Ann Thorac Surg 2009;88:2022-2024. doi:10.1016/j.athoracsur.2009.04.145
© 2009 The Society of Thoracic Surgeons
Case Reports
Stentless Bioprosthesis in a Valved Conduit: Implications for Pulmonary Reconstruction
Isaac George, MDa,*,
Jinesh N. Shah, MDb,
Matthew Bacchetta, MDa,
Allan Stewart, MDa
a Division of Cardiothoracic Surgery, Columbia University College of Physicians and Surgeons, New York, New York
b Department of Radiation Oncology, Columbia University College of Physicians and Surgeons, New York, New York
Accepted for publication April 21, 2009.
* Address correspondence to Dr George, Division of Cardiothoracic Surgery, Milstein, 7GN-435, 177 Fort Washington Ave, New York, NY 10032 (Email: isaacgeorge{at}hotmail.com).
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Abstract
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Pulmonic valve reconstruction is required for various congenital heart diseases and in concert with aortic valve autograft replacement (ie, the Ross procedure). Current techniques using homografts and autografts are often associated with significant morbidity and mortality, and are technically challenging. Furthermore, the long-term durability of these repairs has been questioned, leading to more frequent use of synthetic valved conduits. We report a case of pulmonary valve replacement and right ventricular outflow tract reconstruction using a stentless bioprosthetic aortic valve and polyester graft as a novel approach after radical pulmonary artery sarcoma resection.
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Introduction
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Pulmonic valve reconstruction is required for various congenital heart diseases and in concert with aortic valve autograft replacement (ie, the Ross procedure). Current techniques using homografts and autografts are often associated with significant morbidity and mortality, and are technically challenging. We report a case of pulmonary valve replacement and right ventricular outflow tract (RVOT) reconstruction using a stentless bioprosthetic aortic valve and polyester graft as a novel approach after radical pulmonary artery sarcoma resection. A 29-mm 3F valve was inserted into a 30-mm Valsalva graft and sewn to its base. The valved conduit was subsequently sewn directly to the RVOT and pulmonary artery. Postoperative echocardiography demonstrated a graft peak and mean gradient of 8 mm Hg and 3 mm Hg, respectively. This technique may offer advantages in comparison with current RVOT reconstruction methods.
The patient is a 73-year-old man who carried the diagnosis of pulmonary embolism (PE) 3 months prior to presentation. A computed tomographic angiographic scan revealed a large filling defect in the main pulmonary artery (PA), proximal left PA, right ventricular outflow tract, and in the distal right PA, suggestive of worsening PE. A transthoracic echocardiographic scan demonstrated large mobile masses in the RVOT and main PA, which produced a peak gradient of 50 mm Hg and severe right ventricular dilatation. The patient was taken to the operating room with a presumptive diagnosis of a PA malignancy versus massive pulmonary embolism. After a sternotomy, a large mass was identified, extending from the RVOT, (including the pulmonic valve) to the bifurcation of the PA. The pericardium, pleura, and lung were grossly negative for metastasis, and the decision was made to proceed with a resection.
After standard bi-caval cannulation, cardiopulmonary bypass was instituted, while the valved conduit was prepared simultaneously as follows. A 30-mm Valsalva graft (Gelweave Valsalva; Vascutek Terumo Cardiovascular Systems Inc, Ann Arbor, MI) was selected and sized with a 3F sizer. A 29-mm 3F valve (3F; ATS Medical Inc, Minneapolis, MN) was selected and washed with saline. The valve was inserted into the Valsava portion of the graft with the felt tabs of the valve in alignment with the black marking lines of the graft. The cuff of the valve was sewn to the base of the Valsalva portion of the graft with a continuous 5-0 polypropylene suture. The valve tabs were then retracted cephalad and sewn to the superior aspect of the Valsalva graft (Gelweave Valsalva) with a figure-of-eight suture (4-0 polypropylene). The inferior skirt of the graft was then cut at a 30° angle to allow for proper positioning on the right ventricle (Fig 1). The PA was dissected free from the surrounding structures and was opened distally. The tumor was carefully removed en masse from the branch pulmonary arteries. The dissection was continued below the level of the pulmonic valve and into the RVOT. The RVOT was carefully resected carefully to avoid injury to the septal perforators. The tumor was removed and sent to the pathology department. The right PA was opened and chronic embolus was removed. A piece of autologous pericardium was used to augment the right PA. The conduit was returned to the field and the proximal skirt of the Valsalva graft was fashioned to recreate the anastomotic angle of the infundibulum. A continuous 3-0 polypropylene suture was used to construct the proximal anastomosis from the remaining RVOT to the conduit. Finally, the conduit was cut to the appropriate length, and a continuous 4-0 polypropylene suture was used to create the distal anastomosis. Weaning from bypass was unremarkable, with a total bypass time of 1 hour, 59 minutes, and cross-clamp time of 1 hour, 27 minutes. The postoperative echocardiographic scan demonstrated a homograft peak velocity of 142 cm/s, and peak and mean gradients of 8 mm Hg and 3 mm Hg, respectively. The patient had an uneventful recovery and was discharged home on postoperative day 6 on warfarin therapy. Final surgical pathology revealed a high-grade leiomyosarcoma of the pulmonary artery, with tumor cells seen at the right ventricular margin (stage T2b, N0, M0). The patient began a course of targeted radiation therapy (6,660 cGy) to the pulmonary artery and right ventricular outflow tract and right lower lobar pulmonary artery branch approximately 6 weeks after discharge.
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Fig 1. Photograph showing Valsalva end of 30-mm Valsalva graft (Gelweave Valsalva; Vascutek Terumo Cardiovascular Systems Inc, Ann Arbor, MI) sewn to 29-mm 3F valve (3F; ATS Medical Inc, Minneapolis, MN) using a continuous suture prior to cardiopulmonary bypass. Valve tabs were sewn directly to the graft.
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Comment
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Various congenital procedures necessitate the construction of a right ventricle-PA conduit. Traditionally, this is accomplished with a human allograft. The lack of a quality assurance in cadaveric tissue, combined with the tendency for calcification, may limit longevity [1]. In addition, the availability of allografts is limited, expensive, and requires a repository for storage. The novel tissue valve conduit described herein provides numerous improvements in comparison with previous right ventricle-PA conduits, including (1) significant ease of implantation, (2) outstanding hemodynamics, and (3) potentially safer future reintervention.
In contrast to complex graft-conduit preparations [2, 3], the Valsalva-3F preparation can be quickly constructed and requires only one primary suture line. Because of the large skirt inferior to the Valsalva portion of the graft, a "one size fits all" application is possible. The skirt may be cut on an angle to achieve proper anatomy in an RVOT reconstruction. The pliability of the graft will expand to cover a range of RVOT defects, as demonstrated in this case. The unique design of the Valsalva graft permits a 29-mm 3F valve to be attached prior to beginning the procedure, thereby reducing bypass time.
The hemodynamics demonstrated by this graft-conduit are excellent, as measured by a mean gradient of 3 mm Hg. This is consistent with measurements achieved using the same conduit in 10 patients at our institution for aortic root reconstruction (mean gradient average, 4 mm Hg to 5 mm Hg). Because a 29-mm size valve is used, patient-prosthesis mismatch is virtually impossible to produce. Theoretically, the Valsalva portion of the graft will reduce shear stress on the leaflets and enhance durability. Furthermore, the 3F valve has been shown to distribute stress away from the commissural posts, maintain flow integrity, and exceed durability standards versus other bioprosthetic valves, which are all similar to native valve function [4].
Accelerated fibro calcification of the homograft poses a challenging problem in patients status post Ross procedure or other right ventricle-PA conduits, often prompting reoperation [5]. Because the graft is composed of fabric rather than biologic tissue, immunologic activation, and thereby risk for calcification may be reduced. Finally, reintervention, if necessary, may be accomplished by opening the Valsalva portion of the graft and replacing the valve; conduit resection is unnecessary in this setting. In addition, graft dissection from surrounding structures should be easier compared with an allograft.
The 3F valve sewn into a Valsalva graft is straightforward to fabricate, allows for creation pre-bypass, and provides outstanding hemodynamics. Although longevity has yet to be determined, this conduit may represent a superior alternative to homograft right ventricle-PA reconstruction.
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References
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- Brown JW, Ruzmetov M, Rodefeld, MD, Vijay P, Turrrentine MW. Right ventricular outflow tract reconstruction with an allograft conduit in non-Ross patients: risk factors for allograft dysfunction and failure Ann Thorac Surg 2005;80:655-663.[Abstract/Free Full Text]
- Goetz WA, Tan TE, Lim KH, et al. Autologous pericardial pulmonary conduit with single point attached commissures in a sheep model Eur J Cardiothorac Surg 2008;33:48-52.[Abstract/Free Full Text]
- Ando M, Takahashi Y. Ten-year experience with handmade trileaflet polytetrafluoroethylene valved conduit used for pulmonary reconstruction J Thorac Cardiovasc Surg 2009;137:124-131.[Abstract/Free Full Text]
- Cox JL, Ad N, Myers K, Gharib M, Quijano RC. Tubular heart valves: a new tissue prosthesis design—Preclinical evaluation of the 3F aortic bioprosthesis J Thorac Cardiovasc Surg 2005;130:520-527.[Abstract/Free Full Text]
- Wells WJ, Arroyo Jr H, Bremner RM, Wood J, Starnes VA. Homograft conduit failure in infants is not due to somatic outgrowth J Thorac Cardiovasc Surg 2002;124:88-96.[Abstract/Free Full Text]
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Aortic Root and Right Ventricular Outflow Tract Reconstruction Using Composite Biological Valved Conduits After Failed Ross Procedure
Ann. Thorac. Surg.,
June 1, 2011;
91(6):
e87 - e89.
[Abstract]
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Abstract
Introduction
