Renal anatomy

A 56 year old man is undergoing a radical nephrectomy via a posterior approach. Which of the following structures is most likely to be encountered during the operative approach?

		A.	8th rib
		B.	10th rib
		C.	6th rib
		D.	12th rib
		E.	9th rib

 

The 11th and 12th ribs lie posterior to the kidneys and may be encountered during a posterior approach. A pneumothorax is a recognised complication of this type of surgery.

 

Renal anatomy

Each kidney is about 11cm long, 5cm wide and 3cm thick. They are located in a deep gutter alongside the projecting verterbral bodies, on the anterior surface of psoas major. In most cases the left kidney lies approximately 1.5cm higher than the right. The upper pole of both kidneys approximates with the 11th rib (beware pneumothorax during nephrectomy). On the left hand side the hilum is located at the L1 vertebral level and the right kidney at level L1-2. The lower border of the kidneys is usually alongside L3.
The table below shows the anatomical relations of the kidneys:

Relations

 

Relations	Right Kidney	Left Kidney
Posterior	Quadratus lumborum, diaphragm, psoas major, transversus abdominis	Quadratus lumborum, diaphragm, psoas major, transversus abdominis
Anterior	Hepatic flexure of colon	Stomach, Pancreatic tail
Superior	Liver, adrenal gland	Spleen, adrenal gland

Fascial covering

Each kidney and suprarenal gland is enclosed within a common and layer of investing fascia that is derived from the transversalis fascia into anterior and posterior layers (Gerotas fascia).

Renal structure

Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures. The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter.
Lying in a hollow within the kidney is the renal sinus. This contains:
1. Branches of the renal artery
2. Tributaries of the renal vein
3. Major and minor calyces's
4. Fat

Structures at the renal hilum

The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.