Repair of injured urethras with silk fibroin scaffolds in a rabbit model of onlay urethroplasty.

BACKGROUND: Preclinical validation of scaffold-based technologies in animal models of urethral disease is desired to assess wound healing efficacy in scenarios that mimic the target patient population. This study investigates the feasibility of bilayer silk fibroin (BLSF) scaffolds for the repair of previously damaged urethras in a rabbit model of onlay urethroplasty. MATERIALS AND METHODS: A focal, partial thickness urethral injury was created in adult male rabbits (n = 12) via electrocoagulation and then onlay urethroplasty with 50 mm2 BLSF grafts was carried out 2 wk after injury. Animals were randomly divided into three experimental groups and harvested at 2 wk after electrocoagulation (n = 3), and 1 (n = 3) or 3 (n = 6) months after scaffold implantation. Outcome analyses were performed preoperatively and at 2 wk after injury in all groups as well as at 1 or 3 mo after scaffold grafting and included urethroscopy, retrograde urethrography (RUG), and histological and immunohistochemical analyses. RESULTS: At 2 wk after electrocoagulation, urethroscopic and RUG evaluations confirmed urethral stricture formation in 92% (n = 11/12) of rabbits. Gross tissue assessments at 1 (n = 3) and 3 (n = 6) mo after onlay urethroplasty revealed host tissue ingrowth covering the entire implant site. At 3 mo post-op, RUG analyses of repaired urethral segments demonstrated a 39% reduction in urethral stenosis detected following electrocoagulation injury. Histological and immunohistochemical analyses revealed the formation of innervated, vascularized neotissues with α-smooth muscle actin+ and SM22α+ smooth muscle bundles and pan-cytokeratin + epithelium at graft sites. CONCLUSIONS: These results demonstrate the feasibility of BLSF matrices to support the repair of previously damaged urethral tissues.

A new material to prevent urethral damage after implantation of artificial devices: an experimental study.

OBJECTIVE: To validate the application of the bacterial cellulose (BC) membrane as a protecting bar-rier to the urethra. MATERIALS AND METHODS: Forty female Wistar rats (four groups of 10): Group 1 (sham), the urethra was dissected as in previous groups and nothing applied around; Group 2, received a 0.7cm strip of the BC applied around the urethra just below the bladder neck; Group 3, received a silicon strip with the same dimensions as in group 2; Group 4, had a combination of 2 and 3 groups being the silicon strip applied over the cellulosic material. Half of the animals in each group were killed at 4 and 8 months. Bladder and urethra were fixed in formalin for histological analysis. RESULTS: Inflammatory infiltrates were more intense at 4 months at lymphonodes (80% Grade 2), statistically different in the group 2 compared with groups 1 (p=0.0044) and 3 (p=0.0154). At 8 months, all samples were classified as grade 1 indicating a less intense inflammatory reaction in all groups. In group 2, at 8 months, there was a reduction in epithelial thickness (30±1µm) when com-pared to groups 1 (p=0.0001) and 3 (p<0.0001). Angiogenesis was present in groups 2 and 4 and absent in group 3. In BC implant, at 4 and 8 months, it was significant when comparing groups 4 with 1 (p=0.0159). CONCLUSION: BC membrane was well integrated to the urethral wall promoting tissue remodeling and strengthening based on morphometric and histological results and may be a future option to prevent urethral damage.

Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery.

Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

Tissue-engineered autologous urethras for patients who need reconstruction: an observational study.

BACKGROUND: Complex urethral problems can occur as a result of injury, disease, or congenital defects and treatment options are often limited. Urethras, similar to other long tubularised tissues, can stricture after reconstruction. We aimed to assess the effectiveness of tissue-engineered urethras using patients' own cells in patients who needed urethral reconstruction. METHODS: Five boys who had urethral defects were included in the study. A tissue biopsy was taken from each patient, and the muscle and epithelial cells were expanded and seeded onto tubularised polyglycolic acid:poly(lactide-co-glycolide acid) scaffolds. Patients then underwent urethral reconstruction with the tissue-engineered tubularised urethras. We took patient history, asked patients to complete questionnaires from the International Continence Society (ICS), and did urine analyses, cystourethroscopy, cystourethrography, and flow measurements at 3, 6, 12, 24, 36, 48, 60, and 72 months after surgery. We did serial endoscopic cup biopsies at 3, 12, and 36 months, each time in a different area of the engineered urethras. FINDINGS: Patients had surgery between March 19, 2004, and July 20, 2007. Follow-up was completed by July 31, 2010. Median age was 11 years (range 10-14) at time of surgery and median follow-up was 71 months (range 36-76 months). AE1/AE3, α actin, desmin, and myosin antibodies confirmed the presence of cells of epithelial and muscle lineages on all cultures. The median end maximum urinary flow rate was 27·1 mL/s (range 16-28), and serial radiographic and endoscopic studies showed the maintenance of wide urethral calibres without strictures. Urethral biopsies showed that the engineered grafts had developed a normal appearing architecture by 3 months after implantation. INTERPRETATION: Tubularised urethras can be engineered and remain functional in a clinical setting for up to 6 years. These engineered urethras can be used in patients who need complex urethral reconstruction. FUNDING: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.

[Catheter-associated urinary tract infections: epidemiology and prevention]. / Le infezioni urinarie associate a catetere: epidemiologia e prevenzione.

Urinary tract infections (UTIs) represent the second most often observed infectious diseases in community, following the respiratory tract infections. In the United States, these infections account for up to 7 million/year of visits, with a mean yearly expense for the related antibiotic treatment that has been estimated in more than one billion dollars. In nosocomial setting, UTIs represent the most frequent diseases, whose incidence equates 40% of nosocomial infections overall considered; about 80% of UTIs is related to urinary catheterization. In the present review, the authors, after a brief introduction about epidemiology, pathogenesis and aetiology of urinary tract infections, consider two particular settings: long term care facilities, where UTIs represent the most often diagnosed and treated infections, and the Intensive Care Units where occurrence of urinary tract infections represents an especially frequent event as well. Patients referred to both these settings are particular, as they undergo, in most cases, to urinary catheterization. After describing the pathogenesis of UTIs related to catheterization, either short- or long term, the authors consider the different currently available catheters, focusing on silver-coated and silver alloy coated (silver, gold, and platinum). With regard to this latter issue, results presented by a number of papers in the literature are reported, where clinical experiences following the use of these urinary catheters are described. In their conclusion, authors suggest the opportunity to increase any prevention strategy able to reduce the incidence of infections related to urinary catheterization and its consequences, as a more rational length and modality of catheterization, in addition to the use of innovative catheters.

Endoscopic treatment of vesical and urethral perforations after tension-free vaginal tape (TVT) procedure for female stress urinary incontinence.

UNLABELLED: Stress urinary incontinence is a problem that is prevalent in women, and its treatment with minimally invasive techniques using synthetic materials has increased recently, although the procedure has also brought increased occurrence of specific complications such as vesical and urethral perforations. We describe 11 cases of endoscopic correction of vesical and urethral perforations due to the use of synthetic material for the treatment of stress urinary incontinence. MATERIALS AND METHOD: Eleven patients were treated for complications after undergoing the TVT(R) (tension-free vaginal tape) procedure; 6 of them had the polypropylene tape inside the bladder, and 5 had erosion of the urethra. Endoscopic resection of the polypropylene tapes was performed on all patients. RESULTS: A 6-month follow-up with cystoscopic control showed that the procedures were successful with complete relief of the symptoms except for 1 patient who persisted with the polypropylene tape in the bladder. This patient underwent a new endoscopic resection, and the cystoscopic control exam was normal 3 months later. CONCLUSION: Endoscopic resection of intravesical and intraurethral synthetic tapes can be considered a good alternative for the treatment of complications resulting from the TVT procedure.

A novel use of dextranomer/hyaluronic acid copolymer.

The aim of this study is to present a novel use of Dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of a complicated iatrogenic chronic urethral injury. A 12-year-old boy with a neuropathic bladder presented a groove in the urethral mucosa due to chronic clean intermittent catheterizations (CICs) and suffered a posterior urethral injury during a failed catheterization for a routine examination. The defect on the urethral wall was repaired using Deflux, a technique that is not described in the literature. After the intervention the patient is continuing CICs without further complications.

In vivo coefficient of kinetic friction: study of urinary catheter biocompatibility.

An animal model was developed to measure objectively the in vivo intrinsic coefficient of kinetic friction (COFk) of various catheter materials. Uncoated red rubber catheters had the highest COFk of the three materials tested. The Biocath catheter exhibited less COFk when compared with the standard silicone catheter. Although the etiology of urethral strictures is multifactorial, better biocompatibility as measured by in vivo COFk may be an important factor in the inevitable urethral trauma and irritation associated with indwelling catheterization and possibly with postcatheterization urethral stricture formation.

Finney flexirod prosthesis.

The experience gained from the implantation of 763 Flexirod Prosthesis is described. Special features of this design include a tapered distal tip which provides for better glans stability, a soft hinge which allows for improved penile concealment, and a trimmable tail which, together with preoperative measurement of the penis, allows the surgeon to determine the correct prothesis size well in advance of surgery. The surgical procedure is not difficult, the complication rate is low, device failure is extremely rare, and most patients are restored to a satisfactory sex life.

[Penile fractures: controversy of surgical vs. conservative treatment]. / Konservative vs. operative Therapie der Penisfrakturen.

This paper reviews the current status of information on diagnostic and therapeutic management of penile fractures, focusing on the controversy between surgical vs. conservative treatment of this uncommon injury. Penile fracture, commonly defined as a rupture of the tunica albuginea and corpus cavernosum, is a serious urological disorder demanding surgical management. The diagnostic procedure classically consists of history taking, physical examination and urinary status. Determination of the extent of severity and location of the rupture in the tunica albuginea takes foremost priority and requires additional imaging procedures, such as ultrasound or cavernosography, which will impart enough diagnostic information for the correct choice of treatment. In some cases, the urethra is injured as well. Immediate surgical repair offers complete recovery for patients with penile fracture in most cases, even in the presence of urethral injury. Although penile fracture is easily recognized and can therefore be classified as a "first-look diagnosis", therapy remains controversial to date. The correct therapeutical approach is a vital factor in management, as the associated significant morbidity can result in complete loss of erectile function, painful erections or penis deviation. Early surgical treatment is strongly recommended because of the excellent results, shorter hospitalization, less morbidity and an early return to sexual activity.

[Treatment of posterior urethral break caused by pelvic fracture and inflammatory urethral stricture via laying three silicone tubers into urethra].

We investigated a new approach for the treatment of posterior urethral break caused by pelvic fracture and inflammatory urethral stricture. 7-10 days after the operation of urethral realignment on patients with urethral break caused by pelvic fracture or after forced dilatation of inflammatory urethral stricture, three silicone tubers were laid into urethra and kept there for three months. In 66 cases of urethral break, the cure rate (58/66) was 87.9%, the improving rate (2/66) 3.0% and the failure rate (6/66) 9.1%. In 15 cases of inflammatory urethral stricture, the recovery rate was 100%. In this group of 81 cases, the cure rate was 92.6% and failure rate was only 7.4%. This new therapeutic approach proved to be simple, safe and effective. It could also dramatically reduce the infection or the stricture of urethra.

Histologic changes after urethroplasty using small intestinal submucosa unseeded with cells in rabbits with injured urethra.

OBJECTIVE: To determine whether small intestine submucosa has the same regenerative capacity when urethroplasty is performed in injured urethras. METHODS: Our experiment was conducted in 30 New Zealand male rabbits, all of which had urethral injury. One month after the injury, the animals were randomized into a control group or a group with onlay urethroplasty with small intestine submucosa. The animals were euthanized at 2, 4, 12, 24, and 36 weeks after urethroplasty, and their urethras were removed for histologic and immunohistochemical examination. Before the scheduled euthanasia, urethrography and cystoscopy were performed. RESULTS: After 2 weeks, there was evidence of a continuous monolayer of stratified epithelial cells and absence of smooth muscle fibers. One month later, the epithelium showed no changes from the previously observed features, but some smooth muscle fibers (representing newly formed vessels) became apparent. After 3 months, the graft showed increased concentration of smooth muscle fibers. After 6 and 9 months, the density of smooth muscle cells remained unchanged. Fiber arrangement was irregular, particularly at the anastomosis site. Epithelial and smooth muscle phenotypes were confirmed by immunohistochemistry using anti-pan-citokeratin (AE1/AE3) antibodies and anti-α-smooth muscle actin, respectively. CONCLUSION: Small intestine submucosa promotes regeneration in traumatized urethras, with slightly delayed epithelialization and abnormal distribution of smooth muscle. Urethral damage caused by trauma interferes with the normal healing process.

A new material to prevent urethral damage after implantation of artificial devices: an experimental study

ABSTRACT Objective To validate the application of the bacterial cellulose (BC) membrane as a protecting barrier to the urethra. Materials and Methods Forty female Wistar rats (four groups of 10): Group 1 (sham), the urethra was dissected as in previous groups and nothing applied around; Group 2, received a 0.7cm strip of the BC applied around the urethra just below the bladder neck; Group 3, received a silicon strip with the same dimensions as in group 2; Group 4, had a combination of 2 and 3 groups being the silicon strip applied over the cellulosic material. Half of the animals in each group were killed at 4 and 8 months. Bladder and urethra were fixed in formalin for histological analysis. Results Inflammatory infiltrates were more intense at 4 months at lymphonodes (80% Grade 2), statistically different in the group 2 compared with groups 1 (p=0.0044) and 3 (p=0.0154). At 8 months, all samples were classified as grade 1 indicating a less intense inflammatory reaction in all groups. In group 2, at 8 months, there was a reduction in epithelial thickness (30±1μm) when com-pared to groups 1 (p=0.0001) and 3 (p<0.0001). Angiogenesis was present in groups 2 and 4 and absent in group 3. In BC implant, at 4 and 8 months, it was significant when comparing groups 4 with 1 (p=0.0159). Conclusion BC membrane was well integrated to the urethral wall promoting tissue remodeling and strengthening based on morphometric and histological results and may be a future option to prevent urethral damage.

Comparison of the use of conventional, hydrophilic and gel-lubricated catheters with regard to urethral micro trauma, urinary system infection, and patient satisfaction in patients with spinal cord injury: a randomized controlled study.

BACKGROUND: Management of the lower urinary tract is crucially important in patients with spinal cord injuries in order to prevent damage to the upper urinary tract and to preserve renal function. AIM: This study was designed to compare the use of standard polyvinyl chloride (PVC), hydrophilic-coated, and gel-lubricated non-hydrophilic catheters with regard to urethral micro trauma, urinary system infection, and patient satisfaction in patients with spinal cord injuries. Study design. Randomized, controlled study. SETTING: University hospital, inpatient clinic. POPULATION: Twenty-five male patients with spinal cord injuries. METHODS: The patients were asked to use 3 different types of catheters. The selection of catheter order was determined randomly, and all 3 catheters were used for 6 weeks consecutively. All patients were assessed at the beginning of treatment and at weeks 6, 12, and 18, in terms of urethral cytology, urinalysis, urine culture, and patient satisfaction (Visual Analog Scale, VAS). RESULTS: Ten patients completed the study. Regarding the urethral trauma evaluation, urethral cell counts were reduced with gel-lubricated non-hydrophilic catheter use (P<0.05), increased with PVC catheter use (P<0.05), and showed no change with hydrophilic-coated catheter use (P>0.05). The number of leucocytes in the urine sediment was significantly reduced after gel-lubricated catheter use (P<0.05). There was significantly less microhematuria with hydrophilic-coated and gel-lubricated non-hydrophilic catheter use compared with PVC catheter use (P<0.05). There were no significant differences among catheters with respect to symptomatic urinary tract infection and microbiological analysis of urine culture (P>0.05). The mean VAS was better with the gel-lubricated non-hydrophilic catheter than with the other two catheter types (P<0.05). CONCLUSION: The hydrophilic-coated catheter and especially the gel-lubricated non-hydrophilic catheter reduce trauma to the urethral surfaces and enable easy and comfortable catheterization. CLINICAL REHABILITATION IMPACT: The hydrophilic and gel-lubricated catheters represent an attractive alternative to standard PVC catheters for urological rehabilitation in patients with spinal cord injuries.

[Application of silk fibroin film for repairing rabbit urethral defect].

OBJECTIVE: To evaluate the effect of silk fibroin film for repairing urethral defect in rabbits. METHODS: Twenty-four male New Zealand rabbits were randomized into experimental group, control group I and control group II. In the experimental group, a urethral defect of 1.5 cm was induced in the 12 rabbits and repaired with silk fibroin film. The 6 rabbits in control group I without the surgically induced defect served as the sham operation group, and in control group II consisting of 6 rabbits the urethral defect of 1.5 cm was induced without repair. Histological observation and immunohistochemistry were conducted to examine the regenerative segments of the urethra at regular time points between 2 and 16 weeks postoperatively. RESULTS: The 12 rabbits in the experimental group did not show signs of urethral stricture following the surgery. The implanted silk fibroin film for defect repair was degraded completely at 16 weeks and the defect was repaired with smooth urethral mucous membrane lining and orderly arranged smooth muscle cells. Immunohistochemistry identified the cells lining the defect area as the urethral epithelial cells. CONCLUSION: Silk fibroin film can promote the repair of urethral defect by inducing the growth of the urethral epithelial cells and smooth muscle cells.

Hydrophilic-coated catheters for intermittent catheterisation reduce urethral micro trauma: a prospective, randomised, participant-blinded, crossover study of three different types of catheters.

OBJECTIVE: To compare two hydrophilic-coated (SpeediCath and LoFric and one uncoated gel-lubricated catheter (InCare Advance Plus) concerning withdrawal friction force and urethral micro trauma. METHODS: 49 healthy male volunteers participated in this prospective, randomised, blinded, crossover study of three different bladder catheters. The withdrawal friction force was measured, and urine analysis of blood, nitrite and leucocytes, microbiological analysis of urine cultures and subjective evaluation of the catheters were performed. RESULTS: 40 participants completed the study and were included in the analysis. SpeediCath exerted a significantly lower mean withdrawal friction force and work than the gel-lubricated uncoated catheter, whereas LoFric exerted a significantly higher mean friction force than both of the other catheters. The hydrophilic catheters caused less microscopic haematuria and less pain than the gel-lubricated uncoated catheter. Furthermore, 93% of the participants preferred the hydrophilic catheters. CONCLUSION: Hydrophilic-coated catheters perform better than uncoated catheters with regard to haematuria and preference. SpeediCath, but not LoFric, exerts less withdrawal friction force than InCare Advance Plus.

Sinus formation after insertion of a silicone-coated suburethral sling.

We report the case of a 65-year-old woman who developed a sinus tract after a suburethral synthetic silicone mesh sling placement. After removal of the sling material with debridement and reconstruction of the suburethral tissue, fascia lata harvest with a sling to abdominal rectus fascia was performed. Silicone mesh may erode to form a sinus tract if used as suburethral sling material.