Ann Thorac Surg 2005;80:320-322
© 2005 The Society of Thoracic Surgeons
Case report
Successful Mitral Valve Replacement in a Patient With Ehlers-Danlos Syndrome Type VI
Hiroshi Takano, MD*,
Yuji Miyamoto, MD,
Yoshiki Sawa, MD,
Norihide Fukushima, MD,
Goro Matsumiya, MD,
Tomoyuki Fujita, MD,
Hikaru Matsuda, MD
Division of Cardiovascular Surgery, Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
Accepted for publication December 22, 2003.
* Address reprint requests to Dr Takano, Department of Surgery E-1, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan (Email: htakano-cvs{at}umin.ac.jp).
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Abstract
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A 40-year-old patient with Ehlers-Danlos syndrome type VI (ocular type) had mitral regurgitation due to mitral valve prolapse. Because the patient’s tissue was fragile, we replaced the mitral valve with a reinforced prosthetic valve to prevent paravalvular leakage. The excised mitral leaflet showed significant myxomatous change and decrease in collagen fibers. We believe this is the first report of cardiac surgery in a patient with Ehlers-Danlos syndrome type VI.
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Introduction
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Ehlers-Danlos syndrome (EDS) is a hereditary connective tissue disorder caused by abnormal collagen synthesis, and it is clinically characterized by hyperelastic skin, fragility of the skin and blood vessels, hypermobile joints, and cardiovascular complications. It is a heterogeneous group of disorders; eleven types of EDS have been recognized to date.
Mitral regurgitation, usually due to mitral valve prolapse, has been well recognized in patients with EDS, but only a few cases of mitral valve surgery have been reported. We describe a patient with EDS type VI who was treated successfully with mitral valve replacement (MVR) for mitral regurgitation. We believe this is the first report of cardiac surgery in a patient with EDS type VI.
A 40-year-old man with progressive dyspnea was admitted to a local hospital with a diagnosis of mitral regurgitation and congestive heart failure in March 2002. Although he had a heart murmur that was noticed at age 10 and mitral valve prolapse that was diagnosed at age 26, he had not received medication. After treatment with diuretics and digitalis, he was referred to our department for surgery in April 2002.
Since childhood, physicians had noted blue sclera and hypermobile finger joints, and he had experienced many bone fractures. He underwent left keratoplasty for bullous keratopathy in 1998. As he was suspected of having EDS, at the time of keratoplasty, a skin sample was obtained from him for biochemical analysis of cultured fibroblasts. No decrease in type I or III collagen level was observed, ruling out EDS type IV. The patient’s parents had no clinical characteristics of EDS. The skin biopsy results and his clinical features led to the EDS type VI diagnosis in 1998. The hydroxylysine content of the collagen or lysyl hydroxylase activity in the fibroblasts was not measured for technical reasons.
On admission to our hospital, he was 163 cm in height, 50 kg in weight, and had marfanoid habitus. Thoracolumbar scoliosis and thoracic cage deformity were noted. He had a pansystolic murmur in the mitral area and a diastolic decrescendo murmur in the aortic area. An electrocardiogram showed regular sinus rhythm. An echocardiogram showed severe mitral regurgitation due to both anterior and posterior mitral valve leaflet prolapse and mild aortic regurgitation from the center of the aortic valve. The left ventricle was dilated (7.4 cm in diastole, 4.5 cm in systole). Cardiac catheterization confirmed normal coronary arteries and good left ventricular function (ejection fraction, 79%).
At surgery, the tissue was fragile. The ascending aorta adventitia tore away easily when held with forceps, and the suction device’s metal tip made a hole in the diaphragm. The operation involved cardiopulmonary bypass, moderate hypothermia, and cardioplegic arrest. To avoid doing aortic cannulation, a cannula was inserted into the femoral artery. The mitral valve showed myxomatous regeneration. The chordae tendineae of both anterior and posterior leaflets were grossly elongated but not ruptured. We resected the anterior mitral leaflet. As the mitral annulus also appeared fragile, we replaced the mitral valve with a collar-reinforced prosthetic valve to prevent paravalvular leakage. A 2-cm wide band of annular equine pericardium (XAG-400 [Edwards AG, Irvine, CA]) was attached around the sewing cuff of the prosthetic valve (Sorin Bicarbon prosthetic heart valve [Sorin Biomedica Cardio, Saluggia, Italy]) with a running suture. This composite prosthetic valve was secured by 13 pairs of buttressed sutures through the mitral valve annulus and the sewing cuff of the prosthetic valve, followed by a running suture through an extended annular equine pericardial cuff and the supraannular left atrial wall. The aortic valve was untouched. No homologous blood was transfused during or after the operation.
Microscopic examination of the excised valve showed severely myxomatous degeneration. Masson’s trichrome stain of the leaflet showed scarce, fragmented, and disrupted collagen bundles (Fig 1).
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Fig 1. Histologic sections of excised mitral valve showing severe myxomatous change (Left panel: Hematoxylin & eosin, x200). Collagen bundles (arrows) were very scarce and disrupted. (Right panel: Masson’s trichrome, x200).
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The postoperative course was uneventful. An echocardiogram 5 months postoperatively showed markedly decreased left ventricular dimensions (4.8 cm in diastole, 3.0 cm in systole). No paraprosthetic valvular leakage was observed. The patient was doing well 16 months postoperatively.
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Comment
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Eleven types of EDS have been distinguished by genetic characteristics, biochemical defects, and clinical presentation. Because the natural history and mode of inheritance differ for each type, a correct diagnosis is essential. The fragility of the tissue may also vary, from apparently normal to an extreme friability. Type IV EDS (arterial or ecchymotic type) is considered the most severe form [1], and some authors [2] advise against surgical management of this type because of the risks of bleeding and poor healing.
Ehlers-Danlos syndrome type VI (the ocular type) is an autosomal recessively inherited disorder caused by lysyl hydroxylase deficiency. The deficiency leads to a decrease in both the hydroxylysine content of collagen and the cross links in collagen fibers. To the initially identified clinical features (scoliosis, ocular fragility, keratoconus, soft and velvety hyperextensible skin, and increased joint mobility) a propensity for bleeding or arterial rupture has been added [3].
Mitral regurgitation has been widely recognized in EDS patients. The major cause of mitral regurgitation in these patients is mitral valve prolapse, which is probably due to defective support of the mitral valve apparatus or the laxity or redundancy of the mitral leaflets or lengthening of their chordae [4], or a combination thereof. Although mitral regurgitation is commonly reported in EDS patients, we believe there are only a few reported cases of mitral valve surgery in patients with EDS [5–7], probably because of frequent complications with these patients after cardiac surgery [1, 5].
The optimal operative procedure for mitral regurgitation in EDS patients has yet to be determined. Leier and colleagues [5] reported an EDS type I patient who underwent MVR but died of fulminant cardiac failure secondary to a massive paravalvular leak of the prosthetic mitral valve. Kitagawa and colleagues [6] reported successful MVR in an EDS type III patient and recommended against repairing the mitral valve because of its fragility in such patients. In contrast, Avlonitis and Large [7] reported conducting mitral valve repair and a Maze procedure in an EDS type I or II patient, and recommended that mitral valve repair should even be considered for patients with connective tissue disorders.
We chose to do MVR over mitral valve repair in this patient because the tissue was visibly fragile compared with that in Marfan syndrome patients for whom mitral valve repair has been widely accepted [8]. Moreover, mitral valve fragility may differ by EDS type, and there have been no reported cases of cardiac surgery in EDS type VI patients. After surgery, microscopic examination comparing this patient’s mitral valve with myxomatous mitral valves from Marfan patients (unpublished data) showed that collagen bundles were much scarcer in this patient’s valve. These microscopy findings, which imply that the long-term durability of the repaired mitral valve in EDS patients cannot be assumed, confirmed our choice to perform a MVR instead of a mitral valve repair.
We did not replace the aortic valve in our patient because we believed that the tissue fragility would have made simultaneous mitral and aortic valve replacements too risky. However, aortic regurgitation should be closely followed because it may progress due to the nature of EDS.
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References
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- Cikrit DF, Miles JH, Silver D. Spontaneous arterial perforationthe Ehlers-Danlos specter. J Vasc Surg 1987;5(2):248-255.[Medline]
- Mattar SG, Kumar AG, Lumsden AB. Vascular complications in Ehlers-Danlos syndrome Am Surg 1994;60(11):827-831.[Medline]
- Wenstrup RJ, Murad S, Pinnell SR. Ehlers-Danlos syndrome type VIclinical manifestations of collagen lysyl hydroxylase deficiency. J Pediatr 1989;115(3):405-409.[Medline]
- Cabeen Jr WR, Reza MJ, Kovick RB, Stern MS. Mitral valve prolapse and conduction defects in Ehlers-Danlos syndrome Arch Intern Med 1977;137(9):1227-1231.[Abstract/Free Full Text]
- Leier CV, Call TD, Fulkerson PK, Wooley CF. The spectrum of cardiac defects in the Ehlers-Danlos syndrome, types I and III Ann Intern Med 1980;92(2 Pt 1):171-178.
- Kitagawa M, Nakagawa Y, Shibairi M, et al. Mitral valve replacement in a case of Ehlers-Danlos syndrome Nippon Kyobu Geka Gakkai Zasshi 1984;32(7)1073–7.
- Avlonitis VS, Large SR. Ehlers-Danlos syndromesurgical management of mitral regurgitation and atrial fibrillation. J Heart Valve Dis 1999;8(4):463-465.[Medline]
- Fuzellier JF, Chauvaud SM, Fornes P, et al. Surgical management of mitral regurgitation associated with Marfan’s syndrome Ann Thorac Surg 1998;66(1):68-72.[Abstract/Free Full Text]
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Abstract
Introduction
