621 ECG-gated Cardiac CT facilitates operative planning in patients with Extensive Mitral Annular Calcification

Abstract

Extensive Mitral Annular Calcification (MAC) can represent a significant surgical challenge. Although techniques for complete decalcification are described, some surgeons prefer to remove MAC only when necessary. Preoperative identification of the precise implications of MAC has been difficult. We describe our early experience with ECG-Gated Cardiac CT as a preoperative tool to identify the extent of MAC, and to predict requisite surgical techniques. Chart review was performed to identify all patients with ECG-gated cardiac CT for evaluation of extensive MAC, prior to isolated MVR by a single surgeon between April 2010-April 2011. All CTs were reviewed with a thoracic radiologist pre-operatively. Hospital charts were reviewed retrospectively to determine findings and outcomes. Three patients with pre-operative ECG-gated Cardiac CT for extensive MAC underwent successful MVR, with an uneventful post-operative course, and no evidence of paravalvular leak on follow-up echocardiography. CASE 1: 58-year-old woman with bileaflet prolapse, severe MR, and significant MAC on cardiac catheterization. Cardiac CT identified invasive MAC from P1 to mid-P3, but with an adequate orifice to accommodate a prosthesis. Further, adequate mitral leaflet was present adjacent to the MAC. CT findings predicted that no resection of MAC would be necessary. At surgery, interrupted sutures for MVR were placed through supple leaflet in the region of MAC which was otherwise left undisturbed. CASE 2: 80-year-old woman with symptomatic MS and MR, and nearly circumferential MAC on cardiac catheterization. Cardiac CT confirmed extensive MAC, but with an adequate orifice to accommodate a prosthesis. Anterolaterally, there was only diminutive residual leaflet overlying the MAC. CT findings predicted that resection of MAC and annular reconstruction would be required for the placement of valve sutures. At surgery, full anterolateral decalcification and annular reconstruction was required for successful MVR. CASE 3: 58-year-old woman with fatigue on exertion, and echocardiography demonstrating mild-moderate MR, moderate MS, elevated PA pressure, and severe MAC. Cardiac CT identified extensive circumferential MAC, deeply invasive into the myocardium to the level of the papillary muscles. The residual mitral orifice was insufficient to accept a prosthesis. CT findings predicted that extensive decalcification and reconstruction would be required. Anticipating a high-risk MVR, surgery was delayed until symptoms justified the predicted risk. At eventual surgery, complete anterior decalcification, partial posterior decalcification, and bovine pericardial reconstruction were required for MVR. ECG-gated Cardiac CT is a useful tool to predict requisite operative MVR technique in patients with extensive MAC.