External Ring Annuloplasty Research Articles

Aortic Valve Sparing Surgery: The Use of the Coroneo Extra-Aortic Annuloplasty Ring

Ideal prosthetic aortic valve should maintain excellent hemodynamic characteristics that are sustainable during varying hemodynamic conditions and demands, have minimal trans-aortic pressure gradients, should be durable in the long term, resist thrombus formation without the need for anticoagulation and be straightforward to implant. Unfortunately, the ideal prosthetic aortic valve does not yet exist. This review critically evaluates available-to-the-surgeon options.Critical evaluation of relevant literature sources available on PubMed with the emphasis on current situation and new trend in the aortic valve sparing procedures. Current prosthetic devices are associated with complications such as valve thrombosis and thromboembolic events, bleeding events associated with anticoagulation use and structural valve deterioration. Therefore native valve disease is replaced by prosthetic valve disease. Aortic valve sparing operations were developed to preserve the native aortic valve during surgery for aortic root aneurysm and ascending aortic aneurysm with associated aortic insufficiency, circumventing complications arising from prosthetic valve implantation by preserving the native aortic valve apparatus. There are two fundamental types of aortic valve sparing procedures: remodelling of the aortic root and reimplantation of the aortic valve. Evidence based medicine shows that reimplantation of the aortic valve is in long term associated with lower risk of developing aortic insufficiency. An alternative standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with remodelling technique was presented. Implantation of an external aortic ring provides a reproducible technique for aortic valve repair with great preliminary results.

An expansible aortic ring to preserve aortic root dynamics after aortic valve repair†

Aortic annuloplasty and preservation of root dynamics have been described as factors for durability of aortic valve repair. The objective of this study is to document the first clinical analysis of root dynamics after a standardized valve-sparing procedure for root aneurysms associating a calibrated expansible external aortic ring annuloplasty with a physiological remodelling of the aortic root (CAVIAAR technique: Conservative Aortic Valve surgery for aortic Insufficiency and Aneurysm of the Aortic Root). Of the 600 patients operated on with the CAVIAAR technique, 60 consecutive patients from a single team underwent double independent reading of the echocardiographic analysis performed in the operative period and yearly after discharge until a maximum of 5-year follow-up. Forty-four patients had preoperative aortic insufficiency (AI) ≥grade 2 (73.3%) and 29 patients (48%) had bicuspid valves. The expansible aortic ring (median size 27 (25-27) mm) significantly reduced the aortic annular base diameter (from 28 (25-29) mm to 23 (21-24) mm) (P < 0.001) without a significant median transvalvular gradient increase (P = 0.545). Cusp repair was performed in 55 patients (91.7%). Operative mortality was 1.7% (1). During the median 19-month (95% confidential interval [11-26]) follow-up, annular diameter and cusp effective height remained stable. There were no valve-related reoperations. One patient died at 6 months postoperatively from congestive heart failure. Freedom from AI ≥grade 2 was 100% at 1-year follow-up and 96.8% ± 3.2% at 3-year follow-up. Systolic root expansibility of the four echocardiographic diameters (aortic annular base, sinuses of Valsalva level, sino tubular junction and tubular aorta) was maintained, throughout the follow-up period with the aortic annular base expansibility coefficient having consistently higher values than the three other levels. The expansible aortic ring achieved a complete calibrated external annuloplasty and maintained dynamics of the aortic root at mid-term follow-up. Whether this could be a factor for durability of aortic valve repair is currently under evaluation through the CAVIAAR study 10-year follow-up.

Valve sparing root replacement: the remodeling technique with external ring annuloplasty.

A standardized approach to aortic valve repair is described associating a physiological remodeling of the root, with resuspension of cusp effective height and a subvalvular aortic annuloplasty using an external expansible ring. This device achieves a complete calibrated annuloplasty, in order to increase cups coaptation height and protect the repair. This is a video-atlas describing the surgical steps of a physiological and standardized approach to aortic valve repair, to treat an aortic root aneurysm associated with grade III to IV eccentric aortic insufficiency on a 41-year old patient with a tricuspid aortic valve (Video 1). Ideal valve sparing root replacement procedure should treat dilatation of the aortic annular base, while preserving dynamics of the aortic root with vortices (neosinuses of Valsalva), root expansibility (interleaflet triangles) as well as restoring cusp coaptation (1-5). Video 1 Valve sparing root replacement: the remodeling technique with external ring annuloplasty The two original valve sparing procedures - remodeling of the aortic root and reimplantation of the aortic valve - focused on root reconstruction to reduce the dilated root diameters in order to restore proper valve function (6,7). The reimplantation technique performs external subvalvular aortic annuloplasty but withdraws the sinuses of Valsalva and includes the interleaflet triangles within a graft tube, thus impairing root dynamics (8-11). In contrast, the remodeling technique provides more physiologic movements of the cusps within three reconstructed neo-sinuses, thus preserving root expansibility through the interleaflet triangles, but without addressing annular base dilation (8-13). In vitro and in vivo studies have documented that cusp motion and flow patterns across the reconstructed aortic root are more physiologic (I) after remodeling of the aortic root than after reimplantation of the aortic valve, and (II) after procedures using a prosthetic conduit fashioned with neo- sinuses of Valsalva than without (9-11). Numerous technical variations have aimed to associate preservation of aortic root dynamics with the treatment of dilated native annulus (14,15). This resulted in a lack of standardization and limited their widespread application. Furthermore, most failures with valve sparing techniques are due to residual cusp prolapse, either as a primary unrecognized lesion or secondary to an induced prolapse after root reconstruction (12,16). Schafers et al. proposed to address this issue with a dedicated caliper in order to restore cusp effective height up to 8-10 mm (1,4,12). Therefore we suggest a standardized approach of aortic valve repair addressing both the aorta and the valve, associating a physiological reconstruction of the aortic root according to the remodeling technique, with resuspension of cusp effective height and an expansible subvalvular ring annuloplasty (CAVIAAR technique) (Figure 1) (2,17-19). Figure 1 Remodeling of the aortic root associated to an external subvalvular aortic annuloplasty (CAVIAAR technique), combining advantages of the original remodeling and reimplantation techniques To address the need for a dedicated aortic annuloplasty device, we designed a new expansible aortic ring in order to achieve a complete and calibrated annuloplasty in diastole, while maintaining systolic expansibility of the aortic root (Extra-Aortic™, CORONEO, Inc., Montreal, QC, Canada) (19). As such, cusp coaptation height is increased, reducing stress on the cusps and protecting the repair.

An aortic ring to standardise aortic valve repair: preliminary results of a prospective multicentric cohort of 144 patients☆

Multiplicity of aortic valve repair or sparing techniques results in a lack of standardisation, limiting widespread adoption of such procedures. To treat dilated diameters at the aortic annular base and sinotubular junction while maintaining root dynamics, we propose a standardised and physiological repair approach to the surgical management of aortic root aneurysms, consisting of root remodelling, cusp re-suspension and subvalvular aortic ring annuloplasty. From May 2003 to September 2009, 144 unselected patients with aortic root aneurysms underwent remodelling with external subvalvular ring annuloplasty in 13 centres (21 surgeons). Preoperative aortic insufficiency (AI) > or =grade 2 was present in 63.9% (92), Marfan syndrome in 12.5% (18) and bicuspid valve in 22.9% (33). Cusp repair was performed in 40.3% (58) patients. Valve repair was successful in all but two cases. Repair of cusp prolapse was necessary in 58 patients, significantly more frequent in bicuspid (24/33, 72.7%) than in tricuspid (34/111, 30.6%) valves (p<0.05). Operative mortality was 2.8% (four). Subvalvular ring implantation produced a significant annular base reduction from 27.6+/-2.5 mm to 20.5+/-2.6 mm (p<0.01) without significant mean trans-valvular gradient (7.2+/-1.7 mmHg). During follow-up (median 2.2 years (0.75-4.4, maximum 6.25 years)), five patients died while eight required a re-operation. Six were operated on during our early experience. Strategy for cusp re-suspension evolved over three operative periods, with a significant increase in the rate of cusp repair. From May 2003 to December 2006: eye balling evaluation (15/67 (22.4%)); from January 2007 to August 2008: alignment of cusp free edges (17/38 (44.7%)); and from September 2008 to September 2009: a two-step standardised repair consisting of alignment of cusp free edges and effective height re-suspension (26/39 (66.7%) p<0.05). Freedom from AI> or =grade 2 was 91.3% (115) at the end of follow-up. Implantation of an external aortic ring provides a reproducible technique for aortic valve repair with satisfactory preliminary results. The ongoing CAVIAAR trial (Conservative Aortic Valve surgery for aortic Insufficiency and Aneurysm of the Aortic Root) will compare this standardised repair technique using an expansible aortic ring to mechanical valve replacement.

Aortic prosthetic ring annuloplasty: a useful adjunct to a standardized aortic valve-sparing procedure?☆

Dilation of aortic annulus, sinuses of Valsalva, and sinotubular junction (STJ) diameters are the characteristic lesions of aortic root aneurysm. The remodeling technique reduces STJ diameter and creates three neosinuses of Valsalva. Alternatively, the reimplantation technique reduces both annulus and STJ diameters to the detriment of aortic root dynamics. Although the remodeling technique is recognized as the most physiological valve-sparing procedure, aortic annulus dilation may jeopardize its results. A standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with the remodeling technique is suggested. Eighty-three patients underwent an elective aortic root remodeling procedure, either isolated (group 1, n=34) or combined with an external subvalvular aortic prosthetic ring annuloplasty (group 2, n=49). Preoperative aortic regurgitation was 1.59+/-1.1 (group 1) and 1.97+/-1.3 (group 2) (NS). The aortic annulus was more dilated in group 2 than in group 1 (27+/-2.77 mm vs 26.4+/-2.3 mm, p<0.01). Residual aortic regurgitation > or =grade II was the conversion criteria for aortic valve replacement. Operative mortality was 3.6% (n=3). Intraoperative conversion for valve replacement was 32.7% in group 1 (n=11) versus 4.2% in group 2 (n=2) (p<0.001). In group 1, preoperative annulus diameter was larger for converted than for valve-spared patients (27.6+/-1.7 mm vs 25.2+/-1.5 mm, p<0.02). In group 2, implanted aortic ring significantly reduced annulus diameter (20.6+/-1.8 mm) without significant aortic valve gradient (8.3+/-3 mmHg). Follow-up was 17.2+/-13.4 months (group 1) and 10.41+/-7.95 months (group 2). Reoperation for recurrent aortic regurgitation was 13% in group 1 (n=3) versus 4.2% in group 2 (n=2). Echocardiographic follow-up found residual aortic regurgitation < or =grade I in 17 patients in group 1 (90%) versus 43 patients in group 2 (95.5%) and of grade II in two patients in group 1 (10%) and two patients in group 2 (4.5%). The addition of external aortic prosthetic ring annuloplasty improves the remodeling technique's operative reproducibility and short-term results. Therefore, its use as a systematical adjunct to the remodeling procedure is suggested. However, further long-term evaluation comparing this valve-sparing procedure to composite graft replacement should define the best surgical strategy for aortic root aneurysm.