Coronary reimplantation in aortic root replacement: a method to avoid tension

Aortic Root Reconstruction with a New Dacron Graft Featuring Prefabricated Coronary Side Branches: Lessons Learned from the Cabrol Procedure

BACKGROUND

Coronary button reimplantation can represent a technical challenge of aortic root reconstruction that can be associated with significant morbidity and mortality. With the goal of simplifying coronary reimplantation and reducing the incidence of related complications, we designed a new Dacron graft with prefabricated coronary branches to minimize coronary artery mobilization and prevent the potential mechanical complications of reattachment to the body of the graft.

METHODS

Between June 2010 and May 2012, we implanted the graft in eight patients (six males, two females) ranging in age from 42-68 years (mean, 54 years). Six procedures were modified Bentall reconstructions, and two procedures were valve-sparing root replacements using the reimplantation technique.

RESULTS

There were no complications and no morbidity or mortality related to coronary reattachment. All patients were alive and doing well at a mean follow-up of 26 months (range, 17-38 months). At an extended mean follow-up of 42 months (range, 25-56 months), one patient died of stroke-related complications. No radiologic or clinical evidence of impairment of coronary perfusion was identified in any patient.

CONCLUSIONS

The use of this new graft model may simplify the technique of root reconstruction and potentially lower the incidence of mechanical complications related to coronary button reimplantation.

Coronary reimplantation in aortic root surgery: the trapdoor technique for adults

Coronary ostial reimplantation during aortic root replacement is a key stage of the operation. The "button technique" is the most used method, but there are still concerns about the incidence of coronary pseudoaneurysm formation, bleeding, and distortion of the coronary geometry. We describe how we adapted the trapdoor technique, commonly used in the arterial switch operation in children, to reimplant the coronary ostia in adult patients undergoing aortic root replacement.

Aortic root replacement with absent left-main coronary artery: how to do it

Aortic root replacement in patient with a coronary artery anomaly can be challenging. We describe aortic root replacement in a patient with annuloaortic ectasia and coarctation, who had an absent left main coronary artery. There were separate origins of the left anterior descending and left circumflex coronary arteries from the aorta. The technical modification employed in this case is discussed.

Re-creation of a sinuslike graft expansion in Bentall procedure reduces stress at the coronary button anastomoses: A finite element study

OBJECTIVE

The Bentall procedure is routinely performed using a straight Dacron graft coupled with a mechanical or a biologic valve. Creation of coronary ostia buttons significantly reduces tension on the coronary anastomoses and consequently the incidence of pseudoaneurysm formation. We sought to evaluate if the use of a specifically designed graft with a sinuslike root portion that bulges out upon pressurization can reduce stress on coronary anastomoses. A finite element computer-assisted stress analysis was used to simulate these 2 different anatomic conditions and to analyze tension in computed tomographic scans obtained from patients operated on with either a straight or a "sinus" graft.

METHODS

Theoretical models of the procedures with finite element computer-aided design technique were created and tested with the Abaqus Standard Suite, verifying the pattern of stress and strain when a uniform pressure of 200 mm Hg was applied to the model. Next, using SimpleWare SCanIP technology, computed tomographic scans of patients having both procedures were used to obtain finite element mesh models. A uniform pressure of 200 mm Hg was then applied, and the distribution of stress and strain was analyzed.

RESULTS

Von Mises Charts are color-coded, computational, 3-dimensional stress-pattern graphics that show that stress around the coronary ostia in a standard straight graft model is nearly double compared with the model with sinuses (peak stress of 0.4 Mpa for the sinus model and 0.7 Mpa for the traditional straight model). In computed tomographic scan reconstructions, the stress contour is uniformly distributed in the graft with sinuses, and it is highly concentrated around the ostia in the straight graft. Accordingly, higher-peak stress values are registered in the straight configuration (1.8 MPa for the sinus graft and 2.5 MPa for standard graft).

CONCLUSION

Even though finite elements technique is necessarily a simplification of a real biologic environment, all tests seem to indicate that a standard tubular graft gives a higher stress to coronary sutures. Relieving the stress on the coronary anastomoses by using a graft with preformed sinuses of Valsalva may decrease the incidence of postoperative complications such as bleeding and late pseudoaneurysm formation.

The Valsalva graft in aortic valve repair and replacement

Presentation of the use of the new Valsalva graft that incorporates sinuses of Valsalva: its use is mostly recommended for the reimplantation type of valve sparing procedure where it combines the advantages of proper anatomical reconstruction with those of annular stabilization. Its advantages when used in the remodeling technique or in a classical Bentall procedure are also shown. The problem of graft sizing and of proper geometrical reconstruction of the aortic root are addressed.

One-year appraisal of a new aortic root conduit with sinuses of Valsalva

OBJECTIVES

We evaluate the clinical results 1 year after an anatomic reconstruction of the aortic root in which we used a specifically designed aortic root prosthesis that incorporates the sinuses of Valsalva.

MATERIAL AND METHODS

The new aortic Dacron prosthesis has a proximal portion in the Dacron conduit that expands on implantation, creating pseudosinuses. During a 12-month period, 28 patients (mean age 59 +/- 14 years) underwent a Bentall operation (12 cases), a remodeling procedure (7 cases), and a reimplantation procedure (9 cases) with the use of a new aortic root conduit. All patients had aortic root aneurysm with an anatomically normal (for the valve-sparing procedure) or diseased aortic valve (for the Bentall operation). Five patients had aortic dissection and 5 had Marfan disease. The mean follow-up was 6 +/- 3 months. All patients underwent postoperative transesophageal and transthoracic echocardiographic studies.

RESULTS

All patients survived and were in good clinical condition at the latest follow-up. Postoperative echocardiography showed a marked reduction in ventricular volumes in all patient groups (P <.0005). In the Bentall group the new prosthesis appeared to reduce the tension on the coronary ostial sutures. In patients undergoing both types of valve-sparing procedures a similar normal anatomy of the aortic root was reconstructed. In the reimplantation group the anulus was smaller than in the remodeling group (P =.01). Patients undergoing the reimplantation procedure had less bleeding and a lower incidence of residual valve insufficiency.

CONCLUSIONS

The new aortic root prosthesis allowed the reconstruction of the aortic root anatomy in all types of surgical techniques with low postoperative morbidity.

Aortic root replacement with coronary button re-implantation: low risk and predictable outcome

OBJECTIVE

Cardiac morbidity in aortic root replacement often occurs through myocardial ischaemia. We analyzed a 10 year experience of all root replacement operations by one surgeon to determine the incidence of coronary complications and risk factors for early mortality.

METHODS

The study included 140 aortic root replacement patients (aged from 2 to 77 years; median 53 years) operated between 1988 and 1999. Thirty-four had Marfan's syndrome. Eleven had root infection requiring homograft replacement. Nineteen were reoperations (14%). Concomitant procedures were arch replacement (16), mitral replacement (five), and coronary bypass (22). Mobilization and reimplantation of the coronary ostia was performed in 139 patients. We performed the distal graft anastomosis before right coronary reimplantation.

RESULTS

There were eight hospital deaths (5.7%). Risk factors for hospital mortality were: preoperative NYHA class IV, shock, LVEF < or =30%, acute dissection, concomitant mitral valve replacement, pump time > or = 60 min, reentry for bleeding, and postoperative renal failure. Neither myocardial ischaemia nor right ventricular dysfunction contribute to mortality. There were 18 late deaths with an actuarial survival of 79% at 5 years. There were no late coronary false aneurysms.

CONCLUSIONS

Button reimplantation with the sequence described is predictable and safe. Wrap-around is unnecessary. Coronary aneurysms have been eliminated.