Minimally invasive lateral approaches for the treatment of spinal tumors: single-position surgery without the "flip".

Although primary tumors of the spine and neural elements are rare, metastatic disease to the spine is quite common. Traditionally, surgical treatment for spinal tumor patients involves open decompression with or without stabilization. The single-position minimally invasive (MIS) lateral approach, which has been recently described over the recent decade, allows simultaneous access to the anterior and posterior columns with the patient positioned in the lateral decubitus position. Herein, we review the application of single-position MIS lateral surgery for the treatment of spinal neoplasm. The aim was to review the evolution, operative technique, outcomes, and complications associated with MIS lateral approaches for spinal tumors. The history of spinal tumor diagnosis and management are reviewed and discussed as well as the author's experience and literature regarding spinal tumor treatment outcome and surgical complications, with particular attention to single-position, MIS lateral approaches. In addition, the author's surgical technique is outlined in detail for thoracic, thoracolumbar and lumbar tumors. Furthermore, there are specific indications and complications associated with the surgical treatment of spinal tumors, and the MIS, single-position lateral approach, when applied appropriately, allows for concurrent access to the anterior and posterior column while mitigating the complications associated with traditional, open posterior-based approaches. In the treatment of spinal neoplasms, the goals of surgery are dictated by a number of tumor-specific and patient-specific factors. Therefore, operative treatment of tumors in the future may be a consolidation of historical surgical techniques and MIS, single-position lateral approaches. Regardless, multidisciplinary management is imperative for the individualized treatment of the patient and optimization of outcome.

Biomechanical Evaluation of a Novel Autogenous Bone Interbody Fusion Cage for Posterior Lumbar Interbody Fusion in a Cadaveric Model.

STUDY DESIGN: A human cadaveric biomechanical study of a novel, prefabricated autogenous bone interbody fusion (ABIF) cage. OBJECTIVE: To evaluate the biomechanical properties of the ABIF cage in a single-level construct with and without transpedicular screw and rod fixation. SUMMARY OF BACKGROUND DATA: In current practice, posterior lumbar interbody fusion is generally carried out using synthetic interbody spacers or corticocancellous iliac crest bone graft (ICBG) in combination with posterior instrumentation. However, questions remain concerning the use of synthetic intervertebral implants as well as the morbidity ICBG harvesting. Therefore, ABIF cage has been developed to obviate some of the challenges in conventional posterior lumbar interbody fusion instrumentation and to facilitate the fusion process. METHODS: Eighteen adult cadaveric lumbosacral (L3-S1) specimens were tested. Test conditions included single lumbosacral segments across (1) intact, (2) decompressed, (3) intervertebral cage alone, and (4) intervertebral cage with bilateral transpedicular fixation. Range of motion (ROM), neutral zone (NZ), and axial failure load were tested for each condition. RESULTS: The ICBG, polyetheretherketone cage, or ABIF cage alone exhibited a significantly lower (P < 0.05) ROM and NZ than the decompressed spine. In comparison with the intact spine, all 3 test conditions without supplemental fixation were able to decrease ROM and NZ to near intact levels. When stabilized with pedicle screws, the ROM was significantly less and the NZ was significantly lower (P < 0.05) for each group both compared with the intact spine. In axial compression testing, the failure load of polyetheretherketone cage was the highest, with no significant difference between the ICBG and the ABIF cage. CONCLUSION: These data suggest that the novel ABIF cage can bear the physiological intervertebral peak load, similar to ICBG. When combined with pedicle screw and rod fixation, it exhibits similar biomechanical properties as the polyetheretherketone cage plus posterior instrumentation. Based on the biomechanical properties of ABIF cage, the prospect of these cages in clinical practice is expected.

A comparison of perioperative charges and outcome between open and mini-open approaches for anterior lumbar discectomy and fusion.

The objectives of this study were to examine charge data and long-term outcomes of two approaches for anterior lumbar interbody fusion: a mini-open lateral approach (extreme lateral interbody fusion, XLIF) and an open anterior approach (anterior lumbar interbody fusion, ALIF) through retrospective chart review. A total of 202 patients underwent surgery: 87 with ALIF (Open) and 115 with XLIF (Mini-open) procedures, all with transpedicular fixation. Complications occurred in 16.7% of Open, and 8.2% of Mini-open, procedures (p = 0.041). The mean charges ($US) for one-level Mini-open and Open procedures were $91,995 and $102,146, and for two-level procedures were $124,540 and $144,183, respectively. All differences were statistically significant (p < 0.05). This represents a 10% cost-savings, based on charges, for one-level and 13.6% for two-level Mini-open compared to Open procedures. Functional outcomes improved significantly at two years for both cohorts, although the difference between groups was not statistically significant. In conclusion, the Mini-open approach, compared to the Open, resulted in clinical as well as cost benefits with similar long-term outcomes.

Minimally invasive lateral extracavitary resection of foraminal neurofibromas.

Nerve sheath tumors are the most common spinal tumors but extradural foraminal nerve sheath tumors are much rarer. Traditionally, these nerve sheath tumors have been resected via an open posterior approach. We describe an alternative minimally invasive (MIS) lateral extracavitary approach for resection of symptomatic extradural foraminal spinal neurofibromas. We describe three consecutive male patients (mean age, 37 years) who underwent a successful MIS lateral extracavitary approach for surgical resection of symptomatic extradural spinal neurofibromas. All patients presented with pain and two of the three presented with neurological deficit. Follow-up data, including functional and radiographic outcomes, were collected for all patients. The mean operative time, blood loss, and length of stay were 85 minutes (min) (range, 60-120 min), 150 mL (range, 100-200 mL), and two days (range, 1-3 day), respectively. There were no complications. All patients had complete resolution of their pain and motor deficits. Thus, the MIS lateral extracavitary approach is a safe and feasible alternative for resection of spinal extradural foraminal neurofibromas.