RESUMO

The aim of this study was to compare two receptor sites in ovarian autologous transplantation in mice. Twelve Balb-c mice were randomly divided into three groups of four animals each: G1 - non-transplanted animals, G2 - animals which received the ovarian fragment in the perimetrium, G3 - animals which had the abdominal subcutaneous tissue as a receptor site. For transplantation, mice were subjected to bilateral salpingectomia. The left ovary was submitted for histological processing. The right ovarian cortex was fragmented and reimplanted in the specified places according to the groups. Transplants were recovered in 3/4 of the mice in each treatment group. In vaginal washes, the return of the ovarian activity in half of the females of G3 and 3/4 females of G2 was observed. It was detected the presence of corpora lutea in 1/4 of G3 transplants and half in G2. In follicular population all stages of development were observed. Comparing the receptor sites, it was observed a higher percentage of return to cyclicity, as well as of follicles, in animals which had the perimetrium as the site of transplantation. In the subcutaneous, there was a lower follicular growth and lower quantity of corpus luteum. Thus, ovarian autologous transplantation allocated in the subcutaneous tissue and perimetrium allowed both tissue maintenance and follicular development; however, the site of choice will depend on the final goal one aims with the technique

Objetivou-se comparar dois sítios receptores no transplante autólogo ovariano em camundongas. Doze camundongas BALB/c foram divididas aleatoriamente em três grupos experimentais com quatro animais em cada. O G1 - animais não submetidos ao transplante, G2 - animais que receberam o fragmento ovariano no perimétrio, G3 - animais que tiveram o tecido subcutâneo abdominal como sítio receptor. Para o transplante, as fêmeas foram submetidas à ovariossalpingectomia bilateral. O ovário esquerdo foi encaminhado para processamento histológico. O córtex do ovário direito foi fragmentado e reimplantado nos locais especificados de acordo com os grupos. Os transplantes foram recuperados em 3/4 das camundongas em cada grupo tratado. No lavado vaginal, observou-se em metade das fêmeas do G3 e em 3/4 das fêmeas do G2 retorno da ciclicidade. Observou-se presença de corpos lúteos em 1/4 dos transplantes do G3 e metade nos do G2. Na população folicular, foram observados todos os estádios de desenvolvimento. Comparando os sítios receptores observou-se maior porcentagem de retorno à ciclicidade, bem como de folículos, nos animais que tiveram o perimétrio como local do transplante. Já no subcutâneo houve menor crescimento folicular e menor quantidade de corpos lúteos. Dessa forma, conclui-se que o transplante autólogo ovariano alocado no tecido subcutâneo e no perimétrio permitiu tanto a manutenção tecidual quanto o desenvolvimento folicular, porém, o sítio de escolha vai depender do objetivo final que se almeja com a técnica

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RESUMO

The aim of this study was to compare two receptor sites in ovarian autologous transplantation in mice. Twelve Balb-c mice were randomly divided into three groups of four animals each: G1 - non-transplanted animals, G2 - animals which received the ovarian fragment in the perimetrium, G3 - animals which had the abdominal subcutaneous tissue as a receptor site. For transplantation, mice were subjected to bilateral salpingectomia. The left ovary was submitted for histological processing. The right ovarian cortex was fragmented and reimplanted in the specified places according to the groups. Transplants were recovered in 3/4 of the mice in each treatment group. In vaginal washes, the return of the ovarian activity in half of the females of G3 and 3/4 females of G2 was observed. It was detected the presence of corpora lutea in 1/4 of G3 transplants and half in G2. In follicular population all stages of development were observed. Comparing the receptor sites, it was observed a higher percentage of return to cyclicity, as well as of follicles, in animals which had the perimetrium as the site of transplantation. In the subcutaneous, there was a lower follicular growth and lower quantity of corpus luteum. Thus, ovarian autologous transplantation allocated in the subcutaneous tissue and perimetrium allowed both tissue maintenance and follicular development; however, the site of choice will depend on the final goal one aims with the technique(AU)

Objetivou-se comparar dois sítios receptores no transplante autólogo ovariano em camundongas. Doze camundongas BALB/c foram divididas aleatoriamente em três grupos experimentais com quatro animais em cada. O G1 - animais não submetidos ao transplante, G2 - animais que receberam o fragmento ovariano no perimétrio, G3 - animais que tiveram o tecido subcutâneo abdominal como sítio receptor. Para o transplante, as fêmeas foram submetidas à ovariossalpingectomia bilateral. O ovário esquerdo foi encaminhado para processamento histológico. O córtex do ovário direito foi fragmentado e reimplantado nos locais especificados de acordo com os grupos. Os transplantes foram recuperados em 3/4 das camundongas em cada grupo tratado. No lavado vaginal, observou-se em metade das fêmeas do G3 e em 3/4 das fêmeas do G2 retorno da ciclicidade. Observou-se presença de corpos lúteos em 1/4 dos transplantes do G3 e metade nos do G2. Na população folicular, foram observados todos os estádios de desenvolvimento. Comparando os sítios receptores observou-se maior porcentagem de retorno à ciclicidade, bem como de folículos, nos animais que tiveram o perimétrio como local do transplante. Já no subcutâneo houve menor crescimento folicular e menor quantidade de corpos lúteos. Dessa forma, conclui-se que o transplante autólogo ovariano alocado no tecido subcutâneo e no perimétrio permitiu tanto a manutenção tecidual quanto o desenvolvimento folicular, porém, o sítio de escolha vai depender do objetivo final que se almeja com a técnica(AU)

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OBJECTIVE: To evaluate the use of tunica vaginalis as a dorsal free graft in the first stage of Bracka's urethroplasty in a rabbit animal model using macroscopic and histological analysis. MATERIAL AND METHODS: Surgery was performed on 16 rabbits, divided into four groups of four according to the number of weeks after surgery at which they were killed (2, 4, 8 and 12 weeks). The penile urethra was removed and only the ventral aspect of the urethra was reconstructed using a tunica vaginalis free graft dorsally fixed in the corpora cavernosa. Epithelial, inflammatory and fibrotic changes in the graft were evaluated macroscopically then histologically at the point when each rabbit group was killed. RESULTS: Macroscopic evaluation showed good graft uptake with minimal retraction (P > 0.05). Histological evaluation showed a reduction in the inflammatory process during the first 4 weeks, after which inflammation stabilized. The mesothelium was partially healed at 2 and 8 weeks with a metaplasia defined by a stratified squamous, non-keratinized lining. The grafted area was thinner than the surrounding penile skin and similar to urothelial native epithelium. CONCLUSION: Tunica vaginalis used as a free graft placed dorsally on the corpora cavernosa in the first stage of Bracka's urethroplasty shows good tissue integration and develops into a stratified non- keratinized epithelium (metaplasia) without significant retraction, despite exposure to the external environment.

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OBJECTIVE: To assess the use of tunica vaginalis graft plus onlay preputial island flap in urethral reconstructive surgery in rabbits through histopathology. MATERIAL AND METHODS: We developed an experimental model of urethroplasty that resembles one-stage complex hypospadias surgery with divided urethral plate. The tunica vaginalis graft is dorsally placed to recreate the urethral plate and the internal preputial island flap is placed onlay to complete the urethroplasty. Sixteen animals were divided into four equal groups and sacrificed at 2, 4, 8 and 12 weeks after surgery, the penis being sent for histopathological evaluation. RESULTS: There were no deaths related to the procedure or wound breakdown; all rabbits voided spontaneously after surgery. Two urethrocutaneous fistulae were found. Microscopically, good tissue integration was observed, the tunica vaginalis mesothelium was gradually replaced by a more stratified epithelial lining, similar to the urothelial lining of the native urethra. The stratified squamous non-keratinized lining of the internal preputial island flap also changed into a thinner epithelial lining with only 4-5 cell layers. Two urethral diverticula were found. CONCLUSION: A tunica vaginalis graft placed dorsally plus an onlay internal preputial island flap was shown to be a successful technique for urethroplasty in an animal model.

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INTRODUCTION: Nowadays, buccal mucosa grafts are the most successful method to reconstruct bulbar urethral strictures. Dorsal placement of the graft has been recently proposed, allowing the graft to be spread fixed on the tunica albuginea of the corporal bodies overlying the stricture. The dorsal graft is ingenious and represents a useful addition to the surgical armamentarium, since it offers a better chance for graft take than does the spongiosum when the urethra is diseased and poorly vascularized. We developed an additional reconstructive option using tunica vaginalis grafts, placed dorsally, for the treatment of anterior urethral strictures. SURGICAL TECHNIQUE: A total of 11 patients with anterior urethral strictures were treated with a tunica vaginalis graft urethroplasty. The surgical technique was done as described by Barbagli. The urethra was dissected from the corpora cavernosa and rotated 180 degrees. The dorsal urethral surface was exposed and fully opened. Both the distal and proximal lumina were calibrated. The tunica vaginalis graft was sutured, splayed and quilted over the corpora cavernosa using 6-0 PDS running stitches. The left side of the urethral mucosa was sutured to the graft using 6-0 PDS sutures. A 18F silicone Foley catheter was inserted at this point. The urethra was rotated back to its original position and sutured laterally to the right side of the graft. At the end of the procedure, the graft was completely covered by the urethra. With a follow-up ranging from 7 weeks to 5 months, all patients were voiding well (uroflowmetry > 14 mL per second). CONCLUSION: This initial experience in 11 patients indicates that tunica vaginalis dorsal graft urethroplasty may be considered within the reconstructive armamentarium of genitourinary surgeons.

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INTRODUCTION: Nowadays, buccal mucosa grafts are the most successful method to reconstruct bulbar urethral strictures. Dorsal placement of the graft has been recently proposed, allowing the graft to be spread fixed on the tunica albuginea of the corporal bodies overlying the stricture. The dorsal graft is ingenious and represents a useful addition to the surgical armamentarium, since it offers a better chance for graft take than does the spongiosum when the urethra is diseased and poorly vascularized. We developed an additional reconstructive option using tunica vaginalis grafts, placed dorsally, for the treatment of anterior urethral strictures. SURGICAL TECHNIQUE: A total of 11 patients with anterior urethral strictures were treated with a tunica vaginalis graft urethroplasty. The surgical technique was done as described by Barbagli. The urethra was dissected from the corpora cavernosa and rotated 180 degrees. The dorsal urethral surface was exposed and fully opened. Both the distal and proximal lumina were calibrated. The tunica vaginalis graft was sutured, splayed and quilted over the corpora cavernosa using 6-0 PDS running stitches. The left side of the urethral mucosa was sutured to the graft using 6-0 PDS sutures. A 18F silicone Foley catheter was inserted at this point. The urethra was rotated back to its original position and sutured laterally to the right side of the graft. At the end of the procedure, the graft was completely covered by the urethra. With a follow-up ranging from 7 weeks to 5 months, all patients were voiding well (uroflowmetry > 14 mL per second). CONCLUSION: This initial experience in 11 patients indicates that tunica vaginalis dorsal graft urethroplasty may be considered within the reconstructive armamentarium of genitourinary surgeons.

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PURPOSE: We created an experimental model of urethral defect and then repaired it using a tunica vaginalis graft applied on the dorsal surface of the urethra. We studied the histological and radiological characteristics of free tunica vaginalis graft urethroplasty. MATERIALS AND METHODS: In 20 New Zealand rabbits a dorsal urethral defect was created by excising a portion of the dorsal urethral surface. The tunica vaginalis graft was placed dorsally over the corpora cavernosa and tied with 4 interrupted sutures. The mucosal margin of the urethral defect was sutured to the graft using 6-zero polydioxanone sutures in continuous fashion. The animals were divided into 4 equal groups and were sacrificed 14 days, and 4, 8 and 12 weeks after surgery, respectively. A retrograde urethrogram was done at autopsy. The penis was sent for histological analysis and an experienced pathologist evaluated the severity of acute and chronic inflammation, foreign body reaction and scar formation. RESULTS: There were no deaths related to the procedure and no intraoperative complications. All rabbits voided spontaneously after surgery. Retrograde urethrograms showed no fistula or stricture. As time after surgery increased, the signs of inflammation response disappeared, and the orientation of collagen fibrils and smooth muscle fascicles resembled that of a normal urethra. The mesothelial lining of the tunica vaginalis gradually became replaced by a more stratified epithelial lining, similar to the urothelial lining of the native urethra. CONCLUSIONS: In the current study we noted that a tunica vaginalis graft placed dorsally can be a successful urethral substitute in the animal model.

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