Perioperative Management and Outcome of Bilateral Adrenalectomy in 9 Dogs

Retroperitoneoscopy in the horse: Anatomical study of the retroperitoneal perirenal space and description of a surgical approach

BACKGROUND

Surgical approaches to the kidneys and perirenal structures are uncommonly performed in horses and several complications have been described with the current procedures.

OBJECTIVE

To describe the anatomy of the retroperitoneal perirenal space and investigate a retroperitoneal minimally invasive approach to access the kidney and perirenal structures in horses.

STUDY DESIGN

Descriptive, cadaveric study.

METHODS

Anatomical description of the retroperitoneal space was performed on three equine cadavers and the surgical approach was developed based on these dissections. Ten cadaveric horses underwent a retroperitoneoscopy. Five horses were placed in a right lateral recumbency position to explore the left retroperitoneal space and five horses were placed in a standing position to explore both left and right sides. Anatomical landmarks, working space and access to the renal hilus and perirenal structures were evaluated.

RESULTS

Dissections revealed that kidneys are surrounded by a renal fascia which delimits two spaces: a perirenal space between the kidney and the renal fascia, and a pararenal space between the renal fascia and psoas muscles or peritoneum. The retroperitoneoscopic portal was placed at the level of the dorsal aspect of the tuber coxae, 3 cm caudal to the last rib for the left side and 2 cm caudal to the last rib for the right side. Retroperitoneal access and working space were successfully established in all horses. The standing position allowed an easier dissection than lateral recumbency. Division of the perirenal fat allowed access to the kidney and adrenal glands as well as individualisation of renal vessels and ureter in the renal hilus.

MAIN LIMITATIONS

Study of cadavers precluded appreciation of haemorrhage or use the pulsating vessels as landmarks.

CONCLUSIONS

This study provides a description of the retroperitoneal perirenal space and describes a new surgical approach to access kidneys and perirenal structures in horses.

Outcome in dogs undergoing adrenalectomy for small adrenal gland tumours without vascular invasion

Veterinary studies have reported the outcome of adrenalectomies in dogs; however, these studies typically include a wide variety of adrenal tumour sizes, including cases with or without vascular invasion. The purpose of this study was to report outcome in a cohort of dogs with histologically confirmed small adrenal tumours without vascular invasion treated with adrenalectomy. This retrospective study was conducted using data from the University of Florida and University of California-Davis databases between 2010 and 2017. Dogs were included if they underwent excision of an adrenal gland tumour with a maximal diameter ≤ 3 cm, without evidence of vascular invasion to any location as assessed via computed tomography. Fifty-one dogs met the inclusion criteria. The short-term survival rate of dogs undergoing adrenalectomy was 92.2%, and one-year disease-specific survival was 83.3%. Twenty-eight of 51 (54.9%) dogs were diagnosed with a malignancy. Minor complications were observed commonly intra-operatively and post-operatively. Major complications were observed in six dogs, and included sudden death, respiratory arrest, acute kidney injury, haemorrhage, hypotension and aspiration pneumonia. Short-term mortality occurred in four dogs. Sudden death and haemorrhage were the most common major complications leading to death. While adrenalectomy is sometimes controversial because of the high perioperative mortality rates previously reported, the results of this study support that adrenalectomy for small tumours with no vascular invasion can be performed with low risk.