Low muscle mass determined by psoas muscle area does not correlate with dual-energy x-ray absorptiometry or total lumbar muscle mass scores: A prospective cohort study of patients undergoing vascular surgery.

Background/Objective: Low muscle mass and sarcopenia have been explored as risk factors for poor outcomes following vascular surgery. The findings have been variable. The use of a diverse range of techniques to identify low muscle mass is a confounder in establishing the true relationship between low muscle mass, sarcopenia and outcomes. Our aim was to establish if different scoring methods identified the same patients as sarcopenic. We also explored which method best predicted outcomes. Method: 70 patients undergoing vascular surgery were prospectively assessed for sarcopenia using dual-energy x-ray absorptiometry (DEXA) scan, grip strength and gait speed. These patients underwent abdominal CT imaging as routine care. The muscle mass of each patient was determined using DEXA and by both psoas muscle and total skeletal muscle area on CT, normalised for patient height (PMI and CT-SMI, respectively). Low muscle mass was defined by published age- and sex-specific cut-offs. Grip strength data was combined with muscle mass to define sarcopenic patients. One- and 3-year mortality and time to readmission was recorded. Conclusion and Results: 10-22% of patients had low muscle mass and 4-10% of patients were sarcopenic, depending on the method employed. PMI did not correlate with DEXA or CT-SMI for low muscle mass, but CT-SMI correlated with DEXA (p = 0.0007). For sarcopenia, CT-SMI and DEXA scoring correlated (p = 0.002); PMI correlated with CT-SMI (p = 0.0006) but not DEXA. Low muscle mass by PMI predicted 1-year mortality (p = 0.02, X2 = 5.34, Effect size = 1.04) but the applicability of this finding is limited by the diverse pathologies explored. No other method predicted 1- or 3-year mortality or readmissions in this heterogenous cohort. The psoas area did not correlate with muscle mass defined by DEXA or total lumbar skeletal muscle area. Low psoas muscle index may be an independent marker of poor outcome, unrelated to generalised sarcopenia, and this warrants investigation in specific pathologies. A lower total number of patients were sarcopenic than had been expected, emphasising the need to use population-based pre-defined cut-offs.

Low total psoas area as scored in the clinic setting independently predicts midterm mortality after endovascular aneurysm repair in male patients.

OBJECTIVE: Preoperative sarcopenia is an established risk factor for poor outcomes after surgery. Methods for assessing sarcopenia are either complex, time consuming, or poorly validated. We aimed to assess the interobserver reliability of scoring psoas area at the level of the L3 vertebra and to evaluate whether sarcopenia scored by this simple and rapid method correlated with other fitness scoring methods or impacted on mortality and duration of stay for patients undergoing endovascular aneurysm repair (EVAR). METHODS: We had access to 191 preoperative computed tomography scans of patients who underwent EVAR. For each scan the axial slice at the most caudal level of the L3 vertebra was extracted. Three observers independently calculated the combined cross-sectional area of the left and right psoas muscle at this level. Interobserver variability was calculated as per Band and Altman. Psoas area was normalized for patient height with sarcopenia defined as total psoas area of <500 mm2/m2. The effect of sarcopenia on patient survival was assessed using Cox proportional hazards models. Kaplan-Meier curves are also presented. RESULTS: Interobserver reliability of scoring psoas area was acceptable (reproducibility coefficient as percent of mean for each observer pair: 7.92%, 7.95%, and 14.33%). Sarcopenic patients had poorer survival (hazard ratio, 2.37; P = .011) and an increased hospital duration of stay (4.0 days vs 3.0 days; P = .008) when compared with nonsarcopenic patients. Sarcopenic patients were more likely to self-report as unfit (12.4% vs 33.3%; P = .004). Sarcopenia did not correlate with an increased rate of postprocedure complications. CONCLUSIONS: Psoas area scoring has good interobserver reliability. Preoperative sarcopenia as defined by psoas area was associated with poorer survival and of longer length of stay. As all patients being worked up for an endovascular aortic aneurysm repair will undergo a computed tomography scan, this method is a rapid and effective way to highlight patients in the clinic setting who have an increased risk of morbidity and mortality after EVAR.

Enhancing Postoperative Rehabilitation Following Knee Arthroplasty Using a New Cryotherapy Product: A Prospective Study.

To compare a novel cooling product, Physicool (P, Physicool Ltd, London, England, UK) with a well-established cryotherapy system, Cryocuff (C, Aircast, DJO Global, Vista, California, USA) using pain scores, range of movement (ROM), and cost as outcome measures in the early phase following total knee arthroplasty. We prospectively studied 90 consecutive patients undergoing unilateral total knee arthroplasty by a single surgeon. Following exclusions, 40 patients were recruited to each group. Visual analogue scale (VAS) for pain and ROM before and after application of cooling device was recorded at 24 and 48 hours after surgery. The cost of treatment per patient was also calculated. The VAS were significantly reduced in P on day 1 postsurgery (p = 0.013) and day 2 (p = 0.001) compared to C. A significant increase in ROM was recorded in P at 24 hours (p = 0.004) and at 48 hours (p = 0.009) postsurgery compared to C. The cost benefit of using P over C was approximately £25 per patient. The Physicool system is a safe and effective cooling method for improving pain and ROM in the early postoperative phase following total knee arthroplasty. Furthermore, it offers substantial cost savings.

Fourth ventricle rosette-forming glioneuronal tumour in children: an unusual presentation in an 8-year-old patient, discussion and review of the literature.

INTRODUCTION: Rosette-forming glioneuronal tumour of the fourth ventricle is a rarely described entity. While usually having an indolent course and hence classified as a WHO grade 1 tumour, the precise characteristics and risk of recurrence of this tumour are still unknown. In addition, the preferred treatment modality remains unclear. DISCUSSION: We present a case of an 8-year old with an early recurrence of 9 months after undergoing a sub-total resection of her tumour. Following further resection, there was no tumour present on the 3-month follow-up. In order to better characterise this tumour entity, we performed a review of the available literature on the subject. We found that it mainly affected young adults and had a female predominance. While initially these tumours were described in the fourth ventricle, the current literature suggests that they may be found in a larger variety of sites within the brain and spinal cord. There are several reports of recurrence occurring between 9 months and 10 years following surgery. There is as yet no feature of the tumour that appears to predict the risk of recurrence. CONCLUSION: This phenomenon warrants further examination to discover if there is a sub-section of tumours that is likely to recur, and until this is established, all patients should be followed up at regular intervals.

Z-Beamlet: a multikilojoule, terawatt-class laser system.

A large-aperture (30-cm) kilojoule-class Nd:glass laser system known as Z-Beamlet has been constructed to perform x-ray radiography of high-energy-density science experiments conducted on the Z facility at Sandia National Laboratories, Albuquerque, New Mexico. The laser, operating with typical pulse durations from 0.3 to 1.5 ns, employs a sequence of successively larger multipass amplifiers to achieve up to 3-kJ energy at 1054 nm. Large-aperture frequency conversion and long-distance beam transport can provide on-target energies of up to 1.5 kJ at 527 nm.