Spinal cord ischemia and reinterventions following thoracic endovascular repair for acute type B aortic dissections.

OBJECTIVE: The technical aspects of thoracic endovascular aortic repair (TEVAR) for acute type B aortic dissection (TBAD), specifically the location of proximal seal zone (PSZ) (need to cover the left subclavian artery [LSA]), distal seal zone (DSZ) (length of aortic coverage), benefit of LSA revascularization, and prophylactic lumbar drainage are still debated. Each of these issues has potential benefits but also has known risks. This study aims to identify factors associated with reintervention and spinal cord ischemia (SCI) following TEVAR for acute TBAD with a zone 3 entry tear. METHODS: The Vascular Quality Initiative was queried for TEVARs performed for acute TBAD with zone 3 entry tear, zone 3 proximal zone of disease, treated with TEVAR extending between zone 2 and zone 5. The primary outcomes were SCI and related reintervention. Secondary outcomes were stroke, arm ischemia, and retrograde type A dissection (RTAD). The exposure variables were PSZ 2 vs 3, DSZ 4 vs 5, prophylactic lumbar drain, and LSA revascularization. Univariate analyses were conducted with χ2 analysis, and multivariable logistic regression was used to evaluate association with outcomes. RESULTS: Of 583 patients who met inclusion criteria, 266 had PSZ 2 and 317 had PSZ 3. On univariate analysis, PSZ 2 was associated with a higher rate of reintervention, but PSZ2 was not significant on multivariable analysis after accounting for age, sex, race, smoking, PSZ, DSZ, prophylactic lumbar drain, and LSA patency. PSZ 2 was not associated with SCI, arm ischemia, or RTAD. PSZ 2 was associated with a trend towards a higher rate of stroke. DSZ 4 and DSZ 5 were performed in 161 and 422 TEVARs, respectively, and DSZ 5 was associated with a higher rate of SCI on univariate (3 [1.9%] vs 39 [9.2%]; P = .01) and multivariable (odds ratio, 7.384; 95% confidence interval, 2.193-24.867; P = .001) analyses. Prophylactic lumbar drain placement was not statistically significantly associated with SCI, but lack of postoperative LSA patency was associated with SCI (odds ratio, 2.966; 95% confidence interval, 1.016-8.656; P = .05). CONCLUSIONS: This study found that PSZ 2 was not associated with lower reinterventions or higher rates of SCI but trended towards a higher rate of stroke than PSZ 3. Additionally, DSZ 5 was strongly associated with SCI when compared with DSZ 4, highlighting the importance of limiting aortic coverage to coverage of the proximal entry tear when possible.

The Initial Results of Physician-Modified Fenestrated-Branched Endovascular Repairs of the Aortic Arch and Lessons Learned From the First 21 Cases.

INTRODUCTION: Physician-modified fenestrated-branched endovascular aortic repair (PM-FBEVAR) for the aortic arch provides a minimally invasive treatment option for patients who are too high-risk for open repair. Improvements in technique are gained with ongoing experience with these complex repairs. This study aims to describe outcomes of arch PM-FBEVAR and technical lessons. MATERIALS AND METHODS: A retrospective review of consecutive patients who underwent PM-FBEVAR with zone 0 proximal sealing at a single institution between January 2019 and July 2023 was performed. Cases completed using initial techniques (early technique) were compared with cases using the current techniques (current technique). Modification technique changed to include a self-orienting spine trigger wire and anatomically specific fenestrations or inner branches in the current group. The primary outcome was in-hospital mortality. Secondary outcomes included technical success and 30 day stroke. RESULTS: A total of 21 patients underwent arch PM-FBEVAR, with 7 in the early group and 14 in the current group. Severe comorbidities were present in both groups including chronic obstructive pulmonary disease (COPD) (43% vs 36%), prior open ascending aortic repair (57% vs 43%), and prior stroke (86% vs 21%), respectively. Technical success was the same (86% vs 86%, p=1.0). Fluoroscopy time (56 vs 24 min, p=0.012) and in-hospital death (43% vs 0%, p=0.026) were significantly lower in the current group. A 30 day stroke rate (29% vs 7%, p=0.247) was non-significantly decreased in the current group. All-cause mortality was 100% vs 7% during median follow-up of 8 and 6 months (p<0.001). Three deaths in the early group were related to their aortic arch repair including aortic rupture during endograft advancement and 2 postoperative strokes. CONCLUSION: There is a significant learning curve associated with aortic arch PM-FBEVAR. This study suggests that gained experience, use of the spine trigger wire technique, and precise creation of fenestrations or inner branches can lead to a shorter procedure time and lower complications. CLINICAL IMPACT: Physician modified fenestrated branched endografting is feasible for the aortic arch. The high rate of stroke and perioperative mortality was reduced with incorporation of self-orienting spine trigger wire and anatomically specific inner branch creation.

Readmission after early thoracic endovascular aortic repair versus medical management of acute type B aortic dissection.

BACKGROUND: The use of thoracic endovascular aortic repair (TEVAR) for the management of acute uncomplicated type B aortic dissection (TBAD) has increased. Although the results from early studies were promising, larger randomized trials evaluating TEVAR are lacking. It is also unclear where sufficient equipoise exists for such trials. In the present study, we evaluated the number of readmissions and unplanned operations after TEVAR vs those after medical management as the initial treatment of acute uncomplicated TBAD and the frequency of each treatment in this population. METHODS: We performed a multi-institutional retrospective review of patients with acute TBAD from 2015 to 2020 with the 1-year outcomes available, excluding patients with prior aortic intervention or chronic, iatrogenic or traumatic etiologies. The primary exposure was TEVAR vs medical management at the index admission. The patient demographics, clinical presentation, and imaging findings were analyzed using bivariate and multivariate logistic regression for the primary outcomes of unplanned readmission and/or operation after the initial admission. The secondary outcomes were mortality, myocardial infarction, stroke, renal failure requiring dialysis, retrograde type A dissection, and length of stay. We hypothesized that the readmissions would be higher with medical management. RESULTS: A total of 216 patients with TBAD (47 with complicated and 169 with uncomplicated) from two large academic centers were identified. Of the 169 patients with uncomplicated TBAD, 83 (49%) had been treated medically and 86 (51%) had undergone TEVAR at the initial admission. No differences were found in the demographics or high-risk imaging features at presentation. The medically managed patients had had higher rates of unplanned readmission (34% vs 9%; P = .0001) and operation (28% vs 8%; P = .0007) but shorter lengths of stay (6.3 vs 13.1 days; P < .0001). No differences were found in mortality, although the rate of myocardial infarction was higher in the medically managed group (10.8% vs 2.3%; P = .02). Although 28% of the medically managed patients had later required operation, they had had morbidity and mortality similar to those of patients who had undergone initial TEVAR. Initial medical management was associated with unplanned readmission (odds ratio, 8.3; P = .02) and the need for operation (odds ratio, 4.56; P = .006). No differences were found in the outcomes according to the involved aortic zones. CONCLUSIONS: In the present study, medical management of acute uncomplicated TBAD was associated with higher rates of readmission and the need for unplanned operation compared with TEVAR. However, no differences were found in the 1-year mortality for the patients for whom medical management had failed. Because one half of the patients had undergone medical management and one half had undergone early TEVAR, this finding suggests clinical equipoise for the treatment of acute uncomplicated TBAD. Therefore, a larger randomized trial appears warranted to determine whether a clear benefit exists for early TEVAR.

Emergency and Compassionate Use of a Novel Ascending Endograft for Ascending and Arch Aortic Pathology.

PURPOSE: Patients with complicated ascending aortic pathology, including patients with acute type A aortic dissection may be at extreme risk for open repair. Thoracic endovascular aortic repair (TEVAR), infrequently used for the ascending aorta, may be considered an alternative in this setting. We describe early results for emergency and compassionate (E&C) use of a novel endograft, specifically designed for use to treat pathology of the ascending aorta. MATERIALS AND METHODS: This case series evaluated 19 patients (mean age, 68.84±13.12 years; 57.9% female) treated with ascending TEVAR for acute and chronic acute (4), subacute (1), or chronic (1) aortic dissection or pseudoaneurysm (13). Six of the 19 patients (31.5%) were treated under compassionate use and 13 patients (68.4%) were treated under the emergency use exemption. Ten patients (52.6%) received additional devices to extend treatment into the arch and descending aorta. RESULTS: Device delivery was achieved in all patients (100%). Thirty-day mortality and stroke occurred in 3 patients (15.8%) and in 1 patient (5.3%), respectively. In 1 patient (5.3%), with an Unanticipated Adverse Device Event, the aorta ruptured when the endograft eroded into the adventitial portion of dissection site at the posterior aspect of the ascending wall. Devices were explanted in 2 patients (10.5%), 353 and 610 days after the index procedure, respectively. Six patients had endoleaks (31.6%), including type I (n=2, 10.5%), type II endoleaks (n=3, 15.8%), and indeterminate endoleak (n=1, 5.3%). CONCLUSIONS: Delivery and deployment of a novel ascending thoracic stent graft with or without an additional branched arch extension is feasible in patients with complex anatomy and pathology, including acute aortic dissection and pseudoaneurysm. Additional experience with this novel device will further refine the patient population most suitable for endovascular ascending aortic repair for these pathologies. CLINICAL IMPACT: This study describes a novel stent graft specifically designed for treatment of ascending aortic pathology, including acute type A dissection. The patients described in this series constituted a group outside the formal US FDA sponsored clinical trial, and were those accepted as part of an emergency and compassionate use basis.

ARISE: First-In-Human Evaluation of a Novel Stent Graft to Treat Ascending Aortic Dissection.

BACKGROUND: Operative mortality for type A aortic dissection is still 10-20% at centers of excellence. Additionally, 10-20% are not considered as viable candidates for open surgical repair and not offered life-saving emergency surgery. ARISE is a multicenter investigation evaluating the novel GORE® Ascending Stent Graft (ASG; Flagstaff, AZ). OBJECTIVE: The purpose of this study is to assess early feasibility of using these investigational devices to treat ascending aortic dissection. METHODS: This a prospective, multicenter, non-randomized, single-arm study that enrolls patients at high surgical risk with appropriate anatomical requirements based on computed tomography imaging at 7 of 9 US sites. Devices are delivered transfemorally under fluoroscopic guidance. Primary endpoint is all-cause mortality at 30 days. Secondary endpoints include major adverse cardiovascular and cerebrovascular events (MACCE) at 30 days, 6 months, and 12 months. RESULTS: Nineteen patients were enrolled with a mean age of 75.7 years (range 47-91) and 11 (57.9%) were female. Ten (52.6%) had DeBakey type I disease, and the rest were type II. Sixteen (84.2%) of the patients were acute. Patients were treated with safe access, (7/19 (36.8%) percutaneous, 10/19 (52.6%) transfemoral, 2/19 (10.5%) iliac conduit), delivery, and deployment completed in all cases. Median procedure time was 154 mins (range 52-392) and median contrast used was 111 mL (range 75-200). MACCE at 30 days occurred in 5 patients including mortality 3/19 (15.8%), disabling stroke in 1/19 (5.3%), and myocardial infarction in 1/19 (5.3%). CONCLUSION: Results from the ARISE early feasibility study of a specific ascending stent graft device to treat ascending aortic dissection are promising.

Management strategy for lower extremity malperfusion due to acute aortic dissection.

OBJECTIVE: Aortic dissection can result in devastating cerebral, visceral, renal, spinal, and extremity ischemia. We describe the management and outcomes of patients presenting with aortic dissection and lower extremity malperfusion (LEM). METHODS: A single-center institutional aortic database was queried for patients with aortic dissection and LEM from 2011 to 2019. The primary end point was resolution of LEM after aortic repair. Secondary end points were amputation, in-hospital mortality, time to intervention, and postoperative complications. RESULTS: Of 769 patients with aortic dissection, 42 (5.5%) presented acutely with LEM: 16 with Stanford type A and 26 Stanford type B aortic dissection (age 55 ± 13 years; 90% men). Most presented as Rutherford IIB symptoms, but patients with type A had Rutherford III more often, compared with those with type B. Aortic repair was performed before limb interventions in 36 patients (86%; 19 TEVAR, 16 open arch and ascending repair, and 1 open descending aortic repair with fenestration). Seven (19%) had immediate failure with persistent malperfusion recognized in the operating room and underwent additional limb intervention, including extra-anatomic revascularization (n = 4), iliac stenting (n = 2), and femoral patch with septal fenestration or tacking (n = 2). Three patients (8%) had early delayed failure requiring extra-anatomic bypass in two and amputation in one. In contrast, six patients had limb-first intervention with extra-anatomic revascularization. None had immediate failure, but one-half had early delayed failure requiring proximal aortic intervention: two TEVAR and one open aortic fenestration. Limb-first patients were more likely to have early delayed failure compared with aortic dissection treated first patients (50% vs 8%; P = .029). The amputation rate was 2%, occurring in one type A patient. The overall in-hospital mortality was 7% (n = 3), with no difference between type A and type B aortic dissection. There was no difference in surgical site infection, postoperative dialysis need, stroke, and myocardial infarction. CONCLUSIONS: In patients presenting with acute aortic dissection with limb ischemia, resolution of the malperfusion occurs in the majority of cases after primary aortic dissection intervention, emphasizing the usefulness of urgent TEVAR for complicated type B and open repair of type A before lower extremity intervention. Limb-first interventions have a higher early delayed failure rate and thus require more frequent reoperation. However, the overall amputation rate in LEM owing to aortic dissection remains low.

Periscope sandwich stenting as an alternative to open cervical revascularization of left subclavian artery during zone 2 thoracic endovascular aortic repair.

OBJECTIVE: Revascularization of the left subclavian artery (LSA) during zone 2 thoracic endovascular aortic repair (TEVAR) maintains collateral circulation to decrease ischemic complications, including stroke, spinal cord ischemia, and upper extremity ischemia. Both open surgical and endovascular LSA revascularization techniques have been described, each with unique risks and benefits. We describe our "periscope sandwich" technique for the LSA during zone 2 TEVAR, which maintains antegrade access to the distal abdominal aorta if subsequent interventions are necessary. Technical results and short-term outcomes are compared with LSA open surgical debranching. METHODS: A single-institution retrospective review was performed for patients requiring zone 2 TEVAR with LSA revascularization by periscope sandwich technique or open surgical debranching with subclavian to carotid transposition (SCT) or carotid-subclavian bypass (CSB). The presenting aortic disease and perioperative details were recorded. Intraoperative angiography and postoperative computed tomography images were reviewed for occurrence of endoleak and branch patency. RESULTS: Between January 2013 and December 2018, the LSA was revascularized by periscope sandwich in 18 patients, SCT in 22 patients, and CSB in 13 patients. Compared with open surgical debranching, periscope sandwich had a lower median estimated blood loss (100 mL vs 200 mL for pooled SCT and CSB; P = .03) and lower median case duration (133.5 minutes vs 226 minutes; P < .001). Contrast material volume (120 mL vs 120 mL; P = .98) and fluoroscopy time (13.1 minutes vs 13.3 minutes; P = .92) did not differ significantly between the groups. There was no difference in aorta-related mortality (P = .14), and LSA patency was 100%. Median follow-up for the periscope sandwich group was 11 months, with an overall estimated 91% freedom from gutter leak at 6 months. CONCLUSIONS: LSA periscope sandwich technique provides safe and effective LSA revascularization during zone 2 TEVAR. LSA periscope sandwich can be used emergently with off-the-shelf endovascular components and facilitates future branched-fenestrated endovascular repair of thoracoabdominal aortic diseases.

Complications associated with lumbar drain placement for endovascular aortic repair.

OBJECTIVE: We reviewed the complications associated with perioperative lumbar drain (LD) placement for endovascular aortic repair. METHODS: Patients who had undergone perioperative LD placement for endovascular repair of thoracic and thoracoabdominal aortic pathologies from 2010 to 2019 were reviewed. The primary endpoints were major and minor LD-associated complications. Complications that had resulted in neurological sequelae or had required an intervention or a delay in operation were defined as major. These included intracranial hemorrhage, symptomatic spinal hematoma, cerebrospinal fluid (CSF) leak requiring intervention, meningitis, retained catheter tip, arachnoiditis, and traumatic (or bloody) tap resulting in delayed operation. Minor complications were defined as a bloody tap without a delay in surgery, asymptomatic epidural hematoma, and CSF leak with no intervention required. Isolated headaches were recorded separately owing to the minimal clinical impact. RESULTS: A total of 309 LDs had been placed in 268 consecutive patients for 222 thoracic endovascular aortic repairs, 85 complex endovascular aortic repairs (EVARs; fenestrated branched EVAR/parallel grafting), and 2 EVARs (age, 65 ± 13 years; 71% male) for aortic pathology, including aneurysm (47%), dissection (49%), penetrating aortic ulcer (3%), and traumatic injury (0.6%). A dedicated neurosurgical team performed all LD procedures; most were performed by the same individual, with a technical success rate of 98%. Radiologic guidance was required in 3%. The reasons for unsuccessful placement were body habitus (n = 2) and severe spinal disease (n = 3). Most were placed prophylactically (96%). The overall complication rate was 8.1% (4.2% major and 3.9% minor). Major complications included spinal hematoma with paraplegia in 1 patient, intracranial hemorrhage in 2, meningitis in 2, arachnoiditis in 3, CSF leak requiring a blood patch in 3, bloody tap delaying the operation in 1, and a retained catheter tip in 1 patient. Patients who had undergone previous LD placement had experienced significantly more major LD-related complications (12.2% vs 3%; P = .019). The rate of total LD-associated complications did not differ between prophylactic and emergent therapeutic placements (8.1% vs 7.7%; P = 1.00) nor between major or minor complications. On multivariate analysis, previous LD placement and an overweight body mass index were the only independent predictors of major LD-related complications. CONCLUSIONS: The complications associated with LD placement can be severe even when performed by a dedicated team. Previous LD placement and overweight body mass index were associated with a significantly greater risk of complications; however, emergent therapeutic placement was not. Although these risks are justified for therapeutic LD placement, the benefit of prophylactic LD placement to prevent paraplegia should be weighed against these serious complications.

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.

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.

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.

Lift Sandwich Grafting Enables Transfemoral Abdominal Aortic Branch Incorporation during Endovascular Aortic Repair for Chronic Type B Aortic Dissection.

Chronic type B aortic dissections with continued aneurysmal expansion of the thoracoabdominal aorta after the initial thoracic endovascular aortic repair represent a subset of aortic pathology in which staged distal extension to seal additional septal tears can be advantageous. This approach may require incorporation of visceral or renal branches into the distal seal zone, while maintaining the possibility of further distal extension in the future. We describe a novel technique for incorporation of the celiac axis, with a branch stent graft delivered from a transfemoral approach, then lifted cranially to create an antegrade sandwich graft configuration in a 59-year-old male who presented with a complicated type B aortic dissection requiring coverage of the celiac artery. Utilizing the previous thoracic endograft as a platform for sandwich grafting, a self-expanding stent graft was deployed into the celiac artery from a femoral approach. A steerable sheath with an anchoring balloon was used to lift the stent into an up-facing snorkel position, which was subsequently sandwiched with another thoracic stent graft terminating proximal to the superior mesenteric artery. When single visceral or renal branch incorporation is desired, sandwich grafting via a "lift" technique limits the extent of aortic coverage and reduces the number of branch components, without increasing the complexity of additional visceral and renal branch incorporation during future endovascular aortic repair.

Image Predictors of Treatment Outcome after Thoracic Aortic Dissection Repair.

Treatment of thoracic aortic dissection remains highly challenging and is rapidly evolving. Common classifications of thoracic aortic dissection include the Stanford classification (types A and B) and the DeBakey classification (types I to III), as well as a new supplementary classification geared toward endovascular decision making. By using various imaging techniques, the extent of the dissection, the location of the primary intimal tear, the shape of the aortic arch, and the zonal involvement of the aortic arch-factors that affect the treatment strategy-can easily be identified. Thoracic endovascular aortic repair (TEVAR) is generally performed in two groups of patients: (a) those with a surgically repaired type A dissection, and (b) those with a complicated type B dissection. Several imaging findings can help predict the course of remodeling of the dissected aorta after a repaired type A dissection and TEVAR. A spectrum of imaging findings exist with regard to favorable (positive) or failing (negative) remodeling. A schematic model with imaging support allows the classification of important causes of failing remodeling into proximal and distal groups, on the basis of the origin of the refilling of the false lumen and the underlying pathophysiology of pressurization. Refilling of the false lumen of the aorta after repair of a type A dissection is usually secondary to a persistent intimal tear at the aortic arch, a leak of the distal graft anastomosis, or refilling from the false lumen of a dissected aortic arch vessel. After TEVAR, false lumen refilling is most commonly due to an incomplete seal of the proximal landing related to the aortic tortuosity, an arch branch stump, a supra-arch chimney stent, or the TEVAR technique. Online supplemental material is available for this article. ©RSNA, 2018.

Management of patients with acute aortic syndrome through a regional rapid transport system.

OBJECTIVE: The objective of this study was to describe the outcomes of patients with acute aortic syndrome (AAS) during and after transfer to a regional aortic center by a rapid transport system. METHODS: Review of patients with AAS who were transferred by a rapid transport system to a regional aortic center was performed. Data regarding demographics, diagnosis, comorbidities, transportation, and hospital course were acquired. Severity of existing comorbidities was determined by the Society for Vascular Surgery Comorbidity Severity Score (SVSCSS). The Acute Physiology and Chronic Health Evaluation II (APACHE II) score assessed physiologic instability on admission. Risk factors associated with system-related (transfer and hospital) mortality were identified by univariate and multivariate linear regression analysis. RESULTS: During a recent 18-month period (December 2013-July 2015), 183 patients were transferred by a rapid transport system; 148 (81%) patients were transported by ground and 35 (19%) by air. Median distance traveled was 24 miles (range, 3.6-316 miles); median transport time was 42 minutes (range, 10-144 minutes). Two patients died during transport, one with a type A dissection, the other of a ruptured abdominal aortic aneurysm. There were 118 (66%) patients who received operative intervention. Median time to operation was 6 hours. Type B dissections had the longest median time to operation, 45 hours, with system-related mortality of 1.9%; type A dissections had the shortest median time, 3 hours, and a system-related mortality of 16%. Overall, system-related mortality was 15%. On univariate analysis, factors associated with system-related mortality were age ≥65 years (P = .026), coronary artery disease (P = .030), prior myocardial infarction (P = .049), prior coronary revascularization (P = .002), SVSCSS of >8 (P < .001), abdominal pain (P = .002), systolic blood pressure <90 mm Hg at sending hospital (P = .001), diagnosis of aortic aneurysm (P = .013), systolic blood pressure <90 mm Hg in the intensive care unit (P < .001), and APACHE II score >10 (P = .004). Distance traveled and transport mode and duration were not associated with increased risk of system-related mortality. Only SVSCSS of >8 (odds ratio, 7.73; 95% confidence interval, 2.32-25.8; P = .001) was independently associated with an increase in system-related mortality on multivariate analysis. CONCLUSIONS: Implementation of a rapid transport system, regardless of mode or distance, can facilitate effective transfer of patients with AAS to a regional aortic center. An SVSCSS of >8 predicted an increased system-related mortality and may be a useful metric to assess the appropriateness of patient transfer.

Comparison of intravascular ultrasound- and centerline computed tomography-determined aortic diameters during thoracic endovascular aortic repair.

BACKGROUND: Accurate sizing of stent grafts during thoracic endovascular aortic repair (TEVAR) is critical for a successful outcome. Centerline measurements using three-dimensional reconstruction of preoperative computed tomography angiography (CTA) is the current standard for stent graft sizing. However, this technique is predicated on an idealized straightened aorta and does not account for the variability in the aortic diameter during the cardiac cycle or the overall status of the patient's volume. Intravascular ultrasound (IVUS) offers real-time cross-sectional imaging of the aorta orthogonal to the support wire, thereby providing an adjunctive method for aortic diameter determination at the time of TEVAR. METHODS: A retrospective review was performed on all patients who underwent TEVAR for nontraumatic aortic pathology from July 2015 to December 2015. Preoperative CTA images were reconstructed on a dedicated three-dimensional workstation. CTA centerline aortic diameter measurements were performed in major and minor axes at 1-cm intervals from the left subclavian origin to 20 cm distally. The IVUS images were acquired intraoperatively through 1-cm stepwise pullback along the aorta from the left subclavian origin to 20 cm. IVUS aortic diameters were measured at the maximum phase during the cardiac cycle. The average values of major and minor axes diameters from both modalities were calculated at each location for comparison. Linear regression analysis was performed to evaluate correlation, and Bland-Altman plots assessed agreement between different imaging modalities. RESULTS: During the study period, 26 patients underwent TEVAR. Of these, 20 patients had adequate CTA and IVUS images, providing 355 paired measurements. There was a high correlation between CTA- and IVUS-determined aortic diameters (R = 0.62; P < .001). However, Bland-Altman analysis showed that, compared with CT, IVUS resulted in larger aortic diameters, with the mean difference of 3.09 mm. There was a significant variability between IVUS and CTA with the standard deviation of difference (SD diff) of 4.56 mm. When stratified by the aortic position, a high degree of agreement was observed at the base of the left subclavian (position 0), with a mean difference of -2.69 mm and an SD diff of 4 mm. The agreement was the lowest at the angulated aortic segments (2 cm to 7 cm distal to the subclavian origin) with a mean difference up to 7.96 mm and an SD diff up to 8.27 mm. CONCLUSIONS: IVUS imaging and centerline CTA may provide significantly different aortic diameter measurements, particularly in angulated aortic segments. Caution must be taken when sizing a stent graft using CTA alone, particularly in an angulated proximal landing zone.

Symptomatic Intragraft Thrombus following Endovascular Repair of Blunt Thoracic Aortic Injury.

Thoracic endovascular aortic repair (TEVAR) can be complicated by graft collapse, endoleaks, and stent migration. The incidence of these complications and other outcomes is poorly understood in young trauma victims who receive endovascular aortic repair of blunt thoracic aortic injury (BTAI). A 29-year-old pedestrian was struck by a vehicle resulting in polytrauma including BTAI with transection distal to the left subclavian artery origin. The patient underwent successful TEVAR. Nine months later, the patient developed transient paresthesia below the waist that progressed to bilateral lower extremity paralysis and malperfusion syndrome below the diaphragm including nonpalpable pulses in the lower extremities, acute renal failure, and ischemic colitis. Imaging demonstrated near occlusive thrombosis of the distal end of the thoracic endograft. An emergent axillobifemoral bypass resolved the organ malperfusion and acute limb ischemia. Patients who have undergone TEVAR for BTAI may develop asymptomatic or symptomatic intragraft thrombosis. In patients presenting with malperfusion syndrome below the diaphragm, extra-anatomic bypass can expeditiously resolve symptoms until definitive treatment can be performed. Oversizing of thoracic stents in trauma patient may lead to intragraft thrombosis.

Use of Iliac Branch Endoprosthesis to Rescue Inadvertent False Lumen Deployment of the Innominate Branch Stent During Physician-Modified Fenestrated-Branched Aortic Arch Repair.

A 70-year-old male with a history of 3 prior median sternotomies and on anticoagulation presented with acute chest and back pain associated with a pseudoaneurysm of the ascending and aortic arch in the setting of residual dissection involving the innominate, proximal right carotid, and subclavian arteries. A physician-modified triple vessel fenestrated-branched arch endograft was deployed. The innominate branch stent was deployed from the right carotid cut down, while the left carotid and left subclavian branch stents were placed from a femoral approach. Postoperatively, the innominate branch was found to be deployed in the false lumen of the dissected native innominate artery, leading to continued pressurization of the pseudoaneurysm. This was rescued by placing a Gore Iliac Branch Endoprosthesis (IBE) into the innominate branch through a temporary conduit sewn to the right carotid artery with a right subclavian branch placed via a brachial artery cut down into the internal iliac gate. The use of IBE allowed branch stent extension past the dissected native vessels. The patient had an uneventful recovery without neurologic complications. At 3-month follow-up, the patient remains well with an excluded pseudoaneurysm, and patent bifurcated innominate, bilateral carotid, and subclavian artery branches. A Gore IBE can be utilized in a dissected innominate artery to create an innominate branch device during fenestrated-branched endovascular arch repair.

Characterization of cerebrospinal fluid markers as indicators of spinal cord ischemia following an endovascular aortic aneurysm repair procedure.

OBJECTIVE: Spinal cord ischemia (SCI) remains one of the most devastating complications in both open and endovascular stent graft repair of thoracoabdominal aortic aneurysms. The endovascular aortic aneurysm repair (EVAR) can be either thoracic (TEVAR) when it targets the thoracic aortic aneurysm or fenestrated branched when repair involves the visceral and/or renal arteries. Even though EVAR interventions are less invasive than open repair, they are still associated with a significant risk of SCI. The current primary strategy to prevent SCI after TEVAR is to increase and/or maintain spinal cord perfusion pressure (blood flow) by increasing the mean arterial pressure while simultaneously draining CSF. Although the benefit of CSF drainage in EVAR procedures remains uncertain, it provides an opportunity to study the changes in cytokine and oxidative stress markers that may signal the pathophysiology of SCI following EVAR. The aim of this study was to evaluate the temporal relationship between stent deployment and CSF cytokine and oxidative stress marker levels as predictors of delayed SCI in patients undergoing an EVAR procedure. METHODS: There were 16 EVAR cases across 15 patients enrolled in this study, with 1 patient undergoing the procedure twice 1 year apart. The levels of oxidative stress (8-hydroxy-2'-deoxyguanosine [8-OHdG], glial fibrillary acidic [GFAP], and lactic acid) and proinflammatory (tumor necrosis factor-alpha [TNF-α], interleukin (IL)-6, and IL-1ß) and antiinflammatory (IL-4) markers were quantified at different time points between 0 and 48 hours after EVAR by enzyme-linked immunosorbent assay. The changes in protein levels of both oxidative stress and inflammatory markers were expressed as fold change from the time of the lumbar drain insertion prior to surgery. RESULTS: Following the EVAR procedure, 8-OHdG resulted in the highest upregulation at later time points postoperatively (48 hours) and this increase was positively correlated with TNF-α level. The data also revealed that IL-6 peaked during the stent deployment intervention and this pattern of expression was positively correlated with the expression of lactic acid. No significant changes were noted in the expression levels of GFAP, lactic acid, and IL-1ß. CONCLUSIONS: There appears to be a temporal relationship between lumbar CSF drainage and CSF cytokines and oxidative stress markers that may help 1) identify patients at risk for developing delayed SCI and 2) modify patient management to prevent the damage from delayed SCI.

Outcomes of a Novel Single Branched Aortic Stent Graft for Treatment of Type B Aortic Dissection.

BACKGROUND: Intervention on Type B dissection frequently requires landing the proximal edge of the stent graft between the left common carotid artery and left subclavian artery (LSA). The Gore® TAG® Thoracic Branch Endoprosthesis (TBE) is a technology which allows LSA preservation with a single internal branch. METHODS: This study was a prospective non-randomized single-arm clinical trial of patients with type B aortic dissection that were treated with the single branched device. Patients with operative indications for acute, chronic or residual Type B dissections that originated distal to the origin of a left subclavian artery suitable for branch graft placement were eligible for the study. Native aortic and surgical graft proximal landing zones were eligible. RESULTS: Among the 132 patients, there were 25 (18.9%) acute type B dissections, 79 (59.8%) of chronic type B dissections and 28 (21.1%) of residual dissections after previous open Type A repair. Percutaneous access was used in 105 (79.5%) patients. Overall, 30-day mortality occurred in 6 patients (4.5%). The overall 30 day stroke rate was 2/132(1.5%) and the one-year freedom from stroke was 96.8%. Device Technical Success and Procedural Success was achieved in 129/132(97.7%) and 110/132(83.3%) of subjects, respectively and there was one instance of loss of side branch patency. There was no persistent antegrade false lumen flow observed. CONCLUSIONS: In this study of a novel branched endograft device to preserve the LSA in patients with type B dissection undergoing TEVAR, we demonstrate acceptable safety and efficacy outcomes at one year.

A novel hybrid prosthesis for open repair of acute DeBakey type I dissection with malperfusion: Early results from the PERSEVERE trial.

BACKGROUND: Outcomes after hemiarch repair for acute DeBakey type I aortic dissection (ADTI) remain unfavorable, with high rates of major adverse events and negative aortic remodeling. The PERSEVERE study evaluates the safety and effectiveness of the AMDS Hybrid prosthesis, a novel bare metal stent, in patients presenting with preoperative malperfusion. METHODS: PERSEVERE is a prospective single-arm investigational study conducted at 26 sites in the United States. Ninety-three patients underwent ADTI aortic dissection repair with AMDS implantation. The 30-day primary endpoints are a composite rate of 4 major adverse events and the rate of distal anastomotic new entry tears. The secondary endpoints include aortic remodeling. RESULTS: Clinical malperfusion was documented in 76 patients (82%); only radiographic malperfusion, in 17 (18%). The median follow-up in the 93 patients was 5.6 months. Within 30 days, 9 patients died (9.7%), 10 patients (10.8%) experienced new disabling stroke, and 18 patients (19.4%) had new-onset renal failure requiring ≥1 dialysis treatment. There were no cases of myocardial infarction. The composite rate of major adverse events (27%) was lower than that reported in the reference cohort (58%). There were no distal anastomotic new entry tears. Technical success was achieved in 99% of patients. Early remodeling indicated total aortic diameter stability, true lumen expansion, and false lumen reduction in the treated aortic segment. CONCLUSIONS: Early results show significant reductions in major adverse events and distal anastomotic new entry tears, successfully meeting both primary endpoints. The technical success rate was high. AMDS can be used safely in patients with ADTI dissection with malperfusion.