Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study.

INTRODUCTION: The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions. OBJECTIVE: To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy. METHODS: Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained. RESULTS: Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively. CONCLUSIONS: The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

Dolichoectatic vertebrobasilar aneurysms: a systematic review and meta-analysis of management strategies and outcomes.

OBJECTIVE: The aim of this study was to describe the efficacy, clinical outcomes, and complications of open cerebrovascular surgery, endovascular surgery, and conservative management of dolichoectatic vertebrobasilar aneurysms (DVBAs). METHODS: Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane databases according to PRISMA guidelines. A meta-analysis was conducted for clinical presentation, treatment protocols, and clinical outcomes-good (improved or stable clinical status) or poor (deteriorated clinical status or death)-and mortality rates. RESULTS: The 9 identified articles described 41 cases (27.5%) of open cerebrovascular surgery, 61 endovascular procedures (40.9%), and 47 cases (31.5%) of conservative management for DVBAs. The total cohort had a good outcome rate of 51.9% (95% CI 28.3%-74.6%), a poor outcome rate of 45.5% (95% CI 23.0%-70.1%), and a mortality rate of 22.3% (95% CI 11.8%-38.0%). The treatment groups had comparable good clinical outcome rates (open cerebrovascular surgery group: 24.7% [95% CI 2.9%-78.2%]; endovascular surgery group: 69.0% [95% CI 28.7%-92.5%]; conservative management group: 57.7% [95% CI 13.0%-92.5%]; p = 0.19) and poor outcome rates (open vascular surgery group: 75.3% [95% CI 21.8%-97.1%]; endovascular surgery group: 27.2% [95% CI 5.6%-0.70.2%]; conservative management group: 39.9% [95% CI 9.1%-81.6%]; p = 0.15). The treatment groups also had comparable mortality rates (open vascular surgery group: 39.5% [95% CI 11.4%-76.8%]; endovascular surgery group: 15.8% [95% CI 4.4%-43.0%]; conservative management group: 19.2% [95% CI 6.8%-43.5%]; p = 0.23). CONCLUSIONS: The current study of DVBAs illustrated poor outcomes and high mortality rates regardless of the treatment modality. The subgroup analysis showed heterogeneity among the subgroups and advice for personalized management.

Conventional Angiography in the Assessment of Recently Symptomatic Patients with Ipsilateral Carotid Stenosis.

BACKGROUND AND PURPOSE: Benefits of revascularization for moderate and severe (≥50%) carotid stenosis were established based on digital subtraction angiography (DSA). We aimed to assess the discrepancy between invasive and non-invasive angiography in a consecutive, prospective cohort of patients with recent stroke and non-invasive imaging suggesting ≥50% ipsilateral carotid stenosis. MATERIALS AND METHODS: We reviewed prospectively-collected data for consecutive patients admitted with recent stroke/TIA and ≥50% ipsilateral carotid stenosis on non-invasive imaging over 28 months. All patients underwent DSA to confirm the degree of stenosis per NASCET criteria. All patients with <50% stenosis by DSA were treated with medical therapy only and their recurrent event rates were assessed at 6 months. RESULTS: 148 symptomatic patients with ≥50% ipsilateral carotid stenosis on CTA (82%) and MRA (18%) underwent DSA to confirm degree of stenosis. Median age was 73 years and 64% were male. DSA demonstrated <50% stenosis in 28 patients (19%). Median presenting NIHSS was 1 (IQR 0-3). Median carotid stenosis evaluated by non-invasive imaging was 70% (IQR 60-85%) and by DSA was 40% (IQR 30-45%). One of 28 patients (4%) experienced recurrent nondisabling stroke (NIHSS 1) after stopping dual antiplatelet therapy. CONCLUSION: In nearly one-in-five cases with recent stroke due to ipsilateral carotid stenosis deemed to be candidates for revascularization based on CTA or MRA, DSA led to institution of medical therapy only due to insufficiently severe stenosis. In patients treated with medical therapy based on the findings of <50% stenosis on DSA, the rate of recurrent stroke is low.

Correction to: Radiation exposure to the surgeon during minimally invasive spine procedures is directly estimated by patient dose.

Unfortunately, the first author surname was incorrectly published as "Harrison Farber" instead of "Farber" in original publication.

Impact of depth filtration on disulfide bond reduction during downstream processing of monoclonal antibodies from CHO cell cultures.

Monoclonal antibody interchain disulfide bond reduction was observed in a Chinese Hamster Ovary manufacturing process that used single-use technologies. A similar reduction has been reported for processes that involved high mechanical shear recovery unit operations, such as continuous flow centrifugation and when the clarified harvest was stored under low dissolved oxygen (DO) conditions (Trexler-Schmidt et al., 2010. Biotechnology and Bioengineering, 106(3), 452-461). The work described here identifies disposable depth filtration used during cell culture harvest operations as a shear-inducing unit operation causing cell lysis. As a result, reduction of antibody interchain disulfide bonds was observed through the same mechanisms described for continuous flow centrifugation. Small-scale depth-filtration models were developed, and the differential pressure (Δ P) of the primary depth filter was identified as the key factor contributing to cell lysis. Strong correlations of Δ P and cell lysis were generated by measuring the levels of lactate dehydrogenase and thiol in the filtered harvest material. A simple risk mitigation strategy was implemented during manufacturing by providing an air overlay to the headspace of a single-use storage bag to maintain sufficient DO in the clarified harvest. In addition, enzymatic characterization studies determined that thioredoxin reductase and glucose-6-phosphate dehydrogenase are critical enzymes involved in antibody reduction in a nicotinamide adenine dinucleotide phosphate (NADP + )/NADPH-dependent manner.

Radiation exposure to the surgeon during minimally invasive spine procedures is directly estimated by patient dose.

PURPOSE: Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon's exposure to ionizing radiation is not easily recognizable without a digital dosimeter-something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure. METHODS: The senior surgeon wore a digital dosimeter during all minimally invasive spine fusion procedures performed over a 12-month period. Patient demographics, procedure information, and radiation exposure throughout the procedure were recorded. RESULTS: Fifty-five minimally invasive spine fusions utilizing 330 percutaneous screws were included. Average radiation dose was 0.46 Rad/screw to the patient. Average radiation exposure to the surgeon was 1.06 ± 0.71 µSv/screw, with a strong positive correlation (r = 0.77) to patient dose. The coefficient of determination (r2) was 0.5928, meaning almost two-thirds of the variability in radiation exposure to the surgeon is explained by radiation exposure to the patient. CONCLUSIONS: Intra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material.

Polymicrobial infection alter inflammatory microRNA in rat salivary glands during periodontal disease.

Periodontal disease initiated by subgingival pathogens is linked with diminished secretion of saliva, and implies pathogenic bacteria dissemination to or affects secondary sites such as the salivary glands. MicroRNAs activated in response to bacteria may modulate immune responses against pathogens. Therefore, Sprague-Dawley rats were infected by oral lavage consisting of polymicrobial inocula, namely Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, or sham-infected for 12 weeks (n = 6). We quantified inflammatory miRNA expression levels of miRNA-132, miR-146a, and miR-155 at secondary sites to the primary infection of the gingiva, including submandibular salivary glands, lacrimal glands, and pancreas. The presence of bacteria was detected in situ at secondary sites. Infected rat gingiva showed increased relative expression of miR-155. In contrast, miRNA-155 expression was decreased in submandibular salivary glands, along with positive identification of P. gingivalis in 2/6 and T. denticola in 1/6 rat salivary glands. Furthermore, miRNA-132 and miRNA-146a were significantly decreased in the pancreas of infected rats. This study is the first to show primary periodontal infections can alter miRNA profiles in secondary sites such as the salivary gland and pancreas. Whether these alterations contribute to pathologies of salivary glands in Sjögren's syndrome or of pancreas in diabetes warrants further investigation.

Long-term outcomes of deep pediatric arteriovenous malformations.

OBJECTIVE: Multimodality treatment has been shown to be the optimal management strategy for pediatric arteriovenous malformations (AVMs). Deep AVMs represent a subset of AVMs for which optimal management may be achieved with a combination of radiosurgery and highly selective embolization, in the absence of compelling features requiring operative intervention. The objective of this study was to identify predictors of good functional outcomes in pediatric patients with deep AVMs. METHODS: A retrospective cohort study of the outcomes of 79 patients with deep AVMs from January 1988 through December 2021 was performed. Deep AVMs were defined as those with the majority of the nidus centered in the basal ganglia, thalamus, or brainstem. Collected data included patient demographics and presenting symptoms, presenting modified Rankin Scale (mRS) score, radiographic findings and outcomes, management strategy, complications, and clinical outcomes as indicated by follow-up mRS score. A good outcome was defined as a follow-up mRS score ≤ 2, while a poor outcome was defined as a follow-up mRS score ≥ 3. Statistical analysis was performed to identify factors associated with functional outcomes. RESULTS: With a mean follow-up duration of 85.6 months, there was a 72.2% angiographic obliteration rate, with 75.9% of patients having a good clinical outcome (mRS score ≤ 2). Presenting symptoms and radiographic characteristics were not significantly associated with long-term functional outcomes. There was a significantly higher rate of posttreatment hemorrhage in patients with a poor versus good outcome (11.8% vs 0%, p = 0.010). On multivariate logistic regression analysis, poor long-term functional outcome was only associated with poor presenting mRS score (p = 0.002). CONCLUSIONS: Satisfactory angiographic obliteration rates and good long-term functional outcomes can be achieved for deep AVMs, with stereotactic radiosurgery as the cornerstone of multimodality treatment.

Cervical arterial dissection and traumatic myelopathy following yoga: surgical case report.

INTRODUCTION: Cervical spondylosis can predispose patients to central canal stenosis. In this setting, myelopathy through further flattening of the cord from extrinsic compression can be precipitated by relatively minor traumas. Arterial dissection is similarly considered a result of high velocity or momentum during trauma, commonly associated with fractures, cervical hyperflexion, or direct blunt force to the neck. Overall, precautions for both arterial dissection and myelopathy are rarely considered in low-velocity, static activities such as yoga. CASE PRESENTATION: The authors report the case of a 63-year-old man who suffered concurrent cervical myelopathy from multilevel spondylopathy, right vertebral artery dissection, and left cervical carotid artery dissection following a yoga session. Symptomatology consisted of acute onset neck pain, upper extremity sensory paresthesia, worsening gait and balance, and impaired dexterity for several weeks. Cervical MRI was obtained given myelopathic symptoms and revealed spondylosis with compression and T2 signal change at C3-C4. CT angiography of the neck revealed aforementioned dissections without flow limiting stenosis or occlusion. A therapeutic heparin infusion was started preoperatively until the patient underwent C3-C4 anterior cervical discectomy and fusion. Aspirin and Plavix were then started without incidence and the patient had significant but gradual improvement in myelopathic symptoms at 6-week follow-up. DISCUSSION: The static yet intensive poses associated with yoga present a rare etiology for arterial dissection and myelopathy, but patients with persistent and progressive symptoms should be screened with the appropriate imaging modality. Cervical decompression should be expedited before initiating an antiplatelet medication.

Modulation of high mannose levels in N-linked glycosylation through cell culture process conditions to increase antibody-dependent cell-mediated cytotoxicity activity for an antibody biosimilar.

The regulatory approval of a biosimilar product is contingent on the favorable comparability of its safety and efficacy to that of the innovator product. As such, it is important to match the critical quality attributes of the biosimilar product to that of the innovator product. The N-glycosylation profile of a monoclonal antibody (mAb) can influence effector function activities such as antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity. In this study, we describe efforts to modulate the high-mannose (HM) levels of a biosimilar mAb produced in a Chinese hamster ovary cell fed-batch process. Because the HM level of the mAb was observed to impact ADCC activity, it was desirable to match it to the innovator mAb's levels. Several cell culture process related factors known to modulate the HM content of N-glycosylation were investigated, including osmolality, ammonium chloride (NH4 Cl) addition, glutamine concentration, monensin addition, and the addition of alternate sugars and amino sugars to the feed medium. The process conditions evaluated varied in impact on HM levels, process performance and product quality. One condition, the addition of alternate sugars and amino sugars to feed medium, was identified as the preferred method for increasing HM levels with minimal disruptions to process performance or other product quality attributes. Interestingly, a secondary interaction between sugar and amino sugar supplemented feeds and osmolality was observed during process scale-up. These studies demonstrate sugar and amino sugar concentrations and osmolality are critical variables to evaluate to match HM content in biosimilar and their innovator mAbs.

Symptomatic nonstenotic carotid disease: Evaluation of a proposed classification scheme in a prospective cohort.

INTRODUCTION: Unraveling symptomatic nonstenotic carotid disease (SyNC) as a stroke etiology from other cryptogenic stroke may have important implications for defining natural history and for tailoring secondary prevention strategies. We aim to describe the characteristics of the plaques in a prospectively-collected cohort of patients with non-invasive imaging suggesting symptomatic carotid stenosis but whose DSA demonstrated nonstenotic atheromatous disease, and to evaluate the recurrence rate depending on the type of SyNC. METHODS: We reviewed prospectively-collected data for patients presenting with new neurologic events and non-invasive imaging suggestive of moderate or severe (≥50%) carotid stenosis between July 2016 and October 2018. Patients were included in the present study if the degree of stenosis on DSA was < 50%. We assigned these patients into groups based on a previously-proposed working definition of SyNC, and analyzed the rate of recurrent stroke in the following 6 months. RESULTS: 28 patients had DSA-confirmed < 50% stenosis and constituted the study cohort. The median age was 73 years and 64% were male; median presenting NIHSS was 1 (IQR 0-3). The great majority (86%) of carotid plaques had high-risk features including ulcerated plaque (n = 21, 75%) and plaque > 3 mm thick (n = 18, 64%). 17 of 28 patients (61%) met classification criteria for "definite" or "probable" SyNC. Three of five patients in the "definite SyNC" group experienced recurrent neurologic events. CONCLUSION: The majority of patients with non-invasive imaging suggesting carotid stenosis harbor symptomatic carotid disease per current classifications despite DSA stenosis < 50%. Current classification schema may allow for risk stratification of SyNC patients and these findings warrant further study.

Stereotactic Electroencephalography Implantation Through Nonautologous Cranioplasty: Proof of Concept.

BACKGROUND: Stereoelectroencephalography (SEEG) is an effective method to define the epileptogenic zone (EZ) in patients with medically intractable epilepsy. Typical placement requires passing and anchoring electrodes through native skull. OBJECTIVE: To describe the successful placement of SEEG electrodes in patients without native bone. To the best of our knowledge, the use of SEEG in patients with nonautologous cranioplasties has not been described. METHODS: We describe 3 cases in which SEEG was performed through nonautologous cranioplasty. The first is a 30-yr-old male with a titanium mesh cranioplasty following a left pterional craniotomy for aneurysm clipping. The second is a 51-yr-old female who previously underwent lesionectomy of a ganglioglioma with mesh cranioplasty and subsequent recurrence of her seizures. The third is a 31-yr-old male with a polyether ether ketone cranioplasty following decompressive hemicraniectomy for trauma. RESULTS: SEEG was performed successfully in all three cases without intraoperative difficulties or complications and with excellent electroencephalogram recording and optimal localization of the seizure focus. The EZ was successfully localized in all three patients. There were no limitations related to drilling or inserting the guiding bolt/electrode through the nonautologous cranioplasties. CONCLUSION: SEEG through nonautologous cranioplasties was clinically feasible, safe, and effective in our series. The presence of nonautologous bone cranioplasty should not preclude such patients from undergoing SEEG explorations.

Incidence of adjacent-segment surgery following stand-alone lateral lumbar interbody fusion.

OBJECTIVE: Adjacent-segment disease (ASD) requiring operative intervention is a relatively common long-term consequence of lumbar fusion surgery. Although the incidence of ASD requiring reoperation is well described for traditional posterior lumbar approaches (2.5%-3.9% per year), it remains poorly characterized for stand-alone lateral lumbar interbody fusion (LLIF). In this study, the authors report their institutional experience with ASD requiring reoperation after LLIF over an extended follow-up period of 4 years. METHODS: Medical records were reviewed for 276 consecutive patients who underwent stand-alone LLIF by a single surgeon for degenerative spinal disorders. Inclusion criteria (single-stage, stand-alone LLIF without posterior supplementation, with no prior lumbar instrumentation, and a minimum of 4 years of follow-up) were met by 182 patients, who were analyzed for operative ASD incidence (per-year rate), demographics, and Oswestry Disability Index (ODI) score. Operative ASD was strictly defined as new-onset pathology following index surgery at directly adjacent levels to the prior construct. Operative, rather than symptomatic or radiographic, ASD was analyzed to provide a consistent and impactful endpoint while avoiding retrospective diagnosis. RESULTS: The study cohort of 182 patients had an operative ASD rate of 3.3% (n = 6 procedures) over 4 years of follow-up, for an incidence on Kaplan-Meier survival analysis of 0.88% (95% CI 0.67%-1.09%) per year. In comparing patients with operative ASD with those without, there were no significant differences in mean age (53.7 vs 56.2 years), male sex (33.3% vs 44.9%), smoking status (16.7% vs 25.0%), or number of levels fused (mean 1.33 vs 1.46). The operative ASD cohort had a greater mean BMI (37.3 vs 30.2, p < 0.01). Operative ASD patients had lower baseline ODI scores (33.8 vs 48.3, p = 0.02); however, no difference was observed in ODI at 6 weeks (34.0 vs 39.0) or 3 months (16.0 vs 32.8) postoperatively. CONCLUSIONS: The incidence of ASD in LLIF for degenerative lumbar etiologies in this cohort was 0.88% (95% CI 0.67%-1.09%) per year. Meanwhile, the reported reoperation rates for ASD in posterior spinal approaches was 2.5% to 3.9% per year, which implies that LLIF may be preferable for well-selected patients.

Surgeon and staff radiation exposure in minimally invasive spinal surgery: prospective series using a personal dosimeter.

OBJECTIVE: The level of radiation awareness by surgeons and residents in spinal surgery does not match the ubiquity of fluoroscopy in operating rooms in the United States. The present method of monitoring radiation exposure may contribute to the current deficiency in radiation awareness. Current dosimeters involve a considerable lag from the time that the surgical team is exposed to radiation to the time that they are provided with that exposure data. The objective of the current study was to assess the feasibility of monitoring radiation exposure in operating room personnel during lateral transpsoas lumbar interbody fusion (LLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) procedures by using a wearable personal device with real-time feedback. METHODS: Operating room staff participating in minimally invasive surgical procedures under a single surgeon during a 6-month period were prospectively enrolled in this study. All radiation dose exposures were recorded for each member of the surgical team (surgeon, assistant surgeon, scrub nurse, and circulating nurse) using a personal dosimeter (DoseAware). Radiation doses were recorded in microsieverts (µSv). Comparisons between groups were made using ANOVA with the Tukey post hoc test and Student t-test. RESULTS: Thirty-nine patients underwent interbody fusions: 25 underwent LLIF procedures (14 LLIF alone, 11 LLIF with percutaneous screw placement [PSP]) and 14 underwent MI-TLIF. For each operative scenario per spinal level, the surgeon experienced significantly higher (p < 0.035) average radiation exposure (LLIF: 167.9 µSv, LLIF+PSP: 424.2 µSv, MI-TLIF: 397.9 µSv) than other members of the team, followed by the assistant surgeon (LLIF: 149.7 µSv, LLIF+PSP: 242.3 µSv, MI-TLIF: 274.9 µSv). The scrub nurse (LLIF: 15.4 µSv, LLIF+PSP: 125.7 µSv, MI-TLIF: 183.0 µSv) and circulating nurse (LLIF: 1.2 µSv, LLIF+PSP: 9.2 µSv, MI-TLIF: 102.3 µSv) experienced significantly lower exposures. Radiation exposure was not correlated with the patient's body mass index (p ≥ 0.233); however, it was positively correlated with increasing patient age (p ≤ 0.004). CONCLUSIONS: Real-time monitoring of radiation exposure is currently feasible and shortens the time between exposure and the availability of information regarding that exposure. A shortened feedback loop that offers more reliable and immediate data would conceivably raise the level of concern for radiation exposure in spinal surgeries and could alter patterns of behavior, leading to decreased exposures. Further studies are ongoing to determine the effect of real-time dosimetry in spinal surgery.

Decreasing Radiation Emission in Minimally Invasive Spine Surgery Using Ultra-Low-Radiation Imaging with Image Enhancement: A Prospective Cohort Study.

BACKGROUND: Visualization of the anatomy in minimally invasive surgery (MIS) of the spine is limited and dependent on radiographic imaging, leading to increased radiation exposure to patients and surgical staff. Ultra-low-radiation imaging (ULRI) with image enhancement is a novel technology that may reduce radiation in the operating room. The aim of this study was to compare radiation emission between standard-dose and ULRI fluoroscopy with image enhancement in patients undergoing MIS of the spine. METHODS: This study prospectively enrolled 60 consecutive patients who underwent lateral lumbar interbody fusion, lateral lumbar interbody fusion with percutaneous pedicle screws, or MIS transforaminal lumbar interbody fusion. Standard-dose fluoroscopy was used in 31 cases, and ULRI with image enhancement was used in 29 cases. All imaging emission and radiation doses were recorded. RESULTS: Radiation emission per level was significantly less with ULRI than with standard-dose fluoroscopy for lateral lumbar interbody fusion (36.4 mGy vs. 119.8 mGy, P < 0.001), per screw placed in lateral lumbar interbody fusion (15.4 mGy per screw vs. 47.1 mGy per screw, P < 0.001), and MIS transforaminal lumbar interbody fusion (24.4 mGy vs. 121.6 mGy, P = 0.003). These differences represented reductions in radiation emission of 69.6%, 67.3%, and 79.9%. Total radiation doses per case were also significantly decreased for the transpsoas approach by 68.8%, lateral lumbar interbody fusion with percutaneous pedicle screws by 65.8%, and MIS transforaminal lumbar interbody fusion by 81.0% (P ≤ 0.004). CONCLUSIONS: ULRI with image enhancement has the capacity to significantly decrease radiation emission in minimally invasive procedures without compromising visualization of anatomy or procedure safety.

Operative and peri-operative considerations in the management of brain metastasis.

The number of patients who develop metastatic brain lesions is increasing as the diagnosis and treatment of systemic cancers continues to improve, resulting in longer patient survival. The role of surgery in the management of brain metastasis (BM), particularly multiple and recurrent metastases, remains controversial and continues to evolve. However, with appropriate patient selection, outcomes after surgery are typically favorable. In addition, surgery is the only means to obtain a tissue diagnosis and is the only effective treatment modality to quickly relieve neurological complications or life-threatening symptoms related to significant mass effect, CSF obstruction, and peritumoral edema. As such, a thorough understanding of the role of surgery in patients with metastatic brain lesions, as well as the factors associated with surgical outcomes, is essential for the effective management of this unique and growing patient population.

Evidence based diagnosis and management of chronic subdural hematoma: A review of the literature.

Chronic subdural hematomas are encapsulated blood collections within the dural border cells with characteristic outer "neomembranes". Affected patients are more often male and typically above the age of 70. Imaging shows crescentic layering of fluid in the subdural space on a non-contrast computed tomography (CT) scan, best appreciated on sagittal or coronal reformats. Initial medical management involves reversing anticoagulant/antiplatelet therapies, and often initiation of anti-epileptic drugs (AEDs). Operative interventions, such as twist-drill craniostomy (TDC), burr-hole craniostomy (BHC), and craniotomy are indicated if imaging implies compression (maximum fluid collection thickness >1 cm) or the patient is symptomatic. The effectiveness of various surgical techniques remains poorly characterized, with sparse level 1 evidence, variable outcome measures, and various surgical techniques. Postoperatively, subdural drains can decrease recurrence and sequential compression devices can decrease embolic complications, while measures such as early mobilization and re-initiation of anticoagulation need further study. Non-operative management, including steroid therapy, etizolam, tranexamic acid, and angiotensin converting enzyme inhibitors (ACEI) also remain poorly studied. Recurrent hemorrhages are a major complication affecting around 10-20% of patients, and therefore close follow-up is essential.

Minimally Invasive Lateral Access Surgery and Reoperation Rates: A Multi-Institution Retrospective Review of 2060 Patients.

BACKGROUND: Risk factors for surgical revision remain important because of additional readmission, anesthesia, and morbidity for the patient and significant cost for health care systems. Although the rate of reoperation (RRO) is well described for traditional open posterior (OP) approaches, the RRO in minimally invasive lateral (MIL) surgery remains poorly characterized. This study compares the RRO in patients undergoing decompressive lumbar spine surgery via MIL versus OP approaches. METHODS: Patient demographics and comorbidities were retrospectively collected for 2060 patients undergoing single-stage elective lumbar spinal surgery at multiple institutions. A subset of 1484 patients had long-term data (long-term cohort [LT cohort]). The RRO was compared between approaches through univariate and multivariate analysis. RESULTS: There were 1292 patients (62.7%) who underwent lateral access surgery, whereas 768 patients (37.3%) underwent OP surgery. The MIL cohort was significantly older, had a higher proportion of men, and had more comorbidities than the OP cohort. In the LT cohort, lateral patients were significantly older and had more comorbidities, with a lower body mass index and a lower proportion of men and smokers. Surgical complications between the groups trended to be similar. The MIL cohort had a significantly lower RRO at both 30 days (approximately 57% lower, MIL cohort: 1.01% vs. OP cohort: 2.36%, P = 0.02) and 2 years (approximately 61% lower, MIL cohort: 2.09% vs. OP cohort: 5.37%, P < 0.01) after surgery. On multivariate analysis, surgical approach was the only significant predictor for the RRO at both 30 days (open posterior approach odds ratio [OR], 4.47; 95% confidence interval [CI], 1.33-15.09; P = 0.02) and 2 years (open posterior approach OR, 3.26; 95% CI, 1.26-8.42; P = 0.01). CONCLUSIONS: This study shows that MIL surgical approaches, compared with OP approaches, have a significantly lower RRO after lumbar spine surgery.

Pedicle screw placement accuracy using ultra-low radiation imaging with image enhancement versus conventional fluoroscopy in minimally invasive transforaminal lumbar interbody fusion: an internally randomized controlled trial.

OBJECTIVE A previous study found that ultra-low radiation imaging (ULRI) with image enhancement significantly decreases radiation exposure by roughly 75% for both the patient and operating room personnel during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) (p < 0.001). However, no clinical data exist on whether this imaging modality negatively impacts patient outcomes. Thus, the goal of this randomized controlled trial was to assess pedicle screw placement accuracy with ULRI with image enhancement compared with conventional, standard-dose fluoroscopy for patients undergoing single-level MIS-TLIF. METHODS An institutional review board-approved, prospective internally randomized controlled trial was performed to compare breach rates for pedicle screw placement performed using ULRI with image enhancement versus conventional fluoroscopy. For cannulation and pedicle screw placement, surgery on 1 side (left vs right) was randomly assigned to be performed under ULRI. Screws on the opposite side were placed under conventional fluoroscopy, thereby allowing each patient to serve as his/her own control. In addition to standard intraoperative images to check screw placement, each patient underwent postoperative CT. Three experienced neurosurgeons independently analyzed the images and were blinded as to which imaging modality was used to assist with each screw placement. Screw placement was analyzed for pedicle breach (lateral vs medial and Grade 0 [< 2.0 mm], Grade 1 [2.0-4.0 mm], or Grade 2 [> 4.0 mm]), appropriate screw depth (50%-75% of the vertebral body's anteroposterior dimension), and appropriate screw angle (within 10° of the pedicle angle). The effective breach rate was calculated as the percentage of screws evaluated as breached > 2.0 mm medially or postoperatively symptomatic. RESULTS Twenty-three consecutive patients underwent single-level MIS-TLIF, and their sides were randomly assigned to receive ULRI. No patient had immediate postoperative complications (e.g., neurological decline, need for hardware repositioning). On CT confirmation, 4 screws that had K-wire placement and cannulation under ULRI and screw placement under conventional fluoroscopy showed deviations. There were 2 breaches that deviated medially but both were Grade 0 (< 2.0 mm). Similarly, 2 breaches occurred that were Grade 1 (> 2.0 mm) but both deviated laterally. Therefore, the effective breach rate (breach > 2.0 mm deviated medially) was unchanged in both imaging groups (0% using either ULRI or conventional fluoroscopy; p = 1.00). CONCLUSIONS ULRI with image enhancement does not compromise accuracy during pedicle screw placement compared with conventional fluoroscopy while it significantly decreases radiation exposure to both the patient and operating room personnel.