Intermittent Occlusion Research Articles

Reproducibility of NIRS assessment of muscle oxidative capacity in smokers with and without COPD

Low muscle oxidative capacity contributes to exercise intolerance in chronic obstructive pulmonary disease (COPD). Near-infrared spectroscopy (NIRS) allows non-invasive determination of the muscle oxygen consumption (mV̇O2) recovery rate constant (k), which is proportional to oxidative capacity assuming two conditions are met: 1) exercise intensity is sufficient to fully-activate mitochondrial oxidative enzymes; 2) sufficient O2 availability. We aimed to determine reproducibility (coefficient of variation, CV; intraclass correlation coefficient, ICC) of NIRS k assessment in the gastrocnemius of 64 participants with (FEV1 64±23%predicted) or without COPD (FEV1 98±14%predicted). 10–15s dynamic contractions preceded 6min of intermittent arterial occlusions (5–10s each, ∼250mmHg) for k measurement. k was lower (P<0.05) in COPD (1.43±0.4min−1; CV=9.8±5.9%, ICC=0.88) than controls (1.74±0.69min−1; CV=9.9±8.4%; ICC=0.93). Poor k reproducibility was more common when post-contraction mV̇O2 and deoxygenation were low, suggesting insufficient exercise intensity for mitochondrial activation and/or the NIRS signal contained little light reflected from active muscle. The NIRS assessment was well tolerated and reproducible for muscle dysfunction evaluation in COPD.

Feasiblility to monitor objective compliance with liquid crystal glasses intermittent occlusion therapy

Amblyz liquid crystal glasses utilize an intermittent occlusion technique (at 30-second opaque/transparent intervals) and avoid adhesive to treat amblyopia, potentially improving compliance. Several pilot studies support the effectiveness of this new device making it an interesting option/alternative for amblyopia treatment. However, there are no objective compliance data for these glasses, limiting understanding of the dose-repsonse for this treatment. This study reports the feasibility of a sensor to monitor objective compliance with Amblyz glasses.

A pilot randomized clinical trial of intermittent occlusion therapy liquid crystal glasses versus traditional patching for treatment of moderate unilateral amblyopia

To compare the effectiveness of intermittent occlusion therapy (IO therapy) using liquid crystal glasses and continuous occlusion therapy using traditional adhesive patches for treating amblyopia. Children 3-8years of age with previously untreated, moderate, unilateral amblyopia (visual acuity of 20/40 to 20/100 in the amblyopic eye) were enrolled in this randomized controlled trial. Amblyopia was associated with strabismus, anisometropia, or both. All subjects had worn any optimal refractive correction for at least 12weeks without improvement. Subjects were randomized into two treatment groups: a 4-hour IO therapy group with liquid crystal glasses (Amblyz), set at 30-second opaque/transparent intervals (occluded 50% of wear time), and a 2-hour continuous patching group (occluded 100% of wear time). For each patient, visual acuity was measured using ATS-HOTV before and after 12weeks of treatment. Data from 34 patients were available for analysis. Amblyopic eye visual acuity improvement from baseline was 0.15±0.12 logMAR (95% CI, 0.09-0.15) in the IO therapy group (n=19) and 0.15±0.11 logMAR (95% CI, 0.1-0.15) in the patching group (n=15). In both groups improvement was significant, but the difference between groups was not (P=0.73). No adverse effects were reported. In this pilot study, IO therapy with liquid crystal glasses is not inferior to adhesive patching and is a promising alternative treatment for children 3-8years of age with moderate amblyopia.

Association between Serum Bilirubin and Acute Intraoperative Hyperglycemia Induced by Prolonged Intermittent Hepatic Inflow Occlusion in Living Liver Donors.

BackgroundIntermittent hepatic inflow occlusion (IHIO) is associated with acute hyperglycemia during living donor hepatectomy when the ischemia is prolonged. Bilirubin is a potent antioxidant to play an important role for maintaining insulin sensitivity and preventing hyperglycemia. Thus, we aimed to test whether serum bilirubin level is associated with prolonged IHIO-induced intraoperative hyperglycemia.MethodsSeventy-five living liver donors who underwent a prolonged IHIO with a >30 minute cumulative ischemia were included. The association between preoperative serum bilirubin concentrations and the risk of intraoperative hyperglycemia (blood glucose concentration >180 mg/dl) was analyzed using binary logistic regression with adjusting for potential confounders including age and steatosis.ResultsThe number of donors who underwent 3, 4, 5, and 6 rounds of IHIO was 41, 22, 7, and 5, respectively. Twenty-nine (35%) donors developed intraoperative hyperglycemia. Total bilirubin concentration was inversely associated with hyperglycemia risk (odds ratio [OR] 0.033, 95% confidence interval [CI] 0.004–0.313, P = 0.003). There was an interaction between age and total bilirubin concentration: the effect of lower serum total bilirubin (≤0.7 mg/dl) on the development of hyperglycemia was greater in older donors (>40 years) than in younger donors (P = 0.0.028 versus P = 0.212). Both conjugated bilirubin (OR 0.001 95% CI 0.001–0.684) and unconjugated bilirubin (OR 0.011 95% CI 0.001–0.246) showed an independent association with hyperglycemia risk.ConclusionsLower preoperative serum bilirubin was associated with greater risk of prolonged IHIO-induced hyperglycemia during living donor hepatectomy particularly in older donors. Thus, more meticulous glycemic management is recommended when prolonged IHIO is necessary for surgical purposes in old living donors with lower serum bilirubin levels.

Prolonged and Intermittent Bilateral Common Carotid Artery Occlusion Induces Brain Lipidome Changes in a Rat Stroke Model

Background: Recent studies suggest that prolonged and intermittent bilateral common carotid artery occlusion (prolonged bilateral common carotid artery occlusion (PO) and intermittent bilateral common carotid artery occlusion, respectively) can lead to reduced ischemia brain injury in ischemic tolerance. Objectives: In this study, we aimed to investigate the changes in brain lipidomics following prolonged and intermittent ischemic preconditioning. Materials and Methods: Two groups underwent bilateral common carotid artery occlusion either intermittently (for 3 continuous periods within a timeframe of 20 minutes, releasing 3 consecutive times, yielding a total of 9 minutes (intermittent bilateral common carotid artery occlusion)) or for 9 minutes continuously (prolonged bilateral common carotid artery occlusion). The third and fourth groups were used as control and sham (without ischemia) groups, respectively. The first three groups were subdivided into middle cerebral artery occlusion-operated (middle cerebral artery occlusion MCAO), for 60 minutes of ischemia) and intact (without any surgery) subgroups. After 1 hour of ischemia and 24 hours of reperfusion, the neurologic deficit score (neurological deficit score (NDS)) and the infarct volume (infarct volume) were assessed in the middle cerebral artery occlusion-operated subgroup. Brain lipidomics were measured in the intact subgroup and the sham group. Results: Preconditioning with prolonged bilateral common carotid artery occlusion and intermittent bilateral common carotid artery occlusion significantly decreased the neurological deficit scores and infarct volume and increased the levels of phosphatidylethanolamine, sphingomyelin, cholesterol ester, cholesterol, phosphatidylcholine, and cerebroside in the brain compared with the control and sham groups. Prolonged bilateral common carotid artery occlusion and intermittent bilateral common carotid artery occlusion significantly decreased the brain ceramide and lyso-phosphatidylcholine levels. The triglyceride levels in both groups (intermittent bilateral common carotid artery occlusion and prolonged bilateral common carotid artery occlusion) did not change in comparison with the control and sham groups. Conclusions: Although it seems that further studies are needed to clarify the real mechanisms of ischemic tolerance, ischemic preconditioning could decrease brain ischemia injury via changes in brain lipidomics.

Airway inflammation in patients affected by obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterised by repetitive episodes of upper airway occlusion during sleep. OSA has been shown to be associated with a variable degree of nasal inflammation, uvula mucosal congestion and airway hyperreactivity. The upper airway inflammation, whose clinical importance is uncertain, is characterised by leukocytes infiltration and interstitial oedema. In addition, recent data has shown the presence of neutrophilic inflammation in the lower airways. The current opinion is that airway inflammation is caused by the local, repeated mechanical trauma related to the intermittent airway occlusion typical of the disease. Another potential mechanism involves the intermittent nocturnal hypoxemia that through the phenomenon of the ischemia-reperfusion injury may induce the production of oxygen free radicals and therefore cause local and systemic inflammation. Finally, a state of low-grade systemic inflammation may be related to obesity per se with the pro-inflammatory mediators synthesised in the visceral adipose cells. Several authors stress the role of circulating and local inflammatory mediators, such as pro-inflammatory cytokines, exhaled nitric oxide, pentane and 8-isoprostane as the determinants of inflammation in OSA.

Apoptosis in the Ovine Fetal Brain Following Placental Embolization and Intermittent Umbilical Cord Occlusion.

The purpose of this study was to compare the regional distribution of apoptotic cells in the near term ovine fetal brain caused by prolonged moderate hypoxia, as seen in placental insufficiency, and intermittent severe hypoxia, as seen in umbilical cord compression, which may then contribute to adverse neurodevelopment in the postnatal life. We hypothesized that apoptosis in the fetal brain will be increased in response to both prolonged moderate hypoxia and intermittent severe hypoxia. Twenty-one near term (126-127 days) sheep were divided into 3 groups: control (CON; n = 7), placental embolization (EMB; n = 7), and umbilical cord occlusion (UCO; n = 8). The EMB group had microsphere injections into the umbilical arterial circulation until the oxygen content was at 50% of baseline value. The UCO group had complete cord occlusion for 2 minutes every hour, 6 times a day for 2 consecutive days. At 4 pm on day 2, the animals were euthanized; fetal brains were fixed and prepared for apoptosis staining using the terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay method. In the cerebellar white matter, there was a 3-fold increase in the number of TUNEL positive cells per 1000 cells in both EMB and UCO animals as compared to CON (P = .017). There was also a significant increase in the frontal cortical grey matter (layers 1-3) in EMB animals as compared to CON (P = .014). As such, apoptosis in the near term fetal sheep brain is altered with both sustained moderate hypoxia and intermittent severe hypoxia in the latter part of pregnancy, with potential for long-term neurological sequelae.

Anaesthetic challenges in a child with sickle-cell disease and congenital heart block.

Sir, We present a case report of anaesthetic management of a 12-year-old boy with sickle-cell disease (SCD) and congenital heart block (CHB) with pacemaker [Figure 1], undergoing laparoscopic splenectomy.Figure 1: 12-lead electrocardiography of the patientThe child had suffered sickle-cell crisis and pacemaker malfunction a month back. His preoperative investigations were normal and weight was 30 kg. He received intravenous (IV) fluids during fasting period, pneumococcal vaccine, antibiotic prophylaxis and cefotaxime 500 g IV. The cardiologist changed the mode of pacemaker to asynchronous (fixed rate). Standard American Society of Anesthesiologists monitoring, urine output and temperature monitoring were used. Morphine 4.5 mg IV, thiopentone 150 mg IV and atracurium 0.5 mg/kg IV were used for induction and intubation. Anaesthesia was maintained with isoflurane (MAC: 1.0), air and oxygen (FiO2: 0.5). Pneumoperitoneum was created with CO2 and intra-abdominal pressure was kept around 8–10 mmHg. The surgeon used bipolar cautery, blood loss was approximately 800 ml and 1 unit packed red cell was transfused. The patient was given fluid at 60 ml/h intra-operatively as he had been kept hydrated preoperatively. For post-operative analgesia, paracetamol 500 mg IV was given and skin incision was infiltrated with 12 ml 0.2% ropivacaine. Neuromuscular blockade was reversed and trachea was extubated. The patient remained haemodynamically stable, normothermic and had adequate urine output. Post-operative analgesia was maintained with paracetamol 500 mg IV 8th hourly and fentanyl boluses of 30 μg as rescue analgesic whenever visual analogue scale exceeded 3. The child was discharged on the 7th post-operative day after uneventful course. CHB (incidence 1 in 22,000 live births) with no structural abnormality and when diagnosis is established beyond neonatal period has better survival.[1] Intraoperatively, pacemaker mode is advised to be changed to asynchronous, and bipolar electrocautery is to be used. The availability of manual pacing should be ensured to manage pacemaker malfunction.[2] SCD is the disorder of beta-globin chain characterised by haemolytic anaemia, intermittent vascular occlusion, pulmonary compromise and multi-organ damage. Electrocardiogram changes are non-specific and first-degree heart block may be found.[34] Not usually associated with SCD, CHB in our patient is perhaps an additional finding. Splenectomy is recommended in children older than 2 years or after one major or two minor episodes of splenic sequestration crises.[34] When done laparoscopically, the duration of surgery increases, but hospital stay is decreased.[3] Any major surgery is associated with 7% mortality. Preoperatively, the history of episodes of painful crises must be sought.[4] Pre-operative examination should be thorough as SCD involves multiple organ systems. Neurological evaluation rules out the previous cerebrovascular accident as ischaemic infarcts are common in anaemic children.[3] Kidneys may get involved during advanced disease. Presence of rib infarcts can lead to hypoventilation. Perioperative cardiopulmonary manifestations such as acute chest syndrome usually remain undetected in young children.[34] As dehydration precipitates RBC sickling and occlusion of microvasculature at a level of precapillary sphincters, perioperative hydration must be ensured.[34] There is a controversy regarding blood transfusion, benefit being dilution of haemoglobin S and disadvantage being triggering of sickling.[34] Other factors leading to sickling crises are vascular stasis, hypoxia, metabolic acidosis, hypothermia and presence of infection.[3] Previous case reports have emphasised the importance of preventing sickling crisis perioperatively.[5] To conclude, perioperative anaesthetic management of children suffering from SCD and CHB needs meticulous pre-operative and intra-operative management and post-operative vigilance for preventing sickle-cell crisis and associated complications. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Surgical approach for treatment of obstructive sleep apnea

Obstructive sleep apnea (OSA), most common respiratory disorder of sleep, is characterized by intermittent partial or complete occlusions of the upper airway due to loss of upper airway dilating muscle activity during sleep superimposed on a narrow upper airway. Termination of these events usually requires arousal from sleep and results in sleep fragmentation and hypoxemia, which leads to poor quality of sleep, excessive daytime sleepiness, reduced quality of life and numerous other serious health consequences. Untreated OSA may cause, or be associated with, several adverse outcomes, including daytime sleepiness, increased risk for motor vehicle accidents, cardiovascular disease, and depression. Various treatments are available, including non-surgical treatment such as medication or modification of life style, continuous positive airway pressure (CPAP) and oral appliance (OA). Skeletal surgery for obstructive sleep apnea (OSA) aims to provide more space for the soft tissue in the oropharynx to prevent airway collapse during sleep. Conventional surgical techniques include uvopalatopharyngoplasty(UPPP), genioglossus advancement (GA), and maxillomandibular advancement (MMA). Surgical techniques, efficacy and complications of skeletal surgery are introduced in this review.

Erratum to: Role of central and peripheral opioid receptors in the cardioprotection of intravenous morphine preconditioning.

Both central and peripheral opioid receptors activation produce cardioprotection. This study investigates the role of central and peripheral opioid receptors in intravenous morphine preconditioning (MPC) and ischemic preconditioning (IPC).Sixty-five anesthetized, open chests, male Sprague-Dawley rats were assigned to one of nine groups after intrathecal catheter placement. IPC was induced by three cycles of intermittent occlusion of left anterior descending artery (5 min occlusion interspersed with 5 min of reperfusion). MPC was induced by three consecutive intravenous infusions of 100 μg/kg morphine over five minutes. The opioid receptors antagonist naloxone methiodide (NM), was intravenously or intrathecally, at a dose of 20 mg/kg or 20 μg/kg, given 10 min before IPC or MPC (IVNM + IPC, ITNM + IPC, IVNM + MPC, ITNM +MPC). Control group (CON) and intravenously or intrathecally administered NM (IVNM, ITNM) were used as negative controls, respectively. All hearts were subjected to 30 min of ischemia follow by 2 h of reperfusion. Infarct size, as a percentage of the area at risk, was determined by 2, 3, 5-triphenyltetrazolium staining. Heart rate and mean arterial blood pressure were monitored.The infarct size was significantly reduced in the IPC and MPC groups compared with control. The additional of intravenous or intrathecal NM both reversed the cardioprotective effects of MPC. In comparison only intravenous administration of NM before IPC could attenuate the cardioprotection.MPC could mimic IPC, produce a similar cardioprotective effect. Both central and peripheral opioid receptors mediate in the cardioprotection of MPC, however, only peripheral opioid receptors in IPC.

Keap1-Nrf2 System: Potential Role in Prevention of Sickle Cell Disease Organs Damages and Inflammation

Chronic hemolysis in sickle cell disease (SCD) gives rise to intermittent vessel occlusion. Recurrent ischemia-reperfusion generates high levels of reactive oxygen species (ROS) that leads to cell damage. On the other hand, lysed red blood cells (RBC) released free heme into blood stream, which contributes to generation of oxidant microenvironment. ROS burden generated by heme and ischemia-reperfusion injury contributes to endothelial cell activation that promotes inflammatory response with activation of inflammatory mediators. Sickle cell patients bearing high white blood cell (WBC) count develop severe complications of the disease.Nrf2 is a transcription factor that mediates adaptation to oxidative stress and cell defense. Under homeostatic conditions, Nrf2 is trapped by Keap1 and degraded by proteasome pathway. Upon exposure to stress stimuli, such as ROS and electrophiles, Nrf2 is stabilized and activates transcription of cytoprotective and antioxidants genes. Therefore, we hypothesized that Nrf2 activation might be important for tissue protection in SCD.To evaluate the therapeutic effect of Nrf2 activation on SCD, we used a SCD knock-in mouse model bearing human mutated globin loci. Since Keap1 negatively regulated Nrf2 in normal conditions, we crossed the SCD model mice with Keap1 hypomorphic knockdown (Keap1F/-) mice to generate compound mutant (SCD::Keap1F/-) mice, in which Nrf2 was constitutively activated. Histological analysis of the liver and lung revealed that congestive reaction and necrotic area observed in the SCD mice were significantly reduced in the SCD::Keap1F/- mice. Moreover, liver damage marker alanine transferase (ALT) were also decreased in SCD::Keap1F/- mice compared with SCD mice. We further examined inflammation status using human IL6 reporter mouse system and found that inflammation, which was mainly observed in lung of SCD mice, was markedly improved in the SCD::Keap1F/- mice. Expression levels of inflammatory cytokines IL6 and IL1β in the lung as well as adhesion molecules VCAM and P-selectin in the aorta of SCD::Keap1F/- mice were lower than those of the SCD mice. These results indicate that Nrf2 activation improves organ damage and inflammation in the SCD mice.On the other hand, hemolysis of sickle cells and compensatory stress erythropoiesis did not change substantially between the SCD and the SCD::Keap1F/- mice. These results indicate that Nrf2 activation improves organ damage and inflammation independently from improvement of hemolysis. Previous reports show that free heme released from sickle cells gives rise to ROS-mediate pathological process as inflammation and organ damage in SCD. We therefore measured plasma free heme and downstream product indirect bilirubin in the SCD::Keap1F/- mice, and found that both heme and indirect bilirubin was decreased in the SCD::Keap1F/- mice. These results demonstrate that Nrf2 activation improves SCD symptoms at least in part by elimination of free heme.To determine whether chemical compounds that serve as Nrf2 inducers have a protective potential of SCD mice organs, we treated 6-weeks aged mice with an Nrf2 inducer CDDO-Im (20 μmol/kg) 3 times per week for 3 weeks. CDDO-Im administration progressively reduced WBC numbers in the SCD::Keap1F/- mice. Also we observed decrease in the expression level of IL6 and IL1β in the lung and necrotic area in the liver in CDDO-Im-treated SCD::Keap1F/- mice. These results indicate that administration of a chemical Nrf2 inducer relieves inflammation and organ damage in the SCD mice.Collectively, these data provide the evidence that Nrf2 activation improves ROS-mediated organ damages and inflammation. Associated in the therapy of SCD, Nrf2 inducers could be of benefit to SCD patients. DisclosuresNo relevant conflicts of interest to declare.

Study of gonadal hormones in Egyptian female children with sickle cell anemia in correlation with iron overload: Single center study

Objective/BackgroundSickle cell disease is a hereditary hemoglobinopathy characterized by abnormal hemoglobin production, hemolytic anemia, and intermittent occlusion of small blood vessels, leading to tissue ischemia, chronic organ damage, and organ dysfunction including endocrine organs. The aim of this work was to evaluate some gonadal hormones in female children with sickle cell anemia (SCA) in correlation with iron overload. MethodsThis study was conducted on 40 female children with SCA with a serum ferritin of > 1000ng/mL, who were attendants at the Hematology Unit, Pediatric Department, Tanta University, Tanta, Egypt in the period from May 2012 to April 2014. Their ages ranged from 11 years to 15years and the mean age value was 12.63±1.36 years (Group I). Forty female children with SCA of matched age with no iron overload served as a control Group (Group II). For all patients in Groups I and II the following were performed/assessed: complete blood count, hemoglobin electrophoresis, serum iron status, serum estrogen, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). ResultsThere were significantly higher serum ferritin and serum iron levels and significantly lower total iron binding capacity, FSH, LH, and estrogen levels in Group I compared with Group II (mean serum ferritin was 2635.1±918.9 in Group I vs. 292.55±107.2 in Group II with a p value of .001; mean serum iron was 196.3±55.6 in Group I vs. 120±16.57 in Group II with a p value of .001 and mean serum total iron binding capacity was 247.3±28.6 in Group I vs. 327.8.7±21.96 in Group II with a p value of .001; mean FSH level was 1.36±0.22mIU/mL in Group I vs. 2.64±0.81mIU/mL in Group II with a p value of .021; mean LH level was 0.11±0.006mIU/mL in Group I vs. 1.78±1.12mIU/mL in Group II with a p value of .003; mean estrogen level was 21.45±10.23pg/mL in Group I vs. 42.36±15.44pg/mL in Group II with a p value of 0.001) with significant negative correlation between serum gonadal hormones and serum ferritin (r=− .835 and p value of .01 for FSH and serum ferritin; r=− .597 and a p value of .01 for LH and serum ferritin; and r=− 0.624 and p value of .01 for estrogen and serum ferritin. ConclusionFemale patients with SCA with iron overload may have gonadal hormone deficiency with significant negative correlations between gonadal hormones including FSH, LH, estrogen, and serum ferritin. Recommendations include regular iron chelation for prevention of irreversible damage of the ovaries and attaining normal sexual maturation, and regular follow up for females with SCA with assessment of puberty as they are more vulnerable to develop hypogonadism and may require hormonal replacement therapy.

Abstract 16636: Superior Vena Caval Occlusion: A Novel Approach to Improve Cardiac Function in Heart Failure

Cardiac preload is a primary target of drug therapy for heart failure. No device based approaches to limit preload in heart failure exist. The inferior (IVC) and superior vena cava (SVC) provide two-thirds and one-third of venous return, respectively. We hypothesized that mechanical occlusion of the SVC improves biventricular function in heart failure by reducing ventricular preload. Methods and Results: To test this hypothesis, 4 adult swine underwent 60 minutes of left anterior descending artery occlusion followed by 60 minutes of reperfusion. 1 animal expired due to ventricular fibrillation after reperfusion. The acute hemodynamic effects of transient sequential percutaneous balloon occlusion of the SVC or IVC (n=4) were studied using conductance catheters before the onset of left ventricular (LV) injury. Transient IVC occlusion significantly reduced biventricular volumes, reduced LV stroke volume, and reduced LV peak-systolic pressure (Figure). In contrast, transient SVC occlusion reduced biventricular volumes but increased LV stroke volume, without decreasing LV peak-systolic pressure (Figure). IVC occlusion increased renal vein pressure from 10 to 24 mmHg, whereas SVC occlusion did not alter renal vein pressure. One week after LV injury, the hemodynamics of prolonged SVC occlusion were studied (n=3). Full SVC occlusion for 2 hours reduced biventricular volumes, and increased LV stroke volume, without decreasing LV peak-systolic or systemic blood pressure. Conclusions: SVC occlusion represents a novel device based approach that targets cardiac preload. In contrast to IVC occlusion, transient and prolonged full SVC occlusion was well tolerated. SVC occlusion reduces biventricular volume, while increasing cardiac output and sustaining systemic blood pressure, without adversely affecting renal hemodynamics. Future studies will test the clinical utility of continuous and intermittent SVC occlusion in acute and chronic heart failure.

Amblyopia occlusion therapy compliance: Amblyz liquid crystal glasses versus traditional adhesive patches

Amblyopia treatment with adhesive occlusion patches is frequently inhibited by poor compliance and complaints. Amblyz liquid crystal glasses utilize an intermittent occlusion technique (at 30-second opaque/transparent intervals) and avoid adhesive, potentially improving compliance. This study compares compliance with Amblyz glasses versus patching.

Arm Pain and Discoloration in a 15yo Swimmer

HISTORY: A 15yo swimmer presented with intermittent right shoulder pain, swelling, and purple discoloration. 8 months prior to presentation, the pt was swimming and noticed a gradual onset of right shoulder pain. When she got out of the pool, she noticed slight right arm swelling and purple discoloration from her shoulder down. It took approximately 2 days for her symptoms to completely resolve. She took 1w off swimming and then returned. The next swim again resulted in right arm pain, swelling, and purple discoloration. The pt stopped swimming at that time. Over the next 6 months, she notes intermittent similar but less severe symptoms with most physical activity including softball and basketball. She reports occasional symptoms with no specific activity, and cannot identify a common motion or arm position that brings the symptoms on. Between episodes, she denies any arm swelling, shoulder pain, or discoloration. She is otherwise healthy, and denies left arm symptoms, preceding injury, chest pain, SOB, or persistent swelling of the right arm. PHYSICAL EXAM: Exam reveals a well appearing young female in no acute distress. Shoulders appear symmetric. She has tenderness over the anterior shoulder and AC joint. She has full active and passive ROM of the shoulder. No tests for impingement, RTC syndrome, labral pathology, or instability produce symptoms. Active flexion of shoulder to 165 degrees for 5 minutes did not produce symptoms. During US of the shoulder, with the pts arm at her side and slightly externally rotated, she developed mild mottling of the arm, slight swelling, and pain. She had 2+ radial pulses and no sensory deficits. DDx: Venous thoracic outlet syndrome Neurogenic thoracic outlet syndrome Rotator cuff syndrome Cervical radiculopathy Brachial plexus injury TESTS AND RESULTS: MR Arthrogram: No pathologic findings. RUE Venography: Occlusion of the right subclavian vein with abduction of the right shoulder. Patent subclavian vein in neutral position FINAL WORKING DIAGNOSIS: McCleery’s Syndrome (intermittent subclavian vein occlusion without thrombosis) TREATMENT AND OUTCOMES: Pt is scheduled to undergo surgical thoracic outlet decompression

Deconditioning Or Myopathy? Inactivity Is The Predominant Correlate Of Low Muscle Oxidative Capacity In COPD

Low locomotor muscle oxidative capacity contributes to exercise intolerance in chronic obstructive pulmonary disease (COPD). It is debated whether low muscle oxidative capacity is due to disease related myopathy e.g. inflammation, hypoxia, smoking, reduced growth factors, or to deconditioning induced by physical inactivity. PURPOSE: To determine correlates of muscle oxidative capacity in a large group of smokers with and without COPD. METHODS: Current and former smokers with COPD (GOLD 1-4, n=10/11/6/8; 67±10 yr) and with normal spirometry (GOLD 0, n=36; 61±9 yr) from the COPDGene study volunteered. 7-day triaxial accelerometry estimated daily total energy expenditure (TEE), physical activity level (PAL), and number of steps. Near-infrared spectroscopy (NIRS) was used to determine resting gastrocnemius blood flow (BF), O2 consumption (VO2), O2 saturation, and vasoreactivity. Muscle oxidative capacity was measured by NIRS from the VO2 recovery rate constant (k, min-1), using 10 s light contractions followed by intermittent arterial occlusions: a greater k constitutes a greater oxidative capacity. Blood CRP, IL6, testosterone, TNFα, IGF1 and albumin were measured. Smoking history was assessed by questionnaire. RESULTS: There were no significant differences between subjects with and without COPD in resting muscle BF, VO2, or O2 saturation, vasoreactivity, current smoking, pack years of smoking, or any blood biomarker. k was ∼33% greater (p=0.001) in subjects with normal spirometry (2.0±0.8 min-1) compared to those with airflow obstruction (1.5±0.6 min-1). In univariable analysis, k was significantly (p<0.01) positively associated with TEE (r2=0.26), PAL (r2=0.17), FEV1 %pred (r2=0.09), and negatively with age (r2=0.06, p=0.03). In stepwise multivariable analysis, PAL and daily steps accounted for 34% of variance in k (p<0.001). CONCLUSIONS: Low muscle oxidative capacity was associated with physical inactivity, airflow obstruction and age. A greater fraction of the variance in muscle oxidative capacity was explained by physical inactivity than by disease severity. These data are consistent with the notion that deconditioning represents the predominant cause of muscle dysfunction in current and former smokers with and without COPD. Supported by NIH R01 HL089856, R01 HL089897; SNSF-Novartis P3SMP3_151705/1; UCLA CTSI UL1TR000124.

Pineal cyst resection in the absence of ventriculomegaly or Parinaud's syndrome: clinical outcomes and implications for patient selection

Surgical indications for patients with pineal cysts are controversial. While the majority of patients harboring a pineal cyst require no treatment, surgery is a well-accepted option for a subset of those patients with secondary hydrocephalus or Parinaud's syndrome. The majority of pineal cysts are identified incidentally during workup for other potential conditions, which may or may not be related to the presence of the cyst. In the absence of clear obstruction of CSF pathways, the treatment of presumed symptomatic pineal cysts is debatable. To clarify the role of surgery in these borderline cases, the authors reviewed their experience with resection of pineal cysts in the absence of ventriculomegaly or Parinaud's syndrome. The authors retrospectively reviewed medical records and imaging of all patients surgically treated between 2001 and 2014 with a pineal cyst in the absence of ventriculomegaly and Parinaud's syndrome. The presenting symptoms, preoperative cyst size, preoperative radiographic aqueductal compression, extent of resection, and radiographic and clinical follow-up were documented. Eighteen patients (14 female and 4 male; mean age 24 years, range 4-47 years) underwent cyst resection in the absence of ventriculomegaly or Parinaud's syndrome. Presenting symptoms included headache (17 patients), visual disturbances (10 patients), gait instability (5 patients), dizziness (5 patients), episodic loss of consciousness (2 patients), and hypersomnolence (1 patient). The mean preoperative cyst diameter was 1.5 cm (range 0.9-2.2 cm). All patients had a complete resection. At a mean clinical follow-up of 19.1 months (range postoperative to 71 months), 17 (94%) patients had resolution or improvement of their presenting symptoms. The authors' results suggest that ventriculomegaly and Parinaud's syndrome are not absolute requisites for a pineal cyst to be symptomatic. Analogous to colloid cysts of the third ventricle, intermittent occlusion of cerebrospinal fluid pathways may cause small pineal cysts to become intermittently symptomatic. A select cohort of patients with pineal cysts may benefit from surgery despite a lack of hydrocephalus or other obvious compressive pathology.

Elective Intermittent Temporary Clipping in Aneurysm Surgery: A Practical Protocol

Background Temporary occlusion of the proximal vessel is being increasingly used as an adjunct during aneurysm surgery for safer dissection, evacuation of the aneurysm, and to prevent intraoperative rupture. The guidelines regarding its practice are ambiguous. One of the major concerns is the safe time limit for temporary occlusion. Studies done so far have failed to reach a consensus on this issue. This study is an attempt to provide a practical, safe time period of intermittent occlusion of an artery in the anterior circulation, irrespective of vascular territory. Patients and Methods A total of 68 patients in whom elective, intermittent, temporary clipping of the proximal vessel was employed during aneurysm surgery were prospectively studied. They were divided into two groups, Group I with an occlusion period of less than 7 minutes and Group II with occlusion period of 10 minutes and above per episode. The incidence of complications in both groups, their relationship to the number of intermittent clippings, and the total duration of clipping were analyzed. Results The incidence of complications was more in Group II (23.5 vs. 8.8%). There was a reduction in the incidence of complications when the duration of occlusion per episode was reduced; this, however, was not reflected statistically ( p = 0.1). The total duration of temporary occlusion, when compared, was significantly longer in Group II ( p = 0.000). The total duration of clipping, however, was not significantly different between those who developed complications and those who did not ( p = 0.86). The occurrence of complications did not correlate with the vascular territory, number of intermittent clippings, or the total duration of occlusion within their respective groups. Conclusion Our study supports the view that the proximal vessel can be safely occluded during aneurysm surgery. The total occlusion period could be safely prolonged when employed in an intermittent fashion with periods of reperfusion to attain the objective of safe dissection. The reduction in duration of each episode of occlusion, though resulted in fewer complications, did not reach statistical significance.

Microtubule-Associated Protein 2 and Synaptophysin in the Preterm and Near-Term Ovine Fetal Brain and the Effect of Intermittent Umbilical Cord Occlusion

We have determined the change in immunoreactivity (IR) for microtubule-associated protein 2 (MAP-2) and synaptophysin (SYN) as markers for dendritic and presynaptic nerve development, respectively, in the ovine fetal brain with advancing gestation and in response to intermittent umbilical cord occlusion (UCO), which might then contribute to adverse neurodevelopment. Fetal sheep (control and experimental groups preterm at 111-115 and near term at 132-138 days of gestation; term = 145 days) were studied over 4 days with UCOs performed by inflation of an occluder cuff for 90 seconds every 30 minutes for 3 to 5 hours each day. Animals were then euthanized and fetal brains assessed for IR of MAP-2 and SYN. In control animals, the IR of SYN increased in the gray matter with advancing gestation consistent with a developmental increase in presynaptic vesicles and/or nerve terminals as expected; however, the IR of MAP-2 decreased in all brain regions studied, suggesting concurrent refinement in dendritic branching and spine development. Intermittent UCO as studied with marked but limited hypoxemia resulted in a decrease in IR of SYN for the brain regions of the preterm animals when protein turnover is higher and indicates decreased presynaptic vesicle formation; whereas, MAP-2 IR was selectively increased in the hippocampus CA1 and thalamus of the near-term animals, consistent with reactive dendritic change and heightened vulnerability for neuronal injury. As such, intermittent cord compressions in the ovine fetus can impact protein markers for dendritic and presynaptic nerve development depending on their timing, which might then lead to alterations in synapse formation and neuronal circuitry.

Clinical approach for treatment modality of obstructive sleep apnea: focus on the role of dentists

Obstructive sleep apnea (OSA), most common respiratory disorder of sleep, is characterized by intermittent partial or complete occlusions of the upper airway due to loss of upper airway dilating muscle activity during sleep superimposed on a narrow upper airway. Termination of these events usually requires arousal from sleep and results in sleep fragmentation and hypoxemia, which leads to poor quality of sleep, excessive daytime sleepiness, reduced quality of life and numerous other serious health consequences Untreated OSAS can cause various problems such as hypertension, diabetes, stroke, cardiac disease, daytime sleepiness. Various treatments are available, including non-surgical treatment such as medication or modification of life style, surgical treatment, continuous positive airway pressure (CPAP) and oral appliance (OA). Oral appliance is known to be effective in mild to moderate OSA, also genioglossus muscle advancement (GA) or maxillomandibluar advancement (MMA) is a good option for OSA patients with muscular or skeletal problems. Although the prevalence of OSA is increasing, the proportion of the patient treated by dentist is still very law. Dentists need to understand the mechanism of OSA and develop abilities to treat OSA patients with dental problems. The purpose of this paper is to give a brief overview about OSA and the dentist's role in OSA patients.