Are stents still a useful therapy for benign prostatic hyperplasia?

Putting Patients Ahead by Leaving Nothing Behind: An Emerging Treatment Paradigm in Minimally Invasive Surgical Therapy for Benign Prostatic Hyperplasia

Lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) are highly prevalent in older men. The long-term clinical utility of lifestyle modification and oral medications for LUTS is limited. There is a great clinical need for safe, effective, and durable BPH therapies for men who unsuccessfully attempt conservative measures. Enthusiasm for transurethral resection of the prostate has declined due to surgical risk, high rates of postoperative sexual dysfunction, and the perceived invasive nature therein. Consequently, interest has grown in developing minimally invasive surgical treatments (MISTs) that are efficacious but with a more favorable risk profile in order to better align with patient preferences. This review evaluates currently available MISTs for BPH. Further, we critically examine a "Leave Nothing Behind" philosophy in MIST for BPH since implantation of permanent metallic devices may be associated with increased long-term failure rates.

[Influence of urethral self-dilatation on the morbidity of the artificial urinary sphincter after endoscopic treatment of recurrent stenosis of the vesicourethral anastomosis]

OBJECTIVE

To analyze the morbidity of the practice of daily self-dilatation (SD) in patients undergoing total prostatectomy, who have had artificial urinary sphincter (AUS) for urinary incontinence (UI) and who have had a recurrence of endoscopically treated vesicourethral anastomosis (VUS) stenosis.

MATERIALS AND METHOD

One hundred and thirty-eight patients with SUA for urinary incontinence (UI) fitted between 1998 and 2007 were divided into two groups. Thirty-five patients have had used self-dilatation (SD) for recurrent anastomotic stenosis (SD group) and 103 patients did not perform SD (non-SD group). These two groups were compared for explantation rate (erosion-infection), revision rate (urethral atrophy and mechanical failure) and 2-year functional results. The uni- and multivariate statistical analysis taken into consideration confounding factors such as age and radiotherapy history. The functional assessment was done by the validated IQoL, Ditrovie and MHU tests.

RESULTS

Patients in both groups were comparable except for the importance of urinary incontinence assessed by PAD test and questionnaires. The explantation rate was significantly higher in the "SD" group (28.5% vs 7.77%) and (OR=4.68, 95% CI [1.490-15.257], P=0.006). There was no significant difference between the two groups in the surgical revision rate (32% vs 20%, OR=0.44, P=0.09). The functional results at two years did not show any significant difference.

CONCLUSIONS

The use of self-dilation for recurrence of stenosis of vesicourethral anastomosis after prostatectomy exposes patients fitted with an SUA to a higher explantation rate.

LEVEL OF EVIDENCE

3.

Minimally invasive surgical therapies for benign prostatic hypertrophy: The rise in minimally invasive surgical therapies

The prevalence of benign prostatic hypertrophy (BPH) causing bothersome lower urinary tract symptoms increases with our ageing population. Treatment of BPH traditionally begins with medical therapy and surgical intervention is then considered for those whose symptoms progress despite treatment. Minimally invasive surgical therapies have been developed as an intermediary in the treatment of BPH with the aim of decreasing the invasiveness of interventions. These therapies also aim to reduce morbidity and dysfunction related to invasive surgical procedures. Multiple treatment options exist in this group including mechanical and thermo-ablative strategies. Emerging therapies utilizing differing technologies range from the established to the experimental. We review the current literature related to these minimally invasive therapies and the evidence of their effectiveness in treating BPH. The role of minimally invasive surgical therapies in the treatment of BPH is still yet to be strongly defined. Given the experimental nature of many of the modalities, further study is required prior to their recommendation as alternatives to invasive surgical therapy. More mature evidence is required for the analysis of durability of effect of these therapies to make robust conclusions of their effectiveness.

Evaluation of the anti-migration effect of barbed prostatic stents: in vitro study in urethra-mimicking bovine pericardium phantoms

PURPOSE

This study was designed to compare the migration rates of covered stents with eight, four, and zero barbs in urethra-mimicking bovine pericardium models.

METHODS

Three types of polytetrafluoroethylene-covered retrievable self-expandable prostatic stents, with eight, four, and zero barbs, were tested in bovine pericardium models, consisting of normal saline-filled acrylic containers with tubes at both ends and a replica of the human urethra. The barbs were 2 mm in length and projected 60° toward the urinary bladder. The anti-migration force (AMF) and resistance force against stent removal (RFSR) were measured by an automatic push-pull gauge system at a fixed rate (2 mm/s).

RESULTS

Significant differences in AMF among the three stent types were detected (P < 0.001). Median AMF was far greater for eight-barbed than for four-barbed stents (11.96 vs. 7.55 N, P = 0.003). For stent removal, the difference between 4- and 8-barbed stents were not significant in median static (5.54 vs. 6.08 N, P = 0.15) or sliding (prostatic urethra, 5.32 vs. 5.59 N, P = 0.65; membranous urethra, 7.78 vs. 8.57 N, P = 0.364) RFSR. No perforations or scratched traces were observed during removal of these stents.

CONCLUSIONS

The inclusion of eight barbs projecting 60° toward the urinary bladder were not only effective against stent migration in this model but suggests that these stents may be suitable for the treatment of prostatic urethral strictures without severely irritating the tissue. However, whether these results translate into living urethral tissue is unclear, necessitating further studies.

Critical appraisal of the Spanner™ prostatic stent in the treatment of prostatic obstruction

The Spanner™ stent was first used in patients to relieve bladder outlet obstruction (BOO), and has recently been used in patients following transurethral microwave thermotherapy and men unfit for surgical intervention. We review the current literature on the role of the Spanner stent in treating prostatic obstruction compared to previously reported cases involving the use of temporary stents. The Spanner stent has been found to be successful in treating patients with bladder outlet obstruction from benign prostatic hyperplasia and following high-energy transurethral microwave thermotherapy (TUMT). Patients with the Spanner stent had an increase in peak flow rate and a decrease in post void residual and International Prostate Symptom Scores. In patients treated with TUMT, quality of life measures indicate that the Spanner stent shows increased ease of bladder drainage, decreased leakage, and no adverse effect on daily activities. In patients unfit for surgery, however, there was increased retention and pain requiring stent removal in 63% of cases. The Spanner stent offers ease of insertion with a decrease in voiding symptoms in selected patients. Based on limited data, the Spanner stent has been recommended as a treatment option for men with BOO following TUMT. However, it is not a good treatment option for men unfit for surgery based on an increased incidence of urinary retention and dysuria. The Spanner stent is the only currently approved temporary stent and, based on a literature review, it does not offer significant advantage over previously used temporary stents. It is notable that most researchers have not evaluated the role of detrusor function on the outcomes.

Clinical relevance of urethral stents (Urospiral 2™) placement in patients with prostatic obstacle and concomitant high-risk surgical status or neurological diseases: a feasibility and safety study

AIMS

To review the indications and to assess the functional outcomes after placement of a new temporary urethral stent (TUS) in men with lower urinary tract dysfunction.

METHODS

We retrospectively reviewed the data of men with prostate obstruction and concomitant high-risk surgical status or neurological diseases between 2006 and 2008. TUS placement was performed with Urospiral 2™ which is a temporary, non-expanding, transprostatic stent. Success was defined as follows: when TUS placement allowed patients to void spontaneously and/or when surgery was made feasible after the period of relative contraindication (therapeutic group) or when TUS placement allowed physicians to define the role of prostate obstruction in the patients' voiding disorders and therefore to make an appropriate therapeutic decision (diagnosis group).

RESULTS

We included 94 men with a mean age of 73.3 ± 9 years (48-99) and 5 of them were lost to follow-up. The mean follow-up was 148 ± 100 days (2-1,046) and the mean duration of TUS placement was 155 ± 90 days (2-1,045). After a mean hospital stay of 4.8 ± 3 days (1-31), 84 patients (89%) had recovered spontaneous micturition. In the therapeutic group and the diagnosis group, 23 patients (92%) and 45 patients (70%) voided spontaneously, respectively.

CONCLUSIONS

TUS placement may be proposed temporarily in selected patients with static bladder outlet obstruction due to an enlarged prostate as it allows patients to avoid the use of an indwelling catheter.

Use of a temporary prostatic stent after transurethral microwave thermotherapy reduced voiding symptoms and bother without exacerbating irritative symptoms

OBJECTIVES

To evaluate the ability of a temporary prostatic stent (Spanner [Sp]) to manage voiding symptoms, irritative symptoms, and bother after transurethral microwave thermotherapy (TUMT) for prostatic obstruction.

METHODS

Patients were randomized to the Sp (n = 100) or standard of care (SOC, n = 86) after TUMT with 3 to 10 days of routine catheterization. We evaluated International Prostate Symptom Score (IPSS) voiding subscore, IPSS irritative subscore, voiding diary data, and Benign Prostatic Hyperplasia Impact Index (BII) 7 to 10 days before TUMT and repeated them 1, 2, 4 (stent removal), 5, and 8 weeks after stent insertion.

RESULTS

After 1 week of stent use, the Sp group experienced significantly greater improvements in the IPSS voiding subscore (Sp = -4.9 versus SOC = -2.3, P = 0.002) and individual voiding symptoms assessed by the IPSS (intermittency, weak stream, and straining) and voiding diary data (stream strength, and strain). After 2 weeks, the Sp group showed a trend toward greater improvements in IPSS voiding (P = 0.059) and irritative (P = 0.058) subscores and reported significantly less bother (BII, Sp = -2.1 versus SOC = -1.1, P = 0.033). After stent removal, the Sp group reported significantly greater improvements in the IPSS irritative subscore (5 weeks: Sp = -4.0 versus SOC = -2.7, P = 0.029; 8 weeks: Sp = -5.0 versus SOC = -4.0, P = 0.050), individual voiding (stream strength and dysuria), and irritative (frequency and urgency) symptoms and bother (5 weeks: Sp = -4.0 versus SOC = -2.3, P = 0.002; 8 weeks: Sp = -5.0 versus SOC = -3.1, P = 0.001).

CONCLUSIONS

The Spanner, a temporary prostatic stent, improved voiding symptoms and bother without exacerbating irritative symptoms. Improvements in symptoms and bother were sustained after stent removal.

Two-Stage Transperineal Management of Posterior Urethral Strictures or Bladder Neck Contractures Associated with Urinary Incontinence after Prostate Surgery and Endoscopic Treatment Failures

OBJECTIVES

The treatment of posterior urethral strictures or bladder neck contracture associated with severe urinary incontinence after prostate surgery and failure of endoscopic treatments is controversial. We report our experience with a transperineal approach in two steps: end-to-end urethroplasty/anastomosis and subsequent artificial urinary sphincter implantation.

METHODS

Between September 2001 and January 2005, we observed six patients (58-68 yr old), with a combination of severe urinary incontinence and posterior urethral stricture with anastomotic bladder neck contracture after prostate surgery. In all cases, repeated endoscopic treatments of the strictures failed. The patients underwent transperineal end-to-end urethroplasty or anastomosis followed by transperineal artificial urinary sphincter placement after 6 mo.

RESULTS

After the first surgical step, all patients were completely incontinent with absence of urethral strictures and complete anastomotic healing in all cases. Therefore, all patients underwent artificial urinary sphincter insertion. After a mean follow-up of 38 mo (range: 18-57 mo), five patients are continent with no postvoid residual urine and a perfectly functioning device. One artificial urinary sphincter was removed due to urethral erosion.

CONCLUSIONS

In patients with posterior urethral strictures or bladder neck contractures associated with severe urinary incontinence, an artificial urinary sphincter implantation as a second step allows verification of the outcome of a previous end-to-end urethroplasty or anastomosis and utilizes a dedicated operative field to reduce the risks of prosthesis implants.

Epithelializing Stent for Benign Prostatic Hyperplasia: A Systematic Review of the Literature

PURPOSE

We systematically reviewed the literature on the effectiveness, durability and safety of the UroLume stent for men with benign prostatic hyperplasia.

MATERIALS AND METHODS

We searched the MEDLINE and EMBASE databases for 1989 to 2005. Reference lists of included studies and review articles were also searched. We contacted the UroLume manufacturer and key authors for additional information. Primary outcomes were treatment failure and urological symptom scores. Secondary outcomes were uroflow parameters and minor complications. Two reviewers independently assessed the methodological quality of the studies and extracted data.

RESULTS

A total of 20 case series evaluated the UroLume stent in a total of 990 patients with benign prostatic hyperplasia. Of the patients 84% who were catheter dependent voided spontaneously after stent insertion. Ten studies assessed symptoms before stent insertion and at some point within 1 year after stent insertion. All reported decreases in symptom scores, including Madsen-Iversen by 7.9 to 14.3 points and International Prostate Symptom Score by 10 to 12.4 points. Peak urine flow rates increased by 4.2 to 13.1 ml per second. A total of 104 stents (16%) failed in 606 patients who were evaluable at 1 year and migration was the commonest cause of failure (38 stents or 37%). Most patients initially experienced perineal pain or irritative voiding symptoms following stent placement.

CONCLUSIONS

Of men who were catheter dependent 84% voided spontaneously after insertion of a UroLume stent and the improvement in symptoms was similar to that seen after transurethral prostate resection. However, 1 of 6 men needed the UroLume removed within a year because of complications. Inadequate followup prevented conclusions on stent durability beyond 1 year. This review supports the recommendation that stents should be considered only in patients at high risk.

Evaluation of the Effects of Temporary Covered Nitinol Stent Placement in the Prostatic Urethra: Short-Term Study in the Canine Model

PURPOSE

To evaluate the effect of temporary stent placement on the canine prostatic urethra.

METHODS

Retrievable PTFE-covered nitinol stents were placed in the prostatic urethras of 8 beagle dogs under fluoroscopic guidance. Retrograde urethrography was obtained before and after stenting. Retrograde urethrography and endoscopy were performed 1 and 2 months after deployment. The endoscopic degree of hyperplasia was rated on a scale of 0 to 4 (0 = absence, 4 = occlusion). On day 60, stents were removed and urethrography was performed immediately before euthanasia. Pathologic analysis was performed to determine the degree of glandular atrophy, periurethral fibrosis, and urethral dilation.

RESULTS

Stent deployment was technically successful in 7 animals, and failed in 1 dog due to a narrow urethral lumen. Complete migration was seen in 2 animals at 1 month, and an additional stent was deployed. On day 30, endoscopy showed slight hyperplasia (grade 1) in 3 animals. On day 60, moderate hyperplasia (grade 2) was evidenced in 4 cases. No impairment of urinary flow was seen during follow-up. Retrieval was technically easy to perform, and was successful in all dogs. The major histologic findings were chronic inflammatory cell infiltrates; prostate glandular atrophy, with a mean value of 1.86 (SD 0.90); periurethral fibrosis, with a mean ratio of 29.37 (SD 10.41); and dilatation of the prostatic urethra, with a mean ratio of 6.75 (SD 3.22).

CONCLUSION

Temporary prostatic stent placement in dogs is safe and feasible, causing marked enlargement of the prostatic urethral lumen. Retrievable covered stents may therefore be an option for bladder outlet obstruction management in men.

A Temporary Intraurethral Prostatic Stent Relieves Prostatic Obstruction Following Transurethral Microwave Thermotherapy

PURPOSE

The Spanner, a novel prostatic stent, was evaluated for safety, efficacy and patient tolerance when used to relieve prostatic obstruction following transurethral microwave thermotherapy.

MATERIALS AND METHODS

Following transurethral microwave thermotherapy and routine post-procedure Foley catheterization at 1 of 9 clinical sites 186 patients meeting study criteria were randomized to receive a Spanner (100) or the standard of care (86). Baseline evaluations included post-void residual urine, uroflowmetry, International Prostate Symptom Score and International Prostate Symptom Score quality of life question. These evaluations were repeated at visits 1, 2, 4, 5 and 8 weeks after randomization (Spanner insertion) with the addition of the Spanner satisfaction questionnaire, ease of use assessment and adverse events recording. The Spanner was removed after 4 weeks, at which time the Spanner and standard of care groups underwent cystourethroscopy.

RESULTS

At the 1 and 2-week visits the Spanner group showed significantly greater improvements from baseline in post-void residual urine, uroflowmetry and International Prostate Symptom Score compared to the standard of care group. The Spanner group experienced significantly greater improvements in quality of life at the 5 and 8-week visits. Patient satisfaction with the Spanner exceeded 86%. Cystourethroscopy findings in the Spanner and standard of care groups were comparable and adverse events associated with previous stents were rare.

CONCLUSIONS

The Spanner is a safe, effective and well tolerated temporary stent for severe prostatic obstruction resulting from therapy induced edema after transurethral microwave thermotherapy. It may be a needed addition to the armamentarium for managing bladder outlet obstruction in a broad group of urological patients.

The thermo-expandable metallic stent for managing benign prostatic hyperplasia: a systematic review

OBJECTIVES

To systematically review published reports of the safety, effectiveness and durability of a self-expanding metallic prostatic stent (Memokath, Engineers & Doctors A/S Ltd., Denmark) in patients with benign prostatic hyperplasia (BPH) who are unfit for surgery.

METHODS

We systematically searched the Medline and Embase databases from 1992. The reference lists of included studies and the bibliographies of review articles were also searched. We contacted the manufacturer of Memokath for additional information. The primary outcomes were treatment failure (stent removal, replacement or repositioning) and urological symptom scores. Secondary outcomes were urodynamic indices and minor complications. Two reviewers independently assessed the methodological quality of the studies and extracted data. Data were synthesized using narrative techniques.

RESULTS

In all, 14 case series described the use of the Memokath stent in 839 men with BPH. All patients were at high operative risk. Most studies were of poor quality with an inadequate follow-up. Treatment failure rates were 0-48% but the duration of follow-up was often unclear. Five studies reported International Prostate Symptom Scores and found reductions of 11-19 points after stent insertion. All seven studies that reported on maximum urinary flow rates found that these increased, and the four that described residual urine volumes found that these decreased. Minor complications were inconsistently reported.

CONCLUSIONS

The Memokath stent can provide an effective treatment for BPH in men at high operative risk; it also appears to be safe, but inadequate follow-up does not allow firm conclusions on stent durability.

Can prostate stents be used to predict the outcome of transurethral resection of the prostate in the difficult cases?

PURPOSE OF REVIEW

Endoprosthesis has been used to maintain luminal patency in several different diseases and is well established in cardiovascular and gastrointestinal pathologies. The usefulness and application in prostatic pathology and benign prostatic hyperplasia are not as clear. This report reviews the development of overactive bladder in patients with bladder outlet obstruction due to benign prostatic hyperplasia. It also describes a new application of prostatic stents in patients with combined overactive bladder and bladder outlet obstruction.

RECENT FINDINGS

Over the last few decades, interest has been focused on the pathology of overactive bladder due to bladder outlet obstruction. Persistent outlet obstruction can certainly induce overactivity in some cases. However, the significance of preoperative identification of the latter problem is still an open issue, and it is obviously of vital importance to find instruments to identify parameters of prognostic significance. Different prostatic stents have been used for a variety of purposes. Recent studies have demonstrated that prostatic stents are effective in relieving obstruction and urinary retention. However, the role of prostatic stents in bladder outlet obstruction is still not clear when compared with other minimally invasive options. By using a prostatic stent to simulate transurethral resection of the prostate, the risk of post-resection incontinence in patients with combined severe bladder outlet obstruction and severe overactive bladder has been possible to assess before the operation. However, larger controlled clinical studies are needed to corroborate the value of the test.

SUMMARY

Prostatic obstruction can induce severe overactive bladder in some cases. A prostatic stent to relieve outflow obstruction and to simulate transurethral resection of the prostate decreases the risk of post-resection incontinence in patients with combined severe bladder outlet obstruction and severe overactive bladder because very high risk patients can be excluded from surgery. The stent test indicates that patients who do not leak and experience reduced symptoms when they are relieved of their outlet obstruction can be advised to have a transurethral resection of the prostate.

Acute Urinary Retention: a review of the aetiology and management

Acute retention of urine (AUR) is a common urological emergency characterised by a sudden inability to pass urine associated with lower abdominal pain. In recent years, the natural history and incidence of AUR has become better understood, however, further research into methods to prevent it and evaluation of the impact an episode of AUR has on the patient is required. This review provides an overview of the current management of AUR in men and the impact of the condition on patients' quality of life.