Title: Impact of a Standardized Protocol of Aortic Computer Tomographic Angiography on Planning of Minimally Invasive Mitral Valve Surgery
Abstract: Objective: Right femoral cannulation for extracorporeal circulation (ECC) is a standard procedure for minimally-invasive cardiac surgery (MICS) of the mitral valve. Unfortunately, vascular pathologies may cause serious complications. Pre-operative CT-angiography (CT-A) of the aorta, subclavian, axillary and iliac arteries was implemented as an imaging procedure for patients especially planned for intra-aortic clamping at our department, unless contraindicated (impaired renal function, emergency status). Methods: All patients planned for MICS between July 2017 and October 2018 were retrospectively reviewed (n = 124), and divided into three groups (CT-A vs. CT vs. no CT). Results: In patients without CT (n=42, 33.8%) ECC was always applied via femoral arteries (90.48% right, 9.52% left side). In more than 90%, trans-thoracic aortic clamping was performed. Vascular related complications (dissection, stroke, related in-hospital death) occurred in 3 patients (7.14%). In patients with CT excluding aortic imaging (n=33, 26.6%), also only femoral cannulation was applied (93.94% right side) with vascular related complications in 2 cases (6.25%). However, CT-A (n=49, 39.5%) identified nine patients (18.37%) with vulnerable plaques, 3 patients (6.12%) with severe kinking of iliac vessels, 28 patients (57.14%) with multiple calcified plaques as well as 5 patients (10.20%) with small femoral artery diameter (d ≤ 6 mm). Overall, in 6 patients (12.24%) pathologic findings led to an alternative cannulation via right axillary artery; an additional 3 patients (6.12%) were cannulated via the left femoral artery. 16 patients (32.65%) were suitable for clamping with an intra-aortic clamping device. Only 2 patients (4.08%) suffered from vascular related complications. At discharge, serum creatinine showed no significant changes as a hint to contrast induced nephropathy. Conclusions: CT-A identifies relevant vascular pathologies otherwise undetectable in routine pre-operative preparation. A standardized imaging protocol including the entire aortoiliac vessels may help to customize the operative strategy potentially reducing severe complications in MICS patients.