Bladder augmentation with an omental pedicled gastric seromuscular flap without the necessity of gastric resection

Bladder augmentation in children: current problems and experimental strategies for reconstruction

Bladder augmentation is a demanding surgical procedure and exclusively offered for selected children and has only a small spectrum of indications. Paediatric bladder voiding dysfunction occurs either on a basis of neurological dysfunction caused by congenital neural tube defects or on a basis of rare congenital anatomic malformations. Neurogenic bladder dysfunction often responds well to a combination of specific drugs and/or intermittent self-catheterization. However, selected patients with spinal dysraphism and children with congenital malformations like bladder exstrophy and resulting small bladder capacity might require bladder augmentation. Ileocystoplasty is the preferred method of bladder augmentation to date. Because of the substantial long-and short-term morbidity of augmentation cystoplasty, recent studies have tried to incorporate new techniques and technologies, such as the use of biomaterials to overcome or reduce the adverse effects. In this regard, homografts and allografts have been implemented in bladder augmentation with varying results, but recent studies have shown promising data in terms of proliferation of urothelium and muscle cells by using biological silk grafts.

Histerocystoplasty: a novel surgical procedure in the rat

BACKGROUND

Enterocystoplasties are associated to complications. To avoid them, different types of tissue templates have been used to augment the bladder and induce native bladder regeneration.

MATERIALS AND METHODS

A novel surgical technique for bladder reconstruction using autologous uterine tissue was evaluated in a rat model. Forty-two female Wistar rats were randomly allocated into three groups: sham-operation hysterocystorrhaphy (n = 12), hysterocystoplasty (n = 18), and control (n = 12). Two weeks after surgery, ultrasound examination of the bladder was performed. At 2, 4, or 6 mo after surgery, the rats were anesthetized and blood and urine samples were taken. They were then euthanized and post-mortem and histologic examination were performed. Ultrasound examination, analytical parameters and weight control, as well as gross and histologic examination were performed in all the operated animals. The statistical analysis was performed using Kruskal-Wallis and the extension of Fisher's exact tests. Significance was set at 5% (P < 0.05).

RESULTS

Serum chemistry, blood count and peripheral blood smears, electrolytes, and urinary parameters were all within the normal range for the rat. Histologic sections of the surgically augmented zone between the bladder and uterine horn demonstrated urothelial epithelization, providing adequate coverage of the transition area in 72.22% of the rats that underwent hysterocystoplasty.

CONCLUSIONS

The hysterocystoplasty was technically viable in all the cases and proved to be an easy and safe surgical model for bladder reconstruction. All animals were healthy after surgery and all systemic parameters analyzed were within normal physiologic range for the rat.

Urinary bladder smooth muscle regeneration utilizing bone marrow derived mesenchymal stem cell seeded elastomeric poly(1,8-octanediol-co-citrate) based thin films

Bladder regeneration studies have yielded inconclusive results possibly due to the use of unfavorable cells and primitive scaffold design. We hypothesized that human mesenchymal stem cells seeded onto poly(1,8-octanediol-co-citrate) elastomeric thin films would provide a suitable milieu for partial bladder regeneration. POCfs were created by reacting citric acid with 1,8-octanediol and seeded on opposing faces with human MSCs and urothelial cells; normal bladder smooth muscle cells and UCs, or unseeded POCfs. Partial cystectomized nude rats were augmented with the aforementioned POCfs, enveloped with omentum and sacrificed at 4 and 10 weeks. Isolated bladders were subjected to Trichrome and anti-human gamma-tubulin, calponin, caldesmon, smooth muscle gamma-actin, and elastin stainings. Mechanical testing of POCfs revealed a Young's modulus of 138 kPa with elongation 137% its initial length without permanent deformation demonstrating its high uniaxial elastic potential. Trichrome and immunofluorescent staining of MSC/UC POCf augmented bladders exhibited typical bladder architecture with muscle bundle formation and the expression and retention of bladder smooth muscle contractile proteins of human derivation. Quantitative morphometry of MSC/UC samples revealed muscle/collagen ratios approximately 1.75x greater than SMC/UC controls at 10 weeks. Data demonstrate MSC seeded POCfs support partial regeneration of bladder tissue in vivo.

The repair of a large duodenal defect by a pedicled gastric seromuscular flap

PURPOSE

The aim was to evaluate the efficacy of a pedicled gastric seromuscular flap for the closure of a large duodenal defect.

METHODS

A large defect of the second duodenal part was repaired by a gastric seromuscular flap. Of 35 rats, 9 rats were euthanized at 2 weeks, 12 rats at 2 months, and 14 rats at 4 months for the histopathological evaluation of the patch and normal duodenum (control) adjacent to the patch.

RESULTS

All rats survived. The patch was completely covered by neomucosa in all of the 4-month rats, and in 8 of the 12 2-month rats. The villous height of the neomucosa was significantly higher in the 4-month rats in comparison to the other rats (P < 0.001). However, a normal duodenum had higher villi than in that of the patches (P < 0.001). The crypt density of the neomucosa was significantly increased in the 4-month rats in comparison to the 2-week and the 2-month rats (P < 0.001 and P < 0.05 group, respectively). The crypt density was higher in the controls than in the neomucosa covered patch of the 2-week and the 2-month rats (P < 0.001 and P < 0.05, respectively). The crypt depth of the neomucosa increased significantly in the 4-month rats and in the controls versus the 2-week rats (P < 0.05).

CONCLUSION

The new mucosal barrier overlaying the patch appeared to be satisfactory. This technique, which has not been described previously, is likely to be useful for the repair of the large duodenal defect.

Bladder lithiasis: from open surgery to lithotripsy

Bladder calculi account for 5% of urinary calculi and usually occur because of bladder outlet obstruction, neurogenic voiding dysfunction, infection, or foreign bodies. Children remain at high risk for developing bladder lithiasis in endemic areas. Males with prostate disease or relevant surgery and women who undergo anti-incontinence surgery are at a higher risk for developing vesical lithiasis. Open surgery remains the main treatment of bladder calculus in children. In adults, the classical treatment for bladder calculi is endoscopic transurethral disintegration with mechanical cystolithotripsy, ultrasound, electrohydraulic lithotripsy, Swiss Lithoclast, and holmium:YAG laser. Novel modifications of these treatment modalities have been used for large calculi. Open and endoscopic surgery requires anesthesia and hospitalization. Alternatively, extracorporeal shock wave lithotripsy has been demonstrated to be simple, effective, and well tolerated in high-risk patients. Recently, simultaneous percutaneous suprapubic and transurethral cystolithotripsy has been tested as well as percutaneous cystolithotomy by using a laparoscopic entrapment sac.