Development of technical skills in simulated cerebral aneurysm coiling.

Endovascular surgical procedures require visual-spatial coordination in workspaces with restricted motions and temporally limited imaging. The development of the skills needed for these procedures can be facilitated by 3D simulator-based training. Cerebral angiography (CA) has lagged behind in this training approach due to the lack of validated, realistic training models, relying strictly on clinical case exposure frequency ("number of hours logged") as a means of assessing proficiency. The ANGIO Mentor visual-haptic simulator is regarded as an effective training tool, however, this simulator has not been tested thoroughly in its ability to train interventional skills. In particular, the details of the aneurysm coiling process during simulation-based training have not been assessed. In this study, 12 novice medical students were given simulation-based diagnostic CA training until a procedural plateau in performance, established in our previous work. Subsequently, they were trained using video tutorials and written instructions to identify, measure and intervene with cerebral aneurysms using endovascular coils. Over the span of 6 sessions, participants were assessed on their procedural task time, coiling quantity and quality, and perforation rates. Prior to commencing the study, participant spatial ability was assessed using a mental rotation test (MRT) and used as a comparative baseline for the performance analysis. We found that all individuals were able to perform the procedure faster after 6 sessions, reducing their average time from 42 to 24 minutes. Coil success rate improved over from 82% to 88% and coil packing rate remained consistent at 30% throughout testing. High perforation rate seen at the start of the study showed a trend of decreasing over the latter sessions, however, over half of aneurysms were still being perforated by the novice participants. No change in aneurysm coiling quality was found, with a slight decrease in number of parent artery coil protrusions. High MRT individuals were better able to establish necessary tools prior to coiling, however, no other MRT-specific changes were seen. This work identifies the utility of simulation-based CA training in identifying the particular difficulties trainees experience in learning procedural skills, including prevention of perforations, proper positioning and success of coils within the aneurysm.

Early Goal-directed Therapy During Endovascular Coiling Procedures Following Aneurysmal Subarachnoid Hemorrhage: A Pilot Prospective Randomized Controlled Study.

BACKGROUND: Maintenance of euvolemia and cerebral perfusion are recommended for the prevention of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). We conducted a pilot randomized controlled study to assess the feasibility and efficacy of goal-directed therapy (GDT) to correct fluid and hemodynamic derangements during endovascular coiling in patients with aSAH. METHODS: This study was conducted between November 2015 and February 2019 at a single tertiary center in Canada. Adult patients with aSAH within 5 days of aneurysm rupture were randomly assigned to receive either GDT or standard therapy during endovascular coiling. The incidence of dehydration at presentation and the efficacy of GDT were evaluated. RESULTS: Forty patients were allocated to receive GDT (n=21) or standard therapy (n=19). Sixty percent of all patients were found to have dehydration before the coiling procedure commenced. Compared with standard therapy, GDT reduced the duration of intraoperative hypovolemia (mean difference 37.6 [95% confidence interval, 6.2-37.4] min, P=0.006) and low cardiac index (mean difference 30.7 [95% confidence interval, 9.5-56.9] min, P=0.035). There were no differences between the 2 treatment groups with respect to the incidence of vasospasm, stroke, death, and other complications up to postoperative day 90. CONCLUSIONS: A high proportion of aSAH patients presented at the coiling procedure with dehydration and a low cardiac output state; these derangements were more likely to be corrected if the GDT algorithm was used. Compared with standard therapy, use of the GDT algorithm resulted in earlier recognition and more consistent treatment of dehydration and hemodynamic derangement during endovascular coiling.

Simulation reduces navigational errors in cerebral angiography training.

BACKGROUND: Simulation-based medical education (SBME) is growing as a powerful aid in delivering proficient skills training in many specialties. Cerebral angiography (CA), a spatially and navigationally challenging endovascular procedure, can benefit from SBME by training targetable skills outside of the Angiosuite. In order to standardize and specify training requirements, navigational challenges and needs have to be identified. Furthermore, to enable successful adoption of these strategies, simulation adoption barriers, such as necessity of supervisory resources, must be reduced. In this study, we assessed the navigational challenges in simulated CA through a self-guided novice training program. METHODS: Novice participants (n = 14) received virtual reality (ANGIO Mentor, Simbionix) diagnostic cerebral angiography training and were tested on a right middle cerebral artery aneurysm case over 8 sessions with a reference instructional outline. The navigational trajectories for the guidewire and catheter were analyzed and rates in erroneous vessel access were analyzed. Participants were given a Mental Rotations Test (MRT) and were analyzed based on MRT performance. RESULTS: After 8 sessions, there was a significant (p < 0.05) reduction on navigational error prevalence. The L-SUB and L-CCA saw the biggest drop in erroneous access, whereas the R-ECA, the biggest consumer of error time, saw no changes in access frequency. Individuals with high MRT score performed much better (p < 0.05) than those with low MRT score. CONCLUSIONS: Through self-guided simulation training, we demonstrated the navigational challenges encountered in simulated CA. To establish better assessments and standards in medical training, we can create self-guided training curricula aimed at correcting errors, enabling repetitive practice, and reducing human resource needs.

Stent Placement for Carotid Web.

BACKGROUND: The carotid web is an intraluminal shelf-like projection arising from the posterior wall of the carotid bifurcation and an uncommon etiology of ischemic strokes. We describe the feasibility of endovascular stent placement to treat this condition. CASE REPORT: A 47-year-old woman presented with a sudden occlusion of the right middle cerebral artery. Computed tomography angiography and digital subtraction angiography showed a carotid web in the ipsilateral carotid bifurcation. Treatment included mechanical thrombectomy for the middle cerebral artery occlusion and carotid stent placement to prevent further ischemic episodes from the carotid web. At the 6-month follow-up, good apposition of the stent against the artery wall was noted, and the patient was free of neurologic symptoms. CONCLUSIONS: Carotid artery stent placement is a feasible option in the management of carotid webs.

Evaluation of User Performance in Simulation-Based Diagnostic Cerebral Angiography Training.

Simulation of anatomically complex procedures, such as angiography, is becoming more practical, however, computer-based modules require extensive research to assess their effectiveness. We organized two training schemas - alternating cases and consistent cases - and hypothesized that the alternating practice cases would be beneficial to test performance. Eight residents (4 radiology/4 neurosurgery) and 8 anatomy graduate students were trained on the Simbionix™ simulator in order to assess skill acquisition in diagnostic cerebral angiography over 8 sessions. We found that participants improve on total procedure time and total fluoroscopy time (p<0.05), but not on contrast injected or roadmaps created. There were no significant differences between alternating and consistent training types. Additional work needs to be done with higher sample numbers and visuospatial scores as criteria.

Realism, criterion validity, and training capability of simulated diagnostic cerebral angiography.

Computer-based simulation is increasingly used in medical education for training, assessment, credentialing, and practice. Compared to medical specialties such as anesthesiology and general surgery, the adoption of simulation for neurointerventional training has been slow. This may be due to the limited number of neurointerventional simulators available and the lack of research assessing their validity and training capability. The objective of this study was to assess the realism, validity, and training capability of computer-based simulation for diagnostic cerebral angiography using a commercially available simulator called the ANGIO Mentor Express.

Visual outcomes for surgical treatment of large and giant carotid ophthalmic segment aneurysms: a case series utilizing retrograde suction decompression (the "Dallas technique").

OBJECT: The authors report their results in a series of large or giant carotid ophthalmic segment aneurysms clipped using retrograde suction decompression. METHODS: A retrospective review of clinical data and treatment summaries was performed for 18 patients with large or giant carotid artery ophthalmic segment aneurysms managed operatively via retrograde suction decompression. Visual outcomes, Glasgow Outcome Scale (GOS) scores, and operative complications were determined. Postoperative angiography was assessed. RESULTS: During a 17-year period, 18 patients underwent surgery performed using retrograde suction decompression. The mean aneurysm size was 26 mm. Three patients presented with subarachnoid hemorrhage. Fourteen of 18 patients presented with visual symptoms. Eleven (79%) of these 14 patients experienced visual improvement and the remaining 3 (21%) experienced worsened vision after surgery. Of 3 patients without visual symptoms and a complete visual examination before and after surgery, 1 had visual worsening postoperatively. One aneurysm required trapping and bypass, and all others could be clipped. Postoperative angiography demonstrated complete occlusion in 9 of 17 clipped aneurysms and neck remnants in the other 8 clipped aneurysms. One (5.5%) of 18 patients experienced a stroke. Eighteen patients had a GOS score of 5 (good outcome), and 1 patient had a GOS score of 4 (moderately disabled). There were no deaths. There was no morbidity related to the second incision or decompression procedure. Prolonged improvement did occur, and even in some cases of visual worsening in 1 eye, the overall vision did improve enough to allow driving. CONCLUSIONS: Retrograde suction decompression greatly facilitates surgical clipping for large and giant aneurysms of the ophthalmic segment. Visual preservation and improvement occur in the majority of these cases and is an important outcome measure. Developing endovascular technology must show equivalence or superiority to surgery for this specific outcome.

Outpatient brain tumor surgery: innovation in surgical neurooncology.

OBJECT: Recent studies of conventional craniotomies and image-guided biopsies have afforded a solid characterization of surgical morbidity and the timing of its occurrence. This report outlines a novel 11-year experience with outpatient image-guided biopsy and outpatient craniotomy for supratentorial intraaxial brain tumors. METHODS: During the period between August 1996 and May 2007, 117 awake image-guided biopsies and 145 elective craniotomies for tumor resection were prospectively selected to be performed as outpatient procedures. Data were recorded for each patient regarding tumor histological type, reasons for admission if planned early discharge failed, and surgical complications. RESULTS: Successful discharge from the Day Surgery Unit was possible in 109 (93%) of 117 biopsy cases and 136 (94%) of 145 craniotomy cases (only 2 of which [1.5%] required unplanned readmission after discharge). Neurological worsening occurred in 5.1% of the patients who underwent image-guided biopsies, and in 5.5% of those who underwent outpatient craniotomies (based on intent-to-treat group analysis). No patient suffered an adverse event with alteration in outcome because of planned outpatient discharge. CONCLUSIONS: Outpatient image-guided brain biopsy and outpatient craniotomy for tumor resection are safe and effective procedures in selected patients.