✓ Carotid endarterectomy may carry a substantial risk of morbidity and mortality from major stroke, thus offsetting any statistical benefit in reduction of future stroke. Because of the disturbing ranges in the incidence of stroke morbidity and mortality reported from the several institutional series studying carotid endarterectomy, the authors undertook a prospective review of 142 consecutive carotid endarterectomies performed for symptomatic atherosclerotic occlusive vascular disease on the neurosurgical service, The University of Alabama Hospital. Preoperative risk assessment was performed in each case according to the Mayo Clinic classification system. The overall mortality rate was 1.4% and the major stroke morbidity rate was 0.7%, for a combined major morbidity and mortality rate of 2.1%. The incidence of minor neurological morbidity was 1.4%. There was no morbidity or mortality in the Grade I and II (low-risk) patient groups. This low combined major morbidity and mortality rate of 2.1% for carotid endarterectomy causes the surgical stroke-free survival curve to intersect the medical stroke-free survival curve at an earlier point in time, and thus demonstrates the greater reduction in risk of stroke which accrues over time for the surgically treated patient.
H. Evan Zeiger Jr., Edward J. Zampella, David C. Naftel, Robert D. McKay, Pamela D. Varner and Richard B. Morawetz
R. Shane Tubbs, Robert P. Naftel, William C. Rice, Peter Liechty, Michael Conklin and W. Jerry Oakes
The angulation of the sacrum is easily measured. The authors have previously reported on patients who were symptomatic with a diagnosis of myelomeningocele who were found to have changes in their lumbosacral angle (LSA) corresponding to the onset of symptoms indicative of a tethered spinal cord. The aim of this study was to verify this same finding in a group of patients with occult spinal dysraphism (that is, closed neural tube defect).
A retrospective analysis of 50 consecutive lipomyelomeningocele repair procedures was performed. Data pertaining to 30 age-matched control patients were also analyzed. Measurements were made of the LSA over time in all studied patients harboring lipomyelomeningoceles.
Appropriate imaging was available for 25 cases of lipomyelomeningocele (that is, radiographs of the lumbosacral junction were available from the patient’s perinatal period and at presentation of symptoms of a tethered spinal cord). Roughly one third of these patients suffered symptoms from a tethered spinal cord at the most recent follow-up examination. Nine patients (36%) were found to have corresponding LSA measurements greater than 70°, and seven (28%) of these patients presented with signs and symptoms of a tethered spinal cord, such as decreased lower-extremity function (two patients), urinary bladder incontinence (three patients), back pain (one patient), and lower-extremity paresthesias (one patient). The LSA measurements were statistically greater (p < 0.05) in the symptomatic patient population than in age-matched control patients and asymptomatic patients. Changes in the LSA in these symptomatic patients ranged from 5 to 24° (mean 13°). Changes in the LSA were noted in only two asymptomatic patients. No single sign or symptom of a tethered spinal cord appeared to correlate to any degree of increase in the LSA. Of the 25 patients excluded from this study because perinatal radiographic images were not available, none was symptomatic at the most recent follow-up examination and none had a grossly exaggerated LSA.
Signs and symptoms indicative of a tethered spinal cord appear to correspond to increases in the LSA. Although the authors do not advocate the use of LSA measurement as the sole indicator of a tethered spinal cord, this imaging finding may prove useful to the clinician as an indication of the tethered spinal cord or as an adjunct in verifying symptomatology in patients harboring a lipomyelomeningocele.
R. Shane Tubbs, Cuong J. Bui, William C. Rice, Marios Loukas, Robert P. Naftel, Michael Paul Holcombe and W. Jerry Oakes
Occasional comments are found in the literature regarding patients with lipomyelomeningocele and concomitant Chiari malformation Type I (CM-I). The object of this study was to explore the association between these two conditions.
The authors performed a retrospective database analysis of lipomyelomeningocele cases to identify cases of concomitant CM-I. Analysis of posterior fossa volume (based on the Cavalieri principle) was performed in all identified cases in which appropriate neuroimages were available, and the results were compared with those obtained in age-matched controls.
Seven (13%) of 54 patients with lipomyelomeningocele were found to also have CM-I. Two of these were symptomatic (cervicothoracic syrinx and occipital headaches) and required posterior fossa decompression. No correlation was found between the amount of hindbrain herniation and the level of the conus medullaris or the type of lipomyelomeningocele (for example, caudal or transitional). Volumetric studies of the posterior fossa revealed normal age-matched volumes in all but one patient (who had asymptomatic CM-I).
The incidence of CM-I in patients with lipomyelomeningocele appears to be significantly greater than that of the general population and the association rate is too high for the finding to be a chance occurrence. Decreases in the volume of the posterior cranial fossa were not found in the majority of patients in this small cohort; therefore, the cause of the concomitant occurrence of lipomyelomeningocele and CM-I remains undetermined. Clinicians should consider obtaining imaging studies of the entire neuraxis in patients with lipomyelomeningoceles and should investigate other causes for syringes found in association with lipomyelomeningoceles.
Robert P. Naftel, R. Shane Tubbs, Gavin T. Reed and John C. Wellons III
The authors describe a new technique that may be used in conjunction with neuronavigation or freehand techniques for obtaining small ventricular access. Using this modification, the introducer sheath and trocar can be guided down a ventriculostomy tract with endoscopic visual control. With increasing focus on endoscopic therapies in patients without hydrocephalus, this adjunct, based on the authors' experience, may provide an additional technique for safely treating patients.
Robert P. Naftel, Chevis N. Shannon, Gavin T. Reed, Richard Martin, Jeffrey P. Blount, R. Shane Tubbs and John C. Wellons III
The use of intraventricular endoscopy to achieve diagnosis or to resect accessible intraventricular or paraventricular tumors has been described in the literature in both adults and children. Traditionally, these techniques have not been used in patients with small ventricles due to the perceived risk of greater morbidity. The authors review their experience with the effectiveness and safety of endoscopic brain tumor management in children with small ventricles.
Between July 2002 and December 2009, 24 children with endoscopically managed brain tumors were identified. Radiological images were reviewed by a radiologist blinded to study goals and clinical setting. Patients were categorized into small-ventricle and ventriculomegaly groups based on frontal and occipital horn ratio. Surgical success was defined a priori and analyzed between groups. Trends were identified in selected subgroups, including complications related to pathological diagnosis and surgeon experience.
Six children had small ventricles and 18 had ventriculomegaly. The ability to accomplish surgical goals was statistically equivalent in children with small ventricles and those with ventriculomegaly (83% vs 89%, respectively, p = 1.00). There were no complications in the small-ventricle cohort, but in the ventriculomegaly cohort there were 2 cases of postoperative hemorrhages and 1 case of infection. All hemorrhagic complications occurred in patients with high-grade tumor histopathological type and were early in the surgeon's endoscopic career.
Based on our experience, endoscopy should not be withheld in children with intraventricular tumors and small ventricles. Complications appear to be more dependent on tumor histopathological type and surgeon experience than ventricular size.
R. Shane Tubbs, Joshua Beckman, Robert P. Naftel, Joshua J. Chern, John C. Wellons III, Curtis J. Rozzelle, Jeffrey P. Blount and W. Jerry Oakes
The diagnosis and treatment of Chiari malformation Type I (CM-I) has evolved over the last few decades. The authors present their surgical experience of over 2 decades of treating children with this form of hindbrain herniation.
The authors conducted a retrospective review of their institutional experience with the surgical treatment of the pediatric CM-I from 1989 to 2010.
The 2 most common presentations were headache/neck pain (40%) and scoliosis (18%). Common associated diagnoses included neurofibromatosis Type 1 (5%) and idiopathic growth hormone deficiency (4.2%). Spine anomalies included scoliosis (18%), retroversion of the odontoid process (24%), Klippel-Feil anomaly (3%), and atlantooccipital fusion (8%). Approximately 3% of patients had a known family member with CM-I. Hydrocephalus was present in 48 patients (9.6%). Syringomyelia was present in 285 patients (57%), and at operation, 12% of patients with syringomyelia were found to have an arachnoid veil occluding the fourth ventricular outlet. Fifteen patients (3%) have undergone reoperation for continued symptoms or persistent large syringomyelia. The most likely symptoms and signs to resolve following surgery were Valsalva-induced headache and syringomyelia. The average hospital stay and “return to school” time were 3 and 12 days, respectively. The follow-up for this group ranged from 2 months to 15 years (mean 5 years). Complications occurred in 2.4% of cases; there was no mortality. No patient required acute return to the operating room, and no blood transfusions were performed.
The authors believe this to be the largest reported series of surgically treated pediatric CM-I patients and hope that their experience will be of use to others who treat this surgical entity.
R. Shane Tubbs, Justin D. Hallock, Virginia Radcliff, Robert P. Naftel, Martin Mortazavi, Mohammadali M. Shoja, Marios Loukas and Aaron A. Cohen-Gadol
The specialized ligaments of the craniocervical junction must allow for stability yet functional movement. Because injury to these important structures usually results in death or morbidity, the neurosurgeon should possess a thorough understanding of the anatomy and function of these ligaments. To the authors' knowledge, a comprehensive review of these structures is not available in the medical literature. The aim of the current study was to distill the available literature on each of these structures into one offering.
Report of 4 cases
Joshua J. Chern, Amber S. Gordon, Robert P. Naftel, R. Shane Tubbs, W. Jerry Oakes and John C. Wellons III
Intracranial endoscopy in the treatment of hydrocephalus, arachnoid cysts, or brain tumors has gained wide acceptance, but the use of endoscopy for intradural navigation in the pediatric spine has received much less attention. The aim of the authors' present study was to analyze their experience in using spinal endoscopy to treat various pathologies of the spinal canal.
The authors performed a retrospective review of intradural spinal endoscopic cases at their institution. They describe 4 representative cases, including an arachnoid cyst, intrinsic spinal cord tumor, holocord syrinx, and split cord malformation.
Intradural spinal endoscopy was useful in treating the aforementioned lesions. It resulted in a more limited laminectomy and myelotomy, and it assisted in identifying a residual spinal cord tumor. It was also useful in the fenestration of a multilevel arachnoid cyst and in confirming communication of fluid spaces in the setting of a complex holocord syrinx. Endoscopy aided in the visualization of the spinal cord to ensure the absence of tethering in the case of a long-length Type II split spinal cord malformation.
Based on their experience, the authors found intradural endoscopy to be a useful surgical adjunct and one that helped to decrease morbidity through reduced laminectomy and myelotomy. With advances in technology, the authors believe that intradural endoscopy will begin to be used by more neurosurgeons for treating diseases of this anatomical region.
Robert P. Naftel, Joshua L. Argo, Chevis N. Shannon, Tracy H. Taylor, R. Shane Tubbs, Ronald H. Clements and Mark R. Harrigan
Traditional ventriculoperitoneal (VP) shunt surgery involves insertion of the distal catheter by minilaparotomy. However, minilaparotomy may be a significant source of morbidity during shunt surgery. Laparoscopic insertion of the distal catheter is an alternative technique that may simplify and improve the safety of shunt surgery.
The authors performed a retrospective review of hospital records of all patients undergoing new VP shunt insertion at a tertiary care center between 2004 and 2009. Patient characteristics and outcomes were compared between patients undergoing open or laparoscopic insertion of the distal catheter. Independent variables in the analysis included age, sex, race, body mass index, surgical technique, previous VP shunt placement, previous abdominal procedures, American Society of Anesthesiology (ASA) score, and indication for shunt placement. Dependent variables included the occurrence of shunt failure, cause of shunt failure, complications, length of stay (LOS), LOS after shunt placement, estimated blood loss, and operative time.
The authors identified 810 patients who met the inclusion criteria; open or laparoscopic distal catheter insertion was performed in 335 and 475 patients, respectively. There were no significant differences between the groups regarding age, race, ASA score, or indication for shunt placement. The most common indication was hydrocephalus due to subarachnoid hemorrhage, followed by tumor-associated hydrocephalus, normal pressure hydrocephalus (NPH), and hydrocephalus due to trauma. The incidence of shunt failure was not statistically different between cohorts, occurring in 20.0% of laparoscopic and 20.9% of open catheter placement cases (p = 0.791). With analysis of causes of shunt failure, shunt obstruction occurred significantly more often in the open surgery cohort (p = 0.012). In patients with a known cause shunt obstruction, distal obstruction occurred in 35.7% of the open cohort obstructions and 4.8% of the laparoscopic cohort obstructions (p = 0.014). The relative risk of distal obstruction in open cases compared with laparoscopic cases was 7.50. Infections occurred in 8.2% of laparoscopic cases compared with 6.6% of open cases (p = 0.419). Within the NPH subgroup, the laparoscopically treated patients had significantly more overdrainage (p = 0.040), whereas those in the open cohort experienced significantly more shunt obstructions (p = 0.034). Laparoscopically treated patients had shorter operative times (p < 0.0005), inpatient LOS (p < 0.001), and inpatient LOS after VP shunt placement (p = 0.01) as well as less blood loss (p = 0.058).
To our knowledge this is the largest reported comparison of distal VP shunt catheter insertion techniques. Compared with minilaparotomy, the laparoscopic approach was associated with decreased time in the operating room and a decreased LOS. Moreover, laparoscopy was associated with fewer distal shunt obstructions. Laparoscopic shunt surgery is a viable alternative to traditional shunt surgery.