Scar revision for incompletely or narrowly excised soft tissue sarcomas in dogs.

Objective: Describe clinical features of dogs undergoing scar revision for incompletely or narrowly excised soft tissue sarcomas (STSs) in the absence of gross disease and to determine local recurrence rates following scar revision. Animals: Thirty-three dogs with 33 scars. Procedures: Medical records were reviewed to collect data on signalment, tumor details, pre-surgical diagnostic tests, surgical and pathologic findings for both the initial and revision surgeries, and clinical outcomes. Descriptive statistics were generated. Results: For the initial excision, cytology was performed before surgery in 45.5% (15/33) of dogs, and information on surgical margins was rarely reported [4.0% (1/25) of circumferential and 12.0% (3/25) of deep margins]. Microscopic evidence of residual STS was identified in 18.2% of scars. Recurrence occurred in 3.0% (1/33) of dogs [median follow-up of 1127 d (1 to 3192 d)]; this dog had had no evidence of residual tumor in the scar revision pathology. Conclusions: Despite the low identification rate of residual tumor, the local tumor recurrence rate was 3.0%, which is lower than what is historically reported for incompletely or narrowly excised STSs. Clinical relevance: Scar revision for incompletely or narrowly excised STSs resulted in durable tumor remission in the dogs of this study. Pre-surgical diagnostic tests were not often performed in this study; these may be considered before the first excision to plan surgical margins for potentially reducing the incidence of incomplete or narrow excision. Surgical reports should include details on circumferential and deep margins to guide pathologic interpretation and future scar revision, if required.

Révision des cicatrice pour les sarcomes des tissus mous incomplètement ou étroitement excisés chez le chien. Objectif: Décrire les caractéristiques cliniques des chiens subissant une révision de cicatrice pour des sarcomes des tissus mous (STSs) incomplètement ou étroitement excisés en l'absence de maladie macroscopique et pour déterminer les taux de récidive locale après la révision de cicatrice. Animaux: Trente-trois chiens avec 33 cicatrices. Procédures: Les dossiers médicaux ont été examinés pour recueillir des données sur le signalement, les détails de la tumeur, les tests de diagnostic pré-chirurgicaux, les résultats chirurgicaux et pathologiques pour les chirurgies initiales et de révision, et les résultats cliniques. Des statistiques descriptives ont été générées. Résultats: Pour l'excision initiale, une cytologie a été réalisée avant la chirurgie chez 45,5 % (15/33) des chiens, et les informations sur les marges chirurgicales ont été rarement rapportées [4,0 % (1/25) des marges circonférentielles et 12,0 % (3/25) des marges profondes]. Des preuves microscopiques de STS résiduel ont été identifiées dans 18,2 % des cicatrices. Une récidive est survenue chez 3,0 % (1/33) des chiens [suivi médian de 1127 jours (1 à 3192 jours)]; ce chien n'avait eu aucun signe de tumeur résiduelle dans la pathologie de révision de la cicatrice. Conclusions: Malgré le faible taux d'identification de tumeur résiduelle, le taux de récidive tumorale locale était de 3,0 %, ce qui est inférieur à ce qui est historiquement rapporté pour les STS incomplètement ou étroitement excisés. Pertinence clinique: La révision des cicatrices pour les STS incomplètement ou étroitement excisés a entraîné une rémission tumorale durable chez les chiens de cette étude. Les tests diagnostiques pré-chirurgicaux n'ont pas souvent été effectués dans cette étude; ceux-ci peuvent être envisagés avant la première excision pour planifier les marges chirurgicales afin de réduire potentiellement l'incidence de l'excision incomplète ou étroite. Les rapports chirurgicaux doivent inclure des détails sur les marges circonférentielles et profondes pour guider l'interprétation pathologique et la révision future de la cicatrice, si nécessaire.(Traduit par Dr Serge Messier).

Scar revision for incompletely or narrowly excised cutaneous mast cell tumors in dogs.

Objective: Describe clinical features and outcomes of dogs undergoing scar revision for incompletely or narrowly excised cutaneous mast cell tumors without gross disease. Animals: 52 dogs undergoing 54 scar revisions. Procedures: Retrospective record review with information collected on signalment, tumor type/location, pre-surgical diagnostics, surgical and pathologic findings for the first excision and scar revision surgeries, and follow-up. Descriptive statistics were generated. Results: Prior to initial excision, cytology was performed on 38.9% (21/54) of tumors and the initial surgery report rarely described surgical resection margins [14.6% (7/48) of surgeries]. Residual tumor was identified pathologically in 29.6% (16/54) of scars. Local recurrence following scar revision occurred in 3.7% (2/54) of all scars [median follow-up 881.5 d (range: 0 to 3317 d)]; both scars had either complete excision of residual mast cell tumor or no evidence of mast cell tumor on scar revision and neither dog received radiation therapy. Conclusions: Identification of residual disease was uncommon, and local recurrence was less common than previously reported for incomplete/narrow mast cell tumor excision. Clinical relevance: Scar revision of unplanned primary excisions appears to yield a high likelihood of durable tumor remission in patients. First opinion practitioners are encouraged to avoid unplanned excisions by informing the surgical plan with cytology of the primary tumor and detailing surgical margin excision which may facilitate revision, if necessary.

Révision des cicatrices pour des mastocytes cutanés incomplètement ou étroitement excisés chez le chien. Objectif: Décrire les caractéristiques cliniques et les résultats des chiens subissant une révision de cicatrice pour des tumeurs mastocytaires incomplètement ou étroitement excisées sans maladie grave. Animaux: Cinquante-deux chiens soumis à 54 révisions de cicatrice. Procédures: Examen rétrospectif des dossiers avec des informations recueillies sur le signalement, le type/l'emplacement de la tumeur, les diagnostics pré-chirurgicaux, les résultats chirurgicaux et pathologiques pour les premières chirurgies d'excision et de révision de cicatrice, et le suivi. Des statistiques descriptives ont été générées. Résultats: Avant l'excision initiale, une cytologie a été réalisée sur 38,9 % (21/54) des tumeurs et le rapport chirurgical initial décrivait rarement les marges de résection chirurgicale [14,6 % (7/48) des chirurgies]. Une tumeur résiduelle a été identifiée pathologiquement dans 29,6 % (16/54) des cicatrices. Une récidive locale après révision des cicatrices s'est produite dans 3,7 % (2/54) de toutes les cicatrices [suivi médian de 881,5 jours (intervalle : 0 à 3317 jours)] les deux cicatrices présentaient soit une excision complète du tumeur mastocytaire résiduel, soit aucun signe de tumeur mastocytaire lors de la révision de la cicatrice et aucun chien n'a reçu de radiothérapie. Conclusions: L'identification de la maladie résiduelle était rare et la récidive locale était moins fréquente que précédemment rapportée pour l'excision incomplète/étroite du tumeur mastocytaire. Pertinence clinique: La révision de la cicatrice des excisions primaires non planifiées semble donner une forte probabilité de rémission tumorale durable chez les patients. Les praticiens de première opinion sont encouragés à éviter les excisions non planifiées en informant le plan chirurgical avec la cytologie de la tumeur primaire et en détaillant les marges de l'excision chirurgicale ce qui peut faciliter la révision, si nécessaire.(Traduit par Dr Serge Messier).

Comparison of indirect computed tomographic lymphography and near-infrared fluorescence sentinel lymph node mapping for integumentary canine mast cell tumors.

OBJECTIVE: To compare the independent and combined use of indirect computed tomographic lymphography (ICTL) and near-infrared fluorescence (NIRF) for sentinel lymph node (SLN) mapping in dogs with integumentary mast cell tumors (MCT) and report the metastatic LN rate. STUDY DESIGN: Prospective clinical study. ANIMALS: Twenty client-owned dogs. METHODS: Dogs underwent preoperative ICTL, then intraoperative NIRF SLN mapping and excision of the anatomic lymph node (ALN) and/or SLN, and primary MCT. Technique agreement was complete if the same SLN was detected, and partial if the same SLN was detected along with additional SLN. No agreement occurred if the techniques detected different or no SLN. MCT were graded using two- and three-tier schemes, and LN were graded from HN0-3; HN2-3 were considered metastatic. RESULTS: Complete, partial, and no agreement between ICTL and NIRF was seen in 8/20 (40%), 8/20 (40%), and 4/20 (20%) dogs, respectively. Detection of ICTL-SLN and NIRF-SLN failed in 1/20 (5%) and 4/20 (20%), respectively. Tumors were grade II/low-grade in 19/20 (95%) and grade III/high-grade in 1/20 (5%) dogs. Nineteen out of 20 (95%) dogs had HN2-3 LN. CONCLUSIONS: Technique agreement of at least one SLN was seen in 16/20 (80%) dogs. Although most MCT were classified as intermediate to low grade, LN metastases were commonly detected. CLINICAL SIGNIFICANCE: Combining ICTL and NIRF for MCT SLN mapping yields high SLN detection rates. Lymph node metastasis may be more common than previously reported for intermediate to low grade MCT.

The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs.

OBJECTIVE: To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy. STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Sixteen client-owned dogs. METHODS: Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome. RESULTS: Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF. CONCLUSION: In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study. CLINICAL SIGNIFICANCE: Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.

Canine osteosarcoma cells exhibit basal accumulation of multiple chaperone proteins and are sensitive to small molecule inhibitors of GRP78 and heat shock protein function.

Osteosarcoma is the most common type of bone cancer in dogs and humans, with significant numbers of patients experiencing treatment failure and disease progression. In our search for new approaches to treat osteosarcoma, we previously detected multiple chaperone proteins in the surface-exposed proteome of canine osteosarcoma cells. In the present study, we characterized expression of representative chaperones and find evidence for stress adaptation in canine osteosarcoma cells relative to osteogenic progenitors from normal bone. We compared the cytotoxic potential of direct (HA15) and putative (OSU-03012) inhibitors of Grp78 function and found canine POS and HMPOS osteosarcoma cells to be more sensitive to both compounds than normal cells. HA15 and OSU-03012 increased the thermal stability of Grp78 in intact POS cells at low micromolar concentrations, but each induced distinct patterns in Grp78 expression without significant change in Grp94. Both inhibitors were as effective alone as carboplatin and showed little evidence of synergy in combination treatment. However, HMPOS cells with acquired resistance to carboplatin were sensitive to inhibition of Grp78 (by HA15; OSU-03012), Hsp70 (by VER-155008), and Hsp90 (by 17-AAG) function. These results suggest that multiple nodes within the osteosarcoma chaperome may be relevant chemotherapeutic targets against platinum resistance.

Dogs ≥ five years of age at the time of congenital extrahepatic portosystemic shunt diagnosis have better long-term outcomes with surgical attenuation than with medical management alone.

OBJECTIVE: To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only. ANIMALS: 351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age. PROCEDURES: Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time. RESULTS: 351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%. CLINICAL RELEVANCE: Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.

Intersurgeon agreement in determining 3 cm surgical margins of subcutaneous tumors in dogs.

OBJECTIVE: To evaluate intersurgeon agreement in performing a 3 cm wide surgical excision for subcutaneous malignancies in dogs. STUDY DESIGN: Prospective, blinded, randomized, clinical study. ANIMALS: Client-owned dogs with subcutaneous tumors undergoing curative-intent, wide surgical excision between April 2019 to March 2020. METHODS: Four surgeons, instructed to perform a 3 cm wide excision, each sequentially indicated their proposed skin incision locations around subcutaneous tumors, without knowledge of the other surgeons' proposed incisions. A tripod-mounted camera and laser positioning system were used to photograph each surgeon's proposed margin length. A random-effects model was used to estimate the standard deviation of margin lengths that would be expected from a random sample of surgeons. RESULTS: Each of the four surgeons provided 33 independent radial measurements from 11 tumors (six soft tissue sarcomas and five mast cell tumors), for a total of 132 radial measurements. No individual surgeon consistently proposed longer or shorter margin incision locations. The prediction interval for a future margin measurement was 6 mm, implying that the 95% confidence interval of an individual surgeon's margin length would be within ±6 mm of the mean margin length from a random sample of surgeons. CONCLUSION: Ninety-five percent of surgeons would be expected to deliver a surgical dose between 2.4-3.6 cm, for a theoretically uniform surgical dose of 3 cm wide margins. CLINICAL SIGNIFICANCE: Surgical doses are likely to vary at clinically relevant levels among surgeons, complicating design and interpretation of studies attempting to identify an ideal surgical dose.

Location of the targeted lymph node in a mandibular lymphocentrum: A needle aspiration model in canine cadavers.

Accurate tumour staging has a profound impact on the care and prognosis of oncologic patients. Due to the presence of multiple lymph nodes (LNs) in the mandibular lymphocentrum, clinicians may not know which specific LN they are sampling during routine fine needle aspirations, which introduces a source of uncertainty in accurately determining patient clinical stage. The objective of this cadaveric study was to determine the success of targeting specific mandibular LNs by palpation alone, verified by computed tomography (CT). A 1.5-inch, 22-gauge needle was inserted into the targeted LN (selected by drawing with the equal sample sizes of the left/right mandibular lymphocentrum and the lateral/medial node) and success was evaluated by CT images in transverse, sagittal and dorsal views. The overall success rate of inserting the needle into the targeted LN was 55.9%. One variable was significantly associated with successful needle insertion: lateral (vs. medial) LN location (p = .019). In addition, the distance from the LN to the ventral skin surface in the successful group appeared to be shorter compared to the unsuccessful group (3.37 mm [1.55-6.46] vs. 4.9 mm [1.57-17.79], p = .066). These findings suggest that physical accessibility of the LN is the most important factor for successful needle insertion using palpation. Palpation-based sampling of specific mandibular LNs is often inaccurate and if targeted sampling of a particular LN is required, additional methods should be used to guide accurate sample acquisition.

International Guidelines for Veterinary Tumor Pathology: A Call to Action.

Standardization of tumor assessment lays the foundation for validation of grading systems, permits reproducibility of oncologic studies among investigators, and increases confidence in the significance of study results. Currently, there is minimal methodological standardization for assessing tumors in veterinary medicine, with few attempts to validate published protocols and grading schemes. The current article attempts to address these shortcomings by providing standard guidelines for tumor assessment parameters and protocols for evaluating specific tumor types. More detailed information is available in the Supplemental Files, the intention of which is 2-fold: publication as part of this commentary, but more importantly, these will be available as "living documents" on a website (www.vetcancerprotocols.org), which will be updated as new information is presented in the peer-reviewed literature. Our hope is that veterinary pathologists will agree that this initiative is needed, and will contribute to and utilize this information for routine diagnostic work and oncologic studies. Journal editors and reviewers can utilize checklists to ensure publications include sufficient detail and standardized methods of tumor assessment. To maintain the relevance of the guidelines and protocols, it is critical that the information is periodically updated and revised as new studies are published and validated with the intent of providing a repository of this information. Our hope is that this initiative (a continuation of efforts published in this journal in 2011) will facilitate collaboration and reproducibility between pathologists and institutions, increase case numbers, and strengthen clinical research findings, thus ensuring continued progress in veterinary oncologic pathology and improving patient care.

Targeting Peritumoral Lesions Identified by Computed Tomography and Magnetic Resonance Imaging in Feline Injection-Site Sarcomas for Microscopic Examination.

Peritumoral lesions identified during in vivo imaging of feline injection-site sarcoma (FISS) are frequently interpreted as neoplastic. We recently showed that most peritumoral imaging-identified lesions (PTIILs) in FISS are non-neoplastic. In this article, we describe a protocol to target PTIIL for microscopic examination and report on the protocol's performance. Ten client-owned cats with FISS were prospectively enrolled. A fiducial marker sutured onto the skin, centered on the palpable mass, served as reference point throughout the study. Each FISS and surrounding tissue was imaged in vivo by dual phase computed tomography angiography and multiple magnetic resonance imaging pulse sequences and each PTIIL documented. Subgross measurements obtained during trimming aided localization and identification of PTIIL during microscopy. Histologic findings were categorized by descending clinical relevance: neoplastic, equivocal, non-neoplastic, within normal limits (WNL). Based on in vivo imaging resolution limits, histologic findings were ≥3 mm in at least one dimension and ≥3 mm apart. Surgical margins served as control tissue for PTIILs. Eighty-one of 87 PTIIL were examined histologically; 13 were neoplastic, 16 equivocal, and 28 non-neoplastic; 24 had no identified histologic correlate. Two neoplastic and 10 equivocal findings were located outside of PTIILs but none of them were located in sections of surgical margins. Computation of a simple confusion matrix yielded fair sensitivity (70.4%) and low specificity (59.7%) for prediction of PTIIL by histologic findings. After combining instances of normal microanatomy with non-neoplastic histologic findings, specificity increased (85.1%) and sensitivity decreased (35.8%). The protocol is a blueprint for targeting PTIIL for microscopic examination but may benefit from further refinement.

Experience level as a predictor of entry into the hypotympanum during feline total ear canal ablation and lateral bulla osteotomy.

OBJECTIVES: The study hypotheses were as follows: (1) owing to the unique anatomy of the feline middle ear, the hypotympanum would be entered in less than 100% of cats during total ear canal ablation and lateral bulla osteotomies (TECA-LBOs); and (2) incomplete penetration of the septum and subsequent failure to enter the hypotympanum is more likely to occur in surgeries performed by a novice surgeon when compared with an experienced surgeon and may be under-recognized. METHODS: Head CT was performed in 12 feline cadavers to confirm absence of gross ear disease. A novice surgeon and an experienced surgeon were randomly assigned to perform TECA-LBO on the left or right ear. Surgeons were blinded to each other's surgical technique. CT of cadavers was performed after the procedure. Successful penetration of the septum, entry into the hypotympanic cavity and amount of bone removed in bulla osteotomy, quantified via CT, were compared between the novice surgeon and experienced surgeon. RESULTS: The novice surgeon entered the hypotympanum in 3/12 (25%) procedures, compared with 9/12 (75%) procedures performed by the experienced surgeon. The experienced surgeon performed a larger osteotomy than the novice surgeon (3301 mm vs 1376 mm, P <0.0023). Regardless of surgeon experience, more bone was removed in surgeries in which the hypotympanum was entered. CONCLUSIONS AND RELEVANCE: Our results underscore the need for familiarity with feline middle ear anatomy when performing TECA-LBOs. Postoperative CT is recommended for novice surgeons to confirm entry into the hypotympanum.

Biological behaviour of primary osteosarcoma of the digits, metacarpal and metatarsal bones in dogs.

Osteosarcoma (OSA) arising from the digits, metatarsal and metacarpal bones is rare and may carry a better prognosis compared with other locations. The aim of this study was to retrospectively evaluate the biological behaviour, the progression free interval (PFI), the survival time (ST) and evaluate the effect of adjuvant chemotherapy for OSA affecting these bones. Medical records from two academic institutions were reviewed and 15 cases were included. Descriptive statistics were used for signalment and history. For estimation of median PFI and median ST, the Kaplan-Meier method was utilized. The prognostic effect of chemotherapy, lymphocyte and monocyte count was investigated. Log-rank analysis was used to compare PFI and ST between groups. The overall median PFI and median ST were 377 and 687 days, respectively. No significant differences were noted for any of the variables evaluated. In this study, dogs affected by OSA of digits, metacarpal and metatarsal bones appear to have a longer ST compared with dogs with OSA of other appendicular locations. A study with a larger number of patients is needed to confirm these results and investigate the potential benefit of adjuvant chemotherapy.

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.

Partial cystectomy with a bipolar sealing device in seven dogs with naturally occurring bladder tumors.

OBJECTIVE: To describe the use of a bipolar sealing device (BSD) for partial cystectomy in dogs undergoing excision of bladder tumors. STUDY DESIGN: Multicenter, prospective, clinical pilot study. SAMPLE POPULATION: Seven client-owned dogs with nontrigonal urinary bladder lesions. METHODS: Dogs underwent a sealed partial cystectomy with a BSD, with or without cystoscopic guidance of the resection. The sealed cystectomy site was oversewn with a single-layer simple continuous pattern with monofilament absorbable suture. RESULTS: Sealed partial cystectomy was successfully performed in all dogs, with a median surgical duration of 69 minutes (range, 50-120). Lesions were located at the apex in six dogs and on the ventral midbody of the bladder in one dog. No urine leakage from the BSD luminal seal was visible prior to suture closure in three dogs, while varying amounts of urine leaked from the sealed site in four dogs. Suture was placed over the seal in grossly normal bladder tissue in six dogs and in the BSD peripheral thermal effect zone in one dog; in this latter dog, revision cystorrhaphy was required 3 days later because of uroabdomen. The other six dogs had no clinical evidence of urinary bladder healing complications. CONCLUSION: The integrity of the seal generated by the BSD tested here on partial cystectomies varied between dogs and was unpredictable. CLINICAL SIGNIFICANCE: Sealed partial cystectomy with a BSD may reduce exposure of urinary bladder luminal contents to the surgical site. However, the placement of sutures over the seal and through grossly normal bladder tissue is recommended to prevent postoperative uroabdomen.

Histologically low-grade, yet biologically high-grade, canine cutaneous mast cell tumours: A systematic review and meta-analysis of individual participant data.

Low-grade canine cutaneous mast cell tumour (cMCT) with metastasis at the time of treatment is uncommonly reported, with few studies focusing on this specific clinical entity. The specific objective of this study was to systematically review the veterinary literature and perform a meta-analysis summarizing the clinical presentation, treatments reported and clinical outcomes from dogs with histologically low-grade cMCT and metastasis present at initial treatment. A total of 980 studies were screened with eight publications providing data on 121 dogs ultimately included. The most common treatments were surgery with adjuvant chemotherapy in 83/121 (69%) dogs; combined surgery, radiation and chemotherapy in 17/121 (14%) dogs; chemotherapy alone in 12/121 (10%) dogs and surgery alone in 7/121 (6%) dogs. Dogs with distant metastasis (n = 22) experienced significantly shorter survival compared with those with regional lymph node (RLN) metastasis (n = 99; median 194 vs 637 days; P < .01). Two variables were significantly associated with increased risk of death: presence of distant (vs RLN) metastasis (hazard ratio = 2.60; P < .01) and not receiving surgery as a component of treatment (hazard ratio = 3.79; P < .01). Risk of bias was judged to be low in terms of selection and performance bias but high in terms of detection and exclusion bias. In conclusion, dogs with cMCT and RLN metastasis can be expected to live significantly longer than those with distant metastasis, and surgery appears to have a role in extending survival of metastatic low-grade cMCT.

Delineation of hypoxia-induced proteome shifts in osteosarcoma cells with different metastatic propensities.

Osteosarcoma (OS) is the most common bone cancer in children and young adults. Solid tumors are characterized by intratumoral hypoxia, and hypoxic cells are associated with the transformation to aggressive phenotype and metastasis. The proteome needed to support an aggressive osteosarcoma cell phenotype remains largely undefined. To link metastatic propensity to a hypoxia-induced proteotype, we compared the protein profiles of two isogenic canine OS cell lines, POS (low metastatic) and HMPOS (highly metastatic), under normoxia and hypoxia. Label-free shotgun proteomics was applied to comprehensively characterize the hypoxia-responsive proteome profiles in the OS cell phenotypes. Hypothesis-driven parallel reaction monitoring was used to validate the differential proteins observed in the shotgun data and to monitor proteins of which we expected to exhibit hypoxia responsiveness, but which were absent in the label-free shotgun data. We established a "distance" score (|zHMPOS - zPOS|), and "sensitivity" score (|zHypoxia - zNormoxia) to quantitatively evaluate the proteome shifts exhibited by OS cells in response to hypoxia. Evaluation of the sensitivity scores for the proteome shifts observed and principal component analysis of the hypoxia-responsive proteins indicated that both cell types acquire a proteome that supports a Warburg phenotype with enhanced cell migration and proliferation characteristics. Cell migration and glucose uptake assays combined with protein function inhibitor studies provided further support that hypoxia-driven adaption of pathways associated with glycolytic metabolism, collagen biosynthesis and remodeling, redox regulation and immunomodulatory proteins typify a proteotype associated with an aggressive cancer cell phenotype. Our findings further suggest that proteins involved in collagen remodeling and immune editing may warrant further evaluation as potential targets for anti-metastatic treatment strategies in osteosarcoma.

Long-term clinical outcomes of dogs with single congenital extrahepatic portosystemic shunts attenuated with thin film banding or ameroid ring constrictors.

OBJECTIVE: To compare long-term clinical outcomes of dogs with single congenital extrahepatic portosystemic shunts (CEHPSS) treated with thin film banding (TFB) consisting of polyolefin fiber or ameroid ring constrictor (ARC) placement in dogs. DESIGN: Retrospective, two-center clinical study. ANIMALS: Client-owned dogs (n = 123) with single CEHPSS undergoing gradual attenuation via TFB (n = 85) or ARC (n = 38). METHODS: Medical records of dogs with CEHPSS were reviewed. Follow-up data were collected from the referring veterinarian and/or owner via standardized questionnaire. Data were analyzed to compare short-term mortality rate and long-term outcome (>6 months). RESULTS: Dogs in the TFB group were older than dogs in the ARC group (median age, 19 vs 12 months, respectively; P = .01). There was no difference in survival to discharge between dogs in the TFB (81/85 [95.3%]) and ARC (37/38 [97.4%]; P > .99) groups. Preoperative levetiracetam was more frequently administered to dogs treated with TFB (64/85 [75.3%]) than to dogs treated with ARC (15/38 [39.5%;] P = .0002). Postoperative seizures were reported in 10 (8.1%) dogs; their prevalence did not differ between dogs treated with TFB (9/85 [10.6%]) and dogs treated with ARC (1/38 [2.6%]; P = .17). Median follow-up time for dogs treated with TFB (58.0 months, range 8-130) and ARC (63.3 months, range 7-138; P = .24) did not differ. CONCLUSION: Gradual attenuation of a single CEHPSS with either TFB or ARC resulted in similar long-term clinical outcomes and low postoperative morbidity and mortality rates. CLINICAL SIGNIFICANCE: Thin film banding (polyolefin fiber) offers an alternative leading to clinical outcomes similar to ARC in dogs with single CEHPSS.

Long-term outcomes of dogs undergoing surgical resection of mast cell tumors and soft tissue sarcomas: A prospective 2-year-long study.

OBJECTIVE: Report clinical outcomes of dogs with surgically excised mast cell tumors (MCT) and soft tissue sarcomas (STS). STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Fifty-three dogs with 52 MCT (50 low grade, 2 high grade) and 19 STS (12 grade I, 6 grade II, 1 grade III). METHODS: All dogs were examined at 3, 6, 12, 18, and 24 months postoperatively, with cytologic or histopathologic evaluation of suspected local recurrences. Dogs euthanized because of study tumor-related causes underwent necropsy. RESULTS: Median intraoperative margins were 20 mm and 30 mm wide for MCT and STS, respectively, with 1 fascial plane resected en bloc. The narrowest histologic tumor-free margins measured <1 mm in 21 of 52 (40%) MCT and 7 of 19 (37%) STS. All dogs were followed for 24 months. Two of 50 (4%) low-grade MCT were diagnosed, with local recurrence 181 and 265 days postoperatively. Two of 36 (6%) dogs with low-grade MCT developed visceral metastasis 181 and 730 days postoperatively. One of 2 dogs with high-grade MCT developed local recurrence 115 days postoperatively. No local recurrence or metastasis was diagnosed after excision of 19 STS. CONCLUSION: Local recurrence rates among predominantly low- to intermediate-grade MCT and STS were low, despite a high prevalence of histologic tumor-free margins <1 mm. Surgical recommendations for high-grade tumors cannot be extrapolated from this population. CLINICAL SIGNIFICANCE: Surgeons should seek to achieve microscopically complete excision for MCT and STS while minimizing patient morbidity and considering limitations of histopathology in predicting outcomes.

Influence of use of a bipolar vessel sealing device on short-term postoperative mortality after splenectomy: 203 dogs (2005-2018).

OBJECTIVE: To compare short-term postoperative mortality in dogs after splenectomy performed with or without a bipolar vessel sealing device (BVSD) and to identify variables associated with mortality. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Client-owned dogs (n = 203). METHODS: Medical records of dogs that underwent splenectomy from 2005-2018 were reviewed. Mortality rates were compared between dogs that underwent splenectomy with or without BVSD. Causes of death and variables associated with short-term mortality were assessed. RESULTS: Fifteen of 203 (7.4%) dogs died prior to discharge, and seven (3.4%) dogs died prior to suture removal for a total short-term mortality rate of 22 of 203 (10.8%). The estimated difference in proportion of deaths prior to discharge between the BVSD and non-BVSD groups was -0.01 (95% confidence interval = -0.08 to 0.06). Duration of anesthesia was longer when splenectomy was performed without BVSD (median 168 vs 152 minutes; P = .03). Multivariate analysis identified intraoperative (odds ratio [OR] 5.7) or postoperative (OR 13.6) administration of blood products, increasing duration of anesthesia (OR 1.15 per additional 16 minutes), and intraoperative ventricular arrhythmias (OR 6.8) as significantly associated with death prior to discharge. Intraoperative (OR 3.2) or postoperative (OR 7.7) administration of blood products was associated with death prior to suture removal. CONCLUSION: Use of a BVSD did not appear to increase short-term mortality after splenectomy. CLINICAL SIGNIFICANCE: Dogs undergoing splenectomy that require intraoperative or postoperative transfusions, experience intraoperative ventricular arrhythmias, or have prolonged anesthesia may be at risk for death in the short-term postoperative period.