Does prophylactic use of topical gelatin-thrombin matrix sealant affect postoperative drainage volume and hematoma formation following microendoscopic spine surgery? A randomized controlled trial.

<bold>Background Context: </bold>Microendoscopic spinal surgery has demonstrated efficacy and is increasingly utilized as a minimally invasive approach to neural decompression, but there is a theoretical concern that bleeding and postoperative epidural hematoma (PEH) may occur with increased frequency in a contained small surgical field. Hemostatic agents, such as topical gelatin-thrombin matrix sealant (TGTMS), are routinely used in spine surgery procedures, yet there has been no data on whether PEH is suppressed by these agents when administered in microendoscopic spine surgery.<bold>Purpose: </bold>The purpose of this study was to investigate the effect of TGTMS on bleeding and PEH formation in lumbar micoroendoscopic surgery.<bold>Study Design: </bold>This is a randomized controlled trial (RCT) with additional prospective observational cohort.<bold>Patient Sample: </bold>Patients were registered from July 2017 to September 2018 and a hundred and three patients undergoing microendoscopic laminectomy for lumbar spinal stenosis at a single institution were enrolled in this study.<bold>Outcome Measures: </bold>The primary outcome was the drainage volume within 48 hours after surgery. Secondary outcomes were the numerical rating scale (NRS) of leg pain on the second (NRS2) and seventh day (NRS7) after surgery and the hematoma area ratio (HAR) in horizontal images on magnetic resonance image (MRI).<bold>Methods: </bold>In the RCT, 41 cases that received TGTMS (F group) were compared with 41 control group cases (C group) that did not receive TGTMS at the end of the procedure. Drainage volume, NRS2, NRS7, and HAR on MRI were evaluated. Nineteen cases were excluded from the RCT (I group) due to difficulty of hemostasis during surgery and the intentional use of TGTMS for hemostasis. I group was compared with C group in the drainage volume and NRS of leg pain as a prospective observational study.<bold>Results: </bold>The RCT demonstrated no statistically significant difference in drainage volume between those receiving TGTMS (117.0±71.7; mean±standard deviation) and controls (125.0±127.0; p=.345). The NRS2 and NRS7 was 3.5±2.6 and 2.8±2.5 in the F group, respectively, and 3.1±2.6 and 2.1±2.3 in the C group, respectively. The HAR on MRI was 0.19±0.19 in the F group and 0.17±0.13 in the C group. There was no significant difference in postoperative leg pain and HAR (p=.644 for NRS2, p=.129 for NRS7, and p=.705 for HAR). In the secondary observational cohort, the drainage volume in the I group was 118.3±151.4, and NRS2 and NRS7 was 3.5±2.0 and 2.6±2.6, respectively. There were no statistically significant differences in drainage volume (p=.386) or postoperative NRS of leg pain between these two groups (p=.981 and .477 for NRS2 and NRS7, respectively).<bold>Conclusions: </bold>The prophylactic use of TGTMS in patients undergoing microendoscopic laminotomy for lumbar spinal stenosis did not demonstrate any difference in postoperative bleeding or PEH. Nonetheless, for patients that had active bleeding that required the use of TGTMS, there was no evidence of difference in postoperative clinical outcomes relative to controls. [ABSTRACT FROM AUTHOR]