Clinical Complications Induced by Placental Site Subinvolution: Secondary-Type Hemorrhage after Delivery and Pseudo Aneurysms after Non-Traumatic Delivery may be Caused by Atony Of The Uteroplacental Artery
Author(s): Yuji SHIINA, Masahiro YAMAMOTO, Shiori SANO, Yuta GONAI, Kazuyoshi SAKAI
Background: Persistence of extravillous trophoblasts causes hemorrhage and many other problems.
Methods: Three cases of critical hemorrhage are presented. Two cases of secondary-type postpartum hemorrhages that occurred after discharge and one case of pseudoaneurysms that occurred after miscarriage.
Results: In postpartum hemorrhage cases, placental site subinvolution was diagnosed. Microscopic examination of the resected uterus showed subinvoluted arteries containing large thrombi. Immunohistochemical analysis showed that extravillous trophoblasts were present within the walls of subinvoluted vessels. Failure of involution on the placental site sometimes occurs following miscarriages as well. In post-miscarriage psudoaneurysms case, the distinctive hemorrhage in this patient consisted of bleeding from various sites in the myometrium after the placental chorion had been expelled without leaving a remnant. The bleeding pattern was extremely similar to the postpartum hemorrhage described above. Though, we could not confirm extravillous trophoblasts directly because of the succes of conservative treatment, these postpartum and post-miscarriage hemorrhage were thought to have the same pathophysiology.
Conclusion: The cause of both hemorrhages may have been atony of the uteroplacental artery and can be explained by subinvolution.