Endovascular treatment of a spinal dural arteriovenous malformation (DAVF).

We present a case of a patient with rapid loss of motor strength in his lower extremities. He became bedridden with bowel and bladder incontinence, and developed saddle anesthesia. MRI of the lumbar spine showed edema in the conus medullaris and multiple flow voids within the spinal canal. A spinal angiogram showed a dorsal Type I spinal AVF. This was treated successfully with Onyx 18 (eV3, Irvine, CA). The patient showed rapid post-procedure improvement, and at discharge from the hospital to a rehabilitation center he was fully ambulatory. At 3-year follow-up, the patient was found to ambulate without difficulty. He also had improved saddle anesthesia, and he was voiding spontaneously. There was no evidence of flow voids on repeat MRI of the lumbar spine. The video can be found here: http://youtu.be/SDYNIGNQIW8 .

Transcirculation balloon-assisted stent-supported coil embolization of a basilar tip aneurysm.

We present the case of a balloon-assisted, stent-supported coil embolization of a basilar tip aneurysm. Initially, a balloon extending from the basilar artery into the right PCA was placed. However, even with a more proximal purchase, coils were found to impinge on the left PCA. Subsequently, a transcirculation approach was performed, where the left posterior communicating artery was utilized as a conduit for balloon support and the coils were embolized from the ipsilateral vertebral artery. However, after this transcirculation approach was completed, there was a coil tail extruding from the aneurysm. The balloon was then removed over an exchange wire and a horizontal stent advanced, spanning the entire neck of the aneurysm, eliminating the extruded coil. The video can be found here: http://youtu.be/bMbtZoPnYvo .

Cerebellopontine angle meningiomas: postoperative outcomes in a modern cohort.

OBJECT: Tumors of the cerebellopontine angle (CPA) have always proven difficult for neurosurgeons to optimally manage. Studies investigating the natural history and treatment of vestibular schwannomas have dominated the literature in this regard. Distinguishing meningiomas from schwannomas in this location carries particular importance as each tumor type has certain prognostic and surgical considerations. In this study, the authors have characterized the outcomes of 34 patients surgically treated for CPA meningiomas and have investigated various factors that may affect postoperative neurological function. METHODS: The medical records of patients with CPA meningiomas who underwent surgery from 2005 to 2013 at the Duke University Health System were reviewed. Various patient, clinical, and tumor data were gathered from the medical records including patient demographics, pre- and postoperative neurological examinations, duration of symptoms, procedural details, tumor pathology and size, and treatment characteristics. Differences in continuous variables were then analyzed using the Student t-test while categorical variables were evaluated using the chi-square test. RESULTS: A total of 34 patients underwent surgical treatment for CPA meningiomas during the 8-year period. Jugular foramen invasion was seen in 17.6% of tumors, with nearly half (41.2%) extending into the internal acoustic canal. The most common presenting symptom was hearing loss (58.8%), followed by headache (52.9%) and facial numbness/pain (50.0%). The most common cranial nerve (CN) affected was CN X (11.8%), followed by CNs VI and VII (5.9%). Postoperatively, no patients experienced a decrease in hearing, with only 5.9% of patients experiencing facial nerve palsies. Patients with tumors larger than 3 cm had a significantly higher incidence of permanent CN deficits than those with smaller tumors (45.5% vs 5.9%, respectively; p = 0.011). Also, tumor extension into the jugular foramen was associated with the occurrence of lower CN deficits, none of which occurred in tumors without jugular foramen invasion. Internal acoustic canal tumor extension was not seen to be associated with postoperative complications or CN deficits. CONCLUSIONS: Meningiomas of the CPA are challenging lesions to treat surgically. However, the risk of facial palsy and hearing loss is significantly lower when compared with vestibular schwannomas. Novel methods for preoperative differentiation are needed to appropriately counsel patients on surgical risks. Also, due to the significant potential for neurological deficits, further studies are needed to investigate the utility of radiotherapy for these lesions.

Retrospective analysis of unstaged and staged Gamma Knife surgery with and without preceding embolization for the treatment of arteriovenous malformations.

OBJECT: The authors conducted a retrospective study to examine data on rates of obliteration of arteriovenous malformations (AVMs) with use of various combinations of treatment modalities based on Gamma Knife surgery (GKS). The authors believe that this study is the first to report on patients treated with embolization followed by staged GKS. METHODS: The authors identified 150 patients who underwent GKS for treatment of AVMs between 1994 and 2004. In a retrospective study, 4 independent groups emerged based on the various combinations of treatment: 92 patients who underwent unstaged GKS, 28 patients who underwent embolization followed by unstaged GKS, 23 patients who underwent staged GKS, and 7 patients who underwent embolization followed by staged GKS. A minimum of 3 years of follow-up after the last GKS treatment was required for inclusion in the retrospective analysis. Angiograms, MR images, or CT scans at follow-up were required for calculating rates of obliteration of AVMs. RESULTS: Fifty-seven of 150 patients (38%) supplied angiograms, and overall obliteration was confirmed in 43 of these 57 patients (75.4%). An additional 37 patients had follow-up MR images or CT scans. The overall obliteration rate, including patients with follow-up angiograms and patients with follow-up MR images or CT scans, was 68 of 94 (72.3%). Patients who underwent unstaged GKS had a follow-up rate of 58.7% (54 of 92) and an obliteration rate of 75.9% (41 of 54). Patients who underwent embolization followed by unstaged GKS had a follow-up rate of 53.5% (15 of 28) and an obliteration rate of 60.0% (9 of 15). Patients who underwent staged GKS had a follow-up rate of 82.6% (19 of 23) and an obliteration rate of 73.7% (14 of 19). Patients who underwent embolization followed by staged GKS had a follow-up rate of 85.7% (6 of 7) and an obliteration rate of 66.7% (4 of 6). CONCLUSIONS: Gamma Knife surgery is an effective means of treating AVMs. Embolization prior to GKS may reduce AVM obliteration rates. Staged GKS is a promising method for obtaining high obliteration rates when treating larger AVMs in eloquent locations.

Pedicle screw placement accuracy using ultra-low radiation imaging with image enhancement versus conventional fluoroscopy in minimally invasive transforaminal lumbar interbody fusion: an internally randomized controlled trial.

OBJECTIVE A previous study found that ultra-low radiation imaging (ULRI) with image enhancement significantly decreases radiation exposure by roughly 75% for both the patient and operating room personnel during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) (p < 0.001). However, no clinical data exist on whether this imaging modality negatively impacts patient outcomes. Thus, the goal of this randomized controlled trial was to assess pedicle screw placement accuracy with ULRI with image enhancement compared with conventional, standard-dose fluoroscopy for patients undergoing single-level MIS-TLIF. METHODS An institutional review board-approved, prospective internally randomized controlled trial was performed to compare breach rates for pedicle screw placement performed using ULRI with image enhancement versus conventional fluoroscopy. For cannulation and pedicle screw placement, surgery on 1 side (left vs right) was randomly assigned to be performed under ULRI. Screws on the opposite side were placed under conventional fluoroscopy, thereby allowing each patient to serve as his/her own control. In addition to standard intraoperative images to check screw placement, each patient underwent postoperative CT. Three experienced neurosurgeons independently analyzed the images and were blinded as to which imaging modality was used to assist with each screw placement. Screw placement was analyzed for pedicle breach (lateral vs medial and Grade 0 [< 2.0 mm], Grade 1 [2.0-4.0 mm], or Grade 2 [> 4.0 mm]), appropriate screw depth (50%-75% of the vertebral body's anteroposterior dimension), and appropriate screw angle (within 10° of the pedicle angle). The effective breach rate was calculated as the percentage of screws evaluated as breached > 2.0 mm medially or postoperatively symptomatic. RESULTS Twenty-three consecutive patients underwent single-level MIS-TLIF, and their sides were randomly assigned to receive ULRI. No patient had immediate postoperative complications (e.g., neurological decline, need for hardware repositioning). On CT confirmation, 4 screws that had K-wire placement and cannulation under ULRI and screw placement under conventional fluoroscopy showed deviations. There were 2 breaches that deviated medially but both were Grade 0 (< 2.0 mm). Similarly, 2 breaches occurred that were Grade 1 (> 2.0 mm) but both deviated laterally. Therefore, the effective breach rate (breach > 2.0 mm deviated medially) was unchanged in both imaging groups (0% using either ULRI or conventional fluoroscopy; p = 1.00). CONCLUSIONS ULRI with image enhancement does not compromise accuracy during pedicle screw placement compared with conventional fluoroscopy while it significantly decreases radiation exposure to both the patient and operating room personnel.

Minimally Invasive Lateral Access Surgery and Reoperation Rates: A Multi-Institution Retrospective Review of 2060 Patients.

BACKGROUND: Risk factors for surgical revision remain important because of additional readmission, anesthesia, and morbidity for the patient and significant cost for health care systems. Although the rate of reoperation (RRO) is well described for traditional open posterior (OP) approaches, the RRO in minimally invasive lateral (MIL) surgery remains poorly characterized. This study compares the RRO in patients undergoing decompressive lumbar spine surgery via MIL versus OP approaches. METHODS: Patient demographics and comorbidities were retrospectively collected for 2060 patients undergoing single-stage elective lumbar spinal surgery at multiple institutions. A subset of 1484 patients had long-term data (long-term cohort [LT cohort]). The RRO was compared between approaches through univariate and multivariate analysis. RESULTS: There were 1292 patients (62.7%) who underwent lateral access surgery, whereas 768 patients (37.3%) underwent OP surgery. The MIL cohort was significantly older, had a higher proportion of men, and had more comorbidities than the OP cohort. In the LT cohort, lateral patients were significantly older and had more comorbidities, with a lower body mass index and a lower proportion of men and smokers. Surgical complications between the groups trended to be similar. The MIL cohort had a significantly lower RRO at both 30 days (approximately 57% lower, MIL cohort: 1.01% vs. OP cohort: 2.36%, P = 0.02) and 2 years (approximately 61% lower, MIL cohort: 2.09% vs. OP cohort: 5.37%, P < 0.01) after surgery. On multivariate analysis, surgical approach was the only significant predictor for the RRO at both 30 days (open posterior approach odds ratio [OR], 4.47; 95% confidence interval [CI], 1.33-15.09; P = 0.02) and 2 years (open posterior approach OR, 3.26; 95% CI, 1.26-8.42; P = 0.01). CONCLUSIONS: This study shows that MIL surgical approaches, compared with OP approaches, have a significantly lower RRO after lumbar spine surgery.

Impact of surgical site infection and surgical debridement on lumbar arthrodesis: A single-institution analysis of incidence and risk factors.

This study identifies the rate of pseudarthrosis following surgical debridement for deep lumbar spine surgical site infection and identify associated risk factors. Patients who underwent index lumbar fusion surgery from 2013 to 2014 were included if they met the following criteria: 1) age >18years, 2) had debridement of deep lumbar SSI, and had 3) lumbar spine AP, lateral and flexion/extension X-rays and computed tomography (CT) at 12months or greater postoperatively. Criteria for fusion included 1) solid posterolateral, facet, or disk space bridging bone, 2) no translational or angular motion on flexion/extension X-rays, and 3) intact posterior hardware without evidence of screw lucency or breakage. Twenty-five patients (age 63.2±12.6years, 10 male) involving 58 spinal levels met inclusion criteria. They underwent fusion at a mean of 2.32 [range 1-4] spinal levels. Sixteen (64.0%) patients received interbody grafts at a total of 34 (58.6%) spinal levels. All underwent surgical debridement with removal of all non-incorporated posterior bone graft and devascularized tissue. At one-year postoperatively, (56%) patients and 30 (52%) spinal levels demonstrated radiographic evidence of successful fusion. Interbody cage during initial fusion was significantly associated with successful arthrodesis at follow-up (p=0.017). There is a high rate of pseudoarthrosis in 44% of patients (48% of levels) undergoing lumbar fusion surgery complicated by SSI requiring debridement. Use of interbody cage during initial fusion was significantly associated with higher rate of arthrodesis.

Internally Randomized Control Trial of Radiation Exposure Using Ultra-low Radiation Imaging Versus Traditional C-arm Fluoroscopy for Patients Undergoing Single-level Minimally Invasive Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: To compare radiation exposure between ultra-low radiation imaging (ULRI) with image enhancement and standard-dose fluoroscopy for patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). SUMMARY OF BACKGROUND DATA: Although the benefits of MIS are lauded by many, there is a significant amount of radiation exposure to surgeon and operating room personnel. Our goal with this work was to see if by using ultra-low dose radiation settings coupled with image enhancement, this exposure could be minimized. METHODS: An institutional review board approved, prospective, internally randomized controlled trial was performed comparing ultra-low dose settings coupled with image enhancement software to conventional fluoroscopic imaging. In this study, each patient served as their own control, randomly assigning one side of MIS-TLIF for cannulation and K-wire placement using each imaging modality. Further, the case was also randomly divided into screw placement and cage placement/final images to allow further comparisons amongst patients. Radiation production from the C-arm fluoroscope and radiation exposure to all operating room personnel were recorded. RESULTS: Twenty-four patients were randomly assigned to undergo a single level MIS-TLIF. In no case was low radiation imaging abandoned, and no patient had a neurologic decline or required hardware repositioning. Everyone in the operating room-the physician, scrub nurse, circulator, and anesthesiologist-all benefited with 61.6% to 83.5% reduction in radiation exposure during cannulation and K-wire placement to screw insertion aided by ULRI. In every case but the anesthesiologist dose, this was statistically significant (P < 0.05). This benefit required no additional time (P = 0.78 for K-wire placement). CONCLUSION: ULRI, when aided by image enhancement software, affords the ability for all parties in the operating room to substantially decrease their radiation exposure compared with standard-dose C-arm fluoroscopy without adding additional time or an increased complication rate. LEVEL OF EVIDENCE: 2.

Post-operative delirium is an independent predictor of 30-day hospital readmission after spine surgery in the elderly (≥65years old): A study of 453 consecutive elderly spine surgery patients.

In the last decade, costs of U.S. healthcare expenditures have been soaring, with billions of dollars spent on hospital readmissions. Identifying causes and risk factors can reduce soaring readmission rates and help lower healthcare costs. The aim of this is to determine if post-operative delirium in the elderly is an independent risk factor for 30-day hospital readmission after spine surgery. The medical records of 453 consecutive elderly (≥65years old) patients undergoing spine surgery at Duke University Medical Center from 2008 to 2010 were reviewed. We identified 17 (3.75%) patients who experienced post-operative delirium according to DSM-V criteria. Patient demographics, comorbidities, and post-operative complication rates were collected for each patient. Elderly patients experiencing post-operative delirium had an increased length of hospital stay (10.47days vs. 5.70days, p=0.009). Complication rates were similar between the cohorts with the post-operative delirium patients having increased UTI and superficial surgical site infections. In total, 12.14% of patients were re-admitted within 30-days of discharge, with post-operative delirium patients experiencing approximately a 4-fold increase in 30-day readmission rates (Delirium: 41.18% vs. No Delirium: 11.01%, p=0.002). In a multivariate logistic regression analysis, post-operative delirium is an independent predictor of 30-day readmission after spine surgery in the elderly (p=0.03). Elderly patients experiencing post-operative delirium after spine surgery is an independent risk factor for unplanned readmission within 30-days of discharge. Preventable measures and early awareness of post-operative delirium in the elderly may help reduce readmission rates.

Impact of Intraoperative Steroids on Postoperative Infection Rates and Length of Hospital Stay: A Study of 1200 Spine Surgery Patients.

OBJECTIVE: The use of intraoperative steroids and their effects are relatively unknown and remain controversial. The aim of this study was to determine the effects of intraoperative steroid use on postoperative complications and length of hospital stay after spine surgery. METHODS: Medical records of 1200 adult patients undergoing spine surgery at Duke University Medical Center during the period 2008-2010 were retrospectively reviewed; 495 (41.25%) patients were administered intraoperative steroids, and 705 (58.75%) patients were not administered intraoperative steroids. Patient demographics, comorbidities, and postoperative complication rates were collected. The primary outcomes investigated were postoperative complications, specifically length of hospital stay and infection rates. RESULTS: Patient demographics were similar between both cohorts. Comorbidities were also similar, with the intraoperative steroid use cohort having a higher number of patients with long-term steroid use than the no intraoperative steroid use cohort (6.95% [no steroids] vs. 13.74% [steroid use], P < 0.001). Operative variables, including length of operation and median number of fusion levels operated, were also similar between the 2 groups. Lumbar spine was the most common surgical location. Patients who were administered intraoperative steroids had a shorter length of hospital stay by an average of 1 day (6.06 days ± 6.76 [no steroids] vs. 5.04 days ± 4.86 [steroid use], P = 0.0025), lower rates of urinary tract infections (10.37% [no steroids] vs. 6.88% [steroid use], P = 0.040), and lower rates of other infections that were not deep or superficial surgical site infections (9.22% [no steroids] vs. 6.06% [steroid use], P = 0.0460). CONCLUSIONS: Patients who receive intraoperative steroids have shorter hospital stays and lower infection rates after spine surgery.

Symptomatic Rathke's cleft cyst with a co-existing pituitary tumor; Brief review of the literature.

Pituitary adenomas and Rathke's cleft cysts (RCCs) share a common embryological origin. Occasionally, these two lesions can present within the same patient. We present a case of a 39-year-old male who was found to have a large sellar lesion after complaints of persistent headaches and horizontal nystagmus. Surgical resection revealed components of a RCC co-existing with a pituitary adenoma. A brief review of the literature was performed revealing 38 cases of co-existing Rathke's cleft cysts and pituitary adenomas. Among the cases, the most common symptoms included headache and visual changes. Rathke's cleft cysts and pituitary adenomas are rarely found to co-exist, despite having common embryological origins. We review the existing literature, discuss the common embryology to these two lesions and describe a unique case from our institution of a co-existing Rathke's cleft cyst and pituitary adenoma.

Ammonia-induced brain swelling and neurotoxicity in an organotypic slice model.

OBJECTIVES: Acute liver failure (ALF) produces cerebral dysfunction and edema, mediated in part by elevated ammonia concentrations, often leading to coma and death. The pathophysiology of cerebral edema in ALF is incompletely understood. In vitro models of the cerebral effects of ALF have predominately consisted of dissociated astrocyte cultures or acute brain slices. We describe a stable long-term culture model incorporating both neural and glial elements in a three-dimensional tissue structure offering significant advantages to the study of astrocytic-neuronal interactions in the pathophysiology of cerebral edema and dysfunction in ALF. METHODS: We utilized chronic organotypic slice cultures from mouse forebrain, applying ammonium acetate in iso-osmolar fashion for 72 hours. Imaging of slice thickness to assess for tissue swelling was accomplished in living slices with optical coherence tomography, and confocal microscopy of fluorescence immunochemical and histochemical staining served to assess astrocyte and neuronal numbers, morphology, and volume in the fixed brain slices. RESULTS: Ammonia exposure at 1-10 mM produced swelling of immunochemically identified astrocytes, and at 10 mM resulted in macroscopic tissue swelling, with slice thickness increasing by about 30%. Astrocytes were unchanged in number. In contrast, 10 mM ammonia treatment severely disrupted neuronal morphology and reduced neuronal survival at 72 hours by one-half. DISCUSSION: Elevated ammonia produces astrocytic swelling, tissue swelling, and neuronal toxicity in cerebral tissues. Ammonia-treated organotypic brain slice cultures provide an In vitro model of cerebral effects of conditions relevant to ALF, applicable to pathophysiological investigations.