Tiago Rosito

A new extra-abdominal channel alternative to the mitrofanoff principle: experimental and preliminary clinical experience

INTRODUCTIONnThe appendix is the gold-standard channel for the Mitrofanoff principle in pediatric urology, but the search for alternatives is justified considering it may not be available or preferably used for colonic stomas (Malone antegrade continence enema). The aim of this study is to report on technical feasibility of a new approach for creating catheterizable channels in a rabbit model and to present our preliminary clinical experience.nnnMATERIAL AND METHODSnWe configured a tube from two rectangular skin flaps 1x4 cm opposite each other in the middle line of the lower inferior abdomen. The channel was anastomosed to the bladder dome with embedding sutures to create a valvular mechanism. The experimental study consisted of 12 rabbits, divided in 4 groups according to the sacrifice schedule at 2, 4, 8 and 12 weeks. At 30th postoperative day, an urodynamic evaluation was performed to record continence of the stoma. A histological analysis of the specimens stained with hematoxylin-eosin, Masson trichrome and Picrosirius red was also done in group 2 (sacrifice at 4 weeks postoperatively). We used this method in 3 patients with congenital non-neurogenic bladder disease presenting with massive residual volumes without compliance deficits.nnnRESULTnThe technique proved feasible in all animals, 9 of 12 could be easily catheterized and underwent urodynamic study. No stoma leakage was observed in 7 animals at high bladder pressures (> 50 cm H20) and only 2 animals had some leakage at 40 cm H20. Urodynamics performed through the stoma showed urethral leakage at 20 cm H20, therefore demonstrating the efficacy of the valvular mechanism. Histological analysis confirmed good integration between the tube and the bladder. Mean follow-up of the clinical series (3 patients) was 7.2 months. Two patients remained continent up to 4 hours, whereas 1 patient had some leakage after 2 hours.nnnCONCLUSIONnWe were able to confirm feasibility of a new extra-abdominal channel based on the Mitrofanoff principle and successfully reproduced the method in a clinical setting. Follow-up was short and long term results are required before any conclusive judgment can be made.

Combined laparoscopic appendicovesicostomy (Mitrofanoff) with nephrectomy and orchidopexy in an 8-year-old boy.

Laparoscopy and robotic surgery are progressively gaining popularity in pediatric urology, especially for nephrectomy and orchidopexy. To our knowledge only five laparoscopic intraperitoneal appendicovesicostomy (Mitrofanoff) cases have been described in the pediatric literature. We present for the first time a case of combined use of a laparoscopic approach for appendicovesicostomy, nephrectomy and orchidopexy in an 8-year-old boy.

Macroscopic and histological evaluation of tunica vaginalis dorsal grafting in the first stage of Bracka’s urethroplasty: an experimental study in rabbits

What’s known on the subject? and What does the study add?

Vaginal reconstruction with two lower abdominal skin flaps in rabbits: histological and macroscopic evaluation

OBJECTIVEnTo evaluate the use of two skin flaps of the lower abdominal wall in the creation of a cylindrical conduit in vaginal reconstruction surgery in rabbits, through macroscopic and histological analysis.nnnSTUDY DESIGNnAn experimental study was performed in 16 female New Zealand rabbits, consisting of the use of two rectangular-shaped skin flaps of the lower abdominal wall measuring 1cm longitudinally and 3 cm transversely anastomosed to each other through continuous suture of the edges of the two flaps to create a tube. Hysterectomy and excision of the vaginal vault were performed, and the skin tube was anastomosed to the remaining vaginal stump with separate points of polyglycolic acid 4.0. Animals were divided into 4 groups according to the euthanasia at 2, 4, 8 and 12 weeks, when after excision of the neovagina, macroscopic and histological evaluation with hematoxylin-eosin and Masson trichrome were performed.nnnRESULTSnOf 16 operated rabbits, only 1 presented partial abdominal wall dehiscence, not compromising the flap viability. The macroscopic analysis of the vaginal conduit showed that it was kept open throughout the experimental steps, with a good patency and gauge, showing a slight retraction in the skin conduit length of no statistical significance. In the histopathological analysis, a local inflammatory process in the anastomosis was observed, which was larger in the early evaluation but decreased in late evaluations, as well as the local fibrosis process. Integration of the vaginal and skin epithelia was made with no alterations in their primary characteristics.nnnCONCLUSIONnThe use of two skin flaps of the lower abdominal wall as a vaginal conduit presented good integration between skin and vaginal tissue with minimal length retraction, kept the patency during evaluations and did not show strictures, presenting good local healing and a low rate of complications.