The anatomy of the lateral aspect of the lumbar spine and our lateral microsurgical technique for extreme lateral lumbar disc herniations (ELLDH) is described. This study was based on the microdissection of 4 cadavers, on the morphometric evaluation of these as well as 6 dried cadaver spines and 8 lumbar CT scans, and on the use of this technique on over 200 cases. Level dependent changes in the posterior arch cause a shift of the disc space distally relative to the facet joint, an increasing amount of bone to overlie the intervertebral foramen, and a decreasing amount of working space within the exposure in the caudal direction. Therefore, more bone removal from the lateral aspect of the pars interarticularis and supero-lateral aspect of the facet joint is required in the lower lumbar spine. When the exposed ligamentum flavum is resected, the dorsal root ganglion is seen and access to the herniation and disc space is achieved. Level dependent changes in the pedicles and transverse processes lead to an alteration in the course and relationships of the nerves, thereby influencing the pathophysiology of and surgical technique for the ELLDH. The operative target is the lateral aspect of the pars interarticularis and not the intertransverse space as has been previously described. Our techniques allows for the early identification of the nerve with minimal risks of injury to it, to the adjacent vessels and to the structural integrity of the facet joint and pars interarticularis.

We sought to evaluate differences in perioperative baseline characteristics, operative efficiency, and 30-day safety events for patients undergoing standalone minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) in a hospital versus an ambulatory surgery center (ASC). Methods Patients were retrospectively identified and sequentially enrolled from the office records of a single, community neurosurgeon. Records for the first 50 qualifying patients in the hospital and ASC cohorts were retrieved. Variables collected included: baseline demographic and health status, operative safety (intra-op complications) and efficiency (operative time, fluoroscopy time, etc.), and 30-day post-operative safety (emergency room visits, re-admission, and re-operation). Results At baseline, hospital and ASC patients were equivalent in gender distribution, BMI, and pre-operative narcotic use. Statistically significant differences were found in age and comorbidity burden (ASA status and Charleson Comorbidity Index); p < 0.0001, p = 0.0039, and p < 0.001 respectively. The only significant difference in construct type between hospital and ASC patients was the proportion of one-versus two-level fusions; all two-level fusions were performed in the hospital group. There were no differences in operative time, need for transfusions, or iatrogenic complications. There were also no differences between the groups in 30-day events of ER visits, re-admission, re-operation, or post-operative narcotic refill use. The length of stay was significantly different between the ASC and hospital settings (p < 0.0001). Conclusions As expected, ASC patients were younger and relatively healthier compared to their hospital counterparts. Thirty-day safety events of ER visits, re-admission, re-operation, and narcotic refill utilization were representative of population norms. Patients with standalone, expandable MIS-TLIF underwent efficient operative procedures and experienced minimal 30-day complications independent of their operative status. ASC patients had the added benefit of significantly reduced length of stay over their hospital counterparts. Given the equivalency of the 30-day post-operative course for both patient cohorts, a substantial reduction in economic burden is likely for the ASC patients.

(1) Background: The technological advances achieved with minimally-invasive surgery have enabled procedures to be undertaken in outpatient settings, and there has been growing acceptance of performing minimally-invasive transforaminal interbody fusion (TLIF) in the ambulatory surgery center (ASC). The purposeof this study was to determine the comparative 30 day safety profile for patients treated with TLIF in the ASC versus the hospital setting. (2) Methods: This multi-center study retrospectively collected baseline characteristics, perioperative variables, and 30 day postoperative safety outcomes for patients having a TLIF using the VariLift®-LX expandable lumbar interbody fusion device. Outcomes were compared between patients undergoing TLIF in the ASC (n = 53) versus in the hospital (n = 114). (3) Results: Patients treated in-hospital were significantly older, frailer and more likely to have had previous spinal surgery than ASC patients. Preoperative back and leg pain scores were similar between study groups (median, 7). ASC patients had almost exclusively one-level procedures (98%) vs. 20% of hospital procedures involving two-levels (p = 0.004). Most procedures (>90%) employed a stand-alone device. The median length of stay for hospital patients was five times greater than for ASC patients (1.4 days vs. 0.3 days, p = 0.001). Emergency department visits, re-admissions and reoperations were rare whether the patients were managed in the traditional hospital setting or the ASC. (4) Conclusions: There were equivalent 30 day postoperative safety profiles for patients undergoing a minimally-invasive TLIF irrespective of surgical setting. For appropriately selected surgical candidates, the ASC offers a viable and attractive option for their TLIF procedure with the advantage of same-day discharge and at-home recovery.

(1) Background: The clinical benefits and procedural efficiencies of performing minimally invasive fusion procedures, such as transforaminal lumbar interbody fusion (TLIF), in the ambulatory surgery center (ASC) are becoming increasingly well established. Currently, Medicare does not provide reimbursement for its beneficiaries eligible for TLIF in the ASC due to a lack of evidence regarding procedural safety. However, the initiation of the Hospital Without Walls program allowed for traditional hospital procedures to be relocated to other facilities such as ASCs, providing a unique opportunity to evaluate the utility of TLIF in the ASC in Medicare-age patients. (2) Methods: This single-center, retrospective study compared baseline characteristics, intraoperative variables, and 30-day postoperative safety outcomes between 48 Medicare-age patients undergoing TLIF in the ASC and 48 patients having the same procedure as hospital in-patients. All patients had a one-level TLIF using the VariLift®-LX expandable lumbar interbody fusion device. (3) Results: There were similar patient characteristics, procedural efficiency, and occurrence of clinical 30-day safety events between the two study groups. However, there was a marked and statistically significant difference in the median length of stay favoring TLIF patients treated in the ASC (23.9 h vs. 1.6 h, p = 0.001). All ASC-treated patients were discharged on the day of surgery. Postoperative visits to address adverse events were rare in either group. (4) Conclusions: These findings provide evidence that minimally invasive TLIF can be performed safely and efficiently in the ASC in Medicare-age patients. With same-day discharge, fusion procedures performed in the ASC offer a similar safety and more attractive cost–benefit profile for older patients than the same surgery undertaken in the traditional hospital setting. The Centers for Medicare and Medicaid Services should strongly consider extending the appropriate reimbursement codes (CPT ® 22630, 22633) for minimally invasive TLIF and PLIF to the ASC Covered Procedure List so that Medicare-age patients can realize the clinical benefits of surgeries performed in this setting.

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