Peridural scar and its relation to clinical outcome: a randomised study on surgically treated lumbar disc herniation patients

A prospective randomised 2-year follow-up study on patients undergoing lumbar disc herniation surgery. The objective was to investigate the relationship between peridural scarring and clinical outcome, the scar development 6 and 24 months postoperatively by using MRI, and if ADCON-L (a bioresorbable carbohydrate polymer gel) has an effect on scar size and/or improve patients’ outcome after lumbar disc herniation surgery. The association between peridural scarring and recurrent pain after lumbar disc herniation surgery is debated. Numerous materials have been used in attempts to prevent or reduce postoperative peridural scarring; however, there are conflicting data regarding the clinical effects. The study included 119 patients whose mean age was 39 years (18–66); 51 (47%) were women. Sixty patients (56%) were perioperatively randomised to receive ADCON-L, and 48 (44%) served as controls. All patients underwent MRI at 6 and 24 months postoperatively, and an independent radiologist graded the size, location and development of the scar, by using a previously described scoring system. Pre- and 2-year postoperatively patients graded their leg pain on a visual analogue scale (VAS). At the 2-year follow-up patients rated their satisfaction with treatment (subjective outcome) and were evaluated by an independent neurologist (objective outcome), using MacNab score. There was no relationship between size or localisation of the scar and any of the clinical outcomes (VAS, subjective and objective outcome). The scar size decreased between 6 and 24 months in 49%, was unchanged in 42% and increased in 9% of the patients. Patients treated with ADCON-L did not demonstrate any adverse effects, nor did they demonstrate less scarring or better clinical outcome than control patients. No significant association between the presence of extensive peridural scar or localisation of scar formation and clinical outcome could be detected in the present study. Further, no positive or negative effects of ADCON-L used in disc herniation surgery could be seen

Implantation of amniotic membrane to reduce postlaminectomy epidural adhesions

Postlaminectomy epidural adhesion is implicated as a main cause of “failed back surgery syndrome” and associated with increased risk of complications during revision surgery. Various materials acting as mechanical barriers to reduce fibroblasts infiltration into epidural space have met with limited success. In present research, amniotic membrane (AM) was studied to investigate its effects on reducing epidural scar adhesion after laminectomy in a canine model. Laminectomy sites were created at L-1, L-3, L-5, and L-7 levels in 24 adult mongrel dogs. Freeze dried AM (FAM), cross-linked AM (CAM), and autologous free fat (AFF) were implanted, respectively, at a randomly assigned site in each dog with the remaining untreated site serving as internal control. The animals were sacrificed at 1, 6, and 12 weeks postoperatively. Then, gross pathologic observation including scar amount and adhesion tenacity, qualitative histology evaluation, and quantitative histology analysis were compared. Gross observation demonstrated that scar amount and adhesion tenacity of CAM group were significantly lower in comparison with those of FAM and non-treatment groups. A white, slightly vascularized CAM layer covered the dura mater without tenacious scar adhesion. The histology analysis also indicated reduced fibroblasts infiltration and consequent epidural fibrosis, which were similar to the results of AFF group. In conclusion, the CAM is effective in reducing epidural fibrosis and scar adhesion after laminectomy in canine model. It is a promising biomaterial for future clinical applications

Prevention of epidural scarring after microdiscectomy: a randomized clinical trial comparing gel and expanded polytetrafluoroethylene membrane

A randomized clinical trial compared two materials used to prevent epidural scarring after microdiscectomy. To determine whether ADCON®-L Gel (ALG) or Preclude Spinal Membrane® (PSM) was more effective in preventing scarring, reducing pain, and improving quality of life postoperatively. Postdiscectomy syndrome may result from epidural scarring. Various materials have been used in attempts to prevent this problem, but none have provided optimal results. Previous laboratory and clinical studies have found ALG and PSM to be effective, but none compared the two materials. Thirty-one patients undergoing primary microdiscectomy were randomly assigned to receive either ALG or PSM. Postoperatively, patients were evaluated by magnetic resonance imaging (MRI), with contrast, for volume and rostral–caudal extent of scar tissue and nerve root involvement. Back and leg pain and quality of life were assessed by neurologic examinations and standardized patient surveys. Findings at any reoperations were recorded. Results in the PSM (n = 18) and ALG (n = 13) groups were compared statistically. No operative or postoperative complications occurred. Two patients in each group required reoperation. MRI at 6 months showed no, mild or mild-moderate scarring in most patients, with no significant differences between the ALG and PSM groups in scar volume and extent or nerve root involvement. Neurologic examinations and patient surveys showed substantial reductions in pain over time in both groups but no significant differences between groups. PSM was easy to see and remove at reoperation. PSM and ALG are equally effective in preventing epidural scarring associated with postdiscectomy syndrome