Epidural scarring after lumbar disc surgery: Equivalent scarring with/without free autologous fat grafts

Postoperative Epidural Fibrosis Prevention: Which Is Better-Autologous Fat versus Gelfoam

Study Design

Prospective, randomized study of 100 patients with prolapsed intervertebral disc with an average of 12- to 18-month follow-up postoperatively.

Purpose

To compare the role of Gelfoam and autologous fat in the prevention of postoperative epidural fibrosis (EF) after lumbar spine surgery.

Overview of Literature

EF is a possible sequelae of lumbar disc surgery. Different treatments and surgical strategies have been attempted to prevent postoperative fibrosis without providing consistent long-term results.

Methods

The study was conducted on 100 adult patients. The patients were randomly allocated into two groups of 50 patients each: group A, autologous fat group, and group B, Gelfoam group. The postoperative follow-up was conducted at intervals of 6 weeks, 3 months, 6 months, and 12 months. Both groups were evaluated clinically (Oswestry Low Back Pain Disability Questionnaire [ODI], Visual Analog Scale [VAS], Straight Leg Raising Test [SLRT]) and radiologically (using Ross grading by contrast magnetic resonance imaging [MRI]) for development of radicular pain and hence EF.

Results

Based on the analysis, improvement in mean values of ODI score, VAS score, and SLRT were found to be statistically significant postoperatively at intervals of 6 weeks, 3 months, 6 months, and 12 months when compared individually in both groups. However, improvement was greater in the autologous fat group than in the Gelfoam group. Based on contrast-enhanced MRI, the number of patients who developed EF was smaller in the autologous fat group than in the Gelfoam group.

Conclusions

In the present study, on clinical and radiological assessment, we conclude that both groups prevent radicular pain and postoperative EF individually but relatively autologous fat was found to be more effective than Gelfoam in the prevention of EF and hence radicular pain.

Survey of lumbar discectomy practices: 10 years in the making

Background

Lumbar discectomy is a common spinal procedure. The purpose of this survey is to ascertain neurosurgeons' practices in the surgical management of one-level lumbar discectomies in the Canadian adult population and to determine changes over a 10-year period.

Methods

One-page questionnaire distributed electronically to neurosurgeons in Canada and results were compared with similarly completed survey from 2007.

Results

A total of 109 completed surveys were returned representing 43.8% response rate. This is compared to 112 completed surveys in 2007 reaching 64.4% response rate. Statistically significant differences between the two points in time were noted. There was an increase in spine fellowship training [26 (33.3%) 2017 vs. 15 (15.3%) 2007 (P=0.007)], use of pre-operative magnetic resonance imaging (MRI) [65 (83.3%) 2017 vs. 27 (27.6%) 2007] (P<0.001), use of intramuscular injection [58 (74.4%) 2017 vs. 43 (43.9%) 2007 (P<0.001)], use of both microscope and loupes [20 (25.6%) 2017 vs. 3 (3.1%) 2007 (P<0.001)], use of tubular retraction [26 (33.3%) 2017 vs. 12 (12.2%) 2007 (P=0.001)], use of fibrin glue for a durotomy [72 (92.3%) 2017 vs. 75 (76.5%) 2007 (P=0.007)]. There was an increased rate of same-day discharge in 2017 [46 (59.0%) vs. 18 (18.4%) 2007 (P<0.001)], and quicker return to work [62.8% in 6 weeks or less vs. 39.7% (P=0.003)]. No statistical differences were noted with pre-incision localization, pre-op antibiotics, pre-incision local anesthetic use, use of fat graft or epidural steroids. In either survey the majority would not perform lumbar discectomy on a patient whose primary complaint is back pain.

Conclusions

Our survey identified changes in practice patterns amongst Canadian neurosurgeons with respect to performing one-level lumbar discectomy over the past 10 years. These changes include increased preference for minimally invasive surgical technique, same-day discharge and sooner return to work. Randomized trials would be helpful to provide evidence regarding which practices are associated with better outcomes.

Analysis of risk factors and postoperative predictors for recurrent lumbar disc herniation

Background:

This study identified risk factors and postoperative indicators for recurrent lumbar disc herniations (rLDH) following microdiscectomy.

Methods:

We retrospectively reviewed the 1-year recurrence rate for LDH in 209 consecutive patients undergoing microdiscectomy (2013–2018).

Results:

Utilizing a multivariate analysis, higher body mass index (BMI) and postsurgery Oswestry disability index (ODI) were significantly associated with an increased risk of rLDH.

Conclusion:

Elevated postsurgery ODI and higher BMI were significantly associated with increased risk of rLDH.

Pirfenidone inhibits epidural scar fibroblast proliferation and differentiation by regulating TGF-β1-induced Smad-dependent and -independent pathways

Epidural fibrosis causes serious complications in patients who have undergone laminectomy. Pirfenidone is an effective antifibrotic agent but its effect on epidural fibrosis remains unclear. In this study, we aimed to investigate the effect of pirfenidone on epidural fibrosis and to evaluate its mechanism of action on human epidural scar fibroblasts. In a rat model of laminectomy, the degree of epidural fibrosis was quantified via Rydell standard classification, histological analysis, and collagen density analyses. In cultured human epidural scar fibroblasts, cell proliferation was measured using a Cell Counting Kit-8 and EdU assay. Cell apoptosis was detected using Annexin V/propidium iodide staining, and cytotoxicity was evaluated via lactate dehydrogenase assay. Relative mRNA levels of α-smooth muscle actin (α-SMA) and collagen type I were analyzed using quantitative polymerase chain reaction. The protein expression of α-SMA and collagen type I and the phosphorylation status of Smad2, Smad3, protein kinase B (Akt), and p38 were determined via western blotting. Pirfenidone reduced epidural fibrosis by inhibiting fibroblast proliferation and suppressing collagen formation in rats. It also inhibited human epidural scar fibroblast proliferation with no cytotoxic or apoptotic effects. Pirfenidone inhibited fibroblast differentiation by decreasing TGF-β1-induced transcriptional and translational expression of α-SMA. It inhibited TGF-β1-induced phosphorylation of Smad2, Smad3, Akt, and p38. This study suggests that topical application of pirfenidone could reduce epidural scar adhesion after laminectomy, and that its mechanism of action may be the inhibition of TGF-β1-induced epidural scar fibroblast proliferation and differentiation into myofibroblasts through the attenuation of TGF-β1-induced Smad-dependent and -independent pathways.