The role of drains in lumbar spine fusion.

Objective: To study the role of drains in lumbar spine fusions.

Methods: The charts of 402 patients who underwent lumbar decompression and fusion (LDF) were retrospectively reviewed. Patients were classified per International Classification of Diseases, 9th Edition (ICD-9) procedure code as 81.07 (lateral fusion, 74.9%) and 81.08 (posterior fusion, 25.1%). The investigators studied the prevalence of drain use in lumbar fusion procedures and the impact of drain use on postoperative fever, wound infection, posthemorrhagic anemia, blood transfusion, and hospital cost.

Results: No significant differences in wound infection rates were noted between patients with and without drains (3.5% vs 2.6%, P = 0.627). The difference in postoperative fever rates between patients with and without drains (63.2% vs 52.6%, P = 0.05) was of borderline significance. Posthemorrhagic anemia was statistically more common in patients with drains (23.5% vs 7.7%, P = 0.000). Allogeneic blood transfusion was also statistically more common in the drained group (23.9% vs 6.8%, P = 0.000). Postoperative hemoglobin levels were lower in patients with drains who underwent one-level (9.5 g/dL vs 11.3 g/dL) or two-level (9.3 g/dL vs 10.2 g/dL) spine fusions. In this series in which drains were liberally used, no patient had to return to the operating room because of postoperative hematoma. An increased rate of allogeneic blood transfusion was noticed with posthemorrhagic anemia and drain use. The rate of allogeneic blood transfusion increased from 5.6% in patients without drains or posthemorrhagic anemia to 38.8% in patients with drains and posthemorrhagic anemia as a secondary diagnosis. The use of drains was associated with statistically insignificant increases in length of stay and cost in posterior procedures. Drain use was associated with shorter length of stay and hospital charges in lateral fusions of three or more levels.

Conclusions: Drain use did not increase the risk of wound infection in patients undergoing LDF, but it had some impact on the prevalence of postoperative fever. Drain use was significantly associated with posthemorrhagic anemia and allogeneic blood transfusion. Drain use did not have a significant economic impact on hospital length of stay and charges except in lateral procedures involving three or more levels.