any studies have shown the benefit of perioperative Oral Impact immunomodulation in gastrointestinal, ENT, gynecological and cardiac surgery. Studies in major Urological surgery are rare and not very contributory. The expected benefit is a reduction in postoperative complications and the average length of stay.

Major surgery induces traumatic stress due to the surgical aggression which could lead to major postoperative complications and death when the patient organism is not ready or prepared to support this intense stress. Malnutrition can be caused by chronic starvation, chronic inflammatory disease and acute injury (stress, acute inflammation). Therefore, nutritional supplements are indicated for patients who do not meet their energy needs through oral food ingestion. Immune-modulating nutrient-enriched products containing arginine, Omega-3 polyunsaturated fatty acids (PUFAs), nucleic acids, vitamins and antioxidants (selenium) like ORAL IMPACT (Nestlé) can modulate immune and inflammatory processes in burn, trauma, major surgery and improving clinical outcomes. These immune-modulating nutrient-enriched products have shown their ability to decrease postoperative complications up to 50% in patients undergoing non-gastrointestinal major surgery and length of hospital and ICU stay (Jie B 2012, Drover 2011). Mortality benefits have been demonstrated in one study focused on Neck and Head surgery. (Buijs N, 2010) Before 2019, in our urology surgery setting, it seemed that the postoperative complications rate was clinically increasing despite reliable surgeons and excellent surgery techniques and procedures. It appeared that the sources of these complications might be the weakness of the patients against major surgical stress. Patients might have been malnourished. The nutritional status had been omitted from our preoperative anesthesia assessment and no perioperative nutritional rehabilitation had been performed.

The effect of immune-modulating nutrient-enriched products had been demonstrated mostly in gastrointestinal surgery but also in non-gastrointestinal surgeries such as neck and head cancer surgery, gynecologic cancer surgery and cardiac surgery. There are not studies conducted in urologic major surgery.

Reducing the number of post-operative complications is a major challenge in surgery because they cause an increase in the length of stay, which translates into higher hospital costs for the community. Surgery generates major metabolic stress that the human body must manage. This metabolic stress will manifest itself in an increase in catabolism and a decrease in anabolism, resulting in protein-energy malnutrition in the patient if they are insufficiently prepared. Preoperative undernutrition is one of the risk factors for major postoperative complications.

Moreover, postoperative infection can occur despite the Oral Impact treatment and associated iron and protein-caloric rehabilitation. It is linked to postoperative hypoalbuminemia. The antimicrobial role of albumin in the body is significant due to its antioxidant power. Reduced, non-oxidized albumin is the primary antioxidant in the body. Postoperative inflammation consumes reduced albumin, thereby diminishing the body's antioxidant capacity and exposing it to complications and nosocomial infections. The exogenous supply of reduced albumin is therefore indispensable. The liver's albumin synthesis yield is too low in this inflammatory context, amounting to approximately one vial of 20% albumin per day. Preoperatively, the correction of any hypoalbuminemia is anticipated through the nutritional rehabilitation implemented with the dietitian team. The timing of the surgery does not always allow the body to correct this hypoalbuminemia on its own. It is also essential to correct it postoperatively, in case of complications if necessary, through the exogenous supply of 20% reduced albumin.

Numerous studies have shown the benefit of perioperative Oral Impact immunomodulation in gastrointestinal surgery, ear, nose and throat surgery, gynecological and cardiac surgery.

No studies have been done in major Urological surgery The proposed study will be the first formal evaluation of the benefits and risks of using ORAL IMPACT in the preoperative period of urological surgery. The choice of this clinical project for this research question is justified by the proven benefit of this food substitute perioperatively in gastrointestinal, ear, nose and throat, gynecological and cardiac surgery. We hypothesize that Oral Impact will protect against major postoperative complications and prolonged hospital stay for patients undergoing urological surgery. There are no current guidelines recommending or discouraging the prescription of ORAL IMPACT in urological surgery patients.

Inclusion Criteria:

• 18 years of age and older
• Scheduled major urological surgery: scheduled: cystectomy, nephrectomy, other laparotomies.
• Having expressed their free and informed consent.
• Affiliated to a social security scheme

Exclusion Criteria:

• Immune deficiency.

  • HIV infection.
  • Curative surgery for chronic urinary tract infection.
  • Urgent surgery.
  • Inability to take oral impact 7 days before surgery.
  • Unstable psychiatric state.
  • Infection with COVID 19 during postoperative stay.