Ultrasonographic Guidance (ultrasonographic + guidance)

Distribution by Scientific Domains


Selected Abstracts


Decreased portal flow volume increases the area of necrosis caused by radio frequency ablation in pigs

LIVER INTERNATIONAL, Issue 3 2007
Tsuyoshi Yoshimoto
Abstract Background/aims: Although radio frequency ablation (RFA) has been widely accepted as an effective treatment for hepatocellular carcinoma (HCC), severe complications are not uncommon. Major complications seem to occur as a result of over-ablation beyond the intended area. As most patients with HCC have underlying cirrhosis, we speculated that decreased portal flow might cause the necrosis associated with RFA. To confirm this hypothesis, we examined the area of necrosis resulting from RFA under varying conditions of portal flow in a porcine model. Methods: RFA was performed using ultrasonographic guidance in anesthetized pigs. During the RFA procedure, portal flow was regulated by a balloon catheter, which was set in a portal trunk. The necrosis area was measured after sacrifice and was compared with the hyperechoic area that appeared during ablation. In another session, RFA was performed close to the hepatic vein and endothelial damage was examined. Results: The necrosis area caused by RFA was significantly larger when the portal flow volume was decreased by 50% or more. The hyperechoic lesion was always larger than the area of pathological necrosis regardless of portal flow volume. Under conditions of decreased portal flow, the vessel endothelium near the ablated area was more readily damaged. Conclusion: Decreased portal flow volume resulted in enlargement of the area of necrosis caused by RFA. Our results indicate that over-ablation could easily occur in patients with advanced cirrhosis, and that this could lead to major complications. Ultrasonographic guidance may be helpful for avoiding over-ablation. [source]


Ultrasonographic guidance in pediatric regional anesthesia.

PEDIATRIC ANESTHESIA, Issue 11 2006
Part 2: techniques
Summary The benefits of regional anesthesia are well documented. The downsides of such techniques have been a significant failure rate and a potential for serious complications. Nearly, all regional blocks were first described as essentially ,blind' techniques. The development of high-resolution portable ultrasound (US) has made the use of US for regional anesthesia possible. Improved understanding of sonographic anatomy should lessen both the failure rate and the possibility of incurring serious complications. Natural caution has dictated that only a selection of blocks used in adults has been commonly used in pediatric practice, but with the aid of US, the repertoire of blocks for infants and children may be widened. The second part of this review will concentrate on the practice of both peripheral and central blocks. [source]


Ultrasound-guided training in the performance of brachial plexus block by the posterior approach: an observational study

ANAESTHESIA, Issue 10 2007
G. J. Van Geffen
Summary The application of ultrasonography in guiding and controlling the path of the stimulating needle to the brachial plexus via the posterior approach (Pippa technique) was studied. In 21 ASA physical status 1 and 2 patients, scheduled for surgery of the shoulder or upper arm, needle insertion was monitored by ultrasonography and the interaction between needle, surrounding structures and brachial plexus was followed. During injection, the spread of local anaesthetic was visualised and a prediction of block success was made. One failure was predicted. Complete block was achieved in 20 (95%) patients. One potential complication, puncture of the carotid artery, was prevented using ultrasound. Ultrasound is a useful tool in the training and performance of a neurostimulation-guided brachial plexus block by the posterior approach. Ultrasonographic guidance may prevent serious complications associated with this approach to the brachial plexus. [source]


Influence of liver copper status of mare and newborn foal on the development of osteochondrotic lesions

EQUINE VETERINARY JOURNAL, Issue 1 2003
P. R. van WEEREN
Summary Reason for performing study: To elucidate the highly contentious role of copper in the pathogenesis of osteochondrosis. Hypothesis: There would be no relationship between liver copper concentration of mares and foals and incidence of radiographically detectable osteochondrotic lesions in foals and yearlings was tested. Methods: Liver copper concentration was assessed in biopsies taken within 4 days after birth from both mares and foals and from the same foals at age 5 months. Biopsies were taken in the standing, sedated animal under ultrasonographic guidance. Radiographs were taken of both hocks (lateromedial, dorsoplantar and dorsomedial-plantarolateral oblique views) and stifles (lateromedial and caudolateral-craniomedial oblique views) at ages 5 and 11 months and scored for the presence and severity of osteochondrotic lesions. Results: Copper concentrations in newborn foals were high with a large variation (351 ± 201 mg/kg DM). They declined until reaching values comparable to those in mature animals at 5 months (20 ± 8 mg/kg DM; mares: 19 ± 20 mg/kg DM). Radiographic osteochondrotic lesions decreased in number and severity from 5 to 11 months. This pattern was more predominant in the stifle than in the hock, as has been described previously. Conclusions: There was no relationship between foal or mare liver copper concentration and osteochondrosis status at either 5 or 11 months. However, osteochondrotic lesions in foals with low-level copper status at birth decreased significantly less in number and severity than those in foals with high-level copper status at birth. Potential relevance: It is concluded that copper is not likely to be an important factor in the aetiopathogenesis of osteochondrosis, but this study indicates that there may be a significant effect of high copper status on the natural process of repair of early lesions. [source]


Decreased portal flow volume increases the area of necrosis caused by radio frequency ablation in pigs

LIVER INTERNATIONAL, Issue 3 2007
Tsuyoshi Yoshimoto
Abstract Background/aims: Although radio frequency ablation (RFA) has been widely accepted as an effective treatment for hepatocellular carcinoma (HCC), severe complications are not uncommon. Major complications seem to occur as a result of over-ablation beyond the intended area. As most patients with HCC have underlying cirrhosis, we speculated that decreased portal flow might cause the necrosis associated with RFA. To confirm this hypothesis, we examined the area of necrosis resulting from RFA under varying conditions of portal flow in a porcine model. Methods: RFA was performed using ultrasonographic guidance in anesthetized pigs. During the RFA procedure, portal flow was regulated by a balloon catheter, which was set in a portal trunk. The necrosis area was measured after sacrifice and was compared with the hyperechoic area that appeared during ablation. In another session, RFA was performed close to the hepatic vein and endothelial damage was examined. Results: The necrosis area caused by RFA was significantly larger when the portal flow volume was decreased by 50% or more. The hyperechoic lesion was always larger than the area of pathological necrosis regardless of portal flow volume. Under conditions of decreased portal flow, the vessel endothelium near the ablated area was more readily damaged. Conclusion: Decreased portal flow volume resulted in enlargement of the area of necrosis caused by RFA. Our results indicate that over-ablation could easily occur in patients with advanced cirrhosis, and that this could lead to major complications. Ultrasonographic guidance may be helpful for avoiding over-ablation. [source]


Double-blind, placebo-controlled study to evaluate the efficacy and safety of botulinum toxin type A in the treatment of drooling in parkinsonism

MOVEMENT DISORDERS, Issue 6 2003
Francesca Mancini MD
Abstract Drooling is a frequent symptom in Parkinson's disease (PD), occurring in almost 75% of all patients. Although it is now well known that drooling in PD is the result of swallowing difficulties rather than excessive saliva production, few treatments have been developed to reduce it. Clinical studies suggest that botulinum toxin A (BTX) injections into salivary glands are effective in decreasing drooling in PD patients. In this double-blind, placebo-controlled study, 20 patients with parkinsonism (idiopathic PD or multiple system atrophy), were randomly assigned to receive 450 U of BTX (Dysport; Ipsen, Berkshire, UK) or 2 ml of placebo, injected into the parotids and submandibular glands under ultrasonographic guidance. Treatment efficacy and safety were assessed at baseline, 1 week and 3 months after BTX injections using clinical scales (Drooling Severity and Drooling Frequency scales) and side effects surveillance. After treatment, the average secretion of saliva in the BTX group was significantly lower than in the placebo group, as appraised by clinical measurements. No side effects were observed in either group. BTX injection into parotids and submandibular glands, under ultrasonographic guidance, is an effective and safe treatment for drooling in parkinsonism. © 2003 Movement Disorder Society [source]


Percutaneous radiofrequency ablation of liver cancer in the hepatic dome using the intrapleural fluid infusion technique

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 8 2008
Y. Kondo
Background: Intrapleural fluid infusion improves ultrasonographic visualization of tumours in the hepatic dome. The aim of this study was to assess the safety and long-term efficacy of ultrasonographically guided percutaneous radiofrequency ablation for tumours in the hepatic dome with intrapleural infusion. Methods: Of 2575 patients with hepatocellular carcinoma or hepatic metastases treated with radiofrequency ablation, intrapleural fluid infusion was performed in 587 patients for tumours in the hepatic dome. After the tip of a 14-G metallic needle was positioned in the pleural cavity under ultrasonographic guidance, 500,1000 ml of 5 per cent glucose solution was infused in 5,15 min. Radiofrequency ablation was performed using an internally cooled electrode. Long-term results were evaluated in 347 patients with a single hepatocellular carcinoma who were naive to any treatment. Results: Intrapleural fluid infusion was successfully performed in all 587 patients. The major complication rate on a per tumour basis was similar for patients treated with and without intrapleural infusion (1·6 versus 1·6 per cent; P = 0·924). The overall and recurrence-free survival were both similar for naive patients with a single hepatocellular carcinoma treated with and without intrapleural infusion (P = 0·429 and P = 0·109 respectively). Intrapleural infusion was not associated with lower overall survival in multivariable analysis. Conclusion: With intrapleural fluid infusion, radiofrequency ablation for tumours in the hepatic dome was safe and effective, resulting in satisfactory overall and recurrence-free survival. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]