Drainage after posterior single-level instrumented lumbar fusion: Natural pressure vs negative pressure.

Recent findings have shown a trend toward recommending against the routine use of drains in spinal surgery because it carries the risk for potential complications. However, most surgeons still use closed suction drainage to prevent hematoma formation. This study is to compare the clinical outcomes between natural pressure drainage and negative pressure drainage after posterior lumbar interbody fusion.Consecutive 132 patients who underwent spinal fusion in the Third Hospital of Hebei Medical University and met the inclusion criteria were reviewed from January 2018 to January 2019 and divided into negative pressure drainage group and natural pressure drainage group according to different pressure drainage. There were 64 patients who had a negative pressure drainage placed and 68 patients who had a natural pressure drainage placed. Demographics, intraoperative blood loss, operative room time, drainage volume at the 1st postoperative day, total volume of postoperative drainage, the total drainage days, postoperative temperature, and postoperative complications (wound infection, symptomatic hematoma) were compared between the 2 groups.The median drainage volume at the 1st postoperative day in negative pressure group was 204.89 ± 95.19 mL, while in natural pressure group, it was 141.00 ± 52.19 mL (P = .000). The median total volume of postoperative drainage in negative pressure group was 378.06 ± 117.98 mL, while in natural pressure group, it was 249.32 ± 70.74 mL (P = .000). The median total drainage days between natural pressure group and negative pressure group were obviously different (2.93 ± 0.55 vs 3.51 ± 0.71 days, P = .000). There was no difference in patient characteristics, operative data, postoperative temperature, and complications.Natural pressure drainage significantly reduced postoperative drainage volume and indwelling time, but did not increase postoperative complications. Therefore, it may offer an alternative to negative pressure drainage and is as safe and effective as negative pressure drainage.