To determine if the very long Roux limb gastric bypass is superior to standard gastric bypass as a surgical treatment for morbid obesity in terms of percentage excess weight loss after one year.
The DUCATI-trial is a multi centre, randomized controlled, trial. The study compares very long Roux limb gastric bypass and standard laparoscopic Roux - Y gastric bypass. Patients will be randomly allocated to A) VLRL-RYGB or B) standard LRYGB and will be followed for a period of at least 1 year. The study will be performed in a clinical and outpatient setting with regular visits at 2, 6, and 12 months post intervention.
Randomisation is stratified for the participating centres. Randomisation takes place in the operation room and is single blinded.
Study subjects are selected from a clinical population of the Sint Franciscus Gasthuis, Rotterdam, The Netherlands and the Lievensberg hospital, Bergen op Zoom, The Netherlands. All morbidly obese patients who have had no prior bariatric surgery and who are eligible for primary laparoscopic gastric bypass surgery are candidates for the trial.
Inclusion criteria are:
Age 18–60 years
BMI > 40, or >35 kg/m2 with obesity related co-morbidity
Psychological screening excluding psychiatric and psychological disorders
Informed consent and willing to enter the follow up program after the operation.
Exclusion criteria are:
Prior bariatric surgery
Prior major abdominal surgery (like colonic resection, septic abdomen, aorta surgery, or other procedures with a high risk of intra-abdominal adhesions, which might jeopardise the possibility of performing a VLRL-RYGB, standard LRYGB
ASA (American Society for Anesthesiologists) classification ≥ IV
Endocrine causes, alcohol or drug abuse
Severe concomitant disease (carcinomas, neurodegenerative disorders or other disorders presently representing being considered exclusion criteria for bariatric surgery )
The inability of reading/understanding and filling out questionnaires
VLRL-RYGB or LYRGB is technically not possible as will be determined by the surgeon during surgery.
Study questions and outcome measures
Primary endpoint: Is the VLRL-RYGB superior to standard LRYGB in terms of percentage excess weight loss after one year?
Excess weight (kg) will be calculated with the formula EW = AW-IW (actual weight- ideal weight), IW = 22 × L2 (L = length in meters). The amount of weight loss will be expressed as percentage excess weight loss (%EWL), and calculated with the formula % EWL = (pre-operative BMI – current BMI) / (pre-operative BMI-25) × 100 %.
Secondary endpoint: what is the effect of the interventions on quality-of-life (QOL), cure /improvement of obesity related co-morbidity, complications, malnutrition side effects, re-admission rate, and re-operation rate?
The following outcome measures will be analysed to answer these secondary questions:
Patient’s health-related quality of life (QoL) objectified by the MOS Short Form 36 (SF 36), Gastro-Intestinal Quality of Life Index, and Obesity related Quality of life the Moorehead-Ardelt II questionnaires and the Bariatric Analysis and Reporting Outcome System (BAROS) score.
DM-II, hypertension, hypercholesterolemia, GERD, OSAS and joint-pain will be scored as worsened, same, improved or cured at follow-up visits.
Operating time, mean hospital stay, intra-operative and post-operative morbidity, and in-hospital mortality. Morbidity is defined as reoperations, reinterventions, re-admissions and serious adverse events. Morbidity is classified as major (anastomotic leakage, major peroperative blood loss due to splenic or vascular hemorrhage, pulmonary embolism, intra-abdominal abscess and intra-abdominal hematoma) or minor (wound infection, urinary tract infection and anastomotic stenosis) complications. For analysis the Clavien-Dindo classification will be used . Moreover, the rate of extra outpatient and ER visits due to complaints are recorded.
Biochemical and hormonal values following VLRL-RYGB and standard LRYGB will be evaluated by laboratory testing of the following parameters: Vitamin B1, B6, B12, D, folic acid, HbA1C, ferritin, iron, transferrin, cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, calcium, magnesium, albumin, Apo-B, Zinc, homocysteine, parathomone.
After reviewing the literature we hypothesized that a standardized common channel length of 100 cm should be safe to reduce major nutritional deficiencies, while remaining a long alimentary limb. To ensure a degree of comparability between VLRL-RYGB and standard LRYGB, the BL was set at a fixed length of 60 cm.
Two different approaches for anastomosis are known, being the linear and the circular gastro-enterostomy stapling techniques, which are both allowed in this study, as it does not seem to affect the primary outcome measure; the percentage excess weight loss result (% EWL) . The only prerequisite is that the diameter of the gastro-enterostomy anastomosis will be comparable. As the applied circular stapler anastomosis is 25 mm, the linear stapled anastomosis will need to be 25 mm in diameter as well. The type of technique linear or circular will be registered.
Very long Roux limb gastric bypass
Technique (linear gastro-enterostomy stapling technique):
Approximately 6 cm below the angle of His a calibrated gastric pouch is created using a 34 Fr gastric tube. After creation of the pouch the omentum may be split vertically to ensure safe mobilization of the small intestine if necessary.
The common channel is measured 100 cm from the ileocoecal junction and marked with a temporary suture.
Next, the gastro-enterostomy is created 60 cm from the point of Treitz, followed by creation of the entero-enterostomy between the small intestine proximal from the gastro-enterostomy and the marked point 100 cm proximal to the ileocoecal junction.
After final stapling between the gastro-enterostomy and the entero-enterostomy the alimentary limb is measured using a set 5 cm marking on a babcock clamp.
Standard laparoscopic Roux-en-Y gastric bypass
Technique (linear gastro-enterostomy stapling technique):
Most steps are the same as mentioned for VLRL-RYGB. The only difference is the lengths described in the steps of creating the entero-enterostomy and measuring common channel instead of the alimentary limb.
After creation of the gastro-enterostomy, 60 cm from the point of Treitz, 150 cm is measured distal from the gastro-enterostomy and an entero-enterostomy is created between this point and the small intestine just proximal from the gastro-enterostomy.
After final stapling between the gastro-enterostomy and the entero-enterostomy the common channel is measured using a set 5 cm marking on a babcock clamp.
Technique (circular gastro-enterostomy stapling technique):
Most steps of this procedure are similar to the linear stapling technique. The technique differs in the creation of the gastro-enterostomy and the creation of the entero-enterostomy. Furthermore, in the circular technique the entero-enterostomy is created first.
In both groups and techniques the following is applicable:
Petersen’s space and other internal hernias can be closed by laparoscopic suturing or tackers and an abdominal silicone drain may be left behind at the surgeons’ preference. Staple line bleeding is controlled by electronic scissors, clips, or sutures. Next, the trocars are removed under sight and the skin is closed.
Antithrombosis prophylaxes and a fluid diet are continued for a minimum of two weeks postoperatively.
Sample size determination
The sample size calculation is based on a superiority design, assuming that VLRL-RYGB is superior at 1 year follow-up when compared to standard LRYGB.
H0: mean % EWL at 1 year (standard LRYGB) = mean % EWL at 1 year (VLRL-RYGB)
H1: mean % EWL at 1 year (standard LRYGB) ≠ mean % EWL at 1 year (VLRL-RYGB)
To be able to reject the null hypothesis that mean % EWL at 1 year follow-up after standard LRYGB treatment equals mean % EWL at 1 year follow-up after VLRL-RYGB, at least 2x210 patients need to be included in the analysis. (Mean (SD) % EWL is 69.7 % (25.88) after VLRL-RYGB ; and 62.60 (25.88) after standard LRYGB; power = 80 %, randomization ratio 1:1). Considering a dropout rate of 5 %, the number of patients that need to be included is estimated to be 2x210/.95 = 2x221.1 = 444 (rounded up for equal number of patients per group).
The % EWL data of standard LRYGB are obtained from the meta analysis of Garb et al. . The SD of VLRL-RYGB which currently is unreported is assumed to be equal to the SD of standard LRYGB.
Data will be recorded prospectively on designated case record forms. All data are stored in a database, which is managed by the principal investigator. All adverse events will be investigated by a Data Safety Monitoring Board.
This study will be conducted in accordance to the standards of Good Clinical Practice, in agreement with the Declaration of Helsinki (latest amendment), Dutch law in general and with the W.M.O. in particular.
This trial has been approved by the regional medical ethical committee; Toetsingscommissie Wetenschappelijk Onderzoek Rotterdam e.o. (TWOR) at Maasstad Hospital Rotterdam,The Netherlands.