Intraoperative Performance with the Exoscope in Spine Surgery: An Institutional Experience.

BACKGROUND: Exoscope use in spinal neurosurgery has become a promising surgical option providing enhanced operative field visibility and ergonomics. However, data on its use in spine surgery are underreported in the literature. We aimed to assess the intraoperative outcomes in exoscope-assisted spine surgery compared with similar procedures performed using the operative microscope. METHODS: A retrospective review was performed of all spinal surgeries performed using an exoscope and, subsequently, an equal number of operative microscope cases performed by 2 senior surgeons at a single institution from 2016 to 2023. The variables included demographics, clinical presentation, surgical treatment, and operative outcomes. RESULTS: A total of 123 exoscope spinal surgeries were performed on 116 unique patients with a mean age of 67 ± 14 years, of whom 60 (52%) were women. The microscope group included 126 surgeries on 120 unique patients with a mean age of 62 ± 14 years, of whom 53 (45%) were women. The mean blood loss (28 mL vs. 132 mL; P = 0.0009), operative time (83 minutes vs. 103 minutes; P = 0.006), and length of stay (1.04 days vs. 1.73 days; P = 0.02) were significantly less for the exoscope group than for the microscope group. CONCLUSIONS: The use of the exoscope resulted in a shorter operative time, less blood loss, a shorter length of stay, and favorable clinical outcomes compared with the use of the operative microscope. Neurosurgeons should consider this seemingly efficacious and ergonomically favorable visual technology for spinal surgeries.

Rib fixation for flail chest physiology and the facilitation of safe prone spinal surgery: illustrative case.

BACKGROUND: Spine fractures are frequently associated with additional injuries in the trauma setting, with chest wall trauma being particularly common. Limited literature exists on the management of flail chest physiology with concurrent unstable spinal injury. The authors present a case in which flail chest physiology precluded safe prone surgery and after rib fixation the patient tolerated spinal fixation without further issue. OBSERVATIONS: Flail chest physiology can cause cardiovascular decompensation in the prone position. Stabilization of the chest wall addresses this instability allowing for safe prone spinal surgery. LESSONS: Chest wall fixation should be considered in select cases of flail chest physiology prior to stabilization of the spinal column in the prone position. Further research is necessary to identify patients that are at highest risk to not tolerate prone surgery.

Sacroiliac Joint Fusion-A Shift Toward Variant Anatomy and Clinical Implications.

OBJECTIVE: To investigate impact of patient factors and sacroiliac joint (SIJ) anatomical structure on SIJ fusion outcomes. METHODS: This single-center, retrospective, observational study evaluated patients diagnosed with SIJ dysfunction refractory to conservative measures who had available preoperative imaging of the sacrum and underwent SIJ fusion surgery. The impact of patient sociodemographics on pain improvement was assessed by Mann-Whitney U test. Differences in patient sociodemographics and outcome information between anatomical subtypes were assessed with χ2 and Kruskal-Wallis tests. χ2 test was used to compare joint anatomy distribution between studies analyzing SIJ variations. RESULTS: We included 77 total joints that underwent instrumentation. There were significant differences between the anatomical subtypes with female sex having significantly higher rates of non-normal joint anatomy. Younger age was significantly more common in bipartite/dysmorphic anatomy (53.9 years) than normal anatomy (70 years) (P < 0.05). There was a trend toward better outcomes in bipartite/dysmorphic and accessory variants, while semicircular defect and crescent variants trended toward worse outcomes. Nonnormal anatomy was significantly more frequent in our population than previous reports on nonpathological SIJ. CONCLUSIONS: A pathological SIJ has a significantly higher prevalence of variant joint anatomy. There appears to be a trend toward differences in surgical outcomes based on SIJ anatomy. Future research with larger sample sizes is necessary to confirm these differences.

Ultrasonic spine surgery for every thoracic disc herniation: a 43-patient case series and technical note demonstrating safety and efficacy using a partial transpedicular thoracic discectomy with ultrasonic aspiration and ultrasound guidance.

OBJECTIVE: Thoracic disc herniations (TDHs) are a challenging pathology. A variety of surgical techniques have been used to achieve spinal cord decompression. This series elucidates the versatility, efficacy, and safety of the partial transpedicular approach with the use of intraoperative ultrasound and ultrasonic aspiration for resection of TDHs of various sizes, locations, and consistencies. This technique can be deployed to safely remove all TDHs. METHODS: A retrospective review was performed of patients who underwent a thoracic discectomy via the partial transpedicular approach between January 2014 and December 2020 by a single surgeon. Variables reviewed included demographics, perioperative imaging, and functional outcome scores. RESULTS: A total of 43 patients (53.5% female) underwent 54 discectomies. The most common presenting symptoms were myelopathy (86%), motor weakness (72%), and sensory deficit (65%) with a symptom duration of 10.4 ± 11.6 months. A total of 21 (38.9%) discs were fully calcified on imaging and 15 (27.8%) were partially calcified. A total of 36 (66.7%) were giant TDHs (> 40% canal compromise). The average operative time was 197.2 ± 77.1 minutes with an average blood loss of 238.8 ± 250 ml. Six patients required ICU stays. Hospital length of stay was 4.40 ± 3.4 days. Of patients with follow-up MRI, 38 of 40 (95%) disc levels demonstrated < 20% residual disc. Postoperative Frankel scores (> 3 months) were maintained or improved for all patients, with 28 (65.1%) patients having an increase of 1 grade or more on their Frankel score. Six (14%) patients required repeat surgery, 2 of which were due to reherniation, 2 were from adjacent-level herniation, and 2 others were from wound problems. Patients with calcified TDHs had similar improvement in Frankel grade compared to patients without calcified TDH. Additionally, improvement in intraoperative neuromonitoring was associated with a greater improvement in Frankel grade. CONCLUSIONS: The authors demonstrate a minimally disruptive, posterior approach that uses intraoperative ultrasound and ultrasonic aspiration with excellent outcomes and a complication profile similar to or better than other reported case series. This posterior approach is a valuable complement to the spine surgeon's arsenal for the confident tackling of all TDHs.

Anatomy of the posterolateral spinal epidural ligaments.

BACKGROUND: The epidural ligaments (ELs) (of Hofmann) were described as fibrous bands interconnecting the ventrolateral spinal dura and the posterior longitudinal ligament below L1. They are hardly ever discussed in the literature or considered in hypothesis-driven basic science experiments or spine biomechanical models. METHODS: Intraoperative photographs were obtained to illustrate a group of posterolateral spinal ELs. In addition, electronic database searches (PubMed, Ovid Embase, and SCOPUS) were utilized to summarize the anatomy, and relevant clinical and surgical factors impacting these ELs. RESULTS: ELs attach circumferentially at most spinal levels. They anchor the nerve root sleeves ventrally, and therefore, may play a role in the some idiopathic neurologic deficits (e.g., postoperative radiculopathies, C5 palsies) in patients without radiological compression. The posterolateral ELs originate on the dura dorsal to the nerve root sleeves and insert on the ipsilateral lamina, interlaminar ligament, and facet capsule. They appear to be continuous with the peridural membrane, a fibrovascular sheath that surrounds the thecal sac and serves as a scaffold for the internal vertebral venous plexus of Batson and epidural fat. CONCLUSION: The spinal ELs should be divided sharply during surgery to prevent durotomies, especially in patients with advanced spondylosis and facet arthropathy. Disconnecting these ligaments releases the thecal sac laterally and ventrally, allowing for medial mobilization when performing discectomies or for working in the ventral epidural space.

Microsurgical Management of a Primary Neuroendocrine Tumor of the Filum Terminale: A Surgical Technique.

Neuroendocrine tumors (NETs) are benign tumors of the autonomic nervous system that rarely occur in the spinal canal. The gold standard treatment is gross total resection while preserving the patient's neurologic functioning as complete surgical resection is curative. The surgical management of NETs could pose a challenge given their friable consistency, hypervascular nature, and proclivity to adhere to the cauda equina nerve roots. We present a case of a 62-year-old female with an incidental primary NET arising from the filum terminale internum, review the literature, and describe the surgical technique including the benefits of using an intraoperative ultrasound and some of the pitfalls of relying "blindly" on neuromonitoring. Early identification and disconnection of the tumor's vascular pedicle, which usually runs through the cranial filum, devascularizes the tumor, prevents systemic complications from catecholamine release, and facilitates circumferential dissection off the en passage cauda equina nerve roots. Our patient remains neurologically intact and asymptomatic two years postoperatively and neuroimaging confirmed complete resection.

Paraspinous Muscle Flaps for the Treatment of Complex Spinal Wounds.

MINI: This retrospective case series investigated paraspinous flaps for coverage of complex spinal wounds. 6.90% of patients developed postoperative wound infections and 0.00% of patients required instrumentation removal for infection. This suggests that these flaps may offer a long-term solution in wound management for patients with repeated spinal operations. STUDY DESIGN: Retrospective case series. OBJECTIVE: To investigate the efficacy and complication profile of the use of paraspinous muscle flaps for closure of complex spinal wounds. SUMMARY OF BACKGROUND DATA: Paraspinous muscle flap closure offers an innovative option in difficult-to-manage post-spinal surgery wounds. Current literature reports are mixed in terms of success and complication rates of these flap procedures, with most sources citing a wound complication rate of 20%. METHODS: This case series investigated the hospital course of 58 patients undergoing paraspinous flap closure after spinal surgery between the years 2014 and 2018. Information gathered includes: demographics, surgery indication, location, and length of incision on the spine, nutrition labs, previous spinal surgeries, preoperative wound class, operative times, length of hospital stay, and complication rates including reoperation, wound infection, and other postoperative complications. RESULTS: Of the 58 patients undergoing spinal muscle flap closure, 51 (87.93%) had undergone previous spinal surgery with an average of 2.12 previous surgeries in these patients. Mean albumin and prealbumin were 2.62 and 13.75, respectively. 4/58 (6.90%) developed a wound infection or experienced a continuation of their chronic osteomyelitis. Of the 57 patients that had spinal instrumentation, three (5.26%) had spinal implants removed at the time of surgery and two (3.51%) had it removed or replaced later for mechanical complications. No patients had instrumentation removed for chronic infections. One (1.72%) experienced reoperation for wound-related complications. These rates are lower than most complication rates in the current literature. CONCLUSION: The plastic and reconstructive paraspinous muscle flap has promising results as a closure option for complex spinal wounds following neurosurgical cases. Further investigation is called for to determine the applicability of these results to the general population. LEVEL OF EVIDENCE: 4.

Retrospective case series. To investigate the efficacy and complication profile of the use of paraspinous muscle flaps for closure of complex spinal wounds. Paraspinous muscle flap closure offers an innovative option in difficult-to-manage post-spinal surgery wounds. Current literature reports are mixed in terms of success and complication rates of these flap procedures, with most sources citing a wound complication rate of 20%. This case series investigated the hospital course of 58 patients undergoing paraspinous flap closure after spinal surgery between the years 2014 and 2018. Information gathered includes: demographics, surgery indication, location, and length of incision on the spine, nutrition labs, previous spinal surgeries, preoperative wound class, operative times, length of hospital stay, and complication rates including reoperation, wound infection, and other postoperative complications. Of the 58 patients undergoing spinal muscle flap closure, 51 (87.93%) had undergone previous spinal surgery with an average of 2.12 previous surgeries in these patients. Mean albumin and prealbumin were 2.62 and 13.75, respectively. 4/58 (6.90%) developed a wound infection or experienced a continuation of their chronic osteomyelitis. Of the 57 patients that had spinal instrumentation, three (5.26%) had spinal implants removed at the time of surgery and two (3.51%) had it removed or replaced later for mechanical complications. No patients had instrumentation removed for chronic infections. One (1.72%) experienced reoperation for wound-related complications. These rates are lower than most complication rates in the current literature. The plastic and reconstructive paraspinous muscle flap has promising results as a closure option for complex spinal wounds following neurosurgical cases. Further investigation is called for to determine the applicability of these results to the general population. Level of Evidence: 4.

A Novel Surgical Technique for Management of Giant Central Calcified Thoracic Disk Herniations: A Dual Corridor Method Involving Tubular Transthoracic/Retropleural Approach Followed by a Posterior Transdural Diskectomy.

BACKGROUND: Thoracic disk herniations (TDHs) represent only 0.15% to 1.8% of surgically managed disk herniations but have posed a particular challenge to spine surgeons. Numerous surgical approaches have been cited in the literature with varying degrees of success, technical complexity, and complication profiles. OBJECTIVE: To report a case of a combined lateral retropleural and dorsal transdural approach for complex thoracic discectomy. METHODS: In this report, we describe a combined lateral/retropleural and posterior transdural approach for a patient with a giant calcified TDH that was not amenable to safe removal using a single approach. RESULTS: In complex situations such as this, a dual corridor approach allows for improved visualization and maximal resection opportunity and opens up yet another option to address recalcitrant TDH. CONCLUSION: The staged dual corridor approach is safe and represents a further surgical option for extremely difficult TDH.

Airway pressure release ventilation does not increase intracranial pressure in patients with traumatic brain injury with poor lung compliance.

The use of Airway Pressure Release Ventilation (APRV) in patients with traumatic brain injury (TBI) remains controversial. Some believe that elevated mean airway pressures transmitted to the thorax may cause clinically significant increases in Central Venous Pressure (CVP) and intracranial pressure (ICP) from venous congestion. We perform a retrospective review from 2009 to 2015 of traumatically injured patients who were transitioned from traditional ventilator modes to APRV and also had an ICP monitor in place. Fifteen patients undergoing 19 transitions to APRV were identified. Prior to transitioning to APRV the average static and dynamic compliance was 22.9 +/- 5.6 and 16.5 +/- 4.12 mL/cm H2O. There was no statistical difference in ICP, MAP, and CPP prior to and after transition to APRV. There was a statistically significant increase in CVP, PaO2, and P:F ratio. Individually, only 4 patients had ICP values >20 in the first hour after transitioning to APRV and the rate of ICP elevations was similar between the two modes of ventilation. These data show that APRV is a viable mode of ventilation in patients with TBI who have low lung compliance. The increased CVP of this mode of ventilation did not affect ICP or hemodynamic parameters.

Calcifying Pseudoneoplasm of the Cervicomedullary Junction: Case Report and a Literature Review.

BACKGROUND: Calcifying pseudoneoplasm of the neuroaxis (CAPNON) is a rare, slow-growing tumor of a fibro-osseous origin that may present anywhere in the neuroaxis. Although typically benign, symptoms of CAPNONs typically present secondary to compression and surrounding mass effect. Histologically, the tumor has the characteristics of a foreign body reaction with giant cells, ossification, and the formation of psammoma bodies. On imaging, they can easily be confused with malginant lesions such as chondrosarcoma or chondroblastoma or even more benign pathologies like meningioma. CASE DESCRIPTION: We present a case of a patient with an incidentally found calcifying pseudoneoplasm involving the cervicomedullary junction with further involvement of the vertebral artery and the hypoglossal nerve. We also review the literature on these tumors to date. CONCLUSION: Calcifying pseudoneoplasm of the neuroaxis is a slow-growing, benign, noninfiltrative lesion whose pathogensis and natural history remains unclear. It can appear anywhere in the neuroaxis and does not have a prevelant location. Because of the indolent course and relative rarity of this tumor, there are no current guidelines on the immediate and long-term management of CAPNONs. This entity, although quite rare, should be considered in the differential for calcified lesions at the cervicomedullary junction. The consensus for treatment of CAPNONs when symptomatic is surgical resection.

Intraneural Granular Cell Tumor of a Cervical Dorsal Nerve Root: A Case Report and Review of the Literature.

BACKGROUND: Granular cell tumor (GCT) is a relatively uncommon predominantly benign lesion that usually presents as a solitary, painless cutaneous or submucosal nodule. Most of these tumors are found in the tongue. Although GCT is believed to have a Schwann cell origin, reports of GCT in peripheral and spinal nerves are uncommon. CASE DESCRIPTION: We report the case of a 43-year-old man with neck pain and hand numbness who was found to have a heterogeneously enhancing left-sided C2 nerve sheath tumor on magnetic resonance imaging. He underwent C2 decompression and resection of the left-sided C2 nerve sheath tumor with subsequent C1-C2 arthrodesis and instrumentation. Histopathologic review showed GCT. Review of the literature yielded 4 other reported cases of GCT within the vicinity of a spinal nerve root. Only one of these explicitly showed spinal nerve root involvement. This is a rare case of a GCT presenting as cervical nerve root mass, and what we believe is the first reported case of this in the literature. CONCLUSIONS: The surgeon should be aware of GCT when encountering spinal nerve root tumors because it may alter the surgical approach necessary for adequate resection compared with more commonly encountered nerve sheath tumors.

Neurosurgical decision making: personal and professional preferences.

OBJECT: Physicians are often solicited by patients or colleagues for clinical recommendations they would make for themselves if faced by a clinical situation. The act of making a recommendation can alter the clinical course being taken. The authors sought to understand this dynamic across different neurosurgical scenarios by examining how neurosurgeons value the procedures that they offer. METHODS: The authors conducted an online survey using the Congress of Neurological Surgeons listserv in May 2013. Respondents were randomized to answer either as the surgeon or as the patient. Questions encompassed an array of distinct neurosurgical scenarios. Data on practice parameters and experience levels were also collected. RESULTS: Of the 534 survey responses, 279 responded as the "neurosurgeon" and 255 as the "patient." For both vestibular schwannoma and arteriovenous malformation management, more respondents chose resection for their patient but radiosurgery for themselves (p = 0.002 and p = 0.001, respectively). Aneurysm coiling was chosen more often than clipping, but those whose practice was ≥ 30% open cerebrovascular neurosurgery were less likely to choose coiling. Overall, neurosurgeons who focus predominantly on tumors were more aggressive in managing the glioma, vestibular schwannoma, arteriovenous malformation, and trauma. Neurosurgeons more than 10 years out of residency were less likely to recommend surgery for management of spinal pain, aneurysm, arteriovenous malformation, and trauma scenarios. CONCLUSIONS: In the majority of cases, altering the role of the surgeon did not change the decision to pursue treatment. In certain clinical scenarios, however, neurosurgeons chose treatment options for themselves that were different from what they would have chosen for (or recommended to) their patients. For the management of vestibular schwannomas, arteriovenous malformations, intracranial aneurysms, and hypertensive hemorrhages, responses favored less invasive interventions when the surgeon was the patient. These findings are likely a result of cognitive biases, previous training, experience, areas of expertise, and personal values.

Epidural Blood Patch Performed for Severe Intracranial Hypotension Following Lumbar Cerebrospinal Fluid Drainage for Intracranial Aneurysm Surgery. Retrospective Series and Literature Review.

Intracranial hypotension (IH) can occur following lumbar drainage for clipping of an intracranial aneurysm. We observed 3 cases of IH, which were all successfully treated by epidural blood patch (EBP). Herein, the authors report our cases.

Lumbar laminectomy and fusion with routine local application of vancomycin powder: decreased infection rate in instrumented and non-instrumented cases.

OBJECTIVE: Wound infections are one of the most common and potentially devastating complications of spinal surgery. Intra-wound application of vancomycin powder has been shown to lower the infection risk following posterior instrumented fusion, but little evidence supports use in other spinal operations. The goal of this study is to assess the efficacy of vancomycin powder for lumbar laminectomy and fusion, both instrumented and non-instrumented. METHODS: All cases of lumbar laminectomy and posterior fusion (with or without pedicle screw fixation) by a single surgeon were reviewed from 2007 to 2011. Routine application of 1g vancomycin powder was started in August 2009. Baseline characteristics and operative data were compared between untreated patients and those who received vancomycin powder. Rates of wound infection were compared for all fusions, and then separately for instrumented and non-instrumented cases. RESULTS: 253 patients underwent lumbar laminectomy and fusion between 2007 and 2011. Baseline and operative variables were similar between untreated patients (n=97) and those who received vancomycin powder (n=156). Patients were followed for at least one year. The infection rate fell significantly following introduction of vancomycin powder (from 11% to 0%, p=0.000018). Subgroup analysis revealed significant infection reduction for both instrumented cases (from 12% to 0%, p=0.000806) and non-instrumented cases (from 10% to 0%, p=0.0496). No complications attributable to vancomycin powder were identified. CONCLUSION: Local vancomycin powder appears to lower the risk of wound infection following lumbar laminectomy and fusion, both instrumented and non-instrumented. Further studies are needed to optimize dosing of vancomycin powder, assess long-term safety and efficacy, and evaluate use in other spinal operations.

Decreased risk of wound infection after posterior cervical fusion with routine local application of vancomycin powder.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To assess the ability of local vancomycin powder to prevent wound infection after posterior cervical fusion. SUMMARY OF BACKGROUND DATA: Wound infections are a significant source of morbidity and cost associated with spine surgery. Intraoperative application of vancomycin powder to the wound edges has been shown to lower the infection risk after posterior instrumented thoracolumbar fusion. There is little data on the efficacy and safety of local vancomycin powder in cervical spine surgery. METHODS: All cases of posterior cervical fusion by a single surgeon were reviewed from 2007 to 2011. Routine application of 1 gram of vancomycin powder was started in August 2009. Baseline characteristics, operative details, and rates of wound infection and pseudarthrosis were compared between untreated patients and those who received vancomycin powder. RESULTS: A total 171 patients underwent posterior cervical fusion between 2007 and 2011. Baseline and operative variables were similar between untreated patients (n = 92) and those who received vancomycin powder (n = 79). Patients were followed for a minimum of 1 year (range, 1.1-5.7 yr). The infection rate fell from 10.9% to 2.5% (P = 0.0384) following the introduction of vancomycin powder. The untreated and treated groups had similar rates of pseudarthrosis (5.4% vs. 5.1%). No complications attributable to vancomycin powder were identified. CONCLUSION: Routine local application of vancomycin powder is a low-cost effective strategy for preventing wound infection after posterior cervical fusion. Further studies are needed to optimize dosing, assess long-term safety, and evaluate use in other spinal operations. LEVEL OF EVIDENCE: 2.

C2 nerve root sectioning in posterior C1-2 instrumented fusions.

OBJECTIVE: To analyze qualitatively C2 nerve dysfunction after its transection in C1-2 posterolateral instrumented fusions. METHODS: From 2002-2010, 20 consecutive patients underwent posterolateral instrumented fusions using C1 lateral mass and C2 pars or pedicle screws, mainly for type 2 dens fractures. Screws were placed under lateral fluoroscopic guidance using standard techniques. Bilateral C2 nerve roots were coagulated and transected in all patients. Mean follow-up was 30.7 months and consisted of clinical and radiographic examinations, telephone interviews, and mailed visual analogue scale (VAS) questionnaires assessing C2 nerve dysfunction. RESULTS: One patient was lost to follow-up after the initial postoperative visit. Fusion was evident in all patients with 12 months of follow-up and two of three patients with <12 months of follow-up. There were no instances of unintended neurologic deficits, vascular injury, cerebrospinal fluid (CSF) leak, or hardware malfunction or malposition. By the 2-week or 6-week office visit, 4 of 20 patients complained of sensory disturbance, and 2 had paresthesias in the C2 distribution. After longer follow-up, one additional patient developed mild sensory symptoms. Quality of life was adversely affected in only one patient. No patient developed neuropathic pain at any time after C2 sectioning. CONCLUSIONS: This study is the first series to describe C2 nerve function after posterior atlantoaxial instrumented fusion in adults of all ages. Sacrifice of the C2 nerve root increases fusion surface, allows for better preparation and decortication of the atlantoaxial joint, improves visualization for screw placement, and decreases blood loss and operative time without major clinical consequences.