Role of penile vascular injury in erectile dysfunction after radical prostatectomy

Evaluation of Age- and Radical-Prostatectomy Related Changes in Male Pelvic Floor Anatomy Based on Magnetic Resonance Imaging and 3-Dimensional Reconstruction

Purpose

Puborectalis muscles (PRM) and ischiocavernosus muscles (ICM) play important roles in urinary continence and male erectile functions. Understanding of anatomy and surgical-injury related changes to these muscles is critical to monitor changes in continence or erectile function. Anatomical description of these muscles has undergone revisions because these conclusions were derived from cadavers. Our objectives were to: (i) elucidate male pelvic muscles by in-vivo magnetic resonance imaging (MRI) and 3-dimensional (3-D) reconstruction of these images and (ii) compare PRM and ICM thickness in healthy volunteers and symptomatic patients.

Materials and Methods

Healthy young male (mean age, 25 years; n=5), older male (age, 65–70 years; n=5), and post-prostatectomy patients with erectile dysfunction and urinary incontinence (age, 65–70 years; n=5) were scanned on a 3T-magnetic resonance scanner. Images were acquired from slices above urinary bladder base to urethra entry into penis. Pelvic bone, bladder/urethra, corpus cavernosum, ICM, PRM, and prostate were segmented. 3-D models of each structure were generated and assembled into composite images, and ICM and PRM thicknesses were calculated.

Results

We successfully reconstructed 3-D male pelvic floor anatomy including ICM, PRM, bladder, urethra, bulbospongiosus, corpus cavernosa, prostate and bones from the two groups. We documented significant reduction in PRM and ICM thickness in older men.

Conclusions

This is perhaps the first 3-D reconstruction of male pelvic floor structures based on in-vivo MRI in healthy and symptomatic patients. Observed reduction in PRM and ICM thickness is possibly due to age-related atrophy.

Novel nomogram for the prediction of seminal vesicle invasion including multiparametric magnetic resonance imaging

OBJECTIVES

To create a model that predicts side-specific seminal vesicle invasion using clinical, biopsy and multiparametric magnetic resonance imaging data.

METHODS

We analyzed data from 544 patients who underwent robot-assisted radical prostatectomy at a single institution. To develop a side-specific predictive model, we ultimately considered four variables: prostate-specific antigen, highest ipsilateral biopsy Gleason grade, highest ipsilateral percentage core involvement and seminal vesicle invasion on multiparametric magnetic resonance imaging. A binary multivariable logistic regression model was fitted to predict seminal vesicle invasion. A nomogram was then built based on the coefficients of the resulting logit function. The leave-one-out cross validation method was used for internal validation, and the decision curve analysis for the evaluation of the net clinical benefit.

RESULTS

We relied on 804 side-specific cases after excluding negative biopsy observations (n = 284). Seminal vesicle invasion was reported on multiparametric magnetic resonance imaging in 41 (5%) cases, and on final pathology in 64 (8%) cases. All variables in the model emerged as predictors of seminal vesicle invasion (all P ≤ 0.001) and were subsequently considered to build a nomogram. The area under the curve of multiparametric magnetic resonance imaging alone in predicting seminal vesicle invasion was 59.1%; whereas one of the clinical variables only was 85.1%. The area under the curve of the nomogram resulting from their combination was 86.5%. After internal validation, this resulted in 84.7%. The model achieved good calibration and the decision curve analysis showed its clinical benefit, especially when compared with relying only on multiparametric magnetic resonance imaging prediction of seminal vesicle invasion.

CONCLUSIONS

A nomogram based on clinical and multiparametric magnetic resonance imaging data can predict seminal vesicle invasion and serve as a tool to urologists for surgical planning.

Inflatable penile prosthesis in the radical prostatectomy patient: a review

In the population of patients with prostate cancer, survivorship has come to the forefront of continuity-of-care. In addition to urinary control, erectile function is a significant issue after radical pelvic surgery. Penile prosthesis surgery remains an excellent option for restoring erectile function to those for whom more conservative measures have failed. This review article outlines the anatomical, surgical and post-operative consideration involved in the placement of a penile prosthesis in this special patient population.

Preoperative detection and localization of accessory pudendal artery with contrast-enhanced MR angiography

PURPOSE

To evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography for preoperative detection and localization of accessory pudendal arteries (APAs) in patients with prostate cancer.

MATERIALS AND METHODS

This prospective study was approved by the institutional review board, and informed consent was obtained. Between July 2007 and December 2010, 127 patients underwent contrast-enhanced MR angiography following prostate MR imaging at 3.0 T before robot-assisted laparoscopic radical prostatectomy (RALP). APAs were defined as any arteries located in the periprostatic region and anastomosed with the common penile artery or its branches; they were then subclassified into lateral and apical APAs. For detecting and localizing APAs, MR angiograms were evaluated prospectively by one reader and retrospectively by two independent blinded readers. Diagnostic performance was determined on a per-patient basis by using surgical findings as the reference standard. In addition, the origin of APAs identified at both surgery and contrast-enhanced MR angiography was determined by consensus of two retrospective readers. Interreader agreements were assessed by using k statistics.

RESULTS

At surgery, 19 APAs (seven right apical, three left apical, four right lateral, and five left lateral) were detected in 16 patients, and 16 of these APAs were localized in 13 patients at preoperative contrast-enhanced MR angiography. Prospectively, sensitivity, specificity, and accuracy of contrast-enhanced MR angiography for the localization of APAs were 81.3%, 93.7%, and 92.1%, while retrospectively they were 87.5%, 91.9%, and 91.3% for reader 2 and 75.0%, 90.1%, and 88.2% for reader 3, respectively. Overall interreader agreement was substantial (k = 0.795). Nine and seven APAs originated from the obturator artery and the inferior vesical artery, respectively.

CONCLUSION

Contrast-enhanced MR angiography can be used for the preoperative detection of APAs in patients with prostate cancer.

The incidence and anatomy of accessory pudendal arteries as depicted on multidetector-row CT angiography: clinical implications of preoperative evaluation for laparoscopic and robot-assisted radical prostatectomy

Objective

To help preserve accessory pudendal arteries (APAs) and to ensure optimal postoperative sexual function after a laparoscopic or robot-assisted radical prostatectomy, we have evaluated the incidence of APAs as detected on multidetector-row CT (MDCT) angiography and have provided a detailed anatomical description.

Materials and Methods

The distribution of APAs was evaluated in 121 consecutive male patients between February 2006 and July 2007 who underwent 64-channel MDCT angiography of the lower extremities. We defined an APA as any artery located within the periprostatic region running parallel to the dorsal vascular complex. We also subclassified APAs into lateral and apical APAs. Two radiologists retrospectively evaluated the origin, course and number of APAs; the final APA subclassification based on MDCT angiography source data was determined by consensus.

Results

We identified 44 APAs in 36 of 121 patients (30%). Two distinct varieties of APAs were identified. Thirty-three APAs (75%) coursed near the anterolateral region of the prostatic apex, termed apical APAs. The remaining 11 APAs (25%) coursed along the lateral aspect of the prostate, termed lateral APAs. All APAs originated from the internal obturator artery and iliac artery or a branch of the iliac artery such as the inferior vesical artery. The majority of apical APAs arose from the internal obturator artery (84%). Seven patients (19%) had multiple APAs.

Conclusion

APAs are more frequently detected by the use of MDCT angiography than as suggested by previous surgical studies. The identification of APAs on MDCT angiography may provide useful information for the surgical preservation of APAs during a laparoscopic or robot-assisted radical prostatectomy.

Erectile Dysfunction

Erectile dysfunction has been defined by the National Institutes of Health as the inability to achieve and/or to maintain an erection for satisfactory sexual intercourse. It may result from psychological or organic causes. With the advent of oral pharmacotherapy, the diagnostic approach has significantly changed over the past decade. The number of patients examined at the radiology clinics has also been decreased. However, evaluation by imaging modalities, such as color Doppler ultrasound, cavernosography, and angiography, still remains the cornerstone of the diagnostic workup of the patients with erectile dysfunction. The aim of this review was to focus briefly on the penile anatomy, the pathophysiology of erection, and radiological techniques for investigating vascular causes of erectile dysfunction and findings on different radiological methods.

Sexual function before and after radical retropubic prostatectomy: A systematic review of prognostic indicators for a successful outcome

OBJECTIVES

Erectile dysfunction is common after surgery for prostate cancer. Potency rates after radical retropubic prostatectomy (RRP) vary widely among different studies. Since the introduction of the nerve-sparing technique potency rates have increased. Erectile function recovery rates for selected groups of patients are high. However, studies from community practices have shown less favourable outcomes after RP.

METHODS

We have performed a systematic review of the literature concerning sexual function after RRP and focused on prognostic indicators for a successful sexual outcome.

RESULTS

Most important prognostic factors for the return of potency after RRP are preservation of the neurovascular bundles, age of the patient and sexual function before the operation. Neurogenic and vasculogenic factors seem to play an important role in the aetiology of the erectile dysfunction after surgery. The role of preserving the accessory pudendal artery is not certain, although some investigators found significant hemodynamic changes after sacrificing the accessory pudendal artery. Colour Doppler ultrasound studies in combination with intracavernous injection of vasoactive drugs or after PDE-5 inhibitors administration has shown to be a reliable test for vascular factors.

CONCLUSIONS

After bilateral nerve-sparing RRP sexual potency is preserved in 31-86% of sexually active men with organ-confined disease. The aetiology of impotence following RRP is multifactorial, but neurogenic factors seem to play a major role. Vascular factors may be of importance in selective cases. Colour Doppler ultrasound appears to be the most reliable, non-invasive diagnostic test for erectile dysfunction after RRP in patients who do not respond to pharmacotherapy.

Preoperative parameters, including percent positive biopsy, in predicting seminal vesicle involvement in patients with prostate cancer

PURPOSE

Complete dissection of the SVs during RP can contribute to increased morbidity including erectile dysfunction and incontinence. Therefore we evaluated the clinical parameters associated with a positive SV finding on final pathology and identified those patients with a minimal risk of SV involvement for potential SV sparing surgery.

MATERIALS AND METHODS

We retrospectively reviewed our RP database from 1991 to 1999 to evaluate the incidence and clinical correlates of SV invasion. Variables studied included preoperative total serum PSA, percent positive biopsy cores, DRE and biopsy Gleason score. Statistical analysis included univariate, multivariate regression analysis and ROC curves.

RESULTS

Of our 1,056 patients 79 (7.4%) had SV involvement. Of the 356 patients with less than 17% positive biopsies, only 2 (0.5%) had SV involvement on final pathology. Preoperative PSA, biopsy Gleason score and percent positive biopsies were all highly predictive of SV invasion on multivariate analysis. Percent positive biopsy was found to be the single best predictor of seminal vesicle invasion (p <0.0001).

CONCLUSIONS

In our series percent positive biopsy was the single best predictor of SV invasion at the time of RP. An analysis of preoperative parameters including percent positive biopsy, biopsy Gleason score and preoperative PSA may define a subset of patients in which prospective studies could be used to determine the value and safety of SV sparing surgery.

Is seminal vesicle ablation mandatory for all patients undergoing radical prostatectomy? A multivariate analysis on 1283 patients

OBJECTIVE

With a shift in prostate cancer stage and a majority of patients operated nowadays with PSA levels <10 ng/ml, rates of seminal vesicle (SV) invasion found on radical prostatectomy specimens have decreased as compared to historical data. Since SV-sparing surgery may possibly have an influence on post-operative erectile dysfunction and urinary recovery, we tried to determine which patients could be safely spared SV excision during radical prostatectomy.

MATERIAL AND METHODS

We used preoperative data from 1283 patients operated by radical retropubic prostatectomy--777 with serum PSA <10.0 ng/ml--to predict SV invasion on final pathological examination. Variables analyzed included age, digital rectal examination, serum PSA, biopsy Gleason score and percentage of biopsy cores invaded by prostate cancer. Statistical analysis included univariate, multivariate logistic regression analysis and receiver operating characteristic (ROC) curves.

RESULTS

Out of 1283 patients, 137 (10.6%) had SV involvement, 41/777 (5.2%) with PSA <10.0 ng/ml, 16.1% in the 10-20 ng/ml range and 26.2% when PSA was >20 ng/ml. Percentage of biopsies affected by prostate cancer and biopsy Gleason score were significant predictors of SV invasion in multivariate analysis, both in the entire population and in the subset of patients with PSA <10.0 ng/ml (p < 0.0001). Probability graphs created for patients with PSA <10 ng/ml indicate a risk of seminal invasion <5% when Gleason score on biopsy is <7 or when the percentage of biopsies affected by cancer is <50%.

CONCLUSIONS

Resection of SV might not be "oncologically" necessary in all patients undergoing RP when PSA levels are below 10 ng/ml except when biopsy Gleason score is > or =7 or when more than 50% of prostate biopsy cores show cancer involvement. SV-sparing surgery could be prospectively compared to standard retropubic prostatectomy in selected individuals analyzing potential benefits on erectile function and urinary continence.

Proerectile pharmacological prophylaxis following nerve-sparing radical prostatectomy (NSRP)

The importance of an early pharmacological prophylaxis for erectile function following nerve-sparing radical prostatectomy has been recently stressed by several authors. In spite of that, patient's compliance to erectile rehabilitation protocols seems to be low. The present review is an attempt to define the expected benefits of the currently proposed rehabilitative protocols in terms of cost-efficiency and quality of life. The conclusion is that current scientific evidence in support of an early postoperative use of erectile aids is based mainly on indirect proof of a cavernosal damage that may follow the temporary postoperative 'erectile silence'. Intracavernosal injections or a vacuum device may represent the best first-line treatment option for the first few months from the procedure as their mechanism of action does not require intact neural tissue for erection. Thereafter oral phosphodiesterase 5 inhibitor therapy may be a reasonable choice for those patients who can achieve at least a partial erection. A phosphodiesterase 5 inhibitor may not be effective when spontaneous erections are absent. It is possible, since the rehabilitation of sexual function aims to prevent cavernosal tissue damage by providing oxygenation to the erectile tissue, the choice of a potentially ineffective treatment may jeopardize the results of a reasonable nerve-sparing procedure.

Potency after unilateral nerve sparing surgery: a report on functional and oncological results of unilateral nerve sparing surgery

The objective of the study was to evaluate unilateral nerve sparing prostate surgery. Patient files of men who underwent unilateral nerve sparing radical prostatectomy were analyzed retrospectively after a minimum follow-up period of 18 months. Of 46 patients who received unilateral nerve sparing surgery, 14 (30.4%) regained full potency after surgery. In 92.9% of these patients, recovery occurred within a period of 18 months. Age is the single most important factor in the recuperation of potency after unilateral nerve sparing surgery. Most of the patients (84.8%) reported the ability to achieve orgasm. Of eight patients with positive section margins, two had positive section margins at the spared side only. Unilateral nerve sparing surgery remains a feasible treatment option for prostate cancer.

Is there an optimal time for intracavernous prostaglandin E1 rehabilitation following nonnerve sparing radical prostatectomy? Results from a hemodynamic prospective study

PURPOSE

Previous studies have shown that early intracavernous prostaglandin E1 injection may reduce significantly the incidence of veno-occlusive dysfunction before spontaneous erections recover after nerve sparing radical prostatectomy. We identify the more convenient postoperative timing for successful intracavernous injection rehabilitation in a series of patients who underwent nonnerve sparing radical prostatectomy.

MATERIALS AND METHODS

A total of 73 patients with a normal preoperative International Index of Erectile Function score were randomly allocated to undergo dynamic color Doppler ultrasound study 20 mg. prostaglandin E1 at 1, 2 to 3, 4 to 6 and 7 to 12 months postoperatively, respectively. In all cases the peak systolic velocity, end diastolic velocity and resistance index were evaluated at 5, 10 and 20 minutes after injection.

RESULTS

Of the patients 36 received the intracavernous injection within the first 3 months (group 1) and 37 received it at 4 to 12 months (group 2). A significantly higher proportion of group 1 patients had grade 3 erection compared with group 2. Peak systolic velocity less than 30 cm. per second in at least 1 cavernosal artery was recorded in 22.2% of group 1 patients and 51.3% of group 2 (p >0.05).

CONCLUSIONS

Intracavernous injections after nonnerve sparing radical prostatectomy produce valid erectile responses in a significantly higher proportion of patients when started within month 3 after the operation. Injection given in postoperative month 1 gives the best response rate but with significant complications and poor patient compliance. Arteriogenic and venogenic factors seem to be involved with failure.

Erectile function after radical prostatectomy: a review

OBJECTIVES

Although the high rate of erectile dysfunction (ED) following prostatectomy is well recognised, the aetiology and pathophysiology have not yet been fully elucidated. We examined the current literature as to aetiology, treatment and possible prevention of ED following prostatectomy.

METHOD

Review of the literature by a Medline search.

CONCLUSION

The most important predictors of erectile function are pre-operative erectile function and the nerve sparing nature of the procedure. The former is determined by age and vascular risk-factors whereas the latter is decided by the stage of the tumour and the skill of the surgeon. The value of intraoperative nerve mapping seems limited and the importance of nerve grafting is uncertain. Natural recovery of erection can take as long as 24 months. Patients complain about a lack of professional support. Symptomatic therapy may be applied according to the current general standards of treatment in men with ED.

Is sildenafil failure in men after radical retropubic prostatectomy (RRP) due to arterial disease? Penile duplex Doppler findings in 174 men after RRP

Sildenafil is frequently the first-line treatment for post-radical retropubic prostatectomy (RRP) erectile dysfunction (ED) with maximum treatment satisfaction rates of 43%-80%. The etiology of erectile dysfunction after RRP has been attributed to psychogenic, vascular, veno- occlusive or nerve injury causes. The purpose of this study was to gain insight into the penile duplex Doppler arterial parameters in men with ED after RRP who failed sildenafil. The purpose was to assess whether sildenafil failure after RRP is associated with underlying corporal arterial disease. A total of 174 consecutive men presenting with sildenafil refractory ED after nerve-sparing RRP underwent color duplex penile Doppler evaluation with vasoactive injection. Mean age was 59.6 y and mean time from surgery was 11.6 months. Some 81% (141/174) of the men had no pre-operative ED (PED). Significant differences in penile duplex Doppler parameters for arterial disease were seen between men with and without PED. In men without PED, 19% (27/141) manifested arterial insufficiency. However, in men with PED, 50% (16/33) demonstrated arterial disease. Nerve sparing status did not affect the presence of arterial disease. Sildenafil refractory erectile dysfunction after RRP in men without PED is not predominantly associated with penile Doppler parameters consistent with arterial insufficiency.

Erectile dysfunction after radical prostatectomy: hemodynamic profiles and their correlation with the recovery of erectile function

PURPOSE

Despite the advent of nerve sparing radical prostatectomy some men experience erectile dysfunction. Many of these men have vasculogenic erectile impairment in the form of arterial insufficiency or venous leakage. Recent data imply that early postoperative injection therapy may decrease the rate of erectile dysfunction. We defined hemodynamic patterns in patients who underwent bilateral nerve sparing radical prostatectomy to assess the chronology of venous leakage development and explore the correlation of hemodynamic profiles with the return of functional erection 12 months postoperatively.

MATERIALS AND METHODS

Patients with excellent preoperative erectile function who underwent bilateral nerve sparing surgery and had no pharmacological support for erectile dysfunction in the initial 12 months after surgery received vascular evaluation at presentation. Vascular evaluation involved cavernosometry or penile ultrasonography. Patients were then interviewed again at least 12 months postoperatively to assess the ability to achieve sexual intercourse.

RESULTS

Our study group comprised 96 men with a mean age plus or minus standard deviation of 54 +/- 12 years who met all inclusion criteria. All patients had pathologically proved organ confined disease. Mean time to the initial postoperative presentation was 6 +/- 5 months. Patients were divided into 4 groups according to the time of vascular studies postoperatively, namely less than 4 to 8, 9 to 12 and greater than 12 months. Normal vascular status, arterial insufficiency and venous leakage were diagnosed in 35%, 59% and 26% of the group, respectively. No difference in the incidence of arterial insufficiency was noted in the 4 time groups. Time postoperatively was significantly associated with the incidence of venous leakage (14% at less than 4 months and 35% at between 9 and 12). In regard to the correlation of the vascular diagnosis with the return to functional erection 47% of the normal, 31% of the arteriogenic and 9% of the venous leakage group achieved sexual intercourse 12 months postoperatively.

CONCLUSIONS

These data imply that the longer the duration of erectile dysfunction after radical prostatectomy, the greater the risk of venous leakage. Furthermore, it appears that the prognosis for the return of functional erection is worst when venous leakage is present.

Intraoperative, perioperative, and long-term complications of radical prostatectomy

With improved surgical technique and perioperative care, the intraoperative and early postoperative complications of radical prostatectomy have decreased over the last 2 decades. Incontinence and impotence are two of the most significant long-term complications related to this procedure. Although the wide range of incontinence and impotence rates reported has been attributed to multiple factors, including the method of data collection and patient selection, it is apparent that the surgeon's experience is a significant factor, and that lower long-term morbidity can be expected from centers with more experience with radical prostatectomies. The impact of long-term complications, including urinary and sexual dysfunction, on the quality of life may be less than previously reported and should be discussed with patients.

Effect of radical retropubic prostatectomy on erectile function, evaluated before and after surgery using colour Doppler ultrasonography and nocturnal penile tumescence monitoring

OBJECTIVE

To assess the effect of radical retropubic prostatectomy on erectile function, by evaluating objectively patients' erectile function before and after surgery.

PATIENTS AND METHODS

The study comprised 126 patients with clinically localized prostate cancer who were scheduled to undergo radical retropubic prostatectomy. After giving informed consent for the study, 123 patients underwent intracavernosal injection tests, colour Doppler ultrasonography and nocturnal penile tumescence monitoring before and after surgery.

RESULTS

From the intracavernosal injection tests and nocturnal penile tumescence monitoring, 21 patients (17%) were evaluated as having normal erectile function before surgery. After radical retropubic prostatectomy, nine (43%) of these 21 potent men had preserved erectile function. In eight patients whose neurovascular bundles were preserved, five were potent after surgery. The cause of erectile function after surgery was a neurogenic disorder in seven and a related vascular disorder in five.

CONCLUSION

From objective tests of erectile function on patients scheduled to undergo radical prostatectomy, 17% had normal erectile function. However, even after nerve-sparing radical retropubic prostatectomy, the proportion retaining potency was unsatisfactory. Although a neurological disorder was the main cause of erectile dysfunction after surgery, vascular disorders were also important.

Bilateral nerve graft during radical retropubic prostatectomy: 1-year followup

PURPOSE

With the interposition of a sural nerve graft to replace resected cavernous nerves at radical retropubic prostatectomy, we have previously reported the return of effective erectile function. We determine the efficacy of this procedure in a series of men with at least 1-year followup.

MATERIALS AND METHODS

A total of 12 potent men (mean age plus or minus standard deviation 57 +/- 6 years) with clinically localized prostate cancer underwent radical retropubic prostatectomy, with deliberate wide bilateral neurovascular bundle resection and placement of bilateral nerve grafts. A series of patient and partner erectile dysfunction questionnaires, and patient interviews were performed at 3, 6, 12 and 18 months postoperatively. Only results for those men with a followup of 12 months or greater (mean 16 +/- 4) are presented. A control group of 12 men who had undergone bilateral nerve resection but declined nerve graft placement, was also followed.

RESULTS

Of the 12 men 4 (33%) had spontaneous medically unassisted erections sufficient for sexual intercourse with vaginal penetration. An additional 5 (42%) men describe "40 to 60%" spontaneous erections, with fullness, no rigidity and not able to penetrate. Overall, 9 (75%) men had return of erectile activity. No demonstrable erections occurred before 5 months postoperatively. The greatest return of function was observed at 14 to 18 months after surgery.

CONCLUSIONS

This surgical technique has minimal morbidity and represents a significant advance in prostate cancer surgery in men requiring bilateral nerve resection. Our study clearly demonstrates recovery of erectile function in men who underwent bilateral nerve graft placement during radical retropubic prostatectomy when both cavernous nerves were deliberately resected.

A simple and reliable monitoring system to confirm the preservation of the cavernous nerves

BACKGROUND

It is important to establish a procedure with which to confirm the preservation of the cavernous nerves during nerve-sparing radical surgery. For this purpose, we examined changes in intracavernous pressure (ICP) following electrical stimulation of the neurovascular bundle (NVB) with respect to the continuity of the cavernous nerves.

METHODS

Six cases of radical prostatectomy and eight cases of radical cystoprostatectomy were examined. In all cases, prior to prostate removal, electrical stimulation of the site where the NVB was determined to run was performed and the changes in ICP measured. In eight cases, ICP changes were also measured following prostate removal.

RESULTS

Prior to prostate removal, ICP changes could be measured in all 28 sides of 14 cases. These changes were classified into two patterns: stimulation-related increases of convex waveform (t1) were observed in 24 sides (85.7%); and waveforms with reversed type (t2), which was thought to be an incomplete type t1, were observed in four sides (14.3%). There were no ICP changes following non-sparing or incomplete sparing of NVB macroanatomically. Of five sides where the NVB was supposedly completely preserved macroanatomically, ICP changes consisted of type t1 on three sides, t2 on one side and type t2 or no change on a single side. All measurements were obtained within 10 min. Neither electrical stimulation nor measurement of ICP caused any adverse effects.

CONCLUSION

Intraoperative stimulation of the NVB while monitoring ICP changes provides a simple and reliable method of accurately evaluating the preservation of the cavernous nerves.

Erectile dysfunction following radical therapy for prostate cancer

With the earlier detection of prostate cancer and the increasing demand for treatment of organ-confined dizease, quality of life issues are becoming more important. Development of erectile dysfunction (ED) following radical therapy is a particular concern, and occurs in perhaps a third of patients treated by radiotherapy and 30-70% of patients treated by radical prostatectomy. Although it is assumed that the ED relates to damage to the nerves subserving erection, this view has been questioned recently and in at least a proportion of patients the cause appears to be vascular. Despite the likely cause of their ED, all patients presenting with ED after treatment for prostate cancer should undergo assessment by history and examination to ensure that there are no other correctable risk factors. Patients can then be considered for a number of treatment options, and currently sildenafil (Viagra, Pfizer) is usually used as first-line therapy assuming there are no contraindications, such as severe ischaemic heart disease or nitrate therapy. Sildenafil improves erectile function in 70% of patients with ED post-radiotherapy, but appears less effective in men after radical prostate surgery with a response rate of 40-50%. Other treatment options include self-injection or intra-urethral administration of alprostadil, and some patients are happy to use a vacuum erection device. Finally, if all else fails, patients may be suitable for penile implant surgery.

Assessment of the functional role of accessory pudendal arteries in erection by transrectal color Doppler ultrasound

PURPOSE

Anatomical studies have demonstrated accessory pudendal arteries originating from supralevator vessels in about two-thirds of men. Injury to accessory pudendal arteries derived from inferior vesical and obturator arteries has been reported to be responsible for vasculogenic impotence after nerve sparing radical prostatectomy. We performed transrectal and perineal color Doppler ultrasound in patients before radical pelvic surgery to identify accessory pudendal arteries and assess their functional role during erection.

MATERIALS AND METHODS

A total of 12 patients with a mean age of 60 years were examined before radical prostatectomy (10) or cystoprostatectomy (2). Transrectal and perineal color Doppler flow imaging and spectral waveform analysis were performed. Peak systolic velocity, end diastolic velocity, resistive index and arterial diameter were measured before and during pharmacologically induced erection. Transrectal color Doppler ultrasound data were compared with intraoperative findings.

RESULTS

Transrectal color Doppler ultrasound visualized accessory pudendal arteries derived from supralevator arteries in 9, and prostatic and seminal vesicle arteries in all patients. Perineal color Doppler ultrasound visualized internal pudendal arteries in all patients. After intracavernosal injection of papaverine accessory and internal pudendal arteries displayed similar significant hemodynamic changes. Diameter as well as peak systolic and end diastolic velocities increased, and resistive index decreased. Prostatic and seminal vesicle arteries showed no significant change. Presence and location of accessory pudendal arteries demonstrated by transrectal color Doppler ultrasound were confirmed by intraoperative findings.

CONCLUSIONS

During pharmacologically induced erection hemodynamic changes in accessory and internal pudendal arteries are similar to those described in cavernous arteries, thus demonstrating the functional role of accessory pudendal arteries in penile erection. Color Doppler ultrasound appears to be reliable to examine internal and accessory pudendal arteries based on morphological and functional criteria.

Supra and infralevator neurovascular pathways to the penile corpora cavernosa

The aim of this study was to provide a comprehensive description of both penile innervation and vascularisation. Eighty-five male cadavers were examined through gross and microscopic anatomical analysis. The pelvic nerve plexus had both parasympathetic and sympathetic roots. It was distributed to the external urethral sphincter giving rise to cavernous nerves which anastomosed in 70% of the cases with the pudendal nerve in the penile root. Accessory pudendal arteries were present in the pelvis in 70% of the cases, anastomosing in 70% of the cases with the cavernous arteries that originated from the pudendal arteries. Transalbugineal anastomoses were always seen between the cavernous artery and the spongiosal arterial network. There were 2 venous pathways, 1 in the pelvis and 1 in the perineum with a common origin from the deep dorsal penile vein. It is concluded that there are 2 neurovascular pathways destined for the penis that are topographically distinct. One is located in the pelvis and the other in the perineum. We were unable to determine the functional balance between these 2 anastomosing pathways but experimental data have shown that they are both involved in penile erection. These 2 neurovascular pathways, above and below the levator ani, together with their anastomoses, form a neurovascular loop around the levator ani.

Intraoperative electrical stimulation of cavernosal nerves with monitoring of intracorporeal pressure in patients undergoing nerve sparing radical prostatectomy

OBJECTIVE

To explore the utility of intraoperative cavernosal nerve stimulation in facilitating atraumatic nerve dissection during radical prostatectomy, and thus help predict postoperative erectile function.

PATIENTS AND METHODS

Fourteen patients (aged 51-72 years) underwent nerve-sparing radical retropubic prostatectomy (NSRRP); 10 were potent before surgery (group 1), and four had erectile dysfunction (group 2). A multi-acquisition system (MacLab/8e) with a Macintosh computer was used for real-time display and recording of intracavernosal pressure (ICP) during surgery. Nerves were stimulated with a bipolar probe (monophasic rectangular pulses, 10 mA, 20 Hz, 0.22 s) before and after removal of the gland. The follow-up consisted of interviews with patients and their partners' 12-18 months after treatment.

RESULTS

The mean (sem) basal ICP of 8. 0 (2.0) cmH2O remained unchanged during nerve dissection. The mean increase in ICP during electrical stimulation was >50 cmH2O in seven potent patients (group 1) and was sustained as long as the nerve was stimulated. Postoperatively, these seven patients reported erections sufficient for sexual intercourse. However, the three remaining patients in group 1 had pressure rises of <30 cmH2O, of whom two reported partial erections and one reported total impotence postoperatively. The recovery time for erectile function was 6-12 months after surgery. Two patients from group 2 had transient increases in ICP to <40 cmH2O; one had an increase to 20 cmH2O and one had no response at all. All four patients remained totally impotent postoperatively. There were no complications.

CONCLUSIONS

Intraoperative electrical stimulation of the cavernosal nerves with ICP monitoring before and after NSRRP is a safe and reliable method for documenting nerve continuity and its functional status. Patients who have normal preoperative erectile function and show an adequate rise in ICP upon electrical nerve stimulation during NSRRP will almost certainly be potent after surgery. This tool may be used to facilitate atraumatic nerve dissection during NSRRP.

Current concepts in the management of post‐radical prostatectomy impotence

Erectile dysfunction after radical retropubic prostatectomy has a multifactorial aetiology, including both neurogenic and vasculogenic factors. Postoperative potency is improved with preservation of the neurovascular bundles in a nerve-sparing procedure. Preoperative and intraoperative identification and preservation of accessory pudendal arteries may also improve postoperative potency rates. The early institution of treatment with intracavernous alprostadil appears to improve postoperative potency rates. Treatment with newer therapeutic agents, such as Sildenafil and Invicorp, are both efficacious and well tolerated.

Intracavernous pressure responses to physical and electrical stimulation of the cavernous nerve in rats

OBJECTIVES

To better define the techniques of nerve-sparing prostate dissection that would result in preservation of erectile function, we characterize the effects of physical pressure on the prostate and cavernous nerve, electrical stimulation of the cavernous nerve, and pharmacologic manipulations on intracavernous pressure (ICP) in normal and diabetic rats.

METHODS

Fischer-34 rats, both normal and diabetic, underwent dissections that isolated the cavernous bodies and cavernous nerves. Cavernous body pressures were characterized during surgical manipulation, during electrical stimulation of the cavernous nerves, and following papaverine hydrochloride injection.

RESULTS

In normal rats, baseline cavernous pressures ranged from 5 to 15 cm H2O (mean 12.29). In diabetic rats, the baseline pressure was significantly lower (3 to 7.5 cm H2O). Lateral nerve displacement caused ICP to rise to approximately 35 cm H2O in normal rats, but only to 20 cm H2O in diabetic rats. Electrostimulation resulted in cavernous pressure increases of 10-fold from baseline in normal rats and sevenfold from baseline in diabetic rats. ICPs were not disturbed appreciably with nerve-sparing dissection techniques. Neurotomy resulted in declines in baseline cavernous pressures in all rats. Electrostimulation of the distal end of a severed nerve resulted in pressure rises to 50% of those observed in rats with intact cavernous nerves. Intracavernous papaverine injection before or after nerve stimulation masked subsequent (expected) pressure changes.

CONCLUSIONS

A change in cavernous pressure is a sensitive indicator of cavernous nerve manipulation. Both cavernous pressure measurements and electrostimulation of cavernous nerves may aid surgeons during radical prostatectomy.

Penile arteries in humans. Origin--distribution--variations

The arterial supply to the penis remains unclear. The frequency of occurrence and functional significance of accessory pudendal arteries remains controversial and it has been suggested that the presence of variations is correlated with atheromatous disease involving internal pudendal arteries. We dissected pelvic and penile arteries in 20 adult fresh male cadavers. The results are expressed according to age and the presence of atherosclerosis. Three patterns of penile arterial supply can be described: type I arising exclusively from internal pudendal arteries (3/20), type II arising from both accessory and internal pudendal arteries (14/20) and type III arising exclusively from accessory pudendal arteries (3/20). This study emphasizes the findings previously reported by early anatomists. No correlation between the presence of accessory pudendal arteries and the extent of atheroclerosis was observed. Accordingly we postulate that these variations are usually congenital. Terminal branches of accessory pudendal arteries mainly supply the corpora cavernosa. As they are located very close to the prostate, the risk of injury is high during radical prostatectomy. The possibility of impotence from such injury after radical prostatectomy needs therefore to be reconsidered.

Intraoperative electrostimulation of the cavernous nerve: technique, results and limitations

PURPOSE

We studied the feasibility of inducing penile erection intraoperatively by stimulation of the cavernous nerves.

MATERIALS AND METHODS

In 16 men undergoing retropubic radical prostatectomy and 6 undergoing penile surgery for venous leakage electrostimulation was applied to both sides of the prostatic apex (prostatectomy group) or the hilum of the penis (venous surgery group).

RESULTS

Electrostimulation produced visible erection in 8 of the 16 prostatectomy patients and an increase in intracavernous pressure in 5 of the 6 venous surgery patients.

CONCLUSIONS

Electrostimulation of the cavernous nerves intraoperatively to produce penile erection is feasible. However, the technique must be further refined to be clinically useful, that is to localize the neurovascular bundle in men undergoing prostatectomy.

Radical retropubic prostatectomy: the influence of accessory pudendal arteries on the recovery of sexual function

Arterial insufficiency is a major factor responsible for impotence in men following nerve sparing radical prostatectomy. Previously, accessory internal pudendal arteries have been identified traveling over the anterolateral surface of the prostate. Based on this observation, during the last 7 years we have consistently looked for the presence of these arteries and have developed a surgical technique for their preservation. Between 1987 and 1994, 835 potent men underwent radical prostatectomy and accessory pudendal arteries were identified in 33 (4%). Following the development of the surgical technique, it was possible to preserve arteries in 19 of 24 patients (79%). Followup evaluation of 1 year or longer was available for 22 men who did not undergo wide excision of a neurovascular bundle. Recovery of erection sufficient for unassisted intromission and orgasm occurred in 8 of 12 patients (67%) in whom the arteries were preserved and in 5 of 10 (50%) in whom the arteries were sacrificed. We conclude that 1) the presence of accessory internal pudendal arteries is rare (4%); 2) although these arteries were preserved in 79% of the patients, dissection of these arteries from the dorsal vein complex may be associated with excessive bleeding, and 3) because potency rates are similar in men with or without preservation of accessory arteries, routine preservation may not be productive.

Impact of prostate size on the outcome of transurethral laser evaporation of the prostate for benign prostatic hyperplasia

OBJECTIVES

The aim of this study was to evaluate efficacy and safety of transurethral evaporation of the prostate (TUEP) using neodymium:yttrium-aluminum-garnet (Nd:YAG) laser in prostate glands of various sizes.

METHODS

One hundred consecutive patients with benign prostatic hyperplasia (BPH) and prostate volumes less than 40 cc (group I, n = 41), 41 to 80 cc (group II, n = 39), and more than 80 cc (group III, n = 20), who had preoperative prostate volume estimation by transrectal ultrasound and had completed a minimum of 3 months' follow-up, underwent TUEP. At baseline, and at 3 and 6 months, American Urological Association (AUA) score, peak flow rate (PFR), postvoid residual urine (PVR), and complications, if any, were documented.

RESULTS

There were no significant differences in failure rates, complications, or ability to improve symptom score, PFR, and PVR between patients with prostate glands of various sizes. The mean improvement in PFR at 6 months was: group I, 9.9 cc/s (116%); group II, 7.4 cc/s (81%); and group III, 9.2 cc/s (107%). Reduction in AUA score was: group I, 14.6 (63%); group II, 17.7 (71%); and group III, 16.2 (70%). PVR was: group I, 62.5 cc (51%); group II, 31.4 cc (16%), and group III, 71 cc (83%) (differences not significant). The patients in urinary retention were separately analyzed (group I, 9, group II, 12, and group III, 5) and mean PFR at 6 months was: group I, 18.5 cc/s, group II, 15 cc/s, and group III, 17.1 cc/s. Mean AUA score at 6 months was: group I, 25.8; group II, 21; and group III, 23.6. Mean PVR score was: group I, 370 cc, group II, 439 cc; and group III, 400 cc (differences not significant). Mean postoperative catheterization time was higher in patients with glands larger than 80 cc (2.2 versus 2.9 versus 4.7 days in groups I, II, and III, respectively, P < 0.009 between groups II and III). Incidence of urinary tract infection (10 versus 0%) was greater in patients receiving only 48-hour as opposed to 10-day postoperative antibiotics.

CONCLUSIONS

TUEP appears to be a safe and effective treatment for relief of symptoms of BPH and improvement of PFR in patients with all sizes of prostate glands.

Self-assessment questionnaire for evaluating urinary and intestinal late side effects after pelvic radiotherapy in patients with prostate cancer compared with an age-matched control population

BACKGROUND

Pelvic irradiation to patients with prostate cancer is accompanied by urinary and intestinal reactions. In men older than 60 years, treatment-induced problems should be evaluated in relation to problems in an age-matched nonirradiated population.

METHODS

In the present study, problems in the urinary tract and intestine were evaluated with a self-assessment questionnaire using the linear-analogue scale. The questionnaire was mailed out to 200 patients and to an age-matched population 24-56 months after irradiation.

RESULTS

Twenty-five percent of the control group and 50% of the patient group reported some kind of problem in the urinary tract. The most common urinary problems in the control group and in the patient group, respectively, were urgency (19 and 42%), starting problems (22 and 33%), and leakage (11 and 32%). In the control and patient groups, 14 and 59%, respectively, reported some kind of gastrointestinal problems. The most common intestinal problems in the control and patient groups were respectively, mucus (4 and 38%), cramp (5 and 14%), leakage (2 and 27%), and blood (2 and 36%). Ninety percent of the patients' problems were minor.

CONCLUSION

Pelvic irradiation induced a relatively large number of minor problems, evaluated with a self-assessment questionnaire and compared with an age-matched population of men, of approximately similar magnitude as with a physician's systematic evaluation. The most important urinary factors were urgency and leakage. The most important intestinal factors were blood, mucus, and leakage. The results support the ongoing efforts to use 3-D computed tomography-based conformal therapy to decrease irradiation dose to the rectum and bladder.