2.3.4. Stent graft–induced new entry (SINE)
Dong and colleagues defined SINE as a new tear in the aortic intima induced by the TEVAR stent-graft post- intervention. Proximal SINE is defined as a tear proximal to the stent-graft implanted, leading to RTAD or proximal pseudoaneurysm [37]. Distal SINE (dSINE) occurs distal to the stent-graft landing zone resulting in increased pressure in the FL, leading to further expansion in its diameter [37]. The occurrence of SINE has been frequently reported particularly following TEVAR in un-TBAD [12, 21, 28], with a distal SINE being the most commonly observed type [8, 12, 21, 38].
SINE is considered a dangerous complication of TEVAR, especially since it is usually asymptomatic and incidentally discovered with routine surveillance [39-41]. SINE can also lead to treatment failure as it prevents FL thrombosis by re-establishing its perfusion and subsequently hindering the favourable aortic remodelling [38].
Distal SINE is rarely observed immediately after TEVAR. However, longer follow-up yielded a concerning incidence of 6.22%-26.5% with a mean time for occurrence between 27.78-29.7 months post-procedure [31, 38, 42].
Predictors of dSINE were TEVAR in the chronic phase (OR: 2.6; 95% 31.22-5.68; P=.01), stent grafts with connecting bar (OR: 3.28; 95%CI 1.54-7.0; P<.0) and stent grafts size <165 mm (OR:5.65; 95%CI 2.60-12.64; P<.01) [31]Furthermore, Jang et al. [42] showed that distal oversizing is an independent predictor of dSINE, and proposed accurate stent-graft size selection may reduce the incidence of late dSINE. Medical management can be considered as a treatment option for dSINE, provided that structural stability is present. However, re-intervention is commonly indicated due to increased FL diameter, rupture, pseudoaneurysm or malperfusion [31, 42, 43].
Reintervention with TEVAR in TBAD patients can improve long-term survival. Nevertheless, recurrence rates of dSINE were high after TEVAR reintervention. More tapered stent-grafts and improved techniques may facilitate lower recurrence rates [43].