Cormac O. Maher
Cormac O. Maher and Fraser C. Henderson
Object. Hypertrophy of the superior facet of the inferior vertebra, resulting in a compression of the nerve root at the lateral foraminal exit, is a recognized cause of radicular symptoms, particularly in patients in whom previous lumbar spine surgery has failed. The lesion-specific presenting symptoms, imaging findings, and surgical treatment of this lesion, however, have received little attention. The authors prospectively studied a series of eight consecutive patients, in whom a diagnosis of lumbar stenosis at the lateral foraminal exit had been made, to elucidate the common presenting signs and symptoms of this disorder, as well as to evaluate the success of the operative treatment.
Methods. The eight patients were selected from a group of 250 consecutive patients who presented to a tertiary-care hospital and in whom a diagnosis of long-standing lumbar radiculopathy had been made. In all cases the diagnosis was confirmed by imaging studies and by intraoperative findings. The authors performed decompressive procedures on the nerve root via a medial facet-sparing approach.
Conclusions. The authors conclude that this lesion presents with characteristic physical findings and on imaging studies that distinguish it from other causes of radiculopathy, and they propose a lesion-specific, facet-sparing surgical technique that has yielded excellent results.
Jennifer Strahle and Cormac O. Maher
Cormac O. Maher, James A. Garrity, and Fredric B. Meyer
Ventriculoperitoneal (VP) shunts have not been widely used for idiopathic intracranial hypertension (IIH) because of the difficulty of placing a shunt into normal or small-sized ventricles. The authors report their experience with stereotactic placement of VP shunts for IIH.
The authors reviewed the clinical records of all patients in whom stereotaxis was used to guide the placement of a VP shunt for IIH at their institution. All shunts were placed using stereotactic guidance to target the frontal horn of the lateral ventricle. Patients were contacted at a mean postoperative interval of 15.1 months. No patients were lost to follow up.
The authors identified 13 patients who underwent placement of a stereotactically guided VP shunt for IIH over a 6-year period. A trial of either acetazolamide or steroid therapy had failed in all patients. Prior surgical treatments included optic nerve sheath fenestrations in seven patients and cerebrospinal fluid diversionary procedures, other than stereotactic VP shunt procedures, in nine patients. Twelve patients reported excellent or good durable symptomatic relief at the time of follow up. No patient suffered progression of visual deficits. Four patients experienced persistent headaches following the procedure. Three patients required a revision of the VP shunt for technical failure.
Stereotactically guided VP shunt placement is an effective and durable treatment option in many cases of IIH that are refractory to more traditional medical and surgical approaches.
Cormac O. Maher and Liliana Goumnerova
The aim of this study was to report the long-term outcomes of patients receiving endoscopic ventriculocystocisternostomy (VCC) for suprasellar arachnoid cysts (SACs), and to analyze all published reports on outcomes of ventriculocystostomy (VC) versus VCC to compare the effectiveness of the 2 techniques.
Eleven consecutive patients with previously untreated SACs were surgically treated using endoscopic VCC. Another 2 patients were treated with VCC following ventriculoperitoneal shunt placement. Clinical imaging data were recorded. An analysis was performed of all published patient outcomes following endoscopic VC or VCC for an SAC.
Developmental delay and progressive macrocephaly were the most common preoperative symptoms. At a mean clinical follow-up interval of 63 months, 10 of 11 patients undergoing primary VCC did not require reoperation. An analysis of the literature suggests that VCC may be more effective than VC. Of the 44 reported patients that underwent VC as a first treatment, 7 (16%) required reoperation, and 7 (8%) of 86 patients who underwent VCC as a first treatment required reoperation. When VC or VCC was performed following a prior surgical procedure, 4 of 11 patients undergoing VC had a treatment failure requiring reoperation. In contrast, only 2 of the 17 reported cases of VCC following a prior procedure required further treatment. The difference in reoperation rates following either primary or secondary VC was significantly higher than following primary or secondary VCC (p = 0.04).
The authors conclude that VCC is an effective and durable treatment for symptomatic SACs in most cases.
Incidentally discovered lesions
Cormac O. Maher, Paul Klimo Jr., and Edward R. Smith
Jennifer Strahle and Cormac O. Maher
Cormac O. Maher, Fredric B. Meyer, and Bahram Mokri
Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. In this report the authors review the indications for surgery, surgical techniques, and surgery-related outcomes for these lesions. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement and sagging of the brain. On spinal MR images, diverticula are frequently noted. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Tears in the dura or leaking diverticula that are identified as the sources of the CSF leak often can be ligated or repaired. When a source of CSF egress is not found intraoperatively, packing the epidural space with blood-soaked Gelfoam or muscle at the appropriate level can lead to relief of symptoms. Occasionally the dural defect is large, irregular, or has attenuated borders that may not be possible to repair with sutures. These may be repaired by packing the defect with muscle or blood-soaked Gelfoam. Indications for and outcomes of surgery in patients with this condition will become more defined as surgeons gain experience with these procedures.