Mitral annular disjunction is described as pathological dehiscence between the posterior mitral annulus and the compact left ventricular myocardium on the back wall of the left ventricle. The myocardium in the gap is replaced by fibrous connective tissue. It is believed to cause malignant arrhythmias and is associated with a higher risk of sudden cardiac death, even in young patients. 
 
The patient was a 46-year-old male diagnosed in 2017 with severe mitral valve regurgitation due to posterior mitral leaflet (PML) prolapse. In a clinically stable condition, the patient denied surgery at that time and remained asymptomatic since then. 
 
Seven years later, he suffered sustained ventricular tachycardias (VTs) at home. After successful resuscitation, the initial TTE showed severely reduced left ventricular function of 30 percent and severe mitral regurgitation with marked mitral annular disjunction (MAD) of 12 mm. The patient was transferred to the authors’ clinic for minimally invasive mitral valve surgery. 
 
After standard cannulation of the right femoral vessels, a right lateral minithoracotomy was performed in the anterior axillary line. The pericardium was opened, the aorta was clamped, and the heart was arrested. The left atrium was opened, and the valve was inspected. From this point of view, the MAD was not visible, making meticulous preoperative diagnostics crucial. Stay sutures were placed at the free edge of the PML, which was then detached at the base. At this point, the gap between the anulus and the compact myocardium became visible. 

 
Ethibond 2-0 sutures were placed at the point of the muscular edge to define the new mitral anulus posteriorly. Pledgeted sutures are used if needed. The  
PML was reattached to the mitral anulus using a 5-0 Prolene continuous suture. The prolapse was corrected, and a ring was implanted, using the previously placed sutures posteriorly to close the MAD gap. 
 
The left atrium was closed, the heart deaired, and the cross-clamp was removed. The patient was successfully weaned from cardiopulmonary bypass and transferred to the ICU with moderate catecholamine support. He was extubated eight hours after surgery and discharged on the seventh postoperative day. During the postoperative course, an asymptomatic short episode of self-limiting VTs was seen on the monitor. 
A month later, an implantable cardioverter-defibrillator (ICD) was implanted as secondary prophylaxis. At the six-month follow-up after ICD-Implantation, no arrhythmias were seen. 
 
This surgical technique could successfully reduce the risk of malignant arrhythmias in patients with MAD and can be safely performed through a minimally invasive approach. 

References

1. Zhu L, Chua YL. Mitral Annular Disjunction: Clinical Implications and Surgical Considerations. Cardiol Res. 2023 Dec;14(6):421-428. doi: 10.14740/cr1584. Epub 2023 Dec 9. PMID: 38187510; PMCID: PMC10769617.
2. Avi Sabbag, Benjamin Essayagh, Juan David Ramírez Barrera, Cristina Basso, Ana Berni, Bernard Cosyns, Jean-Claude Deharo, Thomas Deneke, Luigi Di Biase, Maurice Enriquez-Sarano, Erwan Donal, Katsuhiko Imai, Han S Lim, Nina Ajmone Marsan, Mohit K Turagam, Petr Peichl, Sunny S Po, Kristina Hermann Haugaa, Dipen Shah, Marta de Riva Silva, Philippe Bertrand, Magdi Saba, Marc Dweck, Santiago Nava Townsend, Tachapong Ngarmukos, Guilherme Fenelon, Pasquale Santangeli, Leyla Elif Sade, Domenico Corrado, Pier Lambiase, Prashanthan Sanders, Etienne Delacrétaz, Arshad Jahangir, Elizabeth S Kaufman, Daljeet Kaur Saggu, Luc Pierard, Victoria Delgado, Patrizio Lancellotti, EHRA expert consensus statement on arrhythmic mitral valve prolapse and mitral annular disjunction complex in collaboration with the ESC Council on valvular heart disease and the European Association of Cardiovascular Imaging endorsed cby the Heart Rhythm Society, by the Asia Pacific Heart Rhythm Society, and by the Latin American Heart Rhythm Society, EP Europace, Volume 24, Issue 12, December 2022, Pages 1981–2003, https://doi.org/10.1093/europace/euac125

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