Antibiotic-impregnated external ventricular drains
John R. W. Kestle
Daniel E. Couture and Charles L. Branch Jr.
The goal of this prospective study was to review a series of 27 patients who underwent bilateral posterior lumbar interbody fusion with instrumented pedicle fixation and two HYDROSORB (known generically as 70:30 poly[L-lactide-co-D,L-lactide]) rectangular cages packed with locally harvested autograft at a total of 48 levels, and to assess the safety and efficacy of this novel technique. This analysis, conducted at a mean of 26 months of follow up, is the first report of a long-term evaluation of this technique. Fusion rates and clinical outcomes are presented.
A prospective clinical and radiographic review of findings in 27 consecutive patients was performed. Fusion rates and clinical outcome were assessed at 6-month intervals up to the 32-month follow-up end point. Two patients with four corresponding fusion levels were lost to follow up.
Radiographic evidence of satisfactory fusion was achieved in 42 (95.5%) of 44 levels fused. Satisfactory fusion at all levels was achieved in 23 (92%) of 25 patients. Two patients required repeated operations for treatment of symptomatic pseudarthrosis during the study period. The likelihood of all levels attaining fusion in a given patient decreased as the number of levels treated increased, which is consistent with previously published studies. Nonetheless, fusion rates per treated level were similar for patients in whom one to three levels were treated. No significant surgical complication occurred.
Posterior lumbar interbody fusion in which the HYDROSORB bioabsorbable implant packed with locally harvested autograft and segmental internal fixation are used appears to be an interbody fusion alternative whose efficacy is comparable with previously reported procedures.
Atilio E. Palma, Robert T. Wicks, Gautam Popli, and Daniel E. Couture
Corpus callosotomy has been used as a form of surgical palliation for patients suffering from medically refractory generalized seizures, including drop attacks. Callosotomy has traditionally been described as involving a craniotomy with microdissection. MR-guided laser interstitial thermal therapy (MRg-LITT) has recently been used as a minimally invasive method for performing surgical ablation of epileptogenic foci and corpus callosotomy. The authors present 3 cases in which MRg-LITT was used to perform a corpus callosotomy as part of a staged surgical procedure for a patient with multiple seizure types and in instances when further ablation of residual corpus callosum is necessary after a prior open surgical procedure. To the authors’ knowledge, this is the first case series of corpus callosotomy performed using the MRg-LITT system with a 3.3-year average follow-up. Although MRg-LITT is not expected to replace the traditional corpus callosotomy in all cases, it is a safe, effective, and durable alternative to the traditional open corpus callosotomy, particularly in the setting of a prior craniotomy.
Jaclyn J. Renfrow, Garret P. Greeneway, Lacey Carter, and Daniel E. Couture
Craniopharyngiomas frequently recur locally or less commonly along the path of prior resection. Ectopic recurrence is rare, although cases are reported along the neuraxis spanning from the subgaleal space down to the S1 nerve root. This case reports on a girl with a history of craniopharyngioma first resected at 23 months of age with two local suprasellar recurrences managed with repeat craniotomy and external beam radiation therapy. At age 14 she complained of worsening headaches and brain MRI demonstrated an enhancing 1.2-cm cystic lesion in the posterior body of the left lateral ventricle. Pathology following endoscopic resection of the lesion was consistent with an adamantinomatous craniopharyngioma. This case report serves to describe the first reported recurrence of a craniopharyngioma in the lateral ventricle and emphasizes the need for a high index of suspicion along with long-term follow-up of patients with a history of craniopharyngioma.
Analiz Rodriguez, Elizabeth N. Kuhn, Aravind Somasundaram, and Daniel E. Couture
Syringohydromyelia is frequently identified on spinal imaging. The literature provides little guidance to decision making regarding the need for follow-up or treatment. The purpose of this study was to review the authors' experience in managing pediatric syringohydromyelia of unknown cause.
A single-institution retrospective review of all cases involving pediatric patients who underwent spinal MRI from 2002 to 2012 was conducted. Patients with idiopathic syringohydromyelia (IS) were identified and categorized into 2 subgroups: uncomplicated idiopathic syrinx and IS associated with scoliosis. Clinical and radiological course were analyzed.
Ninety-eight patients (50 female, 48 male) met the inclusion criteria. Median age at diagnosis of syrinx was 11.9 years. Median maximum syrinx size was 2 mm (range 0.5–17 mm) and spanned 5 vertebral levels (range 1–20 vertebral levels). Thirty-seven patients had scoliosis. The most common presenting complaint was back pain (26%). Clinical follow-up was available for 78 patients (80%), with a median follow-up of 20.5 months (range 1–143 months). A neurological deficit existed at presentation in 36% of the patients; this was either stable or improved at last follow-up in 64% of cases. Radiological follow-up was available for 38 patients (39%), with a median duration of 13 months (range 2–83 months). There was no change in syrinx size in 76% of patients, while 16% had a decrease and 8% had an increase in syrinx size. Thirty-six patients had both clinical and radiological follow-up. There was concordance between clinical and radiological course in 14 patients (39%), with 11 patients (31%) showing no change and 3 patients (8%) showing clinical and radiological improvement.
No patients had concurrent deterioration in clinical and radiological course. One patient with scoliosis and muscular dystrophy underwent direct surgical treatment of the syrinx and subsequently had a deteriorated clinical course and decreased syrinx size.
There remains a paucity of data regarding the management of pediatric IS. IS in association with scoliosis can complicate neurosurgical decision making. There was no concordance between radiological syrinx size increase and clinical deterioration in this cohort, indicating that surgical decision making should reflect clinical course as opposed to radiological course.
E. Andrew Stevens, Elizabeth Palavecino, Robert J. Sherertz, Zakariya Shihabi, and Daniel E. Couture
Treatment of ventriculoperitoneal shunt infections frequently requires placement of an external ventricular drain (EVD). Surveillance specimens obtained from antibiotic-impregnated (AI) EVDs may be less likely to demonstrate bacterial growth, potentially resulting in undertreatment of an infection. The purpose of this study was to assess whether AI EVDs had any significant effect on bacterial culture results compared with nonantibiotic-impregnated (NAI) EVDs.
In vitro assays were performed using AI EVDs containing minocycline and rifampin (VentriClear II, Medtronic) and NAI EVD controls (Bioglide, Medtronic). The presence of antibiotics was evaluated via capillary electrophoresis of sterile saline drawn from AI and NAI EVDs after predefined incubation intervals. Antimicrobial activity was assessed by evaluating zones of inhibition created by the catheter aspirates on plates inoculated with a quality control strain of Staphylococcus epidermidis (American Type Culture Collection strain 12228). To determine the effects of cultures drawn through AI compared with NAI EVDs, the quality control strain was then incubated within 4 new AI and 4 new NAI EVDs for predefined intervals before being plated on culture media. Spread and streak plate culture results from each type of catheter were compared at each time interval.
Capillary electrophoresis showed that more minocycline than rifampin was eluted from the AI EVDs. Sterile saline samples incubated within the AI EVDs demonstrated zones of growth inhibition when placed on plates of S. epidermidis at all time intervals tested. No zones of inhibition were noted on NAI EVD control plates. When a standardized inoculum of S. epidermidis was drawn through AI and NAI EVDs, antimicrobial effects were observed after incubation in the AI EVD group only. Colony counting demonstrated that significantly fewer colonies resulted from samples drawn through AI compared with NAI EVDs at the multiple time intervals. Similarly, streak plating yielded a statistically significant number of false-negative results from AI compared with NAI EVDs at 2 time intervals.
The findings in the current study indicate that the risk of a false-negative culture result may be increased when a CSF sample is drawn through an AI catheter. In the management of a known shunt infection, a false-negative result from an EVD culture specimen may lead to an inappropriately short duration of antibiotic therapy. These data have significant clinical implications, particularly given the widespread use of AI drains and the current high rates of shunt reinfection after EVD use worldwide.
Daniel E. Couture, John C. Crantford, Aravind Somasundaram, Claire Sanger, Anne E. Argenta, and Lisa R. David
There has been a tremendous increase in the incidence of deformational plagiocephaly in children throughout the world. Therapeutic options include observation, active counterpositioning, external orthotics, and surgery. The current treatment in the US is highly debated, but it typically includes external orthotic helmets in patients with moderate to severe plagiocephaly presenting between 4 and 10 months of age or in children with significant comorbidities limiting passive (no-pressure) therapy. The present study was designed to evaluate 3 key issues: 1) the accuracy of the Argenta classification in defining a progressive degree of severity, 2) identification of an upper age limit when treatment is no longer effective, and 3) the effectiveness of an off-the-shelf prefabricated helmet in correcting deformational plagiocephaly.
An institutional review board–approved retrospective study was conducted of all patients at the authors' clinic in whom deformational plagiocephaly was assessed using the Argenta classification system over a 6-year period; the patients underwent helmet therapy, and a minimum of 3 clinic visits were recorded. Inclusion criteria consisted of an Argenta Type II–V plagiocephalic deformity. Patients' conditions were categorized both by severity of the deformity and by patients' age at presentation. Statistical analysis was conducted using survival analysis.
There were 1050 patients included in the study. Patients with Type III, IV, and V plagiocephaly required progressively longer for deformity correction to be achieved than patients with Type II plagiocephaly (53%, 75%, and 81% longer, respectively [p < 0.0001]). This finding verified that the Argenta stratification indicated a progressive severity of deformity. No statistically significant difference in the time to correction was noted among the different age categories, which suggests that the previously held upper time limit for correction may be inaccurate. An overall correction rate to Type I plagiocephaly of 81.6% was achieved irrespective of severity and degree of the original deformity. This suggests that an inexpensive off-the-shelf molding helmet is highly effective and that expensive custom-fitted orthoses may not be necessary. The patients in the older age group (> 12 months) did not have a statistically significant longer interval to correction than the patients in the youngest age group (< 3 months). The mean length of follow-up was 6.3 months.
Patients treated with passive helmet therapy in the older age group (> 12 months) had an improvement in skull shape within the same treatment interval as the patients in the younger age group (< 3 months). This study supports the use of passive helmet therapy for improvement in deformational plagiocephaly in infants from birth to 18 months of age and verifies the stratification of degree of deformity used in the Argenta classification system.
James L. West, Madison Arnel, Atilio E. Palma, John Frino, Alexander K. Powers, and Daniel E. Couture
Spine surgery is less common in children than adults. These surgeries, like all others, are subject to complications such as bleeding, infection, and CSF leak. The rate of incidental durotomy in the pediatric population, and its associated complications, has scarcely been reported in the literature.
This is a retrospective chart review of all pediatric patients operated on at Wake Forest Baptist Health from 2012 to 2017 who underwent spine surgeries. The authors excluded any procedures with intended durotomy, such as tethered cord release or spinal cord tumor resection.
From 2012 to 2017, 318 pediatric patients underwent surgery for a variety of indications, including adolescent idiopathic scoliosis (51.9%), neuromuscular scoliosis (27.4%), thoracolumbar fracture (2.83%), and other non–fusion-related indications (3.77%). Of these patients, the average age was 14.1 years, and 71.0% were female. There were 6 total incidental durotomies, resulting in an overall incidence of 1.9%. The incidence was 18.5% in revision operations, compared to 0.34% for index surgeries. Comparison of the revision cohort to the durotomy cohort revealed a trend toward increased length of stay, operative time, and blood loss; however, the trends were not statistically significant. The pedicle probe was implicated in 3 cases and the exact cause was not ascertained in the remaining 3 cases. The 3 durotomies caused by pedicle probe were treated with bone wax; 1 was treated with dry Gelfoam application and 2 were treated with primary repair. Only 1 patient had a persistent leak postoperatively that eventually required wound revision.
Incidental durotomy is an uncommon occurrence in the pediatric spinal surgery population. The majority occurred during placement of pedicle screws, and they were easily treated with bone wax at the time of surgery. Awareness of the incidence, predisposing factors, and treatment options is important in preventing complications and disability.
James L. West, Kyle M. Fargen, Wesley Hsu, Charles L. Branch Jr., and Daniel E. Couture
Global access to neurosurgical care is still a work in progress, with many patients in low-income countries not able to access potentially lifesaving neurosurgical procedures. “Big Data” is an increasingly popular data collection and analytical technique predicated on collecting large amounts of data across multiple data sources and types for future analysis. The potential applications of Big Data to global outreach neurosurgery are myriad: from assessing the overall burden of neurosurgical disease to planning cost-effective improvements in access to neurosurgical care, and collecting data on conditions which are rare in developed countries. Although some global neurosurgical outreach programs have intelligently implemented Big Data principles in their global neurosurgery initiatives already, there is still significant progress that remains to be made. Big Data has the potential to drive the efficient improvement of access to neurosurgical care across low- and medium-income countries.
William J. Triffo, J. Daniel Bourland, Daniel E. Couture, Kevin P. McMullen, Stephen B. Tatter, and Padraig P. Morris
Vein of Galen aneurysmal malformations (VGAMs) are uncommon congenital malformations arising from fistulous communication with the median vein of the prosencephalon, a primitive precursor of midline cerebral venous structures. Angiographic embolization is the primary modality for treatment given historically poor microsurgical outcomes. Only a few reports of treatment by Gamma Knife radiosurgery (GKRS) exist in the literature, and the results are variable. The authors present 2 cases of VGAM in which GKRS provided definitive treatment with good outcome: one case involving antenatal presentation of a high-output, mural-type VGAM with complex clinical course refractory to multiple embolic procedures, and the other a choroidal-type VGAM presenting with hemorrhage in an adult and without a feasible embolic approach. With discussion of these cases and review of the literature, the authors advocate inclusion of GKRS as a therapeutic option for treatment of these complex lesions.