Nancy A. Melville

November 11, 2013

ATLANTA — Obese patients with chronic kidney disease who receive bariatric surgery succeed in losing weight; however, their risk for side effects and surgical complications is high, according to a new study.

"Our work demonstrated the efficacy of bariatric surgery in obese patients with chronic kidney disease; however, the rate of complications is higher, and patients need to be counseled about this," said lead investigator Helen MacLaughlin, from King's College Hospital in London.

MacLaughlin and her team presented the results here at Kidney Week 2013: the American Society of Nephrology 46th Annual Meeting.

The retrospective work evaluates the medical records of 74 patients with chronic kidney disease who underwent laparoscopic bariatric surgery at 3 major London teaching hospitals.

Among the patients, 33 were men and 41 were women; their mean age was 52 years. The majority of patients, 59%, had stage 3 kidney disease. More than half, 57%, underwent sleeve gastrectomy; 38% had Roux-en-Y bypass surgery; and 5% received adjustable gastric banding.

At 1 year after surgery, the decrease in excess body mass index (BMI) for patients across all forms of surgery was 61%; the average BMI was 33.2 kg/m2.

Sixteen patients (22%) experienced adverse events, and there were 2 deaths related to surgical complications within 30 days of the surgery. One patient died as a result of bleeding during surgery that required repair, but the patient also experienced cardiac and respiratory arrest; the patient died 17 days later.

The second death was the result of sepsis of unknown cause and multiorgan failure, MacLaughlin said.

The most common side effect was acute kidney injury, occurring in 4% of patients, followed by leak (3%), acidosis and hyperkalemia (3%), postoperative chest infection (3%), vitamin B12 or iron deficiency (3%), fistula or graft failure (3%), and myocardial infarction (1%).

Four additional deaths were reported during the study period, including 2 related to cancer.

As a result of the higher risk associated with bariatric surgery, MacLaughlin said that her center has developed policies for the management of patients with kidney disease.

"We have developed a joint renal-surgical protocol for managing these patients, with specified roles in surgical teams to minimize the risk," she said. "Larger studies are justified to better identify the risk factors for these complications."

I would be extremely cautious in recommending bariatric surgery for these patients. Dr. George Kaysen

Asked by Medscape Medical News to comment on the study, George Kaysen, MD, PhD, from the University of California, Davis, Health Center, in Sacramento, pointed out that previous studies show that mortality in fact declines with increasing BMI in dialysis patients. "Data have shown that at least with regard to end-stage dialysis patients, the higher the BMI, the better the outcome, so it raises the question of the rationale for bariatric surgery in these patients," he noted.

MacLaughlin said that one important reason for having bariatric surgery is to help severely obese patients to achieve a weight that allows them to qualify for kidney transplantation.

Dr. Kaysen said he agrees that that could be a factor, but he added that the results present a few red flags in considering the surgery for kidney patients. "I would be extremely cautious in recommending bariatric surgery for these patients," he said. "It clearly looks like the more severe the kidney disease, the more you might have to lose."

Helen MacLaughlin reports no relevant financial relationships. Dr. Kaysen has disclosed a consultancy agreement with Merck.

Kidney Week 2013: the American Society of Nephrology 46th Annual Meeting: Abstract TH-OR111. Presented November 7, 2013.


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