Significant Extravascular Findings Found During CT for PAD

BY MIRIAM E. TUCKER

WASHINGTON -- Previously undiagnosed, highly significant extravascular findings were discovered in 14% of 275 patients who underwent computed tomography angiography of the lower extremities, according to the results from a retrospective chart review.

These results suggest that "those who interpret these studies should be vigilant about extravascular findings [and] referring physicians, whether they are primary care physicians or vascular specialists, need to be aware such that appropriate follow-up is obtained," according to Dr. Sailendra G. Naidu in a presentation at the annual meeting of the Society of Interventional Radiology.

At the Mayo Clinic, where CT angiography has "pretty much surpassed" conventional angiography for the diagnosis of peripheral vascular disease, Dr. Naidu and his associates conducted a review of all angiogram run-off reports from January 2004 to October 2006.

LOW CLINICAL SIGNIFICANCE FINDINGS WERE SEEN IN 72% OF PATIENTS; 24% HAD MODERATE FINDINGS; AND 14% HAD HIGHLY CLINICALLY SIGNIFICANT FINDINGS.

The patients were 164 men and 111 women, aged 18-97 years with a mean of 72 years. Electronic follow-up ranged from 4 months to 3 years.

Clinical significance of the findings discovered on CT angiography--performed from the diaphragm to the toes--were divided into three categories: low, indicating little if any clinical significance; medium, which were not clinically apparent at the time of diagnosis but knowledge of which could be relevant at a later time (including conditions such as cholelithiasis or renal calculi); and high, defined as previously unknown findings requiring further diagnostic evaluation or findings highly suggestive of neoplasm.

Overall, 77% of the patients were found to have at least one finding, with a total of 462 findings seen in those 213 patients.

Of the total 275 patients, 72% had findings considered to be of low clinical significance, 24% had findings that were deemed of moderate significance, and 14% of the patients were found to have highly clinically significant findings, Dr. Naidu, who is at the Mayo Clinic in Phoenix, reported.

Of the total 43 highly significant findings, the majority involved the kidney (9), lung (7), liver (6), or pancreas (6). Of the 24 highly significant findings that were evaluated further, nine previously undiscovered malignancies were found in seven patients.

These included the case of a 58-year-old woman in whom a left renal mass was found to be renal cell carcinoma and who subsequently underwent a left nephrectomy, and a 75-year-old man with a hypodense lesion in his liver that turned out on biopsy to be cholangiocarcinoma. He was treated with chemotherapy.

The clinically significant noncancerous findings included a case of pulmonary coccidioidomycosis in a 55-year-old woman, treated medically.

The 14% rate of highly significant extravascular findings on CT angiogram in this study is slightly higher than rates found in previous studies, which have ranged from 5.6% (Clin. Radiol. 1999;54:294-300) to 12% (J. Vasc. Surg. 2006;44:998-1001).

This disparity might be because the current study was limited to diagnostic CT angiography and the others have included asymptomatic patients undergoing CT angiography for indications such as renal donor evaluation, Dr. Naidu commented.