Pre-operative Very Low-calorie Protein-based Versus Hypocaloric Enteral Nutrition

Study Overview
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Brief Summary
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Pre-operative weight loss can reduce the risk intra- and post-operative complications but no optimal pre-operative weight loss strategy has been investigated. Very-low-calorie diets (VLCDs) were proven to results in higher metabolic improvements in the short-term than balanced, hypocaloric diets. Therefore, the aim of the study is to investigate whether a VLCD results in lower intra-and post-operative complications compared to a hypocaloric diet. However, to achieve a optimal compliance in patients having experienced multiple dietary intervention failures, administration of the intervention will be performed by the enteral route using a naso-gastric feeding tube.

Detailed Description
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Bariatric surgery is an important treatment strategy for obese patients having failed multiple diet-induced weight loss attempts. On the other hand, severly obese patients have also a high risk of both intra- and post-operative complications. Pre-operative weight loss can reduce these risks but no optimal pre-operative weight loss strategy has been investigated. Very-low-calorie diets (VLCDs) were proven to results in higher metabolic improvements in the short-term than balanced, hypocaloric diets. Therefore, the aim of the study is to investigate whether a VLCD results in lower intra-and post-operative complications compared to a hypocaloric diet. However, to achieve a optimal compliance in patients having experienced multiple dietary intervention failures, administration of the intervention will be performed by the enteral route using a naso-gastric feeding tube.

Official Title
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Pre-operative Very Low-calorie Protein-based Versus Hypocaloric Enteral Nutrition to Improve Intra- and Post-operative Outcomes of Severely Obese Patients Undergoing Bariatric Surgery

Conditions
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Perioperative/Postoperative Complications

Intervention / Treatment
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* Other: Very low-calorie protein-based diet
* Other: Hypocaloric diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patient candidate to laparoscopic bariatric surgery (gastric bypass or sleeve gastrectomy) after multi-disciplinary pre-operative evaluation Availability to long-term post-operative follow-up Normal kidney function serum creatinine ≤ 1,2 mg/dL and glomerular filtration rate ≥ 90 mL/min Normal liver function (aspartate amino-transferase and/or alanine amino-transferase and/or gamma glutamyl transferase < 2 x N) written informed consent Exclusion Criteria: age <18 or >60 anni serum creatinine >1,2 mg/dl liver failure (Child-Pugh ≥ A) insuline-dependent diabetes mellitus atrioventricular block with QT > 0,44 ms Cardiac arrythmias Moderate-severe cardiac failure Hypokaliemia Chronic diarrhoea or vomitus 12-month previous cardio-vascular disease pregnancy and/or lactation current/previous neoplastic disease psychiatric disorders know gastro-intestinal diseases other controindications to enteral nutrition moderate-severe hypo-albuminemia (<3.0 mg/dL) 6-month previous diet-induced weight loss intragastric balloon unavailability to planned measurements

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Very low-calorie protein-based diet<br>Patients will receive a homemade very low-calorie ( 5 kcal/kg of ideal body weight /day) protein-based formula (milk proteins; 1.2 g per kilogram of ideal body weight) for 4 weeks by a polyurethane nasogastric feeding tube. | Other: Very low-calorie protein-based diet<br>* Patients will receive a homemade very low-calorie ( 5 kcal/kg of ideal body weight /day) protein-based formula (milk proteins; 1.2 g per kilogram of ideal body weight) for 4 weeks by a polyurethane nasogastric feeding tube.<br>|
| Active Comparator: Hypocaloric diet<br>Patients will receive a commercial balanced enteral formula ( 20 kcal/kg of ideal body weight /day; protein content, 1.0 g per kilogram of ideal body weight) for 4 weeks by a polyurethane nasogastric feeding tube. | Other: Hypocaloric diet<br>* Patients will receive a commercial balanced enteral formula ( 20 kcal/kg of ideal body weight /day; protein content, 1.0 g per kilogram of ideal body weight) for 4 weeks by a polyurethane nasogastric feeding tube.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgery duration | from skin incision to wound closure | End of surgery, an expected average of 3.5 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Composite intra-operative complications | Hemorrhage, organ perforation or laceration, conversion to open surgery, stapler dysfunction | End of surgery, an expected average of 3.5 hours | 
| Composite post-operative complications | Any-type hemorrhage, any-type infections, wound dehiscence, anastomotic leak, organ dysfunction | 30 days | 
| Intra-operative bleeding |  | End of surgery, an expected average of 3.5 hours | 
| Difficult intubation |  | Before surgery | 
| Time to remove surgical drain |  | Hospital stay, an avarage of 9 days | 
| Total drain fluid production |  | Hospital stay, an avarage of 9 days | 
| Change of multiple biochemical parameters | blood lipids, variables of glucose metabolism and growth-hormone axis | End of dietary intervention, 28 days | 
| Change of multiple anthropometric parameters | body mass index, body weight, waist and hip circumferences | End of dietary intervention, 28 days | 
| Change in liver fibrosis |  | End of dietary intervention, 28 days | 
| Change in liver volume |  | End of dietary intervention, 28 days | 
| Change in visceral fat |  | End of dietary intervention, 28 days | 
| Change of multiple body composition parameters |  | End of dietary intervention, 28 days | 
| Change in handgrip strength |  | End of dietary intervention, 28 days | 
| Change of multiple cardiac morpho-functional parameters |  | End of dietary intervention, 28 days | 
| Length of hospital stay |  | Hospital stay, an avarage of 9 days | 
| Composite complications of enteral feeding | tube dysfunction, nausea, vomiting, diarrhea | End of dietary intervention, 28 days |