Comparison of abdominal depth with subcutaneous fat thickness in predicting surgical site infection among patients undergoing hepatopancreatobiliary surgery: a prospective observational study.

Introduction: Surgical site infection (SSI) is a significant cause of postoperative morbidity resulting in an increased hospital stay and cost. Various measures have been used to predict SSI such as subcutaneous fat thickness (SCFT) and abdominal depth (AD) in case of abdominal surgeries. The objective of the study was to compare SCFT with AD to predict SSI in HPB surgeries. Methods: A prospective observational study was conducted from February 2020 to February 2021, which included 76 patients who underwent elective open hepatopancreatobiliary surgeries. SCFT and AD at the level of the umbilicus were measured preoperatively using the computed tomography abdomen. The occurrence of SSI was evaluated in correlation with SCFT and AD. SCFT and AD were compared using the receiver operating characteristic curve for prediction of SSI. Results: Twenty-five (32.3%) patients who underwent elective HPB surgeries developed SSI. 72% of the SSI were superficial. In multivariate analysis, only SCFT was associated with SSI, which was statistically significant. It was compared with AD using the receiver operating characteristic curve where SCFT proved to be better at predicting SSI (AUC=0.884) with cut-off =2.13 cm, sensitivity 84%, and specificity 86%), compared to AD with an AUC of 0.449. Conclusion: SSI is the common cause of increased morbidity following hepato-pancreato-biliary surgeries with risk factors including SCFT and AD. Approximately one-third of patient developed SSI, with most the common being superficial SSI. SCFT at the incision site was associated with an increased rate of SSI and the better predictor for SSI as compared with the AD.