Asian Cardiovasc Thorac Ann 2007;15:210-213
© 2007 Asia Publishing EXchange Ltd
Mitral Valve Repair for Extended Commissural Prolapse Involving Complex Prolapse
Hironobu Morimoto, MD,
Koji Tsuchiya, MD,
Masato Nakajima, MD,
Okihiko Akashi, MD,
Kaori Kato, MD
Department of Cardiovascular Surgery, Yamanashi Central Hospital, Yamanashi, Japan
For reprint information contact: Hironobu Morimoto, MD Tel: 81 3 3353 8111 Fax: 81 3 3356 0441 Email: hironobu12jp{at}yahoo.co.jp, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
 |
ABSTRACT
|
|---|
We reviewed our experience of mitral valve repair techniques for extended commissural prolapse involving complex prolapse of either or both leaflets, due to chordal rupture or elongation. Between June 1991 and January 2005, 21 of 210 patients who underwent mitral valve repair for mitral regurgitation had extended commissural prolapse involving either or both of the anterior and posterior leaflets. There were 17 (81%) patients with degenerative and 4 (19%) with infective endocarditis. The distribution of diseased mitral commissural lesions was: posteromedial commissure in 14 (67%) patients, anterolateral in 6 (29%), and bilateral in 1 (5%). Reconstructive techniques included leaflet folding plasty in 10, resection-suture in 6, the sliding technique in 2, commissuroplasty in 2, and chordal shortening in 1. There were no perioperative deaths; postoperative mitral regurgitation was none or trivial in 19 patients and mild in 2. The mean follow-up period was 54 months (range, 2–155 months), and no patient required re-operation. There was one late death from a noncardiac cause at 103 months. Mitral valve repair for extended commissural prolapse is satisfactory. We consider leaflet folding plasty and its modification to be effective in patients who require extensive leaflet resection in the commissural area.
|
INTRODUCTION
|
|---|
Mitral valve repair has become the surgical treatment of choice for mitral regurgitation (MR). However, the repair of commissural prolapse is challenging when it involves complex prolapse of either or both of the anterior and posterior leaflets, due to chordal rupture or elongation. Although various reconstructive techniques have previously been introduced, a standard method for complicated lesions has not yet been determined. Recently, we applied the leaflet folding technique described by Grossi and colleagues1 to the repair of extended commissural prolapse.
|
PATIENTS AND METHODS
|
|---|
Between June 1991 and January 2005, 21 of 210 patients who underwent mitral valve repair for MR had extended commissural prolapse involving either or both of the anterior and posterior leaflets. Patient age ranged from 48 to 79 years (mean, 65.4 ± 9.6 years). The preoperative functional status and etiology are given in Table 1
. All patients underwent preoperative transthoracic echocardiography to assess the motion of the cardiac valve, especially MR and etiology. Mitral regurgitation was moderate in 3 patients, moderately severe in 11, and severe in 7. The intraoperative findings of the diseased mitral valve commissural lesions were the posteromedial commissural site in 14 (67%) patients, anterolateral in 6 (29%), and bilateral in 1 (5%). Nine (43%) patients had commissural prolapse involving anterior leaflet prolapse, 6 (29%) had commissural prolapse involving posterior leaflet prolapse, and 6 had commissural prolapse involving both leaflets.
After induction of general anesthesia, transesophageal echocardiography was used for intraoperative evaluation of the mitral valve. Through a median sternotomy, standard cardiopulmonary bypass was instituted with bicaval venous drainage and ascending aortic return, and the left heart was vented through the right upper pulmonary vein. Moderate systemic hypothermia was employed. Under ventricular fibrillation, the left atrium was incised at the posterior interatrial groove, extending posteriorly beneath both caval veins. Mitral valve assessment was performed, including determination of the site of leaflet prolapse, the extent of annular dilatation, and the site of the jet lesion. After antegrade cold blood cardioplegia was administered (with topical hypothermia) and cardiac arrest was obtained, the mitral valve was repaired.
In the repair of extended commissural prolapse, resection of the prolapsed leaflet and reconstruction of the defect is our fundamental consideration. If commissural prolapse is not redundant for resection, we undertake a leaflet-preserving repair, including commissuroplasty using edge-to-edge repair. Reconstructive techniques after resection of the extended commissural prolapse comprised the McGoon2 method with annular plication and leaflet folding plasty (Figure 1). We performed the classic leaflet suturing with annular plication (modified McGoon) in 6 patients, the sliding technique in 2, edge-to-edge repair in 2, chordal shortening in 1, and leaflet folding plasty in 10, of whom 2 underwent leaflet folding plasty combined with commissural annular plication (modified leaflet folding plasty) and 1 had bilateral leaflet folding plasty.3 Rigid ring annuloplasty (Carpentier-Edwards annuloplasty ring, Edwards Lifesciences, Irvine, CA, USA) was carried out in all patients following repair of the mitral valve. Concomitant cardiac procedures were performed in 5 (24%) patients: one had coronary artery bypass grafting and 4 had tricuspid valve repair.
View larger version (46K):
[in this window]
[in a new window]
|
Figure 1. (a) Extended commissural prolapse involving both anterior and posterior leaflets, (b) Resection of prolapsing leaflet including both leaflets, (c) Folding of the cut edges; points 1 and 2 are brought to a common point 3, (d) Anastomosis of the remaining cut edges and ring annuloplasty.
|
|
All patients underwent preoperative and postoperative transthoracic echocardiography. Mitral regurgitation was estimated from the ratio of the regurgitant color Doppler area in the left atrium. Mitral regurgitation was classified into 5 grades: none/trivial = 0; mild = 1; moderate = 2; moderately severe = 3; severe = 4. All patients who underwent mitral valve repair received warfarin therapy for 3 months. Patients with chronic atrial fibrillation were placed on lifelong warfarin therapy. The clinical status of patients was determined by hospital records and telephone interviews.
Data are given as mean ± standard deviation. The Student’s paired t test was used to compare the data. A p value of less than 0.05 was considered statistically significant.
|
RESULTS
|
|---|
The durations of operation, cardiopulmonary bypass, and aortic cross clamping were 212 ± 50, 99 ± 24, and 61 ± 8.7 min, respectively. Echocardiography before discharge (12.9 days postoperatively) demonstrated successful mitral valve repair. The mean degree of MR postoperatively was 0.10 ± 0.30, which was significantly improved compared to the preoperative value of 3.19 ± 0.71 (Table 2). There was mild residual MR in 2 patients. One underwent folding leaflet plasty for bilateral commissural leaflet prolapse due to infective endocarditis. The other had sliding plasty for commissural prolapse involving anterior leaflet prolapse due to degenerative disease. There was neither significant dehiscence of the anastomosis nor residual leaflet prolapse on transthoracic echocardiography. We were unable to identify the cause of mild MR on transthoracic echocardiography. The mean mitral valve area, which was assessed by pressure half-time, was 2.36 cm2 postoperatively. There was no echocardiographic evidence of mitral stenosis in the early postoperative period. New York Heart Association functional status improved to class I or II in all patients.
The 10 patients who underwent folding leaflet plasty and its modification (Folding group) were compared with the others in terms of postoperative mitral valve area and residual MR. Five of the 6 cases with commissural prolapse involving both anterior and posterior leaflets were in the Folding group, as were 3 of 4 cases with infective endocarditis requiring large resection. We applied folding leaflet plasty to repair more extensive commissural prolapse, especially where both leaflets were involved. The mean mitral valve area on postoperative echocardiography was 2.40 cm2 in the Folding group and 2.29 cm2 in the other patients, but the difference was not significant. The mean degree of postoperative MR was 0.10 in the Folding group and 0.09 in the other patients, which was also not significantly different.
Follow-up was complete, with a mean duration of 54 months (range, 2–155 months). There were no hospital deaths, and all patients were discharged without complications. There was one late death due to pneumonia at 103 months after the operation. Freedom from thromboembolism was 95.2% (20/21 patients). No valve re-operation was required during the follow-up period. At the time of the last follow-up, 4 patients had chronic atrial fibrillation, 16 were in sinus rhythm, and one required pacemaker implantation due to sick sinus syndrome at 12 months after the operation. Follow-up echocardiography was available in all patients after a mean of 43.3 months (range, 8–132 months). The mean degree of MR on follow-up was 0.24 ± 0.54, compared with 3.19 ± 0.71, preoperatively ( p < 0.05). Mitral regurgitation at the last echocardiographic follow-up was none or trivial in 17 patients, mild in 3, and moderate in 1 (Table 2
). There was no significant change in the mitral valve area over the follow-up period, and no echocardiographic evidence of mitral stenosis.
|
DISCUSSION
|
|---|
There is now little disagreement that prolapse of the anterior or posterior mitral valve leaflet due to chordal rupture or elongation should be repaired. In general, mitral valve repair has been confirmed by its resulting durability and by the minimal risks of failure and re-operation. Comparative studies have shown better long-term results after valve repair than after valve replacement.4,5 In cases of infective endocarditis, not all patients are candidates for mitral valve repair; however, when possible, it results in very low morbidity and mortality.6,7
Despite the improved results of mitral valve repair, correction of extended commissural prolapse involving either or both of the anterior and posterior leaflets remains a challenging procedure. Kay’s commissural annulorrhaphy has been a reliable technique for repairing commissural lesions.8 However, in cases with extended commissural prolapse or small annulus diameter, excessive annular plication restricts the ultimate annular diameter and the effective orifice area of the repaired mitral valve. Where the commissural prolapse is slight, edge-to-edge repair resolves these problems, but it cannot be used in the repair of extensive commissural prolapse with a redundant and degenerative leaflet. Artificial chordae replacement is difficult to apply at the commissural site because the terminal parts of the commissural chordae have fan-shaped branches extending to the thin leaflet tissue.9,10
We perform artificial chorda replacement in cases of commissural prolapse combined with strut chordal rupture of the anterior leaflet. For repairing large commissural prolapse, proper resection of the prolapsed leaflet will be required in most cases. When degenerative change causes commissural prolapse, we can resect the mitral valve leaflet, based on the repair strategy. However, in cases of commissural prolapse due to infective endocarditis, a larger resection is required because sufficient excision of the infective lesions is essential to prevent recurrence. Resection and suturing with annular plication is simple and useful, but excessive annular plication introduces problems of distortion and stress in the repaired portion. For repairing extended commissural prolapse, especially with involvement of both the anterior and posterior leaflets, we frequently apply leaflet folding plasty and its modification. One could also apply the sliding leaflet technique with modifications, as previously reported.10–13 These are effective techniques, but they require a long incision of the normal leaflet, with suture mobilization. Leaflet folding plasty and its modification resolves these technical difficulties, because reconstruction is only needed in the resected areas. In other words, this method requires neither an additional incision nor a complicated suture reconstruction.3 We consider leaflet folding plasty and its modification to be a simple and effective procedure, especially in patients who require large resection in the commissural area, involving both leaflets. In cases of restricted anterior mitral leaflet and small annular size, postoperative valve restriction and reduced effective orifice area should be considered.
It was concluded that the long-term results of mitral valve repair for extended commissural prolapse involving complex prolapse are satisfactory, with low mortality and morbidity. In particular, folding leaflet plasty and its modification are useful in cases requiring large resection, such as extended prolapse involving both leaflets, but of limited value in cases of restricted anterior mitral leaflet and small annular size.
|
REFERENCES
|
|---|
- Grossi EA, Galloway AC, Kallenbach K, Miller JS, Esposito R, Schwartz DS, et al. Early results of posterior leaflet folding plasty for mitral valve reconstruction. Ann Thorac Surg 1998;65:1057–9.[Abstract/Free Full Text]
- McGoon DC. Repair of mitral insufficiency due to ruptured chordae tendineae. J Thorac Cardiovasc Surg 1960;39:357–62.
- Nakajima M, Tsuchiya K, Inoue H, Kobayashi K, Mizutani E, Takizawa K. Leaflet folding plasty combined with annular plication for mitral valve repair. Ann Thorac Surg 2004;77:1103–4.[Abstract/Free Full Text]
- Mohty D, Orszulak TA, Schaff HV, Avierinos JF, Tajik JA, Enriquez-Sarano M. Very long-term survival and durability of mitral valve repair for mitral valve prolapse. Circulation 2001;104(12 Suppl 1):I1–17.[Medline]
- Enriquez-Sarano M, Schaff HV, Orszulak TA, Tajik AJ, Bailey KR, Frye RL. Valve repair improves the outcome of surgery for mitral regurgitation. A multivariate analysis. Circulation 1995;91:1022–8.[Abstract/Free Full Text]
- Muehrcke DD, Cosgrove DM 3rd, Lytle BW, Taylor PC, Burgar AM, Durnwald CP, et all. Is there an advantage to repairing infected mitral valves? Ann Thorac Surg 1997;63:1718–24.[Abstract/Free Full Text]
- Hendren WG, Morris AS, Rosenkranz ER, Lytle BW, Taylor PC, Stewart WJ, et al. Mitral valve repair for bacterial endocarditis. J Thorac Cardiovasc Surg 1992;103:124–9.[Abstract]
- Kay JH, Egerton WS. The repair of mitral insufficiency associated with ruptured chordae tendineae. Ann Surg 1963;157:351–60.[Medline]
- Zussa C, Frater RW, Polesel E, Galloni M, Valfre C. Artificial mitral valve chordae: experimental and clinical experience. Ann Thorac Surg 1990;50:367–73.[Abstract]
- van Herwerden LA, Taams MA, Bos E. Repair of commissural prolapse by extended leaflet sliding. Ann Thorac Surg 1994;57:387–90.[Abstract]
- Sutlic Z, Schmid C, Borst HG. Repair of flail anterior leaflets of tricuspid and mitral valves by cusp remodeling. Ann Thorac Surg 1990;50:927–30.[Abstract]
- Dreyfus G, Serraf A, Jebara VA, Deloche A, Chauvaud S, Couetil JP, et al. Valve repair in acute endocarditis. Ann Thorac Surg 1990;49:706–13.[Abstract]
- Tsuchiya K, Yoshikai M, Ishitoya H, Sasaki H, Iida Y, Aizawa K. A case of sliding commissuroplasty for the chordal rupture in the paracommissural area. Kyobu Geka 1992;45:1091–3.[Medline]
TOP
ABSTRACT
INTRODUCTION
