Early recovery of urinary continence after robot-assisted radical prostatectomy is associated with membranous urethra and neurovascular bundle preservation

OBJECTIVES

We investigated the correlation between surgical outcomes and postoperative urinary continence recovery in robot-assisted radical prostatectomy (RARP).

METHODS

Patients who underwent RARP in our institution (n = 195) were included in this study. Preserved urethral length (PUL) was assessed during the procedure. Other outcomes of the surgical procedure were collected from operative records. Kaplan-Meier analysis with log-rank test was used to compare urinary continence recovery rate with the PUL, sparing of the neurovascular bundle (NVB), and other surgical procedures. Univariate and multivariate analyses were performed using Cox proportional hazards model, and p-values of <0.05 were considered significant.

RESULTS

Patients with a PUL ≥26 mm had 10.0%, 24.7%, 36.6%, and 89.0% continence recovery rates at 30, 60, 90, and 365 days after surgery, respectively, while patients with a PUL <26 mm had 0%, 17.8%, 26.1%, and 80.9% recovery rates, respectively. Kaplan-Meier curves showed significantly better postoperative urinary continence recovery at 30 days after RARP in patients with a PUL ≥26 mm than those with a PUL <26 mm (p = 0.0028) and in patients with NVB preservation than those with no NVB preservation (p = 0.014). Urinary continence recovery within 30, 60, and 90 days after surgery was 90.6% for patients with a PUL of ≥26 mm and NVB preservation, while only 82.3% for patients with a PUL of <26 mm or no NVB preservation.

CONCLUSION

Our results suggest that a PUL ≥26 mm and NVB preservation after RARP correlate with a significantly higher postoperative rate of recovery of urinary continence.

Application of Periprostatic Nerve Block and Pudendal Nerve Block in Transrectal Ultrasound-Guided Prostate Biopsy

Objective

To investigate the application effects of prostate perineural block combined with pudendal nerve block under transrectal ultrasound guidance in transrectal prostate biopsy.

Methods

Ninety patients who underwent their first transrectal prostate biopsy from November 2021 to July 2022 were included in the study. The patients were divided into three groups: Group A received prostate perineural block, Group B received intrathecal anesthesia, and Group C received pudendal nerve block combined with prostate perineural block. Perioperative indicators, pain levels, and occurrence of complications were compared among the three groups.

Results

Regarding perioperative indicators, after 5 minutes of anesthesia, Group B had the lowest mean arterial pressure (MAP) (P < .05), while Group A had the highest MAP (P < .05). The VAS scores in Groups B and C were lower than that in Group A during probe insertion, prostate puncture, and 2 hours after biopsy (P < .05). There were no significant differences in the occurrence of complications among the three groups (P > .05).

Conclusion

Compared to intrathecal anesthesia, the combination of prostate perineural block and pudendal nerve block provided more stable hemodynamics after 5 minutes of anesthesia. It effectively controlled pain compared to prostate perineural block alone. Nerve block anesthesia facilitated earlier postoperative ambulation, making it suitable for day surgery and in line with the Enhanced Recovery After Surgery concept. Additionally, it had no complications and can be considered for wider application.

Super-veil nerve-sparing extraperitoneal pure single-port robotic-assisted radical prostatectomy on da Vinci Si robotic system

OBJECTIVES

To investigate the safety profile and short-term outcome of super-veil nerve-sparing extraperitoneal single-port robotic-assisted radical prostatectomy (espRARP) on da Vinci Si platform.

METHODS

From December 2018 to March 2021, 106 consecutive patients with treatment-naive prostate cancer were prospectively included. espRARP was performed on da Vinci Si surgical platform. Operative time, estimated blood loss, Clavien-Dindo complication classification, continence, potency recovery, quality-of-life scores, and postoperative prostate-specific antigen (PSA) were documented.

RESULTS

Patients aged 52-79 years (mean ± SD, 64.8 ± 6.15 yrs), with a median PSA of 9.2 ng/ml (IQR: 6.70, 16.83) and median prostate volume of 31.9 ml (IQR: 30.01, 38.54). 95.28% (101/106) were clinically localized. All patients underwent espRARP successfully with no open conversions. Operative time was 94.2 ± 30.26 min with an estimated blood loss of 68.5 ml (range, 50-120 ml). No Grade III complications or above were documented. Positive surgical margin was 17.9% (19/106). Median pain score at discharge was 0 (IQR: 0, 1.75) without use of opioid narcotics. Postoperative length of stay was 3 days (IQR: 1, 3), in which 28 patients were discharged within 24 h. Instant, 1-, 3-, and 6 month continence recovery was 18.9, 45.3, 79.2, 93.4, and 96.4%, respectively. Of the 43 patients who received nerve-sparing procedures, 13 (30.23%) resumed potency 6 months postoperatively. 12 month biochemical recurrence-free survival was 92.77% (77/83).

CONCLUSIONS

Extraperitoneal single-port robotic-assisted radical prostatectomy is a safe and feasible technique. Combined with super-veil nerve-sparing procedures, it may provide satisfactory outcome in short-term functional recovery.

Impact of mpMRI targeted biopsy on intraoperative nerve-sparing (NeuroSAFE) during robot-assisted laparoscopic radical prostatectomy

BACKGROUND

The aim of our study was to evaluate the impact of prostate biopsy technique (transrectal ultrasound (US)-prostate biopsy (PBx) versus multiparametric magnetic resonance imaging (mpMRI) targeted prostate biopsy (MRI-PBx) on intraoperative nerve-sparing and the rate of secondary neurovascular-bundle resection (SNR) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RARP). A real-time investigation with a frozen-section examination (NeuroSAFE) microscopically excluded or confirmed prostate cancer invasion of the nerve structures resulting in preservation of the neurovascular bundle or SNR. Additionally, we analyzed risk factors related to SNR, such as longer operation time and postoperative complications.

METHODS

The total study cohort was stratified according to non-nerve-sparing versus nerve-sparing RARP. Patients with nerve-sparing approach were then stratified according to biopsy technique (PBx vs. MRI-PBx). Further, we compared PBx versus MRI-PBx according to SNR rate.

RESULTS

We included a total of 470 consecutive patients, who underwent RARP for PCa at our institution between January 2016 and December 2019. Patients with a preoperative MRI-PBx had a 2.12-fold higher chance of successful nerve-sparing (without SNR) compared to patients with PBx (p < 0.01). Patients with preoperative MRI-PBx required 73% less intraoperative SNR compared to patients with PBx (p < 0.0001). Prior MRI-PBx is thus a predictor for successful nerve-sparing RARP approach.

CONCLUSION

Preoperative MRI-PBx led to better oncological outcomes and less SNR. Young patients with good erectile function could benefit from a preoperative MRI-PBx before nerve-sparing RARP.

Toggling Technique Allows Retrograde Early Release to Facilitate Neurovascular Bundle Sparing During Robot-Assisted Radical Prostatectomy: A Propensity Score-Matching Study

BACKGROUND

This study aimed to present the surgical facilitation of neurovascular bundle (NVB) sparing using the toggling technique (30° lens down/up switching) and to evaluate erectile dysfunction (ED) recovery after robot-assisted radical prostatectomy (RARP).

METHODS

We assessed 144 patients (group with toggling, n = 72; group without toggling, n = 72) who underwent RARP with bilateral NVB sparing using propensity score matching. Inclusion criteria were ≥ 1 year follow-up and preoperative potency as per the Sexual Health Inventory for Men (SHIM) questionnaire (≥ 17 points). Recovery of ED after RARP was defined as return to baseline sexual function or self-assessment regarding successful intercourse. The subjective surgeon's nerve sparing (SNS) score and tunneling success rates were used to evaluate surgical facilitation. The recovery rate of ED between the groups was analyzed using Kaplan-Meier analysis.

RESULTS

A better ED recovery trend was confirmed according to the SNS score (R² = 0.142, P = 0.004). In the analysis of NVB sparing ease, the toggling group showed higher SNS scores (on right/left side: P = 0.011 and < 0.001, respectively) and overall tunneling success rates (87% vs. 74%, P = 0.001) than the group without toggling. Overall, ED recovery rates were 82% (59/72) and 75% (54/72) in the groups with and without toggling, respectively, at the 1-year follow-up (P = 0.047), and the toggling group showed a faster ED recovery rate at 3 months (47% vs. 35%, P = 0.013). In a specific analysis of the potent cohort (< 60 years, bilateral full NVB spared, SHIM score ≥ 22), the ED recovery rate reached 87% (14/16) in the toggling group.

CONCLUSION

The retrograde early release with the toggling technique improves the facilitation of NVB sparing, leading to improved ED recovery.

Cross-organ sensitization between the prostate and bladder in an experimental rat model of lipopolysaccharide (LPS)-induced chronic pelvic pain syndrome

BACKGROUND

The aim of the current study was to investigate the effects of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) on bladder function via prostate-to-bladder cross-sensitization in a rat model of lipopolysaccharide (LPS)-induced prostate inflammation.

METHODS

Male rats were intraprostatically injected with LPS or saline, serving as control. Micturition parameters were examined in a metabolic cage 10 or 14 days later. Subsequently, to evaluate bladder function, cystometry was performed. Micturition cycles were induced by saline infusion and cholinergic and purinergic contractile responses were measured by intravenous injection with methacholine and ATP, respectively. Thereafter, the prostate and bladder were excised and assessed histopathologically for possible inflammatory changes.

RESULTS

Metabolic cage experiments showed increased urinary frequency in rats with LPS-induced CP/CPPS. Cystometry showed a significant increase in the number of non-voiding contractions, longer voiding time and lower compliance in CP/CPPS animals compared to controls. Induction of CP/CPPS led to significantly reduced cholinergic and purinergic bladder contractile responses. Histopathological analysis demonstrated prostatic inflammation in CP/CPPS animals. There were no significant differences between the groups regarding the extent or the grade of bladder inflammation. Prostate weight was not significantly different between the groups.

CONCLUSIONS

The present study shows that prostate-to-bladder cross-sensitization can be triggered by an infectious focus in the prostate, giving rise to bladder overactivity and alterations in both afferent and efferent signalling. Future studies are required to fully understand the underlying mechanisms.

Use of intraoperative fluorescence to enhance robot-assisted radical prostatectomy

Robot-assisted radical prostatectomy has become the standard of care for the removal of localized prostate cancer. Positive outcomes depend upon the precise removal of the prostate and associated tissue without damage to nearby structures. This process can be aided by fluorescence-guided surgery to enhance the visual contrast between different structures. Here the authors have conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify ten investigations into the use of fluorescence-guided surgery in robot-assisted radical prostatectomy. These studies used fluorescent tracers to identify structures, including the prostate, neurovascular bundle and lymph nodes. These studies demonstrate the safe and effective use of fluorescence-guided surgery in robot-assisted radical prostatectomy and pave the way for further developments in this field.

[Dynamic change in the gene expression profile of rat benign prostate hyperplasia tissue after complete denervation]

OBJECTIVE

To investigate the dynamic change in the gene expression profile of the rat BPH tissue with progressive atrophy after complete denervation.

METHODS

Twelve 29-week-old male rats with spontaneous hypertension and spontaneously developed BPH were used for this study, of which 3 were included in the control (C) group and the other 9 underwent complete denervation of the prostate. At 3, 7 and 11 days after operation (the D3, D7 and D11 groups), all the rats were sacrificed and their ventral prostatic lobes harvested for histopathological examination and RNA extraction, and the RNA samples were subjected to whole genome microarray of the expression profile, followed by real-time RT-PCR validation and bioinformatics analysis.

RESULTS

Progressive atrophy of the BPH tissue was observed in the rats after complete denervation. Whole genome microarray of the expression profile was successfully performed for all the samples, and its reliability validated by real-time RT-PCR of 6 differentially expressed genes selected randomly. Hierarchical clustering analysis showed 108 up-regulated and 175 down-regulated genes in the differentially expressed ones between the D3 and C groups, 462 up-regulated and 189 down-regulated in those between the D7 and C groups, and 548 up-regulated and 256 down-regulated in those between the D11 and C groups. GO functional enrichment analysis indicated that the genes in each differentially expressed gene set participated in hundreds of molecular functions, biological processes and cellular components, while pathway enrichment analysis showed their involvement in hundreds of signaling pathways, of which many were enriched simultaneously in each differentially expressed gene set and ranked as the most enriched ones, and most of the genes involved were up-regulated and related with the activation of the complement system.

CONCLUSIONS

Large numbers of abnormally expressed genes are involved in the progressive atrophy of rat BPH tissue after complete denervation, and these genes participate in hundreds of molecular functions, biological progresses, cellular components and signaling pathways. Abnormal activation of the complement system may play an important role in the progressive atrophy of the BPH tissue.

NeuroSAFE robot-assisted laparoscopic prostatectomy versus standard robot-assisted laparoscopic prostatectomy for men with localised prostate cancer (NeuroSAFE PROOF): protocol for a randomised controlled feasibility study

INTRODUCTION

Robot-assisted laparoscopic prostatectomy (RALP) offers potential cure for localised prostate cancer but is associated with considerable toxicity. Potency and urinary continence are improved when the neurovascular bundles (NVBs) are spared during a nerve spare (NS) RALP. There is reluctance, however, to perform NS RALP when there are concerns that the cancer extends beyond the capsule of the prostate into the NVB, as NS RALP in this instance increases the risk of a positive surgical margin (PSM). The NeuroSAFE technique involves intraoperative fresh-frozen section analysis of the posterolateral aspect of the prostate margin to assess whether cancer extends beyond the capsule. There is evidence from large observational studies that functional outcomes can be improved and PSM rates reduced when the NeuroSAFE technique is used during RALP. To date, however, there has been no randomised controlled trial (RCT) to substantiate this finding. The NeuroSAFE PROOF feasibility study is designed to assess whether it is feasible to randomise men to NeuroSAFE RALP versus a control arm of 'standard of practice' RALP.

METHODS

NeuroSAFE PROOF feasibility study will be a multicentre, single-blinded RCT with patients randomised 1:1 to either NeuroSAFE RALP (intervention) or standard RALP (control). Treatment allocation will occur after trial entry and consent. The primary outcome will be assessed as the successful accrual of 50 men at three sites over 15 months. Secondary outcomes will be used to aid subsequent power calculations for the definitive full-scale RCT and will include rates of NS; PSM; biochemical recurrence; adjuvant treatments; and patient-reported functional outcomes on potency, continence and quality of life.

ETHICS AND DISSEMINATION

NeuroSAFE PROOF has ethical approval (Regional Ethics Committee reference 17/LO/1978). NeuroSAFE PROOF is supported by National Institute for Healthcare Research Research for Patient Benefit funding (NIHR reference PB-PG-1216-20013). Findings will be made available through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03317990.

Vasa nervorum angiogenesis in prostate cancer with perineural invasion

BACKGROUND

Perineural invasion (PNI) is generally accepted as a major route of cancer dissemination in malignancies associated with highly enervated organs. However, the effect of cancer cells on vasa nervorum remains unknown. We studied this effect in locally advanced prostate cancer, a high-risk feature associated with approximately 20% of prostate cancer specific mortality.

METHODS

We used immunohistochemistry for CD34, fibroblast growth factor-2 (FGF-2), FSHR, podoplanin, vascular endothelial growth factor (VEGF), and VEGFR-2 as well as histochemical methods to examine the vasa nervorum of nerves invaded by cancer cells in tissue samples from 85 patients.

RESULTS

The percentage of the nerve area occupied by CD34-positive vasa nervorum endothelial cells in nerves with PNI was much higher than in nerves without PNI (7.3 ± 1.2 vs 1.9 ± 0.4; P < 0.001 and 5.8 ± 0.6 vs 1.23 ± 0.8; P < 0.001 in pT3a and pT3b prostate cancer specimens, respectively). In 19/85 of the patients the CD34-positive vasa nervorum microvessels have a thick basement membrane, similar to the vessels in diabetic microangiopathy. This subendothelial layer contains collagen fibers. Vasa nervorum endothelia and Schwann cells express FGF-2 (nuclear localization) and FSHR (plasma membrane and cytoplasmic staining). Prostate cancer cells invading nerves express VEGF, a critical cytokine in tumor angiogenesis. The vasa nervorum of prostatic nerves with PNI did not express detectable levels of VEGFR-2. No podoplanin-positive lymphatic vessels were seen in nerves.

CONCLUSION

In locally advanced prostate cancer, PNI of cancer cells is associated with formation of new endoneurial capillaries and changes of vasa nervorum morphology.

A randomized controlled comparison between periprostatic nerve block and pelvic plexus block at the base and apex of 14-core prostate biopsies

PURPOSE

To compare the pain control efficacies of the pelvic plexus block (PPB), periprostatic nerve block (PNB), and controls during a 14-core basal and apical core prostate biopsy.

METHODS

This randomized controlled study, performed between January 2015 and January 2016, included patients with an abnormal serum prostate-specific antigen (PSA > 3 ng/mL) level or a palpable nodule on digital rectal examination. The enrolled patients were randomized into three groups: Group 1, intrarectal local anesthesia (IRLA, 10 mL of 2% lidocaine jelly) and PPB with 3.0 mL of 2% lidocaine injected at the bilateral pelvic plexus; Group 2, IRLA and PNB with 3.0 mL of 2% lidocaine injected at both periprostatic nerves; and Group 3, only IRLA. Patients answered the visual analog scale (VAS) questionnaire at 6 time points.

RESULTS

This study consisted of 163 patients (Group 1 = 55, Group 2 = 55, and Group 3 = 53). Pain at the apical biopsy location was less in Groups 1 and 2 than in Group 3 (p < 0.001, p < 0.001) and between the two local anesthetic groups (PNB + IRLA vs PPB + IRLA). Group 2 patients reported less pain than Group 1 patients (p = 0.022). Pain during the basal core biopsy was significantly less in Groups 1 and 2 than in Group 3 (p = 0.002, p < 0.001), but there were no significant differences in pain control between the two methods (PNB + IRLA vs PPB + IRLA, p = 0.054) during basal core biopsy.

CONCLUSIONS

PNB + IRLA is an effective local anesthetic method for reducing pain when performing apical biopsies compared with PPB + IRLA or IRLA alone.

Predictors of deviation in neurovascular bundle preservation during robotic prostatectomy

INTRODUCTION

Neurovascular bundle (NVB) preservation during robot-assisted radical prostatectomy (RARP) directly affects patient functional outcomes. Despite careful surgical planning, many NVB preservation techniques are changed intraoperatively from their preoperative plan. Our objective was to identify risk factors predicting intraoperative change in NVB preservation technique during RARP.

MATERIALS AND METHODS

Prospective data from 578 RARPs performed by a single surgeon between 2010 and 2017 at a tertiary care center. Side-specific NVB preservation technique was planned preoperatively. Surgical techniques were either complete nerve sparing (CNS), or incomplete nerve sparing (INS). Variables included age, tumor grade, prostate volume, number of lifetime biopsies, history of post-biopsy sepsis, and laterality. Variables were modeled in multivariable logistic regressions as potential predictors of deviation in surgical technique. Functional and oncological outcomes were also assessed.

RESULTS

A total of 46.9% of cases underwent some intraoperative change in NVB preservation from their preoperative plan. A total of 37.7% of 880 prostate sides planned for CNS underwent unplanned INS. Older age, Gleason ≥ 3+4, post-biopsy sepsis, prostate volume, and left-sided dissections were significantly associated with unplanned INS. Number of lifetime biopsies was not a predictor of unplanned INS. Patients with an intraoperative change to INS had poorer potency and continence. Study limitations included the retrospective nature of analysis and lack of pathological assessment of NVB preservation.

CONCLUSIONS

Age, Gleason ≥ 3+4, post-biopsy sepsis, prostate volume, and laterality were significant predictors of unplanned INS during RARP, which should guide patient counseling when discussing risks and functional outcomes. The number of lifetime biopsies did not predict unplanned INS, a valuable finding for patients on active surveillance. Our findings highlight the importance of careful preoperative planning and novel adjuncts such as multiparametric MRI.

Influence of the neural microenvironment on prostate cancer

BACKGROUND

Nerves are key factors in prostate cancer (PCa), but the functional role of innervation in prostate cancer is poorly understood. PCa induced neurogenesis and perineural invasion (PNI), are associated with aggressive disease.

METHOD

We denervated rodent prostates chemically and physically, before orthotopically implanting cancer cells. We also performed a human neoadjuvant clinical trial using botulinum toxin type A (Botox) and saline in the same patient, before prostatectomy.

RESULT

Bilateral denervation resulted in reduced tumor incidence and size in mice. Botox treatment in humans resulted in increased apoptosis of cancer cells in the Botox treated side. A similar denervation gene array profile was identified in tumors arising in denervated rodent prostates, in spinal cord injury patients and in the Botox treated side of patients. Denervation induced exhibited a signature gene profile, indicating translation and bioenergetic shutdown. Nerves also regulate basic cellular functions of non-neoplastic epithelial cells.

CONCLUSION

Nerves play a role in the homeostasis of normal epithelial tissues and are involved in prostate cancer tumor survival. This study confirms that interactions between human cancer and nerves are essential to disease progression. This work may make a major impact in general cancer treatment strategies, as nerve/cancer interactions are likely important in other cancers as well. Targeting the neural microenvironment may represent a therapeutic approach for the treatment of human prostate cancer.

Periprostatic innervation: New issues based on segmental analysis of 10 human cadaver pelvic blocs

BACKGROUND

The exact paths of periprostatic nerves have been under debate over the last decades. In the present study, the topographic distribution of nerves around the prostate and their relative distances from the prostatic capsule were analyzed in male cadaver visceral blocs.

METHODS

The pelvic organs from ten fresh male cadavers were removed and serial sectioned en bloc for histological investigation. The macroslices was divided into four sectors. Each sector was centrally covered with a raster dividing each sector in three subsectors numbered clockwise. The prostatic capsule was identified, and distances of 2.5 and 5 mm from the prostate were demarked with lines. We quantified the number of nerve fibers present in each subsector of each slide and recorded their position relative to the prostatic capsule.

RESULTS

In general, the topographic analysis revealed that the majority of nerves were identified in sectors 4 through 9, corresponding to the posterolateral and posterior surfaces of the prostate gland. At the prostate base, the majority of nerves were found at the posterolateral and posterior surfaces of the gland. Within the mid-region of the prostate, the same topographic distribution pattern was observed, but the nerve fibers were closer to the prostatic capsule. At the apical region, the percentage of nerve fibers identified in the anterior region was higher, despite their major concetration in the posterior surface. The nerves identified at the apex were mainly located up to 2.5 mm from the prostate. This proximity to the prostate was specifically observed in the anterolateral and anterior sectors. In the craniocaudal sense, the percentage of nerves identified between 2.5 and 5 mm from the prostatic capsule remained constant.

CONCLUSIONS

A significant number of nerve fibers were present in the anterior and anterolateral positions, especially at the apex. The anterior nerves were closer to the prostate. This proximity suggests that the anterior nerves may participate in local physiology and that the cavernous nerves are probably formed by the posterior nerve fibers. It is likely that the safe distance of 2.5 mm from all surfaces of the prostate may be related to cavernous fiber preservation.

[The role of waterjet dissection in improving erectile function and continence after nerve-sparing prostatectomy]

INTRODUCTION

Erectile dysfunction (ED) and urinary incontinence (UI) following radical prostatectomy (RP) adversely impact patients psycho-emotional status reducing the quality of life and treatment satisfaction.

AIM

To investigate the rates of regaining continence and erectile function (EF) after nerve-sparing radical retropubic prostatectomy (NS-RRP) and nerve-sparing laparoscopic radical prostatectomy (NS-LRP) in the early postoperative period.

MATERIALS AND METHODS

The study comprised 116 patients who preserved sexual activity and the ability to have sex. 64 patients underwent standard resection of NVB (34 RRP and 30 LRP) and in 52 patients the NVB resection was performed using a waterjet dissector (WD) (30 RRP and 22 LRP). All operations were performed by one surgeon with the experience of over 350 RRP and 150 LRP. The study patients had low and moderate risk prostate cancer, according to DAmico risk classification.

RESULTS

Our study findings showed that patients who underwent the WD of NVB had significantly greater IIEF-5 scores (by 2.8 scores) at 8 weeks than after the standard NS-RP. After 6 month follow-up the scores increased by 3.5 points. Patients who underwent NS-RP + WD achieved a successful sexual intercourse 3 months after surgery (regardless of the use of PDE5 inhibitors). In the group of patients who underwent standard NS-RP, it took a longer time to achieve a successful sexual intercourse. Sixty-seven percent of patients who underwent NS-RP + WD were fully continent at one month follow-up after removal of urethral catheter, while most patients treated with standard NS-RP (41%) had mild stress UI. After 3 months follow-up, among patients who underwent NS-RP + WD only one patient had mild stress UI and the vast majority (95%) of patients were fully continent. At 6 months after removal of the urethral catheter there were no significant differences between the groups in regaining urinary continence.

CONCLUSIONS

Waterjet dissection of NVB significantly improves patients postoperative quality of life due to early recovery of urinary continence and EF.

Local anesthesia for transrectal ultrasound-guided biopsy of the prostate: A meta-analysis

A meta-analysis was performed to evaluate the efficacy of local anesthesia in alleviating pain during prostate biopsy. We searched relevant articles in PubMed and Embase. The included studies should be randomized controlled trials (RCT) using local anesthesia to alleviate pain during biopsy, which was recorded by a pain scale. Analgesic efficacy of different local anesthesia techniques were analyzed, including intrarectal local anesthesia (IRLA), periprostatic nerve block (PNB), pelvic plexus block (PPB) and intraprostatic local anesthesia (IPLA). We included 46 RCTs. PNB significantly reduced pain score compared with placebo (-1.27 [95% confidence interval [95% CI] -1.72, -0.82]) or no injection (-1.01 [95% CI -1.2, -0.82]). IRLA with prilocaine-lidocaine cream could also reduced pain (-0.45 [95% CI -0.76, -0.15]), while the IRLA with lidocaine gel was not effective (-0.1 [95% CI -0.24, 0.04]). PNB lateral to the neurovascular bundle had better analgesic effect than at prostate apex (P = 0.02). Combination use of PPB and IRLA considerably alleviated pain of patients compared with the combination of PNB and IRLA (-1.32 [95% CI -1.59, -1.06]). In conclusion, local anesthesia could alleviate patients' pain during the prostate biopsy. PNB was not so effective as PPB.

[ROBOT-ASSISTED RADICAL PROSTATECTOMY FOR MEN AGE 75 AND OLDER]

(Objectives) Surgical treatment prostate cancer in elderly patients is controversial. However, robot-assisted radical prostatectomy (RARP) is a less invasive procedure than conventional surgery. Therefore, we perform RARP for elderly patients whose general condition is good (Performance status ≤1). The aim of this study is to evaluate surgical, oncological and functional outcomes for RARP in men age 75 and older. (Patients and methods) From July 2013 to April 2016, 300 patients underwent RARP at our institution. They were divided into two groups: an older patient group (≥75 years) and a younger patient group (<75 years). Treatment outcomes for each group, including surgical, oncological and functional outcomes, were compared. (Results) There were no statistically significant differences in surgical outcomes with the exception of nerve sparing rates (older patients: 5.9% vs. younger patients: 17.7%, P=0.0192). Importantly, intra- and postoperative complication rates were similar in both groups (minor complication: 7.4% vs. 3.9%, P=0.322, major complication: 0.0% vs. 2.2%, P=0.592). Regarding oncological outcomes, including positive surgical margin rate and PSA failure (PSA>0.2 ng/ml) at 12 months after surgery, no significant differences existed. Lastly, functional outcomes between the groups, including continence (≤1 pads/day) at 12 months after surgery, had no significant differences. (Conclusions) Our data suggests that RARP can be performed safely for men age 75 and older, and can become a good option for older patients with prostate cancer.

Retrograde double-labeling demonstrates convergent afferent innervation of the prostate and bladder

BACKGROUND

Prostatic inflammation is a common histologic finding in men with lower urinary tract symptoms (LUTS). It has been postulated that prostatic inflammation could sensitize afferent neurons innervating the bladder and thereby produce changes in voiding behavior. In support of this, we demonstrate an anatomic basis for pelvic cross-talk involving the prostate and bladder.

METHODS

Retrograde labeling was performed by an application of a neuro-tracer Fast Blue (FB) to one side of either the anterior prostate (AP), dorsal lateral prostate (DLP)/ventral prostate (VP), bladder, or seminal vesicle (SV).

RESULTS

Examination of dorsal root ganglion (DRG) neuron labeling revealed shared afferent innervation of the prostate and bladder at spinal segments of T13, L1, L2, L6, and S1. Dual labeling was performed by an application of FB and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyaine perchlorate (DiI) to the AP and bladder, respectively. We observed double-labeled DRG neurons at T13, L1, L2, L6, and S1--a finding that proves convergent innervation of prostate and bladder.

CONCLUSIONS

Our observations demonstrate the potential for neural cross-talk between the prostate and bladder and support a postulated mechanism that prostatic inflammation may induce hyper-sensitization of bladder afferents and produce irritative LUTS.

Zoomed echo-planar diffusion tensor imaging for MR tractography of the prostate gland neurovascular bundle without an endorectal coil: a feasibility study

PURPOSE

The purpose of this study was to assess the feasibility of zoomed echo-planar imaging (EPI) diffusion tensor imaging (DTI) with 2-channel parallel transmission (pTx) for MR tractography of the periprostatic neurovascular bundle (NVB) without an endorectal coil, and to compare its performance to that of conventionally acquired DTI.

METHODS

8 healthy males (28.9 ± 4.6 years) underwent pelvic phased-array coil prostate MRI on a 3T system using both zoomed-EPI DTI (z-DTI) with 2-channel pTx and conventional single-shot spin-echo EPI DTI (c-DTI) acquisitions with 6 encoding directions and b-values of 0 and 1000 s/mm(2). Fractional anisotropy (FA) maps and tractography analysis incorporating 3D visualization of the NVB were performed from each acquisition. Fiber tract counts, estimated signal-to-noise ratio (eSNR), and image quality measures of the FA maps and NVB tractography were compared. Quantitative and image quality measures were compared using Wilcoxon signed rank tests.

RESULTS

3 of 8 subjects had no tracts detected with c-DTI acquisition, while all 8 had tracts detected with z-DTI. z-DTI acquisition yielded significantly more fiber tracts (c-DTI: 77 ± 116 tracts; z-DTI: 430 ± 228 tracts; p = 0.019) and higher eSNR (c-DTI: 2.9 ± 1.2; z-DTI: 13.17 ± 9.9; p = 0.014). Relative to c-DTI acquisitions, z-DTI FA maps showed significantly reduced artifact (p = 0.008) and reduced anatomic distortion of the prostate (p = 0.010), while z-DTI tractography showed significantly better overall visual quality (p = 0.011), tract symmetry (p = 0.010), tract coherence (p = 0.011), and subjective similarity to the actual NVB (p = 0.011).

CONCLUSION

Zoomed-EPI DTI acquisition for tractography of the prostate gland NVB improves quantitative and qualitative measures of image and tract fiber quality, allowing tractography of the NVB at 3T without using an endorectal coil.

Robotic-assisted Laparoscopic Bilateral Nerve Sparing and Apex Preserving Cystoprostatectomy in Young Men With Bladder Cancer

OBJECTIVE

To describe our technique and outcomes of robotic-assisted nerve-sparing cystoprostatectomy with prostatic apex preservation and orthotopic ileal conduit urinary diversion in young men undergoing robotic-assisted radical cystectomy (RARC) for the management of urothelial carcinoma.

MATERIALS AND METHODS

Young men (<40 years old) with the diagnosis of urothelial carcinoma undergoing RARC with orthotopic neobaldder formation were eligible for our technique of nerve-sparing cystoprostatectomy with prostatic apex preservation at the time of orthotopic ileal conduit urinary diversion. During the apical prostatic dissection step of the RARC, the plane of dissection is directed under the dorsal vein complex and through anterior prostatic fibromuscular stroma. This plane is further carried through the prostatic urethra, transecting the most caudal aspect of prostatic peripheral zone posteriorly, to create a long urethra and a posterior urethral plate formed by peripheral zone of the prostate, which serves as a robust, long stump for the subsequent vesicourethral anastomosis.

RESULTS

From January 2013 to January 2014, 3 men were treated with RARC and intracorporeal neobladder urinary diversion based on the described technique. There were no intraoperative complications. Two patients experienced grade II complications postoperatively. Pathologic assessment demonstrated negative surgical margins in all 3 cases. With mean follow-up time of 28.2 months, 2 out of 3 patients are free from disease recurrence. All patients report daytime urinary continence with no pad usage and potency without the need for phosphodiesterase-5 inhibitors.

CONCLUSION

RARC with bilateral nerve and apical preservation can be performed safely in appropriately selected young patients with excellent functional and acceptable short-term oncologic results.

[Blood vessels and nerves surrounding the seminal vesicles: A clinical anatomic study]

OBJECTIVE

To investigate the precise locations of the blood vessels and nerves surrounding the seminal vesicles (SV) in men and provide some anatomical evidence for SV-related minimally invasive surgery.

METHODS

We observed the courses and distribution of the blood vessels and nerves surrounding SVs and obtained the data for positioning the SV neuroplexes in 20 male pelvises.

RESULTS

One branch of the neuroplexes was distributed to the SVs bilaterally with the neurovascular bundles, (2.85 ± 0.18) cm from the median sulcus of the prostate (MSP), while another branch ran through the Denonvillier fascia behind the SV, (0.81 ± 0.06) cm from the MSP. The arterial SVs (ASV) originated from the inferior vesical artery and fell into 4 types, 55% going directly to the SVs as one branch, 15% running between the SV and the ampulla of the deferent duct as another branch, 25% downward as 2 branches to the SV and between the SV and the ampulla of the deferent duct respectively, and 5% as the other ASVs. The shortest distance from the ASV through the prostatic neuroplexus to the posterior SV was (1.08 ± 0.09) cm.

CONCLUSION

In SV resection, neuroplexus injury can be reduced with a bilateral distance of < 2.85 cm and a posterior distance of < 0.81 cm from the MSP, and so can bleeding by vascular ligation between the SV and the ampulla of the deferent duct.

[Development of a preoperative criterion to select candidates for nerve-sparing radical prostatectomy at Kyoto University Hospital]

Neurovascular bundle (NVB) preservation is a mandatory procedure to maintain erectile function of localized prostate cancer patients after radical prostatectomy (RP). However, in terms of cancer control, indications to select appropriate patients for nerve-sparing RP are still controversial. In this study, we examined the pathological findings of RP specimens to develop a preoperative criterion for NVB preservation during RP. The study included 76 patients who underwent RP at our institution from 2006 to 2008, and we retrospectively analyzed RP specimens pathologically. The distance between NVB and foci of prostate cancer was measured in 135 prostate sides, and preoperative factors which predict the distance of ≤2 mm was evaluated. Univariate analysis showed that side-specific positive biopsy core rate ≥33.3%, side-specific maximum tumor length in biopsy core ≥5 mm and side-specific tumor involvement rate in biopsy core ≥50% was associated with the risk of the distance of ≤2 mm. Multivariate analysis revealed that side-specific positive biopsy core rate ≥33.3% was the only significant predictor of the ipsilateral NVB-tumor distance ≤2 mm (p = 0.0055, odds ratio 3.49). Based on this study, a nerve-sparing criterion of ＜33.3% side-specific percent positive biopsy core was developed at our institution. Prospective data on patients who were applied this criterion are needed to evaluate its clinical safety and feasibility.

Impact of active surveillance on pathology and nerve sparing status

INTRODUCTION

We assessed whether, in comparison to immediate surgery, a time delay in performing radical prostatectomy (RP) in patients electing to undergo a period of active surveillance (AS) of low grade prostate cancer, is associated with adverse pathologic features, biochemical recurrence and the ability to perform effective nerve sparing surgery.

MATERIALS AND METHODS

From our RP database of 2769 patients, we identified 41 men under AS who subsequently underwent RP. This study group was compared to control group A (164 patients who chose RP rather than AS), matched for prostate-specific antigen (PSA) and initial diagnostic biopsy characteristics. With time, PSA and biopsy characteristics in the AS study group changed, prompting these men to undergo RP. These changes were matched to create a separate control group B (123 patients most of whom did not meet AS criteria). The incidence of nerve sparing surgery, pathologic features, and biochemical recurrence were compared. Outcome variables were compared using Chi-square tests of proportions. Fisher's Exact test was used for recurrence rates due to the low expected frequencies in some cells.

RESULTS

Compared with control group A, the AS patients experienced higher rates of Gleason score upgrading (33/41; 81.1% versus 76/164; 46.3%, p < 0.001), biochemical recurrence (5/41; 11.4% versus 2/164; 1.3%, p = 0.012) and lower rates of bilateral nerve sparing surgery (31/41; 75.6% versus 154/164; 93.9%, p < 0.001). Control group B and active surveillance group were comparable across all indices measured.

CONCLUSIONS

Delaying RP, through undergoing a period of AS, had a significant negative impact on the incidence of bilateral nerve sparing surgery and adverse pathologic features when compared to patients with similar parameters at the time of diagnosis. Close monitoring and surveillance biopsies did not improve pathologic outcomes compared to patients from whom a single diagnostic biopsy was obtained (and were not candidates for AS), and who subsequently underwent immediate surgery.

Bilateral cancer in prostate biopsy associates with the presence of extracapsular disease and positive surgical margins in low risk patients: a consideration for bilateral nerve sparing radical prostatectomy decision

PURPOSE

To evaluate the epidemiological, clinical and pathological parameters that may predict the presence of positive surgical margins and extraprostatic disease in patients with low risk [prostate specific antigen (PSA) < 10, and Gleason score ≤ 6, stage T1c)] prostate cancer.

MATERIALS AND METHODS

We retrospectively analyzed the medical records of patients who had undergone radical prostatectomy from January 2005 until January 2011. The analysis comprised patients age, preoperative serum prostate specific antigen (PSA) level, prostate volume, PSA density, biopsy Gleason score, the presence of bilateral disease according to the results of biopsy cores analysis, the percentage of cancer in biopsy material and the presence of high grade prostatic intraepithelial neoplasia.

RESULTS

A total of 117 patients were included in the study. Positive surgical margins were found in 37 (31.6%) patients and 23 (19.7%) had advanced disease. The results of the multivariate analysis showed that bilateral disease was the single significant predictor for advanced disease prediction (P = .04). Same results was obtained by the univariate analysis of the variables for prediction of positive surgical margins, where bilateral disease after biopsy cores analysis was the only factor to be statistical significant (P = .018).

CONCLUSION

Bilateral prostate cancer in prostate biopsy is significantly associated with positive surgical margins and advanced disease in patients that are operated for prostate cancer of low risk.This observation may assist the selection of patients in whom a bilateral nerve sparing radical prostatectomy is planned to be performed.

Temperature-controlled optical stimulation of the rat prostate cavernous nerves

Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (~42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs.

Perineural invasion and TRUS findings are complementary in predicting prostate cancer biology

INTRODUCTION

Clinical variables with more accuracy to predict biologically insignificant prostate cancer are needed. We evaluated the combination of transrectal ultrasound-guided biopsy of the prostate (TRUSBx) pathologic and radiologic findings in their ability to predict the biologic potential of each prostate cancer.

MATERIALS AND METHODS

A total of 1043 consecutive patients who underwent TRUSBx were reviewed. Using pathologic criteria, patients with prostate cancer (n = 529) and those treated with radical prostatectomy (RP) (n = 147) were grouped as: "insignificant" (Gleason score ≤ 6, prostate-specific antigen (PSA) density ≤ 0.15 ng/ml, tumor in ≤ 50% of any single core, and < 33% positive cores) and "significant" prostate cancer. TRUSBx imaging and pathology results were compared with the RP specimen to identify factors predictive of "insignificant" prostate cancer.

RESULTS

TRUSBx pathology results demonstrated perineural invasion in 36.4% of "significant" versus 5.4% of "insignificant" prostate cancers (p < 0.01) and pathologic invasion of periprostatic tissue in 7% of significant versus 0% of insignificant prostate cancers (p < 0.01). TRUS findings concerning for neoplasia were associated with significant tumors (p < 0.01). Multivariable analysis demonstrated perineural invasion in the biopsy specimen (p = 0.03), PSA density (p = 0.02) and maximum tumor volume of any core (p = 0.02) were independently predictive of a significant prostate cancer.

CONCLUSIONS

TRUS findings concerning for measurable tumor and perineural invasion in TRUSBx specimens appear to be complementary to Epstein's pathologic criteria and should be considered to aid in the determination whether a prostate cancer is organ-confined and more likely to be biologically insignificant.

Stereological Quantification of Nerve Fibers Immunoreactive to PGP 9.5, NPY, and VIP in Rat Prostate During Postnatal Development

This work was undertaken to study prostate innervation during the postnatal development of rats. It deals with the quantification of nervous fibers throughout all the regions of the rat prostate during the postnatal development using a general marker for nervous tissue, protein gene product 9.5, and 2 neuropeptides (NPY and VIP). Forty male Wistar rats (prepubertals, pubertals, young, and aged adults) were studied for immunohistochemistry of protein gene product (PGP 9.5), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP). They were also evaluated for length density of nerve fibers (L(V) PGP 9.5, L(V) NPY, L(V) VIP). Nerve fibers immunoreactive to the 3 antigens studied were detected in all the groups and in all the prostate zones. Periductal L(V) NPY evidenced a significant increase in the pubertal group, maintained throughout adult life. Periductal L(V) VIP showed a significant increase in young adults. The length densities of VIP and NPY fibers were significantly higher in periductal and ampular locations in comparison with dorsal and ventral sites. It can be concluded that the relative amount of nerve fibers in rat prostate, detected by PGP 9.5, does not change during postnatal development. There were significant changes in NPY and VIP fibers, showing an increase in periurethral ducts at puberty. The abundance of peptidergic innervation around the excretory ducts is related to their contractility. The development of innervation of periurethral ducts is regulated by androgens.

Subsurface near-infrared laser stimulation of the periprostatic cavernous nerves

Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function and vulnerable to damage during prostate cancer surgery, will require subsurface detection of the CN's beneath a thin fascia layer. This study explores the feasibility of optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near-infrared diode lasers with wavelengths of 1455 and 1550 nm were operated in continuous-wave mode for stimulation of the CN in 8 rats, in vivo. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia with a thickness up to 110 μm and at 1550 nm through fascia with a thickness up to 450 μm. Higher incident laser power was required to produce an ICP response as fascia thickness was increased. Also, weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible as an intermediate step towards developing ONS as an intra-operative diagnostic tool for identification and preservation of the cavernous nerves during prostate cancer surgery.

Diffusion tensor magnetic resonance tractography of the prostate: feasibility for mapping periprostatic fibers

OBJECTIVE

To evaluate the feasibility of diffusion tensor imaging (DTI) tractography of the prostate for mapping of periprostatic neurovascular anatomy.

METHODS

Eight men with prostate cancer scheduled to undergo nerve-sparing robot-assisted radical prostatectomy (RARP) underwent endorectal multiparametric magnetic resonance imaging (MRI) of the prostate with DTI. Tract mapping was accomplished by positioning spherical regions of interest contiguously along the prostatic capsule at the prostatic apex, midgland, and base.

RESULTS

DTI tractography of the prostate effectively visualized periprostatic fiber tract anatomy. There was no significant correlation between total tract number and prostate size, however (Spearman's coefficient = 0.33, P = .42). Variation in tract distribution existed. The total fiber mass was highest in the lower prostate hemisphere at the base of the prostate (mean = 36.9 vs 21.1, P = .0004) and in the upper hemisphere at the apex (mean = 41.6 vs 57.9, P = .006).

CONCLUSION

DTI tractography successfully visualized fiber tracts around the prostate. Gold standard anatomic correlation is needed.

Evaluation of erectile function after laparoscopic radical prostatectomy in a single center

INTRODUCTION

To evaluate erectile function among men who had undergone laparoscopic radical prostatectomy and received postoperative medical therapy for erectile dysfunction.

MATERIALS AND METHODS

We performed a prospective study in men who underwent laparoscopic radical prostatectomy between September 2003 and November 2005 at our center and who received penile rehabilitation after surgery. All patients had antegrade interfascial dissection. They received 10 mg tadalafil on the fifth postoperative day and continued to receive it every other day, regardless of erectile function. Intracavernous injection of alprostadil was initiated at 3 or 6 months depending on response to treatment with tadalafil. Follow up evaluations were done at 3, 6, 12, 18 and 24 months. Oncologic and functional outcomes and compliance were assessed. Patients filled in International Index of Erectile Function-5 (IIEF-5) questionnaires.

RESULTS

Of 1078 men who underwent laparoscopic radical prostatectomy during this time, 586 patients met inclusion criteria, complied with the study medication, and had complete data for 24 months. The patients had a median preoperative baseline IIEF-5 score of 22. A total of 150 patients (26%) underwent unilateral nerve-sparing surgery, while 436 patients (74%) had bilateral nerve-sparing surgery. At 24 months, 35% of patients who underwent unilateral nerve-sparing surgery and 68% of patients who underwent bilateral nerve-sparing surgery reported having sufficient erectile function for intercourse without using intracavernous injection of alprostadil. At 24 months after surgery, the median IIEF-5 score was 13 (1-25) for the whole cohort, 5 (1-25) for patients who had undergone unilateral nerve-sparing surgery, and 15 (1-25) for patients who had undergone bilateral nerve-sparing surgery.

CONCLUSIONS

The findings suggest that adequate patient selection and postoperative medical intervention allows the preservation or recovery of erectile function after laparoscopic radical prostatectomy. Inaccurate selection of patients and postoperative assessment might explain inferior erectile function results following this surgery.

Prediction of functional outcomes after nerve-sparing radical prostatectomy: results of conditional survival analyses

BACKGROUND

In prostate cancer (PCa) patients treated with radical prostatectomy (RP), the rate of urinary continence (UC) and erectile function (EF) recovery may change significantly depending on the time interval between surgery and patient assessment. This effect, known as conditional survival, has not yet been assessed.

OBJECTIVE

Evaluate the conditional rates of UC and EF recovery after nerve-sparing RP (NSRP).

DESIGN, SETTING, AND PARTICIPANTS

We included 1135 PCa patients treated between January 2000 and June 2011 at a single referral center.

INTERVENTION

All patients underwent NSRP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The Kaplan-Meier method assessed the time to recovery of UC (defined as an International Consultation on Incontinence Questionnaire score<6) and of EF (defined as an International Index of Erectile Function-Erectile Function score≥22). Cumulative survival estimates were used to generate conditional recovery rates assessed at a 6-mo interval. Multivariable Cox regression analyses were performed to predict functional outcomes recovery after accounting for confounders.

RESULTS AND LIMITATIONS

UC recovery rates were 89.5%, 94.7%, and 97.0% at 6-, 24-, and 36-mo follow-up, respectively. Corresponding EF recovery rates were 53.6%, 65.0%, and 67.5%, respectively. In patients who were still incontinent at 1, 6, 12, 18, 24, 30, and 36 mo after surgery, UC recovery rates in the following 6-mo period significantly decreased as the time from surgery increased: 74.9%, 58.2%, 41.4%, 14.9%, 24.8%, 24.6%, and 13.3%, respectively. Similarly, in patients still impotent at the same time points, the 6-mo rate of sexual potency recovery was 36.9%, 26.8%, 17.8%, 8.2%, 3.1%, 4.0%, and 0%, respectively. Multivariable analyses confirmed these results. The study is limited by its retrospective design.

CONCLUSIONS

In incontinent and/or impotent patients, the period elapsed from surgery represents an important predictor of the recovery of subsequent functional outcomes. The highest increments in UC and EF recovery were observed during the first year after surgery; they were virtually null after 36 mo.

Accuracy of preoperative endorectal MRI in predicting extracapsular extension and influence on neurovascular bundle sparing in radical prostatectomy

PURPOSE

To evaluate the accuracy of presurgical endorectal MRI (eMRI) for local staging before radical prostatectomy (RP) and its influence on neurovascular bundle (NVB) resection during radical prostatectomy.

PATIENTS AND METHODS

A total of 385 patients with histologically proven prostate cancer (PCa) have been included in this retrospective study between 2004 and 2008. All patients underwent preoperative eMRI at 1.5 T before open RP. Staging results by eMRI were compared with the histopathological findings. The presence of positive surgical margins and extent of nerve-sparing procedure were evaluated. Subgroup analysis of low-risk group and intermediate to high-risk group based on D'Amico criteria was conducted.

RESULTS

In 294 (76.4%) patients, pathological stage was correctly predicted, 69 patients (17.9%) were understaged and 22 (5.7%) overstaged. Overall sensitivity, specificity, negative and positive predictive value for predicting extracapsular extension (ECE) were 41.5, 91.8, 78.0 and 69.0%, respectively. One hundred and fifty-two (48.4%) of the patients classified as stage cT2 by eMRI underwent bilateral NVB sparing, whereas 14 (19.7%) patients with reported ECE underwent bilateral NVB sparing (P < 0.01). Overall positive surgical margin rate was 14.8%. Sensitivity of predicting ECE and positive predictive value were lower in the low-risk group than in the intermediate and high-risk group.

CONCLUSIONS

eMRI is effective in predicting extracapsular extension in an intermediate to high-risk group. Preoperative eMRI in patients with low-risk criteria is not recommended as a routine assessment modality. eMRI findings did appear to influence surgical strategy as patients with imaging findings suggesting >cT2 disease were less likely to undergo NVB sparing.

Quantification of extraprostatic perineural spread and its prognostic value in pT3a pN0 M0 R0 prostate cancer patients

BACKGROUND

The prognostic relevance of the amount of extraprostatic cancer spread in nerves in prostate cancer patients is not well established.

METHODS

Eighty-eight patients were included in our study with pT3a pN0 M0 R0 prostate cancer treated with retropubic prostatectomy. Eighty-seven of them showed perineural invasion, 54 were confined to the prostate, 33 showed cancer spread in extraprostatic nerves, which was quantified by counting each transverse section of nerves infiltrated by cancer in totally embedded specimens. Biochemical relapse was established by serum PSA levels of ≥0.2 ng/ml as well as PSA ≥ 0.4 ng/ml and higher according to the EAU guidelines.

RESULTS

Extraprostatic but not intraprostatic perineural infiltration was significantly more often found in tumors of higher Gleason score. Intraprostatic number of infiltrated nerves (NIN) correlated with extraprostatic NIN. There was no association between extraprostatic or intraprostatic NIN and Gleason score, lymphatic, or blood vessel invasion. Extraprostatic neural infiltration in ≤10 nerves extended relapse free survival in univariate analysis for PSA 0.2 and 0.4 ng/ml (P = 0.002 and P < 0.000001, respectively) and remained significant in multivariate analysis for PSA 0.4 ng/ml (P = 0.039).

CONCLUSIONS

High amount of extraprostatic NIN correlates with tumor progression and seems to be an independent prognostic parameter.

Laparoscopic radical prostatectomy: oncological and functional outcomes of 559 cases in Siriraj Hospital, Thailand

OBJECTIVE

To evaluate the results of oncological and functional outcomes of laparoscopic radical prostatectomy (LRP) during the first five years experience in Siriraj hospital.

MATERIALS AND METHOD

Between September 2004 and September 2009, the functional and oncological outcomes of 559 patients that underwent LRP were retrospectively evaluated.

RESULTS

The distribution of pathological T stage was T2 (52.1%), T3 (39.9%), and T4 (2.9%). Lymph node metastasis (N1) were found in 19 patients (3.4%). The positive margin rates in pT2a-b, pT2c, pT3a, pT3b and pT4 were 13.2%, 34.7%, 65.9%, 72.7% and 76.9%, respectively. The 3-year biological progression free survival (bPFS) rate for all patients was 87.2%. Three-year bPFS rates in pT2a-b, pT2c, pT3a, pT3b and pT4 were 96.3%, 93%, 75%, 55.6% and 62.5% respectively. The continent rate at 12 months was 84% and potency rate at 12 months in group that received bilateral nerve sparing was 29.1%.

CONCLUSION

The oncological and functional results of our first LRPs in Thai men are acceptable and compared well with the early experience of previous studies. However, longer follow up is needed for further evaluation.

Models of inflammation of the lower urinary tract

Inflammation of the lower urinary tract occurs frequently in people. The causes remain obscure, with the exception of urinary tract infection. Animal models have proven useful for investigating and assessing mechanisms underlying symptoms associated with lower urinary tract inflammation and options for suppressing these symptoms. This review will discuss various animal models of lower urinary tract inflammation, including feline spontaneous (interstitial) cystitis, neurogenic cystitis, autoimmune cystitis, cystitis induced by intravesical instillation of chemicals or bacterial products (particularly lipopolysaccharide or LPS), and prostatic inflammation initiated by transurethral instillation of bacteria. Animal models will continue to be of significant value in identifying mechanisms resulting in bladder inflammation, but the relevance of some of these models to the causes underlying clinical disease is unclear. This is primarily because of the lack of understanding of causes of these disorders in people. Comparative and translational studies are required if the full potential of findings obtained with animal models to improve prevention and treatment of lower urinary tract inflammation in people is to be realized.

[Techniques for neurovascular bundle preservation during retropubic radical prostatectomy]

Although radical prostatectomy is a curative therapy that has proven effective in many of our patients with prostate cancer, it is still associated with significant morbidity, which includes postoperative erectile dysfunction among its leading exponents. Potency after the intervention may be influenced by many factors, among which, presence of adequate erectile function before surgery, patient's age, stage of disease at the time of treatment, surgeon's experience and, of course, interpersonal anatomical variations may be pointed out. In recent decades, the exact knowledge of the neuroanatomy of the male pelvis has become very important, for both the student of human anatomy and the pelvic surgeon. Therefore, the anatomical nerve sparing techniques have led to fewer complications related to the injury of these structures. This article presents a brief description of the neuroanatomical substrate of the neurovascular bundles along with a detailed compilation of the different surgical techniques for their preservation during radical retropubic prostatectomy.

Preoperative prediction of neurovascular bundle involvement of localized prostate cancer by combined T2 and diffusion-weighted imaging of magnetic resonance imaging, number of positive biopsy cores, and Gleason score

Because recovery of erectile function and avoidance of positive surgical margins are important but competing outcomes with prostate cancer therapy, the decision to preserve or resect a neurovascular bundle (NVB) during laparoscopic radical prostatectomy (LRP) should be firmly based on information concerning the presence and location of extracapsular extension. In the current retrospective study, the propriety of actual decisions was assessed using preoperative magnetic resonance imaging (MRI), combining T2-weighted imaging (T2WI) with diffusion-weighted imaging (DWI), the apparent diffusion coefficient (ADC), numbers of positive biopsy cores, tumor volume and the Gleason score. MRI before prostate biopsy was performed in 35 patients who underwent LRP for clinically localized prostate cancer. A single radiologist retrospectively assessed whether the tumor localization, capsular penetration, seminal vesicle invasion, NVB involvement, and MRI findings correlated with the postoperative histological results. With the postoperative specimens, 83 lesions demonstrated a Gleason score of 6 or more. Using T2WI with and without DWI and ADC, 39 and 27 of 54 lesions were correctly identified, respectively, the difference being significant. For cancers in the transitional zone, using a threshold Gleason score of 3 or greater, sensitivity was also significantly higher for T2+DWI+ADC than for T2WI alone. Of 35 patients, using all available clinical information (biopsy results including Gleason score, tumor location, percentage of positive biopsy cores, and the percentage of tumor-involved core tissue), we found that the preoperative and postoperative staging were concordant in 25 cases. There is no universal consensus for nerve-sparing LRP; therefore, we performed an additional analysis using simplified clinically defined selection criteria (PSA level >15ng/mL, cT2, less than two positive biopsy scores in the unilateral lobe and less than 30% tumor volume, and a Gleason score of 6). Using this criteria, we selected 12 of 35 patients, and the detection rate of NVB involvement by MRI combined T2WI + DWI + ADC maps was 100% in their 30 lesions, and therefore we consider it safe to perform nerve-sparing LRP using our criteria. Our findings suggest that NVB can be safely preserved in patients with low-grade tumors using simplified clinically defined selection criteria to determine margin involvement.

Parasympathetic innervation maintains epithelial progenitor cells during salivary organogenesis

The maintenance of a progenitor cell population as a reservoir of undifferentiated cells is required for organ development and regeneration. However, the mechanisms by which epithelial progenitor cells are maintained during organogenesis are poorly understood. We report that removal of the parasympathetic ganglion in mouse explant organ culture decreased the number and morphogenesis of keratin 5-positive epithelial progenitor cells. These effects were rescued with an acetylcholine analog. We demonstrate that acetylcholine signaling, via the muscarinic M1 receptor and epidermal growth factor receptor, increased epithelial morphogenesis and proliferation of the keratin 5-positive progenitor cells. Parasympathetic innervation maintained the epithelial progenitor cell population in an undifferentiated state, which was required for organogenesis. This mechanism for epithelial progenitor cell maintenance may be targeted for organ repair or regeneration.

Combined image-processing algorithms for improved optical coherence tomography of prostate nerves

Cavernous nerves course along the surface of the prostate gland and are responsible for erectile function. These nerves are at risk of injury during surgical removal of a cancerous prostate gland. In this work, a combination of segmentation, denoising, and edge detection algorithms are applied to time-domain optical coherence tomography (OCT) images of rat prostate to improve identification of cavernous nerves. First, OCT images of the prostate are segmented to differentiate the cavernous nerves from the prostate gland. Then, a locally adaptive denoising algorithm using a dual-tree complex wavelet transform is applied to reduce speckle noise. Finally, edge detection is used to provide deeper imaging of the prostate gland. Combined application of these three algorithms results in improved signal-to-noise ratio, imaging depth, and automatic identification of the cavernous nerves, which may be of direct benefit for use in laparoscopic and robotic nerve-sparing prostate cancer surgery.

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.

PTPIP51 mRNA and protein expression in tissue microarrays and promoter methylation of benign prostate hyperplasia and prostate carcinoma

BACKGROUND

Protein tyrosine phosphatase interacting protein 51 (PTPIP51) shows a tissue-specific expression pattern and is associated with cellular differentiation and apoptosis in several mammalian tissues. Overexpression of the full-length protein enhances apoptosis. It is also expressed in various carcinomas. In this study the expression of PTPIP51 and its in vitro interaction partners was investigated in human benign prostate hyperplasia (BPH) and in prostate carcinoma (PCa).

METHODS

Tissue microarrays of human BPH and PCa were analyzed by immunohistochemistry. For polymerase chain reaction (PCR), cryo samples of BPH and PCa were used. Bisulfite DNA treatment, followed by sequencing of PCR products was performed in order to analyze CpGs methylation within the promoter region of the PTPIP51 gene.

RESULTS

PTPIP51 mRNA and protein expression was detected in prostatic epithelia of BPH and in tumor cells of PCa, respectively, and within smooth muscle cells of the stromal compartment. A stronger expression was present in nerve fibers, particularly in PCa, in immune cells and in smooth muscle and endothelial cells of vessels of BPH and PCa. On mRNA levels, a slightly elevated expression of PTPIP51 was observed in the PCa group as tested by real-time quantitative PCR analyses. Methylation experiments revealed that at least 70% of methylated CpGs in the CpG island of the PTPIP51 gene promoter region were identified in BPH samples. In contrast, a loss of methylation has been found in the PCa group.

CONCLUSION

The promoter methylation status of PTPIP51 seems to influence the expression of PTPIP51, which was seen as elevated in the PCa.

Can prostate biopsies predict suitability for nerve‐sparing radical prostatectomy?

OBJECTIVE

The process for selecting patients suitable for nerve-sparing radical prostatectomy (NSRP) has been the source of much debate. In this study we analysed the use of prostate biopsies as the principal selection tool.

MATERIAL AND METHODS

Patients undergoing radical retropubic prostatectomy (n = 133) were retrospectively categorized as having "unilateral" (biopsy demonstrated malignancy confined to one side of the gland) or "bilateral" carcinoma. The accuracy and reliability of this categorization were determined by correlation with the final histopathology of the resected radical prostatectomy specimen.

RESULTS

Prostate biopsy suggested "unilateral" carcinoma in 30/58 (52%) and 45/75 (60%) patients diagnosed using transrectal ultrasound-guided (TRUS) and transperineal digital-guided (TP) routes, respectively. Subsequent analysis of the resected specimen, however, revealed "bilateral" malignancy in 50 patients (86%) in the TRUS group and in 63 (84%) in the TP group. Furthermore, positive surgical margins were identified on the "benign" side (by preoperative biopsy) in 6 (20%) patients in the TRUS subgroup whose biopsy had suggested "unilateral" carcinoma, and in 12 (27%) of the comparative TP subgroup.

CONCLUSIONS

Biopsy-suggested "unilateral" carcinoma was associated with both a high incidence of "bilateral" disease on final histology following radical prostatectomy and an alarming incidence (24%) of positive surgical margins on the "benign" side where NSRP might be advocated.

Denoising during optical coherence tomography of the prostate nerves via wavelet shrinkage using dual-tree complex wavelet transform

The dual-tree complex wavelet transform (CDWT) is a relatively recent enhancement to the discrete wavelet transform (DWT), with important additional properties. It is nearly shift-invariant and directionally selective in two and higher dimensions. In this letter, a locally adaptive denoising algorithm is applied to reduce speckle noise in time-domain optical coherence tomography (OCT) images of the prostate. The algorithm is illustrated using DWT and CDWT. Applying the CDWT provides improved results for speckle noise reduction in OCT images. The cavernous nerve and prostate gland can be separated from discontinuities due to noise, and image quality metrics improvements with a signal-to-noise ratio increase of 14 dB are attained.