Hybrid Aortic Arch Repairs

Anatomic Utility of Single Branched Thoracic Endograft During Thoracic Endovascular Aortic Repair

INTRODUCTION

Single branched thoracic endografts (SBTEs) have been designed for pathology requiring zone 2 seal during thoracic endovascular aortic repair (TEVAR). Numerous criteria must be met to allow for their implantation. Our aim was to analyze anatomic suitability for a next generation SBTE.

METHODS

We reviewed 150 TEVAR procedures between 2015 and 2019. Proximal seal was: zone 0 in 21 (16%), zone 1 in 4 (3%), zone 2 in 52 (40%), zone 3 in 45 (35%), and zone 4 or distal in 7 (5%). We analyzed the Zone 2 patient's angiograms and CT angiograms using centerline software to measure arterial diameters and length in relation to the left common carotid artery (LCCA), left subclavian artery (LSA) and proximal extent of aortic disease to determine if patients met anatomic criteria of a novel SBTE.

RESULTS

Zone 2 average age was 64.4 ± 16.3 years; 34 patients were male (65%). Indications for repair were aneurysm (N = 9, 17%), acute dissection (N = 14, 27%), chronic dissection with aneurysmal degeneration (N = 7, 13%), intramural hematoma (N = 9, 17%), penetrating aortic ulcer (N = 5, 10%), and blunt traumatic aortic injury (BTAI, N = 8, 15%). LSA revascularization occurred in 27 patients (52%). Overall, 20 (38.5%) of the zone 2 patients met anatomic criteria. Patients with dissection met anatomic criteria less frequently than aneurysm (33% [10 of 30] vs 64% [9 of 14]). Patients treated for BTAI rarely met the anatomic criteria (1 of 8, 13%). The main anatomic constraints were an inadequate distance from the LCCA to the LSA takeoff and from the LCCA to the start of the aortic disease process.

CONCLUSION

Less than half of patients who require seal in zone 2 met criteria for this SBTE. Patients with aneurysms met anatomic criteria more often than those with dissection. The device would have little applicability in treating patients with BTAI.

Triple-Branched Stent Graft Implantation for Acute Non-A-non-B Aortic Dissection

BACKGROUND

The optimal treatment for acute non-A-non-B aortic dissection remains controversial. Triple-branched stent graft (TBSG) implantation has been used to treat acute type A aortic dissection. This study aimed to evaluate the safety and efficacy of TBSG as a treatment for acute non-A-non-B aortic dissection.

METHODS

Fifty patients with non-A-non-B dissection received TBSG implantation in our center between January 2014 and December 2019. Early mortality, morbidity, and dissected aorta remodeling during follow-up were calculated.

RESULTS

There were no deaths in-hospital or within 30 days. Postoperative complications included pneumonia (n = 12), acute kidney injury (n = 6; preoperative renal malperfusion, n = 4), transient cerebral injury (n = 6; preoperative cerebral malperfusion, n = 4), pleural effusion (n = 4), and pericardial effusion (n = 2). During follow-up, 1 patient experienced a stroke, and 2 patients required secondary interventional therapy for residual dissection below the level of the TBSG. All implanted TBSGs had good positioning, and all sidearm stent graft grafts were fully patent. No retrograde aortic dissection or type I endoleak was detected.

CONCLUSIONS

TBSG implantation for acute non-A-non-B aortic dissection had a low incidence of mortality and morbidity, featuring good remodeling of the dissected aortic wall during follow-up. The early outcomes of this technique were satisfactory.

Aortic arch aneurysm repair - Unsteady hemodynamics and perfusion at different heart rates

The aortic arch aneurysm is a complex disease that requires branching of one or more aortic arch vessels and can be fatal if left untreated. In this in vitro study, we examine the effect of the treatment approach on the unsteady hemodynamics and blood perfusion to the upper vessel's in models of an aortic arch aneurysm, and of the three common repair approaches: open-chest surgical repair, chimney, and hybrid approach. A particle image velocimetry method was used to quantify the unsteady hemodynamics in the four models simulated in a mock circulatory loop, to evaluate unsteady hemodynamic parameters and measure perfusion to the brain and the upper body. According to the findings, in terms of perfusion to the brain and upper body, the surgery model has the highest flow rate comparing to the other models in most heart-rate conditions. It also shows oscillatory parameters in the upper vessels which in normal arteries are correlated with a better arterial function. Between the two endovascular procedures, the hybrid model exhibits slightly better hemodynamic characteristics than the chimney model, with lower shear stresses and more oscillatory flow and WSS in the upper vessels. The hybrid model had lower perfusion flow rates to upper vessels during rest conditions (90BPM). However, unlike the other models, perfusion in the hybrid model increased with heart rate, thus at 135 BPM, it results in flow rate to upper vessels similar to that of the chimney model. The results of this study may shed light on future endograft' design and placement techniques.