Bariatric surgery before and after kidney transplantation: a propensity score-matched analysis

Metabolic and Bariatric Operation and the Path to Kidney Transplantation

BACKGROUND

Obesity is a significant barrier to kidney transplantation for patients with end-stage renal disease (ESRD). We aimed to evaluate the long-term impact of metabolic and bariatric surgery (MBS) on kidney transplantation access and outcomes in individuals with obesity and patients with ESRD.

STUDY DESIGN

A retrospective cohort study using data from 64 US healthcare organizations included 132,989 individuals with obesity (BMI ≥ 30 kg/m²) and ESRD requiring dialysis, of whom 6,263 (4.6%) underwent MBS. Propensity score matching produced 1:1 matched groups of 6,238 patients each, analyzed for 10 years. Primary outcomes included rates of kidney transplant waitlist placement, transplantation, and overall mortality. Secondary outcomes focused on 22,979 transplant recipients, including 1,701 (7.4%) patients who underwent MBS, to evaluate posttransplant adverse events.

RESULTS

During a median follow-up of 33.3 months (MBS) and 28.5 months (controls), patients who underwent MBS demonstrated higher rates of waitlist placement (19.12% vs 10.53%, hazard ratio [HR] 1.800, 95% CI 1.636 to 1.980, p < 0.001) and transplantation (27.06% vs 16.09%, HR 1.712, 95% CI 1.584 to 1.852, p < 0.001) at 10 years, with benefits evident within 1-month postoperation. Mortality was lower in the MBS group (30.55% vs 36.44%, HR 0.768, 95% CI 0.723 to 0.817, p < 0.001). In transplant recipients, patients who underwent MBS had lower cardiovascular complications (37.3% vs 40.6%, risk ratio 0.92, p = 0.007) and all-cause mortality (16.70% vs 20.88%, HR 0.82, p < 0.001), with no significant differences in graft rejection or failure.

CONCLUSIONS

MBS significantly improves access to kidney transplantation and long-term survival for obese patients with ESRD. Patients who underwent MBS demonstrated notable improvements in cardiovascular health, potentially leading to a better quality of life and survival. These findings suggest that MBS should be considered as part of the comprehensive care for this high-risk population.

Cancer incidence following bariatric surgery in renal transplant recipients: a retrospective multi-center analysis

BACKGROUND

Obesity, a known independent risk factor for developing malignancy. Additionally, renal transplant recipients (RTR) confer a 2- to 4-fold increased risk of overall malignancies with an excess absolute risk of .7% per year. While transplant recipients are at risk for obesity and malignancy, the effect of bariatric surgery (BS) in the posttransplantation setting is not well known.

OBJECTIVES

Our study primarily evaluated the impact of BS on cancer incidence in RTR with severe obesity in the posttransplantation setting. Weight loss outcomes were analyzed secondarily.

SETTING

University Hospital.

METHODS

A retrospective study using TriNetX database was developed to analyze cancer outcomes in RTR with posttransplantation BS versus RTR without BS from 2000 to 2023. After the exclusion process and propensity matching, both cohorts consisted of 153 patients.

RESULTS

RTR-BS had a significantly lower incidence of overall cancer and transplant-related cancers (P < .05). No significant difference was identified in cutaneous, gastrointestinal, and reproductive cancers. Percent Excess Weight Loss (%EWL) was significantly lower in RTR-only cohort (11.4%) versus RTR-BS cohort (57.8%) at 5 years. Sleeve gastrectomy (SG) patients (73.19%) had significantly higher %EWL than Roux en-Y gastric bypass (RYGB) patients (49.33%) at 3 years. No difference in cancer incidence was noted between SG and RYGB patients.

CONCLUSION

Postrenal transplantation BS had a diminishing effect on overall and transplant-related cancer incidence in RTR with severe obesity. Significant weight loss was also demonstrated with post-renal transplantation BS.

Global trends of delayed graft function in kidney transplantation from 2013 to 2023: a bibliometric analysis

Delayed graft function (DGF) is an early complication after kidney transplantation. The literature on DGF has experienced substantial growth. However, there is a lack of bibliometric analysis of DGF. This study aimed to analyze the scientific outputs of DGF and explore its hotspots from 2013 to 2023 by using CiteSpace and VOSviewer. The 2058 pieces of literature collected in the Web of Science Core Collection (WOSCC) from 1 January 2013 to 31 December 2023 were visually analyzed in terms of the annual number of publications, authors, countries, journals, literature co-citations, and keyword clustering by using CiteSpace and VOSviewer. We found that the number of papers published in the past ten years showed a trend of first increasing and then decreasing; 2021 was the year with the most posts. The largest number of papers was published by the University of California System, and the largest number of papers was published by the United States. The top five keyword frequency rankings are: 'delayed graft function', 'kidney transplantation', 'renal transplantation', 'survival', and 'recipients'. These emerging trends include 'brain death donors', 'blood absence re-injection injuries', 'tacrolimus', 'older donors and recipients', and 'artificial intelligence and DGF'. In summary, this study reveals the authors and institutions that could be cooperated with and discusses the research hotspots in the past ten years. It provides a reference and direction for future research and application of DGF.

Evaluating the safety of bariatric surgery as a bridge to kidney transplant: a retrospective cohort study

BACKGROUND

Bariatric surgery has been proven safe in end-stage kidney disease (ESKD); however, few studies have evaluated whether a history of bariatric surgery impacts transplant-specific outcomes. We hypothesize that a history of bariatric surgery at the time of transplant does not adversely impact transplant-specific outcomes.

METHODS

The IBM MarketScan Commercial Claims and Encounters database was queried for patients with a history of kidney transplant between 2000 and 2021. Patients were stratified into three groups based on bariatric surgery status and body mass index (BMI) at the time of transplant: patients with obesity (O), patients without obesity (NO), and patients with a history of bariatric surgery (BS). Inverse probability of treatment weighting was used to control for confounding. Adjusted hazard ratios (aHRs) describing the risk of transplant-specific and postoperative outcomes were estimated using weighted Kaplan-Meier curves. Primary outcomes included 30-day and 1-year risk of transplant-specific outcomes. Secondary outcomes included 30-day and 1-year postoperative complications and 30-day and 1-year risk of wound-related complications.

RESULTS

We identified 14,806 patients; 128 in the BS group, 1572 in the O group, and 13,106 in the NO group. There was no difference in 30-day or 1-year risk of transplant-specific complications between the BS and NO group or the O and NO group. Patients with obesity (O) were more likely to experience wound infection (aHR 1.49, 95% CI 1.12-1.99), wound dehiscence (aHR 2.2, 95% CI 1.5-3.2), and minor reoperation (aHR 1.52, 95% CI 1.23-1.89) at 1 year. BS patients had increased risk of wound infection at 1 year (aHR 2.79, 95% CI 1.26-6.16), but were without increase in risk of minor or major reoperation.

CONCLUSION

A history of bariatric surgery does not adversely affect transplant-specific outcomes after kidney transplant. Bariatric surgery can be safely utilized to improve the transplant candidacy of patients with obesity with CKD and ESKD.

Obesity, organ failure, and transplantation: A review of the role of metabolic and bariatric surgery in transplant candidates and recipients

Obesity is a risk factor for kidney, liver, heart, and pulmonary diseases, as well as failure. Solid organ transplantation remains the definitive treatment for the end-stage presentation of these diseases. Among many criteria for organ transplant, efficient management of obesity is required for patients to acquire transplant eligibility. End-stage organ failure and obesity are 2 complex pathologies that are often entwined. Metabolic and bariatric surgery before, during, or after organ transplant has been studied to determine the long-term effect of bariatric surgery on transplant outcomes. In this review, a multidisciplinary group of surgeons from the Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Transplant Surgery presents the current published literature on metabolic and bariatric surgery as a therapeutic option for patients with obesity awaiting solid organ transplantation. This manuscript details the most recent recommendations, pharmacologic considerations, and psychological considerations for this specific cohort of patients. Since level one evidence is not available on many of the topics covered by this review, expert opinion was implemented in several instances. Additional high-quality research in this area will allow for better recommendations and, therefore, treatment strategies for these complex patients.

Future Prospects of Metabolic and Bariatric Surgery: A Comprehensive Review

BACKGROUND

The field of metabolic and bariatric surgery (MBS) is currently an expanding surgical field with constant refinements in techniques, outcomes, indications, and objectives. MBS has been effectively applied across diverse patient demographics, including varying ages, genders, body mass indexes, and comorbidity statuses.

METHODS

We performed a comprehensive literature review of published retrospective cohort studies, meta-analyses, systematic reviews, and literature reviews from inception to 2024, reporting outcomes of MBS using databases such as PubMed, ScienceDirect, and Springer Link.

RESULTS

MBS is a safe and efficient therapeutic option for patients with obesity and associated medical conditions (mortality rate 0.03-0.2%; complication rates 0.4-1%). The favorable safety profile of MBS in the short-, mid-, and long-term offers the potential to treat patients with obesity and type 2 diabetes mellitus, immunosuppression, chronic anticoagulation, neoplastic disease, and end-organ failure without increased morbidity and mortality.

CONCLUSIONS

In conclusion, the future of MBS lies in the ongoing innovation and adapted therapeutic strategies along with the integration of a variety of other techniques for managing obesity. Careful preoperative assessments, coupled with a multidisciplinary approach, remain essential to ensure optimal surgical outcomes and patient satisfaction after MBS.

Obesity, organ failure, and transplantation: a review of the role of metabolic and bariatric surgery in transplant candidates and recipients

Obesity is a risk factor for kidney, liver, heart, and pulmonary diseases, as well as failure. Solid organ transplantation remains the definitive treatment for the end-stage presentation of these diseases. Among many criteria for organ transplant, efficient management of obesity is required for patients to acquire transplant eligibility. End-stage organ failure and obesity are 2 complex pathologies that are often entwined. Metabolic and bariatric surgery before, during, or after organ transplant has been studied to determine the long-term effect of bariatric surgery on transplant outcomes. In this review, a multidisciplinary group of surgeons from the Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Transplant Surgery presents the current published literature on metabolic and bariatric surgery as a therapeutic option for patients with obesity awaiting solid organ transplantation. This manuscript details the most recent recommendations, pharmacologic considerations, and psychological considerations for this specific cohort of patients. Since level one evidence is not available on many of the topics covered by this review, expert opinion was implemented in several instances. Additional high-quality research in this area will allow for better recommendations and, therefore, treatment strategies for these complex patients.

Timing Considerations for Sleeve Gastrectomy in Kidney Transplant Patients: A Single Center Evaluation

Current scientific literature is deficient in detailing the optimal timing for conducting bariatric surgery in relation to kidney transplantation. In this study, we performed a retrospective evaluation of kidney transplant recipients with BMI >35 kg/m2. It aimed to provide data on those who received both sleeve gastrectomy (SG) and kidney transplantation (KT) simultaneously, as well as on patients who underwent SG and KT at different times, either before or after. In addition, the acceptance levels of the bariatric surgery among different scenarios were assessed. Our findings demonstrated that combined KT and SG led to successful weight loss, in contrast to undergoing kidney transplant alone, while maintaining comparable rates of graft and patient survival. Weight loss was similar between recipients who had a combined operation and those who underwent SG following the transplant. Additionally, over a median time frame of 1.7 years, patients who underwent SG before KT exhibited a statistically significant reduction in BMI at the time of the transplant. Notably, our study highlights that patients offered the combined procedure were significantly more likely to undergo SG compared to those for whom SG was presented at a different operative time than the transplant.

Obesity and renal disease: Benefits of bariatric surgery

The prevalence of obesity, a preventable and reversible condition with a high impact on health, continues to rise, especially after the COVID-19 pandemic. Severe overweight is well recognized as a risk factor for diabetes and hypertension, among other conditions, that may increase cardiovascular risk. Obesity has grown simultaneously with a rise in the prevalence of chronic kidney disease, and a pathophysiological link has been established, which explains its role in generating the conditions to facilitate the emergence and maximize the impact of the risk factors of chronic kidney disease and its progression to more advanced stages. Knowing the mechanisms involved and having different tools to reverse the overweight and its consequences, bariatric surgery has arisen as a useful and efficient method, complementary or alternative to others, such as lifestyle changes and/or pharmacotherapy. In a detailed review, the mechanisms involved in the renal consequences of obesity, the impact on risk factors, and the potential benefit of bariatric surgery at different stages of the disease and its progression are exposed and analyzed. Although the observational evidence supports the value of bariatric surgery as a renoprotective measure in individuals with obesity, diabetic or not, randomized studies are expected to establish evidence-based recommendations that demonstrate its positive risk-benefit balance as a complementary or alternative therapeutic tool.