David Choi

Review of metastatic spine tumour classification and indications for surgery: the consensus statement of the Global Spine Tumour Study Group.

Choosing the right operation for metastatic spinal tumours is often difficult, and depends on many factors, including life expectancy and the balance of the risk of surgery against the likelihood of improving quality of life. Several prognostic scores have been devised to help the clinician decide the most appropriate course of action, but there still remains controversy over how to choose the best option; more often the decision is influenced by habit, belief and subjective experience. The purpose of this article is to review the present systems available for classifying spinal metastases, how these classifications can be used to help surgical planning, discuss surgical outcomes, and make suggestions for future research. It is important for spinal surgeons to reach a consensus regarding the classification of spinal metastases and surgical strategies. The authors of this article constitute the Global Spine Tumour Study Group: an international group of spinal surgeons who are dedicated to studying the techniques and outcomes of surgery for spinal tumours, to build on the existing evidence base for the surgical treatment of spinal tumours.

Outcome of 132 operations in 97 patients with chordomas of the craniocervical junction and upper cervical spine.

OBJECTIVETo study the outcomes of surgery for chordomas of the craniocervical junction and upper cervical spine as well as complication rates, survival, and associated adverse factors. METHODSRetrospective review of patients (1982–2007) at 2 European centers who underwent transoral, transfacial, transmandibular, and anterior cervical approaches for excision of chordomas of the craniocervical junction and cervical spine. The χ2 test and Fisher exact test were used to determine significant adverse factors (P < .05), and log-rank survival analysis was used to compare outcome in different groups. RESULTSOne hundred thirty-two operations were performed in 97 patients. The most common operations were transoral surgeries and maxillotomies. After surgery, neck pain was the same or better in 98.1% of patients. Of the 18.6% of patients who presented with myelopathy, 27.8% improved, 44.4% remained unchanged, and 27.8% deteriorated. Major complication rates were velopharyngeal incompetence, 3.1%; vertebral artery stroke, 1%; wound infection, 3.1%; dysphagia, 3.1%; failure of fixation, 2.1%; sepsis, 3.1%; meningitis, 3.1%; and cerebrospinal fluid leakage, 6.2%. Five- and 10-year overall survivals were 55% and 36%, respectively. Patients who presented to our units for revision surgery, after prior attempts at resection elsewhere, were associated with a worse survival than patients who underwent de novo surgery. CONCLUSIONWe present, to our knowledge, the largest published series of chordomas at the craniocervical junction. Complication rates for these major operations can be minimized at specialist centers, with careful patient selection and counseling. As complete or as radical an operation as possible should be performed at first presentation; the best chance for the patient is the first chance.

An experimental model of ventral root repair showing the beneficial effect of transplanting olfactory ensheathing cells.

OBJECTIVEA series of published cases show that repair of brachial plexus injuries by reimplantation of avulsed spinal roots can restore a degree of recovery, particularly to the more proximal shoulder and arm musculature in a proportion of patients. There remains, however, some disagreement regarding how far the benefits outweigh the risks of causing further spinal cord damage. Improving the number of motor fibers regenerating into the reimplanted ventral roots may enhance the muscular recovery, possibly extending it to the more useful distal musculature that would restore a degree of wrist and finger functions. METHODSThis study was based on our previous rat model showing regeneration of severed fibers and resumption of function after transplantation of cultured adult olfactory ensheathing cells into spinal cord injuries and reimplanted dorsal roots. RESULTSWe now report that olfactory ensheathing cells transplanted at the spinal cord interface of reimplanted S1 ventral roots survive and migrate selectively into the ventral root where they associate intimately with regenerating ventral root fibers. Whereas only approximately 20% of the normal complement of fibers enter roots reimplanted without olfactory ensheathing cells, this increases to 80% in the presence of olfactory ensheathing cell transplants. CONCLUSIONThese observations suggest that transplants of olfactory ensheathing cells could improve the outcome of ventral root repair.

Adjacent segment disease after fusion for cervical spondylosis; myth or reality?

Cervical spondylosis is a common cause of radiculopathy and myelopathy, often treated by discectomy and interbody fusion. However, there has been a recent vogue for the use of artificial disc prostheses to decrease the risk of accelerated degenerative disease at adjacent levels. The short-term results of artificial disc replacements have been encouraging, but the long-term justification for using this new technology hinges on whether the incidence of adjacent segment disease decreases. It will also be necessary to demonstrate that movement at the operated levels is maintained and the incidence of device failure is low. We review the radiological, biomechanical and clinical evidence for adjacent segment disease, and the rationale for using artificial cervical disc replacements. There is presently insufficient evidence to justify the widespread use of artificial disc replacements in the treatment of cervical spondylosis, but neither is there sufficient evidence to criticize their use. Present evidence suggests that adjacent segment disease is partly due to the natural history of spondylotic disease and partly due to cervical fusion. Randomized trials are required to ascertain whether the incidence of adjacent segment disease changes with the use of artificial disc replacements in the long term. Indications for the use of artificial discs are presently unclear, but disc replacements might be recommended for ‘young’ patients who require an anterior cervical discectomy, with good ranges of neck movements, and an awareness of the satisfactory short-term results, but lack of long-term outcome data, preferably within the limits of a clinical trial.

Traumatic Spinal Cord Injury—Repair and Regeneration

BACKGROUND Traumatic spinal cord injuries (SCI) have devastating consequences for the physical, financial, and psychosocial well-being of patients and their caregivers. Expediently delivering interventions during the early postinjury period can have a tremendous impact on long-term functional recovery. PATHOPHYSIOLOGY This is largely due to the unique pathophysiology of SCI where the initial traumatic insult (primary injury) is followed by a progressive secondary injury cascade characterized by ischemia, proapoptotic signaling, and peripheral inflammatory cell infiltration. Over the subsequent hours, release of proinflammatory cytokines and cytotoxic debris (DNA, ATP, reactive oxygen species) cyclically adds to the harsh postinjury microenvironment. As the lesions mature into the chronic phase, regeneration is severely impeded by the development of an astroglial-fibrous scar surrounding coalesced cystic cavities. Addressing these challenges forms the basis of current and upcoming treatments for SCI. MANAGEMENT This paper discusses the evidence-based management of a patient with SCI while emphasizing the importance of early definitive care. Key neuroprotective therapies are summarized including surgical decompression, methylprednisolone, and blood pressure augmentation. We then review exciting neuroprotective interventions on the cusp of translation such as Riluzole, Minocycline, magnesium, therapeutic hypothermia, and CSF drainage. We also explore the most promising neuroregenerative strategies in trial today including Cethrin™, anti-NOGO antibody, cell-based approaches, and bioengineered biomaterials. Each section provides a working knowledge of the key preclinical and patient trials relevant to clinicians while highlighting the pathophysiologic rationale for the therapies. CONCLUSION We conclude with our perspectives on the future of treatment and research in this rapidly evolving field.

A prospective observational study of the yield of olfactory ensheathing cells cultured from biopsies of septal nasal mucosa

OBJECTIVE We sought to study the yield of olfactory ensheathing cells from biopsies of the mucosa of the nasal septum. These specialized cells encourage regeneration of nerves of the central nervous system and may be of value for spinal cord and nerve injuries. METHODS We undertook a prospective observational study of biopsies of nasal mucosa by endonasal dissection of the mucosa of the nasal septum during the approach for routine transsphenoidal surgeries. Samples were cultured in the laboratory, and the yield of olfactory ensheathing cells was compared as to the location, size, and weight of the biopsies and the age of the patients. RESULTS A better yield of olfactory ensheathing cells was obtained from areas of the septum that were more superior and posterior in position. The yield was not related to the size of the biopsy or the patients age. CONCLUSION Septal mucosa is a possible source of olfactory ensheathing cells, although the yield may be smaller than that which may be obtained from mucosa of the lateral nasal cavity and superior turbinate.

Cervical Laminectomy vs Laminoplasty: Is There a Difference in Outcome and Postoperative Pain?

BACKGROUND: Cervical laminoplasty is often used for the decompression of multilevel cervical spondylotic myelopathy without creating spinal instability and kyphosis. OBJECTIVE: To assess the axial pain, quality of life, sagittal alignment, and extent of decompression after standard cervical laminectomy or laminoplasty. We further evaluate whether the sagittal alignment changes over time after both procedures and whether axial pain depends on sagittal alignment. METHODS: We reviewed 268 patients with cervical radiculopathy or myelopathy who had undergone standard cervical laminectomy or laminoplasty between January 1999 and January 2009. The clinical outcome was analyzed by visual analog scale for neck pain. The quality of life was analyzed by EQ-5D questionnaire. The degree of deformity and extent of decompression were assessed using the Ishihara index and Pavlovs ratio, respectively. RESULTS: Laminoplasty was associated with more neck pain and worse quality of life when 4 or more levels were decompressed compared with the laminectomy group. For operations of 3 or fewer levels, there was no difference. Interestingly, the radiological effectiveness of decompression was greater in the laminoplasty group. CONCLUSION: Laminoplasty for 4 or more cervical levels was associated with more axial pain and consequently poorer quality of life than laminectomy. There was a similar loss of sagittal alignment in both the laminectomy and laminoplasty groups over time. Our results suggest there is no clear benefit of laminoplasty over laminectomy in patients who do not have spinal instability.

Evolution of Transoral Surgery: Three Decades of Change in Patients, Pathologies, and Indications

BACKGROUND Transoral surgery may be used to approach pathologies at the craniocervical junction. However, the need for this approach has decreased over the past few decades. OBJECTIVE To assess the outcome and complications of transoral surgery and extended transoral approaches at a single UK center between 1980 and 2011. METHODS A retrospective review was performed of 495 ventral midline operations (between 1980 and 2004) and prospective review of 38 operations (2004-2011) in a total of 479 patients. Trends in surgery and factors associated with good or bad outcome were assessed over this 30-year period. RESULTS Of 533 operations, the most frequently performed surgeries were simple transoral surgery (321 operations), transoral surgery with splitting of the palate (107 operations), open-door maxillotomy (58 operations), and mandibulotomy (11 operations). Since the 1990s, there has been a steady decrease in the number of operations performed, mainly due to the decrease in the number of patients with rheumatoid arthritis presenting for surgery. The incidence of craniocervical junction tumors remained constant. The number of complications was significantly associated with the preoperative neurological status, and more complications were seen in myelopathic rheumatoid patients as well as a greater trend in congenital basilar invagination. The rates of pharyngeal infection (0.6%) and cerebrospinal fluid leak (0.3%) for standard transoral surgery were extremely low. CONCLUSION The number of transoral and associated operations has decreased over time. Transoral surgery is now mainly indicated for ventral midline tumors such as chordomas. Transnasal endoscopic techniques show promise, but a major advantage of standard transoral surgery is the low cerebrospinal fluid leak and infection rates.

Novel strategies in brachial plexus repair after traumatic avulsion

Clinical trials in spinal cord injury (SCI) can be affected by many confounding variables including spontaneous recovery, variation in the lesion type and extend. However, the clinical need and the paucity of effective therapies has spawned a large number of animal studies and clinical trials for SCI. In this review, we suggest that brachial plexus avulsion injury, a longitudinal spinal cord lesion, is a simpler model to test methods of spinal cord repair. We explore reconstructive techniques currently explored for the repair of brachial plexus avulsion and focus on the use of olfactory ensheathing cell transplantation as an adjunct treatment in brachial plexus repair.

Cervical arthroplasty: the beginning, the middle, the end?

Abstract Cervical arthroplasty has developed as an alternative to spinal fusion for the treatment of cervical radiculopathy and myelopathy. The popularity of artificial discs has grown as the evidence of complications following arthrodesis has increased, making the theoretical advantages (motion preservation, altering the natural history of disease, prevention of adjacent segment disease) of disc replacement more attractive. However, as more discs are implanted and the length of follow-up increases, reported complications such as heterotopic ossification, device migration and spontaneous fusion of arthroplasty devices are growing. As a result, surgeons and patients face a challenge when deciding between motion-preserving or fusion surgery. Currently, there is inadequate evidence to promote extensive use of artificial discs for cervical spondylosis, despite promising short-term and intermediate clinical outcomes. However, there is also insufficient evidence to cease using them completely. The use of arthroplasty over fusion in the long term can only be justified if the incidence of adjacent segment disease decreases as a result. Despite the level of investment and research into arthroplasty outcomes, long-term follow-up has yet to be completed and has not convincingly demonstrated the effect of artificial discs on adjacent segment disease. Further long-term randomised trials are necessary to determine whether cervical arthroplasty is able to reduce the incidence of adjacent segment disease and, in doing so, replace arthrodesis as the gold standard treatment for cervical spondylosis.