Effects of renal transplantation on erectile dysfunction: a systematic review and meta-analysis

Current treatment options for erectile dysfunction in kidney transplant recipients

INTRODUCTION

Erectile dysfunction (ED) and kidney dysfunction share common risk factors linked to conditions involving endothelial impairment, such as coronary artery disease, dyslipidemia, diabetes mellitus, hypertension, smoking, and obesity. Men with chronic kidney disease experience a high incidence and prevalence of ED. While a functional renal graft can alleviate the issue for some patients, a significant portion of recipients still experience ED (20%-50%).

OBJECTIVES

This narrative review describes the variety of current treatments modalities on ED in kidney transplant recipients (KTRs) and their clinical outcomes.

METHODS

MEDLINE, Web of Science, PubMed, and Google Scholar were used to find eligible articles pertaining to the treatment options of ED in KTRs. A total of 64 articles were evaluated.

RESULTS

In KTRs, ED stems from a multifaceted etiology: anxiety, drug side effects, interference with penile vascularity, or the response of cavernosal muscle to neurotransmitters, along with changes in the endocrine milieu. A diverse range of treatments to restore erectile function has proven to be safe and effective for KTRs. Options include drug therapy, surgical interventions, intracavernosal injection therapies, vacuum erection devices, and extracorporeal shockwave therapy.

CONCLUSION

The initial treatment approach may involve the use of a phosphodiesterase type 5 inhibitors at a low dosage, especially if testosterone-circulating levels align with the diagnosis of hypogonadism. The consideration of a combination therapy involving testosterone and phosphodiesterase type 5 inhibitors should be contemplated due to the associated beneficial effects. Extracorporeal shockwave therapy has shown positive short-term clinical and physiological effects on erectile function in patients who did not respond to first-line treatments, resulting in spontaneous erections sufficient for sexual penetration in 50% of cases. Penile implants should be considered as third-line options based on specific patient needs and compliance with clinical conditions.

Testosterone deficiency in men with end stage renal disease and kidney transplantation: a narrative review

Testosterone deficiency is a prevalent condition that frequently affects individuals with end-stage renal disease (ESRD) and those who have undergone renal transplantation. While the etiology of this condition is complex, its implications in this population are far-reaching, impacting various domains such as endocrine profile, sexual and erectile function, bone mineral density (BMD), anemia, and graft survival following renal transplantation. Herein, we review the most recent literature exploring the pathophysiology of testosterone deficiency in ESRD and renal transplant patients, examining its diverse effects on this demographic, and assessing the advantages of testosterone replacement therapy (TRT). Existing evidence suggests that TRT is a safe intervention in ESRD and renal transplant patients, demonstrating improvements across multiple domains. Despite valuable insights from numerous studies, a critical need persists for larger, high-quality prospective studies to comprehensively grasp the nuances of TRT, especially in this vulnerable population. Proactive screening and treatment of testosterone deficiency may prove beneficial, emphasizing the urgency for further research in this area.

Causal associations between prostate diseases, renal diseases, renal function, and erectile dysfunction risk: a 2-sample Mendelian randomization study

Background

Previous observational studies have found a potential link between prostate disease, particularly prostate cancer (PCa), and kidney disease, specifically chronic renal disease (CKD), in relation to erectile dysfunction (ED), yet the causal relationship between these factors remains uncertain.

Aim

The study sought to explore the potential causal association between prostate diseases, renal diseases, renal function, and risk of ED.

Methods

In this study, 5 analytical approaches were employed to explore the causal relationships between various prostate diseases (PCa and benign prostatic hyperplasia), renal diseases (CKD, immunoglobulin A nephropathy, membranous nephropathy, nephrotic syndrome, and kidney ureter calculi), as well as 8 renal function parameters, with regard to ED. All data pertaining to exposure and outcome factors were acquired from publicly accessible genome-wide association studies. The methods used encompassed inverse variance weighting, MR-Egger, weighted median, simple mode, and weighted mode residual sum and outlier techniques. The MR-Egger intercept test was utilized to assess pleiotropy, while Cochran's Q statistic was employed to measure heterogeneity.

Outcomes

We employed inverse variance weighting MR as the primary statistical method to assess the causal relationship between exposure factors and ED.

Results

Genetically predicted PCa demonstrated a causal association with an elevated risk of ED (odds ratio, 1.125; 95% confidence interval, 1.066-1.186; P < .0001). However, no compelling evidence was found to support associations between genetically determined benign prostatic hyperplasia, CKD, immunoglobulin A nephropathy, membranous nephropathy, nephrotic syndrome, kidney ureter calculi, and the renal function parameters investigated, and the risk of ED.

Clinical Implications

The risk of ED is considerably amplified in patients diagnosed with PCa, thereby highlighting the importance of addressing ED as a significant concern for clinicians treating individuals with PCa.

Strengths and Limitations

This study's strength lies in validating the PCa-ED association using genetic analysis, while its limitation is the heterogeneity in study results.

Conclusion

The results of this study suggest a potential link between PCa and a higher risk of ED.

Prostate Cancer in Transplant Receivers-A Narrative Review on Oncological Outcomes

Prostate cancer (PCa) is a low tumor mutational burden (TMB) cancer with a poor response to immunotherapy. Nonetheless, immunotherapy can be useful, especially in metastatic castration-resistant PCa (mCRPC). Increased cytotoxic T lymphocytes (CTLs) density is correlated with a shorter overall survival (OS), an early biochemical relapse, and a generally poor PCa prognosis. An increased number of CCR4+ regulatory T cells (CCR4 + Tregs) relates to a higher Gleason score or earlier progression. The same therapeutic options are available for renal transplant recipients (RTRs) as for the population, with a comparable functional and oncological outcome. Radical retropubic prostatectomy (RRP) is the most common method of radical treatment in RTRs. Brachytherapy and robot-assisted radical prostatectomy (RARP) seem to be promising therapies. Further studies are needed to assess the need for prostatectomy in low-risk patients before transplantation. The rate of adverse pathological features in RTRs does not seem to differ from those observed in the non-transplant population and the achieved cancer control seems comparable. The association between PCa and transplantation is not entirely clear. Some researchers indicate a possible association between a more frequent occurrence of PCa and a worse prognosis in advanced or metastatic PCa. However, others claim that the risk and survival prognosis is comparable to the non-transplant population.

The Impact of Nutritional Status on Sexual Function in Male Kidney Transplant Recipients

Background and Objectives: Sexual function and nutritional status assessment are relevant topics in chronic kidney disease patients. This study was designed to investigate whether bioelectrical impedance analysis-derived nutritional parameters, nutritional biomarkers, and handgrip strength influence sexual function and to analyze the changes in sexual function after kidney transplantation in men. Materials and Methods: Fifty-four men with kidney failure who had undergone replacement therapy entered the study. In addition, sexual function and nutritional status were evaluated before kidney transplantation and 12 months after. We used the International Index of Erectile Function, bioelectrical impedance analysis, three different malnutrition screening tools, handgrip strength, and anthropometric measurements. The demographic profiles and biochemical nutritional markers were collected. Results: Sexual inactivity was associated with a lower phase angle (6 (1) vs. 7 (1), p < 0.05) and a higher fat mass index (7 (5) vs. 3 (4), p < 0.05). Normal erectile function before kidney transplantation was significantly related to higher fat-free mass (67 (11) vs. 74 (7), p < 0.05) and lean mass (64 (10) vs. 70 (7), p < 0.05). The improvement in erectile function after kidney transplantation was nonsignificant (44% vs. 33%, p = 0.57). Only a weak association between muscle mass and sexual desire 12 months after kidney transplantation was found (rS = 0.36, p = 0.02). Further, linear regression revealed that higher muscle mass could predict better sexual desire after kidney transplantation following adjustment for age, estimated glomerular filtration rate, and diabetes mellitus. Conclusions: Kidney transplantation did not significantly improve erectile dysfunction in our study population. Sexual desire and intercourse satisfaction are the most affected domains in patients with chronic kidney disease. Higher muscle mass predicts higher sexual desire after kidney transplantation. Higher levels of fat-free and lean mass are associated with normal erectile function before kidney transplantation.

Robotic Radical Prostatectomy for Prostate Cancer in Renal Transplant Recipients: Results from a Multicenter Series

BACKGROUND

Despite an expected increase in prostate cancer (PCa) incidence in the renal transplant recipient (RTR) population in the near future, robot-assisted radical prostatectomy (RARP) in these patients has been poorly detailed. It is not well understood whether results are comparable to RARP in the non-RTR setting.

OBJECTIVE

To describe the surgical technique for RARP in RTR and report results from our multi-institutional experience.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective review of the experience of four referral centers.

SURGICAL PROCEDURE

Transperitoneal RARP with pelvic lymph node dissection in selected patients.

MEASUREMENTS

We measured patient, PCa, and graft baseline features; intraoperative and postoperative parameters; complications, (Clavien classification); and oncological and functional outcomes.

RESULTS AND LIMITATIONS

We included 41 men. The median age, American Society of Anesthesiologists score, preoperative renal function, and prostate-specific antigen were 60 yr (interquartile range [IQR] 57-64), 2 points (IQR 2-3), 45 ml/min (IQR 30-62), and 6.5 ng/ml (IQR 5.2-10.2), respectively. Four men (9.8%) had a biopsy Gleason score >7. The majority of the patients (70.7%) did not undergo lymphadenectomy. The median operating time, hospital stay, and catheterization time were 201 min (IQR 170-250), 4 d (IQR 2-6), and 10 d (IQR 7-13), respectively. At final pathology, 11 men had extraprostatic extension and seven had positive surgical margins. At median follow-up of 42 mo (IQR 24-65), four men had biochemical recurrence, including one case of local PCa persistence and one local recurrence. No metastases were recorded while two patients died from non-PCa-related causes. Continence was preserved in 86.1% (p not applicable) and erections in 64.7% (p = 0.0633) of those who were continent/potent before the procedure. Renal function remained unchanged (p = 0.08). No intraoperative complications and one major (Clavien 3a) complication were recorded.

CONCLUSIONS

RARP in RTR is safe and feasible. Overall, operative, oncological, and functional outcomes are comparable to those described for the non-RTR setting, with graft injury remaining undescribed. Further research is needed to confirm our findings.

PATIENT SUMMARY

Robot-assisted removal of the prostate is safe and feasible in patients who have a kidney transplant. Cancer control, urinary and sexual function results, and surgical complications seem to be similar to those for patients without a transplant, but further research is needed.