Clinical outcome of kidney transplantation after bariatric surgery: A single-center, retrospective cohort study

Long-term systemic effects of metabolic bariatric surgery: A multidisciplinary perspective

Background

Obesity is a global health crisis with profound implications on various body systems, contributing to a series of comorbidities. Metabolic Bariatric Surgery (MBS) has emerged as an effective treatment option for severe obesity, with significant weight reduction and potential systemic physiological alterations.

Objectives

This narrative review aims to provide a comprehensive analysis of the long-term effects of MBS on a wide array of body systems, including the heart, liver, kidneys, reproductive system, skin, lungs, digestive tract, pancreas, and blood, as well as related cancers of these organs.

Methods

A systematic search was conducted in academic databases (PubMed, ISI Web of Science, and Scopus) for observational studies and reviews published between July 2000 and December 2023, investigating the association between MBS and the subsequent function of different organ systems. High-quality studies were prioritized to ensure reliable evidence synthesis.

Results

MBS has demonstrated favorable outcomes in reducing cardiovascular disease risk, improving cardiac function, and alleviating heart failure symptoms. It has also been associated with improved respiratory function, remission of obstructive sleep apnea, and reduced cancer incidence and mortality. Additionally, MBS has shown benefits in managing gastrointestinal disorders, enhancing glycemic control, and promoting pancreatic beta-cell regeneration in type 2 diabetes mellitus. However, some methods of MBS are associated with a higher risk of cholelithiasis, GERD, and pancreatic exocrine insufficiency.

Conclusion

MBS has far-reaching systemic effects beyond weight loss, offering potential long-term benefits for various organ systems and comorbidities associated with obesity. For many patients with severe obesity, the potential benefits of Metabolic and Bariatric Surgery (MBS) can outweigh the associated risks. However, careful evaluation by a qualified healthcare professional is crucial to determine candidacy and ensure a successful outcome. Further research is needed to fully elucidate the long-term impacts and tailor personalized treatment approaches.

Bariatric Surgery in Severely Obese Kidney Donors Before Kidney Transplantation: A Retrospective Study

BACKGROUND

Bariatric surgery (BS) is the optimal approach for sustained weight loss and may alter donation candidacy in potential donors with obesity. We evaluated the long-term effects of nephrectomy after BS on metabolic profile, including body mass index, serum lipids and diabetes, and kidney function of donors.

METHODS

This was a single-center retrospective study. Live kidney donors who underwent BS before nephrectomy were matched for age, gender, and body mass index with patients who underwent BS alone and with donors who underwent nephrectomy alone. Estimated glomerular filtration rate (eGFR) was calculated according to Chronic Kidney Disease Epidemiology Collaboration and adjusted to individual body surface area to create absolute eGFR.

RESULTS

Twenty-three patients who underwent BS before kidney donation were matched to 46 controls who underwent BS alone. At the last follow-up, the study group showed significantly worse lipid profile with low-density lipoprotein of 115 ± 25 mg/dL versus the control group with low-density lipoprotein of 99 ± 29 mg/dL ( P  = 0.036) and mean total cholesterol of 191 ± 32 versus 174 ± 33 mg/dL ( P  = 0.046). The second control group of matched nonobese kidney donors (n = 72) had similar serum creatinine, eGFR, and absolute eGFR as the study group before nephrectomy and 1 y after the procedure. At the end of follow-up, the study group had significantly higher absolute eGFR compared with the control group (86 ± 21 versus 76 ± 18 mL/min; P  = 0.02) and similar serum creatinine and eGFR.

CONCLUSIONS

BS before live kidney donation is a safe procedure that could increase the donor pool and improve their health in the long run. Donors should be encouraged to maintain their weight and avoid adverse lipid profile and hyperfiltration.

Bariatric surgery improves access to renal transplantation and is safe in renal failure as well as after transplantation: A systematic review and meta-analysis

INTRODUCTION

Effective workup and listing of end-stage renal disease (ESRD) patients for renal transplantation, often with multiple co-morbidities, poses a challenge for transplant teams. Obesity is a common co-morbidity associated with adverse outcomes in ESRD and kidney transplant (KT) recipients. Bariatric and metabolic surgery (BMS) has long been established as a safe and effective treatment for morbid obesity. In this study, the authors aimed to evaluate the strength of evidence for both the efficacy and safety of bariatric surgery in patients with ESRD or kidney transplantation.

METHODS

A literature search was performed using key terms including "transplantation", "kidney", "renal", "obesity", and "bariatric". Databases searched include MEDLINE, EMBASE and Web of Science from inception to date (April 2021). Methodological quality was assessed using the Newcastle-Ottawa tool. Selected articles were then categorised into patients awaiting waiting list acceptance, patients awaiting transplantation, patients undergoing simultaneous BMS + KT and patients undergoing BMS following a previous renal transplant. Summary effects are presented with a level of statistical significance and 95% Confidence Intervals.

RESULTS

A total of 28 articles were selected following the literature search. Fourteen studies on patients awaiting listing (n = 1903), nine on patients on the KT waiting list (n = 196), a single study on simultaneous BMS and KT and ten studies on patients undergoing BMS following KT (n = 198). Mean change in BMI for patients awaiting listing was -11.3 kg/m² (95%CI: -15.3 to -7.3, p < 0.001), mean change in BMI for patients listed for KT was -11.2 kg/m 2(95%CI: -12.9 to -9.5, p 0.001) and mean change for patients with prior KT was -11.0 kg/m² (95%CI: -7.09 to -14.9, p < 0.001). The combined mortality rate for patients who had undergone both BMS and KT was 4% (n = 15).

DISCUSSION

This review demonstrates BMS is both safe and efficacious in patients with ESRD prior to KT and in those post KT. It would enable difficult-to-list obese recipients the possibility to undergo transplantation and should be considered as part of the work up process.

Bariatric Surgery Outcomes in Patients with Kidney Transplantation

Obesity and kidney transplantation (KTx) are closely related. Obesity increases the risk of chronic kidney disease and can be a relative contraindication for KTx. Besides, KTx recipients are predisposed to obesity and its comorbidities. Consequently, bariatric surgery (BS) emerges as a powerful therapeutic tool either before or after KTx. Since evidence regarding the best approach is still scarce, we aimed to describe renal and metabolic outcomes in a single centre with more than 15-year experience in both surgeries. Methods: A retrospective study including patients who had received a KTx either before or after BS. Usual metabolic and renal outcomes, but also new variables (as renal graft dysfunction) were collected for a minimum follow-up of 1-year post-BS. Results: A total of 11 patients were included: n = 6 (BS-post-KTx) and n = 5 (BS-pre-KTx). One patient was assessed in both groups. No differences in the main outcomes were identified, but BS-post-KTx group tended to gain more weight during the follow-up. The incidence of renal graft dysfunction was comparable (4/6 for BS-post-KTx, 3/5 for BS-pre-KTx) between groups. Conclusions: BS in patients with KTx appears to be safe and effective attending to metabolic and renal outcomes. These results seem irrespective of the time course, except for weight regain, which appears to be a common pattern in the BS-post-KTx group.

Kidney Transplantation in Patients After Bariatric Surgery: High-Volume Bariatric and Transplant Center Experience

BACKGROUND

Kidney transplantation (KTx) is the best type of treatment for patients with end-stage renal disease (ESRD). Unfortunately, obesity may be a contraindication for transplantation. Our study aimed to evaluate the results of KTx in patients who had bariatric surgery (BS) prior to transplantation.

METHODS

A single center, with experience in bariatric and transplant surgery, presents a retrospective study of 13 patients who received a kidney transplant after a gastric bypass (GB) operation between 2012 and 2019.

RESULTS

Thirteen patients, who were potential candidates for KTx, were previously qualified for BS because of a body mass index (BMI) > 35 kg/m². Additionally, all patients had arterial hypertension, 60% of patients had diabetes, and 30% of patients had coronary artery disease. Patients were activated on the waiting list when their BMI was < 35 kg/m². KTx was performed between 5 and 29 months after BS. One patient needed reoperation due to a urinary leak and another patient needed reoperation because of a high-pressure lymphocele. We diagnosed 2 delayed graft functions (DGFs) and 1 acute rejection. One patient died for reasons independent of surgery. The KTx observation period ranged from 3 to 8 years. Currently, 11 patients has stable renal function: creatinine concentration is 0.8-1.8 mg/dL and BMI is between 23 and 35 kg/m².

CONCLUSIONS

Despite the small group of patients, we can assume that kidney transplantation can be safely performed in patients with end-stage renal disease (ESRD) who have previously undergone gastric bypass (GB) as a graft bridging procedure. In some cases, BS may be the only chance of getting an organ.

The application of body mass index-based eligibility criteria may represent an unjustified barrier to renal transplantation in people with obesity

The prevalence of both obesity and end-stage kidney disease is increasing. In many centres, obesity is considered a relative contraindication to kidney transplantation due to an association with short- and longer-term adverse outcomes. This leads to delayed transplant waitlisting and longer organ waiting times for people with obesity. This review evaluates whether intentional pre-transplant weight loss in people with obesity improves kidney transplant outcomes. There are currently no data showing that non-surgical weight loss of 10% or more improves graft or patient survival over 4-5 years. Outcomes from bariatric surgery cohorts have been generally neutral or favourable after pre-transplant weight loss of ~25%. Given the survival benefit of kidney transplantation compared to maintenance dialysis, and the difficulty of achieving and maintaining weight loss, the common practice of recommending weight loss to achieve arbitrary targets prior to waiting list activation needs to be carefully considered.

Clinical outcome of kidney transplantation after bariatric surgery: A single-center, retrospective cohort study

Patients with class II and III obesity and end‐stage renal disease are often ineligible for kidney transplantation (KTx) due to increased postoperative complications and technically challenging surgery. Bariatric surgery (BS) can be an effective solution for KTx candidates who are considered inoperable. The aim of this study is to evaluate outcomes of KTx after BS and to compare the outcomes to obese recipients (BMI ≥ 35 kg/m²) without BS. This retrospective, single‐center study included patients who received KTx after BS between January 1994 and December 2018. The primary outcome was postoperative complications. The secondary outcomes were graft and patient survival. In total, 156 patients were included, of whom 23 underwent BS prior to KTx. There were no significant differences in postoperative complications. After a median follow‐up of 5.1 years, death‐censored graft survival, uncensored graft survival, and patient survival were similar to controls (log rank test p = .845, .659, and .704, respectively). Dialysis pre‐transplantation (Hazard Ratio (HR) 2.55; 95%CI 1.03–6.34, p = .043) and diabetes (HR 2.41; 95%CI 1.11–5.22, p = .027) were independent risk factors for all‐cause mortality. A kidney from a deceased donor was an independent risk factor for death‐censored graft loss (HR 1.98; 95%CI 1.04–3.79, p = .038). Patients who received a KTx after BS have similar outcomes as obese transplant recipients.