Unusual Arteriovenous Malformation in Total Hip Arthroplasty: Case Report of a Complicated Perioperative Course.

It is not common to encounter arteriovenous malformations (AVMs) during total hip arthroplasty (THA). We report the present case to draw attention to the possibility of an AVM during the direct anterior approach (DAA) for THA, which, if not borne in mind, may lead to the myriad of complications related to excessive bleeding. An 81-year-old female presented to the emergency department with a left femoral neck fracture. She elected to undergo a THA via the DAA. Abnormal appearing blood vessels were present near the ascending circumflex branches, which provided difficulty in achieving hemostasis. Excessive blood loss was noted, and the patient received one unit of packed red blood cells during the operation. Hemoglobin and hematocrit dropped in the days following surgery, requiring several additional transfusions of blood products. When the patient complained of progressive left leg swelling on postoperative day 3, a computed tomography revealed large hematomas within the left adductors and the left iliopsoas muscle. Active extravasation was identified arising from a branch of the left profunda femoral artery, as well as an arteriovenous fistula (AVF) in this area. Bleeding was controlled by selective endovascular coil embolization. As of current knowledge, this is the first reported intraoperative discovery of congenital arteriovenous malformation (AVM) with subsequent development of postoperative arteriovenous fistula and associated symptomatic hematomas in the setting of THA using the DAA. Early recognition and intervention of vascular malformations is essential in preventing potential limb- or life-threatening surgical complication.