In-Situ Fenestration of a PTFE Thoracic Aortic Stent Graft for Delayed Left Subclavian Artery Revascularization Following Frozen Elephant Trunk Repair of Type A Aortic Dissection.

Left subclavian artery revascularization during endovascular repair of aortic dissection is often accomplished by left carotid-subclavian artery bypass or transposition. In situ fenestration of thoracic stent grafts provides an alternative method of revascularization without manipulation of the left carotid artery. We describe a case whereby in situ laser fenestration, combined with catheter-directed thrombectomy, was utilized to revascularize a thrombosed left subclavian artery following a frozen elephant trunk repair of type A aortic dissection. A 75-year-old male presented with pericardial tamponade and aortic insufficiency, secondary to type A aortic dissection. Patient underwent an emergent replacement of the aortic root, valve, arch, and ascending aorta in the frozen elephant trunk configuration. The innominate and left carotid arteries were revascularized with a bifurcated bypass graft from the ascending aortic graft. The left subclavian artery (LSCA) was covered with an antegrade deployment of a cTAG stent graft. During the immediate postoperative period, the patient was found to have a dissection of the left common carotid artery (LCCA) and pseudoaneurysm of the bypass graft anastomosis. The left carotid artery was replaced up to the proximal internal carotid. During rehabilitation, the patient developed left subclavian steal syndrome, with a CT angiography demonstrating thrombosis of the subclavian origin, and duplex ultrasound showing a reversal of the left vertebral flow. In order to revascularize the left subclavian artery without using the left carotid as the inflow, the in situ laser fenestration technique was planned. The vertebral artery origin was protected with a neuroclip through a supraclavicular incision. Through a brachial artery cutdown, a 9Fr flex sheath was positioned at the origin of the subclavian artery. A suction thrombectomy catheter was used to create a central channel in the thrombus. A 0.035″ 3.2 mm over-the-wire laser atherectomy catheter was used to create a fenestration through the cTAG stent graft. The subclavian branch stent was stented with an iCast balloon-expandable covered stent, excluding the mural thrombus. The patient recovered well with resolution of symptoms and was discharged home. Postoperative CT scan showed patent left subclavian branch stent and no endoleak across the fenestration of the aortic stent graft. Delayed laser in situ fenestration of a PTFE stent graft can be performed safely. The vertebral artery protection and catheter-directed thrombectomy are important adjuncts to reduce the risk of posterior stroke.

Impact of proximal seal zone length and intramural hematoma on clinical outcomes and aortic remodeling after thoracic endovascular aortic repair for aortic dissections.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) has become standard treatment of complicated type B aortic dissections (TBADs). Whereas adequate proximal seal is a fundamental requisite for TEVAR, what constitutes "adequate" in dissections and its impact on outcomes remain unclear. The goal of this study was to describe the proximal seal zone achieved with associated clinical outcomes and aortic remodeling. METHODS: A retrospective review was performed of TEVARs for TBAD at a single institution from 2006 to 2016. Three-dimensional centerline analysis of preoperative computed tomography was used to identify the primary entry tear, dissection extent, distances between arch branches, and intramural hematoma (IMH) involvement of the proximal seal zone. Patients were categorized into group A, those with proximal extent of seal zone in IMH/dissection-free aorta, and group B, those with landing zone entirely within IMH. Clinical outcomes including retrograde type A dissection (RTAD), death, and aortic reinterventions were recorded. Postoperative computed tomography scans were analyzed for remodeling of the true and false lumen volumes of the thoracic aorta. RESULTS: Seventy-one patients who underwent TEVAR for TBAD were reviewed. Indications for TEVAR included malperfusion, aneurysm, persistent pain, rupture, uncontrolled hypertension, and other. Mean follow-up was 14 months. In 26 (37%) patients, the proximal extent of the seal zone was without IMH, whereas 45 (63%) patients had proximal seal zone entirely in IMH. Proximal seal zone of 2-cm IMH-free aorta was achieved in only six (8.5%) patients. Review of arch anatomy revealed that to create a 2-cm landing zone of IMH-free aorta, 31 (43.7%) patients would have required coverage of all three arch branch vessels. Postoperatively, two patients developed image-proven RTADs requiring open repair, and one patient had sudden death. All three of these patients had TEVAR with the proximal seal zone entirely in IMH. No RTADs occurred in patients whose proximal seal zone involved healthy aortic segment. At 24 months, overall survival was 93% and freedom from aorta-related mortality was 97.4%. Complete thoracic false lumen thrombosis was seen in 46% of patients. Aortic remodeling, such as true lumen expansion, false lumen regression, and false lumen thrombosis, was similar in both groups of patients. CONCLUSIONS: Whereas achieving 2 cm of IMH-free proximal seal zone during TEVAR for TBAD would often require extensive arch branch coverage, failure to achieve any IMH-free proximal seal zone may be associated with higher incidence of RTAD. The length and quality of the proximal seal zone did not affect the subsequent aortic remodeling after TEVAR.

Anatomic suitability for "off-the-shelf" thoracic single side-branched endograft in patients with type B aortic dissection.

OBJECTIVE: Treatment of type B aortic dissections with thoracic endovascular aortic repair (TEVAR) has been adopted in many centers with the goal of covering the proximal entry tear. Coverage of the left subclavian artery (LSCA) is commonly required to achieve a dissection-free proximal seal zone. A novel thoracic single side-branched (TSSB) endograft device offers a potential off-the-shelf option to achieve total endovascular incorporation of LSCA during zone 2 TEVAR. The aim of this study was to determine what percentage of patients with type B aortic dissection who require zone 2 TEVAR meet the anatomical requirements for this device. METHODS: All consecutive patients undergoing TEVAR for type B aortic dissections at a single institution from 2006 to 2016 were evaluated. Three-dimensional centerline reconstruction of preoperative computed tomography angiography was performed to identify the diameter of the aorta, distances between branch vessels, diameter of the target branch vessel, and location of the primary entry tear. Only patients who met criteria for zone 2 TEVAR were included in the analysis. The primary outcome was percentage of patients that meet all anatomical requirements for TSSB. Individual criteria were evaluated independently, and results were stratified by dissection chronicity. RESULTS: Eighty-seven patients who underwent TEVAR for Stanford type B aortic dissections were reviewed. Fifty-seven (66%) would have required zone 2 TEVAR. Indications for TEVAR were malperfusion (12), aneurysm (15), persistent pain (22), rupture (3), uncontrolled hypertension (5), and other (3). Mean follow-up was 19 months (range, 1-72 months). Only 16 of the 57 patients (28%) met all the requirements for anatomic suitability. The primary contributor was that only 49% of patients had sufficient length between arch branches to prevent coverage of a proximal branch. CONCLUSIONS: Although the new TSSB device can allow for a more proximal seal zone and eliminate the need for open aortic arch debranching, only 28% of patients with type B dissection who required zone 2 TEVAR met all the anatomic requirements for this device. Future devices will need to account for the short distance between the left carotid and LSCA to be more broadly applicable.

Association Between Wearable Device-Based Measures of Physical Frailty and Major Adverse Events Following Lower Extremity Revascularization.

Importance: Physical frailty is a key risk factor associated with higher rates of major adverse events (MAEs) after surgery. Assessing physical frailty is often challenging among patients with chronic limb-threatening ischemia (CLTI) who are often unable to perform gait-based assessments because of the presence of plantar wounds. Objective: To test a frailty meter (FM) that does not rely on gait to determine the risk of occurrence of MAEs after revascularization for patients with CLTI. Design, Setting, and Participants: This cohort study included 184 consecutively recruited patients with CLTI at 2 tertiary care centers. After 32 individuals were excluded, 152 participants were included in the study. Data collection was conducted between May 2018 and June 2019. Exposures: Physical frailty measurement within 1 week before limb revascularization and incidence of MAEs for as long as 1 month after surgery. Main Outcomes and Measures: The FM works by quantifying weakness, slowness, rigidity, and exhaustion during a 20-second repetitive elbow flexion-extension exercise using a wrist-worn sensor. The FM generates a frailty index (FI) ranging from 0 to 1; higher values indicate progressively greater severity of physical frailty. Results: Of 152 eligible participants (mean [SD] age, 67.0 [11.8] years; 59 [38.8%] women), 119 (78.2%) were unable to perform the gait test, while all could perform the FM test. Overall, 53 (34.9%), 58 (38.1%), and 41 (27.0%) were classified as robust (FI <0.20), prefrail (FI ≥0.20 to <0.35), or frail (FI ≥0.35), respectively. Within 30 days after surgery, 24 (15.7%) developed MAEs, either major adverse cardiovascular events (MACE; 8 [5.2%]) or major adverse limb events (MALE; 16 [10.5%]). Baseline demographic characteristics were not significantly different between frailty groups. In contrast, the FI was approximately 30% higher in the group that developed MAEs (mean [SD] score, 0.36 [0.14]) than those who were MAE free (mean [SD] score, 0.26 [0.13]; P = .001), with observed MAE rates of 4 patients (7.5%), 7 patients (12.1%), and 13 patients (31.7%) in the robust, prefrail and frail groups, respectively (P = .004). The FI distinguished individuals who developed MACE and MALE from those who were MAE free (MACE: mean [SD] FI score, 0.38 [0.16]; P = .03; MALE: mean [SD] FI score, 0.35 [0.13]; P = .004) after adjusting by body mass index. Conclusions and Relevance: In this cohort study, measuring physical frailty using a wrist-worn sensor during a short upper extremity test was a practical method for stratifying the risk of MAEs following revascularization for CLTI when the administration of gait-based tests is often challenging.