Penile transplantation: the US experience and institutional program set-up

Ethical stakes of penile transplantation: A literature review

BACKGROUND

Vascularized composite allotransplantation has become an alternative reconstruction technique for patients with a severe loss of substance. Today, five human penile transplantations have been reported. The objective of this literature review is to offer an updated overview of the technical and ethical questions surrounding penile transplantation compared with conventional phalloplasty.

MATERIAL AND METHODS

A systematic review was conducted of the literature from 2000 to 2020. A search of PubMed was performed using the keywords: "penile transplantation," "penis transplantation," and "penile vascularized composite allotransplantation." The criteria for the analysis were the type of study, surgical techniques, and ethical concerns.

RESULTS

Thirty-six articles were selected. These articles include reviews, case report, editorials, and preclinical studies. The first article was published in 2003, but the number of articles has increased after the second human transplantation in South Africa in 2014. Surgical techniques and the medication management specific to each team were successful in the 5 transplant cases, but several complications were noted.

CONCLUSION

Two decades of successful penile transplantations have proven the technique to be a viable solution to treat a penile amputation, allowing for a better esthetic and sensitive outcome paired with the possibility of natural urinary and erectile functions. Psychological impact of penile transplantation, selection of patients, complications of immunosuppressive therapies, and surgical technicity are the biggest penile transplantation challenges. Further experimental studies are necessary to produce standardized protocols to safely include penile transplantation in the conventional treatment of a penile amputation.

Vascularized composite allotransplantation of the penis: current status and future perspectives

Given the multifunctional role of the penis in daily life, penile loss can be a physically and emotionally devastating injury. Options to restore penile loss have traditionally relied on autogenous free flap, local flaps, and skin grafts. These techniques provide satisfactory outcomes but carry high rates of urologic and prosthesis-related complications. Vascularized composite allotransplantation may offer a novel solution for these patients through reconstruction with true penile tissue. Still, penile transplants pose ethical, logistical, and psychosocial challenges. These obstacles are made more complex by the limited cases detailed in published literature. A review of the literature was conducted to assay current practices for penile reconstruction. Most modern complex penile reconstructions utilize autogenous pedicled or free tissue flaps, which may be harvested from a variety of donor sites. A total of five penile transplants have been described in the literature. Of these, four report satisfactory outcomes. The advent of genital allotransplantation has recently broadened the landscape of treatment for penile loss. Reconstruction using true penile tissue through vascularized penile allotransplantation has the possibility to engender increased penile function, sensation, and overall quality of life.

Penile reconstruction: An up-to-date review of the literature

Objective

: To review the literature on adult penile reconstruction due to Peyronie’s disease, trauma and cosmesis, while emphasising specific surgical techniques and procedures such as phalloplasty, radial forearm free flap reconstruction, and penile transplant.

Methods

: A comprehensive review of the literature for the years 1992–2020 of the PubMed and SpringerLink databases was performed to identify articles on penile reconstruction. Search terms included ‘penile reconstruction’, ‘penile trauma’, ‘phalloplasty’, ‘penile transplant’, and ‘treatment of Peyronie’s’. Relevant articles were selected. All included studies were performed on adults and written in English.

Results

: We were able to identify 46 papers from PubMed and SpringerLink that included the research terms. From these, we included technical details of procedures and gleaned photographs of their works. Additionally, we included photographs from our institution’s own plication surgery cases.

Conclusions

: The field of adult penile reconstruction is performed for a plethora of reasons. From cosmetic to urgent and from routine to complex, it is most certainly a growing subset of Urology that plays a vital role for the men who need it. To our knowledge, this is the most up-to-date review of adult penile reconstruction.

Infectious complications of vascularized composite allograft transplantation

PURPOSE OF REVIEW

Vascularized composite allograft (VCA) transplants constitute multiple tissues transplanted together as one functional unit. These procedures are increasing in frequency and complexity, yet data about graft survival, quality of life, and infection risk remain limited.

RECENT FINDINGS

Informative guidance for this patient population is often inferred from the solid organ transplantation literature. Yet, it is important to understand that VCA transplantation additionally carries its own significant and distinctive risk factors for infection.

SUMMARY

In this review, we give an overview of previously described infectious complications of VCA transplantation in the literature, discuss risk factors for future infection in these patients, and discuss how to manage such obstacles.

Ethical and societal challenges in penis transplantation

PURPOSE OF REVIEW

To review the current understanding of the ethical and societal difficulties of penile transplantation.

RECENT FINDINGS

Penile transplantation, as with other forms of vascularized composite allotransplantation, has increasing acceptance in society but is still not entirely accepted. Guidelines aiming to help guide future penile transplant programs in an ethical and scientific safe manner were created. Controversies regarding the economic impact, patient safety, and the rights of the patients choosing penile transplant remains.

SUMMARY

Penile transplantation has excellent functional and cosmetic results in the short-term and medium-term. The penis, similar to the face in facial transplantation, carries emotional gravity that relates to visible body parts of another that live forth in a tangible manner contributing to psychological and ethical challenges for both the individual and society more broadly, healthcare administrators, and healthcare workers. In the context of these challenges, controversies emerge related to issues of judgment about what society can and wants to afford. Effects of toxic immunosuppression in a nonlife saving life-enhancing procedure, as well as costs, become arguments that have to be considered in the context of ethical and societal challenges.

Utility of dynamic MRA in the evaluation of male erectile dysfunction

PURPOSE

To assess the efficacy of time-resolved MR angiography (MRA) in evaluating penile vasculature in patients with clinically suspected vascular anomalies contributing to their erectile dysfunction correlating with penile doppler ultrasound (PDUS) findings and clinical outcomes after surgical intervention.

METHODS

Men (n = 26) with signs of early vascular shunting on PDUS underwent time-resolved, contrast-enhanced (0.1 mMol/kg gadobutrol at 1 ml/s followed by saline flush) 3-dimensional spoiled gradient echo T1-weighted MRA sequence performed over 3 min with 4.6 s frame rate after intracavernosal injection of an erectogenic agent. Additional T1- and T2-weighted sequences were performed for anatomic co-localization and tissue characterization. MRA images were evaluated for early filling of draining veins as well as arteriovenous malformations and fistulas and correlated with findings at surgery.

RESULTS

29 MRA examinations on 26 patients (mean age 39 years) demonstrated abnormal early venous drainage (n = 22) as well as diminutive/delayed cavernosal enhancement (n = 3), incomplete tumescence (n = 2), and combined arterial inflow/venous outflow disease (n = 1). The MRA had a concordance of 85.2% at determining the presence, or lack thereof of a shunt/AVM when compared to PDUS.

CONCLUSIONS

Time-resolved MRA allows for both temporal and spatial resolution with visualization of both arterial and venous abnormalities which may be suggested with a screening PDUS examination. This technique allows us to provide detailed anatomic information prior to any surgical intervention.

Emerging Ethical Challenges Raised by the Evolution of Vascularized Composite Allotransplantation

BACKGROUND

Despite early skepticism, the field of vascularized composite allotransplantation (VCA) has demonstrated feasibility. The ethics of VCA have moved past doubts about the morality of attempting such transplants to how to conduct them ethically.

METHODS

Leaders of each program performing and/or evaluating VCA in the United States were invited to participate in a working group to assess the state and future of VCA ethics and policy. Four meetings were held over the course of 1 year to describe key challenges and potential solutions.

RESULTS

Working group participants concluded that VCA holds great promise as treatment for patients with particular injuries or deficits, but the field faces unique challenges to adoption as standard of care, which can only be overcome by data sharing and standardization of evaluation and outcome metrics.

CONCLUSIONS

Adequate attention must be given to concerns including managing the uniquely intense physician-patient relationship, ethical patient selection, ensuring patients have adequate representation, informing and earning the trust of the public for donation, standardizing metrics for success, and fostering an environment of data sharing. These steps are critical to transitioning VCA from research to standard of care and to its insurance coverage inclusion.

Towards clinical application of tissue engineering for erectile penile regeneration

Penile wounds after traumatic and surgical amputation require reconstruction in the form of autologous tissue transfers. However, currently used techniques are associated with high infection rates, implant erosion and donor site morbidity. The use of tissue-engineered neocorpora provides an alternative treatment option. Contemporary tissue-engineering strategies enable the seeding of a biomaterial scaffold and subsequent implantation to construct a neocorpus. Tissue engineering of penile tissue should focus on two main strategies: first, correcting the volume deficit for structural integrity in order to enable urinary voiding in the standing position and second, achieving erectile function for sexual activity. The functional outcomes of the neocorpus can be addressed by optimizing the use of stem cells and scaffolds, or alternatively, the use of gene therapy. Current research in penile tissue engineering is largely restricted to rodent and rabbit models, but the use of larger animal models should be considered as a better representation of the anatomical and physiological function in humans. The development of a cell-seeded scaffold to achieve and maintain erection continues to be a considerable challenge in humans. However, advances in penile tissue engineering show great promise and, in combination with gene therapy and surgical techniques, have the potential to substantially improve patient outcomes.

The Baltimore Criteria for an ethical approach to penile transplantation: a clinical guideline

Significant advances and increasing acceptance of vascularized composite allotransplantation (VCA) have contributed to emerging success of penile transplantation. The aims of penile transplantation are fourfold: adequate urinary function, enabling natural erections, restoration of erogenous sensation and appearance of external male genitalia. Successful penile transplantation also requires limiting risks and managing complications of lifelong immunosuppression. Given the limited experience with this procedure, potential recipients must understand that penile transplantation is not currently standard of care and long-term functional outcomes are unknown. Moreover, these transplants are associated with complex ethical issues. Nevertheless, as the efficacy and safety of penile transplantation are being evaluated, clear indications for transplant are needed. Although preliminary recommendations have been proposed, a more comprehensive framework is needed. We performed a literature review for English language publications related to penile transplantation and ethics. Based on the results of the search, a review of prior recommendations, and our experience performing the first whole male genital allotransplantation including penis, scrotum and abdominal wall; screening and identifying potential donors and recipients for the procedure; and addressing the associated ethical issues, we propose guidelines for responsible penile transplantation: The Baltimore Criteria for an Ethical Approach to Penile Transplantation.

A Review of Current and Emerging Therapeutic Options for Erectile Dysfunction

Contemporary treatment algorithms for erectile dysfunction (ED) involve the use of medical therapies such as phosphodiesterase type 5 (PDE5) inhibitors and intracavernosal injection therapy of vasoactive agents, as well as vacuum erection devices and penile prosthesis implants in medically refractory cases. However, the current therapeutic options only address the symptoms of ED and not the underlying pathogenesis that results in ED. Newer and novel ED therapies aspire to reverse ED conditions by preventing cavernosal fibrosis, promoting endothelial revascularization and modulating various neuro-hormonal pathways. Regenerative therapeutic strategies such as low-intensity shock wave, gene and cellular-based therapies, and penile transplants are designed to improve penile hemodynamics and revitalize the cavernosal smooth muscle to mitigate and/or reverse underlying ED. This state-of-art article evaluates current and emerging therapeutic options for ED.

Non-transecting bulbar urethroplasty is favored over transecting techniques

PURPOSE

To present current evidence supporting the vessel sparing technique to reconstruct bulbar urethral strictures via primary anastomosis.

METHODS

English literature review of presented series of transecting and non-transecting bulbar urethroplasty from 2000 to 2018.

RESULTS

Since its introduction in 2007, vessel-sparing excision and primary anastomosis (VS-EPA) has been utilized in multiple centers across the world. Success rates range from 90 to 98%, comparable to traditional transecting EPA. Complication rates and erectile function outcomes are similar or better in VS-EPA, according to recent publications.

CONCLUSIONS

Non-transection excision and primary anastomosis is a well-tolerated, highly successful reconstructive option for short bulbar urethral strictures in appropriately selected patients. Results are comparable with traditional transecting anastomosis and mid-term multinational follow-up has proven efficacy and safety of the technique. Further well-designed multi-institutional studies are necessary to determine superiority to traditional EPA in terms of surgical outcomes and erectile function preservation.

Techniques and considerations of prosthetic surgery after phalloplasty in the transgender male

For many transgender males, "lower" or "bottom" surgery (the construction of a phallus and scrotum) is the definitive step in their surgical journey for gender affirmation. The implantation of penile and testicular prostheses is often the final anatomic addition and serves to add both functionality and aesthetics to the reconstruction. However, with markedly distinctive anatomy from cis-gender men, the implantation of prostheses designed for cis-male genitalia poses a significant surgical challenge for the reconstructive urologist. The surgical techniques for these procedures remain in their infancy. Implantation of devices originally engineered for cis-men is an imperfect solution but not insurmountable if approached with ingenuity, patience, and persistence. Urologists and patients undergoing implantation should be aware of the high complication rates associated with these procedures as well as the current uncertainty of long-term outcomes. This review provides a comprehensive overview of the perioperative considerations, adaptive surgical techniques, and unique complications of penile and testicular prosthetic implantation in transgender men.