A protocol for the reduction of applied torque on parent vessel duringelastase-induced aneurysm formation using rabbit animal models

Endovascular therapies for intracranial aneurysms requires animal models for testing the safety andeffectiveness prior to translation to the clinic. Rabbits combined with the elastase and right commoncarotid artery (RCCA) ligation methods is currently a widely used animal model for endovascular de-vice testing. However, the injection of elastase utilizing angiocatheters may potentially exerts adversetorque to the parent vessel and the optimal aneurysm creation period has not been well investigated.In this study, we present a modification to the elastase/RCCA-ligation method by replacing the angio-catheter with a butterfly catheter. Formation of saccular aneurysms was introduced in New Zealandwhite rabbits (n=6), and were maintained for 2, 4 and 6 weeks. The formed aneurysms exhibitedan elongated geometry and were stable during the study period. We found that the modification inthe animal surgery procedure provides improved manipulation of the surgical area, prolonged injec-tion of elastase, and effective degradation of the vascular elastic lamina. Compared to the traditionalelastase/RCCA-ligation method, the present technique can more effectively reduce unwanted injury tothe parent vessel and, therefore, improved stability of the vasculature for testing the efficacy of newlydeveloped endovascular embolization devices.

Contamination of Gloved Hands by Multidrug Resistant Bacteria ‎During Small Animal Surgery Wet-labs and its Potential Implication for ‎Occurrence of Surgical Site Infections

This study was carried out to evaluate the level of asepsis at various stages of the surgical procedures during the undergraduate students’ wet-lab sessions. Skin and/or wound swabs were collected from different wet lab groups, sessions and stages. The swabs were processed for bacteriological isolation using standard microbiological procedures. A total of 62 isolates of bacteria belonging to 8 genera: Staphylococcus (n=38), Streptococcus (n=1), Corynebacterium n=4), Escherichia (n=7), Proteus (n=8), Klebsiella (n=2), Serratia (n=1) and Acinetobacter (1), were isolated. The most commonly isolated species of bacteria were Staphylococcus equorum (n=31) and Proteus spp. (n=7), which were detected in swabs from ungloved and gloved hands of surgeon and his assistant, patient’s surgical sites and surgical site infections. All the isolates (Gram-positive and negative) were resistant to at least one antibiotic with resistance to the β-lactam antibiotics: ampicillin (89.3% and 100% and amoxicillin (75% and 100%) most observed. The bacteria were more susceptible to doxycycline (75%) and imipenem (87.5%) respectively. Majority of the isolates (83.3%, n=30) were multidrug resistant, presenting in one of 24 different multidrug resistance patterns. The detection of these bacteria from the normally aseptic surgical procedure indicates a break in asepsis. Similarly, the danger of spreading multidrug resistant bacteria to the surgical wounds may result in wound infection, dehiscence, delayed healing and increased cost of post-surgical management. It is recommended that adherence to stringent pre-surgical and intra-surgical asepsis should be observed.

Common Sources of Pre-, Peri- and Post Surgical Site Infections (SSI) in Dogs during Clinical Students’ Surgical Practice

Surgical site infections (SSI) are important complication of Veterinary surgery. Pre, intra-, and post-surgical procedures are considered to be associated with SSI. An attempt to characterize veterinary SSI in small animal surgery practical was made. 15 dogs were grouped into 5 groups (with each group consisting of 3 dogs), in which skin-defect correction, caudectomy, cystotomy, orchidectomy, or ovariohysterectomy were performed by veterinary students under the guidance of qualified surgeons. Blood samples were obtained pre- and post-surgery. 120 swabs were taken from the following sites; students’ or surgeons’ hands (pre-/post-scrubbing), surgical tables, dog skin, random areas on surgical packs, kennels, and floors of surgical theatre. The microorganisms isolated were as follows; Staphylococcus aureus, Klebsiella spp, Micrococcus luteus, Enterobacter spp, and Bacillus subtilis, with Klebsiella being the highest. Leukocytosis, neutrophilia, monocytosis, increased bands, leukocytopenia, neutropenia, and lymphopenia were observed, with all being signs of infection. This study showed that the sources of SSI were numerous, including the followings; the dogs’ skin microflora, the students’ hands, surgical theater, surgical team, and the kennel. Proper scrubbing techniques should be adopted and maintained. The sterile field created should be kept and proper disinfection of the kennel should be ensured before returning the dogs after surgery.