Animal Surgery Research Articles

161-LB: Inhibition of Kidney SGLT2 Expression following Bariatric Surgery in Mice

Background: Bariatric surgery is known to improve glucose tolerance and weight loss, but can also cause a postprandial increase in renal glucose excretion following oral glucose tolerance test. Both effects have also been observed following treatment with sodium glucose co-transporter 2 (SGLT2) inhibitors. Aim: To investigate whether there is an effect of bariatric surgery (Vertical Sleeve Gastrectomy; VSG) on renal SGLT2 expression in mice. Methods: Fourteen lean mice underwent VSG (n=8) or sham (n=6) surgery. Glucose Tolerance tests with or without treatment with the SGLT2 inhibitor dapagliflozin were performed four weeks post operatively, in order to assess if exogenous SGLT2 inhibition has the same euglycemic effects as bariatric surgery. Kidneys were harvested from fed mice and analysed using Quantitative real-time PCR (qRT-PCR) and immunofluorescence. Results: VSG did not cause any weight loss when compared to sham operated mice (p=0.37, Mann-Whitney test). However, VSG mice displayed significantly improved glucose tolerance (AUC=103 ±6.8; AUC =66.6 ±2.9 in control and VSG mice, respectively; p<0.001), which was not further affected by dapagliflozin (10 mg/kg; p>0.05). In contrast, treatment of sham mice with dapagliflozin increased glucose tolerance, though to a lesser extent than VSG. Nevertheless, qPCR and immunofluorescence analysis on mouse kidneys demonstrated a significant lowering of SGLT2 expression at both the protein (n=5, p=0.0007) and mRNA (n=7, 0<0.0001) levels four weeks after VSG. Correspondingly, glycosuria was observed in 2/5 VSG mice, but not in controls. Conclusions: Both gastric and intestinal surgery in lean animals causes a significant inhibition of SGLT2 in the kidney cortex. These findings are in line with our previous results on the effects of Duodenal Jejunal Bypass in lean rats, and point towards a physiologically-relevant gut-kidney axis. SGLT2 inhibition may thus be an important mechanism through which bariatric surgery improves glucose tolerance in man. Disclosure E. Akalestou: None. L. Lopez Noriega: None. P.L. Chabosseau: None. I. Leclerc: None. G.A. Rutter: Consultant; Self; Sun Pharma. Funding UK Wellcome Trust

The Respiratory Function Grading Scheme: what’s it all about?

The Kennel Club and the University of Cambridge have devised the respiratory function grading scheme designed to advise owners if their dog is affected by BOAS and give guidance to breeders on how to lower the risk of producing affected puppies. Jane Ladlow, Senior Lecturer in Small Animal Surgery at Cambridge, explains what the scheme entails.

Suture length to wound length ratio for simple continuous abdominal closures in veterinary surgery: An experimental in vitro study.

ObjectiveThis study aimed to investigate the suture length to wound length ratio (SL:WL) in an in vitro model of abdominal wall closure. Effects of the surgeon’s experience level on the SL:WL ratio were evaluated, hypothesizing that small animal surgeons do not spontaneously apply SL:WL ratios equal to or larger than 4:1.ProceduresThree groups of surgeons with varying levels of experience performed 4 simple continuous sutures before (3 sutures) and after (1 suture) being educated on principles of the SL:WL ratio. All sutures were evaluated for their gaping, number of stitches, stitch intervals, tissue bite size and suture length.ResultsNo significant differences in suture parameters or SL:WL ratios were found among the 3 groups, and 60.5% of control sutures and 77.0% of test sutures had SL:WL ratios above 4:1. There was a significant improvement in the mean ratio after the information was provided (p = 0.003). Overall, the SL:WL ratios ranged from 1.54:1 to 6.81:1, with 36.3% falling between 4:1 and 5:1 (5.17 mm mean stitch interval, 5.52 mm mean tissue bite size). A significant negative correlation was observed between the SL:WL ratio and the stitch interval to tissue bite ratio (r = -0.886). Forty-nine of 120 sutures fulfilled the current recommendations for abdominal wall closure with a mean SL:WL ratio of 4.1:1.ConclusionA SL:WL ratio larger than 4:1 was achieved in 60% of the control sutures and in 77% of test sutures. Additional animal studies are necessary to evaluate the SL/WL ratio in small animal surgery.

Survey of instructor and student impressions of a high-fidelity model in canine ovariohysterectomy surgical training.

To evaluate the usefulness of a high-fidelity model for teaching ovariohysterectomy (OHE) to veterinary students. Longitudinal survey. Clinicians with ≥2 years postgraduate experience in small animal surgery and a sophomore veterinary student population at 1 institution. Twelve clinicians evaluated the high-fidelity model for realism. Questionnaires were distributed to sophomore veterinary students prior to and after OHE training on the high-fidelity model (SynDaver Surgical Canine) and after performing OHE as primary surgeon with a live dog. Time for students to perform OHE (identify the first ovarian pedicle to transecting the uterine body) and number of technical errors (visceral injury, hemorrhage, loose ligatures) were compared between the model and live dog groups. Evaluators rated the high-fidelity model as moderate-to-highly realistic. Students' confidence improved after practicing on the model in all critical steps and additionally improved after performing an OHE on a live dog. Time to complete the OHE on the model (mean ± SD,73.4 ± 27.1 minutes) and live dogs (83.0 ± 24.7 minutes) did not differ (P = .20). Frequency of hemorrhagic events (P = .77) and accidental visceral injury (P = .30) did not differ between the model and live dogs. However, fewer loose ligatures were placed in live dogs (23/64) compared with the model (22/37; P = .02). The high-fidelity model improved the confidence of sophomore students. The duration of OHE did not differ between the model and live dogs. The high-fidelity model is valuable for improving confidence in veterinary students prior to live-dog OHE.

Femoral and tibial alignments in chihuahuas with patellar luxation by radiograph: Angular values and intra- and inter-observer agreement of measurements.

Measurement of fore and pelvic limb alignment in veterinary orthopedics is significant, as it is in human medicine. The establishment of reference ranges for alignments and comparing measured ranges in diseased animals to these reference values would allow veterinarians to specify the quantitative degree of an angular deformity, plan suitable treatments and evaluate treatment outcomes. Patellar luxation is a common orthopedic disease in small animal clinics. Severe grades of MPL may present with bone deformities or abnormal alignments; therefore, evaluation of the measurement methods of femoral and tibial alignment in dogs with different grades of patellar luxation to assess the accuracy and reliability of the measurements could be useful. In this retrospective study radiographs of 21 client-owned Chihuahuas that had been presented to the Small Animal Surgery of Vetmeduni Vienna from 2012–2016 with a diagnose of patellar luxation were selected. The measurements were performed on frontal, lateral and axial view radiographs to determine the femoral and tibial angles and to evaluate the intra- and inter-observer variabilities of the protocol. Radiographs of each dog were investigated by three observers. Intra-observer variability was based on measurements by each observer who repeated the protocol two times to evaluate repeatability. Inter-observer variability was based on the measurements between the three observers to evaluate the reproducibility of the protocol. The results of the study showed that 92.85% of inter-observer ICC (intra-class correlation coefficient) had high correlation, and the remaining 7.15% had good correlation. Intra-observer ICCs for measurements of the first observer were 28.57% high correlation and 50% good correlation. For the second observer, 100% high correlation was recorded, and for the third observer 71.42% high correlation and 14.28% good correlation was recorded. These results show that the selected methods have high correlation and could be used as a reliable method in veterinary orthopedics.

Sevoflurane enhanced the clearance of Aβ1-40 in hippocampus under surgery via up-regulating AQP-4 expression in astrocyte

The neurotoxicity of anesthetics on developing brain has been a focused issue for years. However, controversy exists between human and animal studies and surgery may be a potential reason for this. The discovery of glymphatic system, a pathway eliminating soluble substance from central nervous system (CNS), together with recent evidence that surgery-induced Aβ increase contributes to cognition dysfunction made us rethink about the influence of anesthetics on cognitive function. The function of glymphatic system was proved to be enhanced by sleep and sedation, so we assumed that under clinical situation Aβ1-40 whose accumulation played important role in cognitive dysfunction was increased by surgery and eliminated from CNS by glymphatic system. The function of glymphatic system is facilitated by aquaporin-4 (AQP-4), a water channel expressed in highly polarized manor in astrocytic endfeet, whose transcription is regulated by nuclear factor of activated T cells 5 (NFAT5). Our results suggest that under brief operation and sevoflurane exposure, surgery may be the main cause of Aβ increase and sevoflurane increase the elimination of Aβ by up-regulating AQP-4 which is the key component in glymphatic system.

Effect of propofol on the haematological profile of pregnant Red Sokoto does

Introduction: Propofol (Diprivan®) is now a mainstay drug during anaesthesia in human and small animal surgeries and this is as a result of its good quality anaesthesia, rapid onset, and short duration of action with rapid recoveries. There is paucity of information in Nigeria as per the use of general anaesthesia to carry out procedures in pregnant red Sokoto Does. The aim of this study is to assess the haematological profile of pregnant red Sokoto doe following propofol anaesthesia and also ascertain the safety of the drug during gestation. Methods: Ten apparently healthy pregnant Red Sokoto does were used for this study. The animals were acclimatised for two weeks and pregnancy was diagnosed using B-mode Real time® transcutaneous ultrasonography. The animals were grouped into two (A and B) comprising five animals each in their first and second trimesters respectively. Propofol at 4 mg/kg and 5 mg/kg was administered to the does in groups A and B respectively. Blood samples were collected via the jugular vein and analysed using full automated blood counter (Ehmma® PCE 210). Results: The result showed that the onset and duration of propofol anaesthesia at the two doses in both groups were smooth and rapid without much excitation. There were no significant (p < 0.05) differences in the blood parameters in both group when compared with the control. Significance: Our study lends credence to the fact that propofol anaesthesia is suitable and safe anaesthetic agents for induction and maintenance of general anaesthesia in pregnant red Sokoto does.

Study on optogenetics technology and the design of its script for virtual simulation experiment

Optogenetics is one of the biggest breakthroughs in neurobiology in recent decades, which is a revolutionary approach to precise intervention of specific cell functions through the combination of optical and genetic engineering techniques. However, this technique involves the interdisciplinary theoretical knowledge and methods, and it requires expensive equipments and long experimental period. Thus, it is not convenient to carry out widely in experiment teaching for undergraduates except the virtual simulation teaching. In present virtual simulation experiment, we aim to learn the basic principle, operation and application of optogenetics and achieve the desired teaching effects by simulating the process of the virus package, simulating the process of the animal selection, surgery and virus stereotactic microinjection, simulating the expression process of photosensitive channel, the extracellular verification process of photosensitive channel function in vivo, and simulating the observation process that optogenetic inhibition of glutamate neurons in the amygdala affect animal fear behavior. In this paper, the content design of the script making of the virtual experiment has been discussed in the above ways. Key words: Virtual simulation experiment; Experimental teaching; Optogenetics; Script

Survey of clinician and student impressions of a synthetic canine model for gastrointestinal surgery training.

To evaluate the perceived efficacy of a high-fidelity synthetic canine model for simulating common gastrointestinal surgical procedures. Survey of students and experienced clinicians. Twelve clinicians with >2 years of postgraduate experience in the field of small animal surgery and 102 senior year veterinary students. The model was subjectively evaluated by 12 clinicians with >2 years of postgraduate experience in the field of small animal surgery. Senior year veterinary students (n = 102) were asked to complete questionnaires before and after a laboratory on common gastrointestinal surgical procedures that included rating of perceived proficiency, anatomical knowledge, and the use of synthetic models compared with live animals. Clinicians assessed most aspects of the model as moderately realistic and unanimously agreed that it would be helpful for students to train on this model prior to live surgery. Student survey response rates were 91% and 99% before and after the laboratory, respectively. The proportion of students that felt moderately-to-highly proficient with the procedures increased from 8% prior to the laboratories to 59% after the laboratories (P < .001). The proportion of students that felt that they had superior-to-excellent knowledge of abdominal surgical anatomy increased from 16% prior to the laboratories to 44% after the laboratories (P < .001). The proportion of students that were satisfied with synthetic models instead of live animals increased from 52% prior to the laboratories to 74% after the laboratories (P = .014). Experienced clinicians considered the model to have moderate realism. A positive shift in the students' self-perceived proficiency with gastrointestinal surgery was evident after the use of the model. This synthetic model should be considered for training of veterinary gastrointestinal surgery. However, comparison studies are recommended to ascertain the relative educational value of this model.

In vitro security of 3 surgical knots placed by novice veterinary students.

To determine the most secure knot when tied by veterinary students in a ligation model. Prospective study. Sixteen first-year veterinary students. Veterinary students were taught 3 knots: surgeon's, Miller's, and strangle. After having demonstrated competence, students tied each knot twice in a vascular ligation model at physiologic pressure. The system was tested for completeness of occlusion and volume of fluid lost over 10 seconds. Time, reattempts, repositioning, correctness, and difficulty score were documented. Students were surveyed before and after training regarding their experience. Students correctly tied 75% of all knots and achieved complete occlusion of the model with 56% of knots. No difference was identified among knot types in correctness, difficulty, complete occlusion, or time to construct the knot. The first surgeon's knot placed by students had more fluid loss than the Miller's knot, but this was not true of the second knot. Incomplete occlusion was common among all knot types, but students generally achieved similar knot security when placing surgeon's, Miller's, and strangle knots on a model. More surgeon's knots failed catastrophically during the first attempt, evidenced by a greater volume of fluid loss. This study does not provide evidence to recommend any of the 3 tested knots as superior to the others to improve the security of ligatures during surgeries performed by students. The prevalence of incomplete occlusion among student knots illustrates the requirement for education regarding knot security and vigilant monitoring of students performing live animal surgeries.

3D-printed Wash Station with Integrated Anesthesia Delivery Manifold for High-throughput Depilation of Laboratory Mice.

Depilation (that is, hair removal) is a necessary prerequisite for many small animal surgeries and optical imaging experiments. Over-the-counter depilatory creams are widely used, owing to their efficacy, safety, and low rates of skin irritation and infection. However, the use of these creams is generally messy and time-consuming and generates considerable waste. Furthermore, the process itself varies markedly among laboratories. Here we present a 3D-printed device that simplifies the depilation procedure by integrating 3 key elements: 1) a multiple-port, self-scavenging anesthesia manifold, 2) curved animal holders with flow-through slats, and 3) a removable waste collection tray. Reflecting insights gained from an international survey about depilatory lab procedures that highlighted the lack of standardized protocols, this apparatus is designed to improve the neatness, throughput, and safety of mouse depilation, resulting in efficient and repeatable processes that bolster the welfare of both researchers and subjects.

Retrospective evaluation of perioperative and short term clinical outcomes in appendicular long bone skeleton fractures repaired via the string of pearls (SOP) locking plate system

BackgroundInternal plate fixation and, more recently, locking plate fixation are commonly used in the repair of fractures in small animal surgery. This retrospective study reviewed the use of the String of Pearls locking plate system in the fixation/repair of appendicular long bone skeleton fractures in 31 small animal veterinary patients (33 fractures).ResultsMajor complications necessitating revision surgery occurred in 7/33 (21%), with implant failure as the inciting cause in all cases. Variables corresponding to an unsuccessful outcome were evaluated, and a correlation was found with plates placed in a bridging manner (placed without rigid anatomic reconstruction, p = 0.02) and length of follow-up (p = 0.01).ConclusionsThe SOP plating system can be used in the repair of appendicular longbone skeletal fractures, however, the authors propose that adjunct fixation, such as intramedullary pin, double plating, or external coaptation would likely improve results and should be considered imperative in cases in which anatomic reconstruction is either not desirable or achievable.

Reactive seizures in cats: A retrospective study of 64 cases

Epileptic seizures are a common indication for neurological evaluation. This retrospective study reviewed 789 cats referred for epileptic seizure evaluation to the Department of Small Animal Medicine and Surgery of the University of Veterinary Medicine in Hannover, between 1998 and 2017. The aim of this study was to determine common causes for reactive seizures (RS) in cats.Reactive seizures were diagnosed in 62 (7.9%) of 789 feline patients. The most common cause of RS was presumptive or confirmed intoxication (n=34/62; 54.8%). Toxins included permethrin (n=5/62; 8.1%), fipronil (n=1/62; 1.6%), and pesticide (n=1/62; 1.6%). Other common causes were hepatic and renal encephalopathy (n=6/62; 9.7% each), hypertension (n=5/62; 8.1%), hyperthyroidism (n=3/62; 4.8%), hypoglycaemia (n=3/62; 4.8%), and hyperglycaemia (n=1/62; 1.6%). Most commonly, cats with RS presented with generalised tonic–clonic seizures (n=25/62; 40.3%). A single status epilepticus was observed in 9.7% (n=6/62) and 4.8% (n=3/62) presented only with cluster seizures. Focal seizures were the only presenting sign in 3.2% (n=2/62) of cases, however in 4.8% (n=3/62) they were accompanied by tonic–clonic seizures. The mean age of all cats presented for RS was 10.8 years. In the intoxication group, the mean age was 2.9 years. Intoxication (confirmed or presumptive) was the most common cause of RS identified. Clinicians should suspect intoxication when other causes of RS are excluded; when there are appropriate historical findings; when the cat is frequently unobserved by the owner; when symptomatic treatment leads to cessation of epileptic seizures; and when seizures do not recur after treatment has been discontinued.

Dorsal Laminectomy to Correct Spinal Stenosis in a Sulcata Tortoise (Centrochelys Sulcata) with Severe Carapacial Pyramiding

Case description: An approximately 17-year-old male African spurred tortoise (Centrochelys sulcata) was presented to the small animal surgery service for loss of pelvic limb motor function of 1-month duration and a lack of response to medical management. Clinical findings: On physical examination, significant carapacial osteoderm pyramiding with a large depression at the level of the fourth vertebral scute was noted. Results of serial neurologic examination revealed nonambulatory paraparesis that progressed to superficial pain positive paraplegia and absent cloacal tone. Both thoracic limbs were within normal limits on neurologic evaluation. A complete blood cell count and biochemistry profile revealed anemia, hyperuricemia, and monocytes containing intracellular bacteria. On computed tomography examination, stenosis and deviation of the spinal column was noted to be causing compression at the level of the fourth vertebral osteoderm. Treatment and outcome: A dorsal laminectomy was performed to relieve the spinal cord compression after removing a rectangular section of carapace. Immediately following surgery, the tortoise was noted to have significant cloacal tone. Unfortunately, the tortoise succumbed to suspected sepsis and toxemia within 48 hours of surgery. Clinical relevance: Carapacial pyramiding is commonly reported in captive tortoises. The changes noted in the carapace are attributed to inappropriate environmental conditions and diet. This case represents the first report of spinal canal and spinal cord stenosis in a tortoise secondary to carapacial pyramiding. The findings in this report suggest that dorsal laminectomy may be a viable treatment option in chelonians with spinal cord compression and neurologic deficits when indicated by clinical presentation.

Pierre M. Montavon (1949-2018).

I remember very well a difficult period at the Vetsuisse Faculty University of Zurich, Switzerland, when Pierre Montavon, already Professor of small animal surgery, felt cheated by the board of directors of the faculty. The financial sources were shortened for his clinic and a team room was assigned to another clinic. Pierre took out his pirate flag and it waved from the window of his office for some weeks, demonstrating that he would not accept the decision, but would follow his own way.

Antimicrobial prophylaxis

Perioperative antibiotics have been recommended in small animal surgery for decades. With the increasing importance of antibiotic stewardship in managing antimicrobial resistance, Professor John Williams, of Vets Now 24/7 Emergency Hospital in Manchester, guides Companion readers through when and why they should be used, and what dosages are appropriate.

Balancing Tricks and Mini-pigs: Steps along the Road to Propofol

Balancing Tricks and Mini-pigs: Steps along the Road to Propofol

Ergonomics in Veterinary Surgery-Risk Assessment With Intraoperative Motion Tracking

Musculoskeletal pain and discomfort are common occupational hazards in surgery, but limited studies have quantified these discomforts in veterinary medicine, where surgeries are performed on large and small animals. The objective of this study is to assess the upper extremities of attending and assisting surgeons soft tissue and orthopaedic small animal surgeries. Inertial measurement units (IMUs) and workload surveys were used to assess the physical workloads. Findings showed that orthopaedic surgeons experienced higher perceived workload and was observed more often in demanding posture than soft tissue surgeons. These results provide understanding of surgeons’ workload that can inform alterations of surgical work environments to reduce musculoskeletal pain and discomfort in the workplace.

Trauma surgery simulation education in Japan: the Advanced Trauma Operative Management course.

Simulation has become an important teaching tool, in part because of changes mandated by restrictions in resident work hours. Simulation models include life‐like mannequins, ex vivo tissue, cadavers, and live animal models. The Advanced Trauma Operative Management (ATOM) course teaches a standard approach for the treatment of traumatic injuries. The 1‐day course includes six lectures in the morning and a live animal surgery laboratory in the afternoon. The animal laboratory includes five standard injury scenarios. Advanced Trauma Operative Management was brought to Japan in 2008 and has carried out 60 courses, training more than 250 surgeons and 70 instructors at six training sites throughout Japan. There have been a number of innovations initiated by ATOM Japan including Nurse Participation Certificates and a course for Trauma Nurses that runs concurrently with the ATOM course. There are other trauma courses given throughout the world, which are scenario‐based and include concurrent nurse training. It is difficult to quantitatively assess the benefits of trauma training to patients. There are a number of documented cases in Japan of surgeons who have had good operative outcomes in the care of traumatically injured patients who attribute the successful management of these patients to participation in the ATOM course. Training in trauma surgery using simulation models and the ATOM course have had a positive impact on surgical training and patient care in Japan. These courses will continue to be modified and refined, resulting in better education and clinical outcomes. Education research is essential to determine the optimum use of the available models.

Studies of Limb Regeneration in Larval Xenopus.

A basic protocol is given for animal maintenance and surgery in studies of hindlimb regeneration in larval Xenopus laevis Unlike urodele limbs, those of larval frogs typically show much more variation in the extent of regeneration after amputation. Such variation can be reduced by optimizing the conditions of larval maintenance to regulate the rates of growth and development, by selecting only larvae with normal rates of growth and morphological development for experimental use, and by attention to precision and consistency in the proximo-distal level of surgical amputation.