Mitral valve repair

Implantable valves, particularly mechanical valves which continue to encroach on tissue valves, are unique. Methods such as valvuloplasty, mitral valve repair, or use of ultrasound are unlikely to reduce the number of valve replacements into the twenty-first century. Valve selection remains in the hands of the surgeon because of the critical nature of the procedure. If anything goes wrong, the result can be catastrophic to the patient. Cost of a valve, from 3000— 4000, is a relatively small part of the cost of open-heart surgery which can mn as high as 30,000. Growth of the cardiovascular valve market has slowed in the United States with the decline of the threat of rheumatic fever. 

The shortage of donor hearts has prompted development of new surgical techniques, including ventricular aneurysm resection, mitral valve repair, and myocardial cell transplantation, which have resulted in variable degrees of symptomatic improvement. 

Mitral valve repair, 3 717 Mitsubishi Gas Chemical Company process, for methyl methacrylate manufacture, 16 245, 248-250 Mitsubishi Kasei one-step MIBK process, 16 339... 

Indications for surgical intervention include regurgitation with NYHA lll-IV symptoms or NHYA >11 with atrial fibrillation refractory to conservative treatment. Several surgical techniques are effective, The Alfieri stitch or edge to edge technique is of interest because one of the percutaneous mitral valve repair techniques is based on an equivalent principle (29,30). Currently two methods for transcatheter mitral valve repair are investigated in clinical trials ... 

I. In 1991, the surgical variant of the edge-to-edge repair technique was first tried in patients that were not suitable for complex mitral valve repair (29). This procedure is still performed with the intention of sewing together part of the free edges of the anterior and posterior valve leaflets in such a way as to construct a double orifice valve to decrease regurgitation. 

Alfieri O, Maisano p De Bonis M, et al. The double-orifice technique in mitral valve repair a simple solution for complex problems. J Thorac Cardiovasc Surg 2001 122 674-681. 

Feldman T Wasserman HS, Herrmann HC, et al. Percutaneous mitral valve repair using the edge-to-edge technique six-month results of the EVEREST Phase I Clinical Trial. J Am Coll Cardiol 2005 46 2134-2140. 

LiddicoatJR, Mac Neill BD, Gillinov AM, et al. Percutaneous mitral valve repair a feasibility study in an ovine model of acute ischemic mitral regurgitation. Catheter Cardiovasc Interv 2003 60 410-416. 

Medical treatment of mitral regurgitation with afterload reduction and diuresis can effectively alleviate symptoms, but has not been shown to prolong survival. The currently recommended treatments for severe mitral regurgitation are surgical mitral valve repair or replacement. Mitral valve replacement with either a bioprosthetic or mechanical valve has the inherent drawbacks of a potential increase in periprocedural... 

Table 7.1 Percutaneous transcatheter mitral valve repair/replacement tech nologies... 

The idea of percutaneous mitral valve replacement may be more challenging than mitral valve repair techniques due to the unique shape and location of the mitral valve and associated apparatus. The Endovalve-Hermann mitral valve replacement system (Endovalve Inc., Princeton, NJ) is a bioprosthetic foldable redeployable valve that allows antegrade trans-septal placement via a 24 French sheath. An early animal study in four sheep has been reported by Hermann at TCT 2007 (Figure 7.8). 

Fedak PW, McCarthy PM, Bonow RO. Evolving concepts and technologies in mitral valve repair. Circulation 2008 117 963-74. 

Savage EB, Ferguson TB Jr, DiSesa VJ, et al. Use of mitral valve repair analysis of contemporary United States experience reported to the Society of Thoracic Surgeons National Cardiac Database. Ann Thorac Surg 2003 75 820—5. 

Lam, B.-K., GiUrnov, A. M. and Cosgrovein, D. M. (November 2003). Failed mitral valve repair caused by polypropylene suture. The Annals of Thoracic Surgery, 76 (5), 1716-1717. 

According to the 2006 ACC/AHA guidelines for the management of patients with valvular heart disease, mitral valve replacement (MVR) is recommended for patients with moderate to severe mitral stenosis (M VA <1.5 cm ), if the patient is not suitable for percutaneous mitral balloon valvulotomy and is not a high-risk candidate [17]. For chronic mitral regurgitation, MVR is only recommended if a patient with LV dysfunction (ejection fraction <0.60 and/or end systolic dimension >40 mm) is deemed not suitable for mitral valve repair. 

---