Benign prostatic hyperplasia: transcatheter arterial embolization as potential treatment--preliminary study in pigs.

PURPOSE: To prospectively evaluate the technical feasibility and safety of transcatheter arterial embolization (TAE) of the prostate in healthy pigs. MATERIALS AND METHODS: The study was approved by the institutional ethics committee for animal research. Sixteen large white male pigs were randomly assigned to the embolization group (n = 8) or control group (n = 8). Selective angiography was performed in all animals after general anesthesia was induced. In the embolization group, microspheres 500-700 microm in diameter were used to occlude the prostatic branches. Three months later, the animals' sexual function while breeding with female pigs was subjectively evaluated by using a three-point scale. At necropsy, the prostates were removed for size measurement and histopathologic examination. Paired Student t and Wilcoxon rank sum tests were used for statistical analysis. RESULTS: TAE was technically successful in all animals, without associated complications. The mean prostate volume after embolization was significantly (P < .001) reduced compared with the mean prostate volume for the group control. No significant difference (P = .328) in sexual function was noted between the two groups. Histologic examination revealed that the microspheres had occluded the arterioles of the prostate, with disappearance of the nearby partially normal gland structure and atrophy of the residual gland tissue. CONCLUSION: TAE of the prostate can induce shrinkage of the prostate without compromising the sexual desire and erectile function of animals. This finding suggests that TAE has potential as an alternative treatment for symptomatic benign prostatic hyperplasia in humans.

Endotracheal stenting therapy in dogs with tracheal collapse.

Tracheal collapse in dogs is a common respiratory disorder, typically presenting with a history of chronic cough, increasing respiratory difficulties, and episodes of dyspnoea. Medical treatment is the therapy of choice and surgical repair is considered when patients do not respond well. Minimally invasive endotracheal stenting is a promising new therapy under investigation, but there remain significant challenges to overcome potential complications. The purpose of this article is to provide a comparative overview of intra-luminal stenting of the trachea in human and veterinary medicine. The currently available stents and their potential clinical application to the veterinary patient will be discussed.

Blood micromolar concentrations of kaempferol afford protection against ischemia/reperfusion-induced damage in rat brain.

The slow time course of neurodegeneration after brain ischemia/reperfusion opened a realistic time window for the application of protective therapies to prevent spreading of brain damage. In this work, we studied the ability of micromolar concentrations of this flavonoid in the blood to protect against brain damage induced by transient focal cerebral ischemia in rats. Transient focal cerebral ischemia was induced by middle cerebral artery occlusion in adult rats and brain damage has been monitored by 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin-eosin (H-E) staining, 'in situ' terminal deoxyribonucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL), 'in situ' metalloproteinase activity using DQ-gelatin and loss of anti-laminin staining. Intravenous injections of kaempferol, at a dose of 10-15 mumol/L of blood 30 min before the induction of a 60 min ischemia-episode and just after reperfusion, led to >90% and 70-80% (TTC, H-E, TUNEL) decrease of brain damage in the temporal-frontal areas of neocortex and striatum, respectively, but only 40-50% decrease of brain damage was observed in the hippocampus and vicinal caudal areas of the striatum. This treatment with kaempferol also produced a similar reduction of metalloproteinase activation and loss of anti-laminin staining in cortical and striatum infarct areas. Kaempferol treatment efficiently protected against nitrosative-oxidative stress after ischemia/reperfusion, as shown by nearly complete protection against the increase of protein nitrotyrosines, and also afforded strong protection against the increase of apoptotic cell death (TUNEL) and biochemical markers of apoptosis, such as caspase-9 activity and poly-(ADP-ribose) polymerase degradation. On these grounds, a potential new therapeutic role of kaempferol to acute treatment of ischemic stroke is suggested.

The measurement of neurovegetative activity during anesthesia and surgery in swine: an evaluation of different techniques.

In this study we evaluated, in 10 sevoflurane-anesthetized pigs undergoing abdominal surgery, different techniques for measuring autonomic nervous system (ANS) activity: ANSiscope index, spectral analysis of heart-rate variability, hemodynamic variables, and plasma catecholamines and cortisol levels. Animals underwent a 120-min anesthesia during which unilateral ovariectomy was performed. Cardiovascular and respiratory responses were monitored. ANSiscope indices (ANSindex sympathetic, ANSindex parasympathetic and balANSindex) were used to monitor ANS activity. Spectral analysis was performed using an autoregressive model with a parametric method. The low frequency (LF) and high frequency (HF) components were used to interpret the power spectral density of short-term electrocardiograms (ECGs). The relationship LF/(LF+HF) reflects sympathetic activity, HF/(LF+HF) indicates parasympathetic activity, and the LF/HF ratio gives the predominance of the system. Plasma concentrations of adrenaline, noradrenaline, and cortisol were determined at different times. Correlation (P < 0.01) was found between the balANSindex and adrenaline levels and between LF/HF ratio and plasma adrenaline concentrations. Moreover, a significant (P < 0.01) correlation was found between the balANSindex and LF/HF ratio. However, no correlation was seen between the registered ANSiscope indices and hemodynamic variables. The correlation seen in this study suggests that the balANSindex could be a useful tool to monitor ANS activity during anesthesia and surgery.

Transfemoral selective "intraluminal wiring" technique for transient middle cerebral artery occlusion in rats.

While the intraluminal thread technique to induce middle cerebral artery occlusion is widely used in animal models of focal cerebral ischemia, it has several drawbacks. The present study describes a new technique involving transfemoral selective intraluminal wiring, and evaluates its technical feasibility, effectiveness, and safety. Twenty-four Wistar rats were used in this work: two for a vascular anatomy study and 22 subjected to middle cerebral artery occlusion for 1 h by our new transfemoral selective "intraluminal wiring" technique. After 24 h of reperfusion, the animals were evaluated neurologically, and then were sacrificed. Macroscopic, histological (2,3,5-triphenyltetrazolium chloride (TTC), hematoxylin-eosin and TUNEL), and biochemical (DNA fragmentation and caspase-3 activity) studies were performed to assess the extent of brain damage produced by focal ischemia. Technical success was obtained in all 22 animals. Signs of focal ischemia and reperfusion, such as necrosis and apoptosis, were detected in the middle cerebral artery territory. No subarachnoid hemorrhage was noticed in any animal. Transfemoral selective intraluminal wiring appears to be a reliable, safe, and minimally invasive technique to induce transient focal cerebral ischemia in rats.

Bispectral index, spectral edge frequency 95%, and median frequency recorded for various concentrations of isoflurane and sevoflurane in pigs.

OBJECTIVE: To evaluate bispectral index (BIS), spectral edge frequency 95% (SEF), and median frequency (MED) in relation to a visual analogue scale (VAS) as indicators of anesthetic depth for various concentrations of sevoflurane and isoflurane in pigs. ANIMALS: 32 pigs. PROCEDURE: Pigs were randomly allocated to 8 groups (4 pigs/group). An electroencephalogram (EEG) was recorded in each conscious pig. Pigs were then anesthetized by use of sevoflurane (n = 16) or isoflurane (16). Agents were administered in oxygen at minimum alveolar concentrations (MACs) of 1, 1.25, 1.5, and 1.75 MAC in a randomized order. End-tidal sevoflurane and isoflurane concentrations were maintained for 30 minutes, after which an EEG was recorded for 5 minutes; BIS, SEF, and MED were then calculated. Anesthetic depth was evaluated by use of the VAS. Cardiovascular and EEG responses to nociceptive stimuli were evaluated for each anesthetic agent. RESULTS: BIS decreased significantly for the various concentrations of each anesthetic. At equivalent MACs, BIS values were significantly higher during sevoflurane-induced anesthesia than during isoflurane-induced anesthesia. Values of MED and SEF decreased significantly from basal values to 1 MAC of sevoflurane and isoflurane. For both agents, there was good correlation between VAS scores and BIS values and between VAS scores and SEF values. CONCLUSIONS AND CLINICAL RELEVANCE: BIS was useful for predicting changes in anesthetic depth at clinical dosages of inhalant anesthetics. Values of BIS, SEF, and MED were significantly higher during anesthesia induced by administration of sevoflurane than during anesthesia induced by administration of isoflurance at equivalent MACs.

Continuous vagus nerve stimulation effects on the gut-brain axis in Swine.

Objectives. This study was designed to assess vagus nerve stimulation effects on the food intake pattern in swine and determine the electrical stimulus direction. Material and Methods. Fifteen Large White pigs were randomly divided into three groups, groups A-C. All animals underwent implantation of a vagus nerve stimulator at the gastro-esophogeal junction. In group A, the stimulation was switched off, whereas stimulation was switched on in groups B and C. Food intake and body weight were registered in groups A and B, but not in group C, which was used to measure direction of stimulation in the vagus and effect on heart rate and blood pressure. Variables measured in group C included the bispectral index, blood pressure, and heart rate. A Student's t-test and one-way analysis of variance were used to detect differences between groups. All animals were sacrificed to identify effects of implantation and stimulation on the vagus nerve. Results. With respect to food intake, there was no difference between groups A and B; however, body weight did register a continuous increase. During stimulation, in group C arterial pressures decreased significantly, whereas the heart rate and bispectral index increased. Conclusion. The stimulation protocol applied in this study was insufficient to cause changes in the feeding behavior of swine; however, it did increase central nervous system activity.

Subxiphoid access to normal pericardium with micropuncture set: technical feasibility study in pigs.

This study was performed with approval from the ethics committee for animal research of the local government. The purpose of the study was to evaluate the technical feasibility of a technique for subxiphoid access to the normal pericardial space with a micropuncture set in 10 large white pigs. With fluoroscopic guidance, a fine needle was inserted through a subxiphoid approach into the anterior mediastinal space to puncture the pericardium, and a micropuncture set was placed in the pericardial space successfully in all animals without complications. Necropsy at 24 hours did not reveal hemomediastinum, hemopericardium, or laceration of the pericardium. Results of the experiments in animals indicated that the technique was feasible and safe.