Abstract and Introduction
Abstract
Morbid obesity is a barrier to renal transplantation and is inadequately addressed by medical therapy. We present results of a prospective evaluation of laparoscopic sleeve gastrectomy (LSG) for patients failing to achieve significant weight loss with medical therapy. Over a 25-month period, 52 obese renal transplant candidates meeting NIH guidelines for metabolic surgery underwent LSG. Mean age was 50.0 ± 10.0 years with an average preoperative BMI of 43.0 ± 5.4 kg/m (range 35.8–67.7 kg/m). Follow-up after LSG was 220 ± 152 days (range 26–733 days) with last BMI of 36.3 ± 5.3 kg/m (range 29.2–49.8 kg/m) with 29 (55.8%) patients achieving goal BMI of <35 kg/m at 92 ± 92 days (range 13–420 days). The mean percentage of excess weight loss (%EWL) was 32.1 ± 17.6% (range 6.7–93.8%). A segmented regression model was used to compare medical therapy versus LSG. This revealed a statistically significant increase in the BMI reduction rate (0.3 kg/m/month versus 1.1 kg/m/month, p < 0.0001). Patients also experienced a 40.9% decrease in anti-hypertensive medications (p < 0.001) and a 49.7% decrease in total daily insulin dose (p < 0.001). LSG is a safe and effective means for addressing obesity in kidney transplant candidates in the context of a multidisciplinary approach.
Introduction
Obesity is a rising pandemic that is most pronounced in developing countries. It has been estimated that by 2030, more than 50% of the U.S. population will have a BMI >30 kg/m. The proportion of patients undergoing renal transplantation who are obese (BMI ≥ 30 kg/m) at the time of transplant is currently 60%.
Obesity is also an important risk factor for complications following renal transplantation. Recent reviews and single center experiences have shown that morbid obesity is associated with increased delayed graft function, wound complications, prolonged hospitalization, new onset diabetes mellitus, acute biopsy proven rejection and reduced graft survival. Higher mortality rates in obese renal transplant recipients are thought to be due to increased rates of postoperative cardiovascular complications including atrial fibrillation and congestive heart failure. Recognition of these associated complications has led to obesity becoming a relative contraindication to renal transplantation with many centers using a BMI of 35–40 kg/m as an upper limit for transplant candidacy. Of note, patients with obesity (class I–III) have a reported lower likelihood of transplantation when compared to a normal BMI patient.
Kidney transplant programs often require that obese transplant candidates meet specified BMI and/or weight loss criteria prior to being approved as a transplant candidate for living donor transplantation or approved for active status on the deceased donor waitlist. Recent SRTR data has shown that obesity is the third leading cause of being inactive on the kidney transplant waitlist. For most obese transplant candidates, medical weight loss has traditionally been the primary approach for achieving pre-transplant weight loss. However, medical weight loss regimens have historically had poor short and long-term success rates. Similarly, we have found medical weight loss regimens prior to kidney transplantation to have high failure rates, with patients often spending years on hold on the deceased donor waitlist without achieving a desired target weight or BMI for transplantation. The importance of this observation is emphasized by the 5–10% per year mortality rate in the deceased donor waiting list. In our program, waitlist mortality rates are 7% per year. Moreover, it is likely that the deceased donor waiting list mortality is higher in obese patients with type II diabetes mellitus.
Metabolic surgery provides an effective and safe alternative to medical weight loss approaches in the general population. Importantly, over the past decade, significant progress has been made in improving results in these procedures. Alexander and colleagues from our transplant program at the University of Cincinnati first demonstrated that metabolic surgery can be safely performed in the dialysis and transplant populations using the Roux-en-Y gastric bypass procedure. Recently we have initiated use of the laparoscopic sleeve gastrectomy (LSG) in lieu of the Roux-en-Y gastric bypass in the kidney transplant patient population, as LSG has demonstrated effective weight loss with substantial reduction in morbidity in the general population. Our intent was to eliminate obesity as a barrier to renal transplantation in our two kidney transplant programs. This prospective evaluation with medical weight loss followed by LSG represents the largest experience to date with LSG in ESRD patients.