Personalised external aortic root support (PEARS) using mesh to prevent aortic root expansion and aortic dissection in people with Marfan syndrome

Evidence-based recommendations on personalised external aortic root support (PEARS) using mesh to prevent aortic root expansion and aortic dissection in people with Marfan syndrome. This involves opening the chest through the breastbone and wrapping a mesh around the outside of the aorta at the part closest to the heart.

# Recommendations
Evidence is adequate on the short-term safety and efficacy of personalised external aortic root support (PEARS) using mesh to prevent aortic root expansion and aortic dissection in people with Marfan syndrome. Evidence on long-term outcomes is limited in quantity and quality. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research. Find out what special arrangements mean on the NICE interventional procedures guidance page.
Clinicians wanting to do PEARS using mesh to prevent aortic root expansion and aortic dissection in people with Marfan syndrome should:
Inform the clinical governance leads in their healthcare organisation.
Give patients (and their families and carers as appropriate) clear written information to support shared decision making, including NICE's information for the public.
Ensure that patients (and their families and carers as appropriate) understand the procedure's safety and efficacy, and any uncertainties about these.
Audit and review clinical outcomes of all patients having the procedure. The main efficacy and safety outcomes identified in this guidance can be entered into NICE's interventional procedure outcomes audit tool (for use at local discretion).
Discuss the outcomes of the procedure during their annual appraisal to reflect, learn and improve.
Healthcare organisations should:
Ensure systems are in place that support clinicians to collect and report data on outcomes and safety for everyone having this procedure.
Regularly review data on outcomes and safety for this procedure.
Patient selection should be done by a multidisciplinary team.
The procedure should only be done in specialist centres with experience of managing this condition, by surgeons trained and experienced in aortic root surgery.
Further research should report details of patient selection, including aortic diameter, and long-term outcomes, including evidence of disease progression, such as dilation and dissection of the aortic root.# The condition, current treatments and procedure

# The condition
Marfan syndrome is a genetic disorder of the connective tissues. One effect of it is that the wall of the aorta can weaken and progressively widen. The wall can tear (dissection) and possibly rupture, which is often fatal. The strongest predictors of dissection are the aortic root size and the rate of change in size over time.

# Current treatments
Conventional treatment involves pre-emptive surgery to replace the ascending aorta with an artificial fabric graft. Some clinicians recommend this when the aortic diameter is 45 mm or more. The aortic valve is also usually replaced but may be conserved. People can experience considerable anxiety waiting for their aorta to reach the size threshold recommended for surgery.
If the person has a mechanical valve implanted, they need lifelong anticoagulation. If a bioprosthetic valve is used, it is likely to eventually fail, and the person will need another operation. Valvesparing root replacement surgery, in which the aorta is replaced with a tube graft and the native aortic valve is conserved, is also suitable for some people with normal valve function. This is technically more challenging, and people may need further surgery to replace the aortic valve at a later date.

# The procedure
The aim of personalised external aortic root support (PEARS) using mesh in people with Marfan syndrome is to reinforce the aortic root and ascending aorta to prevent enlargement and subsequent dissection or rupture. The native aortic valve is left intact so there is no need for lifelong anticoagulation after the procedure. This is a particular advantage for young women considering future conception. Cardiopulmonary bypass is usually not needed, and the operative time is shorter than for traditional aortic root replacement.
The first step of the procedure is to do imaging studies of the ascending aorta and aortic root. Computer-aided design is used to create a 3dimensional model of the aorta, which is then used to make a bespoke external polymer mesh support. The mesh is soft, flexible and porous. Openings for the coronary arteries are fashioned into the mesh support.
Under general anaesthesia, a median sternotomy is done, and the aorta is dissected away from adjacent structures and proximal to the coronary arteries. The mesh support is passed behind the aorta, sutured up the front and secured to the aortoventricular junction. It fully encircles the aortic root and extends from the region of the valve annulus to the origin of the brachiocephalic artery.