Modified Y-V plasty based on MRU evaluation for iatrogenic bladder outlet obliteration: a multicentre experience in China.

PURPOSE: To compare the diagnostic ability of traditional radiographic urethrography and magnetic resonance urethrography (MRU) for iatrogenic bladder outlet obliteration (BOO), and explore the efficacy and complications of laparoscopic modified Y-V plasty for patients selected based on MRU evaluation. METHODS: 31 patients with obliteration segments ≤ 2 cm and no false passages or diverticula based on MRU evaluation from eight centers in China were included. Obliteration segments were measured preoperatively by MRU and conventional RUG/VCUG and compared with intra-operative measurements. Surgical effects were evaluated by uroflow rates, urethrography, or cystoscopy at 1, 3, 6, and 12 months post-operation and then every 12 months. Postoperative urinary continence was assessed by 24-h urine leakage (g/day). RESULTS: The results showed that MRU measured the length of obliteration more accurately than RUG/VCUG (MRU 0.91 ± 0.23 cm, RUG/VCUG 1.72 ± 1.08 cm, Actual length 0.96 ± 0.36 cm, p < 0.001), and clearly detected false passages and diverticula. Laparoscopic Y-V plasty was modified by incisions at 5 and 7 o'clock positions and double-layer suture with barbed sutures. All operations were successfully completed within a median time of 75 (62-192) minutes and without any complications. Urethral patency and urinary continence rates were 90.3% (28/31) and 87.1% (27/31), respectively. Three recurrences were cured by direct visual internal urethrotomy. Four patients had stress urinary incontinence after catheter removal 14 days post-operation, with urine leakage of 80-120 g/day, not relieved during follow-up. CONCLUSIONS: Laparoscopic modified Y-V plasty based on MRU evaluation is a promising approach for iatrogenic BOO, with a high patency rate and a low incontinence rate.

Urethral-sparing laparoscopic simple prostatectomy for the treatment of benign prostatic hyperplasia with asymptomatic urethral stricture after urethral stricture surgery.

OBJECTIVE: To evaluate the efficacy of urethral-sparing laparoscopic simple prostatectomy (US-LSP) for the treatment of large-volume (>80 ml) benign prostatic hyperplasia (BPH) with asymptomatic urethral stricture (urethral lumen > 16 Fr) after urethral stricture surgery. METHODS: We retrospectively analyzed clinical data of 39 large-volume BPH patients with asymptomatic urethral stricture after urethral stricture surgery who underwent US-LSP from January 2016 to October 2021. Postoperative follow-ups were scheduled at 1, 3, and 6 months. RESULTS: All patients affected by significant BPH-related lower urinary tract symptoms (LUTS) including 22 cases with asymptomatic anterior urethral stricture and 17 cases with asymptomatic posterior urethral stricture. Median operative time was 118 min (interquartile range [IQR]100-145). Median estimated blood loss was 224 ml (IQR: 190-255). 33 patients(84.6%) avoided continuous bladder irrigation. Postoperative complications occurred in 5 patients (12.8%), including 4 cases with Clavien-Dindo grade 1 and grade 2 and 1 case with grade 3a. During follow-up, US-LSP presented statistically significant improvements in LUTS compared to baseline (P < 0.05). A total of 25 patients had normal ejaculation preoperatively and 3 patients (12%) complained retrograde ejaculation postoperatively. Two patients (5.1%) reported stress urinary incontinence (SUI) and no patient reported aggravated urethral stricture during follow-up. CONCLUSIONS: US-LSP was safe and effective in treating large-volume BPH with asymptomatic urethral stricture after urethral stricture surgery. Meanwhile, US-LSP could reduce the risk of SUI in patients with asymptomatic posterior urethral stricture and maintain ejaculatory function in a high percentage of patients.

Biodegradable nano black phosphorus based SDF1-α delivery system ameliorates Erectile Dysfunction in a cavernous nerve injury rat model by recruiting endogenous stem/progenitor cells.

Stem cell (SC) therapy has been shown high prospects in erectile dysfunction (ED) treatment. Without ethical issues and risks of immune rejection and tumorigenesis of exogenous SC therapy, endogenous stem/progenitor cells (S/PCs) have a better potential for ED management, and their homing and redistribution are controlled by SDF1-α/CXCR4 axis. Considering black phosphorus nanosheet (BPNS) has emerged as an efficient and safe drug vehicle due to its large surface area, biodegradability, and the ability to retain and slowly release its loaded drugs, BPNS is utilized to load SDF1-α, a chemokine for S/PCs, to construct the BP@SDF1-α complex to efficiently recruit stem cells (SCs) by injury-site injection and thus ameliorate ED within the bilateral cavernous nerve injury (BCNI) rat models. We find that BP@SDF1-α can efficiently recruit exogenous SCs and endogenous S/PCs to corpus cavernosum and main pelvic ganglion (MPG) by local administration. Of note, ascribing to endogenous S/PCs recruitment, it also successfully alleviates ED in BCNI rat models by enhancing the protein expression levels of α-SMA, CD31, and nNOs, and eliciting less collagen deposition in the penis after its combined injection at corpus cavernosum and MPG. Thus, this study provides a new insight into the treatment of ED with endogenous S/PCs. BIODEGRADABLE NANO BLACK PHOSPHORUS BASED SDF1-α DELIVERY SYSTEM AMELIORATES ERECTILE DYSFUNCTION IN A CAVERNOUS NERVE INJURY RAT MODEL BY RECRUITING ENDOGENOUS STEM/PROGENITOR CELLS.

The ultrasonographic characteristics of female periurethral solid masses.

INTRODUCTION AND HYPOTHESIS: Studies on the imaging of female periurethral masses are sparse, and most are focused on cystic lesions. In this article, we studied female periurethral solid masses and reported their ultrasonographic features. METHODS: Fifteen women with periurethral solid masses pathologically diagnosed between January 2008 and April 2021 were assessed. RESULTS: Each patient had only one mass. The pathological types included urethral caruncle (5 patients), urethral leiomyoma (3 patients), urethral malignant tumor (MT) (3 patients), periurethral spindle tumor (3 patients) and cartilage necrosis of pubic symphysis (PS) (1 patient). On ultrasound, all urethral caruncles were located at the urethral meatus. They were hypoechoic/isoechoic and rich in blood flow signal. Each leiomyoma presented as a well-defined hypoechoic mass with an oval shape. The urethral MT had inhomogeneous/isoechoic echoes, with medium to abundant blood flow signal. The spindle cell tumors had regular/irregular shapes, moderate/high density echogenicity and little/rich blood flow signals. The articular cartilage necrosis of PS was regular in shape, with mixed echogenicity and no blood flow. CONCLUSIONS: Ultrasound imaging is a convenient and useful method to evaluate the morphological characteristics of female periurethral solid masses.

[Application of patient-reported outcome measures in the diagnosis and treatment of male urethral stricture: An update].

Urethral stricture is a common and recurrent male disease, and its treatment has been shifted from endoscopic management to urethroplasty, which has greatly improved the success rate of treatment. However, patients and doctors often have different evaluations of the sexual function and lower urinary tract symptoms after urethroplasty, which has attracted the attention of researchers. In recent years, specific questionnaires or scales have been used to evaluate the effects of preoperative and postoperative treatment, laying more stress on the subjective feelings of the patients. Such questionnaires or scales are called patient-reported outcome measures (PROM). This article reviews the application of PROM in recent studies of urethral stricture, focusing on sexual function and lower urinary tract symptoms, aiming to provide some reference for the development and application of PROM in the diagnosis and treatment of male urethral stricture.

Pelvic Injury Discriminative Model Based on Data Mining Algorithm.

OBJECTIVES: To reduce the dimension of characteristic information extracted from pelvic CT images by using principal component analysis (PCA) and partial least squares (PLS) methods. To establish a support vector machine (SVM) classification and identification model to identify if there is pelvic injury by the reduced dimension data and evaluate the feasibility of its application. METHODS: Eighty percent of 146 normal and injured pelvic CT images were randomly selected as training set for model fitting, and the remaining 20% was used as testing set to verify the accuracy of the test, respectively. Through CT image input, preprocessing, feature extraction, feature information dimension reduction, feature selection, parameter selection, model establishment and model comparison, a discriminative model of pelvic injury was established. RESULTS: The PLS dimension reduction method was better than the PCA method and the SVM model was better than the naive Bayesian classifier (NBC) model. The accuracy of the modeling set, leave-one-out cross validation and testing set of the SVM classification model based on 12 PLS factors was 100%, 100% and 93.33%, respectively. CONCLUSIONS: In the evaluation of pelvic injury, the pelvic injury data mining model based on CT images reaches high accuracy, which lays a foundation for automatic and rapid identification of pelvic injuries.

Diagnosis and treatment of anterior urethral strictures in China: an internet-based survey.

BACKGROUND: To investigate the current diagnostic and therapeutic approaches to anterior urethral strictures of Chinese urologists and to compare with developed countries and the American Urologic Association guidelines. METHODS: Anonymous questionnaires were distributed to members of Official Wechat Account of urology from March 19, 2020 to April 10, 2020. Descriptive and multiple correspondence analysis were used to analyze the data. RESULTS: A total of 1276 online questionnaires were received. The response rate was 21.7% (1276/5878). The most common diagnostic methods for anterior urethral stricture were urethrography (90.7%) and urethrocystoscopy (85.4%), while urethral dilation (92.3%) and internal urethrotomy (60.1%) were the main therapeutic procedures. End-to-end urethroplasty (45.2%) was the most common open surgery, followed by skin flap urethroplasty (14.9%) and free graft urethroplasty (12.4%). 76.2% of urologists used urethroplasty only after the failure of minimally invasive surgery (reconstructive ladder treatment strategy). Furthermore, middle-aged or elderly urologists who had attended trainings, had senior practice roles, and who utilized a reconstructive ladder treatment approach were most likely to perform urethroplasties. CONCLUSIONS: Anterior urethral stricture treatment in China is still dominated by minimally invasive surgery, with most urologists using the reconstructive ladder treatment strategy. In general, the overall diagnostic and therapeutic strategies were similar between China and developed countries, with some deviations from the American Urologic Association guidelines.

3D printed hydrogels with oxidized cellulose nanofibers and silk fibroin for the proliferation of lung epithelial stem cells.

A novel biomaterial ink consisting of regenerated silk fibroin (SF) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose (OBC) nanofibrils was developed for 3D printing lung tissue scaffold. Silk fibroin backbones were cross-linked using horseradish peroxide/H2O2 to form printed hydrogel scaffolds. OBC with a concentration of 7wt% increased the viscosity of inks during the printing process and further improved the shape fidelity of the scaffolds. Rheological measurements and image analyses were performed to evaluate inks printability and print shape fidelity. Three-dimensional construct with ten layers could be printed with ink of 1SF-2OBC (SF/OBC = 1/2, w/w). The composite hydrogel of 1SF-1OBC (SF/OBC = 1/1, w/w) printed at 25 °C exhibited a significantly improved compressive strength of 267 ± 13 kPa and a compressive stiffness of 325 ± 14 kPa at 30% strain, respectively. The optimized printing parameters for 1SF-1OBC were 0.3 bar of printing pressure, 45 mm/s of printing speed and 410 µm of nozzle diameter. Furthermore, OBC nanofibrils could be induced to align along the print lines over 60% degree of orientation, which were analyzed by SEM and X-ray diffraction. The orientation of OBC nanofibrils along print lines provided physical cues for guiding the orientation of lung epithelial stem cells, which maintained the ability to proliferate and kept epithelial phenotype after 7 days' culture. The 3D printed SF-OBC scaffolds are promising for applications in lung tissue engineering.

[Application of nocturnal penile tumescence test in the diagnosis of erectile dysfunction].

ED is a common male disease, often caused by neurological, vascular or psychological factors, and the diagnostic methods for ED vary widely. The nocturnal penile tumescence test (NPT) by RigiScan is an objective assessment method used mainly to detect ED and has gained a wide clinical application in recent years. This review focuses on the application value of the six RigiScan parameters in the diagnosis of ED, namely, the number of erections, total erection time, event rigidity of tip/base, event tumescence of tip/base, tumescence activated unit and rigidity activated unit, aiming to provide some help to clinicians and researchers with the application of NPT.

[Treatment of erectile dysfunction caused by cavernous nerve injury: An update].

With the development of prostate surgery and increasing number of patients with pelvic fracture urethral injury, ED caused by cavernous nerve injury (CNI) has attracted more and more medical attention. CNI induces the apoptosis of penile smooth muscle cells and endothelial cells, decreases the density of NOS-positive nerves, and results in the fibrosis of the cavernous smooth muscle. The strategies of nerve regeneration after CNI has been one of the hotspots in the studies of ED. This review focuses on the current treatment strategies to promote the cavernous nerve regeneration and status quo of basic and clinical researches on the treatment of CNI-induced ED. The treatment strategies discussed in this review involve neurotrophic factors, RhoA/ROCK inhibitors, immunophilic ligands, erythropoietin, stem cell therapy, gene therapy, platelet-rich plasma, and low-intensity extracorporeal shock wave therapy, which are all new and suitable for clinical transformation.

Preoperative Transurethral Contrast-Enhanced Ultrasonography in the Diagnosis of Female Urethral Diverticula.

OBJECTIVES: To explore the value of transurethral contrast-enhanced ultrasonography (CEUS) in the diagnosis and evaluation of female urethral diverticula. METHODS: This study prospectively enrolled 35 women with periurethral cystic lesions, who underwent preoperative transurethral CEUS at our single center between April 2015 and May 2017. The diagnosis of a urethral diverticulum was made by the detection of microbubbles inside the lesion. Data regarding the structure and ostia of the diverticula were collected and then compared with intraoperative findings. RESULTS: The median (interquartile range) age of the 35 patients was 43 (34-48) years. The most common manifestations were dysuria (43%) and palpable masses (40%). On transurethral CEUS, 20 patients were found to have urethral diverticula. The diverticula involved the proximal, mid, and distal urethra with different sizes. The shapes of the diverticula were simple in 4 patients (20%), U shaped in 8 patients (40%), and circumferential in 8 patients (40%). A total of 23 ostia were identified. Seventeen women (85%) had 1 ostium, and 3 women (15%) had 2 ostia. Twenty-one diverticular ostia (91%) were located from the 3- to 9-o'clock positions. The median (interquartile range) distance from the diverticular ostia to the bladder neck was 20 (9-31) mm. During surgery, all US presentations correlated well with surgical findings, and 21 patients were confirmed to have urethral diverticula. The transurethral CEUS had sensitivity of 95% and specificity of 100%. CONCLUSIONS: Transurethral CEUS is an effective method for identifying the structure and ostium of female urethral diverticula. It may have a potential role in preoperative planning and surgical management.

Intermediate-Term Outcomes and Complications of Long Segment Urethroplasty with Lingual Mucosa Grafts.

PURPOSE: We evaluated outcomes and donor site complications in male patients with complex urethral strictures who underwent urethroplasty using with long strip oral mucosal grafts. We also analyzed whether a lingual mucosa graft is a good substitute for repairing long segment urethral strictures. MATERIALS AND METHODS: This retrospective study was done in 81 male patients with complex urethral strictures who underwent oral mucosal graft urethroplasty. Patients with long segment (8 cm or greater) anterior urethral strictures who were considered candidates for long strip lingual mucosa graft urethroplasty were included in study. RESULTS: Oral mucosal graft urethroplasty was performed in 81 patients with complex urethral strictures between August 2006 and December 2014. Mean urethral stricture length was 12.1 cm (range 8 to 20). A single 9 to 12 cm long strip lingual mucosa graft was used in 52 patients, a lingual mucosa graft greater than 12 cm was placed in 17 and a lingual mucosa graft combined with a buccal mucosal graft was used in 12. Mean followup was 41 months (range 15 to 86) postoperatively. The overall urethroplasty success rate was 82.7%. Urethral complications developed in 14 patients (17.3%), including urethral strictures in 10 and urethrocutaneous fistulas in 4. At 12 months 5 patients (6.2%) reported minimal difficulty with fine motor movement of the tongue. CONCLUSIONS: Lingual mucosa harvested from the ventrolateral surface of the tongue can provide a wide and long graft that is an excellent urethral substitute. Donor site complications are primarily limited to postoperative year 1. Our study confirms that the lingual mucosa graft is a good substitute for urethral reconstruction and lingual mucosa graft urethroplasty is a valuable procedure to treat long anterior urethral strictures.

Changing trends in the causes and management of male urethral stricture disease in China: an observational descriptive study from 13 centres.

OBJECTIVE: To determine whether there have been any changes in the causes and management of urethral strictures in China. PATIENTS AND METHODS: The data from 4,764 men with urethral stricture disease who underwent treatment at 13 medical centres in China between 2005 and 2010 were retrospectively collected. The databases were analysed for the possible causes, site and treatment techniques for the urethral stricture, as well as for changes in the causes and management of urethral strictures. RESULTS: The most common cause of urethral strictures was trauma, which occurred in 2,466 patients (51.76%). The second most common cause was iatrogenic injures, which occurred in 1,643 patients (34.49%). The most common techniques to treat urethral strictures were endourological surgery (1,740, 36.52%), anastomotic urethroplasty (1,498, 31.44%) and substitution urethroplasty (1,039, 21.81%). A comparison between the first 3 years and the last 3 years showed that the constituent ratio of endourological surgery decreased from 54% to 32.75%, whereas the constituent ratios of anastomotic urethroplasty and substitution urethroplasty increased from 26.73% and 19.18% to 39.93% and 27.32%, respectively (P < 0.05). CONCLUSIONS: During recent years, there has been an increase in the incidence of urethral strictures caused by trauma and iatrogenic injury. Endourological urethral surgery rates decreased significantly, and open urethroplasty rates increased significantly during the last 3 years.

Therapeutic potential of human umbilical cord blood mesenchymal stem cells on erectile function in rats with cavernous nerve injury.

OBJECTIVE: To evaluate the therapeutic potential of human umbilical cord blood mesenchymal stem cells (hUCBMSCs) on promoting erectile function in a rat model of bilateral cavernous nerve (CN) crush injury. RESULTS: Fifty male Sprague-Dawley rats were randomly assigned to sham + PBS group (n = 10), BCNI (bilateral cavernous nerve crush injury) + PBS group (n = 10), BCNI + hUCBMSCs group (n = 30). At day 28 (n = 10) post-surgery, erectile function was examined and histological specimens were harvested. Compared with BCNI + PBS group, hUCBMSC intracavernous injection treatment significantly increased the mean ratio of ICP/MAP, nNOS-positive nerve fibers in the dorsal penile nerve, smooth muscle content, and smooth muscle to collagen ratio in the corpus cavernousum. Electron microscopy revealed few CN and major pelvic ganglion (MPG) lesions in the BCNI + hUCBMSCs group. Injected hUCBMSCs were localized to the sinusoid endothelium of the penis and MPG on day 1, 3, 7, and 28 post-intracavernous injection. CONCLUSION: hUCBMSCs intracavernous injection treatment improves erectile function by inhibiting corpus cavernosum fibrosis and exerting neuroregenerative effects on cell bodies of injured nerves at MPG in a BCNI rat model.

Electrocautery-induced cavernous nerve injury in rats that mimics radical prostatectomy in humans.

OBJECTIVE: To investigate the early and delayed effects of cavernous nerve electrocautery injury (CNEI) in a rat model, with the expectation that this model could be used to test rehabilitation therapies for erectile dysfunction (ED) after radical prostatectomy (RP). MATERIALS AND METHODS: In all, 30 male Sprague-Dawley rats were randomly divided equally into two groups (15 per group). The control group received CNs exposure surgery only and the experimental group received bilateral CNEI. At 1, 4 and 16 weeks after surgery (five rats at each time point), the ratio of maximal intracavernosal pressure (ICP) to mean arterial pressure (MAP) was measured in the two groups. Neurofilament expression in the dorsal penile nerves was assessed by immunofluorescent staining and Masson's trichrome staining was used to assess the smooth muscle to collagen ratio in both groups. RESULTS: At the 1-week follow-up, the mean ICP/MAP was significantly lower in the CNEI group compared with the control group, at 9.94% vs 70.06% (P < 0.05). The mean ICP/MAP in the CNEI group was substantially increased at the 4- (35.97%) and 16-week (37.11%) follow-ups compared with the 1-week follow-up (P < 0.05). At all three follow-up time points, the CNEI group had significantly decreased neurofilament staining compared with the control group (P < 0.05). Also, neurofilament expressions in the CNEI group at both 4 and 16 weeks were significantly higher than that at 1 week (P < 0.05), but there was no difference between 4 and 16 weeks (P > 0.05). The smooth muscle to collagen ratio in the CNEI group was significantly lower than in the control group at the 4- and 16-week follow-ups (P < 0.05), and the ratio at 16 weeks was further reduced compared with that at 4 weeks (P < 0.05). CONCLUSIONS: In the CNEI rat model, we found the damaging effects of CNEI were accompanied by a decline in ICP, reduced numbers of nerve fibres in the dorsal penile nerve, and exacerbated fibrosis in the corpus cavernosum. This may provide a basis for studying potential preventative measures or treatment strategies to ameliorate ED caused by CNEI during RP.

Tissue-engineered buccal mucosa using silk fibroin matrices for urethral reconstruction in a canine model.

BACKGROUND: To investigate the feasibility of urethral reconstruction using tissue-engineered buccal mucosa (TEBM) with silk fibroin (SF) matrices in a canine model. MATERIALS AND METHODS: Autologous oral keratinocytes and autologous fibroblasts were isolated, expanded, and seeded onto SF matrices to obtain TEBM. The TEBM was assessed using hematoxylin and eosin staining and scanning electron microscopy. A 5-cm urethral mucosal defect was created in 10 female canines. Urethroplasty was performed using TEBM in five canines in the experimental group and with SF matrices without cells in the five canines in the comparison group. Retrograde urethrography was performed after 6 mo of grafting. The urethral grafts were analyzed grossly and histologically. RESULTS: The oral keratinocytes and fibroblasts exhibited good biocompatibility with the SF matrices. TEBM could be constructed using SF matrices. The canines implanted with the tissue-engineered mucosa voided without difficulty. The retrograde urethrography revealed no sign of stricture. The histologic staining showed that epithelial cells developed gradually and exhibited stratified epithelial layers at 6 mo. In the comparison group, the canines had difficulty voiding, and the retrograde urethrography showed urethra stricture. The histologic staining showed that one to two layers of epithelial cells developed. CONCLUSIONS: The TEBM using SF matrices could be a potential material for urethra reconstruction.

Optimizing erectile function evaluation pattern in postoperative pelvic fracture-urethral injury patients: introducing PFUI pEF PROM.

PURPOSE: To establish a psychometric validated pelvic fracture-urethral injury postoperative erectile function patient reported outcome measure (PFUI pEF PROM). We also aim to explore PFUI patients' potential classification and suitable postoperative erectile function assessment pattern. METHODS: A total of 93 PFUI patients who treated by excision and primary anastomotic (EPA) urethroplasty from January 2020 to August 2022 were enrolled to this study. Patients who had intercourse completed the IIEF-5, those who had sexual stimulation other than intercourse finished PFUI pEF PROM, and those who performed both completed the IIEF-5, and PFUI pEF PROM. Erection Hardness Score (EHS) was completed by all patients. This PROM was performed psychometric validation and used to find PFUI patients potential classification through latent class analysis. Then, we determined the cut-off value though receiver-operating characteristic (ROC) curve and performed univariate analysis subgroups feature. RESULTS: The PFUI pEF PROM demonstrated high reliability and validity with a Cronbach's alpha of 0.928. It correlated significantly with IIEF-5 (r = 0.550, p < 0.001) and EHS (r = 0.909, p < 0.001). The latent class analysis identified three patient subgroups, with 14.5 as the subgroup cut-off value. Urethral stricture length, IIEF-5, and EHS score were identified as influence factors for maximal erection potential. An assessment pattern combining IIEF-5, EHS, and the PFUI pEF PROM covered 92.5% of patients. CONCLUSION: This PROM effectively addresses the current limitation in assessing erectile function in PFUI patients. This study provides a promising tool for stratified assessment, prediction erection recovery, and treatment guidance in the PFUI Erectile dysfunction field.

Super-resolution imaging of urethral vasculature in healthy pre- and post-menopausal females.

Previous studies have postulated that the urethral vasculature (UV) might play an important role in urinary continence for women. The goal of this research was to compare the UV in pre- and post-menopausal women using a super-resolution ultrasound imaging method called Super Ultrasound for Greater Accuracy and Resolution (SUGAR). We found that post-menopausal women exhibited decreased UV parameters such as fractal dimension, vessel proportion, and mean blood vessel diameter than pre-menopausal women. We also discriminated the vascular pattern in several layers of the urethra and its surrounding in vivo, including the urethral mucosa and submucosa, urethral muscle, and anterior vaginal wall. Besides, the statistical analysis of the vasculature pattern showed that most of the UV parameters peaked at mid-urethra. Ultimately, the UV parameters exhibited a tendency of first increasing, then reducing, and finally decreasing with age.

Evaluation of stretched electrospun silk fibroin matrices seeded with urothelial cells for urethra reconstruction.

BACKGROUND: We investigated the feasibility of urethral reconstruction using stretched electrospun silk fibroin matrices. MATERIALS AND METHODS: A novel electrospun silk fibroin matrix was prepared. The structure of the material was assessed by scanning electron microscopy and a porosity test. Canine urothelial cells were isolated, expanded, and seeded onto the material for 1 wk to obtain a tissue-engineered graft. The tissue-engineered graft was assessed using hematoxylin and eosin staining and scanning electron microscopy. A dorsal urethral mucosal defect was created in nine female beagle dogs. In the experimental group, tissue-engineered mucosa was used to repair urethra mucosa defects in six dogs. No substitute was used in the three dogs of the control group. Retrograde urethrography was performed at 1, 2, and 6 mo after grafting. The urethral grafts were analyzed grossly and histologically. RESULTS: Scanning electron microscope and a porosity test revealed that the material had a three-dimensional porous structure. Urothelial cells grew on the material and showed good biocompatibility with the stretched silk fibroin matrices. Canines implanted with tissue-engineered mucosa voided without difficulty. Retrograde urethrography revealed no signs of stricture. Histologic staining showed gradual epithelial cell development and stratified epithelial layers at 1, 2, and 6 mo. The canines in the control group showed difficulty in voiding. Retrograde urethrography showed urethra stricture. Histologic staining showed that no or only one layer of epithelial cells developed. A severe inflammatory reaction was also observed in the control group. CONCLUSIONS: Stretched electrospun silk fibroin matrices have good biocompatibility with urothelial cells, which could prove to be a potential material for use in urethra reconstruction.

Outcome of small intestinal submucosa graft for repair of anterior urethral strictures.

OBJECTIVES: To investigate the feasibility of small intestinal submucosa graft for the repair of selected anterior urethral strictures. METHODS: From June 2009 to May 2011, 28 men (mean age 39 years) with anterior urethral strictures underwent urethroplasty using a four-layer small intestinal submucosa patch graft in an onlay or inlay fashion. The stricture was localized to the bulbar urethra in eight patients, the bulbopenile area in nine patients and the distal penile urethra in 10 patients. Failed hypospadias was observed in one patient. The mean stricture length was 4.6 cm (range 3.5-7.0 cm). RESULTS: The mean follow-up period was 24.8 months (range 12-30 months). No postoperative complications, such as infection or rejection, were related to the use of heterologous graft material. The patients voided well postoperatively, with peak flows between 16 and 44 mL/s (mean 25.4 mL/s) in 26 patients. Two patients (7.1%) developed a urethral narrowing; this occurred at 5 months in one patient and 6 months in the other, and cystoscopy, which was carried out at 20 and 24 weeks, respectively, showed clear cicatricial tissue at the proximal anastomotic site. Dilation was carried out once every 4-6 months for recurrent stricture in one patient and lingual mucosal graft urethroplasty was carried out in the other patient at 18 months postoperatively. Biopsies were obtained in four patients at 18, 24, 36 and 42 weeks, respectively. Squamous epithelium with or without hyperkeratosis was observed on histological examination of the small intestinal submucosa-grafted areas. CONCLUSIONS: The small intestinal submucosa matrix appears to be a safe and effective reconstructive material for selective use in urethral reconstructive surgery.