Bariatric Surgery for Morbid Obesity in Post-transplant End-Stage Renal Disease
Kidney transplant recipients are at increased risk for developing or worsening obesity after transplantation [11]. Postoperative weight gain following organ transplantation may in part be explained by a direct corticosteroid effect, reduction of leptin synthesis/release and significantly elevated neuropeptide levels as well as lifestyle changes related to psychosocial factors [11]. There may be a need for surgical intervention in post-renal transplant weight gain with new onset or worsening of obesity and obesity-related comorbidities such as diabetes and hypertension.
In the series by Alexander et al. eight had transplantation followed by RYGB. The reduction in excess BMI and resolution of co-morbid conditions was similar to patients without transplantation or chronic renal failure with no major peri-operative morbidity. There was no death in the group who had RYGB after renal transplantation [8]. A small pharmacokinetic study showed that mycophenolic acid, tacrolimus, and sirolimus after gastric bypass would need higher dosing levels to account for the differences in pharmacokinetics, than in the non-bypass population [12]. However in a series by Szomstein et al. five renal transplant patients underwent bariatric surgery. Four patients had RYGB and one had SG. Percent of excess weight loss (%EWL) at 2 years was over 50 % for all patients with resolution or improvement of co-morbidities. There were no postoperative complications in any patients, and no alteration to the dosages of the immunosuppressant drugs after bariatric surgery [13]. In another series by Arias et al. five had transplantation followed by RYGB. One had an anastomotic leak at the gastrojejunal anastomosis that healed with conservative treatment. The remaining four patients did not have any postoperative complications. Three of the patients had diabetes and achieved good control after the surgery. The absorption of immune suppressors was not altered; and some of the patients were even able to reduce their doses.
Hence bariatric surgery can be considered as a treatment option in kidney transplant recipients with weight gain with new onset or worsening of obesity and related comorbidities such as diabetes and hypertension. There is no requirement for alteration in the dosages of the immunosuppressant drugs after bariatric surgery.
