Strategy for thoracic endovascular aortic repair based on collateral circulation to the artery of Adamkiewicz

Patterns of collateral arteries to the spinal cord after thoraco-abdominal aortic aneurysm repair

OBJECTIVES

Our goal was to evaluate postoperative patterns of collateral arteries to the spinal cord during occlusion of the segmental arteries supplying the artery of Adamkiewicz (AKA).

METHODS

Between April 2011 and December 2022, a total of 179 patients underwent thoraco-abdominal aortic aneurysm repair; 141 had an identifiable AKA on preoperative multidetector computed tomography scans, 40 underwent thoraco-abdominal aortic aneurysm replacement (TAAR) and 101 underwent thoracic endovascular aortic repair (TEVAR). New postoperative collateral blood pathways invisible on preoperative contrast-enhanced computed tomography scans were identified in 42 patients (10 patients who had TAAR vs 32 patients who had TEVAR) who underwent preoperative and postoperative multidetector computed tomography scanning for AKA identification.

RESULTS

The thoracodorsal and segmental arteries were the main collateral pathways in both groups. Th9-initiated collaterals were the most common. Collaterals from the internal thoracic artery were observed in the TEVAR group but not in the TAAR group. One patient in the TEVAR group experienced postoperative paraparesis, which was not observed in the TAAR group. Postoperative paraplegia was more common in the non-Th9-origin group, but this difference was not significant.

CONCLUSIONS

Thoracodorsal and segmental arteries may be important collateral pathways after TEVAR and TAAR. For thoracodorsal arteries, preserving the thoracodorsal muscle during the approach would be crucial; for segmental arteries, minimizing the area to be replaced or covered would be paramount. An AKA not initiated at the Th9 level poses a high risk of postoperative paraplegia.

Covering the intercostal artery branching of the Adamkiewicz artery during endovascular aortic repair increases the risk of spinal cord ischemia

Objectives

This study aimed to determine the relationship between covering the intercostal artery branching of the Adamkiewicz artery (ICA-AKA) and spinal cord ischemia (SCI) during thoracic endovascular aortic repair (TEVAR).

Methods

Patients who underwent TEVAR from 2008 to 2022 were enrolled. Stent grafts covered the ICA-AKA in 108 patients (covered AKA group) and stent grafts didn't cover the ICA-AKA in 114 patients (uncovered AKA group). The characteristics of 58 patients from each group were matched based on propensity scores.

Results

No significant differences in SCI rates were detected between the covered AKA (10%; 11/108) and uncovered AKA (3.5%; 4/114) groups (P = .061). Shaggy aorta (odds ratio [OR], 5.16; 95% confidence interval [CI], 1.74-15.3, P = .003), iliac artery access (OR, 6.81; 95% CI, 2.22-20.9, P = .001), and procedural time (OR, 1.01; 95% CI, 1.00-1.02, P = .003) were risk factors for SCI in the entire cohort. Although covering the ICA-AKA (OR, 2.60; 95% CI, 0.86-7.88, P = .058) was not a significant risk factor, shaggy aorta (OR, 8.15; 95% CI, 2.07-32.1, P = .003), iliac artery access (OR, 9.09; 95% CI, 2.22-37.2, P = .002), and procedural time (OR, 1.01; 95% CI, 1.01-1.02, P = .008) were risk factors for SCI in the covered AKA group. No significant risk factors were detected in the uncovered AKA group.

Conclusions

Covering the ICA-AKA was not an independent risk for SCI in TEVAR. However, covering the ICA-AKA was indirectly associated with the risk of SCI in patients with shaggy aorta, iliac access, and procedural time.

Angio Cone-Beam CT (Angio-CBCT) and 3D Road-Mapping for the Detection of Spinal Cord Vascularization in Patients Requiring Treatment for a Thoracic Aortic Lesion: A Feasibility Study

BACKGROUND

Spinal cord ischemia is a major complication of treatment for descending thoracic aorta (DTA) disease. Our objectives were (1) to describe the value of angiographic cone-beam CT (angio-CBCT) and 3D road-mapping to visualize the Adamkiewicz artery (AA) and its feeding artery and (2) to evaluate the impact of AA localization on the patient surgical strategy.

METHODS

Between 2018 and 2020, all patients referred to our institution for a surgical DTA disorder underwent a dedicated AA evaluation by angio-CBCT. If the AA feeding artery was not depicted on angio-CBCT, selective artery catheterization was performed, guided by 3D road-mapping. Intervention modifications, based on AA location and one month of neurologic follow-up after surgery, were recorded.

RESULTS

Twenty-one patients were enrolled. AA was assessable in 100% of patients and in 15 (71%) with angio-CBCT alone. Among them, 10 patients needed 3D road-mapping-guided DSA angiography to visualize the AA feeding artery. The amount of contrast media, irradiation dose, and intervention length were not significantly different whether the AA was assessable or not by angio-CBCT. AA feeding artery localization led to surgical sketch modification for 11 patients.

CONCLUSIONS

Angio-CBCT is an efficient method for AA localization in the surgical planning of DTA disorders.

A Systematic Review of Spinal Cord Ischemia Prevention and Management After Open and Endovascular Aortic Repair

OBJECTIVE

Spinal cord ischemia (SCI) is one of the most devastating complications after descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) repairs. Patients who develop SCI have a poor prognosis with mortality rates reaching 75% within the first year after surgery. Many factors have been shown to increase the risk of this complication, including extent of TAA repair, length of aortic and collateral network coverage, embolization, and reduced spinal cord perfusion pressure. As a result, a variety of treatment strategies have evolved. We aimed to provide an up-to-date review of SCI rates with associated treatment algorithms from open and endovascular DTA and TAA repairs.

METHODS

Using PRISMA guidelines, a literature review with the Medical Subject Headings (MeSH) terms "spinal cord ischemia; spinal cord ischemia prevention and mitigation strategies; spinal cord ischemia rates; spinal cord infarction" was performed in the Cochrane and PubMed databases to seek all peer-reviewed studies of DTA and TAA repairs with SCI complications, limited to 2012-2021 and the English language. MeSH subheadings including diagnosis, complications, physiopathology, surgery, mortality, and therapy were used to further restrict the articles. Studies were excluded if they were not in humans, not pertaining to SCI in DTA/TAA operative repairs, and if the study primarily discussed neuromonitoring techniques. Additionally, studies with <40 patients or limited information regarding SCI protection strategies were excluded. Each study was individually reviewed by two researchers to assess for type and extent of aortic pathology, operative technique, SCI protection or mitigation strategies, rates of overall and permanent SCI symptoms, associations with SCI on multivariate analysis, and mortality.

RESULTS

Of 450 studies returned by the MeSH search strategy, 41 met inclusion criteria and were included in the final analysis. For endovascular DTA repair patients, overall SCI rates ranged from 0-10.6% with permanent SCI symptoms ranging from 0-5.1%. Endovascular and open TAA repairs had rates of overall SCI of 0-35%. Permanent SCI symptom rate was reported by only one open study at 1.1% while endovascular TAA repairs had between 2-20.5%.

CONCLUSION

This review provides an up-to-date review of current rates of SCI as well as prevention and mitigation strategies for DTA and TAA repairs. We find that a multimodal approach, including a bundled institutional protocol, staging of multiple repairs, preservation of collateral blood flow network, augmented spinal cord perfusion, selective cerebrospinal fluid drainage, and distal aortic perfusion in open TAA repairs, appears to be important in reducing the risk of SCI.

Late-Onset Paraplegia After Endovascular Repair of Type B Aortic Dissection Managed by Urgent Left Subclavian Artery Revascularization: A Case Report

Spinal cord ischemia is one of the most unpredictable and feared complications after open surgical or endovascular thoracic aortic repair. Protection of collateral network branches that contribute blood supply to spinal cord is fundamental in the prevention of this catastrophic condition. We report the case of a patient who underwent emergent endovascular treatment for a type B aortic dissection complicated by rupture of the false lumen, with intentional coverage of the left subclavian artery without revascularization. The patient developed paraplegia on the 10th postoperative day, which did not significantly improve with immediate cerebrospinal fluid drainage but fully recovered after urgent left carotid-subclavian bypass.

Advantages of 70-kV CT Angiography for the Visualization of the Adamkiewicz Artery: Comparison with 120-kV Imaging

BACKGROUND AND PURPOSE

Preprocedural identification of the Adamkiewicz artery is crucial in patients with aortic diseases. This study aimed to compare 70-kV CTA with conventional 120-kV CTA for the identification of the Adamkiewicz artery, examining differences in radiation dose and image quality.

MATERIALS AND METHODS

We retrospectively analyzed 2 equal groups of 60 patients who had undergone 70-kV or 120-kV CTA to detect the Adamkiewicz artery before aortic repair. Size-specific dose estimate, the CT number of the aorta, and the contrast-to-noise ratio of the anterior spinal artery to the spinal cord were recorded. Furthermore, detectability of the Adamkiewicz artery was evaluated by using a 4-point continuity score (3, definite to 0, undetectable).

RESULTS

There was significantly lower radiation exposure with 70-kV CTA than 120-kV CTA (median size-specific dose estimate, 23.1 versus 61.3 mGy, respectively; P < .001). CT number and contrast-to-noise ratio were both significantly higher in the 70-kV CTA group than the 120-kV group (999.1 HU compared with 508.7 HU, and 5.6 compared with 3.4, respectively; P < .001 for both). Detectability of the Adamkiewicz artery was not impaired in the 70-kV CTA group (90.0% versus 83.3% in the 120-kV group, P = .28). Moreover, the Adamkiewicz artery was detected with greater confidence with 70-kV CTA, reflected by a significantly superior continuity score (median, 3) compared with 120-kV CTA (median, 2; P = .001).

CONCLUSIONS

Seventy-kilovolt CTA has substantial advantages for the identification of the Adamkiewicz artery before aortic repair, with a significantly lower radiation exposure and superior image quality than 120-kV CTA.

Penetrating thoracic spinal cord injury with ice pick extending into the aorta. A technical note and review of the literature

Background:

Penetrating spinal cord injuries pose a great challenge to both patients and the treating physicians. Although the overall incidence of penetrating spinal cord injury is the highest in the military, the ubiquity of guns in our society continues to make penetrating spinal cord injury prevalent in the civilian population. These types of injuries are particularly complicated because, beyond the trauma to the neural elements and supporting structures, other organs can be affected and a team approach is required for successful treatment.

Case Description:

In this report, the authors present a unique case of an ice pick penetrating posteriorly through the spinal canal into the aorta. The described surgical management involved careful consideration and planning to prevent worsening vascular and neurological compromise. Among the challenges faced are neurological compromise, vascular injury, spinal instability, and cerebrospinal fluid leak.

Conclusion:

To the author’s knowledge, this challenging case represents the first description of a successful removal of a penetrating thoracic spinal foreign body that terminated within the lumen of the thoracic aorta.