- Email: [email protected]
14. Cervical spine fusion using biodegradable cages
Proceedings of the NASS 18th Annual Meeting / The Spine Journal 3 (2003) 67S–171S
73S
CONCLUSIONS: The presence of Apo E4 was associated with a poorer degree of neurological recovery at 6 months and subsequent deterioration after surgery in long term follow-up (1 year). The degree of compression required to make an individual symptomatic was significantly less in those patients with the gene. Genetic factors therefore influence disease symptoms, disease progression and response to surgical intervention. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
4:14 15. Steroids for multi-level cervical corpectomy procedures: do they reduce upper airway edema? A randomized, prospective, double-blind study Sanford Emery, MD1, Sam Akhavan, MD1, Jung Yoo1, Christopher Furey, MD1, James Rowbottom2, Henry Bohlman1; 1Case Western Reserve University, Cleveland, OH, USA; 2University Hospitals of Cleveland, Cleveland, OH, USA
doi: 10.1016/S1529-9430(03)00193-1
HYPOTHESIS: Dexamethasome reduces airway edema and will lead to shorter extubation time in patients undergoing multilevel cervical corpectomy. METHODS: Sixty-six patients undergoing multilevel anterior cervical corpectomy were randomized to two groups of 35 (25 males, 10 females) and 31(19 males, 12 females) patients, receiving either dexamethasone (0.3mg/ kg before incision and 0.15mg/kg at 6 and 12 hours) or saline respectively. Patients were kept intubated following surgery until post-operative day 1 at which time a cuff-leak test was performed to assess for airway edema. If a leak was present, the patients were extubated. Otherwise, the procedure was repeated on each post-operative day until a leak was present. Various factors, such as age, body mass index, duration of anesthesia, intraoperative fluids and blood loss, and post-operative fluids were evaluated. Fisher exact test and Student’s T test were performed to analyze for any difference between the two groups. RESULTS: There were no statistically significant differences between the two groups in any of the factors mentioned above. Five patients out of 35 in the steroid group and 6 out of 31 in the non-steroid group were extubated at greater than 30 hours (p⫽0.22). These patients tended to stay in the hospital an average of 1.4 day longer than patients extubated on postoperative day 1 (p⫽0.045). When both groups were pooled, it was found that females are at significantly greater risk for delayed extubation (p⫽0.004). In general, females were also found to require a smaller sized endotracheal tube when compared to males (p⫽0.0001). DISCUSSION: Our results seem to indicate that dexamethasome does not significantly reduce the time to extubation when compared to a a group receiving saline. These findings are in contrast to children where steroids have been shown to reduce post-extubation stridor by reducing airway edema. Given the potential complications associated with the administration of steroids, we do not recommend their routine use in an attempt to reduce swelling in patients undergoing anterior cervical corpectomies. CONCLUSIONS: In our series of patients, dexamethasome did not significantly shorten the total time of intubation in patients undergoing multilevel anterior cervical corpectomy. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
4:07 14. Cervical spine fusion using biodegradable cages Caleb Lippman, MD1, Michael Hajjar, MD1, Brett Abshire, MD1, George Martin, MD1, Bill Sonstein, MD1, Robert Engelman, DVM, PhD1, David Cahill, MD1; 1University of South Florida, Tampa, FL, USA HYPOTHESIS: We conducted a pilot study to evaluate the use of a bioabsorbable interbody fusion device in goat cervical spine. METHODS: The caprine (goat) cervical spine model was used. Fortytwo animals underwent two level anterior cervical discectomy and fusion: eight received iliac crest autograft, sixteen received a 70:30 polylactic acid/polyglycolic acid (PLA/PGA) cage, filled with either autograft or recombinant human bone morphogenic protein-2 (BMP), and eighteen received a 85:15 PLA/PGA cage, filled with either autograft or BMP. Animals were sacrificed at 3 and 6 months after surgery, and their cervical spines evaluated histologically, radiographically, and physically for fusion. RESULTS: A primarily fibrous union was demonstrated in all animals sacrificed at three months. At six months, bony trabeculae had become more prominent, and the fibrous response less so in all cohorts. This occurred most frequently in those fused with the 70:30 cages filled with BMP, in which 88% had a histologic union which was quantitatively more bony and less fibrous than the other cohorts. 89% of the unions in that cohort were graded quantitatively as having a stable union. Neither solid cages nor functional remnants (long fragments, still in contact and imbedded in both superior and inferior vertebrae) of the 85:15 cage were present at 3 or 6 months post-implantation. The 70:30 cage did not show signs of absorption or degradation at either 3 or 6 months, and appeared to be intact in all specimens. DISCUSSION: Conventional spinal instrumentation, while associated with improved rates of fusion in operative arthrodesis, is associated with several risks, including hardware extrusion with injury to adjacent anatomical structures, and disuse osteopenia as a result of stress shielding. Long-term effects of indwelling spinal instrumentation, although incompletely documented, may be detrimental. One way to avoid such problems would be to use bioabsorbable implantation devices. In this study, placement of a 70:30 PLA/PGA bioabsorbable cage filled with autograft led to a similar stable interbody union rate as that of interspaces fused with tricortical autograft, and a better rate when filled with BMP. Bony fusion was occurring both inside and outside of the cage. CONCLUSIONS: This study established that the 85:15 PLA/PGA cages absorb too quickly to be functionally useful in this model. The 70:30 cages worked as well as tricortical autograft when filled with cancellous autograft, and better when filled with BMP. At six months follow-up, the 70:30 cages have yet to begin absorption. There is little, if any, inflammatory response to the 70:30 cages at 6 months. Future studies should include biomechanical and microradiographical testing, and longer follow-up is necessary in this model to determine when the 70:30 cages are absorbed. DISCLOSURES: Device or drug: bioresorbable interbody cages. Status: investigational. CONFLICT OF INTEREST: David Cahill, MD, grant research support: Synthes and Sofamor Danek. doi: 10.1016/S1529-9430(03)00194-3
doi: 10.1016/S1529-9430(03)00195-5
4:21 16. Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery Alan Hilibrand, MD1, Daniel Schwartz, PhD1, Venkat Sethuraman1, Alexander Vaccaro1, Todd Albert1; 1Thomas Jefferson University, Philadelphia, PA, USA HYPOTHESIS: Although somatosensory evoked potential (SSEP) monitoring has enjoyed widespread use during corrective thoracolumbar surgery, there hasbeenless enthusiasmforits applicationin cervicalspinesurgery.This is due, in part, to the increased risk of selected anterior spinal cord injury to which the SSEP may be insensitive. While the clinical advent of transcranial electric motor evoked potentials (tceMEPs) offers a solution to this SSEP limitation, it has received limited clinical and research attention during corrective spine surgery in general, and cervical spine surgery, in particular. This investigation sought to: compare the statistical operating characteristics of tceMEP versus SSEP monitoring during cervical spine surgery; determine the temporal correlation between significant tceMEP and/or SSEP changes and neurologic sequelae; and identify patient and surgical risk factors associated with intraoperative neurophysiological changes.
73S
CONCLUSIONS: The presence of Apo E4 was associated with a poorer degree of neurological recovery at 6 months and subsequent deterioration after surgery in long term follow-up (1 year). The degree of compression required to make an individual symptomatic was significantly less in those patients with the gene. Genetic factors therefore influence disease symptoms, disease progression and response to surgical intervention. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
4:14 15. Steroids for multi-level cervical corpectomy procedures: do they reduce upper airway edema? A randomized, prospective, double-blind study Sanford Emery, MD1, Sam Akhavan, MD1, Jung Yoo1, Christopher Furey, MD1, James Rowbottom2, Henry Bohlman1; 1Case Western Reserve University, Cleveland, OH, USA; 2University Hospitals of Cleveland, Cleveland, OH, USA
doi: 10.1016/S1529-9430(03)00193-1
HYPOTHESIS: Dexamethasome reduces airway edema and will lead to shorter extubation time in patients undergoing multilevel cervical corpectomy. METHODS: Sixty-six patients undergoing multilevel anterior cervical corpectomy were randomized to two groups of 35 (25 males, 10 females) and 31(19 males, 12 females) patients, receiving either dexamethasone (0.3mg/ kg before incision and 0.15mg/kg at 6 and 12 hours) or saline respectively. Patients were kept intubated following surgery until post-operative day 1 at which time a cuff-leak test was performed to assess for airway edema. If a leak was present, the patients were extubated. Otherwise, the procedure was repeated on each post-operative day until a leak was present. Various factors, such as age, body mass index, duration of anesthesia, intraoperative fluids and blood loss, and post-operative fluids were evaluated. Fisher exact test and Student’s T test were performed to analyze for any difference between the two groups. RESULTS: There were no statistically significant differences between the two groups in any of the factors mentioned above. Five patients out of 35 in the steroid group and 6 out of 31 in the non-steroid group were extubated at greater than 30 hours (p⫽0.22). These patients tended to stay in the hospital an average of 1.4 day longer than patients extubated on postoperative day 1 (p⫽0.045). When both groups were pooled, it was found that females are at significantly greater risk for delayed extubation (p⫽0.004). In general, females were also found to require a smaller sized endotracheal tube when compared to males (p⫽0.0001). DISCUSSION: Our results seem to indicate that dexamethasome does not significantly reduce the time to extubation when compared to a a group receiving saline. These findings are in contrast to children where steroids have been shown to reduce post-extubation stridor by reducing airway edema. Given the potential complications associated with the administration of steroids, we do not recommend their routine use in an attempt to reduce swelling in patients undergoing anterior cervical corpectomies. CONCLUSIONS: In our series of patients, dexamethasome did not significantly shorten the total time of intubation in patients undergoing multilevel anterior cervical corpectomy. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
4:07 14. Cervical spine fusion using biodegradable cages Caleb Lippman, MD1, Michael Hajjar, MD1, Brett Abshire, MD1, George Martin, MD1, Bill Sonstein, MD1, Robert Engelman, DVM, PhD1, David Cahill, MD1; 1University of South Florida, Tampa, FL, USA HYPOTHESIS: We conducted a pilot study to evaluate the use of a bioabsorbable interbody fusion device in goat cervical spine. METHODS: The caprine (goat) cervical spine model was used. Fortytwo animals underwent two level anterior cervical discectomy and fusion: eight received iliac crest autograft, sixteen received a 70:30 polylactic acid/polyglycolic acid (PLA/PGA) cage, filled with either autograft or recombinant human bone morphogenic protein-2 (BMP), and eighteen received a 85:15 PLA/PGA cage, filled with either autograft or BMP. Animals were sacrificed at 3 and 6 months after surgery, and their cervical spines evaluated histologically, radiographically, and physically for fusion. RESULTS: A primarily fibrous union was demonstrated in all animals sacrificed at three months. At six months, bony trabeculae had become more prominent, and the fibrous response less so in all cohorts. This occurred most frequently in those fused with the 70:30 cages filled with BMP, in which 88% had a histologic union which was quantitatively more bony and less fibrous than the other cohorts. 89% of the unions in that cohort were graded quantitatively as having a stable union. Neither solid cages nor functional remnants (long fragments, still in contact and imbedded in both superior and inferior vertebrae) of the 85:15 cage were present at 3 or 6 months post-implantation. The 70:30 cage did not show signs of absorption or degradation at either 3 or 6 months, and appeared to be intact in all specimens. DISCUSSION: Conventional spinal instrumentation, while associated with improved rates of fusion in operative arthrodesis, is associated with several risks, including hardware extrusion with injury to adjacent anatomical structures, and disuse osteopenia as a result of stress shielding. Long-term effects of indwelling spinal instrumentation, although incompletely documented, may be detrimental. One way to avoid such problems would be to use bioabsorbable implantation devices. In this study, placement of a 70:30 PLA/PGA bioabsorbable cage filled with autograft led to a similar stable interbody union rate as that of interspaces fused with tricortical autograft, and a better rate when filled with BMP. Bony fusion was occurring both inside and outside of the cage. CONCLUSIONS: This study established that the 85:15 PLA/PGA cages absorb too quickly to be functionally useful in this model. The 70:30 cages worked as well as tricortical autograft when filled with cancellous autograft, and better when filled with BMP. At six months follow-up, the 70:30 cages have yet to begin absorption. There is little, if any, inflammatory response to the 70:30 cages at 6 months. Future studies should include biomechanical and microradiographical testing, and longer follow-up is necessary in this model to determine when the 70:30 cages are absorbed. DISCLOSURES: Device or drug: bioresorbable interbody cages. Status: investigational. CONFLICT OF INTEREST: David Cahill, MD, grant research support: Synthes and Sofamor Danek. doi: 10.1016/S1529-9430(03)00194-3
doi: 10.1016/S1529-9430(03)00195-5
4:21 16. Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery Alan Hilibrand, MD1, Daniel Schwartz, PhD1, Venkat Sethuraman1, Alexander Vaccaro1, Todd Albert1; 1Thomas Jefferson University, Philadelphia, PA, USA HYPOTHESIS: Although somatosensory evoked potential (SSEP) monitoring has enjoyed widespread use during corrective thoracolumbar surgery, there hasbeenless enthusiasmforits applicationin cervicalspinesurgery.This is due, in part, to the increased risk of selected anterior spinal cord injury to which the SSEP may be insensitive. While the clinical advent of transcranial electric motor evoked potentials (tceMEPs) offers a solution to this SSEP limitation, it has received limited clinical and research attention during corrective spine surgery in general, and cervical spine surgery, in particular. This investigation sought to: compare the statistical operating characteristics of tceMEP versus SSEP monitoring during cervical spine surgery; determine the temporal correlation between significant tceMEP and/or SSEP changes and neurologic sequelae; and identify patient and surgical risk factors associated with intraoperative neurophysiological changes.