Epidural hemostasis by autologous fat graft in minimally invasive surgery for lumbar spinal stenosis: In vivo experimental study.

BACKGROUND: Epidural hemostasis needs to use small, adapted material in minimally invasive surgery, including bilateral decompression via a unilateral approach for lumbar spinal stenosis. Most surgeons avoid external material for hemostasis because of possible neural tissue damage or complications. We compared epidural hemostasis in minimally invasive surgery by fat graft versus gelatin sponge. METHODS: The design was a prospective randomized controlled in-vivo human experimental study. The 24 levels operated on for lumbar spinal stenosis were evaluated in two groups: Group A (control group: gelatin sponge) and Group B (experimental group: fat graft). International Normalized Ratio and Prothrombin Time were assessed preoperatively. Number of cotton hemostats and systolic and diastolic blood pressure were assessed intraoperatively. Epidural hemorrhage area, spinal cord size and ratio of epidural hemorrhage area to spinal cord size were evaluated on early postoperative lumbar MRI. RESULTS: Mean epidural hemorrhage area in groups A and B was respectively 1.3±0.5 and 1.2±0.6cm2, and mean spinal cord size 1.2±0.6 and 1.8±0.6cm2 on early postoperative axial lumbar MRI. The two groups did not significantly differ in ratio of epidural hemorrhage/spinal cord size or number of intraoperative hemostats (P=0.36, and P=0.71). CONCLUSIONS: The autologous fat graft ensured sufficient and safe epidural hemostasis without serious adverse events in minimally invasive spinal surgery, and is preferable as autologous tissue is easily and quickly harvested. The surgeon feels safe with this technique and does not need external hemostatic agents.

Analysis of clinical characteristics and surgical results of upper lumbar disc herniations.

BACKGROUND: Upper lumbar disc herniation (ULDH) is described mostly in levels L1-2, L2-3 and L3-4 of the lumbar spine in the literature and accounts for less than 10% of all disc herniations. The aim of our study was to evaluate the clinical characteristics and surgical results of ULDH. METHODS: In all, 367 patients treated for upper lumbar disc herniation and 2137 treated for lower lumbar disc herniation (LLDH) between January 2008 and January 2017 were included. They were followed up postoperatively at 12 months by radiological investigations, back and leg pain Visual Analogue Scale (VAS), and Oswestry Disability Index (ODI). Preoperative data comprised age group (20-40, 40-60, 60-80 years), gender (male, female), lumbar level (L1-2, L2-3, L3-4), side of disc herniation (left, right) and symptom duration (0-3, 3-6, 6-9 months). RESULTS: ODI and VAS scores improved significantly postoperatively for all patients. Of the 367 ULDH patients, 169 were female (54%) and 198 male (46%), with a mean age of 55.8±10.1 years (range, 35-71). In 174 (47.4%) patients symptom duration was 3 months, in 99 (27.0%) 3-6 months, and in 94 (25.6%) 6-9 months. At 12 months, ODI, back and leg pain VAS scores showed a significant difference in improvement according to ULDH symptom duration<3 months and to LLDH symptom duration<6 months. CONCLUSION: Microdiscectomy in ULDH provided sufficient and safe decompression of neural structures, with significant reduction in symptoms and disability. We suggest that early surgical treatment is an important factor for good outcome in ULDH.