1. Introduction
Thoracic endovascular aortic repair (TEVAR) is widely used for treatment of most thoracic aorta pathologies, including aortic dissection, penetrating aortic ulcer (PAU), and pseudoaneurysm, but remains challenging, particularly for lesions involving aortic arch branch vessels. TEVAR using chimney stent graft is relatively easy to perform; however, it can result in a high incidence of branched stent occlusion and endoleak, due to gutters between stents.[ 1 ] To maintain the normal anatomical structure of the aorta, optimize the blood supply of branch arteries, and avoid gutter formation, branched and fenestrated stent graft techniques are promising alternative TEVAR strategies in complex cases, but are demanding of physician operating skills.[ 2 ] Here, we present a case of successful double-fenestrated stent graft implantation in a patient diagnosed with an irregular aortic arch aneurysm with PAU and intramural hematoma, with good outcomes at 1-year follow-up.
The patient has given his consent to publish his clinical data and images in the journal.
2. Case presentation
A 43-year-old-male patient complaining of paroxysmal chest pain for 1 month, which had been exacerbated for 10 d, was admitted to the Department of Cardiology, General Hospital of Northern Theater Command, Shenyang, Liaoning, China, in December 2019. Acute coronary syndrome and acute pulmonary embolism were both excluded, since initial electrocardiogram, laboratory tests, and imaging examinations, including transthoracic echocardiography, were all negative for those diagnoses. An irregular aortic arch aneurysm, extending from the beginning of the left subclavian artery (LSA) to the descending aorta, was diagnosed and measured by thoracoabdominal computed tomographic angiography (CTA), which also showed ascending aortic dilatation (maximum diameter of 45 mm) [Figure 1 ]. The patient had hypertension (grade I), without regular medical therapy for 5 years, with a family history of hypertension and cerebral infarction. No previous history of heart attack or stroke was claimed, and Marfan syndrome was excluded, according to the revised Ghent nosology for Marfan syndrome.[ 3 ]
Figure 1:: Thoracoabdominal computed tomographic angiography image of the patient on admission. (A) Level of the left subclavian artery ostium; (B) Level of aortic arch ; (C) Level of the distal end of the lesion.
We considered a modified TEVAR technique as most suitable treatment, as the patient refused surgery. The intervention involved: (1) modification and implantation of a double-fenestrated stent graft, to achieve revascularization of the aortic arch through the femoral artery, and left radial artery cannulation under general anesthesia; (2) implantation of a balloon-expandable bare stent inside the modified double-fenestrated stent graft, for better expansion and optimal seal to prevent endoleaks.
Intraoperative angiogram of the aorta was performed [Figure 2 ]. A 5F pigtail catheter was accessed to the ascending aorta via the right femoral artery before angiography, which showed an aortic arch aneurysm (maximal diameter of 75 mm) [Figure 2A ] and aortic reference vessel diameter of 37 mm. Two physicians measured the diameters of the aorta and branches, and locations and angles of the branches via CT three-dimensional (3D) reconstruction [Figure 3 ] [Table 1 ] and aortic angiography. Based on these measurements, one of the 2 physicians created 2 fenestrations at the corresponding sites in the ostium of the left common carotid artery (LCCA) and the LSA in a 40 mm × 40 mm × 150 mm Valiant Captiva thoracic stent graft (Medtronic, Minneapolis, Minnesota, USA) [Figure 4 ] using mini-scissors in vitro , then replaced the modified stent graft back into the delivery system. A TSMG-35-260-LES Extra Stiff Wire Guide (Cook Medical, Bloomington, Indiana, USA) was used to route the 40 mm × 40 mm × 150 mm thoracic stent graft to the aortic arch , with the stent’s proximal end located at the distal edge of the innominate artery ostium. The stent graft was gradually released and adjusted under angiography, then deployed, with systolic blood pressure lowered to 90–100 mmHg, to further improve accuracy when blood flowing through both the LCCA and LSA could be clearly observed. Re-performed angiography showed excellent expansion of the stent graft, without any endoleaks, and no blockage of the innominate artery or LCCA, with blood to the aneurysmal sac through the fenestration, and retention of LSA antegrade flow. A memory snare was delivered to the LSA via the radial artery, and successfully past the fenestration to the aortic arch . Following repeated adjustment of the memory snare and smooth guide wire orientation, the super smooth guidewire was captured and carried outside via the radial artery. Next, a VIABAHN VBH100502W (W.L. Gore & Associates, Flagstaff, Arizona, USA) covered stent graft was routed via a super smooth guidewire to the LSA-aortic arch and deployed after precise positioning. Subsequent angiography showed insufficient expansion, but no endoleaks. To improve efficacy, the femoral artery was accessed with a JR 3.5 8F guiding catheter and a 10 mm × 39 mm PALMAZ GENESIS bare stent (Cordis, Bridgewater, New Jersey, USA) was delivered into the VBH100502W covered stent graft and released at 10 atm after precise positioning. Final angiography showed satisfactory expansion of stent grafts and sufficient blood flow in the aorta, LCCA, and LSA [Figure 2B ]. All guide wires and catheters were removed, the right femoral and left radial arteries repaired, the skin sutured, and the operative areas bandaged.
Table 1 -
Aortic measurements were obtained from the patient using the distal edge of the innominate artery ostium on the greater curvature of the aorta as baseline via three-dimensional computed tomographic reconstruction.
Aortic measurement
Aortic diameter, mm
Branch diameter, mm
Angle,°
Distance, mm
Innominate artery
37.2
10.0
LAO30
0
Left common carotid artery
34.0
8.0
LAO40
11.5
Left subclavian artery
67.4
11.0
LAO56
33.0
LAO: Left anterior oblique.
Figure 2:: Intraoperative angiogram of the aorta. (A) Angiogram before implantation of the aortic stent graft; (B) Angiogram after all 3 stent grafts were deployed.
Figure 3:: Thoracoabdominal three-dimensional computed tomographic reconstruction of the aorta (A and B) and measurements of the innominate artery (C and D), the left common carotid artery (E and F), and the left subclavian artery (G and H).
Figure 4:: The physician created 2 fenestrations in a 40  mm × 40  mm × 150  mm Medtronic VAMF stent graft in vitro . The white arrow shows the fenestration (d = 8  mm) of the left common carotid artery. The black arrow shows the fenestration (d = 6  mm) of the left subclavian artery.
The patient appeared to have no symptoms after the TEVAR and medical treatment with β-blockers, angiotensin-converting enzyme inhibitors, and blood pressure controlled at below 130/90 mmHg. His postoperative recovery was uneventful and he was discharged 3 d after the intervention. According to his first CTA follow-up 1 month later [Figure 5A–C ], compared with preoperative CT images, the stent grafts were well-apposed without endoleak, migration, or branch artery occlusion, and the hematoma was slightly absorbed. His second CTA follow-up 1 year later showed that the hematoma was almost completely absorbed [Figures 5D–F and Figure 6 ]. In addition, the patient has remained asymptomatic, with blood pressure stably controlled at around 120/75 mmHg right side and 105/75 mmHg left side, with good clinical status, during the past year.
Figure 5:: Thoracoabdominal computed tomographic angiography image of the patient at 1-month follow-up (A–C) and at 1-year follow-up (D–F). (A) Level of the LSA ostium at 1-month follow-up; (B) Level of aortic arch at 1-month follow-up; (C) Level of the distal end of the lesion at 1-month follow-up; (D) Level of the LSA ostium at 1-year follow-up; (E) Level of aortic arch at 1-year follow-up; (F) Level of the distal end of the lesion at 1-year follow-up. LSA: Left subclavian artery.
Figure 6:: Thoracoabdominal three-dimensional computed tomographic reconstruction image of the patient at 1-year follow-up. (A) Reconstruction image on left anterior oblique 31º; (B) Reconstruction image on right-anterior oblique 132º.
3. Discussion
In 1994, Dake et al[ 4 ] reported the first successful treatment of aortic aneurysm by aortic endovascular repair (EVAR). Reconstruction of the aortic lumen structure by covering intimal tears or ulcer sites has advantages, including minimal invasiveness and lower risks of early mortality and major complications, compared with traditional surgery. EVAR has become the preferred treatment method for Stanford type B aortic dissection, descending thoracic aortic aneurysm , and infrarenal abdominal aortic aneurysm , due to its good safety profile, relatively low invasiveness, and rapid postoperative recovery. Nevertheless, when lesions involve the aortic arch , problems (ie, insufficient proximal landing zone and vital branch involvement) are often encountered in the application of EVAR, due to its complex anatomy, involving important cerebral vascular branches. At present, common interventional methods include branched and chimney stent graft technologies, as well as custom-made fenestrated, in situ fenestrated, and pre-fenestrated stent graft approaches.[ 5–7 ] Chimney technology tends to result in a high incidence of endoleaks,[ 8 ] and poor long-term prognosis,[ 9 ] as well as retrograde tear. Custom-made fenestrated TEVAR is a feasible approach for specific patients that requires sufficient time and preparation, has a high technical success rate, and acceptable rates of complications, including stroke and paraplegia.[ 10 ] The in situ fenestrated technique is favorable for aortic reconstruction, but can be highly challenging when there is a type III arch, and may require temporary block of the arch blood and implementation of extracorporeal circulation to protect cerebral blood flow. Furthermore, the fact that excessive carotid operation can increase the incidence of neurological complications must be considered. Despite its technical complexity and the requirement for sufficient experience in precise creation of fenestrations and stent graft implantation, lack of which can lead to severe intraoperative complications, in vitro pre-fenestrated stent graft technology prevents the disadvantages of other approaches described above.[ 11–13 ] Branched stent graft technology combined with pre-fenestrated stent graft plays a vital role in fixation, and significantly decreases the incidence of aortic stent displacement. Moreover, branch endoleaks after fenestrated-branched endovascular aortic repair are reported to frequently resolve spontaneously.[ 14 ] This technique broadens the alternatives available for TEVAR of aortic arch diseases, as well as reducing postoperative complications.
One challenge for TEVAR with modified double-fenestrated stent graft during the operation is to ensure accurate alignment of the fenestration with the corresponding vessel orifice by accurate measurement of diameters, clock face angles, and relative distances between branch vessels, as well as precise deployment during the operation. In our case, the patient had an oval aortic arch lumen with an irregular aneurysm involving the LSA, which made the operation more difficult and complex. Furthermore, his LSA orifice was not located at the 12:00 direction on the great curvature of the aortic arch . The LSA presented a sharp angle, rather than being perpendicular to the tangent of the aortic arch , which made it difficult to guide the wire from the aortic arch into this branch. Therefore, to avoid damaging the vessel by excessive adjustment of the wire, a memory snare was applied in the aortic arch to establish a common access connecting the femoral artery with the target LSA to the brachial artery by a through-and-through wire, which facilitated alignment of the fenestration to the target branch. Considering that the aneurysm involved the LSA orifice, and that a fenestrated aortic stent graft alone could not achieve the desired sealing between the endograft and the dilated vascular wall, we applied a balloon-expandable covered stent in the target branch to bridge and stabilize the orifice and optimize sealing of the endograft, with a bare metal stent for reinforcement or relining. Our deployment procedure comprises several steps, as follows: first, intraoperative angiography should be strictly perpendicular to the LSA, to achieve clock face alignment, and the optimal position of the C-arm determined preoperatively on the 3D CT reconstruction; second, make a ring-shaped marker on the fenestration of the stent graft for accurate deployment on the outer curve of the aorta and alignment with the LSA; third, the aortic stent graft is gradually released; and, finally, make a case-by-case decision that whether to apply a balloon-expandable covered stent in the branch to address incomplete apposition of the aortic endograft at the involved vessel orifice.
In our case, it was critical to determine the location and size of multiple fenestrations as accurately as possible through 3D CT reconstruction. In addition, the LSA had an aneurysmal root and presented a sharp angle, rather than being perpendicular to the tangent of the aortic arch , which made it difficult to align the fenestration on the aortic stent with the LSA orifice. Therefore, deployment of the aortic stent required the experience and skills of the physician, which were pivotal for successful apposition and effectiveness of the subsequently deployed branched stent.
4. Conclusion
Use of modified pre-fenestrated stent graft for TEVAR of aortic arch aneurysm is feasible and effective for maintaining the patency of aortic branches and achieving favorable endovascular aortic arch repair. Furthermore, it can avoid the disadvantages of traditional surgery, such as greater trauma and higher rates of complications. The long-term prognosis of patients treated using this technique and the durability of stent grafts require further analysis in studies with larger sample series.
Funding
None.
Conflicts of interest
None.
References
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