Thermo-expandable intraprostatic stents in bladder outlet obstruction: an 8-year study

Fournier's gangrene after insertion of thermo-expandable prostatic stent for benign prostatic hyperplasia: A case report

BACKGROUND

Thermo-expandable urethral stent (Memokath 028) implantation is an alternative treatment for older patients with lower urinary tract symptoms and benign prostatic obstruction. Following prostatic urethral stent implantation, minor complications such as urinary tract infection, irritative symptoms, gross hematuria, and urethral pain have been observed; however, there are no reports of life-threatening events. Herein, we report a critical case of Fournier's gangrene that occurred 7 years after prostatic stenting.

CASE SUMMARY

An 81-years-old man with benign prostatic hyperplasia (volume, 126 ccs; as measured by transrectal ultrasound) had undergone insertion of a thermo-expandable urethral stent (Memokath 028) as he was unfit for surgery under general anesthesia. However, the patient had undergone a suprapubic cystostomy for recurrent acute urinary retention 4 years after the insertion of prostatic stent (Memokath 028). We had planned to remove the Memokath 028; however, the patient was lost to follow-up. The patient presented to the emergency department 3 years after the suprapubic cystostomy with necrotic changes from the right scrotum to the right inguinal area. In digital rectal examination, tenderness and heat of prostate was identified. Also, the black skin color change with foul-smelling from right scrotum to right inguinal area was identified. In computed tomography finding, subcutaneous emphysema was identified to same area. He was diagnosed with Fournier's gangrene based on the physical examination and computed tomography findings. In emergency room, Fournier's gangrene severity index value is seven points. Therefore, he underwent emergent extended surgical debridement and removal of the Memokath 028. Broad-spectrum intravenous antibiotics were administered and additional necrotic tissue debridement was performed. However, the patient died 14 days after surgery due to multiorgan failure.

CONCLUSION

If Memokath 028 for benign prostatic hyperplasia is not working in older patients, its rapid removal may help prevent severe complications.

A state-of-art review on the preservation of sexual function among various minimally invasive surgical treatments for benign prostatic hyperplasia: Impact on erectile and ejaculatory domains

There is a strong association between benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and sexual dysfunction. While transurethral resection of the prostate (TURP) is considered the standard BPH treatment, it is however associated with a high rate of erectile and ejaculatory dysfunctions. Over the past decade, new and novel minimally invasive BPH therapies have been shown to improve various parameters of voiding domains while minimizing adverse sexual effects. These minimally invasive BPH therapies can be largely be divided into those with cavitating technology (Rezum, Histotripsy, Aquablation), intra-prostatic injections (Botulinum neurotoxin Type A, Fexapotide Triflutate, prostate specific antigen-activated protoxin PRX-302), and mechanical devices which include intraprostatic stents (Urospinal 2™, Memotherm™, Memokath™, and Allium triangular prostatic stent™) and intraprostatic devices (iTIND™, Urolift™), as well as prostatic artery embolization. Published literature on these technologies showed reasonable preservation of erectile function with limited data reported on ejaculatory domain. Further validation of the performance of these novel minimally invasive treatment options for LUTS due to BPH in well-designed and multi-centre studies are desired, to evaluate their role (or lack of such a role) in clinical practice and whether these BPH therapies can provide equivalent standard or better than TURP.

Thermo-expandable prostatic stents for bladder outlet obstruction in the frail and elderly population: An underutilized procedure?

Purpose

To report our outcomes with the use of a thermo-expandable metallic intraprostatic stent (Memokath) for patients with bladder outlet obstruction (BOO) secondary to prostatic obstruction, and to assess it is a feasible option for many frail and elderly men unsuitable for surgery.

Materials and Methods

We reviewed patients who underwent insertion of a Memokath stent for BOO over 17 years (January 1999 to December 2015) at one regional center over a long follow-up period (median, 7 years). Patients were selected if they had obstructive urinary symptoms or urinary retention with an indwelling catheter in situ, and were ineligible for transurethral resection of the prostate (TURP) under general or spinal anesthesia. Primary outcomes assessed were the improvement in urinary symptoms and voiding parameters, as well as the ability to void spontaneously if catheterized, along with complications.

Results

One hundred forty-four patients who presented with BOO or urinary retention had a Memokath stent inserted. Ninety patients (62.5%) had a successful stent insertion with a significant difference between the median preoperative (550 mL) and postoperative residual volume (80 mL, p<0.0001). Nearly two-thirds of men (64%) returned to unassisted voiding with no increased risk of complications over time. Fifty-four patients (37.5%) experienced stent failure. Main complications requiring stent removal or repositioning were migration, occlusion, refractory urinary retention and irritative voiding symptoms.

Conclusions

In elderly and frail men with BOO deemed unsuitable to undergo TURP, prostatic stent is a safe and practical alternative to long-term catheterization.

Biofabrication and biomaterials for urinary tract reconstruction

Reconstructive urologists are constantly facing diverse and complex pathologies that require structural and functional restoration of urinary organs. There is always a demand for a biocompatible material to repair or substitute the urinary tract instead of using patient's autologous tissues with its associated morbidity. Biomimetic approaches are tissue-engineering tactics aiming to tailor the material physical and biological properties to behave physiologically similar to the urinary system. This review highlights the different strategies to mimic urinary tissues including modifications in structure, surface chemistry, and cellular response of a range of biological and synthetic materials. The article also outlines the measures to minimize infectious complications, which might lead to graft failure. Relevant experimental and preclinical studies are discussed, as well as promising biomimetic approaches such as three-dimensional bioprinting.

Allium™ TPS--A New Prostatic Stent for the Treatment of Patients with Benign Prostatic Obstruction: The First Report

INTRODUCTION

Several prostatic stents were developed in the last three decades, none of which were able to provide a real alternative in patients unfit or unwilling to undergo classical prostatic surgeries. In this study, we report the results of the use of a newly developed prostatic stent--the Allium™ Triangular Prostatic Stent (TPS).

PATIENTS AND METHODS

The Allium TPS is a highly flexible, nitinol-built polymer-covered stent, which prevents tissue ingrowth and reduces encrustations. Between 2008 and 2014, at two centers (Israel and Turkey), the stent was inserted under local or regional anesthesia in 51 patients with benign prostatic obstruction (BPO) who are unwilling or unfit for surgery. Patients were followed for 12 months from surgery. The primary outcome was symptom improvement as measured by the international prostate symptom score (IPSS) and improvement in peak urinary flow.

RESULTS

Stent insertion was successful in all patients. The mean IPSS decreased from 26.4 to 7.7 on the last follow-up. The mean peak flow increased from 5.5 mL/second before stent insertion to 16.0 mL/second 1 year thereafter. The main adverse effect was transient pain in nine patients. No stent migration or obstruction was seen. Patients reported satisfaction and improvement in quality of life.

CONCLUSION

Our short-term results show that Allium TPS is safe and effective for the treatment of patients with BPO.

Temporary implantable nitinol device (TIND): a novel, minimally invasive treatment for relief of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH): feasibility, safety and functional results at 1 year of follow-up

OBJECTIVES

To report the first clinical experience with a temporary implantable nitinol device (TIND; Medi-Tate(®) ) for the treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

In all, 32 patients with LUTS were enrolled in this prospective study, which was approved by our Institutional Ethics Committee. Inclusion criteria were: age >50 years, International Prostate Symptom Score (IPSS) of ≥10, maximum urinary flow rate (Qmax ) of ≤12 mL/s, and prostate volume of <60 mL. The TIND was implanted within the bladder neck and the prostatic urethra under light sedation, using a rigid cystoscope. The device was removed 5 days later in an outpatient setting. Demographics, perioperative results, complications (according to the Clavien system), functional results and quality of life (QoL) were evaluated. Follow-up assessments were made at 3 and 6 weeks, and 3, 6 and 12 months postoperatively. The Student's t-test, analysis of variance (anova), Kruskall-Wallis test, and simple and multiple linear regression models were used in the statistical analyses.

RESULTS

The mean patient age was 69.4 years, the mean (standard deviation, sd) prostate volume was 29.5 (7.4) mL and the Qmax was 7.6 (2.2) mL/s. The median (interquartile range, IQR) IPSS was 19 (14-23) and QoL score was 3 (3-4). All the implantations were successful, with no intraoperative complications recorded. The mean operative time (sd) was 5.8 (2.5) min and the median (IQR) postoperative stay was 1 (1-2) day. All but one of the devices (96%) was removed 5 days at after implantation in an outpatient setting. Four complications (12.5%) were recorded, including urinary retention (one, 3.1%), transient incontinence due to device displacement (one, 3.1%), prostatic abscess (one, 3.1%), and urinary tract infection (one, 3.1%). Multiple regression analysis failed to identify any independent prognostic factor for complications. There were statistically significant differences in the IPSS, QoL score and Qmax when comparing pre- and postoperative results at every time point. After 12 months, the median (IQR) IPSS and QoL score were 9 (7-13) and 1 (1-2), respectively, and the mean (sd) Qmax was 12 (4.7) mL/s. The mean variations with respect to baseline conditions at the same time points were -45% for the IPSS and +67% for Qmax . At 12 months after surgery (last follow-up visit), no patients required medical therapy or surgical procedures for BPH.

CONCLUSION

TIND implantation is a feasible and safe minimally invasive option for the treatment of BPH-related LUTS. The functional results are encouraging and the treatment significantly improved patient QoL. Further studies are required to assess durability of TIND results and to optimise the indications of such a procedure.

Efficacy of a thermoexpandable metallic prostate stent (Memokath) in elderly patients with urethral obstruction requiring long-term management with urethral Foley catheters

AIM

To investigate whether the insertion of a thermoexpandable metallic prostate stent (Memokath) facilitates the removal of Foley catheters in elderly patients ineligible for urethral obstruction surgery because of the potential complications involved in long-term catheter management.

METHODS

A total of 37 male patients (mean age 79.8 ± 6.2 years) ineligible for surgery under general anesthesia because of advanced age, the presence of post-cerebrovascular disorders or anticoagulant therapy use and who subsequently had a Memokath stent inserted between June 2007 and November 2009 were enrolled in the present study. Patients with spinal injury were excluded. We compared the correlation between prostatic urethral length and total prostate volume (TPV). We also evaluated the postoperative postvoid residual (PVR) and presence of pyuria, and reviewed postoperative complications and unassisted urination ability.

RESULTS

We found a positive correlation between prostatic urethral length and TPV. After the insertion of the Memokath stent, the catheters were removed from all patients who could urinate unassisted. The PVR was <50 mL in 76.4% patients, and there was a 52% improvement in pyuria after insertion of the Memokath stent. The mean postoperative follow-up duration was 33.2 ± 16.7 months. A total of 21 patients (56.7%) were able to urinate unassisted after receiving the Memokath stent. Unassisted urination was difficult in patients with poor performance status. No serious complications were observed after insertion of the Memokath stent.

CONCLUSIONS

The Memokath stent was safe and useful for elderly patients with urethral obstruction and good performance status requiring long-term management with urethral Foley catheters.

Early experience with a thermo-expandable stent (memokath) for the management of recurrent urethral stricture

Purpose

To report our early experience with thermo-expandable urethral stents (Memokath) for the management of recurrent urethral stricture and to assess the efficacy of urethral stents.

Materials and Methods

Between March 2012 and February 2013, 13 patients with recurrent urethral stricture after several attempts with direct visual internal urethrotomy (DVIU) or failed urethroplasty underwent DVIU with thermally expandable, nickel-titanium alloy urethral stent (Memokath) insertion. Follow-up study time points were at 1, 3, 6, 9, and 12 months after stent insertion. Follow-up evaluation included uroflowmetry, retrograde urethrogram, plain radiography, and urinalysis.

Results

The mean patient age was 47.7 years (range, 18 to 74 years). The mean urethral stricture length was 5.54 cm (range, 1 to 12 cm). There were six patients with bulbar, four patients with proximal penile, one patient with distal penile, and two patients with whole penile urethral strictures, respectively. The overall success rate was 69% (9/13) and the mean postoperative peak flow rate was 17.7 mL/s (range, 6 to 28 mL/s). Major complications occurred in four patients including one patient (7.7%) with urethrocutaneous fistula induced by the stent and three patients with urethral hyperplasia. The mean follow-up duration was 8.4 months.

Conclusions

Our initial clinical experience indicates that thermo-expandable stents can be another temporary management option for recurrent urethral stricture patients who are unfit for or refuse urethroplasty. Distal or whole penile urethral stricture can be factors predicting poor results.

The use of a memokath prostatic stent for obstructive voiding symptoms after brachytherapy

INTRODUCTION

Brachytherapy may be complicated by serious obstructive voiding symptoms (OVS). Only conservative treatment options are available in the first 6 months after brachytherapy. We evaluated safety, efficacy and patient tolerance of the Memokath prostatic stent (MPS).

MATERIAL AND METHODS

A MPS was placed in 10 patients with OVS after brachytherapy. Evaluation included uroflowmetry, international prostate symptom score (IPSS), prostate volume and urethrocystoscopy before and 3 months after placement of the stent.

RESULTS

Both the IPSS and uroflowmetry results significantly improved after stent insertion. The mean IPSS decreased from 29/5 to 11/1 and the mean Qmax from the uroflowmetry improved from 4.7 to 11.2 ml/s. The 5 patients who were catheter dependent voided spontaneously with a mean Qmax of 15 ml/s. Two stents migrated towards the bladder, and those patients needed a second stent which was placed without complications. Removal of the stent was easy to perform. Adverse effects were minor with perineal pain and irritative voiding symptoms occurring in 5 patients mainly in the first weeks after insertion. This did not negatively influence quality of life and all patients were more satisfied with the stent than without.

CONCLUSIONS

The MPS provides a safe, effective, and completely reversible treatment for patients with OVS after brachytherapy and was well tolerated.

Thermo-expandable metallic urethral stents for managing recurrent bulbar urethral strictures: To use or not?

Objectives

To assess the role of temporary thermally expandable urethral stents in maintaining urethral patency in patients with a recurrent bulbar urethral stricture.

Patients and methods

Twenty-three men with a recurrent bulbar urethral stricture after several attempts at direct visual internal urethrotomy (DVIU) and/or failed urethroplasty were managed with a thermally expandable, biocompatible nickel–titanium alloy urethral stent (Memokath® MK044, Pnn Medical, Kvistgaard, Denmark). The stents were applied by a special mounting device via a rigid urethroscope after DVIU. All patients were followed using plain radiography, uroflowmetry and urine analysis every 3 months for 1 year, and then every 6 months.

Results

The mean (SD) age of the patients was 55.4 (7.3) years and the mean (SD) stricture length was 3.6 (1.2) cm. All patients tolerated the stent, with minimal discomfort in some patients. Four patients (17%) had urinary tract infections, three (13%) had haematuria, three (13%) had obstructed stents due to encrustation, in five (22%) the stent migrated, and two patients had no delayed complications. The mean (SD) follow-up was 17.4 (6.1) months.

Conclusion

Urethral stenting with nickel–titanium alloy thermally expandable stents can be an acceptable temporary procedure for patients with recurrent bulbar urethral strictures who are unfit for or who refuse urethroplasty. However, they have limitations; the search for an ideal urethral stent continues.

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.

Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer

PURPOSE

A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC).

MATERIAL AND METHODS

The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy.

RESULTS

One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed.

CONCLUSIONS

This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed.

Prophylactic urethral stenting with Memokath® 028SW in prostate cancer patients undergoing prostate 125I seed implants: phase I/II study

Purpose

To study the feasibility/toxicity of urethral stenting with the Memokath^® 028SW stent in patients undergoing prostate implant (PI) for prostate adenocarcinoma.

Material and methods

An Investigational Device Exemption from the Food and Drug Administration (FDA) and institutional review board (IRB) approval were obtained. Twenty patients enrolled. Baseline American Urological Association (AUA) score was obtained prior to PI. Follow-up information was obtained with weekly phone calls for the first 12 weeks and biweekly calls for the next 12 weeks to assess toxicity and AUA score. Removal of the stent was planned at six months after PI, or earlier due to excessive toxicity/patient request.

Results

Median age was 66.5 years. The median prostate volume was 39 cc (range: 10-90). The median baseline AUA score was 7.5 (range: 1-21). Three patients required intermittent self-catheterization (ISC) within 3 days after PI. No patients required ISC beyond day 3 after PI. The median duration of ISC was 1 day (range: 1-2). AUA scores returned to baseline values 6 weeks after PI. The week 6 AUA score was 10 (range: 4-16). Seven patients (35%) underwent early removal because of patient preference. The reasons were: incontinence (n = 3), discomfort (n = 2), hematuria (n = 1), and obstructive symptoms (n = 1). The median time of stent removal in these patients was 13.9 weeks (range: 0.9-21.4). Thirteen patients (65%) had ISC and/or urinary catheterization post stent removal. Median time for ISC use was 10 days (range: 1-90).

Conclusions

Urethral stenting with Memokath^® in patients undergoing PI was feasible, but resulted in relatively high rate of urinary incontinence and discomfort. Given the adverse effects experienced by patients of this study, further studies should focus only on patients with highest risk of urinary obstruction from PI or those with obstruction needing ISC.

Experience with Memokath 051 ureteral stent

OBJECTIVE

The Memokath 051 is a thermo-expandable titanium-nickel spiral developed for long-term ureteral stenting. The aim of this study was to investigate the drainage and safety aspects of this stent.

MATERIAL AND METHODS

A total of 3-4 consecutive patients were included: 22 had benign strictures, five had post-irradiation strictures and seven had malignant strictures. Follow-up visits took place after 1 month and thereafter every 3 months for at least 1 year.

RESULTS

Thirty-three patients had a total of 37 stents inserted uni- or bilaterally. Pre-insertion dilatation was impossible in one patient and difficult in two, all of whom had post-irradiation strictures. Insertion was complicated in seven patients and uneventful in the other 26. Fifteen stents were in place and functioning with no discomfort or complications at death or the end of follow-up (median 14 months; range 3-30 months), while 22 were non-functioning after 1 day to 16 months (median 5 months). Of these 22 stents, 10 had migrated and 12 were malfunctioning. Among the latter, stricture length was underestimated in four patients, and the stents were replaced successfully shortly after insertion. Four stents were occluded by stones after 1-10 months. No tissue ingrowth was seen. Stent removal was easy, with the exception of one patient with stent calcification.

CONCLUSIONS

The Memokath 051 is an alternative for selected patients with non-curable ureteral obstruction but is not suitable for use in patients with functional stenosis or stone formation. Insertion and removal are easy in most patients, but can be difficult or impossible, especially in patients with post-irradiation strictures and retroperitoneal fibrosis. Migration and obstruction can occur and careful follow-up is necessary.

A new fiducial marker for Image-guided radiotherapy of prostate cancer: clinical experience

BACKGROUND

A new fiducial marker for image guided radiotherapy (IGRT) based on a removable prostate stent made of Ni Ti has been developed during two previous clinical feasibility studies. The marker is currently being evaluated for IGRT treatment in a third clinical study.

METHOD

The new marker is used to co-register MR and planning CT scans with high accuracy in the region around the prostate. The co-registered MR-CT volumes are used for delineation of GTV before planning. In each treatment session the IGRT system is used to position the patient before treatment. The IGRT system use a stereo pair of kV images matched to corresponding Digital Reconstructed Radiograms (DRR) from the planning CT scan. The match is done using mutual gray scale information. The pair of DRR's for positioning is created in the IGRT system with a threshold in the Look Up Table (LUT). The resulting match provides the necessary shift in couch coordinates to position the stent with an accuracy of 1-2 mm within the planned position.

RESULTS

At the present time 39 patients have received the new marker. Of the 39 one has migrated to the bladder. Deviations of more than 5 mm between CTV outlined on CT and MR are seen in several cases and in anterior-posterior (AP), left-right (LR) and cranial-caudal (CC) directions. Intra-fraction translation movements up to +/- 3 mm are seen as well. As the stent is also clearly visible on images taken with high voltage x-rays using electronic portal images devices (EPID), the positioning has been verified independently of the IGRT system.

DISCUSSION

The preliminary result of an on going clinical study of a Ni Ti prostate stent, potentially a new fiducial marker for image guided radiotherapy, looks promising. The risk of migration appears to be much lower compared to previous designs.

[Palliative treatment of symptomatic benign prostatic hyperplasia by permanent urethral stent (Ultraflex, Boston Scientific) in high surgical risk patients]

OBJECTIVE

To evaluate the medium-term and long-term results of treatment of symptomatic benign prostatic hyperplasia (BPH) by permanent transprostatic urethral stenting in high surgical risk patients.

MATERIALS AND METHODS

Single-centre retrospective study on 19 consecutive patients with a mean age of 79.5 years (range: 61-96) treated by nitinol permanent urethral stent (Boston Scientific Corp.) from December 1995 to July 2006 for bladder neck obstruction. All patients presented a major contraindication (ASA III or IV) to immediate conventional surgical management. Stenting was performed under endourethral Xylocaine gel local anaesthesia. Fourteen patients presented acute urinary retention and 4 had chronic obstructive renal failure. One patient with an indwelling catheter had a history of recurrent acute prostatitis. The functional results were assessed by resumption of voiding, determination of post-voiding residual volume, serum creatinine and presence or absence of symptomatic urinary tract infection. The anatomical assessment was performed by voiding and retrograde cystourethrography and urethral endoscopy.

RESULTS

This series of 19 patients had a mean follow-up of 20 months (1-62). No intraoperative complication was observed. Resumption of voiding was achieved immediately postoperatively in 18 patients. One patient required more prolonged urinary drainage before voiding was restored. No cases of stent migration were observed. Postoperative serum creatinine was stable. Post-voiding residual volume was less than 100 ml in fifteen patients and less than 200 ml in four patients. One patient was explanted.

CONCLUSION

The treatment of bladder neck obstruction by permanent urethral stenting is an alternative to surgery for patients considered to be temporarily or permanently inoperable. This indication remains exceptional, but should be kept in mind in view of the satisfactory medium-term results to associated with a low morbidity for a procedure performed exclusively under local anaesthesia.

Evidence-based guidelines for the management of lower urinary tract symptoms related to uncomplicated benign prostatic hyperplasia in Italy: updated summary

BACKGROUND AND SCOPE

Despite the high prevalence and huge socio-economic impact of benign prostatic hyperplasia (BPH) in Italy, no national guidelines have been produced so far. This is a summary of the first Italian guidelines on the diagnosis and treatment of lower urinary tract symptoms (LUTS) related to uncomplicated BPH, prepared by a multidisciplinary panel under the auspices of the Italian Association of Urologists and introduced in Italy in 2003. An update compiled by the authors is also included.

METHODS

Relevant papers published from 1998 to 2003 (updated to 2006) were identified through a structured literature review and the quality of evidence presented therein was graded according to the Centre for the Evaluation of Effectiveness in Health Administration (CeVEAS) system. Recommendations were based on evidence from the literature, but also on feedback from practitioners and specialists. MAIN FINDINGS/RECOMMENDATIONS: Given the prevalence of BPH, all men aged > or = 50 years of age should be asked about LUTS and informed about disease characteristics and therapeutic options, while sexual function should always be assessed in patients with severe and long-standing LUTS. Initial assessment should include medical history (including drug and co-morbidity history), digital rectal examination, urinalysis, International Prostate Symptom Score-Quality of Life (IPSS-QoL) and a voiding diary, while prostate-specific antigen (PSA) and measurement of prostate volume by suprapubic ultrasonography are indicated in fully informed patients with a life expectancy of > or = 10 years in whom BPH progression could influence treatment choices. QoL considerations should dictate whether to start active treatment. When QoL is not affected by LUTS, watchful waiting is indicated if symptoms are mild, acceptable if they are moderate. When QoL is affected, medical therapy with alpha1-blockers or 5alpha-reductase inhibitors (the latter indicated in patients with increased prostate volume) is appropriate. Combined therapy with alpha1-blockers + 5alpha-reductase inhibitors should only be considered in patients at high risk for progression (prostate volume > 40 mL or PSA > 4 ng/mL), since the incremental cost of combination therapy vs. monotherapy with alpha1-blockers or finasteride is prohibitive. Selection of the type of surgery should be based on the surgeon's experience, the presence of co-morbid conditions and the size of the prostate. Open prostatectomy and transurethral resection of the prostate (TURP) are recommended in patients with acute or chronic retention of urine, and acceptable in obstructed patients with moderate/severe symptoms and worsened QoL. Transurethral incision of the prostate (TUIP) is acceptable when prostate volume is < or = 30 mL. Holmium laser enucleation of the prostate (HoLEP) may be proposed to motivated patients where expert surgeons are available. Transurethral microwave thermotherapy (TUMT) or transurethral needle ablation (TUNA) may be proposed to motivated patients who prefer to avoid surgery and/or do not respond to medical treatment. The possible effects of medical or surgical treatments on sexual function should always be discussed.

CONCLUSIONS

These guidelines are intended to provide a framework for health professionals involved in BPH management in order to facilitate decision-making in all areas and at all levels of healthcare.

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.

Prostatic stents for the treatment of benign prostatic hyperplasia

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.

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.

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.

The Bell-Shaped Nitinol Prostatic Stent in the Treatment of Lower Urinary Tract Symptoms: Experience in 108 Patients

OBJECTIVES

To assess the efficacy, safety, and durability of the bell-shaped nitinol prostatic stent in the treatment of moderate to severe lower urinary tract symptoms caused by benign prostatic enlargement in otherwise healthy patients.

METHODS

Stents were inserted in an outpatient setting under local anaesthesia. Assessments included maximum urinary flow (Qmax), postvoid residual (PVR) urine volume, International Prostate Symptom Score (IPSS), including quality of life (QoL) item, at baseline and follow-up visits.

RESULTS

108 men were enrolled in the trial. Stents were successfully inserted in 97% of the patients. Spontaneous voiding was achieved in all patients. After one month Qmax (+3.7 ml/s), PVR (-99 ml), IPSS (-12) and QoL (-1.7) all showed statistically significant improvements compared to baseline. Substantial improvements, however, were maintained for only one to two months. The main complications were haematuria (19%), urge incontinence (22%), and migration (15%). The median indwelling time was 105 days. The main reason for removal of stents was worsening of symptoms, which might be attributable to the tilting of stents within the prostatic urethra, found upon removal.

CONCLUSIONS

Insertion of the bell-shaped nitinol prostatic stent temporarily improves voiding parameters and symptom scores. Because of the limited durability, however, the bell-shaped prostatic stent is not suitable for clinical practice.

Feasibility study using a Ni–Ti stent and electronic portal imaging to localize the prostate during radiotherapy

BACKGROUND AND PURPOSE

A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images.

PATIENTS AND METHODS

Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient.

RESULTS

Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm.

CONCLUSIONS

A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia.

Hourglass-shaped nitinol prostatic stent in treatment of patients with lower urinary tract symptoms due to bladder outlet obstruction

OBJECTIVES

To assess the efficacy and safety of the thermoexpandable hourglass-shaped nitinol prostatic stent in the treatment of patients with lower urinary tract symptoms due to bladder outlet obstruction.

METHODS

The stents were inserted in an outpatient setting under local anesthesia and direct vision. Five different stent lengths (2.0 to 4.0 cm) were used, depending on the length of the prostatic urethra. Assessment of voiding function and symptom scores was performed at baseline, directly after stent insertion, at 14 days, and 1, 3, 6, and 12 months after stent placement.

RESULTS

We enrolled 35 men in the trial. In 5 patients, insertion of the stent failed, mainly because of anatomical limitations. After all placement procedures, minimal temporary hematuria was observed. Spontaneous voiding was achieved in all patients, with immediate significant improvements in voiding parameters and symptom scores. The median indwelling time of the stent was 70 days. Kaplan-Meier survival analysis showed that at 14 days and at 3, 6, and 12 months, the stent was still in situ in 73%, 40%, 33%, and 23% of the patients, respectively. The main reason for removal of the stent was migration (93%), in most cases toward the bladder. Removal was uneventful in all but 1 case.

CONCLUSIONS

The placement of the thermoexpandable hourglass-shaped nitinol stent results in relief of outflow obstruction and improvement of symptom scores. Because of the high migration rate, however, this stent design needs further improvement to be suitable for clinical practice.

Thermo-expandable Intra-prostatic Stent in the Treatment of Acute Urinary Retention in Elderly Patients with Significant Co-morbidities

We assess the use of thermo-expandable intra-prostatic stent (Memokath, Engineers and Doctors A/S, Denmark) for the treatment of acute urinary retention (AUR) in men with significant co-morbidities for transurethral resection of prostate (TURP). We evaluate the pre- and post-operative complications, duration of stents in-situ and patients quality of life after the stent insertion. Patients with significant co-morbidities presenting with AUR were selected, who were unfit for TURP. The co-morbidities included ischaemic heart disease, congestive heart failure, and chronic obstructive pulmonary disease. The exclusion criteria were bladder tumour and atonic bladder. The Memokath stents were inserted using a flexible cystoscope under local anaesthesia. The patients were followed up at 3 and 6 months after the procedure and the ones who remained alive were asked to complete self-administered questionnaires and IPSS scores. Fifteen men with acute urinary retention were recruited for stent insertion with the mean age of 87 years. No peri-operative complications were recorded. Three patients died after the insertion with functional Memokath in-situ. Nine patients had good functioning stents post-operatively, and remain catheter free up to 30 months after the procedure. The mean duration of stent life was 18 months. Three long-term complications were detected, including stent migration and prostate overgrowth. The Memokath is a good option for frail elderly patients presenting with AUR. The procedure is safe and has minimal long term complications. The stent also provides a sustained good quality of life for patients and avoids the necessity of long term catheterisation.

Ease of removal of thermo-expandable prostate stents

OBJECTIVE

To report the ease of removal of the Memokath 028 prostatic stent (Engineers & Doctors A/S, Hornbaek, Denmark), an important attribute of the 'ideal' prostatic stent.

PATIENTS AND METHODS

Data on patients who had had a Memokath 028 stent removed in three different centres in Europe over an 8-year period were collected retrospectively. Standardized forms were used to record relevant information from each physician's patient files.

RESULTS

Ninety-three patients had their stents removed at the three reporting centres; the mean indwelling time of their stent was 12.9 months, and most stents were inserted for symptomatic benign prostate disease. Reasons for removal included recurrent outlet or storage-type urinary symptoms, migration of the stent, stent-related pain, recurrent urosepsis and detrusor failure. The stents were removed on a day-case basis in 32% of patients. Topical anaesthesia or no anaesthesia was used in 48%. Of these patients, only 9% described moderate discomfort or worse. The procedure took a mean of 11 min and was felt to be easy or fairly easy in 90% of patients.

CONCLUSIONS

These data show the ease of removal of the Memokath 028 stent, reinforce its overall success in achieving the requirements of the ideal intraprostatic stent, and further emphasize the advantages of this implant over the epithelializing, permanent intraprostatic stent.

Memokath® stents for the treatment of detrusor sphincter dyssynergia (DSD) in men with spinal cord injury: The Princess Royal Spinal Injuries Unit 10-year experience

STUDY DESIGN

Medical records review.

OBJECTIVE

To assess the effectiveness of the Memokath (Engineers and Doctors A/S, Denmark) thermosensitive stent as a 'nondestructive' means of reducing bladder outlet resistance by treating detrusor sphincter dyssynergia (DSD) of neurogenic bladder dysfunction associated with spinal cord injury.

SETTING

Spinal Injuries Unit, Sheffield, England.

METHODS

A medical records review was performed to examine our experience of Memokaths over the last 10 years. During this time, 29 patients with spinal cord injury (17 tetraplegic and 12 paraplegic) underwent stenting of the external urethral sphincter either for prevention of dysreflexic symptoms, high residual urine volumes and subsequent urinary tract infection (UTI) or for protection of the upper tracts.

RESULTS

A total of 33 stents were inserted into 29 men (25-77 years) with suprasacral spinal cord injury. Initial results showed that the Memokath was effective in almost all for relief of dysreflexic symptoms and elimination of DSD on pressure flow urodynamics. However, to date, 30 of the 33 stents have been removed. The overall mean working life of the Memokath was 21 months. Four stents were removed electively and 23 for complications, which included stent migration (seven) and blockage (14). Single-ended stents were more prone to migration, which was rare after 1 year (1-13 months, median 3 months, mean 5.5 months). Stent blockage by encrustation or prostatic ingrowth did not occur before 12 months (12-45 months, median 30, mean 27.9 months).

CONCLUSIONS

In selected patients, temporary, thermo-expandable (Memokath) stents are effective in the treatment of DSD. The 'working life' of a Memokath stent is 21 months; however, complications do occur which may necessitate removal. Our overall experience with Memokath stents was disappointing. In future, Memokath stents will only be inserted after careful consideration in patients with prior 'failed' transurethral sphincterotomy or with caution in patients suitable for reconstructive surgery.

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.

The use of the Memokath stent in the treatment of detrusor sphincter dyssynergia in spinal cord injury patients: a single-centre seven-year experience

AIMS

A retrospective analysis of our seven-year experience with the Memokath urethral stent for the treatment of detrusor sphincter dyssynergia (DSD) in spinal cord injured (SCI) patients.

PATIENTS AND METHODS

Twenty five patients with SCI underwent rhabdosphincter Memokath stent insertion. The mean age was 45.5 years (range 32-65 years). The level of injury was cervical in 14 and thoracic in 11 patients. All patients were shown to have neurogenic detrusor overactivity with DSD associated with high detrusor pressures and incomplete emptying on pre-operative video-cystometrograms (VCMG). The Memokath stent was inserted using a standardized protocol. Follow-up assessment included blood chemistry, ultrasound scan (upper tracts and residual urine) at one and three months after insertion, and a follow-up VCMG at six months. The pre-operative and six-month post-operative VCMG results were analysed by the paired t-test and p value <0.05 was taken as significant.

RESULTS

There was a significant reduction in maximum detrusor pressure, duration of contraction and residual urine volume (p<0.05) on the VCMG six months after insertion of the stent. At present six patients have a Memokath stent in situ at a mean of 34.7 months (range 6-86 months). Nineteen stents were removed for several reasons at a mean of 20.3 months (range 0.25-41 months). These include, exacerbation of autonomic dysreflexic symptoms (n=3); stent migration (n=7); encrustation and stone formation (n=5); incomplete bladder emptying without obstruction (n=3); entrance into fertility program (n=1).

CONCLUSION

The Memokath stent is safe, easy and quick to insert with minimal trauma to the urethra. It is effective in the management of DSD and decreasing the detrusor pressure and residual urine volume in SCI patients. Moreover the ease of its removal in a non-traumatic fashion makes this stent an attractive option when patients are still contemplating the method of bladder management, in those wishing to be involved in fertility program and in recently SCI patients who may recover some manual dexterity to perform clean intermittent self-catheterisation. It must be remembered that this is a temporary stent, as our study clearly shows that the majority are removed within two years of insertion.