Balloon-Assisted Squid 12 Embolization of a Renal Angiomyolipoma With Imaging Findings Suggestive of Arteriovenous Communication: A Technical Report.

Renal angiomyolipomas (AMLs) are benign, hypervascular tumors that require transarterial embolization if ruptured or preemptively if at high risk of hemorrhage (>4 cm, intralesional aneurysms, childbearing age, symptomatic, etc.). The embolic materials of choice, in order to produce permanent occlusions of the distal microvasculature bed of the lesion, are microspheres and liquid embolic agents. Embolization may be technically challenging when imaging suggests arteriovenous (AV) communication because rapid flow can compromise controlled delivery of these agents. We report a 30-year-old woman with intermittent right-flank pain and a 5.0-cm right renal AML. Preprocedural computed tomography angiography demonstrated enlarged perilesional veins with early arterial-phase opacification, raising suspicion of intratumoral arteriovenous communication; however, a discrete arteriovenous fistula or high-flow shunt was not directly demonstrated on digital subtraction angiography. These findings prompted a balloon-assisted flow-control strategy to minimize the risk of reflux and non-target embolization. A Scepter™ Mini dual-lumen occlusion balloon microcatheter (Terumo Neuro, Aliso Viejo, CA, USA; balloon size 2.2×9 mm; distal/proximal outer diameter 1.6/2.8 Fr) was advanced into the dominant feeding artery over a 0.008-inch Traxcess™ Mini guidewire (Terumo Neuro, Aliso Viejo, CA, USA). After the 0.44-mL catheter dead space was primed with dimethyl sulfoxide, one 1.5-mL vial of Squid 12 (Balt, Montmorency, France) was injected slowly under temporary flow arrest. Completion angiography demonstrated complete tumor devascularization with preservation of uninvolved renal parenchymal perfusion, and immediate noncontrast computed tomography showed embolic material confined to the target vessels without visible venous migration. Moderate overnight postembolization pain was controlled with intravenous paracetamol, and the patient was discharged the following day. At three-month follow-up, magnetic resonance imaging demonstrated no residual enhancement and a reduction in calculated tumor volume from 49.5 to 11.6 cm³ (76.5%). This case demonstrates the technical feasibility of balloon-assisted Squid 12 embolization and highlights how preprocedural imaging can directly influence the endovascular strategy in selected complex renal embolization procedures.