Caracterização histológica das margens uretrais em pacientes submetidos a uretroplastia anastomótica bulbar.

• Ano de defesa: 2009
• Autor(a) principal: Schiavini, João Luiz
• Orientador(a): Damião, Ronaldo
• Banca de defesa: Carrerette, Fabrício Borges , Sabaneeff, Jorge , Errico, Giácomo , Fortes, Marco Antonio Quesada Ribeiro
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ciências Médicas
• Departamento: Centro Biomédico::Faculdade de Ciências Médicas
• País: BR
• Palavras-chave em Português: estreitamento uretral; procedimentos cirúrgicos reconstrutivos; colágeno; Uretra; Estenose; Estreitamento; Uretroplastia; Bulbo uretral; Margens cirúrgicas; Urethra; Stenosis; Narrowing; Urethroplasty; Urethral bulb; Surgical margins
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::MEDICINA::CIRURGIA::CIRURGIA UROLOGICA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/8529

Meticulous incision or excision of the stenotic segment and any associated proximal and distal spongiofibrosis is critical to the reliable success of urethroplasty procedures. However, normal urethral limits are determined during surgical reconstruction based on macroscopic aspects only. To our knowledge, microscopic studies evaluating the normal urethral ends have not been done. We aimed to describe the histological pattern of the presumed healthy limits of the urethral stricture disease, and the effect of a suprapubic urinary diversion on the proximal urethral end. Materials and Methods: Samples were obtained from 29 patients 20 to 65 years old (mean age 40.3) who underwent end-to-end bulbar urethroplasty. After urethral strictured segments were excised, biopsies of the presumed healthy ends (proximal and distal) were performed. Structural characterization was evaluated by staining histological sections in Haematoxylin-Eosin, Masson s trichrome, Weigert s resorcin-fuchsin method, and picrosirius-polarization method. At least one month before urethroplasty, suprapubic urinary diversion was performed in fifteen (52%) patients. The control group consisted of 10 bulbar urethras obtained from fresh, macroscopically normal cadavers 21 to 32 years old (mean age 24.7). Results: Urethral strictures were due to contraction of the fibrous tissue which has begun to replace the normal structures of the corpus spongiosum. A replacement of the vascular sinusoids in the corpus spongiosum by a dense extracellular matrix (ECM) occurred in all patients. ECM was formed mainly by collagen (vast majority of them) and elastic fibers. No patient presented microscopic normal urethral ends. All urethral edges presented chronic and/or acute microscopic changes if compared to the control group. With regard to the proximal end, the deposit of ECM presented high cellular density in 18 (62.1%) cases. These cells were predominantly fibroblast and inflammatory cells and were related to the time of the urethral injury and the absence of a suprapubic urinary diversion. Also, in these patients, elastic fibres had a heterogeneous distribution in the proximal urethral end. Epithelial hyperplasia was found in 20 (69%) proximal urethral ends, and acute urethritis with mixed inflammatory cells was also evidenced. With regard to the distribution of collagen I and III, marked differences were found in all groups. Conclusion: Presumed healthy urethral ends of the end-to-end bulbar urethroplasty present structural changes. A suprapubic urinary diversion may influence the composition of the ECM in the proximal bulbar urethra. However, the clinical role of these findings needs further investigation.