Asian Cardiovasc Thorac Ann 1998;6:71-72
© 1998 Asia Publishing EXchange Pte Ltd
First Open-Heart Surgery in Alport Syndrome
Khalid Al Ebrahim, FRCSC,
Mohammed Tahir, MD1,
Hussein Shafei, FRCS
Department of Cardiac Surgery
1 Department of Cardiology Al Hada Armed Forces Hospital Taif, Saudi Arabia
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For reprint information contact: Khalid Al Ebrahim, FRCSC Department of Cardiac Surgery Al Hada Armed Forces Hospital PO Box 1347 Taif, Saudi Arabia Tel:966 2 754 1610 Fax:966 2 754 1238
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ABSTRACT
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We report the first case of open-heart surgery in a patient with Alport syndrome, which refers to the clinical triad of hereditary nephritis, sensory neural deafness, and ocular abnormalities. The conduct of cardiopulmonary bypass, the bleeding tendency, and the precautions taken in a patient with end-stage renal failure are discussed.
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INTRODUCTION
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Alport syndrome is an inherited disorder of collagen metabolism that affects the kidney, the eye, and the cochlea.1–3 The disease exhibits variability in its clinical and pathological manifestations and is genetically heterogeneous. Cardiac valvular involvement has not been reported before in such patients. Our patient had mild aortic regurgitation and severe mitral valve disease with mitral regurgitation that required mitral valve replacement.
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CASE REPORT
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A 30-year-old Saudi male was referred from the nephrology department for investigation of dyspnea and a precordial murmur. He was deaf and had been diagnosed 13 years previously as having Alport syndrome. His brother and one of his cousins had the same disease. The patient was on hemodialysis for end-stage renal failure. He was in sinus rhythm and normotensive. A pansystolic murmur in the mitral area and an early diastolic murmur in the aortic area were detected. His chest radiograph showed cardiomegaly with a left ventricular configuration and pulmonary congestion. Blood biochemistry confirmed end-stage renal failure and his hematology was within normal limits with no thrombocytopenia but a slightly prolonged partial thromboplastin time. His electrocardiogram showed left ventricular enlargement. The echocardiogram revealed severe mitral valve disease, mainly regurgitation with calcification of the anterior leaflet, as well as mild aortic regurgitation. His left ventricular end-diastolic diameter was 68 mm. Cardiac catheterization confirmed these findings.
Hemodialysis was carried out preoperatively. During surgery the fistula was protected with a loose wrapping to avoid compression and hypotension. Aprotinin infusion was given according to the low-dose protocol to reduce bleeding.4 Diffuse intrapericardial adhesions were released. Cardiopulmonary bypass was established using aortic and bicaval cannulation. A hemofilter (COBE Laboratories Ltd, Gloucester, UK) was included in the bypass circuit to avoid fluid overload. As the preoperative transesophageal echocardiogram showed mild-to-moderate aortic insufficiency, blood cardioplegia was delivered initially into the aortic root. This failed to distend properly so a transverse aortotomy was performed for administration of coronary ostial blood cardioplegia. Assessment of the aortic valve showed it to be minimally diseased and with fair coaptation of the three leaflets. A left atriotomy revealed fibrosis and thickening of both mitral leaflets and calcification of the anterior leaflet extending into the anterolateral commissure. The valve was found to be unsuitable for repair. The anterior leaflet and the commissural calcification were excised and a 29-mm Carbomedics mechanical valve was implanted (Sulzer Carbomedics, Inc., Austin, Texas, USA). The patient was successfully weaned from cardiopulmonary bypass and the postoperative course was unremarkable. Light microscopy of the mitral valve showed rheumatic involvement with fibrosis and calcification. Electron microscopy did not show any disruption of type IV collagen.
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DISCUSSION
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There are three modes of transmission of this inherited disease of collagen metabolism. The X-linked dominant form of Alport syndrome that was diagnosed in our patient is caused by a mutation in the Col 4A5 gene that encodes the alpha 5 chain of type IV collagen.1,5 The autosomal recessive form arises from a mutation in the Col 4A3 gene that encodes the alpha 3 chain of type IV collagen or in the Col 4A4 gene that encodes the alpha 4 chain of type IV collagen.1,6,7 An autosomal dominant form of Alport syndrome has also been identified but mutation in this variation of the disease has not yet been described.1 While the diagnosis of Alport syndrome still relies on clinical and pathologic evaluation, immunohistochemical and molecular genetic tools can confirm the diagnosis.1
Open-heart operations using cardiopulmonary bypass for valvular surgery in such patients requires certain precautions in respect of both renal failure and the bleeding tendency. Preoperative hemodialysis is essential for optimal fluid and electrolyte balance. Anesthetic agents, narcotics, sedatives, analgesics, and antibiotics have to be adjusted and monitored carefully to avoid accumulation toxicity. The fistula has to be protected from thrombosis. Intraoperative hemofiltration during cardiopulmonary bypass is essential to achieve an output close to the total intake of intravenous fluids, priming solution, and cardioplegic fluids. Electrolytes and blood gases have to be monitored closely and corrected when indicated. Low-dose aprotinin administration has been found to reduce bleeding in patients with chronic renal failure, especially in the presence of intrapericardial adhesions.4 Preparations have to be made for postoperative hemodialysis as these patients may need hemodialysis at any time according to their electrolyte and fluid status.
The association of Alport syndrome and rheumatic valvular disease is very rare and to our knowledge this is the first patient with Alport syndrome to undergo open-heart surgery.
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REFERENCES
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Ding J, Stitzel J, Berry P, et al. Autosomal recessive Alport syndrome: mutation in the Col 4A3 gene in a woman with Alport syndrome and post-transplant antiglomerular basement membrane nephritis. J Am Soc Nephrol
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ABSTRACT
INTRODUCTION
