Commentary on ‘Early and Long-term Outcome after Open Surgical Suprarenal Aortic Fenestration in Patients with Complicated Acute Type B Aortic Dissection’

Abstract

Intervention for acute complicated type B dissection has received much attention in recent years. The advent of endovascular repair has opened the door for minimally invasive alternatives to open repair, with favourable results. However, the paucity of data on the outcome of alternative treatment strategies hampers possible comparison. Open surgical suprarenal aortic fenestration is one of these alternatives about which there are very few published data. As such, the publication by Szeberin et al. 1 is valuable and helps fill that void.The study must, nevertheless, be put in perspective. Open suprarenal fenestration is undisputedly a major surgical insult, associated with significant peri-operative mortality and morbidity: one in five of patients with a mean age of 55 years died within 30 days. This procedure is unsuitable for frail patients and the risk may only be justified for hard indications such as malperfusion. Patients presenting with rupture are also not candidates for this technique, for obvious reasons.The authors' definition of complicated type B dissection is controversial. While 25% of patients reportedly had malperfusion symptoms at the time of surgery, half were treated for uncontrollable hypertension or pain, which are softer indications that are increasingly rare with contemporary medical management. In a recently published series of 102 acute complicated type B dissection patients treated in Zurich and Uppsala, only 4% were treated for intractable pain and none for uncontrollable hypertension. 2 Furthermore, a substantial proportion was considered complicated on the basis of a narrow true lumen on computed tomography angiography (CTA). Depending on cardiac phase, the mobile lamella of acute dissections may appear to occlude the true lumen completely on static CTA 3,4 ; unless dynamic CTA is used or thrombosis is evident, a narrow true lumen in the absence of symptoms should not prompt surgical repair.The disturbingly high rate of progressive aortic dilatation leading to severe late complications reported by Szeberin et al. is also noteworthy. This suggests the technique is very ineffective in preventing the delayed complications of type B dissection. In fact, it may promote aortic degeneration, and the consequent risk of late aortic related death. Results from the INSTEAD-XL study suggest that endoclosure of the primary entry tear results in favourable aortic remodelling, 5 which seems to be in sharp contrast to fenestration.Lastly, the described technique of open surgical aortic fenestration makes subsequent aortic graft replacement (primary treatment option for most late post-dissection complications in our view) exceptionally more difficult. In acute cases deemed unsuitable for endovascular methods, a more definitive strategy seems better indicated, with cardiopulmonary bypass or other shunt manoeuvres as standard adjuncts.In conclusion, the publication by Szeberin et al. is important to contextualize current management of complicated type B dissections, but primary use of open suprarenal ao...