Evaluation of mediastinoscopy for cranial mediastinal and tracheobronchial lymphadenectomy in canine cadavers

Abstract

AbstractObjectiveTo report technical feasibility and describe procedural details of a novel single incision minimally invasive approach to the mediastinum in cadaver dogs.Study designCadaveric study.AnimalsLarge breed (25–40 kg) cadaver dogs (n = 10).MethodsThree of 10 cadavers were used for preliminary technique development without data recording. Cadaver specimens underwent pre‐ and postoperative thoracic computed tomographic scans. Seven dogs were placed in dorsal recumbency and mediastinoscopy was performed via a SILS port placed cranial to the thoracic inlet with CO2 insufflation of the mediastinum at 2–4 mmHg. Retrieval of all CT and visually identified mediastinal lymph nodes (LN) was attempted; endoscopic compartmental and individual LN dissection times and subjective operative challenges were recorded. Procedural success scores for visualization and dissection as well as NASA‐task force index scores were recorded per lymph node, per cadaver.ResultsMedian time required for initial approach including SILS placement was 5 min (range 5–10 min). Individual LN retrieval times ranged from 2 to 32 min. Mediastinoscopic retrieval of LNs was most commonly successful for the left tracheobronchial LN (7/7), followed by the right tracheobronchial LN (4/7), the left and right sternal LNs (3/7 each), and the cranial mediastinal LNs (1/7). Post‐procedure pleural gas was identified on CT in 4/7 cadavers.ConclusionsMediastinoscopy as reported was feasible in large breed canine cadavers and retrieval or cup biopsy of a variety of lymph nodes is possible from the described approach. Application in living animals and its associated challenges should be further investigated.Clinical significanceMediastinoscopy may provide a novel minimally invasive approach to the evaluation and oncologic staging of the cranial mediastinum in dogs.