Christopher M. Maulucci

Dynamics of subdural hygroma following decompressive craniectomy: a comparative study

OBJECT This retrospective comparative cohort study was aimed at discovering the risk factors associated with subdural hygroma (SDG) following decompressive craniectomy (DC) to relieve intracranial hypertension in severe head injury. METHODS Sixty-eight of 104 patients who had undergone DC during a 48-month period and survived > 30 days were eligible for this study. To assess the dynamics of subdural fluid collections, the authors compared CT scanning data from and the characteristics of 39 patients who had SDGs with the data in 29 patients who did not have hygromas. Variables significant in the appearance, evolution, and resolution of this complication were analyzed in a 36-week longitudinal study. RESULTS The earliest imaging evidence of SDG was seen during the 1st week after DC. The SDG volume peaked between Weeks 3 and 4 post-DC and was gradually resolved by the 17th week. Among the mechanisms of injury, motor vehicle accidents were most often linked to the development of an SDG after DC (p < 0.0007), and falls were least often associated (p < 0.005). Moreover, patients with diffuse brain injury were more prone to this complication (p < 0.0299) than those with an evacuated mass (p < 0.0001). There were no statistically significant differences between patients with and without hygromas in terms of age, sex, Glasgow Coma Scale score, intraventricular and subarachnoid hemorrhage, levels of intracranial pressure and cerebral perfusion pressure, timing of decompression, and the need for CSF diversion. More than 90% of the SDGs were ipsilateral to the side of the craniectomy, and 3 (8%) of 39 SDGs showed evidence of internal bleeding at approximately 8 weeks postinjury. Surgical evacuation was needed in 4 patients with SDGs. CONCLUSIONS High dynamic accidents and patients with diffuse injury were more prone to SDGs. Close to 8% of SDGs converted themselves into subdural hematomas at approximately 2 months postinjury. Although SDGs developed in 39 (approximately 60%) of 68 post-DC patients, surgical evacuation was needed in only 4.

Intraoperative Vancomycin Use in Spinal Surgery: Single Institution Experience and Microbial Trends.

Study Design. Retrospective case series. Objective. To demonstrate the microbial trends of spinal surgical site infections in patients who had previously received crystallized vancomycin in the operative bed. Summary of Background Data. Prior large, case control series demonstrate the significant decrease in surgical site infection with the administration of vancomycin in the wound bed. Methods. A single institution, electronic database search was conducted for all patients who underwent spinal surgery who had received prophylactic crystalline vancomycin powder in the wound bed. Patients with a prior history of wound infection, intrathecal pumps, or spinal stimulators were excluded. Results. A total of 981 consecutive patients (494 males, 487 females; mean age, 59.4 yr; range, 16–95 yr) were identified from January 2011 to June 2013. The average dose of vancomycin powder was 1.13 g (range, 1–6 g). Sixty-six patients (6.71%) were diagnosed with a surgical site infection, of which 51 patients had positive wound cultures (5.2%). Of the 51 positive cultures, the most common organism was Staphylococcus aureus. The average dose of vancomycin was 1.3 g in the 38 cases where a gram-positive organism was cultured. A number of gram-negative infections were encountered such as Serratia marcescens, Enterobacter aerogenes, Bacteroides fragilis, Enterobacter cloacae, Citrobacter koseri, and Pseudomonas aeruginosa. The average dose of vancomycin was 1.2 g in 23 cases where a gram-negative infection was cultured. Fifteen of the 51 positive cultures (29.4%) were polymicrobial. Eight (53%) of these 15 polymicrobial cultures contained 3 or more distinct organisms. Conclusion. Prophylactic intraoperative vancomycin use in the wound bed in spinal surgery may increase the incidence of gram-negative or polymicrobial spinal infections. The use of intraoperative vancomycin may correlate with postoperative seromas, due to the high incidence of nonpositive cultures. Large, randomized, prospective trials are needed to demonstrate causation and dose-response relationship. Level of Evidence: 4

Nasal MRSA colonization: Impact on surgical site infection following spine surgery

BACKGROUND Prior studies published in the cardiothoracic, orthopedic and gastrointestinal surgery have identified the importance of nasal (methicillin-resistant Staphylococcus aureus) MRSA screening and subsequent decolonization to reduce MRSA surgical site infection (SSI). This is the first study to date correlating nasal MRSA colonization with postoperative spinal MRSA SSI. OBJECTIVE To assess the significance of nasal MRSA colonization in the setting of MRSA SSI. METHODS A retrospective electronic chart review of patients from year 2011 to June 2013 was conducted for patients with both nasal MRSA colonization within 30 days prior to spinal surgery. Patients who tested positive for MRSA were put on contact isolation protocol. None of these patients received topical antibiotics for decolonization of nasal MRSA. RESULTS A total of 519 patients were identified; 384 negative (74%), 110 MSSA-positive (21.2%), and 25 (4.8%) MRSA-positive. Culture positive surgical site infection (SSI) was identified in 27 (5.2%) cases and was higher in MRSA-positive group than in MRSA-negative and MSSA-positive groups (12% vs. 5.73% vs. 1.82%; p=0.01). The MRSA SSI rate was 0.96% (n=5). MRSA SSI developed in 8% of the MRSA-positive group as compared to only in 0.61% of MRSA-negative group, with a calculated odds ratio of 14.23 (p=0.02). In the presence of SSI, nasal MRSA colonization was associated with MRSA-positive wound culture (66.67 vs. 12.5%; p<0.0001). CONCLUSION Preoperative nasal MRSA colonization is associated with postoperative spinal MRSA SSI. Preoperative screening and subsequent decolonization using topical antibiotics may help in decreasing the incidence of MRSA SSI after spine surgery. Nasal MRSA+ patients undergoing spinal surgery should be informed regarding their increased risk of developing surgical site infection.

Simulation Training Curricula for Neurosurgical Residents: Cervical Foraminotomy and Durotomy Repair Modules

INTRODUCTION Since 2010, the Congress of Neurological Surgeons (CNS) has offered a neurosurgical skills simulation course for residents and medical students. The authors describe their experience with incorporation of two neurosurgical skills simulation modules into the dedicated resident training curriculum of a single ACGME-accredited training program, using lumbar dural repair (5) and posterior cervical laminoforaminotomy modules from the CNS simulation initiative (6). METHODS Each of the available 22 neurosurgery residents at a single residency program was given two 20-question pretests for a cervical laminoforaminotomy and durotomy repair module as a basic test of regional anatomy, general disease knowledge, surgical decision making, and recently published literature. This was followed by a faculty-directed skills simulation course and concluded with a final 20 question post-test. RESULTS Posterior cervical laminoforaminotomy was performed once by each resident, and grading was conducted using the predetermined OSATs. The overall score was 56.1 (70%, range 26-76, maximum 80 points) with a trend towards higher scores with advanced levels of training. All residents completed the durotomy repair OSATs for a total of three trials. Of a maximum composite score of 60, a mean 37.2 (62%, range 15-58) was scored by the residents (Table 3). The mean OSAT scores for each durotomy trial was 2.66, 3.15, and 3.48 on each success test. A trend towards higher scores in advanced years of training was observed, but did not reach statistical significance (Figure 3). CONCLUSIONS Duty hour limitations and regulatory pressure for enhanced quality and outcomes may limit access of neurosurgical residents to fundamental skills training. Fundamental skills training as part of a validated simulation curriculum can mitigate this challenge to residency education. National development of effective technical simulation modules for use in individual residency training programs is a promising strategy to achieve these goals.

Timing in the surgical evacuation of spinal epidural abscesses.

OBJECT One often overlooked aspect of spinal epidural abscesses (SEAs) is the timing of surgical management. Limited evidence is available correlating earlier intervention with outcomes. Spinal epidural abscesses, once a rare diagnosis carrying a poor prognosis, are steadily becoming more common, with one recent inpatient meta-analysis citing an approximate incidence of 1 in 10,000 admissions with a mortality approaching 16%. One key issue of contention is the benefit of rapid surgical management of SEA to maximize outcomes. Timing of surgical management is definitely one overlooked aspect of care in spinal infections. Therefore, the authors performed a retrospective analysis in which they evaluated patients who underwent early (evacuation within 24 hours) versus delayed surgical intervention (> 24 hours) from the point of diagnosis, in an attempt to test the hypothesis that earlier surgery results in improved outcomes. METHODS A retrospective review of a prospectively maintained adult neurosurgical database from 2009 to 2011 was conducted for patients with the diagnostic heading: epidural abscess, infection, osteomyelitis, osteodiscitis, spondylodiscitis, and abscess. The primary end point for each patient was neurological grade, measured as an American Spinal Injury Association Impairment Scale grade using hospital inpatient records on admission and discharge. Patients were divided into early surgical (< 24 hours) and delayed surgical cohorts. RESULTS Eighty-seven consecutive patients were identified (25 females; mean age 55.5 years, age range 18-87 years). Fifty-four patients received surgery within 24 hours of admission (mean time from admission to incision, 11.2 hours), and 33 underwent surgery longer than 24 hours (mean 59 hours) after admission. Of the 54 patients undergoing early surgery 45 (85%) had a neurological deficit, whereas in the delayed surgical group 21 (64%) of 33 patients presented with a neurological deficit (p = 0.09). Patients in the delayed surgery cohort were significantly older by 10 years (59.6 vs 51.8 years, p = 0.01). With regard to history of prior revision, body mass index, intravenous drug abuse, tobacco use, prior radiation therapy, diabetes, chronic systemic infection, and prior osteomyelitis, there were no significant differences. There was no significant difference between early and delayed surgery groups in neurological grade on presentation, discharge, or location of epidural abscess. The most common organism isolated was Staphylococcus aureus (n = 51, 59.3%). The incidence of methicillin-resistant S. aureus was 21% (18 of 87). CONCLUSIONS Evacuation within 24 hours appeared to have a relative advantage over delayed surgery with regard to discharge neurological grade. However, due to a limited, variable sample size, a significant benefit could not be shown. Further subgroup analyses with larger populations are required.

Surgical management in 40 consecutive patients with cervical spinal epidural abscesses: shifting toward circumferential treatment.

Study Design. Retrospective database review of a prospectively maintained neurosurgical database. Objective. The surgical management of cervical spinal epidural abscesses (CSEA) is reviewed examining the shift from single to staged anteroposterior decompression and stabilization. Summary of Background Data. CSEA management is guided by small case series. Methods. A retrospective review from 1997 to 2011 was conducted for patients with the diagnostic headings: cervical epidural abscess, infection, osteomyelitis, osteodiscitis, spondylodiscitis, and abscess. Comorbidities, risk factors, surgical approach, neurologic grade, and outcomes were recorded. Results. Forty consecutive patients (mean age 53 years, age range 23–74, SD ±14, 10 female) were identified with CSEA in the operative database from 1997 to 2010. Twenty one patients had a body mass index more than 25 (53%), 6 (15%) had diabetes mellitus, 6 (15%) had a prior malignancy with 2 having prior neck irradiation, and 9 (23%) used tobacco products. The most common risk factor associated with CSEA was intravenous drug abuse, found in 10 patients (25%). The most common level of discitis involvement was C6–C7 in 12 (30%) followed by C5–C6 disc in 11 (28%) and least often at C1–C2 level in 2(5%) and C7–T1 in 2(5%). The most common neurologic grades at presentation were AIS D in 20 (50%) followed by AIS E in 9 (28%). All patients received magnetic resonance imaging identifying 17 (43%) with dorsal, 12 ventral (30%), and 11 circumferential epidural abscesses (28%). The majority of patients underwent anterior followed by posterior decompression and stabilization (n = 26, 65%); 8 (20%) underwent a ventral approach and six underwent a dorsal approach (15%). Fusion was achieved in 39 of 40 (97.5%) and not significantly influenced halo use in 10 patients. Conclusions. In this series, patients underwent acute evacuation and spinal cord decompression, and the shift toward staged treatment did not lead to an increased periprocedural complication rate. Level of Evidence: 3

Arachnoiditis ossificans: Clinical series and review of the literature

OBJECTIVE Ossification of the leptomeninges, or arachnoiditis ossificans (AO) of the spine resulting in neurologic decline is a rarely reported disease. To date, there are 72 cases in the literature. The natural history of the disease and the best management strategy for patients with this condition is unknown. A series of five cases is presented adding to the relative paucity of knowledge of this potentially debilitating disease. METHODS A retrospective review of five cases of patients with arachnoiditis ossificans from 2009 to 2013 was conducted. All cases were obtained from a single institution. The diagnosis was based upon computed tomography (CT) and magnetic resonance imaging (MRI) studies. RESULTS All five patients in the series were found have a history of prior spinal procedures. Three of the five patients had no history of intradural procedures or violation of the dura. Three of the patients underwent surgery to address neurologic deficits related to AO. Surgical intervention mainly consisted of decompression via laminectomy without resection of the intradural bony lesions. All patients improved neurologically postoperatively. CONCLUSIONS Arachnoiditis ossificans is a rare disease typically affecting the thoracolumbar spine. It may result in devastating neurological deficits. There is no consensus as to the appropriate treatment strategy and the surgical procedures can be technically demanding due to the tight adherence of the abnormal bone to neural structures. For those patients who exhibit no symptoms referable to the AO, close observation may be performed. However, once progressive neurologic deficits occur due to AO, decompression via laminectomy can be a successful strategy.

C7 intralaminar screw placement, an alternative to lateral mass or pedicle fixation for treatment of cervical spondylytic myelopathy, kyphotic deformity, and trauma: A case report and technical note.

Background: The authors present a case to illustrate the necessity and technical feasibility of C7 laminar screw placement for treatment of sub-axial cervical spondylitic myelopathy. The indications for C7 lateral mass screw placement was required internal fixation, with small lateral masses (8 mm) and pedicles (4 mm). Case Description: A 67-year-old female with compressive myelopathy after a fall from standing is presented. Magnetic resonance (MR) imaging of the cervical spine showed severe C3-6 spondylosis with canal and foraminal compromise. Computed tomography of the cervical spine confirmed the MR imaging findings as well as showed suboptimal lateral mass and pedicles for screw placement. The patient underwent a C3-6 laminectomy, C3-6 lateral mass, and C7 laminar screw placement. Postoperatively, the patient recovered without complication. Conclusion: Internal fixation of the cervical spine after iatrogenic destabilization by decompression of neural elements secondary to advanced spondylosis can be technically challenging. Anatomical landmarks needed for safe placement of lateral mass or pedicle instrumentation are often distorted by the patients’ advanced pathology or Inherent biology. The C7 screw is a key structural element to a long construct and therefore necessitates large lateral masses or pedicles to safely place a functional screw. C7 laminar screws may be placed safely without fluoroscopic guidance when sufficient C7 lateral mass or pedicle screws are not possible or with undue risk.

Efficacy of intraoperative vancomycin powder use in intrathecal baclofen pump implantation procedures: single institutional series in a high risk population.

We aimed to assess the efficacy of intraoperative vancomycin powder in intrathecal baclofen pump placement patients, a high risk population. A retrospective review was conducted using prospectively collected data at an academic tertiary care unit. The neurosurgical adult patient population was queried for all intrathecal baclofen pump implantation procedures. Patients were then reviewed for the use of intraoperative crystalline vancomycin powder. Those with a history of prior surgical site infection, chronic systemic infections or osteomyelitis were excluded. Anhydrous, crystalline vancomycin was utilized in the wound bed after completion of implantation, distributed evenly in the case of multiple incisions. Patients received 500 mg or 1,000 mg of crystallized vancomycin, evenly distributed through the wound layers based on a 70 kg weight cutoff. Intraoperative institutional standards of infection prophylaxis were unchanged throughout the study period. Infection rate of baclofen pump placement prior to the use of vancomycin powder from 2001-2009 at the same institution was monitored. Wound infection rate was tracked for a 12 month postoperative period. Six patients out of 26 baclofen pump implantations (23%) in this cohort were identified to have seven infections despite vancomycin powder placement in the lumbar and catheter wounds. Prior infection rates have been investigated for intrathecal drug delivery systems from 2001 to 2009 at the same institution with an overall infection rate of 3% (8/274). The use of vancomycin powder in patients with implants in this series did not reduce infection rates compared to published historical controls, and was elevated compared to institutional controls. Further prospective study of this high risk patient population is warranted.

Promising Advances in Targeted Cellular Based Therapies: Treatment Update in Spinal Cord Injury

Spinal Cord Injury (SCI) affects approximately 10,000 people per year in North America. Over the last twenty years, significant advances have been made in the understanding the pathophysiology of traumatic spinal cord injuries. In addition there have been concurrent advances in embryonic stem cells (ESCs) and the various pathways of their differentiation into neural stem cells (NSCs) and progenitors. It is hoped that these advancing fields can be merged. The administration of ESCs and NSC cells will reconstitute the architecture of the injured spinal cord as well as spinal cord tracts. Thus, this would result in improved anatomical recovery and plasticity allowing for improved neurologic function and locomotion. The authors provide a brief overview of recent publications to illustrate the various approaches to the treatment of SCI with cellular based therapies, including both pluripotent stem cells and neural-committed lineages. Considerable advances have been made in the field. While there is a growing body of laboratory evidence in the literature to support translating cellular therapies into the clinical setting, there are no definitive answers on the efficacy of cellular based therapies in the clinical setting. A variety of cellular therapies have been implemented in novel clinical trials including OECs, fetal-derived NSCs, and Schwann cells. Further refinement of these methods should be made in the future to limit patient morbidity.