Aortic Allograft Valve Reoperation: Surgical Challenges and Patient Risks

The Sutureless Biological Bentall Procedure: A New Technique to Create a Modular Valve-Conduit Construct

The Perceval sutureless valve (Corcym, Saluggia, Italy) has been effectively adopted by surgeons for the treatment of degenerative aortic valve stenosis. Its simplified true sutureless implantation technique has proven useful for minimally invasive cases, but the use of Perceval as part of more complex root replacement has not previously been described. We present a novel technical modification to the manufactured biologic Bentall, called the sutureless biological Bentall. This technique allows for a true modular valve-conduit construction that will simplify future reintervention.

Transcatheter valve replacement: a revolution

Degenerative aortic stenosis is the most common valvular disease worldwide; however, its physiopathology remains poorly understood. Although, developments in prevention of this disease have remained relatively stagnant, the last decade has brought about innovative treatment options incorporating different percutaneous and surgical approaches. These advances have allowed physicians to offer relief to high-risk patients, previously deemed nonsurgical. Increasingly, there is a shift toward offering percutaneous valve replacement to moderate and low-risk patients with aortic stenosis. Enthusiasm for a new treatment option must always be tempered by caution; as defining appropriate patient selection is essential to achieve optimal outcomes.

Perspective. Reoperative Bentall: choice of conduits

The Bentall procedure represents the gold standard in the treatment of patients requiring aortic root replacement. The most common indications for redo Bentall are structural degeneration or graft infection. Redo aortic root replacement can be performed with low perioperative morbidity and death. The choice of the best conduit is still up for debate but is mandatory to guarantee the best and most durable option for the patient. New options are available to reduce mortality in older or fragile patients and can modify the conduit choice.

Those who do not remember the past are condemned to repeat it

Transcatheter aortic valve replacement (TAVR) for aortic valve stenosis has rapidly progressed from its initial application in the inoperable or high-risk patients to those determined to be intermediate and low risk. It is our concern this has occurred without adequate knowledge or examination of the long-term durability of TAVR valves and the impact on subsequent aortic valve surgery, should it be required. In this editorial, we provide insight and reflect upon lessons learned from past surgical techniques and their subsequent abandonment.

Outcomes of aortic root replacement after previous aortic root replacement: the "true" redo root

BACKGROUND

Aortic reoperations are technically challenging. This study evaluated outcomes after "true" redo root replacement (previous full root replacement) stratified by cause of prosthesis failure.

METHODS

Data were compared for 793 patients who underwent a first-time sternotomy (de novo group) and 120 patients who had previously undergone full aortic root replacement (redo group), of which 76 underwent reoperation due to structural valve deterioration (degenerative group), and 44 due to endocarditis (infection group).

RESULTS

Overall mortality was 4% (n = 28) in the de novo group and 5% (n = 6) in the redo group (p = 0.43) (degenerative group, 3%, infection group, 9%; p = 0.19). The infection group had an increased incidence of renal failure, sternal infection, prolonged ventilation, reoperation for bleeding, multisystem failure, and sepsis, and an increased hospital length of stay. The degenerative group and the de novo group had a similar risk of perioperative death and major complications. The 5-year survival was 86.3% ± 1.3% for the de novo group and 77.3% ± 4.6% for the redo group (p ≤ 0.01; degenerative, 86.3% ± 5%; infection, 65.3% ± 7.7%; p < 0.01; p = 0.98 for de novo vs degenerative). Multivariate analysis demonstrated that reoperation for degenerative failure did not increase the risk of perioperative or late death.

CONCLUSIONS

Redo aortic root replacement can be performed with low perioperative morbidity and death. The presence of infection increases the risk of complications and worsens survival. However, redo root replacement for degenerative failure can be performed with similar short-term complication risk and midterm survival as de novo root replacement.

Sutureless Perceval aortic valve replacement in aortic homograft

We report a case of aortic valve replacement with a sutureless valve in a degenerated aortic homograft. This technique allows rapid aortic valve replacement in a heavily calcified aortic root. It avoids the problems of postoperative prosthetic disinsertion frequently encountered after aortic valve replacement in a calcified annulus. It is particularly suitable in redo procedures for homograft degeneration. It avoids performing a redo Bentall operation with its known morbidity.

Failing stentless aortic valves: redo aortic root replacement or valve in a valve?

OBJECTIVES

Reoperation for failing stentless aortic valve replacement is a technically demanding procedure that has traditionally been tackled in one of two ways: either root replacement or the more conservative option of implanting a stented valve within the valve. We sought to determine the relative operative risks, follow-up status and medium to long-term survival of these two methods.

METHODS

We conducted a retrospective review of a single surgeon's experience of the two techniques over a 10-year period from 2000 to 2010. Excluding cases of active endocarditis, 110 patients were identified, of which 65 underwent 'valve-in-valve' procedures ('Group A') and 45 had redo root replacement ('Group B'). The most common bioprostheses reoperated were homografts (roots or subcoronary implants) and Toronto Stentless Porcine Valves. Aortic valve replacement alone was performed in 68% in Group A and 64% in Group B, with males comprising 75% of Group A and 82% of Group B. Average ages were 61.5 ± 14.2 years and 61.9 ± 12.1 years, respectively.

RESULTS

Operative and cardiopulmonary bypass durations were significantly greater for redo root procedures and correspondingly, postoperative complications were more common. Thirty-day mortality after valve-in-valve replacement was 3%, and after redo root replacement it was 11%. Despite significantly higher transvalvular gradients in Group B, the symptomatic status was equally good at 2 months, 1 year and last follow-up. At an average interval of 5.1 ± 2.7 years for Group A, survival was 83% vs 76% at 7.3 ± 2.9 years for Group B. There have been two reinterventions in Group A and 3 in Group B. Only one valve-in-valve patient has developed a paraprosthetic leak.

CONCLUSIONS

This retrospective review has confirmed our hypothesis that where both root diameter permits and satisfactory debridement can be performed, valve-in-valve replacement is the more conservative surgical strategy for stentless aortic valve replacement revision. Although transvalvular gradients on echocardiography are significantly higher with the introduction of a stented prosthesis, medium-term outcomes in terms of symptomatic status, late complications and reintervention rate were non-inferior. We await the medium-term results of transcatheter aortic valve implantation for the same indication with interest.

Total calcification of an aortic homograft used as aortic root replacement

A 66-year-old man presented with total calcification of a homograft used as aortic root replacement approximately 10 years previously. Reoperation consisted of complete dissection of the homograft and en-bloc replacement with a mechanical conduit. Despite careful dissection the right coronary ostium was disrupted requiring reconstruction by interposition of a saphenous vein segment. Reoperation for failure of homografts used as aortic root replacement represents a major technical challenge.

Aortic reoperation after freestanding homograft and pulmonary autograft root replacement

BACKGROUND

Human allografts and pulmonary autografts offer many advantages as an aortic valve and root substitute. The progressive degeneration of the aortic allograft and the pulmonary autograft has been seen as an important disadvantage, and the need for a reoperation has been perceived as challenging and risky for the patients.

METHODS

Between March 1992 and October 2009, 53 consecutive patients (mean age 50 ± 13 years; 38 male), who had a previous aortic root replacement, underwent redo surgery for failure of the aortic homograft (n = 42) or the pulmonary autograft (n = 11). The median follow-up (available for 47 of 51 patients) was 44 months.

RESULTS

Structural valve deterioration was the main indication for reoperation on the homograft (86%), with an earlier presentation in patients who received homografts from donors more than 55 years old. Failure of the pulmonary autograft occurred primarily because of severe aortic regurgitation predominantly due to dilation of the autograft (n = 5) and autograft valve prolapse (n = 5). The total in-hospital mortality was 3.8% (n = 2). No deaths occurred among patients who previously underwent a Ross procedure. The course was complicated in 25 cases (48%). The cumulative 1-year, 5-year, and 8-year survival rates were 92%, 90%, and 77%, respectively. No late deaths were encountered after reoperation on the pulmonary autograft (maximum follow-up 218 months). Freedom from reoperation (excluding early in-hospital operation) for recurrent aortic valve or root pathology was 97% at 8 years.

CONCLUSIONS

Reoperation after freestanding homograft and pulmonary autograft root replacement can be accomplished safely. The total postoperative morbidity rate is still high.

Re-operations for aortic allograft root failure: experience from a 21-year single-center prospective follow-up study

OBJECTIVE

The study aims to report results of re-operations after aortic allograft root implantation.

METHODS

All consecutive patients in our prospective allograft database, who underwent aortic allograft root implantation, were selected for analysis, and additional information for patients who subsequently underwent re-operation was obtained from hospital records.

RESULTS

From 1989 to 2009, 262 aortic allograft root implantations were performed. Thirty-day mortality was 5.7%. During follow-up, 69 patients died. The actuarial survival was 77.0% (95% confidence interval (CI) 71-83%) after 10 years, and 65.1% (95% CI 57-74%) after 14 years. A total of 52 patients required re-operation. The actuarial freedom from allograft re-operation was 82.9% (Standard Error (SE) 2.9%) after 10 years and 55.7% (SE 5.7%) after 14 years. The actuarial median time to re-operation was 14.8 years. The indications for re-operation were structural valve dysfunction in 46 patients, endocarditis in two patients and non-structural valve dysfunction in four patients. The re-operations included 23 aortic valve replacements (mechanical prostheses 20 and bioprostheses 3), 27 aortic root replacements (mechanical conduits 21, aortic allografts five, and biological conduit one), one trans-apical valve implantation and one primary closure of a false aneurysm. The additional procedures were mitral valve repair (N = 5), mitral valve replacement (N = 1), ascending aortic replacement (N = 5), and coronary artery bypass grafting (CABG) (N = 4; in two patients unforeseen). Thirty-day mortality after re-operation occurred in two patients (3.9%). Five patients died during follow-up. The survival after re-operation was 87.1% (SE 5.5%) after 1 year and 79.3% (SE 7.4%) after 9 years.

CONCLUSIONS

Re-operations after aortic allograft root implantation will be required in a substantial and growing number of patients. These re-operations, although technically demanding, can be performed with satisfying results.