Surgical Techniques for Managing Post-prostatectomy Erectile Dysfunction

Perioperative infection prevention during inflatable penile prosthesis surgery: a narrative review

Background and Objective

Penile prostheses are an option for the management of erectile dysfunction (ED). Over the years penile prosthesis surgery has become increasingly safe owing to improvements such as antibiotic usage, coated devices, and surgical techniques. However, infection remains a dreaded complication during prosthesis surgery. Efforts to minimize risk of infection in the perioperative period have been extensively studied. Herein, we performed a narrative review on preoperative, intraoperative, and postoperative strategies for infection prevention during placement of a penile prosthesis with a comparison of infection prevention strategies to other surgical fields.

Methods

A literature review was performed using PubMed and Google Scholar. Studies evaluating perioperative management of penile prosthesis infection were included. The following search terms were used to for our literature search: penile prosthesis, inflatable penile prosthesis, infection, prevention, perioperative management. Articles were graded based on the 2011 Oxford Centre for Evidence Based Medicine (OCEBM) guidelines and a table was generated with each intervention discussed and its level of evidence based on current literature.

Key Content and Findings

Optimization of patient's comorbid conditions can help reduce risk during prosthesis operations. Monitoring and optimizing a patient's glycemic control has been investigated, but the current literature does not necessarily support a strict hemoglobin A1c (HbA1c) or pre-operative blood glucose level. Surgical field preparation using chlorhexidine-based solutions has been shown to be superior to iodine-based solutions. Appropriately selected peri-operative antibiotics have also been shown to reduce infection risk. Intraoperatively, the use of coated devices in addition to a 'no touch' technique have been shown to significantly reduce the risk of inflatable penile prosthesis (IPP) infection. Post operatively, available evidence of antibiotic use has not been demonstrated to be effective in reducing infection rates.

Conclusions

Surgical infection following placement of an IPP is a devastating and morbid complication with infection rate up as high as 1-3% in virgin cases and 7-18% in revision cases. While perioperative techniques exist and have reduced risk of infection, more prospective data is needed to evaluate the clinical significance of these different approaches. More research in these areas, along with future options such as nanoparticles, antibiotic coated suture, and next generation sequencing (NGS) for bacterial pathogens, may shed light on further ways to optimize infection reduction strategies for prosthesis surgery.

NaV1.7 targeted fluorescence imaging agents for nerve identification during intraoperative procedures

Surgeries and trauma result in traumatic and iatrogenic nerve damage that can result in a debilitating condition that approximately affects 189 million individuals worldwide. The risk of nerve injury during oncologic surgery is increased due to tumors displacing normal nerve location, blood turbidity, and past surgical procedures, which complicate even an experienced surgeon's ability to precisely locate vital nerves. Unfortunately, there is a glaring absence of contrast agents to assist surgeons in safeguarding vital nerves. To address this unmet clinical need, we leveraged the abundant expression of the voltage-gated sodium channel 1.7 (NaV1.7) as an intraoperative marker to access peripheral nerves in vivo, and visualized nerves for surgical guidance using a fluorescently-tagged version of a potent NaV1.7-targeted peptide, Tsp1a, derived from a Peruvian tarantula. We characterized the expression of NaV1.7 in sensory and motor peripheral nerves across mouse, primate, and human specimens and demonstrated universal expression. We synthesized and characterized a total of 10 fluorescently labeled Tsp1a-peptide conjugates to delineate nerves. We tested the ability of these peptide-conjugates to specifically accumulate in mouse nerves with a high signal-to-noise ratio in vivo. Using the best-performing candidate, Tsp1a-IR800, we performed thyroidectomies in non-human primates and demonstrated successful demarcation of the recurrent laryngeal and vagus nerves, which are commonly subjected to irreversible damage. The ability of Tsp1a to enhance nerve contrast during surgery provides opportunities to minimize nerve damage and revolutionize standards of care across various surgical specialties.

The Cavernous Nerve Injury Rat Model: A Pictorial Essay on Post-Radical Prostatectomy Erectile Dysfunction Research

Understanding and addressing post-radical prostatectomy (RP) erectile dysfunction (ED) is of paramount importance for clinicians. Cavernous nerve (CN) injury rat model studies have provided consistently promising experimental data regarding regaining erectile function (EF) after nerve damage-induced ED. However, these findings have failed to translate efficiently into clinical practice, with post-RP ED therapeutic management remaining cumbersome and enigmatic. This disparity highlights the need for further standardization and optimization of the elaborate surgical preparation protocols and multifaceted reporting parameters involved in reliable CN injury rat model experimentation. Even so, despite its technical complexity, this animal model remains instrumental in exploring the functional implications of RP, i.e., surgical lesions of the neurovascular bundles (NVBs). Herein, besides cavernous nerve (CN) dissection, injury, and electrostimulation, multiple pressure measurements, i.e., mean arterial pressure (MAP) and intra-cavernosal pressure (ICP), must also be achieved. A transverse cervical incision allows for carotid artery cannulation and MAP measurements. Conversely, ICP measurements entail circumcising the penis, exposing the ischiocavernous muscle, and inserting a needle into the corporal body. Finally, using an abdominal incision, the prostate is revealed, and the major pelvic ganglia (MPG) and CNs are dissected bilaterally. Specific surgical techniques are used to induce CN injuries. Herein, we provide a narrative and illustrative overview regarding these complex experimental procedures and their particular requirements, reflecting on current evidence and future research perspectives.

Comparison of the efficacy of the early LI-SWT plus daily tadalafil with daily tadalafil only as penile rehabilitation for postprostatectomy erectile dysfunction

This study compares the efficacy of the early low-intensity shock wave therapy (LI-SWT) plus daily tadalafil with daily tadalafil only therapy as penile rehabilitation for postprostatectomy erectile dysfunction in patients with prostate cancer who underwent bilateral interfascial nerve-sparing radical prostatectomy (robotic or open). From April 2019 to March 2021, 165 patients were enrolled, and 80 of them successfully completed this prospective study. Daily tadalafil were administered to all the patients. LI-SWT consisted of a total of six sessions. Each session was performed on days 4, 5, 6, and 7, and on the second and fourth weeks after surgery. Each LI-SWT session consisted of 300 shocks at an energy density of 0.09 mJ/mm2 and a frequency of 120 shocks per minute that were delivered at each of the five treatment points for 15 min. Thirty-nine patients were treated with tadalafil-only (group A) while 41 were treated with tadalafil and LI-SWT simultaneously (group B). At postoperative 6 months, the proportion of patients with erection hardness scores (EHS) ≥ 3 (4/39 vs. 12/41) was significantly higher in group B (p = 0.034), and LI-SWT was the only independent factor for predicting EHS ≥ 3 (OR, 3.621; 95% CI, 1.054-12.437; p = 0.041). There were no serious side effects related to early LI-SWT. Early LI-SWT plus daily tadalafil therapy as penile rehabilitation for postprostatectomy erectile dysfunction is thought to be more efficacious than tadalafil only. Further large-scaled randomized controlled trials will be needed to validate these findings.

Long-term consequences of bilateral cavernous crush injury in normal and diabetic rats: a functional study

A recent statement from the European-Society-for-Sexual-Medicine has highlighted the limitations of using the rat model for nerve-sparing prostatectomy. The use of young rats with no comorbidities and the early evaluation of the erectile function (EF) are deemed a source of bias. Our aim was to evaluate the long-term consequences in EF of bilateral nerve cavernous crush- injury (BNCI) in type 1 diabetic (DM) rats 30-male/12-week-old rats were divided into four groups: Sham, BNCI, DM, and BNCI + DM. Sham group underwent an intraperitoneal injection (IP) of saline solution and after 1 month underwent a sham laparotomy. BNCI underwent an IP of saline solution and after 1 month to BNCI. DM underwent an IP of 60 mg/kg-1-streptozotocin (STZ) and after 1 month to a sham laparotomy. BNCI + DM underwent an IP of 60 mg/kg-1-STZ and after 1 month to BNCI. After 5 months from the induction of diabetes, all rats underwent measurement of intracorporeal pressure (ICP) and mean arterial pressure (MAP) during CN-electrostimulation. Multiple groups were compared using Kruskal-Wallis one-way analysis of variance followed by Mann-Whitney U test for post hoc comparisons. Blood glucose-level was higher (p < 0.05) in the groups with DM and BNCI + DM. After 5-months, DM and BNCI + DM also showed a lower weight compared to other groups (p < 0.05). No differences were noted in ICP/MAP between the sham and BNCI. BNCI + DM showed lower ICP/MAP compared to all the groups (p < 0.05). DM Showed lower ICP/MAP compared to Sham and BNCI (p < 0.05). BNCI in rats without comorbidities did not induce long-term erectile dysfunction (ED) suggesting a spontaneous EF recovery. BNCI in DM induced long-term ED. The results of previous short-term studies can only provide evidence on the time to recovery of spontaneous EF as to the actual EF recovery rate.

Relationships between erectile dysfunction, prostate cancer treatment type and inflatable penile prosthesis implantation

PURPOSE

The prevalence of erectile dysfunction (ED) and the utilization of inflatable penile prosthesis (IPP) among prostate cancer patients are understudied. The aim of the study was to examine the relationships between ED, prostate cancer treatment type and IPP implantation in a national cohort.

MATERIALS AND METHODS

We identified a retrospective cohort of Surveillance, Epidemiology, and End Results (SEER)-Medicare patients diagnosed with locoregional prostate cancer between 2006 and 2011 and treated with surgery or radiation. Chi-square tests were used to detect significant differences in ED rates as well as use of IPP among the subset with ED. Multivariable logistic regression was used to examine factors associated with the use of IPP.

RESULTS

Among 31,233 patients in our cohort, 10,334 (33.1%) received prostatectomy and 20,899 (66.9%) received radiation. ED within 5 years was significantly more common in the prostatectomy group relative to those the radiation group (65.3% vs. 33.8%, p<0.001). In the subset of 13,812 patients with ED, the radiation group had greater median time to ED diagnosis compared to the prostatectomy group (346 vs. 133 days, p<0.001). IPP implantation was more frequent for prostatectomy patients than for radiation patients (3.6% vs. 1.4%, p<0.001). Cancer treatment type, race, and marital status were significantly associated with IPP utilization.

CONCLUSIONS

ED is highly prevalent among prostate cancer patients, and IPP implantation is be underutilized. ED rates, time to ED diagnosis and utilization of IPP differed significantly by prostate cancer treatment type.

Sexual dysfunction damages: A legal database review

INTRODUCTION

Procedural specialties are at higher risk for malpractice claims than non-procedural specialties. Previous studies have examined common damages and malpractice lawsuits resulting from specific procedures. Our goal was to analyze urological interventions that led to sexual dysfunction (SD) claims.

METHODS

The Casetext legal research platform was queried using search terms for medical malpractice and common men's health procedures between 1993 and 2020. In total, 236 cases were found, and 21 cases met the inclusion criteria: malpractice cases against a urologist or urology group, clearly stated legal outcome, and allegation of sexual dysfunction from an intervention that directly caused damages.

RESULTS

A total of 42 damages were cited in 21 lawsuits. The top three damages claimed were erectile dysfunction (ED) (14/42, 33.3%), genital pain syndrome (7/42, 16.7%), and urinary incontinence (5/42, 11.9%). The most commonly cited treatments were urinary catheter placement or removal (3/21, 14.3%), robotic-assisted laparoscopic radical prostatectomy (RALP) (3/21, 14.3%), circumcision (3/21, 14.3%), and penile implant (3/21, 14.3%). In 19 of 21 suits (90.4%), the outcome favored the defendant. Two cases favored the plaintiff: penile implant (failure to prove the patient was permanently, organically impotent prior to the procedure; missed urethral injury at time of surgery, $300 000) and vasectomy (damage to vasculature resulting in loss of testicle, $300 000).

CONCLUSIONS

Most suspected malpractice cases resulting in SD favored the defendant urologist. Interestingly, urinary catheter placement is as likely to result in litigation as other operative interventions, such as RALP, inflatable penile prosthesis, and circumcision. It is possible that thorough preoperative counselling and increased responsiveness to patients' postoperative concerns may have avoided litigation in several cases.

Indications and characteristics of penile traction and vacuum erection devices

A variety of devices are available for the management of patients with erectile dysfunction, Peyronie's disease, penile dysmorphophobia, for support before and after penile prosthesis insertion, and after radical prostatectomy. Traction devices include, but are not limited to, Penimaster PRO (MSP Concept, Berlin, Germany), Andropenis and Andropeyronie (Andromedical, Madrid, Spain), and the Restorex (PathRight Medical, Plymouth, USA). The other type of devices are vacuum devices such the Osbon ErecAid (Timm Medical, MN, USA). Different devices are optimal for different clinical applications, and robust and contemporary clinical data show a variety of strengths and weaknesses for each device. Research currently favours the use of traction devices for improvement of penile curvature and erectile function in patients with Peyronie's disease compared with vacuum devices; Penimaster Pro and Restorex have been shown to be associated with the best outcomes in this indication. Vacuum devices are favoured for treatment of erectile dysfunction and penile length loss after radical prostatectomy; the Osbon ErecAid is the most well-studied device for this indication. Research into other uses of vacuum and traction devices, such as for penile dysmorphophobia or before and after penile prosthesis, is very limited. Compliance, cost and availability remain substantial challenges, and further high-quality evidence is required to clarify the role of traction devices in urology and sexual medicine.

International Continence Society (ICS) report on the terminology for sexual health in men with lower urinary tract (LUT) and pelvic floor (PF) dysfunction

INTRODUCTION

The terminology for sexual health in men with lower urinary tract (LUT) and pelvic floor (PF) dysfunction has not been defined and organized into a clinically based consensus terminology report. The aim of this terminology report is to provide a definitional document within this context that will assist clinical practice and research.

METHODS

This report combines the input of the members of sexual health in men with LUT and PF Dysfunction working group of the International Continence Society (ICS), assisted at intervals by external referees. Appropriate core clinical categories and a sub-classification were developed to give coding to definitions. An extensive process of 18 rounds of internal and external review was involved to exhaustively examine each definition, with decision-making by collective opinion (consensus). The Committee retained evidence-based definitions, identified gaps, and updated or discarded outdated definitions. Expert opinions were used when evidence was insufficient or absent.

RESULTS

A terminology report for sexual health in men with LUT and PF dysfunction, encompassing 198 (178 NEW) separate definitions, has been developed. It is clinically based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different speciality groups involved. Conservative and surgical managements are major additions and appropriate figures have been included to supplement and clarify the text. Emerging concepts and measurements, in use in the literature and offering further research potential, but requiring further validation, have been included as an appendix. Interval (5-10 years) review is anticipated to keep the document updated.

CONCLUSION

A consensus-based terminology report for sexual health in men with LUT and PF dysfunction has been produced to aid clinical practice and research. The definitions that have been adopted are those that are most strongly supported by the literature at this time or are considered clinical principles or consensus of experts' opinions.

Neurovascular bundle preservation in robotic-assisted radical prostatectomy: How I do it after 15.000 cases

Despite the neuroanatomy knowledge of the prostate described initially in the 1980's and the robotic surgery advantages in terms of operative view magnification, potency outcomes following robotic-assisted radical prostatectomy still challenge surgeons and patients due to its multifactorial etiology. Recent studies performed in our center have described that, in addition to the surgical technique, some important factors are associated with erectile dysfunction (ED) following robotic-assisted radical prostatectomy (RARP). These include preoperative Sexual Health Inventory for Men (SHIM) score, age, preoperative Gleason score, and Charlson Comorbidity Index (CCI). After performing 15,000 cases, in this article we described our current Robotic-assisted Radical Prostatectomy technique with details and considerations regarding the optimal approach to neurovascular bundle preservation.

Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA)

INTRODUCTION

Current non-invasive treatments for erectile dysfunction (ED) include oral medications, intracavernosal injections, and vacuum-assisted devices. Though these therapies work well for many, a subset of patients have contraindications or are unsatisfied with these options. Restorative therapies for ED are a new frontier of treatments focused on regenerating diseased tissue and providing a potential "cure" for ED.

AIM

The aim of this position statement is to examine existing clinical trial data for restorative therapies and identify elements that require further research before widespread adoption.

METHODS

A literature review was performed to identify all clinical trials performed with regenerative therapy for ED. This includes treatments such as stem cell therapy (SCT), platelet rich plasma (PRP), and restorative related technologies like low-intensity shockwave therapy (LiSWT).

MAIN OUTCOME MEASURES

Most clinical trials in restorative therapies were assessed for safety, feasibility, or efficacy. This included recording adverse events, changes in sexual function and erectile function questionnaires, and diagnostics measures.

RESULTS

To date there is an absence of robust clinical data supporting the efficacy of restorative therapies regarding ED, though technologies such as LiSWT have established relative safety.

CONCLUSIONS

Restorative therapies are a promising technology that represents a new frontier of treatment geared towards reversing disease pathology rather than just treating symptoms. However, current published clinical studies are limited. Future work needs to be adequately powered, multi-center, randomized, sham/placebo-controlled trials in well-characterized patient populations to ensure safety and demonstrate efficacy. Until these studies are done, restorative therapies should be reserved for clinical trials and not offered in routine clinical practice. Liu JL, Chu KY, Gabrielson AT, et al. Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA). J Sex Med 2021;9:100343.

Comprehensive approach for preserving cavernous nerves and erectile function after radical prostatectomy in the era of robotic surgery

A nerve-sparing procedure during robot-assisted radical prostatectomy has been considered one of the most important techniques for preserving postoperative genitourinary function. The reason is that adequate nerve-sparing procedures could preserve both erectile function and lower urinary tract function after surgery. When a nerve-sparing procedure is carried out, the cavernous nerves themselves cannot be visualized, despite the magnified viewing field during robot-assisted radical prostatectomy. Thus, nerve-sparing procedures have been considered challenging operations, even now. However, because not all surgeons have carried out a sufficient number of nerve-sparing procedures, the development of new nerve-sparing procedures or new methods for mapping the cavernous nerves is required. Recently, various new operative techniques, for example, Retzius-sparing robot-assisted radical prostatectomy, transvesical robot-assisted radical prostatectomy and retrograde release of neurovascular bundle technique during robot-assisted radical prostatectomy, have been developed. In addition, new surgical devices, for example, biological/bioengineering solutions for cavernous nerve protection and devices for identifying the cavernous nerves during radical prostatectomy, have developed to preserve the cavernous nerves. In contrast, limitations or problems in preserving cavernous nerves and postoperative erectile function have become apparent. In particular, the recovery rate of erectile function, the positive surgical margin rate at the site of nerve-sparing and the indications for nerve sparing have become obvious with the accumulation of much evidence. Furthermore, predictive factors for postoperative erectile function after nerve-sparing procedures have also been clarified. In this article, the importance of a comprehensive approach for early recovery of erectile function in the robot-assisted radical prostatectomy era is discussed.

Prevalence of post-prostatectomy erectile dysfunction and a review of the recommended therapeutic modalities

Radical prostatectomy (RP) represents one of the most commonly used first-line treatment modalities in men with localized prostate cancer. One of the most feared post-surgical complications is erectile dysfunction (ED), usually caused by direct damage to the cavernous nerves or due to neuropraxia. Penile rehabilitation is an emerging concept that was proposed to stimulate and accelerate recovery of erectile function after RP. The goal is to improve blood flow to the penis, increasing cavernous oxygenation and avoiding fibrosis. The most common used modalities include oral phosphodiesterase type 5 inhibitors (PDE5-I), vacuum erection devices (VEDs), intracorporeal injection (ICI) therapy, medicated urethral system for erections (MUSE), and a combination of these treatments. For those patients with severe ED, ED refractory to medical therapy and/or seeking long term reliable results, the penile prosthesis implant remains an excellent alternative. We conducted a broad review of post-prostatectomy ED prevalence with different techniques and the success rates of the different therapeutic approaches.

UK practice for penile prosthesis surgery: baseline analysis of the British Association of Urological Surgeons (BAUS) Penile Prosthesis Audit

OBJECTIVES

To undertake a prospective multicentre national audit of penile prosthesis practice in the UK over a 3-year period.

PATIENTS AND METHODS

Data were submitted by urological surgeons as part of the British Association of Urological Surgeons Penile Prosthesis National Audit. Patients receiving a penile prosthesis (inflatable or malleable) were included as part of a prospective registry over a 3-year period. Data were validated and then analysed using a software package (Tableau).

RESULTS

A total of 1071 penile prosthesis procedures were included from 22 centres. The three commonest aetiological factors for erectile dysfunction were diabetes, prostate surgery and Peyronie's disease. Of the recorded data, inflatable penile prostheses were the commonest devices implanted, with 665 devices used (62.1%), whereas malleable prostheses accounted for 14.2% of the implants. Recorded intra-operative complications included urethral injury (0.7%, n = 7), corporal perforation (1.1%, n = 12) and cross-over (0.6%, n = 6). Known postoperative complications were recorded in 9.8% of patients (74/752), with the two most frequently reported being postoperative penile pain (n = 11) and scrotal haematoma (n = 14).

CONCLUSION

This baseline analysis is the largest prospective registry of penile prostheses procedures to date. The data show that, over the 3-year collection period in the UK, there are now fewer surgeons performing the procedure, together with a reduction in the number of centres. Peri-operative complications were infrequent, and the rate of implant abortion (e.g. as a result of urethral injury) was very low. Further follow-up data will be required to publish long-term outcomes and patient satisfaction.

European Society for Sexual Medicine Consensus Statement on the Use of the Cavernous Nerve Injury Rodent Model to Study Postradical Prostatectomy Erectile Dysfunction

INTRODUCTION

Rodent animal models are currently the most used in vivo model in translational studies looking into the pathophysiology of erectile dysfunction after nerve-sparing radical prostatectomy.

AIM

This European Society for Sexual Medicine (ESSM) statement aims to guide scientists toward utilization of the rodent model in an appropriate, timely, and proficient fashion.

METHODS

MEDLINE and EMBASE databases were searched for basic science studies, using a rodent animal model, looking into the consequence of pelvic nerve injury on erectile function.

MAIN OUTCOME MEASURES

The authors present a consensus on how to best perform experiments with this rodent model, the details of the technique, and highlight possible pitfalls.

RESULTS

Owing to the specific issue-basic science-Oxford 2011 Levels of Evidence criteria cannot be applied. However, ESSM statements on this topic will be provided in which we summarize the ESSM position on various aspects of the model such as the use of the Animal Research Reporting In Vivo Experiments guideline and the of common range parameter for nerve stimulation. We also highlighted the translational limits of the model.

CONCLUSION

The following statements were formulated as a suggestive guidance for scientists using the cavernous nerve injury model. With this, we hope to standardize and further improve the quality of research in this field. It must be noted that this model has its limitations. Weyne E, Ilg MM, Cakir OO, et al. European Society for Sexual Medicine Consensus Statement on the Use of the Cavernous Nerve Injury Rodent Model to Study Postradical Prostatectomy Erectile Dysfunction. Sex Med 2020;8:327-337.

Stem Cell/Oxygen-Releasing Microparticle Enhances Erectile Function in a Cavernous Nerve Injury Model

Erectile dysfunction caused by damage to the cavernous nerve is a common complication of radical prostatectomy for patients with localized prostate cancer. Various studies have investigated repair of damaged tissue and prevention of fibrosis in the corpus cavernosum using stem cell therapy. However, stem cell therapy has limitations, including insufficient nutrient and oxygen supply to transplanted stem cells. This study investigated whether stem cell/oxygen-releasing hollow microparticles (HPs) had therapeutic effect on erectile dysfunction in a rat model of bilateral cavernous nerve injury (BCNI). Therapeutic effects were observed in the BCNI model at 1, 2, and 4 weeks postcavernous nerve injury. Erectile function further improved after treatment with stem cell/oxygen-releasing HP system compared with treatment with only stem cells at 4 weeks. Stem cell/oxygen-releasing HP system increased cyclic guanosine monophosphate (cGMP) level and neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), α-smooth muscle actin (α-SMA), and muscarinic acetylcholine receptor 3 (M3) expression while decreasing fibrosis and apoptosis in the corpus cavernosum. Our results clearly show that stem cell survival increases around transplanted stem cell/oxygen-releasing hybrid system site. Taken together, an oxygen-releasing HP system supported prolonged stem cell survival, sustaining the paracrine effect of the stem cells, and consequently enhancing erectile function. These findings show promise with regard to prolonged stem cell survival in stem cell applications for various diseases and types of tissue damage. Impact statement In this study, we used an oxygen-releasing hollow microparticles (HPs) system with stem cells to attempt to overcome certain limitations of stem cell therapy, including insufficient nutrient and oxygen supplies for transplanted stem cells. Our results demonstrated that a stem cell/oxygen-releasing HP hybrid system could further improve erectile function, cyclic guanosine monophosphate (cGMP) level, and NOS level in a bilateral cavernous nerve injury rat model through prolonged stem cell survival. Our data suggest that a stem cell/oxygen-releasing HP system is a promising clinical treatment option for postprostatectomy erectile dysfunction. Furthermore, this system may be relevant in different disease therapies and regenerative medicine.

Locally advanced prostate cancer imaging findings and implications for treatment from the surgical perspective

The anatomy of the prostate is reviewed in the context of discussing the staging of prostate cancer and patterns of tumor spread. The utility of prostate magnetic resonance imaging along with new advancements in tumor staging are discussed specifically in locally advanced disease. What should be included in the radiology report carries a substantial weight to formulate the urologist's decision in regards to the selection of surgical candidates, preoperative planning and avoiding postoperative complications.

Clinical and oncological outcomes of robot-assisted radical prostatectomy with nerve sparing vs. non-nerve sparing for high-risk prostate cancer cases

Robot-assisted radical prostatectomy (RARP) is one of the most widely used procedures for localized prostate cancer (PCa). In the present study, the clinical and oncological outcomes of RARP with bilateral or unilateral nerve sparing (NS) for D'Amico high-risk PCa cases were assessed. Among the 767 cases who received RARP at Fujita Health University Hospital between August 2009 and December 2016, 230 high-risk PCa cases who were observed for >6 months comprised the retrospective study cohort. Bilateral NS was performed with the bilateral neurovascular bundle in eight, unilateral in 125 and none in 97 cases. Perioperative parameters [surgery time, console time, estimated blood loss, pathological stage, positive lymph node metastases [pN (+)], and surgical margin positivity] did not exhibit significant differences between the NS and non-NS cohorts. During a median follow-up time of 25 months, the 1- and 3-year biochemical recurrence (BCR)-free survival rates in the NS/non-NS cohorts were 84.4/86.0 and 72.7/75.0%, respectively. There were no significant differences identified between the two groups at each time period. According to multivariate analysis, the resection margin was an important factor for time to BCR, regardless of the NS technique used. The numbers of pads used daily at 3 and 6 months after RARP between the NS/non-NS cohorts were 1.1/1.5 and 0.6/1.0, respectively (P=0.045 and P=0.009), suggesting that the NS technique resulted in significantly improved outcomes regarding urinary continence recovery. In selected high-risk PCa cases, the NS technique resulted in equivalent oncological outcomes and improved urinary continence compared with the non-NS RARP group.