Personalised external aortic root support (PEARS) to stabilise an aortic root aneurysm

Abstract

Patients with congenitally determined aortic root aneurysms are at risk of aortic valve regurgitation, aortic dissection, rupture and death. Personalised external aortic root support (PEARS) may provide an alternative to aortic root replacement. This was a multi-centre, prospective cohort of all consecutive patients who received ExoVasc mesh implants for a dilated aortic root between 2004 and 2017. Baseline and peri-operative characteristics, as well as early postoperative outcomes are described, and time-related survival and re-operation free survival are estimated using the Kaplan-Meier method. From 2004 through 2017, 117 consecutive patients have received ExoVasc mesh implants for aortic root aneurysm. The inclusion criteria were an aortic root/sinus of Valsalva and ascending aorta with asymptomatic dilatation of between 40 and 50 mm in diameter in patients aged 16 years or more. Patients with more than mild aortic regurgitation were excluded. There was one early death. The length of stay was within seven days in 75% of patients. In conclusion, the operation achieves the objectives of valve-sparing root replacement. PEARS may be seen as a low-risk conservative operation, which can be applied earlier on in the disease process, and which is complementary to more invasive procedures, such as valve-sparing root replacement or total root replacement.

Keywords: Marfan syndrome; aortic root aneurysm; personalised medicine; prophylactic surgery.

Figure 1.. From left to right the figure illustrates the design, manufacture and implantation of the ExoVasc personalised mesh support. Digital image (a) is used to make a 3D replica (b) of the patient’s aortic root and ascending aorta. On this a customised sleeve of an open mesh fabric is manufactured (c). Each stage requires expertise and time is measured in hours. The aorta is dissected down to the aortoventricular junction (d). The dissection extends proximal to both coronary ostia. The longitudinal seam in the mesh is opened and incisions made to the point where the coronary arteries must pass through fashioning asterisk shaped incisions to conserve the mesh support. It extends to the aorto-ventricular junction and distally to just beyond the brachiocephalic artery (e). The final picture (f) is of the image of the first recipient (TG) 15 years after the operation

Figure 2.. Patient XN16 who is the only case to have died with the mesh in place. This occurred 4.5 years after operation. The upper two panels are aorta from the arch beyond the mesh at low power (a) and high power (b) where the loss of the structure of the media characteristic of Marfan syndrome can be seen. Below (c) the mesh (filaments cut in cross-section, marked) is surrounded by healthy collagen fully incorporating it. At high power (d) the media has a normal appearance. The pathological interpretation is that the support has allowed the collagen to be restored to a normal appearance

Figure 3.. Cumulative plot of patients operated from May 2004 to December 2017

Figure 4.. This flow chart includes all 117 consecutive patients for whom there was an intention to treat and who had surgery before the end of December 2017. All perioperative adverse events, conversions and adverse outcomes are described in the Appendix of Clinical Events. There is 100% follow-up and all patients are traceable

Figure 5.. Kaplan-Meier analysis prepared by Professor J J M Takkenberg. Time-to-event analysis shows two deaths at 5 days and at 4.5 years and two re-operations at 6 and 9 years. The small numbers of patients ‘at risk’ with more than 2 years of follow-up affects the appearance of the chart. The single event at 9 years has a large impact on the overall analysis of survival because of the few patients operated on that long ago