By Piergiorgio Cao
Aortic arch debranching followed by thoracic endovascular aortic repair (TEVAR) represents a less invasive approach for the treatment of arch diseases especially in high-risk patients. The feasibility of this approach has been supported by several reports and recent systematic reviews. However, there is conflicting information about the early safety with respect to patient selection and disease extension, while the long-term durability remains largely unsettled.
The best approach for aortic arch disease is currently being debated, as most of the data available in literature are mainly based on limited series and heterogeneous populations. We have recently reviewed our experience (Aortic arch debranching and thoracic endovascular repair. De Rango P, Cao P, et al. JVS 2013) in hybrid and endovascular approaches for the treatment of arch diseases with the aim to evaluate early and mid-term outcomes in a consecutive series of patients undergoing arch debranching procedures.
Between February 2005 and February 2013, 104 consecutive patients underwent partial or total debranching associated with the positioning of one or more thoracic endografts. Nineteen patients (18.3%) underwent total arch debranching. In the remaining 85, single or multiple supra-aortic vessel debranching was achieved with extra-thoracic bypass or transpositions, or the chimney technique. Six cases were managed by chimney or branched stent grafts: four were total endovascular procedures (one three-vessel arch chimney for zone 0 and three single left subclavian artery chimneys for zone 2 repairs), and two were hybrid procedures for zone 0 repairs (one innominate chimney and one innominate branched thoracic stent graft, both associated with carotid-carotid-subclavian bypass).
At 30 days, six deaths (5.8%), four strokes (3.8%), and three persistent deficits of spinal cord ischemia (2.9%) of any severity occurred. Four 30-day deaths and one stroke occurred in patients undergoing total arch debranching (landing zone 0); the remaining two deaths and two strokes occurred in patients with landing zone 1. No 30-day stroke or death occurred in patients undergoing procedures with landing zone 2. Total debranching accounted for a 30-day mortality risk significantly higher than for the partial debranching group (OR, 11.1; 95% CI, 1.86–65.90; p=0.010). Furthermore, extension to ascending aorta (landing zone 0) has been confirmed as the only multivariate independent predictor for perioperative mortality (odds ratio, 9.6; 95% confidence interval, 1.54–59.90; p=0.015).
Four de novo retrograde dissections were recorded at 30 days: three occurred in patients with zone 0 repair and two were fatal. Kaplan-Meier survival rates were 89% at one year, 82.8% at three years, and 70.9% at five years. Rates of freedom from persistent endoleak of any type were 96.1% at one year, 92.5% at three years, and 88.3% at five years.
Five reinterventions were performed up to five years, four of which were endovascular procedures. Morphology analysis on surviving patients at follow-up CTA scan showed that shrinkage >5mm was detectable in 34 aneurysms, with an absence of growth >5mm achieved in 95.7% of aneurysms undergoing imaging at five years after repair.
During the last few months our series has been expanded with several procedures, many of which were performed in landing zone 0. In particular, in addition to cases of total surgical debranching or branched endograft, we have performed four chimney procedures in landing zone 0. In all four procedures, performed in an emergency setting, the postoperative CTA showed a type I proximal endoleak arising from the channels between the chimney grafts (gutters). The four patients underwent an endoleak embolisation procedure, which was successful in two cases.
In conclusion, despite the perioperative mortality risk, the late outcome of endovascular arch repair presents a low rate of aorta-related deaths and reinterventions and acceptable mid-term survival. Furthermore, more than one third of the aneurysm diameters decreased over five years as a measure of the long-term efficacy of treatment. Retrograde type A dissection and stroke remain major concerns in the perioperative period. The endoleak arising from the gutter in chimney procedures appears to be difficult to be managed. The implementation of endovascular techniques might be useful to avoid arch manipulations and thereby decreasing the risk of perioperative major adverse events, especially in the landing in zone 0. However, this approach is not yet supported by robust data.
Piergiorgio Cao is professor of Vascular Surgery, University of Perugia, and chief of Vascular Surgery, Azienda Ospedaliera S Camillo-Forlanini, Rome, Italy