Very Low Calorie Diet Before Gastric Bypass Cuts Complications

November 22, 2011

NEW YORK (Reuters Health) Nov 21 - Patients who followed a very low calorie diet (VLCD) for 14 days before gastric bypass surgery had fewer postoperative complications in a recent multicenter randomized trial.

A pre-op VLCD didn't significantly affect operative time, but surgeons perceived the operations to be less difficult in the VLCD group.

The study shows "that even a small amount of preoperative weight loss improves operative outcomes of LRYGBP (laparoscopic Roux-en-Y gastric bypass surgery)," writes Dr. Clifford W. Deveney of Oregon Health and Sciences University in Portland in an editorial published with a report of the study this month in Archives of Surgery.

The authors, led by Dr. Yves Van Nieuwenhove of the University Hospital Ghent in Belgium, note that many centers now prescribe weight loss diets before bariatric surgery because such diets have been shown to reduce liver volume, abdominal and subcutaneous fat mass, and comorbidities.

But the research team wanted to study the effects of a VLCD more closely, to assess the risks that might be conferred by undergoing surgery in a catabolic state.

At five high-volume centers, Dr. Van Nieuwenhove and colleagues randomly assigned 298 volunteers to one of two protocols: a two-week, 800-calorie diet consisting of five meal-replacement shakes a day, or the patient's normal diet. On average, the VLCD group lost 4.9 kg before surgery, compared to 0.4 kg for the control group.

All participating surgeons had performed at least 50 LRYGBP operations previously. When they used a 100-mm visual analog scale to rate procedure difficulty (0 the least difficult, 100 most difficult), the median score was 26 for the VLCD group compared to 35 for the control group (P=0.04).

There was no difference in mean operating time (81 min in the VLCD patients and 80 min in control patients), nor in estimated blood loss or intraoperative complication rates.

At 30 days after surgery, however, researchers had recorded 18 complications in the control group vs eight in the VLCD group (P=0.04).

There was also no difference in weight lost in the month after surgery or mean body mass index, however.

"Although this regimen does not seem to affect short-term weight reduction, our data strongly suggest a potential for the reduction of postoperative complications," Dr. Van Nieuwenhove and his colleagues write. "We therefore conclude that a preoperative VLCD regimen should be recommended for morbidly obese patients -- and also for modestly obese patients -- undergoing bariatric surgical procedures."


Arch Surg 2011;146;1300-1305.