Efficiency of octenidine dihydrochloride alcohol combination compared to ethanol based skin antiseptics for preoperative skin preparation in dogs.

OBJECTIVE: To quantify the bacterial burden after skin disinfection using an alcohol octenidine dihydrochloride combination (Octenisept®) compared to an 74.1% ethanol 10% 2-propanol combination (Softasept N®). STUDY DESIGN: Prospective randomized clinical trial. MATERIAL & METHODS: 61 dogs undergoing clean or clean-contaminated surgeries (excluding surgeries on the gastrointestinal tract) were randomly assigned to group O (skin disinfection with alcohol and octenidine dihydrochloride after washing with octenidine containing soap) or to control group C (skin disinfection using the ethanol-2-propanol combination after washing with a neutral soap without antiseptic ingredients). Samples were then taken from 8 different locations within the surgical field at four different stages: after clipping, after washing, after disinfection and one hour later. At each stage, two different sampling techniques (wet-dry swab technique (WDS) and contact plates (CP)) were used for quantitative analysis of bacterial counts. RESULTS: WDS detected about 100-fold more bacteria compared to CP sampling in cases with high bacterial burden, but was not accurate enough to detect small numbers. CP sampling was therefore used for comparison of treatment protocols. 30 dogs were assigned to group O and 31 to group C. A relative reduction of 69% in group O and 77 percent in group C was observed after the soap wash. No significant differences were detected between both groups. Washing and disinfection resulted in a reduction of bacterial counts of 99.99% in group O versus 99.7% in group C (p = 0.018). Bacterial reduction one hour after washing and disinfection was significantly higher in group O (99.9%) than in group C (98.5%, p = 0.001). CONCLUSION: Additional octenidine dihydrochloride provided a slightly better decontamination effect after disinfection, particularly one hour after, which means it may only be indicated in longer surgeries. WDS is more sensitive but less specific to detect bacteria on the skin than the CP sampling.

Impact of Surgical Lights on the Performance of Fluorescence-Guided Surgery Systems: A Pilot Study.

Fluorescence-guided surgery can aid in the intraoperative visualization of target tissues, with promising applications in human and veterinary surgical oncology. The aim of this study was to evaluate the performances of two fluoresce camera systems, IC-FlowTM and VisionsenseTM VS3 Iridum, for the detection of two non-targeted (ICG and IRDye-800) and two targeted fluorophores (AngiostampTM and FAP-Cyan) under different room light conditions, including ambient light, new generation LED, and halogen artificial light sources, which are commonly used in operating theaters. Six dilutions of the fluorophores were imaged in phantom kits using the two camera systems. The limit of detection (LOD) and mean signal-to-background ratio (mSBR) were determined. The highest values of mSBR and a lower LOD were obtained in dark conditions for both systems. Under room lights, the capabilities decreased, but the mSBR remained greater than 3 (=clearly detectable signal). LOD and mSBR worsened under surgical lights for both camera systems, with a greater impact from halogen bulbs on VisionsenseTM VS3 Iridium and of the LED lights on IC-Flow due to a contribution of these lights in the near-infrared spectrum. When considering implementing FGS into the clinical routine, surgeons should cautiously evaluate the spectral contribution of the lights in the operating theater.

Performance of two clinical fluorescence imaging systems with different targeted and non-targeted near-infrared fluorophores: a cadaveric explorative study.

Introduction: Near-infrared (NIR) fluorescence-guided surgery is increasingly utilized in humans and pets. As clinical imaging systems are optimized for Indocyanine green (ICG) detection, the usage of targeted dyes necessitates the validation of these systems for each dye. We investigated the impact of skin pigmentation and tissue overlay on the sensitivity of two NIR cameras (IC-FlowTM, VisionsenseTM VS3 Iridum) for the detection of non-targeted (ICG, IRDye800) and targeted (AngiostampTM, FAP-Cyan) NIR fluorophores in an ex vivo big animal model. Methods: We quantitatively measured the limit of detection (LOD) and signal-to-background ratio (SBR) and implemented a semi-quantitative visual score to account for subjective interpretation of images by the surgeon. Results: VisionsenseTM VS3 Iridum outperformed IC-FlowTM in terms of LOD and SBR for the detection of all dyes except FAP-Cyan. Median SBR was negatively affected by skin pigmentation and tissue overlay with both camera systems. Level of agreement between quantitative and semi-quantitative visual score and interobserver agreement were better with VisionsenseTM VS3 Iridum. Conclusion: The overlay of different tissue types and skin pigmentation may negatively affect the ability of the two tested camera systems to identify nanomolar concentrations of targeted-fluorescent dyes and should be considered when planning surgical applications.

Lymph node metastasis in feline cutaneous low-grade mast cell tumours.

OBJECTIVES: This retrospective study aimed to determine the incidence of nodal metastatic disease in cats affected by low-grade cutaneous mast cell tumours (MCTs) in our study population. METHODS: The clinical records of two centres were retrospectively searched for cats with cutaneous MCTs that had undergone lymphadenectomy of enlarged and non-enlarged lymph nodes. All primary tumours were histologically reviewed by two experienced pathologists and graded as high- or low-grade based on the grading system for feline cutaneous MCT. We graded the lymph nodes based on the grading scheme used for canine MCTs and considered HN2 and HN3 nodes to be metastatic. The number of patients with nodal metastasis was calculated. RESULTS: We identified 17 cats with cutaneous MCT resection and concurrent lymphadenectomy. All 21 MCTs were graded as low grade and 30 nodes were removed, with 12 being considered early or overtly metastatic (HN2 or HN3, respectively). Based on nodal status, 10/17 (59%) cats were affected by nodal metastasis in our population. CONCLUSIONS AND RELEVANCE: In contrast to previous reports, high percentage of cats with cutaneous MCTs in which lymphadenectomy was performed were presented with metastatic lymph nodes. The clinical relevance of this finding and a potential benefit of lymphadenectomy must be determined in future studies.

Proteomic profiling of canine fibrosarcoma and adjacent peritumoral tissue.

Fibrosarcoma (FSA) are rare soft tissue tumors that display aggressive local behavior and invasive growth leading to high rates of tumor recurrence. While the low incidence in humans hampers detailed understanding of the disease, FSA are frequent in dogs and present potential models for the human condition. However, a lack of in-depth molecular characterization of FSA and unaffected peritumoral tissue (PTT) in both species impedes the translational potential of dogs. To address this shortcoming, we characterized canine FSA and matched skeletal muscle, adipose and connective tissue using laser-capture microdissection (LCM) and LC-MS/MS in 30 formalin-fixed paraffin embedded (FFPE) specimens. Principal component analysis of 3'530 different proteins detected across all samples clearly separates the four tissues, with several targets strongly differentiating tumor from all three PTTs. 25 proteins were exclusively found in tumor tissue in ≥80% of cases. Among these, CD68 (a macrophage marker), Optineurin (OPTN), Nuclear receptor coactivator 5 (NCOA5), RAP1GDS1 (Rap1 GTPase-GDP dissociation stimulator 1) and Stromal cell derived factor 2 like 1 (SDF2L1) were present in ≥90% of FSA. Protein expression across all FSA was highly homogeneous and characterized by MYC and TP53 signaling, hyperactive EIF2 and immune-related changes as well as strongly decreased oxidative phosphorylation and oxidative lipid metabolism. Finally, we demonstrate significant molecular homology between canine FSA and human soft-tissue sarcomas, emphasizing the relevance of studying canine FSA as a model for human FSA. In conclusion, we provide the first detailed overview of proteomic changes in FSA and surrounding PTT with relevance for the human disease.

Long-term outcome after total scapulectomy for the treatment of osteosarcoma in a cat.

Case summary: A 10-year-old neutered female domestic shorthair cat was presented for acute lameness of the right forelimb after a pathological fracture caused by scapular osteosarcoma. Total scapulectomy was performed, including the glenoid, and the humerus was sutured to the second rib via a bone tunnel in the humeral head. Two months postoperatively, the cat showed mild lameness without any other impairment or signs of pain. The owner reported that the cat was back to normal activity, including climbing and running. Follow-up checks 6 and 18 months after surgery were unremarkable. At the final follow-up, 33 months postoperatively, the cat showed mild lameness, but the orthopaedic examination was still non-painful. Walking fluoroscopy revealed a failure of the fixation of the humeral head, which was now travelling along ribs 1-4 with each step. The owner still rated the cat's quality of life and leg function as excellent. Relevance and novel information: Suture fixation of the humerus to the second rib via a bone tunnel in the humeral head after performing total scapulectomy, and the long-term outcome of the procedure, has so far not been described in cats. While the technique initially led to full return of limb function, the fixation was found to have failed at 33 months after surgery, resulting in a gait alteration that did not impair activity or quality of life.

Indocyanine-based near-infrared lymphography for real-time detection of lymphatics in a cat with multiple mast cell tumours.

CASE SUMMARY: An 11-year-old female domestic shorthair cat was presented with cutaneous mast cell tumours (MCTs) localised at the right temporal region, the left buccal region and on the third digit of the right thoracic limb. Staging was negative and locoregional lymph nodes appeared normal, based on clinical findings. During surgery, real-time indocyanine green (ICG)-based lymphography was performed to detect the cutaneous draining pattern of all the primary MCTs. ICG was injected intracutaneously in four quadrants around each tumour, and a clear lymphogram was visible shortly after injection. Using near-infrared lymphography (NIR-L) for guidance, all lymphadenectomies were performed in 12 mins or less, with a maximal incision length of 3.5 cm. The smallest resected node was 0.9 cm in diameter. All MCTs were classified as low-grade cutaneous MCT. All four ICG-positive lymph nodes were considered premetastatic or metastatic. The only ICG-negative resected node was also negative for tumour cells. No complications related to NIR-L were recorded. RELEVANCE AND NOVEL INFORMATION: This is the first description of NIR-L in a cat with MCT. Application was straightforward and ICG enrichment only occurred in the metastatic nodes, suggesting correct identification of lymphatic draining patterns. Of note, as previously described in dogs, we did detect nodal metastasis, despite low-grade primary tumours. The clinical relevance should be evaluated in future studies.

Filling the vacuum: Role of negative pressure wound therapy in open wound management in cats.

PRACTICAL RELEVANCE: Open wounds and their treatment present a common challenge in veterinary practice. Approaching 15 years ago negative pressure wound therapy (NPWT) started to be incorporated into clinical veterinary medicine, and its availability is becoming more widespread in Europe and the USA. Use of this therapy has the potential to significantly increase the healing rate of open wounds as well as free skin grafts in small animals, and it has been occasionally described for the management of feline wounds. AIM: This review describes the mechanisms of action of, and indications for, NPWT, and offers recommendations for NPWT specific to feline patients. EVIDENCE BASE: The information presented is based on the current evidence and the author's clinical experience of the technique gained over the past 12 years. Comparative studies of different treatment options are lacking and, since wound healing in cats and dogs differs, cat-specific studies are especially needed. Well-designed wound healing studies comparing different advanced techniques will improve open wound healing in cats in the future, and potentially allow better understanding of the role of NPWT in this setting.

Comparison of Negative Pressure Wound Therapy and Silver-Coated Foam Dressings in Open Wound Treatment in Dogs: A Prospective Controlled Clinical Trial.

OBJECTIVES: To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. STUDY TYPE: Prospective randomized clinical study MATERIALS AND METHODS: Dogs (n = 26) undergoing open-wound treatment were randomly assigned to one of two groups: Group A (n = 13) NPWT; Group B (n = 13) silver-coated foam dressing. Pairs of patients were matched based on wound conformation, localization, and underlying cause and compared in terms of duration of previous treatment, development of wound size (wound planimetry), time to closure, bacterial bio-burden and complications. Wound dressing changes were performed every 3 days during the first 9 days of therapy for both groups. Statistical analysis was performed. RESULTS: Pre-treatment signalment and bacterial status were comparable between groups. Total time to closure was significantly (p = 0.018) shorter in Group A (14.2 days) compared with Group B (28.6 days), and wound planimetry on days 3, 6 and 9 showed significant greater reduction in total wound area for Group A at all-time points (p < 0.05). Furthermore, wounds in Group A showed less progression of local infection than did wounds in Group B (p = 0.01). CONCLUSION: NPWT-treated wounds showed faster closure, improved macro-deformation and less local signs of infection.

Treatment of a perforating thoracic bite wound in a dog with negative pressure wound therapy.

CASE DESCRIPTION A 4-year-old male Dachshund was examined following a bite attack that had occurred 5 days previously. The dog had acutely deteriorated despite IV antimicrobial treatment and fluid therapy. CLINICAL FINDINGS On initial examination, the patient was recumbent with signs of septic shock and a flail chest. Three penetrating wounds in the left thoracic wall with malodorous discharge were evident. The animal trauma triage score was 8 out of 18. Thoracic and abdominal radiography revealed displaced fractures of the left seventh, eighth, and ninth ribs and extensive subcutaneous emphysema. Additionally, a marked diffuse bronchointerstitial pattern, areas of alveolar pattern, and pneumothorax were present bilaterally. TREATMENT AND OUTCOME Open surgical debridement with left lateral lung lobectomy and resection of portions of the left thoracic wall were performed. Extensive soft tissue loss precluded primary reconstruction. The defect was stabilized with a polypropylene mesh implant, and negative pressure wound therapy (NPWT) at -100 mm Hg was initiated. Microbial culture and susceptibility testing of tissue samples indicated the presence of multidrug-resistant Staphylococcus pseudintermedius. The NPWT dressing was changed 2, 5, and 7 days after surgery. Treatment was well tolerated, and the mesh was completely covered with granulation tissue 10 days after surgery. On follow-up 5, 7, 12, and 19 months after surgery, the dog was clinically normal with no apparent complications. CLINICAL RELEVANCE Findings suggested that NPWT may be a valuable adjunct when treating small animal patients with severe thoracic trauma.

Negative pressure wound therapy augmented full-thickness free skin grafting in the cat: outcome in 10 grafts transferred to six cats.

OBJECTIVES: The aim of this clinical evaluation was to describe the technique and outcomes of negative pressure wound therapy (NPWT) augmented skin grafting in cats. METHODS: Cats with soft tissue and skin defects (n = 6) underwent open wound management. Wounds were initially covered using a NPWT system that was changed to polyurethane foam dressing once infection was controlled and granulation started. Final closure was achieved after establishment of a healthy, fully granulated wound bed by grafting of free full-thickness skin from the lateral abdominal wall. The freshly grafted skin was then treated with an NPWT dressing at a pressure of -125 mmHg for 3 days, with dressing changes performed daily. Percentage graft take, complications, wound bioburden and cosmetic outcome were recorded. RESULTS: The mean duration of open wound management was 21.4 days (range 3.0-45.0 days), with a mean duration of NPWT of 8.0 days (range 3.0-14.0 days). Five cats received a single graft, while one cat had five grafts transferred to the right hindlimb. In 7/10 grafts, graft take was 100%, in two grafts take was 95% and in one graft take was 80% (mean take rate 97%). Therapy was well tolerated in all patients. The grafted site displayed normal hair regrowth in four cats, sparse hair regrowth in one and no hair growth at all in one patient. Skin sensation was normal in all grafted patients. CONCLUSIONS AND RELEVANCE: Skin graft augmentation using NPWT in cats is a feasible option that allows graft fixation, even in anatomically demanding areas. Graft take rate reported here is slightly higher than documented in previous reports.