Robotic Orthotopic Neobladder: The Two Chimney Technique

Bladder substitution following radical cystectomy for urothelial cancer (transitional cell carcinoma) has become increasingly common and in many centers has evolved to become the standard method of urinary diversion. Orthotopic neobladder has been a commonly used option for urinary diversion since the 1980s. Advantages of this type of diversion are the ability to avoid an ostomy, voiding function similar to the native bladder, and improved cosmesis. Robotic intracorporeal neobladder creation has demonstrated similar outcomes to open technique and represents a promising minimally invasive diversion for the future. The Studer pouch is widely used nowadays, yet there are still some drawbacks. Therefore, we designed a technique that would offer an orthotopic ureteroileal anastomosis by using a two chimney modification. This modification is simple to handle, safe and free of ureteric stricture or reflux. With low stricture rates, this modified procedure of ureterointestinal anastomosis, is worthy of further promotion.

Bladder Substitution: The Role of Tissue Engineering and Biomaterials

Tissue engineering could play a major role in the setting of urinary diversion. Several conditions cause the functional or anatomic loss of urinary bladder, requiring reconstructive procedures on the urinary tract. Three main approaches are possible: (i) incontinent cutaneous diversion, such as ureterocutaneostomy, colonic or ileal conduit, (ii) continent pouch created using different segments of the gastrointestinal system and a cutaneous stoma, and (iii) orthotopic urinary diversion with an intestinal segment with spherical configuration and anastomosis to the urethra (neobladder, orthotopic bladder substitution). However, urinary diversions are associated with numerous complications, such as mucus production, electrolyte imbalances and increased malignant transformation potential. In this context, tissue engineering would have the fundamental role of creating a suitable material for urinary diversion, avoiding the use of bowel segments, and reducing complications. Materials used for the purpose of urinary substitution are biological in case of acellular tissue matrices and naturally derived materials, or artificial in case of synthetic polymers. However, only limited success has been achieved so far. The aim of this review is to present the ideal properties of a urinary tissue engineered scaffold and to examine the results achieved so far. The most promising studies have been highlighted in order to guide the choice of scaffolds and cells type for further evolutions.

Human adipose-derived mesenchymal stem cells accelerate decellularized neobladder regeneration

Decellularized natural bladder matrices (neobladders) represent an exciting means to regenerate the bladder following bladder cancer-associated cystectomy. In this study, we compare the evolution of decellularized matrices with recellularized matrices by seeding it with human adipose-derived mesenchymal stem cells (ADSC) after implantation following partial cystectomy in rats. We discovered significant anatomical differences since 10 days after neobladder implantation with the ADSC-containing matrices promoting a significant recovery of mature p63- and cytokeratin 7-positive urothelium. We also discovered significantly induced expression of the vimentin mesoderm marker in the submucosal layer in ADSC-seeded matrices. Interestingly, we found a higher expression of smooth muscle actin in transversal and longitudinal smooth muscle layers with ADSC-seeded matrices. Furthermore, ADSC also showed increased vascularization and nerve innervation of the neobladder as determined by the distribution of CD31 and S100β reactivity, respectively. We believe that ADSC and their paracrine-acting pro-regenerative secretome within decellularized matrices represent an efficient bladder substitution strategy; however, we require a fuller understanding of the mechanisms involved before clinical studies can begin.

Advances in bladder substitution and creation of neobladders in children

Cystectomy and urinary bladder substitution are rare in children but may be necessary in some cases of bladder exstrophy, in the setting of malignancy, or in other settings in which the bladder is severely dysfunctional. This article details advances in surgical techniques in creating continent urinary diversions in this specialized pediatric population.