Os odontoideum was first described in the late 1880s and still remains a mystery in many respects. The genesis of os odontoideum is thought to be prior bone injury to the odontoid, but a developmental cause probably also exists. The spectrum of presentation is striking and ranges from patients who are asymptomatic or have only neck pain to those with acute quadriplegia, chronic myelopathy, or even sudden death. By definition, the presence of an os odontoideum renders the C1–2 region unstable, even under physiological loads in some patients. The consequences of this instability are exemplified by numerous cases in the literature in which a patient with os odontoideum has suffered a spinal cord injury after minor trauma. Although there is little debate that patients with os odontoideum and clinical or radiographic evidence of neurological injury or spinal cord compression should undergo surgery, the dispute continues regarding the care of asymptomatic patients whose os odontoideum is discovered incidentally. The authors' clinical experience leads them to believe that certain subgroups of asymptomatic patients should be strongly considered for surgery. These subgroups include those who are young, have anatomy favorable for surgical intervention, and show evidence of instability on flexion-extension cervical spine x-rays. This recommendation is bolstered by the fact that surgical fusion of the C1–2 region has evolved greatly and can now be done with considerable safety and success. When atlantoaxial instrumentation is used, fusion rates for os odontoideum should approach 100%.
Paul Klimo Jr., Valerie Coon, and Douglas Brockmeyer
Paul Klimo Jr., Brian T. Ragel, Michael Rosner, Wayne Gluf, and Randall McCafferty
Penetrating spinal injury (PSI), although an infrequent injury in the civilian population, is not an infrequent injury in military conflicts. Throughout military history, the role of surgery in the treatment of PSI has been controversial. The US is currently involved in 2 military campaigns, the hallmark of both being the widespread use of various explosive devices. The authors reviewed the evidence for or against the use of decompressive laminectomy to treat PSI to provide a triservice (US Army, Navy, and Air Force) consensus and treatment recommendations for military neurosurgeons and spine surgeons.
A US National Library of Medicine PubMed database search that identified all literature dealing with acute management of PSI from military conflicts and civilian urban trauma centers in the post–Vietnam War period was undertaken.
Nineteen retrospective case series (11 military and 8 civilian) met the study criteria. Eleven military articles covered a 20-year time span that included 782 patients who suffered either gunshot or blast-related projectile wounds. Four papers included sufficient data that analyzed the effectiveness of surgery compared with nonoperative management, 6 papers concluded that surgery was of no benefit, 2 papers indicated that surgery did have a role, and 3 papers made no comment. Eight civilian articles covered a 9-year time span that included 653 patients with spinal gunshot wounds. Two articles lacked any comparative data because of treatment bias. Two papers concluded that decompressive laminectomy had a beneficial role, 1 paper favored the removal of intracanal bullets between T-12 and L-4, and 5 papers indicated that surgery was of no benefit.
Based on the authors' military and civilian PubMed literature search, most of the evidence suggests that decompressive laminectomy does not improve neurological function in patients with PSI. However, there are serious methodological shortcomings in both literature groups. For this and other reasons, neurosurgeons from the US Air Force, Army, and Navy collectively believe that decompression should still be considered for any patient with an incomplete neurological injury and continued spinal canal compromise, ideally within 24–48 hours of injury; the patient should be stabilized concurrently if it is believed that the spinal injury is unstable. The authors recognize the highly controversial nature of this topic and hope that this literature review and the proposed treatment recommendations will be a valuable resource for deployed neurosurgeons. Ultimately, the deployed neurosurgeon must make the final treatment decision based on his or her opinion of the literature, individual abilities, and facility resources available.
Paul Klimo Jr. and Brian T. Ragel
ιˆητρός γάρ αˆνήρ πολλω∼ν αˆντάξιος αˆ´λλων ιˆούς τ´ εˆκτάμνειν εˆπί τ´ ηˆ´πια φάρμακα πάσσειν.
For a physician has the worth of many other warriors, both for the excision of arrows and for the administration of soothing drugs. Homer, Iliad XI.514–515
Ever since armed conflict has been used as a means to settle disputes among men, there have been those who have been tasked to mend the wounds that ravage a soldier's body from the weapons of war. The Iliad portrays the pivotal 10th year of the legendary Trojan War, during which a schism in the Greek leadership prolongs the extended siege of the city of Troy. In the midst of this martial epic come the lines quoted above, quietly attesting to the value of the military physician, even under the crude conditions of the Greek Dark Age. They are uttered by Idomeneus, one of the foremost Greeks, when he is enjoining one of his comrades, Nestor, to rescue the injured Greek physician Machaon and take him back from the line to treat his wounds. He is afraid that Machaon will be captured by the Trojans, a loss far greater than that of any other single warrior.
Duty to country has helped shape the careers of many neurosurgeons, including iconic US figures such as Harvey Cushing and Donald Matson. This issue of Neurosurgical Focus celebrates the rich history of military neurosurgery from the wars of yesterday to the conflicts of today. We have been humbled by the tremendous response to this topic. The 25 articles within this issue will provide the reader with both a broad and an in-depth look at the many facets of military neurosurgery. We have attempted to group articles based on their predominant topic. We also encourage our audience to read other recently published articles. –4
The first 8 articles relate to the current conflicts in Afghanistan and Iraq. The lead article, written by Randy Bell and colleagues from the National Naval Medical Center and Walter Reed Army Medical Center, discusses what is arguably one of the most important contributions by military neurosurgeons from these 2 conflicts: the rapid and aggressive use of decompressive craniectomies. This is followed by articles on decompressive craniectomy techniques by Ragel and colleagues and cranioplasty outcomes by Stephens and colleagues. After reading these articles, the reader will come away with an appreciation of the often complex nature of wartime penetrating and closed-head injuries and the remarkable recovery that many injured soldiers make with time.
Brian T. Ragel, Paul Klimo Jr., Robert J. Kowalski, Randall R. McCafferty, Jeannette M. Liu, Derek A. Taggard, David Garrett Jr., and Sidney B. Brevard
“Operation Enduring Freedom” is the US war effort in Afghanistan in its global war on terror. One US military neurosurgeon is deployed in support of Operation Enduring Freedom to provide care for both battlefield injuries and humanitarian work. Here, the authors analyze a 24-month neurosurgical caseload experience in Afghanistan.
Operative logs were analyzed between October 2007 and September 2009. Operative cases were divided into minor procedures (for example, placement of an intracranial pressure monitor) and major procedures (for example, craniotomy) for both battle injuries and humanitarian work. Battle injuries were defined as injuries sustained by soldiers while in the line of duty or injuries to Afghan civilians from weapons of war. Humanitarian work consisted of providing medical care to Afghans.
Six neurosurgeons covering a 24-month period performed 115 minor procedures and 210 major surgical procedures cases. Operations for battlefield injuries included 106 craniotomies, 25 spine surgeries, and 18 miscellaneous surgeries. Humanitarian work included 32 craniotomies (23 for trauma, 3 for tumor, 6 for other reasons, such as cyst fenestration), 27 spine surgeries (12 for degenerative conditions, 9 for trauma, 4 for myelomeningocele closure, and 2 for the treatment of infection), and 2 miscellaneous surgeries.
Military neurosurgeons have provided surgical care at rates of 71% (149/210) for battlefield injuries and 29% (61/210) for humanitarian work. Of the operations for battle trauma, 50% (106/210) were cranial and 11% (25/210) spinal surgeries. Fifteen percent (32/210) and 13% (27/210) of operations were for humanitarian cranial and spine procedures, respectively. Overall, military neurosurgeons in Afghanistan are performing life-saving cranial and spine stabilization procedures for battlefield trauma and acting as general neurosurgeons for the Afghan community.
Brian T. Ragel, Paul Klimo Jr., Jonathan E. Martin, Richard J. Teff, Hans E. Bakken, and Rocco A. Armonda
Decompressive craniectomy (DC) with dural expansion is a life-saving neurosurgical procedure performed for recalcitrant intracranial hypertension due to trauma, stroke, and a multitude of other etiologies. Illustratively, we describe technique and lessons learned using DC for battlefield trauma.
Neurosurgical operative logs from service (October 2007 to September 2009) in Afghanistan that detail DC cases for trauma were analyzed. Illustrative examples of frontotemporoparietal and bifrontal DC that depict battlefield experience performing these procedures are presented with attention drawn to the L.G. Kempe hemispherectomy incision, brainstem decompression techniques, and dural onlay substitutes.
Ninety craniotomies were performed for trauma over the time period analyzed. Of these, 28 (31%) were DCs. Of the 28 DCs, 24 (86%) were frontotemporoparietal DCs, 7 (25%) were bifrontal DCs, and 2 (7%) were suboccipital DCs. Decompressive craniectomies were performed for 19 penetrating head injuries (13 gunshot wounds and 6 explosions) and 9 severe closed head injuries (6 war-related explosions and 3 others).
Thirty-one percent of craniotomies performed for trauma were DCs. Battlefield neurosurgeons use DC to allow for safe transfer of neurologically ill patients to tertiary military hospitals, which can be located 8–18 hours from a war zone. The authors recommend the L.G. Kempe incision for blood supply preservation, large craniectomies to prevent brain strangulation over bone edges, minimal brain debridement, adequate brainstem decompression, and dural onlay substitutes for dural closure.
Michael Finn, Paul Klimo Jr., and William T. Couldwell
✓Dural arteriovenous fistulas (dAVFs) are acquired direct arteriovenous shunts that often drain into the dural venous sinus. Treatment options generally involve disrupting the abnormal vascular conduits by using a combination of modalities, including surgical disconnection, radiosurgery, and transarterial and transvenous embolization. Often these modalities provide only partial treatment of fistulous lesions, and thus the fistula recurs and symptoms result. The authors report on a novel surgical technique in which the involved venous sinuses are skeletonized and an interpositional dural substitute is placed between the disconnected sinus and native dura mater and over the pial surface adjacent to the sinus. The technique, which is demonstrated in an illustrative case, is intended to preserve native venous drainage and to prevent recruitment of new vascularization to the venous sinus postoperatively. The authors have not observed reconstitution of fistulas over areas treated with this technique, which offers the advantage of inhibiting vascular ingrowth (refistulization) while maintaining venous sinus patency.
Paul Klimo Jr. and Richard H. Schmidt
✓The elucidation of predictive factors of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major area of both clinical and basic science research. It is becoming clear that many factors contribute to this phenomenon. The most consistent predictor of vasospasm has been the amount of SAH seen on the postictal computed tomography scan. Over the last 30 years, it has become clear that the greater the amount of blood within the basal cisterns, the greater the risk of vasospasm. To evaluate this risk, various grading schemes have been proposed, from simple to elaborate, the most widely known being the Fisher scale. Most recently, volumetric quantification and clearance models have provided the most detailed analysis. Intraventricular hemorrhage, although not supported as strongly as cisternal SAH, has also been shown to be a risk factor for vasospasm.
Paul Klimo Jr., John R. W. Kestle, and Meic H. Schmidt
Spinal cord compression is one of the most dreaded complications of metastatic cancer. It can lead to a number of sequelae, including pain, spinal instability, neurological deficits, and a reduction in the patient's quality of life. Except in selected circumstances, treatment is palliative. Treatment options include surgery, radiation, and chemotherapy. The goal of this study was to summarize the existing data on the outcomes of various treatment methods for metastatic spinal epidural disease and to make appropriate recommendations for their use.
The authors used a search strategy that included an electronic database search, a manual search of journals, analysis of bibliographies in relevant review papers, and consultation with the senior author. There is good evidence, including Class I data, that steroid drugs constitute a beneficial adjunctive therapy in patients with myelopathy from epidural compression. Historically, conventional radiation therapy has been viewed as the first-line treatment because it has been shown to be as effective as a decompressive laminectomy, with a lower incidence of complications (Class II data). Nevertheless, in the last 20 years there has been remarkable progress in surgical techniques and technology. Currently, the goals of surgery are to achieve a circumferential decompression of the spinal cord, and to reconstruct and immediately stabilize the spinal column. Results in a large body of literature support the belief that surgery is better at retaining or regaining neurological function than radiation and that surgery is highly effective in relieving pain. Most of the data on the treatment of metastatic spinal disease are Class II or III, but the preliminary results of a well-designed, randomized controlled trial in which surgery is compared with standard radiation therapy represents the first Class I data.
As the number of treatment options for metastatic spinal disease has grown, it has become clear that effective implementation of these treatments can only be achieved by a multidisciplinary approach.
Case report and classification scheme
Paul Klimo Jr., Ganesh Rao, Richard H. Schmidt, and Meic H. Schmidt
Nerve sheath tumors that involve the sacrum are rare. Delayed presentation is common because of their slow-growing nature, the permissive surrounding anatomical environment, and nonspecific symptoms. Consequently, these tumors are usually of considerable size at the time of diagnosis.
The authors discuss a case of a sacral nerve sheath tumor. They also propose a classification scheme for these tumors based on their location with respect to the sacrum into three types (Types I–III). Type I tumors are confined to the sacrum; Type II originate within the sacrum but then locally metastasize through the anterior and posterior sacral walls into the presacral and subcutaneous spaces, respectively; and Type III are located primarily in the presacral/retroperitoneal area. The overwhelming majority of sacral nerve sheath tumors are schwannomas. Neurofibromas and malignant nerve sheath tumors are exceedingly rare. Regardless of their histological features, the goal of treatment is complete excision. Adjuvant radiotherapy may be used in patients in whom resection was subtotal. Approaches to the sacrum can generally be classified as anterior or posterior. Type I tumors may be resected via a posterior approach alone, Type III may require an anterior approach, and Type II tumors usually require combined anterior–posterior surgery.