Augmenting Veterinary Minimally Invasive Surgery: Evidence-based Review of Foundational and Novel Devices and Technology.

Veterinary minimally invasive surgery continues to grow as a specialty. With increasing experience in this field, comes improved accessibility as well as progressive complexity of procedures performed. Advancement in technology has been both a response to the growth and a necessary driver of continued refinement of this field. Innovative research leading to advancements in surgical equipment has led to the development of novel image acquisition platforms, cannulas, smoke evacuation systems, antifog devices, instrumentation, and ligating/hemostatic devices. These innovations will be reviewed and potential clinical applications are discussed.

Looking to the Future; Veterinary Robotic Surgery.

This article details the rise of surgical robots in the human surgical sphere as well as their use in veterinary medicine. Sections will describe in detail the equipment required for these procedures and the advantages and disadvantages of their use. Specific attention is given to the articulated instrumentation, which affords psychomotor benefits not only for surgical precision but also for surgeon ergonomics. A discussion of the possible indications and current use of robotics in veterinary medicine and the challenges to integrating robotics is also provided.

Three-dimensional printed guides for screw placement in equine navicular bones.

OBJECTIVE: To determine the influence of a custom 3D-printed guide for placement of cortical bone screws in the equine navicular bone. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Eight pairs of normal adult equine forelimbs. METHODS: A 3.5 × 55 mm cortical screw was placed in the longitudinal axis of each intact navicular bone. Screws were placed with a 3D-printed guide (3D) in one bone and with a traditional aiming device (AD) in the contralateral bone within each pair. Duration of surgery and the number of fluoroscopy images were compared between techniques. Screw placement was subjectively evaluated by gross examination and scored by three boarded veterinary surgeons. RESULTS: The use of a 3D-printed guide reduced the duration of surgery by 6.6 min (±1.5 min) compared to traditional screw placement (20.7 min ± 4.8 min, p < .01). Fewer peri-operative fluoroscopic images were obtained when the 3D guide was used (18 images ± 2.6 images vs. 40 images ± 5.1, p < .01). No difference was detected in navicular screw placement. CONCLUSION: The use of a 3D guide decreased the time required to place screws and the number of intraoperative images taken without affecting screw placement in intact navicular bones. CLINICAL RELEVANCE: 3D-printed guides can aid in the study, practice, and execution of surgical procedures reducing surgical time and radiation exposure throughout the operative period achieving similar results to those obtained with a conventional approach.

A survey of work-related musculoskeletal disorders associated with performing laparoscopic veterinary surgery.

OBJECTIVE: To assess the prevalence of work-related musculoskeletal disorders (WRMD) associated with laparoscopy in veterinary surgery. STUDY DESIGN: Cross-sectional survey. SAMPLE POPULATION: Veterinary surgeons who perform laparoscopy. METHODS: Responses were collected with data regarding laparoscopic activities and experience as well as whether the respondents experienced pain as a result of laparoscopy and, if so, additional information on this topic. Variables associated with the risk of experiencing pain were determined by using χ2 tests and odds ratios (OR). RESULTS: There were 149 respondents, an estimated 6% response proportion. Forty percent experienced pain that they attributed to the use of laparoscopic instruments during or after laparoscopic surgery. Surgeons who perform laparoscopic surgery frequently (at least monthly) were more likely to experience pain as a result of laparoscopic surgery compared with those who perform laparoscopic surgery infrequently (OR 2.25; 95% confidence interval 1.07-4.75; P = .033). Pain during or after laparoscopic surgery was most often experienced in the neck (81%), back (77%), and shoulders (75%), with 90% of respondents reporting that surgery exacerbated their pain. Fifty-four percent of respondents experienced the pain at home, 64% had taken painkillers for the pain, and 46% had sought other treatment for the pain such as physiotherapy, chiropractic treatment, or seeing a doctor. CONCLUSION: Laparoscopic surgery was a potential source of pain in a proportion of surgeons. Surgeons who frequently perform laparoscopic surgery were more likely to experience a WRMD. CLINICAL SIGNIFICANCE: Work-related musculoskeletal disorders may occur as a result of performing laparoscopic surgery.

Suture length to wound length ratio in 175 small animal abdominal midline closures.

Experimental and human studies have reported the advantages of a suture length to wound length (SL:WL) ratio greater than 4:1 in midline abdominal closure. This is achieved when the tissue bite (TB) is equal to or larger than the stitch interval (SI). Although TB and SI values are recommended in some textbooks, SL:WL ratios are rarely reported in veterinary textbooks. Additionally, no clinical data regarding these parameters could be found in small animals. Therefore, the aim of this study was to evaluate the SL:WL ratio of midline laparotomy closure in dogs and cats performed by surgeons with different levels of expertise and to compare the findings with current textbook recommendations. Midline laparotomy incisions of 100 dogs and 75 cats were closed in continuous pattern by diplomates and residents of both the European College of Veterinary Surgeons (ECVS) and the European College of Animal Reproduction (ECAR). The mean SL:WL ratio was 2.5 ± 0.7:1. The surgeons´ level of experience and the species and body weights of the animals did not have any significant influence on the SL:WL ratio. A moderate negative correlation was observed between the mean SI to mean TB (SI:TB) ratio and the SL:WL ratio. In this study, the mean SI matched the textbook recommendations both in feline and canine species, whereas the TB in cats was different. In this study, the SL:WL ratio was less than 4:1 without apparent complications. Because of the low prevalence of incisional hernia in dogs and cats larger studies are necessary to evaluate clinical significance of the presented data.

Hydrogen peroxide plasma sterilization of a waterproof, high-definition video camera case for intraoperative imaging in veterinary surgery.

OBJECTIVE: To evaluate the safety and usability of a wearable, waterproof high-definition camera/case for acquisition of surgical images by sterile personnel. STUDY DESIGN: An in vitro study to test the efficacy of biodecontamination of camera cases. Usability for intraoperative image acquisition was assessed in clinical procedures. METHODS: Two waterproof GoPro Hero4 Silver camera cases were inoculated by immersion in media containing Staphylococcus pseudointermedius or Escherichia coli at ≥5.50E+07 colony forming units/mL. Cases were biodecontaminated by manual washing and hydrogen peroxide plasma sterilization. Cultures were obtained by swab and by immersion in enrichment broth before and after each contamination/decontamination cycle (n = 4). The cameras were then applied by a surgeon in clinical procedures by using either a headband or handheld mode and were assessed for usability according to 5 user characteristics. RESULTS: Cultures of all poststerilization swabs were negative. One of 8 cultures was positive in enrichment broth, consistent with a low level of contamination in 1 sample. Usability of the camera was considered poor in headband mode, with limited battery life, inability to control camera functions, and lack of zoom function affecting image quality. Handheld operation of the camera by the primary surgeon improved usability, allowing close-up still and video intraoperative image acquisition. CONCLUSION: Vaporized hydrogen peroxide sterilization of this camera case was considered effective for biodecontamination. Handheld operation improved usability for intraoperative image acquisition. CLINICAL SIGNIFICANCE: Vaporized hydrogen peroxide sterilization and thorough manual washing of a waterproof camera may provide cost effective intraoperative image acquisition for documentation purposes.

Do different characteristics of two emasculators make a difference in equine castration?

BACKGROUND: The Serra and Reimer emasculators are frequently used in equine orchiectomy. They differ in jaw profile and the mechanism by which they achieve haemostasis. OBJECTIVES: To investigate whether the haemostatic capacities of the Reimer and Serra emasculators in open and closed castration differ, to compare the haemostatic capacities of each emasculator in both open and closed castration, and to assess whether the tensile strength of the parietal tunic in closed castration differs according to whether a Reimer or Serra emasculator is used. STUDY DESIGN: Ex vivo randomised study. METHODS: Eighty equine cadaver testes were randomly assigned to two groups for, respectively, open and closed castration. Each group was divided into two subgroups for castration with a Serra or Reimer castrator, respectively. Testicular artery leaking pressure was measured by dye injection. In closed castration, the tensile strength of the parietal tunic was measured with a tensiometer. RESULTS: In open castration, the Reimer emasculator resisted significantly higher pressure (median: 706.1 mmHg; interquartile range [IQR]: 597.6-735.5 mmHg) than the Serra emasculator (median: 349.4 mmHg; IQR: 261.1-468.9 mmHg) (P<0.001), whereas no difference was found in closed castration (Serra emasculator, median: 382.5 mmHg [IQR: 294.2-568.2 mmHg]; Reimer emasculator, median: 419.2 mmHg [IQR: 294.2-616.0 mmHg]). The Reimer emasculator resisted significantly higher pressure in the open (median: 706.1 mmHg; IQR: 597.6-735.5 mmHg) compared with the closed (median: 419.2 mmHg; IQR: 294.2-616.0 mmHg) technique (P = 0.03). Parietal tunic tensile strength did not differ significantly by emasculator (mean ± s.d.: Serra, 12.65 ± 7.35; Reimer, 17.55 ± 11.76). MAIN LIMITATIONS: Limitations are inherent to the ex vivo study design. Post-surgery implications were investigated only in the short term and no account was taken of tissue inflammation and oedema, which may influence the integrity of the tissue. CONCLUSIONS: These results suggest it may be preferable to use a Reimer emasculator in open castration. In this ex vivo model of closed castration, no differences between the emasculators were observed.

Comparison of design features and mechanical properties of commercially available Veress needles.

OBJECTIVE: To compare design features and mechanical properties of 13 commercially available Veress needles (VN). STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Veress needles from 9 manufacturers (6 reusable, 6 disposable, and 1 with a reusable stylet combined with a disposable cannula) were included in the study. METHODS: Veress needles are designed with a spring-loaded stylet to protect the tip of the cannula following insertion into the abdomen. Stylet forces were measured with a scale in a test jig by moving the stylet in 0.5 mm steps into the hollow cannula. Forces and spring rates were derived from force-displacement plots. Mass, mechanical dimensions, and the bevel angle and geometry were assessed. Differences between VN models were analyzed with a univariate analysis of variance. Results are reported as mean ± SD or median (range). RESULTS: Physical and mechanical parameters differed between models. The exposed stylet length was 3.5 mm (2-7). Three bevel geometries (bias, lancet type, and back-cut) with angles between 20° and 40° were identified. Reusable VN weigh more (24.9 ± 2.2 g) than disposable designs (6.0 ± 2.3 g). The mean values for the spring rate and the residual stylet force were 0.23 ± 0.08 Nmm-1 and 0.94 ± 0.28 N, respectively. The mean force required to move the stylet to the cannula tip was 1.81 ± 0.29 N and 2.77 ± 0.54 N to move to the proximal end of the bevel. CONCLUSION: Commercially available VN use diverse bevel geometries and have different mechanical characteristics. Studies investigating laparoscopic entry complications should explicitly report the type of VN model used.

INTRAOPERATIVE IMAGE NAVIGATION: EXPERIMENTAL STUDY OF THE FEASIBILITY AND SURGEON PREFERENCE BETWEEN A STERILE ENCASED NINTENDO WIITM REMOTE AND STANDARD WIRELESS COMPUTER MOUSE.

Diagnostic imaging plays an important role in the operating room, providing surgeons with a reference and surgical plan. Surgeon autonomy in the operating room has been suggested to decrease errors that stem from communication mistakes. A standard computer mouse was compared to a wireless remote-control style controller for computer game consoles (Wiimote) for the navigation of diagnostic imaging studies by sterile personnel in this prospective survey study. Participants were recruited from a cohort of residents and faculty that use the surgical suites at our institution. Outcome assessments were based on survey data completed by study participants following each use of either the mouse or Wiimote, and compared using an analysis of variance. The mouse was significantly preferred by the study participants in the categories of handling, accuracy and efficiency, and overall satisfaction (P <0.05). The mouse was preferred to both the Wiimote and to no device, when participants were asked to rank options for image navigation. This indicates the need for the implementation of intraoperative image navigation devices, to increase surgeon autonomy in the operating room.

Frequency of Undetected Glove Perforation and Associated Risk Factors in Equine Surgery.

OBJECTIVE: To estimate the frequency of undetected perforations in surgical gloves during equine surgery and to identify risk factors associated with occurrence. STUDY DESIGN: Observational cohort study. SAMPLE POPULATION: Surgical gloves-292 pairs. METHODS: Water leak tests were performed on gloves after equine surgery to detect perforations. Fifty pairs of unused gloves were also tested. Potential risk factors were recorded. Logistic regression was used to explore associations between putative risk factors and perforation. RESULTS: No perforations were detected in the unused gloves. Of 292 pairs of used gloves tested, 80 (27%) had at least one glove perforation per pair. The frequency of perforations was not different between surgery diplomates and residents (P=.69). The length and type of surgery were significantly associated with the likelihood of undetected glove perforation with surgeries longer than 60 minutes approximately 2.5 times more likely to result in glove perforation (P=.005). Surgery classified as soft tissue, orthopedic or exploratory celiotomy was 3 times more likely to result in glove perforation than minimally invasive surgery. The perforations occurred significantly more frequently in the nondominant hand (19%) than the dominant hand (11%) (P=.009). CONCLUSION: There is a high occurrence of undetected glove perforation in equine surgery. Precautions can be suggested based on this study although further investigation is required to assess whether glove perforations are associated with surgical site infections.

Update on Surgical Principles and Equipment.

The diversity implicit in exotic animal surgery requires a tailored approach to optimize successful outcomes. Outlined is information on patient preparation, instrumentation, hemostatic techniques, and magnification as it pertains to the exotic animal. Application of topical antiseptic solutions and judicious removal of pelage and feathers will decrease bacterial load during patient preparation. The use of specific barrier protection ensures proper aseptic technique and enables optimal patient monitoring. Magnification combined with a focal light source enhances visual acuity, allowing for better use of delicate instrumentation and identification of anatomic structures.

Ex vivo comparison of the giant and transfixing knot in equine open and closed castration.

REASONS FOR PERFORMING STUDY: In equine castration, application of a ligature on the spermatic cord to prevent complications such as haemorrhage and evisceration has been reported with controversial results. Characteristics of commonly used knots have not been studied. OBJECTIVES: To compare the modified transfixing and giant knots and the emasculator in open and closed equine castration techniques. STUDY DESIGN: Ex vivo experiment. METHODS: A total of 144 testicles were randomly assigned to 2 groups for open or closed castration. Both groups were divided into 3 subgroups of 18 specimens each: emasculator only, emasculator plus giant knot and emasculator plus transfixing knot and the open castration group also contained 2 further subgroups of 18 testicles each: giant knot only and transfixing knot only. The length of suture material used was measured for each knot and the leaking pressure of the testicular artery measured using dye injection. In the closed castration group, parietal tunic tensile strength was measured with a tensiometer. RESULTS: Leaking pressure was higher in open compared with closed castration, with no significant difference among subgroups. In the closed castration group, minimum leaking pressure for the emasculator plus transfixing knot and emasculator only subgroups were close to standard physiological arterial pressures. The giant knot required less suture material than the transfixing knot. Parietal tunic tensile strength was higher when ligatures were applied. CONCLUSIONS: The giant and transfixing knot techniques have comparable haemostatic capability and parietal tunic tensile strength, but the giant knot requires less suture material. In open castration, using the emasculator alone may produce adequate haemostasis. In closed castration, using the giant knot in combination with the emasculator increases the bursting pressure and possibly reduces the incidence of haemorrhage. In closed castration, application of a ligature may reduce the risk of evisceration.

Facilitation of soft tissue surgery: surgical staplers and vessel sealing devices.

Recent advances and acceptance of various medical devices have clearly helped in the efficiency, simplicity, and effectiveness of veterinary surgery. The goals of surgery include efficient methods and minimal surgical times, delicate tissue handling techniques, confidence with tissue reconstruction, and minimizing contamination, leakage and complications. Mechanical means of suturing, cutting, and hemostasis assist with accomplishing these goals. Most recently, stapling instrumentation and vascular sealing devices have become common instruments on all levels of surgery because of their ease of use and increase in surgical efficiency.

Comparison of 3 methods of onychectomy.

The frequency of claw regrowth, bony remnants, and complications in cats that underwent forelimb onychectomy using laser, scalpel, or guillotine techniques were evaluated. Eighty-seven client-owned cats were recruited from 27 veterinary clinics in the Canadian Atlantic provinces. At least 1 year after onychectomy the cats underwent a physical examination, gait analysis, and radiographic evaluation by 1 of 2 authors. There was no significant difference in the frequency of claw regrowth among the 3 methods (P = 0.283). Significantly more cats had bony remnants following guillotine onychectomy (P < 0.001). Bony remnants were significantly associated with claw regrowth (P = 0.001). Cats that underwent laser onychectomy had significantly less post-operative complications (P = 0.023). The long-term outcome was not significantly different among the 3 methods. We conclude that leaving remnants of the third phalanx in situ is associated with an increased frequency of claw regrowth. Laser onychectomy may be preferred to reduce the risk of post-operative complications, bony remnants, and claw regrowth.

Comparaison de 3 méthodes d'onychectomie. La fréquence de la repousse des griffes, des reliquats osseux et des complications chez les chats qui avaient subi une onychectomie des pattes avant en utilisant le laser, le scalpel, ou les techniques de guillotine a été évaluée. Quatre-vingt-sept chats appartenant à des clients ont été recrutés dans 27 cliniques vétérinaires des provinces de l'Atlantique du Canada. Au moins 1 an après l'onychectomie, les chats ont subi une évaluation physique, une analyse de la démarche et une évaluation radiographique par 1 des 2 auteurs. Il n'y avait pas de différence significative dans la fréquence de la repousse des griffes entre les 3 méthodes (P = 0,283). Un nombre significativement supérieur de chats avaient des reliquats osseux après l'onychectomie à la guillotine (P < 0,001). Les reliquats osseux étaient significativement associés à la repousse de griffes (P = 0,001). Les chats qui ont subi une onychectomie au laser présentaient un nombre significativement inférieur de complications postopératoires (P = 0,023). Les résultats à long terme n'étaient pas significativement différents entre les 3 méthodes. Nous avons conclu que la présence de reliquats in situ dans la troisième phalange est associée à une fréquence accrue de repousse des griffes. L'onychectomie au laser peut être préférable pour réduire le risque de complications postopératoires, des reliquats et de la repousse des griffes.(Traduit par Isabelle Vallières).

Knot security and tensile strength of suture materials.

OBJECTIVE: To evaluate knot security and tensile failure load of suture tied in simple interrupted, beginning continuous, and ending continuous patterns for 11 suture materials commonly used in small animal surgery. STUDY DESIGN: Mechanical study. METHODS: For each of 11 suture material types, and 5 knot sizes (2, 3, 4, 5, and 6 throws) 2 surgeons each tied 6 knots (n = 12 for each knot size in 11 suture materials). Three types of patterns were evaluated: a simple interrupted square knot, a square knot beginning a simple continuous pattern, and the knot ending a simple continuous pattern. All knots were incubated in healthy canine donor plasma at 40°C for a minimum of 24 hours. Sutures were evaluated for knot security (knots untied, suture failed by breaking, suture slipped from the clamps, or suture untied before testing) and maximum load carried before knot slippage or knot failure (termed tensile failure load). RESULTS: Significant differences were found in knot security and tensile failure load among suture types. There was no significant difference between the simple interrupted knots and the knots at the beginning of a simple continuous pattern; however, both were significantly less likely to fail than the knots tied at the end of a simple continuous pattern. The number of throws per knot had a significant effect for knot security and tensile failure load. Surgeon experience had a significant effect on failure mode and tensile failure load. CONCLUSIONS: Suture type, number of throws per knot (knot size), suture pattern, and surgeon experience play an important role in knot security and should be considered when performing surgery.

Evaluation of bacterial contamination on surgical drapes following use of the Bair Hugger(®) forced air warming system.

This pilot study determined the rate of bacterial contamination on surgical drapes of small animal patients warmed intra-operatively with the Bair Hugger(®) forced air warming system compared to a control method. Surgical drapes of 100 patients undergoing clean surgical procedures were swabbed with aerobic culturettes at the beginning and end of surgery. Samples were cultured on Trypticase soy agar. Contamination of the surgical drapes was identified in 6/98 cases (6.1%). There was no significant difference in the number of contaminated surgical drapes between the Bair Hugger(®) and control groups (P = 0.47).

Évaluation de la contamination bactérienne des champs opératoires après l'utilisation du système de chauffage à air pulsé Bair HuggerMD . Cette étude pilote a déterminé le taux de contamination bactérienne des champs opératoires de patients petits animaux réchauffés lors du processus peropératoire à l'aide du système de chauffage à air pulsé Bair HuggerMD comparativement à une méthode témoin. Les champs opératoires de 100 patients subissant des interventions chirurgicales propres ont été écouvillonnés avec des Culturettes aérobies au début et à la fin de la chirurgie. Les échantillons ont été cultivés sur gélose Trypticase soja. La contamination des champs opératoires a été identifiée dans 6/98 cas (6,1 %). Il n'y avait aucune différence significative dans le nombre de champs opératoires contaminés entre le groupe Bair HuggerMD et le groupe témoin (P = 0,47).(Traduit par Isabelle Vallières).

Veterinary Keyhole Surgery

Laparoscopic surgery is the gold standard for many procedures in human surgery, yet is still in its infancy in veterinary surgery. Often called "keyhole surgery" in the lay press it is also referred to as minimally invasive surgery, endosurgery, or videosurgery (see the glossary). In the United Kingdom it is estimated that less than 1% of suitable veterinary procedures are performed by minimally invasive surgical techniques.

Derivaciones portosistemáticas congénitas: reporte de caso en un canino / Congenital portosystemics shunts: case report in a dog

Las derivaciones portocava extrahepáticas son anomalías vasculares donde la circulación portal se conecta con la circulación sistemática. En los caninos constituyen el 45% de las anomalías portovasculares, registrándose un predisposición racial. El objetivo de este trabajo es presentar los hallazgos ecográficos en un canino de raza Yorkshire. Se observó disminución del tamaño hepático, con la presencia de un vaso anómalo que comunicaba la vena porta con la vena cava, y donde el Doppler color registró turbulencia. Luego de la corrección quirúrgica, se observó un aumento del diámetro de la vena porta, con aumento del tamaño del órgano. En el diagnóstico de las derivaciones vasculares extra hepáticas, la ecografía tiene la ventaja de ser un método no invasivo que da información sobre el parénquima hepático y la vasculatura, sirviendo de guía para la selección de los procedimientos quirúrgicos.