5.3 Hybrid aortic repair

When the entry tear occurs in the proximal aortic arch more invasive solutions can be necessary which include hybrid repair that involves rerouting of the arch branches and zone 0 TEVAR or arch replacement. A recent systematic review and meta-analysis by Carino et al. demonstrated that these hybrid techniques have been utilised for Non-A non-B dissections in 21% of total surgical cases (Carino et al. , 2019). Zone 0 TEVAR use in hybrid procedures for acute dissection has been shown to be considered dangerous with a significantly higher risk of retrograde dissection in comparison to a more distal landing zone (Cao et al. , 2012; Canaud et al. , 2014; Czerny et al. , 2012).
A 2020 study by Wang et al. describe the outcomes of 28 patients with non-A non-B dissection who underwent a novel hybrid surgery (Wanget al. , 2020). The novel hybrid surgery, also termed the ‘inclusion aortic arch technique’ involves initially a transverse incision of the aortic arch wall and bilateral antegrade cerebral perfusion was accomplished after cannulating the left common carotid artery (Liu et al. , 2020). Then the intimal tear of the dissection was identified and sealed using mattress sutures of 4-0 Prolene. An appropriate stent graft was subsequently introduced into the descending aorta and after stent graft released where its proximal edge was just distal to the left subclavian artery ostium with double check, the vascular graft was trimmed into an elliptical shape around the left common carotid and left subclavian artery orifices. Following this, pledgetted stitches were placed at the left subclavian artery orifice’s lower margin with a 4-0 polypropylene double armed suture needle therefore immobilising the vascular graft and aortic arch tissue. A single suture was then used to stitch the vascular graft to the anterior aortic arch wall from outside to inside the aortic arch and then reverse the direction through the aortic arch wall and vascular graft layers. Another suture is then added to accomplish the continuous suture by the anastomosis of the posterior aortic arch wall and vascular graft as deep as possible. Following this the trimmed vascular graft was attached firmly to the aortic wall. The initial transverse aortic arch wall incision was then closed with 4-0 Prolene sutures. Arterial cannulation blood was then used for de-airing through the aortic arch incision before the last sutures, antegrade systemic perfusion was resumed and the patient rewarmed (Wang et al. , 2020).
All patients in this cohort of 28 non-A non-B dissection patients underwent an emergency operation (Wang et al. , 2020). The authors reported no early adverse event such as in-hospital mortalities, re-explorations for haemorrhage, paraplegia, stroke, endoleak or left subclavian artery occlusions (Wang et al. , 2020). Mean follow-up time was 39.12±15.04 months, however one patient was lost during this time and another died suddenly due to false lumen patency in the aortic arch and descending aorta without any symptoms (Wang et al. , 2020). At 6 months the computer tomography angiography showed significantly smaller distal aortic arch diameters and descending aorta diameters than were measured pre-operatively (Wang et al. , 2020). No incidences of paraplegia, cerebral infarction, upper limb ischemia or left subclavian artery ischemia events were reported during the follow up period. The authors concluded that their inclusion aortic arch technique is both safe, effective and simple treatment for non-A non-B dissections which avoids endoleak, requires no blood products and demonstrates satisfactory early outcomes (Wang et al. , 2020).
A 2014 study by Kefeng et al. describes the use of a hybrid procedure for 15 patients with non-A non-B aortic dissections (10 acute, 5 chronic) (Kefeng et al. , 2014). The hybrid procedure performed in these patients comprised of 7 patients with zone 1 inclusion and 8 patients with zone 2. The authors report a technical success rate of 100% and no incidences of paraplegia were reported (Kefeng et al. , 2014). 30-day mortality and incident of stroke were 0%. However, during the follow-up period (median follow-up of 12 months) a stroke and death occurred in one patient who was not associated with an endograft complication. During this follow-up period, overall mortality was 6.7% and the overall late endoleak rate was 7.7% however no retrograde dissection occurred across the cohort (Kefeng et al. , 2014). The authors also report no differences in outcome between acute and chronic dissection or proximal landing zones except for proximal endograft dimension (Kefeng et al. , 2014).
An earlier paper published by Bünger et al. reported outcomes of 75 consecutive patients of which a subgroup of 45 patients underwent hybrid aortic repair for non-A non-B aortic dissection (Bünger et al. , 2013). Complete supra-aortic debranching was performed on 6 patients in zone 0, and partial debranching in 39 patients (16 in zone 1 and 23 in zone 2). Technical success was reported at 86.7% and the 30-day mortality rate at 4.4%. The in-hospital mortality was 11.1% following the deaths of 3 patients after days 33, 35, and 111 (Bünger et al. , 2013). After a median follow up of 20.8 months, the overall mortality reported was 13.3% (Bünger et al. , 2013). Additionally, the stroke rate recorded was 8.8% and paraplegia developed in one patient with complete recovery following a spinal drainage. Retrograde dissection also occurred in one patient 14 days after complete debranching and zone 0 TEVAR with a fatal outcome. The authors report the overall early and late endoleak occurrence rates were 27% and 43% respectively (Bünger et al. , 2013). Reintervention was required in 8 patients and freedom from reintervention was reported at 91% at 1 year and 81% at 2 years (Bünger et al. , 2013). Bünger et al. concluded that hybrid repair in zones 1 and 2 proved a viable alternative to conventional aortic arch surgery in these patients despite persistent issues with stroke and endoleak rate. Treatment of non-A non-B dissection patients with supra-aortic debranching and TEVAR in zone 0 however is associated with high mortality (Bünger et al. , 2013).