Urethral Stent Research Articles

Experience with the Spanner Prostatic Stent in Patients Unfit for Surgery: An Observational Study

Prostatic stents offer a third clinical option for patients with bladder-outlet obstruction who are unfit for surgical relief and wish to avoid long-term catheterization. We report our experience with the Abbey-Moor Spanner temporary prostatic stent in patients with acute and chronic symptoms of bladder-outlet obstruction secondary to benign or malignant disease who were unfit for surgery because of age or cardiorespiratory disease. A series of 43 consecutive patients stented March 2004 through November 2005 were reviewed retrospectively. Stents were removed and replaced every 3 months if tolerated. More than half of the patients (63%) had an unsatisfactory outcome, namely, immediate or delayed retention or elective removal because of unbearable symptoms. The remaining 37% of patients had a satisfactory outcome and either continue to have the stent in situ after a mean of five changes or are stent free after a successful voiding trial. Only 21% of the patients in whom stenting was indicated continued to have a stent in situ at the end of the study. We suggest that in such patients, a temporary stent such as the AbbeyMoor Spanner should be used for only 3 months as a trial of stenting followed by a trial of stent-free voiding, with the patient converted to permanent prostatic stenting if voiding is unsuccessful.

Infant feeding tube as urinary tract stent

Background: The infant feeding tube is a cheap and readily available device with many uses in the urinary tract. Many types of stents are available in the market but among other factors, cost and affordability limit their use in developing countries and remote areas. Aim: To document experience with infant feeding tubes as stents in the urinary tract. Methods: Data from the hospital records of patients who required stents at the University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria were obtained from their case notes from May 2003 to May 2006. Information extracted from these case notes included: age and sex of patient, indications for stenting, stent-related complications and outcome of surgery. The data were analysed using Microsoft Excel Software. Results: Thirty-three patients who required stents within the period were included in the study. In nineteen patients (57.6%) feeding tubes were used as urethral stents while in 14 (42.4%) as ureteric stents. Operations requiring stents include: dismembered pyeloplasty 9.1% (3), ureteric re-implantation 24.3% (8), ureterolithotomy 9.1% (3), and urethroplasty 57.6% (19). The stents were left in situ for 2-3 weeks depending on the indication. Ureteric stents were left for 3 weeks while urethral stents were usually left for 2 weeks. However, where a significant complication was noted, the stent was removed. Complications noted in 4 patients (12.1%) which were probably stent-related include: bladder spasm, infection and wound dehiscence. Conclusion: Infant feeding tubes can be used as suitable urinary tract stents where expensive stents are not available. Keywords : Feeding tubes, Stents, Urologic surgery. Port Harcourt Medical Journal Vol. 1 (2) 2007: pp. 96-98

Outcome after treatment of detrusor–sphincter dyssynergia by temporary stent

To evaluate follow-up treatments used after treatment of detrusor-sphincter dyssynergia (DSD) by a temporary urethral sphincter stent. Between February 1994 and June 2003, 147 men with a mean age of 41.3+/-14.4 years were treated by temporary urethral stent inserted across the external sphincter for DSD. The underlying neurologic disease was quadriplegia in 85 cases, multiple sclerosis in 24 cases and paraplegia in 21 cases. A Nissenkorn (Bard) stent was used in 130 cases and a Diabolo (Porgès) stent was used in 17 cases. All patients were either unable to or they refused to perform intermittent self-catheterization. DSD was demonstrated by urodynamic studies in every case. The mean duration of temporary stenting was 10.15+/-16.07 months. After temporary stenting, 92 patients were treated by permanent stent (Ultraflex, Boston Scientifics), 7 started intermittent self-catheterization, 12 had repeated changes of the temporary stent, 4 had an indwelling catheter, 3 underwent cystectomy with non-continent diversion, 2 were treated by endoscopic sphincterotomy, 1 was treated by bladder neck incision, 1 was treated by neuromodulation and 1 was treated by cystostomy. Fifteen patients were lost to follow-up. Two patients died during follow-up (not related to DSD). After treatment of DSD by a temporary urethral sphincter stent, 70.7% of patients subsequently require a permanent urethral sphincter stent. This period allows selection of patients unlikely to benefit from permanent urethral sphincter stent.

Managing the local complications of locally advanced prostate cancer

Complications of locally advanced prostate cancer are often overlooked in the overall treatment of prostate cancer, can have significant morbidity, and can provide a challenge for the treating urologist. Despite advances in early detection and treatment of prostate cancer, as many as 10% of patients present with or develop symptomatic locally advanced prostate cancer. Prostate cancer locally invading the urethra can be effectively managed with transurethral resection or ablation procedures or urethral stenting. Obstruction of one or both ureters is managed with either ureteral stenting or nephrostomy drainage. Bulky pelvic recurrence resulting in significant hematuria, rectal involvement, or severe pelvic pain can be difficult to manage, with some advocating cystoprostatectomy or pelvic exenteration to provide palliation. Surgical intervention for locally advanced prostate cancer can provide significant improvement in quality of life and should not be restricted to patients who have curable disease.

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

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

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

Endourethral prostheses for urethral stricture

A number of urethral stents made of different materials, with different time of indwelling and different designs, primarily based on the vascular stent concept, have been applied in the clinical practice so far. According to the published studies, urethral stents have justified their clinical application, however with certain limitations. Within an attempt to overcome the limitations, a covered, temporary urethral stent was initially designed by Daniel Yachie and Zeljko Markovic in Allium corporation from Israel. With its triangular shape, the stent is a replica of the obstructive urethral lumen. The follow-up of resuIts was done according to a priori established protocol including the following: UCG, uroflowmetry and interview with patients. Due to stent migration, the stent over stent technique was applied in two case, while reposition by balloon-catheter outward traction was performed in two cases of caudal migration. No irritative discomforts were reported in the first 6 months after stent dwelling. Uroflowmetric controls verified at least four times better results than before the insertion. Given it is the question of covered stent, there is no possibility of proliferative secondary lumen obstruction. On account of soft structure and conic shape of posterior part of stent, no lesions of the external urethral sphincter were manifested. The stent is simply withdrawn after 12 months by outward traction using the forceps at the time when the stent construction turns into soft and straight wire. After 12-16 months in all cases we removel stent and in all patients we find complete recanalisation without any disuric problem. In 5 cases we find new "contact" stricture on anterior part of stent and treated succeed with balloon recanalisation.

Nova generacija stentova uretre-Allium u terapiji simptomatskog uvecanja prostate razlicite etiologije

A number of urethral stents made of different materials, with different time of indwelling and different designs, primarily based on the vascular stent concept, have been applied in the clinical practice so far. According to the published studies, urethral stents have justified their clinical application, however with certain limitations. Within an attempt to overcome the limitations, a covered, temporary urethral stent was initially designed by Daniel Yachie and Ijko Markovi in Allium corporation from Israel. With its triangular shape, the stent is a replica of the obstructive prostatic urethral lumen. In has been applied in a series of 14 patients with lower urinary tract symptoms caused by the obstruction at the level of the prostatic urethra. The subjects were averagely aged 77.4 +/- 5.1 years. Allium prostatic stent remained in place in the patients for 4.93 +/- 3.17 months, at the average.

Prostatic stents for the treatment of benign prostatic hyperplasia

The insertion of prostatic stents in the treatment of lower urinary tract symptoms in men secondary to benign prostatic obstruction from benign prostatic hyperplasia has proven to be an effective modality in properly selected patients. We review the current literature on the role of prostatic stents in the treatment of bladder outlet obstruction secondary to benign prostatic hyperplasia. Permanent stents such as the Urolume and the Memokath offer efficacious and safe treatment alternatives for men with bladder outlet obstruction from benign prostatic hyperplasia who are deemed high surgical risks for traditional transurethral resection of the prostate. When removal of permanent prostatic stent is necessary, the design of the Memokath allows for an easier removal than that of the Urolume. Temporary stents are being investigated as a means to treat the transient bladder outlet obstruction frequently observed after minimally invasive thermotherapy procedures aimed at treating benign prostatic obstruction, with both biodegradable and retrievable stents shown as successful modalities for this indication. Prostatic stents remain an option to treat men with benign prostatic obstruction/bladder outlet obstruction; however, stent migration remains an obstacle to their widespread use. The key to obtaining optimal outcomes in men with benign prostatic hyperplasia is careful patient selection and experience with proper stent deployment.

Pediatric Posterior Urethral Disruption With Resultant Iatrogenic Dilutional Hyponatremia

This report addresses a case of iatrogenic dilutional hyponatremia in a pediatric male trauma victim with a Grade III posterior urethral disruption. Suprapubic catheter placement was undertaken soon after the patient arrived at the Emergency Department. Primary realignment (urethral stenting with a catheter) was undertaken by way of a combined transurethral/percutaneous transvesical approach. Postoperatively, the patient developed a pseudo-transurethral resection (TUR) syndrome, which included dilutional hyponatremia (nadir serum Na 121 meq/L), hypotension (blood pressure was 100/60 mmHg), and heart rate 115 beats/minute although without evidence of cognitive change. The pathophysiology likely involved fluid absorption through open posterior urethral veins. With gentle administration of hypertonic saline, the patient's hyponatremia subsequently resolved.

One-Stage Urethral Reconstruction for Stricture Recurrence After Urethral Stent Placement

We report our 8-year experience with 1-stage open urethral reconstruction in 10 patients with recurrent bulbar and/or membranous strictures after UroLume urethral stent placement. Ten consecutive referral patients underwent preoperative contrast imaging and urethroscopy followed by primary anastomotic repair or substitution urethroplasty, with concomitant open UroLume removal (when the stent was still present). Postoperative evaluation included contrast imaging 3 weeks after surgery, urethroscopy 4 months after surgery, uroflowmetry, and American Urological Association symptom score assessment. At a medium followup of 51.2 months all patients remain free of bulbar or membranous stricture recurrence. No patient has required dilation or any other intervention. One-stage open reconstruction with stent extraction offers a definitive treatment option with a high success rate for patients with recurrent bulbar and/or membranous strictures following urethral stent placement.

Management of Severe Urethral Complications of Prostate Cancer Therapy

We present our management of urethral stenosis and rectourinary fistula resulting from prostate cancer therapy. We concentrated on cases refractory to minimally invasive treatment, such as dilation, urethrotomy, and urinary and/or fecal diversion. In our prospectively collected urethral reconstruction database we identified patients who underwent reconstruction of urethral stenosis or rectourinary fistula who also received prior treatment for prostate cancer. We documented demographics, prostate cancer pretreatment characteristics, prostate cancer therapy type, urethral reconstruction type and success. A total of 48 patients met the inclusion criteria, including 16 with rectourinary fistula and 32 with urethral stenosis. Urethral complications followed prior radical prostatectomy, brachytherapy, external beam radiotherapy, cryotherapy, thermal ablation and any combination of these procedures. Stenosis repair was successful in 23 of 32 cases (73%) and it differed little between anterior and posterior urethral stenosis. Repair was accomplished by anastomotic urethroplasty in 19 cases, flap urethroplasty in 2, perineal urethrostomy in 2 and a urethral stent in 9. Prior external beam radiotherapy was a risk factor for urethral reconstruction failure. Fistula repair was successful in 14 of 15 patients (93%), excluding 1 who died postoperatively. The complexity of fistula management was dictated by fistula size and the presence or absence of coincident urethral stenosis. Urethral stenosis or rectourethral fistula following prostate cancer therapy can be managed by urethral reconstruction, such that normal voiding via the urethra is maintained, rather than abandoning the urethral outlet and performing heterotopic diversion. This can be accomplished with an acceptable rate of failure, given the complexity of the cases.

Clinical utility of “blind placement” prostatic stent in patients with benign prostatic obstruction: A prospective study

Objectives To assess the efficacy and safety of two versions of a blind placement temporary prostatic stent in the treatment of patients with benign prostatic obstruction. Methods Two versions of a prostatic stent (blind placement stent 1 [BPS-1] and BPS-2) were blindly inserted in an outpatient setting under local anesthesia. An assessment of voiding function, symptom scores, and complications was performed at baseline, directly after stent insertion, and at 14 and 28 days after stent placement. Results A total of 55 men were enrolled in the trial. Most stents of both types were successfully placed. Spontaneous voiding was achieved in all patients immediately after stent insertion, with improvements in voiding parameters and symptom scores. In patients with the BPS-1, migration occurred in 85%. In patients with the BPS-2, migration occurred in 5%. The median indwelling time of the stent was 16 and 38 days for the BPS-1 and BPS-2, respectively. Removal was successful in all but 1 case (BPS-2). Conclusions The BPS-1 is not suitable for clinical practice because of the significantly high migration rate. The bulbar segment of the BPS-2 can prevent stent migration. However, patients experienced significant discomfort after insertion of the BPS-2. The voiding parameters and symptom scores of the BPS-2 were not significantly improved. Therefore, the BPS-2 is also not useful for clinical practice. Additional adjustment in the design of the BPS is needed to overcome these problems.

Covered Retrievable Prostatic Urethral Stents: Feasibility Study in a Canine Model

To evaluate the feasibility of use of a covered, retrievable prostatic urethral stent and to determine urethrographic and histologic changes in the prostate induced by the stent in a canine model. Polytetrafluoroethylene-covered retrievable nitinol stents were placed in the normal prostatic urethras of 13 dogs. The stents were removed 8 weeks after placement. The dogs were killed immediately after stent removal (group 1, n = 5) or 8 weeks after stent removal (group 2, n = 8). Retrograde urethrograms were obtained every 2 weeks after stent placement and after stent removal in dogs that had not been killed. The histologic changes in the prostate were compared between the two groups. Stent placement was technically successful in all dogs. In two dogs, a second stent was placed because of migration of the first stent into the urinary bladder. Stent removal was successful in 12 dogs. One stent was removed in its expanded state. On follow-up urethrograms, dilation of the prostatic urethra persisted until animals were killed (P = .14). The mucosal hyperplasia that occurred after stent placement at both ends of the stent gradually decreased after stent removal (P < .001). Histologic examination revealed prostate glandular atrophy and periurethral fibrosis, which did not differ between the two groups (P = .72 and P = .83, respectively). Papillary hyperplasia of the uroepithelium and submucosal inflammatory cell infiltration was decreased significantly in group 2 compared with group 1 (P = .002, P = .011, respectively). Covered retrievable prostatic urethral stents seem to be feasible for use in the canine prostatic urethra. The stent-induced prostatic urethral dilation and prostate glandular atrophy persist until 8 weeks after stent removal.

UP-02.12: Long-term experience with Memotherm urethral stents in the management of BPH and urethral strictures

To study the long-term results of Thermosensitive Memotherm Stents in the management of high risk BPH and recurrent bulbar urethral strictures.

UP-01.79: The good and bad of urethral stents

We describe our experience with the use of urethral stents for the management of urethral stricture disease. We highlight the utility of the stent in select cases and the management restenosis after stent placement.

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

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. 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. 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. 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.

Management of detrusor–external sphincter dyssynergia

Detrusor-external sphincter dyssynergia (DSD) is a debilitating problem in patients with spinal cord injury. DSD carries a high risk of complications, and even life expectancy can be affected. The mainstay of treatment is the use of antimuscarinic medication and catheterization, but in those for whom this is not possible external sphincterotomy has been the traditional management route. External sphincterotomy, however, is associated with significant risks, including hemorrhage, erectile dysfunction and the need for repeat procedures, and over the last decade alternatives have been investigated, such as urethral stents and botulinum toxin injection. We present a review of DSD, including the current management strategies and prospects for future treatment.

Foreskin Preservation in Penile Surgery

Most hypospadias repairs performed in the United States involve the removal of any foreskin that is not used in the repair, resulting in a circumcised penis. Occasionally, the wishes of the parents or the child are for the final appearance to be that of a normal uncircumcised penis. We report our collective experience from 4 institutions in the reconstruction of the foreskin during penile surgery. A total of 58 patients underwent penile surgery with reconstruction of the foreskin during a 6-year period. Of the patients 49 underwent hypospadias repair, 8 underwent phalloplasty for chordee correction without hypospadias and 1 underwent reconstruction of the foreskin for a dorsal hood without hypospadias or chordee. Of the 49 hypospadias repairs 46 were distal, 2 mid shaft and 1 proximal shaft. The technique for foreskin reconstruction consisted of a multilayered reapproximation of the lateral margins of the dorsal hood after completion of the urethroplasty and glanuloplasty. Among 49 hypospadias repairs 2 patients had dehiscence of the reconstructed foreskin, with development of a urethral fistula in 1. Of the 58 total patients undergoing penile surgery 56 had retractable foreskin, of whom 4 required postoperative steroid application. Three patients/parents requested a secondary circumcision, 2 for an unacceptable cosmetic result and 1 based on personal preference. Foreskin reconstruction in association with penile surgery can be performed safely and with a low complication rate in appropriately selected patients. Cases with a higher risk of complications include those involving more proximal hypospadias and those requiring complete degloving of the penile shaft. Of the reconstructions resulting in phimosis most can be salvaged with the application of steroids.

Pan-urethral strictures can develop as a complication of UroLume placement for bulbar stricture disease in patients with hypospadias

We report the development of pan-urethral strictures in 2 patients with hypospadias who underwent UroLume urethral stent placement for bulbar urethral stricture disease before referral to our institution. To our knowledge, this devastating complication has never previously been reported. The likely etiology was ischemic urethral stenosis secondary to occlusion of bulbar arteries, the dominant urethral blood supply in hypospadias patients who lack a secondary retrograde blood supply through the glans penis. We conclude that hypospadias should be an absolute contraindication to urethral stent placement.