Critical Care Medicine-Neurologic Disorders>>>>>Vascular Disorders
Question 2#

A patient presents to the hospital for elective abdominal aortic aneurysm (AAA) repair. Which of the patients would MOST likely benefit from surgical intervention?

a. A 60-year-old male patient with asymptomatic 5.3-cm aneurysm discovered during abdominal computer tomography (CT) scan for colon cancer staging
b. A 46-year-old male patient with a 5.2-cm aneurysm with back pain
c. A 52-year-old female patient with a 4.9-cm aneurysm awaiting kidney transplant
d. A 40-year-old female patient with a known aneurysm measuring 5.1-cm on follow-up imaging with prior study demonstrating a size of 5.0 cm 2 years ago

Correct Answer is B

Comment:

Correct Answer: B

Based on the 2018 Society for Vascular Surgery practice guidelines, the strongest level recommendation is to pursue elective surgical repair in patients with AAA >5.5 cm, saccular aneurysms, and any aneurysm that is symptomatic (B) (back pain, abdominal pain), as these incur the highest risk of rupture. Likewise, strong evidence exists to serially monitor aortic dilation <4.0 cm, as the risk of rupture is low. However, a gray area exists for patients with aneurysms 5.0 to 5.4 cm. Several studies did not show statistically significant improvement in the clinical outcomes when comparing early intervention to surveillance for both endovascular and open repair. Weak evidence suggests that young patients, especially women, may benefit from earlier intervention (D). Similarly low-level recommendation suggests that repair for patients with smaller aneurysms who will require chemotherapy, radiation therapy, or solid organ transplant may be considered (C).

Ultrasonography is the standard method for screening and serially monitoring AAAs. Ultrasonography has a nearly 100% sensitivity in the diagnosis of AAAs and is preferred because of its relatively low cost, widespread availability, and noninvasive nature. It is accurate to within ∼0.3 cm aneurysm diameter and is highly reproducible with different operators. However, it is limited by potentially suboptimal imaging in obese patients and disruption from bowel gas, and it cannot identify proximal and distal extent of the aneurysm. CT is the imaging modality of choice when ultrasound images are suboptimal. It also provides additional information regarding the extent of the aneurysm and its relationship to surrounding structures. 

Strong evidence suggests elective surgical intervention for patients with AAA >5.5 cm, symptomatic aneurysms, and saccular aneurysms, as these carry the highest risk of rupture.

References:

  1. Gloviczki P, Lawrence PF, Forbes TL. Update of the Society for Vascular Surgery abdominal aortic aneurysm guidelines. J Vasc Surg. 2018;67(1):1. doi:10.1016/j.jvs.2017.11.022.
  2. Filardo G, Powell JT, Martinez MA, Ballard DJ. Surgery for small asymptomatic abdominal aortic Aaneurysms. Cochrane Database Syst Rev. 2015;(2):CD001835. doi:10.1002/14651858.cd001835.pub4.