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Reinforcement of the Pulmonary Autograft with a Prosthetic Graft to Prevent Dilatation After the Ross Procedure

      The Ross operation remains a controversial procedure, because concern exists regarding late dilation of the neoartic root and progressive regurgitation of the autograft valve. We present a technique of external reinforcement of the autograft, which is inserted into a prosthetic Dacron graft with an artificial aortic root configuration. This approach should help to prevent neoaortic root dilation. Between 2006 and 2010, 16 patients (range: 16-45 years) underwent a Ross procedure using this technique at 2 institutions. Indications were aortic regurgitation (n = 2), aortic stenosis (n = 11), combined aortic stenosis and insufficiency (n = 3). There was no early or late death in this small series. One patient had to be reoperated because of aortic regurgitation, without dilation of the autograft. In this patient, a mild asymmetric regurgitation jet was already observed at discharge echocardiography. Echocardiographic follow-up confirmed absence of aortic insufficiency >1+ in 14 patients after a mean of 24 months. As expected, no neo-aortic root dilation was observed during follow-up. Inclusion of the autograft within a root prosthesis may be indicated in situations known for late autograft dilation, namely, bicuspid aortic valve, predominant aortic insufficiency, and ascending aortic enlargement.
      The main advantages of the Ross technique are the use of the patient's own valve as an aortic valve substitute with excellent hemodynamics, low risk of endocarditis, no need for anticoagulation, and some growth potential in small children.
      • Pasquali S.K.
      • Cohen M.S.
      • Shera D.
      • et al.
      The relationship between neo-aortic dilatation, insufficiency and reintervention following the Ross procedure in infants, children and young adults.
      • Elkins R.C.
      The Ross operation: a 12-year experience.
      • Sievers H.H.
      • Hanke T.
      • Stierle U.
      • et al.
      A critical reappraisal of the Ross operation: renaissance of the subcoronary implantation technique?.
      Dilation of the pulmonary autograft remains a matter of concern because it may lead to progressive regurgitation of the neoaortic valve when the procedure is performed as a full root replacement.
      • Sundt T.M.
      • Moon M.R.
      • Hu H.
      Reoperation for dilatation of the pulmonary autograft after the Ross procedure.
      • Takkenberg J.J.
      • Klieverik L.M.
      • Schoof P.H.
      • et al.
      The Ross procedure: a systematic review and metaanalysis.

      Operative Technique

      The operation is performed using moderate hypothermic cardiopulmonary bypass (standard aortic and bicaval cannulation) and 1 shot of 100 mL crystalloid cardioplegia (Cardioplexol; Swisscardiotech, Berne, Switzerland). The autograft is harvested as described in the original technique with a short muscular rim of right ventricular outflow tract. The adventitial tissue is removed. The diameter of the autograft is assessed by using standard valve sizers. Subsequently, a 2- to 3-mm larger polyester Valsalva vascular prosthesis (Vascutek woven polyester graft Gelweave; Terumo Cardiovascular Systems Inc., Ann Arbor, MI) is chosen (Table 1).
      Table 1Size of the Pulmonary and Aortic Root, as Well as Autograft and Homograft and Mean Ischemic and Perfusion Time
      Mean diameter of the pulmonary autograft23.7 ± 2.6 mm
      Mean diameter of the aortic annulus22.6 ± 3.1 mm
      Mean diameter of the ascending aorta at sinotubular junction24.6 ± 2.8 mm
      Mean diameter of the midascending aorta28.9 ± 1.3 mm
      Mean diameter of the Valsalva graft26.5 ± 2.2 mm
      Mean diameter of the pulmonary homograft25.0 ± 2.3 mm
      Mean aortic cross-clamp time
      RVOT reconstruction performed on beating heart in 5 patients.
      73 ± 16 min
      Mean cardiopulmonary bypass time91 ± 25 min
      low asterisk RVOT reconstruction performed on beating heart in 5 patients.
      Following tailoring of the prosthesis to an appropriate length by leaving only a small rim of about 2 to 3 mm of the proximal collar (proximal to the artificial root), the autograft is inserted into the vascular prosthesis and the pulmonary autograft annulus is fixed with a running suture of 4-0 prolene at the proximal end of the Valsalva prosthesis (Fig. 1A). If the height of the autograft is smaller than the Valsalva part of the prosthesis, the proximal skirt can be completely removed, to preserve an “artificial” sinotubular junction at the level of the commissures of the autograft. Then the distal end of the autograft is sutured to the vascular prosthesis. Both suture lines can be facilitated by placing a Hegar dilator through the autograft lumen, or provisory stay sutures above the 3 commissures (Fig. 1B).
      • Juthier F.
      • Banfi C.
      • Vincentelli A.
      • et al.
      Modified Ross operation with reinforcement of the pulmonary autograft: six-year results.
      Afterward, a standard technique of complete root replacement is used. The reinforced autograft is sutured at the annular level of the excised aortic valve either with continuous running 4-0 polypropylene suture or with interrupted sutures (Fig. 2, left). After careful determination of the optimal site for coronary ostia reimplantation, large windows are made into the graft and corresponding button holes into the wall of the pulmonary artery (neo-aortic root) using an aortic punch (Fig. 1, right). The coronary arteries are reimplanted with a 6-0 running suture between the coronaries and the autograft only; the graft is not included in this suture to avoid blood accumulation between the autograft and the vascular graft in case oozing should occur early postoperatively.
      • Juthier F.
      • Banfi C.
      • Vincentelli A.
      • et al.
      Modified Ross operation with reinforcement of the pulmonary autograft: six-year results.
      • Carrel T.
      • Schwerzmann M.
      • Eckstein F.
      • et al.
      Preliminary results following reinforcement of the pulmonary autograft to prevent dilatation after the Ross procedure.
      The right ventricular outflow tract is reconstructed with a pulmonary homograft in a conventional fashion using continuous sutures for both the proximal and the distal anastomoses. This part of the procedure can usually be performed during reperfusion.
      Figure thumbnail gr1
      Figure 1The autograft is inserted into the prosthesis and fixed with a running suture of 4-0 prolene at the proximal (A) and distal (C) endings. Diameter of the Valsalva prosthesis is chosen 2 to 4 mm larger than the diameter of the pulmonary autograft. The proximal end (collar) of the prosthesis is trimmed, leaving only a rim of 1 to 2 mm below the sinus enlargement. 1 = native aortic root (to be excised); 2 = pulmonary autograft; V = Valsalva reinforced autograft. (Color version of figure is available online at http://www.optechtcs.com.)
      Figure thumbnail gr2
      Figure 2A standard technique of complete root replacement with running sutures is used for the implantation of the autograft. The coronary ostia are implanted with a running suture after using an aortic punch for performing button holes (arrow) into the Valsalva graft (V) and the pulmonary autograft. 3 = pulmonary homograft; V + 2 = Valsalva reinforced autograft with the 2 coronary buttons. (Color version of figure is available online at http://www.optechtcs.com.)
      When indicated, the ascending aorta is replaced with the remaining tubular part of the graft. If the native ascending aorta is dilated up to the proximal arch, the distal anastomosis at the level of the arch is performed during moderate hypothermic (28°C) circulatory arrest using selective antegrade perfusion for cerebral protection.

      Experience and Results

      Between 2006 and 2010, 16 patients (age range: 15-45 years) with congenital aortic disease underwent the Ross procedure, according to this technique. A bicuspid aortic valve was present in 9 patients and balloon valvuloplasty had been performed in 7 patients.
      All patients were submitted to echocardiographic examinations (obtained intraoperatively, before discharge, at 6 months and 1 year, and yearly thereafter). Autograft valve function, homograft or right ventricular outflow tract conduit valve function, and left ventricular function were assessed using M-mode, 2-dimensional echocardiography, and color flow Doppler.
      Hospital mortality was 0%. Re-exploration because of bleeding was necessary in 1 patient. There were no other complications. During early follow-up (up to 48 months so far), 1 patient required reoperation. Echocardiographic follow-up confirmed the absence of aortic insufficiency more than +1 in 14 patients.

      Conclusions

      One of the most important concerns regarding the Ross procedure is the fact that the pulmonary autograft is exposed to systemic pressure. A substantial number of papers thus report a progressive dilation of the neoaortic root with consecutive autograft insufficiency in the long term.
      • Carrel T.
      • Schwerzmann M.
      • Eckstein F.
      • et al.
      Preliminary results following reinforcement of the pulmonary autograft to prevent dilatation after the Ross procedure.
      The original description of the Ross procedure recommended suturing the autograft in a subcoronary position, which did not allow long-term dilation. Based on excellent results observed in 347 patients, Sievers and coworkers concluded that the subcoronary implantation should be the first choice when a Ross procedure is performed.
      • Sievers H.H.
      • Hanke T.
      • Stierle U.
      • et al.
      A critical reappraisal of the Ross operation: renaissance of the subcoronary implantation technique?.
      The present technique is a simple and reproducible additional step, which does not require significant additional time. Continued follow-up will demonstrate if mid- to long-term dilation of the pulmonary autograft can be avoided.

      References

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