Stroke Microsurgical Thrombectomy Human Placenta Simulator.

BACKGROUND: Stroke microsurgical cerebrovascular thrombectomy reports are limited, although this technique could be used in many centers as a primary treatment or a salvage intervention option. It requires great ability, so our aim is to describe and validate a stroke microsurgical thrombectomy ex vivo simulator with operative nuances analysis. METHODS: Human placenta (HP) models simulated middle cerebral artery vessels with intraluminal thrombus to be microsurgically excised. Six neurosurgeons performed 1-mm and 2-mm longitudinal and transverse arteriotomy in different arteries to remove a 1.5-cm length thrombus. Validation through construct validity compared time to complete the task, complete vessel cleaning, vessel manipulation, vessel stenosis, and leakage in both techniques. RESULTS: All 6 HP models reproduced with fidelity stroke microsurgical thrombectomy, so participants completed 24 sessions, 4 for each neurosurgeon on the same model in different arteries. Construct validity highlighted microsurgical technical difficulties with positive results obtained by parameters variation during performance. Transverse arteriotomy with 1-mm length had best results (P < 0.05) allowing complete thrombus removal, less stenosis, and minor leakage in abbreviated time. CONCLUSIONS: A HP simulator can reproduce with high fidelity all stroke microsurgical thrombectomy part tasks. Transverse 1-mm arteriotomy followed by thrombectomy and 2 simple sutures can fulfill all quality assurance aspects in such intervention accordingly to training model, due to easier vessel opening, complete thrombus removal, no stenosis, and faster microsuture.

Improving Stroke Care in Times of the COVID-19 Pandemic Through Simulation: Practice Your Protocols!

During the coronavirus disease 2019 (COVID-19) pandemic, infectious disease control is of utmost importance in acute stroke treatment. This is a new situation for most stroke teams that often leads to uncertainty among physicians, nurses, and technicians who are in immediate contact with patients. The situation is made even more complicated by numerous new regulations and protocols that are released in rapid succession. Herein, we are describing our experience with simulation training for COVID-19 stroke treatment protocols. One week of simulation training allowed us to identify numerous latent safety threats and to adjust our institution-specific protocols to mitigate them. It also helped our physicians and nurses to practice relevant tasks and behavioral patterns (eg, proper donning and doffing PPE, where to dispose potentially contaminated equipment) to minimize their infectious exposure and to adapt to the new situation. We therefore strongly encourage other hospitals to adopt simulation training to prepare their medical teams for code strokes during the COVID-19 pandemic.

Using G-FAST to recognize emergent large vessel occlusion: a training program for a prehospital bypass strategy.

INTRODUCTION: The shorter the time between the onset of symptoms and reperfusion using endovascular thrombectomy, the better the functional outcome of patients. A training program was designed for emergency medical technicians (EMTs) to learn the gaze-face-arm-speech-time test (G-FAST) score for initiating a prehospital bypass strategy in an urban city. This study aimed to evaluate the effect of the training program on EMTs. METHODS: All EMTs in the city were invited to join the training program. The program consisted of a 30 min lecture and a 20 min video which demonstrated the G-FAST evaluation. The participants underwent tests before and after the program. The tests included (1) a questionnaire of knowledge, attitudes, confidence, and behaviors towards stroke care; and (2) watching 10 different scenarios in a video and answering questions, including eight sub-questions of G-FAST parameters, and choosing a suitable receiving hospital. RESULTS: In total, 1058 EMTs completed the training program. After the program, significant improvement was noted in knowledge, attitudes, and confidence, as well as scenario judgement. The performance of the EMTs in evaluating G-FAST criteria in comatose patients was relatively poor in the pre-test and improved significantly after the training course. Although the participants answered the G-FAST items correctly, they tended to overtriage the patients and refer them to higher-level hospitals. CONCLUSIONS: A short training program can improve the ability to identify stroke patients and choose a suitable receiving hospital. A future training program could put further emphasis on how to evaluate comatose patients and choose a suitable receiving hospital.

Validation studies of virtual reality simulation performance metrics for mechanical thrombectomy in ischemic stroke.

INTRODUCTION: Mechanical thrombectomy (MT) has transformed the treatment of ischemic stroke. However, patient access to MT may be limited due to a shortage of doctors specifically trained to perform MT. The studies reported here were done to (1) develop, operationally define, and seek consensus from procedure experts on the metrics which best characterize a reference procedure for the performance of an MT for ischemic stroke and (2) evaluate their construct validity when implemented in a virtual reality (VR) simulation. METHODS: In study 1, the metrics for a reference approach to an MT procedure for ischemic stroke of 10 phases, 46 steps, and 56 errors and critical errors, were presented to an international Delphi panel of 21 consultant level interventional neuroradiologists (INRs). In study 2, the metrics were used to assess 8 expert and 10 novice INRs performing a VR simulated routine MT procedure. RESULTS: In study 1, the Delphi panel reached consensus on the appropriateness of the procedure metrics for a reference approach to MT in ischemic stroke. Group differences in median scores in study 2 demonstrated that experienced INRs performed the case 19% faster (P=0.029), completed 40% more procedure phases (P=0.009), 20% more steps (P=0.012), and made 42% fewer errors (P=0.016) than the novice group. CONCLUSIONS: The international Delphi panel agreed metrics implemented in a VR simulation of MT distinguished between the computer scored procedure performance of INR experts and novices. The studies reported here support the demonstration of face, content, and construct validity of the MT metrics.

Visual Aids for Patient, Family, and Physician Decision Making About Endovascular Thrombectomy for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Rapid decision making optimizes outcomes from endovascular thrombectomy for acute cerebral ischemia. Visual displays facilitate swift review of potential outcomes and can accelerate decision processes. METHODS: From patient-level, pooled randomized trial data, 100 person-icon arrays (Kuiper-Marshall personographs) were generated showing beneficial and adverse effects of endovascular thrombectomy for patients with acute cerebral ischemia and large vessel occlusion using (1) automated (algorithmic) and (2) expert-guided joint outcome table specification. RESULTS: For the full 7-category modified Rankin Scale, thrombectomy added to IV tPA (intravenous tissue-type plasminogen activator) alone had number needed to treat to benefit 2.9 (95% confidence interval, 2.6-3.3) and number needed to harm 68.9 (95% confidence interval, 40-250); thrombectomy for patients ineligible for IV tPA had number needed to treat to benefit 2.3 (95% confidence interval, 2.1-2.5) and number needed to harm 100 (95% confidence interval, 62.5-250). Visual displays of treatment effects on 100 patients showed: with thrombectomy added to IV tPA alone, 34 patients have better disability outcome, including 14 more normal or near normal (modified Rankin Scale, 0-1); with thrombectomy for patients ineligible for IV tPA, 44 patients have a better disability outcome, including 16 more normal or nearly normal. Displays also showed that harm (increased modified Rankin Scale final disability) occurred in 1 of 100 patients in both populations, mediated by increased new territory infarcts. The person-icon figures integrated these outcomes, and early side-effects, in a single display. CONCLUSIONS: Visual decision aids are now available to rapidly educate healthcare providers, patients, and families about benefits and risks of endovascular thrombectomy, both when added to IV tPA in tPA-eligible patients and as the sole reperfusion treatment in tPA-ineligible patients.

Human placenta as an ex vivo vascular model for neurointerventional research.

BACKGROUND: Human placenta is a convenient resource for biomedical research, and has not yet been used for neurointerventional surgery research. OBJECTIVE: Our objective was to explore the feasibility of using human placenta to test various endovascular interventions and for training. DESIGN: 18 placentas soon after delivery were prepared for six pilot studies. (1) Study on anatomical similarity to human cerebral vessel. (2) Simulation of stent assisted coiling and flow diversion on an aneurysm model. (3) Simulation of intra-arterial thrombolysis. (4) Simulation of embolization of arteriovenous malformation with glues. (5) Simulation of mechanical thrombolysis and comparison of different devices. (6) Vascular model for training of neurointerventionalists. RESULTS: When the chorionic plate vessels were compared with the cerebral cortical vessels, similarities were found in vascular branch patterns, histological cross sections, and angiographic appearances. Due to the semitransparency of its vessel wall, performance of flow diverter and stent assisted coiling of an aneurysm could be visualized under direct microscopic observation. Similarly, timing of clot lysis and glue polymerization could be estimated. Endothelial change after thrombectomy could be assessed by histological methods. From these pilot studies, the placenta model could be adopted to simulate various clinical situations. It is also ideal for interventional radiology training. CONCLUSIONS: It is feasible to adopt the human placenta as an ex vivo vascular model in neurointerventional surgery research due to the fact that its vessels resemble the brain vasculature.

Performance and training standards for endovascular ischemic stroke treatment.

Stroke is the third-leading cause of death in the United States, Canada, Europe, and Japan. According to the American Heart Association and the American Stroke Association, 750,000 new strokes occur each year, resulting in 200,000 deaths (or 1 of every 16 deaths) per year in the United States alone. Endovascular therapy for patients with acute ischemic stroke is an area of intense investigation. The American Stroke Association has given a qualified endorsement of intra-arterial (IA) thrombolysis in selected patients. IA thrombolysis has been studied in 2 randomized trials and numerous case series. Although 2 devices have been granted FDA 3 approval with an indication for mechanical stroke thrombectomy, none of these devices has demonstrated efficacy in improving patient outcomes. This report defines what constitutes adequate training to perform neuroendovascular procedures in patients with acute ischemic stroke and identifies the performance standards that should be adopted to assess outcomes. These guidelines have been written and approved by multiple neuroscience societies that historically have been directly involved in the medical, surgical, and endovascular care of patients with acute stroke, including the Neurovascular Coalition and its participating societies: the Society of NeuroInterventional Surgery; American Academy of Neurology; American Association of Neurological Surgeons, Cerebrovascular Section; and Society of Vascular & Interventional Neurology.

A novel technique for creating solid renal pseudotumors and renal vein-inferior vena caval pseudothrombus in a porcine and cadaveric model.

PURPOSE: We developed a simple means to replicate kidney tumors in an animal and cadaver model that could be used to create pseudotumors of different sizes and locations for use in surgical training. MATERIALS AND METHODS: Various substances were injected ex vivo into the parenchyma of porcine kidneys to identify an optimal pseudotumor model. Renal pseudotumors were created percutaneously and endoscopically using 8 live pigs and a human cadaver model. A renal vein pseudothrombus porcine model was also created by injecting pseudothrombus material into the renal vein after renal hilar clamping. Procedures performed on pseudotumors included robotic partial nephrectomy, percutaneous biopsy and robotic nephrectomy with renal vein thrombectomy. All specimens were analyzed after resection. RESULTS: The most ideal pseudotumor models were created from a mixture of gelatin, Metamucil and methylene blue (metagel) or from Kromopan hydrocolloid. We created 33 tumors 0.5 to 3.5 cm in size (mean 2.8). All tumors were a solid palpable mass on gross examination and ultrasonography revealed clearly visible hyperechoic lesions in 30 of 33. A renal vein tumor pseudothrombus model was successfully created in 3 pigs. We successfully performed robotic excision of pseudotumors, including partial nephrectomy for 16 and radical nephrectomy with renal vein thrombectomy for 3. Percutaneous needle core biopsy under ultrasound guidance was also successfully performed. CONCLUSIONS: We describe what is to our knowledge a novel technique of creating solid renal tumors and tumor thrombi that can be used for training in minimally invasive kidney surgery.

Performance of procedures by nephrologists and nephrology fellows at U.S. nephrology training programs.

BACKGROUND AND OBJECTIVES: Some procedures (e.g., placement of temporary hemodialysis catheters and kidney biopsies) are required in nephrology fellowship training. Others (e.g., placement of tunneled hemodialysis catheters, ultrasonography, and hemodialysis access interventions) are not required but are performed at some centers. To assess the procedures performed by nephrologists and nephrology fellows at U.S. adult nephrology training programs and the number of procedures required for fellow competency, a survey was conducted of all such training programs. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: An on-line survey was e-mailed to the directors of all U.S. adult nephrology fellowship programs in October to November 2007. RESULTS: Responses were received from 93 of 136 programs. Nephrologists and nephrology trainees perform native and transplant kidney biopsies in 98% to 99% of programs and, in about half of programs, also perform the ultrasound guidance. Diagnostic ultrasounds are performed at fewer programs. Temporary dialysis catheters are inserted at nearly all programs. Tunneled hemodialysis catheters and peritoneal dialysis catheters are placed at < or =20% of programs. Interventional procedures on hemodialysis access are performed at 13% to 21% of programs. Continuous renal replacement therapy is performed at 99% of programs, plasmapheresis at 40%. Many programs either do not specify a minimum number of supervised procedures that need to be performed to demonstrate competence or require a very limited number. CONCLUSIONS: Core procedures are performed at almost all programs. Experience and training in other procedures are variable. Many programs have limited requirements for the number of procedures trainees need to perform to demonstrate competence.