Semilunar Valve Switch Procedure: Autotransplantation of the Native Aortic Valve to the Pulmonary Position in the Ross Procedure

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1 Semilunar Valve Switch Procedure: Autotransplantation of the Native Aortic Valve to the Pulmonary Position in the Ross Procedure Patrick T. Roughneen, FRCS, Serafin Y. DeLeon, MD, Benjamin W. Eidem, MD, Neil J. Thomas, MD, Frank Cetta, MD, Dolores A. Vitullo, MD, Kathy E. Magliato, MD, Teresa E. Berry, MD, and Mamdouh Bakhos, MD Departments of Thoracic and Cardiovascular Surgery and Pediatrics, Loyola University Medical School, Stritch School of Medicine, Maywood, Illinois Background. The Ross procedure has gained wide acceptance in young patients with aortic valve disease. The durability of the pulmonary autograft in the aortic position has been proved, with up to 24 years of followup. The homograft pulmonary valve, however, has limited longevity. To circumvent this problem we harvested, repaired, and reimplanted the native aortic valve with intact commissures in the pulmonary position in 13 patients undergoing the Ross procedure for aortic insufficiency. Methods. The cause of aortic insufficiency was rheumatic in 6 patients, congenital in 4, post aortic valvotomy in 2, and bacterial endocarditis in 1. Patient age ranged from 5 to 45 years (mean, 17 9 years). Root replacement technique with coronary artery reimplantation was used. In the first 4 patients, the native aortic valve was sutured into the right ventricular outflow tract, and a polytetrafluorethylene patch was used to reconstruct the main pulmonary artery. In the last 9 patients, the aortic valve and polytetrafluorethylene patch were made into a conduit by another surgeon while the left-sided reconstruction was performed. Results. All patients had marked reduction of left ventricular dilation and good function of the reimplanted native aortic valve, with up to 50 months of follow-up (mean, months; range, 12 to 50 months). Two patients died 15 and 26 days, respectively, of a false aneurysm rupture at the distal aortic anastomosis. In the remaining 11 patients, 9 (82%) had mild or absent, and 2 (18%) had mild to moderate, neoaortic valve regurgitation. Similarly, 9 patients (82%) had mild or absent, and 2 (18%) had mild to moderate, neopulmonary valve regurgitation. Mild neopulmonary valve stenosis was present in 6 patients (54%) (mean gradient, 29 4 mm Hg; range, 25 to 35 mm Hg). All surviving patients are in functional New York Heart Association functional class I. Conclusions. We conclude that use of the native aortic valve with the Ross procedure makes the procedure attractive and potentially curative. The diseased aortic valve works well in the pulmonary position because of lower pressure and resistance. The valve leaflets should remain viable and grow in both the pulmonary and aortic positions because they derive nutrition directly from the blood. (Ann Thorac Surg 1999;67:745 50) 1999 by The Society of Thoracic Surgeons Accepted for publication July 24, Address reprint requests to Dr Roughneen, Department of Thoracic and Cardiovascular Surgery, Stritch School of Medicine, Loyola University Medical Center, 2160 S. First Ave, Maywood, IL Since the first description of autotransplantation of the native pulmonary valve to the aortic position by Ross in 1967 [1], this procedure has gained acceptance in the treatment of aortic valve disease [2]. Recently, this operation has become the procedure of choice for many infants and children with aortic valve disease [3 8]. The benefits of the pulmonary autograft in the aortic position include growth, lack of degeneration, and avoidance of anticoagulation [9 11]. Although the pulmonary autograft has demonstrated satisfactory function over a 24-year follow-up period, the homograft in the pulmonary position is subject to degenerative change [12]. Elkins and colleagues [4] analyzed 8-year data demonstrating a low freedom (94% 3%) from reoperation in children who underwent the Ross procedure; however, the pulmonary homograft will subsequently require replacement. Sixteen-year data from Gerosa and colleagues [9] have demonstrated freedom from reoperation of the homograft to be 80% in children undergoing this procedure. In addition to the problems of degeneration, lack of growth of the homograft remains a significant disadvantage when the procedure is used in infants and children. To circumvent the problems of homograft degeneration and lack of growth, we started implanting the reconstructed native aortic valve in the pulmonary position with the Ross procedure (semilunar valve switch procedure). Since our initial description of this procedure [13, 14], we have performed the semilunar valve switch procedure in 13 patients with varied aortic 1999 by The Society of Thoracic Surgeons /99/$20.00 Published by Elsevier Science Inc PII S (99)

2 746 ROUGHNEEN ET AL Ann Thorac Surg SEMILUNAR VALVE SWITCH PROCEDURE 1999;67: Fig 1. Harvest of the aortic valve with intact commissure. (A) Harvest of the pulmonary autograft. (B) Harvest of the native aortic valve. (C to E) Implantation of the aortic autograft in the pulmonary position using the freehand technique. After the autograft is sewn in position, the wall of the neopulmonary artery is completed using a polytetrafluoroethylene patch. (F to I) Construction of the composite aortic autograft. valve disease. The present report describes our experience. Patients and Methods The 13 patients have ranged in age from 5 to 45 years (mean, 17 9 years). Preoperative echocardiography was performed in 12 patients and angiography in 1 for evaluation of aortic and pulmonary valve function. Aortic valve regurgitation was graded as moderate or severe. Left ventricular outflow tract anatomy was also determined. Postoperative echocardiography was performed in all patients. Aortic and pulmonary valve function were assessed. If present, peak aortic or pulmonary valve gradient was quantified by Doppler echocardiography. Aortic or pulmonary regurgitation was quantified as mild, moderate, or severe. The cause of aortic insufficiency was rheumatic in 6 patients, congenital bicuspid aortic valves in 4, post aortic valvotomy in 2, and bacterial endocarditis in 1. Surgical Technique All patients underwent median sternotomy and were placed on cardiopulmonary support using a single arterial and bicaval venous cannulation with systemic hypothermia (28 C). The aortic cross-clamp was placed, and antegrade blood cardioplegia was administered directly into the coronary orifices through the aortic transection site. Thereafter, retrograde cold blood cardioplegia was administered every 10 to 15 minutes during the period of aortic cross-clamping, and ice slush was topically applied. The pulmonary artery was opened proximal to the bifurcation, and the pulmonary valve was inspected for suitability for the Ross procedure. The aorta was completely transsected, and the aortic valve was inspected. Incision was then made on the infundibulum of the right ventricle, and the pulmonary autograft was harvested. The muscle was divided with great care so as not to injure the first septal perforating branch of the left anterior descending coronary artery. The right and left coronary arteries were detached from the aorta with a cuff of aortic wall. The aortic valve was then harvested (Fig 1). An incision was made in the region of the left coronary sinus, and the valve was excised from its attachment to the aortic annulus. The aortic commissures were included in the autograft by incising both above and beneath the commissure. The harvested autograft consisted of the valve leaflets, their associated commissures, and a generous portion of aortic wall associated with the noncoronary sinus. In our first 4 cases the aortic autograft was sewn in the pulmonary position (Fig 1, C to E; Fig 2), and a polytetrafluoroethylene patch was used to complete the repair. In the last 9 cases the autograft was taken to the back table for construction of the composite graft (Fig 1, F to I; Fig 3). The aortic valve leaflets, commissure, and aorta were sewn to a patch of 0.6-mm polytetrafluoroethylene with a window to accommodate the harvested portion of the noncoronary aortic wall. The polytetrafluoroethylene patch was made into a tube using a running 5.0-mm polytetrafluoroethylene suture to form the completed composite graft. Autologous pericardium was used to augment the depth of the leaflets by inter-

3 Ann Thorac Surg ROUGHNEEN ET AL 1999;67: SEMILUNAR VALVE SWITCH PROCEDURE 747 posing a strip of pericardium between the incised edge of the valve leaflet and the neopulmonary wall. While one surgeon performed construction of the autograft conduit, the other performed aortic root replacement. In performing the latter we used a two-layer technique, inverting the autograft in the left ventricular outflow tract. The autograft was sewn to the aortic annulus with a continuous 4/0 prolene suture. A second layer of the 5/0 prolene suture was used to approximate the aortic wall distal to the annulus with the adventitia of the pulmonary autograft. Incisions were then made in the region of the left and right coronary sinuses of the neoaorta, and the coronary arteries were reimplanted with a 6/0 prolene suture. The aortic distal anastomosis was completed using a 4/0 prolene suture. In our last 4 cases we reinforced the distal anastomosis with a strip of native pericardium. The composite aortic autograft was sewn in the pulmonary position using a 4/0 polytetrafluoroethylene suture. After reconstruction of the right ventricular outflow tract, all patients underwent uneventful rewarming and weaning from cardiopulmonary bypass. Follow-up All patients were followed-up postoperatively, and transthoracic echocardiography was performed to assess the function of the pulmonary and aortic valve autografts. Echocardiographic grading of stenosis or insufficiency of the implanted valves was determined as mild, moderate, or severe. Doppler gradients, when present, were calculated on the basis of peak velocity across the stenotic area. The functional status of patients was classified according to New York Heart Association function class criteria. Results are expressed as mean standard deviation. Fig 2. The freehand technique of autograft placement in the right ventricular outflow tract (superior view). Results After the semilunar valve switch procedure, there was satisfactory relief of aortic regurgitation in all patients, with good function of both the aortic and pulmonary autografts on immediate postoperative echocardiographic evaluation (Table 1; Fig 4). There were two early deaths. One patient died suddenly on the 26th postoperative day of rupture of a false aneurysm at the site of the distal aortic anastomosis. The second patient had a satisfactory hospital course and was discharged on postoperative day 5. While at home she suddenly developed chest pain after straining, after which she went into cardiac arrest and died on the 15th postoperative day. Autopsy demonstrated a tear at the distal aortic anastomotic site, at the junction of the aorta, neoaorta, and right coronary artery anastomosis. We consider both deaths to be secondary to the fragile nature of the pulmonary autograft in the immediate postoperative period, before long-term adaptation of the neoaortic wall to systemic pressures. To prevent this complication we used a circular strip of pericardium to reinforce the distal anastomosis in the latter patients in our series. The remaining 11 Fig 3. The composite aortic autograft: (a) superior view; (b) lateral view. Note that 40% of the circumference of the composite autograft consists of native aorta.

4 748 ROUGHNEEN ET AL Ann Thorac Surg SEMILUNAR VALVE SWITCH PROCEDURE 1999;67: Table 1. Clinical Data of 13 Patients Undergoing the Semilunar Valve Switch Procedure Pt No. Age (y) Sex Pathologic Findings Preop Echo Findings Date of Operation (mo/y) Postop Echo Findings Follow-up (mo) Current Status 1 11 M Congenital bicuspid Severe AR, mild AS 4/94 Mild AR, mild PR (4 y) 2 19 M Rheumatic Severe AR 6/94 Mild AR, mild (25 mm Hg) (2 y) 3 18 M Rheumatic Severe AR, 6/94 Mild AR, mild MR moderate PR/ mild PS (25 mm Hg) (2 wk) 4 12 F Rheumatic Severe AR, mild MR 12/94 Mild AR, mild PR, mild TR (2 y) 5 17 F Rheumatic Severe AR 4/95 Mild to moderate AR (2 y) 6 16 M Rheumatic Severe AR, 8/95 Mild AR, mild PS mild MR, (30 mm Hg); mild TR moderate PR, MR, TR (7 d) 7 16 F Rheumatic Severe AR, moderate AS (50 mm Hg) 8 45 M Congenital bicuspid Severe AR (cath LV 186/24, AO 186/66) 9 20 F Congenital bicuspid, AS, S/P Ao Valvotomy 2 Severe AR, moderate AS 10 5 M Endocarditis Severe AR, mild AS (30 mm Hg) 8/95 Mild AR, mild (26 mm Hg) (14 mo) 4/96 Mild AR, mild PR (26 mo) M Rheumatic Severe AR 4/97 Mild AR (RF 14%), mild TR (3 mo) M Congenital bicuspid, AS, S/P Ao valvotomy Mild AS, severe AR 50 Well 48 Well... Died postop day 26; false aneurysm, distal Ao anastomosis, tamponade 42 Well 38 Well 34 Well 34 Well 27 Well 10/96 Mild TR (7 d)... Died postop day 15; false aneurysm, distal Ao anastomosis 12/96 Mild AR, mild 18 Well (33 mm Hg) (8 mo) 6/97 Mild AR, mild (35 mm Hg) (5 mo) M Congenital bicuspid Severe AR 6/97 Mild to moderate AR, moderate PR (10 mo) 14 Well 12 Well 12 Well Ao aortic; AR aortic regurgitation; AS aortic stenosis; cath LV left ventricular catheterization; d days; Echo echocardiographic; F female; M male; MR mitral regurgitation; Postop postoperative; PR pulmonary regurgitation; Preop preoperative;ps pulmonary stenosis; Pt patient; RF regurgitant; S/P status post; TR tricuspid regurgitation. patients are all in New York Heart Association functional class I. Mean follow-up is months (range, 12 to 50 months). Echocardiography showed excellent biventricular function in all patients. Nine patients (82%) demonstrated mild or absent, and 2 (18%) mild to moderate, neoaortic valve regurgitation. Similarly, 9 patients (82%) demonstrated mild or absent, and 2 (18%) mild to moderate, neopulmonary valve regurgitation. Mild neopulmonary valve stenosis was present in 6 patients (54%) (gradient range, 25 to 35 mm Hg; mean, 29 4 mm Hg). Comment The Ross procedure has gained widespread acceptance secondary to application of the root replacement technique and improvements in myocardial protection. It is considered by many to be the operation of choice for patients less than 50 years of age with aortic valve disease and no associated coronary artery disease [12]. The procedure has also gained some acceptance in congenital heart operation for children with critical aortic stenosis either as the first operative procedure or after previous balloon or surgical valvotomy [3 8].

5 Ann Thorac Surg ROUGHNEEN ET AL 1999;67: SEMILUNAR VALVE SWITCH PROCEDURE 749 Fig 4. Transesophageal echocardiographic scans from a patient undergoing the semilunar valve switch: (a) preoperative scan demonstrating incompetent aortic valve; (b) scan showing aortic valve transposed to the pulmonary position. The 25-year data of Ross and colleagues [11] demonstrate 69% freedom from reoperation of the pulmonary autograft. The reoperation rate is probably high because it includes those early patients who underwent subcoronary autograft implantation and the inclusion autograft cylinder technique. Nevertheless, the ability of the pulmonary valve to withstand the systolic pressure and remain competent is clear. A major drawback of the Ross procedure is the need for a pulmonary homograft that will need replacement because of calcification and degeneration. Sixteen-year follow-up data have demonstrated 80% 10% freedom from reoperation in the right ventricular outflow tract [9]. Elkins and colleagues [10] similarly demonstrated the need for reoperation in the right ventricular outflow tract in children undergoing the Ross procedure. Although freedom from reoperation in the pulmonary homograft at 8 years was relatively low (94% 3%) in their series, the pulmonary homograft valve will eventually degenerate and calcify [4, 15]. They also demonstrated that cryopreserved homografts tend to undergo significant annular reduction after implantation, resulting in significant pulmonary regurgitation. Early severe homograft valve degeneration occurring within the first year of implantation has also been reported [16]. These latter failures may be attributable to an immunologic rejection of the homograft. Histologic studies of explanted homografts demonstrate their acellular nature, consisting mainly of a fibrous skeleton with dystrophic calcification [16]. In contrast, explanted autografts demonstrate cellular viability along with structural fibrous elements and absence of dystrophic calcification [16]. On the basis of the longevity and growth characteristics of the pulmonary autograft with total root replacement techniques, use of the native aortic valve in the pulmonary position becomes an attractive option. Although the aortic valve may be incompetent in the systemic circulation, its function on the right side is usually adequate when subjected to lower pressures in the pulmonary circulation. When present, the consequences of mild pulmonary regurgitation are physiologically acceptable and similar to those seen when homografts are used [4]. Reconstruction of the native aortic valve using autologous pericardium to augment the aortic leaflets further improves its competence. Follow-up of our patients has demonstrated satisfactory function of the aortic autograft, with most of our surviving patients having no or mild pulmonary valve insufficiency up to 44 months of follow up. The two deaths we encountered were secondary to delayed dehiscence at the distal pulmonary autograft anastomosis. We now routinely reinforce this area with a pericardial strip. Of note, Black and colleagues [17] also reported on the need to reinforce the distal autograft by using native noncoronary sinus wall in patients undergoing the Ross procedure. They had noted friability and bleeding at the distal pulmonary autograft anastomosis, attributing these lesions to the thin and delicate nature of the autograft. The semilunar valve switch procedure has significant economic advantages over the classic Ross procedure, which requires a pulmonary homograft. Use of the native aortic valve in the pulmonary position obviates the need for a foreign valve that is expensive and not readily available. Such economic advantages are particularly attractive in developing countries where isolated rheumatic aortic valve insufficiency is common. Postvalvotomy aortic valves and rheumatic valves tend to have thickened leaflets. Although leaflets augmented with pericardium function well in the short term, there are legitimate concerns as to whether they will function adequately over the long term. However, thickened pulmonary valves have remained functional after pulmonary valvotomy. Calcification of thickened valves seen on the left side does not appear to occur in the pulmonary position, probably because of lower shear forces. Additionally, concerns about the possibility of the rheumatic process involving the pulmonary or aortic valve are legitimate, as reported by Al-Halees and colleagues [18], who described recurrence of rheumatic disease in the pulmonary autograft. Continued penicillin prophylaxis, however, should minimize such recurrence. Our current indications for performing the semilunar valve switch are in children and young adults in whom the aortic valve is suitable for construction of a competent autograft. With use of our modification of the Ross procedure, we believe that the aortic autograft may avoid the need for reoperation secondary to growth constraints or

6 750 ROUGHNEEN ET AL Ann Thorac Surg SEMILUNAR VALVE SWITCH PROCEDURE 1999;67: calcific degeneration resulting from homograft use. Furthermore, we believe that the semilunar valve switch procedure has pertinent economic advantages to substantiate its use in both developed and undeveloped countries. We thank Maureen Kletecka and Anne Mikesh for their excellent help in the preparation of the manuscript. References 1. Ross DN. Replacement of the aortic and pulmonary valves with a pulmonary autograft. Lancet 1967;2: Oury JH. Clinical aspects of the Ross procedure: indications and contraindications. Semin Thorac Cardiovasc Surg 1996; 8: Starnes VA, Luciani GB, Wells WJ, Allen RB, Lewis AB. Aortic root replacement with the pulmonary autograft in children with complex left heart obstruction. Ann Thorac Surg 1996;62: Elkins R, Knott-Craig C, Ward K, Lane M. The Ross operation in children: 10-year experience. Ann Thorac Surg 1998; 65: Sudow G, Solyma L, Berggren H, Eriksson B, Holmgren D, Gilljam T. Aortic valve replacement with a pulmonary autograft in infants with critical aortic stenosis. J Thorac Cardiovasc Surg 1996;112: Reddy VM, Rajasinghe HA, McElhinney DB, et al. Extending the limits of the Ross procedure. Ann Thorac Surg 1995;60: S Elkins RC, Knott Craig CJ, Ward KE, McCue C, Lane MM. Pulmonary autograft in children: realized growth potential. Ann Thorac Surg 1994;57: Schoof PH, Cromme Dijkhuis AH, Borgers JJ, et al. Aortic root replacement with pulmonary autograft in children. J Thorac Cardiovasc Surg 1994;107: Gerosa G, McKay R, Ross DN. Replacement of the aortic valve or root with a pulmonary autograft in children. Ann Thorac Surg 1991;51: Elkins RC, Santangelo K, Stelger P, Randolph JD, Knott- Craig CJ. Pulmonary autograft replacement of the aortic valve: an evolution of technique. J Cardiac Surg 1992;7: Ross D, Jackson M, Davies J. The pulmonary autograft a permanent aortic valve. Eur J Cardiothorac Surg 1992;6: Matsuki O, Okita Y, Almeida RS, et al. Two decades experience with aortic valve replacement with pulmonary autograft. J Thorac Cardiovasc Surg 1988;95: DeLeon SY, Quinones JA, Miles RH, et al. Use of the native aortic valve as the pulmonary valve in the Ross procedure. Ann Thorac Surg 1995;59: DeLeon SY, Quinones JA, Vitullo DA, et al. Semilunar valve switch in aortic insufficiency. Eur J Cardiothorac Surg 1995;9: Ward K, Elkins R, Overholt E, et al. Evaluation of cryopreserved homografts in the right ventricular outflow tract after the Ross procedure: intermediate term follow up. J Heart Valve Dis 1997;6: Ross D. The pulmonary autograft: history and basic techniques. Sem Thorac Cardiovasc Surg 1996;8: Black M, Van Son JA, Hanley F. Modified pulmonary autograft aortic root replacement: the sinus obliteration technique. Ann Thorac Surg 1995;60: Al-Halees Z, Kumar N, Gallo R, Gometza B, Duran C. Pulmonary autograft for aortic valve replacement in rheumatic disease: a caveat. Ann Thorac Surg 1995;60:S INVITED COMMENTARY The report by Roughneen and colleagues is thoughtprovoking and innovative in their attempt to circumvent the problem of homograft valve tissue reconstruction of the right ventricular outflow tract after the Ross procedure. Most patients with aortic valve disease have normal right heart structure and function, and the incidence of significant elevation of pulmonary artery resistance is very low in this subset of patients. Thus, replacement of the pulmonary valve with a nonstenotic but regurgitant aortic valve leads to a very acceptable hemodynamic situation on the pulmonary side of the circulation. Although homograft valve conduits in the right ventricular outflow tract work well acutely with regard to minimal regurgitation, many of these homografts will develop shortening and contracture of the leaflets, so that they become significantly insufficient within a year or two after operation. Thus, if one can use primarily autologous tissue that will not become stenotic in the right-sided reconstruction, the result should be at least as good as, and maybe better than, the intermediate-term results using cryopreserved homografts. I am concerned, however, about their finding that more than half of the patients have pulmonary valve Doppler gradients that suggest mild resting obstruction. Whether this will be progressive remains to be seen, and we look forward to further reports and follow-up from this group of investigators. I believe that the most exciting and present-day implication of this new technique is the obvious cost-savings that could be realized if this technique gains widespread acceptance and is proved to have the durability of the prosthetic valve. In the present-day era of conservation of resources, the idea of valve recycling is intriguing and should promote further laboratory investigation and clinical application of this technique to try and answer these questions. I look forward, in anticipation, to further research in this very exciting area of cardiac operation. Kent E. Ward, MD Department of Pediatric Cardiology University of Oklahoma Health Sciences Center PO Box Oklahoma City, OK by The Society of Thoracic Surgeons /99/$20.00 Published by Elsevier Science Inc PII S (99)