Robotically-Assisted Mitral Valve Commissuroplasty: An Easy Fix for a Complex Jet

This video demonstrates a robotically-assisted mitral valve commissuroplasty in a young patient who presented with a complex mitral regurgitant jet and unclear mechanism of the regurgitation. A 41-year-old man was referred to the authors for consideration of mitral valve repair. He was found to have a mitral valve murmur during a routine physical exam. He denied any symptoms despite being quite active. His past medical history included only previous melanoma resection and hypertension. The preoperative transthoracic echocardiogram showed a severe mitral valve regurgitation with a complex jet with no precise mechanism of the regurgitation. The jet originated laterally; no prolapse was seen. The intraoperative transesophageal echocardiogram showed a localized prolapse at the anterolateral commissure, where a complex jet originated.

The jet crossed along the coaptation zone towards the medial aspect of the mitral valve, as demonstrated in the video. The 3D reconstruction confirmed a localized prolapse at the anterolateral commissure as the mechanism of regurgitation. A minimally invasive robotically-assisted mitral valve repair was offered as the patient fulfilled each one of the preoperative robotic safety criteria as demonstrated in this algorithm. The patient was positioned with the right chest in 30o rotation, the right arm abducted to expose the axilla. A 4 cm long incision was performed at the 4th intercostal space anterior to the anterior axillary line. Three 8 mm ports were inserted: 1. the left atrial retractor port was inserted in the 4th ICS at the midclavicular line, 2. the right robotic arm port in the 6th ICS at the anterior axillary line, and 3. the left robotic arm port in the 2nd ICS. These three ports create an equilateral triangle, which corresponds to the base of a virtual pyramid that has its tip on the right superior pulmonary vein. Two small stabs for the Chitwood clamp and left atrial vent were also performed.

Once this set-up was accomplished, heparin was given, and femoral arterial and venous cannulations were carried out. The cardioplegia catheter was inserted under direct vision in the aortic root. After commencing cardiopulmonary bypass, the Chitwood cross-clamp was applied to the ascending aorta, and 1200 ml of Del Nido cardioplegia was delivered. After the cardiac arrest, the robot was docked. The left atrium was open in the usual fashion, and the left atrial vent and retractor were inserted. The atriotomy was carried out, and the left atrial retractor repositioned to optimize exposure. Then, the mitral valve was assessed. Anterolateral commissural prolapse was confirmed, as demonstrated in the video. The authors use 4-0 polypropylene sutures to close the commissure. First, we place a single stitch to delineate the distal aspect of the prolapsing commissure. This stitch works as a reference point. Another 4-0 polypropylene suture is used to close the commissure from the previous stitch to the annulus as shown here. Then run this suture from the reference point to the annulus and back to the reference point where it is tied up.

Next, perform the mitral annuloplasty with a flexible Duran band. Three polyester sutures are utilized. The first two sutures measure 12 cm long and the last 10 cm long. Pass the first suture through the band and anchor it to the posteromedial trigone. Run this suture along the mitral annulus in a clockwise fashion. When this suture gets 2 cm short, the second 12-cm long polyester suture is used to continue the band implantation in the same fashion. The two sutures are joined as demonstrated here. Usually, the second suture reaches close to the anterolateral commissure. Lastly, take the 10 cm long polyester suture through the other end of the band and anchor it to the anterolateral trigone. Run it counterclockwise and tie it to the last suture. The combination of a flexible band with preformed polyester sutures increases efficiency as robotic handling is remarkably facilitated. Once the annuloplasty was finished, the valve was tested with saline. The mitral valve was competent.

The left atrium was closed with two preformed looped PTFE sutures. Each PTFE suture has a preformed loop at its end. Take the first bite at the corner and pass the suture through the loop, locking it. This avoids knot tying at the corners as demonstrated here. The use of pre-looped PTFE suture not only decreases the number of knot tying but also allows for better suture sliding through the atrial tissue, increasing efficiency. Run the PTFE suture from each corner to the center, where they are tied up after the removal of the LV vent.

This is the authors’ technique of choice for left atrial closure in any robotic case. The left atrium was de-aired, and the cross-clamp was removed. The result is shown here. The postoperative transesophageal echo showed a normal functional mitral valve with no regurgitation and the transmitral gradient of 2 mm Hg. In conclusion, mitral valve commissuroplasty is easily performed robotically and should be the standard of care in selected patients. Commissural leaks usually look complex on echocardiography, especially transthoracic. However, the repair is straightforward.

References

1. Gillinov AM, Mihaljevic T, Javadikasgari H, Suri RM, Mick SL, Navia JL, et al. Early results of robotically assisted mitral valve surgery: Analysis of the first 1000 cases. J Thorac Cardiovasc Surg. 2018;155(1):82-91.e2.
2. Chemtob RA, Wierup P, Mick S, Gillinov M. Choosing the "Best" surgical techniques for mitral valve repair: Lessons from the literature. J Card Surg. 2019;34(8):717-727.

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