Bladder Surgery Research Articles

BRL37344, a β3-adrenergic Receptor Agonist, Decreases Nerve-evoked Contractions in Human Detrusor Smooth Muscle Isolated Strips: Role of BK Channels

To investigate the mechanism by which BRL37344, a β3-adrenergic receptor (β3-ARs) agonist, facilitates the inhibition of nerve-evoked contractions in human detrusor smooth muscle (DSM) isolated strips and to identify the role of large-conductance Ca(2+)-activated K(+) (BK) channels in this process. Human DSM specimens were obtained from open bladder surgeries on patients without preoperative history of overactive bladder symptoms. Isometric DSM tension recordings were conducted using force-displacement transducers and thermostatically controlled tissue baths. Nerve-evoked contractions were generated by electrical field stimulation (EFS). BRL37344, a β3-AR agonist, significantly decreased the amplitude, muscle force, and duration of the DSM contractions induced by 20 Hz EFS, in a concentration-dependent manner. This BRL37344-mediated inhibition of the amplitude and muscle force of the nerve-evoked DSM contraction was significantly reduced by iberiotoxin, a highly selective inhibitor of the BK channel, revealing a role for BK channels in the β3-AR-induced inhibition of human DSM nerve-evoked contractions. We further used atropine, α,β-methylene-ATP, and suramin to separate the cholinergic and purinergic components of human DSM nerve-evoked contractions. We found that the β3-AR agonist, BRL37344, inhibited both components of the EFS-induced (0.5-50 Hz) DSM contractions. This study supports the concept that β3-AR agonists inhibit nerve-evoked contractions in human DSM. We have further revealed that BK channels play a critical role in BRL37344-mediated relaxation of nerve-evoked contractions in human DSM. The study suggests that in addition to β3-ARs, BK channels may also represent promising pharmacologic targets in the treatment of urinary bladder dysfunction.

Neurogenic Detrusor Overactivity Is Associated with Decreased Expression and Function of the Large Conductance Voltage- and Ca2+-Activated K+ Channels

Patients suffering from a variety of neurological diseases such as spinal cord injury, Parkinson’s disease, and multiple sclerosis often develop neurogenic detrusor overactivity (NDO), which currently lacks a universally effective therapy. Here, we tested the hypothesis that NDO is associated with changes in detrusor smooth muscle (DSM) large conductance Ca2+-activated K+ (BK) channel expression and function. DSM tissue samples from 33 patients were obtained during open bladder surgeries. NDO patients were clinically characterized preoperatively with pressure-flow urodynamics demonstrating detrusor overactivity, in the setting of a clinically relevant neurological condition. Control patients did not have overactive bladder and did not have a clinically relevant neurological disease. We conducted quantitative polymerase chain reactions (qPCR), perforated patch-clamp electrophysiology on freshly-isolated DSM cells, and functional studies on DSM contractility. qPCR experiments revealed that DSM samples from NDO patients showed decreased BK channel mRNA expression in comparison to controls. Patch-clamp experiments demonstrated reduced whole cell and transient BK currents (TBKCs) in freshly-isolated DSM cells from NDO patients. Functional studies on DSM contractility showed that spontaneous phasic contractions had a decreased sensitivity to iberiotoxin, a selective BK channel inhibitor, in DSM strips isolated from NDO patients. These results reveal the novel finding that NDO is associated with decreased DSM BK channel expression and function leading to increased DSM excitability and contractility. BK channel openers or BK channel gene transfer could be an alternative strategy to control NDO. Future clinical trials are needed to evaluate the value of BK channel opening drugs or gene therapies for NDO treatment and to identify any possible adverse effects.

Symptomatic Extraperitoneal Bladder Perforation Following Transurethral Bladder Surgery: Imaging with CT Urography

An 80 year-old man presented to his primary care physician with painless gross hematuria. He reported having intermittent episodes of pink urine containing small clots for about three months. He was initially treated with a single course of ciprofloxacin for presumed urinary tract infection. His symptoms did not improve with antibiotic therapy and he was then referred to our institution for a computed tomography (CT) urogram. CT urogram showed a 4 x 3.6 centimeter (cm) infiltrating solid mass along the left lateral posterior wall of the urinary bladder (Figure-1). Tumor also extended along the bladder dome. Prostate enlargement and bladder diverticula were also present. He was referred to the urology service and subsequently underwent transurethral resection of bladder tumor (TURBT) with fulguration. No intraoperative complications were noted and he returned to the recovery room in satisfactory condition on continuous bladder irrigation. Pathologic examination revealed a 5 cm transitional cell carcinoma with high grade growth pattern invading the deep muscular layer. On postoperative day one, the patient reported abdominal pain and general discomfort. Physical exam revealed a grossly distended abdomen which was tender to palpation with positive guarding and decreased bowel sounds. He Symptomatic Extraperitoneal Bladder Perforation Following Transurethral Bladder Surgery: Imaging with CT Urography _______________________________________________

Risk Factors for Progression or Improvement of Lower Urinary Tract Symptoms in a Prospective Cohort of Men

We determined the metabolic, lifestyle and physical factors associated with progression or improvement of storage and voiding lower urinary tract symptoms in a population based cohort of men. After the exclusion of men with prostate or bladder cancer and/or surgery from the study, progression and improvement of storage and voiding lower urinary tract symptoms was assessed using the AUA-SI (American Urological Association symptom index) in 780 men, age 35 to 80 years at baseline, who attended 5-year followup clinics. Storage and voiding lower urinary tract symptoms progressed in 39.8% (308) and 32.3% (250) of men, and improved in 33.1% (256) and 23.4% (181), respectively. In final adjusted regression models greater bother and physical activity at baseline predicted improvement in storage and voiding lower urinary tract symptoms, while greater income, high-density lipoprotein cholesterol and lower triglycerides predicted improvement of storage lower urinary tract symptoms only. Being widowed, higher plasma estradiol and depression at baseline predicted the progression of storage and voiding lower urinary tract symptoms, while greater abdominal fat mass and obstructive sleep apnea risk predicted the progression of storage lower urinary tract symptoms only. Older age, lower high-density lipoprotein cholesterol, testosterone, income, previous benign prostatic hyperplasia and erectile dysfunction at baseline predicted the progression of voiding lower urinary tract symptoms only. The initiation or continued use of α-blockers or anticholinergics (storage lower urinary tract symptoms), and 5α-reductase inhibitors (voiding lower urinary tract symptoms), were associated with symptom improvement. Lower urinary tract symptoms may progress or remit. Even accounting for medication use, progression may be associated with modifiable disease, or metabolic or behavioral factors, which are also risk factors for type 2 diabetes and cardiovascular disease. These factors should be looked for and managed.

Adjustable male sling: our experiences with placement of adjustable male sling, including a case of exstrophy-epispadias: initial report.

To present our experience of using an adjustable male sling, Argus® (Promedone SA; Cordoba, Argentina), in patients with stress urinary incontinence (SUI), and report its success, extension of indications, and management of complications. We retrospectively evaluated Argus implantation results in 17 patients, including 15 post prostatectomy incontinence, one exstrophy-epispadias, and one neurogenic bladder patient. Of 17 patients, 12 had severe (more than 5 pads daily) and 5 had moderate SUI (2 to 5 pads daily). Seven patients had history of previous surgeries. Patients were evaluated pre-operatively with urodynamic study and cystoscopy. After median follow-up of 11.8 months (range, 3 to 22 months), 9 patients were continent, 7 had mild SUI (1 pad daily), and one had the device removed due to perineal and bladder symptoms. Argus adjustment was done in 10 out of 17 patients; 8 tightening and 2 loosening. In a totally incontinent exstrophy-epispadias patient with a history of multiple bladder surgeries, continence was achieved after device readjustment. In a patient with neurogenic bladder with a history of cystoplasty, severe SUI changed into a moderate sporadic SUI. In 2 patients, prosthesis infection occurred, which was managed with antibiotics without the need for Argus explantation. Argus is a simple and good device to control incontinence in men. It may also be used in exstrophy-epispadias patient who is not a candidate for urinary sphincter implantation. Infection complication may be managed conservatively. To the best of our knowledge, this is the first report of successful Argus implantation in exstrophy-epispadias patient.

Ephedrine hydrochloride: Novel use in the management of resistant non-neurogenic daytime urinary incontinence in children

ObjectiveTo determine whether the adrenoceptor agonist, ephedrine hydrochloride, is an effective treatment for resistant non-neurogenic daytime urinary incontinence in children. MethodsFrom 2000 to 2010, eighteen children with resistant non-neurogenic daytime urinary incontinence were treated with oral ephedrine hydrochloride at our institution. Sixteen were female and two were male. Median age at treatment was 12 years (range 5–15 years). Two children had spina bifida occulta. There were no other co-morbidities. Multiple anticholinergics were prescribed and dose maximized to support a bladder and bowel training programme, without achieving continence in this resistant group of children. Pre-treatment urodynamics were normal in 10, but revealed an open bladder neck in 8 patients. None showed detrusor over-activity. Oral ephedrine hydrochloride was started at 7.5 mg or 15 mg twice daily and titrated up to a maximum of 30 mg four times daily according to response. ResultsMedian follow-up was 7 years (range 6–8 years). Seventeen children (94%) reported improvement in symptoms and six (33%) achieved complete urinary continence. All patients maintained compliant bladders on post-treatment urodynamics. Seven of the 8 previously open bladder necks were closed. No patients reported any significant side effects. Patients with open bladder necks on pre-treatment urodynamics were more likely to show a full response to ephedrine (odds ratio 15; 95% CI 1.2–185.2). ConclusionsOral ephedrine hydrochloride is an effective treatment for carefully selected children with resistant non-neurogenic daytime urinary incontinence.

Urinary Retention Due to Benign Tumor of the Bladder Neck in a Woman; A Rare Case of Papillary Cystitis

Urinary retention (UR) is not common in women. There are numerous causes now recognized in women, broadly categorized as infective, pharmacological, neurological, anatomical, myopathic and functional. As opposed to the male, obstructive UR is unusual in women. A 56-year-old woman presented with urinary retention. She reported difficulty in urination for more than 15 days. She had no history of urinary tract infection, bladder surgery and catheterization. Her physical examination revealed a soft tissue mass obstructing the external orifice of the urethra. After its partial removal the patient regained her ability to urinate. The patient underwent urological investigation. Ultrasound examination of the urinary system was normal. Cystoscopic examination revealed a papillary lesion with broad base floating along the bladder neck. The patient underwent transurethral resection of the bladder tumor. Pathological examination diagnosed papillary cystitis. She was scheduled for a regular follow-up with urine cytology, ultrasound and cystoscopy. One year after diagnosis the patient remains free of symptoms and no recurrence was observed. Papillary and polypoid cystitis are benign lesions, however under certain circumstances they should be considered in the differential diagnosis of transitional cell carcinoma of the bladder. Lack of the prominent inflammation and edema that characterizes both papillary and polypoid cystitis, and absence of a history of recent bladder catheterization and presence of vesical fistula may facilitate the decision to biopsy the lesion. To our knowledge, this is the first case of papillary cystitis presenting with urinary retention in a woman to be reported in the literature.

Obesity, diabetes and aggressive prostate cancer hormone-naïve at initial diagnosis.

IntroductionEpidemiologic studies have implicated obesity in prostate cancer (PCa) development and aggressiveness; nevertheless, no clear consensus has been reached. The aim of the research was to investigate the association of obesity with PCa, hormone-naïve at initial diagnosis.MethodsA retrospective analysis of 266 patients undergoing prostate biopsy at our institution, between 2006 and 2009, was conducted. We examined obesity and PCa association in 133 patients with PCa, hormone-naïve at initial diagnosis, versus 133 age-matched controls. Men with incomplete data available, a history of hormone therapy or chemotherapy, prostate or bladder surgery were excluded.ResultsObesity was significantly associated (OR 2.25) with aggressive PCa (Gleason score ≥7) and inversely related (OR 0.35) to non-aggressive PCa (Gleason score ≤6). Particularly, obesity in diabetic patients was significantly linked with aggressive PCa (OR 4.17). No association was noted between obesity and PCa development.ConclusionsIn our study, obese patients, particularly in combination with diabetes mellitus (DM), were more likely to present with more aggressive PCa. Further research with larger samples should be done to confirm these associations and to stabilize future prevention strategies.

Self-Inflicted Male Bladder Foreign Body: Its Endoscopic Removal Using a Rigid Cystoscope and a Suprapubic Forceps

Introduction. Herein we present an interesting technique for the removal of bladder foreign body (BFB) in which a combination of endoscopic and suprapubic cystostomy was used. Case Presentation. The patient was a case of illicit drug abuser who self-introduced an electrical wire into his bladder. After its failed cystoscopic removal, the foreign body was removed suprapubically without open bladder surgery. Discussions. Bladder foreign bodies are not uncommon. Based on the literature review, mainly open surgeries were used for their treatment. Using of our less invasive technique is a good way for escaping from open cystostomy. Conclusion. Endoscopic removal of the bladder foreign bodies is possible without any need for open bladder surgery.

Spontaneous Bladder Perforation in an Infant Neurogenic Bladder: Laparoscopic Management

Spontaneous bladder perforation is an uncommon event in childhood. It is usually associated with bladder augmentation. We are presenting a case of bladder rupture in an infant with neurogenic bladder without prior bladder surgery. Three days after lipomyelomeningocele excision the patient showed signs and symptoms of acute abdomen. The ultrasound exploration revealed significant amount of intraperitoneal free fluid and therefore a laparoscopic exploration was performed. A posterior bladder rupture was diagnosed and repaired laparoscopically. Currently, being 3 years old, she keeps successfully dry with clean intermittent catheterization. Neurogenic bladder voiding function can change at any time of its evolution and lead to complications. Early diagnosis of spontaneous bladder rupture is of paramount importance, so it is essential to think about it in the differential diagnosis of acute abdomen.

SUPERIOR SOMATIC PAIN RELIEF AND IMPROVED VISCERAL PAIN CONTROL IS ACHIEVED USING PRE-EMPTIVE ANALGESIA FOR LAPAROSCOPIC CHOLECYSTECTOMY: A RANDOMIZED CONTROLLED TRIAL

BACKGROUND:Laparoscopic cholecystectomy, although is less invasive than open surgery, is not completely pain free. The use of local anaesthesia to relieve pain following this procedure is a common practice. However, it remains debatable whether a pre- or post-operative drug administration is more effective. Here, we investigated the role of preemptive local anaesthetic infiltration given pre- or post-incisional, in relieving the pain during laparoscopic surgery.METHODOLOGY:A randomized controlled trial was conducted with 96 patients receiving 0.5% Bupivacaine 100mg. Group A (n=48) received post-incisional skin infiltration whilst Group B (n=48) received pre-incisional infiltration. Incisional (somatic) and intra-abdominal (visceral) pain was assessed using Visual Analog Scale (VAS) at day 0, day 1 and day 7 post-operative days.RESULT:Baseline characteristics between the two groups were similar. Incisional pain was lower in Group B as compared to Group A at day 0 (P=0.03) and day 1 (P 0.05).CONCLUSION:Administration of pre-incisional local anaesthesia offers better pre-emptive pain relief measure than post-incisional administration by reducing somatic and visceral pain in laparoscopic gall bladder surgery.

Laparoscopic nephroureterectomy with concomitant open bladder cuff excision: a single center experience.

To evaluate the efficacy of laparoscopic nephroureterectomy and open bladder cuff excision for management of upper urinary tract urothelial carcinoma. Twenty-two patients with upper urinary tract urothelial carcinoma, who had undergone laparoscopic nephroureterectomy and open bladder cuff excision between September 2004 and October 2010, were studied retrospectively. Operation time, blood loss, analgesic dose, and complications were recorded. Local and port site recurrence, distant metastasis, and survival rate were also evaluated. Patients consisted of 18 men and 4 women, with the mean age of 64.1 years (range, 52 to 83 years). Right upper urinary tract was the involved site in 12 patients and left in 10 patients. Mean operation time was 216 minutes (range, 145 to 395 minutes) and mean hospital stay was 4.3 days. Mean follow-up period was 36.57 months (range, 6 to 65 months). No trocar site recurrence occurred. Three-year overall survival and metastasis-free survival were 95% and 90%, respectively. Laparoscopic nephroureterectomy along with open bladder cuff excision harbors an advantage of laparoscopy concomitant with simplicity and safety of open excision of distal ureter and bladder cuff through the same inevitable incision that is needed for specimen retrieval, without adding any more morbidity to the patient, a win-win radical surgery.

Retroperitoneoscopic Hand-Assisted Nephroureterectomy Using a Homemade Device

To carry out hand-assisted retroperitoneoscopic nephroureterectomy (HARN) and open bladder cuff excision using a homemade hand-assist device. Twenty-four consecutive patients with upper tract transitional cell carcinoma received HARN and open bladder cuff excisions. The procedures were carried out using a homemade hand-assist device comprising a medium-sized Alexis wound retractor and surgical gloves. The Alexis wound retractor was positioned through a 7-8-cm Gibson incision ready for use. The surgeon inserted the double-gloved, nondominant hand into the retroperitoneal space via the wound retractor. During the procedure, the cuff of the surgeon's outer surgical glove was turned outside-in and snapped onto the external ring of the Alexis wound retractor to prevent carbon dioxide gas leakage. We successfully created pneumoretroperitoneum by insufflating with carbon dioxide at 15 mm Hg. The procedure was carried out through the 7-8-cm Gibson incision and two additional laparoscopic ports. All procedures were performed without complication. The mean estimated blood loss was 81 mL. The mean operation time was 103 minutes. Morphine (mean, 17.6 mg) was administered for pain relief for 1-3 days following surgery. The mean time for recommencing oral intake was 1.5 days, and that to ambulation was 2.0 days. There were no wound complications related to the homemade hand-assist device. Preliminary results show that carrying out HARN using a homemade hand-assist device is safe and feasible. Our homemade hand-assist device offers a cost reduction for the HARN procedure over using commercially available devices.

Hospitalization Trends After Prostate and Bladder Surgery: Implications of Potential Payment Reforms

Hospital stays have decreased for patients undergoing surgery for urological cancer. However, there are concerns that patients are being discharged from the hospital prematurely. We examined associations between hospital stay and short-term outcomes for a low risk procedure (prostatectomy) and high risk procedure (cystectomy). We used SEER (Surveillance, Epidemiology and End Results)-Medicare data from 1992 through 2005 to identify 46,781 prostatectomy and 9,035 cystectomy cases. We assessed our main outcome (adjusted likelihood of hospital readmission within 30 days) using a logistic regression model. Secondary outcomes included mortality rates and discharge disposition. In comparing patients from 1992 to 1993, to 2004 to 2005, hospital stay decreased approximately 3 days for both surgeries (relative decrease of more than 50% for prostatectomy and 21% for cystectomy). Hospital readmission rates were 4.5% and 25.2% for prostatectomy and cystectomy, respectively, and remained stable with time. Skilled nursing/intermediate care use was stable for patients who underwent prostatectomy (approximately 1%), but increased from 8.2% (95% CI 5.4-11.4) to 18.9% (95% CI 16.8-21.3) for those treated with cystectomy. Use of home care increased from 8.1% (95% CI 7.3-9.0) to 11.1% (95% CI 10.1-12.1) and from 34.2% (95% CI 29.7-38.7) to 47.5% (95% CI 44.5-50.1) for prostatectomy and cystectomy cases, respectively. Reductions in hospital stay were more dramatic for patients who underwent prostatectomy and were associated with stable short-term outcomes. Conversely, smaller reductions in hospitalization for patients undergoing cystectomy were met with substantial increases in the use of post-acute care. Going forward, close surveillance of how imminent policy reforms affect patterns and quality of care will be necessary.

Anterior vesical hitch – A step to enhance safety of percutaneous access to bladder

PurposeTo describe the novel technique of anterior vesical hitch to enhance the efficacy and safety of percutaneous bladder surgery. Materials and methodsThe anterior bladder wall is anchored to the anterior abdominal wall with the help of a prolene suture passed slightly lateral to the midline midway between the pubic symphysis and umbilicus. Percutaneous cystolitholapaxy and antegrade posterior urethral valve ablation were performed after anterior vesical hitch in five pediatric male patients. Data collected included operative parameters and complications related to the technique. ResultsMean patient age was 2.9 years (range 1.5–6 years). Three patients had bladder stones and two had posterior urethral valves. Mean time to achieve bilateral parietal fixation of the bladder was 7 min 20 s. There was no intraoperative slippage of Amplatz sheath or suture cut through. No bleeding from the puncture site was encountered. No postoperative complication related to the percutaneous access tract was noted in any patient. ConclusionsThe anterior vesical hitch procedure is safe and easy. It prevents slippage of Amplatz sheath during percutaneous access to the bladder lumen.

Effects of exposure to pile-driving sounds on the lake sturgeon, Nile tilapia and hogchoker

Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon (Acipenser fulvescens)--with an open (physostomous) swim bladder, Nile tilapia (Oreochromis niloticus)--with a closed (physoclistous) swim bladder and the hogchoker (Trinectes maculatus)--a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SEL(cum) and SEL(ss) respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders.

Sequential robotic-assisted bladder diverticulectomy and radical prostatectomy. Technique and review of the literature

INTRODUCTIONAcquired bladder diverticula (BD) in men over the age of 60 are usually due to bladder outlet obstruction (BOO) secondary to prostatic enlargement. In cases of clinical significant BD with persistent symptoms or complications surgical excision should be considered. In the treatment of BD it is important to address the BOO with a bladder outlet procedure either simultaneously or in a staged fashion. PRESENTATION OF CASEWe present to the best of our knowledge, the first case of sequential robotic-assisted bladder diverticulectomy (RABD) combined with robotic-assisted radical prostatectomy (RARP) in a patient with large diverticula and malignant prostate enlargement as the cause of BOO. DISCUSSIONConcomitant open radical prostatectomy and bladder diverticulectomy series have been described, while minimal invasive procedures combining BD excision with relive of BOO especially due to benign prostatic enlargement have been reported to be safe and effective. CONCLUSIONConcomitant RABD with RARP is a safe and effective procedure with excellent oncological and functional results.

Repair of pediatric bladder rupture improves survival: results from the National Trauma Data Bank

Background/purposeThe urinary bladder is the second most commonly injured genitourinary organ. The objective of this study was to describe the management of pediatric traumatic bladder ruptures in the United States and their association with surgical repair and mortality. MethodsWe searched the 2002-2008 National Trauma Data Bank for all pediatric (<18 years old) subjects with bladder rupture. Demographics, mechanism of injury, coexisting injury severity, and operative interventions for bladder and other abdominal trauma are described. Multivariate logistic regression analysis was used to examine the relationship between bladder rupture and both bladder surgery and in-hospital mortality. ResultsWe identified 816 children who sustained bladder trauma. Forty-four percent underwent bladder surgery, including 17% with an intraperitoneal injury. Eighteen percent had 2 intra-abdominal injuries, and 40% underwent surgery to other abdominal organs. In multivariate analysis, operative bladder repair reduced the likelihood of in-hospital mortality by 82%. A greater likelihood of dying was seen among the uninsured and those with more severe injuries and multiple abdominal injuries. ConclusionsAfter bladder trauma, pediatric patients demonstrate significantly improved survival when the bladder is surgically repaired. With only 67% of intraperitoneal bladder injuries being repaired, there appears to be underuse of a life-saving procedure.

In-vivo performance of high-density collagen gel tubes for urethral regeneration in a rabbit model

Congenital malformations or injuries of the urethra can be treated using existing autologous tissue, but these procedures are sometimes associated with severe complications. Therefore, tissue engineering may be advantageous for generating urethral grafts. We evaluated engineered high-density collagen gel tubes as urethral grafts in 16 male New Zealand white rabbits. The constructs were either acellular or seeded with autologous smooth muscle cells, isolated from an open bladder biopsy. After the formation of a urethral defect by excision, the tissue-engineered grafts were interposed between the remaining urethral ends. No catheter was placed postoperatively. The animals were evaluated at 1 or 3 months by contrast urethrography and histological examination. Comparing the graft caliber to the control urethra at 3 months, a larger caliber was found in the cell-seeded grafts (96.6% of the normal caliber) than in the acellular grafts (42.3%). Histology of acellular and cell-seeded grafts did not show any sign of inflammation, and spontaneous regrowth of urothelium could be demonstrated in all grafts. Urethral fistulae, sometimes associated with stenosis, were observed, which might be prevented by urethral catheter application. High-density collagen gel tubes may be clinically useful as an effective treatment of congenital and acquired urethral pathologies.

Cell-seeded tubular acellular matrix for replacing a long circumferential urethral defect in a canine model: Is it clinically applicable?

ObjectiveTo evaluate the feasibility of replacing a relatively long segment of the canine urethra by a tube of cell-seeded acellular collagen bladder matrix. Materials and methodsThe study included 14 female mongrel dogs in which a 3-cm segment of the whole urethral circumference was excised and replaced by a tube of acellular matrix seeded with autologous urothelial cells. The acellular matrix was obtained from the excised bladder of female donor dogs that were not included in the study. Autologous cells were obtained from the study dogs by open bladder biopsy, with subsequent in vitro expansion and cultivation. Urethroplasty was performed over a 16 F urethral catheter that was kept for 4weeks. The dogs were killed humanely (one every week for 4weeks and then one monthly for 10months). After stent removal, retrograde urethrography was used each month in the living dogs. If retention occurred a urethrogram was taken and then the dog was killed humanely. All grafts from dogs were harvested and sent for histopathological examination. ResultsExploration at 1, 2, 3 and 4weeks showed progressive shrinkage in length, together with relative narrowing of the lumen. Three dogs developed retention within a week after stent removal and the other seven developed retention within 4months. Retrograde urethrograms showed evidence of stricture and/or fistula at the graft site in all dogs. On exploration, grafts showed marked shrinkage (0.6–1.2cm in length) with complete obliteration of their lumens. Histopathological examination showed extensive fibrosis of the matrix with no evident urothelial architecture. ConclusionCell-seeded acellular matrix tube is insufficient to replace a 3-cm circumferential urethral defect in dogs.