Reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography in hypervascular spinal metastases prior embolization.

OBJECTIVES: Preoperative embolization of hypervascular spinal metastases (HSM) is efficient to reduce perioperative bleeding. However, intra-arterial digital subtraction angiography (IA-DSA) must confirm the hypervascular nature and rule out spinal cord arterial feeders. This study aimed to evaluate the reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) in assessing HSM prior to embolization. METHODS: All consecutive patients referred for preoperative embolization of an HSM were prospectively included. TR-CE-MRA sequences and selective IA-DSA were performed prior to embolization. Two readers independently reviewed imaging data to grade tumor vascularity (using a 3-grade and a dichotomized "yes vs no" scale) and identify the arterial supply of the spinal cord. Interobserver and intermodality agreements were estimated using kappa statistics. RESULTS: Thirty patients included between 2016 and 2019 were assessed for 55 levels. Interobserver agreement was moderate (κ = 0.52; 95% CI [0.09-0.81]) for TR-CE-MRA. Intermodality agreement between TR-CE-MRA and IA-DSA was good (κ = 0.74; 95% CI [0.37-1.00]). TR-CE-MRA had a sensitivity of 97.9%, a specificity of 71.4%, a positive predictive value of 95.9%, a negative predictive value of 83.3%, and an overall accuracy of 94.6%, for differentiating hypervascular from non-hypervascular SM. The arterial supply of the spine was assessable in 2/30 (6.7%) cases with no interobserver agreement (κ < 0). CONCLUSIONS: TR-CE-MRA can reliably differentiate hypervascular from non-hypervascular SM and thereby avoid futile IA-DSAs. However, TR-CE-MRA was not able to evaluate the vascular supply of the spinal cord at the target levels, thus limiting its scope as a pretherapeutic assessment tool. KEY POINTS: • TR-CE-MRA aids in distinguishing hypervascular from non-hypervascular spinal metastases. • TR-CE-MRA could avoid one-quarter of patients referred for HSM embolization to undergo futile conventional angiography. • TR-CE-MRA's spatial resolution is insufficient to replace IA-DSA in the pretherapeutic assessment of the spinal cord vascular anatomy.

Higher complications after previous external beam radiation for extremity soft-tissue sarcoma in the surgical treatment of a local recurrence: a comparative retrospective study of one hundred and three patients.

PURPOSE: The use of adjuvant radiation in the treatment of soft-tissue sarcoma (STS) is equivocal in selected cases. Our objective was to compare the short-term outcomes in patients operated on for a local recurrence who had radiation for the primary tumour to those who were spared radiation. METHODS: This was a retrospective study of 103 patients treated for a local recurrence: 48 (47%) with previous radiation and 55 (53%) without. Our primary outcome criterion was to identify the differences in the local treatment provided. Secondary outcomes were the cumulative incidence of a surgical site infection/wound complication (SSI/WC), variables associated with SSI/WC, and local recurrence. RESULTS: Amputation and the incidence of re-operation were significantly more frequent in patients who received previous radiation compared to patients without previous radiation (27% vs 9%, p = 0.02, for amputation; 26% vs 36% at 2 years for SSI/WC, p = 0.049). Multivariable regression models found previous radiation (p = 0.049), arteriopathy (p = 0.012), location at lower limb (p = 0.09), and use of a flap (0.0048) associated with the risk of SSI/WC. CONCLUSIONS: Previous radiation is associated with an increased risk of amputation and reoperation for SSI/WC when treating a local recurrence. This information should be accounted for when deciding for the use of radiation.

Sagittal plane assessment of manual concave rod bending for posterior correction in adolescents with idiopathic thoracic scoliosis (Lenke 1 and 3).

OBJECTIVES: The objectives of this study were to evaluate the repeatability and reproducibility of a method for measuring freehand rod bending and to analyze the relationship between the rod's bend and the resulting sagittal correction. MATERIALS AND METHODS: All the children who underwent correction by posterior translation using pedicle screws at all levels were included prospectively in 2018 and 2019. The rod's sagittal parameters were measured retrospectively by three independent surgeons on two separate occasions using the same protocol. After the rods were bent but before they were inserted, the surgeon traced the contours of the rods on a sheet of paper that was later scanned and analyzed semiautomatically. The spinal parameters were calculated based on biplanar radiographs taken preoperatively, postoperatively and at the final follow-up visit. Patients who had less than 10° thoracic kyphosis (T5-T12) made up the "Lenke N-" subgroup. RESULTS: Thirty patients were included (14 of whom were Lenke N-) who had a Cobb angle of 59.2±11.3° preoperatively and 13.3±8.4° postoperatively (p<0.00001). The inter- and intrarater ICC for the rod measurements were>0.9 (excellent). The mean kyphosis of the concave rod was 48.4±5.7° (38.3-60.9°). The mean change in T5-T12 kyphosis was 9.7±10.8° (-14.3-30.8°) (p<0.0001) in the entire population, while it was 17.7±7.1° (5.5-30.8°) (p<0.0001) in the Lenke N- subgroup. The change in thoracic kyphosis was positively correlated with the kyphosis of the concave rod (rho=0.52; p=0.003). CONCLUSION: This study found excellent reproducibility and repeatability of measuring freehand rod bending. The kyphosis applied to the concave rod is positively correlated to the change in the resulting kyphosis and made it possible to restore satisfactory thoracic kyphosis. LEVEL OF EVIDENCE: III.

Onyx injection by direct puncture for presurgical embolization of a C2 hypervascular metastasis from a thyroid cancer.

Surgery for spinal hypervascular lesions, such as hemangioma or metastases from thyroid or renal cancer, may be challenging because of the risk of massive blood loss.1 To overcome this limitation, presurgical embolization has gained acceptance to reduce this risk.2 However, some configurations, such as the origin of a radiculomedullary artery close to the vessels feeding the lesion or when the lesion is supplied by vessels feeding an eloquent territory, may limit the possibility of presurgical embolization, especially with microparticles.3 Direct percutaneous puncture of the spinal lesion and subsequent embolization with liquid embolic agent may be a valuable option in such challenging cases.4 We present a case of presurgical embolization of a C2 metastasis from a thyroid cancer using Onyx-18 injected by direct puncture (video 1). In this technical video, we stress the technical aspects of the direct puncture technique and the safety rules to avoid neurological complications. neurintsurg;14/1/neurintsurg-2020-017180/V1F1V1Video 1.

Fear Avoidance Beliefs and Outcome After Surgery for Degenerative Lumbar Spine.

STUDY DESIGN: This was a prospective cohort study. OBJECTIVE: The aim of this study is to question the influence of fear avoidance beliefs on functional outcome following surgery for degenerative lumbar spine. BACKGROUND: Fear avoidance beliefs are well-studied modifiers of low back pain. Nonetheless, the influence of fear avoidance beliefs on the outcome of spinal surgery remains controversial. METHODS: We conducted a prospective cohort study including patients undergoing surgery for degenerative lumbar discopathy, spondylolisthesis, and stenosis. Patients completed a preoperative questionnaire including the Fear Avoidance Beliefs Questionnaire (FABQ) as well as Visual Analog Scales for radicular and lumbar pain (VAS-R/L), Oswestry Disability Index (ODI), and Short-Form 36 health survey (SF36). Functional outcome was measured at least 6 months after surgery using ODI. RESULTS: Sixty-three patients with a mean follow-up of 254 days (8.5 mo, minimum=179 d, maximum=534 d) were included in the study. Women showed stronger work-related fear avoidance beliefs but there was no other difference in baseline characteristics and functional outcome between patients with low or high (>75th percentile) baseline FABQ-P or FABQ-W scores. Individual variables associated with whether patients reached minimal clinically important difference for ODI were: working status [odds ratio (OR)=0.13; 95% confidence interval (95% CI), 0.03-0.62; P =0.01], American Society of Anesthesiologists classification score (OR=0.32; 95% CI, 0.11-0.92; P =0.03), preoperative duration of symptoms (OR=0.94; 95% CI, 0.89-0.99; P =0.03), and preoperative ODI (OR=1.03; 95% CI, 1.00-1.07; P =0.05). Neither physical nor work-related preoperative FABQ scores were predictors of functional results. CONCLUSIONS: In our study, the FABQ was not associated with functional outcome following surgery for degenerative lumbar spine. Other psychological patient-reported measures are needed to refine selection of patients undergoing spine surgery in order to ensure better outcomes.

Influence of Renal Function and Age on the Pharmacokinetics of Levofloxacin in Patients with Bone and Joint Infections.

Despite its efficacy and toxicity being exposure-related, levofloxacin pharmacokinetics in patients with bone and joint infections has been poorly described to date, so the possible need for a dose adjustment is unknown in this population. A prospective population pharmacokinetic study was conducted in 59 patients to answer this question. The final model consisted of a one-compartment model with first-order absorption and elimination. Mean parameter estimates (% interindividual variability) were 0.895 h-1 for the absorption rate constant (Ka), 6.10 L/h (40%) for the apparent clearance (CL/F), 90.6 L (25%) for the apparent distribution volume (V/F). Age and glomerular filtration rate (GFR), estimated by the modification of diet in renal disease formula, were related to CL/F by power models, and CL/F was found to increase for increasing GFR and decreasing age. For a similar GFR, the simulated area under the curve (AUC) was 55% higher in 70 years-old patients compared to 30 year-old patients. Based on this model, a 750 mg dose should provide an optimal exposure (AUC/ minimum inhibitory concentration (MIC) ≥100), with the possible exception of patients older than 60 years and with GFR <70 mL/min/m² who may necessitate a dose reduction, and patients with infections caused by bacteria with MIC close to 1 mg/L who may need an increase in the dose.