Split-plot marine experiment to assess ecophysiological responses of Gelidium corneum assemblages

Canopy-forming macroalgae are facing large declines due to climate change worldwide. The foundation species Gelidium corneum (Hudson) J.V. Lamouroux has shown a long-term decline in the Southeastern Bay of Biscay. We conducted an in situ experiment to investigate the combined effect of solar radiation and nutrient availability on the photosynthetic acclimation and growth of this macrophyte, and on the species richness and diversity of the assemblages that it forms. Photochemical stress in G. corneum was found to be greater at the end of the study, probably as a result of a prolonged exposure to high irradiance (PAR and UVR) and due to high temperatures during summer. We found an acclimation of G. corneum specimens to summer light and thermal conditions through dynamic/reversible photoinhibition and a decrease in photosynthetic efficiency. Nutrients may also have had a positive effect in dealing with the negative effects of these stressors. Under ongoing global climate change and projections for the future, further research will be needed to better understand the effects not only on canopy forming species but also on the whole community and thus on the functioning of the ecosystem.

AB0556 CHARACTERISTICS OF PATIENTS DIAGNOSED WITH UNDIFFERENTIATED CONNECTIVE TISSUE DISEASE

Background

Patients with undifferentiated connective tissue disease (UCTD) struggle with physical symptoms as well as diagnostic uncertainty.1 UCTD diagnosis requires exclusion of other connective tissue diseases (CTD). Prior studies use variable definitions of UCTD that do not account for updated classification criteria thus limiting generalizability.

Objectives

We identified characteristics associated with rheumatologist-diagnosed UCTD, applied strict exclusion criteria, and compared UCTD patients to those with criteria-defined CTD.

Methods

We recruited patients ≥18 years old seen between 2018-2022 who had rheumatologist-diagnosed UCTD with positive ANA and ≥1 sign/symptom of a CTD. We reviewed medical records to identify those who fulfilled ACR/EULAR-endorsed classification criteria for SLE, RA, SSc, Primary Sjögren’s, Idiopathic Inflammatory Myopathy, and 2006 Revised Sapporo Criteria for APS. We compared sociodemographic, clinical, serologic, and treatment variables between UCTD and CTD using chi-square, Fisher’s exact, and t-tests.

Results

Of 89 patients with rheumatologist-diagnosed UCTD (mean age 49.0 ± 13.7 years, 97.8% female, 66.3% White), 59 (66.3%) had UCTD and 30 (33.7%) had criteria-defined CTD (27 SLE, 3 SLE and RA, 1 RA, and 1 APS).

Patients in both groups had similar non-criteria manifestations, most commonly arthralgia (89.8% UCTD vs. 83.3% CTD, p=0.50) and fatigue (55.9% UCTD vs. 73.3% CTD, p=0.17). Compared to patients with CTD, those with UCTD were less likely to have nonerosive arthritis (27.1% vs. 56.7%, p=0.01) (Table 1).

Table 1.

Characteristics of Patients with UCTD or Criteria-Defined CTD

UCTD1 (n=57), N (%)CTD2 (n=32), N (%)p-valuesClinical3,4•,4nicalN (%))cs of Pa16 (27.1)17 (56.7)0.01•.0156.7) (%))cs of Patients with UCTD or Criteria31 (52.5)18 (60.0)0.65•.6560.0) (%))cs of Patient7 (11.9)4 (13.3)1.0•.013.3)) (%))cs of Patients with UCTD or Criteria-Defined C27 (45.8)14 (46.7)1.0•.0(46.7) (%))cs of Patien24 (40.7)11 (36.7)0.82Serology3•erology) (%))cs of Patients with UCTD or Criteria-Defined CTDth19 (32.2)19 (63.3)<0.01•0.013.3) (%))cs of Patien9 (15.3)13 (4.3)<0.01•0.01.3)) (%))22 (37.3)25 (83.3)<0.01•0.013.3) (%))cs of Patients w10 (16.9)6 (20.0))0.77•.770.0)) (%))cs of Patients with UCTD or Criteria-D6 (10.2)2 (6.7)0.71•.71.7))) (%))cs of Patients with UCTD or Criteria-Defined CTDther CTDs. Our fi18 (30.5)10 (33.3)0.81•.8133.3) (%))cs11 (18.6)6 (20.0)1.0

1. Do not fulfill ACR/EULAR classification criteria for SLE, RA, SSc, PSS, IIM, APS.

2. Diagnosed with UCTD and fulfill ≥1 set of listed CTD classification criteria.

3. Defined per listed classification criteria

4. Criteria with n≤5: fever, proteinuria/cellular casts, pulmonary hypertension, interstitial lung disease, dysphagia/esophageal dysmotility

Patients with UCTD were less likely than those with CTD to have any hematologic manifestation (lymphopenia, leukopenia, thrombocytopenia, or hemolytic anemia) (p=0.02), anti-dsDNA or anti-Smith antibodies (p<0.01), or hypocomplementemia (p<0.01). The frequency of RA, Sjogren’s, and APS-related serologies did not differ between groups (Table 1).

Compared to those with CTD, UCTD patients were less likely to have ever received systemic corticosteroids (71.2% vs. 96.7%, p<0.01); ever use of any disease-modifying antirheumatic drug (DMARD) was similar (35.6% vs. 46.7%, p=0.36).

Conclusion

Among patients diagnosed with UCTD, 66.3% met a stringent definition. Compared to those with criteria-defined CTD, UCTD patients had lower frequency of arthritis, hematologic abnormalities, SLE-specific antibodies, and hypocomplementemia. While use of DMARDs did not differ, UCTD patients were less likely to use systemic corticosteroids.

Rheumatologists diagnose UCTD even when criteria are met for other CTDs. Our findings suggest UCTD is nonetheless a distinct clinical entity; more rigorous characterization will enable generalizable prognostic and therapy trials.

References

[1]Siegel CH, et al. J Clin Rheumatol 2021 Mar 5. doi: 0.1097/RHU. 0000000000001714

Disclosure of Interests

None declared

POS0715 QUANTIFYING THE PSYCHOSOCIAL IMPACT OF UNDIFFERENTIATED CONNECTIVE TISSUE DISEASE (UCTD)

Background:

Only half of patients diagnosed with SLE fulfill classification criteria; the rest have “SLE-like” illnesses such as UCTD. SLE patients are known to experience impaired health-related quality of life (HRQoL) and significant anxiety, depression, and fatigue,1 yet the psychosocial aspects of UCTD are less established. In a qualitative study, we found that most UCTD patients had engaged in psychotherapy and felt additional support was needed.2

Objectives:

Using multiple validated instruments, this study aims to quantify the psychosocial impact of UCTD.

Methods:

The Hospital for Special Surgery UCTD and Overlap Registry includes UCTD patients aged ≥ 18 years with ANA ≥ 1:80 and ≥ 1 sign or symptom of rheumatic disease who do not fulfill classification criteria for a defined CTD. We administered the 36-Item Short Form Health Survey (SF-36), General Anxiety Disorder-7 (GAD-7), Beck Depression Inventory (BDI), and Fatigue Severity Scale (FSS) to all patients to assess HRQoL, anxiety, depression, and fatigue. Instruments were scored based on established algorithms and results were summarized using predefined scales and severity thresholds.

Results:

The composite questionnaire was administered to 85 UCTD patients and completed by 75 (97.3% female, 60% white, mean age ± SD 48.8 ± 13.6 years). The SF-36 Physical Component Summary mean score was 37.8 and Mental Component Summary mean score was 41.1. Across the 8 SF-36 subscales, mean scores were lowest for role limitations due to physical health (39.3) and vitality (39.7) and highest for physical functioning (67.2), role limitations due to emotional health (67.1), and mental health (67.1). Approximately half of UCTD patients reported anxiety (GAD-7 ≥ 6); 20% had moderate/severe anxiety (GAD-7 ≥ 10). The prevalence of depression (BDI ≥ 14) was 26.7%; 13.3% had moderate/severe depression (BDI ≥ 20). Fatigue (FSS ≥ 3) was reported by 82.8% of patients (median FSS score of 4.7) [Table 1].

Table 1.

Psychosocial Survey Scores of Patients with Undifferentiated Connective Tissue Disease (n=75)

36-Item Short Form Health Survey (SF-36)Range 1-100 – Mean (SD)*Physical Component Summary∘Physical functioning∘Role-Physical∘Bodily PainoGeneral Health38.2 (11.2)67.2 (26.3)39.3 (46.3)49.5 (22.1)42.9 (21.5)Mental Component Summary∘Vitality∘Social Functioning∘Role-EmotionaloMental Health41.3 (10.7)39.7 (21.7)59.3 (25.9)67.1 (41.9)67.1 (18.3)Generalized Anxiety Disorder-7 (GAD-7)Range 0-21 – N (%)**None [0-5]Mild [6-10]Moderate [11-15]Severe [16-21]38 (50.7)22 (29.3)14 (18.7)1 (1.3)Beck Depression Inventory (BDI)Range 0-63 – N (%)**Minimal [0-13]Mild [14-19]Moderate [20-28]Severe [29-63]55 (73.3)10 (13.3)7 (9.3)3 (4.0)Fatigue Severity Scale (FSS) Range 1-7 – Median (IQR)**4.7 (1.5)

*Higher number indicates better health state. **Higher number indicates greater severity.

Conclusion:

UCTD patients have significantly impaired HRQoL and a high prevalence of anxiety, depression, and fatigue, suggesting substantial psychosocial impact of UCTD comparable to that reported in SLE.3,4 Impaired HRQoL in UCTD is driven to similar degrees by aspects of physical and mental health. In future studies, we will compare age- and sex- matched UCTD to SLE patients and longitudinally evaluate psychosocial metrics alongside clinical trajectories.

References:

[1]Dietz B, Katz P, Dall’Era M, et al. Major depression and adverse patient-reported outcomes in systemic lupus erythematosus: Results from a prospective longitudinal cohort. Arthritis Care Res. 2021;73(1):48-54.

[2]Siegel CH, Kleinman J, Barbhaiya M, et al. The psychosocial impact of undifferentiated connective tissue disease on patient health and well-being: A qualitative study. J Clin Rheumatol. In press.

[3]Gu M, Cheng Q, Wang X, et al. The impact of SLE on health-related quality of life assessed with SF-36: A systemic review and meta-analysis. Lupus. 2019;28(3):371-382.

[4]Zhang L, Fu T, Yin R, Zhang Q, Shen B. Prevalence of depression and anxiety in systemic lupus erythematosus: A systematic review and meta-analysis. BMC Psychiatry. 2017;17(1).

Acknowledgements:

This project was supported by the Barbara Volcker Center for Women and Rheumatic Diseases and the Robin J. Sillau Memorial Research Fund for Connective Tissue Disease. Dr. Barbhaiya is supported by the Rheumatology Research Foundation Investigator Award.

Disclosure of Interests:

None declared

Validation of a deep learning reconstruction framework for 3D delayed myocardial enhancement imaging

Funding Acknowledgements

Type of funding sources: None.

Introduction

Myocardial delayed enhancement (MDE) MRI plays an important role in the identification of several cardiac conditions, both ischemic and non-ischemic (e.g. myocarditis, IDC, amyloidosis). 3D imaging offers increased resolution, full heart coverage and better depiction of complex pathologies, but its image quality is limited by long acquisition times.

Deep learning (DL) models enable advanced reconstruction algorithms that yield regularized images in practical computation times. In this study we evaluate a novel 3D-DL reconstruction to overcome the trade-off between reconstructed quality and acquisition time on MDE data.

Methods

A group of 14 subjects referred for CMR (5 F / 9 M, 59 ± 11 y.o., 78 ± 13 kg) were scanned with a 3D MDE sequence prototype: SPGR with IR preparation, fat & spatial saturation, respiratory navigator, ARC 2x, FOV 40x40cm, ST 1.4-2.4mm, matrix 280²-320², FA 20deg, BW 62.5 kHz, TE 2.1 ± 0.1ms, TI based on a CINE IR scout. All were retrospectively reconstructed using a 3D DL algorithm, trained on a database of over 700 datasets to reconstruct high-quality images with adjustable noise reduction.

The images were compared with standard 3D Cartesian reconstruction by two experienced cardiologists, to identify alterations in morphology or contrast distribution. Noise was estimated using the intensity standard deviation on a blood pool ROI. Feature preservation was estimated using the structural similarity index (SSI).

Results

The new method improved perceived image quality without loss of structural information or resolution (fig 1). Quantitative analysis (fig 2) confirmed these results: The average coefficient of variation in the blood was 0.08 ± 0.02 in the reference and 0.05 ± 0.02 with the new method; Given a target image noise level, DL reconstruction yielded up to 10% better SSI, compared to anisotropic filtering.

The clinical review didn’t reveal diagnostically significant alterations of structure or uptake pattern. A perceived reduction of sharpness was initially reported but individual examination of landmarks (e.g. pulmonary and coronary arteries) confirmed that no relevant features were being lost with the new reconstruction.

Discussion

The 3D MDE images obtained with DL reconstruction improved the trade-off between image noise -estimated by the blood pool intensity deviation- and feature preservation -estimated by SSI-.

Consistent improvement of image quality without morphological alterations of diagnostic relevance indicates that the new method can be considered for clinical practice. The next step in the validation process will require testing the robustness over a large set of cases with heterogeneous acquisition settings.

Conclusion

We presented the preliminary evaluation of a deep learning reconstruction method with 3D myocardial delayed enhancement data. The results show systematic improvement of overall image quality without loss of relevant diagnostic information.

Abstract Figure.

Improving the robustness of MOLLI T1 maps with a dedicated motion correction algorithm

Funding Acknowledgements

Type of funding sources: None.

Introduction

Myocardial T1 mapping constitutes a reliable indicator of heart diseases related to changes of myocardial extracellular content (e.g. oedema, fibrosis) as well as fat, iron and amyloid content.

T1-mapping techniques rely on fitting a model to a series of MRI measurements. Alignment between these measurements is required for accurate T1 estimation. This is limited by triggering accuracy and patient motion. Image registration is often applied to improve the alignment. In the case of MOLLI series, registration is compromised by contrast variation between the images.

We present the validation of a new registration method, designed to account for the contrast properties of MOLLI data.

Methods

A cohort of 186 patients referred for a CMR was included in this study (115 M / 71 F; weight 75 ± 15 Kg; age 55 ± 16). Scans on a 3.0T MR included a MOLLI sequence with target parameters: 2D bSSFP, 160x148, pFOV 0.8-1.0, 1.4x1.4mm², ST 8mm, TE 1.4ms, TR 3.0ms, FA 35deg, NEX 1, BW 100kHz, 2x ASSET, 5(3)3.

Cartesian 2D reconstruction followed by motion correction was applied retrospectively. A new correction algorithm was implemented, based on a similarity criterion that accounted for T1 relaxation: It consisted of an iterative approach alternating polarity estimation, T1 fitting, relaxation simulation and frame registration. The coefficient of determination (R²) was used as a quality measure. A representative subset of the results was reviewed by two experienced cardiologists.

Results

All reconstructions (totalling 1133 2D MOLLI series) yielded qualitatively correct T1 maps. Results with the new method were compared to conventional motion correction and no correction.

The number of pixels with R²&gt;0.95 was 85%±9% with standard motion correction and 90%±7% with the new dedicated method. In terms of improvement w.r.t. uncorrected data, the standard method yielded +3%±8% and the new one +9%±8%. Motion correction caused noticeable performance degradation in 12% of cases with the standard method, compared to 0.2% with the proposed method.

The relative performance of the different methods can be appreciated in Figure 3.

Discussion

Despite T1 mapping techniques constituting a reliable diagnostic tool in cardiac imaging, they remain sensitive to patient motion and triggering inaccuracies, making them vulnerable to arrhythmia episodes.

Improving the similarity criterion by accounting for T1 relaxation significantly decreased the incidence of misregistration and subsequent T1 inaccuracies. Using the R² of the voxel-wise T1 fit as a surrogate of alignment allowed to confirm the increased robustness of the new, dedicated motion correction method for MOLLI series.

Conclusion

We have demonstrated a new reconstruction pipeline with built-in registration, optimized for MOLLI T1-mapping. Using a large database of clinical data, the new method has been shown to improve the robustness to motion of cardiac T1 mapping.

Abstract Figure.

61 Swim-up and microfluidic techniques improve the kinetic parameters of selected bovine spermatozoa for invitro fertilization: Preliminary results

For invitro embryo production, spermatozoa with fertilizing capacity must possess optimal kinetic, morphometric, vitality, and DNA integrity characteristics. The objective of this study was to evaluate the effect of 3 sperm selection methods on sperm quality and invitro embryonic development in bovine. Frozen commercial semen (0.5 mL/straws) from one bull with known fertility was thawed at 37°C for 20s and was divided for 3 sperm selection techniques: density gradient, swim-up, and microfluidic sperm sorting. The sperm kinetic parameters (VCL=curvilinear velocity, VSL=straight line velocity, VAP=average path velocity, ALH=lateral displacement of sperm head, BCF=beat frequency cross, STR=path straightness) were assessed using computer-assisted sperm analysis (CASA). Sperm morphometric parameters were evaluated using Diff-Quick staining followed by automated analysis. To assess vitality, the sperm were stained with propidium iodide and acridine orange, then analysed under a fluorescence microscope. In addition, DNA fragmentation was assessed using sperm chromatin dispersion method. Last, the fertilizing capacity of the selected sperm was tested by fertilizing cumulus–oocyte complexes (2×106 sperm mL−1) obtained from slaughterhouse ovaries and matured invitro for 24h. A standardized invitro embryo production protocol was used with commercial medium from Vitrogen. The cleavage rate and blastocyst yield were measured on Day 2 and 7, respectively (fertilization=Day 0). The results were calculated with analysis of variance and Tukey’s test (P&lt;0.05). The values of sperm kinetic parameters obtained with swim-up (VCL 132.5µm/s; VSL 73.5µm/s) and microfluidic technique (VCL 129.5µm/s; VSL 64.4µm/s) were significantly higher (P&lt;0.05) than those obtained by density gradient (VCL 98.3µm/s; VSL 45.01µm/s). However, the total and progressive motility by density gradient method was slightly higher (89% and 57%) compared with that assessed by swim-up (64% and 43%) or microfluidic technique (74% and 54%) respectively. Microfluidic sorting (11.3%) showed lower (P&lt;0.05) DNA fragmentation levels compared with density gradient method (16.6%), whereas the swim-up technique (12.5%) was similar between both groups. No significant difference was detected between the 3 groups for sperm morphometric and vitality parameters. Moreover, cleavage rates were similar (P&gt;0.05) between the 3 sperm selection techniques: density gradient (84.0%), swim-up (75.2%), and microfluidic sorting (67.3%). However, blastocyst yield was significantly higher (P&lt;0.05) using sperm selected by density gradient (28.1%) and swim-up (21.9%) compared with microfluidic sorting (15.3%). In conclusion, sperm selection using microfluidic and swim-up techniques improved kinetic parameters with lower levels of DNA fragmentation, without affecting sperm morphometry. However, both the density gradient and swim-up techniques are efficient systems for producing invitro bovine embryo.

T1 mapping of the remote non-infarct myocardium for predicting adverse left ventricular remodeling following STEMI

Background

Adverse Left Ventricular (LV) remodeling (ALVR) following ST-segment Elevation Myocardial Infarction (STEMI) is the result of numerous mechanical, neurohormonal, micro and macrovascular factors, and remains a major clinical problem. Cardiac Magnetic Resonance (CMR) is a multimodality technique that provides comprehensive functional and tissue characterization of infarcted and non-infarcted myocardium. Whether changes in the extracellular matrix in the remote myocardium in patients following a STEMI are associated with adverse LV remodeling has been a topic of debate.

Aim

We explored the additive value of native T1 variation (ΔnT1) and derived-extracellular volume (ECV) fraction in the remote non-infarcted myocardium as predictors of adverse LV remodeling following STEMI.

Methods

A total of 99 subjects (83% male) with their first mechanically reperfused STEMI underwent CMR within 2 weeks and at 6 months, including T1 mapping prior and 15 to 20 minutes following a bolus of gadolinium (0.2 mmol/kg), with a MOLLI sequence. ECV and nT1 values were computed by averaging co-registered ROIs in three distinct segments in the remote non-infarcted myocardium.

Results

Baseline nT1 but not ECV correlated with infarct size (r=0.349, P&lt;0.001 and r=0.162, P=0.096 respectively). In addition, ΔnT1 but not ΔECV correlated with an increase in LV end-diastolic volume index (LVEDVi) (r=0.268, P&lt;0.01 and r=0.113, P=0.285).

ALVR, defined as Δ&gt;20% inLVEDVi, occurred in 21 cases, despite optimal medical therapy. Subjects with ALVR showed greater ΔnT1 (13.2±44.1 vs −5.2±30.2 ms, P&lt;0.05) but no significant differences in ΔECV (1.27±2.77 vs 0.72±2.45%, P=0.401). Also, subjects with ALVR were more likely hypertensive (67 vs 33%, P&lt;0.05), had more segments with microvascular obstruction (2.1±2.2 vs 0.8±1.7, P&lt;0.01) and lower baseline EF (39.8±8.8 vs 44.6±9.6%, P&lt;0.05). Infarct size was not significantly larger in ALVR subjects (20.7±13.4 vs 17.5±13.0% LV mass, P=0.322). A multivariate analysis including all these factors, showed the extent of microvascular obstruction (ExpoB: 1.35 [1.05–1.73], P=0.019) and remote ΔnT1 (ExpoB: 1.02 [1.00–1.03], P=0.026) to be the independent predictors of ALVR.

Conclusions

The nT1 variation in remote non-infarcted myocardium and the extent of microvascular obstruction are superior to ECV changes and infarct size in predicting ALVR following STEMI.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fundaciό La Maratό TV3 2015 30 31 32. Fondos FEDER

Redefining anterior ankle arthroscopic anatomy: medial and lateral ankle collateral ligaments are visible through dorsiflexion and non-distraction anterior ankle arthroscopy

PURPOSE

A thorough understanding of the arthroscopic anatomy is important to recognise pathological conditions. Although some ankle ligaments have been described as intra-articular structures, no studies have assessed the full visibility of these structures. The purpose of this study was to assess arthroscopic visibility of medial and lateral ankle collateral ligaments.

METHODS

Arthroscopy was performed in 20 fresh frozen ankles. The arthroscope was introduced through the anteromedial portal and the anterior compartment was explored in ankle dorsiflexion without distraction. Intra-articular structures were tagged using a suture-passer introduced percutaneously and they were listed in a table according to the surgeon's identification. After the arthroscopic procedure, the ankles were dissected to identify the suture-tagged structures.

RESULTS

According to the suture-tagged structures, 100% correlation was found between arthroscopy and dissection. In the anterior compartment, the superior fascicle of the anterior talofibular ligament, the distal fascicle of the anterior tibiofibular ligament and the anterior tibiotalar ligament on the medial side were observed. The deep fascicle of the posterior tibiofibular ligament and the intermalleolar ligament were tagged at the posterior compartment.

CONCLUSION

Ankle dorsiflexion and non-distraction arthroscopic technique allows full visualisation of the medial and lateral ankle collateral ligaments: the superior fascicle of the anterior talofibular ligament, the distal fascicle of the anterior tibiofibular ligament and the anterior tibiotalar ligament. When using distraction, posterior structures as the deep fascicle of the posterior tibiofibular ligament and the intermalleolar ligament can be observed with anterior arthroscopy.

The lateral ankle ligaments are interconnected: the medial connecting fibres between the anterior talofibular, calcaneofibular and posterior talofibular ligaments

PURPOSE

A deep knowledge of lateral ankle ligaments is necessary to understand its function, pathophysiology and treatment options. The ankle lateral collateral ligament is formed by the anterior talofibular ligament (ATFL), the calcaneofibular (CFL) and the posterior talofibular ligament (PTFL). Although previous studies have reported connections between these ligaments on its lateral side, no studies have specifically assessed connections on the medial side. The aim of this study was to assess the morphology and consistency of the medial connections between the components of the lateral collateral ligament complex of the ankle.

METHODS

Forty fresh-frozen ankle specimens were dissected to look for connections between the three lateral ankle ligaments. After visualization of the lateral ligaments was achieved, the fibula was amputated and ligament insertions were released at the talar and calcaneal insertion points. Observation of the connections and video analysis of the dynamic relationships of ligament connections were performed.

RESULTS

Connections were found in all cases between the ATFL and PTFL, the ATFL and CFL, and the CFL and PTFL. Connections between ATFL and PTFL were not homogeneous. Although connections between the ATFLif and PTFL were noted in all cases (40), only 17 ankles (42.5%) had connections between the ATFLsf and PTFL. The amount of fibres of connection was also variable.

CONCLUSION

Connections between the three components of the lateral collateral ligament of the ankle may be observed from the medial aspect of the ankle, and this may have important implications for arthroscopic lateral ligament repair.

Anatomic lectures on structures at risk prior to cadaveric courses reduce injury to the superficial peroneal nerve, the commonest complication in ankle arthroscopy

PURPOSE

To assess the effectiveness of cadaveric ankle arthroscopy courses in reducing iatrogenic injuries.

METHODS

A total of 60 novice surgeons enrolled in a basic cadaveric ankle arthroscopy course were divided into two groups. Group A (n = 32) was lectured on portal placement and use of the arthroscope, whereas group B (n = 28) was in addition lectured on specific portal-related complications. Following the performance of anterior ankle arthroscopy and hindfoot endoscopy, the specimens were dissected and carefully assessed for detection of any iatrogenic injuries.

RESULTS

The rate of injury to the superficial peroneal nerve (SPN) was reduced from 25 to 3.6%, in group A compared with B (p = 0.033). Injuries to the peroneus tertius or extensor digitorum longus, the flexor hallucis longus and the tibial nerve or the Achilles tendon were also reduced in group B. Overall, the number of uninjured specimens was 50% (n = 30) and higher in group B (57%) than group A (44%). Lesions to the plantaris tendon, the sural nerve or the posterior tibial artery were more common in group B, however, without reaching statistical significance. Overall, 25 (13.9%) anatomic structures were injured in anterior arthroscopy compared to 18 (5%) in hindfoot endoscopy, out of a potential total of 180 and 360, respectively (p = 0.001).

CONCLUSION

Dedicated lectures on portal-related complications have proven useful in reducing the risk of injury to the SPN, the commonest iatrogenic injury encountered in ankle arthroscopy. Hindfoot endoscopy is significantly safer than anterior ankle arthroscopy in terms of injury to anatomical structures.

A step-by-step arthroscopic examination of the anterior ankle compartment

PURPOSE

Despite the increased use of ankle dorsiflexion without distraction, no reports have specifically addressed the arthroscopic anatomy of the ankle in this position. The purpose of this study was to describe the normal arthroscopic anatomy of the ankle joint, when using the ankle dorsiflexion and the dynamic distraction technique, and to propose an arthroscopic examination system for the anterior ankle compartment.

METHODS

Ankle arthroscopy was performed in 20 fresh frozen specimens. Arthroscopic examination was performed with the arthroscope introduced through the anteromedial portal. The anterior compartment was examined in ankle dorsiflexion without distraction. The compartment was examined in four steps: (1) lateral area including the lateral gutter; (2) the central area of the anterior tibial rim; (3) the medial area including the medial gutter; (4) the talar neck. Next, distraction was applied to visualise the anterior compartment again and to examine the central and posterior ankle compartments.

RESULTS

Anatomic intra-articular structures were visualised in all specimens. Four intra-articular fat pads, one anteromedial, two syndesmotic and another posteromedial, were constantly observed. A description of the normal arthroscopic anatomy of the ankle using the ankle dorsiflexion and the dynamic distraction technique is detailed for the anterior, central and posterior compartments.

CONCLUSION

The ankle arthroscopic procedure without distraction allows constant visualisation of the ATFL's superior fascicle on the floor of the lateral gutter, the ATiFL's distal fascicle laterally and the most anterior margin of the deltoid ligament in the medial gutter (anterior tibiotalar ligament). However, ankle distraction is required to observe the central and posterior compartments, but it does not provide optimal visualisation of the anterior ankle compartment structures.

LEVEL OF EVIDENCE

V.

The anterior tibiofibular ligament has a constant distal fascicle that contacts the anterolateral part of the talus

PURPOSE

The anterior tibiofibular ligament (ATiFL) and its distal fascicle have been the subject of numerous studies, mainly due to the involvement of this ligament in anterolateral soft-tissue impingement of the ankle. There is currently no firm evidence related to the incidence of the distal fascicle or the frequency with which it is in contact with the talus, or whether this is a constant anatomic finding. In addition, the terminology used to refer to this structure is not accurate and varies widely in previous studies. The purpose of this study was to perform an anatomic study on a large number of specimens to clarify the anatomy of the anterior tibiofibular ligament, and specifically its distal fascicle, and its possible role in anterior ankle impingement syndrome.

METHODS

During a 7-year period (2010-2016), cadaveric ankle specimens dissected at our Anatomy Department were included in this study, accounting for a total of 154 ankles. The incidence of the distal fascicle and its contact with the talus were documented.

RESULTS

One hundred and seventeen ankles were included [78 men, 39 women, with a median age of 79.3 years (range 51-100 years)]. The ATiFL was found to have a distal fascicle in 100% of ankles, contacting the anterolateral part of the talus in all cases. The contact was increased in plantarflexion and reduced in dorsiflexion and finally disappeared completely in maximum dorsiflexion.

CONCLUSIONS

The ATiFL has a constant distal fascicle that is in contact with the talus in the neutral position and in plantar flexion. Contact disappears in maximum dorsiflexion.

P4421Increased circulating levels of VCAM-1 correlate with left atrial remodeling in highly trained athletes

Introduction

Reports have shown increased risk of atrial fibrillation (AF) in athletes. Vascular cell adhesion molecule-1 (VCAM1) is associated with new onset AF in general population. VCAM1 and its relation with left atrial (LA) remodeling have not been investigated in athletes.

Purpose

To study VCAM1 and LA remodeling in marathon runners.

Methods

Study of 36 male marathon runners in the training period previous to race (42 km) and 18 sedentary controls with no risk factors. Athletes were divided in two groups according to highest training intensity reached (group 1, >100 km/week; group 2, 50–100 km/week). Previous to race in all subjects, VCAM1 serum levels were measured by ELISA and an echocardiogram was performed. In athletes, VCAM1 was measured immediately post-race. Wilcoxon and Spearman were used.

Results

See table. Group 1 showed a significant increment in VCAM1 post-race (651±350 to 905±373 ng/mL; p=0.002) as compared to group 2 with no increment (533±133 to 651±138 ng/mL; p=0.117). In athletes, a moderate correlation between LA volume and VCAM1 was found (rho: 0.483; p=0.007).

Baseline characteristics Group 1 (n=18) Group 2 (n=18) Controls (n=18) p value Age (years) 37±6 38±5 36±4 0.373 Heart rate (bpm) 53±8 57±7 69±6 * 0.001 Body surface area (m2) 1.8±0.1 1.8±0.1 1.9±0.1 0.075 LV diastolic diameter (mm) 49±5 48±5 46±4 0.404 LV systolic diameter (mm) 29±5 30±5 30±4 0.879 Septal wall (mm) 9.1±1.2† 8.2±1.1 8.1±0.8 0.005 Posterior wall (mm) 9.3±2.1† 8.5±1.2 7.6±0.8 0.001 Ejection fraction (%) 55±3 55±6 57±4 0.110 LV mass index (g/m2) 106±27† 78±18 58±11 0.001 LA volume (mL/m2) 42±8† 30±11 25±9 0.001 E wave (cm/sec) 78±13 84±12 77±15 0.217 A wave (cm/sec) 50±12 53±10 48±16 0.438 DT (msec) 233±65 229±65 221±66 0.184 VCAM1 (ng/mL) 651±350† 533±133 440±98 0.022 Mean ± SD. *p<0.05 vs group 1 and 2 post Kruskall-Wallis; †p<0.05 vs other groups post Kruskall-Wallis. LV, left ventricle; LA, left atrium; DT, deceleration time.

Conclusions

Most trained athletes had increased levels of VCAM1 as compared to controls and less trained athletes. They also showed an increment post-effort. VCAM1 is related to LA remodeling in athletes. VCAM1 could be a potential biomarker of AF in athletes which should be confirmed.

Acknowledgement/Funding

FONDECYT 1170963 (LG); FONDAP 15130011 (LG,SL)

X-shaped inferior extensor retinaculum and its doubtful use in the Bröstrom-Gould procedure

PURPOSE

The inferior extensor retinaculum (IER) is an aponeurotic structure located in the anterior aspect of the ankle. According to the literature, it can be used to reinforce a repair of the anterior talofibular ligament in ankle instability. Despite its usual description as an Y-shaped structure, it is still unclear which part of the retinaculum is used for this purpose, or if it is instead the crural fascia that is being used. The purpose of this study is to define the anatomical characteristics of the IER to better understand its role in the Broström-Gould procedure.

METHODS

Twenty-one ankles were dissected. The morphology of the IER and its relationship with neighbouring structures were recorded.

RESULTS

Seventeen (81%) of the IER in this study had an X-shaped morphology, with the presence of an additional oblique superolateral band. This band, by far the thinnest of the retinaculum, is supposed to be used to reinforce the repair of the anterior talofibular ligament. The intermediate dorsal cutaneous nerve (lateral branch of the superficial peroneal nerve) was found to cross the retinaculum in all cases.

CONCLUSIONS

The IER is most commonly seen as an X-shaped structure, but the fact that the oblique superolateral band is a thin band of tissue probably indicates that it may not add significant strength to ankle stability. Furthermore, the close relationship of the retinaculum with the superficial peroneal nerve is another factor to consider before deciding to perform a Broström-Gould procedure. These anatomical findings advise against the use of the Gould augmentation.

Comparison of treatment of basal cell carcinoma between surgery and intralesional photodynamic therapy: A cross-sectional study

BACKGROUND

Surgery is the treatment of choice in basal cell carcinoma (BCC), but new less invasive techniques are in development such as photodynamic therapy. The main problem of this technique is the limited depth penetration of topical photosensitizers. The use of an intralesional photosensitizer plus an irradiation with a 630 nm laser should increase this penetration.

OBJETIVES

To compare the effectiveness in treatment of BCC between surgery and intralesional photodynamic therapy (I-PDT). To identify the clearance rate differences between intralesional or external irradiation in I-PTD group.

METHODS

A retrospective study of 102 patients with different histological types of BCC (mean depth of 2.44 mm) was performed. A total of 51 patients were treated with surgery and 51 with I-PDT, injecting 5-aminolevulinic acid 1% in the tumor and later irradiated with a 630 nm laser (intralesionally or externally: 25 and 26 patients respectively). Histological samples were obtained before and after treatment.

RESULTS

A total of 41/51 Patients in the surgery group vs 42/51 patients in I-PDT group achieved a complete clearance after treatment (p 0.79). There were no differences in success rates between intralesional vs external irradiation in I-PDT group (p 0.46).

LIMITATIONS

Small sample size and retrospective study.

CONCLUSION

I-PDT achieved high clearance rates in the treatment of BCC similar to surgery. There were no differences in success rates between intralesional vs external irradiation in I-PDT group. PDT might be an interesting option of treatment where surgery it is not possible.

Development and assessment of the disposition index based on the oral glucose tolerance test in subjects with different glycaemic status

Insulin secretion and insulin sensitivity indexes are related by hyperbolic functions, allowing the calculation of the disposition index (DI) as the product of the acute insulin response (AIR) and the insulin sensitivity index (Si) from intravenous glucose tolerance test (IVGTT). Our objective was to develop an oral-DI based on the oral glucose tolerance test (OGTT) and to assess its association with glucose tolerance status. This research is structured in three studies. Study 1: OGTT were performed in 833 non-diabetic Chilean women (18-60 years) without family history of diabetes mellitus. Study 2: an independent group of n = 57 non-diabetic (18-46 years) without family history of diabetes mellitus carried out an OGTT and an abbreviated IVGTT. Study 3: a sample of 1674 Chilean adults (18-60 years) with different glycaemic status performed an OGTT. An adequate statistical fit for a rectangular hyperbola was found between the area under the curve of insulin-to-glucose ratio (AUCI/G-R) and the Matsuda ISI-COMP index (study 1). The oral-DI derived as AUCI/G-R × ISI-COMP was previously termed insulin-secretion-sensitivity index-2 (ISSI-2). ISSI-2 significantly correlated with DI from IVGTT (rho = 0.34; p = 0.009) (study 2). ISSI-2 shows important differences across groups of subjects with different glycaemic status (study 3). We have confirmed that ISSI-2 replicates the mathematical properties of DI, showing significant correlations with DI from the abbreviated MM-IVGTT. These results indicate that ISSI-2 constitutes a surrogate measure of insulin secretion relative to insulin sensitivity and emphasizes the pivotal role of impaired insulin secretion in the development of glucose homeostasis dysregulation.

The in vitro immunomodulatory effect of extracellular products (ECPs) of Vagococcus fluvialis L21 on European sea bass (Dicentrarchus labrax) leucocytes

The immune associated genes, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-α (TNF-α), ciclo-oxigenase-2 (COX-2), and Mx gene were studied by real-time PCR in head-kidney leucocytes of sea bass after incubation with the extracellular products (ECPs) of the probiotic strain Vagococcus fluvialis L21 and polyinosinic:polycytidylic acid (POLY I:C), at different times (T1.5, T6, T12, T24, T48 and T72). In general, we can observe how pro-inflammatory cytokines IL-1β, TNF-α, IL-6 and COX-2 studied displayed a strong peak after stimulation with 1.5 h of ECPs of V. fluvialis L21, significant differences (P < 0.05) exist with other periods and with the POLY I: C at the same time. Similarly to the case of IL-10 also produced a statistically significant (P < 0.05) peak of expression on leukocytes that were stimulated with the ECPs of V. fluvialis L21. In the case of Mx gene expression, we note that in almost all sampling times there is an up-regulation of the Mx gene in leucocytes incubated with ECPs and POLY I:C compared to the control and Mx expression was higher in leucocytes that were stimulated with the ECPs of V. fluvialis for all times, except in T24. With these results we can consider that the ECPs of V. fluvialis L21 have a great power of stimulating the in vitro expression of immune-related genes and may even be useful as adjuvants for vaccine in aquaculture.