Page 9 - Read Online

Page 4 of 16 Katz et al. Vessel Plus 2023;7:1 https://dx.doi.org/10.20517/2574-1209.2022.52

Preoperative neurological assessment should include a physical exam to detect baseline neurological deficits,
duplex ultrasonography of the carotid arteries in patients older than age 60, and computed tomographic
angiography with 3-dimensional reconstruction to evaluate the size and contour of the aorta, detect the
presence of thrombus or atheroma, and identify any anatomical variants - for example, atypical location of
major spinal cord branches such as the artery of Adamkiewicz (which is present in 85% of the population,
[6]
on the left side more than 75% of the time and between T8 and L1 in approximately 90% of people ) or
collateral blood flow that could affect the surgical approach. Treatment of symptomatic or severe
asymptomatic carotid occlusive disease should be considered before proceeding with TAAA or DTA repair,
depending on the severity of the cerebrovascular disease and the urgency of the thoracic aortic intervention.

Patients who undergo repair under hypothermic circulatory arrest have a greatly increased incidence of
[7]
stroke, up to 9% . The typical indications for circulatory arrest are rupture and aneurysm anatomy
unsuitable for clamping from the thoracoabdominal incision. Otherwise, the use of this technique is rare in
our clinical practice. Significant dementia or other neurological conditions may contraindicate surgical
repair and should be discussed with the patient’s family.

Neurological (spinal cord)
Spinal cord injury resulting from inadequate spinal cord perfusion during TAAA or DTA repair occurs in
up to 20% of patients, with higher rates associated with Crawford extent II and III aneurysms; 2% to 3% of
these patients will develop permanent paresis or paraplegia . Sarcopenia and associated frailty have been
[7-9]
[10]
associated with increased risk for paraplegia . Assessment for gait speed and grip strength are included in a
frailty assessment to better delineate the risks of surgery. Patients are counseled in detail and in advance
about the risk for spinal cord injury, given its life-altering impact.

Pulmonary
Concurrent pulmonary disease is present in 35% to 45% of TAAA patients . Ongoing tobacco use is widely
[7]
prevalent among these patients (79%); consequently, chronic obstructive pulmonary disease (COPD) has
been shown to be significantly more frequent (1.8-fold) in patients with aortic aneurysms than in those
without [7,11,12] . At least two studies have shown that COPD is associated with aortic aneurysm rupture [12,13] .
Moreover, the pain caused by the large incision across the thoracic and abdominal cavities can increase the
risk for atelectasis and pulmonary complications.

Patients should undergo preoperative pulmonary workup to establish their ability to tolerate open surgery
and prolonged intraoperative single-lung ventilation, which is required for TAAA repair. Preoperative
pulmonary function should be evaluated with spirometry, diffusing capacity for carbon monoxide, and, in
higher-risk patients, arterial blood gas assessment of oxygenation and ventilation. Smoking history should
be obtained, and counseling for immediate smoking cessation should be provided. Patients who previously
underwent aortic arch or descending thoracic aortic surgery may already experience hoarseness; direct
laryngoscopy by an otorhinolaryngologist should be obtained for baseline assessment of vocal cord
mobility. Higher-risk patients are candidates for preoperative pulmonary optimization with inhaled
bronchodilators and/or steroids, risk stratification for postoperative prolonged ventilation, or consideration
of pharmacological adjuvants (such as inhaled pulmonary vasodilators). In cases of severe pulmonary
dysfunction, reconsideration of the appropriateness of surgery and the feasibility of an endovascular
alternative is warranted.

Pleural effusion, although more frequently present in cases of acute aortic dissection, is a known
presentation in patients with a DTA or TAAA. Large effusions usually indicate aneurysm dissection or
rupture with hemorrhage into the pleural space, whereas smaller effusions are predominantly exudative and