Complicated TBAD is challenging because its formidable risk of malperfusion, AD progression, and aorta rupture. The in-hospital mortality of patients with complicated TBAD was reported to be nearly 50%, while 10% for uncomplicated TBAD [17, 18]. Many interventions have been used to improve the survival of complicated TBAD patients, with none becoming the predominant therapy. In the current study, our single-center experience of open SET with subclavian artery for treatment of complicated TBAD patients shows a satisfactory clinical outcome, indicating that it is an alternative reliable treatment.
In patients with uncomplicated TBAD, the disease course can be safely stabilized via controlling the pain, blood pressure, and heart rate by medicine therapy. Current data show that TEVAR could improve aortic remodeling and decease disease progression and aorta-related mortality, but TEVAR manifests no clinical benefit on overall survival compared with medicine treatment for patients with uncomplicated TBAD [19, 20]. Even so, obliterating the intimal tear with membrane-covered stent-graft is the main treatment in clinical practice and TEVAR is also recommended for uncomplicated TBAD with a B level of evidence (Class of recommendation, IIa). While for complicated TBAD, both TEVAR and surgery therapy are recommended with a same evidence level of C [8]. In a retrospective study and meta-analysis, the author found that TEVAR and open surgical repair showed a similar long-term survival [21]. A report from the international registry of acute aortic dissections indicated that TEVAR is associated with better short-term outcomes of in-hospital mortality and complications [22]. With the minimally invasive nature and better clinical outcomes, TEVAR has been the preferred procedure for complicated TBAD.
A majority of patients with complicated TBAD could be treated with satisfactory results. However, in clinical practice, the anatomic complexity of aorta and branches, dissection location, and aortic arch angle often limit the use of the TEVAR, and TEVAR alone could not control the dissection progression and even cause severe complications. A proximal landing zone with a least of 1.5cm between the intimal tear or dissection and the origin of the LSCA is necessary for the safe and precise stent implantation. Without enough landing zone, stents shifting would lead to LSCA closure or endoleak, and need re-intervention [21]. Blocking LSCA to obliterate intimal tear completely was associated with increased incidence of stroke, upper limb ischemia, and endoleak [23-25]. TEVAR with additional assistive techniques, such as chimney technique and supra-arch branch vessel bypass, is a more proper therapeutic way for complicated TBAD. But it correlated with increased operation difficulty, radiation exposure of both doctor and patient, contrast dosage, and medical cost [26].
Sometimes open surgery repair is preferred because of anatomic contraindications, dissection extension without a proximal landing zone, and concomitant aortic lesion. Compared with TEVAR, open SET has advantages of accurate stent positioning and implanting, reduced risk of stent shift and endoleak, reduced intramural blood clots entering circulation via precise suture, and well aortic reconstruction through stent expanding induced aortic layers adhesion. In Sun and colleagues’ work, open surgery of total arch replacement with SET implantation showed favorable outcomes in both acute and chronic TBAD [13, 14]. Additionally, open SET technique for complicated TBAD exhibited a good outcome [27], indicating it as an alternative feasible and safe option. Another study reported that open surgery repair, and TEVAR has similar early complications and mortality, but open surgery repair has better long-term outcomes of fewer re-intervention and improved survival [21]. In our study, all ten patients received open SET technique with satisfactory clinical outcomes also supports that open SET is an alternative therapy for complicated TBAD.
For patients with TBAD and distal aortic arch involvement, Sun and colleagues reported a one-step technique of open SET with LSCA-LCCA bypass and achieved a satisfactory clinical outcome [15]. It has the advantages of avoiding graft-related complications via preserving the autologous normal aortic wall, completely closing the false lumen, easier and safer features than TEVAR, and avoiding proximal endoleaks and retrograde dissection by fixing stent graft firmly [15]. In this study, six patients received open SET with LSCA-LCCA bypass for complicated TBAD, which also confirmed the satisfactory clinical outcomes of this technique.
In our study, no in-hospital mortality occurred. Though 70% patients have postoperative liver dysfunction, they were all transient, and recover well when discharge. Postoperative MV time and ICU length of stay are much longer in our study by comparison with Zhu and colleagues’ work [15]. It is because that three patients in our study have complications of respiratory insufficiency, unstable circulation, pneumonia, AKI, re-intubation, and postoperative delirium. These complications might correlate with longer duration of CPB, aortic cross clamp time, selective cerebral perfusion in our study, and perioperation management, indicating that a good heart team necessitate both surgical skills and post-operation management. Two patients with AKI gradually recovered, with one completely recovery and one receiving long-term medication use. These outcomes of no mortality, acceptable complication, and good prognosis proved the efficacy of SET or SET with subclavian artery correction for patients with complicated TBAD. Limitations should be concerned in currents study. Only ten patients with different forms of TBAD were included; no control group was involved, and the follow-up is relatively short. Well-designed studies with control group, large sample, and long follow-up are warranted to further investigate the effect of SET with subclavian artery correction in complicated TBAD patients.