Ascending aortic aneurysm repair 44 years after Starr–Edwards caged-ball aortic valve replacement

Abstract

We report a case of ascending aortic aneurysm repair and redo aortic valve replacement with a bioprosthesis 44 years after aortic valve replacement with a Starr–Edwards metal caged-ball prosthesis. The patient presented with a moderately stenotic caged-ball valve and a 50-mm ascending aortic aneurysm on a routine follow-up transthoracic echocardiography. We replaced the valve with a bioprosthesis at the time of aortic repair as the patient wished to stop anticoagulation therapy. Intraoperatively, we found that the cloth covering of the cage was nearly completely destroyed.

INTRODUCTION

Metal caged-ball valve prostheses have been used since 1960 [1]. The longevity and long-term complications of these prostheses are unknown, with few cases reported on functional valves more than 30 years after implantation. We report a case of an ascending aortic aneurysm in a man with a functional Starr–Edwards (SE) caged-ball aortic valve prosthesis 44 years after implantation, but the cloth covering of the cage was nearly completely destroyed.

CASE

An asymptomatic 57-year-old man with a history of an aortic valve replacement (AVR) and patch enlargement of the aorta with an SE caged-ball prosthesis (Model 2320) for bicuspid aortic valve at the age of 14 years was referred for evaluation of an ascending aortic aneurysm. A routine transthoracic echocardiogram revealed an ascending aortic aneurysm measuring 50 mm. He had moderate aortic stenosis with the peak and mean gradient of 48 and 25 mmHg, effective orifice area of 1.48 cm² and ejection fraction of 65%. Risks and benefits of aneurysm repair, along with an option to exchange the mechanical valve with bioprosthesis, were discussed on multiple occasions. He elected to proceed with repair of the aneurysm and re-AVR with a bioprosthesis.

Upon reopening the sternum from caudad to cephalad, a dense adhesion between the ascending aorta to the sternum, which could not be dissected with Metzenbaum scissors, was encountered, and we believed that it was unsafe to dissect under high aortic pressure. Thus, total cardiopulmonary bypass via the right common femoral artery and vein and systemic cooling were initiated to decompress the aorta and prepare for possible circulatory arrest. The decompressed aorta allowed for further dissection, and resternotomy was completed without rupturing the aorta. The superior vena cava was cannulated with isolation using a tourniquet for retrograde cerebral perfusion, a retrograde cardioplegia catheter was placed into the coronary sinus and a left ventricular sump was inserted. Circulation was then arrested and retrograde cerebral perfusion initiated. Inspection revealed aneurysm involving the ascending transverse aortic arch and proximal transverse aortic arch. These were resected and replaced with a 30-mm woven Dacron graft using a running 4-0 polypropylene suture. Systemic circulation was reinitiated via the side arm of the Dacron graft, and femoral artery cannula was decannulated. The patient was rewarmed.

Attention was then turned to the aortic valve. An SE metal caged-ball valve (Fig. 1A and B) was carefully resected, and all the previous sutures and pledgets were removed. Of note, the cloth covering of the cage was almost completely worn out. After copious irrigation, rereplacement with a 27-mm Carpentier-Edwards PERIMOUNT Magna Ease (Edwards Lifesciences Corp., Irvine, CA, USA) was performed. The aortic graft was trimmed and sutured to the proximal ascending aorta with a 3-0 polypropylene running suture. The patient was weaned off cardiopulmonary bypass, and the chest was closed in a routine fashion. Bypass time was 198 min, and cardiac arrest time was 111 min. Circulatory arrest and retrograde cerebral perfusion time were 18 and 13 min with the lowest bladder temperature of 21.8°C. Pathology from the aneurysm revealed a slightly thickened intima without atherosclerosis, unremarkable medial elastin fibre and patchy dystrophic calcification of the adventitia. Postoperatively, the patient showed left hemiparesis (muscle strength 4/5), resulting from an embolic stroke to the distal middle cerebral artery and left the hospital on postoperative day 10 for rehabilitation. The patient recovered full strength within a month and has had a 1-year follow-up evaluation without residual symptoms.

Figure 1:

(A) The caged-ball valve in the aortic position. (B) An explanted caged-ball valve.

DISCUSSION

The SE caged-ball valve was first successfully implanted in 1960. Reported complications of the valve include thromboembolism, bleeding, endocarditis, paravalvular leak, aortic insufficiency, haemolysis and ball variance [1]. The patient did not have a definite indication for redo-AVR alone; however, replacement with a bioprosthesis was planned in conjunction with the aortic aneurysm repair due to the patient’s preference to stop lifelong anticoagulation. Intraoperatively, we found that the cloth cover on the cage was destroyed over time with near-complete disappearance, which implies not only that the thrombus but also the cloth covering of the cage may have been the source of embolism in this model. Our finding was consistent with a report by Warnes et al. in 1983 [2]. Thus, if a patient experiences multiple embolic strokes, regardless of anticoagulation control, the destruction of the cloth coating in these types of valve should be considered [3].

It has been previously suggested that ascending aortic aneurysm may be either a long-term result of the SE caged-ball valve or a progression of aortic dilation—often seen in patients with bicuspid aortic valve. Schmitto et al. [4] have recently reported ascending aneurysms under similar circumstances, both of which were detected and repaired 39 years after AVR with SE caged-ball valve. Pathology reports from index operations were unavailable in all reported cases. Further investigation is needed in these areas, specifically into the changes of the biomechanical forces and aortic wall after AVR [5].

CONCLUSION

Patients surviving decades after valve replacement require surveillance for aortic aneurysm. The cloth cover on the SE metal caged-ball valve may be destroyed over time.

Conflict of interest: Anthony L. Estrera is a consultant for WL Gore. The other authors declared no conflict of interest.