How far is the left circumflex coronary artery from the mitral annulus?

The relationship between the distance from the mitral annulus to the left circumflex coronary artery (LCX) and iatrogenic LCX injury has been questioned. This study was designed to determine the high-risk sites of LCX injury with an anatomical approach using multiple detector-computed tomography (MDCT) scanning taken before mitral valve annuloplasty (MVA). The purpose of this study is to prevent LCX injury in patients unable to receive MDCT before mitral valve surgery.

In 2018, we performed MVA on 59 patients, 52 of whom had undergone preoperative MDCT scanning. We retrospectively analyzed the MDCT images of these 52 patients and measured the shortest distance from the mitral annulus to the LCX in three dimensions. Also, we divided the mitral annulus into 12 clockwise areas (A0-A11) to identify the exact location.

The site of closest proximity and their numbers of patients were as follows: A6, 1 patient; A8, 2 patients; A9, 32 patients; and A10, 17 patients. Nine (17.3%) of the 52 patients had the shortest distance of less than 2 mm. The shortest distance according to the dominance of coronary artery showed no significant difference (p = 0.81).

The site of closest proximity from the mitral annulus to the LCX was concentrated on the A8 to A10 areas and it is an interesting result that as many as 17% of patients have their coronary arteries less than 2 mm away from the annulus.