N-Butyl Cyanoacrylate Embolization with Blood Flow Control of an Arterioportal Shunt That Developed after Radiofrequency Ablation of Hepatocellular Carcinoma

We present a case of a patient with rapid deterioration of esophageal varices caused by portal hypertension accompanied by a large arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma. We used n-butyl cyanoacrylate (NBCA) as an embolic material to achieve pinpoint embolization of the shunt, because the microcatheter tip was 2 cm away from the shunt site. Under hepatic arterial flow control using a balloon catheter, the arterioportal shunt was successfully embolized with NBCA, which caused an improvement in the esophageal varices.

Interferential electrical stimulation improves peripheral vasodilatation in healthy individuals

BACKGROUND: Interferential electrical stimulation (IES), which may be linked to greater penetration of deep tissue, may restore blood flow by sympathetic nervous modulation; however, studies have found no association between the frequency and duration of the application and blood flow. We hypothesized that 30 min of IES applied to the ganglion stellate region might improve blood flow redistribution. OBJECTIVES: The purpose of this study was to determine the effect of IES on metaboreflex activation in healthy individuals. METHOD: Interferential electrical stimulation or a placebo stimulus (same protocol without electrical output) was applied to the stellate ganglion region in eleven healthy subjects (age 25±1.3 years) prior to exercise. Mean blood pressure (MBP), heart rate (HR), calf blood flow (CBF) and calf vascular resistance (CVR) were measured throughout exercise protocols (submaximal static handgrip exercise) and with recovery periods with or without postexercise circulatory occlusion (PECO+ and PECO -, respectively). Muscle metaboreflex control of calf vascular resistance was estimated by subtracting the area under the curve when circulation was occluded from the area under the curve from the AUC without circulatory occlusion. RESULTS: At peak exercise, increases in mean blood pressure were attenuated by IES (p<0.05), and the effect persisted under both the PECO+ and PECO- treatments. IES promoted higher CBF and lower CVR during exercise and recovery. Likewise, IES induced a reduction in the estimated muscle metaboreflex control (placebo, 21±5 units vs. IES, 6±3, p<0.01). CONCLUSION: Acute application of IES prior to exercise attenuates the increase in blood pressure and vasoconstriction during exercise and metaboreflex activation in healthy subjects. .

Mechanisms of heat acclimation with endurance training in humans: a role of active cutaneous vasodilator / 体力科学

Hypovolemia and hyperosmolality due to thermal dehydration suppress thermoregulatory responses of sweating and cutaneous vasodilation in humans, resulting in increasing a risk of heat illness. Recently, we found in young and older subjects that an ingestion of carbohydrate-protein supplement immediately after a bout of exercise during training accelerated an increase in plasma volume and an improvement of thermoregulatory responses. These results suggest that change in plasma volume alters cutaneous vasodilation and sweat rate through baroreflexes; however, no electrical signals in the efferent path of the reflex loop have not been identified. We have recently successfully recorded skin sympathetic nerve signal components synchronized and non-synchronized with cardiac cycles, separately, in passively heated young subjects, and found that although both components increased with cutaneous vasodilation and sweat rate in hyperthermia, an increase in synchronized component was suppressed by hypovolemia with suppressed cutaneous vasidilation, while an increase in non-synchronized component was not suppressed as sweat rate. On the other hand, we found that hyperosmolality suppressed the increases of both components with suppressed cutaneous vasodilation and sweat rate. These results suggest that a synchronized component controls cutaneous vasodilation while a non-synchronized component controls sweat rate, and also that beat-by-beat changes in atrial pressure due to a fluctuation of venous return to the heart varies cutaneous vasodilation through baroreflexes but not sweat rate.