Shun Nakaji

Mitral valve repair for degenerative disease with leaflet prolapse: to improve long-term outcomes

PurposeResidual mitral regurgitation (MR) is a risk factor of reoperation. Here we report the midterm results of mitral valve repair for degenerative disease with mitral valve prolapse and identify important factors for durable repair.MethodsFrom April 1999 to September 2007, 116 patients with leaflet prolapse (59 men; mean age 63 years) underwent mitral valve repair; they consisted of 19 anterior, 67 posterior, 23 bileaflet, and 7 isolated commissures. The mean clinical and echocardiographic follow-ups were at 4.1 ± 2.3 and 3.3 ± 2.4 years, respectively.ResultsAltogether, 12 patients showed recurrent moderate or severe MR during the follow-up period; and 10 of the 12 patients (83.8%) had recurrent moderate or severe MR within 1.5 years. Causes of early MR recurrence were dehiscence of sutured segments and ineffectiveness of the artificial chords. The rates of freedom from reoperation at 3 and 7 years were 95.3% ± 2.0% and 91.0% ± 4.7%, respectively. The rates of freedom from recurrent moderate or severe MR at 3 and 7 years were 90.5% ± 2.9% and 83.8% ± 5.9%, respectively.ConclusionsThe prevention of dehiscence of the sutured segment and reestablishment of coaptation using artifi- cial chords are imperative to maintain the durability of mitral valve repair for patients with degenerative disease.

Characteristics and treatment strategies of mitral regurgitation associated with undifferentiated papillary muscle

PurposeIn this report we review our experience of operations on mitral regurgitation associated with abnormal papillary muscles/chordae tendineae of the mitral valves and discussed the clinical characteristics, operative findings, and treatment strategies.MethodsUndifferentiated papillary muscle was defined as a hypoplastic chordae tendineae with anomalous formation of papillary muscles attached to the mitral valves directly. Consecutive 87 patients undergoing surgery for mitral regurgitation at our institution were reviewed and 6 of them had undifferentiated papillary muscle.ResultsThe underlying mechanism of regurgitation was prolapse at the center of the anterior leaflet in 3 cases and tethering, a wide area of myxomatous degeneration, and annular dilatation in one case, respectively. Five patients underwent mitral valve plasty and 1 patient received replacement. Anomalous formation of chordae tendineae was corrected by resection and suture with transplantation at the tip of the leaflet to which abnormal chordae were attached in 2 cases, while resection and suture with chordal shortening was performed in 1 case, and chordal reconstruction using artificial chordae was employed in 2 cases. There was no operative death, and postoperative echocardiography showed no residual regurgitation in any of the cases.ConclusionsMitral regurgitation associated with undifferentiated papillary muscle resulted from prolapse or tethering and impaired flexibility of leaflets. It was possible to successfully treat the patients by mitral valve plasty unless complex congenital cardiac malformation coexisted. Detailed examinations of attached papillary muscle by echocardiography and intraoperative inspection are necessary and surgical techniques should be selected appropriately in each case.

Mitral Leaflet Restoration Using a Billowing Leaflet in Active Infective Endocarditis

A key to the success of mitral valve repair in patients with infective endocarditis is the technique used for reconstruction of the missing leaflet. We report the case of a 47-year-old man with active mitral infective endocarditis. After dissection of the infected segments of P3 and the posteromedial commissure, the defect was reconstructed using tissue from a billowing A2 medial and A3 segment. Chordal transfer with an anterior chord was performed to correct the A3 mild prolapse. Follow-up echocardiography showed recovery of mitral valve morphology and function without regurgitation.

Surgical technique of double valve replacement in a patient with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is an inherited connective tissue disorder. Left ventricle dilation and valve insufficiency are complications in patients with OI and such patients are at high risk of mortality and complications related to bleeding and tissue friability during cardiac surgery. Valve dehiscence due to extreme friability of the annulus is a major complication of cardiac valve replacement with OI. We describe OI in a male patient who underwent double valve replacement with mechanical valves using a tissue protective method to prevent valve dehiscence.