Postpartum patient is simultaneously diagnosed with Arteriovenous Malformation (AVM) and Retained Products of Conception (RPOC).
AVMs are rare and can be diagnosed with ultrasound or CT angiography, while RPOC can occur due to placenta accreta spectrum disorders.
The 28-year-old patient had a history of Acute Myeloid Leukemia (AML), Anti-Kell antibodies, and a previously treated postpartum AVM. She had ongoing vaginal bleeding due to suspected AVM or RPOC.
Sonohysterogram and CT angiogram confirmed the presence of RPOC and a right-sided AVM.
A combined laparoscopic and hysteroscopic surgery was performed to ligate the feeding vessel for the right uterine AVM and to resect the retained placenta. Ensuring haemostasis was a critical step in both procedures.
Post-operatively, successful treatment of the uterine AVM and removal of RPOC were confirmed. The patient will be followed in their subsequent pregnancy, and more research is needed on recurrence risks and fertility impact.
In this video, we present the case of a postpartum patient with a diagnosis of simultaneous AVM and RPOC secondary to invasive placentation. A tandem laparoscopic and hysteroscopic approach was performed to resect the RPOCs and surgically ligate the AVM. The objectives include outlining the background of these two gynaecologic pathologies, and highlighting surgical treatment. We will identify future research directions.
Background on Arteriovenous Malformation (AVM)
AVMs are a rare occurrence of an abnormal non-functional connection between arteries and veins without an intervening capillary bed. Uterine AVMs can be congenital or acquired, with many of those acquired occurring after pregnancy or iatrogenic procedures such as D&Cs. Patients present with heavy uterine bleeding or delayed PPH. AVMs can be reliably diagnosed with ultrasound via a colour Doppler. CT angiography remains the current gold standard for a diagnosis. Treatment can occur non-invasively through IR embolization, though there have been case reports of surgical ligation of the feeding vessels.
Background on Resection of Retained Products of Conception (RPOC)
Retained products of conception following delivery can be due to placenta accreta spectrum disorders, which happens when trophoblastic tissue invades into the myometrium and sometimes beyond. Several similar risk factors, including a previous history and uterine surgeries, can increase the risk. Management of RPOCs depend on patient haemodynamics and can include expectant, medical and surgical options, such as D&C or hysteroscopic resection.
Our case involves a 28-year-old, G3P2A1L1, who is four months postpartum from a preterm birth at 27 weeks. Her history is significant for AML post bone marrow transplant, Anti-Kell antibodies and postpartum AVM in 2019 managed with IR embolization of the left uterine artery. Her surgical history is significant for a total of two D&Cs. In October 2019, NH had had a 20-week loss that was complicated by PPH with manual removal of retained placenta and D&C.
Two months postpartum, she had ongoing vaginal bleeding, with an ultrasound querying either AVM or RPOC. Awaiting surgery, she unfortunately had abrupt vaginal bleeding, requiring IR embolization of the left uterine artery, with AVM diagnosed. She remained well and had no issues conceiving a subsequent pregnancy. In December 2020 she delivered preterm at 27 weeks, with again a PPH requiring manual removal of placenta and D&C. Given increased vaginal discharge and spotting, NH presented with an ultrasound diagnosing RPOC, which was treated with misoprostol. Further investigations ensued.
Sonohysterogram was performed by the MIS team. There was an apparent hyperechoic intrauterine mass consistent with RPOC, and increased vascularity along the right uterine wall with aliasing of blood flow suggesting a right-sided AVM. A confirmatory CT angiogram was performed, identifying the right uterine AVM. Surgical considerations of this challenging case included ruling out GTD, managing both AVM and RPOC with the patient’s wishes for future fertility. We preserved blood through optimisation of anaemia with IV iron, and intra-operative management of Vasopressin peri-cervical block with Tranexamic Acid IV.
The combined procedure involved a laparoscopy to ligate the feeding vessel for the right uterine AVM, and hysteroscopic resection of retained placenta that was invading the myometrium. We will highlight the surgical steps of ligation of the AVM as follows.
Six Step Approach
Step one, identify anatomy.
Step two, access the retroperitoneum, which can be done by opening the peritoneum lateral to the IP over the ileac vessels, and bluntly pushing and spreading in this space. The medial umbilical ligament can be a helpful abdominal landmark that can be traced towards the obliterated umbilical artery.
Step three, identify the ureter, which can be found coursing over the ileac vessels in the medial leaf of the broad ligament. The obliterated umbilical ligament can be identified in this space and be used to trace the internal ileac artery.
Step four, identify the feeding vessel, which in this case is the right internal ileac artery. The obliterated umbilical ligament can be grasped and lifted laterally, providing room for dissection around the artery.
Step five, ligate the feeding vessel. 5mm clips are deployed here around the artery, after both sides have been clearly delineated around the vessel.
Step six, ensure hemostasis.
Surgical Steps for Resecting the RPOCs
In the following video, we will identify the surgical steps involved in resecting the RPOCs. Step one, identify the RPOC. Step two, resect the RPOCs, which can be done with a loop resectoscope and use of evacuation with polyp forceps. Blunt pressure with the resectoscope loop weakened the placental myometrial interface, and the RPOC was extracted with several passes of the polyp forceps. Step three, resect the base of the RPOCs. Step four, ensure haemostasis. Step five, maintain uterine distension with an intrauterine Foley.
Post-operatively, this patient did very well. A sonohysterogram identified a preserved uterine cavity, with obvious resection of the left uterine wall, where the RPOC was anchored. Final pathology confirmed normal placental tissue, but a placenta accreta spectrum. A Doppler ultrasound confirmed reduced flow at the right uterine wall, suggesting treatment of the uterine AVM. The patient will be followed in MFM in their subsequent pregnancy. Future research is required in examining recurrence risks and the impact on fertility.
Thank you to our patients and healthcare team at McMaster University.