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).