High prevalence of abdominal aortic aneurysm in patients with chronic low back pain.

Low back pain (LBP) is one of the most common symptoms in outpatient clinics, and abdominal aortic aneurysm (AAA) is one of the causes of LBP. In the present study, we examined the prevalence of chronic LBP in patients with aortic aneurysm. The study included 23 patients with AAA and 23 patients with thoracic aortic aneurysm (TAA); all of them visited a regional center hospital in Akita, Japan. A total of 207 hypertension patients were also enrolled as a control. Chronic LBP was defined in patients who visited the orthopedic outpatient clinic for the LBP treatment for more than three months. The prevalence of chronic LBP in the AAA group (52.2%) was significantly higher than that in the TAA (17.4%, P < 0.05) or hypertension patients (11.6%, P < 0.01). The rate of a trigger point (TP) injection was significantly higher in the AAA group or the TAA group than that in hypertension patients (P < 0.01, P < 0.05), but there was no significant difference between the AAA and TAA groups. The TP injection represents an injection of local anesthesia to the low back muscles. We also evaluated the involvement of various factors in LBP caused by AAA, such as age, gender, blood pressure, the existence of dissection, and the maximum diameter of AAA, but none of them showed significant relationship to LBP. The prevalence of LBP is high in AAA patients, and doctors who treat chronic LBP should be aware of AAA as a potential cause of LBP.