Experimental application of tissue engineered constructions for urethroplasty

Introduction. For diseases such as stricture and obliteration of the urethra, urethral hypospadias, reconstructive operations are required. The buccal mucosa is the material most commonly used for these operations. The search for alternative materials, carried out in order to reduce trauma and complications in the donor area, is an urgent area of modern urology. Tissue engineered constructions (TEC) can be used as such material.Objective. Justification of the possibility of applying a TEC based on the biodegradable polymers and seeded with autologous buccal epithelium (BE) cells as an implantable material for urethroplasty in an experiment.Methods and Materials. TEC based on poly-L-lactide-caprolactone (PLC) and poly-L-lactide-glycolide (PLG) seeded with BCs was created. Rabbits (n=12) underwent a biopsy of the oral mucosa, BCs were isolated, cultured and PLC-PLG scaffold was seeded with cells. TECs seeded with autological BCs were used on the model of acute trauma of rabbit urethra for replacement urethroplasty.Results. The results were evaluated after 12 weeks, according to the histological examination, there was a repair of the urethral mucosa. According to the data of retrograde urethrography, no impaired urethra patency was detected.Conclusion. TEC (PLK-PLG) seeded with autologous BCs ensured the maintenance of the rabbit urethral lumen which is necessary for adequate urination. This TEC could be recommended for the further clinical studies.

Determination of Stent Load Conditions in New Zealand White Rabbit Urethra

Background: Frequency of urethral stenosis makes it necessary to develop new innovative methods of treating this disease. This pathology most often occurs in men and manifests itself in painful urination, reduced urine flow, or total urinary retention. This is a condition that requires immediate medical intervention. Methods: Experimental tests were carried out on a rabbit in order to determine the changes of pressure in the urethra system and to estimate the velocity of urine flow. For this purpose, a measuring system was proposed to measure the pressure of a fluid-filled urethra. A fluoroscope was used to observe the deformability of the bladder and urethra canal. Results: Based on these tests, the range of changes in the urethra tube diameter, the pressures inside the system, and the flow velocity during micturition were determined. Conclusions: The presented studies allowed determining the behavior of the urethra under the conditions of urinary filling. The fluid-filled bladder and urethra increased their dimensions significantly. Such large changes require that the stents used for the treatment of urethral stenosis should not have a fixed diameter but should adapt to changing urethral dimensions.