A fully automatic method for vascular tortuosity feature extraction in the supra-aortic region: unraveling possibilities in stroke treatment planning

Vascular tortuosity of supra-aortic vessels is widely considered one of the main reasons for failure and delays in endovascular treatment of large vessel occlusion in patients with acute ischemic stroke. Characterization of tortuosity is a challenging task due to the lack of objective, robust and effective analysis tools. We present a fully automatic method for arterial segmentation, vessel labelling and tortuosity feature extraction applied to the supra-aortic region. A sample of 566 computed tomography angiography scans from acute ischemic stroke patients (aged 74.8 ± 12.9, 51.0% females) were used for training, validation and testing of a segmentation module based on a U-Net architecture (162 cases) and a vessel labelling module powered by a graph U-Net (566 cases). Successively, 30 cases were processed for testing of a tortuosity feature extraction module. Measurements obtained through automatic processing were compared to manual annotations from two observers for a thorough validation of the method. The proposed feature extraction method presented similar performance to the inter-rater variability observed in the measurement of 33 geometrical and morphological features of the arterial anatomy in the supra-aortic region. This system will contribute to the development of more complex models to advance the treatment of stroke by adding immediate automation, objectivity, repeatability and robustness to the vascular tortuosity characterization of patients.

C48 PROGNOSTIC IMPACT OF ECHOCARDIOGRAPHIC RESTRICTIVE FILLING PATTERN IN PATIENTS AFFECTED BY HYPERTROPHIC CARDIOMYOPATHY AND PRESERVED SYSTOLIC EJECTION FRACTION

Background

“Restrictive phenotype” is an uncommon presentation of Hypertrophic Cardiomyopathy (HCM), associated with severe functional limitation and poor prognosis. For this reason, current therapeutic aims are prevention of complications through periodic follow–ups and diagnostic investigations, up to the ICD placement.

Objectives

The primary aim of this study was to evaluate the impact of the restrictive filling pattern in HCM on the incidence of complex composite outcome included arrhythmic events, events related to heart failure and general events, correlating it to clinical and imaging data.

Methods

This study is an experimental, multicentric, retrospective and non–randomized analysis, including all patients over the age of 18 suffering from classical HCM, excluding phenocopies and systolic dysfunction. Patients were followed up and selected by specialized Centers of Trieste and Turin and divided by degree of diastolic dysfunction, particularly on the basis of the presence or absence of the restrictive filling pattern.

Results

A total of 367 patients with HCM were included. Restrictive filling pattern was present in 23 patients (6.3%). This subgroup of patients was younger than all other patients (P < 0.001); percentage of ICD patients suffering from severe diastolic dysfunction at follow–up is significantly higher than patients without restrictive filling pattern (39.1% vs 4.1%, P < 0.001). On average, left atrial volume has larger sizes in restrictive filling pattern (109.7ml, SD 43.06 vs 82.8ml, SD 35.81, P = 0.003). Patients with restrictive filling pattern, compared to other patients, are more subjected to heart transplantation (8.7% vs 0.3%, P = 0.009) and hospitalized for heart failure (21.7% vs 7.8%, P = 0.028). Restrictive pattern was not an independent predictor of adverse events at the multivariable analysis. In our cohort, the independent predictors were found to be the left atrium diameter and the presence of LGE on CMR.

Conclusions

In patients with HCM and preserved EF, the evidence of a restrictive diastolic pattern identifies a poor prognosis subgroup. Severe diastolic alteration was not associated with a significant independent role either for events related to heart failure, or for arrhythmic events during a median follow up of 7 years. However, the high rate of ICD implantation in patients with severe diastolic dysfunction suggests a high clinical perception of adverse events in this subgroup.

Angioplasty with a retrievable stent to treat vasospasm secondary to subarachnoid hemorrhage due to an aneurysm: a multicenter study of safety and efficacy

OBJECTIVE

To determine the safety and efficacy of angioplasty with a retrievable stent in treating vasospasm secondary to subarachnoid hemorrhage (SAH) due to an aneurysm.

METHODS

We retrospectively analyzed prospectively collected data from consecutive patients undergoing endovascular angioplasty with a retrievable stent to treat vasospasm related to SAH due to an aneurysm in four neurointerventional radiology departments between January 2018 and July 2019. We included patients aged>18 years with vasospasm>50% of the internal carotid artery (ICA), anterior cerebral artery (ACA), and / or middle cerebral artery (MCA) secondary to SAH due to an aneurysm treated with endovascular angioplasty with a retrievable stent. The variables used to measure safety were complications of the procedure and clinical complications. The variables used to measure radiological efficacy were improvement in the degree of stenosis after endovascular treatment and improvement or normalization of cerebral circulation time CTT).

RESULTS

We included 16 angioplasty procedures with retrievable stents in 13 patients, in which 33 arterial segments were treated (10 ICA, 15 MCA, and 8 ACA). We observed no complications of the procedure in any patients and no clinical complications in patients who were not intubated. All but one of the patients who had delayed CTT at the beginning of the procedure showed improvements in CTT. The mean improvement in the degree of stenosis was 18%±11.65% in the ICA, 30.67%±18.45% in the MCA, and 28.38%±15.49% in the ACA. No statistically significant associations were observed between endovascular treatment variables and the degree of improvement in stenosis.

CONCLUSION

Angioplasty with a retrievable stent is a safe and efficacious treatment for vasospasm secondary to SAH due to an aneurysm, improving CTT and stenosis.

Mechanical thrombectomy with a novel stent retriever with multifunctional zones: Initial clinical experience with the NeVa™ thrombectomy device

BACKGROUND AND PURPOSE

The NeVa™ (Vesalio, Nashville, Tennessee) thrombectomy device is a CE-approved novel hybrid-cell stent retriever with offset enlarged openings coupled with functional zones and a closed distal end. The device was designed to incorporate and trap resistant emboli. The purpose was to determine the safety and efficacy of the NeVa™ stent.

METHODS

Prospective data was collected on the first thirty consecutive patients treated at four stroke centers with NeVa™ as first line treatment between December 2017 and May 2018. Clinical outcome measures included re-perfusion scores after each pass, complications (per-procedural complications, device related adverse events, all intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) on follow up imaging), 24 hour NIHSS, mRS at discharge and 90 days. Baseline data as well as treatment parameters were documented.

RESULTS

Mean presenting NIHSS was 16. Sites of primary occlusion were 10 ICA, 16 M1-MCA, 3 M2-MCA and one basilar. There were five tandem occlusions. Reperfusion outcomes after each NeVa pass; TICI ≥ 2b after first pass 63%, after 1 or 2 passes 83%, after 1 to 3 passes 90%. TICI 2c-3 after first pass 47%, after 1-2 passes 57%, after 1-3 passes 60%. TICI ≥ 2b after final pass 93%; TICI 2c-3, 63%. There were no device related serious averse events and no sICH. Clot material was partially or completely incorporated into the device after 70% passes. The mean 24 hour NIHSS was 7 and the 90 day mRS was 0-2 in 53%.

CONCLUSIONS

The NeVa™ device demonstrated a high rate of first pass complete reperfusion effect, a good safety profile and favorable 90 day clinical outcomes in this initial clinical experience.

Access to Endovascular Treatment in Remote Areas

Background and Purpose—

Since demonstration of the benefit of endovascular treatment (EVT) in acute ischemic stroke patients with proximal arterial occlusion, stroke care systems need to be reorganized to deliver EVT in a timely and equitable way. We analyzed differences in the access to EVT by geographical areas in Catalonia, a territory with a highly decentralized stroke model.

Methods—

We studied 965 patients treated with EVT from a prospective multicenter population-based registry of stroke patients treated with reperfusion therapies in Catalonia, Spain (SONIIA). Three different areas were defined: (A) health areas primarily covered by Comprehensive Stroke Centers, (B) areas primarily covered by local stroke centers located less than hour away from a Comprehensive Stroke Center, and (C) areas primarily covered by local stroke centers located more than hour away from a Comprehensive Stroke Center. We compared the number of EVT×100 000 inhabitants/year and time from stroke onset to groin puncture between groups.

Results—

Baseline characteristics were similar between groups. Throughout the study period, there were significant differences in the population rates of EVT across geographical areas. EVT rates by 100 000 in 2015 were 10.5 in A area, 3.7 in B, and 2.7 in C. Time from symptom onset to groin puncture was 82 minutes longer in group B (312 minutes [245–435]) and 120 minutes longer in group C (350 minutes [284–408]) compared with group A (230 minutes [160–407]; P <0.001).

Conclusions—

Accessibility to EVT from remote areas is hampered by lower rate and longer time to treatment compared with areas covered directly by Comprehensive Stroke Centers.

Lulwoana sp., a dark septate endophyte in roots of Posidonia oceanica (L.) Delile seagrass

Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anchored on rock than on matte and sand. In root sections, an inter- and intracellular septate mycelium, producing intracellular microsclerotia, was detected from the rhizodermis to the vascular cylinder. Using isolation techniques, we obtained, from both sampling sites, sterile, slow-growing fungal colonies, dark in colour, with septate mycelium, belonging to the dark septate endophytes (DSEs). DNA sequencing of the internal transcribed spacer (ITS) region identified these colonies as Lulwoana sp. To our knowledge, this is the first report of Lulwoana sp. as DSE in roots of P. oceanica. Moreover, the highest fungal colonisation, detected in P. oceanica roots growing on rock, suggests that the presence of the DSE may help the host in several ways, particularly in capturing mineral nutrients through lytic activity.

Effect of different substrata on rhizome growth, leaf biometry and shoot density of Posidonia oceanica

The effects of different substratum typologies on Posidonia oceanica growth and morphology were estimated in four Sicilian meadows using Generalized and Linear Mixed Models combined with retrodating and biometric analyses. Substratum exerted a multiple effect, resulting in different biometric features for P. oceanica shoots settled on rock from those growing on sand and matte. On rock, values for growth rate, leaf length and shoot surface were lower than those on other substrata, with 42%, 23% and 32% the highest degree of difference respectively. The present study may have interesting methodological consequences for the comprehensive understanding of the causative variables potentially affecting meadows features and their health status. The importance of substratum in the prediction of likely biometry changes in P. oceanica meadows, means that knowledge of substratum type should receive due attention in the future to derive reliable estimates of meadow status.