Three Steps Hybrid Treatment: En Bloc Resection, Endovascular Treatment and Microsurgical Reconstruction. Case Report of a Giant Dorsum-Abdominal-Pelvic Arteriovenous Malformation.

Arteriovenous malformations (AVMs) are a rare condition involving the trunk. We present a case of a 55-year-old woman affected by a giant dorsum-abdominal-pelvic AVM, even after multiple endovascular and surgical treatments over decades which required a different surgical approach. AngioCT scan was performed to identify the feeding vessels, the mass' extension and involvement of underlying tissues. Multidisciplinary discussion agreed on multistep treatment. First, we performed an en bloc resection starting from the right pelvis, moving cranially and laterally toward the right armpit, then removing medially toward the vertebral column, leaving a defect of 30 × 10 cm. Then a selective angiography and a paravertebral embolization of remaining AVM at the T7-level were performed. Reconstruction was then completed with a left hemiabdomen DIEP free flap. We anastomosed one branch of the DIEA to the SCIA and one comitantae vein to the SCIV to assure lateral flow. Then we performed the anastomosis between the DIEA and the second comitantae vein respectively to a branch of TDA and to a branch of the serratus vein. The follow up at 6 months has satisfactory results for both patient and surgeon. This challenging case could provide an alternative for radical surgical excision combined with an endovascular control and microsurgical reconstruction. We describe what we believe to be the first reported giant AVM treated with this sequence multistep surgeries.