33rd Annual Scientific Meeting proceedings

Introduction: Sentinel lymph nodes (SLNs) refer to the first group of lymph nodes draining the primary tumour. SLN lymphadenectomy allows a more accurate staging and may also be therapeutic. Although lymphadenectomy is considered a relatively benign procedure, complications of variable severity may occur, particularly if SLNs are not readily accessible. The aim of this retrospective study was to describe the frequency and type of complications associated with retropharyngeal (R), axillary (A), and medial iliac (MI) lymphadenectomy in dogs with cutaneous/subcutaneous malignant tumours.

Materials and methods: Medical records were searched to identify dogs undergoing preoperative (with or without intraoperative) SLN mapping and subsequent R, A, and/or MI lymphadenectomy. Intraoperative and postoperative complications were recorded. The following variables were investigated to identify possible risk factors for complications: primary tumour histopathology; number, size, and location of excised SLNs; histological SLN status; anaesthesia time.

Results: 124 SLNs (67A, 30MI, 27R) were excised in 98 dogs. One intraoperative complication was recorded (difficulty in intraoperative identification of A SLN). Minor short-term postoperative complications were reported in 21 (16.9%) dogs, including seroma (4A, 2R, 1MI), oedema (3A, 2R, 1MI), surgical site infection (1R, 1A, 1MI), wound dehiscence (3MI), and hematoma (1A, 1MI); all were treated conservatively. MI lymphadenectomy was associated with the highest complication rate. None of the evaluated variables were significantly associated with the development of complications.

Conclusions: Lymphadenectomy of R, A, and MI SLNs is safe; complications are infrequent and self-limiting. The higher complication rate associated with MI lymphadenectomy may be linked to the caudal laparotomy.