Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

Utility of Early Post-treatment Single-Photon Emission Computed Tomography Imaging to Predict Outcome in Stroke Patients Treated with Intravenous Tissue Plasminogen Activator

It is important to predict the outcome of tissue plasminogen activator (tPA)-treated patients early after the treatment for considering the post-tPA treatment option. We assessed cerebral blood flow (CBF) of tPA-treated patients with single-photon emission computed tomography (SPECT) 1 hour after tPA infusion to predict the patient outcome. Technetium-99m-hexamethylpropyleneamine oxime SPECT was performed in 35 consecutive tPA-treated patients. Asymmetry index, a contralateral-to-ipsilateral ratio of CBF, was calculated to analyze CBF quantitatively. Hypoperfusion or hyperperfusion was defined as a decrease of 25% or more or a increase of 25% or more in asymmetry index, respectively. Of all 35 patients, 23 had only hypoperfusion, 8 had both hypoperfusion and hyperperfusion, 2 had only hyperperfusion, and 2 had no perfusion abnormality. When evaluating the association between hypoperfusion and outcome, hypoperfusion volumes were significantly correlated with the modified Rankin Scale at 3 months (r = .634, P < .001). Hyperperfusion was observed in 10 patients (28.6%) and they showed a marked National Institutes of Health Stroke Scale score improvement in the first 24-hour period, which were significantly greater than those of 25 patients without hyperperfusion (P = .033). Eight patients (22.9%) with intracerebral hemorrhage (ICH) were all asymptomatic. Most ICHs were located in hypoperfusion areas, and no ICH was related to hyperperfusion. The results of the present study demonstrated that hypoperfusion volume was associated with poor outcome, whereas the presence of hyperperfusion seemed to be predictive of symptom improvement but not of development of ICH. Taken together, early post-treatment SPECT imaging seems to be a useful biomarker of outcome in tPA-treated patients

A Rare Case with a Solitary Fibrous Tumour of the Colon and an Epithelioid Angiomyolipoma of the Kidney

Solitary fibrous tumour is a soft tissue tumour composed of a subset of fibroblast-like cells and frequently needs immunohistochemical staining for final diagnosis. Epithelioid angiomyolipoma is a variant of angiomyolipoma but characterized by the absence of both adipocytes and abnormal blood vessels. We introduce a very rare case with the combination of these two tumours. A Japanese female patient without significant symptom was hospitalized and operated due to multiple uterine leiomyomas. During the operation, the surgeons found another tumour attaching to serosa of sigmoid colon. This tumour was resected and interpreted as solitary fibrous tumour, suspicious of malignancy. After 13 months of treatment, she was hospitalized again due to hematuria. The doctors detected a tumour in her right kidney. After consultation, laparoscopic right nephrectomy was done. The pathological result of this tumour was epithelioid angiomyolipoma. This is the first report on this very rare combination of tumours with extensive immunohistochemical demonstration of both tumours. Hereby, we review clinical information and histopathological findings together with discussion on each tumour