Analysis of reported adverse events of pipeline stents for intracranial aneurysms using the FDA MAUDE database.

OBJECTIVE: Flow diverting stents (FDS) are a validated device in the treatment of intracranial aneurysms, allowing for minimally invasive intervention. However, after its approval for use in the United States in 2011, post-market surveillance of adverse events is limited. This study aims to address this critical knowledge gap by analyzing the FDA Manufacturer and User Facility Device Experience (MAUDE) database for patient and device related (PR and DR) reports of adverse events and malfunctions. METHODS: Using post-market surveillance data from the MAUDE database, PR and DR reports from January 2012-December 2021 were extracted, compiled, and analyzed with R-Studio version 2021.09.2. PR and DR reports with insufficient information were excluded. Raw information was organized, and further author generated classifications were created for both PR and DR reports. RESULTS: A total of 2203 PR and 4017 DR events were recorded. The most frequently reported PR adverse event categories were cerebrovascular (60%), death (11%), and neurological (8%). The most frequent PR adverse event reports were death (11%), thrombosis/thrombus (9%) cerebral infarction (8%), decreased therapeutic response (7%), stroke/cerebrovascular accident (6%), intracranial hemorrhage (5%), aneurysm (4%), occlusion (4%), headache (4%), neurological deficit/dysfunction (3%). The most frequent DR reports were activation/positioning/separation problems (52%), break (9%), device operates differently than expected (4%), difficult to open or close (4%), material deformation (3%), migration or expulsion of device (3%), detachment of device or device component (2%). CONCLUSIONS: Post-market surveillance is important to guide patient counselling and identify adverse events and device problems that were not identified in initial trials. We present frequent reports of several types of cerebrovascular and neurological adverse events as well as the most common device shortcomings that should be explored by manufacturers and future studies. Although inherent limitations to the MAUDE database are present, our results highlight important PR and DR complications that can help optimize patient counseling and device development.

MedCDI: A technology-based documentation and quality improvement initiative in neurosurgery.

Background: Clinical documentation of patient care alters coding accuracy of Medicare Severity Diagnosis-Related Groups (MS-DRGs), expected mortality, and expected length of stay (LOS) which impact quality metrics. We aimed to determine if neurosurgical quality metrics could be improved by facilitating accurate documentation and subsequently developed a mobile application and educational video to target areas of opportunity. Methods: Vizient software was used to analyze MS-DRGs and expected LOS for sample of patients requiring surgery for spinal pathology, brain tumors, and subarachnoid hemorrhage (SAH) between January 2019 and August 2021. Chart reviews were conducted to discover variables missed by documenting provider and/or coder. Results: Review of 114 spinal surgeries, 20 brain tumors, and 53 SAH patients revealed at least one additional variable impacting LOS in 43% of spine, 75% of brain tumor, and 92% of SAH patients, with an average of 1 (1.25), 2 (1.75), and 3 (2.89) new variables, respectively. Recalculated expected LOS increased by an average of 0.86 days for spine, 3.08 for brain tumor, and 6.46 for SAH cases. Conclusion: Efforts to accurately document patient care can improve quality metrics such as expected LOS, mortality, and cost estimates. We determined several missing variables which impact quality metrics, showing opportunity exists in neurosurgical documentation improvement. Subsequently, we developed an educational video and mobile-supported application to specifically target these variables. To the best of our knowledge, this represents the first initiative to utilize the proven powers of mobile phones in health care toward the novel application of specifically improving neurosurgical quality metrics.

Endovascular treatment of a sacral dural arteriovenous fistula.

Spinal dural arteriovenous fistula (SDAVF) is a rare pathological communication between arterial and venous vessels within the spinal dural sheath. Clinical presentation includes progressive spinal cord symptoms including gait difficulty, sensory disturbances, changes in bowel or bladder function, and sexual dysfunction. These fistulas are most often present in the thoracolumbar region. Diagnoses of SDVAFs are commonly missed, possibly due to the low index of suspicion, non-specific symptoms and challenging imaging. In this case report, we describe a rare presentation of a sacral SDAVF which was detected by collective efforts between endovascular neurosurgery and interventional radiology. We outline the diagnostic and imaging challenges we faced to discover the fistula. In particular, mechanical pump injection instead of hand injection during angiography was required to reveal the fistula. Following identification, the fistula was successfully treated endovascularly by using onyx (ethylene vinyl alcohol glue), a less invasive alternative to surgical intervention.

Prevalence of Potentially Clinically Significant Magnetic Resonance Imaging Findings in Athletes with and without Sport-Related Concussion.

Previous studies have shown that mild traumatic brain injury (mTBI) can cause abnormalities in clinically relevant magnetic resonance imaging (MRI) sequences. No large-scale study, however, has prospectively assessed this in athletes with sport-related concussion (SRC). The aim of the current study was to characterize and compare the prevalence of acute, trauma-related MRI findings and clinically significant, non-specific MRI findings in athletes with and without SRC. College and high-school athletes were prospectively enrolled and participated in scanning sessions between January 2015 through August 2017. Concussed contact sport athletes (n = 138; 14 female [F]; 19.5 ± 1.6 years) completed up to four scanning sessions after SRC. Non-concussed contact (n = 135; 15 F; 19.7 ± 1.6) and non-contact athletes (n = 96; 15 F; 20.0 ± 1.7) completed similar scanning sessions and served as controls. Board-certified neuroradiologists, blinded to SRC status, reviewed T1-weighted and T2-weighted fluid-attenuated inversion recovery and T2*-weighted and T2-weighted images for acute (i.e., injury-related) or non-acute findings that prompted recommendation for clinical follow-up. Concussed athletes were more likely to have MRI findings relative to contact (30.4% vs. 15.6%; odds ratio [OR] = 2.32; p = 0.01) and non-contact control athletes (19.8%; OR = 2.11; p = 0.04). Female athletes were more likely to have MRI findings than males (43.2% vs. 19.4%; OR = 2.62; p = 0.01). One athlete with SRC had an acute, injury-related finding; group differences were largely driven by increased rate of non-specific white matter hyperintensities in concussed athletes. This prospective, large-scale study demonstrates that <1% of SRCs are associated with acute injury findings on qualitative structural MRI, providing empirical support for clinical guidelines that do not recommend use of MRI after SRC.

Multimodal endovascular therapy of traumatic and spontaneous carotid cavernous fistula using coils, n-BCA, Onyx and stent graft.

BACKGROUND AND PURPOSE: Carotid cavernous fistula (CCF) can be classified as either direct or indirect according to the arterial feeder source. The current standard treatment for CCF is endovascular embolization. In this case series, 21 CCF (direct and indirect) embolization procedures were treated with multimodal endovascular therapy to explore safety, technique and clinical efficacy. METHOD AND PATIENTS: The neurointerventional database was reviewed for all cases of CCF. Demographic information, indications for the procedure, presenting symptoms, endovascular therapy types, complications and procedure angiographic and clinical efficacy were collected. RESULTS: 21 CCF embolization procedures were performed using multimodal therapy on 15 patients (eight females and seven males) with a mean age of 56.4±22.4 years (15-90 years), with 60% traumatic CCF and 40% spontaneous CCF presenting mainly with typical visual symptoms. 10 patients were treated in one session, four patients underwent two sessions and one required three sessions of endovascular therapy. Complete fistula occlusion was achieved in 10/15 patients (73.3%) in one session and in 14/15 (93.3%) patients after two or more sessions. One patient's symptoms (case No 15) improved dramatically after the second session despite incomplete obliteration of the CCF. No periprocedural complications were reported. Long term follow-up showed one recurrence of the CCF with a mean follow-up time of 201±17.2 months (range 1-56 months). Patient No 6 was lost to follow-up. CONCLUSION: Multimodal endovascular embolization of CCF appears to be safe with a high success rate of complete obliteration. This case series demonstrates complete occlusion in 73.3% of the patients after one session and in 93.3% after the second session.

Subdural hematomas in chronic dialysis patients: significant and increasing.

BACKGROUND AND OBJECTIVES: Subdural hematoma is a known complication of long-term hemodialysis. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: The US Renal Data System was used to determine the occurrence rate of nontraumatic subdural hematoma in long-term dialysis patients and to evaluate time trends. RESULTS: The occurrence rate of subdural hematoma in long-term dialysis patients is 10 times higher than that of the general population. From 1991 to 2002, the occurrence rate of subdural hematoma in hemodialysis patients doubled, whereas it did not change in peritoneal dialysis patients. CONCLUSIONS: This high occurrence rate of subdural hematoma and its recent increase may be related to increased use of anticoagulants in long-term hemodialysis patients.

Biomechanical characterization of internal layer subfailure in blunt arterial injury.

Blunt carotid artery injuries occur in 0.3% of blunt injured patients and may lead to devastating neurological consequences. However, arterial mechanics leading to internal layer subfailure have not been quantified. Twenty-two human carotid artery segments and 18 porcine thoracic aorta segments were opened to expose the intimal side and longitudinally distracted to failure. Porcine aortas were a geometrically accurate model of human carotid arteries. Internal layer subfailures were identified using videography and correlated with mechanical data. Ninety-three percent (93%) of vessels demonstrated subfailure prior to catastrophic failure. All subfailures occurred on the intimal surface. Initial subfailure occurred at 79% of the stress and 85% of the strain to catastrophic failure in younger porcine specimens, compared to 44% and 60%, respectively, in older human specimens. In most cases, multiple subfailures occurred prior to catastrophic failure. Due to limitations in human specimen quality (age, prior storage), young and fresh porcine aorta specimens are likely a more accurate model of clinical blunt carotid artery injuries. Present results indicate that vessels are acutely capable of maintaining physiologic function following initial subfailure. Delayed symptomatology commonly associated with blunt arterial injuries is explained by this mechanics-based and experimentally quantified onset of subcatastrophic failure.

Perioperative assessment of coagulability in neurosurgical patients using thromboelastography.

BACKGROUND: Thrombelastography is a useful technique for evaluating coagulability. We hypothesized that it could be used to determine postoperative hematologic complications during and after neurologic surgery. METHODS: Forty-six neurosurgical patients were stratified by diagnosis: subarachnoid hemorrhage from ruptured intracranially aneurysms, intracranial-axial lesions, intracranial-extra-axial lesions, and degenerative spine disease. Thromboelastograms were performed before, during, and after surgery. Hematologic data were collected preoperatively and postoperatively; computed tomography scans and lower extremity Doppler sonography were performed postoperatively. A thrombosis index (TI) was used to assess coagulability. RESULTS: Coagulability increased over the course of surgery for all patients (p < 0.0001). In craniotomy patients, coagulability increased over the course of surgery (p < 0.05) with the most dramatic increase from intubation to skin incision (p < 0.05), and then after tumor removal or aneurysm clipping (p < 0.10). Univariate analysis among craniotomy patients showed that female gender (p < 0.0004) and smoking (p < 0.06) were associated with hypercoagulability. Among craniotomy patients, younger age was associated with hypercoagulability in the preoperative period (p < 0.01). There was no significant association between coagulability and aspirin or NSAID use, or intraoperative fluid volume. No patient developed a postoperative hematoma and one patient (2.2%) developed a lower extremity deep vein thrombosis. CONCLUSIONS: Increased coagulability begins between induction of anesthesia and skin incision, and continues to increase throughout surgery. These changes are more pronounced in patients undergoing craniotomy compared to patients undergoing spine procedures.

Brain atrophy in mild or moderate traumatic brain injury: a longitudinal quantitative analysis.

BACKGROUND AND PURPOSE: Although mild or moderate traumatic brain injury (TBI) is known to cause persistent neurologic sequelae, the underlying structural changes remain elusive. Our purpose was to assess decreases in the volume of brain parenchyma (VBP) in patients with TBI and to determine if clinical parameters are predictors of the extent of atrophy. METHODS: We retrospectively assessed the total VBP in 14 patients with mild or moderate TBI at more than 3 months after injury and in seven patients at two time points more than 3 months apart. VBP was calculated from whole-brain MR images and then normalized by calculating the percent VBP (%VBP) to correct for intraindividual variations in cranial size. Clinical parameters at the time of trauma were evaluated for potential predictors of atrophy. Findings were compared with those of control subjects of similar ages. RESULTS: In the single time-point analysis, brain volumes, CSF volumes, and %VBP were not significantly different between patients and control subjects. In the longitudinal analysis, the rate of decline in %VBP (0.02 versus 0.0064 U/day, P =.05) and the change in %VBP between the first and second time points (-4.16 +/- 1.68 versus -1.49 +/- 1.7, P =.022 [mean +/-SD]) were significantly greater in patients. Change in %VBP was significantly greater in patients with loss of consciousness (LOC) than in those without LOC (P =.023). CONCLUSION: Whole-brain atrophy occurs after mild or moderate TBI and is evident at an average of 11 months after trauma. Injury that produces LOC leads to more atrophy. These findings may help elucidate an etiology for the persistent or new neurologic deficits that occur months after injury.

Intravascular coagulation: a major secondary insult in nonfatal traumatic brain injury.

OBJECT: The goal of this study was to determine the frequency with which cerebral intravascular coagulation (IC) complicates traumatic brain injury (TBI). The authors also investigated the incidence of IC in relation to varying mechanisms, time courses, and severities of TBI and in different species. METHODS: Tissue was sampled from surgical specimens of human cerebral contusions, from rats with lateral fluid-percussion injuries, and from pigs with head rotational acceleration injuries. Immunohistochemical fluorescent staining for antithrombin III was performed to detect cerebral intravascular microthrombi. Abundant IC was found in all specimens, and microthrombi had formed in arterioles and venules of all sizes, ranging from 10 to 600 microm. Although it was more pronounced in focal lesions and more severe injuries, considerable IC was also observed in mild and diffuse injuries. The authors found a strong association between the severity of coagulopathy and the density of IC. CONCLUSIONS: These results strongly support the contention that IC is a universal response to TBI and an important secondary cerebral insult.

Alternative management considerations for ethmoidal dural arteriovenous fistulas.

BACKGROUND: Ethmoidal dural arteriovenous fistulas (EDAFs) are an unusual type of intracranial vascular lesion that commonly present with acute hemorrhage. They are often best treated surgically; however, recent endovascular advances raise questions concerning the best therapeutic approach. METHODS: We present 7 cases of EDAFs managed at this institution over a 6-year period, which demonstrate the broad spectrum of clinical behavior associated with the lesions. Four patients presented with intracranial hemorrhage, 1 patient with rapidly progressive dementia, 1 patient with a proptotic, red eye, and 1 with a retro-orbital headache. RESULTS: One patient underwent no treatment, 1 underwent embolization alone, 2 underwent embolization and resection, and 3 patients underwent resection alone. There was complete obliteration of the EDAF in all of the patients who underwent surgical resection. Embolization was performed through the external carotid circulation and not the ophthalmic artery. There were no treatment-related neurologic deficits. CONCLUSIONS: Treatment is best managed with a multidisciplinary approach, which emphasizes complete resection of the lesions with assistance from interventional neuroradiology techniques. However, each patient must be evaluated independently as treatment may vary depending on the angioarchitecture of the lesion.