Identification of reversed portal flow on 4DCT and of factors contributing to reversed portal flow in patients with liver cirrhosis and portosystemic shunt before interventional radiology procedures.

AIM: Patients with liver cirrhosis and portosystemic shunt occasionally develop reversed portal flow in the portal venous system. The factors contributing to reversed portal flow in these patients remain unclear. The aim of this study was to identify factors contributing to reversed portal flow in patients with portosystemic shunts based on four-dimensional computed tomography (4DCT), which visualized flow dynamics in the portal venous system. METHODS: Data from 34 consecutive patients with portosystemic shunts who had undergone 4DCT before interventional radiology procedures were retrospectively investigated in this study. Uni- and multivariate analyses were performed to identify factors contributing to reversed portal flow. RESULTS: Flow dynamics could be visualized on 4DCT in 32 of the 34 patients. Fifteen patients had forward portal flow; 17 had reversed portal flow. The main portal, splenic, and superior mesenteric veins displayed reversed portal flow in five, 12, and five vessels, respectively. Portosystemic shunt originating from splenic and superior mesenteric veins, worse albumin-bilirubin score, and small main portal vein diameter were significant factors contributing to reversed portal flow in both univariate (p = 0.049, p = 0.027, and p = 0.002) and multivariate (odds ratio [OR] 6.345, p = 0.012; OR 4.279, p = 0.039; and OR 5.516, p = 0.019) analyses. CONCLUSIONS: The reversed portal flow was visualized on 4DCT. Portosystemic shunt originating distant to the liver, worse albumin-bilirubin score, and small diameter of the main portal vein were factors contributing to reversed flow in the portal venous system.

A case of delayed respiratory depression caused by accidental subcutaneous opioid infusion.

We report a case of delayed respiratory depression due to accidental subcutaneous opioid infusion. A healthy 33-year-old woman underwent orthopedic surgery under general anesthesia. Before the end of the operation, it was noticed that a part of the opioid infusion had been administered subcutaneously. About 15 min after tracheal extubation, the patient developed respiratory depression and loss of consciousness. The patient recovered with the use of jaw lift together with bag-valve-mask ventilation. We believe that accidental subcutaneous opioid accumulation may have caused the respiratory depression.

[Vital Sign Changes and the Requirement of Analgesics after Discontinuation of Dexmedetomidine in Patients after Esophageal Cancer Surgery.]

BACKGROUND: There is few study to examine the vital sign changes and the requirement of analgesics after discontinuation of dexmedetomidine in postopera- tive patients. METHODS: This is a retrospective observational study conducted in 74 patients after esophageal cancer sur- gery. We recorded vital signs including blood pressure, heart rate and respiratory rate one hour before discon- tinuation of dexmedetomidine, and at 1, 2, 4, 6 hours after its discontinuation. We also recorded the use of opioid and analgesic within 6 hours after discontinua- tion. RESULTS: Mean blood pressure, pulse rate, and respi- ratory rate significantly increased after DEX discon- tinuation. Compared with the data before discontinua- tion, the mean blood pressure increased by 13.3 mmHg, heart rate increased by 7.5 beats - min- and respira- tory rate increased by 3.0 times - min-' in average at 6 hours after discontinuation. There were 28 patients (38%) who required the additional analgesics within 6 hours after discontinuation. CONCLUSIONS: After discontinuation of dexmedetomi- dine, significant changes of vital signs, especially in mean blood pressure, were observed in post-esopha- gectomy patients. About 38% of them required addi- tional analgesics within 6 hours after dexmedetomidine discontinuation.

Clinical Experience of Dual-phase Cone Beam Computed Tomography during Hepatic Arteriography to Apply 3D-DSA.

We report on the methods and experiences of the dual-phase cone beam computed tomography during hepatic arteriography (CBCTHA) to apply the 3D-DSA. A total of 32 ml contrast medium (150 mgI/ml) was injected at the rate of 2.0 ml/s for 16 s. The early phase scan was initiated 10 s after the start of contrast media injection. The delayed phase scan was started 40 s after that (24 s after the end of CM injection). When using the dual phase CBCTHA, it was able to obtain the classical hepatocellular carcinoma (HCC) images same as computed tomography during hepatic arteriography (CTHA). In the early phase, the tumor can be highly enhanced against the liver parenchyma. In delayed phase, corona enhancement was clearly appeared at the liver parenchyma. Of 58 cases of acquisitions, we experienced six cases with miss breath holding and 14 cases with over the field of view (FOV) due to hepatomegaly. We evaluated the tumor contrast in 18 cases because the other 40 cases were not applied to our criteria. The pixel values of ROIs on the tumor, coronal enhancement, and liver parenchyma were measured, respectively. Then, we calculated tumor-parenchyma contrast (T-P contrast), corona-tumor contrast (C-T contrast), and corona-parenchyma contrast (C-P contrast). The T-P contrast was 358±112, the C-T contrast was 132±51, and the C-P contrast was 168±66. The contrast was clearly visualized among them. The dual-phase CBCTHA that applies the 3D-DSA is a simple and useful technique for hepatocellular carcinoma treatment.

Understanding the Scatter Radiation Distribution during C-arm CT Examination: A Body Phantom Study.

The purpose of this study was to understand the scatter radiation distribution during C-arm CT examination in the interventional radiography (IVR) room to show the escaped area and the radiation protective method. The C-arm rotates 200° in 5 s. The tube voltage was 90 kV, and the entrance dose to the detector was 0.36 µGy/frame during C-arm CT examination. The scattered doses were measured each 50 cm from the isocenter like a grid pattern. The heights of the measurement were 50, 100, and 150 cm from the floor. The maximum scattered doses were 38.23±0.60 µGy at 50 cm, 43.86±0.20 µGy at 100 cm, and 25.78±0.37 µGy at 150 cm. The scatter radiation distribution at 100 cm was the highest scattered dose. The operator should protect their reproductive gland, thyroid, and lens. The scattered dose was low behind the C-arm body and the bed, so they will be able to become the escaped area for staff.

Quantification of pulmonary perfusion using LSIM-CT correlates with pulmonary hemodynamics in patients with CTEPD.

Background: Lung subtraction iodine mapping (LSIM)-CT is a clinically useful technique that can visualize pulmonary mal-perfusion in patients with chronic thromboembolic pulmonary disease (CTEPD). However, little is known about the associations of LSIM images with hemodynamic parameters of patients with CTEPD. This study investigates a parameter of LSIM images associated with mean pulmonary arterial pressure (mPAP) and validates the association between pulmonary vascular resistance, right atrial pressure, cardiac index, and exercise capacity in patients with CTEPD. Methods: This single-center, prospective, observational study involved 30 patients diagnosed with CTEPD using lung perfusion scintigraphy. To examine the correlation of decreased pulmonary perfusion area (DPA) with mPAP, areas with 0-10, 0-15, 0-20, and 0-30 HU in lung subtraction images were adopted in statistical analysis. The DPA to total lung volume ratio (DPA ratio, %) was calculated as the ratio of each DPA volume to the total lung volume. To assess the correlation between DPA ratios of 0-10, 0-15, 0-20, and 0-30 HU and mPAP, Spearman's rank correlation coefficient was used. Results: The DPA ratio of 0-10 HU had the most preferable correlation with mPAP than DPA ratios of 0-15, 0-20, and 0-30 HU (ρ = 0.440, P = 0.015). The DPA ratio of 0-10 HU significantly correlates with pulmonary vascular resistance (ρ = 0.445, P = 0.015). The receiver operating characteristic curve analysis indicated that the best cutoff value of the DPA ratio of 0-10 HU for the prediction of an mPAP of ≥30 mmHg was 8.5% (AUC, 0.773; 95% CI, 0.572-0.974; sensitivity, 83.3%; specificity, 75.0%). Multivariate linear regression analysis, which was adjusted for the main pulmonary arterial to ascending aortic diameter ratio and right ventricular to left ventricular diameter ratio, indicated that the DPA ratio of 0-10 HU was independently and significantly associated with mPAP (B = 89.7; 95% CI, 46.3-133.1, P < 0.001). Conclusion: The DPA ratio calculated using LSIM-CT is possibly useful for estimating the hemodynamic status in patients with CTEPD.

T-5224, a selective inhibitor of c-Fos/activator protein-1, attenuates lipopolysaccharide-induced liver injury in mice.

The effect of T-5224, a selective inhibitor of c-Fos/activator protein (AP)-1, on lipopolysaccharide (LPS) induced liver injury was examined in mice. Administration of LPS (10 mg kg(-1), i.p.) markedly increased serum levels of tumor necrosis factor-alpha (TNFα), high mobility group box 1 (HMGB1), alanine aminotransferase/aspartate aminotransferase (ALT/AST), liver tissue levels of macrophage-inflammatory protein-1 alpha (MIP-1α) and monocyte chemoattractant protein-1 (MCP-1), as well as hepatic necrosis and inflammation, leading to 67 % lethality. Administration of T-5224 (300 mg kg(-1), p.o.) after intraperitoneal injection of LPS imparted appreciable protection against acute elevations in serum levels of TNFα, HMGB1, ALT/AST as well as in liver tissue levels of MIP-1α and MCP-1, and reduced the lethality (27 %). These data indicate that T-5224 ameliorates liver injury and improves survival through decreasing production of proinflammatory cytokines and chemokines in endotoxemic mice.

Computed tomography to identify risk factors for left circumflex artery injury during mitral surgery.

OBJECTIVES: Cases in which the left circumflex coronary artery (LCX) runs close to the mitral annulus are considered high risk for LCX injury during mitral surgery. We investigated the anatomical relationship between the LCX and the mitral annulus using 3-dimensional (3D) computed tomography (CT). METHODS: We constructed 3D-CT images of the LCX and the mitral annulus before surgery in 122 patients with mitral regurgitation (MR). We classified coronary dominance by 3D-CT and MR aetiologies (degenerative, atrial functional MR, ventricular functional MR and Barlow's disease) using echocardiography. We detected the point on the mitral annulus closest to the LCX (X point) and measured the minimum distance from the LCX to the mitral annulus (mCAD). We judged whether atrioventricular disjunction existed using CT. We also investigated the factors affecting mCAD and examined how coronary dominance and MR aetiologies relate to the location of the X point. RESULTS: The median mCAD was 4.2 mm (range 0.9-11.4 mm). Considering coronary dominance and MR aetiologies, mCAD was shorter in patients with left coronary dominance and Barlow's disease. The X point mostly existed on the lateral side of the posterior annulus, but it sometimes existed on the medial side. Multiple regression revealed left dominance and mitral annular disjunction as significant factors affecting mCAD (P = 0.01). CONCLUSIONS: The anatomical relationship between the LCX and the mitral annulus can be recognized using superimposed 3D-CT images. This approach is useful to avoid LCX injury in mitral valve surgery since the X point varies between patients.

Visualization of flow dynamics in the portal circulation using 320-detector-row computed tomography: a feasibility study.

Multidetector row computed tomography (CT) scanners perform dynamic scanning and have a wide scan range. Time-resolved three-dimensional CT (i.e., 4D CT) has recently enabled visualization of flow in neurovascular vessels. We hypothesized that 4D CT technology would be a useful and non-invasive method for visualizing the flow dynamics of the portal circulation. The aim of this study was to evaluate the technical feasibility of 4D CT for visualizing flow dynamics in the portal circulation using 320-detector-row CT. 4D CT images of 18 consecutive patients with portal circulation including gastrorenal shunt were retrospectively evaluated for their ability to generate flow dynamics of the portal circulation. Flow dynamics could be visualized by 4D CT in 68 of the 72 vessels in the portal vein, splenic vein, superior mesenteric vein, and gastrorenal shunt. Flow direction could not be identified in four vessels, all of them being superior mesenteric veins. Flow direction was recognized on 4D CT in the 68 vessels of the portal circulation. A preliminary validation study revealed that flow direction of all 19 vessels in the portal circulation had concordance between 4D CT and color Doppler ultrasound. 4D CT could visualize flow dynamics of the portal circulation.

Resting-state brain functional connectivity in patients with chronic pain who responded to subanesthetic-dose ketamine.

Ketamine has been used to treat chronic pain; however, it is still unknown as to what types of chronic pain is ketamine effective against. To identify the effect of administration of subanesthetic-dose ketamine in patients with chronic pain and to clarify the mechanism of the effect, we retrospectively investigated brain functional connectivity using resting-state functional magnetic resonance imaging (rs-fMRI). Patients were divided into responders (Group R: ≥50% improvement on Numerical Rating Scale) and non-responders (Group NR). We compared the differences in terms of brain functional connectivity by seed-to-voxel correlation analysis. Two-sample t-test revealed significant lower connectivity between the medial prefrontal cortex (mPFC) and precuneus in Group R. We also found a significant negative correlation between the improvement rate and functional connectivity strength between the mPFC and precuneus. These findings suggest that subanesthetic-dose ketamine is effective in patients with chronic pain whose brain functional connectivity between the mPFC and precuneus is low. We believe that the current study explored for the first time the correlation between brain functional connectivity and the effect of subanesthetic-dose ketamine for chronic pain and indicated the possibility of use of the predictive marker in pharmacological treatment of chronic pain.

A case of ventilatory impairment during per-oral endoscopic myotomy under general anesthesia.

ᅟ: We report a case of unexpected ventilatory impairment that occurred during per-oral endoscopic myotomy (POEM) under general anesthesia. A 73-year-old woman underwent POEM for Jackhammer esophagus. The patient developed hypercarbia, pneumoperitoneum, and severe subcutaneous emphysema during the operation. Although she was treated with abdominal paracentesis, it became difficult to ventilate her lungs a few minutes later. We recommended the surgeons to interrupt the procedure and proposed repeating the abdominal paracentesis. Simultaneously, we switched to manual ventilation and waited for the subcutaneous emphysema to subside. Thereafter, her respiratory status gradually improved and the surgeons were able to continue the operation. We considered that the main reason for our patient's severe ventilatory impairment was that the length of surgical dissection was longer than usual.

Anesthetic management and associated complications of peroral endoscopic myotomy: A case series.

AIM: To investigate the anesthetic management of peroral endoscopic myotomy (POEM) and its associated complications. METHODS: This study was a single-center, retrospective, observational study comprising a case series of all patients who underwent POEM in our hospital from April 2015 to November 2016. We collected data regarding patient characteristics, anesthetic methods, surgical factors, and complications using an electronic chart. RESULTS: There were 86 patients who underwent POEM in our hospital during the study period. Preoperatively, patients were maintained on a low residue diet for 48 h prior to the procedure. They were fasted of solids for 24 h before surgery. There was one case of aspiration (1.2%). During POEM, patients were positioned supine with the upper abdomen covered by a clear drape so that pneumoperitoneum could be timeously identified. In three cases, the peak airway pressure exceeded 35 cmH2O during volume controlled ventilation with tidal volumes of 6-8 mL/kg and subsequent impairment of ventilation. These cases had been diagnosed with spastic esophageal disorders (SEDs) and the length of the muscular incision on the esophageal side was longer than normal. CONCLUSION: In the anesthetic management of POEM, it is important to prevent aspiration during induction of anesthesia and to identify and treat complications associated with CO2 insufflation.

[Incidence and clinical characteristics of perioperative pulmonary thromboembolism under the use of intermittent pneumatic compression as a preventive measure].

Pulmonary thromboembolism (PTE) is a crucial complication characterized by rapid onset and a high mortality rate. There are few reports concerning perioperative incidence of PTE and deep vein thrombosis (DVT) among Japanese population. All surgical patients excluding young patients for minor surgery were equipped with calf- or thigh-length intermittent pneumatic compression (IPC) device as a DVT preventive method during the period of immobility. Incidence and clinical characteristics of perioperative PTE and DVT under the use of IPC device were analyzed at Kobe University Hospital. One patient developed DVT and four patients developed PTE among the 6500 surgical cases. All patients with DVT or PTE were 66 years or older, and all patients were diagnosed by computer tomography, venography and pulmonary angiography between 7 to 14 days after each operation. One patient was surgically treated by embolectomy and removal of intraarterial thrombus, and others were treated with thrombolysis, anticoagulants and placement of vena cava filters. For prevention of DVT and PTE, other preventive methods such as anticoagulants and prolonged application of IPC should be necessary.