Nomogram prediction model. The receiver operating characteristic (ROC) curve of the predictive model for predicting postoperative skeletal muscle reduction in patients with extensive resection of liver cancer in the validation group was drawn, and the clinical decision curve analysis (DCA) was used to verify the clinical practical value of the model. The patients were followed up until 3 years after the operation. The survival status of the patients was recorded through outpatient reexamination and telephone follow-up, the Kaplan-Meier method was used to evaluate the impact of skeletal muscle reduction on overall survival, and the Cox proportional hazards model was used to correct for confounding factors such as operation time.

The incidences of postoperative skeletal muscle reduction in the training group and the validation group were 42.31% (33/78) and 44.51% (81/182), respectively, there was no statistically significant difference between the groups (P>0.05). In the training group, those with a postoperative skeletal muscle index change rate of ≤-3.6% were classified as the musculoskeletal reduction group (n=81), and the remaining 101 cases were classified as the normal musculoskeletal group. The incidences of preoperative muscle atrophy, postoperative WBC levels, operation time, blood loss volume, microvascular invasion, incidence of concurrent incision infection, incidence of concurrent organ/cavity infection, and incidence of concurrent bacteremia in the skeletal muscle reduction group and the skeletal muscle normal group were compared, with statistically significant differences (P<0.05). Logistic multivariate analysis showed that preoperative sarcopenia, WBC level, operation time, blood loss, microvascular invasion, concurrent incision infection, concurrent organ/cavity infection, and concurrent bacteremia were all independent risk factors affecting postoperative skeletal muscle reduction in patients with extensive resection of liver cancer (P<0.05). The area under the curve (AUC) of the model in the training group and the validation group was 0.853 (95% CI: 0.802-0.904) and 0.808 (95% CI: 0.721-0.895), respectively. The sensitivity and specificity of the validation group were 80.66% and 81.30%, respectively. The Hosmer-Lemeshow goodness-fit test was used to evaluate the calibration degree. Both the training group (χ²=6.32, P=0.612) and the validation group (χ²=5.84, P=0.665) showed good calibration performance, and DCA analysis indicated that the model had a high clinical net rate of return. At the follow-up, the median follow-up time for the surviving patients was 28 months, and the median overall survival of the total cohort was 35.7 months. In the univariate analysis, the overall survival period of the skeletal muscle reduction group was shorter than that of the normal skeletal muscle group (P=0.014). Multivariate analysis showed that skeletal muscle reduction was an independent risk factor for postoperative death (P<0.001).

Patients with extensive resection of liver cancer have a relatively high risk of postoperative skeletal muscle reduction, which is related to factors such as preoperative sarcopenia, inflammatory response, operation time, blood loss, microvascular invasion, and complications. The prediction model established based on the above factors can provide a reliable reference for the risk assessment of postoperative skeletal muscle reduction in patients with extensive resection of liver cancer.