✓The authors report on a patient harboring an unruptured cortical arteriovenous malformation (AVM), who had presented with obstructive hydrocephalus due to compression of the cerebral aqueduct by a large venous varix. Although patients with ruptured AVMs are known to either present with or later suffer from obstructive hydrocephalus, those with unruptured AVMs who present in this manner are quite rare. Moreover, hydrocephalus caused by a venous varix draining an AVM, to our knowledge, has never been previously reported in the literature. This report serves to illustrate two primary points, namely, that tortuous venous varices draining AVMs can result in obstructive hydrocephalus and that this unusual circumstance can be fostered in the setting of venous outflow obstruction.
Case report and review of the literature
Stefan A. Mindea, Benson P. Yang, and H. Hunt Batjer
Varun R. Kshettry, Stefan A. Mindea, and H. Hunt Batjer
✓Cranial injuries were among the earliest neurosurgical problems faced by ancient physicians and surgeons. In this review, the authors trace the development of neurosurgical theory and practice for the treatment of cranial injuries beginning from the earliest ancient evidence available to the collapse of the Greco–Roman civilizations. The earliest neurosurgical procedure was trephination, which modern scientists believe was used to treat skull fractures in some civilizations. The Egyptian papyri of Edwin Smith provide a thorough description of 27 head injuries with astute observations of clinical signs and symptoms, but little information on the treatment of these injuries. Hippocrates offered the first classification of skull fractures and discussion of which types required trephining, in addition to refining this technique. Hippocrates was also the first to understand the basis of increased intracranial pressure. After Hippocrates, the physicians of the Alexandrian school provided further insight into the clinical evaluation of patients with head trauma, including the rudiments of a Glasgow Coma Scale. Finally, Galen of Pergamon, a physician to fallen gladiators, substantially contributed to the understanding of the neuroanatomy and physiology. He also described his own classification system for skull fractures and further refined the surgical technique of trephination. From the study of these important ancient figures, it is clearly evident that the knowledge and experience gained from the management of cranial injuries has laid the foundation not only for how these injuries are managed today, but also for the development of the field of neurosurgery.
Benson P. Yang, Stefan A. Mindea, and Arthur J. DiPatri Jr.
Michael Y. Wang, Ram Vasudevan, and Stefan A. Mindea
Adjacent-segment degeneration and stenosis are common in patients who have undergone previous lumbar fusion. Treatment typically involves a revision posterior approach, which requires management of postoperative scar tissue and previously implanted instrumentation. A minimally invasive lateral approach allows the surgeon to potentially reduce the risk of these hazards. The technique relies on indirect decompression to treat central and foraminal stenosis and placement of a graft with a large surface area to promote robust fusion and stability in concert with the surrounding tensioned ligaments. The goal in this study was to determine if lateral interbody fusion without supplemental pedicle screws is effective in treating adjacent-segment disease.
For a 30-month study period at two institutions, the authors obtained all cases of lumbar fusion with new back and leg pain due to adjacent-segment stenosis and spondylosis failing conservative measures. All patients had undergone minimally invasive lateral interbody fusion from the side of greater leg pain without supplemental pedicle screw fixation. Patients were excluded from the study if they had undergone surgery for a nondegenerative etiology such as infection or trauma. They were also excluded if the intervention involved supplemental posterior instrumented fusion with transpedicular screws. Postoperative metrics included numeric pain scale (NPS) scores for leg and back pain. All patients underwent dynamic radiographs and CT scanning to assess stability and fusion after surgery.
During the 30-month study period, 21 patients (43% female) were successfully treated using minimally invasive lateral interbody fusion without the need for subsequent posterior transpedicular fixation. The mean patient age was 61 years (range 37–87 years). Four patients had two adjacent levels fused, while the remainder had single-level surgery. All patients underwent surgery without conversion to a traditional open technique, and recombinant human bone morphogenetic protein–2 was used in the interbody space in all cases. The mean follow-up was 23.6 months. The mean operative time was 86 minutes, and the mean blood loss was 93 ml. There were no major intraoperative complications, but one patient underwent subsequent direct decompression in a delayed fashion. The leg pain NPS score improved from a mean of 6.3 to 1.9 (p < 0.01), and the back pain NPS score improved from a mean of 7.5 to 2.9 (p < 0.01). Intervertebral settling averaged 1.7 mm. All patients had bridging bone on CT scanning at the last follow-up, indicating solid bony fusion.
Adjacent-segment stenosis and spondylosis can be treated with a number of different operative techniques. Lateral interbody fusion provides an attractive alternative with reduced blood loss and complications, as there is no need to re-explore a previous laminectomy site. In this limited series a minimally invasive lateral approach provided high fusion rates when performed with osteobiological adjuvants.
Brian A. O'Shaughnessy, Sean A. Salehi, Stefan A. Mindea, and H. Hunt Batjer
Cerebral revascularization, an indispensable component of neurovascular surgery, has been performed in the treatment of cranial base tumors, complex cerebral aneurysms, and occlusive cerebrovascular disease. The goal of a revascularization procedure is to augment blood flow distally. It can therefore be used as an adjunctive measure in the treatment of complex neurosurgical disease processes that require parent artery sacrifice for definitive treatment. In the treatment of giant anterior circulation aneurysms, for instance, a cerebral revascularization procedure may be considered in patients in whom the collateral circulation is marginal and in whom lesions may be treated either using a Hunterian-based strategy or clip-assisted reconstruction requiring a prolonged period of temporary occlusion. To date, there is no entirely effective method known to produce long-term tolerance to carotid artery (CA) sacrifice and, largely for that reason, some neurovascular surgeons advocate universal revascularization. The authors of this report, however, prefer to perform revascularization only in the limited subset of patients in whom preoperative assessment has revealed risk factors for cerebral ischemia due to hypoperfusion. In this paper, the authors introduce their protocol for assessing cerebrovascular reserve capacity, indications for cerebral revascularization in the treatment of complex anterior circulation aneurysms, and discuss their rationale for choosing to practice selective, rather than universal, revascularization.
Stefan A. Mindea, Benson P. Yang, Robert Shenkar, Bernard Bendok, H. Hunt Batjer, and Issam A. Awad
✓ Familial disease is responsible for one third to one half of cerebral cavernous malformation (CCM) cases presenting to clinical attention. Much has been learned in the past decade about the genetics of these cases, which are all inherited in an autosomal dominant pattern, at three known chromosome loci. Unique features of inherited CCMs in Hispanic-Americans of Mexican descent have been described. The respective genes for each locus have been identified and preliminary observations on disease pathways and mechanisms are coming to light, including possible explanations for selectivity of neural milieu and relationships to endothelial layer abnormalities. Mechanisms of lesion genesis in cases of genetic predisposition are being investigated, with evidence to support a two-hit model emerging from somatic mutation screening of the lesions themselves and from lesion formation in transgenic murine models of the disease. Other information on potential inflammatory factors has emerged from differential gene expression studies. Unique phenotypic features of solitary versus familial cases have emerged: different associations with venous developmental anomaly and the exceptionally high penetrance rates that are found in inherited cases when high-sensitivity screening is performed with gradient echo magnetic resonance imaging. This information has changed the landscape of screening and counseling for patients and their families, and promises to lead to the development of new tools for predicting, explaining, and modifying disease behavior.
Stefan A. Mindea, Keith J. Kaplan, Michael A. Howard, and Shaun T. O'leary
✓Granular cell tumors (GCTs) are benign lesions that, paradoxically, despite originating from the Schwann cell, are most commonly seen in nonneuronal tissue including the skin, subcutaneous tissue, and tongue. Their presence in the brachial plexus is quite rare, but their involvement of peripheral nerves is exceptional. The authors report on a case of GCT involving the axillary nerve in a 54-year-old woman who underwent complete resection of the lesion. To the author's knowledge, this case marks the first report of a GCT involving the axillary nerve. Aspects pertaining to the radiographic and histopathological features as well as the surgical management of this lesion are discussed.
Stefan A. Mindea, Benson P. Yang, Bernard R. Bendok, Jeffrey W. Miller, and H. Hunt Batjer
✓Cerebral vasospasm is a significant cause of morbidity and mortality in patients who have sustained a subarachnoid hemorrhage from aneurysm rupture. Symptomatic cerebral vasospasm is also a strong predictor of poor clinical outcome and has thus drawn a great deal of interest from cerebrovascular surgeons. Although medical management is the cornerstone of treatment for this condition, endovascular intervention may be warranted for those in whom this treatment fails and in whom symptomatic vasospasm subsequently develops. The rapid advancements in endovascular techniques and pharmacological agents used to combat this pathological state continue to offer promise in broadening the available treatment armamentarium. In this article the authors discuss the rationale and basis for using the various endovascular options for the treatment of cerebral vasospasm, and they also discuss the limitations, complications, and efficacy of these treatment strategies in regard to neurological condition and outcome.
Stefan A. Mindea, Sean A. Salehi, Aruna Ganju, Michael K. Rosner, Brian A. O'Shaughnessy, Allan Jorge, and Stephen L. Ondra
Lumbosacropelvic junction instability may result from a variety of disease processes including primary and meta-static sacral tumors and degenerative disease. Regardless of the origin of the disease, restoring or maintaining spinal stability at this junction is essential for normal translation of axial forces from the lumbar spine and sacrum to the pelvis. Spinal stability is also critical for maintaining structural integrity, preventing neurological function deterioration, and alleviating resultant mechanical or axial pain. In this report, the authors describe one option for safe and effective spinal pelvic stabilization by using a transiliac rod and iliac bolt construct, which results in early postoperative ambulation, preserved neurological function, and reduced axial pain in selected patients.
Joshua J. Loya, Stefan A. Mindea, Hong Yu, Chitra Venkatasubramanian, Steven D. Chang, and Terry C. Burns
Intracranial hypotension is a disorder of CSF hypovolemia due to iatrogenic or spontaneous spinal CSF leakage. Rarely, positional headaches may progress to coma, with frequent misdiagnosis. The authors review reported cases of verified intracranial hypotension–associated coma, including 3 previously unpublished cases, totaling 29. Most patients presented with headache prior to neurological deterioration, with positional symptoms elicited in almost half. Eight patients had recently undergone a spinal procedure such as lumbar drainage. Diagnostic workup almost always began with a head CT scan. Subdural collections were present in 86%; however, intracranial hypotension was frequently unrecognized as the underlying cause. Twelve patients underwent one or more procedures to evacuate the collections, sometimes with transiently improved mental status. However, no patient experienced lasting neurological improvement after subdural fluid evacuation alone, and some deteriorated further. Intracranial hypotension was diagnosed in most patients via MRI studies, which were often obtained due to failure to improve after subdural hematoma (SDH) evacuation. Once the diagnosis of intracranial hypotension was made, placement of epidural blood patches was curative in 85% of patients. Twenty-seven patients (93%) experienced favorable outcomes after diagnosis and treatment; 1 patient died, and 1 patient had a morbid outcome secondary to duret hemorrhages. The literature review revealed that numerous additional patients with clinical histories consistent with intracranial hypotension but no radiological confirmation developed SDH following a spinal procedure. Several such patients experienced poor outcomes, and there were multiple deaths. To facilitate recognition of this treatable but potentially life-threatening condition, the authors propose criteria that should prompt intracranial hypotension workup in the comatose patient and present a stepwise management algorithm to guide the appropriate diagnosis and treatment of these patients.