Extrapelvic flow patterns during double balloon-occluded arterial infusion chemotherapy for bladder cancer: implications for neurological safety

Abstract Purpose To evaluate extrapelvic hemodynamics during double balloon-occluded arterial infusion (D-BOAI) chemotherapy for bladder cancer and to explore a potential mechanism underlying the low incidence of neurological complications. Materials and methods One hundred sides from fifty patients were analyzed. A double-balloon catheter was positioned into the contralateral internal iliac artery via the femoral artery approach. Digital subtraction angiography was performed with all four balloons fully inflated, which enabled visual assessment of blood flow in the superior gluteal artery (SGA) and inferior gluteal artery (IGA). Blood flow in the IGA was classified into the following three types: anterograde flow (Type 1), weak reversed flow (Type 2), and strong reversed flow (Type 3). The assessment was performed by consensus among two interventional radiologists. Results No inflow of the contrast medium into the SGA was observed in all 100 sides. The frequency of Type 1 flow was 11%, Type 2 flow was 45% and Type 3 flow was 44% in the IGA. Interobserver agreement for the three IGA flow classification was substantial, with a weighted kappa coefficient of 0.79. None of the 50 patients suffered from Grade 2 or more severe neurological complications as assessed by the National Cancer Institute’s Common Terminology Criteria for Adverse Events v6.0 in the buttocks or lower extremities. Conclusion D-BOAI is associated with consistent blockade of SGA inflow and frequent reversed flow in the IGA. These hemodynamic patterns may reduce drug exposure to nerves supplied by these arteries and may partly explain the low incidence of neurological complications reported with this technique. These findings provide a framework for understanding procedure-related hemodynamics and may help optimize catheter-based drug delivery strategies.