Several changes occurred in the neurosurgical codes for CPT 1999, including a new intraoperative microscopy code-69990. Previously, there were several ways to code for the utilization of an intraoperative microscope, including 61712, as well as the -20 modifier. Both of these options have been eliminated and replaced by 69990, which describes the use of the intraoperative microscope in the performance of microsurgery.
This code is valued for the work required in performing microdissection. The operative note should include the reason that microdissection was required for managing the problem. A specific description of the microdissection performed should also be made in the body of the operative note. The code was not intended to describe using the microscope for illumination or magnification alone, but rather for the work of microdissection. Consequently, this code should not be used for use of loupe magnification.
When to use a Modifier
Since this code is an “add-on code,” it should not be appended with the -51 multiple procedure modifier. This code is valued only for intraoperative work and is never used alone. Therefore, one would not expect an additional reduction by the multiple procedure rule. The code may be used once for an operative procedure. Medicare does not reimburse 69990 with the -80 modifier for an assistant surgeon.
CPT lists a series of codes in which the microdissection is an integral component of the work. In the neurosurgical section, procedures that include valuation of microdissection are transsphenoidal hypophysectomy (61548), anterior cervical or thoracic discectomy and osteophytectomy (63075-63078), and internal neurolysis (64727). Although lumbar discectomy (63030) was not specifically excluded, Medicare has not paid for microdissection in lumbar discectomy in the past, and it has been suggested that procedures not previously paid with the 61712 or -20 modifier will not be paid with 69990.
As with other codes, the relative value units (RVU) for microdissection have been gradually declining over the last few years. In 1998, the relative value for 61712 was 8.26 RVU. With the change to 69990 in 1999, the value was reduced to 6.02 units. Concurrent reduction in the conversion factor further accentuated the impact of the reduced value. Although the decline to 5.95 units for 2000 was minor, an increase in the conversion factor was concurrently instituted.
For More Information
The American Medical Association publishes CPT Assistant, which discusses in greater detail the interpretation and appropriate use of CPT codes. Last year, the April issue described the use of 69990.
Gregory J. Przybylski, MD, is Assistant Professor of Neurosurgery at Thomas Jefferson Medical College and a faculty member for the AANS Reimbursement courses.
The coding procedures expressed in this article should not be construed as AANS policy, procedure or standard of care. The AANS disclaims any liability or responsibility for the consequences of any actions taken in reliance on the coding procedures suggested.