Phase II Trial of Immunonutrition in Hepatectomy

Major hepatectomy remains a cornerstone in the curative management of primary and secondary liver tumors. Despite substantial advances in surgical techniques, anesthesia, and perioperative care, hepatectomy continues to be associated with considerable postoperative morbidity and mortality. Reported morbidity rates range from 22% to 40%, while mortality rates vary between 4% and 11%, largely driven by postoperative infectious complications, liver failure, and systemic inflammatory responses. Optimization of preoperative patient status, particularly nutritional and immune function, has therefore emerged as a critical area of interest to improve postoperative outcomes.

Immunonutrition, defined as nutritional supplementation enriched with specific substrates such as arginine, omega-3 fatty acids, and nucleotides, has demonstrated beneficial effects in patients undergoing major gastrointestinal surgery, pancreatic resections, and liver transplantation. These formulations are thought to modulate immune response, attenuate postoperative inflammation, improve protein synthesis, and enhance wound healing. However, evidence supporting the routine use of immunonutrition in patients undergoing hepatectomy remains limited and inconsistent. Existing meta-analyses suggest reductions in postoperative infectious complications and length of hospital stay, but uncertainty persists regarding its overall clinical benefit, particularly in relation to objective nutritional and immunological markers.

The prognostic nutritional index (PNI), calculated using serum albumin levels and total lymphocyte count, is a validated composite marker reflecting both nutritional and immune status. Multiple studies and meta-analyses have shown that a higher preoperative PNI is associated with improved postoperative outcomes and survival following hepatectomy. Furthermore, recent evidence indicates that inflammatory and nutritional biomarkers, including dynamic changes in albumin-based indices, are strong predictors of postoperative morbidity. These findings suggest that targeted immunonutritional interventions capable of improving PNI may translate into meaningful clinical benefits.

Against this background, the present study is designed to evaluate whether preoperative immunonutrition can improve PNI in patients undergoing major hepatectomy for liver tumors. The central hypothesis is that short-term preoperative immunonutrition leads to a measurable improvement in PNI compared with standard nutritional care.

The aim of the study is to assess the effect of preoperative immunonutrition on the prognostic nutritional index in patients planned for major hepatectomy.

The primary objective is to compare the mean change in PNI between patients receiving immunonutrition and those receiving standard nutritional care.

Secondary objectives include evaluating the impact of immunonutrition on postoperative complications, incidence of post-hepatectomy liver failure, length of intensive care unit stay, overall hospital stay, and 90-day postoperative mortality.

This is an open-label, randomized, phase II controlled trial conducted at Tata Memorial Hospital, Mumbai. Adult patients (≥18 years) with liver tumors scheduled for major hepatectomy, defined as resection of three or more liver segments, and classified as ASA physical status I-III will be eligible for inclusion. Patients with severe renal dysfunction, hypersensitivity to immunonutritional components, inability to tolerate oral intake, pregnancy, or conditions impairing informed consent will be excluded.

Eligible patients providing written informed consent will be randomized in a 1:1 ratio into one of two study groups using a centrally generated permuted-block randomization sequence. The intervention group will receive preoperative immunonutrition in addition to their usual oral intake for seven consecutive days prior to surgery. The immunonutritional supplement will be administered in weight-adjusted doses and compliance will be monitored through patient records and telephonic reminders. The control group will continue with their usual oral intake; patients identified as malnourished in this group will receive standard nutritional supplementation as per institutional protocols.

Blood samples will be collected at baseline and repeated on the day prior to surgery to assess serum albumin, lymphocyte count, and inflammatory markers. PNI will be calculated at baseline and preoperatively to evaluate the effect of the intervention. Postoperative assessments will include serial liver function tests, documentation of complications up to 90 days, and recording of ICU and hospital stay durations.

A total of 100 patients (50 per group) will be enrolled over two years, providing adequate power to detect a clinically meaningful difference in PNI between groups. Data will be collected prospectively and analyzed using appropriate statistical methods. Continuous variables will be summarized using means and standard deviations, while categorical variables will be expressed as proportions. The primary endpoint will be analyzed by comparing mean PNI differences between groups, with secondary outcomes evaluated using standard comparative statistical tests.

In summary, this study seeks to generate high-quality prospective evidence on the role of preoperative immunonutrition in improving nutritional and immune status, as measured by PNI, in patients undergoing major hepatectomy. The findings have the potential to inform perioperative nutritional strategies and improve postoperative outcomes in this high-risk surgical population.