MMCTS
(March 15, 2006). doi:10.1510/mmcts.2005.001131
Copyright © 2006 European Association for Cardio-thoracic Surgery
Procedure
Minimally invasive aortic valve replacement
Tomislav Mihaljevic1,*,
Marc A. Gillinov1 and
Delos M. Cosgrove
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
* Corresponding author: * Tel.: +1-216-444-0648. E-mail: mihaljt{at}ccf.org
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Summary
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Partial upper sternotomy results in excellent exposure and a safe conduct of a variety of operations on the aortic valve and ascending aorta. The sternotomy extends into the right fourth intercostal space and is performed through an 8–10 cm long skin incision. The pericardium is open in the midline and aorta and right atrium are cannulated directly. Aortic valve is exposed through the oblique aortotomy, after placement of retraction sutures to the commissures. The aortic valve is excised and annulus meticulously debrided. Aortic valve prosthesis is then inserted into the annulus using a pledgeted non-absorbable suture. The procedure is performed with the usual surgical instrumentation and can therefore be easily adopted. We discuss the indications, surgical technique and results of this technique.
Key Words: Aortic valve • Aortic stenosis • Aortic regurgitation • Aortic valve surgery
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Introduction
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The goal of minimally invasive approaches for treatment of valvular heart disease is to reduce the trauma to the patient, while preserving the quality and safety of conventional surgical approaches. The proximity of the aortic valve to the sternum allowed a rapid development of a variety of less invasive approaches for the treatment of aortic valve disease [1,2]. The initially described parasternal approach which included limited resection of right costal cartilages was quickly abandoned, due to the high incidence of postoperative lung herniation [3]. Transverse sternotomy which allowed an excellent exposure of the aortic valve was developed later, but abandoned due to occasional sternal instability, and the need to sacrifice one or both internal mammary arteries. We describe our experience with partial upper sternotomy, which became the preferred approach for minimally invasive operations on the aortic valve and ascending aorta.
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Surgical technique
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After induction of general anesthesia the patient is positioned supine with the rolled towel between the shoulder blades. A transesophageal echocardiographic probe is inserted to allow detailed intraoperative echocardiographic exam. The patient is prepped and draped in usual sterile fashion (Video 1).
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Video 1 Positioning of the patients.
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Limited skin incision (8–10 cm) is made starting half-way between the sternal notch and manubrium. Partial upper sternotomy is perfomed extending into the right fourth intercostal space. The anterior mediastinal fat tissue and thymic remnants are divided and ligated for better hemostasis (Video 2).
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Video 2 Limited skin incision and partial upper sternotomy.
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The pericadium is open in the midline and pericadial sutures are tacked to the skin edges. This enhances the exposure of the ascending aorta and the right atrium. The cardiopulmonary bypass is then established by cannulation of the distal ascending aorta and the right atrium. The vacuum assisted venous drainage allows the use of smaller venous cannula and enhances venous drainage. Aortic cross-clamp is performed with a flexible aortic clamp, which allows an unobstructed view of the operative field (Video 3).
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Video 3 Cannulation.
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Myocardial arrest is accomplished with the use of cold antegrade cardioplegia through the aortic root. Additional doses of cardioplegia can be given directly through the coronary ostia. Oblique aortotomy is performed and the heavily calcified bicuspid aortic valve is exposed. Traction sutures in the cranial aspect of aortotomy, combined with additional traction sutures at the level of commissures, can further improve exposure of the valve and coronary ostia (Video 4).
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Video 4 Conduct of aortotomy and exposure of the aortic valve.
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The aortic valve is excised in its entirety and annulus is carefully debrided with the pituitary rounger. Non-everted pledgeted sutures (2-0 Ethibond – MMCTSLink 97), are then placed into the annulus, and the biological aortic prosthesis is sutured into place. Both coronary ostia are visualized at the completion of the procedure (Video 5).
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Video 5 Valve excision and debridement of the annulus.
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Aortotomy is closed using a running non-absorbable suture (4-0 Prolene – MMCTSLink 50), and aortic root is deaired. Aortic cross-clamp is removed. Temporary ventricular pacemaker wires and mediastinal drains are placed while the heart is decompressed on cardiopulmonary bypass (Videos 6 and 7).
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Video 6 Placement of pledgeted sutures and sizing of the aortic annulus.
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Video 7 Closure of the aortotomy and deairing of the heart.
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The patient is weaned from cardiopulmonary bypass and the heart is deaired through the vent in the ascending aorta. The function of the prosthesis and deairing process are monitored with the transesophageal echocardiogram. The patient is decannulated and hemostasis is peformed. Sternal edges are reaproximated with stainless steel wires. Skin and subcutaneous tissue are closed with absorbable suture in layers (Video 8).
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Video 8 Drain placement and closure of the partial sternotomy.
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Results
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Minimally invasive approach for the aortic valve replacement has been in use as the primary approach for the isolate aortic valve surgery at the Cleveland Clinic since 1995. The approach was used primarily for the aortic valve replacement or repair. However, the same incision was successfully used for combined aortic valve replacement and replacement of the ascending aorta in a smaller number of patients. The operative mortality was not affected by the choice of incision. Conversion to complete sternotomy was required in less than 2% of patients. Mean aortic occlusion time and cardiopulmonary bypass times were comparable to the population of patients operated through conventional approach. The comparison with median sternotomy demonstrates a reduction in both postoperative length of stay and direct hospital costs.
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Discussion
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Minimally invasive aortic valve surgery represents a safe approach for the treatment of a variety of aortic valve disorders and the disease of the ascending aorta. Partial upper sternotomy allows uncompromized view of the operative field, and therefore allows the conduct of the operation with standard surgical instruments [4]. One of the initial concerns with the use of partial sternotomy for aortic valve replacement was the inability to deair the heart in conventional fashion. We routinely use intraoperative transesophageal echocardiography for the guidance of appropriate deairing of the heart prior to the separation from cardiopulmonary bypass. In addition, routine use of carbon dioxide in the operative field has lowered the risk of stroke and made it comparable to the one observed in conventional approaches. The incision also provides the opportunity for combined operations on the ascending aorta, mitral and tricuspid valve. The lack of dependence on expensive high-tech equipment makes this technique attractive to every cardiac surgeon. The retrospective comparison with median sternotomy demonstrates a reduction in both postoperative length of stay and direct hospital costs [1]. In a large prospective randomized trial minimally invasive aortic valve replacement was associated with longer operative times, less blood loss and better cosmetic results [5]. The application of the minimally invasive approach is particularly beneficial for older patients, resulting in shorter hospital stay and in a greater percentage of patients discharged home [6]. The minimally invasive approach should be considered for all eligible patients with aortic valve disease.
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Footnotes
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1 Tomislav Mihaljevic and Dr. Marc A. Gillinov serves as a consultant for Edwards Lifesciences. 
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References
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- Mihaljevic T, Cohn LH, Unic D, Aranki SF, Couper GS, Byrne JG. One thousand minimally invasive valve operations: early and late results. Ann Surg 2004;240:529–534.[Medline]
- Cosgrove DM, Sabik JF, Navia JL. Minimally invasive operations. Ann Thorac Surg 1998;65:1535–1538.[Abstract/Free Full Text]
- Gillinov AM, Cosgrove DM. Minimally invasive mitral valve surgery: mini-sternotomy with extended transseptal approach. Semin Thorac Cardiovasc Surg 1999;11:206–211.[Medline]
- Gillinov AM, Banbury MK, Cosgrove DM. Hemisternotomy approach for aortic and mitral valve surgery. J Card Surg 2000;15:15–20.[Medline]
- Dogan S, Dzemali O, Wimmer-Greinecker G, Derra P, Doss M, Khan MF, Aybek T, Kleine P, Moritz A. Minimally invasive versus conventional aortic valve replacement: a prospective randomized trial. J Heart Valve Dis 2003;12:76–80.[Medline]
- Sharony R, Grossi EA, Saunders PC, Schwarz CF, Ribakove GH, Culliford AT, Ursomanno P, Baumann FG, Galloway AC, Colvin SB. Minimally invasive aortic valve surgery in the elderly: case-control study. Circulation 2003;108(Suppl 1):II43–II47.
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Summary
Introduction