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Posterior mitral valve restoration for ischemic regurgitation
Posterior Mitral Valve Restoration for Ischemic Regurgitation Pino Fundaro`, MD, Marco Pocar, MD, PhD, Andrea Moneta, MD, Francesco Donatelli, MD, and Adalberto Grossi, MD
Chronic ischemic mitral regurgitation is traditionally a complex lesion to repair. Only restrictive annuloplasty has become an accepted strategy to avoid valve replacement, but results are unsatisfactory in some subgroups of patients. We describe an original technique that addresses the pathophysiologic mechanisms responsible for one of the most common subtypes of ischemic mitral
regurgitation, ie, asymmetric tethering of the mitral leaflets after inferior myocardial infarction. The technique includes partial detachment of the posterior leaflet from the mitral annulus, annular plication, and posterior cusp plasty. (Ann Thorac Surg 2004;77:729 –30) © 2004 by The Society of Thoracic Surgeons
C
tended to include the central portion of the posterior leaflet (Figure 1A, B). The secondary chordae are transected to increase posterior leaflet mobility, whereas basal chordae are preserved to avoid weakening of the atrio-ventricular junction. The detached portion of the mitral annulus is plicated with interrupted sutures and the resulting defect in the posterior leaflet closed with a running suture (Figure 1C). It should be noticed that, as a consequence of the adjacent plication, the defect at the base of the posterior leaflet is oriented in a radial direction. The plicated annulus is reinforced with a short Gore-Tex strip or posterior annuloplasty band (Figure 1D). Transesophageal echocardiography is routinely performed after discontinuation of cardiopulmonary bypass and showed mild or no regurgitation in all patients.
hronic ischemic mitral regurgitation (IMR) is a functional disorder secondary to postinfarction left ventricular (LV) remodeling. Among the pathophysiologic mechanisms encompassed by IMR, two are prevalent: asymmetric apical displacement of the posterior papillary muscle in case of previous inferior myocardial infarction (MI) and global LV dilation with tethering of both leaflets toward the LV apex, generally following extensive anteroseptal MI. Since November 2000, the technique described has been performed in 9 patients and mainly addresses the first pathophysiologic mechanism attempting to correct posterior leaflet tethering.
Technique The operation is performed through a median sternotomy on cardiopulmonary bypass with bicaval and aortic cannulation. Antegrade and retrograde cold blood cardioplegic arrest is routinely employed at our Institution. The mitral valve is approached through a standard left atriotomy. Three stay sutures are first placed in the mitral annulus, at the two commissures and at the posterior leaflet midpoint, to optimize exposure and allow accurate valve assessment. By definition, no structural lesions of the leaflets and chordae are present in pure IMR. A scarred atrophic posterior papillary muscle may be observed (3 out of 9 patients, in our experience). Posterior annular dilation of varying degree is usually present. The portion of the posterior mitral leaflet attached to the postero-medial papillary muscle appears stretched toward the LV apex and may be difficult to mobilize. An incision is performed to detach the tethered segment of the posterior leaflet from the mitral annulus and ex-
Accepted for publication April 14, 2003. Address reprint requests to Dr Fundaro`, Corso Vercelli, 35, 20144, Milan, Italy; e-mail: [email protected].
© 2004 by The Society of Thoracic Surgeons Published by Elsevier Inc
Comment Traditionally, chronic IMR is a complex lesion to repair and valve replacement is still widely performed to treat this condition. IMR is related to displacement of one or both papillary muscles and/or mitral annular dilation. Leaflet tethering usually prevails in the posterior portion and results in asymmetric and restricted motion of the posterior mitral leaflet during systole and anterior leaflet “pseudoprolapse” [1, 2]. Although not unvariably atrophied, the posterior papillary muscle is generally displaced toward the apex at echocardiography in patients with post-MI regional LV inferior wall dyskinesia or extensive akinesia [1]. Current conservative surgical approaches to IMR mainly focus on annular reduction, with or without implantation of a prosthetic ring [3– 6]. However, because persisting regurgitation of varying degree is frequently observed with annuloplasty alone, a more sophisticated surgical approach to IMR appears indicated [2, 7]. In this respect, a strictly anatomic correction would imply surgical restoration of LV geometry to abolish functional IMR. It has been stated that the most important goal in repairing the valve is to reduce and fix the mitral annular dimension in the antero–posterior (septal– 0003-4975/04/$30.00 doi:10.1016/S0003-4975(03)01048-8
CASE REPORTS
Divisione e Cattedra di Cardiochirurgia, IRCCS Ospedale Maggiore e Universita` degli Studi di Milano, Milan, Italy
730
` ET AL HOW TO DO IT FUNDARO ISCHEMIC MITRAL VALVE RESTORATION
Ann Thorac Surg 2004;77:729 –30
Fig 1. (A) Incision line at the base of the posterior mitral leaflet. (B) Detached posterior leaflet everted anteriorly. (C) Annular plication with interrupted sutures and resulting defect at the leaflet’s base. (D) Defect closed with a running suture and reinforcement of the plicated annulus. Notice how x and y are initially situated near the midpoint of the incision (B), but correspond to the ends of the plicated tissues after the surgical reconstruction (C).
CASE REPORTS
lateral in anatomic terms) axis [2, 8], which may be obtained by implanting stiffer rings [3]. However, these impair or completely abolish annular dynamic motion, which appears important for better preservation of LV function, especially in patients with ischemic cardiomyopathy [4]. In conclusion the procedure has been developed to restore a normal distance between the mitral valve attachments, ie, the annulus and papillary muscle tip, and modifies the anatomy at the valvular level to correct a functional disorder produced primarily by a LV lesion. More specifically, annular geometry is restored with a near-to-normal ratio between the antero–posterior and intercommissural diameters (3:4, according to Carpentier). Plication reduces the circumference of the posterior annulus and “repositions” the tethered portion of the mitral valve more anteriorly. The posterior leaflet is extended on the antero–posterior axis and reduced on the intercommissural axis, allowing better coaptation in the segment adjacent to annular plication. Finally, no occurrence of systolic anterior motion was observed. Further investigation and follow-up are warranted to validate preliminary results.
References 1. Kumanohoso T, Otsuji Y, Yoshifuku S, et al. Mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior myocardial infarction: quantitative analysis of left ventricular and mitral valve geometry in 103 patients with prior myocardial infarction. J Thorac Cardiovasc Surg 2003; 125:135–43. 2. Miller DC. Ischemic mitral regurgitation redux—To repair or to replace? J Thorac Cardiovasc Surg 2001;122:1059 –62. 3. Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediate-term outcome of mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998;115:381–8. 4. Radovanovic N, Mihajlovic B, Selestiansky J, et al. Reductive annuloplasty of double orifices in patients with primary dilated cardiomyopathy. Ann Thorac Surg 2002;73:751–5. 5. Grossi EA, Goldberg JD, LaPietra A, et al. Ischemic mitral valve reconstruction and replacement: comparison of longterm survival and complications. J Thorac Cardiovasc Surg 2001;122:1107–24. 6. Gillinov AM, Wierup PN, Blackstone EH, et al. Is repair preferable to replacement for ischemic mitral regurgitation? J Thorac Cardiovasc Surg 2001;122:1125–41. 7. Messas E, Guerrero JL, Handschumacher MD, et al. Chordal cutting. A new therapeutic approach for ischemic mitral regurgitation. Circulation 2001;104:1958 –63. 8. Timek TA, Lai DT, Tibayan F, et al. Septal-lateral annular cinching abolishes acute ischemic mitral regurgitation. J Thorac Cardiovasc Surg 2002;23:881–8.
Chronic ischemic mitral regurgitation is traditionally a complex lesion to repair. Only restrictive annuloplasty has become an accepted strategy to avoid valve replacement, but results are unsatisfactory in some subgroups of patients. We describe an original technique that addresses the pathophysiologic mechanisms responsible for one of the most common subtypes of ischemic mitral
regurgitation, ie, asymmetric tethering of the mitral leaflets after inferior myocardial infarction. The technique includes partial detachment of the posterior leaflet from the mitral annulus, annular plication, and posterior cusp plasty. (Ann Thorac Surg 2004;77:729 –30) © 2004 by The Society of Thoracic Surgeons
C
tended to include the central portion of the posterior leaflet (Figure 1A, B). The secondary chordae are transected to increase posterior leaflet mobility, whereas basal chordae are preserved to avoid weakening of the atrio-ventricular junction. The detached portion of the mitral annulus is plicated with interrupted sutures and the resulting defect in the posterior leaflet closed with a running suture (Figure 1C). It should be noticed that, as a consequence of the adjacent plication, the defect at the base of the posterior leaflet is oriented in a radial direction. The plicated annulus is reinforced with a short Gore-Tex strip or posterior annuloplasty band (Figure 1D). Transesophageal echocardiography is routinely performed after discontinuation of cardiopulmonary bypass and showed mild or no regurgitation in all patients.
hronic ischemic mitral regurgitation (IMR) is a functional disorder secondary to postinfarction left ventricular (LV) remodeling. Among the pathophysiologic mechanisms encompassed by IMR, two are prevalent: asymmetric apical displacement of the posterior papillary muscle in case of previous inferior myocardial infarction (MI) and global LV dilation with tethering of both leaflets toward the LV apex, generally following extensive anteroseptal MI. Since November 2000, the technique described has been performed in 9 patients and mainly addresses the first pathophysiologic mechanism attempting to correct posterior leaflet tethering.
Technique The operation is performed through a median sternotomy on cardiopulmonary bypass with bicaval and aortic cannulation. Antegrade and retrograde cold blood cardioplegic arrest is routinely employed at our Institution. The mitral valve is approached through a standard left atriotomy. Three stay sutures are first placed in the mitral annulus, at the two commissures and at the posterior leaflet midpoint, to optimize exposure and allow accurate valve assessment. By definition, no structural lesions of the leaflets and chordae are present in pure IMR. A scarred atrophic posterior papillary muscle may be observed (3 out of 9 patients, in our experience). Posterior annular dilation of varying degree is usually present. The portion of the posterior mitral leaflet attached to the postero-medial papillary muscle appears stretched toward the LV apex and may be difficult to mobilize. An incision is performed to detach the tethered segment of the posterior leaflet from the mitral annulus and ex-
Accepted for publication April 14, 2003. Address reprint requests to Dr Fundaro`, Corso Vercelli, 35, 20144, Milan, Italy; e-mail: [email protected].
© 2004 by The Society of Thoracic Surgeons Published by Elsevier Inc
Comment Traditionally, chronic IMR is a complex lesion to repair and valve replacement is still widely performed to treat this condition. IMR is related to displacement of one or both papillary muscles and/or mitral annular dilation. Leaflet tethering usually prevails in the posterior portion and results in asymmetric and restricted motion of the posterior mitral leaflet during systole and anterior leaflet “pseudoprolapse” [1, 2]. Although not unvariably atrophied, the posterior papillary muscle is generally displaced toward the apex at echocardiography in patients with post-MI regional LV inferior wall dyskinesia or extensive akinesia [1]. Current conservative surgical approaches to IMR mainly focus on annular reduction, with or without implantation of a prosthetic ring [3– 6]. However, because persisting regurgitation of varying degree is frequently observed with annuloplasty alone, a more sophisticated surgical approach to IMR appears indicated [2, 7]. In this respect, a strictly anatomic correction would imply surgical restoration of LV geometry to abolish functional IMR. It has been stated that the most important goal in repairing the valve is to reduce and fix the mitral annular dimension in the antero–posterior (septal– 0003-4975/04/$30.00 doi:10.1016/S0003-4975(03)01048-8
CASE REPORTS
Divisione e Cattedra di Cardiochirurgia, IRCCS Ospedale Maggiore e Universita` degli Studi di Milano, Milan, Italy
730
` ET AL HOW TO DO IT FUNDARO ISCHEMIC MITRAL VALVE RESTORATION
Ann Thorac Surg 2004;77:729 –30
Fig 1. (A) Incision line at the base of the posterior mitral leaflet. (B) Detached posterior leaflet everted anteriorly. (C) Annular plication with interrupted sutures and resulting defect at the leaflet’s base. (D) Defect closed with a running suture and reinforcement of the plicated annulus. Notice how x and y are initially situated near the midpoint of the incision (B), but correspond to the ends of the plicated tissues after the surgical reconstruction (C).
CASE REPORTS
lateral in anatomic terms) axis [2, 8], which may be obtained by implanting stiffer rings [3]. However, these impair or completely abolish annular dynamic motion, which appears important for better preservation of LV function, especially in patients with ischemic cardiomyopathy [4]. In conclusion the procedure has been developed to restore a normal distance between the mitral valve attachments, ie, the annulus and papillary muscle tip, and modifies the anatomy at the valvular level to correct a functional disorder produced primarily by a LV lesion. More specifically, annular geometry is restored with a near-to-normal ratio between the antero–posterior and intercommissural diameters (3:4, according to Carpentier). Plication reduces the circumference of the posterior annulus and “repositions” the tethered portion of the mitral valve more anteriorly. The posterior leaflet is extended on the antero–posterior axis and reduced on the intercommissural axis, allowing better coaptation in the segment adjacent to annular plication. Finally, no occurrence of systolic anterior motion was observed. Further investigation and follow-up are warranted to validate preliminary results.
References 1. Kumanohoso T, Otsuji Y, Yoshifuku S, et al. Mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior myocardial infarction: quantitative analysis of left ventricular and mitral valve geometry in 103 patients with prior myocardial infarction. J Thorac Cardiovasc Surg 2003; 125:135–43. 2. Miller DC. Ischemic mitral regurgitation redux—To repair or to replace? J Thorac Cardiovasc Surg 2001;122:1059 –62. 3. Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediate-term outcome of mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998;115:381–8. 4. Radovanovic N, Mihajlovic B, Selestiansky J, et al. Reductive annuloplasty of double orifices in patients with primary dilated cardiomyopathy. Ann Thorac Surg 2002;73:751–5. 5. Grossi EA, Goldberg JD, LaPietra A, et al. Ischemic mitral valve reconstruction and replacement: comparison of longterm survival and complications. J Thorac Cardiovasc Surg 2001;122:1107–24. 6. Gillinov AM, Wierup PN, Blackstone EH, et al. Is repair preferable to replacement for ischemic mitral regurgitation? J Thorac Cardiovasc Surg 2001;122:1125–41. 7. Messas E, Guerrero JL, Handschumacher MD, et al. Chordal cutting. A new therapeutic approach for ischemic mitral regurgitation. Circulation 2001;104:1958 –63. 8. Timek TA, Lai DT, Tibayan F, et al. Septal-lateral annular cinching abolishes acute ischemic mitral regurgitation. J Thorac Cardiovasc Surg 2002;23:881–8.