Medusa's Wrath: Bleeding Giant Scalp Arteriovenous Malformation in an Adult: A Case Report.

Background: Scalp arteriovenous malformation (AVM) is a rare congenital disease that may present with massive bleeding. To date, surgical excision remains the definitive management. However, the procedure could lead to intraoperative bleeding due to the tumor's high blood flow and complex vascularity.

Case Report: A 49-year old Filipino male presented with a bleeding giant scalp AVM. Computed tomographic scan and duplex studies showed multiple feeding vessels with turbulent flow arising primarily from the right superficial temporal, right posterior auricular, and occipital vessels. Prior to surgery, the patient underwent transfusion due to preoperative hemoglobin of 6 g/dL. Proximal control of the right external carotid artery was performed through a supine position and left in place to reduce the majority of blood flow to the AVM. The patient was turned to a prone position for surgical planning to achieve maximal skin-sparing dissection prior to excision. First, ligation of bilateral superficial temporal and posterior auricular arteries was performed. Next, excision above the periosteum with segmental ligation of feeding vessels around the AVM was carried out. Reconstruction of the defect was done via scalp advancement flap and split-thickness skin grafting. Intraoperative blood loss was 1.6 L. On the sixth postoperative day, the patient was discharged with 100% graft take.

Conclusion: Management of scalp AV malformation is challenging, and despite measures to decrease intraoperative bleeding, blood loss is still high. While preoperative embolization has been reported to decrease the risk of bleeding, this procedure is not currently available in our setting. Our case highlights the complexity of giant scalp AV malformation management in a limited-resource setting. Even in the absence of endovascular intervention, outright surgical excision of AVM can be performed, albeit with higher levels of blood loss.