Asian Cardiovasc Thorac Ann 2006;14:e76-e79
© 2006 Asia Publishing EXchange Ltd
Apicoaortic Valved Conduit for a Patient With Porcelain Aorta
Tsukasa Miyatake, MD,
Toshifumi Murashita, MD,
Noriko Oyama, MD1,
Satoshi Yamada, MD2,
Kaoru Komuro, MD2,
Keishu Yasuda, MD
Department of Cardiovascular Surgery
1 Department of Radiology
2 Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan
For reprint information contact: Tsukasa Miyatake, MD Tel: 81 16 624 3181 Fax: 81 16 624 1125 Email: tmiyatak{at}yahoo.co.jp, Department of Thoracic Surgery, Ashikawa City Hospital, Kinseicho 1-1-65, Asahikawa 070-8610, Japan.
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ABSTRACT
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A 69-year-old woman had severe aortic stenosis with a circumferentially calcified aorta from the ascending aorta to the aortic arch, and moderately impaired left ventricular function. Implantation of an apicoaortic valved conduit was performed as aortic clamping was not feasible. The early results were excellent.
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INTRODUCTION
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In the management of patients with porcelain aorta who require aortic valve replacement, the pump strategy and local management of the aorta are important to avoid embolization of atheromatous material from the aorta, and to achieve a secure hemostasis of the aortotomy suture line. An apicoaortic valved conduit is one of the options for high-risk patients with porcelain aorta.
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CASE REPORT
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A 69-year-old woman had a history of left ventricular (LV) hypertrophy of 20 years duration. Her symptoms gradually progressed, she developed cough and stridor, and was admitted in New York Heart Association functional class III. She had undergone radiation therapy 4 times for left breast cancer, non-Hodgkin’s lymphoma, and recurrences of both. Her echocardiogram showed severe aortic stenosis with an aortic valve area of 0.37 cm2 and a pressure gradient of 120 mm Hg, trivial to mild aortic regurgitation, and pericardial effusion. Her LV wall motion was diffusely hypokinetic, LV diastolic and systolic diameters were 45 mm and 33 mm, respectively, and fractional shortening was 27%, indicating moderately impaired LV function. Chest radiography and computed tomography showed a heavily calcified aorta from the sinus of Valsalva to the distal arch (Figure 1
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Figure 1. Preoperative computed tomography showing the circumferentially calcified aorta from the sinus of Valsalva to the distal aortic arch.
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Since an aortotomy was considered difficult, it was decided to implant an apicoaortic valved conduit. The technical details of this procedure have been described previously.1 A left thoracotomy in the 5th intercostal space was performed in the hemi-decubitus position. Cardiopulmonary bypass was started with right femorofemoral cannulation. A composite graft of a 21 mm Carpentier-Edwards bioprosthesis (Baxter Healthcare Corp., Irvine, CA, USA) and a 24 mm Gelseal graft (Vascutek, Inchinnan, Scotland, UK) was anastomosed to the descending aorta just above the diaphragm, with partial clamping. A venting tube was inserted into the left atrium through the left atrial appendage, and rectal temperature was cooled to 28°C. The LV apex was opened under ventricular fibrillation and a 16F Foley catheter was inserted through the stab wound in the LV apex to control bleeding from the aortic root due to aortic regurgitation. This catheter also made muscle resection of the apex easier and safer by protecting the intraventricular apparatus. A 20 mm diameter sizer was passed after muscular resection of the LV apex. A 22 mm Gelseal graft was anastomosed to the LV apex with a felt strip (Figure 2a) and then to the composite graft which had been anastomosed to the descending aorta (Figure 2b). Spontaneous beating was obtained after rewarming, and the patient was easily weaned off bypass. The duration of ventricular fibrillation was 51 min, and the bypass time was 168 min.
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Figure 2. Operative technique: (a) the left ventricular apex was opened, a Foley catheter was inserted, and a 22-mm Gelseal graft was anastomosed to the apex with a felt strip; (b) A valved conduit, made from a 24-mm Gelseal graft and a 21-mm bioprosthesis, was anastomosed to the descending aorta. D = diagonal branch, DesAo = descending aorta, LAD = left descending branch, LV = left ventricle.
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The patient was extubated the following morning and moved to the ward after one day in the intensive care unit. Transthoracic echocardiography on postoperative day 17 showed the LV diastolic diameter was 40 mm and fractional shortening was 34%. The pressure gradient across the aortic valve was 37 mm Hg. The calculated stroke volume through the conduit was 56 mL per beat. Color Doppler echocardiography at the aortic arch showed forward flow to the arch from both the ascending and descending aorta, indicating that blood flow from the aortic valve and the conduit met at the level of the aortic arch. Three-dimensional computed tomography showed good construction of the apicoaortic conduit (Figure 3). No anastomotic stenosis between the LV apex and conduit was indicated in either the systolic or diastolic phase by magnetic resonance imaging (Figure 4). The patient was discharged after 31 days, and no anastomotic stenosis was detected 8 months postoperatively.
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Figure 3. Postoperative 3-dimensional computed tomography showing good construction of the apicoaortic conduit.
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Figure 4. No anastomotic stenosis between the left ventricular apex and the conduit is indicated in both (a) systolic and (b) diastolic phases by magnetic resonance imaging.
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DISCUSSION
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The operative management of a patient with porcelain aorta can be complex.2–5 A calcified ascending aorta complicates aortic valve replacement because the aorta can be difficult to open, annular sutures and aortic repair sutures are difficult to insert, and the risk of stroke or myocardial infarction from embolic material is increased. Several techniques with varying degrees of complexity have been described to manage the calcified aorta. For cardiopulmonary bypass or aortic crossclamping, femoral or axillary artery cannulation and hypothermic circulatory arrest have been recommended.2,5,6 Others advocate balloon occlusion of the ascending aorta. Ascending aortic replacement, endarterectomy, and insertion of a composite valve graft with coronary artery bypass to the distal coronary artery have been reported.4,6 These procedures often require deep-hypothermic circulatory arrest, and insertion of a composite graft with or without coronary artery bypass is an extensive and complex operation, particularly for patients who are elderly with limited cardiac and pulmonary reserve or impaired LV function. Alternatively, the LV apex-to-aorta valved conduit has been reported in a limited number of patients with porcelain aorta.3
This patient had moderately impaired LV function and previous radiation therapy. Her aortic calcification was extensive. As a result of recent advances in computed tomography, evaluation of the calcification, atheromatous changes of the aorta, and extent of disease can be determined. If aortic valve replacement had been attempted, endarterectomy or full aortic arch replacement might have been required. Good results post endarterectomy were reported by Svensson and colleagues,4 but the possibilities of stroke and dissection remain. If aortic root and/or arch replacement had been performed, the circulatory arrest time for this patient would have been too long. Thus, implantation of an apicoaortic conduit was preferred.
There are some reports of apicoaortic conduits in patients with idiopathic hypertrophic subaortic stenosis or congenital obstruction of LV outflow.1,7,8 Some surgeons have recommended this strategy for aortic stenosis with porcelain aorta, although there are no reports of large numbers of cases. In the 1980s, stenosis of the anastomosis between the LV apex and the conduit was reported, but recently, good long-term results with this procedure for congenital obstruction of LV outflow have been described. Commercially available stented conduits have been used to avoid stenosis of the LV apex-conduit anastomosis; however, we used an artificial graft without a rigid stent because the stented conduit is not available in our country. In this case, a good-sized hole, 20 mm in diameter, was made under direct vision, the incision was extended posteriorly, and a beveled anastomosis was made to avoid kinking. Although long-term follow-up is certainly required, the excellent early results are promising and support the use of an apicoaortic valved conduit for high-risk patients with porcelain aorta.
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ACKNOWLEDGMENTS
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The authors thank Dr. Yasuhiro Kamikubo and Dr. Toru Watanabe for the perioperative care of the patient.
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REFERENCES
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- Cooley DA, Norman JC, Reul GJ Jr, Kidd JN, Nihill MR. Surgical treatment of left ventricular outflow tract obstruction with apicoaortic valved conduit. Surgery 1976;80:674–80.[Medline]
- Coselli JS, Crawford ES. Aortic valve replacement in the patient with extensive calcification of the ascending aorta (the porcelain aorta). J Thorac Cardiovasc Surg 1986;91:184–7.[Abstract]
- Tanaka S, Kakihata H, Urayama K, Kuji N, Maida K. Apico-aortic conduit bypass operation in a patient with calcified ascending aorta due to Werner’s syndrome. J Cardiovasc Surg (Torino) 1987;28:391–4.[Medline]
- Svensson LG, Sun J, Cruz HA, Shahian DM. Endarterectomy for calcified porcelain aorta associated with aortic valve stenosis. Ann Thorac Surg 1996;61:149–52.[Abstract/Free Full Text]
- Byrne JG, Aranki SF, Cohn LH. Aortic valve operations under deep hypothermic circulatory arrest for the porcelain aorta: "no-touch" technique. Ann Thorac Surg 1998;65:1313–5.[Abstract/Free Full Text]
- Gillinov AM, Lytle BW, Hoang V, Cosgrove DM, Banbury MK, McCarthy PM, et al. The atherosclerotic aorta at aortic valve replacement: surgical strategies and results. J Thorac Cardiovasc Surg 2000;120:957–63.[Abstract/Free Full Text]
- Bernhard WF, Poirier V, LaFarge CG. Relief of congenital obstruction to left ventricular outflow with a ventricular-aortic prosthesis. J Thorac Cardiovasc Surg 1975;69:223–9.[Abstract]
- Renzulli A, Gregorio R, De Feo M, Ismeno G, Covino FE, Cotrufo M. Long-term results of apico-aortic valved conduit for severe idiopathic hypertrophic subaortic stenosis. Tex Heart Inst J 2000;27:24–8[Medline]
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ABSTRACT
INTRODUCTION
