The anatomic continuity between the mitral and aortic valves is a fibrous, avascular, and fully dynamic portion of the heart that can potentially be the site of aortic valve injury during mitral annuloplasty or replacement [15]. Although surgeons practicing MVR in big-volume centers can be exposed to this complication during their professional career, the paucity of reported cases in the literature surprisingly makes us speculate that the proper number of iatrogenic aortic valve injury is underestimated. Aortic valve injury, especially of the left or non-coronary leaflet, usually occurs during the placement of the anterior mitral annuloplasty stitches while bringing the tip of 2 − 0 mattress braided sutures’ needle back from the left ventricular to the left atrial side across the anterior annulus. Partial rings can potentially decrease the risk of aortic valve injury as the portion of the anterior annulus between both trigonal areas does not necessitate any stitch placement. In all previously reported articles, AR resulted from tethering of left or non-coronary leaflet due to an inadvertently placed suture preventing proper cusp mobility [2, 4, 6, 7, 13] or perforation of one of the three aortic leaflets tackled by an improperly orientated needle during its passage through the anterior mitral annulus [3, 5, 8, 9, 11, 12, 14]. The non-coronary leaflet is more likely to suffer from injury than the left and right coronary leaflets. Out of the total 19 patients previously presented in the literature, 13 had injury of the non-coronary leaflet [2, 3, 8, 9, 11,12,13], 5 had that of the left coronary leaflet [3,4,5,6,7], and one had that of the right coronary leaflet [14]. In our case, the mechanism of progressive AR was probably due to the gradual increase of the non-coronary leaflet tear, as was previously described by Lakew et al. in three patients who underwent minimally invasive MVR [9]. Their patients gradually developed relevant AR over the postoperative course and required aortic valve repair 22 days, 6.5 months, and 4 years after their MVR [9]. Although advanced robotic technology enables better visualization of the annulus coupled with high definition and 3-dimensional secondary vision compared to minimally invasive techniques, the lack of tactile feedback in robotic surgery still persists, limiting the surgeon’s ability to assess suture depth, tension, and needle orientation [16].
In conclusion, the function of the aortic valve should be carefully checked on a routine basis on intraoperative post-repair TEE. The echocardiographer and the surgeon should seriously consider any change, even mild, in the degree of AR. In this condition, a better assessment of the mechanism of AR by intraoperative post-repair three-dimensional TEE should be adopted as a strategy [10]. If any potential aortic valve injury is suspected, exploration of the aortic valve at the time of the same surgery might be considered in conventional mitral valve procedures. The dilemma will persist in case of minimally invasive or robotic mitral procedures, whether or not post-repair AR changes have to impose the conversion of the incision.
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