Limb Remote Ischemic Preconditioning Applied During Sevoflurane Anesthesia Does Not Protect the Lungs in Patients Undergoing Adult Heart Valve Surgery.

BACKGROUND: Two consistent overall cell protective preconditioning treatments should provide more protection. We hypothesized that limb remote ischemic preconditioning (RIPC, second preconditioning stimulus) applied during sevoflurane inhalation (first preconditioning stimulus) would provide more protection to the lungs of patients undergoing adult heart valve surgery. METHODS: In this randomized, placebo-controlled, double-blind trial, 50 patients were assigned to the RIPC group or the placebo group (1:1). Patients in the RIPC group received three 5-min cycles of 300 mmHg cuff inflation/deflation of the left-side lower limb before aortic cross-clamping. Anesthesia consisted of opioids and propofol for induction and sevoflurane for maintenance. The primary end point was comparison of the postoperative arterial-alveolar oxygen tension ratio (a/A ratio) between groups. Secondary end points included comparisons of pulmonary variables, postoperative morbidity and mortality and regional and systemic inflammatory cytokines between groups. RESULTS: In the RIPC group, the a/A ratio and other pulmonary variables exhibited no significant differences throughout the study period compared with the placebo group. No significant differences in either plasma or bronchoalveolar lavage levels of TNF- α were noted between the groups at 10 min after anesthetic induction and 1 h after cross-clamp release. The percentage of neutrophils at 12 h postoperation was significantly increased in the RIPC group compared with the placebo group (91.34±0.00 vs. 89.42±0.10, P = 0.023). CONCLUSIONS: Limb RIPC applied during sevoflurane anesthesia did not provide additional significant pulmonary protection following adult valvular cardiac surgery.

Evaluation of the performance of two neutral oral contrast agents in computed tomography enterography: A randomized controlled trial.

OBJECTIVE: To compare the performances, tolerability and acceptability of mannitol and polyethylene glycol (PEG) as oral contrast agents in patients undergoing computed tomography enterography (CTE). METHODS: Patients aged 18-75 years indicated for CTE were randomized to receive either mannitol or PEG as contrast agents. The coronal reconstructed images of each abdominal quadrant were assessed for maximum distention, proportion of distended bowel loops, presence of inhomogeneous contents and visibility of the small bowel wall. Overall subjective imaging quality assessment and patients' tolerability and acceptability were recorded. RESULTS: Seventy patients were enrolled and randomized into two groups. In the per-protocol analysis, no significant differences in imaging quality was found in bowel distention maximum diameter, wall visibility and intestinal homogeneity (all P > 0.05). The mean nausea score was lower in the mannitol group (0 [0-0] vs 1.0 [0-3.0], P < 0.001). Mannitol was superior to PEG in taste (9.0 [8.0-10.0] vs 7.0 [5.0-8.0], P < 0.001), patients' willingness to reuse the drug (9.0 [8.0-10.0] vs 8.0 [7.0-9.0], P = 0.036), satisfaction (9.0 [8.0-10.0] vs 8.0 [7.0-9.0], P = 0.022) and ease of completion (9.0 [8.0-9.3] vs 8.0 [6.5-9.0], P = 0.030). CONCLUSIONS: Both mannitol and PEG provided good bowel distention and visualization of the bowel wall. However, mannitol was significantly superior to PEG in patients' tolerability and acceptability.

Noninvasive evaluation of radiation-enhanced glioma cells invasiveness by ultra-high-field (1)H-MRS in vitro.

INTRODUCTION: Glioma is the most common type of the primary CNS tumor. Radiotherapy is an important treatment measure after surgery. However, its highly invasive character is the main reason of postoperative recurrence. The aim of the study was to probe the correlation between the invasion ability and the metabolite characteristics of glioma cells at the cellular level after irradiation by using 14.7T high-resolution nuclear proton magnetic resonance spectroscopy ((1)H-MRS). METHODS: To determine the matrix metalloproteinase-2 (MMP-2) activity and metabolite ratios of glioma cells after irradiation with different doses of X-rays, U87 and C6 glioma cells were exposed to X-ray irradiation of 0, 1, 5, 10, and 15Gy. After 20h, the perchloric acid (PCA) extraction method was used to evaluate water-soluble metabolites [choline (Cho), creatine (Cr), and N-acetylaspartate (NAA)], and (1)H-MRS patterns and changes in metabolite ratios were observed in vitro by 14.7T high resolution (1)H-MRS. Matrigel invasion assays and gelatin zymography were performed to test the invasion ability of U87 and C6 glioma cells. RESULTS: Good MR spectra were obtained from PCA method extracts of U87 and C6 glioma cells. Both radiation-induced MMP-2 activity and the Cho/Cr and Cho/NAA ratios increased after irradiation, and their increase occurred in a dose-dependent manner. The MMP-2 activity and the Cho/Cr and Cho/NAA ratios of glioma cells increased after irradiation up to 10Gy and decreased thereafter. In particular, the Cho/NAA ratio of U87 cells increased from 3.55±0.06 (0Gy) to 9.13±0.30 (10Gy) and then declined to 5.94±0.15 (15Gy). Furthermore, the invasion ability of glioma cells had a strong positive correlation with the Cho/Cr and Cho/NAA ratios. Both the Cho/Cr ratio and the Cho/NAA ratio of U87 glioma cells were highly positively correlated with the number of invading cells in the Matrigel invasion assay. The Pearson's correlation coefficient (r) values of U87 cells were 0.89 (Cho/Cr ratio versus invasion ability) and 0.91 (Cho/NAA ratio versus invasion ability) (P<0.01). C6 cells exhibited similar changes to those of U87 cells. CONCLUSIONS: In vitro high-resolution (1)H-MRS is useful for detecting glioma invasiveness at the cellular level.

Bilateral subclavian vein sheaths for superior vena cava drainage during thoracoscopic repair of atrial septal defects: cosmetic outcomes, safety and effectiveness.

OBJECTIVE: To investigate the cosmetic outcomes, safety and effectiveness of using bilateral subclavian vein sheaths for superior vena cava drainage during thoracoscopic repair of atrial septal defects. METHODS: Sixty-one consecutive adults scheduled for thoracoscopic repair of atrial septal defects between July 2012 and June 2013 were randomized into two groups: one group underwent placement of a 16 Fr percutaneous superior vena cava cannula (n = 30) and the other group underwent placement of bilateral 8 Fr subclavian vein sheaths (n = 31) for superior vena cava drainage during peripheral cardiopulmonary bypass. The perioperative data, central venous pressure during cardiopulmonary bypass, complications and the patient satisfaction scale scores for the incisions were compared between the two groups. RESULTS: The theoretical cardiopulmonary bypass flow rate was reached without complications in all patients. The average central venous pressure during cardiopulmonary bypass was not significantly different between the two groups [(6.9 ± 3.1) mmHg vs. (7.0 ± 3.5) mmHg, p=0.92]. The patient satisfaction scale scores for the incisions were significantly higher in the patients who underwent placement of bilateral subclavian vein sheaths than in the patients who underwent placement of a percutaneous superior vena cava cannula [(2.81 ± 0.75) vs. (2.07 ± 0.74), p<0.001]. CONCLUSIONS: Placement of bilateral subclavian vein sheaths is a safe and effective alternative to placement of a percutaneous superior vena cava cannula for superior vena cava drainage during thoracoscopic repair of atrial septal defects and results in greater patient satisfaction with the cosmetic outcome.

Superior vena cava drainage during thoracoscopic cardiac surgery: bilateral internal jugular vein sheaths versus one percutaneous superior vena cava cannula.

OBJECTIVE: To evaluate bilateral internal jugular vein sheaths as a replacement of one percutaneous superior vena cava cannula for superior vena cava drainage during thoracoscopic cardiac surgery. DESIGN: A prospective and randomized study. SETTING: Single cardiovascular institute. PARTICIPANTS: Adults undergoing thoracoscopic cardiac surgery. INTERVENTIONS: Patients were randomized into a percutaneous superior vena cava cannula group and a bilateral internal jugular vein sheaths group. The superior vena cava drainage for cardiopulmonary bypass was performed with one percutaneous superior vena cava cannula (14-18 Fr) or the bilateral internal jugular vein sheaths (8 Fr). MEASUREMENTS AND MAIN RESULTS: Both interventions reached theoretic flow rate in all patients. In patients weighing<50 kg (n=38) and 50-70 kg (n=64), the average central venous pressure values during cardiopulmonary bypass of both groups showed no significant differences. The patients weighing>70 kg (n=15) in the bilateral internal jugular vein sheaths group had a normal average central venous pressure value, but it was significantly higher than that of percutaneous superior vena cava cannula group ([10.5±3.1] mmHg vs. [4.5±4.4] mmHg, p=0.013). The patient satisfaction scale scores for the cervical incisions were significantly higher in the bilateral internal jugular vein sheaths group than in the percutaneous superior vena cava cannula group ([2.6±0.9] vs. [2.1±0.8], p=0.002). CONCLUSIONS: The bilateral internal jugular vein sheaths were a feasible and effective option to replace one percutaneous superior vena cava cannula during thoracoscopic cardiac surgery, with better patient satisfaction.

Preoperative demonstration of neurovascular relationship in trigeminal neuralgia by using 3D FIESTA sequence.

PURPOSE: The purpose of the study was to evaluate the value of high-resolution three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) imaging in the visualization of neurovascular relationship in patients with trigeminal neuralgia (TN). METHODS: Thirty-seven patients with unilateral typical TN underwent 3D FIESTA imaging. Neurovascular relationship at the trigeminal root entry zone was reviewed by an experienced neuroradiologist, who was blinded to the clinical details. The imaging results were compared with the operative findings in all patients. RESULTS: In 37 patients with TN, 3D FIESTA imaging identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves. Based on surgical findings, the sensitivity and specificity of magnetic resonance (MR) imaging were 97.2% and 100%, respectively. Agreement between the position (medial, lateral, superior and inferior) of the compressing vessel relative to the trigeminal nerve identified by MR imaging and surgery was excellent (K=0.81; 95% confidence interval, 0.56-1.00). A statistically significant difference was found between the site of neurovascular contact and the clinical symptom related to the trigeminal branch (Fisher's Exact Test, P<.001). CONCLUSIONS: Use of 3D FIESTA sequence enables accurate visualization of neurovascular contact in patients with TN. Anatomic relationships defined by this method can be useful in surgical planning and predicting surgical findings.

Detection of hemorrhagic hypointense foci in radiation injury region using susceptibility-weighted imaging.

BACKGROUND: Susceptibility-weighted imaging (SWI), a novel, highly sensitive 3D gradient echo MR imaging technique, is used to detect hemorrhage. PURPOSE: To evaluate SWI at 3.0T for detection and visualization of hemorrhage at radiation injury region after radiotherapy for brain glioma. MATERIAL AND METHODS: In 16 patients who had radiation injury in the vicinity of the previously resected and irradiated high-grade brain glioma, SWI examinations were performed on a 3T MR scanner. The presence of intralesional hypointense foci on SWI was evaluated by two neuroradiologists. Frequency of these foci on SWI was assessed and the number of these foci was counted. Diagnosis of radiation injury was assigned by means of histopathology or follow-up MR image. RESULTS: In all 16 cases with cerebral radiation injury, nine were verified by means of histopathologic examination, seven by follow-up image. While in one patient quality of SWI was poor, in all remaining patients diagnostic-quality SWI was obtained. The intralesional hypointense foci were detected in 12 of 15 patients. These hypointense foci were nodular, angular, or tubular regions of low signal intensity on SWI. The distribution of these foci was diffusive (n=5) or scattered (n=7). Number of these foci per cm(2) on SWI was 7.25 ± 3.67. CONCLUSION: SWI is a novel and promising technique for evaluation of hemorrhage at radiation injury regions in the vicinity of the previously treated gliomas.

Multivoxel 3D proton MR spectroscopy in the distinction of recurrent glioma from radiation injury.

OBJECTIVE: To explore the usefulness of multivoxel 3D proton MR spectroscopy ((1)H-MRS) in assessing the recurrent contrast-enhancing areas at the site of the previously treated gliomas. MATERIALS AND METHODS: In 28 patients who had new contrast-enhancing lesions in the vicinity of the previously resected and irradiated high-grade glioma, 3D (1)H-MRS examinations were performed on a 3.0T MR scanner. Spectral data for N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were analyzed in all patients. Receiver operating characteristic analysis was performed, and the threshold value for tumor differentiation was determined. Diagnosis of these lesions was assigned by means of histopathology and follow-up. RESULTS: Diagnostic-quality 3D (1)H-MRS with quantifiable Cho, Cr, and NAA peaks was obtained in 92.9% of the cases. The Cho/NAA and Cho/Cr ratios were significantly higher in recurrent tumor than in radiation injury (P < 0.01), whereas the NAA/Cr ratios were lower in recurrent tumor than in radiation injury (P = 0.02). The Cho/Cr and Cho/NAA ratios were significantly higher in radiation injury than in normal-appearing white matter (P < 0.01), however, the NAA/Cr ratios were lower in radiation injury than in normal-appearing white matter (P = 0.01). Using receiver operating characteristic analysis, the resulting sensitivity, specificity and diagnostic accuracy of 3D (1)H-MRS were 94.1%, 100%, and 96.2%, respectively, based on the cut-off values of 1.71 for Cho/Cr or 1.71 for Cho/NAA or both as tumor criterion. CONCLUSION: 3D (1)H-MRS could differentiate recurrent tumor from radiation injury in patients with recurrent contrast-enhancing lesions in the vicinity of the previously treated gliomas.

Distinction between recurrent glioma and radiation injury using magnetic resonance spectroscopy in combination with diffusion-weighted imaging.

PURPOSE: The aim of this study was to explore the diagnostic effectiveness of magnetic resonance (MR) spectroscopy with diffusion-weighted imaging on the evaluation of the recurrent contrast-enhancing areas at the site of treated gliomas. METHODS AND MATERIALS: In 55 patients who had new contrast-enhancing lesions in the vicinity of the previously resected and irradiated high-grade gliomas, two-dimensional MR spectroscopy and diffusion-weighted imaging were performed. Spectral data for N-acetylaspartate (NAA), choline (Cho), creatine (Cr), lipid (Lip), and lactate (Lac) were analyzed in conjunction with the apparent diffusion coefficient (ADC) in all patients. Diagnosis of these lesions was assigned by means of follow-up or histopathology. RESULTS: The Cho/NAA and Cho/Cr ratios were significantly higher in recurrent tumor than in regions of radiation injury (p < 0.01). The ADC value and ADC ratios (ADC of contrast-enhancing lesion to matching structure in the contralateral hemisphere) were significantly higher in radiation injury regions than in recurrent tumor (p < 0.01). With MR spectroscopic data, two variables (Cho/NAA and Cho/Cr ratios) were shown to differentiate recurrent glioma from radiation injury, and 85.5% of total subjects were correctly classified into groups. However, with discriminant analysis of MR spectroscopy imaging plus diffusion-weighted imaging, three variables (Cho/NAA, Cho/Cr, and ADC ratio) were identified and 96.4% of total subjects were correctly classified. There was a significant difference between the diagnostic accuracy of the two discriminant analyses (Chi-square = 3.96, p = 0.046). CONCLUSION: Using discriminant analysis, this study found that MR spectroscopy in combination with ADC ratio, rather than ADC value, can improve the ability to differentiate recurrent glioma and radiation injury.

[Quantitative analysis of brain volume by in vivo magnetic resonance imaging in normal adults].

OBJECTIVE: To quantify neuroanatomical parameters with magnetic resonance imaging (MRI) and to explore the relationship between these parameters and age. METHODS: Totally 150 adults aged 18-83 years received 3D fast spoiled gradient echo imaging. Volume of intracranial space, whole brain, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) were measured and normalized. RESULTS: Normative volumetric estimates were obtained for all subjects and presented by age and sex. There was not significantly age-related change in intracranial space volume. Whole brain volume did not significantly change before 30 years, thereafter, decline with age. SM volume decreased linearly with age. CSF volume increased linearly with age. WM volume and GM/WM ratio demonstrated a quadragnetic pattern of change with age. WM volume increased slightly in subjects until the age of 45 years, and it decreased thereafter. However, GM/ WM ratio decreased quickly in subjects until the age of 55 years, and it decreased slightly thereafter. Although the volumes of intracranial space and whole brain had significant differences between male and female (P < 0.05), the volumes of whole brain, GM, and CSF had no significant differences after normalization. CONCLUSION: In vivo MRI can measure the normal patterns of age- and sex-related changes in intracranial space, whole brain, GM, WM, and CSF, and may facilitate the appraisal of abnormal brain volumes. Keased linearly words: brain;ge. WM vol urement; magnetic resonance imaging