Abstract: Objective To investigate the impact of preoperative frailty on surgical site infection (SSI) after partial hepatectomy in elderly patients, and to identify associated risk factors for infection. Methods A total of 224 patients aged ≥60 years who were scheduled for elective partial hepatectomy at the Hepatobiliary Center of Jiangsu Province Hospital from January to December 2024 were enrolled. Preoperative frailty was assessed on admission using the FRAIL scale (frailty defined as a score ≥3). Data on demographics, comorbidities, preoperative laboratory indices, and perioperative variables were collected. Patients were grouped according to the occurrence of postoperative SSI for comparison. Multivariable logistic regression analysis was used to identify independent risk factors for SSI. Results Among the 224 patients, 61 were frail and 163 were non-frail, with a preoperative frailty prevalence of 27.23%. Postoperative SSI occurred in 28 patients (12.50%). The incidence rate of SSI was significantly higher in the frailty group than that in the non-frailty group (29.51% vs 6.13%, P<0.001). Multivariable logistic regression identified that preoperative frailty (OR=7.720, 95%CI: 1.502-39.671, P=0.014), elevated preoperative C-reactive protein (OR=3.399, 95%CI: 1.971-5.861), higher platelet-to-lymphocyte ratio (OR=1.026, 95%CI: 1.009-1.044), and longer operative time (OR=1.019, 95%CI: 1.007-1.031) were independent risk factors for SSI. Conclusions Preoperative frailty significantly increases the risk of SSI in elderly patients undergoing partial hepatectomy. Routine preoperative frailty screening and risk stratification, together with targeted perioperative management incorporating inflammatory markers and operative time, may help reduce the incidence of SSI.

Key words: frailty, aged, partial hepatectomy, incision infection