Valve Sparing Aortic Root Replacement for Dilatation of the Pulmonary Autograft and Aortic Regurgitation After the Ross Procedure

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1 Valve Sparing Aortic Root Replacement for Dilatation of the Pulmonary Autograft and Aortic Regurgitation After the Ross Procedure Toru Ishizaka, MD, Eric J. Devaney, MD, Stephen R. Ramsburgh, MD, Takaaki Suzuki, MD, Richard G. Ohye, MD, and Edward L. Bove, MD Division of Pediatric Cardiovascular Surgery, Section of Cardiac Surgery, Department of Surgery, and Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan Background. Aortic insufficiency secondary to progressive dilatation of the pulmonary autograft is being recognized with increasing frequency after the Ross procedure. We reviewed our experience with valve-sparing aortic root replacement concomitant with aortic annuloplasty to assess the effectiveness of this approach. Methods. Four patients, aged 8 to 27 years, presented with moderate to severe aortic insufficiency associated with progressive root dilatation from 1 to 8 years after a Ross procedure. All patients had 0 to 1 aortic insufficiency early after the Ross procedure, with a mean maximal sinus diameter of 37 mm (range 30 to 45 mm). At reoperation the maximum diameter of the root ranged from 45 to 55 mm (mean 50 4 mm). A valve-sparing aortic root replacement with annular reduction was performed. The annulus was decreased from a mean of 27 mm to 23 mm. For the root replacement, 1 patient underwent a standard root remodeling procedure; in the others, a separate piece of scalloped Dacron (C.R. Bard, Haverhill, PA) graft material was used for each sinus to facilitate optimal exposure. Results. All 4 patients are in New York Heart Association functional class I at a mean follow-up of 6 months. The most recent echocardiography demonstrated 0 to 1 aortic insufficiency with good left ventricular function. Histology of the excised pulmonary autograft walls demonstrated severe elastin fragmentation. Conclusions. Aortic root remodeling with annular reduction is an effective treatment for aortic root dilatation and aortic insufficiency after the Ross operation. This procedure allows correction of aortic insufficiency and avoids the need for a prosthetic valve and anticoagulation. (Ann Thorac Surg 2003;75: ) 2003 by The Society of Thoracic Surgeons Over the past decade, the use of the Ross procedure has increased dramatically. This can be attributed to its growth potential among infants and children, avoidance of anticoagulation and freedom from the risks of thromboembolism, valve-related morbidity, and structural valve deterioration. Although its use is justified by the reports of satisfactory long-term results [1 3], it has been increasingly recognized that in some patients progressive dilatation of the pulmonary autograft involving dilation of the sinotubular junction, sinuses of Valsalva, and autograft valve annulus may result in significant autograft regurgitation [4 6]. When the autograft valve leaflets remain normal, these patients may benefit from a valve-sparing root replacement operation. In this report, we describe our experience with reoperation for progressive autograft dilatation accompanied by aortic insufficiency after the Ross procedure. Accepted for publication Nov 25, Address reprint requests to Dr Bove, Section of Cardiac Surgery, F7830 Mott Hospital, 1500 East Medical Center Dr, Ann Arbor, MI 48109; elbove@med.umich.edu. Material and Methods Between October 2001 and May 2002, 4 male patients between the ages of 8 and 27 years were referred to our institution with aortic insufficiency and significant aortic root dilatation from 1 to 8 years after a Ross procedure. All patients originally underwent a complete root replacement technique. Demographic and diagnostic features are summarized in Table 1. 1 had previously undergone closure of a ventricular septal defect and resection of a subaortic membrane at 2 years of age. He underwent a Ross/Konno operation for aortic and subaortic stenosis with bicuspid aortic valve at the age of 5 years. The aortic annulus was enlarged from 11 to 17 mm by a partial thickness septal incision [7], and a pulmonary autograft with a diameter of 18 mm was implanted using a continuous polypropylene suture. A noncircumferential pericardial strip was used posteriorly and in the region of the right ventricular endocardium. 2 had previously undergone open valvotomy for aortic stenosis due to a bicuspid aortic valve at 7 months of age. He underwent a Ross procedure for aortic regurgitation at the age of 14 years. At the time of the Ross operation, the diameter of the aortic annulus and the pulmonary autograft as measured with cali by The Society of Thoracic Surgeons /03/$30.00 Published by Elsevier Science Inc PII S (02)

2 Ann Thorac Surg ISHIZAKA ET AL 2003;75: REOPERATION AFTER ROSS PROCEDURE Table 1. Summary of Data Before Valve Sparing Root Replacement Age (y) Weight (kg) Original Disease Years Post-Ross AR Post-Ross AR Reop. Diameter of Sinotubular Junction (mm) Diameter of Sinus of Valsalva (mm) LVDd/Ds (mm) 1519 LVFS (%) Post-Ross Reop. Post-Ross Reop. Reop. Reop. CARDIOVASCULAR BAV, VSD, SubAS /24 46 s/p VSDC, SubASR BAV, AR s/p Open 4 trace /50 27 valvotomy ASR NA 33 NA 49 53/ BAV, ASR /45 29 AR aortic regurgitation; ASR aortic stenosis and regurgitation; BAV bicuspid aortic valve; LVDd/Ds left ventricular end-diastolic/ end-systolic dimension; LVFS left ventricular fractional shortening; Reop. reoperation; SubAS subvalvular aortic stenosis; SubASR resection of subvalvular aortic stenosis; VSD ventricular septal defect; VSDC VSD closure. brated dilators were 24 and 26 mm, respectively. The autograft was implanted with a continuous polypropylene suture with a circumferential felt strip incorporated into the suture line. 3 underwent Ross operation for a tricuspid aortic valve with aortic stenosis and insufficiency at the age of 21 years. A 29-mm pulmonary autograft was implanted without use of reinforcement of the aortic annulus, which was also measured at 29 mm in diameter. 4 underwent Ross operation for a bicuspid aortic valve associated with aortic stenosis and insufficiency at the age of 12 years. At the time of the Ross operation, the aortic annulus was plicated from 28 to 24 mm, and a 25-mm pulmonary autograft was implanted with a circumferential strip of autologous glutaraldehyde-treated pericardium [8]. The degree of neoaortic insufficiency at early postoperative echocardiography after the Ross operation was 1 in patients 1 and 4, trace in patient 2, and 0 in patient 3. Serial Doppler echocardiography demonstrated increasing aortic root dimensions with progression of central aortic insufficiency to 3 or more in all 4 patients. In patient 4, in addition to the central insufficiency, there was a jet from a small defect at the base of the left coronary leaflet near the commissure of the left and the right coronary cusps. This jet had not been detected in the early postoperative studies. The function of the cryopreserved pulmonary allograft in the pulmonic position was normal in each patient and none were replaced. Surgical Technique Reoperation was performed at an interval of 1 to 8 years after the Ross procedure (mean 4 3 years). A valvesparing aortic root replacement concomitant with an aortic annulus reduction procedure was performed. Data at reoperation are summarized in Table 2. At reoperation, the valve leaflets appeared to be normal except in patient 4. In this patient, a 6-mm hole in the base of the left coronary leaflet was found, which was primarily closed with interrupted 6-0 Prolene (Ethicon, Somerville, NJ) sutures. There was no evidence of endocarditis and the remainder of the leaflets appeared to be normal. In each patient, annular reduction was performed with a circumferential continuous horizontal mattress suture of 2-0 Prolene. This was placed on the autograft wall just beneath the hinge point of the valve leaflets and passed outside of the wall at the noncoronary cusp, where it was tied down over a calibrated dilator (Fig 1A, 1B) [9]. The size of the dilator was determined by comparison with the normal expected aortic annulus size based on the patient s body surface area [10]. The sinuses of Valsalva were excised, sparing the coronary buttons and the commissural attachments of the valve leaflets. In patient 1, the root was reconstructed with a Hemashield graft fashioned with scallops (Meadox Medicals Inc, Oakland, NJ) to resuspend the autograft valve leaflets. In the remaining 3 patients, each sinus was reconstructed individually with a separate piece of scalloped graft, thereby facilitating exposure for the anastomosis of each sinus and the coronary buttons. The size of each scalloped graft was determined by first selecting a Dacron (C.R. Bard, Haverhill, PA) tube graft that was 2 mm smaller than the final aortic annular diameter. One end of the tube graft was then cut into three equal sinuses, which were then used to replace the excised native sinus Table 2. Summary of Data at Valve Sparing Root Replacement Annular Reduction at Reoperation (mm) Size of Hemashield Graft CPB Time (min) Cross-Clamp Time (min) 1 22 mm 3 19 mm 20 mm mm 3 24 mm 22 mm mm 3 25 mm 24 mm mm 3 24 mm 22 mm CPB cardiopulmonary bypass.

3 1520 ISHIZAKA ET AL Ann Thorac Surg REOPERATION AFTER ROSS PROCEDURE 2003;75: buttressed by a Teflon (Impra Inc, subsidiary of L.R. Bard, Tempe, AZ) felt strip 3 mm in width. Results Postoperative data are listed in Table 3. The degree of aortic insufficiency, as assessed by intraoperative transesophageal echocardiography, after repair was 0 in pa- Fig 1. (A) Placement of the annular reduction suture using continuous horizontal mattress stitch of 2-0 Prolene (Ethicon, Somerville, NJ) suture. (B) The suture is tied over the calibrated dilator to fix the size of the annulus. of Valsalva. The highest point of the valve commissure determined the height of each new sinus. After completing the root reconstruction, a Hemashield tube graft (Boston Scientific/Meadox, Oakland, NJ) was interposed between the newly reconstructed aortic root and the native aorta (Fig 2A, 2B). The size of this graft was the same as that used to construct the separate sinuses except in patient 1, for whom a 20-mm (instead of 18-mm) graft was chosen because of likely continued growth. Each suture line except for the coronary buttons was Fig 2. (A) A separate piece of a scalloped graft was used for the reconstruction of each sinus to optimize exposure. (B) The coronary arteries are reimplanted and the same graft is interposed between the root and the ascending aorta.

4 Ann Thorac Surg ISHIZAKA ET AL 2003;75: REOPERATION AFTER ROSS PROCEDURE Table 3. Summary of Data After Valve-Sparing Root Replacement AR After Redo (TEE-OR) Use of Blood Products Hospital Stay (days) Follow-up (mo) NYHA Class Recent Echo AR Recent Echo LVDd/Ds (mm) 1521 Recent Echo LVFS (%) CARDIOVASCULAR 1 0 No / Trace No Trace 59/ Trace No Trace 47/ No /34 34 AR aortic regurgitation; Echo echocardiogram; LVDd diastolic left ventricular dimension; LVDs systolic left ventricular dimension; LVFS left ventricular shortening fraction; NYHA Class New York Heart Association functional class; TEE-OR transesophageal echocardiography in operating room. tient 1, trace in patients 2 and 3, and 1 in patient 4. No blood transfusions were required in any case. All of the patients are doing well from 3 to 9 months after the operation, and the most recent Doppler echocardiographic assessments revealed no interval changes compared with the initial intraoperative results (0 to 1 regurgitation). Both the pulmonary autograft wall and the native ascending aorta were sent for histologic examination. In each case, the autograft wall demonstrated diffuse fragmentation and loss of elastic lamina with varying degrees of mucopolysaccharide deposition (Movat stain; Fig 3). There was no discernible histologic change in the native ascending aortic wall. Comment The valve annulus, sinuses of Valsalva, and sinotubular junction of the pulmonary autograft are known to show an increase in size after the Ross operation [4 6]. This increase may be secondary to passive dilatation due to exposure to higher blood pressure [11], mismatch of the pulmonary autograft and the aortic annulus or ascending aorta [8, 12], an intrinsic abnormality of the pulmonary root possibly associated with congenital aortic valve disease [5], or normal somatic growth in the pediatric Fig 3. A full-thickness section of resected pulmonary autograft in patient 2, showing diffuse fragmentation of elastic lamina and deposition of mucopolysaccharide (Movat stain, original magnification 200). population [13]. In the majority of cases the function of the autograft valve is preserved despite dilation of the aortic root [4, 6, 14]. However when the root dilatation leads to significant autograft valve insufficiency, or when the dilatation rapidly progresses into an aneurysm, reoperation is indicated. The treatment options are a Bentall procedure [15], rereplacement of the aortic root with a homograft [5, 16], replacement of the aortic valve with supported or unsupported aortoplasty [17], separate replacement of the aortic valve and the ascending aorta [18], or valve-sparing root replacement [19, 20]. In our own experience, in addition to the 4 patients in this report, 2 additional patients have required reoperation for autograft insufficiency (aortic valve replacement and Bentall operation in 1 patient each) among the initial 154 Ross operations performed in children and adolescents. We now prefer valve-sparing root replacement as a first option, as it obviates the need for anticoagulation and preserves the physiologic hemodynamics of the ventricular outflow, especially when the valve leaflets remain normal. Although the procedure described by David and colleagues is also an attractive option [20], it has been our preference to use the technique described here for its technical simplicity, particularly in younger children. The appropriate timing of reoperation in this clinical setting has yet to be determined, especially in the pediatric population. David and colleagues [5] reported that reoperation is indicated when the aortic root dimension exceeds 55 mm in diameter. Although the sizes in our cases did not exceed this criterion, earlier intervention for these patients is likely to increase the chances of preserving the autograft valve. Recently, Sundt and colleagues [21] reported a case of valve-sparing root replacement for root dilatation without autograft valve regurgitation after a Ross procedure. Our 4 cases were complicated by significant aortic insufficiency due to dilatation of the sinotubular junction as well as dilatation of the autograft annulus and sinuses of Valsalva. Therefore, a reduction annuloplasty with a circumferential pursestring suture was placed below the annulus in addition to the aortic root remodeling, as described by Elkins and associates [9, 22]. They described the use of the reduction annuloplasty at reoperation after the Ross operation in patients with central insufficiency and aortic annular dilatation. They also reported the use of that technique at the time of the Ross operation in

5 1522 ISHIZAKA ET AL Ann Thorac Surg REOPERATION AFTER ROSS PROCEDURE 2003;75: patients with a dilated annulus, demonstrating satisfactory late results with no increase in size of the annulus or in valve insufficiency. Morishita and coworkers [23] have supported the use of tripartite scalloped grafts for the reconstruction of the sinuses of Valsalva, based on the observation that each aortic sinus is not equal in size in human cadavers. Although the use of this technique requires an additional graft-to-graft anastomosis, it provides improved exposure of the suture line for each scallop and the coronary buttons. Moreover, tailoring the graft to the exact size of each sinus is facilitated, making mathematical formulas unnecessary. Histologic abnormalities of pulmonary arterial wall media, including elastin fragmentation (as observed in our patients), changes in smooth muscle cell orientation, and cystic medial necrosis have been reported by several authors [16, 21, 24]. Although we cannot determine whether the striking histologic features of the autograft media in our cases represent a preexisting abnormality, the findings support the concept that technical considerations to prevent root dilatation at the Ross operation are warranted, as well as careful annual echocardiographic monitoring after the Ross operation. We currently prefer a circumferential Dacron strip around the aortic annulus and the sinotubular junction as reinforcement during the Ross operation in adolescents and older patients, although its efficacy for preventing dilatation is yet to be determined. Furthermore, this would not be expected to prevent dilatation at the sinus level. In conclusion, an aortic root remodeling operation and autograft valve repair with an annular reduction suture is an effective alternative for the treatment of aortic root dilatation and autograft valve insufficiency after the Ross operation. This procedure allows correction of valve insufficiency and avoids the need for a prosthetic valve and anticoagulation. Although this is a small series with a short follow-up period, the preliminary results are encouraging. References 1. Ross D, Jackson M, Davies J. Pulmonary autograft aortic valve replacement: long-term results. J Card Surg 1991;6: Oury JH, Mackey SK, Duran CMG. Critical Analysis of the Ross procedure: do its problems justify wider application? Semin Thorac Cardiovasc Surg 1999;11(Suppl 1): Kouchoukos NT, Davila-Roman VG, Spray TL, Murphy SF, Perrillo JB. Replacement of the aortic root with a pulmonary autograft in children and young adults with aortic valve disease. N Engl J Med 1994;57: Hokken RB, Bogers AJJC, Taams MA, et al. Does the pulmonary autograft in the aortic position in adults increase in diameter? An echocardiographic study. J Thorac Cardiovasc Surg 1997;113: David TE, Omran A, Ivanov J, et al. 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