Clinical and Imaging Outcomes of Surgically Repaired Cerebrospinal Fluid-Venous Fistulas Identified by Lateral Decubitus Digital Subtraction Myelography.

OBJECTIVE: To describe clinical and radiographic outcomes of surgical repair of cerebrospinal fluid-venous fistula (CVF), an increasingly recognized cause of spontaneous intracranial hypotension that is poorly responsive to epidural blood patch (EBP). METHODS: Retrospective review identified adult patients who had lateral decubitus digital subtraction myelography indicative of cerebrospinal fluid leak at Mayo Clinic between November 2018 and February 2020, with clearly localized CVF, followed by surgical treatment. Patients without available imaging before or after surgery were excluded. History of EBP and clinical response to EBP were evaluated along with surgical outcomes. RESULTS: Of 25 patients with CVF who met protocol criteria and were included in the data analysis, 22 (88%) received EBP, but clinical benefit lasting ≥4 weeks occurred in only 2 of 22 (9%). Headache was the most prominent preoperative feature among patients (24/25; 96%). Following surgery, 18 of 24 (75%) patients had complete headache improvement, 4 (17%) had partial improvement, and 2 (8%) had no improvement. Ten of 25 (40%) patients reported cognitive disturbance at baseline; at follow-up, 5 of 10 (50%) had complete improvement, 3 (30%) had partial improvement, and 2 (20%) had no improvement. On postoperative brain magnetic resonance imaging, 6 of 25 (24%) patients had complete resolution of findings by Bern score criteria, 18 (72%) showed partial improvement, and 1 (4%) patient showed no improvement. Adverse events were minor and included surgical site pain and paresthesias. CONCLUSIONS: Surgical repair of CVF resulted in improvements in headache and other symptoms, with few side effects.

Modulation of Cerebral Function by Muscle Afferent Activity, with Reference to Intravenous Succinylcholine.

Cerebral Function and Muscle Afferent Activity Following Intravenous Succinylcholine in Dogs Anesthetized with Halothane: The Effects of Pretreatment with a Defasciculating Dose of Pancuronium. By WL Lanier, PA Iaizzo, and JH Milde. Anesthesiology 1989; 71:87-95. Reprinted with permission. By the mid-1980s, it was widely assumed that if the depolarizing muscle relaxant, succinylcholine, given IV, produced increases in intracranial pressure, it did so because fasciculations produced increases in intrathoracic and central venous pressures that were transferred to the brain; however, there was no direct evidence that this was true. In contrast, we explored the possibility that the succinylcholine effect on the brain was explained by the afferentation theory of cerebral arousal, which predicts that agents or maneuvers that stimulate muscle stretch receptors will tend to stimulate the brain. Our research in tracheally intubated, lightly anesthetized dogs discovered that IV succinylcholine (which does not cross the blood-brain barrier) produced a doubling of cerebral blood flow that lasted for 30 min and corresponded to activation of the electroencephalogram and increases in intracranial pressure. Later, in our Classic Paper, we were able to assess simultaneously cerebral physiology and afferent nerve traffic emanating from muscle stretch receptors (primarily muscle spindles). We affirmed that the cerebral arousal response to succinylcholine was indeed driven by muscle afferent traffic and was independent of fasciculations or increases in intrathoracic or central venous pressures. Later research in complementary models demonstrated that endogenous movement (e.g., coughing, hiccups) produced a cerebral response very similar to IV succinylcholine, apparently as a result of the same muscle afferent mechanisms, independent of intrathoracic and central venous pressures. Thus, the importance of afferentation theory as a driver of the cerebral state of arousal and cerebral physiology during anesthesia was affirmed.

Pituitary Tumor Surgery: Comparison of Endoscopic and Microscopic Techniques at a Single Center.

OBJECTIVE: To understand the transition from microscopic surgery (MS) to endoscopic surgery (ES) on the pituitary across the United States, we assessed a single institution practicing both procedures to discern advantages and disadvantages for each. PATIENTS AND METHODS: Retrospective institutional chart review of 534 patients in a large practice over a 6-year period (January 1, 2014, to December 31, 2019) comparing a single MS neurosurgeon with a single ES neurosurgeon operating on the same days. RESULTS: In this series, 14% (n=75) of patients had a prior operation, there were no carotid artery injuries, the overall risk for a postoperative infection was 0.4% (n=2), and risk for a postoperative cerebrospinal fluid leak requiring treatment was 2.0% (n=11). Mean ± SD hospital stay was 1.3±0.04 days; readmission for any reason within 30 days occurred in 3.4% (n=18) of patients. The mean volumetric resection for MS was 86.9%±1.7% and for ES was 91.7%±1.3% (P=.03). There was a higher rate of notable events (P=.015) with MS, but MS had 16% lower cost and operative times were 48 minutes shorter than for ES (83±7 vs 131±6 minutes). The ES required substantially fewer postoperative secondary treatments such as radiation therapy (P=.003). CONCLUSION: Pituitary surgery is a very safe and effective procedure regardless of technique. The MS has shorter operative times and overall lower cost. The ES results in increased volumetric resection and fewer secondary treatments. Both techniques can be valuable to a large practice, and understanding these niches is important when selecting optimal approaches to pituitary surgery for a given patient.

Dealing with inappropriate-, low-quality-, and other forms of challenging peer review, including hostile referees and inflammatory or confusing critiques: Prevention and treatment.

Within the context of journal peer review, when high-quality referee input is coupled with appropriate editorial oversight from a journal's leadership, the result can be the selection and publication of high-quality manuscripts that are ideally targeted to the journal's readership's interests. However, in its worse forms, flawed referee input and indifferent- or misdirected journal leadership can result in damage to the quality of materials published and the relationships among, and careers of, the involved parties. This article identifies methods that journals can employ to select journal leaders and educate authors, referees, and editors in an attempt to prophylax against problematic peer review. The article then identifies 17 categories of inappropriate or flawed critiques. Next it outlines a plan of action: 1) to prevent potentially harmful reviews from reaching authors, and 2) for instructing authors on how to respond to perceived challenging or problematic reviews, or perceived erroneous journal decisions. Elsewhere, the article introduces an approach to diffuse hostilities that may follow the publication of controversial articles. The synthesis within this article approaches peer review as a continuous quality improvement exercise in which referees, authors, and journal leadership will gain a broader understanding of the standards of biomedical publication and professionalism.

Evidence versus advocacy, as related to radiofrequency denervation in the treatment of chronic low back pain and the MINT trials.

In 2017, JAMA: Journal of the American Medical Association published the results of the MINT trials, prospective research involving 681 patients, all of whom received exercise therapy for low back pain. Half of the patients were randomized to additionally receive radiofrequency denervation (RFD) treatment. 88% of patients completed the 3-month follow-up, and 77% completed the 12-month follow-up. In this context, RFD provided no added benefit over the baseline of exercise therapy. In 2018, five authors, all experts in pain medicine, published a 'Daring Discourse' article in the journal Regional Anesthesia and Pain Medicine (RAPM), criticizing the findings of the MINT trials. Although 3 of the 5 authors of the RAPM 'Daring Discourse' article reported in conflict of interest statements-as is appropriate-that they were consultants to corporations that produce RFD equipment, the authors failed to disclose that 4 of 5 are on the editorial board of RAPM and all 5 are current officers in the medical organization that owns RAPM: that is, the American Society of Regional Anesthesia and Pain Medicine. Noteworthy, there was no published response from the MINT trial investigators to the Daring Discourse criticisms, either in the aforementioned example or in downstream venues where some of the same Daring Discourse authors continued their widely disseminated criticisms of the JAMA/MINT trials report. We believe that these actions taken by the Daring Discourse authors and RAPM have unfairly tipped the scales in the evaluation and application of RFD treatment of low back pain. In our commentary, we discuss: (1) the challenges associated with using clinical trials to predict clinical efficacy, (2) appropriate and inappropriate uses of postpublication commentary on original research findings, (3) the use of inappropriate commentary (and related means) to alter clinical practice in the presence of contradictory research findings, and (4) potential conflicts of interest related to the authors' and Journal's publication of the unopposed MINT trials criticism.

Effect of Promotion via Social Media on Access of Articles in an Academic Medical Journal: A Randomized Controlled Trial.

PURPOSE: To study the effect of a planned social media promotion strategy on access of online articles in an established academic medical journal. METHOD: This was a single-masked, randomized controlled trial using articles published in Mayo Clinic Proceedings, a large-circulation general/internal medicine journal. Articles published during the months of October, November, and December 2015 (n = 68) were randomized to social media promotion (SoMe) using Twitter, Facebook, and LinkedIn or to no social media promotion (NoSoMe), for 30 days (beginning with the date of online article publication). Journal website visits and full-text article downloads were compared for 0-30 and 31-60 days following online publication between SoMe versus NoSoMe using a Wilcoxon rank-sum test. RESULTS: Website access of articles from 0 to 30 days was significantly higher in the SoMe group (n = 34) compared with the NoSoMe group (n = 34): 1,070 median downloads versus 265, P < .001. Similarly, full-text article downloads from 0-30 days were significantly higher in the SoMe group: 1,042 median downloads versus 142, P < .001. Compared with the NoSoMe articles, articles randomized to SoMe received a greater number of website visits via Twitter (90 vs 1), Facebook (526 vs 2.5), and LinkedIn (31.5 vs 0)-all P < .001. CONCLUSIONS: Articles randomized to SoMe were more widely accessed compared with those without social media promotion. These findings show a possible role, benefit, and need for further study of a carefully planned social media promotion strategy in an academic medical journal.

Hydraulic stimulation of carotid artery baroreceptors as a likely cause of transient asystolic cardiac arrest during diagnostic angiography or surgical endarterectomy.

We describe two patients-both who underwent general anesthesia-in whom we theorize that hydraulic pressure on carotid artery baroreceptors resulted in transient asystolic cardiac arrest (TACA) during diagnostic or therapeutic procedures. Patient #1 was a 58-year-old female who experienced TACA in response to rapid injection of radiocontrast material into the carotid artery during diagnostic cerebral angiography. Her history was remarkable for aneurysmal subarachnoid hemorrhage at least 13 hr prior to angiography, radiographic evidence of intracranial hypertension, and baseline bradycardia, collectively suggestive of increases in baseline vagal tone. Potentially contributing to TACA, the patient had a 90° curve in the internal carotid artery, just distal to the carotid bifurcation and tip of the angiography catheter, that likely diminished runoff of injected contrast solution and, in turn, would have exacerbated any intracarotid pressure increases in response to injection. There was no evidence of increased baseline vagal tone in Patient #2, a 79-year-old female having carotid endarterectomy surgery. She experienced TACA immediately after full release of an occlusive clamp on the common carotid artery proximal to the now closed carotid arteriotomy, but while the internal carotid was still occluded. Of note, the carotid artery baroreceptors were not treated with local anesthetic in these patients, thus they should have retained much of their normal function. We describe the possible pathomechanisms involved in TACA in these patients, measures to diminish the likelihood of the phenomenon occurring in future patients, and methods for treating the asystole.

Flick-Spin Methodology for Improving Cannulation Success in Tortuous and Valve-Rich Peripheral Veins.

Peripheral veins often contain tortuosities and valves that hinder the effective passage of intravenous catheters to the full extent of catheter length. This report describes a methodology termed flick-spin that has proven efficacious for venous catheter passage in tortuous and valve-rich peripheral veins. The method relies on (1) applying longitudinal tension to the vessel in an attempt to straighten it, (2) rotating or spinning the catheter along its longitudinal axis, and (3) flicking the skin or visible vein just beyond the catheter tip, all during catheter advancement. Additionally, lateral pressure may also be applied to the vessel-ie, proximal to the catheter tip and during catheter advancement-to fine-tune catheter tip direction. The report contains multiple illustrations to communicate the anatomic, physiologic, and technical underpinnings of the technique, as well as instructions for troubleshooting common problems.

Neuroanesthesiology Update.

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

Real-Time Cineangiography Visualization of Cerebral Aneurysm Rupture in an Awake Patient: Anatomic, Physiological, and Functional Correlates.

Intracranial aneurysms are common and, on a population-based perspective, are a major cause of morbidity and mortality as a result of mass effect or rupture. Cerebral angiography is the primary technique used for the diagnosis of cerebral aneurysms, and the imaging data have additional utility for planning medical, endovascular, or surgical treatments. An extremely rare periprocedural complication of cerebral angiography is rupture of the aneurysm, either as a chance phenomenon or as a result of some physiologic change or mechanical effect. We report on a single awake, alert patient who experienced intraprocedural aneurysm rupture that was recorded in real time during diagnostic cerebral angiography and subsequently proved fatal. Rupture occurred shortly after the completion of contrast material injection into a semi-open vascular bed and appeared to be temporally unrelated to any supranormal change in systemic physiology. No therapeutic endovascular procedure was planned or attempted. From the high-quality sequential, frame-by-frame images, and electronic sedation and anesthesiology records, plus our own real-time observations (G.L., W.L.L.), we were able (for educational purposes) to reconstruct the time course of rupture of the aneurysm, the velocity and pattern of blood escaping the aneurysm and entering the subarachnoid space, and other physiologic and functional correlates (blood pressure changes, alterations in consciousness) that may be critical to our understanding of the mechanism and consequences of aneurysm rupture.

Exposure to Surgery and Anesthesia After Concussion Due to Mild Traumatic Brain Injury.

OBJECTIVE: To describe the epidemiology of surgical and anesthetic procedures in patients recently diagnosed as having a concussion due to mild traumatic brain injury. PATIENTS AND METHODS: Study patients presented to a tertiary care center after a concussion due to mild traumatic brain injury from July 1, 2005, through June 30, 2015, and underwent a surgical procedure and anesthesia support under the direct or indirect care of a physician anesthesiologist. RESULTS: During the study period, 1038 patients met all the study inclusion criteria and subsequently received 1820 anesthetics. In this population of anesthetized patients, rates of diagnosed concussions due to sports injuries, falls, and assaults, but not motor vehicle accidents, increased during 2010-2011. Concussions were diagnosed in 965 patients (93%) within 1 week after injury. In the 552 patients who had surgery within 1 week after concussive injury, 29 (5%) had anesthesia and surgical procedures unrelated to their concussion-producing traumatic injury. The highest use of surgery occurred early after injury and most frequently required general anesthesia. Orthopedic and general surgical procedures accounted for 57% of procedures. Nine patients received 29 anesthetics before a concussion diagnosis, and all of these patients had been involved in motor vehicle accidents and received at least 1 anesthetic within 1 week of injury. CONCLUSION: Surgical and anesthesia use are common in patients after concussion. Clinicians should have increased awareness for concussion in patients who sustain a trauma and may need to take measures to avoid potentially injury-augmenting cerebral physiology in these patients.