Use of a Bipolar Vessel-Sealing Device for Splenic Parenchymal Resection in Three Dogs and One Cat.

Based on splenic abnormalities noted during surgery, four client-owned animals (three dogs, one cat) undergoing exploratory laparotomy were identified as candidates for partial splenectomy. In three cases, small mass lesions of the spleen were identified on elective exploratory laparotomy. In one case, the patient was referred for emergency surgery for diaphragmatic hernia with entrapment of stomach and spleen. The discovery of avulsion of a significant portion of the splenic mesentery led to the decision to perform partial splenectomy in this case. All animals included in the study underwent partial splenectomy by one of two board-certified veterinary surgeons at a multispecialty hospital between 2014 and 2018. The same type of bipolar vessel-sealing device was used in each surgery, and three of four partial splenectomy cases recovered uneventfully. One patient went into cardiopulmonary arrest hours after surgery and died; however, this is not suspected to be due to the described partial splenectomy technique. The bipolar vessel-sealing device is suitable for use in resection of the splenic parenchyma in some canine and feline patients. This technique is designed to decrease surgical time, provide effective hemostasis, and preserve the important functions of the spleen that are lost when total splenectomy is undertaken.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model.

OBJECTIVE: To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies. STUDY DESIGN: Ex vivo, simple randomized study. SAMPLE POPULATION: Urinary bladders harvested from canine cadavers (n = 23). METHODS: Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies. RESULTS: Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders. CONCLUSION: Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure. CLINICAL SIGNIFICANCE: This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Influence of a customized three-dimensionally printed drill guide on the accuracy of pedicle screw placement in lumbosacral vertebrae: An ex vivo study.

OBJECTIVE: To compare the accuracy of pedicle screw insertion (PSI) into canine lumbosacral vertebrae with custom-made three-dimensionally (3D)-printed drill guides or freehand insertion. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Nineteen canine lumbosacral specimens. METHODS: Drill guides for PSI were designed on the basis of safe screw insertion trajectories by using preoperative computed tomography (CT) and produced by 3D printing of templates. Right and left sides of the specimens were randomly allocated to two groups; 4-mm pedicle screws were inserted in L5-L6 and L7-S1 spinal segments either freehand (control group) or with custom-made drill guides (guide group). Sixty-six screws were inserted with each method. Insertion angles (α, ß), bone stock, and vertebral canal breach were assessed according to postoperative CT. χ2 Tests were used to compare vertebral canal breach between groups and vertebrae. RESULTS: Breaches in the vertebral canal were less common (P < .001) when screws were placed with a guide in the guide group (9/66, 14%) than without a guide (30/66, 45%). The rate of vertebral canal breach differed at L5 (P = .021) but not at L6 (P = .05), L7 (P = .075) or S1 (P = .658). The angle of insertion (α) did not differ between specimens with and without breaches (guide, P = .068; control, P = .394). CONCLUSION: The use of a customized 3D-printed guide generally improved the accuracy of PSI in canine lumbosacral vertebrae, although statistical significance was reached only at L5. CLINICAL SIGNIFICANCE: The use of customized drill guides may be considered as an alternative to freehand PSI in the lumbosacral area, especially for L5-L6 vertebrae.

Ex Vivo Comparison of the Accuracy of a Clamped with a Hand-Held Drill Guide for Drilling Distal Third Metacarpals and Metatarsals in Equids.

OBJECTIVES: The aim of this study was to determine whether a clamped drill guide can be used effectively to drill across equine distal third metacarpals and metatarsals and to compare accuracy and speed of a drilling with a hand-held drill guide. STUDY DESIGN: Eighty equine cadaver limbs were divided between four surgeons with varying experience. The limbs were randomly allocated to clamped or hand-held drill guides and placed in a stand in an upright/standing position on a metal table. Drilling times from cis- to trans cortices were measured. Post-drilling computed tomography images were used to assess drilling deviations in the dorsopalmar and proximodistal directions. RESULTS: Mean proximodistal deviation of the drill hole was distad for both guides and significantly (p = 0.01) less for the clamped drill guide +0.35° (range: -5.42°, +6.61°, standard deviation [SD] ± 3.18°) than the hand-held drill guide +2.05° (range: -5.24°, +9.81°, SD ± 3.69°). Mean dorsopalmar/plantar deviation was non-significantly (p = 0.17) less for the clamped drill guide -0.27° (range: -9.72°, +6.58°, SD ± 3.57°) than the hand-held drill guide +0.60° (range: -9.74°, + 12.33°, SD ± 4.51°). Mean time taken to drill from cis to trans cortex was significantly (p < 0.001) shorter with the clamped drill guide (41.2s) than the hand-held guide (56.6s). CONCLUSION: The clamped drill guide could be used successfully on the equine distal third metacarpals and metatarsals and resulted in some improved accuracy and reduced drilling time compared with the hand-held guide. The use of the clamped drill guide in vivo could be supported. This may be of benefit for certain fracture repairs in equids.

Technological Advances in Surgical Equipment in Exotic Pet Medicine.

Surgery can be challenging in exotic pets owing to their small size and blood volume, and their increased anesthetic risk compared with small animals. Various devices are available to facilitate suturing, cutting, and hemostasis in the human and veterinary fields. These surgical equipment improve the simplicity, rapidity, and effectiveness of surgery. Vessel-sealing devices, radiosurgery, lasers, and ultrasound devices are commonly used because of their ease of use and increase in surgical efficiency. Other surgical devices are available (eg, stapling devices) but are not discussed in this article.

Initial adhesion of methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains to untreated and electropolished surgical steel drill bits.

Electropolishing of stainless steel has been thoroughly investigated as a prophylactic measure to prevent bacterial colonization of orthopaedic implants and infection. Initial bacterial adhesion onto surgical drill bits as a possible factor for orthopaedic surgical site infections has not yet been documented. The present study investigated the influence of electropolishing on initial staphylococcal adhesion onto AISI 440A stainless steel drill bits. Specifically, one methicillin-susceptible standard laboratory Staphylococcus aureus type strain (DSM 20231T), one methicillin-resistant S. aureus reference strain (DSM 46320) and one methicillin-resistant clinical isolate from an infected orthopaedic implant were used. After standard sterilization, drill bits were immersed in the respective bacterial suspension; bacteria adherent to surface were harvested by vortexing the drill bits in phosphate-buffered saline and viable counts of bacteria transferred from the suspension were made (transferred to log10 for further analysis). Electropolishing significantly reduced adhesion of the clinical S. aureus strain and the S. aureus DSM 20231T. However, electropolishing significantly increased adhesion of the S. aureus DSM 46320. These results show that electropolishing significantly influences initial adhesion of S. aureus strains to surgical drill bits and that the nature of this influence depends on the S. aureus strain examined. For a general recommendation of electropolishing drill bits and guidelines for their handling during surgery, further studies with more strains isolated from infected wounds are suggested.

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.

Presence of digital dermatitis treponemes on cattle and sheep hoof trimming equipment.

Digital dermatitis (DD) is an infectious foot disease causing severe lameness in dairy cattle (worldwide) and sheep (UK). This study investigated whether DD Treponema phylogroups can be present on equipment used to trim ruminant hooves and, therefore, consider this trimming equipment as a possible vector for the transmission of DD. Equipment was tested after being used to trim DD symptomatic and asymptomatic cattle and sheep hooves, and subsequently after disinfection of equipment. After trimming, 'Treponema medium/Treponema vincentii-like', 'Treponema phagedenis-like' and 'Treponema denticola/T putidum-like' DD spirochaetes, were shown to be present on 23/37 (62%), 21/37 (57%) and 20/37 (54%) of knives, respectively. After disinfection, detection rates for the DD treponemes were 9/37 (24%), 6/37 (16%) and 3/37 (8%), respectively. Following culture of a swab, an isolate belonging to the T phagedenis-like spirochaetes was identified from a knife sample after trimming a DD positive cow. No isolates were obtained from knife samples after disinfection. This new data has, for the first time, identified treponemes in the farm environment, and highlighted disinfection of hoof trimming equipment between animals and between farms, as a logical precaution to limit the spread of DD.

Development of a neurosurgical operating table for adult cattle and changes in intracranial pressure and blood pressure in adult cattle undergoing long-time isoflurane anesthesia.

We developed a neurosurgical operating table for restraining adult cattle in the sternal recumbent position during long-time inhalation anesthesia, and examined intracranial pressure (ICP), blood pressure and blood gases during isoflurane anesthesia. We confirmed that the maintenance of inhalation anesthesia, the restraint of cattle in the sternal recumbent position and bringing the cattle out of anesthesia could all be carried out safely using the operating table we produced. For the purposes of the present experiment, the cattle were divided into 2 groups: the SR group, which underwent sternal recumbency for 8 hr under isoflurane anesthesia using the neurosurgical operating table, and the RR group, which underwent right lateral recumbency for 3 hr under isoflurane anesthesia on a standard operating table. The mean ICP was found to be significantly lower in the SR group than in the RR group during anesthesia, and PaO2 was significantly higher in the SR group. In the SR group, no complications such as regurgitation or ruminal tympany occurred for 8 hr after the induction of anesthesia, and recovery from anesthesia was uneventful. In contrast, all RR cattle showed ruminal tympany and regurgitated ruminal fluid at 3 hr after the induction of anesthesia. Thus, the neurosurgical operating table developed in the present study may be useful for long-time anesthesia and neurosurgery of adult cattle.

Comparison of two oxygen delivery systems for safe sedation and spinal anesthesia in sheep.

Proper oxygenation is critical to prevent hypoxia and myocardial ischemia in animals during pharmacological sedation. The authors compared the efficacy of two oxygen delivery masks during sedation and spinal anesthesia for knee surgery in sheep.

Methods of positioning fish for surgery or other procedures out of water.

Several methods are available for positioning fish and other aquatic species during surgery or other experimental procedures out of water. This paper reviews current methods in the light of criteria for humane handling, and suggests the implementation of a novel method, currently used for positioning mammals during surgery, that gives optimal support and a minimum of damage.

History and instrumentation of laparoscopic surgery.

Equine surgery continues to benefit from advances in endoscopic surgical techniques. Much of what we have learned in equine endoscopy comes from techniques used in humans. Descriptions of the normal anatomy of the standing horse and advances in instrumentation have improved our ability to perform laparoscopic surgery in standing and dorsally recumbent horses. This article describes the history of laparoscopy and available instrumentation.

Biomechanical comparison of the Herbert and AO cortical bone screws for compression of an equine third carpal bone dorsal plane slab osteotomy.

OBJECTIVE: To assess feasibility of insertion of 4.5-mm Herbert cannulated bone screws (HS) using fluoroscopic guidance and compare the mechanical shear strength of these HS and 4.5-mm AO cortical bone screws (AO) for fixation of dorsal plane slab osteotomies in equine cadaver third carpal bones (C3). ANIMALS OR SAMPLE POPULATION: Eight equine cadavers. METHODS: Bone mineral composition and density of contralateral C3 were confirmed to be equivalent using dual-energy x-ray absorptiometry. A standard 10-mm C3 slab osteotomy was reduced using HS or AO instrumentation under fluoroscopic guidance. Specimens were loaded in shear until failure, using a materials testing apparatus. RESULTS: HS and AO instrumentation allowed accurate reconstruction of the osteotomy, but there was difficulty encountered seating the HS proximal self-tapping threads. There was no significant difference in maximal load to failure, stiffness, or mode of failure of constructs created with the HS and AO screws. CONCLUSIONS: Use of 4.5-mm HS for repair of C3 radial facet, dorsal plane slab fractures may result in a mechanically comparable fixation to a repair using a 4.5-mm AO. Equine dorsal C3 may be too dense, however, to allow placement of the proximal self tapping threads of the HS without potentially excessive application of torque to the screw itself. CLINICAL RELEVANCE: Dorsal plane, radial facet slab fractures of the equine C3 are a significant clinical problem. Accurate reconstruction and stabilization are necessary for return to athletic function.

Surgical materials and wound closure techniques.

Recent innovations in surgical materials have helped to enhance wound healing and protect surgical wounds from infection. Materials such as polyglyconate have been evaluated in equine tissues and found efficacious. Other materials, such as poliglecaprone 25, appear to have qualities useful to equine surgery but are untested in equine tissues. Care must be taken to fully evaluate a new surgical material because its usefulness in equine tissues may not match that in human or laboratory animal tissues. Furthermore, use of disposable materials in surgery, although considered ideal for maintenance of sterility, may come under more scrutiny in the future as environmental issues gain prominence. We tend to reserve disposable materials for prolonged procedures and for procedures that carry high risk of failure if infection develops.

Instrumentation and techniques for laparoscopic and thoracoscopic surgery in the horse.

Equine surgery continues to benefit from advances in laparoscopic techniques. Descriptions of the normal anatomy of the standing horse and advances in instrumentation have improved our ability to perform laparoscopic surgery in both standing and dorsally recumbent horses. The common uses for laparoscopy are diagnostic laparoscopy, cryptorchidectomy, ovariectomy, and diagnostic thoracoscopy. Other reported uses include inguinal hernia repair, ruptured bladder repair, and ventral colopexy.

Advances in equine arthroscopy.

Surgical procedures completed under arthroscopic guidance have become commonplace in many equine practices and have largely replaced surgery using arthrotomy incisions. With a limited amount of equipment, numerous diagnostic and surgical procedures can be completed. Surgeons need to become familiar with regional and intraarticular (intrasynovial) anatomy to ensure that proper surgical approaches are used, access to the lesion will be realized, and potential complications will be minimized. Specialized motorized instruments and surgical lasers are now available and may be useful in the treatment of selected clinical cases.

Evaluation of a biofragmentable anastomosis ring for small intestinal anastomosis in ponies.

Six ponies divided into two groups of three were used in a double crossover study design. Group 1 ponies had a small intestinal resection and anastomosis performed using a biofragmentable anastomosis ring (BAR); group 2 ponies had a hand-sewn small intestinal resection and anastomosis using a Gambee suture pattern. Approximately 30 days later, all ponies had a second celiotomy and anastomosed segments were removed. Group 1 ponies had a hand-sewn anastomosis performed and group 2 had a BAR. The anastomotic sites were collected at necropsy approximately 30 days later. Anastomosed intestinal segments were evaluated with ultrasound to determine lumen diameter, area, circumference, and wall thickness. Gross descriptions of adhesions were recorded and sections of the anastomotic site were taken for histological evaluation. Time to perform the BAR anastomosis was significantly less (P = .0004) than for the hand-sewn Gambee anastomosis. Ponies with handsewn anastomoses had no signs of colic, whereas five of six ponies with BAR anastomoses had several episodes of abdominal discomfort, between day 16 to 18, corresponding to the time of BAR disintegration as determined by abdominal radiographs. Hand-sewn anastomoses had a tendency to have more adhesion formation than BAR anastomoses, but all anastomoses, except one BAR anastomosis, were graded as having a low obstructive potential. BAR anastomoses had a significantly larger mean index of stenosis for intraluminal diameter (76% +/- 13.6), area (93.7% +/- 6.01) and circumference (75.8% +/- 14.0) than the hand-sewn anastomoses (26.6% +/- 11.9; 44.6% +/- 19.5; 26.8% +/- 12.7). The BAR anastomoses also had a significantly smaller mean intraluminal diameter (0.96 cm +/- 0.49), area (0.838 cm2 +/- 0.65) and circumference (3.28 cm +/- 1.63) than the hand sewn anastomoses (3.11 cm +/- 0.73; 7.99 cm2 +/- 3.9; 10.3 cm +/- 2.47). In addition, the BAR anastomoses had a significantly larger (P = .0069) bowel wall thickness at the anastomoses and a significantly larger (P = .047) wall thickness proximal to the anastomosis than the hand-sewn anastomoses, indicating some degree of hypertrophy because of chronic obstruction. No significant difference was found in the diameter, area, or circumference between bowel proximal and distal to the anastomosis for either the BAR or Gambee techniques, or between the BAR and Gambee anastomosis as a measure of chronic obstruction. There was a significantly higher (P = .0043) histological score (worse healing) for mucosal healing and continuity for the BAR, as well as a tendency to score higher for inflammation, anastomotic alignment, and anastomotic fibrosis. The BAR technique had a significantly higher (P = .0043) total histological score than the Gambee technique. Although the BAR was advantageous in many respects, results of this study suggest that it should not be used for equine small intestinal anastomosis because of the potential for stricture formation.

Modification of surgery equipment for ovine surgery.

Surgery equipment was modified for ovine surgery. Pre- and postoperative holding pens were designed to meet the specific requirements of sheep. A hydraulic trolley lift was constructed and operating tables fitted with spilltrays. A gag was made to protect Magill tubing and the indifferent electrode was altered for electrosurgery. For fluoroscopy a flexible table was constructed to accommodate sheep.