The effective and long-term sustained outcomes of bariatric surgery in the general population have led many to consider bariatric surgery in morbidly obese patients with chronic kidney disease (CKD). As most transplant centers have strict criteria for listing patients based on BMI, patients with BMI > 35 become ineligible for transplant. Hence, most series on CKD includes these patients who were subjected to bariatric surgery. Bariatric surgery with its effect on weight reduction and reduction of comorbidities could help these patients become eligible and also improve associated comorbidities. In a small series by Koshy et al. three patients with end-stage renal disease (ESRD) underwent adjustable gastric banding (AGB) to qualify for renal transplantation. All underwent uncomplicated kidney transplantations. There was no change in post-operative renal function. All 3 had an excess weight loss ranging from 35 to 41 %, at 12 and 15 months with resolution of co-morbidities later meeting the BMI criterion for transplantation allowing for renal transplantation. Long –term success was however not assessed [6]. In another series by Newcomb et al. three patients with end stage renal disease (ESRD) underwent AGB to qualify for renal transplantation. All underwent uncomplicated kidney transplantations. All lost weight at follow-up, meeting the BMI criterion for transplantation allowing for renal transplantation to proceed and in addition had resolution/improvement of obesity related co-morbidities with stable renal function. Again this series did not report long –term success [7]. In a series by Alexander et al. 30 morbidly obese patients with chronic renal failure/post-transplantation underwent gastric bypass. 19 patients had CRF at the time of Roux en Y gastric bypass (RYGB), eight had transplantation followed by RYGB, and three had RYGB and then transplantation. The reduction in excess BMI and resolution of co-morbid conditions was similar to patients without transplantation or chronic renal failure. The only perioperative complication among the group was a wound separation. No patients required blood transfusions in the perioperative period. One patient died 7.9 years after a RYGB and 6.1 years after transplantation from cardiovascular disease related to longstanding diabetes [8]. Takata et al. reported 7 morbidly obese patients with ESRD needing transplantation who underwent RYGB without morbidity and mortality with a mean percentage of excess weight loss at ≥9 months of 61 % with improvement or resolution obesity-associated co-morbidities in all patients. All eventually qualified for renal transplantation [9]. In a recent series by Lin et al. six pre-transplant patients with end-stage renal disease underwent sleeve gastrectomy (SG). All patients met the institution’s BMI cutoffs for transplantation by 12 months after the procedure. There were no deaths, and there was 1 temporary renal insufficiency. The mean percentage of excess weight loss was 50 % at 1 year. One patient’s renal function stabilized, and he was taken off the transplant list. One patient received a combined liver and kidney transplant and 1 received a kidney transplant [10].

Thus a SG or a RYGB can be performed safely in patients with CKD/ESRD. Also the risk of worsening renal function in the post-operative period is low with low morbidity. They achieve excellent weight loss and improvement in obesity-related co-morbidities with improved candidacy for renal transplantation.

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.

Considering the excellent outcomes of bariatric surgery in the general population and CKD patients in a pre-transplant setting have led many to further consider bariatric surgery in morbidly obese patients with cirrhosis. Obese liver transplant candidates showed higher wound infection rates, had increased intraoperative blood transfusion, longer operating times, reduced early graft survival and increased early deaths from multi-organ failure in comparison to non-obese candidates [2, 4, 14]. Thus most transplant centers based on established criteria prevent patients with morbid obesity to be listed for transplantation. Thus the definitive treatment of obesity will be of great benefit to transplant recipients. However the perioperative risk for cirrhotic patients with decompensated liver disease and significant portal hypertension for any surgical intervention is very high. Most series of bariatric surgery in cirrhotics in pre-transplant setting are therefore restricted to bariatric surgery performed in Childs A and selected Childs B cirrhosis without portal hypertension or after transjugular intrahepatic intrabdominal shunt (TIPS).

In a series by Takata et al. six morbidly obese patients with cirrhosis (4 Child A and 2 Child B) underwent SG. There was no mortality. Two developed complications, 1 postoperative bleeding and the other encephalopathy which recovered. There was no liver decompensation. At a mean follow-up of 12.4 months, the mean percentage of excess weight loss at >9 months was 33 % Five of the 6 patients subsequently became candidates for liver transplantation [9]. In another series by Shimizu et al. colleagues 23 patients (22 with Child-Pugh class A and 1 with Child-Pugh class B) underwent bariatric surgery [15]. Fourteen patients underwent a RYGB, eight patients an SG, and one patient an AGB. Two patients had a SG after TIPS. There was no perioperative mortality. There was 1 leak each in the RYGB and SG groups. There was no liver decompensation. Mean excess weight loss was 67 % at 12 months’ follow up [16]. In a series by Dallal and colleagues, 30 patients, 90 % of whom were diagnosed intraoperatively with cirrhosis underwent bariatric surgery. All were Child’s A without obvious portal hypertension [17]. Twenty-seven patients underwent a RYGB and three patients underwent an SG. There were no perioperative deaths. There was no liver decompensation. Early complications occurred in nine patients and included 1 anastomotic leak, 4 acute tubular necrosis, 2 prolonged intubation, 1 ileus, and 2 needing blood transfusion. There was one late unrelated death and one patient with prolonged nausea and protein malnutrition at an average follow-up time of 16 months. The average percent excess weight loss was 63 ± 15 % at >12 months.

Thus there exists a few series in literature that suggests that a SG or a RYGB can be performed safely in Childs A and selected patients with Childs B cirrhosis without portal HT or after TIPS. These patients may have an increased incidence of complications without much fear of liver decompensation and mortality. Patients achieved excellent weight loss and improvement in obesity-related co-morbidities with improved candidacy for liver transplantation. However because of small series and limited follow-up it is not entirely clear which surgical modality is safest in cirrhotics. SG is a less-invasive approach but may pose a significant bleeding risk and RYGB may make the fundus inaccessible if further varices should develop. RYGB may benefit some patients with metabolic syndrome better than a SG but it remains unknown whether it may complicate a future liver transplant because of lack of endoscopic access to biliary tree and malabsorption.