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

Epidemiology of combined clavicle and rib fractures:a systematic review

Purpose The aim of this systematic review was to provide an overview of the incidence of combined clavicle and rib fractures and the association between these two injuries. Methods A systematic literature search was performed in the MEDLINE, EMBASE, and CENTRAL databases on the 14(th) of August 2020. Outcome measures were incidence, hospital length of stay (HLOS), intensive care unit admission and length of stay (ILOS), duration of mechanical ventilation (DMV), mortality, chest tube duration, Constant-Murley score, union and complications. Results Seven studies with a total of 71,572 patients were included, comprising five studies on epidemiology and two studies on treatment. Among blunt chest trauma patients, 18.6% had concomitant clavicle and rib fractures. The incidence of rib fractures in polytrauma patients with clavicle fractures was 56-60.6% versus 29% in patients without clavicle fractures. Vice versa, 14-18.8% of patients with multiple rib fractures had concomitant clavicle fractures compared to 7.1% in patients without multiple rib fractures. One study reported no complications after fixation of both injuries. Another study on treatment, reported shorter ILOS and less complications among operatively versus conservatively treated patients (5.4 +/- 1.5 versus 21 +/- 13.6 days). Conclusion Clavicle fractures and rib fractures are closely related in polytrauma patients and almost a fifth of all blunt chest trauma patients sustain both injuries. Definitive conclusions could not be drawn on treatment of the combined injury. Future research should further investigate indications and benefits of operative treatment of this injury

Comparison of Peptide Array Substrate Phosphorylation of c-Raf and Mitogen Activated Protein Kinase Kinase Kinase 8

Kinases are pivotal regulators of cellular physiology. The human genome contains more than 500 putative kinases, which exert their action via the phosphorylation of specific substrates. The determinants of this specificity are still only partly understood and as a consequence it is difficult to predict kinase substrate preferences from the primary structure, hampering the understanding of kinase function in physiology and prompting the development of technologies that allow easy assessment of kinase substrate consensus sequences. Hence, we decided to explore the usefulness of phosphorylation of peptide arrays comprising of 1176 different peptide substrates with recombinant kinases for determining kinase substrate preferences, based on the contribution of individual amino acids to total array phosphorylation. Employing this technology, we were able to determine the consensus peptide sequences for substrates of both c-Raf and Mitogen Activated Protein Kinase Kinase Kinase 8, two highly homologous kinases with distinct signalling roles in cellular physiology. The results show that although consensus sequences for these two kinases identified through our analysis share important chemical similarities, there is still some sequence specificity that could explain the different biological action of the two enzymes. Thus peptide arrays are a useful instrument for deducing substrate consensus sequences and highly homologous kinases can differ in their requirement for phosphorylation events

Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study

AbstractBackgroundThe optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists.MethodsAn online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use and timing of fine needle aspiration (FNA), antibiotics, catheter drainage and (minimally invasive) necrosectomy.ResultsThe response rate was 74% (N = 87). None of the respondents use FNA routinely, 85% selectively and 15% never. Most respondents (87%) use a step-up approach in patients with infected necrosis. Walled-off necrosis (WON) is considered a prerequisite for endoscopic drainage and percutaneous drainage by 66% and 12%, respectively. After diagnosing infected necrosis, 55% routinely postpone invasive interventions, whereas 45% proceed immediately to intervention. Lack of consensus about timing of intervention was apparent on day 14 with proven infected necrosis (58% intervention vs. 42% non-invasive) as well as on day 20 with only clinically suspected infected necrosis (59% intervention vs. 41% non-invasive).DiscussionThe step-up approach is the preferred treatment strategy in infected necrotizing pancreatitis amongst expert pancreatologists. There is no uniformity regarding the use of FNA and timing of intervention in the first 2–3 weeks of infected necrotizing pancreatitis

Non-operative vs. operative treatment for multiple rib fractures after blunt thoracic trauma: a multicenter prospective cohort study

Background Patients with multiple rib fractures without a clinical flail chest are increasingly being treated with rib fixation; however, high-quality evidence to support this development is lacking. Methods We conducted a prospective multicenter observational study comparing rib fixation to non-operative treatment in all patients aged 18 years and older with computed tomography confirmed multiple rib fractures without a clinical flail chest. Three centers performed rib fixation as standard of care. For adequate comparison, the other three centers performed only non-operative treatment. As such clinical equipoise formed the basis for the comparison in this study. Patients were matched using propensity score matching. Results In total 927 patients with multiple rib fractures were included. In the three hospitals that performed rib fixation, 80 (14%) out of 591 patients underwent rib fixation. From the nonoperative centers, on average 71 patients were adequately matched to 71 rib fixation patients after propensity score matching. Rib fixation was associated with an increase in hospital length of stay (HLOS) of 4.9 days (95%CI 0.8-9.1, p = 0.02) and a decrease in quality of life (QoL) measured by the EQ5D questionnaire at 1 year of 0.1 (95% CI - 0.2-0.0, p = 0.035) compared to non-operative treatment. A subgroup analysis of patients who received operative care within 72 h showed a similar decrease in QoL. Up to 22 patients (28%) who underwent surgery experienced implant-related irritation. Conclusions We found no benefits and only detrimental effects associated with rib fixation. Based on these results, we do not recommend rib fixation as the standard of care for patients with multiple rib fractures

Editor's Choice – Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

Objective: The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Methods: This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests. Results: The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38–50) mm and 68 (IQR 58–85) mm, respectively. Mortality was 1.3% (95% CI 0.7–2.4) after eIAA repair and 25.5% (95% CI 18.0–34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively). Conclusion: In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair

Common variants at the MHC locus and at chromosome 16q24.1 predispose to Barrett's esophagus

Barrett's esophagus is an increasingly common disease that is strongly associated with reflux of stomach acid and usually a hiatus hernia, and it strongly predisposes to esophageal adenocarcinoma (EAC), a tumor with a very poor prognosis. We report the first genome-wide association study on Barrett's esophagus, comprising 1,852 UK cases and 5,172 UK controls in the discovery stage and 5,986 cases and 12,825 controls in the replication stage. Variants at two loci were associated with disease risk: chromosome 6p21, rs9257809 (P combined = 4.09 × 10-9; odds ratio (OR) = 1.21, 95% confidence interval (CI) =1.13-1.28), within the major histocompatibility complex locus, and chromosome 16q24, rs9936833 (P combined = 2.74 × 10-10; OR = 1.14, 95% CI = 1.10-1.19), for which the closest protein-coding gene is FOXF1, which is implicated in esophageal development and structure. We found evidence that many common variants of small effect contribute to genetic susceptibility to Barrett's esophagus and that SNP alleles predisposing to obesity also increase risk for Barrett's esophagus. © 2012 Nature America, Inc. All rights reserved