Present status of reconstructive surgery for aortic valve disease

Which Aortic Valve Can Be Surgically Reconstructed?

Purpose of Review

Preservation or repair of the aortic valve has evolved dynamically in the past 20 years. It leads to a high freedom from valve-related complications if an adequate valve durability can be achieved; it may possibly also improve survival. To date, little structured information is available about which valves can be repaired and which should better be replaced.

Recent Findings

For surgical decision-making, the size of the aortic root is important and the anatomy of the aortic valve must be considered. In the presence of root aneurysm, most tricuspid and bicuspid aortic valves can be preserved. In aortic regurgitation and normal aortic dimensions, the majority of tricuspid and bicuspid aortic valves can be repaired with good long-term durability. In bicuspid aortic valves, the morphologic characteristics must be taken into consideration. Unicuspid and quadricuspid aortic valves can be repaired in selected cases. Generally, cusp calcification is a sign of a poor substrate for repair; the same is true for cusp retraction and cusp destruction due to active endocarditis. They are associated with limited valve durability.

Summary

Using current concepts, many non-calcified aortic valves can be repaired. Modern imaging, in particular three-dimensional transesophageal echocardiography (TEE), should be able to define repairable aortic valves with a high probability.

Aortic Valve Reconstruction: Midterm Results from Central Chest Hospital

From September 1994 to September 1999, 50 patients underwent successful aortic valve reconstruction. Four were lost to follow-up, there were 2 early and 2 late deaths. The remaining 35 males and 11 females (mean age, 39.1 years) were followed up for 1 to 61 months (mean, 30.75 months). Most had rheumatic disease (27), the others had infective endocarditis (16) or degenerative disease (3). There was isolated aortic valve disease in 22 cases, double-valve disease in 16, triple-valve disease in 7, and 1 other. Preoperative aortic regurgitation was severe in most cases and the mean ejection fraction was 55.3%. Surgical procedures included subcommissural annuloplasty (14), cusp thinning (13), commissurotomy (10), and free-edge unrolling (10). Cusp extension with autologous pericardium was performed in 9 patients and aortic valve replacement with autologous pericardium in 22. Nine patients needed aortic valve replacement at a mean of 15.8 months postoperatively. The other 33 patients experienced marked improvements in aortic valve function. Aortic valve reconstruction is recommended in selected patients but reoperation remains an important problem. Long-term follow-up is needed to assess the role of this operation.

Outcomes of aortic valve repair according to valve morphology and surgical techniques

OBJECTIVES

The aim of this study was to assess the impact of aortic valve morphology and different surgical aortic valve repair techniques on long-term clinical outcomes.

METHODS

Between February 2003 and May 2010, 216 patients with aortic insufficiency underwent aortic valve repair in our institution. Ages ranged between 26 and 82 years (mean 53 ± 15 years). Aortic valve dysfunctions, according to functional classification, were: type I in 55 patients (25.5%), type II in 126 (58.3%) and type III in 35 (16.2%). Sixty-six patients (27.7%) had a bicuspid valve. Aortic valve repair techniques included sub-commissural plasty in 138 patients, plication in 84, free-edge reinforcement in 80, resection of raphe plus re-suturing in 40 and the chordae technique in 52. Concomitant surgical procedures were CABG in 22 (10%) patients, mitral valve repair in 12 (5.5%), aortic valve-sparing re-implantation in 78 (36%) and ascending aorta replacement in 69 (32%). Mean follow-up was 42 ± 16 months and was 100% complete.

RESULTS

There were six early deaths (2.7%). Overall late survival was 91.5% (18 late deaths). There were 15 (6.9%) late cardiac-related deaths. NYHA functional class was ≤ II in all patients. At follow-up, 28 (14.5%) patients had recurrent aortic insufficiency ≥ grade II. The freedom from valve-related events was significantly different between bicuspid and tricuspid valve implantation (P < 0.01), between type I + II and type III (P < 0.001) dysfunction and between the chordae technique and plication, compared to free-edge reinforcement (P < 0.01). Statistically-significant differences were found between patients who underwent aortic valve repair plus root re-implantation, compared to those who underwent isolated aortic valve repair (P = 0.02).

CONCLUSIONS

Aortic valve repair including aortic annulus stabilization is a safe surgical option with either tricuspid or bicuspid valves; even more so if associated with root re-implantation. Patients with calcified bicuspid valves have poor results.

Is repair of aortic valve regurgitation a safe alternative to valve replacement?

OBJECTIVE

To assess outcome of valve repair in patients with aortic valve regurgitation with emphasis on incidence and risk of reoperation.

METHODS

We retrospectively reviewed 160 consecutive patients (127 men) who underwent aortic valve repair between 1986 and 2001. Ages ranged from 14 to 84 years (mean 55 +/- 17 years). Patients were categorized according to the main etiology of valve disease; 63 patients (39%) had annular dilation leading to central leakage, 54 (34%) had bicuspid valve, 34 (21%) with tricuspid valve had cusp prolapse, and 9 (6%) had cusp perforation. Repair methods included commissural plication (n = 154, 96%), partial cusp resection with plication (n = 47, 29%), resuspension or cusp shortening (n = 44, 28%), and closure of cusp perforation (n = 10, 6%).

RESULTS

There was 1 early death (0.6%). Two patients required re-repair of the aortic valve during initial hospitalization. During a mean follow-up of 4.2 years, there were 16 late deaths. Overall, 16 of 159 hospital survivors had late reoperation on the aortic valve (mean interval 2.8 years) without early mortality. Risks of reoperation on the aortic valve were 9%, 11%, and 15% at 3, 5, and 7 years, respectively.

CONCLUSIONS

Aortic valve repair can be performed with low risk and excellent freedom from valve-related morbidity and mortality. Late recurrence of aortic valve regurgitation led to reoperation in 8.8% of patients, but mortality associated with subsequent procedures is low. Aortic valve repair appears to be a good option for selected patients, particularly young patients who wish to avoid chronic anticoagulation with warfarin.

Creating a bicuspid valve from the aortic wall: a new surgical approach on aortic valve disease (in vitro study)

We described a new technique (called 'bicuspidization'), which is performed by using autogenous material, without replacement of the aortic valves for the surgical treatment of aortic stenosis and/or insufficiency and tested it in in vitro sheep model. Different stress conditions were simulated by applying three different flow patterns (hemodynamic challenge tests) successively by using a centrifugal pump. It was demonstrated that the competency of the new bicuspid valves was excellent (zero insufficiency). There was a 10-11 mm Hg-increase on trans-valvular gradient comparing the normal hearts. The autogenous bicuspid valve has not blocked the way of the coronary flow in the closed position.

Repair of moderate aortic valve lesions associated with other pathology: an 11-year follow-up

OBJECTIVES

The presence of moderate aortic valve (AV) lesions associated with other pathologies that require surgery presents a problem since ignoring or replacing the valve seems unsatisfactory. AV repair can be an attractive alternative if shown to perform satisfactory.

METHODS

To evaluate this possibility, all consecutive AV patients who underwent operation between July 1988 and July 1999 were reviewed. Out of 1764 AV patients, 239 (14%) underwent repair and 86 (study group) had moderate lesions associated with mitral (73), tricuspid (33), coronary disease (5) and others (8). Mean age was 28 years (range 2--66); 78% were rheumatic, 71% were in sinus rhythm and 71% in NYHA class III--IV.

RESULTS

There were seven hospital deaths (8%) and three patients were lost to follow-up (95% complete). Late mortality was 8% and 10-year actuarial survival was 86 +/- 4.5% (excluding hospital mortality). There were four (5%) embolic events (actuarial freedom 94 +/- 3.5%). Twenty-one patients required reoperation with two mortalities. The AV was not touched in five patients. In the remaining 16, the AV was replaced. Only one patient had isolated AV replacement while in all others, additionally, the mitral, tricuspid, or both required surgery. All reoperated patients had rheumatic etiology. Actuarial freedom from AV dysfunction at 8 years was 68 +/- 7.5%.

CONCLUSIONS

Repair of associated moderate AV lesion is worth considering even in a predominantly young rheumatic population.

Repair of the truncal valve and associated interrupted arch in neonates with truncus arteriosus

OBJECTIVE

Truncal valve regurgitation and interrupted aortic arch have frequently been identified as risk factors in the repair of truncus arteriosus. We wished to examine these factors in the current era including the impact of truncal valve repair.

METHODS

Between January 1992 and August 1998, 50 patients underwent surgical repair of truncus arteriosus. Their ages ranged from 2 days to 6 months (median, 2 weeks). Nine patients had associated interrupted aortic arch. Of the 14 patients (28%) in whom truncal valve regurgitation was diagnosed preoperatively, 5 had mild regurgitation, 5 had moderate regurgitation, and 4 had severe regurgitation. Five underwent truncal valve repair and 1 underwent homograft replacement of the truncal valve with coronary reimplantation.

RESULTS

The actuarial survival was 96% at 30 days, 1 year, and 3 years. There were no deaths in patients with associated interrupted aortic arch. The 2 deaths in the series occurred in patients with truncal valve regurgitation, neither of whom underwent repair. Postoperative transthoracic echocardiography in patients who underwent valve repair showed minimal residual valvular regurgitation. None of the patients has required reoperation because of truncal valve problems or aortic arch stenosis at a median follow-up of 23 months (range, 1-60 months). Conduit replacement has been done in 17 patients (34%) after a mean duration of 2 years. The freedom from reoperation for those who had an aortic homograft was 4 years and for those who had a pulmonary homograft was 3 years.

CONCLUSION

Despite the magnitude of the operation, excellent results can be achieved in complex forms of truncus arteriosus. In the current era interrupted aortic arch is no longer a risk factor for repair of truncus. Aggressive application of truncal valvuloplasty methods should neutralize the traditional risk factor of truncal valve regurgitation.

Intermediate-term durability of bicuspid aortic valve repair for prolapsing leaflet

OBJECTIVE

To determine the durability of repair of a bicuspid aortic valve with leaflet prolapse, and to identify factors associated with repair failure.

METHODS

From November 1988 to January 1997, 94 patients with a bicuspid aortic valve and regurgitation from leaflet prolapse had aortic valve repair. In 66 patients, the repair employed triangular resection of the prolapsing leaflet. The remainder underwent mid-leaflet plication of the prolapsing leaflet. Mean age was 38 +/- 10 years and 93% were male. Median follow-up was 5.5 years (range 0.2-9 years). Factors associated with aortic valve competence and durability were identified by multivariable logistic and hazard function analyses.

RESULTS

Early valve competence was more difficult to achieve in patients with large, poor functioning ventricles (P = 0.02). Aortic valve reoperation was necessary in 12 patients that included three re-repairs and nine aortic valve replacements. Freedom from reoperation was 95, 87 and 84% at 1, 5 and 7 years, respectively. The instantaneous risk of reoperation was highest immediately after operation, and fell rapidly to approximately 2% per year and less after 2 years. The only risk factor identified was the presence of residual aortic regurgitation (trace to mild in 35 cases) on immediate intraoperative post-repair transesophageal echocardiography. Late aortic regurgitation did not progress detectably across time (P = 0.3). There were no deaths, early or late.

CONCLUSION

Bicuspid aortic valve repair for prolapsing leaflet is a safe procedure with good intermediate-term outcome. However, any residual aortic regurgitation jeopardizes repair durability and initial repair achievement is more difficult in patients with dilated, poor functioning ventricles.

Aortic valve reconstruction associated to ascending aorta tubular graft replacement in aortic incompetence by annuloaortic ectasia

OBJECTIVE

Aortic valve incompetence associated with severe aortic ectasia is usually treated by aortic valve and ascending aorta replacement. In cases of isolated aortic ectasia or in Type A aortic dissection the valve is often normal and the incompetence is just due to annular dilatation. Such conditions lead to the application of various valve-sparing surgical techniques, as described by Senning et al., showing the advantages of preservation of the native valve, but the disadvantage of a high technical complexity and a high incidence of recidivation.

METHODS

We describe a valve-sparing surgical procedure, which has the advantage of a direct and simple approach together with satisfying mid-term results. After the aortic bulb has been fully transected, the excessive wall tissue is resected by two or three triangular excisions just above the valve commissures. Wall excision was indicated in those patients with an aortic diameter exceeding 65 mm at the sino-tubular junction. Tissue excision should not exert tension on to the coronary ostia or excessively reduce aortic diameter. Three external Teflon strips, overriding each other, are placed around the aortic bulb and are included in the direct suture of the edges of the triangular excisions. They are fixed by a running suture over the free border of the bulb. Aortic valve commissures are resuspended when needed. In this way, the aortic bulb, with a competent valve, is wrapped in a prosthetic and inextensible graft. The aortic continuity is then re-established with the interposition of a tubular dacron graft.

RESULTS

From April 1990 to December 1995, 21 patients (mean age 48 years, range 32-70) scheduled for surgery for aortic valve incompetence associated with annuloaortic ectasia were treated with this technique. In one patient the procedure failed to achieve a satisfying valve competence and the valve was replaced. In another case a prolapse of the non-coronary cusp required reoperation with aortic valve replacement, without further complications. At follow-up time (mean 42 months, range 18-78), all patients were well and healthy, with control echoes showing no residual valve incompetence and with invariate bulb diameters at every successive examination.

CONCLUSIONS

Our experience shows that this new valve-sparing approach allows safe and persistent correction of aortic valve incompetence and annuloaortic ectasia although longer term follow up is needed.

Clinical and echocardiographic follow-up after aortic valve reconstruction with bovine or autologous pericardium

Eighty-six patients, mean age 29 +/- 15 years, underwent aortic valve reconstruction with bovine or autologous pericardial tissue. Mean clinical follow-up was 35 months. Echocardiographic data were assessed in 65 patients with follow-up > or = 6 months. There were two in-hospital and three late deaths. Warfarin was not given, and no thromboembolic events occurred. Five (6%) patients needed reoperation because of severe aortic regurgitation. Peak aortic valve gradients remained low (26 +/- 14 mm Hg for the bovine group and 16 +/- 16 mm Hg for the autologous group). One patient is awaiting surgery for aortic stenosis after 76 months. Leaflet thickening at latest follow-up was marked in six (9%) patients. Left ventricular dimensions normalized postoperatively and showed only insignificant increase during follow-up. This technique is a promising alternative to valve prosthesis in selected patients; however, longer follow-up is necessary to assess long-term results.

Aortic Valve Repair: Initial Experience from Central Chest Hospital

From September 1994 to September 1995, 24 patients underwent aortic valve repair in our hospital. It was successful in 21 cases and failed in the other 3 patients. There were 13 males and 8 females. The age range was between 20 and 60 years with a mean age of 35.6 years. Follow-up was complete in all patients. The mean follow-up time was 6.2 months, ranging from 3 weeks to 13 months. Aortic valve lesions in these patients were caused by rheumatic disease (17), endocarditis (2), congenital (1), and degenerative (1) conditions. The most common anatomic lesions were cusp thickening, cusp retraction, commissural fusion, and calcification. Most of the patients had other procedures along with aortic valve repair, including mitral valve repair (13), mitral valve replacement (3), tricuspid annuloplasty (2), and tricuspid repair (1). The most common surgical procedures were subcommissural annuloplasty, commissurotomy, cusp thinning, and free-edge unrolling. Cusp extension, using autologous pericardium was performed in 3 cases. Almost all of the patients needed multiple procedures (mean 3.4 procedures per patient). There was no hospital mortality nor valve-related complication in our series. No patient had a thromboembolic problem. Postoperative echocardiography showed an improvement in the mean aortic valve area and the pressure gradient across the aortic valve in patients with stenosis, and a decrease in the severity of aortic regurgitation in those with regurgitant lesions. We concluded that early results of aortic valve repair were encouraging and may be a good alternative treatment, especially in certain groups of patients.

Osteogenesis imperfecta and cardiovascular diseases

Aortic and mitral valvular insufficiency in patients with osteogenesis imperfecta result from an underlying defect in connective tissue formation. The surgical cases reported in the literature have included mechanical and bioprosthetic valve replacement as well as attempts at repair and reconstruction. Despite complications related to bleeding and tissue friability, acceptable results have been obtained. In this report, we describe aortic regurgitation secondary to osteogenesis imperfecta treated with homograft replacement. The unique cardiovascular complications of osteogenesis imperfecta and the available therapeutic options are discussed in light of the literature review.

Repair of insufficient bicuspid aortic valves

A technique for the repair of bicuspid aortic valves that includes resection of the flail segment of the prolapsing leaflet, annuloplasty, and resection of the raphe, when present, has been reported. To assess the efficacy of this technique in the repair of insufficient bicuspid aortic valves, the results in 72 consecutive patients were assessed. The mean age of the patients was 39 +/- 11 years; 94% were male. Fifty-six patients (78%) underwent isolated aortic valve repair, 9 (12.5%) underwent aortic and mitral valve repair, and 7 (9.7%) had other associated procedures. All patients underwent leaflet resection, including 35 (48%) at the raphe. The mean aortic occlusion time was 39 +/- 12 minutes. There were no operative deaths. The severity of aortic insufficiency, as assessed by Doppler echocardiography (graded from 0 to 4) preoperatively and intraoperatively and at late follow-up, was 3.6 +/- 0.6, 0.4 +/- 0.4, and 0.9 +/- 0.8, respectively, with a p value of < 0.0001 for the latter two values versus the preoperative one. There have been no postoperative deaths. Patients did not receive anticoagulation treatment and there were no strokes or episodes of endocarditis. Six patients have required reoperation; 3 underwent repeat repair. The Kaplan-Meier freedom from aortic valve reoperation probabilities at 12 and 24 months were 94% and 89.5%, respectively. We conclude that valvuloplasty for insufficient bicuspid aortic valves is technically safe, is associated with a low incidence of recurrent insufficiency, and has been associated with no other valve-related complications.

New Trends in Aortic Valve Surgery: A critical Review of Standard Prosthesis v. Stentless Replacement and Repair

Different alternatives for the surgical treatment of aortic valve disease have been recently introduced. All consecutive patients who underwent aortic valve surgery between July 1988 and March 1994 were reviewed. There were 674 patients with a mean age of 32.4 years, mean preoperative functional class of 2.82, and rheumatic etiology in 59% of the cases. The patients were divided into 3 groups: Group I. standard aortic valve replacement with biological and mechanical prosthesis ( n = 313); Group II. stentless aortic valve replacement using homograft, pulmonary autograft and reconstruction with pericardium ( n = 145); and Group HI. aortic valve repair ( n = 216). The hospital mortality was 6.07% for the standard, 0.68% for the stentless, and 3.70% for the repair. Total follow-up was 1,304.75 patient years with a mean of 21.93 months. The actuarial survival at 66 months excluding hospital mortality was 85.24 ± 4.59% in the standard replacement, 92.63 ± 4.03% in the stentless, and 91.20 ± 3.02% in the repair group. The highest incidence of reoperation corresponded to the repair group with an actuarial freedom from reoperation of 74.26 ±7.03%, v. 92.52 ±4.52% in the standard and 85.11 ± 6.71% in the stentless group. There were no thromboembolic events in the isolated aortic valve survivors in both the stentless and repair groups and 1.28% patient years in the standard. We conclude that both the stentless aortic valve replacement and the aortic repair represent a good alternative v. standard replacement, especially for those young rheumatic patients in which anticoagulation and durability of the prosthesis is still a problem.