| Co-Investigator(Kenkyū-buntansha) |
NISHIJIMA Koji University of Fukui Hospital, Assistant Professor, 医学部附属病院, 助手 (80334837)
KOTSUJI Fumikazu University of Fukui, Faculty of Medical Sciences, Professor, 医学部, 教授 (50153573)
FUKUDA Shin University of Fukui Hospital, Assistant Professor, 医学部附属病院, 助手 (40397279)
YOSHII Kumiko University of Fukui, Faculty of Medical Sciences, Assistant Professor, 医学部, 助手 (20397285)
打波 郁子 福井大学, 医学部附属病院, 医員 (30397252)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Objective: Although the removal of adnexa has been the traditional surgery in torsion, recent reports have advocated conservative surgery, including detorsion, with follow-up. As conservative management has come to be increasingly selected, the effects of detorsion on the ovary have been widely studied. Nevertheless, to our knowledge, no studies have examined the tubal resistance to ischemia. This study was intended to demonstrate the effects of adnexal torsion on tubal histology and apoptotic changes using an animal model.
Materials and Methods: We designed an adnexal torsion model using 16-week-old female Japanese White rabbits weighing approximately 3,000 g. A laparotomy was performed by midsagittal incision in the lower abdomen under an intravenous anesthesia of pentobarbital sodium salt. A puncture was made using a JELCO 22 G needle in the vascular area of the mesovaria; there the trocar was indwelled. An adnexal torsion was created by twisting the ovaries and tubes three times (10
… More
80°) using that trocar and then fixing on the peritonea with 3-0 vicryl. Following an ischemic period of 24, 72, 120, 240, or 720 h, the twisted adnexa were surgically removed and fixed for histopathological examination. The contralateral adnexa were used as controls.
All specimens were fixed in 10% buffered formalin, embedded in paraffin, and stained with hematoxylin-eosin (HE) for histological examination. The specimens were also stained with TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) to reveal the presence of cells that underwent apoptosis and were quantified according to the apoptosis score. Ultrastructural analyses of adnexas were also made using electron microscopy.
Results: An examination was made of six rabbits in each group. Although operative death, attributed to respiratory depressant effect of pentobarbital sodium salt, occurred in two cases, no incomplete rabbit data existed except for those two.
Although severe hemorrhage concealing ovarian parenchyma with infarct was prominent during 72 h torsion, the fallopian tubes showed no histological or ultrastructural changes even after 720 h torsion. Despite the above changes in the ischemic site, the histology of the contralateral adnexa was unaffected. As for the tubes, the apoptosis score showed no significant changes even after 720 h torsion.
Discussion: We designed an animal model for adnexal torsion using 16-week-old rabbits. Fallopian tubes are highly resistant to ischemic damage caused by torsion. We assume that its subtle blood vessel control might support such a resistance. Furthermore, it is important to consider mammals' reproductive functions.
Because histologically intact tubes were observed even after 720 h of ischemia in our animal model, it is likely that conservative therapy for adnexal torsion will preserve normal tubal function in spite of the ischemic insult. Although our results for rabbits cannot be inferred to be similar to those of humans, in many cases of uterine adnexal torsion, we can avoid salpingectomy. In conclusion, results of our study support the importance of conservative surgical management of tubes in adnexal torsion. Less
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