INDIRECT COMPUTED TOMOGRAPHIC LYMPHOGRAPHY FOR ILIOSACRAL LYMPHATIC MAPPING IN A COHORT OF DOGS WITH ANAL SAC GLAND ADENOCARCINOMA: TECHNIQUE DESCRIPTION.

Sentinel lymph node mapping can help to direct surgical oncologic staging and metastatic disease detection in patients with complex lymphatic pathways. We hypothesized that indirect computed tomographic lymphography (ICTL) with a water-soluble iodinated contrast agent would successfully map lymphatic pathways of the iliosacral lymphatic center in dogs with anal sac gland carcinoma, providing a potential preoperative method for iliosacral sentinel lymph node identification in dogs. Thirteen adult dogs diagnosed with anal sac gland carcinoma were enrolled in this prospective, pilot study, and ICTL was performed via peritumoral contrast injection with serial caudal abdominal computed tomography scans for iliosacral sentinel lymph node identification. Technical and descriptive details for ICTL were recorded, including patient positioning, total contrast injection volume, timing of contrast visualization, and sentinel lymph nodes and lymphatic pathways identified. Indirect CT lymphography identified lymphatic pathways and sentinel lymph nodes in 12/13 cases (92%). Identified sentinel lymph nodes were ipsilateral to the anal sac gland carcinoma in 8/12 and contralateral to the anal sac gland carcinoma in 4/12 cases. Sacral, internal iliac, and medial iliac lymph nodes were identified as sentinel lymph nodes, and patterns were widely variable. Patient positioning and timing of imaging may impact successful sentinel lymph node identification. Positioning in supported sternal recumbency is recommended. Results indicate that ICTL may be a feasible technique for sentinel lymph node identification in dogs with anal sac gland carcinoma and offer preliminary data to drive further investigation of iliosacral lymphatic metastatic patterns using ICTL and sentinel lymph node biopsy.

Postoperative Respiratory Function and Survival After Pneumonectomy in Dogs and Cats.

OBJECTIVE: To describe indications for, and outcomes after, pneumonectomy in dogs and cats, including assessment of immediate postoperative respiratory function in comparison to dogs undergoing single lung lobectomy. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n=16) and cats (n=7) with naturally occurring pulmonary disease. METHODS: Medical records (1990-2014) of dogs and cats undergoing right or left pneumonectomy were reviewed. Data retrieved included signalment, history, preoperative diagnostics, operative descriptions, postoperative data including respiratory function, and postdischarge outcomes. For respiratory function comparisons, medical records of dogs having undergone a single lung lobectomy via median sternotomy (n=15) or intercostal thoracotomy (n=15) were reviewed. RESULTS: Twenty-three cases (16 dogs, 7 cats) were included. Pneumonectomy was performed for congenital (1 dog, 1 cat), neoplastic (8 dogs, 1 cat), and infectious (7 dogs, 5 cats) disease. Postoperative aspiration pneumonia occurred in 2 dogs; 15 of 16 dogs (94%) and 6/7 cats (86%) survived to hospital discharge. After pneumonectomy, dogs had a significantly higher postoperative PaO2 on 21% oxygen (P=.033) and lower postoperative A-a gradient (P=.004) compared to dogs undergoing single lung lobectomy. Survival times (right-censored at last follow-up) for dogs ranged from 2 days to 7 years (estimated median=1,868 days) and for cats from 1-585 days. CONCLUSION: Dogs and cats have acceptable respiratory function immediately postoperatively and most have protracted long-term survival after pneumonectomy for a variety of pulmonary diseases.