Anatomy of the Kidney
The kidneys are located in the retroperitoneal space. The area surrounding the kidney is called the perirenal space (Figure 1, number 5). This space is enclosed by the renal fascia (Figure 1, number 7). The perirenal space consists mainly of adipose tissue; also, the renal vasculature, lymphatic system, and adrenal gland can be found within the perirenal space. The kidney itself is captured by a thick fibrous capsule that serves as protection to the soft renal tissue (Figure 1, number 6). Of note, the capsule does not cover the renal sinus, leaving an opening for the renal artery, renal vein, renal nerve. and renal pelvis to either enter or exit. Within the kidney, the glomeruli are located in the cortex, and the tubules descend into the medulla.
Anatomy of the Kidney and the Perirenal Space
The kidney is surrounded by the renal capsule. Histologically this capsule is made of dense irregular collagen tissue, making it particularly rigid. Around the renal capsule the perirenal space is bordered by the renal fascia and is made up of mainly adipose tissue. The renal sinus (4) is not covered by renal capsule and is therefore sensitive for local fat infiltration and compression of vasculature.
Compression of the kidney and renal vasculature can therefore theoretically arise from increased pressures in 3 different compartments. An overview of the current data on increased pressure in the different compartments can be found in Table 1.
JACC Heart Fail. 2022;10(3):175-183. © 2022 American College of Cardiology Foundation