From tissue engineering to regenerative medicine in urology--the potential and the pitfalls.

Tissue engineering is a promising technique for the development of biological substitutes that can restore, maintain, or improve tissue function. The creation of human tissue-engineered products, generated of autologous somatic cells or adult stem cells with or without seeding of biocompatible matrices is a vision to resolve the lack of tissues and organs for transplantation and to offer new options for reconstructive surgery. Tissue engineering in urology aims at the reconstruction of the urinary tract by creating anatomically and functionally equal tissue. It is a rapidly evolving field in basic research and the transfer into the clinic has yet to be realized. Necessary steps from bench to bed are the proof of principle in animal models and the proof of concept in clinical trials following good manufacturing practice and ethical and legal requirements for human tissue-engineered products. Up to now, obstacles still occur in the neovascularization of implants and ingrowth of nerves in vivo. Moreover the harvesting of mesenchymal stem cells out of bone marrow as well as the explant of urothelial cells yet demands rather invasive surgery to achieve a successful outcome. Thus, other cell sources and harvesting techniques like placenta and adipose tissue for mesenchymal stem cells and bladder irrigation for urothelial cells require closer investigation.

Closing the tract of mini-percutaneous nephrolithotomy with gelatine matrix hemostatic sealant can replace nephrostomy tube placement.

OBJECTIVES: To investigate the outcomes using gelatine matrix hemostatic sealant to close the tract after mini-percutaneous nephrolithotomy (mini-PCNL), resulting in a tubeless setting. METHODS: After complete stone removal after mini-PCNL, a double-J ureteral stent was placed in an antegrade manner. After withdrawing the 17F Amplatz sheet from the collecting system under direct vision without irrigation, the urothelium collapsed. While retracting the sheet further, the gelatine matrix hemostatic sealant was injected. The skin incision was closed with glue. An ultrasound examination was performed on the first postoperative day to exclude the presence of urine extravasation. RESULTS: Mini-PCNL was performed in 11 patients, either as a primary, small stone, single-access procedure or as a second-look mini-PCNL because of small residual fragments after extracorporeal shock wave lithotripsy. The time to seal the mini-PCNL tract through the kidney parenchyma was 2 to 5 minutes. The mean operative time was 79 minutes. In the first 5 cases, intravenous urography was performed in addition to ultrasonography and demonstrated an intact collecting system. The subsequent procedures demonstrated similar findings, with the exception of 1 case of temporary paravasation. In all other patients, the catheter was removed on the first postoperative day. Ten of 11 patients had an uneventful follow-up until removal of the double-J catheter. No major complications were observed. CONCLUSIONS: Closing the tract of the mini-PCNL with gelatine matrix hemostatic sealant is a safe and fast alternative and provides the option of discharging the patient in good condition without the commonly used nephrostomy tube.

Radical cystectomy and orthotopic bladder replacement in females.

INTRODUCTION: More than 15 years ago, several centers started to offer urethra-sparing cystectomy and orthotopic urinary diversion for female patients with bladder malignancies. Several studies have been published, outlining both the anatomical and oncological aspects of such an approach. METHODS: In this contribution, the main aspects regarding the surgical technique of cystectomy and orthotopic urinary diversion in female patients, including technical variations which have been derived over the years, are presented. RESULTS AND CONCLUSION: The video shows a detailed description of the surgical technique, and the main steps of the procedure are demonstrated in schematic drawings as well as in animations to facilitate understanding. Emphasis is given on important anatomical and physiological aspects, which have influenced the current surgical steps. Possible sequelae on oncological and functional outcome, which play an important role in the evaluation of this procedure, are also discussed.