Successful percutaneous drainage of a refractory caudal mediastinal paraesophageal abscess in a dog.

OBJECTIVE: To describe a novel technique for paraesophageal abscess drainage in a dog. CASE SUMMARY: A 6-year-old dog presented for pyrexia of unknown origin, subsequently confirmed to be due to a paraesophageal abscess. This was managed by the ultrasound-guided placement of a thoracostomy tube into the abscess, allowing drainage to be performed. This led to clinical resolution and, at an 8-month follow-up, the dog continued to do well. NEW OR UNIQUE INFORMATION PROVIDED: Paraesophageal abscessation is typically managed with surgical intervention, which carries inherent risks and complications. This report describes a novel technique that did not require general anesthesia or invasive surgical intervention, achieving clinical remission without any adverse effects. It also summarizes the current literature available on this condition.

Comparing the accuracy of freehand, fluoroscopically guided and aiming device-assisted drilling in veterinary orthopaedic surgery.

BACKGROUND: Drilling accuracy is essential in the correct positioning of implants and avoidance of iatrogenic damage to surrounding tissues. The use of augmented drilling methods has been documented as an approach to improving the accuracy of drilling. The aim of this study was to compare the accuracy of two augmented drilling methods (fluoroscopically guided and aiming device) to freehand (FH) drilling. METHODS: Three experienced specialist surgeons and three veterinary surgeons without primary orthopaedic experience drilled into synthetic bone towards a target using the three different methods at three different angles (0°, 10° and 20°). The duration of drilling was recorded, and the accuracy of drilling was measured using photographs before and after drilling. RESULTS: The two augmented methods were more accurate than FH drilling in synthetic bone, with the aiming device producing the greatest accuracy. Increased angulation of drilling decreased the drilling accuracy. Surgeon experience did not impact on drilling accuracy. Surgeon inexperience and augmented drilling methods both increased the time taken to drill. CONCLUSION: The use of augmented drilling methods improved the accuracy of drilling, and surgeons should consider their use when drilling in anatomical regions where the margin of error is small.

Early partial portal venous contrast enhancement in canine CT-Angiography.

Early partial portal vein contrast enhancement (EPoVE) during the late arterial phase is seen in CT angiography of dogs. Previously, it has been a finding attributed to arterioportal vascular anomalies. However, EPoVE may be a normal feature of venous return from abdominal organs. This prospective, descriptive study investigated the origin of EPoVE using four-dimensional CT (4D-CT). Sixteen dogs undergoing 4D-CT for disease of the cranial abdomen were prospectively collected. Regions of interest were placed in the hepatic artery (HA), gastroduodenal vein (GV), extrahepatic portal vein (EHPV) cranial and caudal to the GV, and splenic vein (SV) caudal to its EHPV entry. Times to earliest, partial, full, and maximal vascular enhancement were recorded. A mixed model analysis of variance was used to compare time-to-contrast enhancement between vessels. The number, origin, and time of EPoVE were recorded if visible. A total of 24 EPoVE areas were observed in all dogs. Most dogs had either one (10/16) or two (5/16) areas of EPoVE. The origin of EPoVE was identified in 14 of 24 areas: the GV in five areas, cranial mesenteric vein in four areas, pancreatic branch of SV in three areas, and SV in two areas. The time-to-contrast-enhancement was significantly different for the individual veins compared to the HA. EPoVE during the late arterial phase is a common phenomenon of early portal venous drainage of abdominal organs; it should not be interpreted as pathognomonic for arterioportal vascular anomalies, which should be diagnosed based on additional criteria.

Investigation of the in vitro antimicrobial activity of triclosan-coated suture material on bacteria commonly isolated from wounds in dogs.

OBJECTIVE: To investigate in vitro effects of triclosan coating of suture materials on the growth of clinically relevant bacteria isolated from wounds in dogs. SAMPLE: 6 types of suture material and 10 isolates each of methicillin-susceptible Staphylococcus pseudintermedius, methicillin-resistant S pseudintermedius, Escherichia coli, and AmpC ß-lactamase and extended-spectrum ß-lactamase-producing E coli from clinical wound infections. PROCEDURES: Isolates were cultured on Mueller-Hinton agar with 3 types of triclosan-coated suture, uncoated counterparts of the same suture types, and positive and negative controls. Zones of inhibition (ZOIs) were measured after overnight incubation. Sustained antimicrobial activity assays were performed with susceptible isolates. The ZOI measurements and durations of sustained antimicrobial activity were compared among suture types and isolates by statistical methods. Suture surface characteristics and bacterial adherence were evaluated qualitatively with scanning electron microscopy. RESULTS: ZOIs were generated only by triclosan-coated materials; triclosan-coated suture had sustained antimicrobial activity (inhibition) for 3 to 29 days against all tested pathogens. The ZOIs around triclosan-coated suture were significantly greater for S pseudintermedius isolates than for E coli isolates. Bacterial adherence to uncoated polyglactin-910 was greatest, followed by triclosan-coated polyglactin-910, and then uncoated monofilament sutures, with least adherence to coated monofilament sutures. CONCLUSIONS AND CLINICAL RELEVANCE: Surface characteristics of suture materials may be as important or more important than triclosan coating for microbial inhibition; however, triclosan coating appeared to affect bacterial adherence for multifilament sutures. Triclosan-coated, particularly monofilament, sutures inhibited pathogens commonly isolated from wounds of dogs, including multidrug-resistant bacteria. Further studies are required to assess clinical efficacy of triclosan-coated suture materials in vivo.

Evaluation of a pre-tied ligature loop for canine total lung lobectomy.

OBJECTIVE: To determine the ability of a pre-tied ligature loop (PLL) to create a seal against physiological airway pressures after total lung lobectomy and report outcomes in dogs requiring lung lobectomy. STUDY DESIGN: Ex vivo experimental randomized study and clinical case study. SAMPLE POPULATION: Thirty cadaveric canine lung lobes and 5 client-owned dogs. METHODS: Thirty canine lung lobes from dogs weighing 22.5-35 kg were randomized to lobectomy with stapler, PLL, or suture ligation. After lobectomy, each bronchial stump was submerged in water, and the mainstem airway pressure was increased to 80 mm Hg. Leakage was compared between techniques. The PLL was subsequently used in 5 dogs (17-25 kg) with neoplastic disease requiring total lung lobectomy. RESULTS: Two stapled and 4 sutured bronchial stumps leaked at supraphysiological pressures >15 mm Hg. One stapled bronchial stump failed at a physiological airway pressure (5 mm Hg). None of the PLL lobectomies leaked. The incidence of bronchial stump failures did not differ among techniques (P = .15). Lung lobectomy was performed successfully with the PLL in 5 clinical cases with no intraoperative or postoperative complications; median follow-up time was 6 months. CONCLUSION: Bronchial ligation with the PLL reliably resisted physiological airway pressures and performed comparably to current standard techniques in cadavers. The PLL provided an adequate air and vascular seal in 5 clinical cases undergoing total lung lobectomy. CLINICAL RELEVANCE: Pre-tied ligature loops provide an alternative method for total lung lobectomy in dogs.

Sequential drilling and drill angulation reduce the accuracy of drill hole start location in a synthetic bone model.

The accuracy of drill hole location is critical for implant placement in orthopaedic surgery. Increasing drill bit size sequentially has been suggested as a method for improving the accuracy of drill hole start location. The aim of this study was to determine whether sequential drilling or drill angulation would alter accuracy of drill hole start location. Three specialist veterinary surgeons drilled holes in synthetic bone models either directly, or with sequentially increasing drill bit sizes. Drilling was performed at 0o, 10o and 20o to perpendicular to the bone models. Three synthetic bone models were used to mimic canine cancellous and cortical bones. Sequential drilling resulted in greater inaccuracy in drill hole location when assessing all drilling angles together. There was no influence of surgeon or synthetic bone density on drilling accuracy. The combination of drill angulation and sequential drilling increased inaccuracy in drill hole start location. We conclude that sequential drilling decreased accuracy of drill hole location in the synthetic bone model when drilling was angled. Inaccuracy associated with the drill hole start location should be taken into account when performing surgery, although the magnitude of inaccuracy is low when compared with other sources of error such as angulation.

Mechanical properties of 6 finger-trap suture techniques.

OBJECTIVE: To identify the most common methods used by surgeons to place finger-trap sutures (FTS), and determine their influence on the biomechanical properties of constructs. STUDY DESIGN: Questionnaire and experimental study. METHODS: Six commonly used FTS methods (A-F) were identified from literature review and questionnaire. Constructs made with 3-metric nylon suture and 18-French polyurethane esophagostomy tubing were tested in axial loading to failure. Two patterns (B and D) selected based on common use and biomechanical performance were further tested, with 2, 4, and 8 repeats along the tube. Displacement, load, and energy at failure were compared between constructs, and failure mode was video recorded. RESULTS: Patterns E and F were susceptible to slipping (P < .001). Patterns A and D were stiffer than pattern E, and patterns A-D were stiffer than pattern F (P = .012). Patterns A and B had less extension than pattern E and F, and patterns A-D had less extension than pattern F (P = .002). 87.5% of FTS failed by breaking at the first suture knot. The number of repeats had no effect on FTS performance, but catastrophic failure occurred in 2 constructs with 2 repeats. CONCLUSION: The mechanical behavior of suture-tube constructs and failure mode is affected by the FTS pattern. Patterns E and F are not advocated due to suture slippage. The number of repeats may not affect the FTS performance, but a minimum of 4 repeats is recommended. Overall, patterns B, C, and D performed the best in axial loading.

Canine intrahepatic vasculature: is a functional anatomic model relevant to the dog?

OBJECTIVE: To clarify canine intrahepatic portal and hepatic venous system anatomy using corrosion casting and advanced imaging and to devise a novel functional anatomic model of the canine liver to investigate whether this could help guide the planning and surgical procedure of partial hepatic lobectomy and interventional radiological procedures. STUDY DESIGN: Prospective experimental study. ANIMALS: Adult Greyhound cadavers (n = 8). METHODS: Portal and hepatic vein corrosion casts of healthy livers were assessed using computed tomography (CT). RESULTS: The hepatic lobes have a consistent hilar hepatic and portal vein supply with some variation in the number of intrahepatic branches. For all specimens, 3 surgically resectable areas were identified in the left lateral lobe and 2 surgically resectable areas were identified in the right medial lobe as defined by a functional anatomic model. CONCLUSIONS: CT of detailed acrylic casts allowed complex intrahepatic vascular relationships to be investigated and compared with previous studies. Improving understanding of the intrahepatic vascular supply facilitates interpretation of advanced images in clinical patients, the planning and performance of surgical procedures, and may facilitate interventional vascular procedures, such as intravenous embolization of portosystemic shunts. Functional division of the canine liver similar to human models is possible. The left lateral and right medial lobes can be consistently divided into surgically resectable functional areas and partial lobectomies can be performed following a functional model; further study in clinically affected animals would be required to investigate the relevance of this functional model in the dog.

Radial artery pseudoaneurysm in a Maine Coon cat.

OBJECTIVE: To report the diagnosis and treatment of a radial artery pseudoaneurysm in a cat. STUDY DESIGN: Clinical report. ANIMAL: Maine Coon cat (8-year-old neutered male). METHODS: Ultrasonographic and angiographic examination of a fluctuant, nonpainful, 3 cm × 1.5 cm subcutaneous swelling on the craniomedial distal aspect of the right radius that occurred 40 days after suspected cat bite trauma was consistent with a radial artery pseudoaneurysm. After ligation of the radial artery proximal to the lesion, the pseudoaneurysm was surgically excised. RESULTS: The excised tissue had hemorrhage and fibrin surrounded by a thick fibrous granulating capsule of variably mature fibroblasts and focal areas of inflammatory cells (lymphocytes, plasma cells, and macrophages) consistent with a pseudoaneurysm. Surgical excision resulted in resolution of clinical signs. CONCLUSIONS: Ultrasonography enabled prompt, noninvasive diagnosis of pseudoaneurysm. Angiography or computed tomography may be useful to aid diagnosis and assess the collateral blood supply to the manus before surgical treatment.