J Thorac Cardiovasc Surg 2007;133:1633-1635
© 2007 The American Association for Thoracic Surgery
Reducing the posterior wall length by using a small endoventricular patch for ischemic mitral regurgitation
Hiroshi Tanaka, MD*,
Kenji Okada, MD,
Keitaro Nakagiri, MD,
Yujiro Kawanishi, MD,
Masamichi Matsumori, MD,
Yutaka Okita, MD
Department of Cardiovascular, Thoracic, and Pediatric Surgery, Kobe University Hospital, Kobe, Japan.
Received for publication December 3, 2006; revisions received January 23, 2007; accepted for publication January 29, 2007.
* Address for reprints: Hiroshi Tanaka, MD, Kobe University Hospital, Department of Cardiovascular, Thoracic, and Pediatric Surgery, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Japan. (Email: hirot{at}ams.odn.ne.jp).
Surgical treatment of ischemic mitral regurgitation remains controversial. We report 2 cases of ischemic mitral regurgitation complicated with a posterior basal aneurysm successfully treated with a small endoventricular patch to reduce the infarct posterior length.
Clinical Summaries
Patient 1
A 58-year-old man was referred to our institution for ischemic heart disease. Coronary angiography revealed a severe 3-vessel disease. Echocardiography demonstrated a moderate mitral regurgitation and a localized posterior basal aneurysm. The anterior wall motion was normal, and the cause of mitral regurgitation was leaflet tethering 10 mm in depth, mainly in the posterior leaflet retracted by the posterior papillary muscle (Figure 1, A).
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Figure 1. A, Preoperative echocardiogram showing a posterior basal aneurysm (white arrow) and severe mitral regurgitation caused by the posterior mitral leaflet tethering retracted to the posterior papillary muscle during systole 10 mm in depth (white line). B and C, Postoperative echocardiography showing no tethering of the posterior mitral leaflet. The white arrow indicates the endoventricular patch. Dd, Dimension diastole; Ds, dimension systole; FS, fractional shortening.
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At the time of surgical intervention with cardiopulmonary bypass, the aorta was clamped, and cardioplegic arrest was obtained. The left ventriculotomy was made through the aneurysm parallel to the posterior descending artery. The endocardial boundary between the infarction and the normal myocardium was distinct, and the orifice of the aneurysm was 3 x 4 cm in size. The posterior papillary muscle was not involved in the infarction. A 2 x 3–cm triangular woven Dacron patch (Hemashield patch, Boston Scientific) was sutured to the mitral annulus cranially, to the posterior wall laterally, and to the septum medially with 4-0 polypropylene (Prolene, Ethicon) sutures. The ventriculotomy was closed with 3-0 polypropylene (Prolene) sutures. The left atrium was opened, and a mitral annuloplasty ring (Physio-ring, 26 mm, Edwards Lifesciences) was sutured to the annulus. Echocardiography 2 weeks (Figure 1, B) and 4 months (Figure 1, C) after surgical intervention revealed no mitral regurgitation and no leaflet tethering, and the patient is asymptomatic.
Patient 2
An 80-year-old man was referred for ischemic mitral regurgitation. The left ventriculogram showed a localized posterior basal aneurysm with an orifice of 4 x 6 cm and normal anterior wall motion. Preoperative echocardiography demonstrated tethering of the posterior mitral leaflet, and the depth of tethering was 10 mm. He was treated surgically with a small endoventricular patch, 3 x 5 cm in size, and mitral annuloplasty. Postoperative echocardiography 2 years after the operation showed only trivial mitral regurgitation.
Discussion
Not only ring annuloplasty but also additional procedures to correct the left ventricular geometry are required to achieve a better long-term outcome for ischemic mitral regurgitation.1
Apical displacement of papillary muscles caused by ischemic cardiomyopathy leads to tethering of the chords and decreased leaflet coaptation. Papillary muscle approximation, infarct plication, and exclusion of infarct area have been reported for patients with ischemic cardiomyopathy involving the anterior wall to correct the displacement.2 On the contrary, Frater and colleagues3 described that localized posterior infarction caused failure of posterior ventricular shortening, which brought about ischemic mitral insufficiency. For this pathology, "geometric endo-ventricular patch repair of inferior left ventricular scars" was introduced; however, the details of the mechanism of correction for mitral regurgitation were not described.4 Kron and associates5 have introduced a procedure in which a suture between the posterior papillary muscle and the mitral annulus is shortened to alleviate tethering of the posterior mitral leaflet for this entity. In our cases preoperative echocardiography revealed a localized ventricular aneurysm that protruded during systole, preventing the papillary muscle toward the mitral annulus. The leaflet coaptation depth was 10 mm in each case, and myocardial contraction, except for aneurysm, was almost normal. Papillary muscle shortening during systole has been reported to be 2 to 4 mm in length, which is thought to be disregarded for contribution to the leaflet tethering. Therefore, the leaflet tethering would be mainly contributed by papillary muscle dislocation in these cases. We applied a small endoventricular patch, which would secure more physiologically for a longer time than Kron’s procedure, to reduce 1 cm in length longitudinally and laterally the infarct posterior wall (Figure 2). This technique could be useful for ischemic mitral regurgitation in patients who have localized dyskinesis in the posterior left ventricular wall.
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Figure 2. A, Preoperative. Posterior basal aneurysm causing dislocation of the posterior papillary muscle from the mitral leaflet, which provokes leaflet tethering (small arrow). The white arrow indicates mitral regurgitation. B, Postoperative. A small-sized patch applied to the aneurysm prevents the posterior papillary muscle from moving away from the mitral leaflet.
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References
- Liel-Cohen N, Otsuji Y, Vlahakes GJ. Functional ischemic mitral regurgitation can persist despite ring annuloplasty: mechanistic insights. Circulation 1997;96:I-540.
- Dor V, Sabatier M, Di Donate M, Montiglio F, Toso A, Maioli M. Efficacy of endoventricular patch plasty in large postinfarction akinetic scar and severe left ventricular dysfunction: comparison with a series of large dyskineteic scars. J Thorac Cardiovasc Surg 1998;116:50-59.[Abstract/Free Full Text]
- Frater RMW, Cornelissen P, Sisto D. Mechanism of ischemic mitral insufficiency and their surgical correction. In: Vetter HO, Hetzer R, Schmutzler H, editors. Ischemic mitral incompetence. New York: Springer-Verlag; 1991. pp. 117-130.
- Raman J, Dixit A, Storer M, Buxton BF. Geometric endo-ventricular patch repair of inferior left ventricular scars improves mitral regurgitation and clinical outcome. Ann Thorac Surg 2001;72(suppl):S1055-S1058.[Abstract/Free Full Text]
- Kron IL, Green GR, Cope JT. Surgical relocation of the posterior papillary muscle in chronic ischemic mitral regurgitation. Ann Thorac Surg 2002;74:600-601.[Abstract/Free Full Text]
