Lichen sclerosis-induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft.

BACKGROUND: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). METHODS: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. RESULTS: Thirty patients were identified. The median age (range) was 39 (25-61) years and a median (range) stricture length was 8 (6-14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12-24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2-11) ml/s preoperatively to 18 (range: 6-23) ml/s at the 6th month (p value < 0.001). CONCLUSION: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

A wavelet gradient sparsity based algorithm for reconstruction of reduced-view tomography datasets obtained with a monochromatic synchrotron-based X-ray source.

High-resolution synchrotron computed tomography (CT) is very helpful in the diagnosis and monitor of chronic diseases including osteoporosis. Osteoporosis is characterized by low bone mass and cortical bone porosity best imaged with CT. Synchrotron CT requires a large number of angular projections to reconstruct images with high resolution for detailed and accurate diagnosis. However, this poses great risks and challenges for serial in-vivo human and animal imaging due to a large amount of X-ray radiation dose required that can damage living specimens. Also, longer scan times are associated with increased risk of specimen movement and motion artifact in the reconstructed images. We developed a wavelet-gradient sparsity based algorithm to be utilized as a synchrotron tomography reconstruction technique allowing accurate reconstruction of cortical bone porosity assessed for in-vivo preclinical study which significantly reduces the radiation dose and scan time required while maintaining satisfactory image resolution for diagnosis. The results of our study on a rat forelimb sample imaged in the Biomedical Imaging and Therapy Bending Magnet (BMIT-BM) beamline at the Canadian Light Source show that the proposed algorithm can produce satisfactory image quality with more than 50 percent X-ray dose reduction as indicated by both visual and quantitative-based performance.

Management of long segment anterior urethral stricture (≥ 8cm) using buccal mucosal (BM) graft and penile skin (PS) flap: outcome and predictors of failure

ABSTRACT Purpose To evaluate the surgical outcome and predictors of failure of substitution urethroplasty using either dorsal onlay buccal mucosal (BM) graft or ventral onlay penile skin flap (PS) for anterior urethral stricture ≥ 8cm. Patients and methods Between March 2010 and January 2016, 50 patients with anterior urethral stricture ≥ 8 cm were treated at our hospital. The surgical outcome and success rate were assessed. The predictors of failure were analyzed using multivariate analysis. Failure was considered when subsequent urethrotomy or urethroplasty were needed. Results Dorsal onlay BM graft was carried out in 24 patients, while PS urethroplasty in 26 patients. There was no significant difference between both groups regarding patients demographics, stricture characteristics or follow-up period. One case in the BM group was lost during follow-up. Stricture recurrence was detected in 7 (30.4%) patients out of BM group while in 6 (23.1%) patients out of PS group (p value= 0.5). No significant differences between both groups regarding overall early and late complications were observed. Occurrence of early complications and the stricture length were the only predictors of failure in univariate analysis, while in multivariate analysis the occurrence of early complications was only significant. Conclusion On short-term follow-up, both dorsal onlay BM graft and ventral onlay PS flap urethroplasty have similar success rates. However, BM graft has a potential advantage to reduce operative time and is also technically easier. The surgeon should avoid early local complications as they represent a higher risk for failure.

Management of long segment anterior urethral stricture (≥ 8cm) using buccal mucosal (BM) graft and penile skin (PS) flap: outcome and predictors of failure.

PURPOSE: To evaluate the surgical outcome and predictors of failure of substitution urethroplasty using either dorsal onlay buccal mucosal (BM) graft or ventral onlay penile skin flap (PS) for anterior urethral stricture ≥ 8cm. PATIENTS AND METHODS: Between March 2010 and January 2016, 50 patients with anterior urethral stricture ≥ 8 cm were treated at our hospital. The surgical outcome and success rate were assessed. The predictors of failure were analyzed using multivariate analysis. Failure was considered when subsequent urethrotomy or urethroplasty were needed. RESULTS: Dorsal onlay BM graft was carried out in 24 patients, while PS urethroplasty in 26 patients. There was no significant difference between both groups regarding patients demographics, stricture characteristics or follow-up period. One case in the BM group was lost during follow- up. Stricture recurrence was detected in 7 (30.4%) patients out of BM group while in 6 (23.1%) patients out of PS group (p value= 0.5). No significant differences between both groups regarding overall early and late complications were observed. Occurrence of early complications and the stricture length were the only predictors of failure in univariate analysis, while in multivariate analysis the occurrence of early complications was only significant. CONCLUSION: On short-term follow-up, both dorsal onlay BM graft and ventral onlay PS flap urethroplasty have similar success rates. However, BM graft has a potential advantage to reduce operative time and is also technically easier. The surgeon should avoid early local complications as they represent a higher risk for failure.

Evaluation of an experimental dental porcelain.

The aim of this study was to evaluate fracture toughness, hardness, ceramic/metal bond strength and microstructure of experimental dental porcelain and compare it with commercial type. Specimens of specific dimensions were prepared. Fracture toughness was assessed by a three-point bending test. The Vickers hardness was measured using a microhardness tester. The ceramometal bond strength was measured using a universal testing machine. The load was applied at the porcelain/metal interface via a chisel edged blade with a crosshead speed of 2.0 mm/min until fracture. The polished specimens of dental porcelain were chemically etched and the microstructure was analyzed with a scanning electron microscope. The results showed comparable fracture toughness and bond strength for both materials, while the experimental porcelain exhibited higher hardness. The experimental porcelain showed uniform cohesive failure while the commercial type showed mixed mode of failure. The microstructure of the experimental porcelain was tetragonal leucite crystals dispersed randomly in a glass matrix. The leucite crystals exist in two forms, acicular and rod like structures. It was concluded that the experimental porcelain has adequate fracture toughness and ceramic/metal bond strength that can resist the rapid crack propagation and its consequent catastrophic failure, which indicates a material serviceability in the oral cavity.