Is assessment of skeletal muscle mass useful to predict time-to-awake in awake craniotomies?

Awake craniotomy is the gold standard for the resection of brain lesions near eloquent areas. For the commonly used asleep-awake-asleep technique, the patient must be awake and fully cooperative as soon as possible after discontinuation of anesthetics. A shorter emergence time is essential to decrease the likelihood of adverse events. Previous research found no relationship between body mass index (BMI) and time-to-awake for intravenous anesthesia with propofol, which is a lipophilic agent. As BMI cannot differentiate between fat and muscle tissue, we hypothesize that skeletal muscle mass, particularly when combined with BMI, may better predict time-to-awake from propofol sedation. We aimed to evaluate the relationship between skeletal muscle mass and the time-to-awake in patients undergoing awake craniotomy, as well as the interaction between skeletal muscle mass and BMI. In 260 patients undergoing an awake craniotomy, we used preoperative magnetic resonance imaging to assess temporalis muscle and cross-sectional skeletal muscle area of the masseter muscles and at level of the third cervical vertebra. Time-to-awake was dichotomized as ≤20 and >20 minutes. No association between various measures of skeletal muscle mass and time-to-awake was observed, and no interaction between skeletal muscle mass and BMI was found (all P > .05). Likewise, patients with a high BMI and low skeletal muscle mass (indicating an increased proportion of fat tissue) did not have a prolonged time-to-awake. Skeletal muscle mass did not predict time-to-awake in patients undergoing awake craniotomy, neither in isolation nor in combination with a high BMI.

Masseter muscle parameters can function as an alternative for skeletal muscle mass assessments on cross-sectional imaging at lumbar or cervical vertebral levels.

BACKGROUND: Patients with head and neck cancer are at increased risk of developing low skeletal muscle mass (SMM), which is associated with adverse treatment outcomes and prognosis. Low SMM is most commonly assessed by the skeletal muscle cross sectional area (CSA) at the third lumbar vertebra (L3) or more recently the third cervical vertebra (C3). L3 is not routinely imaged and C3 may be impacted by disease or treatment. As an alternative we analyzed masseter muscle characteristics and their relationship with L3 and C3 skeletal muscle CSA and overall survival (OS). METHODS: In this single-center retrospective study, 99 patients with head and neck cancer who underwent whole body FDG-PET/CT-scans were reviewed. Of these patients, L3 CSA, C3 CSA, masseter CSA, masseter thickness, masseter volume, masseter Hounsfield Unit values, lumbar skeletal muscle index (LSMI), cervical skeletal muscle index (CSMI), and masseter skeletal muscle index (MSMI) were recorded and correlated with each other and with OS. RESULTS: We included 72 male and 27 female patients. The masseter muscle parameters differed significantly between sexes. The Spearman correlation coefficients for C3 CSA-Masseter volume and L3 CSA-Masseter volume were 0.639 and 0.531 (P<0.001) respectively. In multivariate analysis low MSMI was a predictor of OS (HR 2.227, P=0.009). CONCLUSIONS: There is a moderate to strong association between the masseter muscle volume (MV) and C3 CSA and L3 CSA. MSMI predicts OS. Further research should investigate the relationship between muscle function and masseter muscle parameters and impacting factors on masseter muscle dimensions.

Omniflow II biosynthetic grafts versus expanded polytetrafluoroethylene grafts for infrainguinal bypass surgery. A single-center retrospective analysis.

INTRODUCTION: The aim of this study is to evaluate the outcome of Omniflow II biosynthetic vascular grafts as compared to synthetic expanded polytetrafluoroethylene (ePTFE) grafts in infrainguinal bypass surgery. METHODS: A single-center, retrospective, observational study was performed reviewing patients with critical limb ischemia who underwent infrainguinal bypass surgery between 2014 and 2018. Patients characteristics, graft characteristics, and treatment outcomes were collected. Patency rates were compared using Kaplan-Meier estimates. RESULTS: Sixty bypasses were performed in 57 patients. For above-knee surgery, six were Omniflow and 13 were synthetic. For below-knee surgery, 19 were Omniflow and 22 were synthetic. Patient characteristics between groups were similar. However, American Society of Anesthesiologists (ASA) classification scores were higher in the Omniflow group as compared to ePTFE (88% was ASA 3 or higher versus 60%; p = 0.018). Furthermore, wound, ischemia, and foot infection (WIfI) composite scores were higher in the Omniflow group (p = 0.0001). There was a trend toward more active infection at time of surgery in the Omniflow group (40 vs 22.9%, p = 0.15). At 1 year, primary patency rates were 60.0% versus 46.9% for above-knee Omniflow versus ePTFE grafts, respectively (p = 0.72). Secondary patency rates were 80.0% versus 82.5% (p = 0.89), and limb salvage rates were 83.3% versus 100% (p = 0.14). For below-knee surgery, 1- and 2-year primary patency rates in Omniflow versus ePTFE grafts were 36.0% versus 41.8% (p = 0.60) and 36.0% versus 31.1% (p = 0.87). Secondary patency rates were 66.8% versus 75.2% at 1 year (p = 0.53) and 58.8% versus 48.3% (p = 0.77) at 2 years. Below-knee limb salvage rates for Omniflow versus ePTFE after 2 years were 88.0% versus 68.3% (p = 0.28), respectively. Aneurysmal degeneration occurred in 2/25 (8%) in the Omniflow group and 0/35 (0%) in the ePTFE group. Bypass infections occurred in 2/25 (8%) in the Omniflow group and 0/35 (0%) in the ePTFE group (p = 0.09). CONCLUSION: Omniflow bypasses were more commonly implanted in patients with higher limb infection rate as confirmed with a higher adapted WIfI score. A trend toward a higher infection rate of Omniflow grafts was observed but not statistically significant. Graft infection rates were relatively low and treatable with antibiotics. No significant difference in graft performance was observed. The choice between the two studied grafts remains based on surgeon's preference.

Feasibility of assessment of skeletal muscle mass on a single cross-sectional image at the level of the fourth thoracic vertebra.

BACKGROUND: Skeletal muscle mass (SMM) determined on computed tomography (CT) is emerging as a novel imaging biomarker. Cross-sectional area (CSA) of SMM at the level of the third lumbar vertebra (L3) on abdominal imaging is considered the clinical reference standard for measuring SMM. In certain patient groups, such as those with oncological or non-oncological lung disease like COVID-19, a chest CT may be available while an abdominal CT is not. The purpose of this study was to investigate whether determining SMM on a chest CT is a feasible alternative to abdominal CT. RESEARCH QUESTION: What is the correlation between SMM measurements at the level of L3 and the level of the fourth thoracic vertebra (Th4)? STUDY DESIGN AND METHODS: In this study we retrospectively analyzed abdominal and thoracic series of whole-body CT-scans of trauma patients (N = 47) and head and neck cancer patients (N = 194). All abdominal muscles were delineated on a single axial slice at the level of L3. The erector spinae, levator scapulae, rhomboideus minor and major and pectoralis minor and major muscles were delineated on a single axial slice at the level of Th4. CSA of the muscles at Th4 and the L3 level were compared using linear regression, and a multivariate linear regression model was established. RESULTS: Muscle CSA at level Th4 strongly correlates with L3 muscle CSA (r = 0.791, p < 0.05). A multivariate model incorporating the patient characteristics arm positioning, age, sex, and weight achieved a stronger correlation (r = 0.856, p < 0.05). INTERPRETATION: Skeletal muscle CSA measured at the level of Th4 is a feasible alternative to measurements at L3. This allows diagnosing low SMM using clinically available thoracic CT-scans. SMM measurements at the level of Th4 may become a prognostic or triage tool when faced with mechanical ventilator shortage.

[Tick-borne encephalitis in the Netherlands]. / Teken-encefalitis in Nederland.

Tick-borne encephalitis (TBE) is endemic in South-Scandinavia, Central Europe and Eastern Europe. In 2016 the first patient was reported with TBE virus infection contracted in the Netherlands, in a forested area between Driebergen and Maarn (near Utrecht). At the time, field research did not identify any TBE-positive ticks at the supposed infection site. In the last two years, two patients have been diagnosed with TBE in the Diakonessenhuis Hospital in Utrecht; one patient was bitten by a tick in the Netherlands. This time round, tests on ticks from a different area near Utrecht (the forests around Zeist) did identify TBE-positive ticks. TBE infection is often asymptomatic. However, in a small proportion of patients, disease can develop and there is currently no curative therapy available. An effective vaccine is available. At the moment no vaccination recommendation is issued in the Netherlands. TBE should be considered in patients presenting with fever after a recent tick bite. When neurological symptoms appear, referral to a neurologist is necessary.