RPS 909 - Neuro-interventions

Purpose:

Therapeutic application for tremor treatment by transcranial high-intensity focused ultrasound (HIFU) demands a precise analysis of physical and control parameters to obtain optimal outcome. Our objective was to define the correlation between periprocedural parameters regarding HIFU procedures and treatment outcome.

Methods and materials:

57 patients with essential tremor (ET) and Parkinson disease (PD) tremor were treated using an MRgFUS brain system (ExAblate 4000, InSightec) in a 3T MR scanner (MR750, GE Healthcare). We retrospectively evaluated the intraprocedural MR-thermometry, measuring the accumulated thermal dose (ATD) size and temperature and the number of sonications and values of maximum energy delivered and temperatures reached. The periprocedural parameter profiles were correlated with the corresponding treatment outcome assessed using the Fahn-Tolosa-Marin scale after 1 day, 1 month, 3 months, and 6 months follow-up.

Results:

Statistical analysis showed a mean ATD temperature significantly correlated with FTM scores after 1 day and 1 month follow up (p<0.005) We did not find any statistically significant correlation between ATD temperature and FTM in 3 and 6 months follow-up, or between clinical outcomes and other periprocedural parameters.

Conclusion:

According to our preliminary results, intraprocedural ATD after the procedure may have a possible predictive value of treatment outcome after MRgFUS thalamotomy in patients with ET and PD tremor.

Limitations:

The limited number of patients available could be a hindrance for statistical significativity.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To show the effectiveness and safety of SQUID 12 in the embolisation of cerebral dural arteriovenous fistulas (cDAVF).

Methods and materials:

From June 2017-January 2019, the authors retrospectively reviewed clinical, demographic, and embolisation data of 13 consecutive patients with cDAVF (3 IIb, 5 Cognard III, and 5 Cognard IV) who underwent embolisation using the SQUID 12. 4 patients were symptomatic for headache, 2 patients presented with vertigo and confusion, 2 patients with tinnitus, 1 patient with a bruit, and 1 patient with aphasia; 3 patients were asymptomatic. The number of arteries catheterised for embolisation, the total amount of embolic agent, the rate of occlusion, the time of the procedure, and the rate of complication were recorded. Mid-term follow-up with MR and DSA was reviewed.

Results:

In 11 patients, the cDAVF closure was accomplished at the end of the procedure; in one case, a double staged treatment was performed, while in another case, a small remnant was left. The average time of injection was 36 minutes and the average amount of SQUID 12 was 2.8 mL. One patient with a cDAVF of traverse sinus region (Cognard III) experienced a facial palsy which resolved after 2 weeks of corticosteroids; no other complications were recorded. Mid-term MR and angiographic follow-up confirmed complete occlusion of the cDAVFs in 12 patients; in 1 patient with an infratentorial fistula, a small relapse was detected.

Conclusion:

The treatment of the DAVFs by using SQUID 12 seems to be effective and safe. The lower viscosity allow a distal migration of the agent, a lesser proximal reflux, and a deeper penetration in the cDAVF.

Limitations:

A mall sample size and a retrospective study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To assess the doses received by patients during interventional neuroradiology procedures and to establish their dose range.

Methods and materials:

Our study included all patients who underwent diagnostic and therapeutic interventional neuroradiology procedures from December 2017-June 2019 at our institution. The following variables were taken into account: dose area product, air kerma, and fluoroscopy exposure time. Peak skin dose was calculated from a published dose conversion formula for interventional procedures: PSD=249+5.2*DAP. We estimated an effective dose from DAP using a dose conversion factor, where DCC= ED/DAP, and calculated a brain dose using the ED and tissue weighing factor provided by ICRP-103.

Results:

There were 224 cerebral angiographies, 55 aneurism embolisations, and 21 combined procedures. We calculated the total mean±SD and third quartiles for all dependent variables: DAP (93.95±50.48 Gy-cm²; 116.23 Gy-cm²), AK (595.23±382.07 Gy; 680.94 Gy), T (7.43±7.37 min; 9.26 min), ED (13.62±7.32 mSv; 16.85 mSv), and PSD (0.49±0.26 Gy; 0.60 Gy). Estimated brain doses for diagnostic, therapeutic, combined, and all procedures in total were 254.62 mGy, 227.84 mGy, 341.12 mGy, and 272.4 mGy. Post hoc analysis determined a Bonferroni correction of critical value which was significant for each test: DAP-procedure type (0.016), AK-procedure type (0.000), ED-procedure type (0.016), and PSD-procedure type (0.016).

Conclusion:

Interventional neuroradiology procedures show significant variability in radiation dose due to patient constitution, radiologist expertise, and equipment factors. Knowing the doses can have a great benefit in terms of prevention of possible radiation effects.

Limitations:

There is no standardised method for effective dose calculation.

Ethics committee approval

Approved by Institutional Ethics Committee.

Funding:

No funding was received for this work.

Purpose:

To evaluate collateral circulation in patients with an acute ischaemic stroke (AIS) who underwent endovascular thrombectomy (ET) in order to investigate its value in the prediction of clinical outcome.

Methods and materials:

We retrospectively investigated 120 patients with CTA-proven large vessel occlusion (LVO) treated with ET from January 2014-September 2019. Good collateral (GC), good recanalisation rate (RR), and clinical assessment (CA) were defined respectively by a collateral flow grading system (ASITN/SIR) score ≥2, a thrombolysis in cerebral infarction (TICI) score ≥2b, and the NIHSS scale before and 24 hours after ET.

Results:

The patients were divided into two groups due to the presence of GC (63%) or not named worse collateral (WC) (37%). Each group was analysed in relation to onset time, TICI, and NIHSS using Spearman's rank correlation coefficient. Although analogue onset time of symptoms was considered, the 24h-NIHSS score was better in the GC-group than the WC-group (p<0.001). GC were also associated with a better RR (p<0.05).

Conclusion:

In line with the recent randomised studies, the analysis of collateral and a better selection of patients have to be mandatory for a better clinical outcome.

Limitations:

A small sample.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

The effect of endovascular thrombectomy performed more than 6 hours after the onset of ischaemic stroke has been shown by the DAWN and DEFUSE-3 trials. In these trials, strict criteria were employed for patient selection, including perfusion CT. We performed a retrospective single-centre evaluation of patient treated 6 to 24 hours after stroke onset without perfusion CT selection.

Methods and materials:

On a total of 212 patients who received endovascular thrombectomy for major intracranial vessel occlusion, we identified 55 patients who were treated 6 to 24 hours after stroke onset. Patients were selected on the basis of clinical and radiological criteria. Co-primary endpoints were the rate of functional independence (0, 1, or 2 on the mRS) at 90 days and post-treatment symptomatic intracranial haemorrhage (ECASS II criteria). Secondary endpoints were an early therapeutic response and successful recanalisation.

Results:

Out of 55 patient, 22 (40%) were functionally independent at 90 days (mRS 0-2). Of these, 11 were mRS 0, 7 were mRS 1, and 4 were mRS 2, while the rate of symptomatic intracranial haemorrhage was 4 out 55 (7%). Early therapeutic response was achieved in 22 out of 55 patients (40%). Successful recanalisation was achieved in 44 out of 55 patients (80%).

Conclusion:

Our data confirms that endovascular thrombectomy for large intracranial vessel occlusion in a later time window is safe and effective, even without CT-perfusion patient selection. A larger population of patients can potentially benefit from endovascular thrombectomy even without applying strict selection criteria, compared to DWAN and DEFUSE-3 trials.

Limitations:

A retrospective, monocentric study with a small sample size.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

Optimal blood pressure (BP) management in the acute period of ischaemic stroke remains uncertain, specifically in patients undergoing endovascular treatment (EVT). We evaluated the association between BP levels post-EVT and outcome, according to recanalisation status.

Methods and materials:

We included patients from the MR CLEAN registry who underwent EVT from March 2014-June 2016 in 7 centres registering post-EVT BP values. The primary outcome was the functional outcome (modified Rankin scale) at 90 days. Secondary outcomes were sICH and early neurological deficit (NIHSS at 24h). BP parameters were mean, maximum, and minimum systolic (SBP), and mean arterial pressure (MAP) during the first 6 hours post-EVT. We used multilevel regression analysis to account for the repeated measures per patient to evaluate the association between BP and outcomes, adjusted for centre and prognostic factors, and we tested for interaction between BP and recanalisation status.

Results:

In total, 867 patients were included for analyses. Mean SBP and MAP were 140 ± 22 mmHg and 99 ± 18 mmHg, respectively. Maximum SBP and MAP were associated with worse functional outcome (adjusted common odds ratio per 10mmHg (acOR) 0.93, 95% CI 0.88 to 0.98 and acOR 0.42, 95% CI 0.21 to 0.86) and higher NIHSS scores (β 0.55, 95% CI 0.33-0.77 and β 5.5, 95% CI 2.7 to 8.4). Maximum SBP was associated with higher sICH rates (adjusted OR 1.28, 95% CI 1.14 to 1.49). There was no effect of mean or minimum BP on outcome and no interaction between BP and recanalisation status.

Conclusion:

Higher maximum SBP and MAP levels in the first 6 hours after EVT are associated with worse functional and neurological outcomes and higher sICH rates.

Limitations:

n/a

Ethics committee approval

https://www.mrclean-trial.org

Funding:

https://www.mrclean-trial.org

Purpose:

To evaluate the response and survival of malignant recurrent neoplasms located in the head and neck area post repetitive transarterial chemoperfusion (TACP) as a palliative treatment method.

Methods and materials:

47 patients (33 males, 14 females) were treated in 4-week intervals using TACP with mitomycin C 8.5 mg/m², gemcitabine 1000 mg/m², and cisplatin 35mg/m². Before treatment, a multiparametric MRI was performed in order to evaluate the size, location, and volume of the tumour prior to TACP. After TACP, a CT scan was performed for the exclusion of possible side-effects. Tumour response was evaluated according to the RECIST criteria.

Results:

TACP was well-tolerated without significant side-effects. According to the RECIST criteria, 29.79% (n=14) of the patients presented with partial remission (PR), 68.09% (n=32) showed stable disease (SD), and 2.13% (n=1) had progressive disease (PD). The median survival rate of the patients from the start of TACP therapy was 14.7 months. Patients with PR after the first treatment session presented with significantly better survival (p=0.03) with a mean of 21.4 months, while patients with SD only presented with a survival of 11.3 months.

Conclusion:

TACP seems to be an effective palliative treatment option in patients with head and neck tumours.

Limitations:

A limited number of patients were included.

Ethics committee approval

Approval by the Institutional Review Board.

Funding:

No funding was received for this work.