Neurosurgery Coding Alert

Answer: In 2001, CPT added 61697 (Surgery of complex intracranial aneurysm, intracranial approach; carotid circulation) and 61698 (... vertebrobasilar circulation) to describe surgery of complex aneurysm. CPT includes a parenthetical explanation for these codes, stating "61697, 61698 involve aneurysms that are larger than 15 mm or with calcification of the aneurysm neck, or with incorporation of normal vessels into the aneurysm neck, or a procedure requiring temporary vessel occlusion, trapping or cardiopulmonary bypass to successfully treat the aneurysm." In other words, the aneurysm qualifies as complex either because of its large size or because of the need for extra effort to control bleeding or prevent further damage to the blood vessels.

Also in 2001, CPT revised the descriptors for 61700 (Surgery of simple intracranial aneurysm, intracranial approach; carotid circulation) and 61702 (... vertebro-basilar circulation) to include the word "simple" and further differentiate them from 61697-61698. But the difference in relative value units (RVUs) between the complex and simple codes is relatively minor (89.25 RVUs for 61697 versus 89.12 RVUs for 61700; 85.71 RVUs for 61698 versus 85.47 RVUs for 61702). Despite the name, an aneurysm that is defined as "simple" under CPT guidelines may still require a complicated or difficult repair, in which case you may append modifier -22 (Unusual procedural services) to 61700-61702 for additional reimbursement.