Postoperative In-Stent Thrombus Formation Following Frozen Elephant Trunk Total Arch Repair

Abstract

ObjectivesOur aim was to investigate the occurrence and clinical consequence of postoperative in-stent thrombus formation following the frozen elephant trunk (FET) procedure.MethodsPostoperative computed tomography angiography (CTA) scans of all 304 patients following the FET procedure between 04/2014 and 11/2021 were analysed retrospectively. Thrombus size and location were assessed in multiplanar reconstruction using IMPAX EE (Agfa HealthCare N.V., Morstel, Belgium) software. Patients’ characteristics and clinical outcomes were evaluated between patients with and without thrombus formation.ResultsDuring the study period, we detected a new postoperative in-stent thrombus in 19 patients (6%). These patients were significantly older (p = 0.009), predominantly female (p = 0.002) and were more commonly treated for aortic aneurysms (p = 0.001). In 15 patients (79%), the thrombi were located in the distal half of the FET stent-graft. Thrombus size was 18.9 mm (first quartile: 12.1; third quartile: 33.2). Distal embolisation occurred in 4 patients (21%) causing one in-hospital death caused by severe visceral ischaemia. Therapeutic anticoagulation was initiated in all patients. Overstenting with a conventional stent-graft placed within the FET stent-graft was the treatment in 2 patients (11%). Outcomes were comparable both groups. Female sex (p = 0.005; OR: 4.289) and an aortic aneurysm (p = 0.023; OR: 5.198) were identified as significant predictors for thrombus development.ConclusionPostoperative new thrombus formation within the FET stent-graft is a new, rare, but clinically highly relevant event. The embolisation of these thrombi can result in dismal postoperative outcomes. More research is therefore required to better identify patients at risk and improve perioperative treatment.

Risk factors, prevention, and therapy of intraluminal stent thrombosis in frozen elephant trunk prostheses—what we know so far

“…Diagnosis is usually made by contrast enhanced computed tomography, which is recommended for long-term follow up in current guidelines ( 20 ). As usual in the analysis of aortic pathologies, all measurements should be made in multiplanar reconstruction and strictly perpendicular to the aortic axis ( 21 ). Although not explicitly stated in practice guidelines, many centers perform standard pre-discharge CT-angiography especially with a focus on early ILT formation ( 21 – 23 ).…”

“…As usual in the analysis of aortic pathologies, all measurements should be made in multiplanar reconstruction and strictly perpendicular to the aortic axis ( 21 ). Although not explicitly stated in practice guidelines, many centers perform standard pre-discharge CT-angiography especially with a focus on early ILT formation ( 21 – 23 ). If CT-angiography is inconclusive, Martens et al .…”

“…In the currently available studies focusing specifically on ILT formation, reported incidence of postoperative ILT after the frozen elephant trunk procedure ranges from 6% to 16.8% of cases ( 21 , 23 ) ( Table 1 ). Contrary to that, this phenomenon has not been reported in the initial pioneering experience reports of the frozen elephant trunk technique ( 26 , 27 ).…”

“…Walter et al . reported that thrombi were predominantly located in the distal half of the FET stent portion ( 21 ). Likewise, Martens et al .…”

“…Here, Walter et al . identified descending aortic aneurysms as an independent risk factor in multivariate regression analysis ( 21 ). Furthermore, the Freiburg group around Misfeld et al .…”