Readmission rates after intraoperative durotomy and repair in outpatient lumbar spinal surgery.

Background: Postoperative management following durotomy and subsequent repair typically involves inpatient admission for at least 24 hours. Spinal headaches are the principal symptom signifying ongoing CSF leak and require monitored activity restriction. More recently, patients are being discharged same-day following durotomy repair. The goal of this study was to assess the risk of readmission after same-day discharge following intraoperative durotomy and repair. Methods: In this retrospective review, 273 instances of durotomy and subsequent primary repair were identified out of 3,391 patients that underwent lumbar spine surgery at a single center between October 2012 and September 2017 were identified. Out of the 273 cases, 111 (40.7%) were planned as ambulatory day surgery. Fifty-two patients (46.8%) were discharged home as planned, while 59 (53.2%) were admitted postoperatively. Following the surgical encounter, patients that were readmitted within 30 days due to durotomy-related symptoms were identified. Relative risk ratios for readmission were assessed between patients who were discharged same-day versus admitted postoperatively. Results: Of the 52 patients discharged home same day, 2 were readmitted (3.8%); of the 59 patients admitted postoperatively, 5 were readmitted (8.5%). No dural tears required return to OR for management of complications, and there was an overall durotomy rate of 8.1%. Compared to patients discharged home same-day, patients admitted after durotomy repair were: older (p=.001), had a diagnosis of stenosis (vs herniated nucleus pulposus) (p=.004), had a laminectomy (vs a microdiscectomy) (p=.007), had surgery Monday-Thursday (p=.004), and had surgery by a lower volume surgeon (p=.016). The relative risk of readmission in patients admitted at the time of index procedure was not statistically different compared with those discharged the same-day as planned (RR: 2.20, 95% CI: 0.45,10.88). Conclusion: In patients undergoing outpatient spine procedures, discharge home after intraoperative durotomy and repair may not confer an increased risk of readmission. One factor that was not examined was subjective assessment of repair quality, which may imply more significant CSF leak, thus leading to admission. We believe this data suggests that postoperative course following durotomy repair may have similar outcomes - specifically readmission - whether or not a patient is admitted. This data may also influence direct cost savings due to decreased length of stay.