Right Atrial Inflow Balloon Occlusion for Zone Zero Thoracic Endovascular Repair: Safety, Efficacy and Predictors of Response

Abstract

<h2>Objective</h2><p>Right atrial inflow occlusion with an inferior vena cava (IVC) balloon offers an alternative to traditional rapid ventricular pacing for cardiac output control during deployment of thoracic endografts. Landing in zone 0 demands more precise and significant reductions of aortic impulse. We aim to evaluate the safety and efficacy of IVC balloon occlusion, and determine the predictors of the blood pressure response in patients who underwent branched aortic arch endovascular repair.</p><h2>Methods</h2><p>Consecutive patients who underwent endovascular repair of arch aneurysms using custom-made inner side branch aortic endografts landing in zone 0 were studied. IVC balloon occlusion was used routinely for blood pressure reduction with a systolic target of 70 mmHg. The intraoperative arterial blood pressure response was matched to procedural fluoroscopy. Primary outcomes were the safety and efficacy of IVC balloon occlusion. Secondary outcomes include the predictors of the blood pressure response during induction, deployment, and recovery phases of hypotension.</p><h2>Results</h2><p>A total of 23 patients were included (91.3% male; mean age, 75.7 years). The mean duration of IVC balloon occlusion was 65 seconds (range, 35-109 seconds), Graft deployment took a mean time of 16.2 seconds (range, 5-30 seconds). A systolic blood pressure (SBP) lower than 70 mmHg could be achieved in 95.7% of patients within 60 seconds (mean, 55.4 mmHg). The mean recovery time was 33.1 seconds (range, 25-45 seconds) (Table I) (Fig 1). No cardiac complications occurred, and all endograft deployments were accurate. On risk factor analysis, induction of hypotension was hastened by a lower mean intraoperative SBP (<em>P</em> = .016). The lowest SBP attained was related to lower SBP before balloon occlusion (<em>P</em> = .003). A shorter balloon occlusion time would lead to faster recovery of hypotension (<em>P</em> = .021).</p><h2>Conclusions</h2><p>IVC balloon occlusion is a simple and effective method for reduction of aortic impulse for zone 0 thoracic endovascular repair. A lower SBP leads to better response.</p>