Minimally Invasive Mitral Valve Repair Through Nonresectional Posterior Leaflet Remodeling

In this video, the authors present a novel technique for the correction of mitral regurgitation associated with degenerative disease of the posterior leaflet, called posterior leaflet remodeling or free margin running suture. This technique has been developed in the setting of minimally invasive surgery, although it can be employed through sternotomy.

In the first procedure shown, the authors consider a patient with prolapse of the P2 and P3 scallops. Three-dimensional echocardiography confirmed the extension of the prolapse of these two segments. An endoscopic HeartPort technique was employed with endoclamping of the ascending aorta. Hydrostatic tests confirmed the mechanism of regurgitation being extensive prolapse and tissue excess of two scallops of the posterior leaflet. An anatomical requirement for the performance of the posterior leaflet remodeling technique is the presence of at least one normal scallop in terms of height and morphology; in the case shown, this was P1.

The technique consists of two rows of continuous suture passed through the free margin of the prolapsing scallops until the free margin of the normal scallop. A double-armed 4-0 Gore-Tex® suture was employed. The first row was started at the more distal prolapsing scallop. Several sequential passages were performed in order to obtain a purse-string effect. The distance between the edge of the leaflet and the suture row will ultimately dictate the height of the coaptation line. The suture was continued until it reached the normal scallop. At this point, the second suture row was begun using the second suture end. In the same way, several passages were performed through the diseased segments until the normal scallop was reached. Optimal tension of the double suture row was ensured, and the suture was finally tied at the level of the normal scallop. With this procedure, the prolapsing segments were constrained at the height of the normal scallop; prolapse was therefore corrected, and at the same time a large coaptation surface was created. Hydrostatic testing confirmed correction of regurgitation, but residual prolapse of P3 was also observed. Therefore, a complementary paracommissural free margin running suture was performed in order to correct the residual prolapse.

This technique is best suited for valves with large amounts of excess tissue. In the case of localized prolapse and limited excess tissue, the free margin running suture technique might be contraindicated, since a lateral coaptation defect might be created.

Final hydrostatic testing showed an adequate result. Blue dye coloration of the coaptation line revealed the extension of the coaptation surface. It is important to avoid undersized ring annuloplasty, since the anterior shift of the coaptation line associated with the technique might expose to the appearance of systolic anterior motion of the anterior leaflet. In the first procedure shown, a 30 mm ring was implanted. Control echocardiography confirmed the absence of residual regurgitation, visually preserved motion of the reconstructed posterior leaflet, and a 3 mm Hg average transmitral gradient. As a typical result associated with the free margin running suture or posterior leaflet remodeling, remarkable coaptation lengths were observed. In a follow-up study over 37 patients, average coaptation length was 1.1 mm. This might have favorable prognostic implications in the long term.

The second procedure illustrates a less frequent situation: severe mitral regurgitation associated with extensive prolapse of the P1 and P2 segments with a normal P3 scallop. Hydrostatic testing confirmed the echocardiography findings. The two rows of the free margin running suture technique were then conducted in the inverse fashion, from P1 until reaching the normal P3 segment. Similarly, blue dye coloration applied at the coaptation line during post-repair hydrostatic testing was used to demonstrate the coaptation surface lying below. Of note, the measurement of the aortic root pressure through the distal end of the IntraClude™ balloon helps to demonstrate the intraventricular pressure achieved during testing. The final hydrostatic testing was satisfactory. Control echocardiography showed good results with the absence of residual regurgitation and a 2 mm Hg average transmitral gradient.

This approach has been practiced so far in around 100 patients in two centers. An initial follow-up on the first 37 cases (average 2.1 years) has reported one case of 2+/4+ residual mitral regurgitation, no other instances of recurrence, and an average 1.1 ± 0.2 cm coaptation length at echocardiography.

Suggested Reading

1. Agnino A, Parrinello M, Panisi P, Anselmi A. Novel nonresectional posterior leaflet remodeling approach for minimally invasive mitral repair. J Thorac Cardiovasc Surg. 2017;154(4):1247-1249.
2. Agnino A, Lanzone AM, Albertini A, Anselmi A. Follow-up of the novel free margin running suture technique for mitral valve repair [Epub ahead of print Jun 13, 2018]. Thorac Cardiovasc Surg.
3. Minimally invasive mitral valve repair through nonresectional posterior leaflet remodeling. Communication presented at: 32nd Annual Meeting of the European Association for Cardio-Thoracic Surgery; October 18-20, 2018; Milan, Italy.