✓ The authors describe a case of noncommunicating syringomyelia associated with Chiari malformation Type I in a patient in whom acute symptomatic exacerbation occurred following cervical spine trauma. Surgical stabilization and realignment of the spine resulted in marked resolution of the neurological abnormalities, and subsequent magnetic resonance imaging demonstrated persistent collapse of the syrinx. The authors review the various factors in the pathogenesis of this unusual sequence of events.
Joseph Cusick and Zvi Lidar
Jason Lifshutz, Zvi Lidar, and Dennis Maiman
The development of alternative approaches to spine disorders marked an evolutionary change in the methods by which surgeons address diseases that affect the ventral portion of the spine. From the advent of spinal surgery until quite recently, physicians used posterior approaches almost exclusively for the treatment of all pathological processes. Surgeons subsequently became frustrated and disenchanted with outcomes of patients with anterior vertebral body disease when these procedures were applied. This sentiment is best reflected in the surgical thought related to Pott disease. In this paper, the authors chart the development of an influential approach to the spine that is designed to address these issues: the lateral extracavitary approach. They trace its origins to early precursor procedures and follow its use in current practice for the treatment of a variety of spinal disorders. They also examine its applications, role, and continued importance in the age of minimally invasive surgery.
Jason Lifshutz, Zvi Lidar, and Dennis Maiman
✓ Ankylosing spondylitis (AS) is a rheumatic disease characterized by consolidation of the articulating surfaces and inflammation of the vertebral column. Because of its associated spine stiffness and secondary osteoporosis, patients with this disorder are at increased risk of vertebral fractures. Ankylosing spondylitis presents a significant challenge to spine surgeons because of its complex effects on the spine, extraarticular organ manifestations, and potential neurological and functional sequelae. Traumatic thoracic and lumbar spine injuries in this patient population may be associated with injury to the aorta either due to direct mechanical trauma or to blunt forces associated with the spine fracture. This complication and association is thought to be the result of pathophysiological changes that cause the aorta to become firmly adherent to the anterior longitudinal ligament.
The authors present a case of AS in a patient with a thoracic spine fracture and in whom a delayed thoracic aortic pseudoaneurysm ruptured. To the best of the authors' knowledge, only five cases of this complex condition have been reported since 1980. Recognition of the potential for aortic injury in patients with AS should prompt early investigation of the aorta in cases involving numerous fractures and assist in surgical planning to avoid this lethal injury.
Zvi Lidar, Shlomi Constantini, Gilad J. Regev, and Khalil Salame
Postlaminectomy cervical kyphosis is one of the most challenging entities in spine surgery. Correction of this deformity usually requires anterior fusion with plating and a strut graft or interbody cage and posterior fusion with screws and rods. The situation is more complicated in the young child because fusion may affect future growth of the cervical spine. There is also a paucity of adequate instrumentation for the small bony structures. Some authors have reported utilization of absorbable cervical plates for fusion in pediatric patients with favorable results.
The authors present a modified surgical technique that was used for circumferential fusion in a 2-year-old girl with cervical kyphosis and recurrent neurofibroma. Anterior fusion was performed using an autologous rib graft and an absorbable cervical plate. This was followed by posterior fusion using rib bone and cables. Previous reports on the use of absorbable cervical plates are reviewed and the advantages of the current technique are discussed.
Eyal Behrbalk, Khalil Salame, Gilad J. Regev, Ory Keynan, Bronek Boszczyk, and Zvi Lidar
A retrospective study analyzing medical files of patients who had undergone surgical management for cervical spondylotic myelopathy (CSM) at a single tertiary hospital was performed to determine the time needed by community care physicians to reach a diagnosis of CSM in patients presenting with typical myelopathic signs and symptoms, and to establish the reasons for the delayed diagnosis when present.
Previous studies have documented that early diagnosis and surgical treatment of CSM may improve patients' neurological as well as general outcome. However, patients complaining of symptoms compatible with CSM may undergo lengthy medical investigations and treatments by community-based physicians before a correct diagnosis is made. The authors have found no published data on the process and time frame involved in attaining a diagnosis of CSM in the community setting.
The medical records of 42 patients were retrospectively reviewed for demographic data, symptoms, time to diagnosis, physician specialty, number of visits involved in the diagnostic process, and neurological status prior to surgery.
The mean time delay from initiation of symptoms to diagnosis of CSM was 2.2 ± 2.3 years. The majority of symptomatic patients (90.4%) initially presented to a family practitioner (69%) or an orthopedic surgeon (21.4%), with fewer patients (9.6%) referring to other disciplines (for example, the emergency department) for initial care. In contrast, the diagnosis of CSM was most often made by neurosurgeons (38.1%) and neurologists (28.6%), and less frequently by orthopedic surgeons (19%) or family physicians (4.8%).
The diagnosis of CSM in the community is frequently delayed, leading to late referral for surgery. A higher index of suspicion for this debilitating entity is required from family practitioners and community-based orthopedic surgeons to prevent neurological sequelae.
Roberto Spiegelmann, Zvi Lidar, Jana Gofman, Dror Alezra, Moshe Hadani, and Raphael Pfeffer
Object. The use of radiosurgery in the treatment of acoustic neuromas has increased substantially during the last decade. Most published experience relates to the use of the gamma knife. In this report, the authors review the methods and results of linear accelerator (LINAC) radiosurgery in 44 patients with acoustic neuromas who were treated between 1993 and 1997.
Methods. Computerized tomography scanning was selected as the stereotactic imaging modality for target definition. A single, conformally shaped isocenter was used in the treatment of 40 patients; two or three isocenters were used in four patients who harbored very irregular tumors. The radiation dose directed to the tumor border was the only parameter that changed during the study period: in the first 24 patients who were treated the dose was 15 to 20 Gy, whereas in the last 20 patients the dose was reduced to 11 to 14 Gy. After a mean follow-up period of 32 months (range 12–60 months), 98% of the tumors were controlled. The actuarial hearing preservation rate was 71%. New transient facial neuropathy developed in 24% of the patients and persisted to a mild degree in 8%. Radiation dose correlated significantly with the incidence of cranial neuropathy, particularly in large tumors (≥ 4 cm3).
Conclusions. Single-isocenter LINAC radiosurgery proved to be an effective treatment for acoustic neuromas in this series, with results that were comparable with those reported for gamma knife radiosurgery and multiple isocenters.
Zvi Lidar, Yael Mardor, Tali Jonas, Raphael Pfeffer, Meir Faibel, Dvora Nass, Moshe Hadani, and Zvi Ram
Object. A minority of patients with recurrent glioblastomas multiforme (GBMs) responds to systemic chemotherapy. The authors investigated the safety and efficacy of intratumoral convection-enhanced delivery (CED) of paclitaxel in patients harboring histologically confirmed recurrent GBMs and anaplastic astrocytomas.
Methods. Fifteen patients received a total of 20 cycles of intratumoral CED of paclitaxel. The patients were observed daily by performing diffusion-weighted (DW) magnetic resonance (MR) imaging to assess the convective process and routine diagnostic MR imaging to identify the tumor response. Effective convection was determined by the progression of the hyperintense signal within the tumor on DW MR images, which corresponded to a subsequent lytic tumor response displayed on conventional MR images. Of the 15 patients, five complete responses and six partial responses were observed, giving a response rate of 73%. The antitumor effect was confirmed by one biopsy and three en bloc resections of tumors, which showed a complete response, and by one tumor resection, which demonstrated a partial response. Lack of convection and a poor tumor response was associated with leakage of the convected drug into the subarachnoid space, ventricles, and cavities formed by previous resections, and was seen in tumors containing widespread necrosis. Complications included transient chemical meningitis in six patients, infectious complications in three patients, and transient neurological deterioration in four patients (presumably due to increased peritumoral edema).
Conclusions. On the basis of our data we suggest that CED of paclitaxel in patients with recurrent malignant gliomas is associated with a high antitumor response rate, although it is associated with a significant incidence of treatment-associated complications. Diffusion-weighted MR images may be used to predict a response by demonstrating the extent of convection during treatment. Optimization of this therapeutic approach to enhance its efficacy and reduce its toxicity should be explored further.
Ori Barzilai, Zvi Lidar, Shlomi Constantini, Khalil Salame, Yifat Bitan-Talmor, and Akiva Korn
Intramedullary spinal cord tumors (IMSCTs) represent a rare entity, accounting for 4%–10% of all central nervous system tumors. Microsurgical resection of IMSCTs is currently considered the primary treatment modality. Intraoperative neurophysiological monitoring (IONM) has been shown to aid in maximizing tumor resection and minimizing neurological morbidity, consequently improving patient outcome. The gold standard for IONM to date is multimodality monitoring, consisting of both somatosensory evoked potentials, as well as muscle-based transcranial electric motor evoked potentials (tcMEPs). Monitoring of tcMEPs is optimal when combining transcranial electrically stimulated muscle tcMEPs with D-wave monitoring. Despite continuous monitoring of these modalities, when classic monitoring techniques are used, there can be an inherent delay in time between actual structural or vascular-based injury to the corticospinal tracts (CSTs) and its revelation. Often, tcMEP stimulation is precluded by the surgeon’s preference that the patient not twitch, especially at the most crucial times during resection. In addition, D-wave monitoring may require a few seconds of averaging until updating, and can be somewhat indiscriminate to laterality. Therefore, a method that will provide immediate information regarding the vulnerability of the CSTs is still needed.
The authors performed a retrospective series review of resection of IMSCTs using the tip of an ultrasonic aspirator for continuous proximity mapping of the motor fibers within the spinal cord, along with classic muscle-based tcMEP and D-wave monitoring.
The authors present their preliminary experience with 6 patients who underwent resection of an IMSCT using the tip of an ultrasonic aspirator for continuous proximity mapping of the motor fibers within the spinal cord, together with classic muscle-based tcMEP and D-wave monitoring. This fusion of technologies can potentially assist in optimizing resection while preserving neurological function in these challenging surgeries.
Khalil Salame, Shimon Maimon, Gilad J. Regev, Tali Jonas Kimchi, Akiva Korn, Laurence Mangel, and Zvi Lidar
Preoperative embolization is performed before spine tumor surgery when significant intraoperative hemorrhage is anticipated. Occlusion of radicular and segmental arteries may result in spinal ischemia. The goal of this study was to check whether neurophysiological monitoring during preoperative angiography in patients scheduled for total en bloc spondylectomy (TES) of spine tumors improves the safety of vessel occlusion.
This was a case series study of patients who underwent tumor embolization under somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring in preparation for TES in treating spine tumors. The angiography findings, the embolized vessels, and the results are presented.
Five patients whose ages ranged from 33 to 75 years and who had thoracic spine tumors are reported. Four patients suffered from primary tumor and 1 patient had a metastatic tumor. Radicular arteries at the tumor level, 1 level above, and 1 level below were permanently occluded when SSEPs and MEPs were preserved during temporary occlusion. No complications were encountered during or after the angiography procedure and embolization.
Temporary occlusion with electrophysiological monitoring during preoperative angiography may improve the safety of permanent radicular artery occlusion, including the artery of Adamkiewicz in patients undergoing TES for the treatment of spine tumors.
Assaf Berger, Laurence Mangel, Sharif Basal, Zvi Lidar, Gilad J Regev, Morsi Khashan, Dror Ofir, and Khalil Salame
Surgery for foot drop secondary to lumbar degenerative disease is not always associated with postoperative functional improvement. It is still unclear whether early decompression results in better functional recovery and how soon surgery should be performed. This study aimed to evaluate predicting factors that affect short- and long-term recovery outcomes and to explore the relationship between timing of lumbar decompression and recovery from foot drop in an attempt to identify a cutoff time from symptom onset until decompression for optimal functional improvement.
The authors collected demographic, clinical, and radiographic data on patients who underwent surgery for foot drop due to lumbar degenerative disease. Clinical data included tibialis anterior muscle (TAM) strength before and after surgery, duration of preoperative motor weakness, and duration of radicular pain until surgery. TAM strength was recorded at the immediate postoperative period and 1 month after surgery while long-term follow-up on functional outcomes were obtained at ≥ 2 years postsurgery by telephone interview. Data including degree and duration of preoperative motor weakness as well as the occurrence of pain and its duration were collected to analyze their impact on short- and long-term outcomes.
The majority of patients (70%) showed functional improvement within 1 month postsurgery and 40% recovered to normal or near-normal strength. Univariate analysis revealed a trend toward lower improvement rates in patients with preoperative weakness of more than 3 weeks (33%) compared with patients who were operated on earlier (76.5%, p = 0.034). In a multivariate analysis, the only significant predictor for maximal strength recovery was TAM strength before surgery (OR 6.80, 95% CI 1.38–33.42, p = 0.018). Maximal recovery by 1 month after surgery was significantly associated with sustained long-term functional improvement (p = 0.006).
Early surgery may improve the recovery rate in patients with foot drop caused by lumbar degenerative disease, yet the strongest predictor for the extent of recovery is the severity of preoperative TAM weakness. Maximal recovery in the short-term postoperative period is associated with sustained long-term functional improvement and independence.