Bibek Chandra Sutradhar

Comparison of the cytotoxic effects of bupivacaine, lidocaine, and mepivacaine in equine articular chondrocytes

OBJECTIVE To compare the chondrotoxicity of bupivacaine, lidocaine, and mepivacaine in equine articular chondrocytes in vitro. STUDY DESIGN Prospective, experimental study. STUDY MATERIAL Equine articular chondrocytes. METHODS Primary cultured equine chondrocytes were exposed to 0.5% bupivacaine, 2% lidocaine, or 2% mepivacaine for 30 or 60 minutes. After treatment, cell viability was evaluated by trypan blue exclusion and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay in a dose dependent manner. Apoptosis and necrosis of chondrocytes were analyzed with the double staining of Hoechst 33258 and propidium iodide using fluorescence microscopy, and the results were confirmed using flow cytometry. RESULTS After 30-minute exposure, trypan blue exclusion assay revealed that cell viability of 0.5% bupivacaine group was 28.73±8.44%, and those of 2% lidocaine and 2% mepivacaine were 66.85±6.03% and 86.27±2.00%, respectively. The viability of chondrocytes after saline treatment was 95.95±2.75%. The results of MTT assay and fluorescence microscopy had similar tendency with trypan blue assay. Each result showed that bupivacaine was the most toxic of the three local anaesthetics. Mepivacaine was less toxic than lidocaine. The results of the viability test suggest that bupivacaine and lidocaine exhibit a marked chondrotoxicity, and that this is mainly due to necrosis rather than apoptosis. CONCLUSIONS AND CLINICAL RELEVANCE Bupivacaine may induce detrimental chondrotoxicity when administered intra-articularly, especially in patients with joint disease, and we suggest that it should be used cautiously in equine practice. Mepivacaine may be an alternative to both bupivacaine and lidocaine.

Comparison between open and closed methods of herniorrhaphy in calves affected with umbilical hernia

Umbilical hernias in calves commonly present to veterinary clinics, which are normally secondary to failure of the normal closure of the umbilical ring, and which result in the protrusion of abdominal contents into the overlying subcutis. The aim of this study was to compare the suitability of commonly-used herniorrhaphies for the treatment of reducible umbilical hernia in calves. Thirty-four clinical cases presenting to the Veterinary Teaching Hospital, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh from July 2004 to July 2007 were subjected to comprehensive study including history, classification of hernias, size of the hernial rings, presence of adhesion with the hernial sacs, postoperative care and follow-up. They were reducible, non-painful and had no evidence of infection present on palpation. The results revealed a gender influence, with the incidence of umbilical hernia being higher in female calves than in males. Out of the 34 clinical cases, 14 were treated by open method of herniorrhaphy and 20 were treated by closed method. Complications of hernia were higher (21%) in open method-treated cases than in closed method-treated cases (5%). Hernia recurred in three calves treated with open herniorrhaphy within 2 weeks of the procedure, with swelling in situ and muscular weakness at the site of operation. Shorter operation time and excellent healing rate (80%) were found in calves treated with closed herniorrhaphy. These findings suggest that the closed herniorrhaphy is better than the commonly-used open method for the correction of reducible umbilical hernia in calves.