Interim report in humans of a previously described technique in an animal model: closure of bladder exstrophy with rectus abdominis muscle flap-II

Closure and augmentation of bladder exstrophy using rectus abdominis musculo-peritoneal flap

Background:

The aim of this study was to investigate the efficacy of the rectus abdominis myo-peritoneal flap (RAMP) technique for the closure and augmentation of small, non-elastic, non-compliant bladder exstrophies.

Materials and Methods:

The RAMP technique was used in three boys with bladder exstrophy who presented late with small, non-elastic, non-compliant bladder. The clinical outcome, imaging, cystoscopy, biochemical and microbiological studies were assessed during a follow-up of 36 months.

Results:

Bladder closure and augmentation was achieved in all patients without any complications. There were no urinary tract infections, metabolic problems or electrolyte disturbances and the kidney function remained normal in all patients. Radiography confirmed intact function and anatomy of the urinary tract and cystoscopy showed complete coverage of the inner peritoneal layer of RAMP with uroepithelium. No stone formation or mucous production was detected.

Conclusions:

The RAMP technique is a good alternative for closing bladder exstrophies and achieves an increase in bladder capacity and compliance. The technique is indicated in the closure of large bladder defects, bladder exstrophies with small, inelastic, non-compliant bladder remnants and failed primary closures.

One-stage posttraumatic bladder reconstruction and soft-tissue coverage of the lower abdomen or perineum

Mutilating injury on pelvis may be complicated by urinary bladder ruptures and soft-tissue avulsion of the lower abdominal wall or perineum. With retraction of the avulsed abdominal wall or perineum, as well as bladder tissue loss secondary to trauma or infection, direct closure the injured bladder often leads to excessive tension, resulting in ischemia and eventual failure of repair. The authors successfully managed 4 patients with such injuries using the pedicled vastus lateralis myocutaneous flap. No major complications occurred and intact bladders were confirmed with cystograms. Three (75%) of them were able to void normally within 1 year. It is concluded that the pedicled vastus lateralis myocutaneous flap is an ideal option for posttraumatic bladder reconstruction and soft-tissue coverage of the lower abdomen or perineum; whereas the undersurface of the muscle serves as a substitute for the missing bladder wall, the remaining part of the muscle, as well as the subcutaneous fat, provide sufficient bulk for dead space obliteration.

The rectus abdominis musculoperitoneal (RAMP) flap for the reconstruction of complicated pharyngoesophageal defects

In the advanced stage of hypopharyngeal cancer, extensive resection may sometimes leave both the cervical soft tissue and pharyngoesophageal defects that must be reconstructed at the same time. In this study, a new reconstructive method using the rectus abdominis musculoperitoneal flap is described. Three patients underwent pharyngoesophageal reconstruction by this method. Complete survival of the flaps was seen in all patients, but one patient developed a fistula due to rapid local recurrence of the tumour. We believe that the rectus abdominis musculoperitoneal flap can be an alternative choice for reconstruction of pharyngoesophageal defect, especially when there is a large area of cervical soft tissue defect at the same time.

Vaginal Reconstruction With a Rectus Abdominis Musculoperitoneal Flap

In more than 300 clinical cases, the authors have observed and documented the presence of a branch of the deep inferior epigastric artery that penetrates the posterior rectus sheath near the umbilicus. Their cadaveric anatomic and animal injection studies confirm the vascularity of the peritoneum via the deep inferior epigastric artery. They report 2 patients treated with a new technique of vaginal reconstruction using a thin, pliable flap with a peritoneal-lined rectus abdominis muscle based on the deep inferior epigastric vessels.

The peritoneal free flap: an anatomic study

In view of a possible clinical application of an isolated microvascular peritoneal flap, an anatomic study was performed in order to determine the peritoneal vascular territory of the deep inferior epigastric artery. For this, the deep inferior epigastric artery was injected unilaterally with Araldite in 30 embalmed cadavers and bilaterally with india ink in 15 fresh cadavers. In 70 percent of the embalmed cadavers, a constant pattern of three branches from the deep inferior epigastric artery could be identified. The peritoneal vascular supply is not derived solely from these three branches but also from multiple small branches sprouting directly from the main stem of the deep inferior epigastric artery and from segmental and muscular branches. Therefore, classification of peritoneal branches arising from the deep inferior epigastric artery seems to be of little clinical importance. In all cases, the india ink injected in the deep inferior epigastric artery colored a similar territory of the parietal peritoneum. Considering the magnitude of the peritoneal vascularization by the deep inferior epigastric artery, implementation of an isolated free or pedicled peritoneal flap seems to be possible. Such a microvascular peritoneal flap vascularized by the deep inferior epigastric artery may be used, for example, for reconstruction of mucosal defects in the head and neck region.

Female bladder exstrophy

Bladder exstrophy is one of the most challenging congenital urinary tract abnormalities. Apart from the open bladder the patient also has various other abnormalities, including urogenital, musculoskeletal and anorectal defects. The size of the exstrophic bladder varies from patient to patient. In the female the clitoris to bifid and the vagina is anteriorly placed. In this paper various aspects of female bladder exstrophy are reviewed in detail, including incidence, etiology, anatomy and clinical features, together with early, medium-term and long-term surgical management. The aim is to achieve a functional bladder closure, although some patients are better off with a urinary diversion. Considering the complexity of the urogenital problems and the surgical management thereof, all patients require lifelong follow-up.

Cultured urothelium in sheep bladder augmentation

In search of alternatives for urothelial-lined augmentation or reconstruction of the urinary bladder, this study combined the application of seromuscular gastrointestinal (GI) segments with the use of in-vitro cultured, autologous urothelial cells in a sheep model. A cell culture system was set up for establishment and expansion of urothelial cells out of small biopsies from bladder mucosa. A biodegradable carrier made of lactidcaprolactoncopolymer was introduced, allowing upside-down transplantation of cell cultures in vivo. Bladder mucosal biopsies were taken from 14 sheep (mean weight 13.3 kg) with an average yield of 3.5×10(5) viable cells/cm(2) after trypsinization. Primary low-density cultures grew to confluence within 5-7 days. Secondary cultures were established on the biodegradable film and were available a week later. They were transplanted onto demucosalized segments of stomach (group 1) or colon (group 2) in 5 animals each, followed by bladder incorporation in clam fashion. The earliest specimens, demonstrating survival and some proliferation of the cultured urothelium in both groups, were obtained 13 days postoperatively. To exclude urothelial regrowth, a temporary pouch grafted with cultured urothelium was created in 2 more sheep of each group. Biopsies were taken after 2 and 3 weeks, respectively, when the reopened pouch was integrated into the bladder (delayed augmentation). In these pouches, adherence and proliferation of urothelial cells could not be demonstrated. Limited radiologic and urodynamic investigations after 5-6-month follow-up revealed good shape, capacity, and compliance of the primarily augmented bladders only. The results indicate that urothelial cell cultures can be established and applied in vivo. Despite upside-down transplantation, they are able to survive on seromuscular segments in an autologous setting. The bladder environment is necessary to promote complete covering of the seromuscular segments. Based on our histologic findings, the share of both resident bladder urothelium and transplanted cells in the formation of the final urothelial lining remains uncertain. Morphologic and urodynamic follow-up data indicate that this process can be accelerated by the transplanted urothelial cells, reducing fibrotic changes of the GI segments. The functional quality of the augmented bladder seemed to improve compared to results after seromuscular augmentation alone.