Faris Shweikeh

Near-infrared imaging of brain tumors using the Tumor Paint BLZ-100 to achieve near-complete resection of brain tumors.

OBJECTnThe intraoperative clear delineation between brain tumor and normal tissue in real time is required to ensure near-complete resection without damaging the nearby eloquent brain. Tumor Paint BLZ-100, a tumor ligand chlorotoxin (CTX) conjugated to indocyanine green (ICG), has shown potential to be a targeted contrast agent. There are many infrared imaging systems in use, but they are not optimized to the low concentration and amount of ICG. The authors present a novel proof-of-concept near-infrared (NIR) imaging system using a standard charge-coupled device (CCD) camera for visualizing low levels of ICG attached to the tumors. This system is small, inexpensive, and sensitive. The imaging system uses a narrow-band laser at 785 nm and a notch filter in front of the sensor at the band. The camera is a 2-CCD camera, which uses identical CCDs for both visible and NIR light.nnnMETHODSnThe NIR system is tested with serial dilution of BLZ-100 from 1 μM to 50 pM in 5% Intralipid solution while the excitation energy is varied from 5 to 40 mW/cm(2). The analog gain of the CCD was changed from 0, 6, and 12 dB to determine the signal-to-noise ratio. In addition to the Intralipid solution, BLZ-100 was injected 48 hours before euthanizing the mice that were implanted with the human glioma cell line. The brain was removed and imaged using the NIR imaging system.nnnRESULTSnThe authors results show that the NIR imaging system using a standard CCD is able to visualize the ICG down to 50 nM of concentration with a high signal-to-noise ratio. The preliminary experiment on human glioma implanted in mouse brains demonstrated that BLZ-100 has a high affinity for glioma compared with normal brain tissue. Additionally, the results show that NIR excitation is able to penetrate deeply and has a potential to visualize metastatic lesions that are separate from the main tumor.nnnCONCLUSIONSnThe authors have seen that BLZ-100 has a very high affinity toward human gliomas. They also describe a small, cost-effective, and sensitive NIR system for visualizing brain tumors tagged using BLZ-100. The authors hope that the use of BLZ-100 along with NIR imaging will be useful to delineate the brain tumors in real time and assist surgeons in near-complete tumor removal to increase survival and reduce neurological deficits.

Clinical and radiographic outcomes of minimally invasive percutaneous pedicle screw placement with intraoperative CT (O-arm) image guidance navigation

OBJECTnIntraoperative CT image-guided navigation (IGN) has been increasingly incorporated into minimally invasive spine surgery (MIS). The vast improvement in image resolution and virtual real-time images with CT-IGN has proven superiority over traditional fluoroscopic techniques. The authors describe their perioperative MIS technique using the O-arm with navigation, and they report their postoperative experience, accuracy results, and technical aspects.nnnMETHODSnA retrospective review of 48 consecutive adult patients undergoing minimally invasive percutaneous posterior spinal fusion with intraoperative CT-IGN between July 2010 and August 2013 at Cedars-Sinai Medical Center was performed. Two surgeons assessed 290 screws in a blinded fashion on intraoperative O-arm images and postoperative CT scans for bony pedicle wall breach. Grade 1 breach was defined to be < 2 mm, Grade 2 breach to be between 2 and 4 mm, and a Grade 3 breach to be > 4 mm. Additionally, anterior vertebral body breach was recorded.nnnRESULTSnOf 290 pedicle screws placed, 280 (96.6%) were in an acceptable position without cortical wall or anterior breach. Of the 10 breaches (3.4%) 5 were lateral (50%), 4 were medial, and 1 was anterior; 90% of breaches were Grade 1-2 and all medial breaches were Grade 1. The one Grade 3 breach was lateral. No vascular or neurological complications were observed intraoperatively, and no significant postoperative complications were noted. The mean clinical follow-up period was 18 months (range 3-39 months). The overall clinical outcomes, measured using the visual analog scale (back pain scores), were improved significantly postoperatively at 3 months compared with preoperatively (visual analog score 6.35 vs 3.57; p < 0.0001). No revision surgery was performed for screw misplacement or neurological deterioration.nnnCONCLUSIONSnNew CT-IGN with the mobile O-arm scanner has increased the accuracy of pedicle screw/instrumentation placement using MIS techniques. The authors high (96.6%) accuracy rate in MIS compares favorably with historical published accuracy rates for fluoroscopy-based techniques. Additional advantages of CT-IGN over fluoroscopic imaging methods are lower occupational radiation exposure for the surgical team, reduced need for postoperative imaging, and decreased rates of revision surgery. For now, the authors simply conclude that use of intraoperative CT-IGN is safe and accurate.

Brain Metastasis in Bone and Soft Tissue Cancers: A Review of Incidence, Interventions, and Outcomes

Bone and soft tissue malignancies account for a small portion of brain metastases. In this review, we characterize their incidence, treatments, and prognosis. Most of the data in the literature is based on case reports and small case series. Less than 5% of brain metastases are from bone and soft tissue sarcomas, occurring most commonly in Ewings sarcoma, malignant fibrous tumors, and osteosarcoma. Mean interval from initial cancer diagnosis to brain metastasis is in the range of 20–30 months, with most being detected before 24 months (osteosarcoma, Ewing sarcoma, chordoma, angiosarcoma, and rhabdomyosarcoma), some at 24–36 months (malignant fibrous tumors, malignant peripheral nerve sheath tumors, and alveolar soft part sarcoma), and a few after 36 months (chondrosarcoma and liposarcoma). Overall mean survival ranges between 7 and 16 months, with the majority surviving < 12 months (Ewings sarcoma, liposarcoma, malignant fibrous tumors, malignant peripheral nerve sheath tumors, angiosarcoma and chordomas). Management is heterogeneous involving surgery, radiosurgery, radiotherapy, and chemotherapy. While a survival advantage may exist for those given aggressive treatment involving surgical resection, such patients tended to have a favorable preoperative performance status and minimal systemic disease.

National Trends, Complications, and Hospital Charges in Pediatric Patients with Chiari Malformation Type I Treated with Posterior Fossa Decompression with and without Duraplasty

Background: The treatment of type 1 Chiari malformation (CM-1) with posterior fossa decompression without (PFD) or with duraplasty (PFDD) is controversial. The authors analyze both options in a national sample of pediatric patients. Methods: Utilizing the Kids Inpatient Database, CM-1 patients undergoing PFD or PFDD from 2000 through 2009 were analyzed. Results: 1,593 patients with PFD and 1,056 with PFDD were evaluated. The average age was 10.3 years, slightly younger in PFD (9.8 vs. 10.9 years, p = 0.001). PFDD patients were more likely White (81.2 vs 75.6%, p = 0.04) and less likely admitted emergently (8.4 vs. 13.8%, p = 0.007). They also underwent more reoperations (2.1 vs. 0.7%, p = 0.01), had more procedure-related complications (2.3 vs. 0.8%, p = 0.003), a longer length of stay (4.4 vs. 3.8 days, p = 0.001) and higher charges (USD 35,321 vs. 31,483, p = 0.01). Conclusions: This large national study indicates that PFDD is performed more often in Caucasians, less so emergently, and associated with significantly more complications and immediate reoperations, while PFD is more frequent in those with syringomyelia and more economical, requiring fewer hospital resources. Overall, PFD is more favorable for CM-1, though it would be prudent to conduct a prospective trial, as this analysis is limited by data on preoperative presentations and long-term outcomes.

Robotics and the spine: a review of current and ongoing applications

OBJECTnRobotics in the operating room has shown great use and versatility in multiple surgical fields. Robot-assisted spine surgery has gained significant favor over its relatively short existence, due to its intuitive promise of higher surgical accuracy and better outcomes with fewer complications. Here, the authors analyze the existing literature on this growing technology in the era of minimally invasive spine surgery.nnnMETHODSnIn an attempt to provide the most recent, up-to-date review of the current literature on robotic spine surgery, a search of the existing literature was conducted to obtain all relevant studies on robotics as it relates to its application in spine surgery and other interventions.nnnRESULTSnIn all, 45 articles were included in the analysis. The authors discuss the current status of this technology and its potential in multiple arenas of spinal interventions, mainly spine surgery and spine biomechanics testing.nnnCONCLUSIONSnThere are numerous potential advantages and limitations to robotic spine surgery, as suggested in published case reports and in retrospective and prospective studies. Randomized controlled trials are few in number and show conflicting results regarding accuracy. The present limitations may be surmountable with future technological improvements, greater surgeon experience, reduced cost, improved operating room dynamics, and more training of surgical team members. Given the promise of robotics for improvements in spine surgery and spine biomechanics testing, more studies are needed to further explore the applicability of this technology in the spinal operating room. Due to the significant cost of the robotic equipment, studies are needed to substantiate that the increased equipment costs will result in significant benefits that will justify the expense.

Instrumenting the small thoracic pedicle: the role of intraoperative computed tomography image-guided surgery.

OBJECTnTraditionally, instrumentation of thoracic pedicles has been more difficult because of their relatively smaller size. Thoracic pedicles are at risk for violation during surgical instrumentation, as is commonly seen in patients with scoliosis and in women. The laterally based in-out-in approach, which technically results in a lateral breach, is sometimes used in small pedicles to decrease the comparative risk of a medial breach with neurological involvement. In this study the authors evaluated the role of CT image-guided surgery in navigating screws in small thoracic pedicles.nnnMETHODSnThoracic (T1-12) pedicle screw placements using the O-arm imaging system (Medtronic Inc.) were evaluated for accuracy with preoperative and postoperative CT. Small pedicles were defined as those ≤ 3 mm in the narrowest diameter orthogonal to the long axis of the pedicle on a trajectory entering the vertebral body on preinstrumentation CT. A subset of very small pedicles (≤ 2 mm in the narrowest diameter, 13 pedicles) was also analyzed. Screw accuracy was categorized as good (< 1 mm of pedicle breach in any direction or in-out-in screws), fair (1-3 mm of breach), or poor (> 3 mm of breach).nnnRESULTSnTwenty-one consecutive patients (age range 32-71 years) had large (45 screws) and small (52 screws) thoracic pedicles. The median pedicle diameter was 2.5 mm (range 0.9-3 mm) for small and 3.9 mm (3.1-6.7 mm) for large pedicles. Computed tomography-guided surgical navigation led to accurate screw placement in both small (good 100%, fair 0%, poor 0%) and large (good 96.6%, fair 0%, poor 3.4%) pedicles. Good screw placement in very small or small pedicles occurred with an in-out-in trajectory more often than in large pedicles (large 6.8% vs small 36.5%, p < 0.0005; vs very small 69.2%, p < 0.0001). There were no medial breaches even though 75 of the 97 screws were placed in postmenopausal women, traditionally at higher risk for osteoporosis.nnnCONCLUSIONSnComputed tomography-guided surgical navigation allows for safe, effective, and accurate instrumentation of small (≤ 3 mm) to very small (≤ 2 mm) thoracic pedicles.

Disparities in clinical and economic outcomes in children and adolescents following surgery for tethered cord syndrome in the United States

OBJECTnTethered cord syndrome (TCS) is a common spinal abnormality. In this study, the authors analyzed demographics, complications, and outcomes in children and adolescents who underwent surgery for TCS.nnnMETHODSnUsing the national Kids Inpatient Database (KID), the authors retrospectively identified patients with a primary diagnosis of TCS who were treated with spinal laminectomy and discharged in 2000, 2003, 2006, and 2009. Descriptive analysis was provided for patient- and hospital-level characteristics. Mortality, complications, non-routine discharges, in-hospital length of stay (LOS), and total charges were documented for the entire cohort and age-specific cohorts (0-5, 6-10, 11-15, and 16-20 years). Comparisons by complications and age groups were conducted.nnnRESULTSnA total of 7397 children and adolescents met the criteria in the 4 studied years. The mean age was 5.7 years; 55.3% of patients were younger than 5 years, 21.5% were 6-10 years, and 16.2% were 11-15 years. Most surgeries were performed in patients who were female (55.0%) and white (64.4%) and were performed at large (49.8%), teaching (94.2%), and urban (99.1%) childrens (89.3%) hospitals. The trend showed an increase in prevalence from 2000 (19.9%) to 2009 (29.6%). Common comorbidities included anomalies in spinal curvature (16.7%), urinary or bladder dysfunction (14.3%), and spinal stenosis/spondylosis (1.4%). Non-routine discharges (3.3%) were significantly higher with advancing age, increasing from 2.2% in those younger than 5 years to 9.0% in those older than 15 years (p < 0.0001). There was a similar increasing trend for complications (6.8% to 13.9%, respectively, p < 0.0001) and average LOS (3.5 to 5.1 days, respectively, p < 0.0001). Hospital charges increased with age from an average of

Scoliosis surgery in the elderly: Complications, readmissions, reoperations and mortality

28,521 in those younger than 5 years to

Suprasellar Mature Cystic Teratoma: An Unusual Location for an Uncommon Tumor

36,855 in those older than 15 years (p < 0.0001).nnnCONCLUSIONSnThere was a steady trend of increasing operative treatment for TCS over the more recent years. The nationwide analysis was also indicative of an existing disparity, based on age, in complications, outcomes, and charges following TCS surgical correction. Older children tended to have more complications, longer LOS, more non-routine discharges, and higher hospital costs. The results are highly supportive of surgery at a younger age for this condition. Future research should investigate this correlation, especially considering the efforts to control and reduce health care costs.

Differences in surgical outcomes for patients with craniosynostosis in the US: impact of socioeconomic variables and race.

The operative management of scoliosis in the elderly remains controversial. The authors of this study sought to evaluate outcomes in elderly patients with scoliosis undergoing deformity correction. Patient data was obtained from a 5% sample of the Medicare Provided Analysis and Review database (MEDPAR). Patients over 65years of age with scoliosis undergoing corrective surgery were identified between the years 2005 to 2011. A total of 453 patients were analyzed: 262 (57%) between ages 66 to 74years, and 191 (42%) over the age of 75years. Female predominance (78%) was observed in this sample. Pre-diagnosis follow-up averaged 118months. Post-surgery follow-up averaged 33months. Patients between 66 and 74years old were mostly discharged home, while patients over the age of 75years were discharged to skilled nursing facilities (SNFs) (38.55% versus 34.04%, p value=0.0011). Readmission rates were lower in patients between 66 and 74years old when compared to patients over the age of 75years (9.92% versus 17.28%, p value=0.0217). Complication rates 30-days after discharge were less in patients between 66 and 74years, compared to those over 75years (21% versus 26.6%, respectively), but this was not statistically significant. These findings suggest varying outcomes following scoliosis surgery in the elderly, but interpretation of these results is weakened by the inherent limitations of database utilization. Future prospective studies are needed to understand risk factors and other confounding variables, such as discharge disposition, that may influence outcomes.