Sterilization with fibrin sealant in a rabbit uterine horn model

A aplicação de adesivo de cianoacrilato por histeroscopia e os testes de perviedade na esterilização tubária de ovelhas

OBJETIVO: avaliar, por meio de testes de prenhez e de perviedade, a eficácia da obstrução tubária de ovelhas com adesivo de cianoacrilato aplicado por via histeroscópica. MÉTODO: 12 ovelhas adultas, com uma gestação anterior, foram distribuídas em três grupos: G-PO (n=3) submetidas à laqueadura tubária tipo Pomeroy; G-SH (n=3) aplicação de solução salina no istmo tubário por histeroscopia, e G-AD (n=6) aplicação de 0,5mL de n-butil-2-cianoacrilato no interior do istmo tubário, por histeroscopia. Depois de acasaladas por 90 dias com machos de comprovada fertilidade, as ovelhas não prenhas foram submetidas à laparotomia, retiradas as tubas uterinas, medidos os seus diâmetros e preparadas para testes de perviedade pela aplicação de azul de metileno e de pressão hidráulica (80mmHg). RESULTADOS: As ovelhas de G-PO e G-AD não ficaram prenhas (0%), em contraste com as SH (100%). O G-PO apresentou maior concentração de aderências (66,6%) e de granulomas (100%) em relação ao grupo AD (0%); o adesivo manteve-se íntegro no lúmen tubário. O diâmetro da tuba uterina em G-AD (0,650 ± 0,16 cm) foi significantemente maior do que o das tubas em G-PO (0,195 ± 0,04* cm) (p=0,01). Os testes de perviedade de pressão e corante foram negativos para todo o grupo PO e somente um animal em AD mostrou-se positivo para o teste de pressão. CONCLUSÃO: a aplicação histeroscópica de cianoacrilato no lúmen tubário de ovelhas impediu eficientemente a fecundação, constituindo procedimento eficaz e de boas perspectivas para aplicação futura em humanos.

Hysteroscopy and the butyl-cyanoacrylate on experimental sterilization of rabbit uterine tubes

PURPOSE: To assess the sterilization effectiveness on uterine tube of rabbit by the cyanoacrylate adhesive. METHODS: Hysteroscopy tubal catheterization was performed randomly in 12 animals (24 uterine tubes) assigned to the sham group (GS) and 15 animals (30 uterine tubes) to the n-butyl-cyanoacrylate (GB). The female rabbits were observed during 30, 90 and 180 days and mated to fertile males. The no pregnant rabbits were submitted to in vitro burst pressure test for patency by air insufflation (40 mmHg). The microscopic assessment was performed to parameters of damages in epithelium caused by the adhesive, the degree of inflammatory process, morphometry data values of tube diameter (UT) (cm), mucosa thickness (MT) and the myosalpinx thickness (MyT) (mm). The mucosa cells densitometry (total optical density) was expressed by the amount of DNA. The significance of the differences in histological scores and in thickness measurements were made by ANOVA test (P value < 0.05). RESULTS: In all animals of GB: the adhesive was attached to the mucosa; there was no pregnancy; no records of significant degree on inflammatory process; the patency test was negative and densitometry of DNA showed similar values to the both groups independently of observation periods. The layers thickness of GB-UT(1.118±0.117), GB-MT(0.447±0.247) and GB-MyT(0.853±0.097) were larger than the GS-UT(0.666±0.409), GS-MT(0.211±0.070) and GS-MyT(0.442±0.143). CONCLUSION: This approach offers a safe and feasible method of uterine tube obstruction.

Hysteroscopic sterilization with occlusion of sheep uterine tube using n-butyl-2-cyanoacrylate adhesive

PURPOSE: To evaluate the fertility and analyze the macroscopic, microscopic and morphometric aspects of sheep uterine tube sterilization with a hysteroscopically insert of n-butyl-2-cyanoacrylate adhesive. METHODS: 12 adult sheep, with one previous pregnancy, were distributed as follows: group L (n=3) subjected to laparotomy and Pomeroy uterine tube ligation, group S (n=3) subjected to hysteroscopic application of saline solution in tube isthmus and group AD(n=6), that was subjected to hysteroscopic application of 0.5 ml of n-2-butil-cyanoacrylate in tube isthmus. They were mated with fertile males for ninety days. The non pregnant sheep, at the 90th day, were subjected to laparotomy with uterus and tubes uterine resection. The fragments of uterine tubes were fixated in 10% formalin and processes for histology evaluated, and slices dyes for H.E. Data were evaluated by Wilcoxon and Mann-Whitney and Fisher's exact test. RESULTS: All sheep from groups L and AD did not get pregnant (0%) in contrast with sheep from group S (100%); the adhesive remained integral in the uterine tube lumen. The percentual of adherences (66.6%) and fibrosis responses (100%) was significantly higher in the group L than group AD (0%) (p<0.01). The diameter of the caudal tube in group AD (2652.15 ± 45.76 mm) was significantly wider than that of the group L (1868.27 ± 56.11* µm) (p < 0.05). CONCLUSION: The hysteroscopic insertion of cyanoacrylate in the uterine tube lumen of sheep was effective to obstruct the uterine tube and to promote the sterilization.

A review of selective salpingography and fallopian tube catheterization

Use of selective salpingography and fallopian tube recanalization has revolutionized the diagnosis and treatment of infertility. Selective salpingography, a diagnostic procedure in which the fallopian tube is directly opacified through a catheter placed in the tubal ostium, has been used since the late 1980s to differentiate spasm from true obstruction and to clarify discrepant findings from other tests. In fallopian tube recanalization, a catheter and guide wire system is used to clear proximal tubal obstructions. The recanalization procedure is simple for interventional radiologists to perform and is successfully completed in most patients (71%-92%). Pregnancy rates after the procedure have been variable, with an average rate of 30%. The combination of selective salpingography with fallopian tube recanalization has improved the overall management of infertility caused by tubal obstruction. The same catheterization technique used in fallopian tube recanalization is currently being explored for use in tubal sterilization.

Tubal sterilization by means of endoluminal coagulation: an in vivo study in rabbits

This study was conducted to investigate the effectiveness and safety of endoluminal tubal coagulation in obliterating the tubal lumen in rabbits. Forty female rabbits were subjected to laparotomy and hysterotomy. Endoluminal tubal coagulation was induced over a length of 3 cm in the proximal, extramural fallopian tube by using a heated stainless steel cannula or a cylindrical diffusing tip emitting argon laser radiation for one to 5 minutes. Tubal patency was evaluated by observing patterns of injected methylene blue and/or breeding success rates. Postoperative recovery was uneventful in all animals. A negative methylene blue test indicated occlusion in 51 of 52 tubes (tubal occlusion rate 98.1%), and a contraception rate of 100% in all 17 uteri in which the tube had been treated. The described endoluminal tubal coagulation method proved suitable for safe and effective sterilization in rabbits and has potential as a new transcervical tubal sterilization method for humans.