Howard J. Silberstein

Revision rate of pediatric ventriculoperitoneal shunts after 15 years

OBJECT Ventriculoperitoneal (VP) shunt placement remains the mainstay treatment for pediatric hydrocephalus. These devices have a relatively high complication and failure rate, often requiring multiple revisions. The authors present a single institutions experience of pediatric patients treated with VP shunts. With an average follow-up time of 20 years, this study is among the longest reports of VP shunt revision in the literature to date. Hydrocephalus origins, shunt revision rates, and causes of shunt failure are described. Patients who underwent their first shunt revision more than 10 years after initial shunt placement were also explored. METHODS A retrospective chart review was performed on all pediatric patients who underwent VP shunt placement from January 1990 through November 1996 at the University of Rochester Medical Center. Only patients who had at least 15 years of follow-up since their initial shunting procedure were included. RESULTS A total of 234 procedures were performed on 64 patients, with a mean follow-up of 19.9 years. Patients ranged from a few days to 17.2 years old when they received their original shunt, with a median age of 4 months; 84.5% of the patients required 1 or more shunt revisions and 4.7% required 10 or more. Congenital defects, Chiari Type II malformations, tumors, and intraventricular hemorrhage were the most common causes of hydrocephalus. Overall, patients averaged 2.66 revisions, with proximal (27%) and distal (15%) catheter occlusion, disconnection (11%), and infection (9%) comprising the most common reasons for shunt malfunction. Notably, 12.5% of patients did not require their first shunt revision until more than 10 years after initial device placement, a previously undescribed finding due to the short follow-up duration in previous studies. CONCLUSIONS This long-term retrospective analysis of pediatric VP shunt placement revealed a relatively high rate of complications with need for shunt revision as late as 17 years after initial placement. Catheter occlusion represented a significant percentage of shunt failures. Cerebrospinal fluid shunting has a propensity for mechanical failure and patients with VP shunts should receive follow-up through the transition to adulthood.

Prenatal diagnosis of terminal myelocystocele in the fetal surgery era: Case report

OBJECTIVE AND IMPORTANCE We report a case of a child with terminal myelocystocele (TMC). This case exemplifies the importance of performing a multidisciplinary evaluation and magnetic resonance imaging in the patient with suspected meningomyelocele when fetal surgery is being considered. CLINICAL PRESENTATION This patient was evaluated at the Center for Fetal Diagnosis and Treatment and considered for fetal surgery to repair meningomyelocele. TECHNIQUE A follow-up based on both ultrasound and magnetic resonance imaging was performed throughout pregnancy. CONCLUSION Although a definitive diagnosis of TMC was not established prenatally, the patient was not offered fetal surgery, based on multiple selection criteria. We correlate the pathophysiology of TMC with the radiographic and amniocentesis findings. TMC must be considered in the differential diagnosis in a fetus with a dysraphic defect.

Meningioma: The role of a foreign body and irradiation in tumor formation

A case of meningioma is reported. At the age of 18 years, the patient had undergone insertion of a Torkildsen shunt through a posteroparietal burr hole for obstructive hydrocephalus secondary to a tumor of the pineal region, of which no biopsy had been made. After the hydrocephalus was relieved, he underwent irradiation of the tumor. Thirty years later, he was treated for an intracranial meningioma wrapped around the shunt. The tumor followed the shunt in all of its intracranial course. Microscopy disclosed pieces of the shunt tube within the meningioma. The role of a foreign body and irradiation in the induction of meningiomas is discussed, and a comprehensive review of the literature is presented.

Risk factors associated with venous thromboembolism in patients undergoing spine surgery

OBJECTIVE Patients undergoing spinal surgery are at risk for developing venous thromboembolism (VTE). The authors sought to identify risk factors for VTE in these patients. METHODS The American College of Surgeons National Surgical Quality Improvement Project database for the years 2006-2010 was reviewed for patients who had undergone spinal surgery according to their primary Current Procedural Terminology code(s). Clinical factors were analyzed to identify associations with VTE. RESULTS Patients who underwent spinal surgery (n = 22,434) were identified. The rate of VTE in the cohort was 1.1% (pulmonary embolism 0.4%; deep vein thrombosis 0.8%). Multivariate binary logistic regression analysis revealed 13 factors associated with VTE. Preoperative factors included dependent functional status, paraplegia, quadriplegia, disseminated cancer, inpatient status, hypertension, history of transient ischemic attack, sepsis, and African American race. Operative factors included surgery duration > 4 hours, emergency presentation, and American Society of Anesthesiologists Class III-V, whereas postoperative sepsis was the only significant postoperative factor. A risk score was developed based on the number of factors present in each patient. Patients with a score of ≥ 7 had a 100-fold increased risk of developing VTE over patients with a score of 0. The receiver-operating-characteristic curve of the risk score generated an area under the curve of 0.756 (95% CI 0.726-0.787). CONCLUSIONS A risk score based on race, preoperative comorbidities, and operative characteristics of patients undergoing spinal surgery predicts the postoperative VTE rate. Many of these risks can be identified before surgery. Future protocols should focus on VTE prevention in patients who are predisposed to it.

Case 163: Solitary Neurocysticercosis

While a parenchymal cysticercal lesion in the brain may cause a diagnostic dilemma, radiologic features correlate with pathologic findings and can aid in the diagnosis of solitary cerebral neurocysticercosis.

Aneurysmal bone cyst: surgical management in the pediatric cervical spine.

Study Design Case report. Objective To present 2 cases of aneurysmal bone cyst in the cervical spine of children who were aggressively treated with resection, fusion, and stabilization with hardware to achieve complete cure and future stability. Summary of Background Data Aneurysmal bone cyst is a rapidly expanding and destructive bone lesion of unknown etiology. Current approaches to treatment include surgical en bloc excision, complete curettage, selective arterial embolization, radiotherapy, and intralesional injection with a sclerosing agent. Fusion and stabilization with instrumentation have often been avoided in children due to concerns over instability following future axial skeleton growth. Methods The authors present 2 case reports of aneurysmal bone cyst in the cervical spine of children, both demonstrating deeply involved lesions with extensive bone destruction. Both were treated aggressively with resection, fusion, and stabilization with instrumentation. Additionally, the relevant background literature is briefly discussed. Results Both patients had an uncomplicated postoperative course. At 36- and 18-month follow-up, both patients have no cervical spine instability or recurrence of tumor. Conclusion Treatment of aneurysmal bone cyst in the cervical spine is challenging when it occurs in close proximity to neural and vascular structures. Future stability of the cervical spine is a concern, especially when there is significant involvement of the vertebral body and posterior elements. At 36- and 18-month follow-up, the surgical approach to aneurysmal bone cyst presented here provided these patients with complete curative treatment and preservation of cervical spine stability.

Risk Modeling Predicts Complication Rates for Spinal Surgery.

Study Design. Retrospective review of clinical data registry. Objective. In the current era of quality reporting and pay for performance, neurosurgeons must develop models to identify patients at high risk of complications. We sought to identify risk factors for complications in spine surgery and to develop a score predictive of complications. Summary of Background Data. We examined spinal surgeries from the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) database. 22,430 cases were identified based on common procedural terminology. Methods. Univariate analysis followed by multivariate regression was used to identify significant factors. Results. The overall complication rate for the cohort was 9.9%. The most common complications were postoperative bleeding requiring transfusion (4.1%), nonwound infections (3.1%), and wound-related infections (2.2%). Multivariate regression analysis identified 20 factors associated with complications. Assigning 1 point for the presence of each factor a risk model was developed. The range of scores for the cohort was 0 to 13 with a median score of 4. Complication rates for a risk score of 0 to 4 was 3.7% and for scores 5 to 13 was 18.5%. The risk model robustly predicted complication rates, with complication rate of 1.2% for score of 0 (n = 412, 1.8% of total) and 63.6% and 100% for scores of 12 and 13 (n = 22 patients, 0.1% of total cohort) respectively (P < 0.001). The risk score also correlated strongly with total length of stay, mortality, and total work relative value units for the case. Conclusion. Patient-specific risk factors including comorbidities are strongly associated with surgical complications, length of stay, cost of care, and mortality in spine surgery and can be used to develop risk models that are highly predictive of complications. Level of Evidence: 3

Cervical Laminoplasty as a Management Option for Patients With Cervical Spondylotic Myelopathy: A Series of 40 Patients

BACKGROUNDCervical spondylotic myelopathy (CSM) is one of the leading causes of spinal cord dysfunction in the adult population. Laminoplasty is an effective decompressive procedure for the treatment of CSM. OBJECTIVEWe present our experience with 40 patients who underwent cervical laminoplasty using titanium miniplates for CSM. METHODSWe performed a retrospective review of the medical records of a consecutive series of patients with CSM treated with laminoplasty at the University of Rochester Medical Center or Rochester General Hospital. We documented patient demographic data, presenting symptoms, and postoperative outcome. Data are also presented regarding the general cost of constructs for a hypothetical 3-level fusion. RESULTSForty patients underwent cervical laminoplasty; all were available for follow-up. The mean number of levels was 4. All patients were myelopathic, and 17 (42.5%) had signs of radiculopathy preoperatively. Preoperatively, 62.5% of patients had a Nurick grade of 2 or worse. The average follow-up was 31.3 months. The median length of stay was 48 hours. On clinical evaluation, 36 of 40 patients demonstrated an improvement in their myelopathic symptoms; 4 were unchanged. Postoperative kyphosis did not develop in any patients. CONCLUSIONThe management of CSM for each of its etiologies remains controversial. As demonstrated in our series, laminoplasty is a cost-effective, decompressive procedure for the treatment of CSM, providing a less destabilizing alternative to laminectomy while preserving mobility. Cervical laminoplasty should be considered in the management of multilevel spondylosis because of its ease of exposure, ability to decompress, effective preservation of motion, maintenance of spinal stability, and overall cost.

Delayed sub-aponeurotic fluid collections in infancy: Three cases and a review of the literature

Background: Sub-aponeurotic fluid collections (SFCs) in the neonatal period are poorly described in the literature. We describe the occurrence, possible etiologies and treatment of sub-aponeurotic fluid collections following the neonatal period. Case Description: We present 3 cases of previously healthy children who developed soft, fluctuant, extracranial masses several weeks after birth. All 3 children were seen by a pediatric neurosurgeon after parents noticed scalp masses between 5 and 9 weeks of age. All 3 children were found to be otherwise healthy. Two of the children were born via C-section and 1 child was born vaginally. The vaginal delivery was described as difficult and utilized vacuum assist. Scalp electrodes were placed in all 3 children for intensive monitoring during labor. These children received plain skull x-rays to assess for abnormalities, and 2 of the children underwent a non-contrast brain CT scan to better characterize the fluid collection. Plain x-rays and CT scans showed no abnormalities of the skull or ventricles. In both patients who underwent a CT scan, a soft tissue prominence was noted with a Hounsfield unit similar to water. All cases resolved between 5 and 9 weeks after initial presentation, with no long-term sequelae. Conclusion: SFCs presenting after the neonatal period are usually associated with benign soft tissue swellings. Use of fetal scalp electrodes has been shown to cause cerebrospinal fluid (CSF) leakage in the neonatal period and may result in delayed SFC. This condition is benign, and the recommended course of treatment is conservative management.

Indications for Pediatric External Ventricular Drain Placement and Risk Factors for Conversion to a Ventriculoperitoneal Shunt

Background/Aims: The external ventricular drain (EVD) is commonly used for the treatment of hydrocephalus and intracranial pressure (ICP) monitoring. In this study, we retrospectively reviewed indications for EVD placement over the last 20 years in pediatric patients at our institution. Additionally, we evaluated the rate that an EVD needed to be converted to a ventriculoperitoneal shunt (VPS) and ascertained how hydrocephalus etiology impacted long-term drainage requirements. Methods: Patients that received an EVD between 1990 and 2010 at our institution were identified using billing codes. Demographics, etiology of hydrocephalus, length of stay (LOS) and EVD duration were recorded. Only patients receiving their first EVD were included; those with any prior ventricular catheter (including prior shunts) were excluded from this study. Results: A total of 180 patients underwent first-time placement of an EVD over the 20-year period. Of these, 78.9% were placed on the right side and 81.7% were performed through a frontal burr hole site. The average age of all patients at their initial procedure was 9.3 years (median 9.8; range 0-18), hospital LOS was 22.5 days (median 16; range 1-174) and EVD duration was 7.8 days (median 7; range 1-37). Trauma (43.3%) and neoplasms (32.2%) were the most common indications. Approximately, one quarter of the patients were unable to become EVD independent and, therefore, required a VPS. Only patients receiving an EVD for traumatic brain injury were significantly less likely to be converted to a shunt than other causes of hydrocephalus (relative risk, RR = 0.18, 95% confidence interval, CI = 0.07-0.46). Conversely, patients with neoplasms (RR = 3.56, 95% CI = 1.74-7.31), obstructive hydrocephalus (RR = 5.48, 95% CI = 1.37-22.0) and intraventricular hemorrhage (RR = 9.86, 95% CI = 1.05-92.3) were more likely to need a shunt. Conclusion: Traumatic brain injuries and neoplasms represent the most common indications for EVD placement in the pediatric population. While patients with neoplasm were much more likely to need conversion to a VPS for long-term cerebrospinal fluid diversion, the majority of EVDs in patients with head injuries were successfully weaned.