Early diffusion-weighted MRI lesions after treatment of unruptured intracranial aneurysms: a prospective study

Incidence and Characteristics of Cerebral Infarction After Microsurgical Clipping of Unruptured Anterior Circulation Cerebral Aneurysms: Diffusion-Weighted Imaging-Based Analysis of 600 Patients

BACKGROUND AND OBJECTIVES

Postclipping cerebral infarction (PCI) remains a major concern after treatment for unruptured intracranial aneurysms (UIAs). However, studies of microsurgical clipping based on diffusion-weighted imaging are limited. We aimed to present the incidence, risk factors, and types of PCI and its radiological and clinical characteristics.

METHODS

This was a retrospective single-center study in which patients were scheduled to undergo microsurgical clipping for anterior circulation UIAs. The overall incidence and risk factors were calculated. Based on the operation and relevant artery, we categorized PCI on diffusion-weighted imaging into 4 types and presented their radiological and clinical characteristics.

RESULTS

We reviewed the radiological and clinical data of 605 patients. The overall incidence of PCI was 16.7% (101/605), of which asymptomatic infarction was 14.9% (90/605) and symptomatic infarction was 1.8% (11/605). Hypertension (adjusted odds ratio [aOR], 2.258; 95% confidence interval [CI]: 1.330-3.833), temporary clipping (aOR, 1.690; 95% CI: 1.034-2.760), multiple aneurysm locations (aOR, 1.832; 95% CI: 1.084-3.095), and aneurysm dome size (aOR, 1.094; 95% CI: 1.006-1.190) were independent risk factors for PCI. Type II (perianeurysmal perforator) infarction was the most common type of PCI (48.6%) and the most common cause of symptomatic infarction (72.7%). Types II and III (distal embolic) infarctions correlated with atherosclerotic changes in the aneurysm wall and temporary clipping (62.4% and 70.6%, respectively). The type IV (unrelated) infarction group had a higher incidence of systemic atherosclerosis (55%).

CONCLUSION

Microsurgical clipping is a safe and viable option for the treatment of anterior circulation UIAs. However, modification of the surgical technique, preoperative radiological assessment, and patient selection are required to reduce the incidence of PCI.

Diffusion-weighted imaging lesions after intracranial aneurysm treatment with Pipeline Flex and Pipeline Flex with Shield technology: a retrospective cohort analysis

BACKGROUND

The Pipeline Flex embolization device with Shield technology (PED Shield) is the first flow diverter for brain aneurysm treatment approved in the United States using surface-modified technology. The effect of PED Shield on decreasing perioperative diffusion-weighted imaging positive (DWI+) hits, as a marker for in-human decrease thrombogenicity, is unclear.

OBJECTIVE

To determine if the number of periprocedural DWI+ lesions differs between patients with an aneurysm treated with PED Flex and PED Shield.

METHODS

This retrospective study compares the outcomes of consecutive patients with an aneurysm treated with PED Flex and PED Shield. The primary outcome of interest was the occurrence of DWI+ lesions. We also assessed potential predictors of DWI+ lesions and compared the outcomes between on-label and off-label treatment indications.

RESULTS

89 patients were included, 48 (54%) treated with PED Flex and 41 (46%) with PED Shield. After matching, the incidence of DWI+ lesions was 61% and 62% for the PED Flex and PED Shield groups, respectively. Results were consistent across each model with no significant differences in DWI+ lesions between treatment groups, and effect sizes ranging from OR=1.08 (95% CI 0.41 to 2.89) after propensity score matching to OR=1.84 (95% CI 0.65 to 5.47) after multivariable regression. Multivariable models demonstrated reduced DWI+ lesions with balloon-assisted therapies and posterior circulation treatment, while a significant linear relationship was encountered with fluoroscopy time.

CONCLUSION

There was no significant difference in the incidence of perioperative DWI+ lesions between patients with an aneurysm treated with PED Flex and PED Shield. Larger cohorts are likely needed to demonstrate differences between the devices.

DWI-Detected Ischemic Lesions after Endovascular Treatment for Cerebral Aneurysms: An Updated Systematic Review and Meta-analysis

BACKGROUND AND PURPOSE

DWI-detected ischemic lesions are potential complications of endovascular procedures that are performed to treat intracranial aneurysms. We completed a systematic review and meta-analysis to identify the occurrence of DWI-detected ischemic lesions after endovascular treatment for intracranial aneurysms.

MATERIALS AND METHODS

A systematic literature search of PubMed, the Web of Science, EMBASE, and Scopus between January 2000 and June 2022 of post-endovascular procedures for intracranial aneurysm studies was conducted using the Nested Knowledge AutoLit software. The main outcome was DWI-detected ischemic lesions within 5 days of the procedures. Information regarding associated risk factors such as the type of procedure, patient demographics, and aneurysm characteristics was also collected.

RESULTS

Twenty-nine studies with 2686 patients were included. The overall incidence of DWI ischemic lesions was 47.0% (95% CI, 39.6%-55.8%). The highest rate of lesions was seen with flow diversion at 62.4% (95% CI, 48.4%-80.5%), followed by complex procedures at 49.3% (95% CI, 29.5%-82.1%), stent-assisted coiling at 47.5% (95% CI, 34.6%-65.3%), simple coiling at 47.1% (95% CI, 35.7%-62.3%), and balloon-assisted coiling at 37.0% (95% CI, 28.3%-48.4%). The differences among different techniques were not statistically significant; however, there was significant heterogeneity and a significant risk of publication bias among included studies.

CONCLUSIONS

Many patients who undergo endovascular procedures for intracranial aneurysms present with new postprocedural DWI-detected ischemic lesions, regardless of the endovascular procedure used. Future studies and meta-analyses are needed to investigate early and long-term outcomes of such small infarcts.

Thromboembolic complications during and after embolization of unruptured aneurysms: A chronological outcome in periprocedural thromboembolic events

Background

Ischemic complications develop after elective coil embolization procedures at a certain rate. The prevention of these events has been a longstanding issue for many interventional neuroradiologists. This study aimed to clarify whether procedural ischemic events after unruptured aneurysm embolization decrease over time with perioperative anti-thromboembolic treatment or surgical experience.

Methods

This study included patients with cerebral aneurysms in our institution between July 2012 and June 2020. Dual-antiplatelet therapy (DAPT) was performed (Phase 1). Thromboembolic events developed at a certain rate; thus, rivaroxaban was administered with single-antiplatelet therapy (SAPT) to improve thromboembolic results (Phase 2), showing better outcomes than in Phase 1. Subsequently, DAPT was administered again (Phase 3). Ischemic complications were evaluated in each phase or compared between the DAPT group and the direct oral anticoagulant (DOAC) with the clopidogrel (DOAC+SAPT) group.

Results

Relatively, fewer symptomatic ischemic events were noted in Phase 2 or the DOAC+SAPT group, but the outcome was not better in Phase 3 than in Phase 2. Symptomatic complications were more common in Phase 3 than in Phases 1 and 2.

Conclusion

Ischemic complications occurred at a certain rate after endovascular procedures for unruptured aneurysms. The incidence did not decrease over time; particularly, standard DAPT plus postoperative anti-thromboembolic medication did not adequately decrease complications in Phase 3 compared to Phases 1 and 2. Therefore, accumulated experience or a learning curve could not explain the results. DOAC administration might decrease the risk of these events, but further accumulation of evidence or prospective investigation is warranted.

Preoperative cerebral angiography nearly doubles the rate of diffusion-weighted imaging lesion detection following minimally invasive surgery for intracerebral hemorrhage

BACKGROUND

Diffusion-weighted imaging (DWI) lesions have been linked to poor outcomes after intracerebral hemorrhage (ICH). We aimed to assess the impact of cerebral digital subtraction angiography (DSA) on the presence of DWI lesions in patients who underwent minimally invasive surgery (MIS) for ICH.

METHODS

Retrospective chart review was performed on ICH patients treated with MIS in a single health system from 2015 to 2021. One hundred and seventy consecutive patients who underwent postoperative MRIs were reviewed. Univariate analyses were conducted to determine associations. Variables with p<0.05 were included in multivariate analyses.

RESULTS

DWI lesions were present in 88 (52%) patients who underwent MIS for ICH. Of the 83 patients who underwent preoperative DSA, 56 (67%) patients demonstrated DWI lesions. In this DSA cohort, older age, severe leukoaraiosis, larger preoperative hematoma volume, and increased presenting National Institutes of Health Stroke Score (NIHSS) were independently associated with DWI lesion identification (p<0.05). In contrast, of 87 patients who did not undergo DSA, 32 (37%) patients demonstrated DWI lesions on MRI. In the non-DSA cohort, presenting systolic blood pressure, intraventricular hemorrhage, and NIHSS were independently associated with DWI lesions (p<0.05). Higher DWI lesion burden was independently associated with poor modified Rankin Scale (mRS) at 6 months on a univariate (p=0.02) and multivariate level (p=0.02).

CONCLUSIONS

In this cohort of ICH patients who underwent minimally invasive evacuation, preprocedural angiography was associated with the presence of DWI lesions on post-ICH evacuation MRI. Furthermore, the burden of DWI lesions portends a worse prognosis after ICH.

Clinical and subclinical microemboli following neuroangiography in children

BACKGROUND

To assess the frequency, imaging appearances, and risk factors of brain microemboli following pediatric neuroangiography, as assessed by early diffusion-weighted MRI imaging (DWI).

METHODS

This single-center, retrospective analysis investigated early DWI post-pediatric neuroangiography. Patients aged 0-18 years who had diagnostic neuroangiography and DWI within a week postprocedure were included. Data on clinical and procedural parameters and MRI findings were recorded. Univariate and multivariate analyses were performed on the following risk factors: age, weight, vasculopathy, antiplatelet drug use, access type, intraprocedural heparin, procedure duration, neck arteries catheterized, and angiographic runs. A p-value<0.05 indicated statistical significance.

RESULTS

Eighty-two children were included (40.2% female), mean age 10.1±4.5 years (range: 7 months-17 years). There were no intraprocedural thromboembolic complications recognized. DWI positivity was seen following 3.6% (3/82) procedures: two with transient symptoms, and one instance of silent microemboli. There were no territorial infarcts or clinical stroke. Children with underlying vasculopathy had a higher risk of microemboli from angiography than children without vasculopathy (OR 31.6, p=0.02), and the OR of microemboli following transradial angiography was 79.1 (p=0.005) as compared with transfemoral angiography. Univariate and multivariate analysis showed a significant association between microemboli and number of angiographic runs (p=0.004). Follow-up MRI in all three patients showed no residual abnormal signal.

CONCLUSIONS

Cerebral microemboli are unusual following uncomplicated neuroangiography in children. However, in the presence of underlying vasculopathy and with transradial technique, the incidence approaches that reported in the adult literature. An increased association with the number of angiographic runs is an important and controllable factor.

Diffusion-weighted imaging lesions after endovascular treatment of cerebral aneurysms: A network meta-analysis

Background

Thromboembolism is one of the common complications in endovascular treatments including coiling alone, stent-assisted coiling (SAC), balloon-assisted coiling (BAC), and flow-diverting (FD) stents. Such treatments are widely used in intracranial aneurysms (IAs), which usually present as positive lesions in diffusion-weighted imaging (DWI). Whether these adjunctive techniques increase postprocedural DWI-positive lesions after endovascular treatment remains unclear.

Methods

A thorough electronic search for the literature published in English between January 2000 and October 2022 was conducted on PubMed, Medline, and EMBASE. Eighteen studies (3 cohort studies and 15 case-control studies) involving 1,843 patients with unruptured IAs (UIAs) were included. We performed a frequentist framework network meta-analysis (NMA) to compare the rank risks of cerebral thromboembolism of the above four endovascular treatments. The incoherence test was used to analyze the statistical disagreement between direct and indirect evidence. Funnel plots were used to analyze publication bias.

Results

The incidences of DWI lesions in patients who received FD stents, SAC, BAC, and coiling alone were 66.1% (109/165), 37.6% (299/795), 31.1% (236/759), and 25.6% (236/921). The incidence of DWI lesions in patients who received FD stents was higher than that in patients who received SAC [OR: 2.40; 95% CI (1.15, 5.00), P < 0.05], BAC [OR: 2.62; 95% CI (1.19, 5.77), P < 0.05], or coiling alone [OR: 2.77; 95% CI (1.26, 6.07), P < 0.05]. The incoherence test showed preferable consistency in this NMA. No obvious publication bias was found in the funnel plot.

Conclusion

FD stent placement brings more ischemic lesions identified by DWI than any other procedures for patients with UIA. The characteristics of FD stents may result in a high incidence of DWI lesions.

Enhance Safety in Aneurysm Surgery: Strategies for Prevention of Intraoperative Vascular Complications

Complications during surgery for intracranial aneurysms can be devastating. Notorious pitfalls include premature rupture, parent vessel occlusion, local cerebral injury and brain contusion, and incomplete neck obliteration. These unfavorable intraoperative events can result in major neurological deficits with permanent morbidity and even mortality. Herein, the author highlights the relevant surgical strategies used in his daily practice of aneurysm surgery (e.g., aneurysm clipping with adenosine-induced temporary cardiac arrest), application of which may help prevent vascular complications and enhance surgical safety through reduction of the associated risks, thus allowing improvement of postoperative outcomes. Overall, all described methods and techniques should be considered as small pieces in the complex puzzle of prevention of vascular complications during aneurysm surgery.

Perfusion strategy using axillary or femoral cannulation for minimally invasive cardiac surgery: experience in 270 patients with computed tomography-based criteria

OBJECTIVES

In patients with atherosclerotic disease, minimally invasive cardiac surgery using retrograde perfusion for cardiopulmonary bypass via femoral cannulation (FC) carries a higher risk of brain embolization compared with antegrade perfusion. However, guidelines for selecting antegrade versus retrograde perfusion do not exist. We developed a computed tomography (CT)-based perfusion strategy and assessed outcomes.

METHODS

We studied 270 minimally invasive cardiac surgery patients, aged 68 ± 13, 124 female, body surface area 1.6 ± 0.2 m2. Antegrade perfusion using axillary cannulation (AC) was selected if any of the following preoperative enhanced CT scan criteria were satisfied anywhere in the aorta or iliac arteries: thrombosis thickness >3 mm, thrombosis >one-third of the total circumference and calcification present in the total circumference. FC was selected otherwise. Asymptomatic brain injury was assessed by diffusion-weighted magnetic resonance imaging.

RESULTS

AC and FC were selected in 95 (35%) and 175 patients, respectively. AC patients were 10 years older (P < 0.001) and had higher EuroSCORE II (2.7 ± 3.4 vs 1.7 ± 1.9, P = 0.002). The median cardiopulmonary time and cross-clamp times were not significantly different. No patients died in hospital. There was no immediate stroke in either group during 48 h after surgery. Asymptomatic brain injury was detected in 25 (26%) and 27 (15%) AC and FC patients, respectively, P = 0.03.

CONCLUSIONS

We believe our CT-based perfusion strategy using AC or FC minimized brain embolic rates. AC can be a good alternative to prevent brain embolization for minimally invasive cardiac surgery patients with advanced atherosclerotic disease.

Remote ischemic preconditioning for elective endovascular intracranial aneurysm repair: a feasibility study

OBJECTIVES

Remote ischemic preconditioning has been proposed as a possible potential treatment for ischemic stroke. However, neuroprotective benefits of the pre-procedural administration of remote ischemic preconditioning have not been investigated in patients undergoing an elective endovascular intracranial aneurysm repair procedure. This study investigated the safety and feasibility of remote ischemic preconditioning in patients with an unruptured intracranial aneurysm who undergo elective endovascular treatment.

METHODS

In this single-center prospective study, patients with an unruptured intracranial aneurysm undergoing elective endovascular treatment with flow diverters or coiling were recruited. Patients received three intermittent cycles of 5 minutes arm ischemia followed by reperfusion using manual blood cuff inflation/deflation less than 5 hours prior to endovascular treatment. Patients were monitored and followed up for remote ischemic preconditioning-related adverse events and ischemic brain lesions by diffusion -weighted magnetic resonance imaging within 48 hours following endovascular treatment.

RESULTS

A total of seven patients aged 60 ± 5 years with an unruptured intracranial aneurysm successfully completed a total of 21 sessions of remote ischemic preconditioning and the required procedures. Except for two patients who developed skin petechiae over their arms, no other serious procedure-related adverse events were observed as a result of the remote ischemic preconditioning procedure. On follow-up diffusion -weighted magnetic resonance imaging, a total of 19 ischemic brain lesions with a median (interquartile range) volume of 245 (61-466) mm³ were found in four out of seven patients.

CONCLUSIONS

The application of remote ischemic preconditioning prior to endovascular intracranial aneurysm repair was well tolerated, safe and clinically feasible. Larger sham-controlled clinical trials are required to determine the safety and efficacy of this therapeutic strategy in mitigating ischemic damage following endovascular treatment of intracranial aneurysms.

Rapid ventricular pacing for clip reconstruction of complex unruptured intracranial aneurysms: results of an interdisciplinary prospective trial

OBJECTIVE

To date, treatment of complex unruptured intracranial aneurysms (UIAs) remains challenging. Therefore, advanced techniques are required to achieve an optimal result in treating these patients safely. In this study, the safety and efficacy of rapid ventricular pacing (RVP) to facilitate microsurgical clip reconstruction was investigated prospectively in a joined neurosurgery, anesthesiology, and cardiology study.

METHODS

Patients with complex UIAs were prospectively enrolled. Both the safety and efficacy of RVP were evaluated by recording cardiovascular events and outcomes of patients as well as the amount of aneurysm occlusion after the surgical clip reconstruction procedure. A questionnaire was used to evaluate aneurysm preparation and clip application under RVP.

RESULTS

Twenty patients (mean age 51.6 years, range 28–66 years) were included in this study. Electrode positioning was easy in 19 (95%) of 20 patients, and removal of electrodes was easily accomplished in all patients (100%). No complications associated with the placement of the pacing electrodes occurred, such as cardiac perforation or cardiac tamponade. RVP was applied in 16 patients. The mean aneurysm size was 11.1 ± 5.5 mm (range 6–30 mm). RVP proved to be a very helpful tool in aneurysm preparation and clip application in 15 (94%) of 16 patients. RVP was used for a mean duration of 60 ± 25 seconds, a mean heart rate of 173 ± 23 bpm (range 150–210 bpm), and a reduction of mean arterial pressure to 35–55 mm Hg. RVP leads to softening of the aneurysm sac facilitating its mobilization, clip application, and closure of the clip blades. In 2 patients, cardiac events were documented that resolved without permanent sequelae in both. In every patient with successful RVP (n = 14) a total or near-total aneurysm occlusion was documented. In the 1 patient in whom the second RVP failed due to pacemaker electrode dislocation, additional temporary clipping was required to secure the aneurysm, but was not as sufficient as RVP. This led to an incomplete clipping of the aneurysm and finally a remnant on postoperative digital subtraction angiography. A pacemaker lead dislocation occurred in 3 (19%) of 16 patients, but intraoperative repositioning requires less than 20 seconds. Outcome was favorable in all patients according to the modified Rankin Scale.

CONCLUSIONS

To the best of the authors’ knowledge this is the first prospective interdisciplinary study of RVP use in patients with UIAs. RVP is an elegant technique that facilitates clip reconstruction in complex UIAs. The safety of the procedure is good. However, because this procedure requires extensive preoperative cardiological workup of the patient and an experienced neurosurgery and neuroanesthesiology team with much cerebrovascular expertise, actually it remains reserved for selected elective cases and highly specialized centers.

Clinical trial registration no.: NCT02766972 (clinicaltrials.gov)