Clinical trial NCT05918471: PReoperative Very Low Energy Diets for Obese PAtients Undergoing Non-bariatric Surgery
Official title: PReoperative Very Low Energy Diets for Obese PAtients Undergoing Non-bariatric Surgery: A Randomized Evaluation (PREPARE Pilot)
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Obesity
Non-Bariatric Surgery
Preoperative Weight Loss
Preoperative Optimization
Lead sponsor: McMaster University
Sponsor class: OTHER
Collaborators: name: Queen's University
First posted: 2023-06-26
Enrollment: 88
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: This is a multi-center, blinded, parallel pilot RCT.
Primary purpose: TREATMENT

Brief summary: The PREPARE Pilot randomized controlled trial (RCT) is a multi-center, parallel, blinded RCT that aims to assess the feasibility of a full RCT comparing preoperative very low energy diets (VLEDs) to standard of care prior to elective non-bariatric surgery for obese patients in terms of overall 30-day postoperative morbidity. Adult patients with body mass indices (BMIs) greater than 30 kg/m2 will be randomized 1:1 to receive 3-weeks of preoperative VLED plus preoperative weight loss counselling or preoperative weight loss counselling alone. This trial will enroll patients to assess recruitment, compliance, and follow-up completion to assess the feasibility of a full RCT powered to assess for differences in 30-day postoperative between VLEDs and standard of care arms.

Detailed description: Obesity is a worldwide epidemic affecting upwards of 700 million people. The economic burden in the United States and Canada are estimated at over $2 trillion and $100 billion United States dollars (USD), respectively, and the resultant healthcare consequences can be devastating for systems and patients alike. Obesity is a systemic disease with devastating consequences for patients undergoing any form of operative intervention. Obese patients presenting in need of medical and surgical intervention are at 2-to-6 fold higher risk of prolonged hospitalization, infectious morbidity, venous thromboembolism, and more. To pre-emptively mitigate some of these concerns, prescribed preoperative weight loss via VLEDs has become a standard of care for obese patients undergoing bariatric surgery (i.e., weight loss surgery). While VLEDs have become a standard in obese patients undergoing bariatric surgery, largely due to the significant reduction of peri-organ fat for better visualization, their application to obese patients undergoing other types of surgery remains limited. A previous systematic review and meta-analysis that identified 13 studies evaluating the use of preoperative VLEDs in obese patients undergoing orthopaedic, vascular, colorectal, upper gastrointestinal, gynecological, and a variety of general surgery procedures for benign disease (e.g., cholecystectomy, abdominal wall hernia). While data were heterogenous, preoperative VLEDs reliably resulted in significant weight loss (3.2-19.2kg) with high rates of compliance to the protocols (94-100%). Adverse event rates were low (\<14% in most studies). There were no significant differences in postoperative outcomes, though again pooled analyses included a small number of patients and there were wide corresponding 95% CIs. Overall, this review suggested the evidence for routine use of VLEDs in obese patients undergoing major surgery is compromised by heterogeneous small studies with methodological limitations. A large, definitive trial is required to resolve this uncertainty. Prior to a definitive trial to compare the efficacy of VLEDs in obese patients undergoing major surgery, a pilot RCT is required. A pilot trial will provide the following critical feasibility insights: (1) Assessment of recruitment and randomization ability; (2) Evaluation of compliance to VLED regimens; and (3) Assessment of our ability follow patients completely. The objective of this pilot RCT is to determine the feasibility of a multicenter RCT comparing obese patients (i.e., BMI \> 30kg/m2) receiving VLEDs versus control prior to elective non-bariatric surgery in terms of perioperative outcomes.

Eligibility criteria: Inclusion Criteria:

* Older than 18 years of age
* BMI of greater than 30 kg/m2
* Undergoing major elective non-bariatric surgery. Major surgery is defined as any operation performed under general anesthesia requiring a skin incision extending beyond the subcutaneous tissue.

Exclusion Criteria:

* Undergoing bariatric surgery
* Undergoing neurologic surgery
* Undergoing urgent or emergent surgery
* Recently diagnosed myocardial infarction or unstable angina (i.e., within past six months)
* Diagnosed moderate-to-severe renal dysfunction (i.e., eGFR less than 30mL/min/1.73m2)
* Diagnosed severe liver dysfunction (i.e., cirrhosis, portal hypertension, hepatic encephalopathy, hepatorenal syndrome)
* Recently diagnosed alcohol or drug use disorders (i.e., excessive use of substance within past six months)
* Experienced a recent episode of gout (i.e., within past six months)
* Medical history of porphyria; (10) Known allergy to any Optifast ingredient
* Enrolled in other prospective studies with similar interventions and/or outcomes. Co-enrollment may be deemed appropriate if the steering committees of the respective trials review the details of participation.
* Pregnant or breastfeeding women
* Patients unable to provide informed consent.

Primary outcomes:
measure: Recruitment rate
timeFrame: 1 year
measure: Intervention compliance
timeFrame: 1 year
measure: Follow-up completion
timeFrame: 1 year
measure: Network development
timeFrame: 1 year
Secondary outcomes:
measure: VLED associated adverse events
timeFrame: Three-week VLED intervention period.
measure: Overall 30-day postoperative morbidity
timeFrame: 30-days following index operation.
measure: 30-day system-specific complications
timeFrame: 30-days following index operation.
measure: 30-day postoperative mortality
timeFrame: 30-days following index operation.
measure: Preoperative weight loss
timeFrame: Three-week VLED intervention period.
measure: Operative time
timeFrame: Intraoperative
measure: Intraoperative blood loss
timeFrame: Intraoperative
measure: Surgeon-perceived technical difficulty
timeFrame: Intraoperative
measure: Postoperative length of stay
timeFrame: Through postoperative stay, a mean of 3 days
measure: Health-related quality of life
timeFrame: 30 days
Other outcomes:
Locations:
city: Hamilton
country: Canada
facility: Hamilton General
state: Ontario
city: Hamilton
country: Canada
facility: St. Joseph's Healthcare Hamilton
state: Ontario
city: Hamilton
country: Canada
facility: Juravinski Hospital
state: Ontario
city: Kingston
country: Canada
facility: Kingston Health Sciences Centre
state: Ontario
Study officials:
affiliation: McMaster University
name: Tyler J McKechnie, MD
role: PRINCIPAL_INVESTIGATOR
References: