Professor Nicholas James Bacon FRCVS
Academic and research departmentsSchool of Veterinary Medicine, Faculty of Health and Medical Sciences.
OBJECTIVE To compare erythrocyte recovery by a cell salvage device between swab-washing by manual agitation or filtration. SAMPLE 12 recently expired units of canine packed RBCs. PROCEDURE The packed RBC units underwent quality analysis before donation from a pet blood bank. Each unit was volume-expanded with anticoagulant and subsequently divided into 2 equal aliquots used to soak surgical swabs before washing. Two different swab-washing techniques were evaluated—standard swab-washing–manual agitation (SW-MA) and swab-washing–filtration (SW-F)—with a novel prototype device. The resulting bloody fluid was processed using the Cell Saver Elite Autotransfusion System (Haemonetics). The volume, manual PCV, CBC, and RBC mass, calculated as the product of the volume and PCV, were measured before and after salvaging. Last, the RBC mass recovery was recorded as a percentage. RESULTS The RBC mass recovered from SW-MA and SW-F averaged 85.73% and 83.99%, respectively. There was no significant difference in RBC recovery between the 2 methods (P = .52). CLINICAL RELEVANCE SW-MA and SW-F recovered a similar quantity of RBCs from blood-soaked swabs in an ex vivo setting.
Objective To determine the ability of a cell salvage device to recover canine erythrocytes by direct aspiration of diluted packed red blood cells (pRBC) and saline rinse from blood-soaked surgical swabs. Study design Experimental study. Sample population Twelve recently expired units of canine pRBC. Methods pRBC units donated from a pet blood bank (after quality analysis) were diluted with anticoagulant, divided into two equal aliquots, and subsequently harvested by direct suction (Su), or soaked into swabs, saline-rinsed and suctioned (Sw). The volume of product, manual packed cell volume (PCV), and red blood cell mass (rbcM) were measured and compared before and after salvaging. The rbcM recovery was recorded as percentage ([rbcM post salvage]/[rbcM presalvage]x100). Statistical analysis of all measured values was performed (significance p
The definitive diagnosis of canine soft-tissue sarcomas (STSs) is based on histological assessment of formalin-fixed tissues. Assessment of parameters, such as degree of differentiation, necrosis score and mitotic score, give rise to a final tumour grade, which is important in determining prognosis and subsequent treatment modalities. However, grading discrepancies are reported to occur in human and canine STSs, which can result in complications regarding treatment plans. The introduction of digital pathology has the potential to help improve STS grading via automated determination of the presence and extent of necrosis. The detected necrotic regions can be factored in the grading scheme or excluded before analysing the remaining tissue. Here we describe a method to detect tumour necrosis in histopathological whole-slide images (WSIs) of STSs using machine learning. Annotated areas of necrosis were extracted from WSIs and the patches containing necrotic tissue fed into a pre-trained DenseNet161 convolutional neural network (CNN) for training, testing and validation. The proposed CNN architecture reported favourable results, with an overall validation accuracy of 92.7% for necrosis detection which represents the number of correctly classified data instances over the total number of data instances. The proposed method, when vigorously validated represents a promising tool to assist pathologists in evaluating necrosis in canine STS tumours, by increasing efficiency, accuracy and reducing inter-rater variation.
Necrosis seen in histopathology Whole Slide Images is a major criterion that contributes towards scoring tumour grade which then determines treatment options. However conventional manual assessment suffers from inter-operator reproducibility impacting grading precision. To address this, automatic necrosis detection using AI may be used to assess necrosis for final scoring that contributes towards the final clinical grade. Using deep learning AI, we describe a novel approach for automating necrosis detection in Whole Slide Images, tested on a canine Soft Tissue Sarcoma (cSTS) data set consisting of canine Perivascular Wall Tumours (cPWTs). A patch-based deep learning approach was developed where different variations of training a DenseNet-161 Convolutional Neural Network architecture were investigated as well as a stacking ensemble. An optimised DenseNet-161 with post-processing produced a hold-out test F1-score of 0.708 demonstrating state-of-the-art performance. This represents a novel first-time automated necrosis detection method in the cSTS domain as well specifically in detecting necrosis in cPWTs demonstrating a significant step forward in reproducible and reliable necrosis assessment for improving the precision of tumour grading.
OBJECTIVES: To evaluate intraoperative irradiation (IORT) as a method of limb spare with preservation of the radiocarpal joint. STUDY DESIGN: Prospective case series. ANIMALS: Dogs (n=5) with stage II sarcoma of the distal aspect of the radius. METHODS: A bone segment containing the tumor was isolated surgically, treated by IORT, reimplanted, and secured by internal fixation. In 1 dog, the postradiation tumor bed was curetted and filled with bone cement. Dogs were administered alternating adriamycin and carboplatin starting 2 weeks after IORT and monitored at regular intervals. RESULTS: Four dogs had osteosarcoma and 1 had undifferentiated sarcoma. Implant failure (n=3), deep tissue infection (3), and pathologic fracture (3) resulted in amputation (3) or pancarpal plating (2). The dog with undifferentiated sarcoma was euthanatized because of suspected tumor recurrence 4 months postoperatively. Osteotomy healing was documented by radiography (1), histopathology (2), or by direct observation (2). CONCLUSIONS: A technique for limb-sparing surgery of the distal portion of the radius in dogs using IORT had advantages include healing of the autograft and a source for a perfectly fitting autograft but did not appear to offer any advantage with respect to infection rate. Long-term preservation of the radiocarpal joint was not successful. CLINICAL RELEVANCE: It was not possible to preserve the function of the radiocarpal joint and so this technique cannot be recommended currently. Further study is needed to evaluate whether or not IORT can be considered in combination with pancarpal plating and possibly curettage and cementation of the tumor to prevent subchondral bone collapse.
Vacuum-assisted closure (VAC) is a wound management therapy that creates local negative pressure over a wound bed to promote healing. Benefits of VAC therapy include removal of fluid from the extravascular space, improved circulation, enhanced granulation tissue formation, increased bacterial clearance, and hastening of wound closure. This article describes the mechanism of action of VAC therapy, reviews application techniques, and lists potential complications and contraindications.
© 2013 John Wiley & Sons, Ltd.The parathyroid glands in dogs and cats are tan-colored ovoid structures closely associated with each thyroid gland. Parathyroid hormone (PTH) release is controlled by calcium receptors on the chief cells in the parathyroid glands in response to hypocalcemia. PTH has a short half-life (3-5 min) in serum and so a steady rate of secretion is necessary to maintain serum PTH concentrations. Natural variations in PTH concentration occur in healthy dogs. Exploratory surgery with parathyroidectomy in dogs with primary hyperparathyroidism serves as both a diagnostic test and definitive therapy. Surgery should be advocated to reduce the risk of urolithiasis and urinary tract infection, as well as improving the clinical signs seen with hypercalcemia such as polydipsia, polyuria, weakness, and decreased appetite. Surgical excision alone is the most widely performed treatment for primary hyperparathyroidism and a cure rate of 94% is reported if all autonomously functioning parathyroid tissue is removed.
The purpose of this retrospective study was to compare the accuracy of computed tomographic angiography (CTA) and abdominal ultrasonography in detecting and characterizing portosystemic shunts (PSS) in dogs. Medical records of 76 dogs that underwent CTA and/or abdominal ultrasonography suspected to have PSS were reviewed. Presence or absence, and characterization of PSS (when present) on CTA were reviewed by a board-certified veterinary radiologist that was blinded to the clinical findings. The abdominal ultrasonography findings were reviewed from the medical records. Visualization and description of the origin and insertion of PSS on CTA and abdominal ultrasonography were related with laboratory, surgical, or mesenteric portographic confirmation of the presence or absence of PSS. The sensitivity for detection of PSS with CTA (96%) was significantly higher than abdominal ultrasonography (68%; P < 0.001). The specificities for CTA and abdominal ultrasonography were 89% and 84%, respectively (P = 0.727). Computed tomographic angiography detected the correct origin in 15 of 16 dogs and correct insertion in 15 of 16 dogs with congenital PSS. Abdominal ultrasonography detected the correct origin in 24 of 30 dogs and correct insertion in 20 of 33 dogs with congenital PSS. Multiple acquired PSS were seen in four of five dogs and in one of six dogs on CTA and abdominal ultrasonography, respectively. Computed tomographic angiography was 5.5 times more likely to correctly ascertain the presence or absence of PSS when compared to abdominal ultrasonography (P = 0.02). Findings indicated that CTA is a noninvasive diagnostic modality that is superior to abdominal ultrasonography for the detection and characterization of PSS in dogs.
CASE DESCRIPTION 4 dogs were examined because of pleural effusion and ventricular tachycardia, coughing and supraventricular tachycardia, appendicular osteosarcoma, and syncopal episodes. CLINICAL FINDINGS In all 4 dogs, a heart base tumor was identified by means of thoracic CT. TREATMENT AND OUTCOME In all 4 dogs, the heart base tumors were treated by means of stereotactic body radiation therapy. Dogs were anesthetized, and neuromuscular blockade was achieved with atracurium or vecuronium. A circle rebreathing system with 15 m (50 feet) of anesthetic tubing coursing through the vault wall was used to connect the patient to the anesthesia machine, which was located in the control room. After a brief period of hyperventilation, an inspiratory breath was held at 20 cm H2O for the duration of beam delivery. Each beam delivery lasted between 30 and 100 seconds. Immediately following the breath hold, assisted ventilation was resumed. Mean treatment delivery time for each patient was 26 minutes; mean total anesthesia time was 89 minutes. All patients recovered without complications. There was no evidence of hemoglobin desaturation or hypercapnia during the anesthetic procedure.
Vacuum-assisted closure (VAC) is a wound management system that exposes a wound bed to local negative pressure to promote healing. Benefits of VAC therapy include removal of fluid from the extravascular space, improved circulation, enhanced granulation tissue formation, and increased bacterial clearance. VAC therapy has been used extensively in human patients to treat a variety of acute and chronic wound conditions. This article reviews the use of VAC therapy in a variety of wound conditions and describes our experiences with using VAC therapy in dogs and cats at the University of Florida. © Copyright 2010 MediMedia Animal Health.
© 2015, Universidad de Antioquia. All rights reserved.Background: vascular access ports (VAPs) are designed to allow repeated access to the vascular system with minimum patient distress. Objective: to describe the surgical technique, care and complications of jugular VAPs currently used at the Veterinary Oncology Service of the University of Florida Small Animal Hospital. Conclusion: the VAPs can remain in site for long terms (months) with minimum complications, and its placement is a reliable technique that should be considered by veterinarians, particularly for a long-term treatment.
Yunnan Baiyao is a Chinese herbal medicine that has been utilized for its anti-inflammatory, haemostatic, wound healing and pain relieving properties in people. It has been utilized in the veterinary profession to control bleeding in dogs with hemangiosarcoma (HSA) and has been anecdotally reported to prolong survival times in dogs with this neoplasm. This study evaluated the in vitro activity of Yunnan Baiyao against three canine HSA cell lines after treatment with increasing concentrations of Yunnan Baiyao (50, 100, 200, 400, 600 and 800 µg mL(-1) ) at 24, 48 and 72 h. Mean half maximum inhibitory concentration (IC50 ) at 72 h for DEN, Fitz, SB was 369.9, 275.9 and 325.3 µg mL(-1) , respectively. Caspase-3/7 activity increased in correlation with the IC50 in each cell line which was confirmed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL, APO-BRDU Kit; BD Biosciences, San Jose, CA, USA) assay. VEGF in cell supernatant was also quantified. Overall, the study found that Yunnan Baiyao causes dose and time dependent HSA cell death through initiation of caspase-mediated apoptosis, which supports future studies involving Yunnan Baiyao.
OBJECTIVE: To evaluate clinical outcome of dogs with appendicular osteosarcoma (OSA) treated with stereotactic radiosurgery (SRS) and subsequent internal fixation of a pathologic fracture. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs with spontaneous-occurring appendicular OSA (n = 6). METHODS: Medical records (May 2002-January 2008) of dogs that had SRS for appendicular OSA were reviewed. Dogs were included if they had a pathologic fracture either before or after SRS and were treated with internal fixation. Signalment, history, physical examination findings, clinicopathologic data, diagnostic imaging findings, biopsy results, surgical complications, number of surgeries, adjuvant therapy, development of metastatic disease and cause of death were recorded. RESULTS: Six dogs met the inclusion criteria. Two dogs had a pathologic fracture at admission and 4 dogs developed a fracture after SRS with a mean ± SD time to fracture development of 6.25 ± 1.65 months. The first 3 fractures were repaired using an open approach and the latter three using minimally invasive percutaneous osteosynthesis (MIPO). Infection occurred in 5 dogs and implant failure in 3. Limb function was subjectively assessed as good in all dogs when the implants were stable and infections were subclinical. Survival times ranged from 364-897 days; 1 dog was lost to follow-up. CONCLUSIONS: Fracture repair using internal fixation should be considered a viable limb-sparing alternative for pathologic fractures that have been treated with SRS.
A 10.5-year-old crossbreed dog was presented with a history of hypoglycaemic episodes and elevated serum insulin concentration. A pancreatic mass was removed at surgery along with an enlarged draining lymph node. An unresectable hepatic nodule was also present. Immunohistochemistry confirmed the pancreatic and lymph node masses as functional mixed acinar-endocrine carcinoma, previously unreported in domestic species. Persistent hypoglycaemia and hyperinsulinaemia post-operatively was highly suggestive of the hepatic mass being a functional metastasis. The dog was managed on prednisolone and remained asymptomatic 9 months post-operatively. This tumour type has only been rarely reported in human patients and may highlight the need for more rigorous immunohistochemical staining of pancreatic masses in veterinary species to identify the prevalence of this tumour type.
Vacuum-assisted closure (VAC) is a wound management system that exposes a wound bed to local negative pressure to promote healing. Benefits of VAC therapy include removal of fluid from the extravascular space, improved circulation, enhanced granulation tissue formation, and increased bacterial clearance. VAC therapy has been used extensively in human patients to treat a variety of acute and chronic wound conditions. This article reviews the use of VAC therapy in a variety of wound conditions and describes our experiences with using VAC therapy in dogs and cats at the University of Florida.
Objective: The aim of this study was to investigate the prevalence of pulmonary nodules at presentation in cases of soft tissue sarcoma (STS) in dogs with no previous thoracic imaging. Animals: Client-owned dogs with a histologic diagnosis of STS. Procedures: Dogs were retrospectively included in this study if the first thoracic imaging performed was at the time of presentation to our referral center. De novo and recurrent tumors were included, and information regarding tumor grade, history (primary mass vs scar vs recurrence), duration, location and size was also collected. Results: One hundred and forty-six dogs were included. Routine staging was performed with computed tomography (131 dogs, 89.7%) or 3-view thoracic radiographs (15 dogs, 10.3%). STS were grade 1 in 55.5% of dogs, grade 2 in 27.4% and grade 3 in 17.1%. Pulmonary nodules suggestive of metastasis were present in 11.7% of cases overall and in 6.5%, 5.6% and 37.5% of grade 1, grade 2 and grade 3 STS cases, respectively. Tumor grade (low/intermediate versus high) and tumor duration ( 3 months) were significantly associated with presence of pulmonary nodules at presentation. Conclusions and Clinical Relevance: This is the first large study reporting prevalence of pulmonary nodules at presentation in dogs with STS having had no previous thoracic imaging. The prevalence of pulmonary nodules suggestive of metastasis at presentation is low (