The Impact of Morbid Obesity on Hospital Length of Stay in Kidney Transplant Recipients

Management of obesity in kidney transplant candidates and recipients: A clinical practice guideline by the Descartes working group of ERA

The clinical practice guideline Management of Obesity in Kidney Transplant Candidates and Recipients was developed to guide decision-making in caring for people with end-stage kidney disease (ESKD) living with obesity. The document considers the challenges in defining obesity, weighs interventions for treating obesity in kidney transplant candidates as well as recipients and reflects on the impact of obesity on the likelihood of wait-listing as well as its effect on transplant outcomes. It was designed to inform management decisions related to this topic and provide the backdrop for shared decision-making. This guideline was developed by the European Renal Association’s Developing Education Science and Care for Renal Transplantation in European States working group. The group was supplemented with selected methodologists to supervise the project and provide methodological expertise in guideline development throughout the process. The guideline targets any healthcare professional treating or caring for people with ESKD being considered for kidney transplantation or having received a donor kidney. This includes nephrologists, transplant physicians, transplant surgeons, general practitioners, dialysis and transplant nurses. Development of this guideline followed an explicit process of evidence review. Treatment approaches and guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendations Assessment, Development and Evaluation approach. Limitations of the evidence are discussed and areas of future research are presented.

Obesity in the Kidney Transplant Process

Obesity, which has become an increasing problem worldwide, poses a risk for kidney transplant recipients both before and after surgery. In this literature review, we studied the effects of obesity before and after kidney transplant. There are numerous studies and different opinions on the effects of obesity on graft function before and after transplant. Obesity prolongs surgery time and the ischemic process. A large cohort study of 11 836 recipients noted a close association between body mass index and delayed renal transplant and delayed graft function. However, another study found that being overweight or obese before transplant did not have any effects over the medium and long term. A 20-year follow-up study indicated that the firstyear body mass index in recipients after renal transplant had a greater effect on graft function and survival than body mass index before transplant. Still, another study found that body mass index had no effects on graft function and survival. In the study, 3-year graft function and mortality rates of morbidly obese people without diabetes, the functional status without dialysis, and living-donor transplant were reported to be much lower than in those with normal weight. In conclusion, there is no consensus on the effects of obesity before and after transplant, and it has been pointed out that more research should be done on this subject.

Frailty, Length of Stay, and Mortality in Kidney Transplant Recipients: A National Registry and Prospective Cohort Study

OBJECTIVE

To test whether frailty, a novel measure of physiologic reserve, is associated with longer kidney transplant (KT) length of stay (LOS), and modifies the association between LOS and mortality.

BACKGROUND

Better understanding of LOS is necessary for informed consent and discharge planning. Mortality resulting from longer LOS has important regulatory implications for hospital and transplant programs. Which recipients are at risk of prolonged LOS and its effect on mortality are unclear. Frailty is a novel preoperative predictor of poor KT outcomes including delayed graft function, early hospital readmission, immunosuppression intolerance, and mortality.

METHODS

We used registry-augmented hybrid methods, a novel approach to risk adjustment, to adjust for LOS risk factors from the Scientific Registry of Transplant Recipients (n = 74,859) and tested whether (1) frailty, measured immediately before KT in a novel cohort (n = 589), was associated with LOS (LOS: negative binomial regression; LOS ≥2 weeks: logistic regression) and (2) whether frailty modified the association between LOS and mortality (interaction term analysis).

RESULTS

Frailty was independently associated with longer LOS [relative risk = 1.15, 95% confidence interval (CI): 1.03-1.29; P = 0.01] and LOS ≥2 weeks (odds ratio = 1.57, 95% CI: 1.06-2.33; P = 0.03) after accounting for registry-based risk factors, including delayed graft function. Frailty also attenuated the association between LOS and mortality (nonfrail hazard rate = 1.55 95% CI: 1.30-1.86; P < 0.001; frail hazard rate = 0.97, 95% CI: 0.79-1.19, P = 0.80; P for interaction = 0.001).

CONCLUSIONS

Frail KT recipients are more likely to experience a longer LOS. Longer LOS among nonfrail recipients may be a marker of increased mortality risk. Frailty is a measure of physiologic reserve that may be an important clinical marker of longer surgical LOS.

Single Center Experience With Robotic Kidney Transplantation for Recipients With BMI of 40 kg/m2 Or Greater: A Comparison With the UNOS Registry

BACKGROUND

Obesity represents a barrier to kidney transplantation, but the increasing prevalence among renal failure patients has forced some centers to carefully consider such candidates. Morbidly obese patients may be at increased risk of delayed graft function, higher postoperative complications, and inferior graft outcomes. Nevertheless, mortality on the waiting list remains significantly higher than after transplant. We have applied minimally invasive surgery to perform kidney transplant in individuals with body mass index (BMI) of 40 kg/m or greater. We compared our results to the national United Network of Organ Sharing database.

METHODS

The United Network of Organ Sharing registry was reviewed for adult living donor kidney transplant recipients with BMI of 40 kg/m or greater performed from September 2009 to December 2014. We compared transplants performed with robotic technique (RKT) versus patients performed with open surgery at all US centers including our own (open kidney transplant). Subgroup analysis in patients with BMI of 45 kg/m or greater was conducted. We compared outcomes including patient and graft survival, renal function, and technical complications.

RESULTS

Robotic kidney transplantation group had a significantly higher mean BMI overall. The 1-year patient and graft survival rates were similar between groups. Renal function was also similar at 6, 12, and 36 months. Thrombosis caused 1.3% of the graft losses in open kidney transplant and 0% in the RKT group. Interestingly, 52.8% of the overall experience in patients with BMI of 45 kg/m or greater was performed with the robotic technique.

CONCLUSIONS

Robotic surgery offers similar patient and graft survivals with comparable renal function to open technique. Robotic kidney transplantation permits transplantation in extreme BMI categories without additional technical complications. Further studies are required to establish the role of RKT for obese candidates but preliminary data are encouraging.

From chronic kidney disease to kidney transplantation: The impact of obesity and its treatment modalities

Obesity is associated with worse short-term outcomes after kidney transplantation but the effect on long-term outcomes is unknown. Although some studies have reported worse outcomes for obese recipients when compared to recipients with a BMI in the normal range, obese recipients who receive a transplant have better outcomes than those who remain wait-listed. Whether transplant candidates should be advised to lose weight before or after transplant has been debated and this is mainly due to the gap in the literature linking pre-transplant weight loss with better outcomes post-transplantation. The issue is further complicated by the use of BMI as a metric of body fat, the obesity paradox in dialysis patients and the different ethical viewpoints of utility versus equity. Measures used to reduce weight loss, including orlistat and bariatric surgery (in particular those with a malabsorptive component), have been associated with enteric hyperoxaluria with consequent risk of nephrolithiasis and oxalate nephropathy. In this review, we discuss the evidence regarding the use of weight loss measures in the kidney transplant candidate and recipient with a view to recommending whether weight loss should be pursued before or after kidney transplantation.