Intraoperative image guidance for cervical spine surgery.

Intraoperative image-guidance in spinal surgery has been influenced by various technological developments in imaging science since the early 1990s. The technology has evolved from simple fluoroscopic-based guidance to state-of-art intraoperative computed tomography (iCT)-based navigation systems. Although the intraoperative navigation is more commonly used in thoracolumbar spine surgery, this newer imaging platform has rapidly gained popularity in cervical approaches. The purpose of this manuscript is to address the applications of advanced image-guidance in cervical spine surgery and to describe the use of intraoperative neuro-navigation in surgical planning and execution. In this review, we aim to cover the following surgical techniques: anterior cervical approaches, atlanto-axial fixation, subaxial instrumentation, percutaneous interfacet cage implantation as well as minimally invasive posterior cervical foraminotomy (PCF) and unilateral laminotomy for bilateral decompression. The currently available data suggested that the use of 3D navigation significantly reduces the screw malposition, operative time, mean blood loss, radiation exposure, and complication rates in comparison to the conventional fluoroscopic-guidance. With the advancements in technology and surgical techniques, 3D navigation has potential to replace conventional fluoroscopy completely.

Minimally Invasive Posterior Cervical Foraminotomy Using 3-Dimensional Total Navigation: 2-Dimensional Operative Video.

Minimally invasive posterior cervical foraminotomy (MPCF) has shown comparable outcomes to those of an open approach, with shorter operation times and length of hospital stays, as well as decreased blood loss and inpatient analgesic use. This surgical technique is mainly used to treat unilateral radiculopathy due to foraminal soft disc fragments or bone spurs. Three-dimensional (3D) navigation-guidance facilitates the surgical workflow, and it is utilized in planning the incision, determining the extent of the medial facetectomy, and confirming sufficient decompression, especially in the lower cervical spine and cervicothoracic junction, where the shoulders make localization with fluoroscopy difficult. In this video, we present the case of a 49-yr-old male patient with mechanical neck pain and C8 radiculopathy due to multilevel cervical spinal stenosis with disc herniations and C7-T1 right-sided foraminal stenosis. There was loss of cervical lordosis at the upper levels. The patient underwent anterior cervical discectomy and fusion (ACDF) at the C4-5, C5-6, and C6-7 levels to treat mechanical neck pain and restore lordosis. In order to avoid an extra-level fusion and preserve motion, we performed a right-sided C7-T1 MPCF using a portable intraoperative computed tomography (iCT) scanner (Airo®; Brainlab AG, Feldkirchen, Germany), combined with 3D computer navigation to address the patient's radicular symptoms. Patient consent was obtained prior to performing the procedure.

Defining the MIS-TLIF: A Systematic Review of Techniques and Technologies Used by Surgeons Worldwide.

STUDY DESIGN: Systematic review. OBJECTIVE: To date there is no consensus among surgeons as to what defines an MIS-TLIF (transforaminal lumbar interbody fusion using minimally invasive spine surgery) compared to an open or mini-open TLIF. This systematic review aimed to examine the MIS-TLIF techniques reported in the recent body of literature to help provide a definition of what constitutes the MIS-TLIF, based on the consensus of the majority of surgeons. METHODS: We created a database of articles published about MIS-TLIF between 2010 and 2018. We evaluated the technical components of the MIS-TLIF including instruments and incisions used as well the order in which key steps are performed. RESULTS: We could identify several patterns for MIS-TLIF performance that seemed agreed upon by the majority of MIS surgeons: use of paramedian incisions; use of a tubular retractor to perform a total facetectomy, decompression, and interbody cage implantation; and percutaneous insertion of the pedicle-screw rod constructs with intraoperative imaging. CONCLUSION: Based on this review of the literature, the key features used by surgeons performing MIS TLIF include the use of nonexpandable or expandable tubular retractors, a paramedian or lateral incision, and the use of a microscope or endoscope for visualization. Approaches using expandable nontubular retractors, those that require extensive subperiosteal dissection from the midline laterally, or specular-based retractors with wide pedicle to pedicle exposure are far less likely to be promoted as an MIS-based approach. A definition is necessary to improve the communication among spine surgeons in research as well as patient education.

Indirect Decompression Failure After Lateral Lumbar Interbody Fusion-Reported Failures and Predictive Factors: Systematic Review.

BACKGROUND: In patients with symptomatic lumbar stenosis undergoing lateral transpsoas approach for lumbar interbody fusion (LLIF) surgery, it is not always clear when indirect decompression is sufficient in order to achieve symptom resolution. Indirect decompression failure (IDF), defined as "postoperative persistent symptoms of nerve compression with or without a second direct decompression surgery to reach adequate symptom resolution," is not widely reported. This information, however, is critical to better understand the indications, the potential, and the limitations of indirect decompression. OBJECTIVE: The purpose of this study was to systematically review the current literature on IDF after LLIF. METHODS: A literature search was performed on PubMed. We included randomized controlled trials and prospective, retrospective, case-control studies, and case reports. Information on sample size, demographics, procedure, number and location of involved levels, follow-up time, and complications were extracted. RESULTS: After applying the exclusion criteria, we included 9 of the 268 screened articles that reported failure. A total of 632 patients were screened in these articles and detailed information was provided. Average follow-up time was 21 months. Overall reported incidence of IDF was 9%. CONCLUSION: Failures of decompression via LLIF are inconsistently reported and the incidence is approximately 9%. IDF failure in LLIF may be underreported or misinterpreted as a complication. We propose to include the term "IDF" as described in this article to differentiate them from complications for future studies. A better understanding of why IDF occurs will allow surgeons to better plan surgical intervention and will avoid revision surgery.

Tandem Microscopic Slalom Technique: The Use of 2 Microscopes Simultaneously Performing Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Spinal Stenosis.

STUDY DESIGN: Technical note, retrospective case series. OBJECTIVE: Lumbar stenosis can be effectively treated using tubular unilateral laminotomy for bilateral decompression (ULBD). For multilevel stenosis, a multilevel ULBD through separate, alternating crossover approaches has been described as the "slalom technique." To increase efficacy, we introduced this approach with 2 microscopes simultaneously. METHODS: We collected data on 13 patients, with multilevel lumbar stenosis, operated at our institution between 2015 and 2016 by the aforementioned technique. We assessed surgical time (ST), estimated blood loss (EBL), complications, and revision surgeries. Furthermore, we provide a stepwise instruction for performing the tandem microscopic slalom technique in a safe and efficient manner. RESULTS: The mean age of the patients was 68 ± 8 years. The ST per level was 68 ± 19 minutes with an EBL per level of 39 ± 30 mL. We had no intraoperative complications and none of our patients required a revision surgery during a mean follow-up of 12 months. CONCLUSIONS: We have shown that this technique is feasible and can be performed safely for multisegmental lumbar spinal stenosis with minimal tissue trauma and low EBL. Furthermore, randomized controlled studies with a larger sample size may be necessary to drive any final conclusions.

Less Invasive Cervical Decompression via Unilateral Tubular Laminotomy Using 3-Dimensional Total Navigation: 2-Dimensional Operative Video.

This video demonstrates the step-by-step surgical technique for a less invasive cervical unilateral laminotomy for bilateral decompression (cervical ULBD). This technique allows surgeons to address bilateral cervical pathology while minimizing approach-related complications.1 In the video, we present the case of a 72-yr-old female patient with a past medical history of C3-C4 anterior cervical discectomy and fusion who presented in clinic with persistent posterior spinal cord compression and signal change. The patient had bilateral hand numbness, weakness, poor dexterity, and a positive Hoffman's sign. The patient was treated via a C3-C4 less invasive cervical ULBD using a mobile 3-dimensional (3D) C-arm (Ziehm Vision RFD 3D®, Nürnberg, Germany) combined with 3D computer navigation. Patient consent was obtained prior to performing the procedure. Contrary to anterior techniques, posterior cervical approaches avoid potential dysphasia, recurrent laryngeal nerve injury, and adjacent segment degeneration. Furthermore, the less invasive cervical ULBD results in decreased pain and postoperative narcotic usage, shorter hospital stays and fewer infections compared to open approaches, as well as a lower risk for postlaminectomy kyphosis and deformity, since it requires less muscle disruption and bony removal. Additionally, the use of total 3D navigation facilitates the workflow and minimizes radiation exposure.

Ten-Step Minimally Invasive Cervical Decompression via Unilateral Tubular Laminotomy: Technical Note and Early Clinical Experience.

BACKGROUND: Minimally invasive techniques utilizing tubular retractors have become an increasingly popular approach to the spinal column. The concept of a unilateral laminotomy for bilateral decompression (ULBD), first applied in the lumbar spine, has recently been applied to the cervical spine for the treatment of cervical spondylotic myelopathy (CSM). A better understanding of the indications and surgical techniques is required to effectively educate surgeons on how to appropriately and safely perform tubular cervical laminotomy via ULBD. OBJECTIVE: To describe a 10-step technique for minimally invasive cervical laminotomy and report our early clinical experience. METHODS: A retrospective review identified 15 patients with CSM who were treated with this procedure. Visual analogue scale (VAS), neck disability index (NDI), and modified Japanese Orthopaedic Association (mJOA) scores were obtained pre- and postoperatively. RESULTS: The mean age of the 15 patients was 73.1 ± 6.8 yr. The median number of levels treated was 1 (range 1-3). Mean operative time was 125.3 ± 30.8 or 81.7 ± 19.2 min per level. Mean estimated blood loss was 57.3 ± 24.6 cc. Median postoperative hospital length of stay was 36 h. No complications were encountered. Median follow-up was 18 mo. Mean pre- and postoperative VAS were 6.4 ± 2.4 and 1.0 ± 0.8, respectively (P < .001). Mean pre- and postoperative NDI were 46.4 ± 19.2 and 7.0 ± 6.9, respectively (P < .001). Mean pre- and postoperative Mjoa were 11.3 ± 2.5 and 14.5 ± 0.5, respectively (P < .001). CONCLUSION: In our early clinical experience, minimally invasive cervical ULBD is safe and effective. Adherence to the presented 10-step technique will allow surgeons to safely address bilateral cervical pathology while avoiding complications.

Minimally Invasive Transforaminal Lumbar Interbody Fusion using 3-Dimensional Total Navigation: 2-Dimensional Operative Video.

This video demonstrates the workflow of a minimally invasive transforaminal interbody fusion (MIS-TLIF) using a portable intraoperative CT (iCT) scanner, (Airo®, Brainlab AG, Feldkirchen, Germany), combined with state-of-the-art total 3D computer navigation. The navigation is used not only for instrumentation but also for intraoperative planning throughout the procedure, inserting the cage, therefore, completely eliminating the need for fluoroscopy. In this video, we present a case of a 72-yr-old female patient with a history of lower back pain, right lower extremity radicular pain and weakness for 2 yr due to L4-L5 spondylolisthesis with instability and severe lumbar spinal stenosis. The patient is treated by a L4-L5 unilateral laminotomy for bilateral decompression (ULBD) and MIS-TLIF. MIS-TLIF using total 3D navigation significantly improves the workflow of the conventional TLIF procedure. The tailored access to the spine is translated into smaller but more efficient surgical corridors. This modification in a "total navigation" modality minimizes the staff radiation exposure to 0 by navigating in real time over iCT obtained images that can be acquired while the surgical staff is protected or outside the OR. Furthermore, this technique makes real-time and virtual intraoperative imaging of screws and their planned trajectory feasible. 3D Navigation eliminates the need for K-Wires, thus decreasing the risk of vascular penetration injury due to K-Wire malpositioning. 3D navigation can also predict the positioning of the interbody cage, thereby, decreasing the risk of malpositioning or subsidence. Patient consent was obtained prior to performing the procedure.

Minimally Invasive Laminotomy for Contralateral "Over-the-Top" Foraminal Decompression Using 3-Dimensional Total Navigation: 2-Dimensional Operative Video.

This video demonstrates the step-by-step surgical technique for the minimally invasive laminotomy for contralateral "over-the-top" foraminal decompression. This technique allows for excellent decompression with clearance of the contralateral recess and foramen. In the video, we present the case of a 51-yr-old female patient with a past medical history of left L5-S1 microdiscectomy who presented in clinic with residual/recurrent foraminal disc herniation at L5-S1 compressing the left L5 nerve root. The patient had left lower extremity pain in the left hip and thigh that radiated down the front and side of the leg, as well as tingling and numbness in the left foot. The patient was treated via a L5-S1 microdiscectomy using a portable intraoperative computed tomography scanner, (Airo®, Brainlab AG, Feldkirchen, Germany), combined with 3-dimensional (3D) computer navigation. Patient consent was obtained prior to performing the procedure. The main advantage of this technique is the direct "over-the-top" trajectory to the foraminal pathology that minimizes the need of facet joint resection. The use of 3D navigation facilitates surgical planning and further minimizes facet joint compromise. Particularly, the inferior facet contralateral to the approach side as well as its outer capsular surroundings can be preserved. Recent biomechanical studies have shown that "over-the-top" decompression produces significantly less instability than a traditional open midline laminectomy.

Bow Hunter Syndrome with Associated Pseudoaneurysm.

BACKGROUND: Bow hunter syndrome describes a mechanical compression of the vertebral artery on head rotation leading to reversible symptomatic vertebrobasilar insufficiency. Patients are commonly presenting with syncope, vertigo, dizziness, and visual disturbances. These symptoms usually resolve when the head is turned back into neutral position. Treatment options involve surgical decompression with or without fusion, bypass surgery, or endovascular intervention. CASE DESCRIPTION: We report about a 49-year-old female who presented with vague neck pain and severe vertigo, nausea, and near syncope when her head turned up and right. Computed tomography angiography revealed a pseudoaneurysm at the dominant left V3 and near total occlusion of the left vertebral artery as it exited the C2 foramen when the head was turned to the previously mentioned position. The patient could be successfully treated by computed tomography-navigated posterior instrumentation using bilateral C1 lateral mass screws and C2 translaminar screws. To promote segmental fusion, bilateral intrafacet cages were implanted. Postoperatively, the patient remained without neurologic deficits and experienced no further episodes of the preoperatively reported transient vertebrobasilar insufficiency symptoms. CONCLUSIONS: The reported case is unique as the bow hunter syndrome was further complicated by a pseudoaneurysm of the V3 segment. Surgical intervention proved to be an efficient treatment by stabilizing the affected segment in this patient.

Superficial Siderosis of Central Nervous System as Primary Clinical Manifestation Secondary to Intradural Thoracic Disk Herniation.

BACKGROUND: Superficial siderosis of the central nervous system is a rare neurologic disorder characterized by the superficial deposition of hemosiderin in the subpial layer resulting in iron-related progressive neurodegeneration. CASE DESCRIPTION: In this report, we present a case of superficial siderosis of the central nervous system secondary to an intradural thoracic disk herniation causing a cerebrospinal fluid (CSF) leak. CONCLUSIONS: The patient was successfully treated with T6-T8 transpedicular partial corpectomy, as well as diskectomy with decompression followed by watertight closure of the CSF leak. Intraoperative watertight closure of the CSF leak was achieved.

"One and a half" minimally invasive transforaminal lumbar interbody fusion: single level transforaminal lumbar interbody fusion with adjacent segment unilateral laminotomy for bilateral decompression for spondylolisthesis with bisegmental stenosis.

Symptomatic lumbar spondylolisthesis is commonly accompanied by spinal stenosis in multiple segments. These pathologies are routinely treated by multilevel decompression and instrumented fusion. However, it was hypothesized that a minimally invasive surgery (MIS) fusion in the unstable segment combined with a unilateral laminotomy for bilateral decompression (ULBD) in the adjacent stenotic segment is a biomechanically feasible alternative to a two-level fusion and superior to open laminectomy adjacent to a fused segment. This concept has demonstrated success in a recently published biomechanical cadaver study performed by our group. The present article offers a detailed step by step technical description for an MIS-TLIF (transforaminal lumbar interbody fusion) with adjacent ULBD.

Dual Anti-angiogenic Chemotherapy with Temozolomide and Celecoxib in Selected Patients with Malignant Glioma Not Eligible for Standard Treatment.

AIM: Due to their high rate of neo-angiogenesis, malignant gliomas may qualify for treatment with anti-angiogenic substances. We report on a series of patients with malignant glioma not eligible for standard postoperative combined radiochemotherapy due to decreased health status. PATIENTS AND METHODS: A total of nine patients with malignant glioma, postoperatively presenting with a Karnofsky performance score (KPS) below 70, were treated with standalone metronomic low-dose chemotherapy with temozolomide and celecoxib (cyclo-oxygenase-2 inhibitor). Overall survival was defined as the primary end-point and the functional status (KPS) and time to progression as secondary end-points of our analysis. RESULTS: The median KPS after surgery was 60. Treatment achieved a decrease in tumor and edema volume and, more importantly, preserved the functional status defined as the ability to care for self (KPS 70%) until disease progression. No notable side-effects were recorded. CONCLUSION: In patients with decreased general condition (KPS <70), not eligible for standard treatment, anti-angiogenic therapy offers a reasonable alternative approach. Our results indicate prolonged survival and preserved quality of life in comparison to best supportive care.