Extravasation of rhBMP-2 with use of postoperative drains after posterolateral spinal fusion.
ABSTRACT Prospective measurement of rhBMP-2 from drains in a cohort of patients undergoing posterolateral spinal fusion.
To quantify the amount of rhBMP-2 that extravasates into drains after posterolateral fusion using its current commercially available form, rhBMP-2 within an absorbable collagen sponge.
Retention of rhBMP-2 at the fusion site is essential for clinical efficacy and avoidance of unintentional bony growth in other areas of the spine. In vitro studies have shown a large degree of rhBMP-2 release from the sponge within the first 48 hours. It is unknown what effect drainage may have on changing the local concentration of BMP at the posterolateral site.
The entire contents of drains were collected for 48 hours after surgery from 9 patients who underwent instrumented posterolateral fusion with rhBMP-2. The total amount collected was calculated from the concentration of BMP-2 as measured by enzyme-linked immunosorbent assay.
A median 68 microg of BMP-2 (range, 13-498) was recovered from drains, representing a median 0.58% (range, 0.21%-4.2%) of the amount implanted; adjusted for yield rate, a median 1.08% was recovered. No significant relationships were found between percentage of BMP-2 extravasation and amount implanted, number of levels, blood loss, and drainage output. A mean 54% of the total amount recovered was in the drain within the first 6 hours.
The greater bleeding and muscular compression associated with posterolateral fusion did not result in a substantial amount of rhBMP-2 extravasation into postoperative drains. Based on the small rates of recovery, suction drains may be placed after even complex surgeries involving large blood loss without the loss of significant amounts of the implanted rhBMP-2 into the drain.
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ABSTRACT: OBJECITVE: Concerns over increased wound complication rates have been raised when bone morphogenic protein (BMP) is employed as an adjunct for fusion in spinal surgery. In this study we evaluated 50 consecutive patients undergoing long-segment thoraco-lumbar spinal fusions with BMP to assess drain output and the rates of reoperation for infection or seroma. METHODS: Inclusion criteria included: patients undergoing 4 or more levels of posterior instrumented thoracolumbar fusion, use of BMP, age >18 years, and a perioperative followup of ≥ 60 days. Drain output, length of time of drainage, and need for reoperation for wound seroma or infection were reviewed. RESULTS: 87 patients met inclusion criteria and had a mean age of 58.5 years (SD 16, range 20- 81). The average number of levels instrumented and arthrodesed with BMP was 9.2 (SD 3.7; range 4-18), and the average dose of BMP used was 31.2 mg (SD 9.6, range 12-48) or 2.6 large sponges. Patients required drainage for a mean of 4.9 days (SD 1.3, range 3-9). The average total output was 1923cc (SD 865, range 530-4310cc). The wound infection rate was 2.3% (2 cases of deep wound infection that required reoperation). There was one (1.1%) hematoma, and one (1.1%) sterile seroma, both requiring evacuation. No other wound complications were noted. CONCLUSIONS: Use of BMP for long-segment posterior thoraco-lumbar fusions may be associated with significant drain output, requiring multiple days of drainage. However, when drained adequately, infections and seromas occur infrequently.World Neurosurgery 08/2012; 80(1-2). DOI:10.1016/j.wneu.2012.08.003 · 2.42 Impact Factor
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ABSTRACT: Bone morphogenetic proteins (BMPs) are widely used as bone graft substitutes in spinal fusion, but are associated with numerous adverse effects. The growth factor Nel-like molecule-1 (Nell-1) is mechanistically distinct from BMPs and can minimize complications associated with BMP therapies. This study evaluates the efficacy of Nell-1 combined with demineralized bone matrix (DBM) as a novel bone graft material for interbody spine fusion using sheep, a phylogenetically advanced animal with biomechanical similarities to human spine. Nell-1+sheep DBM or Nell-1+heat-inactivated DBM (inDBM) (to determine the osteogenic effect of residual growth factors in DBM) were implanted in surgical sites as follows: (1) DBM only (control) (n=8); (2) DBM+0.3 mg/mL Nell-1 (n=8); (3) DBM+0.6 mg/mL Nell-1 (n=8); (4) inDBM only (control) (n=4); (5) inDBM+0.3 mg/mL Nell-1 (n=4); (6) inDBM+0.6 mg/mL Nell-1 (n=4). Fusion was assessed by computed tomography, microcomputed tomography, and histology. One hundred percent fusion was achieved by 3 months in the DBM+0.6 mg/mL Nell-1 group and by 4 months in the inDBM+0.6 mg/mL Nell-1 group; bone volume and mineral density were increased by 58% and 47%, respectively. These fusion rates are comparable to published reports on BMP-2 or autograft bone efficacy in sheep. Nell-1 is an independently potent osteogenic molecule that is efficacious and easily applied when combined with DBM.Tissue Engineering Part A 02/2011; 17(7-8):1123-35. DOI:10.1089/ten.TEA.2010.0486 · 4.64 Impact Factor