As imaging tests are common during medical check-ups, coexisting thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs) are often discovered incidentally. About 10%-20% of patients with AAAs have accompanying TAAs [1]. The most frequent combinations involve descending thoracic aortic pathologies and infrarenal abdominal aneurysms [2]. If TAA and AAA exist simultaneously, multistage surgery is usually considered. However, multistage surgery can bring the burden of multiple anesthesia and an increased risk of complications, such as rupture, while waiting for a second operation. Vascular surgeons, who perform endovascular access, can effectively manage TAAs, except when zone 0 is involved; therefore, if treatment for both lesions is necessary, simultaneous procedures may be considered. We report two cases of simultaneous endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR) for AAA and TAA using a debranching procedure.

This study is retrospective case study and is exempt from Pusan National University Institutionl Review Board deliberation. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

1) Case 1

A 74-year-old male patient with hypertension presented to the emergency department with dyspnea. Computed tomography (CT) angiography showed 4.2 cm sized saccular TAA involving the aortic arch just distal to the left subclavian artery (LSA) and 5.6 cm sized AAA in the infrarenal region. An endovascular approach was selected instead of open repair to reduce the invasiveness of the procedure. In addition, simultaneous endovascular treatment was planned for both pathologies (Fig. 1).

Figure 1. A 4.2 cm-sized saccular thoracic aortic aneurysm (arrow) involving the aortic arch in initial computed tomography (CT) angiography (A) and intra-op angiography (B). Initial CT angiography showed 5.6 cm sized infrarenal abdominal aorta (C). Both pathologies were present in the three-dimensional reconstructive image (D).

Surgery was performed under general anesthesia in the following order: left common carotid artery (LCA)-LSA bypass, TEVAR, and EVAR. After a transverse incision was made over the left clavicle, the platysma and sternocleidomastoid muscles were gently dissected. The junction between the vertebral artery and LSA was identified, and a bypass was performed from the LCA to the LSA in an end-to-side anastomosis fashion using a 7 mm polytetrafluoroethylene (PTFE) graft followed by LSA ligation proximal to the left vertebral artery. TEVAR was performed as the second procedure, and the operation was conducted with a cerebrospinal fluid (CSF) drainage. The placement of the CSF drainage catheter had been arranged in consultation with the Department of Neurosurgery the day before surgery. The administered level was L4-5, and drainage was initiated after insertion. Through this protocol, the CSF was typically drained at a rate of 10 mL/h, with a target CSF pressure of <10 mmHg. TEVAR was performed using a stent graft (Zenith Alpha, Cook Medical) with a diameter of 40 mm and length of 167 mm. The distal landing zone of the stent graft was at the T6 vertebra. EVAR was performed as the third procedure. Since this patient had a right internal iliac artery aneurysm, internal iliac artery embolization was performed initially using multiple coils, followed by EVAR. Standard deployment of the main body (Zenith Flex, Cook Medical) was followed by ipsilateral and contralateral limb extensions. Preoperative creatinine was 0.86 mg/dL and postoperative creatinine was 0.83 mg/dL. The total operative time was 335 minutes. Specific findings suggestive of spinal cord ischemia (SCI), such as diminished motor function and sensation in the extremities, were not observed during postoperative care. After 3 days, follow-up CT angiography was conducted, revealing intact blood flow with minimal type IV endoleak on the aortic arch and type II endoleak on the abdominal aorta. Postoperative care was completed, and the patient was discharged. A follow-up CT angiography at 3 months showed no additional endoleaks (Fig. 2).

Figure 2. Intraoperative angiography showed full-covered graft with a bypass from the left carotid artery to the left subclavian artery (A). Endograft deployment on abdominal aortic aneurysm was performed successfully, and the embolization of the right internal iliac artery was also completed (B). Both procedure outcomes were depicted in a three-dimensional reconstructive image (C).

2) Case 2

A 79-year-old male patient with hypertension and coronary artery disease visited our outpatient clinic. During a medical check-up, a 5.6 cm-sized infrarenal AAA with saccular TAAs on the proximal and distal thoracic aorta was accidentally found. The patient had a history of acute myocardial infarction 3 years prior, and a coronary stent was placed in the mid-right coronary artery at that time. Subsequently, the patient regularly received clopidogrel. Similar to Case 1, the endovascular approach was planned to be performed simultaneously for both pathologies (Fig. 3).

Figure 3. Initial computed tomography angiography showed multiple saccular aneurysms on the thoracic aorta (A) and a 5.6 cm-sized infrarenal abdominal aortic aneurysm (B). Both pathologies were presented in three-dimensional reconstructive images (C).

Surgery was performed in the following order: LCA-LSA bypass, TEVAR, and EVAR. All procedures were performed under general anesthesia. Bypass was performed from LCA to LSA with end-to-side anastomosis using a 7 mm PTFE graft like the previous case. Additionally, proximal LSA ligation was performed.

TEVAR was performed as the second procedure, and CSF drainage was performed using the same protocol, followed by EVAR. The preoperative creatinine was 1.05 mg/dL and the postoperative creatinine was 0.83 mg/dL. The total operative time was 285 minutes. Postoperatively, specific findings suggestive of SCI, were not observed. After 4 days, follow-up CT angiography was performed, and blood flow was intact, with minimal type II endoleak on the abdominal aorta. However, thrombotic occlusion of the LCA-LSA bypass graft was noted, and open thrombectomy was performed. Follow-up CT angiography was performed at 3 months, and there was no additional endoleak (Fig. 4).

Figure 4. Intra-op angiography presented that saccular aneurysm on the upper thoracic aorta was covered with endograft deployment (A), and abdominal aortic aneurysm was also covered with endograft successfully (B). Both procedure outcomes were presented in the three-dimensional reconstructive image (C).

As the average age of the social population continues to rise, the incidence of vascular diseases and the prevalence of aneurysms also increase [3]. Most aneurysm diseases progress chronically; however, sudden ruptures can be fatal. In recent decades, endovascular aneurysm or aortic repair has become an acceptable alternative to open surgery for the treatment of TAA and AAAs, particularly in cases that meet specific anatomical criteria conducive to endovascular repair [4]. Endovascular treatment can be a safe and effective treatment option for high-risk surgical candidates and has a complication rate similar to that of open surgery over a 10-year follow-up period [5,6].

SCI is a serious complication of TEVAR due to blocking of the blood supply to the spinal cord by the stent graft during the procedure. The risk of SCI is multifactorial and related to the extent of aortic stent graft coverage, challenging aortic anatomy, and prolonged operative time [1]. Patients with SCI have lower survival rates than those without, highlighting the importance of preventing SCI [7,8]. Theoretically, it is possible to create a higher ischemic risk due to proceeding with broader range of aortic coverage in simultaneous EVAR and TEVAR. In a single procedure, the SCI risk in TEVAR is reported to be higher than that in EVAR. However, Zhang et al. [9] asserted that there was no significant difference in postoperative complications between a single TEVAR procedure and simultaneous EVAR and TEVAR. Comparing with multistage procedures, simultaneous procedures can also reduce the need for additional surgical interventions and general anesthesia. It also achieves the management of overall aortic pathologies, reducing the risk of interval aortic complications [2].

In our study, the thoracic pathologies were located in the upper thoracic aorta in both cases. As is well known, the location of endograft placement in TAA and the coverage of anterior spinal artery and Adamkiewicz artery are important risk factors regarding the development of SCI. Placing the endograft too low in the descending thoracic aorta can obstruct the blood flow to the lower spinal cord, increasing the risk of ischemia. The TEVAR procedures in our cases did not include the lower thoracic aorta, and the length of the stent graft for TEVAR was relatively short. Therefore, we suspected that these simultaneous procedures could be successfully performed without SCI complications. However, this procedure should be performed carefully considering the anatomical structure.

Regarding the need for CSF drainage in our cases, it is debatable whether these two patients required CSF drainage because the location of stent graft placement in our cases did not involve the lower thoracic aorta, and CSF drainage also carries the risk of complications such as infection, CSF leak, and hemorrhage. However, in the first case, the patient had an internal iliac artery aneurysm requiring embolization. The internal iliac artery contributes to collateral blood supply to the spinal cord; therefore, embolization of the internal iliac artery during TEVAR can potentially increase the risk of SCI.

To establish a secure landing zone, additional aortic branches must be covered during TEVAR. This is often constrained by neighboring critical branches, with procedures requiring Zone 2 coverage being the most common [10]. Except for Zone 0 coverage, vascular surgeons have sufficient ability to perform bypass surgery. In our cases, both patients required LSA coverage. In accordance with the Society for Vascular Surgery (SVS) guidelines for elective endovascular repair of a TAA, which necessitated coverage of the LSA for adequate stent graft seal for adequate stent graft seal, LCA-LSA bypass procedures were performed using a PTFE graft in both cases [11]. According to a previous study, the 5-year graft patency and cerebrovascular accident rates for patients with carotid-subclavian bypass are better with prosthetic grafts than with vein grafts [12].

Simultaneous EVAR and TEVAR can be considered in cases of coexisting TAAs and AAAs when applicable anatomy is present. While the risk of SCI remains a topic of debate, this approach can potentially reduce the need for additional surgical interventions and the risk of interval aortic complications.

Hyuk Jae Jung has been the associate editor of VSI since 2016. He was not involved in the review process. Otherwise, no potential conflict of interest relevant to this article was reported.

Concept and design: MK, HJJ. Analysis and interpretation: MK, HJJ. Data collection: MK, HJJ, DHK, MY. Writing the article: MK, HJJ, JHH, DHK. Critical revision of the article: MK, HJJ, DHK, MY. Final approval of the article: all authors. Statistical analysis: none. Obtained funding: none. Overall responsibility: HJJ.