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Michael Y. Wang, Tetsuya Goto, Enrico Tessitore and Anand Veeravagu

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Giacomo Pacchiarotti, Michael Y. Wang, John Paul G. Kolcun, Ken Hsuan-kan Chang, Motasem Al Maaieh, Victor S. Reis and Dao M. Nguyen

Solitary paravertebral schwannomas in the thoracic spine and lacking an intraspinal component are uncommon. These benign nerve sheath tumors are typically treated using complete resection with an excellent outcome. Resection of these tumors is achieved by an anterior approach via open thoracotomy or minimally invasive thoracoscopy, by a posterior approach via laminectomy, or by a combination of both approaches. These tumors most commonly occur in the midthoracic region, for which surgical removal is usually straightforward. The authors of this report describe 2 cases of paravertebral schwannoma at extreme locations of the posterior mediastinum, one at the superior sulcus and the other at the inferior sulcus of the thoracic cavity, for which the usual surgical approaches for safe resection can be challenging. The tumors were completely resected with robot-assisted thoracoscopic surgery. This report suggests that single-stage anterior surgery for this type of tumor in extreme locations is safe and effective with this novel minimally invasive technique.

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Michael Y. Wang, Peng-Yuan Chang and Jay Grossman

OBJECTIVE

Over the past decade, Enhancing Recovery After Surgery (ERAS) programs have been implemented throughout the world across multiple surgical disciplines. However, to date no spinal surgery equivalent has been described. In this report the authors review the development and implementation of a “fast track” surgical approach for lumbar fusion.

METHODS

The first 42 consecutive cases in which patients were treated with the new surgical procedure were reviewed. A combination of endoscopic decompression, expandable cage deployment, and percutaneous screw placement were performed with liposomal bupivacaine anesthesia to allow the surgery to be performed without general endotracheal anesthesia.

RESULTS

In all cases the surgical procedure was performed successfully without conversion to an open operation. The patients' mean age (± SD) was 66.1 ± 11.7 years, the male/female ratio was 20:22, and a total of 47 levels were treated. The mean operative time was 94.6 ± 22.4 minutes, the mean intraoperative blood loss was 66 ± 30 ml, and the mean hospital length of stay was 1.29 ± 0.9 nights. Early follow-up showed a significant improvement in the mean Oswestry Disability Index score (from 40 ± 13 to 17 ± 11, p = 0.0001). Return to the operating room was required in 2 cases due to infection and in 1 case due to cage displacement. An iterative quality improvement program demonstrated areas of improvement, including steps to minimize infection, improve postoperative analgesia, and reduce cage osteolysis.

CONCLUSIONS

ERAS programs for improving spinal fusion surgery are possible and necessary. This report demonstrates a first foray to apply these principles through 1) a patient-focused approach, 2) reducing the stress of the operation, and 3) an iterative improvement process.

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Khoi D. Than, Paul Park, Kai-Ming Fu, Stacie Nguyen, Michael Y. Wang, Dean Chou, Pierce D. Nunley, Neel Anand, Richard G. Fessler, Christopher I. Shaffrey, Shay Bess, Behrooz A. Akbarnia, Vedat Deviren, Juan S. Uribe, Frank La Marca, Adam S. Kanter, David O. Okonkwo, Gregory M. Mundis Jr., Praveen V. Mummaneni and the International Spine Study Group

OBJECTIVE

Minimally invasive surgery (MIS) techniques are increasingly used to treat adult spinal deformity. However, standard minimally invasive spinal deformity techniques have a more limited ability to restore sagittal balance and match the pelvic incidence–lumbar lordosis (PI-LL) than traditional open surgery. This study sought to compare “best” versus “worst” outcomes of MIS to identify variables that may predispose patients to postoperative success.

METHODS

A retrospective review of minimally invasive spinal deformity surgery cases was performed to identify parameters in the 20% of patients who had the greatest improvement in Oswestry Disability Index (ODI) scores versus those in the 20% of patients who had the least improvement in ODI scores at 2 years' follow-up.

RESULTS

One hundred four patients met the inclusion criteria, and the top 20% of patients in terms of ODI improvement at 2 years (best group, 22 patients) were compared with the bottom 20% (worst group, 21 patients). There were no statistically significant differences in age, body mass index, pre- and postoperative Cobb angles, pelvic tilt, pelvic incidence, levels fused, operating room time, and blood loss between the best and worst groups. However, the mean preoperative ODI score was significantly higher (worse disability) at baseline in the group that had the greatest improvement in ODI score (58.2 vs 39.7, p < 0.001). There was no difference in preoperative PI-LL mismatch (12.8° best vs 19.5° worst, p = 0.298). The best group had significantly less postoperative sagittal vertical axis (SVA; 3.4 vs 6.9 cm, p = 0.043) and postoperative PI-LL mismatch (10.4° vs 19.4°, p = 0.027) than the worst group. The best group also had better postoperative visual analog scale back and leg pain scores (p = 0.001 and p = 0.046, respectively).

CONCLUSIONS

The authors recommend that spinal deformity surgeons using MIS techniques focus on correcting a patient's PI-LL mismatch to within 10° and restoring SVA to < 5 cm. Restoration of these parameters seems to impact which patients will attain the greatest degree of improvement in ODI outcomes, while the spines of patients who do the worst are not appropriately corrected and may be fused into a fixed sagittal plane deformity.

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Peng-Yuan Chang and Michael Y. Wang

In minimally invasive spinal fusion surgery, transforaminal lumbar (sacral) interbody fusion (TLIF) is one of the most common procedures that provides both anterior and posterior column support without retraction or violation to the neural structure. Direct and indirect decompression can be done through this single approach. Preoperative plain radiographs and MR scan should be carefully evaluated. This video demonstrates a standard approach for how to perform a minimally invasive transforaminal lumbosacral interbody fusion.

The video can be found here: https://youtu.be/bhEeafKJ370.

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Michael G. Fehlings, Lindsay Tetreault, Patrick C. Hsieh, Vincent Traynelis and Michael Y. Wang

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Karthik Madhavan, Lee Onn Chieng, Hanyao Foong and Michael Y. Wang

OBJECTIVE

Cervical spondylotic myelopathy usually presents in the 5th decade of life or later but can also present earlier in patients with congenital spinal stenosis. As life expectancy continues to increase in the United States, the preconceived reluctance toward operating on the elderly population based on older publications must be rethought. It is a known fact that outcomes in the elderly cannot be as robust as those in the younger population. There are no publications with detailed meta-analyses to determine an acceptable level of outcome in this population. In this review, the authors compare elderly patients older than 75 years to a nonelderly population, and they discuss some of the relevant strategies to minimize complications.

METHODS

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors performed a PubMed database search to identify English-language literature published between 1995 and 2015. Combinations of the following phrases that describe the age group (“elderly,” “non-elderly,” “old,” “age”) and the disease of interest as well as management (“surgical outcome,” “surgery,” “cervical spondylotic myelopathy,” “cervical degenerative myelopathy”) were constructed when searching for relevant articles. Two reviewers independently assessed the outcomes, and any disagreement was discussed with the first author until it was resolved. A random-effects model was applied to assess pooled data due to high heterogeneity between studies. The mean difference (MD) and odds ratio were calculated for continuous and dichromatic parameters, respectively.

RESULTS

Eighteen studies comprising elderly (n = 1169) and nonelderly (n = 1699) patients who received surgical treatment for cervical spondylotic myelopathy were included in this meta-analysis. Of these studies, 5 were prospective and 13 were retrospective. Intraoperatively, both groups required a similar amount of operation time (p = 0.35). The elderly group had lower Japanese Orthopaedic Association (JOA) scores (MD −1.36, 95% CI −1.62 to −1.09; p < 0.00001) to begin with compared with the nonelderly group. The nonelderly group also had a higher postoperative JOA score (MD −1.11, 95% CI −1.44 to −0.79; p < 0.00001), therefore demonstrating a higher recovery rate from surgeries (MD −11.98, 95% CI −16.16 to −7.79; p < 0.00001). The length of stay (MD 4.14, 95% CI 3.54–4.73; p < 0.00001) was slightly longer in the elderly group. In terms of radiological outcomes, the elderly group had a smaller postoperative Cobb angle but a greater increase in spinal canal diameter compared with the nonelderly group. The complication rates were not significant.

CONCLUSIONS

Cervical myelopathy is a disease of the elderly, and age is an independent factor for recovery from surgery. Postoperative and long-term outcomes have been remarkable in terms of improvement in mobility and independence requiring reduced nursing care. There is definitely a higher potential risk while operating on the elderly population, but no significant difference in the incidence of postoperative complications was noted. Withholding surgery from the elderly population can lead to increased morbidity due to rapid progression of symptoms in addition to deconditioning from lack of mobility and independence. Reduction in operative time under anesthesia, lower blood loss, and perioperative fluid management have been shown to minimize the complication rate. The authors request that neurosurgeons weigh the potential benefit against the risks for every patient before withholding surgery from elderly patients.

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Michael Y. Wang and Gerd Bordon

OBJECTIVE

Pedicle subtraction osteotomy (PSO) is a powerful but high-risk surgical technique for destabilizing the spine for deformity correction in both the sagittal and coronal planes. Numerous reports have demonstrated the benefits of this technique for realigning the spine in a physiological posture; however, the open surgical technique is associated with a high complication rate. In this report the authors review data obtained in a series of patients who underwent PSO through a less invasive approach.

METHODS

Sixteen patients with severe coronal- and/or sagittal-plane deformities were treated in this series. Conservative measures had failed in all cases and patients had undergone a single-level PSO or extended PSO at L-2 or L-3. Fixation was accomplished using percutaneous instrumentation and interbody or facet joint fusions were used at the remaining levels. None of the procedures were aborted or converted to a traditional open procedure. Standard clinical and radiographic measures were used to assess patient outcomes.

RESULTS

Mean age was 68.8 years and mean follow-up duration was 17.7 months. An average of 7.6 levels were fused, and 50% of the patients had bilateral iliac screw fixation, with all constructs crossing both the thoracolumbar and lumbosacral junctions. Operative time averaged 356 ± 50 minutes and there was a mean blood loss of 843 ± 339 ml.

The leg visual analog scale score improved from a mean of 5.7 ± 2.7 to one of 1.3 ± 1.6, and the back visual analog scale score improved from a mean of 8.6 ± 1.3 to one of 2.4 ± 2.1. The Oswestry Disability Index score improved from a mean of 50.1 ± 14.4 to 16.4 ± 12.7, representing a mean reduction of 36.0 ± 16.9 points. The SF-36 physical component summary score changed from a mean of 43.4 ± 2.6 to one of 47.0 ± 4.3, and the SF-36 mental component summary score changed from a mean of 46.7 ± 3.6 to 46.30 ± 3.0.

Coronal alignment improved from a mean of 27.9 ± 43.6 mm to 16.0 ± 17.2 mm. The lumbar Cobb angle improved from a mean of 41.2° ± 18.4° to 15.4° ± 9.6°, and lumbar lordosis improved from 23.1° ± 15.9° to 48.6° ± 11.7°. Pelvic tilt improved from a mean of 33.7° ± 8.6° to 24.4° ± 6.5°, and the sagittal vertical axis improved from 102.4 ± 73.4 mm to 42.2 ± 39.9 mm. The final lumbar lordosis–pelvic incidence difference averaged 8.4° ± 12.1°. There were 4 patients who failed to achieve less than or equal to a 10° mismatch on this parameter. Ten of the 16 patients underwent delayed postoperative CT, and 8 of these had developed a solid arthrodesis at all levels treated. A total of 6 complications occurred in this series. There were no cases of symptomatic proximal junction kyphosis.

CONCLUSIONS

Advancements in minimally invasive technique have resulted in the ability to manage increasingly complex deformities with hybrid approaches. In this limited series, the authors describe the results of utilizing a tissue-sparing mini-open PSO to correct severe spinal deformities. This method was technically feasible in all cases with acceptable radiographic outcomes similar to open surgery. However, high complication rates associated with these deformity corrections remain problematic.

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Joanna E. Gernsback and Michael Y. Wang

Vertebral augmentation with cement has become a common procedure for the treatment of compression fractures, leading to a growing population who have had this procedure and are now in need of another spinal surgery. This technical note reports an undescribed method for placing pedicle screws through a previously cemented level.