The kidneys are paired organs located retroperitoneally on either side of the vertebral column. Each kidney is bean-shaped and surrounded by three layers - a fibrous capsule, perirenal fat, and renal fascia. The kidneys receive their blood supply from the renal arteries and drain into the renal veins. They have an extensive arterial supply that branches into segments and interlobar arteries within renal columns. The kidneys also have a complex calyceal system that drains urine into the renal pelvis and ureters. Percutaneous access for procedures must consider the location of calyces and vascular anatomy to avoid complications.

1. RENAL ANATOMY
Dr. Manoj Kumar Deepak, M.S
Resident
Urology
SRM Medical college and hospital

2. GENERAL ANATOMY OF THE
KIDNEYS
• Paired,
• bean-shaped organs
located on either side of
the vertebral column in
the retroperitonum.
• Infront of the 11th & 12th
rib
• Right kidney is lower than
the left.

3. The kidney is related anteriorly to the abdominal
viscera and
posteriorly to the osteomuscular area.
In the recumbent position, the kidneys may extend
from T12 to L3, but in the erect position extend
from L1 to L4.
The kidneys changes position during different
phases of respiration.
They move inferiorly approximately
3 cm (one vertebral body) during inspiration and
during changing body position

4. Coverings of
kidneys
The kidneys are surrounded by a
smooth, tough fibrous capsule,
– which is easily removed under
normal conditions.
– Perirenal fat: adipose tissue
lies outside the fibrous
capsule
it extends into the renal hilum, into
the space – a.k.a renal sinus.

5. Renal (Gerota) fascia
• – It covers kidneys and adrenals, it continues medially to
fuse with the contralateral side
• This fascia extends inferomedially along the abdominal ureter
as a periureteral fascia.
• It is closed superiorly and laterally - anatomic barrier to the
spread of malignancy and a means of containing perinephric
fluid collections.
• open inferiorly, perinephric fluid collections can track inferiorly
into the pelvis without violating the Gerota fascia.

7. PARA RENAL FAT
• Para renal fat is a layer of adipose
tissue, the occupies the
retroperitoneum , which is most
obvious posteriorly and represents
the extraperitoneal fat of the
lumbar region.
• It is necessary to main the position of
the kidney.
• In thin young females devoid of para
renal fat, Nephroptosis can occur.
POINT TO REMEMBER IN
PERCUTANEOUS PUNCTURE:
• Nephroptosis can cause difficulty in
establishing access.

8. SIZE
• Length: 10-12 cm
• Width: 5-7.5 cm
• Thickness: 2.5-3.0 cm
• Approximate weight:
135 g in women and 150 g in men.

9. Each kidney has two surfaces (anteriolateral and
posteromedial) , two borders (lateral and medial), and
two poles (superior and inferior.)

10. 1a
3
2
1b

11. SURGICAL ANATOMY OF THE
KIDNEYS
POINTS TO REMEMBER DURING
PERCUTANEOUS PUNCTURE
• This brings the upper pole calyces medial
and superficial (dorsal) in relation to the lower
pole calyces,
• The lower pole of the kidney lies laterally and
anteriorly relative to upper pole.

12. ANTERIOR RELATIONS OF THE RIGHT
KIDNEY
• The anterior surface of the right
kidney is related to :
– Right adrenal gland
– Liver
– Second part of duodenum-
needs to be mobilized to reach
the hilum on the right side
– Ascending colon
– Hepatic flexure of the colon

13. ANTERIOR RELATIONS OF THE
LEFT KIDNEY
The anterior surface of the left kidney is related
to:
• Left adrenal gland
• Pancreas
• Splenic vessels
• Stomach
• Spleen
• Duodenojejunal flexure
• Ligament of Treitz
• Inferior mesenteric vein
• Descending colon
• Splenic flexure of the colon
• Loops of jejunum

14. POSTERIOR RELATIONS
OF THE
KIDNEYS
The posterior surfaces of the kidneys
are related to:
– Psoas muscles
– Transversus abdominis
muscles
– Quadratus lumborum muscles
– Diaphragm
– 12th thoracic nerves
– Iliohypogastric nerves
– Ilioinguinal nerves
– Subcostal vessels

15. – Anterior layer of
thoracolumbar (lumbodorsal)
fascia
– Transversalis fascia
– Pararenal fat
– 11th and 12th ribs
– Pleurae
– Posterior layer of Gerota's
fascia
– Perirenal fat
– Medial and lateral arcuate
ligaments of the diaphragm

16. Anatomic relations of the kidneys.
A.Posterior relations to the muscles of the posterior body
wall and ribs.
B.Relations to the pleural reflections and skeleton
posteriorly.
Risk of pleural
puncture during
supra costal puncture

17. • Therefore percutaneous
access to the collecting
system is usually performed
through a renal pyramid into
a calyx to avoid these
columns of Bertin containing
larger blood vessels

18. • The lateral border of the
kidney is related to :
– the perirenal fat,
– Gerota's fascia, and
– Pararenal fat.
• Lateral contour may have a
focal renal parenchymal
bulge known as a
dromedary hump,- no
pathological significance

19. Medial border
• In the medial border of each kidney
there is a vertical fissure called the
renal porta or hilum.
• The concavity of the hilum is
continuous with the renal sinus.
• The renal arteries and nerves enter
through the renal hilum
• Veins, lymphatics, and proximal ureter
exit through it.
• The renal pelvis most commonly
lies posterior to the renal vessels

20. •Within the renal sinus is the intra-renal pelvis,
a funnel- shaped sac formed by the widely
expanded portion of the proximal ureter and by
the junctions of the major calices.
•In some instances the renal pelvis is small, lacks an
extrarenal portion, and is located entirely within the
renal parenchyma.

21. •The UPPER POLE of each kidney is related to its
associated adrenal gland, separated from it only by
a thin diaphragm of connective tissue originating
from the fascia of Gerota, which totally envelops
each adrenal.
•The right and left adrenal glands are located
superomedially at the front of the upper part of
each kidney.
•The LOWER POLE is occasionally located close
to the lumbar triangle.
•Associated with the psoas medially
• quadratus lumborum and transversus abdominis
laterally

22. Gross and microscopic anatomy
• Pale outer cortex
• Dark inner medulla
• Medulla is divided into 8 to 18 striated,
conically shaped areas called renal
pyramids
• Apex of the pyramids forms the renal
papilla, and each papilla is cupped by an
individual minor Calyx

23. • Cortex extends downward between
the individual pyramids to form the
columns of Bertin
• Interlobar arteries traverse these
columns of Bertin
• Pyramids and their associated
cortex form the lobes of the kidney.

24. Papilla
Minor
calyx
Major
calyx
Pelvis
INFUNDIBULUM
CALYCEAL ANATOMY

25. • If only one papilla drains into a minor calyx, it is described as
a simple calyx.
• Two or more papillae entering the calyx, it is termed a
compound calyx.
• There are 5 to 14 minor calyces in each kidney
• There are three calyceal groups: the upper, middle, and
lower.
• Compound calyces are the rule in the upper calyceal group,
are common in the lower calyceal group, and are rare in the
middle calyceal group.
• The minor calyces, either directly or after coalescing into
major calyces, drain by infundibula into the renal pelvis
• The compound calyces of the poles of the kidney are oriented
facing their respective poles.
• The middle calyces typically are arranged in a series of
paired anterior and posterior calyces
• The simple calyces usually come in pairs, one facing

26. • In about two thirds of kidneys, there are two major calyceal
systems—an upper and lower one—and the middle calyces drain into
either or both systems.
• In the other one third of kidneys, the middle calyx drains into the pelvis
direcly or via an infundibulum.
• Drainage of the upper pole into the renal pelvis is by a single midline
infundibulum in most kidneys.
• Drainage from the lower pole is via a single infundibulum in about one
half of kidneys and otherwise.

27. • An important consideration for
percutaneous renal surgery is
determining the anterior-posterior
orientation of the calyces to establish
access.
• The distinction pertains to the middle and
lower calyceal system, which contains (in
almost all middle systems and
approximately one half of the lower
system) paired anterior and posterior minor
calyces.
• Paired anterior and posterior calyces
usually enter at about 90 degrees from
each other.
• The relative medial-lateral orientation (on
anterior-posterior radiography) is

28. • In a Brödel-type kidney, this unit is rotated
anteriorly, such that the posterior calyces are
about 20 degrees behind the frontal plane and
the anterior calyces are 70 degrees in front of
the frontal plane. The posterior calyces are
lateral, and the anterior calyces are medial in
this case.
• The Hodson-type kidney is the opposite; the
calyceal pairs are rotated posteriorly, with the
posterior calyces 70 degrees behind the
frontal plane and appearing medial and the
anterior calyces 20 degrees in front of the
frontal plane and appearing lateral. Most

29. • Right kidneys have a Brödel-type orientation (posterior calyces are
lateral), and most left kidneys have a Hodson-type orientation.
• Because variation is considerable, the mediolateral orientation
of the calyces on anteroposterior radiography cannot be used
to reliably determine the optimal calyx for entry, and additional
maneuvers are required to determine the exact calyceal
anatomy.

30. • One reliable anatomic distinction is that the upper calyceal group
is situated in a mediolateral orientation in 95% of kidneys, in
contrast with the anteroposterior orientation of the middle and
lower calyceal groups in 100% and 95% of kidneys.
• This means that most calyces of the upper pole are suitable for
percutaneous access from the posterior approach, whereas
care must be taken to select a posterior minor calyx in the
middle and lower groups.
• Within the lower calyceal group, the most inferior calyx is usually
anterior, but the next most cephalad calyx is usually posterior.

31. • The functional unit of the kidney is the
nephron.
• Approximately 0.4 to 1.2 million nephrons
are found in each adult kidney.
• The nephron consists of a glomerulus,
(capillary tuft) surrounded by epithelial cells
and the thin, fibrous Bowman capsule.
• The filtrate passes into the Bowman space
and then into the proximal convoluted
tubule, through the thin and thick limbs of
the loop of Henle, to the macula densa
adjacent to the glomerulus, and into the
distal convoluted tubule.
• It then enters the collecting tubules and
the ducts of Bellini.
MICROSCOPIC ANATOMY

32. ARTERIAL
SUPPLY
• The paired renal arteries :
– originate from the lateral wall of the aorta
– just below the origin of the SMA
– between the L1 and L2 vertebrae.
• The origin of the longer right renal artery is more
posterior than the left.
• Arising from each renal artery are before its
trifurcation are two small arteries:
– the inferior suprarenal artery
– the artery for the renal pelvis and proximal ureter.

33. Segmental branches of the right renal artery demonstrated
by renal angiogram (A) and corresponding diagram (B).

34. • Each artery reaching the hilum divides into
anterior and posterior divisions in relation to
the renal pelvis.
• Furthermore, the five branches of each
renal artery participate in the formation of
four renal segments:
(1) apical(superior),
(2)anterior (subdivided into superior and inferior),
(3)posterior, and
(4)basilar (inferior)

35. Typical segmental circulation of the right kidney, shown
diagrammatically. Notethat the posterior segmental artery is usually
the first branch of the main renal artery, and extends behind the
renal pelvis.

36. The intrarenal course and relation to the anterior
calices of the apical, basilar, and anterior
segmental arteries. Note the short length of the
apical branch. The posterior branch is shown by a

37. The branch of the renal artery supplying the posterior segment of the
kidney passes along the posterior surface of the renal pelvis and then
divides into smaller branches that course between the posterior calices.
The apical, basilar, and anterior branches are shown by broken lines.

38. BRÖDEL'S LINE
• Relatively avascular area of the kidney.
•Located slightly behind the convex border at the
posterior half of the kidney
•It marks the junction of the area supplied by
the anterior and posterior divisions of the renal
artery.
•Incision in this area will permit removal of a
stone within the renal calices with minimal
damage. (Anatropic pyelolithotomy)

39. Scheme of the anterior and posterior branches of the renal
artery, in a horizontal section of the kidney. The
"avascular" line is the region of overlap between the
anterior and posterior branches, situated posterolaterally
rather than laterally because of the wider distribution of
the anterior branches.

40. Avascular plane of
kidney.

41. • Each renal arteriole is an “end-artery,”
• For this reason, renal arterial vascular injury must be
avoided to prevent loss of renal function.
• The potential for arterial injury is least in Brödel’s line
RENAL
ARTERY
INTERLOBAR ARCUATE
INTER
LOBULAR
AFFERENT
ARTERIOLE
Corticomedullary jn Columns od bertin
Pyramids

42. Multiple renal arteries supply one renal segment while
accessory arteries supply only part of the segment. It is
advisable to ligate only the accessory arteries.
An accessory artery of the lower pole may
produce ureteric obstruction with secondary
hydronephrosis.
Ligation of an accessory renal artery can result
in the production of an area of infarction of
variable size, though often small. Renovascular

43. Schematic drawings of accessory renal arteries. A. Right
kidney. B. Leftkidney. RK, right kidney; LK, left kidney; RU,
right ureter; LU, left ureter; ROA, right ovarian artery; LOA,
proximal part of the left ovarian artery; ROV, right ovarian
vein; A, aorta; IVC, inferior vena cava; RARA, right
accessory renal artery; LARA, left accessory renal artery.

44. Venous drainage
• The kidney is drained by several veins which together
form the renal vein.
Left renal vein Right renal vein
longer shorter

45. Lymphatics
• Follow the blood vessels and
form large lymphatic trunks.
• The trunks exit through the renal sinus
receiving communicating lymphatics
from the renal capsule and
perinephric fat.
• Lymphatics from the renal pelvis and
upper ureter communicate with
others at the renal hilum.

46. Regional lymphatic drainage of the right kidney.
Green nodes, anterior; black nodes, posterior. Solid
lines, anterior lymphatic channels; dashed
lines,posterior lymphatic channels. Arrow leads to
thoracic duct.
The lymphatics of the
right kidney
•drain into lymph nodes
located between the IVC
and the aorta, lateral
paracaval nodes, and
anterior and posterior
inferior vena caval lymph
nodes.
•They also drain upward
toward the right diaphragm,
and downward to the
common iliac lymph nodes.
•Also into the thoracic duct
or crossing the midline into
the left lateral aortic lymph
nodes.

47. Regional lymphatic drainage of the left kidney. Green
nodes, anterior; black nodes, posterior. Solid lines,
anterior lymphatic channels; dashed lines, posterior
lymphatic channels. Arrows lead to thoracic duct.
The lymphatics of the left
kidney
•drain into the lateral
paraaortic lymph nodes and
anterior and posterior aortic
lymph nodes.
•to the diaphragm and
downward to lymph nodes
associated with the inferior
mesenteric artery.

48. INNERVATI
ON
• The kidneys characteristically exhibit a very rich network of
neural elements that originate at the celiac
ganglion, aorticorenal plexus, and intermesenteric
plexuses.
• These elements intermingle, form plexuses, and follow the renal
artery.
• Thoracic nerves T10 to L1 participate in the innervation of the kidney.
• They receive pain fibers from the renal pelvis and proximal ureter that
enter the spinal cord at those levels of the spinal nerves.
• The renal nerves have a vasomotor function.
• The right and left vagus nerves participate in the formation of the
renal plexus.

49. • Point to remember before percutaneous /
open renal surgery.
• Nephroptosis can occur, especially in thin
women with a paucity of perirenal fat. In such
cases, the kidney not only descends but also
rotates anteriorly. This can be troublesome
during percutaneous punctures with the patient
in a prone position.
• The position of right kidney
• The longitudinal axis of the kidneys from the
vertical and the rotation of the kidney, this brings
the upper pole calyces medial and superficial
(dorsal) in relation to the lower pole calyces,

50. • The pleura can be punctured during entry into the upper pole. (Supra
costal)
• The ribs curve inferiorly from medial to lateral, such that more portions of
the kidney can be approached medially.
• Both the liver and spleen can extend lateral to the kidneys and are
therefore at risk for injury with a lateral puncture into the kidney
• The ascending and descending colon can be lateral or even posterior
to the right and left kidneys.
• Any organ can be injured with a misdirected or excessively deep
puncture.
• Avoid injury to the 11th and 12th intercostal nerves, not only to avoid
postoperative paresthesias and neuralgias, but also to avoid
postoperative bulging from partial paralysis of the muscles involved.