Laparoscopic adrenalectomy for resection of non-invasive adrenal tumors is associated with excellent outcomes and low conversion rates in experienced centers

Objective: To report outcomes from a large cohort of dogs undergoing laparoscopic adrenalectomy for resection of unilateral adrenal masses.
Animals: 260 client-owned dogs from 7 veterinary institutions.
Procedures: Medical records were reviewed and signalment, clinicopathologic features, surgical outcomes including conversion to open surgery, mass recurrence and long-term outcome were recorded.
Results: Lesions were left-sided in 157 dogs and rightsided in 101 dogs. In 83 dogs the mass encompassed the entire gland; in 100 and 41 dogs the mass principally involved the cranial or caudal poles, respectively. Mean maximal diameter of the mass was 2.9cm. Histopathologic evaluation of resected masses revealed adrenocortical carcinoma (105), adrenocortical adenoma (86), pheochromocytoma (45) and other diagnoses (5). Conversion to an open approach was performed in 25/260 (9.6%) dogs. For each 1 grade increase in body condition score, the odds of conversion significantly increased (OR=1.61, 95% CI: 1.05-2.47; p=0.029). Capsular penetration occurred in 41/260 (15.8%). 247/260 (95%) dogs were discharged from the hospital. Tumor recurrence at the previous adrenalectomy site occurred in 16 of 153 (10.5%). Odds of recurrence were 6.6 times higher among dogs with capsular penetration at surgery (p=0.003). At follow-up 98 dogs had died (median 17.5 months [range 0.5-72 months] postoperatively) and 139 remained alive (median 12 months [range 1-68 months] postoperatively).
Conclusion: In centers with experience in minimally invasive surgery, laparoscopic adrenalectomy is associated with low conversion rate and high survival to discharge.