Research News From Dr. Anne Child MD FRCP
Personalised External Aortic Root Support (PEARS), a new external ‘wrap’ technique for treatment of ascending aortic aneurysm, is gaining support worldwide. Its benefits include low surgical risk and rapid recovery time which provide more choice for Marfan syndrome patients. The choice of surgical technique should nevertheless be discussed with the cardiologist and surgical team on an individual basis. The technique is available in 25 surgical centres worldwide, including 8 in the UK. Mr Tal Golesworthy, the first patient to benefit from this technique, has provided a recent update which is summarised below.
240 patients have been treated, including 163 males and 77 females, ranging in age from pre-teens to the 70s. The first patient treated is doing well at 15 years post-operative; a further 18 patients are 10 years post-operative; while 42 patients are 5 years post-operative. Marfan syndrome accounts for the majority of patients, numbering 147, with 13 patients having mitral valve repair at the same time. Further diagnoses include Loeys-Dietz syndrome (12), Bicuspid Aortic Valve disease (18), unknown cause aortic aneurysm (15), ACTA2 (2), aortic valve disease (19) and congenital structural heart disease (4).
Two patients had coronary angiograms and the openings of the coronary arteries appeared normal, and the walls of the coronary arteries appeared smooth.
Incorporation of the ExoVasc® implant
One patient died of an unrelated event 4½ years after PEARS surgery, and microscopic examination of his aortic wall showed that the textile implant had been fully incorporated into the wall of the aorta.
Repair of the middle layer of the aorta inside the implant
In Marfan syndrome patients, where Fibrillin deficiency is the prime cause of aortic wall weakness, the middle layer of the aorta inside the implant appears to return to normal appearance under the microscope. This is thought to be due to relieving the tensile load (the extra stretchiness) from the middle layer, by wrapping the aorta.
Recovery of leakage of the aortic valve
In 12 cases where aortic leakage (regurgitation) was reported prior to surgery, after implantation of the mesh, echocardiogram exam reported reduction / eradication of the aortic valve leakage. In these cases, the surgeon chose the narrow implant (diameter 95%), and so this approach is recommended if the valve is leaking prior to surgery.
Not all patients are suitable for this latest surgical approach. In particular, one patient had a severe dip in the chest (pectus excavatum), which made access to the aorta very difficult. A second patient had already undergone one operation for aortic valve replacement and in addition had disease of the heart muscle (cardiomyopathy). He also had a partial blockage of one of the coronary arteries prior to surgery. This patient died six months later of heart failure.
Surgical operation times have been about 2-3 hours. This contrasts well with open heart surgery where patients might be anaesthetised for between 4-7 hours. Thus the procedure costs less, and should improve patient experience and recovery.
PEARS surgery is carried out on a beating heart, so cardiopulmonary bypass, with its complications, is not necessary.
At least four female Marfan patients who have received an implant have subsequently had five uneventful pregnancies and deliveries of five infants without evidence of further aortic dilatation in the mother.
Clinical centres offering PEARS surgery
In 2004, one centre was offering one operation. The uptake by both surgical centres and patients has increased so that in 2019 there are 25 surgical centres: 8 in the UK; 1 each in Belgium, Netherlands and Malaysia; 2 each in Ireland and New Zealand; 3 in Australia; and 7 in the Czech Republic.
Formal clinical trial
After consultations with experts, the decision was taken that patient numbers involved are too small to provide statistical significance to any randomised trial. Moreover, patients should learn about the classical open heart surgery approach with 1-2% mortality risk in expert hands, and the PEARS approach with a mortality rate now the same as the classical approach. It is up to the patient to decide, with their surgeon, which operation is best. It is judged unethical for patients to be placed at random in the PEARS surgical group or the classical group, and so no formal clinical trial has been designed.
Summary prepared by Dr Anne Child from document by Tal Golesworthy found on the PEARS website.