Cormac O. Maher
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.
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.
Jennifer Strahle and Cormac O. Maher
Incidentally discovered lesions
Cormac O. Maher, Paul Klimo Jr., and Edward R. Smith
Cormac O. Maher, Steven R. Buchman, Edward O'Hara, and Aaron A. Cohen-Gadol
Surgery for cranial deformity was associated with significant surgical morbidity during the early part of the 20th century. For this reason, Harvey Cushing was initially not in favor of surgical treatment of craniosynostosis. Later in his career, Cushing began to operate on these children, although it never became a major focus of his practice. Several examples of his patients with cranial deformity are presented, and his limited role in the development of this field is discussed.
D. Andrew Wilkinson, Kyle Johnson, Hugh J. L. Garton, Karin M. Muraszko, and Cormac O. Maher
The goal of this analysis was to define temporal and geographic trends in the surgical treatment of Chiari malformation Type I (CM-I) in a large, privately insured health care network.
The authors examined de-identified insurance claims data from a large, privately insured health care network of over 58 million beneficiaries throughout the United States for the period between 2001 and 2014 for all patients undergoing surgical treatment of CM-I. Using a combination of International Classification of Diseases (ICD) diagnosis codes and Current Procedural Terminology (CPT) codes, the authors identified CM-I and associated diagnoses and procedures over a 14-year period, highlighting temporal and geographic trends in the performance of CM-I decompression (CMD) surgery as well as commonly associated procedures.
There were 2434 surgical procedures performed for CMD among the beneficiaries during the 14-year interval; 34% were performed in patients younger than 20 years of age. The rate of CMD increased 51% from the first half to the second half of the study period among younger patients (p < 0.001) and increased 28% among adult patients between 20 and 65 years of age (p < 0.001). A large sex difference was noted among adult patients; 78% of adult patients undergoing CMD were female compared with only 53% of the children. Pediatric patients undergoing CMD were more likely to be white with a higher household net worth. Regional variability was identified among rates of CMD as well. The average annual rate of surgery ranged from 0.8 surgeries per 100,000 insured person-years in the Pacific census division to 2.0 surgeries per 100,000 insured person-years in the East South Central census division.
Analysis of a large nationwide health care network showed recently increasing rates of CMD in children and adults over the past 14 years.
Jeffrey L. Nadel, D. Andrew Wilkinson, Hugh J. L. Garton, Karin M. Muraszko, and Cormac O. Maher
The goal of this study was to determine the rates of screening and surgery for foramen magnum stenosis in children with achondroplasia in a large, privately insured healthcare network.
Rates of screening and surgery for foramen magnum stenosis in children with achondroplasia were determined using de-identified insurance claims data from a large, privately insured healthcare network of over 58 million beneficiaries across the United States between 2001 and 2014. Cases of achondroplasia and screening and surgery claims were identified using a combination of International Classification of Diseases diagnosis codes and Current Procedural Terminology codes. American Academy of Pediatrics (AAP) practice guidelines were used to determine screening trends.
The search yielded 3577 children age 19 years or younger with achondroplasia. Of them, 236 met criteria for inclusion in the screening analysis. Among the screening cohort, 41.9% received some form of screening for foramen magnum stenosis, whereas 13.9% of patients were fully and appropriately screened according to the 2005 guidelines from the AAP. The screening rate significantly increased after the issuance of the AAP guidelines. Among all children in the cohort, 25 underwent cervicomedullary decompression for foramen magnum stenosis. The incidence rate of undergoing cervicomedullary decompression was highest in infancy (28 per 1000 patient-years) and decreased with age (5 per 1000 patient-years for all other ages combined).
Children with achondroplasia continue to be underscreened for foramen magnum stenosis, although screening rates have improved since the release of the 2005 AAP surveillance guidelines. The incidence of surgery was highest in infants and decreased with age.