Hepatic retractor in an ex vivo model

Abstract Purpose: To discuss the use of models of hepatic retraction by laparoscopy, to present a new Hepatic Retractor (HR) and to evaluate its practicality, efficacy and safety in Esophageal Hiatus Exposure (EHE). Methods: Experimental cross - sectional study with a quantitative character. It was carried out in the Laboratory of Health Training of Christus University Center. The sample consisted of 12 livers of adult pigs weighing between 30 and 45 kg. A circular-shaped HR, 5 cm diameter and deformable materials was developed with a polypropylene cloth, metallic guide wire, epidural needle plastic guide and nylon string. The practicality of HR management was measured by the time required to use the instrument, efficacy by exposure to the operative field and safety by macroscopic assessment of liver damage. Results: The average time to complete the procedure was 3.24 minutes and reached less than 2 minutes after 12 repetitions. In eight experiments the maximum degree of EHE was obtained. No macroscopic lesions were observed. Conclusion: The use of HR described can broaden the operative field, without causing macroscopic liver lesions and prolonging the surgical time.

Possible analgesic effect of vigabrin in animal experimental chronic neuropathic pain

Since anticonvulsants have been used for treating neuralgias, an interest has arisen to experimentally test vigabatrin for its gabaergic mechanism of action. For this, 41 Wistar rats were used, and in 25 of them a constractive sciatic neuropathy was induced (Bennet & Xie model). For testing pain symptoms, spontaneous (Scratching) and evoked behaviors to noxious (46 degrees Celsius) and non-noxious (40 degrees Celsius) thermal stimuli were quatified. Moreover, a comparative pharmacological study of vigabatrin with other analgesic anticonvulsant drugs was also performed. The results showed a possible dose-dependent analgesic effect of vigabatrin (gamma-vinyl-GABA) on experimental neuropathic pain, as shown vy the significant (p<0.05) decreasing effect of vigabatrin on scratching and by its significant (p>0.05) increasing effect on the latency of the right hindpaw withdrawal of the animals to noxious thermal stimulus. This was corroborated by similar findings with analgesic anticonvulsants (carbamazepine, phenytoin and valproic acid). This possible and not yet described analgesic effect of vigabatrin seems not to be opioid mediated.