Comparison of procedural time with two different ultrasound-guided approaches for dorsalis pedis artery cannulation in adult patients: A randomized trial

BACKGROUND

In adult patients, there has never been an evaluation of short-axis out-of-plane versus long-axis in-plane approaches of ultrasound-guided dorsalis pedis artery cannulation. This research was conducted to compare these two techniques to cannulate the dorsal pedis artery.

METHODS

In this trial, 128 adult patients undergoing surgery and necessitating arterial cannulation were examined. Dorsalis pedis artery cannulation was performed utilizing an ultrasound by long-axis in-plane approach (group L) or short-axis out-of-plane (group S) techniques.

RESULTS

Group S had a higher first attempt success rate than group L (46.9% vs 28.6%, p = 0.039). The S group had a lower assessment time than the L group (11.48 ± 3.07 vs 19.68 ± 2.79 s; p = 0.000). Cannulation time was higher in the S group (18.91 ± 1.92 s) compared to the L group (12.48 ± 1.61 s; p = 0.000). Nevertheless, the total procedure time was comparable between the L group and the S group (32.16 ± 2.95 vs 30.42 ± 4.07 s; p = 0.107).

CONCLUSIONS

In adults, both views of ultrasonography can be used to guide DPA cannulation. The cannulation time for the DPA in L group was less than the S group, whereas the assessment time was less in S group. The total procedure time, however, was similar between both the groups.

Short-axis versus long-axis approach for ultrasound-guided vascular access: An updated systematic review and meta-analysis of randomised controlled trials

Background and Aims

There are two approaches for ultrasound (US)-guided vessel cannulation: the short axis (SA) approach and the long axis (LA) approach. However, it remains to be seen which approach is better. Therefore, we performed the present updated systematic review and meta-analysis to assess the effectiveness and safety of US-guided vascular cannulation between the SA and LA techniques.

Methods

We performed a comprehensive electronic database search in PubMed, Embase, Cochrane Library and Web of Science for the relevant studies from inception to June 2022. Randomised controlled trials comparing the SA approach and the LA approach for US-guided vascular access were incorporated in this updated meta-analysis. The first-attempt success rate was the primary outcome. The secondary outcomes were the overall success rate, cannulation time, number of attempts and the incidence of complications. The statistical analysis was conducted using RevMan software (version 5.4; the Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark). The Cochrane risk of bias tool was used to evaluate each study's potential risk for bias.

Results

In total, 16 studies consisting of 1885 participants were incorporated in this updated meta-analysis. No statistically significant difference was found between the SA and LA vascular access techniques for first-pass success rate (risk ratio = 1.07, 95% confidence interval: 0.94-1.22). The overall cannulation success rate, complication rate, average cannulation time and average number of attempts were not significantly different between the SA and LA groups.

Conclusion

This updated meta-analysis demonstrated that the SA and LA approaches of US-guided vessel cannulation are similar regarding first-pass success, overall cannulation success rate, total complication rate, cannulation time and the number of attempts.

Ultrasound-guided vascular access for CIED implantation: A step-by-step guide

INTRODUCTION

Vascular access is required for most cardiac electrophysiology procedures. Over the past 2 decades, ultrasound guidance has increased in utilization as the primary method for assisting operators in gaining access to cardiac implantable electronic device (CIED) implantation.

METHODS

Ultrasound guidance using a technique that includes both short-axis and long-axis views combined with a twisting needle motion after maximal tenting provides an extremely safe and reproducible technique for vascular access for all CIED procedures.

RESULTS AND CONCLUSIONS

In this manuscript and accompanying videos, a step-by-step guide is explained for optimal ultrasound-guided visualization and needle maneuver technique to maximize safety and efficiency for vascular access in all CIED procedures.

Data-Driven Clustering of Functional Signals Reveals Gradients in Processing Both within the Anterior Hippocampus and across Its Long Axis

A particularly elusive puzzle concerning the hippocampus is how the structural differences along its long anteroposterior axis might beget meaningful functional differences, particularly in terms of the granularity of information processing. One measure posits to quantify this granularity by calculating the average statistical independence of the BOLD signal across neighboring voxels, or intervoxel similarity (IVS), and has shown the anterior hippocampus to process coarser-grained information than the posterior hippocampus. This measure, however, has yielded opposing results in studies of developmental and healthy aging samples, which also varied in fMRI acquisition parameters and hippocampal parcellation methods. To reconcile these findings, we measured IVS across two separate resting-state fMRI acquisitions and compared the results across many of the most widely used parcellation methods in a large young-adult sample of male and female humans (Acquisition 1, N = 233; Acquisition 2, N = 176). Finding conflicting results across acquisitions and parcellations, we reasoned that a data-driven approach to hippocampal parcellation is necessary. To this end, we implemented a group masked independent components analysis to identify functional subunits of the hippocampus, most notably separating the anterior hippocampus into separate anterior-medial, anterior-lateral, and posteroanterior-lateral components. Measuring IVS across these components revealed a decrease in IVS along the medial-lateral axis of the anterior hippocampus but an increase from anterior to posterior. We conclude that intervoxel similarity is deeply affected by parcellation and that grounding one's parcellation in a functionally informed approach might allow for a more complex and reliable characterization of the hippocampus.SIGNIFICANCE STATEMENT Processing information along hierarchical scales of granularity is critical for many of the feats of cognition considered most human. Recently, the changes in structure, cortical connectivity, and apparent functional properties across parcels of the hippocampal long axis have been hypothesized to underlie this hierarchical gradient in information processing. We show here, however, that the choice of parcellation method itself drastically affects one particular measure of granularity across the hippocampus and that a functionally informed approach to parcellation reveals gradients both within the anterior hippocampus and in nonlinear form across the long axis. These results point to the issue of parcellation as a critical one in the study of the hippocampus and reorient interpretation of existing results.

Ultrasound-Guided Long-Axis Versus Short-Axis Femoral Artery Catheterization in Neonates and Infants Undergoing Cardiac Surgery: A Randomized Controlled Study

OBJECTIVE

The objective of the present study was to compare ultrasound-guided long-axis (LAX) and short-axis (SAX) femoral artery catheterization in neonates and infants undergoing cardiac surgery.

DESIGN

A single-center, prospective, randomized, single-blinded, controlled study.

SETTING

This study was conducted in the operating room and intensive care unit of the division of cardiac surgery, Mansoura University Children's Hospital, Egypt.

PARTICIPANTS

Ninety neonates and infants undergoing elective cardiac surgery were enrolled in this study and randomly allocated to ultrasound-guided LAX and SAX groups.

INTERVENTIONS

Ultrasound-guided femoral artery catheterization was done using either LAX (in-plane) or SAX (out-of-plane) technique.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was the rate of a successful first puncture. The secondary outcome measures were the rates of mechanical complications, failure rate, time to a successful first, second, and third puncture, total time of catheterization, and imaging time. The first puncture success rate was significantly higher (p = 0.048) in the LAX group (34 of 41, 82.9%) than in the SAX group (25 of 41, 60.9%). The mean time to a successful first puncture was significantly shorter (p < 0.001) in the LAX group (153.1 ± 30.1 seconds) than in the SAX group (227.2 ± 48.8 seconds). The total catheterization time was significantly shorter in the LAX group than in the SAX group. There was no significant difference in the rate of complication.

CONCLUSION

With a single experienced operator performing the ultrasound-guided femoral artery cannulation, the LAX technique resulted in a higher first puncture success rate and shorter time to cannulation than the SAX technique.

Mechanochemical Crosstalk Produces Cell-Intrinsic Patterning of the Cortex to Orient the Mitotic Spindle

Proliferating animal cells are able to orient their mitotic spindles along their interphase cell axis, setting up the axis of cell division, despite rounding up as they enter mitosis. This has previously been attributed to molecular memory and, more specifically, to the maintenance of adhesions and retraction fibers in mitosis [1-6], which are thought to act as local cues that pattern cortical Gαi, LGN, and nuclear mitotic apparatus protein (NuMA) [3, 7-18]. This cortical machinery then recruits and activates Dynein motors, which pull on astral microtubules to position the mitotic spindle. Here, we reveal a dynamic two-way crosstalk between the spindle and cortical motor complexes that depends on a Ran-guanosine triphosphate (GTP) signal [12], which is sufficient to drive continuous monopolar spindle motion independently of adhesive cues in flattened human cells in culture. Building on previous work [1, 12, 19-23], we implemented a physical model of the system that recapitulates the observed spindle-cortex interactions. Strikingly, when this model was used to study spindle dynamics in cells entering mitosis, the chromatin-based signal was found to preferentially clear force generators from the short cell axis, so that cortical motors pulling on astral microtubules align bipolar spindles with the interphase long cell axis, without requiring a fixed cue or a physical memory of interphase shape. Thus, our analysis shows that the ability of chromatin to pattern the cortex during the process of mitotic rounding is sufficient to translate interphase shape into a cortical pattern that can be read by the spindle, which then guides the axis of cell division.

A prospective, randomised, comparative study to evaluate long axis, short axis and medial oblique axis approach for ultrasound-guided internal jugular vein cannulation

Background and Aims:

The Ultrasound (USG)-guided internal jugular vein (IJV) cannulation can be performed using different approaches like short axis (SAX), long axis (LAX), oblique axis (OAX) or medial oblique axis (M-OAX). We aimed to determine which view was optimal for IJV cannulation.

Methods:

After ethical committee approval and written informed consent, this prospective, randomised, controlled trial was conducted on 108 patients. Patients were allocated into one of the three groups: A (SAX), B (LAX) and C (M-OAX approach) for USG-guided IJV cannulation. The number of needle passes, the success of IJV cannulation and its diameter, venous access time, guidewire time, catheterisation time and complications if any were recorded. Statistical analysis was performed by SPSS version 17.0.

Results:

First needle pass success rate was highest in M-OAX (97.2%) followed by SAX (88.9%) and then LAX (77.8%) but it was statistically insignificant among the groups. Mean venous access, guidewire insertion and catheterisation time were shortest in M-OAX followed by SAX and then LAX approach. It was statistically significant between LAX and SAX and between LAX and M-OAX group. (P < 0.001). The carotid puncture was noticed in two patients in the LAX group. The overall success rate and the number of needle passes were comparable among the groups.

Conclusion:

The M-OAX approach is a safe and effective technique for USG-guided IJV cannulation when compared to SAX and LAX approaches.

Parcellation of the Hippocampus Using Resting Functional Connectivity in Temporal Lobe Epilepsy

We have previously shown that the connectivity of the hippocampus to other regions of the default mode network (DMN) is a strong indicator of memory ability in people with temporal lobe epilepsy (TLE). Recent work in the cognitive neuroscience literature has suggested that the anterior and posterior aspects of the hippocampus have distinct connections to the rest of the DMN and may support different memory operations. Further, structural analysis of epileptogenic hippocampi has found greater atrophy, characterized by mesial temporal sclerosis, in the anterior region of the hippocampus. Here, we used resting state FMRI data to parcellate the hippocampus according to its functional connectivity to the rest of the brain in people with left lateralized TLE (LTLE) and right lateralized TLE (RTLE), and in a group of neurologically healthy controls. We found similar anterior and posterior compartments in all groups. However, there was weaker connectivity of the epileptogenic hippocampus to multiple regions of the DMN. Both TLE groups showed reduced connectivity of the posterior hippocampus to key hubs of the DMN, the posterior cingulate cortex (PCC) and the medial pre-frontal cortex (mPFC). In the LTLE group, the anterior hippocampus also showed reduced connectivity to the DMN, and this effect was influenced by the presence of mesial temporal sclerosis. When we explored brain-behavior relationships, we found that reduced connectivity of the left anterior hippocampus to the DMN hubs related to poorer verbal memory ability in people with LTLE, and reduced connectivity of the right posterior hippocampus to the PCC related to poorer visual memory ability in those with RTLE. These findings may inform models regarding functional distinctions of the hippocampal anteroposterior axis.

Cognitive mapping style relates to posterior-anterior hippocampal volume ratio

As London taxi drivers acquire "the knowledge" and develop a detailed cognitive map of London, their posterior hippocampi (pHPC) gradually increase in volume, reflecting an increasing pHPC/aHPC volume ratio. In the mnemonic domain, greater pHPC/aHPC volume ratios in young adults have been found to relate to better recollection ability, indicating that the balance between pHPC and aHPC volumes might be reflective of cross-domain individual differences. Here, we examined participants' self-reported use of cognitive map-based navigational strategies in relation to their pHPC/aHPC hippocampal volume ratio. We find that greater reported cognitive map use was related to significantly greater posterior, relative to anterior, hippocampal volume in two separate samples of young adults. Further, greater reported cognitive map usage correlated with better performance on a self-initiated navigation task. Together, these data help to advance our understanding of differences between aHPC and pHPC and the greater role of pHPC in spatial mapping.

Posttraumatic Stress Disorder and Depression Symptom Severities Are Differentially Associated With Hippocampal Subfield Volume Loss in Combat Veterans

Background

Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hippocampal subfields. Here, we apply a volumetric analysis of hippocampal subfields to data from a group of combat-exposed Veterans.

Method

Veterans (total, n = 68, posttraumatic stress disorder, n = 36; combat control, n = 32) completed high-resolution structural magnetic resonance imaging. Based on previously validated methods, hippocampal subfield volume measurements were conducted using FreeSurfer 6.0. The Clinician-Administered PTSD Scale assessed posttraumatic stress disorder symptom severity; Beck Depression Inventory assessed depressive symptom severity. Controlling for age and intracranial volume, partial correlation analysis examined the relationship between hippocampal subfields and symptom severity. Correction for multiple comparisons was performed using false discovery rate. Gender, intelligence, combat severity, comorbid anxiety, alcohol/substance use disorder, and medication status were investigated as potential confounds.

Results

In the whole sample, total hippocampal volume negatively correlated with Clinician-Administered PTSD Scale and Beck Depression Inventory scores. Of the 10 hippocampal subfields, Clinician-Administered PTSD Scale symptom severity negatively correlated with the hippocampus–amygdala transition area (HATA). Beck Depression Inventory scores negatively correlated with dentate gyrus, cornu ammonis 4 (CA4), HATA, CA2/3, molecular layer, and CA1. Follow-up analysis limited to the posttraumatic stress disorder group showed a negative correlation between Clinician-Administered PTSD Scale symptom severity and each of HATA, CA2/3, molecular layer, and CA4.

Conclusion

This study provides the first evidence relating posttraumatic stress disorder and depression symptoms to abnormalities in the HATA, an anterior hippocampal region highly connected to prefrontal-amygdala circuitry. Notably, dentate gyrus abnormalities were associated with depression severity but not posttraumatic stress disorder symptoms. Future confirmatory studies should determine the extent to which dentate gyrus volume can differentiate between posttraumatic stress disorder- and depression-related pathophysiology.

Long-axis view for ultrasound-guided central venous catheter placement via the internal jugular vein

BACKGROUND

In modern practice, real-time ultrasound guidance is commonly employed for the placement of internal jugular vein catheters. With a new tool, such as ultrasound, comes the opportunity to refine and further optimize the ultrasound view during jugular vein catheterization. We describe jugular vein access techniques and use the long-axis view as an alternative to the commonly employed short-axis cross-section view for internal jugular vein access and cannulation.

CONCLUSION

The long-axis ultrasound-guided internal jugular vein approach for internal jugular vein cannulation is a useful alternative technique that can provide better needle tip and guidewire visualization than the more traditional short-axis ultrasound view.

Real-time sonographically guided percutaneous dilatational tracheostomy using a long-axis approach compared to the landmark technique

OBJECTIVES

Sonographic evaluation of neck anatomy before performing percutaneous dilatational tracheostomy (PDT) has been shown to predict PDT success. In this study, we compared the real-time, long-axis, in-plane approach to the traditional bronchoscopically guided landmark technique.

METHODS

Data were analyzed from a prospectively maintained PDT database at a university tertiary care medical intensive care unit. A convenience sample of adult patients requiring PDT for prolonged mechanical ventilation dependence was enrolled. Critical care fellows, under direct supervision of an attending intensivist, performed all PDTs. Tracheostomy performance from the sonographically guided and landmark techniques was compared.

RESULTS

Twenty-three patients were enrolled: 11 in the sonography group and 12 in the landmark group. Initial midline introducer needle puncture was achieved in 72.7% in the sonography group compared to 8.3% in the landmark group (P< .001). The mean number of introducer needle punctures ± SD was significantly lower in the sonography group compared to the landmark group (1.4 ± 0.7 versus 2.6 ± 0.9; P < .001). The total tracheostomy time was 11.4 ± 4.2 minutes in the sonography group versus 15.3 ± 6.8 minutes in the landmark group (P = .12). Sonography accurately predicted tracheal ring space insertion in 90.9% of patients. Procedural complications did not differ significantly between the groups.

CONCLUSIONS

Percutaneous dilatational tracheostomy under real-time sonographic guidance using a long-axis approach may increase the rate of midline punctures and decrease the number of needle punctures when compared to the landmark technique. Sonographic guidance can also help guide accurate and efficient placement of a tracheostomy tube into the desired tracheal ring space.

Long axis strain by MRI and echocardiography in a postmyocardial infarct population

PURPOSE

To compare long axis strain (LAS) by magnetic resonance imaging (MRI) and echocardiography in a postinfarct patient population. Long axis left ventricle (LV) function is a sensitive index of incipient heart failure by echocardiography, but is less well established in MRI. LAS is an index of global LV function, which is easily assessed in cine loops provided by most cardiac MRI protocols.

MATERIALS AND METHODS

In all, 116 patients (57 ± 9 years) were studied the same day using echocardiography and MRI 7.4 ± 4.1 months after a first myocardial infarction. LV length was measured in end diastole and end systole in conventional cine images with a temporal resolution of 50 msec or less, and LAS (%) was calculated as the change in LV length, relative to end diastole. Infarct mass was assessed by contrast-enhanced MRI.

RESULTS

LAS was progressively reduced in patients with larger infarcts, and demonstrated good correlations with infarct mass (r = 0.55, P < 0.01). There was a good agreement between LAS assessed by echocardiography and MRI (r = 0.77, P < 0.01), and between LAS by MRI and speckle tracking strain by echocardiography (r = 0.74, P < 0.01).

CONCLUSION

LAS is an index that allows measurement of LV long axis function by conventional cine MRI.

Left ventricular long axis function in diastolic heart failure is reduced in both diastole and systole: time for a redefinition?

OBJECTIVE

To test the hypothesis that, when measured in the long axis, left ventricular systolic function is abnormal in patients with diastolic heart failure.

DESIGN

A case-control study.

SETTING

University teaching hospital (tertiary referral centre).

PATIENTS

68 patients with heart failure, 29 with a left ventricular ejection fraction (LVEF) of > 0.45 and diastolic dysfunction (diastolic heart failure), 39 with an LVEF of </= 0.45 (systolic heart failure), and 105 normal subjects, including 33 age matched controls.

METHODS

LVEF was measured by cross sectional Simpson's method, and mitral annular amplitudes and velocities by M mode and tissue Doppler echocardiography, respectively, along with mitral Doppler inflow velocities. Results were compared between the three groups.

MAIN OUTCOME MEASURES

Peak systolic mitral annular velocity and amplitude between the different groups.

RESULTS

The mitral annular peak mean velocity and amplitude in systole were lower in the patients with diastolic heart failure (mean (SEM), 4.8 (0.2) cm/s) than in the age matched normal controls (6.1 (0.14) cm/s), but higher than those with systolic heart failure (2.8 (0.13) cm/s) (all p < 0.001). Similar changes were seen the mitral annular amplitude during systole. Peak early diastolic velocity and amplitude were also significantly reduced in the group with diastolic heart failure. Left ventricular hypertrophy was evident in over 95% patients in both diastolic and systolic heart failure groups, with a comparable left ventricular mass index.

CONCLUSIONS

In patients with diastolic heart failure and evidence of left ventricular hypertrophy, there is systolic left ventricular impairment as measured by myocardial Doppler imaging of the longitudinal axis. Thus subtle abnormalities of systolic function are present in patients with heart failure and a normal left ventricular ejection fraction, and there appears to be a continuum of systolic function between those with truly normal, mildly impaired (labelled diastolic heart failure), and obviously abnormal left ventricular systolic function. Isolated diastolic dysfunction is uncommon.