Mitral Repair with Premeasured Chord in Endoscopic Cardiac Surgery
An eighty-eight-year-old man with a history of hypertension, pulmonary embolism, prostate cancer, and right hip and femur surgery came to the cardiology clinic with progressive shortness of breath in recent months. His physical examination revealed a grade IV systolic murmur and irregular heart rhythm. Electrocardiography confirmed atrial fibrillation. A cardiac ultrasound reported severe mitral regurgitation, mild to moderate tricuspid regurgitation, and preserved left ventricle function. Further coronary angiography found 50 percent stenosis in the middle of the LAD. Therefore, the patient was transferred to a cardiac surgeon for a surgical opinion. Following a discussion, a decision was made to proceed to an endoscopic mitral valve procedure.
The Surgery
During the operation, preoperative transesophageal echocardiography revealed prolapse of P3 with rupture of the chordae. A right minithoracotomy was performed, and cardiopulmonary bypass was initiated by open femoral cannulation. The patient’s body temperature was cooled to 32 degrees Celcius and an endoballoon was placed in the ascending aorta for the administration of cardioplegia. The mitral valve was accessed through a left atriotomy. After exposure of the mitral valve, the prolapsing segment and ruptured chords were identified. Without measuring the length of chords, a set of 16 mm premeasured chords was implanted on the head of the posteromedial papillary muscle. Two premeasured PTFE chordal loops were then sutured individually to the leaflet edge of the prolapsing portion, and one premeasured loop was used to close the commissure between A3 and P3.
Additional procedures included mitral valve repair with a 34 mm incomplete band for annuloplasty and left atrial cryoablation. The postoperative transesophageal echocardiography revealed trivial mitral valve regurgitation. The ECG showed normal sinus rhythm.
On postoperative day one, the patient was extubated smoothly in the intensive care unit. He was transferred to the ward on postoperative day three. However, due to his difficulty urinating, he had a delayed discharge on postoperative day nine. One month after discharge, he was living independently and drove himself in for his follow-up.
Discussion
The use of artificial chords has shown its benefit and durability for mitral valve repair (1). During operation, techniques on how to measure and create correct lengths of artificial chords are important to understand (2). However, deciding the correct length of chords can be challenging to young surgeons. According to several data, the mean of anterior leaflet chords is around 23 mm and that of posterior leaflet chords is 16–19 mm (3,4). Operators could use these data as a reference to select the proper length of chords.
In this case, the mitral valve repair was successful when a set of 16 mm premeasured chords were used without measuring the length of posterior leaflet chords. The authors believe using the average length of chords as references would make it easy to select the length of premeasured chords.
Reference(s)
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2. von Oppell UO, Mohr FW. Chordal replacement for both minimally invasive and conventional mitral valve surgery using premeasured Gore-Tex loops. The Annals of Thoracic Surgery. 2000 Dec;70(6):2166–8.
3. Gillinov AM, Banbury MK. Pre-Measured Artificial Chordae for Mitral Valve Repair. The Annals of Thoracic Surgery. 2007 Dec;84(6):2127–9.
4. Axtell AL, Moonsamy P, Dal-Bianco JP, Passeri JJ, Sundt TM, Melnitchouk S. Minimally Invasive Nonresectional Mitral Valve Repair Can Be Performed With Excellent Outcomes. The Annals of Thoracic Surgery. 2020 Feb;109(2):437–44.