Objective:To investigate the effect of modified York-Mason technique on urethrorectal fistula after radical prostatectomy.Methods:A retrospective analysis of clinical data from 20 patients with urethrorectal fistula after radical prostatectomy admitted to Shanghai Sixth People's Hospital from May 2016 to October 2022 was conducted. Patients’ average age was (76.6±4.2) years. The etiology was rectal injury during radical prostatectomy. Patients present urine leakage from the anus during micturition. 2 cases also had bladder neck stenosis, and 1 case had urinary incontinence.3 cases had radiotherapy history because of prostate cancer. The average duration of urethrorectal fistula was (1.8±2.3)years. Preoperative imaging confirmed the presence of contrast agent flowing from the bladder neck into the rectum. Three suspicious patients also underwent CT three-dimensional reconstruction. Urethroscopy revealed a depression at the bladder neck in five cases. Anorectal examination in five cases showed the formation of gas bubbles in the lower anterior wall of the rectum, along with a concave anterior wall. The distance from the fistula to the anal margin was (6.0±2.1) cm, with fistula diameters ≥1 cm in twelve cases, <1 cm in eight cases. Twelve patients had previously undergone cystotomy, and seventeen patients had undergone colostomy. The modified York-Mason procedure was adopted for all 20 cases. The patients were under general anesthesia and placed in the prone jackknife position, with the buttocks spread and fixed to the sides to expose the anus. An 8 cm-long incision was made from two points near the sacrococcygeal joint to the anal edge, representing the modified York-Mason approach. After dividing the anal sphincter muscle, both sides were marked using 3-0 chromium thread for subsequent anal reconstruction. The urethrorectal fistula was exposed, and the urethral side of the fistula was sutured with 4-0 absorbable thread, while the anterior rectal wall side was sutured with 3-0 absorbable thread. In cases of bladder neck stenosis, urethral internal incision was performed, and a urethral catheter was retained for 3 weeks postoperatively. Perianal incision drainage tubes were removed after three days. Patients had colostomy repair could eat the day after surgery, while those who didn’t were fast for five days and received intravenous nutrition.Results:All 20 cases in this group were successfully completed without complications during surgery. Follow-up ranged from 10 to 48 months after surgery. Seventeen (17/20)cases had unobstructed urination, with a maximum urine flow rate >15 ml, and no urine leakage from the anus. Postoperative urethrography and cystourethroscopy showed there were no urethrorectal fistulas in 15 cases. None of the patients experienced fecal incontinence after the surgery, except for three patients with a history of radiotherapy who continued to experience anal leakage. One patient underwent a second modified York-Mason procedure and achieved complete recovery three months after the second surgery. Another patient had anal discharge, and the fistula healed after two weeks of urethral catheter retention. One patient refused further treatment due to advanced age and frailty but still had anal leakage. Another patient experienced regular urethral dilation for urination difficulties, while one patient continued to have urinary incontinence.Conclusions:The modified York-Mason technique could be an effective method for urethrorectal fistula after radical prostatectomy with high success rate and few side effects.

Objective:To explore the efficacy of pedicled bladder muscle flap in the repair of urinary tract obstruction.Methods:The data of 26 patients with urinary tract obstruction admitted to Shanghai Sixth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine from March 2016 to June 2021 were retrospectively reviewed. There were 14 males and 12 females, with the age ranged from 2 to 75 years old. Refractory bladder neck obstruction after prostatic hyperplasia surgery in 12 cases, with the age of (70.0±3.5) years old.They all experienced at least 2 times of transurethral stenosis incisionor resection. Transpubic cystostomy tube was placed in 9 patients. Posttraumatic pelvic fractures lead to bladder neck atresia and urethral injury in 6 girls, with the age of (10.5±2.1) years old. The bladder neck atresia and urethral obliteration length was 1-2 cm determined by urethrography. Eight cases suffered ureteral strictures after gynecological myomectomy or ureteroscopy holmium laser lithotripsy(4 cases of each type), including two males and six females, with the age of (55.0±3.2) years old. The length of ureteral stricture or defect was 5-6 cm determined by intravenous urography(IVU) or CT urography(CTU). The patients with bladder neck obstruction underwent the following surgery: The "Y" incision of the bladder and stenosis of the prostate urethra was performed and the pedicled bladder muscle flap was inserted into the normal urethral mucosa to complete the Y-V plasty. In the 6 girl patients, pedicled bladder muscle flap(2-4 cm) augmented reconstruction were performed. All above 18 patients, whose urethral catheter was indwelled for 3-4 weeks, urinary flow rate and urethroscopy examination were performed to evaluate the effect of surgery 4 weeks and 3 months after the operation. As the 8 cases with ureteral strictures, the pedicled bladder muscle flap (7-8 cm) ureteroplasty was performed and the ureteral stent was retained for 4 weeks. Ultrasonography and IVU/CTU were performed 4 weeks and 3 months postoperatively. The patency of the ureteral lumen and whether it is accompanied by hydronephrosis, lower back pain, and urinary tract infection were assessed.Results:All patients underwent pedicled bladder muscle flap reconstructive surgery successfully and no serious complications occurred postoperatively. The patients were followed up for (8.2± 2.2) months. As urethral catheters were removed, 10 patients with refractory neck obstruction could return to normal urination with the urinary flow Q max (17.2±2.8)ml/s, while 2 patient had dysuria and were treated with regular urethral dilatation. The catheter was removed 4 weeks after the reconstructive surgery in 6 girls with bladder neck atresia and urethral injury after posttraumatic pelvic fracture. Five could successfully urinate with the urinary flow Q max of (16.7±1.1)ml/s, and one girl had urinary incontinence, waiting for further operation.The ureteral stent was removed after ureteroplasty in 8 patients. CTU and IVU examination showed no ureters with obstruction.No one had low back pain, discomfort, or urinary tract infection. Conclusions:The reconstruction using the pedicled bladder muscle flap was a convenient, minimally invasive and effective technique for the management of adjacent lower ureters, bladder neck, and proximal urethra.

Objective:To investigate the clinical efficacy of lingual mucosa graft coupled penis flap urethroplasty for crippled hypospadias.Methods:Between January 2016 and August 2019, 16 patients with crippled hypospadias in Shanghai Sixth People's Hospital were included in this study. Their mean age was 35.2 years (range from 25 to 44 years). All patients presented voiding difficulty and failed after 2 or more times of urethroplasty. Their mean times was 4.6(range from 2 to 7 times). Uroflowmetry examination showed their mean Q max was 6.7 ml/s (range from 3.8 to 9.6ml/s). Chordee was found in six patients. Urethrocele was found in 2 patients. Urethrocutaneous fistula was found in 2 patients. All patients received lingual mucosa graft coupled penis flap urethroplasty. By removing the ischemic and fibrotic urethra, urethral plate was reconstructed with lingual mucosa graft and the penis flap was transplanted to cover the reconstructed urethra plate to form a new urethral lumen, which was used to repair the defective urethra. The catheters were removed three weeks after the surgery. Uroflowmetry examination, cystourethrography and cystoscope were performed after the catheters out. Results:All patients underwent smooth surgery with an average duration of 128.4 minutes (range from 105 to 150 minutes). After mean follow-up of 18.6 months (range from 3 to 30 months), successful outcome was achieved in 14 patients and uroflowmetry examination at the seventh week after surgery showed their mean Q max was 22.4 ml/s (range from 15.6 to 29.8 ml/s). 2 cases had urethrocutaneous fistula which were cured after repair of penile urethral fistula. 2 patients still had a certain level of chordee while they were satisfied with the appearance of their penis, so there was no further treatment. Conclusions:Single stage lingual mucosa graft coupled penis flap urethroplasty has short operation period, relatively high success rate and relatively few complications. Single stage lingual mucosa graft coupled penile flap urethroplasty is an available option for crippled hypospadias with several times of failed urethroplasty.

Objective:To investigate the effect of gracilis flap in repair of radiation-induced vesicovaginal fistula.Methods:The data of 18 patients with radiation-induced vesicovaginal fistula treated in the Sixth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine from March 2021 to August 2022 were retrospectively reviewed. Their age was (57.3±10.4) years. All patients underwent radical surgery for cervical cancer, and received (24.6±2.8)(range from 20 to 30)times of radiotherapy after surger. The median time between the end of radiotherapy and the onset of vesicovaginal fistula was 14.0(7.8, 18.2)months. The median duration of fistula urine was 12.0(9.8, 18.0)months. All patients were required to use median 19.5(15.8, 27.5) pads per day before surgery. The life quality score(QOL)of 18 cases was median 5.0(5.0, 6.0) points. Three cases had performed laparoscopic vesicovaginal fistula repair, two cases had underwent transvaginal vesicovaginal fistula repair, one case had underwent transvaginal and laparoscopic vesicovaginal fistula repair successively, and the remaining 12 cases were new vesicovaginal fistulas. Two cases were combined with rectovaginal fistulas. All patients underwent the repair of vesicovaginal fistula with gracilis flap interposition in prone and folded knife position, by transvaginal route, the vesicovaginal fistula was mobilized and the two layers were closed, and the vascular pedicle gracilis flap of left inner leg was romoved under the skin tunnel to repair the vesicovaginal fistula. Meanwhile, two cases combined rectovaginal fistulas were repaired and closed the rectovaginal fistulas. The urinary catheters were removed at 3 weeks after the operation and urination was recorded.Results:All patients underwent smooth surgery in (96.6±13.2) minutes. The median follow-up was 13.0(9.8, 20.2)(range from 6 to 24)months. The median number of urine pads used per day in 18 patients was 2.0(1.0, 11.8), and significantly reduced ( P<0.01).QOL score was median 1.0(0, 4.2) point and significantly reduced ( P<0.01).Successful outcome was achieved in 12 patients with no leakage of urine in the vagina. Two cases developed urinary incontinence and required conservative treatment, but the curative effect was poor. Two cases still had vaginal urine leakage performed vesicovaginal fistula repair again. One case was successfully repaired without significant urine leakage.The other case still had significant urine leakage and the QOL score was 3 points. She refused further treatment for self-satisfied. Two cases still had vesicovaginal fistula and rectovaginal fistula after the surgery, and refused further surgery. Conclusions:Repair with gracilis flap interposition is a surgical method with few complications and reliable surgical effect for patients with radiation-induced vesicovaginal fistula.

With the continuously increasing demands of plastic products in the current society, the challenge of disposing plastic waste is constantly increasing, leading to the urgent need of mitigating plastic pollution. As a consequence, much attention has been paid to biodegradable plastics due to their degradability in a bio-active environment under certain conditions. Biodegradable plastics herald vast development potentials and considerable market prospects. The degradation of numerous types of biodegradable plastics will be affected by many factors. A thorough understanding of degradation mechanisms as well as functional microbial strains and enzymes is the key to comprehensive utilization and efficient treatment and disposal of biodegradable plastics. The article summarized the types, properties, advantages and disadvantages, and main applications of common biodegradable plastics. The degradation mechanisms, functional microbial strains and enzymes, as well as the degradation degree and duration under different environmental conditions, were also summarized. This review may help better understand the degradation of biodegradable plastics wastes.
Biodegradable Plastics ; Biodegradation, Environmental