Partial Right Atrial Inflow Occlusion for Transient Systemic Hypotension During Deployment of Thoracic Stentgrafts

Inferior Vena Cava-Balloon Occlusion and Its Effect on the Myocardium During Endograft Deployment in the Arch

PURPOSE

To evaluate the impact of cava balloon occlusion on the myocardium during endovascular repair of thoracic aortic pathologies.

MATERIAL AND METHODS

A prospective observational cohort study of 21 patients who underwent endovascular repair of aortic arch and thoracic aorta in a single tertiary referral center with use of inferior vena cava (IVC) balloon occlusion as a method of intraoperative cardiac output reduction. Pre-, intra-, and postoperative measurements of heart rate, blood pressure, stroke volume index, and central venous oxygen saturation were noted. High-sensitive serum troponin levels were also analyzed according to a pre-established protocol. Endpoints were cardiac troponin T levels after induced hypotension and left ventricular ejection fraction during follow-up. Secondary endpoints were procedure technical success and overall survival.

RESULTS

Twenty-one patients (18 male, median age 69, (62-75, IQR)) enrolled in the study between May 2015 and January 2019. Indication for endovascular treatment was an aortic arch aneurysm (n=10), descending aortic aneurysm (n=8), lusorian artery aneurysm (n=2), and thoracoabdominal aortic aneurysm (n=1). Median time to reach half mean arterial pressure was 60 seconds while median recovery time of blood pressure was 135 seconds. In 5 (24%) cases, we observed a > 50% change of Troponin T on the reference level. Technical success was achieved in all cases. Two (10%) patients developed new and persistent atrial fibrillation and 1 (5%) suffered a peri-operative ST-elevation myocardial infarction.

CONCLUSION

The use of IVC balloon occlusion is a feasible technique for cardiac output reduction during endovascular repair of thoracic aortic pathologies. One fourth of the patients develop significant troponin leakage but the significance of the finding needs further studies.

Contemporary uses of inferior vena cava balloon occlusion

The evolution of the hybrid operative environment has expanded the utility of inferior vena cava balloon occlusion (IVCBO) in contemporary surgical practice. First described in the management of acute decompensated heart failure and venous thromboembolism, IVCBO has been utilised in deployment of thoracic endoprosthesis, repair of aorto-caval fistula, management of inferior vena cava (IVC) tumour thrombus and abdominal IVC trauma. More recently, IVCBO has also been utilised as a therapeutic strategy to assist patients with reduced ejection fraction and exercise tolerance in the form of an implantable device. Here we present a narrative review of the physiological impact of IVCBO as well as its historical, contemporary and future uses. The contemporary utilisation of IVCBO is a novel example of employing endovascular technology in the hybrid operative environment; paramount for the modern vascular surgeon who is now increasingly involved in multi-disciplinary management of complex clinical presentations.

Transesophageal Echocardiography Guided Partial Right Atrial Inflow Occlusion - A Case Study

Deployment of stent-grafts and other endovascular devices is a common technique for various vascular repair procedures. Induced, transient, periods of hypotension are essential to the precise deployment of a device as this minimizes displacement that can result from high pressure aortic flow. Partial inflow occlusion of the right atrium is a reliable, precise, and safe method of achieving this. We present a case where intraoperative transesophageal echocardiography (TEE) was used to guide and confirm balloon placement for right atrium inflow occlusion during a thoracic endovascular aneurysm repair (TEVAR) procedure for repair of an aortic dissection in a 67 year old male. This highlights a novel use of TEE in the context of endovascular surgery, and showcases an alternative method of reliably achieving transient hypotension.