Heterotopic bone formation within the spinal canal is a known complication of bone morphogenetic protein–2 (BMP-2) and presents a clinical and surgical challenge. Imaging modalities are routinely used for operative planning in this setting. Here, the authors present the case of a 59-year-old woman with cauda equina syndrome following intraoperative BMP-2 administration. Plain film myelographic studies showed a region of severe stenosis that was underappreciated on CT myelography due to a heterotopic bony lesion mimicking the dorsal aspect of a circumferentially patent thecal sac. When evaluating spinal stenosis under these circumstances, it is important to carefully consider plain myelographic images in addition to postmyelography CT images as the latter may underestimate the true degree of stenosis due to the potentially similar radiographic appearances of evolving BMP-2–induced heterotopic bone and intrathecal contrast. Alternatively, comparison of sequentially acquired noncontrast CT scans with CT myelographic images may also assist in distinguishing BMP-2–induced heterotopic bony lesions from the thecal sac. Further studies are needed to elucidate the roles of the available imaging techniques in this setting and to characterize the connection between the radiographic and histological appearances of BMP-2–induced heterotopic bone.
Timothy Chryssikos, Kenneth M. Crandall and Charles A. Sansur
Kenneth M. Crandall, Esperanza Pacheco-Jacome and David I. Sandberg
✓ The authors report the case of a 3-year-old boy who presented with neck pain after falling from a low height and who was discharged from the emergency department after imaging studies were noted to be normal. He presented again 2 months later with continued neck pain, and repeated imaging demonstrated a fracture of the odontoid basilar synchondrosis that had not been shown on the initial studies. Based on the normal alignment of his spine and evidence of early bone fusion at the time of his second presentation, he underwent cervical orthosis therapy only. To the authors' knowledge, this is the first reported case of an odontoid synchondrosis fracture in which computed tomography scans were normal at presentation.
George M. Ghobrial, Kenneth M. Crandall, Anthony Lau, Seth K. Williams and Allan D. Levi
The objective of this study was to describe the use of a minimally invasive surgical treatment of lumbar spondylolysis in athletes by a fluoroscopically guided direct pars screw placement with recombinant human bone morphogenetic protein–2 (rhBMP-2) and to report on clinical and radiographic outcomes.
A retrospective review was conducted of all patients treated surgically for lumbar spondylolysis via a minimally invasive direct pars repair with cannulated screws. Demographic information, clinical features of presentation, perioperative and intraoperative radiographic imaging, and postoperative data were collected. A 1-cm midline incision was performed for the placement of bilateral pars screws utilizing biplanar fluoroscopy, followed by placement of a fully threaded 4.0-mm-diameter titanium cannulated screw. A tubular table-mounted retractor was utilized for direct pars fracture visualization and debridement through a separate incision. The now-visualized pars fracture could then be decorticated, with care taken not to damage the titanium screw when using a high-speed drill. Local bone obtained from the curettage was then placed in the defect with 1.05 mg rhBMP-2 divided equally between the bilateral pars defects.
Nine patients were identified (mean age 17.7 ± 3.42 years, range 14–25 years; 6 male and 3 female). All patients had bilateral pars fractures of L-4 (n = 4) or L-5 (n = 5). The mean duration of preoperative symptoms was 17.22 ± 13.2 months (range 9–48 months). The mean operative duration was 189 ± 29 minutes (range 151–228 minutes). The mean intraoperative blood loss was 17.5 ± 10 ml (range 10–30 ml). Radiographic follow-up was available in all cases; the mean length of time from surgery to the most recent imaging study was 30.8 ± 23.3 months (range 3–59 months). The mean hospital length of stay was 1.13 ± 0.35 days (range 1–2 days). There were no intraoperative complications.
Lumbar spondylolysis treatment with a minimally invasive direct pars repair is a safe and technically feasible option that minimizes muscle and soft-tissue dissection, which may particularly benefit adolescent patients with a desire to return to a high level of physical activity.
Gabriella M. Paisan, Kenneth M. Crandall, Stephanie Chen, S. Shelby Burks, Laurence R. Sands and Allan D. Levi
Anterior sacral meningoceles (ASMs) are rare lesions often associated with connective tissue disorders. These lesions are typically treated posteriorly via closure of the dural stalk. However, given their insidious nature, ASMs can be quite large on presentation, and this approach may not provide adequate decompression. In this case report, the authors describe the successful treatment of a large ASM through drainage and watertight closure of the cyst with an omental flap.
A 43-year-old woman with a history of Marfan syndrome and a large ASM was referred for neurosurgical intervention. The ASM was filling the pelvic cavity and causing severe compression of the bladder. The patient underwent surgical decompression of the cyst through an anterior transabdominal approach and closure of the fistulous tract with a pedicled omental flap. This is the first reported case of successful closure of an ASM with an omental flap. At the 6-month follow-up, the ASM had not recurred on imaging and the patient’s symptoms had resolved.
Anterior sacral meningoceles are rare lesions that often require neurosurgical intervention. Although most can be treated posteriorly, large ASMs compressing the abdominal or pelvic organs may require a transabdominal approach. Moreover, ASMs with wide dural stalks may benefit from closure with an omental flap.
David I. Sandberg, Kenneth M. Crandall, Carol K. Petito, Kyle R. Padgett, John Landrum, Darwin Babino, Danshe He, Juan Solano, Manuel Gonzalez-Brito and John W. Kuluz
The authors hypothesized that chemotherapy infusions directly into the fourth ventricle may potentially play a role in treating malignant posterior fossa tumors. In this study the safety and pharmacokinetics of etoposide administration into the fourth ventricle was tested using an indwelling catheter in piglets.
A closed-tip silicone lumbar drain catheter was inserted into the fourth ventricle via a posterior fossa craniectomy and 5 daily infusions of etoposide (0.5 mg in 5 animals) or normal saline (in 2 animals) were instilled. Piglets (10–18 kg, 2–3 months of age) underwent daily neurological examinations and 4.7-T magnetic resonance (MR) imaging after the final infusion and were then killed for postmortem examination. Pharmacokinetics were studied using reversed-phase high-performance liquid chromatography on cerebrospinal fluid (CSF) samples at 0.25, 1, 2, 4, 8, 12, and 24 hours after etoposide infusion. Peak and trough CSF etoposide levels were measured for each subsequent infusion. Serum etoposide levels were obtained at 2 and 4 hours after infusion.
All piglets remained neurologically intact, and MR images demonstrated catheter placement within the fourth ventricle without signal changes in the brainstem or cerebellum. Serum etoposide was absent at 2 and 4 hours after intraventricular infusions. When adequate samples could be obtained for analysis, CSF etoposide levels peaked 15 minutes after infusion and progressively decreased. Cytotoxic levels (> 0.1 μg/ml) were maintained for 5 consecutive peak and trough measurements with 1 exception. Etoposide-related neuropathology included moderate-to-severe T-lymphocytic meningitis and fourth and lateral ventricular choroid plexitis with associated subependymal inflammation.
Etoposide can be infused directly into the fourth ventricle without clinical or imaging evidence of damage. Cytotoxic CSF etoposide levels can be maintained for 24 hours with a single daily infusion into the fourth ventricle using an indwelling catheter. Intraventricular etoposide elicits an inflammatory response, the long-term effects of which are as yet undetermined.
George M. Ghobrial, Michael Y. Wang, Barth A. Green, Howard B. Levene, Glen Manzano, Steven Vanni, Robert M. Starke, George Jimsheleishvili, Kenneth M. Crandall, Marina Dididze and Allan D. Levi
The aim of this study was to determine the efficacy of 2 common preoperative surgical skin antiseptic agents, ChloraPrep and Betadine, in the reduction of postoperative surgical site infection (SSI) in spinal surgery procedures.
Two preoperative surgical skin antiseptic agents—ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol) and Betadine (7.5% povidone-iodine solution)—were prospectively compared across 2 consecutive time periods for all consecutive adult neurosurgical spine patients. The primary end point was the incidence of SSI.
A total of 6959 consecutive spinal surgery patients were identified from July 1, 2011, through August 31, 2015, with 4495 (64.6%) and 2464 (35.4%) patients treated at facilities 1 and 2, respectively. Sixty-nine (0.992%) SSIs were observed. There was no significant difference in the incidence of infection between patients prepared with Betadine (33 [1.036%] of 3185) and those prepared with ChloraPrep (36 [0.954%] of 3774; p = 0.728). Neither was there a significant difference in the incidence of infection in the patients treated at facility 1 (52 [1.157%] of 4495) versus facility 2 (17 [0.690%] of 2464; p = 0.06). Among the patients with SSI, the most common indication was degenerative disease (48 [69.6%] of 69). Fifty-one (74%) patients with SSI had undergone instrumented fusions in the index operation, and 38 (55%) patients with SSI had undergone revision surgeries. The incidence of SSI for minimally invasive and open surgery was 0.226% (2 of 885 cases) and 1.103% (67 of 6074 cases), respectively.
The choice of either ChloraPrep or Betadine for preoperative skin antisepsis in spinal surgery had no significant impact on the incidence of postoperative SSI.