Automated thermal imaging monitors the local response to cervical cancer brachytherapy.

Malignant tumors have high metabolic and perfusion rates, which result in a unique temperature distribution as compared to healthy tissues. Here, we sought to characterize the thermal response of the cervix following brachytherapy in women with advanced cervical carcinoma. Six patients underwent imaging with a thermal camera before a brachytherapy treatment session and after a 7-day follow-up period. A designated algorithm was used to calculate and store the texture parameters of the examined tissues across all time points. We used supervised machine learning classification methods (K Nearest Neighbors and Support Vector Machine) and unsupervised machine learning classification (K-means). Our algorithms demonstrated a 100% detection rate for physiological changes in cervical tumors before and after brachytherapy. Thus, we showed that thermal imaging combined with advanced feature extraction could potentially be used to detect tissue-specific changes in the cervix in response to local brachytherapy for cervical cancer.

Advances in the Use of Electrospun Nanofibrous Polymeric Matrix for Dermal Healing at the Donor Site After the Split-Thickness Skin Graft Excision: A Prospective, Randomized, Controlled, Open-Label, Multicenter Study.

Dressings used to manage donor site wounds (DSWs) have up to 40% of patients experiencing complications that may cause suboptimal scarring. We evaluated the efficacy and safety of a portable electrospun nanofibrous matrix that provides contactless management of DSWs compared with standard dressing techniques. This study included adult patients who underwent an excised split-thickness skin graft (STSG) with a DSW area of 10 to 200 cm2. Patients were allocated into two groups; ie, the nanofiber group managed with a nanofibrous polymer-based matrix, and the control group managed using the standard of care such as Jelonet® or Biatain® Ibu dressing. Primary outcomes were postoperative dermal healing efficacy assessed by Draize scores. The time to complete re-epithelialization was also recorded. Secondary outcomes included postoperative adverse events, pain, and infections during the first 21 days and extended 12-month follow-up. The itching and scarring were recorded during the extended follow-up (months 1, 3, 6, 9, and 12) using Numerical-Analogue-Score and Vancouver scores, respectively. The nanofiber and control groups included 21 and 20 patients, respectively. The Draize dermal irritation scores were significantly lower in the nanofiber vs control group (Z = -2.509; P = .028) on the first postoperative day but became similar afterward (Z ≥ -1.62; P ≥ .198). In addition, the average time to re-epithelialization was similar in the nanofiber (17.9 ± 4.4 days) and control group (18.3 ± 4.5 days; Z = -0.299; P = .764), so were postoperative adverse events, pain, and infection incidence, itching and scarring. The safety and efficacy of electrospun nanofibrous matrix are similar to standard wound care allowing its use as an alternative donor site dressing following the STSG excision.

Non-Trigeminal Nociceptive Innervation of the Posterior Dura: Implications to Occipital Headache.

Current understanding of the origin of occipital headache falls short of distinguishing between cause and effect. Most preclinical studies involving trigeminovascular neurons sample neurons that are responsive to stimulation of dural areas in the anterior 2/3 of the cranium and the periorbital skin. Hypothesizing that occipital headache may involve activation of meningeal nociceptors that innervate the posterior ⅓ of the dura, we sought to map the origin and course of meningeal nociceptors that innervate the posterior dura overlying the cerebellum. Using AAV-GFP tracing and single-unit recording techniques in male rats, we found that neurons in C2-C3 DRGs innervate the dura of the posterior fossa; that nearly half originate in DRG neurons containing CGRP and TRPV1; that nerve bundles traverse suboccipital muscles before entering the cranium through bony canals and large foramens; that central neurons receiving nociceptive information from the posterior dura are located in C2-C4 spinal cord and that their cutaneous and muscle receptive fields are found around the ears, occipital skin and neck muscles; and that administration of inflammatory mediators to their dural receptive field, sensitize their responses to stimulation of the posterior dura, peri-occipital skin and neck muscles. These findings lend rationale for the common practice of attempting to alleviate migraine headaches by targeting the greater and lesser occipital nerves with anesthetics. The findings also raise the possibility that such procedures may be more beneficial for alleviating occipital than non-occipital headaches and that occipital migraines may be associated more closely with cerebellar abnormalities than in non-occipital migraines.SIGNIFICANCE STATEMENT Occipital headaches are common in both migraine and non-migraine headaches. Historically, two distinct scenarios have been proposed for such headaches; the first suggests that the headaches are caused by spasm or tension of scalp, shoulders, and neck muscles inserted in the occipital region, whereas the second suggests that these headaches are initiated by activation of meningeal nociceptors. The current study shows that the posterior dura overlying the cerebellum is innervated by cervicovascular neurons in C2 DRG whose axons reach the posterior dura through multiple intracranial and extracranial pathways, and sensitization of central cervicovascular neurons from the posterior dura can result in hyper-responsiveness to stimulation of neck muscles. The findings suggest that the origin of occipital and frontal migraine may differ.

Tracking patients with chronic occipital headache after occipital nerve decompression surgery: A case series.

BACKGROUND: The therapeutic benefit of nerve decompression surgeries for chronic headache/migraine are controversial. AIM: To provide clinical characteristics of headache type and treatment outcome of occipital nerve decompression surgery. METHODS: A retrospective review of clinical records. Inclusion criteria were evidence of chronic occipital headache with and without migrainous features and tenderness of neck muscles, occipital allodynia, and inadequate response to prophylactic drugs. RESULTS: Surgical decompression of the greater and lesser occipital nerves provided complete and extended (3-6 years) relief of new daily persistent headache in case 3 (46 year old female), and of chronic post-traumatic headache in cases 4 and 6 (35 and 30 year old females, respectively), partial relief of chronic headache/migraine in cases 1 and 2 (41 year old female and 36 year old male), and no relief of episodic (cases 3 and 4) or chronic migraine (case 5, 52 year old male), or chronic tension-type headache (case 7, 31 year old male). CONCLUSIONS: As a case series, this study cannot test a hypothesis or determine cause and effect. However, the complete elimination of new daily persistent headache and post-traumatic headache, and the partial elimination of chronic headache/migraine in two patients - all refractory to other treatment approaches - supports and justifies the effort to continue to generate data that can help determine whether decompression nerve surgeries are beneficial in the treatment of certain types of chronic headache.

The migraine eye: distinct rod-driven retinal pathways' response to dim light challenges the visual cortex hyperexcitability theory.

Migraine-type photophobia, most commonly described as exacerbation of headache by light, affects nearly 90% of the patients. It is the most bothersome symptom accompanying an attack. Using subjective psychophysical assessments, we showed that migraine patients are more sensitive to all colors of light during ictal than during interictal phase and that control subjects do not experience pain when exposed to different colors of light. Based on these findings, we suggested that color preference is unique to migraineurs (as it was not found in control subjects) rather than migraine phase (as it was found in both phases). To identify the origin of this photophobia in migraineurs, we compared the electrical waveforms that were generated in the retina and visual cortex of 46 interictal migraineurs to those generated in 42 healthy controls using color-based electroretinography and visual-evoked potential paradigms. Unexpectedly, it was the amplitude of the retinal rod-driven b wave, which was consistently larger (by 14%-19% in the light-adapted and 18%-34% in the dark-adapted flash ERG) in the migraineurs than in the controls, rather than the retinal cone-driven a wave or the visual-evoked potentials that differs most strikingly between the 2 groups. Mechanistically, these findings suggest that the inherent hypersensitivity to light among migraine patients may originate in the retinal rods rather than retinal cones or the visual cortex. Clinically, the findings may explain why migraineurs complain that the light is too bright even when it is dim to the extent that nonmigraineurs feel as if they are in a cave.

Color-selective photophobia in ictal vs interictal migraineurs and in healthy controls.

Aversion to light is common among migraineurs undergoing acute attacks. Using psychophysical assessments in patients with episodic migraine, we reported that white, blue, amber, and red lights exacerbate migraine headache in a significantly larger percentage of patients and to a greater extent compared with green light. This study aimed at determining whether these findings are phase-dependent-namely, manifested exclusively during migraine (ictally) but not in its absence (interictally), or condition-dependent-ie, expressed uniquely in migraineurs but not in healthy controls. To determine whether the color preference of migraine-type photophobia is phase- or condition-dependent, we compared the effects of each color of light in each intensity between migraineurs during and in-between attacks and healthy controls. During the ictal and interictal phases, the proportion of migraineurs reporting changes in headache severity when exposed to the different colors of light increased in accordance with elevated light intensities. During the ictal phase, white, blue, amber, and red lights exacerbated headaches in ∼80% of the patients; however, during the interictal phase, light initiated headache in only 16% to 19%. Notably, green light exacerbated headaches in 40% and triggered headaches in 3% of the patients studied during the ictal and interictal phases, respectively. With one exception (highest red light intensity), no control subject reported headache in response to the light stimuli. These findings suggest that color preference is unique to migraineurs-as it was not found in control subjects-and that it is independent of whether or not the patients are in their ictal or interictal phase.

[TECHNOLOGICAL SOLUTIONS FOR THE IMPROVEMENT OF OUTCOMES IN CARDIAC SURGERY OF OCTOGENARIAN PATIENTS].

INTRODUCTION: The current review addresses present-day technological advances in cardiac surgery performed on octogenarian patients, namely off-pump coronary artery bypass grafting (CABG), proximal anastomosis device, routine use of intraoperative epiaortic ultrasound, transcatheter aortic valve implantation (TAVI), and brain protection during cardiac surgery. Conflict of Interest: Gil Bolotin served as a scientific advisor for Cardiogard Ltd., which is addressed in this review paper.

Fremanezumab-A Humanized Monoclonal Anti-CGRP Antibody-Inhibits Thinly Myelinated (Aδ) But Not Unmyelinated (C) Meningeal Nociceptors.

Calcitonin gene-related peptide (CGRP), the most abundant neuropeptide in primary afferent sensory neurons, is strongly implicated in the pathophysiology of migraine headache, but its role in migraine is still equivocal. As a new approach to migraine treatment, humanized anti-CGRP monoclonal antibodies (CGRP-mAbs) were developed to reduce the availability of CGRP, and were found effective in reducing the frequency of chronic and episodic migraine. We recently tested the effect of fremanezumab (TEV-48125), a CGRP-mAb, on the activity of second-order trigeminovascular dorsal horn neurons that receive peripheral input from the cranial dura, and found a selective inhibition of high-threshold but not wide-dynamic range class of neurons. To investigate the basis for this selective inhibitory effect, and further explore the mechanism of action of CGRP-mAbs, we tested the effect of fremanezumab on the cortical spreading depression-evoked activation of mechanosensitive primary afferent meningeal nociceptors that innervate the cranial dura, using single-unit recording in the trigeminal ganglion of anesthetized male rats. Fremanezumab pretreatment selectively inhibited the responsiveness of Aδ neurons, but not C-fiber neurons, as reflected in a decrease in the percentage of neurons that showed activation by cortical spreading depression. These findings identify Aδ meningeal nociceptors as a likely site of action of fremanezumab in the prevention of headache. The selectivity in its peripheral inhibitory action may partly account for fremanezumab's selective inhibition of high-threshold, as a result of a predominant A-δ input to high-threshold neurons, but not wide dynamic-range dorsal horn neurons, and why it may not be effective in all migraine patients.SIGNIFICANCE STATEMENT Recently, we reported that humanized CGRP monoclonal antibodies (CGRP-mAbs) prevent activation and sensitization of high-threshold (HT) but not wide-dynamic range trigeminovascular neurons by cortical spreading depression (CSD). In the current paper, we report that CGRP-mAbs prevent the activation of Aδ but not C-type meningeal nociceptors by CSD. This is the first identification of an anti-migraine drug that appears to be selective for Aδ-fibers (peripherally) and HT neurons (centrally). As the main CGRP-mAb site of action appears to be situated outside the brain, we conclude that the initiation of the headache phase of migraine depends on activation of meningeal nociceptors, and that for selected patients, activation of the Aδ-HT pain pathway may be sufficient for the generation of headache perception.

Neural mechanism for hypothalamic-mediated autonomic responses to light during migraine.

Migraineurs avoid light because it intensifies their headache. However, this is not the only reason for their aversion to light. Studying migraineurs and control subjects, we found that lights triggered more changes in autonomic functions and negative emotions during, rather than in the absence of, migraine or in control subjects, and that the association between light and positive emotions was stronger in control subjects than migraineurs. Seeking to define a neuroanatomical substrate for these findings, we showed that, in rats, axons of retinal ganglion cells converge on hypothalamic neurons that project directly to nuclei in the brainstem and spinal cord that regulate parasympathetic and sympathetic functions and contain dopamine, histamine, orexin, melanin-concentrating hormone, oxytocin, and vasopressin. Although the rat studies define frameworks for conceptualizing how light triggers the symptoms described by patients, the human studies suggest that the aversive nature of light is more complex than its association with headache intensification.

Selective Inhibition of Trigeminovascular Neurons by Fremanezumab: A Humanized Monoclonal Anti-CGRP Antibody.

A large body of evidence supports an important role for calcitonin gene-related peptide (CGRP) in migraine pathophysiology. This evidence gave rise to a global effort to develop a new generation of therapeutics that inhibit the interaction of CGRP with its receptor in migraineurs. Recently, a new class of such drugs, humanized anti-CGRP monoclonal antibodies (CGRP-mAbs), were found to be effective in reducing the frequency of migraine. The purpose of this study was to better understand how the CGRP-mAb fremanezumab (TEV-48125) modulates meningeal sensory pathways. To answer this question, we used single-unit recording to determine the effects of fremanezumab (30 mg/kg, IV) and its isotype control Ab on spontaneous and evoked activity in naive and cortical spreading depression (CSD)-sensitized trigeminovascular neurons in the spinal trigeminal nucleus of anesthetized male and female rats. The study demonstrates that, in both sexes, fremanezumab inhibited naive high-threshold (HT) neurons, but not wide-dynamic range trigeminovascular neurons, and that the inhibitory effects on the neurons were limited to their activation from the intracranial dura but not facial skin or cornea. In addition, when given sufficient time, fremanezumab prevents the activation and sensitization of HT neurons by CSD. Mechanistically, these findings suggest that HT neurons play a critical role in the initiation of the perception of headache and the development of cutaneous allodynia and central sensitization. Clinically, the findings may help to explain the therapeutic benefit of CGRP-mAb in reducing headaches of intracranial origin such as migraine with aura and why this therapeutic approach may not be effective for every migraine patient.SIGNIFICANCE STATEMENT Calcitonin gene-related peptide (CGRP) monoclonal antibodies (CGRP-mAbs) are capable of preventing migraine. However, their mechanism of action is unknown. In the current study, we show that, if given enough time, a CGRP-mAb can prevent the activation and sensitization of high-threshold (central) trigeminovascular neurons by cortical spreading depression, but not their activation from the skin or cornea, suggesting a potential explanation for selectivity to migraine headache, but not other pains, and a predominantly peripheral site of action.

Migraine photophobia originating in cone-driven retinal pathways.

Migraine headache is uniquely exacerbated by light. Using psychophysical assessments in patients with normal eyesight we found that green light exacerbates migraine headache significantly less than white, blue, amber or red lights. To delineate mechanisms, we used electroretinography and visual evoked potential recording in patients, and multi-unit recording of dura- and light-sensitive thalamic neurons in rats to show that green activates cone-driven retinal pathways to a lesser extent than white, blue and red; that thalamic neurons are most responsive to blue and least responsive to green; and that cortical responses to green are significantly smaller than those generated by blue, amber and red lights. These findings suggest that patients' experience with colour and migraine photophobia could originate in cone-driven retinal pathways, fine-tuned in relay thalamic neurons outside the main visual pathway, and preserved by the cortex. Additionally, the findings provide substrate for the soothing effects of green light.

Psychological Factors and Conditioned Pain Modulation: A Meta-Analysis.

OBJECTIVE: Conditioned pain modulation (CPM) responses may be affected by psychological factors such as anxiety, depression, and pain catastrophizing; however, most studies on CPM do not address these relations as their primary outcome. The aim of this meta-analysis was to analyze the findings regarding the associations between CPM responses and psychological factors in both pain-free individuals and pain patients. MATERIALS AND METHODS: After a comprehensive PubMed search, 37 articles were found to be suitable for inclusion. Analyses used DerSimonian and Laird's random-effects model on Fisher's z-transforms of correlations; potential publication bias was tested using funnel plots and Egger's regression test for funnel plot asymmetry. Six meta-analyses were performed examining the correlations between anxiety, depression, and pain catastrophizing, and CPM responses in healthy individuals and pain patients. RESULTS: No significant correlations between CPM responses and any of the examined psychological factors were found. However, a secondary analysis, comparing modality-specific CPM responses and psychological factors in healthy individuals, revealed the following: (1) pressure-based CPM responses were correlated with anxiety (grand mean correlation in original units r=-0.1087; 95% confidence limits, -0.1752 to -0.0411); (2) heat-based CPM was correlated with depression (r=0.2443; 95% confidence limits, 0.0150 to 0.4492); and (3) electrical-based CPM was correlated with pain catastrophizing levels (r=-0.1501; 95% confidence limits, -0.2403 to -0.0574). DISCUSSION: Certain psychological factors seem to be associated with modality-specific CPM responses in healthy individuals. This potentially supports the notion that CPM paradigms evoked by different stimulation modalities represent different underlying mechanisms.

FDG PET/CT for assessing the resectability of NSCLC patients with N2 disease after neoadjuvant therapy.

OBJECTIVE: Neoadjuvant chemoradiotherapy (CMRT) is the most effective treatment of stage III non-small-cell lung cancer (NSCLC). The present study aimed at assessing FDG PET/CT for defining the response of N2 disease to neoadjuvant CMRT, as surgical resection after such therapy significantly improves 5-year survival in responding N2 disease. METHODS: Forty-five patients with locally advanced NSCLC underwent both pre-neoadjuvant therapy FDG PET/CT and post-neoadjuvant therapy FDG PET/CT followed by anatomical resection of lung and ipsilateral mediastinal lymph nodes (LN). Seventeen of these patients who had PET/CT studies in our institution and were operated after CMRT were retrospectively included in the study group (12 males, ages 43-78 years; stage IIIA: 14 patients, stage IIIB: 3 patients). PET/CT response in N2 was visually scored per-lymph node station and per patient. Quantitative N2 response was evaluated by SUVmax and total lesion glycolysis (TLG) measurements after therapy alone and in comparison with pre-therapy values. PET/CT N2 response was confirmed at surgery. RESULTS: Seventeen NSCLC patients with 29 metastatic N2 lymph nodes (LN) were assessed. Histopathology confirmed 14 responders and 3 non-responders, and was available in 20/29 metastatic LN, showing complete response in 17 and residual disease in 3 LN. LN-based visual analysis of N2 response on PET/CT defined 3 TP, 16 TN and 1 FP, for sensitivity, specificity, accuracy, negative and positive predictive values (NPV and PPV) of 100, 94, 95, 100 and 75%, respectively. Patient-based visual analysis defined 3 TP, 13 TN and 1 FP study, for sensitivity, specificity, accuracy, NPV and PPV of 100, 93, 94, 100 and 75%, respectively. Nodal-based quantitative analysis of FDG uptake in N2 nodes revealed a significant difference between responding and non-responding LN only of SUVmax post-therapy (2.5 ± 1.21 vs. 3.5 ± 2.36, P = 0.04). CONCLUSION: FDG PET/CT after neoadjuvant therapy accurately defined response in metastatic N2 nodes of NSCLC patients, presenting very high sensitivity and NPV for detecting responding nodes. PET/CT may enable selection of candidates for curative resection of stage III NSCLC. Mediastinoscopy may not be mandatory in patients with a negative PET/CT after neoadjuvant therapy.

Simvastatin and vitamin D for migraine prevention: A randomized, controlled trial.

OBJECTIVE: The aim of this work was to assess efficacy and tolerability of simvastatin plus vitamin D for migraine prevention in adults with episodic migraine. METHODS: We performed a randomized, double-blind, placebo-controlled trial with a 12-week baseline period and 24-week intervention period in 57 adults with episodic migraine. Participants were randomly assigned to simvastatin 20 mg tablets twice-daily plus vitamin D3 1,000 international units capsules twice-daily or matching placebo tablets and capsules. RESULTS: Compared to placebo, participants using simvastatin plus vitamin D3 demonstrated a greater decrease in number of migraine days from the baseline period to intervention weeks 1 to 12: a change of -8.0 (interquartile range [IQR]: -15.0 to -2.0) days in the active treatment group versus +1.0 (IQR: -1.0 to + 6.0) days in the placebo group, p < 0.001; and to intervention weeks 13 to 24: a change of -9.0 (IQR: -13 to -5) days in the active group versus +3.0 (IQR: -1.0 to + 5.0) days in the placebo group, p < 0.001. In the active treatment group, 8 patients (25%) experienced 50% reduction in the number of migraine days at 12 weeks and 9 (29%) at 24 weeks postrandomization. In comparison, only 1 patient (3%) in the placebo group (p = 0.03) experienced such a reduction. Adverse events were similar in both active treatment and placebo groups. INTERPRETATION: The results demonstrate that simvastatin plus vitamin D is effective for prevention of headache in adults with episodic migraine. Given statins' ability to repair endothelial dysfunction, this economical approach may also reduce the increased risk for vascular diseases among migraineurs.

Conditioned pain modulation.

PURPOSE OF REVIEW: Conditioned pain modulation (CPM) paradigms have been increasingly used over the past few years to assess endogenous analgesia capacity in healthy individuals and pain patients. The current review concentrates on selected recent literature advancing our understanding and practice of CPM. RECENT FINDINGS: The main themes covered by the present CPM review include underlying mechanisms, approaches to experimental investigation, practicality in clinical practice, neurophysiological and psychophysiological correlates, and pharmacological solutions to pain modulation dysfunction. SUMMARY: The reviewed literature refines the methodology used for eliciting CPM responses and characterizing their physiological attributes in healthy individuals and pain patients, and exemplifies the materializing concept of individualized pain medicine through targeting impaired mechanisms of pain modulation by designated drugs for optimal pain alleviation.

Novel emboli protection system during cardiac surgery: a multi-center, randomized, clinical trial.

BACKGROUND: Stroke is a major cause of morbidity and mortality during open-heart surgery. Up to 60% of intraoperative cerebral events are emboli induced. This randomized, controlled, multicenter trial is the first human study evaluating the safety and efficacy of a novel aortic cannula producing simultaneous forward flow and backward suction for extracting solid and gaseous emboli from the ascending aorta and aortic arch upon their intraoperative release. METHODS: Sixty-six patients (25 females; 68±10 years) undergoing elective aortic valve replacement surgery, with or without coronary artery bypass graft surgery, were randomized to the use of the CardioGard (CardioGard Medical, Or-Yehuda, Israel) Emboli Protection cannula ("treatment") or a standard ("control") aortic cannula. The primary endpoint was the volume of new brain lesions measured by diffusion-weighted magnetic resonance imaging (DW-MRI), performed preoperatively and postoperatively. Device safety was investigated by comparisons of complications rate, namely neurologic events, stroke, renal insufficiency and death. RESULTS: Of 66 patients (34 in the treatment group), 51 completed the presurgery and postsurgery MRI (27 in the treatment group). The volume of new brain lesion for the treatment group was (mean±standard error of the mean) 44.00±64.00 versus 126.56±28.74 mm3 in the control group (p=0.004). Of the treatment group, 41% demonstrated new postoperative lesions versus 66% in the control group (p=0.03). The complication rate was comparable in both groups. CONCLUSIONS: The CardioGard cannula is safe and efficient in use during open-heart surgery. Efficacy was demonstrated by the removal of a substantial amount of emboli, a significant reduction in the volume of new brain lesions, and the percentage of patients experiencing new brain lesions.

A novel amiodarone-eluting biological glue for reducing postoperative atrial fibrillation: first animal trial.

OBJECTIVE: Postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery, leading to increased morbidity and mortality. The aim of this preliminary study was to evaluate a novel drug delivery system for local release of amiodarone. METHODS: In the current prospective study, 9 goats underwent attachment of right atrial (RA) epicardial electrodes. Alginate-based glue with amiodarone was applied to the RA of the treatment groups. Rapid atrial response (RAR) to burst pacing was assessed before application and in the third postoperative day (POD3). Average RAR frequency was defined as the average percentage of inductions resulting in RAR per animal. Myocardial and extracardiac tissue amiodarone concentrations were analyzed. RESULTS: Differences in RAR proportions between baseline and POD3 were greater in the treatment group versus the control group (P = .034). Average RAR frequency was reduced by 34% in the treatment group (baseline: 65%; POD3: 31%), while it was increased by 11.3% in the control (baseline:43.8%; POD3: 55%). The treatment group demonstrated a greater proportion of animals meeting the success criterion of net percentage reduction in RAR frequency greater than 25% (P = .047). The average amount of total amiodarone detected in the RA was 104.4 ± 28.9 µg; the transmural concentration was linearly distributed (P < .0001). Extracardiac tissue concentrations were below the detection level. CONCLUSIONS: Local alginate-based amiodarone delivery demonstrated an RAR frequency reduction of clinical importance in response to burst pacing. The electrophysiological response was achieved while maintaining below-detection systemic drug levels. Current findings may point to the system's future applicability in reducing POAF risk in humans.

Novel emboli protection cannula during cardiac surgery: first animal study.

BACKGROUND: Stroke after open heart surgery is a major cause of morbidity and mortality. Up to 60% of intraoperative cerebral events are caused by emboli generated by manipulations of the aorta during surgery. This is the first animal study evaluating the safety and efficacy of a novel aortic cannula designed to extract solid and gaseous emboli during cardiac surgery. METHODS: Seven domestic pigs were connected to cardiopulmonary bypass using a CardioGard 24F aortic cannula. Three pigs that were cannulated with a standard aortic cannula were defined as controls. Several main flow and suction regimens were carried out. Osseous particles of different sizes were injected into the proximal aorta to simulate emboli. RESULTS: The CardioGard cannula demonstrated an overall emboli retrieval rate of 77%. A rate of 88.45% was demonstrated during the low-flow regimen used clinically during aortic manipulation. Gaseous and solid emboli were eliminated by suction, as demonstrated by epi-carotid ultrasound. No significant changes were observed in hemodynamic and laboratory parameters. CONCLUSIONS: The CardioGard cannula is as simple to use as a regular commercially available aortic cannula, having a similar safety profile and proven efficacy in capturing intraoperative emboli.

A novel emboli protection cannula during cardiac surgery: in vitro results.

OBJECTIVE: Intraoperative cerebral events are mainly caused by emboli generated by operative manipulation of the aorta. This study aimed to delineate the distribution profiles of emboli with 2 widely used cannulae and a third novel research cannula that simultaneously produces forward flow and backward suction to extract emboli from the distal aorta during cardiac surgery. METHODS: The current in vitro study used a silicone model of the aortic arch and branches. The main outcome measure was the distribution profile of embolic particles of different sizes to the aortic branches; 2 commercial cannulae and a third novel cannula with and without suction were used. The research cannula was examined at different suction levels and the amount of particles retrieved was measured. RESULTS: For the research curved-tip cannula, most of the small emboli were released into the brachiocephalic trunk in the model (P < .05). For the straight-tip cannula, most of the small emboli were released into the descending aorta (P < .05). Regarding the commercial curved-tipped cannula, most of the small emboli were released into the brachiocephalic trunk (47.14% ± 4.78%; P < .05) and the medium and large emboli were predominantly released into the descending aorta. Using suction, the research cannula retrieved most of the emboli released into the aorta for all particle sizes (50%-83%; P < .05). CONCLUSIONS: A straight-tip cannula may be safer in terms of cerebral embolic consequences during cardiac surgery. Furthermore, the use of the research aortic cannula may be beneficial in the cardiac surgery setting by reducing the postoperative risk for stroke.