COMMENT
Acute iatrogenic complications of MV repair depend on the techniques applied by the surgeons to correct the valvular lesions (SAM) and on the position of the stitches used to implant a ring or band to reshape the annulus (CX injury).
SAM is specific of the correction of degenerative MR, while CX injury can happen every time stitches are passed close to the mitral annulus. SAM has been widely studied and many strategies have been suggested to prevent or to correct it. However, even if surgeons are aware of this possibility, the prevalence of SAM has remained more or less the same on the last decades, being 9.1% in 1994 [26], 8.4% in 2007 [27], and 8.1% in 2017 [28]. In the most recent experience [4], the prevalence was 13%, but, after adequate surgical or medical treatment, still 3.7% of the patients with MV repair were discharged with SAM.
CX injury is surely less frequent, but possibly underdiagnosed, but it has to be suspected any time there is a difficult weaning from CPB or there are sign of ischemic event. However, it is not part of the surgeons’ mentality the necessity to have a preoperative diagnosis on the CX relationships with the annulus. The mechanism of injury, moreover, is not always the same. A short distance between the CX and the annulus exposes to the danger of passing a stitch trough the artery, whereas attracting the CX towards the annulus can happen independently from the CX position. It is evident that, to cause occlusion or severe stenosis by attraction, the CX has to be far from the annulus, as in the case shown in Figure 2. Intraoperative echocardiographic evaluation of the CX flow is the most helpful tool we have to diagnose the complication independently from the mechanism, and to promptly react to avoid or to limit a dangerous perioperative myocardial infarction.