Triangular Resection to Treat Extensive Anterior Mitral Valve Leaflet Prolapse: Technical Tips

Abstract

Background

Myxomatous degeneration of the anterior mitral leaflet is difficult to treat with chordal replacement. Triangular resection offers effective results because it can remove any redundant prolapsed lesion.

Methods

To optimize surgical outcomes, we developed a marking stitch to decide on the cut range. Between 2004 and 2024, we repaired 382 type 2 mitral regurgitation, 66 of which were anterior prolapse. Twenty-four patients with myxomatous extensive anterior leaflet prolapse underwent triangular resection. We followed the patients with echocardiogram yearly. A suture was placed on both sides of the lesion and was tied. A leakage test was performed. If no leakage was found, we marked the cut line, removed the suture, cut the marked line triangularly, and sutured by two layers with 6-0 polypropylene suture. Then implant the annuloplasty ring.

Results

All patients were successfully repaired. One patient with Barlow disease was re-repaired 8 years postoperatively, because of recurrent mitral regurgitation. The other 23 patients had no mitral regurgitation graded as more than mild, and 1-21 year follow-up reports they have remained healthy.

Conclusions

Myxomatous extensive anterior mitral prolapse can be effectively repaired by the triangular resection. Our tips for deciding on the cut range can be useful.

In Short.

• ▪Myxomatous degeneration of the anterior mitral leaflet, characterized by large, floppy lesions, poses a significant surgical challenge.
• ▪Although traditional techniques, such as artificial chord replacement, often prove inadequate, triangular resection offers a more effective alternative.
• ▪However, deciding on the cutting area, especially the resection, is difficult. Many surgeons hesitate to cut the anterior mitral leaflet widely. We develop the new technique to decide the resection area. This procedure is simple and easy, we do not hesitate to use it regularly.

Myxomatous degeneration of the anterior mitral valve leaflet, characterized by a large, floppy lesion with ruptured or elongated chordae tendineae, differs notably from fibroelastic deficiency. Although fibroelastic deficiency, characterized by low-grade degeneration, thin leaflet tissue, and chordal rupture, can be effectively managed with artificial chordal replacement or repositioning, myxomatous degeneration is often best treated with triangular resection. To optimize surgical outcomes, we developed a trial suture technique to delineate the resection area precisely. We present a detailed surgical technique description and favorable long-term outcomes (up to 21 years).

Patients and Methods

Between 2004 and 2024, we repaired 382 type 2 mitral regurgitation, 66 of which were anterior and bileaflet prolapse. In 42 cases of fibroelastic deficiency, we adopted artificial chordae. Twenty-four patients with myxomatous extensive anterior leaflet prolapse underwent triangular resection. In this group, the mean age of the participants was 60.7 ± 10.9 years, with a male predominance (83.3%). After the operation we followed the patients with echocardiogram yearly. The mean follow-up duration was 8. ± 6.2 years, with a maximum follow-up of 21 years.

Operative Method

A 4-0 suture was placed on both sides of the anterior degenerative lesion (Figure 1). The suture was tied, pushing the lesion into the left ventricle. A water leakage test was performed to assess valve competence. The height of the resection was checked to ensure adequate tissue removal without excessive leaflet shortening. Residual prolapse or mitral leakage was noted. The procedure could be repeated; however, this was not required in our cases. Next, the suture was marked to indicate the desired resection depth (Figure 2). The trial suture was cut at the marked point, defining the base of a low isosceles triangle. The apex of this triangle represents the boundary between the smooth and rough zones, with the triangle measuring approximately 4 cm in width (Figure 3). Subsequently, we sutured the cut edge using a 6-0 polypropylene running suture in 2 layers. An annuloplasty ring was secured (Figure 4). The operative techniques are shown in the Video. Additional polytetrafluoroethylene sutures as chords were not used as artificial chordae tendineae.

Figure 1.

Single suture is placed at both ends of the prolapsed lesion.

Figure 2.

The suture is tightened, and valve height, mitral regurgitation, and residual prolapse are assessed using a water leakage test.

Figure 3.

The sutured points and the apex of the triangle, indicating the boundary between the smooth and rough zones, are marked. Triangular excision is subsequently performed.

Figure 4.

The incision edges are sutured, followed by the placement of an annuloplasty ring.

Results

In total, 24 valves were successfully repaired, with no reported deaths or complications. Postoperatively, no residual mitral regurgitation was observed. During the follow-up period, the reoperation-free and mitral regurgitation–free survival rate was 95.8% at 8.8 years. The follow-up rate was 100%. One patient with Barlow disease, who initially underwent a commissural annuloplasty, required reoperation 8 years postoperatively. This patient successfully underwent a rerepair using a full-ring annuloplasty.

Comment

Large anterior leaflet mitral valve extensive prolapse poses a significant surgical challenge. Although surgical options include artificial chord replacement and prosthetic valve implantation, artificial chord replacement has several limitations, relating to the chord attachment site and long-term durability, for example. Grossi and associates¹ have demonstrated that the suboptimal durability of artificial chord replacements often necessitates reoperation with triangular resection. This technique involves more extensive resections than limited triangular resections.² Seitelberger and colleagues³ reported a triangular plication technique without resection, demonstrating an 86% durability rate over 36 months. Although long-term data for this technique are limited, our findings indicate a 95.8% reoperation-free rate at a mean follow-up of 8.8 years. The sole reoperation occurred in a patient with Barlow disease and an incomplete ring, emphasizing the importance of selecting a larger ring during the initial procedure.⁴ Saunders and coworkers⁵ demonstrated favorable long-term durability of triangular anterior mitral valve resection based on a 25-year experience, with an additional 11 years of follow-up data.⁶

In conclusion, myxomatous degenerative anterior mitral prolapse can be effectively repaired using the extensive triangular resection technique. This method offers excellent long-term durability, is technically straightforward, and does not require additional artificial chord techniques. Considering its proven efficacy, we recommend this approach for suitable patients.