The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke.

OBJECTIVES: This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes. METHODS: This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed. RESULTS: Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively. CONCLUSION: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study. CLINICAL RELEVANCE STATEMENT: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. KEY POINTS: • Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.

The Influence of Flush Methods on Transfemoral Catheter Cerebral Angiography: Continuous Flush versus Intermittent Flush.

PURPOSE: To evaluate the influence of different flush methods on transfemoral cerebral angiography (TFCA). MATERIALS AND METHODS: This single-blind randomized controlled trial included 50 patients who had undergone TFCA. Balanced block randomization was used to allocate participants into intermittent-flush (n = 25) and continuous-flush (n = 25) groups. Differences in procedure duration, amounts of contrast medium and heparinized saline used, heparin dose, blood loss, fluoroscopy time, radiation dose, and occurrence of new embolic signal (NES) on diffusion-weighted imaging (DWI) were compared between the two groups. RESULTS: The procedure duration was shorter in the continuous-flush group (mean 26.5 min ± 3.7) than in the intermittent-flush group (mean 29.6 min ± 2.8) (P = .004). Amounts of injected contrast medium (mean 20.2 mL ± 4.4 vs 57.1 mL ± 9.0), wasted heparinized saline (mean 19.8 mL ± 9.6 vs 92.3 mL ± 16.7), and aspirated blood (mean 4.7 mL ± 1.3 vs 13.2 mL ± 2.9) were lower in the continuous-flush group than in the intermittent-flush group (P < .001). The amount of injected (or infused) heparinized saline, heparin dose, fluoroscopy time, radiation dose, and occurrence of NES on DWI did not differ between the groups (P > .05). CONCLUSIONS: The use of continuous flushing during TFCA reduced the procedure time, amount of contrast medium needed, amount of wasted heparinized saline, and blood loss, but no difference in the occurrence of NES on DWI was noted between the groups.

Cervical ganglioneuroma as a rare cause of cervicogenic headache: A case report and literature review.

BACKGROUND: Cervicogenic headache is characterized by chronic posterior neck pain radiating to one side of the head, resulting from cervical spine bone or soft tissue diseases. Cervical ganglioneuroma (GN), a rare benign neuroblastic tumor, especially in the cervical spine, may cause cervicogenic headache-like symptoms. OBJECTIVE: We report a case of GN which was surgically removed successfully to relieve the symptom. CASE REPORT: A 68-year-old male presented with right posterior neck pain with referred pain to the ipsilateral occipital area in May 2020. Despite administration of medications, physical therapy, and spine interventions, the symptoms intermittently recurred over one year. In July 2021, the patient complained of painful limitation of neck motion, especially on right-sided bending; no motor or sensory deficits, except for subjective numbness of the finger tips, were detected. Plain radiography of the cervical spine showed moderate degenerative changes in the mid-cervical spine. Cervical MRI revealed a cystic mass (1.5 cm × 0.5 cm × 1 cm-in size) around the right C2 dorsal root ganglion adjacent to the C1-C2 facet joint. His symptoms significantly improved after complete tumor excision. CONCLUSION: GN of the upper cervical spine should be considered when persistent cervicogenic headache is refractory to conservative management. In such a case, advanced imaging studies such as MRI should be performed for early diagnosis and appropriate treatment.

Quantitative Comparison of Vertebral Structural Changes After Percutaneous Vertebroplasty Between Unilateral Extrapedicular Approach and Bilateral Transpedicular Approach Using Voxel-Based Morphometry.

OBJECTIVE: To compare unilateral extrapedicular vertebroplasty (UEV) and bilateral transpedicular vertebroplasty (BTV) by quantitatively calculating the structural changes of fractured vertebral body after percutaneous vertebroplasty (PVP) using 3-dimensional voxel-based morphometry (VBM). METHODS: We calculated bone cement volume (BCV); vertebral body volume (VBV); leaked intradiscal BCV; and spatial, symmetric, and even bone cement distribution (BCD) in and out of 222 vertebral bodies treated with 2 different PVPs using VBM and evaluated the incidence of subsequent vertebral compression fracture (SVCF). Statistical analyses were conducted to compare values between the 2 different PVPs. RESULTS: Relative BCV, which is a potential risk factor for SVCF, was higher in the BTV group based on the data using VBM (0.22±0.03 vs. 0.29±0.03; p<0.001, t-test); however, the SVCF incidence between the 2 surgeries was not significantly different (UEV, 24.7%; BTV, 31%; p=0.046, chi-square test). Spatial, even, and symmetric BCD along the 3 axes was not significantly different between UEV and BTV using VBM (x, y, z-axis, p=0.893, p= 0.590, p=0.908 respectively, chi-square test). CONCLUSION: Contrary to intuitive concerns, UEV can inject a sufficient and more optimal BCV than BTV. Additionally, it can inject bone cement spatially, symmetrically, and evenly well-distributed without an increased rate of intradiscal leakage and SVCF compared with BTV based on VBM. Therefore, UEV could be a superior alternative surgical method with similar clinical effectiveness and safety, considering the above results and the consensus that UEV is less invasive.

Nerve root anomaly as a cause of unexpected outcomes of epidural steroid injections in lumbar radiculopathy: A case report.

BACKGROUND: Spinal nerve root anomaly is a rare feature that can result in unexpected outcomes in epidural steroid injections or surgical procedures. Preoperative diagnostic tools for root anomalies are limited, as they are usually found intraoperatively. OBJECTIVE: This case report aims to propose an effective diagnostic process for nerve root anomalies by introducing clinical manifestations, electrodiagnostic findings, and sophisticated imaging techniques such as coronal view magnetic resonance imaging (MRI) of the lumbosacral spine. CASE DESCRIPTION: A 43-year-old female complained of low back pain with radicular pain to the lower extremities. Based on physical examination, electrodiagnosis, and imaging studies, right L5 radiculopathy was diagnosed. Repetitive image-guided epidural steroid injections presented unsuccessful outcomes. She was then referred to a neurosurgeon for surgical decompression, which resulted in significant improvement in her radicular pain. A nerve root anomaly was found intraoperatively, and the coronal images of postoperative MRI depicted the conjoined nerve root of the lumbar spine. CONCLUSION: When proper image-guided spinal interventions for discogenic radicular pain are not effective, a clinician should be advised to consider the possibility of anatomical variation, including nerve root anomalies. Early diagnosis of nerve root anomalies by utilizing multiple diagnostic tools, especially coronal MRI, can aid in preoperative diagnosis and proper clinical decisions for symptom management.

Clinical, Radiographic, and Morphometric Risk Factors for Adjacent and Remote Vertebral Compression Fractures Over a Minimum Follow-up of 4 Years After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: Novel Three-dimensional Voxel-Based Morphometric Analysis.

OBJECTIVE: This study aimed to analyze the risk factors for secondary new vertebral compression fractures (SNVCFs) after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures. METHODS: We evaluated the association of SNVCFs (adjacent vertebral compression fractures [AVCFs] and remote vertebral compression fractures) with clinical, radiographic, and PVP procedure-related morphologic parameters based on the data collected from 402 patients over a minimum follow-up of 4 years after PVP. Procedure-related morphologic parameters were assessed using a three-dimensional voxel-based analysis. Univariate and multivariate regression analyses were conducted. RESULTS: On univariate analysis, bone mineral density (BMD), preoperative compression ratio, preoperative sagittal index (SI), and intradiscal bone cement leakage were significantly associated with SNVCF and AVCF (P < 0.05), whereas only BMD and preoperative SI were significantly associated with remote vertebral compression fracture (P < 0.05). A large ratio of bone cement volume to vertebral body volume and skewed bone cement distribution along the inferior-to-superior axis were especially significant risk factors for AVCF (P = 0.027 and P = 0.029, respectively). On multivariate analysis, BMD was significantly associated with SNVCF (P = 0.041), whereas upper adjacent intradiscal bone cement leakage was significantly associated with AVCF (P = 0.003). CONCLUSIONS: Low BMD, high preoperative compression ratio, and high preoperative SI may be predictive factors for SNVCFs. In particular, to prevent AVCF, the injected bone cement should be distributed both evenly and symmetrically along the inferior-to-superior axis and the relative bone cement volume should not be excessive. Bone cement should be injected carefully to avoid upper adjacent intradiscal leakage. Prompt BMD correction is important to prevent SNVCF.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions.

OBJECTIVE: The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. METHODS: We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. RESULTS: The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. CONCLUSION: Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

The Risk Factors for Hydrocephalus and Subdural Hygroma after Decompressive Craniectomy in Head Injured Patients.

OBJECTIVE: The present study aims to investigate 1) the risk factors for hydrocephalus and subdural hygroma (SDG) occurring after decompressive craniectomy (DC), and 2) the association between the type of SDG and hydrocephalus. METHODS: We retrospectively reviewed the clinical and radiological features of 92 patients who underwent DC procedures after severe head injuries. The risk factors for developing post-traumatic hydrocephalus (PTH) and SDG were analyzed. Types of SDGs were classified according to location and their relationship with hydrocephalus was investigated. RESULTS: Ultimately, 26.09% (24/92) of these patients developed PTH. In the univariate analyses, hydrocephalus was statically associated with large bone flap diameter, large craniectomy area, bilateral craniectomy, intraventricular hemorrhage, contralateral or interhemisheric SDGs, and delayed cranioplasty. However, in the multivariate analysis, only large craniectomy area (adjusted OR=4.66; p=0.0239) and contralateral SDG (adjusted OR=6.62; p=0.0105) were significant independent risk factors for developing hydrocephalus after DC. The incidence of overall SDGs after DC was 55.43% (51/92). Subgroup analysis results were separated by SDG types. Statistically significant associations between hydrocephalus were found in multivariate analysis in the contralateral (adjusted OR=5.58; p=0.0074) and interhemispheric (adjusted OR=17.63; p=0.0113) types. CONCLUSION: For patients who are subjected to DC following severe head trauma, hydrocephalus is associated with a large craniectomy area and contralateral SDG. For SDGs after DC that occur on the interhemispherical or controlateral side of the craniectomy, careful follow-up monitoring for the potential progression into hydrocephalus is needed.

Renal subcapsular hematoma after percutaneous transfemoral angiography.

Vascular complications after percutaneous angiography include hematoma, pseudoaneurysm, arteriovenous fistula, thromboembolism, arterial laceration and infection. Hematomas may occur in the groin, thigh, retroperitoneal, intraperitoneal, or abdominal wall. A 54-year-old female underwent percutaneous transfemoral angiography for the evaluation of cerebral aneurysm. Renal subcapsular hematoma developed 3 hours after the procedure. Renal subcapsular hematoma after percutaneous angiography is very rare. We investigated the possible causes of renal subcapsular hematoma. To avoid this rare complication, we need to perform guide-wire passage carefully from the beginning of the procedure under full visual monitoring.

Assessment of the optimal site of femoral artery puncture and angiographic anatomical study of the common femoral artery.

OBJECTIVE: The purpose of this study was to evaluate demographic and clinical factors affecting the common femoral artery diameter and length, and anatomical relationship between the femoral head and the common femoral artery during angiography. METHODS: We retrospectively reviewed 109 femoral angiograms. We collected the clinical data of the patients and estimated the common femoral artery diameter and length. We divided the areas in the angiogram from cephalic to caudal direction (zone 0 to 5). The lowest levels of the inferior epigastric artery loop and points of the common femoral artery bifurcation were checked. RESULTS: The luminal diameter of the common femoral artery was 6.19±1.20 mm. Height, weight, body surface area, as well as common femoral artery diameter were significantly greater in men than in women (p<0.005). The length of the common femoral artery was 27.59±8.87 mm. Height, weight and body surface area showed strong positive relationships with common femoral artery diameter. All of the inferior epigastric artery loops were located above the center of the femoral head. The point of common femoral artery bifurcation was above the center of the femoral head in 4.59% of femoral angiograms. CONCLUSIONS: Males and patients with a high body surface area have a larger common femoral artery diameter. The cumulative probability of optimal targeting between the lowest margin of the inferior epigastric artery loop and the common femoral artery bifurcation is the highest in zone 3 puncture.

Microbiology and epidemiology of infectious spinal disease.

OBJECTIVE: Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes. METHODS: A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05. RESULTS: Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases. CONCLUSION: Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy.

Rat peripheral nerve regeneration using nerve guidance channel by porcine small intestinal submucosa.

OBJECTIVE: In order to develop a novel nerve guidance channel using porcine small intestinal submucosa (SIS) for nerve regeneration, we investigated the possibility of SIS, a tissue consisting of acellular collagen material without cellular immunogenicity, and containing many kinds of growth factors, as a natural material with a new bioactive functionality. METHODS: Left sciatic nerves were cut 5 mm in length, in 14 Sprague-Dawley rats. Grafts between the cut nerve ends were performed with a silicone tube (Silicon group, n=7) and rolled porcine SIS (SIS group, n=7). All rats underwent a motor function test and an electromyography (EMG) study on 4 and 10 weeks after grafting. After last EMG studies, the grafts, including proximal and distal nerve segments, were retrieved for histological analysis. RESULTS: Foot ulcers, due to hypesthesia, were fewer in SIS group than in Silicon group. The run time tests for motor function study were 2.67 seconds in Silicon group and 5.92 seconds in SIS group. Rats in SIS group showed a better EMG response for distal motor latency and amplitude than in Silicon group. Histologically, all grafts contained some axons and myelination. However, the number of axons and the degree of myelination were significantly higher in SIS group than Silicon group. CONCLUSION: These results show that the porcine SIS was an excellent option as a natural biomaterial for peripheral nerve regeneration since this material contains many kinds of nerve growth factors. Furthermore, it could be used as a biocompatible barrier covering neural tissue.

Anterior cervical plating technique to prevent adjacent-level ossification development.

BACKGROUND CONTEXT: The proximity (<5 mm) of the plate to the adjacent disc space is known to be a critical risk factor for adjacent-level ossification development (ALOD). As plates provide many advantages including higher fusion rates and improved alignment, their use will continue. Instead, it is necessary to modify the plating techniques to minimize this complication. PURPOSE: To determine if our newer plating technique decreases the incidence of ALOD after anterior cervical plating. STUDY DESIGN: Retrospective matched cohort analysis of preoperative and postoperative radiographic data. PATIENT SAMPLE: One hundred patients were classified into two groups; conventional (C) and new (N) plating techniques. The control group (Group C) was matched to the study group (Group N) in a 1:1 fashion using matching criteria of age (within 5 years), gender, number of fusion levels, and comorbidities, including diabetes and tobacco use. OUTCOME MEASURES: The lateral plain X-rays of cervical spine taken at postoperative 6 months and 2 years were used for analysis. METHODS: In Group N, the cranial and caudal screws were started at the anterior end plate corners and angled away from the end plates so as to use the shortest possible plate and maximize the distance to the adjacent end plates. Group C was the historical control using a longer plate with more orthogonal screw angulation. On postoperative 6-week lateral films, the distances from the tip of the plate to both cranial and caudal adjacent discs (plate-to-disc distances) were measured. Based on the postoperative 2-year radiographs, the incidence of ALOD was determined, and the severity of ossification was classified on a scale ranging from Grade 0 (no ossification) to Grade 3 (complete bridging). RESULTS: Mean plate-to-disc distances in Group N were significantly longer at both cranial and caudal adjacent levels than those in Group C (p<.001). The incidence of ALOD was significantly lower in Group N than in Group C, both at the cranial adjacent disc spaces (42% vs. 72%) and caudal adjacent disc spaces (20% vs. 42%) (p<.05). Severe ossification (Grade 2 or greater) also developed less frequently in Group N at cranial and caudal levels (6% vs. 20%, respectively; p<.05). CONCLUSIONS: The new technique of using a shorter plate with longer angulated screws resulted in significantly reduced incidence and severity of ALOD.

Dysregulated Expression Profiles of MicroRNAs of Experimentally Induced Cerebral Aneurysms in Rats.

OBJECTIVE: Cerebral aneurysm (CA) is an important acquired cerebrovascular disease that can cause catastrophic results. MicroRNAs (miRNAs) are small non-coding RNAs, playing essential roles in modulating basic physiologic and pathological processes. Currently, evidences have been established about biologic relationship between miRNAs and abdominal aortic aneurysms. However, biologic roles of miRNAs in CA formation have not been explained yet. We employed microarray analysis to detect and compare miRNA expression profiles in late stage of CA in rat model. METHODS: Twenty-six, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n=11) were fed a normal diet, and the experimental animals (n=26) were fed a normal diet with 1% normal saline for 3 months. Then, the rats were sacrificed, their cerebral arteries were dissected, and the five regions of aneurysmal dilation on the left posterior communicating artery were cut for miRNA microarrays analysis. Six miRNAs (miRNA-1, miRNA-223, miRNA-24-1-5p, miRNA-551b, miRNA-433, and miRNA-489) were randomly chosen for validation using real-time quantitative PCR. RESULTS: Among a set of differentially expressed miRNAs, 14 miRNAs were over-expressed more than 200% and 6 miRNAs were down-expressed lower than 50% in the CA tissues. CONCLUSION: The results show that miRNAs might take part in CA formation probably by affecting multiple target genes and signaling pathways. Further investigations to identify the exact roles of these miRNAs in CA formation are required.

Hemostatic techniques reduce hospital stay following multilevel posterior cervical spine surgery.

BACKGROUND: Despite meticulous hemostasis, persistent postoperative drain output following posterior cervical spine procedures often necessitates a prolonged length of hospital stay. We sought to determine if thrombin-soaked absorbable gelatin compressed sponge can decrease postoperative drain output and the length of hospital stay after multilevel posterior cervical spine surgery. METHODS: We performed a retrospective analysis of forty-three pairs of patients who had undergone either posterior cervical decompression and/or fusion of three or more levels by the same surgeon. The patients were matched according to intraoperative blood loss, age, sex, and number of involved levels. Control patients were managed between 2004 and 2007, whereas study patients were managed between 2008 and 2011. The only variable between the study and control groups was that, in the study group, absorbable gelatin compressed sponge was soaked in thrombin and applied over the exposed spine before wound closure. A subfascial drain was used in all patients. Total drain output, time for the drainage to decrease to <30 mL per eight-hour shift (at which point the drain was discontinued), the length of stay, the number of readmissions, and postoperative complications were analyzed. RESULTS: Total drain output averaged 93 mL in the study group and 204 mL in the control group (p < 0.0001). The average time for the drainage to decrease to <30 mL per eight-hour shift was 2.5 shifts in the study group and 4.4 shifts in the control group (p < 0.0001). Length of stay averaged 1.3 days (cumulative total, fifty-seven days) in the study group and 2.2 days (cumulative total, ninety-five days) in the control group (p < 0.0001). Persistent drain output was the primary reason preventing discharge on the first postoperative day. There were no infections, epidural hematomas, or readmissions within thirty days of discharge in either group. No patient developed adverse reactions attributable to the thrombin-soaked absorbable gelatin compressed sponge. CONCLUSIONS: Application of thrombin-soaked absorbable gelatin compressed sponge at the end of multilevel posterior cervical spinal surgery significantly decreased postoperative drain output and consequent hospital stay. LEVEL OF EVIDENCE: Therapeutic Level III.

Major complications in revision adult deformity surgery: risk factors and clinical outcomes with 2- to 7-year follow-up.

STUDY DESIGN: Retrospective cohort comparative study. OBJECTIVE: To determine the prevalence of major complications, identify risk factors, and assess long-term clinical benefit after revision adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA: No study has analyzed risk factors for major complications in long revision fusion surgery and whether or not occurrence of a major complication affects ultimate clinical outcome. METHODS: Analysis of consecutive adult patients who underwent multilevel revision surgery for spinal deformity with a minimum 2-year follow-up was performed. All complications were classified as either major or minor. Outcome analysis was conducted with the Scoliosis Research Society and Oswestry Disability Index scores. RESULTS: A total of 166 patients (mean age = 53.8 years) were identified with a mean follow-up of 3.5 years (range: 2-7). Primary diagnoses included idiopathic/de novo scoliosis (107), degenerative (35), trauma (7), neuromuscular scoliosis (6), congenital deformity (5), ankylosing spondylitis (2), tumor (2), Scheuermann kyphosis (1), and rheumatoid arthritis (1). Most common secondary diagnoses that necessitated revision surgery were adjacent segment disease, fixed sagittal imbalance, and pseudarthrosis. Overall, 34.3% of patients developed major complications (19.3% perioperative; 18.7% follow-up). Associated risk factors for perioperative complications were patient- (age > 60 years, medical comorbidities, obesity) and surgery-related (pedicle subtraction osteotomy). Performance of a 3-column osteotomy and postoperative radiographic changes that suggested progressive loss of sagittal correction were recognized as risk factors for follow-up complications. Equivalent outcome scores were reported by patients preoperatively, but those experiencing follow-up complications reported lower scores at the final follow-up. CONCLUSION: Overall, 34.4% of patients experienced major complications after long revision fusion surgery. Different risk factors were identified for perioperative versus follow-up complications. The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.

Comparative analysis of clinical outcome and complications in primary versus revision adult scoliosis surgery.

STUDY DESIGN: A retrospective case comparison study. OBJECTIVE: We compared clinical outcome and complications in adult patients who underwent primary (P) versus revision (R) scoliosis surgery. SUMMARY OF BACKGROUND DATA: There is a paucity of data comparing P versus R adult scoliosis patients with respect to their complication rates and clinical outcome. METHODS: Assessment of 250 consecutive adult patients who underwent P versus R surgery for idiopathic or de novo scoliosis between 2002 and 2007, with a minimum 2-year follow-up, was performed. RESULTS: There were 126 patients in the P group and 124 in the R group. Mean age at surgery (P = 51.2 vs. R = 51.6 years, P = 0.79), length of follow-up (P = 3.6 vs. R = 3.6 years, P = 0.94), comorbidities (P = 0.43), and smoking status (P = 0.98) were similar between the 2 groups. Body mass index (P = 25.5 vs. R = 27.4 kg/m, P = 0.01), number of final instrumented levels (P = 10.5 vs. R 12.1 levels, P = 0.00), fusion to the sacrum (P = 61.0% vs. R = 87.1%, P = 0.00), osteotomy (P = 14.3% vs. R = 54.9%, P = 0.00), length of surgery (P = 6.5 vs. R = 8.2 hours, P = 0.00), and estimated blood loss (P = 1072.1 vs. R = 1401.3 mL, P = 0.05) were different. Primary patients had significantly lower overall complications than revision patients (P = 45.2% vs. R = 58.2%, P = 0.042). Primary patients reported significantly higher preoperative and final clinical outcome measures in function, pain, and subscore SRS domains and ODI compared with revision patients (all P < 0.05). Patients older than 60 years of age, however, reported similar SRS and ODI scores between the 2 groups. The extent of surgical benefit patients received, that is, final minus preoperative score, was similar in all categories between the 2 groups. CONCLUSION: Adult patients undergoing primary scoliosis surgery had significantly lower overall complications compared with revision patients. Primary patients reported higher preoperative and final clinical outcome measures than revision patients, although this difference disappeared in older patients. The benefit of surgery was similar between the 2 groups.

Epidural block-induced ligamentum flavum hematoma mimicking epidural hematoma in the lumbar spine: a case report.

BACKGROUND CONTEXT: The ligamentum flavum may undergo various pathologic changes, including hypertrophy, calcification, ossification, and cyst formation. Ligamentum flavum hematoma (LFH) is a rare cause of spinal nerve root or cord compression and usually occurs in the lumbar spine. We report a 66-year-old woman with LFH occurring after an epidural block, mimicking epidural hematoma on lumbar spine magnetic resonance imaging (MRI). PURPOSE: To document MRI findings of epidural block-induced LFH mimicking epidural hematoma. STUDY DESIGN/SETTING: A case report. METHODS: A 66-year-old woman presented with a 6-month history of pain in the left buttock and suffered abrupt weakness and numbness in her left leg after an epidural block procedure without any other trauma history. Lumbar spine MRI with enhancement showed a hematoma-like mass in the posterior epidural space at L3-L4 level. RESULTS: The patient underwent a left hemilaminectomy at the L3 level, and a surgeon found a small hematoma between inner and outer walls of ligamentum flavum instead of an epidural hematoma and performed the removal of the hypertrophied ligamentum flavum including the intraligamentary lesion. Histopathologic examination confirmed the lesion as hematoma in the left ligamentum flavum. After surgery, the patient recovered without significant neurologic deficit. CONCLUSIONS: Epidural block-induced LFH can mimic posterior epidural hematoma on MRI. Careful evaluation of hematoma, location, and imaging findings is required for accurate diagnosis.

Clinical and radiologic outcome of laminar screw at C2 and C7 for posterior instrumentation--review of 25 cases and comparison of C2 and C7 intralaminar screw fixation.

BACKGROUND: The aim of this study is 2-fold: to analyze a clinical case series in which we used laminar screws for cervical posterior instrumentation and to describe the difference between C2 and C7 laminar screws in terms of technique and anatomy. METHODS: Data were obtained from 25 patients who underwent cervical posterior fixation with intralaminar screws at C2 or C7. C2 intralaminar screw instrumentation was used for 7 patients requiring occipitocervical fixation (basilar invagination [3 patients], C1 unstable bursting fracture [1 patient], C1-C2 instability with occipital assimilation [2 patients], and dystopic os odontoideum [1 patient]), 13 patients with C1-C2 instability, 1 patient with C2-C3 subluxation, and 4 patients undergoing C7 fixation due to pseudoarthrosis or cervical instability after trauma. A total of 34 laminar screws were placed including 1 thoracic laminar screw, and the patients were assessed both clinically and radiographically. RESULTS: There were no instances where a screw violated the spinal canal nor any hardware fractures noted during the follow-up period. As for perioperative complications, there were 2 cases of postoperative wound infection, 1 case of dural laceration during dissection, and 2 cases of partial dorsal laminar breach. However, there was no neurologic compromise in any of the cases. The fusion success rate was 100%. CONCLUSION: These preliminary results support the use of intralaminar screws for posterior instrumentation at C2 and C7.