Predictive ability of fine-needle aspirate cytology for incompletely resected mast cell tumor surgical sites.

The goal of this study was to evaluate whether fine-needle aspirate cytology of a previous surgical site was predictive of recurrence for incompletely excised mast cell tumors (MCTs). Electronic medical records were searched for dogs diagnosed with MCTs; those with histologically confirmed, incompletely resected MCTs evaluated by scar aspiration cytology within 60 days after surgery were included for analysis. Variables were compared between groups using Fisher's exact test and logistic regression. Twenty-nine cutaneous and 7 subcutaneous tumors were evaluated. Local recurrence, confirmed by either histopathology or cytology, occurred in 13.8% of cases. No significant differences were identified for any variables other than surgical site cytology status. The negative predictive value of surgical site aspirate cytology without residual mast cell tumor was 93.5%, with an overall predictive accuracy of 88.9%. For the dogs evaluated in this report, surgical site aspiration cytology was predictive of local disease control for incompletely resected MCTs.

Capacité prédictive de la cytologie d'aspiration à l'aiguille fine de sites de chirurgie de résection incomplète de mastocytomes. L'objectif de la présente étude était d'évaluer si la cytologie d'aspiration à l'aiguille fine d'un site chirurgical antérieur permettait de prédire une récurrence lors de l'excision incomplète d'un mastocytome (MCT). Les dossiers médicaux électroniques furent examinés pour trouver des chiens avec un diagnostic de MCT; ceux avec confirmation histologique d'un MCT avec résection incomplète évaluée par cytologie d'une aspiration de la cicatrice en dedans de 60 jours après la chirurgie furent inclus pour analyse. Les variables furent comparées entre les groupes en utilisant le test exact de Fisher et une régression logistique. Vingt-neuf tumeurs cutanées et sept tumeurs sous-cutanées furent évaluées. Une récurrence locale, confirmée par histopathologie ou cytologie, est survenue dans 13,8 % des cas. Aucune différence significative ne fut détectée pour les différentes variables autres que le statut de la cytologie du site chirurgical. La valeur prédictive négative de la cytologie d'une aspiration du site chirurgical sans cellule résiduelle du mastocytome était de 93,5 % avec une précision prédictive globale de 88,9 %. Pour les chiens examinés dans cette étude, la cytologie d'une aspiration du site chirurgical était prédictive d'une maîtrise locale de la maladie lors de résection incomplète d'un MCT.(Traduit par Dr Serge Messier).

Total laryngectomy and permanent tracheostomy in six dogs.

The objective of this report is to describe the surgical technique for total laryngectomy and outcome in six dogs. Laryngeal cancer is an uncommon and challenging clinical problem. Total laryngectomy can provide local disease control but is uncommonly performed. Detailed procedural descriptions are limited and similarly limited information is available regarding patient outcome. Institutional medical records were searched for dogs treated with total laryngectomy. Six dogs were identified. The procedure resulted in postoperative quality of life similar to permanent tracheostomy alone. Surgical margin status was evaluated in five of six cases and was complete in those five. All dogs survived to discharge from the hospital. Complications were mostly related to tracheostomy occlusion or collapse which is recognized as a complication associated with permanent tracheostomy. Patient quality of life was acceptable. Local recurrence was suspected in one dog. Recurrence was not observed in the case with unknown margin status.

Total prostatectomy as a treatment for prostatic carcinoma in 25 dogs.

OBJECTIVE: To describe the complications and outcome after total prostatectomy in dogs with histologically confirmed prostatic carcinoma. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: 25 client-owned dogs. METHODS: Medical records of dogs undergoing total prostatectomy were reviewed from 2004 to 2016. Data retrieved included signalment, presenting signs, preoperative clinical findings, laboratory data, diagnostic imaging, surgical technique, histologic diagnosis, postoperative complications, occurrence of postoperative metastasis, and survival. RESULTS: Twenty-five dogs underwent total prostatectomy for prostatic carcinoma. Urinary anastomotic techniques included urethrourethral anastomosis in 14 dogs, cystourethral anastomosis in 9 dogs, ureterocolonic anastomosis in 1 dog, and anastomosis between the bladder neck and penile urethra in 1 dog. All dogs survived to discharge. Fifteen dogs were diagnosed with transitional cell carcinoma, 8 dogs with prostatic adenocarcinoma, 1 with prostatic cystadenocarcinoma, and 1 with an undifferentiated carcinoma. Permanent postoperative urinary incontinence was present in 8 of 23 dogs. The median survival time was shorter in dogs with extracapsular tumor extension compared with those with intracapsular tumors. The overall median survival time was 231 days (range, 24-1255), with 1- and 2-year survival rates equal to 32% and 12%, respectively. CONCLUSION AND CLINICAL SIGNIFICANCE: Total prostatectomy, combined with adjunct therapies, prolongs survival and lowers complication rates compared to previous reports of dogs with prostatic carcinoma. It should be noted, however, that case selection likely played a significant role in postoperative outcome.

A comparison of microRNA expression profiles from splenic hemangiosarcoma, splenic nodular hyperplasia, and normal spleens of dogs.

BACKGROUND: Splenic masses are common in older dogs; yet diagnosis preceding splenectomy and histopathology remains elusive. MicroRNAs (miRNAs) are short, non-coding RNAs that play a role in post-transcriptional regulation, and differential expression of miRNAs between normal and tumor tissue has been used to diagnose neoplastic diseases. The objective of this study was to determine differential expression of miRNAs by use of RNA-sequencing in canine spleens that were histologically confirmed as hemangiosarcoma, nodular hyperplasia, or normal. RESULTS: Twenty-two miRNAs were found to be differentially expressed in hemangiosarcoma samples (4 between hemangiosarcoma and both nodular hyperplasia and normal spleen and 18 between hemangiosarcoma and normal spleen only). In particular, mir-26a, mir-126, mir-139, mir-140, mir-150, mir-203, mir-424, mir-503, mir-505, mir-542, mir-30e, mir-33b, mir-365, mir-758, mir-22, and mir-452 are of interest in the pathogenesis of hemangiosarcoma. CONCLUSIONS: Findings of this study confirm the hypothesis that miRNA expression profiles are different between canine splenic hemangiosarcoma, nodular hyperplasia, and normal spleens. A large portion of the differentially expressed miRNAs have roles in angiogenesis, with an additional group of miRNAs being dysregulated in vascular disease processes. Two other miRNAs have been implicated in cancer pathways such as PTEN and cell cycle checkpoints. The finding of multiple miRNAs with roles in angiogenesis and vascular disease is important, as hemangiosarcoma is a tumor of endothelial cells, which are driven by angiogenic stimuli. This study shows that miRNA dysregulation is a potential player in the pathogenesis of canine splenic hemangiosarcoma.

Effect of histologic processing on dimensions of skin samples obtained from cat cadavers.

OBJECTIVE To determine changes in dimensions of feline skin samples as a result of histologic processing and to identify factors that contributed to changes in dimensions of skin samples after sample collection. SAMPLE Cadavers of 12 clinically normal cats. PROCEDURES Skin samples were obtained bilaterally from 3 locations (neck, thorax, and tibia) of each cadaver; half of the thoracic samples included underlying muscle. Length, width, and depth were measured at 5 time points (before excision, after excision, after application of ink to mark tissue margins, after fixation in neutral-buffered 10% formalin for 36 hours, and after completion of histologic processing and staining with H&E stain). Measurements obtained after sample collection were compared with measurements obtained before excision. RESULTS At the final time point, tissue samples had decreased in length (mean decrease, 32.40%) and width (mean decrease, 34.21%) and increased in depth (mean increase, 54.95%). Tissue from the tibia had the most shrinkage in length and width and that from the neck had the least shrinkage. Inclusion of underlying muscle on thoracic skin samples did not affect the degree of change in dimensions. CONCLUSIONS AND CLINICAL RELEVANCE In this study, each step during processing from excision to formalin fixation and histologic processing induced changes in tissue dimensions, which were manifested principally as shrinkage in length and width and increase in depth. Most of the changes occured during histologic processing. Inclusion of muscle did not affect thoracic skin shrinkage. Shrinkage should be a consideration when interpreting surgical margins in clinical cases. 945).

Role of surgery in multimodal cancer therapy for small animals.

Surgery is a critical component in the treatment of most solid tumors in small animals. Surgery is increasingly combined with adjuvant therapies such as chemotherapy and radiation so surgeons who are treating cancer must have a good understanding of surgical oncology principles, cancer biology, and the roles and potential interactions of surgery, radiation, and chemotherapy. The sequencing plan for these modalities should be determined before treatment is initiated. The surgical oncologist must have a working knowledge of chemotherapy agents and radiation and the effect of these treatments on the ability of tissues to heal and the outcome for the patient.

Hemipelvectomy: outcome in 84 dogs and 16 cats. A veterinary society of surgical oncology retrospective study.

OBJECTIVE: To report clinical findings, perioperative complications and long-term outcome in dogs and cats that had hemipelvectomy surgery for treatment of neoplasia. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Dogs (n = 84) and cats (16). METHODS: Medical records (January 2000 to December 2009) of dogs and cats that had hemipelvectomy at participating institutions were reviewed. Postoperative progress and current status of the patient at the time of the study was determined by either medical record review, or via telephone contact with the referring veterinarian or owner. RESULTS: Complications were infrequent and usually minor. Hemorrhage was the main intraoperative complication; 2 dogs required blood transfusion. One dog developed an incisional hernia. In dogs, hemangiosarcoma had the worst prognosis with a median survival time (MST) of 179 days. MST for chondrosarcoma (1232 days), osteosarcoma (533 days), and soft tissue sarcoma (373 days) were not statistically different. Median disease-free interval (DFI) for local recurrence of all tumor types was 257 days. Cats had 75% survival at 1 year, which was significantly longer than dogs. CONCLUSIONS: Survival times for most tumor types can be good, but surgical margins should be carefully evaluated to ensure complete tumor removal. Adjuvant therapies may be advisable particularly for dogs to reduce rates of local recurrence or distant metastasis.

Differences in cutaneous wound healing between dogs and cats.

Regardless of the species involved, wound healing follows a predictable course of overlapping phases. In spite of these commonalities, significant species differences in cutaneous wound healing have been uncovered in the Equidae and, more recently, between the dog and cat. It has also recently been shown that the subcutaneous tissues play an important supporting role in cutaneous wound healing, which may help to ex-plain healing differences between cats and dogs. These discoveries may improve veterinarians' understanding of problem wound healing in the cat and, hopefully, lead to better strategies for wound management in this sometimes troublesome species.

Comparison of the role of the subcutaneous tissues in cutaneous wound healing in the dog and cat.

OBJECTIVE: To describe and compare the contribution of the subcutaneous tissues to 1st and 2nd intention cutaneous wound healing in the dog and cat. STUDY DESIGN: Experimental study. ANIMALS: Domestic shorthaired cats (n=6) and 6 beagle dogs. METHODS: Paired wounds were created on either side of the dorsal midline; the subcutaneous tissue was removed on 1 side and left intact on the other. Square, open wounds of the dorsal aspect of the thorax were observed for 21 days to monitor granulation tissue formation, wound contraction, epithelialization, and total healing (contraction+epithelialization). Breaking strength of sutured linear wounds was measured 7 days after wounding. Laser-Doppler perfusion imaging (LDPI) was used to measure cutaneous perfusion. RESULTS: First intention healing: subcutaneous tissue removal had no consistent effect on sutured wound strength at 7 days in dogs or cats. Second intention healing: removal of subcutaneous tissue reduced wound perfusion, granulation, contraction, epithelialization, and total healing. Granulation tissue formation and wound contraction were delayed to a significantly greater degree in cats than in dogs (P<.05). Two dogs (33%) had minor wound infections. CONCLUSIONS: The subcutaneous tissues make an important contribution to 2nd intention cutaneous healing. Dog and cat wounds had delayed 2nd intention healing when subcutaneous tissues were removed; wounds in dogs, but not cats, had largely recovered from this delay by 21 days. CLINICAL RELEVANCE: Extensive debridement of subcutaneous tissue may delay wound healing particularly in feline patients. A higher risk for wound infections may accompany extensive removal of subcutaneous tissues in dogs.

Buried tension sutures: force-tension comparisons of pulley, double butterfly, mattress, and simple interrupted suture patterns.

OBJECTIVES: To compare suture patterns (simple interrupted, modified pulley, horizontal mattress, double butterfly) by use of a novel in vitro model that quantifies force required for closure against tension. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Suture constructs. METHODS: An in vitro suturing frame was constructed with extension springs to provide a standard resistance against movement of 2 panels of loops toward each other. Four different suture patterns were applied to the frame in randomized trials. The frame was affixed to a tensiometer that measured the force required for each suture pattern to close a fixed distance (3.81 cm) at a constant rate (5.08 cm/min) against the tension (0.6 kg/cm) of the extension springs. The closure distance and tension were selected subjectively to mimic tension encountered clinically during wound reconstruction oncologic surgical procedures. RESULTS: The modified pulley suture required the least force to close, followed by the double butterfly, simple interrupted, and horizontal mattress patterns. CONCLUSIONS: The modified pulley suture and double butterfly suture patterns require less force to close a given distance under tension than either simple interrupted or horizontal mattress suture patterns. CLINICAL RELEVANCE: Application of tension relieving suture techniques for fascia, subcutaneous, and buried-knot subdermal suturing should be considered to facilitate direct closure of wounds under tension. Modified pulley and double butterfly suture patterns offer some mechanical advantage by requiring less force to achieve closure compared with other suture patterns that might be used in reconstructive surgery.

Bilateral rostral maxillectomy and nasal planectomy for large rostral maxillofacial neoplasms in six dogs and one cat.

This paper describes in detail an aggressive rostral maxillectomy procedure in one cat and six dogs, and the postoperative complications and outcomes are reported. The surgeries were performed to attempt complete excision of large and extensive rostral maxillary fibrosarcomas (n=4), squamous cell carcinomas (n=2), or poorly differentiated mesenchymal neoplasia (n=1). The surgeries involved transection of the maxilla at the level of premolar (PM)1 and PM2 in a cat and two dogs, and between PM2 and PM3 in four dogs. There were no intraoperative complications. Complete margins of resection were obtained in all cases. The postoperative appearance was acceptable to owners. Local recurrence was only observed in one dog (10 months after surgery) during a follow-up period of 11 to 66 months (median, 21.5 months).

Pre- and postoperative force plate analysis of dogs with experimentally transected cranial cruciate ligaments treated using tibial plateau leveling osteotomy.

OBJECTIVE: Quantitative and objective assessment of hindlimb kinetics after cranial cruciate ligament (CrCL) transection and subsequent stifle stabilization using the tibial plateau leveling osteotomy (TPLO) in normal dogs. STUDY DESIGN: In vivo experimental biomechanical evaluation. ANIMALS: Six healthy adult foxhounds. METHODS: Dogs were screened by orthopedic and radiographic examination before study entry. Force plate analysis of gait was measured before extirpation of the right CrCL and TPLO and again at 8 and 18 weeks after surgery. RESULTS: There was a significant decrease in peak vertical forces (PVFs) and vertical impulse (VI) of the treated hindlimb at 8 weeks when compared with preoperative and 18-week measurements. When compared with preoperative values, there was no significant difference in 18 week PVF and VI in dogs that had TPLO. CONCLUSION: TPLO can restore kinetic measures of limb function at 18-weeks after surgery when compared with preoperative values after experimental transection of the CrCL in dogs. CLINICAL RELEVANCE: TPLO induces lameness that returns to near normal at 18 weeks. The severity and duration of lameness was similar to that reported for other experimental models of stifle instability repaired by different techniques.

Cutaneous wound healing in the cat: a macroscopic description and comparison with cutaneous wound healing in the dog.

OBJECTIVE: To describe the macroscopic features of first and second intention cutaneous wound healing in the cat and compare with the dog. STUDY DESIGN: Experimental study. ANIMALS: Domestic shorthaired cats (6) and beagle dogs (6). METHODS: Square, open cutaneous wounds created on the dorsal aspect of the thorax were evaluated for 21 days for temporal and spatial development of granulation tissue, wound contraction, epithelialization, and total healing. To evaluate first intention healing, breaking strength of sutured linear cutaneous wounds was measured at 7 days post-wounding. Laser-Doppler perfusion imaging was used to measure cutaneous perfusion. RESULTS: First intention healing: sutured wounds in cats were only half as strong as those in dogs at day 7 (0.406 versus 0.818 kg breaking strength). Second intention healing: cats produced significantly less granulation tissue than dogs, with a peripheral, rather than central distribution. Wound epithelialization and total wound healing (total reduction in open wound area from contraction and epithelialization) were greater for dogs than for cats over 21 days. Wound contraction on day 7 was greater for dogs, but not on day 14 or 21. Cutaneous perfusion was initially greater for dogs than for cats, but no differences were detected after day 7. CONCLUSIONS: Significant, previously unreported differences in cutaneous wound healing exist between cats and dogs. In general, cutaneous wounds in cats are slower to heal. Cats and dogs also appear to use different mechanisms of second intention healing. In cats wounds close mainly by contraction of the wound edges, whereas in dogs wounds close more from central pull, and epithelialization. CLINICAL RELEVANCE: Surgeons should view the cat as a unique species, which presents its own special challenges in wound healing, and should take this into account when planning treatment of feline wounds, either by primary closure, or by second intention healing.

The effect of a porcine-derived small intestinal submucosa product on wounds with exposed bone in dogs.

OBJECTIVE: To determine the effect of a porcine-derived small intestinal submucosa product (PSIS) on healing time, epithelialization, angiogenesis, contraction, and inflammation of wounds with exposed bone on the distal aspect of the limbs of dogs. STUDY DESIGN: Prospective, controlled, experimental study. ANIMAL POPULATION: 10 young adult, purpose-bred, male Beagles. METHODS: Small wounds with exposed bone were created on the lateral aspect of metatarsal V and the medial aspect of metatarsal II on both hindlimbs. Three sheets of PSIS were sutured into the wounds of the treated limb, and the other limb served as a control. On day 10, punch biopsies of the medial metatarsal wounds were collected and were evaluated microscopically after routine hematoxylin and eosin and phosphotungstic acid hematoxylin (PTAH) staining. The lateral metatarsal wounds were evaluated by planimetry and laser Doppler perfusion imaging on days 7, 14, and 21. Time until complete wound healing was also recorded. The level of significance was set at P < or =.05 for all statistical analyses. RESULTS: Laser Doppler perfusion measurements were significantly higher in control wounds on day 7, but no differences were noted on days 14 and 21. No significant differences in planimetric values, histopathologic appearance, or time until complete wound healing were noted among treated and control groups. CONCLUSIONS: No objective differences in healing were noted between control wounds and wounds treated with PSIS. CLINICAL RELEVANCE: There appears to be no contraindication to the use of PSIS on clean wounds with exposed bone on the distal limbs of dogs. However, our objective data provides no evidence that this product affects epithelialization, contraction, or time to complete healing in wounds with exposed bone.