Patient-reported sexual function after nerve-sparing radical retropubic prostatectomy

Nerve graft for erectile dysfunction after radical prostatectomy: animal study and clinical data-a narrative review

Introduced in the late 1990s, nerve grafting, particularly with sural and genitofemoral nerves, aims to enhance erectile function recovery when neurovascular bundles cannot be preserved following radical prostatectomy. Over the past three decades, researchers have conducted numerous animal and clinical studies to explore the application and clinical effectiveness of this method, with the hope of benefiting patients suffering from erectile dysfunction after radical prostatectomy. Animal studies have demonstrated the potential of various grafting materials, including autologous nerve and vein grafts, and bioengineered grafts, in promoting nerve regeneration and erectile function recovery. Clinical studies, especially those focusing on sural and genitofemoral nerve grafts, have shown mixed results with varied success rates due to methodological weaknesses and small sample sizes. This review thoroughly incorporates current data, explores emerging nerve grafting methods, demonstrates the complexity of nerve grafting outcomes, and emphasizes the necessity for continuous research, including multi-institutional randomized controlled trials, to establish standardized protocols and optimize patient selection for nerve grafting in the management of erectile dysfunction after radical prostatectomy.

Buyang Huanwu Decoction Ameliorates Damage of Erectile Tissue and Function Following Bilateral Cavernous Nerve Injury

OBJECTIVE

To verify the effect of Buyang Huanwu Decoction (BHD) in ameliorating erectile dysfunction (ED) after radical prostatectomy (RP).

METHODS

The composition of BHD was verified by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) analysis. Bilateral cavernous nerve crush injury (BCNI) in rats was used to mimic the neurovascular injury occurring after RP. By the envelope method, forty rats were randomly divided into 4 groups as follows: sham (cavernous nerves exposed only), model (BCNI), low-dosage BHD [LBHD, 12.8 g/(kg·d)], and high-dosage BHD [HBHD, 51.2 g/(kg·d)] groups, 10 rats in each group, feeding for 3 weeks respectively. Erectile function was evaluated by measuring intracavernosal pressure (ICP). Changes in the histopathology of corpus cavernosum (CC) were examined by hematoxylin-eosin staining. Meanwhile, the fibrosis of CC was measured by Masson's trichrome staining and Western blot was used to detect the expressions of collagen I, transforming growth factor beta 1 (TGF- β 1) and α-smooth muscle actin (α-SMA). Apoptosis index was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) and Western blot for determining the expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax). The oxidative stress in the CC were assessed by the superoxide dismutase (SOD), malondialdehyde (MDA) and reactive oxygen species (ROS) levels. The proteins expression of c-Jun N-terminal kinase (JNK) and c-Jun were detected by Western blot. In addition, the expression of α-SMA and p-c-Jun in the CC was observed by double immunofluorescence staining.

RESULTS

The UPLC-QTOF-MS/MS analysis showed that BHD contained calycosin-7-O- β -D-glucoside, ononin, calycosin and formononetin. Compared with the model group, LBHD and HBHD treatment improved the ICP and the circumference, area, and weight of CC (P<0.05 or P<0.01). Furthermore, LBHD and HBHD treatments increased CC smooth muscle content and decreased apoptosis index (P<0.05 or P<0.01). LBHD and HBHD also elevated SOD and expression level of α -SMA and Bcl-2, and reduced MDA and ROS levels, as well as expression of TGF- β 1, collagen I, Bax, p-c-JNK, p-JNK in the CC compared with the model group (P<0.05 or P<0.01). The double immunofluorescence staining showed that the fluorescence degree of p-c-Jun in both LBHD and HBHD treatment groups was significantly reduced, whereas the α -SMA expression increased (P<0.05 or P<0.01).

CONCLUSIONS

BHD can improve ED of rats with BCNI, which is related to inhibiting fibrosis, apoptosis, and oxidative stress of CC. The ROS/JNK/c-Jun signaling pathway may play an important role in the process.

Nerve Targeting via Myelin Protein Zero and the Impact of Dimerization on Binding Affinity

BACKGROUND

Surgically induced nerve damage is a common but debilitating side effect. By developing tracers that specifically target the most abundant protein in peripheral myelin, namely myelin protein zero (P0), we intend to support fluorescence-guided nerve-sparing surgery. To that end, we aimed to develop a dimeric tracer that shows a superior affinity for P0.

METHODS

Following truncation of homotypic P0 protein-based peptide sequences and fluorescence labeling, the lead compound Cy5-P0_101-125 was selected. Using a bifunctional fluorescent dye, the dimeric Cy5-(P0_101-125)₂ was created. Assessment of the performance of the mono- and bi-labeled compounds was based on (photo)physical evaluation. This was followed by in vitro assessment in P0 expressing Schwannoma cell cultures by means of fluorescence confocal imaging (specificity, location of binding) and flow cytometry (binding affinity; K_D).

RESULTS

Dimerization resulted in a 1.5-fold increase in affinity compared to the mono-labeled counterpart (70.3 +/- 10.0 nM vs. 104.9 +/- 16.7 nM; p = 0.003) which resulted in a 4-fold increase in staining efficiency in P0 expressing Schwannoma cells. Presence of two targeting vectors also improves a pharmacokinetics of labeled compounds by lowering serum binding and optical stability by preventing dye stacking.

CONCLUSIONS

Dimerization of the nerve-targeting peptide P0_101-125 proves a valid strategy to improve P0 targeting.

Identification of patients at risk for biochemical recurrence after radical prostatectomy with intra-operative frozen section

OBJECTIVE

To identify patients at risk for biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) with intra-operative whole-mount frozen section (FS) of the prostate.

MATERIAL AND METHODS

We examined differences in BCR between patients with initial negative surgical margins at FS, patients with final negative surgical margins with initial positive margins at FS without residual PCa after secondary tumour resection, and patients with final negative surgical margins with initially positive margins at FS with residual PCa in the secondary tumour resection specimen. Institutional data of 883 consecutive patients undergoing RP were collected. Intra-operative whole-mount FS was routinely used to check for margin status and, if necessary, to resect more periprostatic tissue in order to achieve negative margins. Patients with lymph node-positive disease or final positive surgical margins were excluded from the analysis. Kaplan-Meier curves and multivariable Cox proportional hazards regression analyses adjusting for clinical covariates were employed to examine differences in biochemical recurrence-free survival (BRFS) according to the resection status mentioned above.

RESULTS

The median follow-up was 22.4 months. The 1- and 2-year BRFS rates in patients with (81.0% and 72.9%, respectively; P = 0.001) and without residual PCa (90.3% and 82.3%, respectively; P = 0.033) after secondary tumour resection were significantly lower compared to patients with initial R0 status (93.4% and 90.9%, respectively). On multivariable Cox regression only residual PCa in the secondary tumour resection was associated with a higher risk of BCR compared to initial R0 status (hazard ratio 1.99, 95% confidence interval 1.01-3.92; P = 0.046).

CONCLUSION

Despite being classified as having a negative surgical margin, patients with residual PCa in the secondary tumour resection specimen face a high risk of BCR. These findings warrant closer post-RP surveillance of this particular subgroup. Further research of this high-risk subset of patients should focus on examining whether these patients benefit from early salvage therapy and how resection status impacts oncological outcomes in the changing landscape of PCa treatment.

The Role of Ninjurin1 and Its Impact beyond the Nervous System

Ninjurin1 (Ninj1) is a double-transmembrane cell surface protein that could promote nerve regeneration in the process of the peripheral nervous system injury and repairment. Nonetheless, the accurate function of Ninj1 in the central nervous system and outside the nervous system is not completely clear. According to the recent studies, we found that Ninj1 is also aberrantly expressed in various pathophysiological processes in vivo, including inflammation, tumorigenesis, and vascular, bone, and muscle homeostasis. These findings suggest that Ninj1 may play an influential role during these pathophysiological processes. Our review summarizes the diverse roles of Ninj1 in multiple pathophysiological processes inside and outside the nervous system. Ninj1 should be considered as an important and novel therapeutic target in certain diseases, such as inflammatory diseases and ischemic diseases. Our study provided a better understanding of Ninj1 in different pathophysiological processes and thereby provided the theoretical support for further research.

Oral Administration of the p75 Neurotrophin Receptor Modulator, LM11A-31, Improves Erectile Function in a Mouse Model of Cavernous Nerve Injury

BACKGROUND

Radical prostatectomy for prostate cancer can not only induce cavernous nerve injury (CNI), but also causes cavernous hypoxia and cavernous structural changes, which lead to a poor response to phosphodiesterase 5 inhibitors.

AIM

To investigate the therapeutic effect of oral administration of LM11A-31, a small molecule p75 neurotrophin receptor (p75^NTR) ligand and proNGF antagonist, in a mouse model of bilateral CNI, which mimics nerve injury-induced erectile dysfunction after radical prostatectomy.

METHODS

8-week-old male C57BL/6 mice were divided into sham operation and CNI groups. Each group was divided into 2 subgroups: phosphate-buffered saline and LM11A-31 (50 mg/kg/day) being administered once daily starting 3 days before CNI via oral gavage. 2 weeks after CNI, we measured erectile function by electrical stimulation of the bilateral cavernous nerve. The penis was harvested for histologic examination and Western blot analysis. The major pelvic ganglia was harvested and cultured for assays of ex vivo neurite outgrowth.

OUTCOMES

Intracavernous pressure, neurovascular regeneration in the penis, in vivo or ex vivo functional evaluation, and cell survival signaling were measured.

RESULTS

Erectile function was decreased in the CNI group (44% of the sham operation group), while administration of LM11A-31 led to a significant improvement of erectile function (70% of the sham operation group) in association with increased neurovascular content, including cavernous endothelial cells, pericytes, and neuronal processes. Immunohistochemical and Western blot analyses showed significantly increased p75^NTR expression in the dorsal nerve of CNI mice, which was attenuated by LM11A-31 treatment. Protein expression of active PI3K, AKT, and endothelial nitric oxide synthase was increased, and cell death and c-Jun N-terminal kinase signaling was significantly attenuated after LM11A-31 treatment. Furthermore, LM11A-31 promoted neurite sprouting in cultured major pelvic ganglia after lipopolysaccharide exposure.

CLINICAL IMPLICATIONS

LM11A-31 may be used as a strategy to treat erectile dysfunction after radical prostatectomy or in men with neurovascular diseases.

STRENGTHS & LIMITATIONS

Unlike biological therapeutics, such as proteins, gene therapies, or stem cells, the clinical application of LM11A-31 would likely be relatively less complex and low cost. Our study has some limitations. Future studies will assess the optimal dosing and duration of the compound. Given its plasma half-life of approximately 1 hour, it is possible that dosing more than once per day will provide added efficacy.

CONCLUSION

Specific inhibition of the proNGF-p75^NTR degenerative signaling via oral administration of LM11A-31 represents a novel therapeutic strategy for erectile dysfunction induced by nerve injury. Yin GN, Ock J, Limanjaya A, et al. Oral Administration of the p75 Neurotrophin Receptor Modulator, LM11A-31, Improves Erectile Function in a Mouse Model of Cavernous Nerve Injury. J Sex Med 2021;18:17-28.

Pericyte-Derived Extracellular Vesicle-Mimetic Nanovesicles Restore Erectile Function by Enhancing Neurovascular Regeneration in a Mouse Model of Cavernous Nerve Injury

BACKGROUND

Extracellular vesicle (EV)-mimetic nanovesicles (NVs) from embryonic stem cells have been observed to stimulate neurovascular regeneration in the streptozotocin-induced diabetic mouse. Pericytes play important roles in maintaining penile erection, yet no previous studies have explored the effects of pericyte-derived NVs (PC-NVs) in neurovascular regeneration in the context of erectile dysfunction.

AIM

To investigate the potential effect of PC-NVs in neurovascular regeneration.

METHODS

PC-NVs were isolated from mouse cavernous pericytes, and neurovascular regeneration was evaluated in an in vitro study. Twelve-week-old C57BL/6J mice were used to prepare cavernous nerve injury model. Erectile function evaluation, histologic examination of the penis, and Western blots were assessed 2 weeks after model creation and PC-NVs treatment.

OUTCOMES

The main outcomes of this study are PC-NVs characterization, intracavernous pressure, neurovascular regeneration in the penis, and in vitro functional evaluation.

RESULTS

The PC-NVs were extracted and characterized by cryotransmission electron microscopy and EV-positive (Alix, TSG101, CD81) and EV-negative (GM130) markers. In the in vivo studies, PC-NVs successfully improved erectile function in cavernous nerve injury mice (∼82% of control values). Immunofluorescence staining showed significant increases in pericytes, endothelial cell, and neuronal contents. In the in vitro studies, PC-NVs significantly increased mouse cavernous endothelial cells tube formation, Schwann cell migration, and dorsal root ganglion and major pelvic ganglion neurite sprouting. Finally, Western blot analysis revealed that PC-NVs upregulated cell survival signaling (Akt and eNOS) and induced the expression of neurotrophic factors (brain-derived neurotrophic factor, neurotrophin-3, and nerve growth factor).

CLINICAL IMPLICATIONS

PC-NVs may be used as a strategy to treat erectile dysfunction after radical prostatectomy or in men with neurovascular diseases.

STRENGTHS & LIMITATIONS

We evaluated the effect of PC-NVs in vitro and in a mouse nerve injury model, cavernous nerve injury. Additional studies are necessary to determine the detailed mechanisms of neurovascular improvement. Further study is needed to test whether PC-NVs are also effective when given weeks or months after nerve injury.

CONCLUSION

PC-NVs significantly improved erectile function by enhancing neurovascular regeneration. Local treatment with PC-NVs may represent a promising therapeutic strategy for the treatment of neurovascular diseases. Yin GN, Park S-H, Ock J, et al. Pericyte-Derived Extracellular Vesicle-Mimetic Nanovesicles Restore Erectile Function by Enhancing Neurovascular Regeneration in a Mouse Model of Cavernous Nerve Injury. J Sex Med 2020;17:2118-2128.

Losartan improves erectile function through suppression of corporal apoptosis and oxidative stress in rats with cavernous nerve injury

This study aimed to investigate the functional and morphological changes in the corpus cavernosum after cavernous nerve (CN) injury or neurectomy and then reveal whether treatment with the angiotensin II Type 1 receptor antagonist losartan would improve erectile function as well as its potential mechanisms. A total of 48 10-week-old Sprague-Dawley male rats, weighing 300-350 g, were randomly divided into the following four groups (n = 12 per group): sham operation (Sham) group, bilateral cavernous nerve injury (BCNI) group, losartan-treated BCNI (BCNI + Losartan) group, and bilateral cavernous neurectomy (Neurectomy) group. Losartan was administered once daily by oral gavage at a dose of 30 mg kg^-1 day^-1 for 4 weeks starting on the day of surgery. The BCNI and the Neurectomy groups exhibited decreases in erectile response and increases in apoptosis and oxidative stress, compared with the Sham group. Treatment with losartan could have a modest effect on erectile function and significantly prevent corporal apoptosis and oxidative stress. The phospho-B-cell lymphoma 2 (Bcl-2)-associated death promoter (p-Bad)/Bad and phospho-the protein kinase B (p-AKT)/AKT ratios were substantially lower, while the Bcl-2-associated X protein (Bax)/Bcl-2 ratio, nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap-1), transforming growth factor-β 1 (TGF-β 1) and heme oxygenase-1 (HO-1) levels, and caspase-3 activity were higher in the BCNI and Neurectomy groups than in the Sham group. After 4 weeks of daily administration with losartan, these expression levels were remarkably attenuated compared with the BCNI group. Taken together, our results suggested that early administration of losartan after CN injury could slightly improve erectile function and significantly reduce corporal apoptosis and oxidative stress by inhibiting the Akt/Bad/Bax/caspase-3 and Nrf2/Keap-1 pathways.

Comprehensive Analysis of lncRNA Expression Pattern and lncRNA-miRNA-mRNA Network in a Rat Model With Cavernous Nerve Injury Erectile Dysfunction

BACKGROUND

Long noncoding RNAs (lncRNAs) are differentially expressed in erectile dysfunction (ED) associated with aging and diabetes mellitus; however, the lncRNA expression profile in cavernous nerve (CN) injury-related ED (CNI-ED) is unknown.

AIM

To investigate the dysregulated lncRNAs, microRNAs (miRNAs), and mRNA expression in CNI-ED and construct a potential lncRNA-miRNA-mRNA network.

METHODS

22 male Sprague-Dawley (SD) rats were divided into bilateral CN crush (BCNC) and Sham groups. Using second-generation high-throughput sequencing technology, we analyzed the expression profiles of lncRNA, miRNA, and mRNA of the 2 groups. 17 differentially expressed lncRNAs were selected and further validated by quantitative real-time polymerase chain reaction (RT-qPCR). The lncRNA-miRNA-mRNA network, Gene Ontology (GO) term enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using Cytoscape.

OUTCOMES

Intra-cavernosal pressure, mean arterial pressure, smooth muscle content, and the expression of miRNA, mRNA, and lncRNA were measured.

RESULTS

The BCNC group showed decreased intra-cavernosal/mean arterial pressure as well as decreased smooth muscle/collagen ratios compared with the Sham group. The RNA sequencing results revealed dysregulated expressions of 65 lncRNA, 14 miRNA, and 750 mRNA in the BCNC group based on the following criteria: fold change >2 and P < .05. Among the 17 lncRNAs further selected based on mean count number >4 in both groups, 3 lncRNAs (TCONS_00028173, TCONS_00049985, and TCONS_00058429) were further validated for differential expression by RT-qPCR. GO analysis suggests that these 3 lncRNAs could regulate various processes such as myotube differentiation and muscle cell differentiation. Furthermore, the KEGG pathway analysis showed that the mRNAs in the competing endogenous RNA (ceRNA) network are involved in pathways, including axon guidance and vascular endothelial growth factor signaling pathway.

CLINICAL TRANSLATION

Our findings may provide new information on molecular pathophysiology of CNI-ED and suggest further research to find a more effective therapy for CNI-ED.

STRENGTHS & LIMITATIONS

This study is the first to identify the lncRNA expression pattern and propose a ceRNA network in a rat model with cavernous nerve injury-related erectile dysfunction. However, analogous studies are needed to confirm these findings in humans. In addition, we constructed the network by only confirming the lncRNA.

CONCLUSION

Our study reveals differential expression profiles of lncRNAs, miRNAs, and mRNAs between the BCNC and Sham groups and suggests that these differentially expressed lncRNAs may play critical roles in CNI-ED by regulating apoptosis and fibrosis in the corpus cavernosum via targeting mRNAs or miRNAs. Cong R, Wang Y, Wang Y. Comprehensive Analysis of lncRNA Expression Pattern and lncRNA-miRNA-mRNA Network in a Rat Model With Cavernous Nerve Injury Erectile Dysfunction. J Sex Med 2020;17:1603-1617.

Assessing Extraprostatic Extension with Multiparametric MRI of the Prostate: Mehralivand Extraprostatic Extension Grade or Extraprostatic Extension Likert Scale?

Purpose

To validate the MRI grading system proposed by Mehralivand et al in 2019 (the "extraprostatic extension [EPE] grade") in an independent cohort and to compare the Mehralivand EPE grading system with EPE interpretation on the basis of a five-point Likert score ("EPE Likert").

Materials and Methods

A total of 310 consecutive patients underwent multiparametric MRI according to a standardized institutional protocol before radical prostatectomy was performed by using the same 1.5-T MRI unit at a single institution between 2010 and 2012. Two radiologists blinded to clinical information assessed EPE according to standardized criteria. On the basis of the readings performed until 2017, the diagnostic performance of EPE Likert and Mehralivand EPE score were compared using receiver operating characteristics (ROC) and decision curve methodology against histologic EPE as standard of reference. Prediction of biochemical recurrence-free survival (BRFS) was assessed by Kaplan-Meier analysis and log rank test.

Results

Of the 310 patients, 80 patients (26%) had EPE, including 33 with radial distance 1.1 mm or greater. Interrater reliability was fair (weighted κ 0.47 and 0.45) for both EPE grade and EPE Likert. Sensitivity for identifying EPE using EPE grade versus EPE Likert was 0.83 versus 0.86 and 0.86 versus 0.91 for radiologist 1 and 2, respectively. Specificity was 0.48 versus 0.58 and 0.39 versus 0.70 (P < .05 for radiologist 2). There were no significant differences in the ROC area under the curve or on decision curve analysis. Both EPE grade and EPE Likert were significant predictors of BRFS.

Conclusion

Mehralivand EPE grade and EPE Likert have equivalent diagnostic performance for predicting EPE and BRFS with a similar degree of observer dependence.© RSNA, 2020Keywords: MR-Imaging, Neoplasms-Primary, Observer Performance, Outcomes Analysis, Prostate, StagingSupplemental material is available for this article.See also the commentary by Choyke in this issue.

Postoperative radiotherapy for prostate cancer : Morbidity of local-only or local-plus-pelvic radiotherapy

PURPOSE

The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer.

MATERIALS AND METHODS

Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups.

RESULTS

For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5‑year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5‑year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%.

CONCLUSIONS

Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4‑field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects.

[Surgical approach and sexual outcomes after radical prostatectomy]

BACKGROUND

Radical prostatectomy is curative surgical treatment of choice for localized prostate cancer. The objectives are cancer control, preservation of continence and preservation of sexuality, the combination of the three constituting the Trifecta.

OBJECTIVE

The objective of this study was to assess, through the analysis of the literature, the sexual outcomes according to surgical approach: radical prostatectomy by laparotomy (PRL), laparoscopic radical prostatectomy (PRLa) and laparoscopic robot-assisted radical prostatectomy (PRLaRA), when nerve sparing was practiced.

METHODS

An exhaustive and retrospective review of literature was conducted using the Pubmed search with the following keywords: "Prostatic Neoplasms" [Mesh], "Prostatectomy" [Mesh], "Erectile Dysfunction" [Mesh], "Robotics" [Mesh], "Laparoscopy" [Mesh], Nerve sparing.

SELECTION CRITERIA

The selected articles were prospective or retrospective series including more than 200 patients, randomized trials and meta-analyses published between 1990 and 2014.

RESULTS

A total of 21 prospective studies (6 on PRL, 4 on PRLa and 11 on PRLaRA), 12 retrospective studies (6 on PRL, 1 on PRLa and 5 on PRLaRA), 2 randomized controlled trial and 3 meta-analyses were selected from 1992 to 2013. There was no evidence of the superiority of one surgical approach compared to others in terms of sexuality.

LIMITS

Articles with level 1 of scientific evidence have discordant results, due to heterogeneity in the assessment criteria of postoperative sexual function.

CONCLUSION

According to our knowledge, there is currently no difference in terms of sexual outcomes between PRL, PRLA and PRLaRA approaches.

Gene expression profile comparison in the penile tissue of diabetes and cavernous nerve injury-induced erectile dysfunction rat model

PURPOSE

To investigate the effects of cavernous nerve injury (CNI) on gene expression profiles in the cavernosal tissue of a CNI-induced erectile dysfunction (ED) model and to provide a basis for future investigations to discover potential target genes for ED treatment.

MATERIALS AND METHODS

Young adult rats were divided randomly into 2 groups: sham operation and bilateral CN resection. At 12 weeks after CNI we measured erectile responses and performed microarray experiments and gene set enrichment analysis to reveal gene signatures that were enriched in the CNI-induced ED model. Alterations in gene signatures were compared with those in the diabetes-induced ED model. The diabetic-induced ED data is taken from GSE2457.

RESULTS

The mean ratio of intracavernosal pressure/blood pressure for the CNI group (0.54±0.4 cmH2O) was significantly lower than that in the sham operation group (0.73±0.8 cmH2O, p<0.05). Supervised and unsupervised clustering analysis showed that the diabetes- and CNI-induced ED cavernous tissues had different gene expression profiles from normal cavernous tissues. We identified 46 genes that were upregulated and 77 genes that were downregulated in both the CNI- and diabetes-induced ED models.

CONCLUSIONS

Our genome-wide and computational studies provide the groundwork for understanding complex mechanisms and molecular signature changes in ED.

Role of Schwann cells in the regeneration of penile and peripheral nerves

Schwann cells (SCs) are the principal glia of the peripheral nervous system. The end point of SC development is the formation of myelinating and nonmyelinating cells which ensheath large and small diameter axons, respectively. They play an important role in axon regeneration after injury, including cavernous nerve injury that leads to erectile dysfunction (ED). Despite improvement in radical prostatectomy surgical techniques, many patients still suffer from ED postoperatively as surgical trauma causes traction injuries and local inflammatory changes in the neuronal microenvironment of the autonomic fibers innervating the penis resulting in pathophysiological alterations in the end organ. The aim of this review is to summarize contemporary evidence regarding: (1) the origin and development of SCs in the peripheral and penile nerve system; (2) Wallerian degeneration and SC plastic change following peripheral and penile nerve injury; (3) how SCs promote peripheral and penile nerve regeneration by secreting neurotrophic factors; (4) and strategies targeting SCs to accelerate peripheral nerve regeneration. We searched PubMed for articles related to these topics in both animal models and human research and found numerous studies suggesting that SCs could be a novel target for treatment of nerve injury-induced ED.

Erectile Function Recovery After Nerve-Sparing Radical Prostatectomy for Prostate Cancer: Is Back to Baseline Status Enough for Patient Satisfaction?

INTRODUCTION

Several definitions of erectile function (EF) recovery after bilateral nerve-sparing radical prostatectomy (BNSRP) have been proposed based on the results of the International Index of EF (IIEF).

AIM

We aimed at evaluating overall satisfaction (OS) after BNSRP according to the ability to achieve the pretreatment EF.

METHODS

We evaluated data of 652 patients treated with BNSRP for clinically localized prostate cancer (PCa). Erectile dysfunction (ED) was classified according to the IIEF-EF domain score. Return to baseline EF was defined as patients who reached the same preoperative ED category during the 3-year follow-up. Cox regression analyses were fitted to predict return to baseline IIEF-EF and to predict OS defined according to the IIEF-OS in the overall population. Logistic regression analyses were performed to analyze OS in men who reached the back to baseline status.

MAIN OUTCOME MEASURES

The outcome of the study was to evaluate back to baseline EF status and to correlate it with postoperative OS.

RESULTS

Preoperative satisfaction was reported by 218 (33.4%) patients. Postoperative satisfaction was achieved by 103 patients. Overall, 383 patients were able to achieve the preoperative IIEF-EF score. However, only 26.9% reported being satisfied. Age and preoperative IIEF-EF score were significantly associated with baseline IIEF-EF recovery (all P ≤ .02). Patients who were able to return to baseline IIEF-EF were more likely to be satisfied (P < .001). Time elapsed between surgery and achievement of baseline IIEF-EF was significantly associated with OS (P < .001). Among patients who were able to achieve the baseline IIEF-EF score, a preoperative IIEF-EF of 22-25 and 26-30 was significantly associated with postoperative satisfaction (all P < .001).

CONCLUSION

After BNSRP, reaching the baseline IIEF-EF score is not always sufficient to obtain patient satisfaction. Only patients with a preoperative IIEF-EF ≥22 who reached the baseline score after surgery considered themselves satisfied. This should be taken into account in preoperative patient counseling.

Multiple Orgasms in Men-What We Know So Far

INTRODUCTION

There is much popular discussion on strategies to facilitate multiple orgasms in men (ie, 100,000+ hits in Google), yet the topic has not received an objective comprehensive review in the literature.

AIM

To review the literature on male multiple orgasms.

METHODS

We searched the literature for publications on "male multiple orgasms" and factors influencing male multiple orgasms in Google, PubMed, and PsychINFO. This yielded 15 relevant publications.

MAIN OUTCOME MEASURES

A comprehensive overview on the topic of male multiple orgasms and factors that influence the propensity of men to experience multiple orgasms.

RESULTS

Few men are multiorgasmic: <10% for those in their 20s, and <7% after the age of 30. The literature suggests 2 types of male multiple orgasms: "sporadic" multiorgasms, with interorgasmic intervals of several minutes, and "condensed" multiorgasms, with bursts of 2-4 orgasms within a few seconds to 2 minutes. Multiple orgasms appear physiologically similar to the single orgasm in mono-orgasmic men. However, in a single case study, a multiorgasmic man did not experience with his first orgasm the prolactin surge that usually occurs with orgasm in mono-orgasmic men. Various factors may facilitate multiple orgasms: (1) practicing to have an orgasm without ejaculation; (2) using psychostimulant drugs; (3) having multiple and/or novel sexual partners; or (4) using sex toys to enhance tactile stimulation. However, confirmatory physiological data on any of these factors are few. In some cases, the ability to experience multiple orgasms may increase after medical procedures that reduce ejaculation (eg, prostatectomy or castration), but what factor(s) influence this phenomenon is poorly investigated.

CONCLUSION

Despite popular interest, the topic of male multiple orgasms has received surprisingly little scientific assessment. The role of ejaculation and physiological change during the refractory period in inhibiting multiple orgasms has barely been investigated.

Evaluating the Impact of PSA as a Selection Criteria for Nerve Sparing Radical Prostatectomy in a Screened Cohort

Purpose. We investigated whether NS-RP increased risk of PSA failure and whether PSA should be included as a selection criterion for NS. Methods. We evaluated 357 consecutive men with screen-detected PC who underwent open RP without adjuvant radiotherapy between 9/11/2001 and 12/30/2008. Criteria for NS included Gleason score ≤3 + 4, percentage of positive biopsies (PPB) ≤50%, percentage of core involvement ≤50%, nonapical location, no perineural invasion, and no palpable disease on pre- or intraoperative exam but did not include a PSA threshold. Cox multivariable regression assessed whether increasing PSA or unilateral- or bilateral-NS versus non-NS-RP was associated with PSA failure adjusting for prognostic factors. Results. After a median follow-up of 3.96 years, 34 men sustained PSA failure (9.5%). Increasing PSA was significantly associated with increased risk of PSA failure in the interaction model (adjusted hazard ratio (AHR): 1.09 [95% CI: 1.03-1.16]; P = 0.005), whereas unilateral (AHR: 1.24 [95% CI: 0.36-4.34]; P = 0.73) or bilateral NS (AHR: 0.41 [95% CI: 0.06-2.59]; P = 0.34) versus non-NS RP was not. Conclusion. NS-RP in a screened cohort did not increase risk of PSA failure using NS criteria not including PSA.

Intracavernous delivery of clonal mesenchymal stem cells restores erectile function in a mouse model of cavernous nerve injury

INTRODUCTION

Recently, much attention has focused on stem cell therapy; bone marrow-derived stem cells (BMSCs) are one of the most studied mesenchymal stem cells used in the field of erectile dysfunction (ED). However, a major limitation for the clinical application of stem cell therapy is the heterogeneous nature of the isolated cells, which may cause different treatment outcomes.

AIM

We investigated the effectiveness of mouse clonal BMSCs obtained from a single colony by using subfractionation culturing method (SCM) for erectile function in a mouse model of cavernous nerve injury (CNI).

METHODS

Twelve-week-old C57BL/6J mice were divided into four groups: sham operation group, bilateral CNI group receiving a single intracavernous (IC) injection of phosphate-buffered saline (20 μL) or clonal BMSCs (3 × 10(5) cells/20 μL), and receiving a single intraperitoneal (IP) injection of clonal BMSCs (3 × 10(5) cells/20 μL).

MAIN OUTCOME MEASURES

The clonal BMSC line was analyzed for cell-surface epitopes by using fluorescence-activated cell sorting and for differentiation potential. Two weeks after CNI and treatment, erectile function was measured by electrically stimulating the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis.

RESULTS

Clonal BMSCs expressed cell surface markers for mesenchymal stem cells and were capable of differentiating into several lineages, including adipogenic, osteogenic, and chondrogenic cells. Both IC and IP injections of clonal BMSCs significantly restored cavernous endothelial and smooth muscle content, and penile nNOS and neurofilament content in CNI mice. IC injection of clonal BMSCs induced significant recovery of erectile function, which reached 90-100% of the sham control values, whereas IP injection of clonal BMSCs partially restored erectile function.

CONCLUSION

We established a homogeneous population of mouse clonal BMSCs using SCM; clonal BMSCs successfully restored erectile function in CNI mice. The homogeneous nature of clonal mesenchymal stem cells may allow their clinical applications.

Effectiveness of intracavernous delivery of adenovirus encoding Smad7 gene on erectile function in a mouse model of cavernous nerve injury

INTRODUCTION

Men with erectile dysfunction (ED) respond poorly to oral phosphodiesterase-5 inhibitors following radical prostatectomy. Recent studies have reported that up-regulation of transforming growth factor-β1 (TGF-β1) and activation of the Smad signaling pathway play important roles in cavernous fibrosis and in the deterioration of erectile function in a mouse model of cavernous nerve injury (CNI) and in patients with spinal cord injury. The mothers against decapentaplegic homolog 7 (Smad7) is known to inhibit the phosphorylation of Smad2 and Smad3.

AIM

To investigate the effectiveness of adenoviruses encoding Smad7 gene (Ad-Smad7) on erectile function in a mouse model of CNI.

METHODS

Twelve-week-old C57BL/6J mice were used and distributed into 7 groups: sham operation group, untreated CNI group, and CNI groups receiving a single intracavernous injection of adenovirus encoding LacZ (1 × 10(8) virus particles [vp]/20 μL) or adenovirus encoding Smad7 (Ad-Smad7; 1 × 10(7), 1 × 10(8), 2 × 10(8), or 1 × 10(9) vp/20 μL).

MAIN OUTCOME MEASURES

Two weeks after bilateral cavernous nerve crushing and treatment, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis.

RESULTS

The highest erectile response was noted in CNI mice treated with Ad-Smad7 at a dose of 1 × 10(8)  vp, which reached up to 82-85% of sham control values. Local delivery of Ad-Smad7 significantly decreased endothelial cell apoptosis and the production of extracellular matrix proteins, including plasminogen activator inhibitor-1, fibronectin, collagen I, and collagen IV, and induced endothelial nitric oxide synthase phosphorylation in the corpus cavernosum tissue of CNI mice.

CONCLUSION

The adenovirus-mediated gene transfer of Smad7 successfully restored erectile function by enhancing endothelial cell function and through antifibrotic effects. These findings suggest that inhibition of the TGF-β signaling pathway by use of Smad7 may represent a promising therapeutic strategy for ED induced by radical prostatectomy.

Nerve injury-induced protein 1 (Ninjurin-1) is a novel therapeutic target for cavernous nerve injury-induced erectile dysfunction in mice

INTRODUCTION

Radical prostatectomy for prostate cancer can not only induce cavernous nerve injury (CNI) but also result in structural changes in the cavernous tissues. Nerve injury-induced protein 1, Ninjurin-1 (Ninj1), is known to be involved in neuroinflammatory processes and to be related to vascular regression during the embryonic period.

AIM

The study aims to determine whether and how Ninj1 neutralizing antibody (Ninj1-Ab) restores erectile function in mice with CNI.

METHODS

Twelve-week-old C57BL/6J mice were used and distributed into four groups: sham operation group and CNI groups receiving a single intracavernous injection of immunoglobulin G (IgG) control antibody, low-dose Ninj1-Ab (1.0 μg/20 μL), or high-dose Ninj1-Ab (2.5 μg/20 μL).

MAIN OUTCOME MEASURES

One week after bilateral cavernous nerve crush, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis.

RESULTS

The cavernous expression of Ninj1 protein was upregulated up to 7 days after CNI and returned to baseline levels thereafter. Local delivery of Ninj1-Ab significantly increased penile neuronal nitric oxide synthase and neurofilament contents, induced cavernous endothelial proliferation and phosphorylation of Akt and endothelial nitric oxide synthase, and decreased endothelial cell apoptosis in the CNI mice by upregulating angiopoietin-1 and downregulating angiopoietin-2. High-dose Ninj1-Ab induced profound restoration of erectile function in the CNI mice (91% of sham control values), whereas low-dose Ninj1-Ab elicited partial improvement.

CONCLUSION

The dual neurotrophic and angiogenic effects of Ninj1 blockade may provide a good opportunity for treating erectile dysfunction resulting from radical prostatectomy.

Radical prostatectomy, sparing of the seminal vesicles, and painful orgasm

INTRODUCTION

Erectile dysfunction has been widely investigated as the major factor responsible for sexual bother in patients after radical prostatectomy (RP); painful orgasm (PO) is one element of this bother, but little is known about its prevalence and its effects on sexual health.

AIM

This study aims to investigate the prevalence of PO and to identify potential risk factors.

MAIN OUTCOME MEASURES

A total of 1,411 consecutive patients underwent open (radical retropubic prostatectomy) or robot-assisted laparoscopic RP between 2002 and 2006. The patients were asked to complete a study-specific questionnaire.

METHODS

Of a total of 145 questions, 5 dealt with the orgasmic characteristics. The questionnaire was also administered to a comparison group of 442 persons, matched for age and area of residency.

RESULTS

The response rate was 91% (1,288 patients). A total of 143 (11%) patients reported PO. Among the 834 men being able to have an orgasm, the prevalence was 18% vs. 6% in the comparison group (relative risk [RR] 2.8, 95% confidence interval [CI] 1.7-4.5). When analyzed as independent variables, bilateral seminal vesicle (SV)-sparing approach (RR 2.33, 95% CI 1.0-5.3, P = 0.045) and age <60 years were significantly related to the presence of PO (95% CI 0.5-0.9, P = 0.019). After adjustment for age, bilateral SV-sparing still remained a significant predictor for occurrence of PO.

CONCLUSIONS

We found that PO occurs significantly more often in patients undergoing bilateral SV-sparing RP when compared with age-matched comparison population.

Sexuality in adult cancer survivors: challenges and intervention

Sexual dysfunction is one of the most common and distressing consequences of cancer treatment. Although some treatment-related sexual adverse effects are short-term, many survivors face long-term effects such as treatment-induced menopause, altered gonadal function, and significant surgical disfigurement. Profound sexual dysfunction has been shown to have a significant negative effect on quality of life. Although these problems have been well documented and there are a range of intervention strategies that can help patients cope with treatment-related sexual problems, many survivors do not feel prepared for potential sexual changes and often do not receive adequate support to manage sexual dysfunction. Numerous barriers contribute to this underprovided aspect of survivorship care, including lack of provider training and access to readily available resources. In addition, psychological, relational, and cultural factors significantly influence sexuality but are often not taken into consideration in research and clinical practice. By taking an integrative approach and providing survivors with appropriate screening, information, and support, sexual dysfunction and accompanying distress can be significantly alleviated. In this article, we aim to provide a concise review of the most common sexual problems experienced by survivors and highlight some of the most promising evidence-based practices for assessment and intervention. We also address limitations encountered in research and practice and explore future directions, including suggestions for adopting an integrative treatment model to address sexual dysfunction in a cancer survivorship treatment setting.

Differential expression of nerve injury-induced protein 1 (ninjurin 1) in in vivo and in vitro models for diabetic erectile dysfunction

Purpose

Endothelial dysfunction and peripheral neuropathy are important mechanisms responsible for diabetes-induced erectile dysfunction (ED). Nerve injury-induced protein 1 (Ninjurin 1) is known to be related to neuroinflammatory processes and is also reported to induce vascular regression during the developmental period. In the present study, we determined the differential expression of Ninjurin 1 in penile tissue of streptozotocin (STZ)-induced diabetic mice with ED.

Materials and Methods

Diabetes was induced in 8-week-old C57BL/6J mice by intraperitoneal injections of STZ (50 mg/kg for 5 days). Eight weeks later, erectile function was measured by electrical stimulation of the cavernous nerve (n=6 per group). The penis was then harvested for immunohistochemical analysis and Western blot analysis for Ninjurin 1 (n=4 per group). We also determined Ninjurin 1 expression in primary cultured mouse cavernous endothelial cells (MCECs) incubated under the following conditions: normal glucose condition (5 mM), high-glucose condition (30 mM), and high-glucose condition (30 mM)+insulin (1 nM).

Results

The expression of Ninjurin 1 protein was significantly higher in both cavernous endothelial cells and the dorsal nerve bundle of diabetic mice than in those of controls. In the in vitro study in MCECs, Ninjurin 1 expression was also significantly increased by the high-glucose condition and was returned to baseline levels by treatment with insulin.

Conclusions

Regarding the role of Ninjurin 1 in neuropathy and vascular regression, it would be interesting to examine the effects of inhibition of Ninjurin 1 on erectile function in animal models of ED with a vascular or neurogenic cause.

Pathological confirmation of nerve-sparing types performed during robot-assisted radical prostatectomy (RARP)

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Incremental nerve-sparing techniques (NSTs) improve postoperative erectile function after robot-assisted radical prostatectomy (RARP). However, there are no studies to date that histologically confirm the surgeon intended NST. Thus, in the present study, we histologically confirmed that the surgeon performed the nerve preservation as his intended NSTs during RARP. Also, we found that there was more variability in fascia width outcome on the left side compared with the right. Therefore, when performing nerve preservation on the surgeon's non-dominant side, we need to pay more close attention.

OBJECTIVES

To confirm that the surgeon achieved true intended histological nerve sparing during robot-assisted radical prostatectomy (RARP) by studying RP specimens. To aid the novice robotic surgeon to develop the skills of RARP.

PATIENTS AND METHODS

Between June 2008 and May 2009, 122 consecutive patients underwent RARP by a single surgeon (K.K.B.). The degree of nerve sparing (wide resection [WR], interfascial nerve sparing [ITE-NS], intrafascial nerve sparing [ITR-NS]) on both sides was recorded. The posterior sectors of RP specimens from distal, mid, and proximal parts were evaluated. Fascia width (FW) of each position in RP specimens were compared across nerve-sparing types (NSTs). FW was recorded at 15 ° intervals (3-9 o'clock position), measured as the distance between the outermost prostate gland and surgical margin. The slides were reviewed by an experienced uropathologist who was 'blinded' to the NST.

RESULTS

In all, 93 men were included. The overall mean (sd) FW was the greatest in the order of WR, ITE-NS, and ITR-NS, at 2.42 (1.62), 1.71 (1.40) and 1.16 (1.08) mm, respectively (P < 0.001). FW was statistically significantly correlated with the surgical technique used. When the surgeon intended to perform various levels of nerve sparing, these were reflected in the FW. Interestingly, the left-side FW showed more variability than the right side. We suspect that this was a result of the surgeon's right-hand dominance. Erectile function (EF) recovery rate according to NST was 88.9%, 77.3%, 65.6%, 56.3%, and 0% in bilateral ITR-NS, ITR-NS/ITE-NS, bilateral ITE-NS, ITE-NS/WR, and bilateral WR, respectively. To further validate and confirm these preliminary findings, additional studies involving multicentre cohorts would be required.

CONCLUSIONS

The surgeon intended dissection and FW correlate, with ITR-NS providing the narrowest FW and the EF recovery rate was the highest in bilateral ITR-NS. There was more variability in FW outcome on the left side than the right. The novice robotic surgeon should consider this variability when performing RARP. It may have implications for technique improvement on nerve preservation for EF.

Late gastrointestinal and urogenital side-effects after radiotherapy--incidence and prevalence. Subgroup-analysis within the prospective Austrian-German phase II multicenter trial for localized prostate cancer

PURPOSE

In general late side-effects after prostate cancer radiotherapy are presented by the use of actuarial incidence rates. The aim of this analysis was to describe additional relevant aspects of late side effects after prostate cancer radiotherapy.

MATERIALS AND METHODS

All 178 primary prostate-cancer patients were treated within the Austrian-German multicenter trial by three-dimensional radiotherapy up to a local dose of 70 Gy (low/intermediate-risk) or 74 Gy (high-risk), respectively. Late gastrointestinal/urogenital (GI/GU) side-effects were prospectively assessed by the use of EORTC/RTOG score. Maximum side-effects, actuarial incidence rate and prevalence rates, initial appearance and duration of ≥grade 2 toxicity were evaluated.

RESULTS

Median follow-up was 74 months. Late GI/GU side-effects ≥grade 2 were detected in 15% (27/178) and 22% (40/178). The corresponding 5-year actuarial incidence rates for GI/GU side-effects were 19% and 23%, whereas the prevalence was 1-2% and 2-7% after 5 years, respectively. Late side effects ≥grade 2 appeared within 5 years after radiotherapy in all patients with GI side-effects (27/27) and in 85% (34/40) of the patients with GU side-effects, respectively and lasted for less than 3 years in 90% (GI) and 98% (GU).

CONCLUSIONS

This study demonstrates that the majority of late GI and GU side effects after primary external beam radiotherapy for prostate cancer are transient. Using only actuarial incidence rates for reporting side effects may lead to misinterpretation or overestimation. The combination of incidence and prevalence rates provides a more comprehensive view on the complex issue of late side effects.

Early postoperative pelvic-floor biofeedback improves erectile function in men undergoing radical prostatectomy: a prospective, randomized, controlled trial

Erectile dysfunction (ED) and urinary incontinence are common complications following radical prostatectomy (RP). Although pelvic-floor biofeedback training (PFBT) may improve urinary continence following RP, its effects on the recovery of potency are unknown. Fifty-two patients selected for RP were prospectively randomized for a treatment group (n=26) receiving PFBT once a week for 3 months and home exercises or a control group (n=26), in which patients received verbal instructions to contract the pelvic floor. Erectile function (EF) was evaluated with the International Index of Erectile Function-5 (IIEF-5) before surgery and 1, 3, 6 and 12 months postoperatively. Patients were considered potent when they had a total IIEF-5 score>20. Continence status was assessed and defined as the use of no pads. Groups were comparable in terms of age, body mass index, diabetes, pathological tumor stage and neurovascular bundle preservation. A significant reduction in IIEF-5 scores was observed after surgery in both groups. In the treatment group, 8 (47.1%) patients recovered potency 12 months postoperatively, as opposed to 2 (12.5%) in the control group (P=0.032). The absolute risk reduction was 34.6% (95% confidence interval (CI): 3.8-64%) and the number needed to treat was 3 (95% CI: 1.5-17.2). A strong association between recovery of potency and urinary continence was observed, with continent patients having a 5.4 higher chance of being potent (P=0.04). Early PFBT appears to have a significant impact on the recovery of EF after RP. Urinary continence status was a good indicator of EF recovery, with continent patients having a higher chance of being potent.

Increasing the dose of vardenafil on a daily basis does not improve erectile function after unilateral nerve-sparing radical prostatectomy

INTRODUCTION

Several treatment regimens for rehabilitation of erectile function (EF) after nerve-sparing radical prostatectomy (nsRP) are currently discussed. The optimal and most cost-effective therapy is still not found yet.

AIM

To evaluate the effect of vardenafil, a PDE5 inhibitor, dose escalation on recovery of EF after unilateral nsRP.

METHODS

Thirty-six sexually active patients received a unilateral nsRP. All patients completed an International Index of Erectile Function-5 items (IIEF-5) questionnaire concerning EF preoperatively. Group 1 (N = 12 patients) received vardenafil 5 mg/day vs. group 2 (N = 12) who received vardenafil 10 mg/day at night beginning the day of catheter removal. A control of 12 patients underwent follow-up without PDE5 inhibitors.

MAIN OUTCOME MEASURE

The IIEF-5 was the primary end point. IIEF-5 questionnaires were completed at baseline, 3, 6, and 12 months after nsRP.

RESULTS

In group 1 (5 mg/day vardenafil) the IIEF-5 score decreased from a preoperative 22.4 mean score to 4.2 at 3 months, 8.9 at 6 months, and 13.4 mean score at 12 months after nsRP vs. preoperative 22.8, 4.1 at 3 months, 7.9 at 6 months, and 12.8 mean score at 12 months in group 2 (10 mg/day vardenafil). In the control group the preoperative IIEF-5 mean score of 21.9 decreased to 3.8 at 3 months, 6.1 at 6 months, and 8.9 at 12 months. Statistical evaluation showed significant difference in IIEF-5 score and time to recovery of EF between groups 1 and 3 and between groups 2 and 3 (P < 0.01). No statistical differences were found between groups 1 and 2.

CONCLUSIONS

Daily low-dose vardenafil lead to significant improvement of recovery of EF. In this study doubling the dosage did not improve the recovery of EF further.

Among potent men post radical prostatectomy, does the need for phosphodiesterase inhibitors have an impact on sexual bother scores?

Study Type - Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Although phosphodiesterase inhibitor use post radical prostatectomy improves potency, little is known about its affects on sexual bother. We found no difference in sexual bother scores between patients who use and do not use phosphodiesterase inhibitors. This suggests that the current definition of potency, inclusive of medication use, is valid with respect to sexual bother.

OBJECTIVE

To determine whether the current definition of potency, inclusive of phosphodiesterase inhibitor (PDEi) use, is valid with respect to sexual bother (SB). This will be assessed by characterizing the effect of PDEi use on SB scores in men who are potent post radical prostatectomy.

PATIENTS AND METHODS

The study population consisted of patients who were potent both before and after radical prostatectomy, with at least 2 years of follow-up. Disease-specific quality of life data were evaluated by the University of California, Los Angeles, Prostate Cancer Index (PCI) survey. The relationships between changes in sexual function (SF) and SB and use of PDEi over time were evaluated by mixed model analysis controlling for age, clinical risk group, marital status, and time of PCI assessment.

RESULTS

Of the 246 patients who met the study criteria, 39% reported PDEi use at some point after treatment. PDEi use was not associated with improved SF (P= 0.81). Furthermore, PDEi use was not associated with a change in SB (P= 0.36). Both SF and SB were significantly associated with time of assessment and age, and SF and SB each improved over time. In addition, SB was significantly associated with marital status.

CONCLUSIONS

In this analysis, there was no difference in SF scores between men who were potent with or without the use of PDEi. Furthermore, there was no difference in SB scores between men who were potent with or without the use of PDEi. This suggests that the current, inclusive, definition of potency is valid with respect to SB.

Complications, urinary continence, and oncologic outcomes of laparoscopic radical prostatectomy: single-surgeon experience for the first 100 cases

Objective. The aim of the present study was to evaluate initial learning curves of laparoscopic radical prostatectomy (LRP) with regard to complications, urinary continence, and oncologic outcome. Materials and Methods. We retrospectively reviewed 100 consecutive patients with clinically localized prostate cancer. All 100 patients underwent LRP performed by the same urologist at one institution.

RESULTS

Mean operating time (208.4 ± 48.6 min), estimated blood loss (495.8 ± 436.5 mL), allogeneic blood transfusion rate (0%), and intraoperative complications diminished with surgical experience. Positive margin rate varied greatly among pathological stage (positive margin rates: pT2 = 20.5%; pT3 = 63.0%). A trend towards reduction of positive surgical margins in pT2 cases was apparent with increasing experience. Intraoperative and early complications occurred in 2.0% of patients. In all patients, 85.9% used none or no more than one pad per 24 h at 6 months postoperatively. Prostate-specific antigen recurrence was seen in only 2 patients. Conclusions. In the present series of 100 patients, our retrospective evaluation confirms that LRP provides satisfactory results.

Radical retropubic prostatectomy: a review of outcomes and side-effects

BACKGROUND

Radical prostatectomy (RP) is worldwide probably the most common procedure to treat localized prostate cancer (PC). Due to a more widespread use of Prostate-Specific Antigen (PSA) testing, patients operated today are often younger and have organ confined disease justifying a more preservative surgery. At the same time, surgical technique has improved resulting in lower risk of permanent side-effects. This paper aims to give an overview of results from modern surgery regarding cancer control and side-effects. A brief overview of the history is given.

MATERIAL AND METHODS

A literature research identified recently published papers focusing on outcome and side-effects after RP.

RESULTS

One large randomized study (SPCG-4) compared RP and watchful waiting (WW). The study showed that RP was superior to WW in preventing local progression (RR = 0.36), distant metastasis (RR = 0.65) and death from PC (RR = 0.65). Observational studies also show a better outcome for men treated with RP compared to WW. Peri-operative mortality after RP is low in most material around 0.1%. The risk of stricture of the vesico-urethral anastomosis has decreased with improved technique from historically 10-20% to a low incidence of around 2-9% today. Also the risk of incontinence has declined with improved technique. However, while the rates of severe incontinence is usually very low, as many as 30% still report light incontinence after long-term follow-up. Erectile dysfunction (ED) is still a frequent side-effect after RP. This risk is dependent on age, pre-operative sexual function, surgical technique and other risk factors for ED such as smoking, diabetes, etc. In selected subgroups the risk of ED is low. Inguinal hernia is a more recently described complication after open retropubic RP with a postoperative incidence of 15-20% within three years of surgery.

CONCLUSION

RP is an effective method to achieve cancer control in selected patients. With modern technique it is a safe procedure with a low risk of permanent side-effects except for ED.

Transplantation of muscle-derived stem cells into the corpus cavernosum restores erectile function in a rat model of cavernous nerve injury

Purpose

Muscle-derived stem cells (MDSCs) harvested from skeletal muscles have the advantage of providing easier access and do not pose the immunogenic risks of embryonic stem cells. We investigated the effect of intracavernosal transplantation of MDSCs on erectile function in rats with bilateral cavernous nerve injury.

Materials and Methods

Adult male white rats underwent experimentation in 3 groups: group I, sham operation; group II, bilateral cavernous nerve injury; group III, bilateral cavernous nerve injury with MDSC injection. MDSCs were harvested from the femoral muscle of rats and were then injected into the cavernosum. Survival of MDSCs and measurement of erectile function was studied after 4 weeks. We checked the intracavernosal pressure (ICP) and obtained penile tissue. The expression of cyclic guanosine monophosphate (cGMP) was analyzed.

Results

Four weeks after transplantation, PKH-26-labeled MDSCs were identified in the cavernosal tissues of group III. Peak ICP and the drop rate of group II were 52±8.7 mmHg and 34±6.5 mmHg/min, respectively, whereas peak ICP and the drop rate of group III were 97±15.6 mmHg and 17±4.9 mmHg/min, respectively, showing that erectile function improved after MDSC transplantation (p<0.05). The expression of cGMP was significantly lower in group II (21.9±5.8 fmol/well) than in group I and group III (70.2±10.3 and 58.9±10.5 fmol/well, respectively).

Conclusions

In a cavernous nerve injury rat model, intracavernosal transplantation of MDSCs showed acceptable survival of MDSCs as well as improvement of erectile function.

Contemporary radical prostatectomy

Purpose. Patients diagnosed with clinically localized prostate cancer have more surgical treatment options than in the past. This paper focuses on the procedures' oncological or functional outcomes and perioperative morbidities of radical retropubic prostatectomy, radical perineal prostatectomy, and robotic-assisted laparoscopic radical prostatectomy. Materials and Methods. A MEDLINE/PubMed search of the literature on radical prostatectomy and other new management options was performed. Results. Compared to the open procedures, robotic-assisted radical prostatectomy has no confirmed significant difference in most literatures besides less blood loss and blood transfusion. Nerve sparing is a safe means of preserving potency on well-selected patients undergoing radical prostatectomy. Positive surgical margin rates of radical prostatectomy affect the recurrence and survival of prostate cancer. The urinary and sexual function outcomes have been vastly improved. Neoadjuvant treatment only affects the rate of positive surgical margin. Adjuvant therapy can delay and reduce the risk of recurrence and improve the survival of the high risk prostate cancer. Conclusions. For the majority of patients with organ-confined prostate cancer, radical prostatectomy remains a most effective approach. Radical perineal prostatectomy remains a viable approach for patients with morbid obesity, prior pelvic surgery, or prior pelvic radiation. Robot-assisted laparoscopic prostatectomy (RALP) has become popular among surgeons but has not yet become the firmly established standard of care. Long-term data have confirmed the efficacy of radical retropubic prostatectomy with disease control rates and cancer-specific survival rates.

[Counselling for erectile dysfunction during inpatient rehabilitation after radical prostatectomy]

For men erectile function is essential for quality of life. Besides urine incontinence postsurgical erectile dysfunction (ED) following radical prostatectomy (RPE) represents a significant and prevalent problem. One of the first approaches to this condition should be a consultation performed by professionals in a rehabilitation clinic.A total of 149 patients post RPE participated in this prospective study. All patients were questioned about their understanding of postoperative surgical ED after RPE and if affected they were asked about their own psychological burden as well as their knowledge of possible therapy options. The qualities of presurgical patient information as well as the modules of information pertaining to ED during the rehabilitation were evaluated. Of the patients, 53% expressed that they experienced a considerable burden due to postsurgical ED during their follow-up rehabilitation (AR group) and 70% of the patients during oncological rehabilitation treatment (rehab group). Men who were sexually more active prior to surgery suffered more from postsurgical ED than their less active counterparts. A negative correlation between psychological burden and age was found in the AR group, which however was levelled in the rehab group. Particularly in older patients the burden of ED increases with more time elapsing after the operation. The medical information on ED therapy options provided during the inpatient rehabilitation was considered to be essential by 60% of the men in the AR group and 48% of the patients in the rehab group.Therapeutic possibilities for postsurgical ED following RPE cannot always be given to patients in the preoperative phase or during their stay in the hospital. Since however a large majority of men suffer from postoperative ED following RPE a specialized inpatient urological rehabilitation is suited for a comprehensive consultation.

Neuroanatomical study of periprostatic nerve distributions using human cadaver prostate

We investigated the distribution and navigation of periprostatic nerve fibers and constructed a 3-dimensional model of nerve distribution. A total of 5 cadaver specimens were serially sectioned in a transverse direction with 0.5 cm intervals. Hematoxylineosin staining and immunohistochemical staining were then performed on whole-mount sections. Three representative slides from the base, mid-part, and apex of each prostate were subsequently divided into 4 sectors: two lateral, one ventral, and one dorsal (rectal) part. The number of nerve fibers, the distance from nerve fiber to prostate capsule, and the nerve fiber diameters were analyzed on each sector from the representative slides by microscopy. Periprostatic nerve fibers revealed a relatively even distribution in both lateral and dorsal parts of the prostate. There was no difference in the distances from the prostate capsule to nerve fibers. Nerve fibers in the ventral area were also thinner as compared to other areas. In conclusion, periprostatic nerve fibers were observed to be distributed evenly in the periprostatic area, with the exception of the ventral area. As the number of nerve fibers on the ventral part is fewer in comparison, an excessive high up incision is insignificant during the nerve-sparing radical prostatectomy.

Erectile function recovery rate after radical prostatectomy: a meta-analysis

INTRODUCTION

Erectile function recovery (EFR) rates after radical prostatectomy (RP) vary greatly based on a number of factors, such as erectile dysfunction (ED) definition, data acquisition means, time-point postsurgery, and population studied.

AIM

To conduct a meta-analysis of carefully selected reports from the available literature to define the EFR rate post-RP.

MAIN OUTCOME MEASURES

EFR rate after RP.

METHODS

An EMBASE and MEDLINE search was conducted for the time range 1985-2007. Articles were assessed blindly by strict inclusion criteria: report of EFR data post-RP, study population >or=50 patients, >or=1 year follow-up, nerve-sparing status declared, no presurgery ED, and no other prostate cancer therapy. Meta-analysis was conducted to determine the EFR rate and relative risks (RR) for dichotomous subgroups.

RESULTS

A total of 212 relevant studies were identified; only 22 (10%) met the inclusion criteria and were analyzed (9,965 RPs, EFR data: 4,983 subjects). Mean study population size: 226.5, standard deviation = 384.1 (range: 17-1,834). Overall EFR rate was 58%. Single center series publications (k = 19) reported a higher EFR rate compared with multicenter series publications (k = 3): 60% vs. 33%, RR = 1.82, P = 0.001. Studies reporting >or=18-month follow-up (k = 10) reported higher EFR rate vs. studies with <18-month follow-up (k = 12), 60% vs. 56%, RR = 1.07, P = 0.02. Open RP (k = 16) and laparoscopic RP (k = 4) had similar EFR (57% vs. 58%), while robot-assisted RP resulted in a higher EFR rate (k = 2), 73% compared with these other approaches, P = 0.001. Patients <60 years old had a higher EFR rate vs. patients >or=60 years, 77% vs. 61%, RR = 1.26, P = 0.001.

CONCLUSIONS

These data indicate that most of the published literature does not meet strict criteria for reporting post-RP EFR. Single and multiple surgeon series have comparable EFR rates, but single center studies have a higher EFR. Younger men have higher EFR and no significant difference in EFR between ORP and LRP is evident.