Postsurgical State Research Articles

Numerical simulation of endovascular treatment options for cerebral aneurysms

AbstractPredicting the long‐term success of endovascular interventions in the clinical management of cerebral aneurysms requires detailed insight into the patient‐specific physiological conditions. In this work, we not only propose numerical representations of endovascular medical devices such as coils, flow diverters or Woven EndoBridge but also outline numerical models for the prediction of blood flow patterns in the aneurysm cavity right after a surgical intervention. Detailed knowledge about the postsurgical state then lays the basis to assess the chances of a stable occlusion of the aneurysm required for a long‐term treatment success. To this end, we propose mathematical and mechanical models of endovascular medical devices made out of thin metal wires. These can then be used for fully resolved flow simulations of the postsurgical blood flow, which in this work will be performed by means of a Lattice Boltzmann method applied to the incompressible Navier–Stokes equations and patient‐specific geometries. To probe the suitability of homogenized models, we also investigate poro‐elastic models to represent such medical devices. In particular, we examine the validity of this modeling approach for flow diverter placement across the opening of the aneurysm cavity. For both approaches, physiologically meaningful boundary conditions are provided from reduced‐order models of the vascular system. The present study demonstrates our capabilities to predict the postsurgical state and lays a solid foundation to tackle the prediction of thrombus formation and, thus, the aneurysm occlusion in a next step.

MATHEMATICAL MODELING OF VARIANTS OF TRANSPEDICULAR FIXATION AT THE THORACOLUMBAR JUNCTION AFTER ТHХІІ VERTEBRECTOMY DURING TRUNK BACKWARD BENDING

Fractures at the thoracolumbar junction are the most common traumatic spinal injuries. Advances in instrumentation for vertebral body replacement have significantly improved surgical techniques.However, the biomechanical characteristics of stabilizing surgeries have been insufficiently studied. Objective. To investigate the stressstrain state (SSS) of a mathematical finite element model of the humanthoracolumbar spine during trunk backward bending after ТhХІІ vertebra resection, considering different transpedicular fixation options. Methods. A mathematical finite element model of the humanthoracolumbar spine — ThIX‒LV vertebrae — was developed. The ТhХІІ vertebra was removed, and an interbody support and transpedicularsystem with 8 screws were implanted to simulate the postsurgical state after a ТhХІІ burst fracture with wide laminectomy, facetectomy, and corpectomy. The influence of transpedicular screw length and the presence of cross-links on the SSS of the model wasexamined. Results. The use of bicortical screws reduced stress levels in the bone elements of the model, except in the regions around the screws in the lumbar vertebrae, when compared to short screws.Installing cross-links decreased stress levels at all control points compared to models without cross-links. Specifically, in the presence of cross-links, the SSS values at the entry points of the short screwsinto the vertebral bodies of ThX, ThXI, LI, and LII were 2.3, 1.8, 1.2, and 5.0MPa, respectively, compared to 2.7, 2.0, 1.5, and 6.1 MPa in the models without cross-links. In the case of bicortical screwswithout cross-links, the stress values at the screw entry points into the pedicles of the corresponding vertebrae were 2.9, 1.5, 8.2, and 11.2 MPa, respectively, compared to 2.7, 1.5, 7.5, and 10.2 MPa in the models with cross-links. Conclusions. When the trunk is tilted backward, the use of cross-links reduces stress levels at all control points in the models, regardless of the screw length used. Bicortical transpedicular screws increase stress levels on the screws themselves and in the lumbar vertebral bodies surrounding them.

Brainstem Modulation of Nociception by Periaqueductal Gray Neurons Expressing the μ-Opioid Receptor in Mice.

Pharmacologic manipulations directed at the periaqueductal gray have demonstrated the importance of the μ-opioid receptor in modulating reflexive responses to nociception. The authors hypothesized that a supraspinal pathway centered on neurons in the periaqueductal gray containing the μ-opioid receptor could modulate nociceptive and itch behaviors. The study used anatomical, optogenetic, and chemogenetic approaches in male and female mice to manipulate μ-opioid receptor neurons in the periaqueductal gray. Behavioral assays including von Frey, Hargreaves, cold plantar, chloroquine-induced itch, hotplate, formalin-induced injury, capsaicin-induced injury, and open field tests were used. In separate experiments, naloxone was administered in a postsurgical model of latent sensitization. Activation of μ-opioid receptor neurons in the periaqueductal gray increased jumping (least-squares mean difference of -3.30 s; 95% CI, -6.17 to -0.44; P = 0.023; n = 7 or 8 mice per group), reduced itch responses (least-squares mean difference of 70 scratching bouts; 95% CI, 35 to 105; P < 0.001; n = 8 mice), and elicited modestly antinociceptive effects (least-squares mean difference of -0.7 g on mechanical and -10.24 s on thermal testing; 95% CI, -1.3 to -0.2 and 95% CI, -13.77 to -6.70, and P = 0.005 and P < 0.001, respectively; n = 8 mice). Last, the study uncovered the role of the periaqueductal gray in suppressing hyperalgesia after a postsurgical state of latent sensitization (least-squares mean difference comparing saline and naloxone of -12 jumps; 95% CI, -17 to -7; P < 0.001 for controls; and -2 jumps; 95% CI, -7 to 4; P = 0.706 after optogenetic stimulation; n = 7 to 9 mice per group). μ-Opioid receptor neurons in the periaqueductal gray modulate distinct nocifensive behaviors: their activation reduced responses to mechanical and thermal testing, and attenuated scratching behaviors, but facilitated escape responses. The findings emphasize the role of the periaqueductal gray in the behavioral expression of nociception using reflexive and noxious paradigms.

Management of scleral melt.

Scleral melting, while rare, can lead to significant ocular morbidity. Several possible risk factors for scleral melt have been identified, such as infection, autoimmune disease, trauma, and post-surgical state, and these may act in combination with each other. Treatment should be tailored according to the etiology and severity of the scleral melt. Medical management may be indicated, especially in cases of autoimmune-related melt; however, surgical procedures are often necessary due to compromised ocular integrity and limited penetration of medications into the avascular sclera. An understanding of the surgical options available and their operative outcomes is particularly important when choosing the appropriate treatment protocol for each patient.

Abstract 15237: Alterations in the Human Mitral Valve in-vivo Functional State in Mitraclip Repair

Introduction: The MitraClip for treatment of mitral regurgitation (MR) is a generally safe and effective procedure. However, recent clinical trials have reported contradictory outcomes, and long-term efficacy remains almost completely unknown. Therefore, there is an urgent need for quantitative, patient-specific treatment optimization grounded on a robust understanding of the functional consequences of the MitraClip repair procedure on each patient-specific mitral valve (MV). Methods: Real-time 3D echocardiography images of ten MR patients’ MVs were acquired during the MitraClip procedure. These images were analyzed using our validated noninvasive strain estimation method to compute the pre-operative leaflet strain fields in the circumferential and radial directions. For the post-operative analysis, 3D MitraClip models were implemented in the corresponding size and number in the simulation to directly grasp the MV leaflets at echo-dictated positions. Results: The MV pre-surgical states were highly variable in both geometry and deformation, underscoring the heterogeneity of the MR in the patient population. There were also no consistent post-surgical global or local strain patterns between MVs. However, the pre- and post-surgical strain fields in the same MV were significantly better correlated than random pre- and post-surgical pairs (p &lt; 0.005). This quantitative result implies that the post-surgical state for each patient can be predicted from available pre-surgical data-derived modelling. Conclusions: Due to the highly variable pre-surgical state of regurgitant MVs, a patient-specific approach to MitraClip repair is crucial to improving long-term patient outcomes. Moreover, these findings suggest that the post-surgical state can be correlated to, and therefore predicted from, the pre-surgical state, which would lay the foundation for quantitative surgical planning, tailored patient selection, and ultimately, a more durable repair.

Psychological factors and trajectories of post-surgical pain: A longitudinal prospective study.

A significant proportion of patients do not experience relief from pain during the early postsurgical period after joint arthroplasty and are at risk for developing chronic pain. The objectives of this study were to identify biopsychosocial factors associated with acute postsurgical pain trajectories and with pain intensity and interference after 1, 3, and 12 months. Two hundred ten patients listed for joint arthroplasty filled a presurgical battery of questionnaires assessing presurgical pain intensity, catastrophizing, emotional distress, state anxiety and depression, self-efficacy, central sensitization, and executive functions. From the day after surgery, they were asked to fill a 7-day diary, including questions about postsurgical pain and postsurgical state catastrophizing. Finally, they provided data about pain intensity and interference after 1, 3, and 12 months. Predictors of acute pain trajectories were investigated using multilevel growth curve analysis. Results showed that central sensitization was a predictor of the intercept of pain trajectories and daily postsurgical catastrophizing was a significant covariate of pain intensity in the acute phase. Analyses of follow-up data showed that central sensitization was a predictor of pain intensity and pain interference at 3 and 12 months, that emotional distress was related with pain intensity and interference at 1 month, and with pain interference at 3 months, and that cognitive flexibility was associated with pain interference at 1 month. Assessment of these factors could enable to identify patients at risk for worse outcomes and to plan targeted treatments to be implemented during the patient's inward stay.

Histone modification of pain-related gene expression in spinal cord neurons under a persistent postsurgical pain-like state by electrocautery

Chronic postsurgical pain (CPSP) is a serious problem. We developed a mouse model of CPSP induced by electrocautery and examined the mechanism of CPSP. In this mouse model, while both incision and electrocautery each produced acute allodynia, persistent allodynia was only observed after electrocautery. Under these conditions, we found that the mRNA levels of Small proline rich protein 1A (Sprr1a) and Annexin A10 (Anxa10), which are the key modulators of neuropathic pain, in the spinal cord were more potently and persistently increased by electrocautery than by incision. Furthermore, these genes were overexpressed almost exclusively in chronic postsurgical pain-activated neurons. This event was associated with decreased levels of tri-methylated histone H3 at Lys27 and increased levels of acetylated histone H3 at Lys27 at their promoter regions. On the other hand, persistent allodynia and overexpression of Sprr1a and Anxa10 after electrocautery were dramatically suppressed by systemic administration of GSK-J4, which is a selective H3K27 demethylase inhibitor. These results suggest that the effects of electrocautery contribute to CPSP along with synaptic plasticity and epigenetic modification.

BiCyCLE NMES\u2014neuromuscular electrical stimulation in the perioperative treatment of sarcopenia and myosteatosis in advanced rectal cancer patients: design and methodology of a phase II randomised controlled trial

BackgroundColorectal cancer is associated with secondary sarcopenia (muscle loss) and myosteatosis (fatty infiltration of muscle) and patients who exhibit these host characteristics have poorer outcomes following surgery. Furthermore, patients, who undergo curative advanced rectal cancer surgery such as pelvic exenteration, are at risk of skeletal muscle loss due to immobility, malnutrition and a post-surgical catabolic state. Neuromuscular electrical stimulation (NMES) may be a feasible adjunctive treatment to help ameliorate these adverse side-effects. Hence, the purpose of this study is to investigate NMES as an adjunctive pre- and post-operative treatment for rectal cancer patients in the radical pelvic surgery setting and to provide early indicative evidence of efficacy in relation to key health outcomes.MethodIn a phase II, double-blind, randomised controlled study, 58 patients will be recruited and randomised (1:1) to either a treatment (NMES plus standard care) or placebo (sham-NMES plus standard care) group. The intervention will begin 2 weeks pre-operatively and continue for 8 weeks after exenterative surgery. The primary outcome will be change in mean skeletal muscle attenuation, a surrogate marker of myosteatosis. Sarcopenia, quality of life, inflammatory status and cancer specific outcomes will also be assessed.DiscussionThis phase II randomised controlled trial will provide important preliminary evidence of the potential for this adjunctive treatment. It will provide guidance on subsequent development of phase 3 studies on the clinical benefit of NMES for rectal cancer patients in the radical pelvic surgery setting.Trial registrationProtocol version 6.0; 05/06/20. ClinicalTrials.gov NCT04065984. Registered on 22 August 2019; recruiting.

Abnormal Cardiac Repolarization After Seizure Episodes in Structural Brain Diseases: Cardiac Manifestation of Electrical Remodeling in the Brain?

BackgroundAbnormal cardiac repolarization is observed in patients with epilepsy and can be associated with sudden death. We investigated whether structural brain abnormalities are correlated with abnormal cardiac repolarizations in patients with seizure or epilepsy.Methods and ResultsWe retrospectively analyzed and compared 12‐lead ECG parameters following seizures between patients with and without structural brain abnormalities. A total of 96 patients were included: 33 women (17 with and 16 without brain abnormality) and 63 men (44 with and 19 without brain abnormality). Brain abnormalities included past stroke, chronic hematoma, remote bleeding, tumor, trauma, and postsurgical state. ECG parameters were comparable for heart rate, PR interval, and QRS duration between groups. In contrast, corrected QT intervals evaluated by Fridericia, Framingham, and Bazett formulas were prolonged in patients with brain abnormality compared with those without (women: Fridericia [normal versus abnormal], 397.4±32.7 versus 470.9±48.9; P=0.002; Framingham, 351.0±40.1 versus 406.2±46.1; P=0.002; Bazett, 423.8±38.3 versus 507.7±56.6; P<0.0001; men: Fridericia, 403.8±30.4 versus 471.0±47.1; P<0.0001; Framingham, 342.7±36.4 versus 409.4±45.8; P<0.0001; Bazett, 439.3±38.6 versus 506.2±56.8; P<0.0001). QT dispersion and Tpeak−Tend intervals were comparable between groups. We also observed abnormal ST‐segment elevation in 5 patients. Importantly, no patients showed fatal arrhythmias during or after seizures.ConclusionsOur study demonstrated that brain abnormalities can be associated with abnormal cardiac repolarization after seizures, which might be a manifestation of electrophysiological remodeling in the brain.

Infective costochondritis and multiple abscesses in a healthy adult

Infective costochondritis is particularly associated with chest wall trauma, postsurgical state, compromised host and intravenous drug abuse.[1][1] Differentiating costochondritis with an infection from that without an infection is sometimes difficult....

Albumin as prognostic value in hospitalised patients with femur neck fracture

Post-surgical state there might be a low formation of the albumin in liver or high degradation of the albumin. In either of the ways the serum albumin will be lowered. Stress and strain is also known to cause hypoalbuminemia i.e low serum level of albumin. Since albumin is a protein it has to be transcribed rom the genes and studies have shown that TNF - alpha supresses this transcription process.

Comparison of the result of Doppler sonography before and after laparoscopic artery and lymphatic sparing varicocelectomy with microsurgical subinguinal varicocelectomy.

Background:Based on the importance of varicocele, the aim of this is to compare the comparison between doppler sonography before and after laparoscopic lymphatic sparing varicocelectomy and microsurgical subinguinal varicocelectomy.Patients and Methods:Patients with primary varicocele who were referred to Ahwaz Imam Khomeini Hospital after informed consent were included. Primary information included varicocele severity, pain intensity, latency, Doppler sonography (Resistive index (RI), venous return, venous diameter before and after Valsalva) were obtained, and then patients were entered into one of the two groups of surgery. The admission duration, return to work duration, the pain and analgesic consumption, and the length of anxiety were recorded in patients. Patients were examined 3 months later, and the severity of varicocele in the examination, pain score, latency, Doppler sonography indices, sperm indices in both groups were registered. In the end, the information is entered into Statistical Package for the Social Sciences (SPSS) statistical software and evaluated.Results:We observed that the severity of varicocele (P = 0.34), pain (P = 0.45), latralite (P = 0.56), RI (P = 0.65), intravenous diameter (P = 0.75) did not show statistically significant difference between the two groups, also in evaluating these indices after surgery, there were significant differences between the two groups in pain (P = 0.04) and time for return to work (P = 0.036).Conclusions:The methods used in varicocelectomy did not have any effect on the outcome of the treatment. Accordingly, using any of these methods can improve the post-surgical state of the patients and promote the fertility performance and reduction of complications due to surgery in patients.

Association Between Quantitative Electroencephalogram Frequency Composition and Post-Surgical Evolution in Pharmacoresistant Temporal Lobe Epilepsy Patients.

The purpose of this paper is to estimate the association between quantitative electroencephalogram frequency composition (QEEGC) and post-surgical evolution in patients with pharmacoresistant temporal lobe epilepsy (TLE) and to evaluate the predictive value of QEEGC before and after surgery. A prospective, longitudinal study was made at International Neurological Restoration Center, Havana, Cuba. Twenty-nine patients with TLE submitted to epilepsy surgery were evaluated before surgery, and six months and two years after. They were classified as unsatisfactory and satisfactory post-surgical clinical evolution using the Modified Engels Scale. Eighty-seven electroencephalograms with quantitative narrow- and broad-band measures were analyzed. A Mann Whitney test (p > 0.05) showed that QEEGC before surgery was similar between groups independently of two years post-surgical evolution. A Mann Whitney test (p ˂ 0.05) showed that subjects with two years satisfactory post-surgical evolution had greater alpha power compared to subjects with two years unsatisfactory post-surgical evolution that showed greater theta power. A Wilcoxon test (p ˂ 0.05) showed that alpha and theta power increased for two groups from pre-surgical state to post-surgical state. Logit regression (p ˂ 0.05) showed that six months after surgery, quantitative electroencephalogram frequency value with the greatest power at occipital regions shows predictive value for two years evolution. QEEGC can be a tool to predict the outcome of epilepsy surgery.

Small Bowel Hemorrhage Due to Ectopic Varices Between the Inferior Mesenteric Vein and the Left Gonadal Vein

Ectopic varices account for only 3-5% of all varices, but they have a 4-fold increased risk of bleeding when compared to esophageal varices. Endoscopic treatment of ectopic varices is often hindered by the difficulty in reaching some of these locations, and oftentimes alternative means of hemostasis will need to be pursued. Here we discuss a case of hemorrhage arising from ectopic varices between the inferior mesenteric vein (IMV) and left gonadal vein (LGV). A 62-year-old female with a history of alcoholic cirrhosis, decompensated by bouts of severe hepatic encephalopathy, and laparoscopic sigmoid colectomy for diverticular disease, presented to the Emergency Department with symptomatic anemia in the setting of maroon stools, found to have a hemoglobin level of 6.2 g/dL. Following resuscitation, the patient underwent esophagogastroduodenoscopy (EGD) and colonoscopy, which failed to identify a culprit lesion. In the ensuing days, the patient continued to have maroon stools and daily blood transfusion requirements. Further evaluation with capsule endoscopy and double-balloon enteroscopy were inconclusive. Tagged RBC scan and CT angiography were likewise negative, though CT angiogram did note prominent venous collaterals associated with the IMV and LGV, concerning for ectopic varices (Figure 1). An interdisciplinary meeting between Gastroenterology, Hepatology, Hepatobiliary Surgery, and Interventional Radiology was held to discuss potential options. Transjugular intrahepatic portosystemic shunt was contraindicated due to the degree of liver decompensation. Given the lack of other identifiable lesions, it was felt reasonable to attempt direct embolization of the varicosities between her IMV and LGV. Pre-embolization venogram did demonstrate a large shunt with extensive varices between the IMV and LGV (Figure 2). Amplatzer plugs and embolization coils were successfully deployed into 3 branches of the distal IMV (Figure 3). The patient was monitored in the hospital for a few days with stability of her hemoglobin, and she was discharged home. The patient followed up 1 month post-hospitalization with no recurrence of bleeding. Case Highlights: This case illustrates the difficulty that may be encountered in the identification and treatment of ectopic varices. In this case, the unusual location of her varices is postulated to have been related to her post-surgical state. A multi-disciplinary approach was needed in order to properly manage and treat this patient.2008_A Figure 1. CT angiogram demonstrating large venous collateralization between the IMV and left gonadal vein.2008_B Figure 2. Pre-embolization venogram demonstrating extensive network of varices with drainage by the left gonadal vein.2008_C Figure 3. Post-embolization venogram demonstrating complete occlusion of flow after deployment of Amplatzer plugs and coils into branches of the IMV.

P476 Using small bowel and colon video capsule endoscopy to optimise Crohn’s disease therapy may improve patient quality of life

Video capsule endoscopy (VCE) is a widely accepted technology that has application for monitoring of patients diagnosed with Crohn’s disease (CD). Due to the chronic nature of CD, using endoscopic monitoring to optimise treatment may have a considerable impact on both care costs and patient’s quality of life (QoL). This study aims to identify patient subgroups who may benefit from the use of pan-intestinal VCE. Extended analysis of patient outcomes of a previously published, patient-level, care pathway model that is specific to CD. In the model, treatment and monitoring can influence the onset, progression, or remission of CD flares, fistula, abscess, bowel resection, and death. The model compares outcomes with VCE to the current common monitoring practice of colonoscopy ± MRE or CTE. Data for VCE were derived from PillCam (Medtronic Inc.), which can assess both the small-bowel and colon in a single procedure. Outcomes for 40,000 simulated patients over 20 years were assessed. Cost of care and patient QoL were compared between monitoring options and stratified by patient subgroup. Subgroups based on the patient’s initial health state in the model were: remission, non-active symptomatic, active symptomatic, active non-symptomatic, treatment, treatment failure, surgery, or post-surgery. All subgroups were mutually exclusive. Differences between groups were quantified by the Wilcoxon-signed rank and the odds ratio (OR) with significance at the 95% level (p < 0.05). Overall, patients had significantly lower costs (p < 0.001) and higher QoL (p < 0.001) with use of VCE compared with common monitoring practice. Even patients in remission, the state with the least benefit from VCE, saw QoL improvement in 68% of cases. Patients in an active symptomatic or post-surgical state were the most likely to experience QoL improvement (both 79%). All groups displayed a significantly higher chance of QoL improvement over patients in remission (Figure 1). The likelihood of cost-savings was significantly higher during treatment (OR: 1.11, 1.03–1.19) or surgery (OR: 1.27, 1.13–1.41) when compared with remission. Odds ratio of a positive QoL/Costs difference compared with starting the simulation in remission. Error bars represent the 95% confidence interval. Assessing the extent of active CD with small bowel and colon VCE is likely beneficial for patient QoL and may also help reduce care costs. Targeting certain subgroups may amplify the advantages of VCE. Patients in need of more frequent follow-up, such as those on biological treatment, post-surgery, or with active symptoms, may be especially benefited by pan-intestinal VCE.

Preemptive analgesia in orthopedic surgery: a literature review

Pain after surgery is a maladaptive response. Acute postoperative pain is an important predictive factor for chronic post-surgical pain, which is observed in 10–65% of patients after surgery. Therefore controlling pain after surgery is very important. Reducing postoperative pain will result in more patient satisfaction, less complications due to immobility and decreased hospitalization periods. In this review, the use of preemptive analgesia in orthopedic surgery with a great variety of medications and interventions is examined. A search with the key words of “preemptive analgesia”, “orthopedic surgery” and “post-surgical pain” was conducted in online database PubMed, EBSCO, Elsevier (ClinicalKey), SpringerLink and OVID. Then selected articles from 5 years relevant with the application of preemptive analgesia in orthopedic surgery were analyzed. Finally we show some interventions with the outcomes and the challenges and new investigations suggested. The results showed that preemptive analgesia can be from regional blockade and local wound infiltration before incision to application of oral or intravenous medication before beginning surgery (NSAIDs, Gabapentin, Pregabalin, Dextromethorphan, Melatonin, Multimodal and Opioids) and the new approaches like transcutaneous electrical nerve stimulation (TENS). Preemptive analgesia has an important role in diminishing the pain rate in the post-surgical state, lowering pain medication intake and improving the patient satisfaction and early mobilization.

In Vivo Measures of Shear Wave Speed as a Predictor of Tendon Elasticity and Strength

The purpose of this study was to assess the potential for ultrasound shear wave elastography (SWE) to measure tissue elasticity and ultimate stress in both intact and healing tendons. The lateral gastrocnemius (Achilles) tendons of 41 New Zealand white rabbits were surgically severed and repaired with growth factor coated sutures. SWE imaging was used to measure shear wave speed (SWS) in both the medial and lateral tendons pre-surgery, and at 2 and 4 wk post-surgery. Rabbits were euthanized at 4 wk, and both medial and lateral tendons underwent mechanical testing to failure. SWS significantly (p < 0.001) decreased an average of 17% between the intact and post-surgical state across all tendons. SWS was significantly (p < 0.001) correlated with both the tendon elastic modulus (r = 0.52) and ultimate stress (r = 0.58). Thus, ultrasound SWE is a potentially promising non-invasive technology for quantitatively assessing the mechanical integrity of pre-operative and post-operative tendons.

Cerebral analgesic response to nonsteroidal anti-inflammatory drug ibuprofen.

Nonopioid agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs), are the most commonly used class of analgesics. Increasing evidence suggests that cyclooxygenase (COX) inhibition at both peripheral and central sites can contribute to the antihyperalgesic effects of NSAIDs, with the predominant clinical effect being mediated centrally. In this study, we examined the cerebral response to ibuprofen in presurgical and postsurgical states and looked at the analgesic interaction between surgical state and treatment. We used an established clinical pain model involving third molar extraction, and quantitative arterial spin labelling (ASL) imaging to measure changes in tonic/ongoing neural activity. Concurrent to the ASL scans, we presented visual analogue scales inside the scanner to evaluate the subjective experience of pain. This novel methodology was incorporated into a randomized double-blind placebo-controlled design, with an open method of drug administration. We found that independent of its antinociceptive action, ibuprofen has no effect on regional cerebral blood flow under pain-free conditions (presurgery). However, in the postsurgical state, we observed increased activation of top-down modulatory circuits, which was accompanied by decreases in the areas engaged because of ongoing pain. Our findings demonstrate that ibuprofen has a measurable analgesic response in the human brain, with the subjective effects of pain relief reflected in two distinct brain networks. The observed activation of descending modulatory circuits warrants further investigation, as this may provide new insights into the inhibitory mechanisms of analgesia that might be exploited to improve safety and efficacy in pain management.

他動的足関節運動中の弾性ストッキングの圧迫圧と筋酸素化状態の測定

Purpose: The purpose of this study was to simultaneously measure time course changes in pressure of compression stocking and oxygenation state of the gastrocnemius muscle (MG) during passive dorsiflexion in patients who admitted to the ICU after surgery. Methods: Participants comprised five patients in post-surgical state of esophageal cancer (mean age, 59.4±6.1 years). Patients were performed exercise consisted of 10 cycles involving passive dorsiflexion and release until a few hours after surgery. Changes in oxygenated hemoglobin (oxy-Hb), deoxygenated hemoglobin (deoxy-Hb) and total hemoglobin (t-Hb) of medial belly of the MG were measured by near infrared spectroscopy. Changes in pressure of compression stocking was simultaneously measured at the lateral side of the MG. Results: The compression pressure was 20.4±1.6 mmHg at rest and increased up to 4.2±3.2 mmHg during dorsiflexion. oxy-, deoxy-, and t-Hb decreased during dorsiflexion, and recovered during release. t-Hb after 5-min passive exercise significantly decreased as compared with those before exercise. Conclusions: Increase in compression pressure during dorsiflexion may induced by changes in shape of calf. Passive exercise for 5 min might decrease muscle blood volume in patients while wearing compression stockings studies.

Biomechanical Test of Three Methods to Treat Thumb CMC Arthritis.

Background Basilar thumb arthritis, or first carpometacarpal arthritis, is a common condition, predominantly affecting women. Surgical treatment of this condition is highly varied. One common method consists of trapezium excision and a concomitant procedure for treatment of the "floating" thumb metacarpal. That procedures vary suggests that no method has an "outcome" advantage over another. However, the frequency of side effects is higher in more complex procedures. Question/Purposes We speculated that in vitro testing might identify a potential outcome difference that has been difficult to measure in vivo. Since the more complex procedure to treat this condition has a higher frequency of clinical side effects, we hoped to determine its functional value compared with less complex procedures. Methods A two-degrees-of-freedom biomechanical cadaver study examined simulated pinch strength and metacarpal subsidence during pinch. Three methods were compared with each other and against the normal pretreatment state: trapezial excision alone; trapezial excision and suture suspensionplasty (TESS); and trapezial excision followed by a ligament reconstruction using one-half of the flexor carpi radialis and tendon interposition (LRTI). Results After TESS, the loaded mean height of the arthroplasty space was 1.20 cm. This was statistically less than the pretreatment height of 1.50 cm (P < 0.05). However, the height maintained after LRTI (1.00 cm) was also statistically less than pretreatment state (P < 0.05) and less than TESS (P < 0.05). Trapezial excision alone was least successful at maintaining height. In contrast, the mean key pinch measured after treatment could not be predicted by treatment employed. Conclusions In summary, the tested technique of TESS appears to be biomechanically sound as related to maintenance of first metacarpal height. In in vitro testing it is superior to excision alone and at least equal to the ligament reconstruction method tested. Analysis of our data shows that 96% of the overall height (distance) maintained post excision is explained by surgical state. Clinical Relevance Trapezial height is preserved using support schemes in a laboratory setting. In the in vivo postsurgical state, clinical intrinsic muscle function may be superior when support is used compared with trapeziectomy alone.