Effectiveness of hormonal tourniquet by vasopressin during myomectomy through vasopressin V1a receptor ubiquitously expressed in myometrium.

To elucidate the mechanism by which myometrial vasopressin injection promotes hemostasis during myomectomy, we examined the expression of vasopressin V1a receptor transcripts in the myometrium. Vasopressin V1a receptor expression was ubiquitous, and the transcripts were detected in the myometrium not only of cycling and pregnant patients, but also of postmenopausal or GnRH agonist-treated patients. Based on these observations, we applied intraoperative myometrial vasopressin injection during myomectomy in a non-randomized study in a total of 84 patients. Vasopressin injection significantly reduced the intraoperative blood loss and postoperative hemoglobin fall in patients without and with GnRH agonist pretreatment. No serious complications occurred on account of the vasopressin injection. We conclude that intraoperative vasopressin injection is effective as a hormonal tourniquet even in GnRH agonist-pretreated myomectomy.