Establishment of a method for calculating standard splenic volume and its use in the evaluation of functional hepatic reserve

Background and aim: To objectively assess splenic volume preoperatively, the Standard Splenic Volume (SSV) was calculated for each patient. Whether it could be used to evaluate the functional hepatic reserve less invasively before major hepatectomy was then examined. Patients and methods: SSV was calculated for 70 patients who had undergone surgery, excluding liver surgery, for benign disease or early-stage cancer. The postoperative clinical courses of 63 patients who had undergone a sectionectomy or hemihepatectomy were then retrospectively investigated by comparing the preoperative splenic volume with each patient’s SSV. Results: The following equation was obtained: SSV (cm³)=177.7 × Body Surface Area (BSA)-179.9. None of the patients in the preoperative Splenic Volume (SV)/SSV<1.1 group had total Bilirubin (T-Bil) levels ≥ 1.2 mg/dl in late postoperative period. In contrast, nine (30%) of the patients in the preoperative SV/SSV ≥ 1.1 group (n=30) had T-Bil levels ≥ 1.2 mg/dl in late postoperative period. Conclusion: By comparing the preoperative SV and SSV of patients, objective assessments of the patients’ preoperative portal venous pressure were obtained noninvasively. We believe that this ratio may provide useful information for evaluating functional hepatic reserve at the time of initial surgery for diseases that may require repeat hepatectomies or multidisciplinary treatment.