Immune Modulation by Enhanced vs Standard Prehabilitation Program Before Major Surgery

Over 30 million surgeries are performed annually in the US. Up to 30% of surgical patients experience delayed surgical recovery, marked by prolonged post-surgical pain, opioid consumption, and functional impairment, which contributes $8 billion annually to US health care costs. Novel interventions that improve the resolution of pain, minimize opioid exposure, and accelerate functional recovery after surgery are urgently needed. Multi-modal pre-operative optimization programs (or "prehab") integrating exercise, nutrition, and stress reduction have been shown to safely and effectively improve outcomes after surgery. However, no objective biological markers assess prehab effectiveness and are able to tailor prehab programs to individual patients. Surgery is a profound immunological perturbation, during which a complex network of innate and adaptive immune cells is mobilized to organize the recovery process of wound healing, tissue repair, and pain resolution. As such, the in-depth assessment of a patient's immune system before surgery is a promising approach to tailor prehab programs to modifiable biological markers associated with surgical recovery. The primary goal of this clinical trial is to determine the effect of a personalized prehab program on patients immunological status before surgery.

The study design is a prospective monocenter single-blinded randomized controlled trial in patients undergoing elective major abdominal surgery. * Patients will be recruited during the surgical consultation, at least 14 days prior to surgery. If they choose to enroll, they will undergo randomization on the day of enrollment. * Prehabilitation (Day 0): personalized or standard prehabilitation program will be proposed to the patients for a period of 2 to 6 weeks. Immunological, nutritional, physical, cognitive, anxiety and quality of life status will be quantified at baseline by previously trained personnel. * From the beginning (Day 0) to the end of the prehabilitation program (Day 14 to Day 42): every 7 days, a compliance questionnaire will be filled by phone, by a trained member of the research team blinded to the treatment arm of the study * End of the prehabilitation period (Day 14 to Day 42): Immunological, nutritional, physical, cognitive and anxiety status after prehabilitation will be recorded by a trained member of the research team blinded to the treatment arm of the study. * Surgery (Day S) * Post operative period * From Day S (2 hours after surgery end) to discharge from the hospital, length of stay, pain and adverse clinical events will be measured and recorded. * Immunological status will be assessed at Day S+1 by blood draw. * Cognitive function, neuropathic pain and quality of life will be assessed at Day S + 30.