J Neurol Surg A Cent Eur Neurosurg 2014; 75 - p27
DOI: 10.1055/s-0034-1383763

Early Two-Year Safety Data for an Annular Closure Device: Interim Results from a Multicenter, Prospective, Randomized Clinical Trial

J. Kienzler 1, J. Fandino 1, F. Martens 2, R. Hes 3, G. J. Bouma 4, Anular Closure RCT Study Group 5, P. D. Klassen 6
  • 1Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland
  • 2OLV Ziekenhuis, Aalst, Belgium
  • 3ZNA Middleheim, Antwerp, Belgium
  • 4St. Lucas-Andreas Ziekenhuis, Amsterdam, the Netherlands
  • 5Anular Closure RCT Study Group, Woburn, United States
  • 6St. Bonifatius Hospital GmbH, Lingen, Germany

Aim: Lumbar discectomy is the most commonly performed spine surgery, generally resulting in immediate relief of symptoms from herniated or bulging discs. Long term results are less encouraging, with many patients suffering reherniations and/or continued degeneration. Studies have shown that limited nucleus removal results in reduced back pain in the long term. However, limited nucleus removal also leads to more frequent reherniation, particularly in patients with large annular defects. Implantation of an annular closure device (ACD) may allow for the advantages of limited nucleus removal without increased reherniation risk as well as the potential degeneration associated with aggressive nucleus removal. We report here interim results of an ongoing randomized clinical trial (RCT) of an ACD.

Methods: The Barricaid® ACD (Intrinsic Therapeutics; Woburn, MA, USA) consists of a polyester mesh that occludes the annular defect, and is held in place by a titanium bone anchor. This CE-marked device is currently being marketed and is also being studied in a multicenter, post-marketing, randomized, controlled trial in Europe (http://clinicaltrials.gov/ct2/show/NCT01283438). Randomization (1:1, Barricaid:Discectomy-only) is web-based and is performed intra-operatively, following discectomy and confirmation of annular defect size (minimum 4x6mm, maximum 6x10mm). Inclusion criteria include six weeks conservative care, no prior surgery at the index level, minimum Oswestry (40/100) and minimum leg pain (40/100). Reoperations and adverse events are tracked prospectively, and patients are evaluated clinically and radiographically at 6 weeks; 3 and 6 months; and annually until the last patient enrolled has reached 24 months.

Results: 421 patients have been enrolled through September 2013, with 251 past one year and 90 past two years. Similar numbers of patients in each group have reported an adverse event (Barricaid 49%=102/210, Control 53%=112/211), with fewer serious adverse events (SAE) reported for Barricaid patients (40 vs. 63). The Barricaid group had 62% fewer symptomatic reherniations, (10 vs. 26), 59% fewer reoperations at the index level (14 vs. 34), and 74% fewer reoperations following recurrence including repeat reoperations (7 vs. 27).

Conclusions: This interim report of an ongoing RCT provides an initial view of safety and performance outcomes with use of an ACD compared with discectomy alone.