Discussion
We report here a successful surgical treatment of a potential life-threatening complication of PMC.
The treatment of SVMS has been revolutionized since the development of PMC in 1980s: trans-septal catheterization is one of the most crucial procedural steps and the Inoue balloon technique is the standard of care for PMC.(1)
According to the latest ESC/EACTS Guidelines PMC represents the first-line treatment (class I, level B) for most symptomatic SVMS and favourable morphology.(1)
However, albeit very high procedural success rates of PMC have been reported by Bauleti et al.(2), long-term freedom from reintervention (either repeat PMC and surgery) is only about 38±2%.
In addition, PMC in-hospital mortality rate is up to 0.4% and the most common complications were embolic stroke and severe mitral regurgitations, occurring in 0.3% and 3.4% respectively.(3)
Finally, Iung et al. (4) reported an incidence of technical failure of 1.2%, due to hemopericardium, embolism, inability to cross the septum, or inability to position the balloon across the valve.
The need for surgery was estimated to occur in 4.7% during the first post-procedural month.
As far as causes of cardiac perforation during PMC are concerned, several mechanisms have been identified(5) 1) apical tears by straight-tip balloon catheters driven distally during mitral valve dilatation, 2) apical perforations by guidewires introduced through catheters wedged in the apex, 3) tear of the posterior right atrial wall by dilatation of the track produced by very low septal punctures, 4) right ventricular perforation by a pacing catheter, and 5) perforation of the aortic root and adjacent right atrium by sliding up of the trans-septal set. Of note, cardiac perforation was identified to be significantly related to the total experience at the Center and to patient age.
In our case, a type 5 mechanism of perforation occurred, despite the high-volume experience of the performing Centre.
In conclusion, local policies may allow risky percutaneous procedures to be performed in high-volume Cardiology Centres without cardiac Surgery onsite. Although we recommend these procedures to be “centralized” in third-level Hospitals with prompt availability of on-site Cardiac Surgery, successful surgical treatment of life-threatening complications following risky percutaneous procedures in unfavourable logistics can be achieved by a Heart Team approach providing ad-hoc availability of dedicated “stand-by” operating theatre.