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Endovascular stent grafting for ascending aorta repair in high-risk patients

Open ArchivePublished:September 10, 2014DOI:https://doi.org/10.1016/j.jtcvs.2014.07.109

      Objectives

      Standard treatment of ascending aortic pathology is open repair, but some patients are too high risk. Thoracic endovascular aortic repair (TEVAR) of the ascending aorta has been used as an alternative. Our objectives were to characterize patients, describe repair methods, and assess outcomes.

      Methods

      From 2006 to 2014, 22 patients underwent supracoronary ascending TEVAR for acute Type A dissection (n = 9), intramural hematoma (n = 2), pseudoaneurysm (n = 9), chronic dissection (n = 2), or aorta-cardiac fistula (n = 2). Mean age was 71 ± 13 years and the maximum proximal aortic diameter was 6 ± 1 cm. Devices were delivered via a transfemoral (n = 10), transapical (n = 7), or axillary (n = 5) artery approach. The proximal landing zone was at the sinotubular junction in 14 patients, mid to distal ascending aorta in 3 patients, and surgical graft from previous ascending repair in 5 patients. More than 1 device was used in 15 patients. Imaging and engineering analysis was performed for all patients.

      Results

      There were 3 hospital deaths (13.6%) (tamponade in 1 patient, bleed from left atrial fistula in another patient). One patient had partial occlusion of the left coronary artery requiring open conversion and died later from multiorgan failure. One patient required early open conversion for retained delivery system. There were 3 strokes, 2 myocardial infarctions, and 2 tracheostomies, but there was no new-onset renal failure. Median follow-up was 12 months. Six patients developed type 1 endoleak: 2 were treated endovascularly, 1 with open repair, 1 resolved, 1 refused treatment, and 1 is being watched. In 2 patients, initial TEVAR was performed as a bridge for ruptured high-risk dissection and were later converted to open repair. Reoperations also included removal of stent graft due to distal migration and repair of left ventricular pseudoaneurysm. There were 3 late deaths. Actual survival at 30 days, 1 year, and 5 years was 86%, 80%, and 75%, respectively.

      Conclusions

      Ascending TEVAR is a feasible alternative to medical therapy for repair of acute and chronic ascending disease in high-risk patients. Development of devices dedicated to treat ascending aortic pathology is needed to improve outcomes.

      CTSNet classification

      Abbreviations and Acronyms:

      CT (computed tomography), TEVAR (thoracic endovascular aortic repair)
      Video clip is available online.
      Conventional treatment of ascending aortic aneurysm or dissection is open repair, but some patients are too high risk for this approach and may benefit from a less invasive alternative with thoracic endovascular aortic repair (TEVAR).
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      • et al.
      Contemporary results of surgery in acute type A aortic dissection: The International Registry of Acute Aortic Dissection experience.
      • Roselli E.E.
      • Brozzi N.
      • Albacker T.
      • Lytle B.W.
      Transapical endovascular ascending repair for inoperable acute type a dissection.
      Several studies have reported safety and effectiveness of TEVAR of the descending aorta, but the role of TEVAR for treating ascending aortic pathology is less well known. Only a small number of studies have described outcomes with this approach.
      • Roselli E.E.
      • Brozzi N.
      • Albacker T.
      • Lytle B.W.
      Transapical endovascular ascending repair for inoperable acute type a dissection.
      • Ihnken K.
      • Sze D.
      • Dake M.D.
      • Fleischmann D.
      • Van der Starre P.
      • Robbins R.
      Successful treatment of Stanford type A dissection by placement of a covered stent graft in the ascending aorta.
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      • Zhou J.
      • Zhao Z.
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      • Feng R.
      • et al.
      Endovascular repair of ascending aortic dissection.
      • Preventza O.
      • Henry M.J.
      • Cheong B.Y.
      • Coselli J.S.
      Endovascular repair of the ascending aorta: when and how to implement the current technology.
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      • et al.
      Endovascular management of ascending aortic pathology.
      • Ronchey S.
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      • Fazzini S.
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      • Tolenaar J.L.
      • et al.
      Endovascular stenting of the ascending aorta for type A aortic dissections in patients at high risk for open surgery.
      • Senay S.
      • Alhan C.
      • Toraman F.
      • Karabulut H.
      • Dagdelen S.
      • Cagil H.
      Endovascular stent-graft treatment of type A dissection: case report and review of literature.
      • Nordon I.M.
      • Hinchliffe R.J.
      • Morgan R.
      • Loftus I.M.
      • Jahangiri M.
      • Thompson M.M.
      Currently there are no commercially available endovascular devices specifically designed to treat the ascending aorta. Compared with TEVAR of the descending thoracic aorta, endovascular therapy for the ascending aorta is challenged by more complex pathology, hemodynamic characteristics, and anatomy. Despite these issues, we have used various endovascular devices to treat high-risk patients without other reasonable treatment options.
      Objectives of our study were to explore the feasibility of TEVAR as an alternative to medical therapy for treating ascending aorta pathology in high-risk patients. Patients are characterized, outcomes are assessed, and recommendations for improvement are formulated based on imaging and engineering analysis.

      Patients and Methods

       Patient Characteristics and Risk Factors

      From 2006 to 2014, 22 patients underwent endovascular supracoronary ascending aortic repair at Cleveland Clinic. Presentation and indications for repair included acute Type A dissection (n = 9; 41%), acute intramural hematoma (n = 2; 9%), pseudoaneurysm (n = 9; 36%), and chronic dissection with aneurysm (n = 2; 9%). One patient presented with hemoptysis and heart failure due to a pseudoaneurysm to pulmonary artery fistula, and another presented with heart failure due to acute dissection of a chronic aneurysm that developed fistula into the dome of the left atrium. Mean age was 70 ± 13 years, 50% were men, and the preoperative mean maximum aortic diameter was 6 ± 1.0 cm.
      Sixteen patients (73%) had a history of previous major cardiac or aortic operation and of these, 4 had multiple previous cardiac operations. All patients were considered too high risk for conventional open repair at the time of presentation. Additional patient details are summarized in Table 1.
      Table 1Patient characteristics
      Overall (N = 22)Acute Type A/IMH (n = 11)Ascending pseudoaneurysm (n = 9)Chronic dissection (n = 2)
      Mean age, y72 ± 1075 ± 1069 ± 870 ± 3
      Male11 (50)5 (50)7 (78)1 (33)
      Baseline comorbidities
       Hypertension20 (91)11 (100)9 (100)2 (100)
       Coronary artery disease11 (50)4 (36)7 (78)0 (0)
       Prior myocardial infarction6 (27)4 (36)2 (22)0 (0)
       Prior stroke4 (18)3 (27)1 (11)0 (0)
       Chronic obstructive pulmonary disease6 (27)4 (36)3 (33)0 (0)
       Chronic renal insufficiency5 (23)2 (18)3 (33)0 (0)
       Atrial fibrillation5 (23)3 (27)1 (11)1 (50)
       Congestive heart failure8 (36)2 (18)5 (63)1 (50)
       Coagulopathy3 (14)3 (27)1 (11)0 (0)
       Respiratory failure2 (9)2 (18)1 (11)0 (0)
       Pericardial effusion4 (18)4 (36)0 (0)0 (0)
       ≥Moderately severe aortic insufficiency4 (18)4 (36)0 (0)0 (0)
       Mild to moderate mitral regurgitation11 (50)4 (36)5 (63)2 (100)
       Malignancy5 (23)2 (18)1 (13)2 (100)
       Diabetes3 (14)3 (27)0 (0)0 (0)
       Liver failure1 (5)0 (0)1 (13)0 (0)
       Prior cardiac/aortic surgery16 (73)5 (45)9 (100)2 (100)
      Values are presented as mean ± standard deviation or n (%). Type A, Type A dissection; IMH, intramural hematoma.

       Imaging analysis

      Detailed imaging analysis was performed in all patients. Computed tomography (CT) scans were reviewed using 3-dimensional imaging software (Terarecon, San Mateo, Calif). Aortic and branch vessel diameter measurements were obtained at multiple landmarks. Length measurements were also taken from the highest coronary to the origin of brachiocephalic artery along 3 paths: the greater curvature, central line of flow, and the lesser curvature. These results are summarized in Table 2.
      Table 2Imaging analysis
      Overall (N = 22)Acute type A/IMH (n = 11)Ascending pseudoaneurysm (n = 9)Chronic dissection (n = 2)
      Aortic diameter, cm
       Mean maximum ascending5.9 ± 25.86 ± 16.2 ± 0.84.7 ± 0.6
       Maximum diameter at sinotubular junction3.8 ± 14.5 ± 13.6 ± 0.33.9 ± 0.2
       TL or inner diameter at sinotubular junction3.4 ± 13.6 ± 0.53.1 ± 0.33.6 ± 0.05
       Maximum distal ascending diameter4.6 ± 14.1 ± 0.65 ± 14.7 ± 0.5
       TL or inner distal ascending diameter3.4 ± 23.4 ± 0.53.4 ± 0.43.9 ± 0.2
      Length highest coronary to innominate artery
       Greater curvature9.6 ± 210 ± 29.3 ± 19.7 ± 0.1
       Central7.8 ± 17.8 ± 17.9 ± 17.8 ± 005
       Lesser curvature6.4 ± 16.3 ± 16.3 ± 0.96.3 ± 0.9
      Distance: Entry tear/pseudoaneurysm to coronary artery3.1 ± 11.8 ± 0.33.8 ± 15.1 ± 1
      Distance: Entry tear/pseudoaneurysm to innominate artery3.6 ± 24.1 ± 23.5 ± 12.3 ± 0.3
      Size of defect (entry tear/pseudoaneurysm neck)17 ± 81.5 ± 0.42.1 ± 0.8
      Aortic arch anatomy
       Mean diameter, cm
      Left subclavian artery1.2 ± 0.11.2 ± 0.21.2 ± 0.41.2 ± 0.1
      Left common carotid1.5 ± 0.61.4 ± 0.51.4 ± 0.61.4 ± 0.6
      Innominate artery1.9 ± 0.51.7 ± 0.41.8 ± 0.51.9 ± 0.5
       Bovine arch4211
       Branch head vessel involvement3300
      Values are presented as mean ± standard deviation or number. Type A, Type A dissection; IMH, intramural hematoma; TL, true lumen.

       Presentation

       Acute Type A dissection and intramural hematoma

      All acute Type A dissection patients (n = 9; 41%) presented as an emergency. Of these, 4 patients (44%) had pericardial effusion, including 1 patient who refused blood transfusion for religious reasons. Four patients (44%) presented with moderately severe aortic insufficiency, whereas 3 patients (33%) had respiratory failure—1 already had tracheostomy in place at the time of presentation and the other 2 were intubated on arrival. Two additional patients presented with chest pain and intramural hematoma with a penetrating ulcer and were treated urgently (Figure 1). All patients in this group were deemed extremely high risk for open repair but had the potential for a reasonable quality of life if they were to survive the acute insult. Endovascular therapy was chosen over medical therapy for 1 of 2 reasons: they had favorable morphology believed to be amenable to definitive repair or they had unfavorable morphology that put them at immediate risk of death without mechanical treatment. The latter were treated with the understanding that the endovascular approach may serve as a bridge to later definitive open repair if their risk improved.
      Figure thumbnail gr1
      Figure 1Preoperative computed tomography, intraoperative fluoroscopy (intra), and postoperative images (post-balloon) of a patient with an ascending intramural hematoma complicated by temporary coronary artery coverage rescued by balloon repositioning.

       Ascending pseudoaneurysm

      In contrast to patients with acute Type A dissection, 8 patients with ascending pseudoaneurysm presented in a stable condition, except for 1 who presented with hemoptysis, respiratory failure, and cardiogenic shock due to an 8.6-cm pseudoaneurysm with a fistula to the right main pulmonary artery in the setting of chronic dissection beyond a previous repair. All patients had a history of previous cardiac surgery and the mean interval to ascending TEVAR was 6.4 ± 5 years. Previous procedures included coronary bypass in 4 patients who developed pseudoaneurysm at the site of a proximal vein graft anastomosis. In the other 5 patients, the prior procedure included root and ascending aortic repair for dissection or aneurysm and aortic valve replacement (n = 4) or resuspension (n = 1). In these patients the pseudoaneurysm arose near the site of the distal graft anastomosis to native aorta (Figure 2).
      Figure thumbnail gr2
      Figure 2Pre- (pre-op) and postoperative (post-op) reconstructed computed tomography images of a patient with an ascending pseudoaneurysm after previous root replacement.

       Chronic dissection

      Two patients presented with complications related to residual chronic dissection after acute Type A repair. Both patients had a small communication between the true and false lumen at the distal anastomosis of the ascending graft. One patient had persistent hemolysis without another source for anemia and required >30 units of blood transfused over a 4-month period with severe left ventricular dysfunction (ejection fraction, 10%-15%) without clear etiology. The other patient had growth of her arch by approximately 15 mm only 4 months following the initial emergency dissection repair (Figure 3). Ascending TEVAR was technically successful in the second patient, but the other required emergency conversion for a retained delivery system. The delivery system was removed under circulatory arrest and the stent graft was left intact.
      Figure thumbnail gr3
      Figure 3Pre- and postoperative (3 months) reconstructed computed tomography images of a patient with chronic dissection and rapid aneurysm growth.

       Operative Details and Technique

      Stent grafts were used in 21 patients (95%) (see Table 3). In 1 patient attempted stent graft delivery was aborted due to difficulty in crossing an existing mechanical aortic valve. This is the patient who presented with pseudoaneurysm after previous Type A repair and fistula from the aorta to pulmonary artery. The pulmonary artery and aortic defects were plugged with atrial septal closure devices and the aorta device was reinforced by a balloon-expandable stent in the ascending aorta.
      Table 3Operative details
      PatientAgeGenderIndicationAppr.Device(s)OutcomeDetails/events
      191MType ATAGore, MedtronicLate deathCOD: unknown
      256FType ATACookEndo Reintv

      Late death
      Type 1 endoleak→TEVAR extension with talent

      COD: pneumonia
      379MType ATFCookLate deathCOD: Lung cancer
      475FType ATFGoreAcute deathEndoleak, rupture
      582FType ATFCookAcute deathLM coverage→open conversion, COD: multi-organ failure
      651FType ATACookAliveEarly endoleak resolved, definitive repair
      784MType ATACookAcute deathCOD: bleeding aorto-atrial fistula, tamponade
      883FType ATACookAliveType 1 endoleak, refused reintervention
      979MType ATFGoreEndo, open reintvTEVAR treated rupture→type 1 endoleak→endo extension, later open repair
      1069FIMHTACookAliveDefinitive repair
      1181FIMHTFGoreAliveDefinitive repair
      1238MPseudoATAxASD + BMSOpen ReintvPseudoA—Pulmonary artery fistula plugged as bridge to open repair→open ascending arch repair

      Definitive repair
      1384MPseudoATFMedtronicAliveDefinitive repair
      1463FPseudoATFCookAliveDefinitive repair
      1555MPseudoATAxCookOpen ReintvPseudoA resolved→Stent migration to arch on CT→open retrieval
      1673MPseudoATFCookAliveDefinitive repair
      1763MPseudoATAxCookEndo ReintvDefinitive repair coil embolization into pseudoA at endoleak, definitive repair
      1864MPseudoATACookAliveDefinitive repair
      1988MPseudoATAxGoreAliveDefinitive repair
      2061FPseudoATFCookAliveSmall endoleak, monitored
      2164MC.DissectionTAxCookOpen Reintv1. Retained delivery system→open conversion direct device fixation
      2. Late left ventricular apex pseudoaneurysm repair, definitive repair
      2274FC.DissectionTFCookAliveDefinitive repair
      Appr., Approach for device delivery; M, male; Type A, acute type A dissection; TA, transapical; COD, cause of death; F, female; Endo, endovascular; Reintv, reintervention; TEVAR, thoracic endovascular aortic repair; IMH, intramural hematoma; TF, transfemoral; LM, left main coronary artery; TAx, transaxillary; ASD, atrial septal defect closure device; BMS, bare metal stent; PseudoA, pseudoaneurysm; CT, computed tomography; C.Dissection, chronic dissection.
      All procedures were done under general anesthesia with heparin for anticoagulation. Device delivery was transfemoral (n = 10), transapical (n = 7), or through the axillary artery (n = 5). Transfemoral delivery was performed through a cut-down exposure of the common femoral artery and stiff wire access across the aortic valve. For transapical delivery, through and through wire access into the left subclavian artery was obtained using a snare technique. Axillary artery approach was performed through a 10-mm surgical graft conduit. In 1 patient with very severe left ventricular dysfunction due to untreated hypothyroidism, the device was deployed while the patient was on full cardiopulmonary bypass. In all others, hemodynamic displacement forces were reduced by rapid ventricular pacing during the device deployment. Transesophageal echocardiography was used in addition to fluoroscopic guidance. Completion angiogram was performed to assess coronary and brachiocephalic vessel patency, and to rule out endoleak. All patients were transferred to the intensive care unit intubated.
      In patients who underwent ascending aortic stent grafting, 16 out of 21 patients had proximal landing zone in the native proximal aorta: sinotubular junction in 13 and mid to distal ascending aorta in 2 patients. In the other 5 patients, the proximal landing zone was a surgical graft from previous open ascending aortic repair. More than 1 device was used in 14 patients (64%).

       Additional intraoperative procedures

      Five patients had coronary artery access obtained during the ascending repair. In 2 patients, coronary intervention was planned: a clinically important circumflex artery stenosis was stented and a saphenous vein graft where pseudoaneurysm originated was coiled to avoid type 2 endoleak. In 3 others, wire access was obtained due to concern that the device would be deployed close to the origin.
      Two patients required intraoperative open conversion to manage acute complications. In 1 patient who underwent transfemoral emergency TEVAR for acute Type A dissection, there was a partial occlusion of the left coronary artery by the stent graft. The patient was immediately placed on cardiopulmonary bypass support via cannulation of the femoral vessels. Initial attempts at balloon-facilitated repositioning was not successful. During hypothermic circulatory arrest, the stent graft was removed and the ascending aorta was replaced. This patient died on postoperative day 6 due to stroke and multiorgan failure. A second patient who required open conversion had chronic dissection after previous Type A repair. This patient had persistent hemolysis from a small entry tear at the distal suture line. The device was delivered from the left axillary artery. After deploying the stent graft, a portion of the delivery system was retained. Following multiple failed attempts at removal of the delivery system, the patient was placed on cardiopulmonary bypass support, cooled, and redo sternotomy was performed. Previous surgical graft was opened and the delivery system released. The remaining proximal end of the stent graft was secured with sutures and the aortotomy was closed.
      One patient was placed on cardiopulmonary bypass temporarily after stent-grafting an acute dissection due to poorly tolerated rapid ventricular pacing, but was easily weaned after resuscitation. Two other patients had temporary coverage of a coronary artery by the stent graft, but were salvaged by balloon repositioning of the device distally (Coda; Cook, Bloomington, Ind) (Figure 1). Both had immediate hemodynamic recovery, normalization of the electrocardiogram, and no clinical sequelae of the ischemic event.

       Definitions, Follow-up, Statistics, and Engineering Analysis

      Stroke was defined as neurologic deficit lasting >24 hours confirmed by cross-sectional imaging of the brain or documentation by a neurologist. Renal failure was defined as the need for hemodialysis and respiratory failure was defined as the need for reintubation or tracheostomy postoperatively. CT was performed before discharge and during outpatient follow-up scheduled at 3 months then annually unless otherwise indicated. Median follow-up was 12 months.
      Descriptive statistical analyses are used to present variables for the study. Continuous variables are presented as median or mean ± standard deviation, and categorical variables are presented as percentages.
      Each operation was retrospectively reviewed from the initial planning stages through late follow-up imaging with a critical eye toward improvement. An ideal result was that in which the device primarily and definitively treated the presenting indicated problem in a manner comparable to the desired expected result of stent grafting for an on-label indication without life-threatening intraoperative or hospital complications. All others were considered to have fallen short of this ideal. Shortcomings of each operation were classified as being related to the patient, device, or delivery issues. Patients' issues included anatomic, morphologic, or physiologic concerns. Device-related issues included factors like size, shape, fixation, and conformability. Delivery modes of failure included access, mode of expansion, and accuracy in positioning.

      Results

       Early

      Two patients (9%) required early conversion to open repair as described above. There were 3 hospital deaths (13.6%); 1 was intraoperative. All 3 underwent emergency repair of acute Type A dissection. One refused blood transfusions for religious reasons and died on postoperative day 4 due to rupture and tamponade. Another had a dissected chronic ascending aneurysm that eroded into the left atrium and bled from the left atrium after ascending stent grafting and resulted in tamponade and intraoperative death. The third patient died from multiorgan failure on postoperative day 6 after partial occlusion of the left coronary artery required conversion to open repair. The patient who required open conversion for a retained delivery system tolerated the repair, stopped hemolyzing, and had full recovery of his systolic function but required later reoperation for an apical pseudoaneurysm. This patient is still alive and doing well 4 years later.
      Three patients (13.6%) had stroke, 2 had myocardial infarction (9%), and 2 patients (9%) required tracheostomy for respiratory failure. Six patients had a history of chronic renal insufficiency, but there was no new onset renal failure requiring dialysis.

       Late

      There were 3 late deaths: 1 patient died of lung cancer, 1 died of pneumonia, and the cause is unknown in the third. The latter was a 91-year old man who experienced a stroke and was discharged to a nursing facility where he died. Actual survival at 30 days, 1 year, and 5 years was 86%, 77%, and 73%, respectively. Six of 19 survivors (32%) required late reinterventions (4 open, 2 endovascular).

       Late Reinterventions

      One patient had distal migration of the stent graft into his arch found incidentally during follow-up CT at 6 months. The patient had no symptoms, but his pseudoaneurysm had completely resolved. The pseudoaneurysm repair was done endovascularly because he was acutely ill, but he had since recovered and was taken electively for open extraction of the device. The other late unanticipated reoperation was performed for left ventricular apex pseudoaneurysm caused by wire perforation in the patient who had difficult delivery system extraction.
      In 2 other patients, open reoperations were planned. At the time of initial emergency TEVAR both patients were too sick for open repair. One had acute dissection and rupture only 2 months following mitral repair and coronary bypass grafting complicated by myocardial infarction requiring coronary stenting. The rupture was successfully treated by stent grafting and the residual dissection and aneurysm were treated 4 months later when clopidogrel could be safely stopped. The other patient presented with hemoptysis, in respiratory failure and cardiogenic shock due to high output fistula. The fistula was treated endovascularly, the patient's condition was stabilized, and he was safely taken for redo open repair 6 days later.

       Endovascular Reinterventions

      One patient was treated with TEVAR extension for distal type 1 endoleak and it resolved. Another patient underwent coil embolization of the pseudoaneurysm for endoleak. There were 4 other type 1 endoleaks. One was the planned conversion described above, 1 without aneurysm resolved slowly over a 2-year period, 1 refused further treatment, and the last patient is being monitored expectantly.

       Engineering Analysis

      Seven patients (32%) had an ideal result after the initial procedure. In 9 others, secondary success was achieved with an adjunctive procedure either at the time of the initial repair or at a later reintervention, for a rate of secondary success achieved in 73%. Of the 6 incomplete repairs, 3 died in hospital and 3 others have untreated endoleaks. One died before the endoleak was addressed, 1 refused additional therapy, and the third is being monitored. Of the various modes of failure identified, 6 were deemed patient-related, 7 were deemed device-related, and 9 were delivery-related. In 7 patients mode of failure was attributable to 2 categories.

      Discussion

       Principal Findings

      For patients at excessive risk for conventional repair of acute ascending dissection, pseudoaneurysm, or chronic dissection, endovascular repair may offer a reasonable option over medical therapy. The morbidity is significant, but the procedure can be lifesaving in selected patients. Better outcomes may be achieved with an improved understanding of patient selection, and development of ascending aorta-specific devices and delivery systems for treating high-risk patients.

       Patient Selection

      Several different devices are now commercially available for stent grafting the descending aorta, and some of these are now approved for use in dissections as well as aneurysms. The ascending aorta is very different from the descending aorta in size, shape, hemodynamic forces, and proximity to other anatomic structures. These differences are important to consider when selecting endovascular therapy.
      The proximity of the aortic valve and coronary arteries to the ascending aorta make it particularly challenging to obtain seal and fixation within the proximal landing zone.
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      • et al.
      Computed tomography-based anatomic characterization of proximal aortic dissection with consideration for endovascular candidacy.
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      • et al.
      Endovascular approaches to acute aortic type A dissection: a CT-based feasibility study.
      Current guidelines for stent grafting of the descending aorta typically recommend a 2-cm length for the proximal landing zone, but this length is most important for treating degenerative fusiform aneurysm where there is greater potential for device migration compared with patients with the pathologies described in our experience. Others have suggested strict criteria for stent grafting the ascending aorta with a landing zone of at least 2 cm and aortic diameter <40 mm.
      • Lu Q.
      • Feng J.
      • Zhou J.
      • Zhao Z.
      • Bao J.
      • Feng R.
      • et al.
      Endovascular repair of ascending aortic dissection.
      • Preventza O.
      • Henry M.J.
      • Cheong B.Y.
      • Coselli J.S.
      Endovascular repair of the ascending aorta: when and how to implement the current technology.
      • Ronchey S.
      • Serrao E.
      • Alberti V.
      • Fazzini S.
      • Trimarchi S.
      • Tolenaar J.L.
      • et al.
      Endovascular stenting of the ascending aorta for type A aortic dissections in patients at high risk for open surgery.
      • Moon M.C.
      • Greenberg R.K.
      • Morales J.P.
      • Martin Z.
      • Lu Q.
      • Dowdall J.F.
      • et al.
      Computed tomography-based anatomic characterization of proximal aortic dissection with consideration for endovascular candidacy.
      In our experience, this was most easily achievable in the subset of patients who presented with pseudoaneurysm and chronic dissection. In these patients, the mean distance from the highest coronary artery to the neck of the pseudoaneurysm or distal suture line was 3.8 ± 1 cm and 5.1 ± 1 cm, respectively (Table 1). Preventza and colleagues
      • Preventza O.
      • Henry M.J.
      • Cheong B.Y.
      • Coselli J.S.
      Endovascular repair of the ascending aorta: when and how to implement the current technology.
      recently described their successful experience with ascending stent grafting in 6 patients with pseudoaneurysm, none of whom had acute Type A dissection.
      Several other reports of ascending stent grafting have been described in patients with Type A dissection.
      • Roselli E.E.
      • Brozzi N.
      • Albacker T.
      • Lytle B.W.
      Transapical endovascular ascending repair for inoperable acute type a dissection.
      • Ihnken K.
      • Sze D.
      • Dake M.D.
      • Fleischmann D.
      • Van der Starre P.
      • Robbins R.
      Successful treatment of Stanford type A dissection by placement of a covered stent graft in the ascending aorta.
      • Lu Q.
      • Feng J.
      • Zhou J.
      • Zhao Z.
      • Bao J.
      • Feng R.
      • et al.
      Endovascular repair of ascending aortic dissection.
      • Ronchey S.
      • Serrao E.
      • Alberti V.
      • Fazzini S.
      • Trimarchi S.
      • Tolenaar J.L.
      • et al.
      Endovascular stenting of the ascending aorta for type A aortic dissections in patients at high risk for open surgery.
      • Senay S.
      • Alhan C.
      • Toraman F.
      • Karabulut H.
      • Dagdelen S.
      • Cagil H.
      Endovascular stent-graft treatment of type A dissection: case report and review of literature.
      In our subset of patients with acute Type A dissection, 7 had the dissection extend at least partially into the aortic root and 4 patients had at least moderately severe (ie, 3+) aortic insufficiency. The mean distance from highest coronary to entry tear measured only 1.8 ± 0.3 cm on center line of flow analysis, and the aorta was short. In both patients with intramural hematoma, it extended to the root. Despite these anatomic challenges, the valve function improved to mild in each of those 4 patients, and the patients with intramural hematoma fared very well. Nonetheless, all 3 early deaths occurred in patients presenting with acute Type A dissection. The 3 late deaths also occurred in this subset, but only one of those was potentially related to the dissection and operation. All 6 patient-related modes of failure occurred in these patients as well, and they represent the sickest cohort of the series. Although the entry tear was particularly close to the aortic root in several of these patients, the greater challenge occurred in those patients who had that finding in combination with a preexisting ascending aneurysm that presented as acute dissection. This combination was particularly bad because it led to difficulty with both the proximal and distal landing zones.
      Understanding the limitations of this technology is critical to understanding its application. Even in a patient in whom an ideal definitive repair may not be expected with endovascular therapy, the treatment may still be valuable. In 2 of our patients we were able to bridge them from presentation in extremis to an eventual open repair that they may not have tolerated otherwise.

       Device Considerations

      Currently available stent grafts do not fully address the unique features of ascending aortic anatomy. The ascending aorta is typically broader in diameter than the descending aorta, and because it is a curved structure, there is a significant difference in lengths along the greater and lesser curves. In a few instances the ascending aorta was long enough to use a 10-cm thoracic stent graft, but in most, adequate coverage was obtained by the use of aortic extension cuffs from either thoracic or infrarenal stent-graft systems. Multiple cuffs were used in most patients. The length along the greater curve was accurate in predicting the adequate length needed. Ascending aorta-specific device designs should include larger-diameter devices with a precurved shape in shorter lengths (on average about 7-9 cm).
      • Moon M.C.
      • Greenberg R.K.
      • Morales J.P.
      • Martin Z.
      • Lu Q.
      • Dowdall J.F.
      • et al.
      Computed tomography-based anatomic characterization of proximal aortic dissection with consideration for endovascular candidacy.
      • Lu T.C.
      • Huber C.H.
      • Rizzo E.
      • Dehmeshki J.
      • von Segesser L.K.
      • Qanadli S.D.
      Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies.
      • Sobocinski J.
      • O'Brien N.
      • Maurel B.
      • Bartoli M.
      • Goueffic Y.
      • Sassard T.
      • et al.
      Endovascular approaches to acute aortic type A dissection: a CT-based feasibility study.
      Improved conformability of the device to fit the curvature of the aorta and provide a better seal along entry tears could also be important characteristics to consider.
      Excessive hemodynamic forces in the ascending aorta typically lead to variations in diameter of the normal ascending aorta by at least 8%.
      • Lu T.C.
      • Huber C.H.
      • Rizzo E.
      • Dehmeshki J.
      • von Segesser L.K.
      • Qanadli S.D.
      Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies.
      These changes may compromise precise deployment of the devices and can also increase the risk for late migration. In our patient with the late incidental finding of device migration, we suspect the device was undersized. For chronic disease indications we recommend oversizing by about 20% instead of the typical <10% recommended for acute dissections.
      Other future considerations for durable device design include the use of active fixation adjuncts, such as barbs, or off-the-shelf versions with a branch for the brachiocephalic artery.
      • Haulon S.
      • Greenberg R.K.
      • Spear R.
      • Eagleton M.
      • Abraham C.
      • Lioupis C.
      • et al.
      Global experience with an inner branched arch endograft.

       Delivery for Ascending TEVAR

      The most common inadequacies were related to delivery issues. The device not only commonly needs to be accurately positioned with a margin of error of <1 to 2 mm, but it needs to lie coaxially across the sinutubular junction. All 3 of the patients who had inadvertent coronary coverage had the device delivered from a transfemoral approach and 2 of these even had the at-risk coronary artery accessed preemptively with a coronary artery wire that did not prove to be very helpful. Use of the ventricular apex or axillary artery shortens the length of delivery and therefore may improve accuracy. In patients who had transapical delivery, the wire access was established “through and through” from the apex to the left axillary, providing more ability to adjust the position of the device at the time of deployment. Fortunately, in 2 patients in whom the coronary artery was covered, we were able to salvage the procedure by repositioning the device with inflation of and ejection against a large conformable balloon. Improved delivery systems should allow for a graduated deployment to improve accuracy and the potential for repositioning.
      Hussain and colleagues
      • Hussain J.
      • Strumpf R.
      • Wheatley G.
      • Diethrich E.
      Percutaneous closure of aortic pseudoaneurysm by Amplatzer occluder device-case series of six patients.
      reported their experience using atrial septal defect closure devices for treating ascending aortic pseudoaneurysm in 6 patients with moderate success. We found this approach useful as a bailout in a patient in whom we could not traverse a mechanical valve. This highlights the importance of having a delivery system with a short tip, and more importantly the flexibility to provide both endovascular and open rescue procedures to address potential complications in these evolving procedures performed on high-risk patients.
      • Roselli E.E.
      • Idrees J.
      • Mick S.
      • Kapadia S.
      • Tuzcu M.
      • Svensson L.G.
      • et al.
      Emergency use of cardiopulmonary bypass in complicated transcatheter aortic valve replacement: importance of a heart team approach.

      Conclusions

      Endovascular therapy of the ascending aorta is feasible and can be lifesaving in patients who are too high risk for open repair. Better outcomes may be achieved with development and refinement of new stent graft devices and delivery systems specifically designed to treat ascending aortic pathology.

      Supplementary Data

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      Linked Article

      • Notice of Correction
        The Journal of Thoracic and Cardiovascular SurgeryVol. 152Issue 1
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          Re: Roselli EE, Idrees J, Greenberg RK, Johnston DR, Lytle BW. Endovascular stent grafting for ascending aorta repair in high-risk patients. J Thorac Cardiovasc Surg. 2015;149:144-54.
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