Interact CardioVasc Thorac Surg 2009;9:703-705. doi:10.1510/icvts.2009.213959
© 2009 European Association of Cardio-Thoracic Surgery
Case report - Cardiac general |
Apico-aortic conduit for aortic stenosis with a porcelain aorta; technical modification for apical outflow
Masanori Hirota*,
Masaya Oi,
Tadashi Omoto and
Takeo Tedoriya
Department of Thoracic and Cardiovascular Surgery, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ward, Tokyo, 142-8666, Japan
Received 8 June 2009;
received in revised form 17 June 2009;
accepted 18 June 2009
*Corresponding author. Tel.: +81-3-3784-8588; fax: +81-3-3784-8307.
E-mail address: mhirota{at}khc.biglobe.ne.jp (M. Hirota).
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Abstract
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A successful apico-aortic bypass for a patient with a porcelain aorta suffering from aortic stenosis is reported. A sewing cuff with an outflow graft to the apex and a hand-made composite graft were used instead of a rigid apical connector.
Key Words: Apico-aortic bypass; Porcelain aorta; Aortic stenosis
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1. Introduction
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Although aortic valve replacement is recommended as the standard surgical procedure for severe aortic stenosis, technical modification is very important to reduce surgical complications for the patients with advanced progression of atherosclerosis. One of the most deleterious complications is embolization of atheromatous material from the aortic wall, resulting in transient or permanent neurological deficits [1]. In particular, great attention is required in high-risk patients with a history of cerebrovascular disease and/or patients with a severely calcified aortic wall.
Apico-aortic bypass is an alternative surgical option to aortic valve replacement for the patients with a porcelain aorta or left ventricular (LV) outflow tract obstruction or who have undergone previous surgery, such as coronary artery bypass grafting [2, 3]. Currently, a rigid right-angled apical connector is available for this procedure, and good surgical outcome has been reported [3]. However, this material is not commercially available in Japan. A case of aortic stenosis with a porcelain aorta successfully treated surgically using a sewing cuff with outflow onto the apex and a hand-made composite graft is reported.
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2. Clinical summary
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A 79-year-old man was referred to our unit due to severe exertional dyspnea. He had chronic renal failure due to renal sclerosis requiring hemodialysis for 12 years. Hemodynamics during hemodialysis had been unstable for three months. Two-dimensional echocardiography disclosed good LV function but aortic stenosis with a peak flow velocity of 4.1 m/s. Coronary angiography revealed no stenosis in the coronary arteries. Brain computed tomography (CT) showed multiple small low-density areas suggesting cerebrovascular disease. Chest CT revealed severe calcification of the aortic valves, annulus, ascending aorta, and aortic arch. Abdominal CT demonstrated a previously implanted Y-shaped graft for atherosclerosis obliterans, which was sewn to the abdominal aorta in side-to-end fashion and extended to bilateral femoral arteries; i.e. aorto-bifemoral bypass. Apico-aortic bypass was planned due to a porcelain aorta with severely calcified aortic annulus. Also the femoral artery was considered unreasonable arterial inflow for cardiopulmonary bypass (CPB) due to a previous operation.
Under general anesthesia, the patient was prepped in the right lateral decubitus position. The left thoracotomy was performed in the 6th intercostal space. Under general heparinization, the descending aorta was side-clamped for distal anastomosis. A 20-mm woven polyester vascular graft (Hemashield Gold; Boston Scientific, Natick, MA) with side-branch (10 mm) was sewn to the descending aorta with a 4-0 polypropylene running suture in side-to-end fashion. During creation of distal anastomosis, a hand-made composite graft was made with a 21-mm stentless bioprosthetic valve (Prima PLUS; Edwards Lifesciences, Irvine, CA) and a 20-mm woven polyester vascular graft (Fig. 1a).
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Fig. 1. (a) A hand-made composite graft was created using a 21-mm stentless bioprosthetic valve and a 20-mm woven polyester vascular graft. The coronary ostium of the stentless valve was closed with a 6-0 polypropylene over-and-over suture. (b) A sewing cuff with a 16-mm outflow is commercially available in Japan (Toyobo Co. Ltd, Osaka, Japan). The material is generally used as a part of ventricular assist device system to create the apical outflow of the left ventricle. (c) A 14-mm tissue puncher through a sewing cuff with a 16-mm outflow.
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After pericardiotomy, the apex of the heart was exposed to fix a sewing cuff with a 16-mm outflow, which is commercially available in Japan (Toyobo Co. Ltd, Osaka, Japan), with eleven 4-0 polypropylene mattress sutures with pledgets. The material is generally used as a part of the ventricular assist device system to create apical outflow of the LV (Fig. 1b). After fixation of the cuff onto the apex, CPB was commenced by return to side-branch of the distal graft and drainage from the right femoral vein. Hemodynamics were maintained with total circulatory support by CPB under normothermia. The heart was kept beating in head-down position. Through the outflow of the cuff, apical myocardium was removed with a 14-mm tissue puncher (Guister, Tuttlingen, Germany) (Fig. 1c). A 16-mm Hegar dilator was passed through the coring hole via the cuff. Proximal end of the composite graft was sewn to apical myocardium under the cuff to include a 16-mm outflow with four 2-0 polypropylene mattress sutures with pledgets and 3-0 polypropylene running sutures. Big bites are required for this anastomosis to achieve firm fixation and local hemostasis. Distal end of the composite graft was covered with a 1-cm strip of a 20-mm woven polyester vascular graft to reinforce the anastomosis. Distal end of the composite graft was sewn to proximal end of a 20-mm woven polyester vascular graft with a 5-0 polypropylene running suture in end-to-end fashion. The postoperative schematic drawing is shown in Fig. 2a. During the operation, the heart was kept beating in sinus rhythm without ventricular fibrillation. Total CPB time was 57 min.
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Fig. 2. (a) The schematic drawing of this procedure. (b) Postoperative three-dimensional computed tomography showing the apico-aortic valved conduit without stenosis or kinking.
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The postoperative course was uneventful, and hemodialysis was stable after the operation. The peak flow velocity across native aortic valve was about 2.5 m/s. Chest CT demonstrated no compression and no stenosis of the apico-aortic conduit (Fig. 2b).
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3. Discussion
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An apico-aortic conduit was successfully used in a patient with a porcelain aorta suffering from aortic stenosis. Due to lack of availability of a rigid right-angled apical connector in Japan, we utilized a sewing cuff with outflow onto the apex and a hand-made composite graft.
In this case, we used a sewing cuff with a 16-mm outflow. One of the advantages of this material is good fixation onto the apex of the LV, resulting in less surgical hemorrhage between apical myocardium and the cuff. Furthermore, big bites for apical myocardium effectively include the sewing cuff with outflow during proximal anastomosis between apical myocardium and the composite graft. Thus, this sewing cuff functions as a cushion for proximal anastomosis, contributing to better surgical hemostasis than a rigid apical connector.
Although the adequate area of the apical outflow is unknown for this procedure, a sufficient area is ideally required to keep total circulatory volume across the apico-aortic conduit. Although a 16-mm outflow diameter would be the marginal size for adult patients, pressure overload for the LV was alleviated; a peak flow velocity across native aortic valve decreased from 4.1 to 2.5 m/s. Thus, this technique with these materials relieved the severity of aortic stenosis.
The least invasive strategy would include off-pump apico-aortic conduit insertion with a rigid apical connector [4] and transapical aortic valve implantation [5]. However, both materials are not commercially available in Japan. As a next step for less-invasive off-pump strategy, it is very important to control hemorrhage from the apical outflow. Vassiliades et al. reported the efficacy of an occlusion balloon catheter through the apical connector [4]. In the future we will try the off-pump method with available materials.
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4. Conclusion
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We report a successful case of apico-aortic bypass as a surgical alternative to aortic valve replacement. When a rigid apical connector is not available, technical modifications are important to reduce surgical risk.
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References
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Abstract
1. Introduction