Ureteropyeloscopic anatomy of the renal pelvis of the horse.

This research article explores the endoscopic appearance and structure of the renal pelvis and terminal recesses of a horse’s kidney, using methods like magnetic resonance imaging, visual inspection of corrosion casts, and transurethral ureteropyeloscopy. The study confirms the shape of the equine renal pelvis, the outlets of its multiple ducts, and variations in its anatomy, thereby informing future diagnostic and therapeutic procedures.

Objective of the Research

• The primary purpose of the research was to study the anatomy of the horse’s upper urinary collecting system, particularly the renal pelvis and terminal recesses, with a focus on their endoscopic appearance within a living horse. This information is vital because it is sparsely documented, potentially limiting effective ureteropyeloscopy.

Methodology

• The study involved kidneys harvested from 10 horses, with procedures conducted post-mortem.
• Magnetic resonance imaging (MRI) was initially carried out after distending the renal pelvis with an elastomer casting material, followed by the examination of corrosion casts.
• The team performed transurethral ureteropyeloscopy on the upper urinary tract in four horses, after which a histological and immunohistochemical study of the renal medulla and pelvis was conducted on three of the animals.

Results and Findings

• The equine renal pelvis was confirmed to be a funnel-shaped cavity, which was flattened dorsoventrally in the craniocaudal direction.
• Multiple papillary ducts from the central part of the kidney were found to open into the renal pelvis along a roughly 3cm long renal crest, whilst papillary ducts from each kidney’s pole opened into two long (5-10cm), narrow, terminal recesses that ended near the ends of the renal crest.
• The study also documented minor anatomical variations in the renal crest and the terminal recess openings.
• The openings of the terminal recesses, which narrow at their connection with the renal pelvis, could be visualised during ureteropyeloscopy in all horses.
• The study found that current endoscopic equipment could successfully visualise the renal pelvis, but could not adequately advance into the terminal recesses.

Conclusion

• The findings from this study will provide valuable guidance in relation to future diagnostic and therapeutic ureteropyeloscopy procedures.
• It will give practitioners a deeper understanding of the equine renal pelvis’ structure and its variations, possibly improving techniques in veterinary medicine further.