Abstract
Bird-beak configuration after endovascular arch repair refers to a gap between the proximal stent and the lesser curvature of the aortic arch that can potentially lead to life-threatening complications through the formation of a 1A endoleak. This case describes a patient who developed a symptomatic type 1A endoleak due to bird-beaking, years after thoracic endovascular aneurysm repair and a complex supra-aortic debranching. The case was further complicated by a stenosis of the left common carotid artery diagnosed with duplex ultrasound and intraoperative transcranial Doppler exam. Zone 0 thoracic endovascular aneurysm repair was performed with the Gore Thoracic Branch Endograft device with additional retrograde left carotid stenting. We demonstrate the importance and clinical applicability of multimodality imaging during preoperative and intraoperative evaluation, which can help in decision-making, troubleshooting, and to guide the procedure.
Key words: aortic surgery, bird-beak, endoleak, TBE, TEVAR
Graphical Abstract
Visual Summary.
Timeline of Patient History, Presentation, and Hospital Course
History of Presentation
A 78-year-old male presented with acute-onset chest and right shoulder pain that started the prior evening. On presentation, he was normotensive, nontachycardic, afebrile, and on room air. Physical examination revealed no neurologic deficits, and all peripheral pulses were palpable.
Past Medical History
The patient's medical history included permanent pacemaker implantation, stage-III chronic kidney disease, obesity, hypertension, previous transient ischemic attack, former smoker, and complex aortic history: thoracic endovascular aortic repair (TEVAR) in 2006 for Stanford Type B Aortic Dissection with visceral malperfusion. In 2013, due to a type 1A endoleak, he underwent Zone 0 debranching (bypass from the aorta to a conduit graft supplying the innominate artery and left common carotid, with left carotid-subclavian bypass) and antegrade TEVAR (Figure 1).
Figure 1.
Three-Dimensional Reconstruction and Animation of Preoperative Aortic Anatomy
A depiction of complex aortic anatomy at the time of presentation. The patient had undergone TEVAR for TBAD and a second antegrade TEVAR with supra-aortic debranching for type 1A endoleak. Now, one arch vessel is present originating from the mid-ascending aorta which bifurcates into the innominate artery and left common carotid artery. The left common carotid artery perfuses the left subclavian artery via a carotid-subclavian bypass graft. CCA = common carotid artery; LA = patient left; RA = patient right; SCL = subclavian artery; TBAD = type B aortic dissection; TEVAR = thoracic endovascular aneurysm repair.
Differential Diagnosis
Differential diagnoses included acute coronary syndrome, aortic stent graft endoleak, aortic dissection, aneurysm expansion, pulmonary embolism, and aortic rupture.
Investigations
Significant laboratory results on arrival: white blood cell count 7.11, Hgb 16.2, troponin 19, B-type natriuretic peptide 496, creatinine 1.62.
Computed tomography angiography (CTA) performed in the emergency department revealed a type 1A endoleak due to bird-beaking phenomenon of the proximal aortic stent graft and a stable complex thoracoabdominal dissection with extension into the left common iliac artery. The true lumen perfuses the celiac, superior mesenteric, right renal, and inferior mesenteric arteries. The false lumen perfuses the left renal artery (Figure 2).
Figure 2.
Preoperative CTA Diagnosing Type 1A Endoleak
(A and B) CTA evaluation diagnosing type 1A endoleak due to bird-beaking phenomenon of the proximal aortic stent graft. A known stable complex thoracoabdominal aortic dissection with the true lumen perfusing the (C) celiac artery, (D) superior mesenteric artery, (E) right renal artery, and (G) inferior mesenteric artery. (F) The false lumen perfuses the left renal artery. (H) The dissection extends into the left common iliac artery. CTA = computed tomography angiography.
Management
Given his age, cardiac disease, prior sternotomy, and adequate aortic landing zone (2.5 cm distance to the conduit graft), the decision was made to attempt an endovascular repair with proximal extension using a 45 mm × 10 cm GORE C-TAG stent graft (W.L. Gore & Associates). Intravascular ultrasound (IVUS) was used to confirm location in the true lumen prior to deployment. After deployment, there was persistent type 1A endoleak. GORE Trilobe balloon angioplasty was performed on the entire length of the stent graft, but the prior 37-mm TEVAR was constraining the new 45-mm stent graft and stopping it from approximating to the lesser curvature (Figure 3).
Figure 3.
Aortic Arch Angiogram at Completion of TEVAR With Persistent Type 1A Endoleak
Fluoroscopic image showing completion thoracic aortogram after deployment and balloon angioplasty of a 45 mm × 10 cm GORE C-TAG stent graft. Inner curvature approximation is constrained by the prior 37-mm TEVAR leading to persistent “bird-beak” configuration and type 1A endoleak. Adequate perfusion of the conduit graft and coronaries visualized. TEVAR = thoracic endovascular aneurysm repair.
The initial case was stopped. IVUS was performed showing no retrograde dissection, and large sheaths were removed from the groin and closed with Perclose vascular closure devices. On review of the index-case intraoperative transcranial Doppler (TCD), right-to-left shunting suggested left carotid stenosis (Figure 4). Formal carotid duplex was completed which localized significant stenosis at the left common carotid artery to graft anastomosis. He was brought back to the operating room 2 days later with a plan for a single-branch thoracic endograft implantation (GORE thoracic branch endoprosthesis [TBE]; 45 mm × 15 cm with a 12-mm side port; W.L. Gore & Associates) and a left common carotid artery stent (8 mm × 5 cm Viabahn; W.L. Gore & Associates).
Figure 4.
Intraoperative Neuromonitoring With Transcranial Doppler Ultrasound
(A) Preoperative carotid duplex ultrasound: delayed systolic upstroke seen on the left side (circle). (B) Dampened waveform was seen on the left middle cerebral artery (MCA) on the preoperative transcranial Doppler (TCD) exam. (C) Reversed flow (circle) seen in the left vertebral artery. (D) Improved left MCA waveform seen on intraoperative TCD monitoring after stenting (upper arrow). A matching pulsatility index (PI) trend sign seen after stenting (lower arrow) suggests the resolution of stenosis. Previously seen low PI values were the effect of autoregulation due to proximal stenosis on the left side.
Access was obtained in the right brachial artery and the right common femoral artery. The single-vessel conduit graft was cannulated from femoral access, but the Viabahn could not be delivered into the graft due to its sharp reverse takeoff angle. The decision was made to expose the distal left common carotid artery. It was then accessed in a retrograde fashion, and the proximal stenosis was treated with covered stenting with improvement in stenosis on completion angiogram and in TCD waveforms (Figures 4 and 5).
Figure 5.
Post-Left Common Carotid Stenting Angiogram
Fluoroscopic image with fusion markers (representing proximal extent of prior TEVAR, conduit graft origin, and conduit graft bifurcation) and angiogram showing resolution of common carotid artery-conduit graft anastomosis after deployment of a 8 mm × 5 cm Viabahn stent. TEVAR = thoracic endovascular aneurysm repair.
Next, the femoral sheath was upsized to a 26-F GORE dry seal sheath, and an 8-F sheath was introduced into the right brachial artery. The brachial wire was snared and retrieved from the femoral access to allow it to be loaded through the GORE-TBE's side branch on the back table. The device was then introduced from femoral access over a stiff wire, positioned, and deployed under rapid ventricular pacing to prevent displacement and infolding of the proximal edge of the stent graft. An angiogram through the brachial sheath suggested excellent positioning. The side branch component (12 mm × 15 mm × 6 cm) was advanced through brachial access, positioned, and deployed. Postdeployment balloon angioplasty was performed on the main body and side branch. Completion angiogram showed resolution of type 1A endoleak and excellent filling of coronary arteries and the conduit graft (Figure 6).
Figure 6.
Aortic Arch Angiogram After Deployment of TBE
Completion angiogram of the aortic arch after deployment of the GORE TBE (45 mm × 15 cm with a 12-mm side port) and GORE branched limb (12 mm × 15 mm × 6 cm) and balloon angioplasty showing resolution of type 1A endoleak and preservation of blood flow to the coronary arteries and conduit graft. TBE = thoracic branch endograft.
Outcome and Follow-Up
Postoperatively, he was transferred to the intensive care unit without complication. He was transferred out of the intensive care unit on postoperative day 1 and discharged home on day 2 on Dual-antiplatelet therapy is Aspirin 81 mg PO daily, clopidogrel 75 mg PO daily. He remained neurologically intact and had resolution of his chest pain. CTA chest at 1-month follow-up in the clinic showed continued resolution of type 1A endoleak.
Discussion
The bird-beak configuration in endovascular aortic repair represents a critical challenge due to its potential to create a persistent gap between the stent graft and the lesser curvature of the aortic arch. This gap may lead to type 1A endoleak, which poses a significant risk for aneurysm expansion, rupture, and other life-threatening complications.1, 2, 3 This case highlights the delayed manifestation of a symptomatic type 1A endoleak caused by bird-beaking, emphasizing the importance of vigilant long-term surveillance in patients with complex aortic repair. Bird-beaking typically arises in situations of suboptimal proximal landing zones, such as sharp angulation in the aortic arch or inadequate graft oversizing.4, 5, 6 In this case, contributing factors were likely the proximal extent of the prior stent graft terminating in the distal ascending aorta from the prior surgeries and the steep arch angulation.
Endovascular repair of a type 1A endoleak requires meticulous planning and execution. In this case, the proximal extension with a GORE C-TAG stent graft alone did not achieve adequate seal due to persistent bird-beaking caused by the constraints of the prior stent graft, which prevented the new graft's proximal end from reaching proper alignment with the aortic wall, despite the use of a conformable device. This underscores the importance of selecting devices with sufficient radial force, considering advanced solutions such as branched or fenestrated aortic stent grafts, and the difficulty with creating an adequate seal zone in the aortic arch.
TBE received Food and Drug Administration approval in 2022. This endograft has a modular buildup featuring the main body (TBE), which is intended to be deployed in Ishimaru Zone 2, with one side portal for the left subclavian artery as per the manufacturer's Instructions For Use.7,8 In this case, the device was used out of Instructions For Use recommendations to avoid a complex open operation, challenged with inherent higher morbidity and mortality in this elderly patient, especially considering comorbidities and the prior sternotomy.
Multimodality imaging guided every stage of this case, from diagnosis to treatment planning and intraoperative troubleshooting. Preoperative CTA characterized the type 1A endoleak, while TCD and duplex provided essential hemodynamic data on the status of supra-aortic circulation. Intraoperatively, IVUS confirmed cannulation of the true lumen and the absence of retrograde dissection, while 2D-3D fusion image guidance and angiography ensured optimal device deployment and resolution of the endoleak.9, 10, 11, 12 This case underscores the value of combining advanced imaging techniques for optimal outcomes in complex aortic repair.
This case also highlights the importance of long-term follow-up in patients with prior TEVAR, especially those with anatomically complex repairs. Delayed complications such as bird-beaking and stenosis at graft anastomoses can present years after the initial procedure. Regular imaging surveillance with CTA or duplex ultrasound can identify early signs of complications, allowing for timely intervention before catastrophic events occur.9, 10, 11, 12
Conclusions
An elderly male patient presented with potentially life-threatening complications years after complex hybrid treatment of a Stanford type B aortic dissection. The patient was treated comprehensively using a wide array of imaging technologies that facilitated diagnostics and endovascular treatment. The management of delayed symptomatic type 1A endoleak due to bird-beaking in this case underscores the complexity of endovascular re-interventions in patients with prior TEVAR and supra-aortic debranching.
Take-Home Messages
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•
The delayed symptomatic type 1A endoleak caused by bird-beaking highlights the critical need for long-term surveillance and tailored management strategies in patients with prior thoracic endovascular aneurysm repair and complex aortic anatomies.
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Multimodality imaging and advanced endovascular technologies, such as branched stent grafts, are essential for successful diagnosis, decision-making, and repair in these challenging cases.
Equipment List.
| Imaging |
|
|
|
|
| Index case (TEVAR) | ||
|---|---|---|
| Device | Catalog ID Number | Company |
| Ultrasound machine | K200964 | Sonosite |
| Micropuncture needle, wire, 5-F sheath | G48006 | Cook |
| 0.035-inch J wire and 6-F sheath | RSS602 | Terumo |
| 0.035-inch Glidewire × 260 cm, angled tip | GR3509 | Terumo |
| 0.035-inch Amplatz Super Stiff Guidewire × 260 cm, J-tip | G45208 | Boston Scientific |
| 0.035-inch Starter Benson Wire × 260 cm | M001491481 | Boston Scientific |
| Vascular torque device | TD01 | Merit Medical Systems |
| 5-F × 100 cm Bern catheter | 31-405 | Cook |
| 9-F × 100 cm Coda Balloon | G03832 | Cook |
| Sizing Catheter 5-F × 100 cm SidePort PIG | 7602-20M100SH | Merit Medical Systems |
| Dilator, 14-F | G00996 | Cook |
| Dilator, 16-F | G01212 | Cook |
| Dilator, 20-F | G01471 | Cook |
| GORE C-TAG Stent Graft (45 mm × 10 cm) | TGM454510 | W.L. Gore & Associates |
| GORE Trilobe Balloon Catheter | BCL2645 | W.L. Gore & Associates |
| Perclose ProGlide Suture-Mediated Closure Devices | 12,673-03 | Abbott Vascular |
| 24-F × 33 cm GORE Dry Seal Sheath | DSF2433 | W.L. Gore & Associates |
| Ventricle pacing wire | 401,686 | Abbott Vascular |
| IVUS | 88,901 | Phillips |
| Transcranial Doppler | NG2 | Neurasignal |
| Second case: zone 0 TBE and left common carotid stenting | ||
|---|---|---|
| Device | Catalog ID Number | Company |
| Ultrasound machine | K200964 | Sonosite |
| Micropuncture needle, wire, 5-F sheath | G48006 | Cook |
| 0.035-inch J wire and 6-F sheath | RSS602 | Terumo |
| 9-F Sheath × 25 cm | RSB903 | Cook |
| Cook Indy Snare | G51836 | Cook |
| 8-F sheath × 55 cm | G56233 | Cook |
| 8-F Sheath × 90 cm | 54-89001 | Cook |
| 0.035-inch Glidewire × 260 cm, standard tip | GR3509 | Terumo |
| 0.035-inch Glidewire × 260 cm, angled tip | GS3509 | Terumo |
| 0.035-inch Lunderquist Extra Stiff Guidewire × 260 cm, J-tip | G53971 | Cook |
| 0.035-inch Starter Benson Wire × 260 cm | M001491481 | Boston Scientific |
| Roadrunner Uniglide 0.035-inch angled stiff × 320 cm | G30507 | Cook |
| 0.018-inch × 180 cm Platinum Plus Guidewire | M001466010 | Boston Scientific |
| 0.018-inch × 260 cm Platinum Plus Guidewire | M001466020 | Boston Scientific |
| Vascular torque device | TD01 | Merit Medical Systems |
| 5-F × 100 cm Bern catheter | 31-405 | Cook |
| 9-F × 100 cm Coda Balloon | G03832 | Cook |
| Sizing Catheter 5-F × 100 cm SidePort PIG | 7602-20M100SH | Merit Medical Systems Inc |
| Dilator, 14-F | G00996 | Cook |
| Dilator, 16-F | G01212 | Cook |
| Dilator, 20-F | G01471 | Cook |
| GORE TAG Thoracic Branch Endoprosthesis (45 mm × 12 mm × 15 cm) 26-F | TAC124515 A | W.L. Gore & Associates |
| Stent Graft GORE Thoracic Drug Coated 15 mm × 12 mm × 6 cm | TSB121506 A | W.L. Gore & Associates |
| Viabahn Stent (left common carotid) (8 mm × 5 cm) | VBJR080502 A | W.L. Gore & Associates |
| 135 cm × 2.0 cm 7-F Balloon | G35547 | |
| GORE Trilobe Balloon Catheter | BCL2645 | W.L. Gore & Associates |
| Perclose ProGlide Suture-Mediated Closure Devices | 12,773 03 | Abbott Vascular |
| 26-F Gore Dryseal Sheath | DSF2633 | W.L. Gore & Associates |
| Pacing wire | 401,686 | Abbott Vascular |
| IVUS | 88,901 | Phillips |
| Transcranial Doppler | NG2 | Neurasignal |
| Pack CV Minor Open Surgical Set | 111,250 | Medline |
| 2-0 PDS | ETHZ259H | Ethicon |
| 3-0 PDS | ETHZ338H | Ethicon |
| 4-0 Monocryl | ETHY426H | Ethicon |
| Dermabond | DHVM12 | Ethicon |
Funding Support and Author Disclosures
Internal funding was provided for the salary of the research assistant who wrote this paper. Dr Lumsden is a consultant for Boston Scientific, W.L. Gore, Siemens. Dr Atkins is a consultant for Gore Medical and a primary investigator for TEVAR studies and on their scientific advisory board. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
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