Vicinity Of Large Vessels Research Articles

Restriction of tamponation for purulent diseases

To enhance the outflow of pus, a gauze tamponade is usually used, but it is imperfect due to frequent drying in the skin opening, due to which a delay of pus is formed; in addition, with it, an injury is inflicted, accompanied by damage to the protective granulation shaft and soreness. Bier sees pain as nature's protest against tamponation; the latter is especially dangerous in the vicinity of large vessels and tendons, which can die with it.

The impact of “physiological correction” on functional connectivity analysis of pharmacological resting state fMRI

Growing interest in pharmacological resting state fMRI (RSfMRI) necessitates developing standardized and robust analytical approaches that are insensitive to spurious correlated physiological signals. However, in pharmacological experiments physiological variations constitute an important aspect of the pharmacodynamic/pharmacokinetic profile of drug action; therefore retrospective corrective methods that discard physiological signals as noise may not be suitable. Previously, we have shown that template-based dual regression analysis is a sensitive method for model-free and objective detection of drug-specific effects on functional brain connectivity. In the current study, the robustness of this standard approach to physiological variations in a placebo controlled, repeated measures pharmacological RSfMRI study of morphine and alcohol in 12 healthy young men is tested. The impact of physiology-related variations on statistical inferences has been studied by: 1) modeling average physiological rates in higher level group analysis; 2) Regressing out the instantaneous respiration variation (RV); 3) applying retrospective image correction (RETROICOR) in the preprocessing stage; and 4) performing combined RV and heart rate correction (RVHRCOR) by regressing out physiological pulses convolved with canonical respiratory and cardiac hemodynamic response functions. Results indicate regional sensitivity of the BOLD signal to physiological variations, especially in the vicinity of large vessels, plus certain brain structures that are reported to be involved in physiological regulation, such as posterior cingulate, precuneus, medial prefrontal and insular cortices, as well as the thalamus, cerebellum and the brainstem. The largest impact of "correction" on final statistical test outcomes resulted from including the average respiration frequency and heart rate in the higher-level group analysis. Overall, the template-based dual regression method seems robust against physical noise that is corrected by RV regression or RETROICOR. However, convolving the RV and HR with canonical hemodynamic response functions caused a notable change in the BOLD signal variance, and in resting state connectivity estimates. The impact of RVHRCOR on statistical tests was limited to elimination of both morphine and alcohol effects related to the somatosensory network that consists of insula and cingulate cortex-important structures for autonomic regulation. Although our data do not warrant speculations about neuronal or vascular origins of these effects, these observations raise caution about the implications of physiological 'noise' and the risks of introducing false positives (e.g. increased white matter connectivity) by using generalized physiological correction methods in pharmacological studies. The obvious sensitivity of the posterior part of the default mode network to different correction schemes, underlines the importance of controlling for physiological fluctuations in seed-based functional connectivity analyses.

Reply: Assessment of Hepatocarcinoma Response to Radiofrequency

We are grateful for the comments by Pompili et al. [1] concerning our work on hepatocellular carcinoma radiofrequency [2]. We found a low complete pathologic response rate of 46.7% and no significant difference between tumors with a diameter smaller or greater than 3 cm. Pompili et al. are disappointed by this fact since in their own experience [2] and that of others [3], nodes smaller than 3 cm have a higher pathologic response rate. It is logical to expect such correlation since the area of high temperature produced by the radiofrequency device can better pass over the boundaries of smaller tumors than those of larger nodes. However, that has not been our experience nor was it that of other investigators. Martin et al. [4] focused on this issue and they did not find any significant correlation between pathologic response and tumor size. Lu et al. [5] did not find clear differences when they stratified the nodes according to size and found only a marginal nonsignificant difference in tumors greater than 4 cm, with worse response. In other works there is no mention of any possible correlation between size and response [6, 7]. Concerning our own series, we can clarify that the aimed treatment volume was always greater than the lesion volume. Also, the procedure was performed with curative intent despite all the patients being candidates for transplant because of the uncertainty of how long they would be on the waiting list. The proportion of cases with tumors in the vicinity of large vessels was similar in patients with a tumor either smaller or larger than 3 cm in diameter. We have no explanation for this lack of correlation between pathologic response and node diameter, and we do not want to speculate. We admit, however, that a larger sample could show some difference, but for now we cannot change our conclusion that radiofrequency cannot be considered to be a radical or curative intent. This does not mean that radiofrequency is not useful, although it achieves only partial responses, because its use allows patients to stay on the transplant waiting list [8] and to reach long survival times without other therapies [9]. Finally, the American Association for the Study of Liver Disease recommendations [10] state that local ablation is safe and effective therapy for patients who cannot undergo resection is a bridge to transplantation. However, this statement does not imply that local ablation procedures can be considered as radical treatments.

European Survey on the Application of Vascular Clamping in Liver Surgery

Background: This study evaluated the frequency, the indications and techniques of vascular clamping during liver resection and during thermal destruction therapies, as currently used by hepatic surgeons throughout Europe. Methods: A web-based questionnaire was distributed among 621 physicians, including all members of the European Hepato-Pancreato-Biliary Association and the European Surgical Association. Results: The overall response rate was 50%. During liver resection, vascular clamping is never applied by 10%, on indication by 71%, and routinely by 19%. Routine clamping is particularly performed by high-volume and senior surgeons and appears to be associated with longer ischaemia times. Intermittent inflow occlusion is the clamping method of choice for more than 65% of surgeons and total ischaemia times are usually limited to 15–30 min. During thermal ablation, vascular clamping is never used by 57%, on indication by 37%, and routinely by 7%; it is particularly applied for large tumours and for tumours close to large vessels, and ischaemia times are shorter. Conclusions: Vascular clamping during liver resection is frequently used; during thermal ablation it is preserved for larger tumours or tumours in the vicinity of large vessels. Complete inflow occlusion is the most frequently used technique, with a distinct preference for intermittent clamping.