Download Anatomy of

Clinically Oriented Anatomy of
Retroperitoneum, Kidneys and
Adrenals
Associate Professor
Dr. Alexey Podcheko
Spring 2015
Learning Objectives
To know anatomy and clinical aspects of of
1. Retroperitoneal space
2. Kidneys
3. Adrenal glands
Retroperitoneal Structures
The retroperitoneal space (retroperitoneum):
 anatomical space behind the peritoneum.
 There is no clear delineating anatomical structures
 Organs having peritoneum on their anterior side are referred
to be retroperitoneal
Retroperitoneal Structures
 not suspended by
mesentery
 retroperitoneum is
subdivided into the
following spaces:
1. Perirenal space
2. Anterior pararenal
space - includes
duodenum, pancreas,
and ascending &
transverse colon
3. Posterior pararenal
space - includes
iliopsoas muscle, ureter,
and branches of IVC
and their lymphatics
Anterior pararenal
Posterior pararenal space
Retroperitoneal Structures
Primarily retroperitoneal:
 Adrenal gland
 Kidneys & ureters
 Bladder
 Aorta & inferior vena cava
 Rectum (lower third)
Secondarily retroperitoneal:
•Parts of the duodenum
•Pancreas (except the tail)
•Ascending & Descending Colon
Retroperitoneal Structures
A useful mnemonic to aid recollection of the abdominal
retroperitoneal viscera is SAD PUCKER, or DUKE CRAPS:
S = Suprarenal glands (aka the adrenal glands)
A = Aorta/IVC
D = Duodenum (2nd & 3rd segments [may be the 4th
segment])
P = Pancreas (only head, neck, and body are
retroperitoneal)
U = Ureters
C = Colon (ascending & descending colons: the transverse
& sigmoid retain mesocolon)
K = Kidneys
E = Esophagus
R = Rectum
KIDNEYS
•The kidneys produce urine
that is conveyed by the ureters
to the urinary bladder in the
pelvis
•The superomedial aspect of
each kidney normally contacts
a suprarenal gland enclosed in
a fibrous capsule and a
cushion of pararenal fat
•A weak fascial septum
separates the suprarenal
glands from the kidneys so that
they are not actually attached
to each other
•The suprarenal glands
function as part of the
endocrine system, completely
separate in function from the
kidneys.
Perinephric fat
•Perinephric fat (the perirenal fat capsule) surrounds the kidneys and
their vessels as it extends into their hollow centers, the renal sinuses.
Renal Fascia
The kidneys, suprarenal glands, and the perinephric fat surrounding them are
enclosed (except inferiorly) by a condensed, membranous layer of renal fascia,
which continues medially to ensheath the renal vessels, blending with the
vascular sheaths of the latter.
Renal Fascia, contd.
•Inferomedially, a delicate extension of the renal fascia is prolonged along the
ureter as the periureteric fascia
•External to the renal fascia is paranephric fat (or the pararenal fat body), the
extraperitoneal fat of the lumbar region that is most obvious posterior to the
kidney
•The renal fascia sends collagen bundles through the paranephric fat.
Renal Fascia, contd.
•The collagen bundles, renal fascia, and perinephric and paranephric
fat, along with the binding provided by the renal vessels and ureter,
hold the kidneys in a relatively fixed position (T12-L3)
•However, movement of the kidneys occurs during respiration
and when changing from the supine to the erect position, and
vice versa.
Renal Fascia, contd.
•Superiorly, the renal
fascia is continuous
with the fascia on the
inferior surface of the
diaphragm
(diaphragmatic
fascia); thus the
primary attachment of
the suprarenal glands
is to the diaphragm.
•Inferiorly, the
anterior and
posterior layers of
renal fascia are
only loosely united.
Perinephric Abscess
•The attachments of the
renal fascia determine the
path of extension of a
.
perinephric
abscess –
pus in the perinephric fat
•Fascia at the renal hilum
attaches to the renal
vessels and ureter,
usually preventing the
spread of pus to the
contralateral side
•Pus from an abscess (or
blood from an injured
kidney) may force its way
into the pelvis between
the loosely attached
anterior and posterior
layers of the pelvic fascia.
Nephroptosis
•Because the layers of renal fascia do not fuse firmly inferiorly to
offer resistance, abnormally mobile kidneys may descend more than
the normal 3 cm when the body is erect.
•When kidneys descend, the suprarenal glands remain in place
because they lie in a separate fascial compartment and are firmly
attached to the diaphragm.
Nephroptosis, contd.
•Nephroptosis (dropped kidney) is distinguished from an ectopic kidney
(congenital misplaced kidney) by a ureter of normal length that has loose coiling
or kinks because the distance to the bladder has been reduced.
Symptoms of intermittent pain in the renal region, relieved by lying down,
appear to result from traction on the renal vessels.
Kidneys Anatomy 1
•The ovoid kidneys remove excess water,
salts, and wastes of protein metabolism
from the blood while returning nutrients
and chemicals to the blood.
•They lie retroperitoneally on the posterior
abdominal wall, one on each side of the
vertebral column at the level of the T12 - L3
vertebrae.
L: Liver, P: Pancreas, LS:
Lesser sac, S: Spleen, C:
Colon, V: Inferior vena cava, A:
Abdominal aorta, D:
Duodenum, RK: Right kidney,
LK: Left kidney
Kidneys Anatomy 2
•The right kidney usually lies
slightly inferior to the left
kidney, probably owing to its
relationship to the liver.
• During life, the kidneys
are reddish brown and
measure approximately 10
cm in length, 5 cm in
width, and 2.5 cm in
thickness.
Kidneys Anatomy 3
Superiorly, the kidneys are associated with the
diaphragm, which separates them from the pleural
cavities and the 12th ribs.
More inferiorly, the posterior
surfaces of the kidney are
related to the quadratus
lumborum muscle.
12th rib
Kidneys Anatomy 4
•The subcostal nerve and vessels and the iliohypogastric and ilioinguinal nerves
descend diagonally across the posterior surfaces of the kidneys.
12th rib
Kidneys Anatomy 5
The liver, duodenum, and ascending
colon are anterior to the right
kidney.
The right kidney is separated from
the liver by the hepatorenal recess.
The left kidney is related to the
stomach, spleen, pancreas,
jejunum, and descending colon.
Kidneys Anatomy: Hilum
•At the concave medial margin of each kidney is a vertical cleft, the renal hilum,
where the renal artery enters and the renal vein and renal pelvis leave the renal
sinus.
•At the hilum, the renal vein is anterior to the renal artery, which is
anterior to the renal pelvis.
Kidneys Anatomy: Sinus
The renal hilum is the entrance to a space within the kidney, the renal sinus,
which is occupied by the renal pelvis, calices, vessels, and nerves and a variable
amount of fat.
Kidneys Anatomy: Poles, Margins, Surfaces
Each kidney has anterior and posterior surfaces, medial and lateral margins, and superior
and inferior poles.
Kidneys Anatomy: Position
However, because of the protrusion of the lumbar vertebral column into the abdominal
cavity, the kidneys are obliquely placed, lying at an angle to each other.
Kidneys Anatomy: Renal Pelvis
The lateral margin of each kidney is convex, and the medial margin is concave where the
renal sinus and renal pelvis are located.
The indented medial margin gives the kidney a
somewhat bean-shaped appearance.
The renal pelvis is the flattened, funnel-shaped
expansion of the superior end of the ureter.
The apex of the renal pelvis is continuous with the
ureter.
Kidneys Anatomy: Calyces and Papillas
The renal pelvis receives two or three major calices (calyces), each of which divides into
two or three minor calices.
Each minor calyx is indented by the
renal papilla, the apex of the renal
pyramid, from which the urine is
excreted.
Kidneys Anatomy: Pyramides
In living persons, the renal pelvis and its calices are usually collapsed (empty).
The pyramids and their associated cortex form the lobes of the kidney.
The lobes are visible on the external surfaces of the kidneys in fetuses,
and evidence of the lobes may persist for some time after birth.
Renal Transplantation
Renal transplantation is now an established operation for the treatment of
selected cases of chronic renal failure.
The kidney can be removed from the
donor without damaging the suprarenal
gland because of the weak septum of
renal fascia that separates the kidney
from this gland.
The site for transplanting a kidney is in
the iliac fossa of the greater pelvis.
This site supports the
transplanted kidney, so that
traction is not placed on the
surgically anastomosed
vessels.
The renal artery and vein are joined to the external iliac artery and vein,
respectively, and the ureter is sutured into the urinary bladder.
Renal Cysts
Cysts in the kidney, multiple or
solitary, are common findings
during ultrasound examinations
and dissection of cadavers.
Adult polycystic disease of the
kidneys is an important cause
of renal failure; it is inherited
as an autosomal dominant
trait.
The kidneys are markedly
enlarged and distorted by cysts
as large as 5 cm.
Ureters
•The ureters are muscular ducts (25 30 cm long) with narrow lumina that
carry urine from the kidneys to the
urinary bladder.
•They run inferiorly from the apex
of the renal pelves at the hila of
the kidneys, passing over the
pelvic brim at the bifurcation of
the common iliac arteries.
•They then run along the lateral
wall of the pelvis and enter the
urinary bladder.
•The abdominal parts of the
ureters adhere closely to the
parietal peritoneum and are
retroperitoneal throughout their
course
Ureters: Constricted Areas
The ureters are normally
constricted to a variable
degree in three places:
(1) at the junction of the
ureters and renal pelves,
(2) where the ureters cross
the brim of the pelvic inlet,
and
(3) during their passage
through the wall of the
urinary bladder.
These constricted areas are
potential sites of obstruction by
ureteric (kidney) stones.
Ureters: Blood Supply
•Abdominal portion of the ureter -renal
arteries, testicular, ovarian arteries, the
abdominal aorta, and the common iliac
arteries.
•The branches approach the ureters
medially and divide into ascending and
descending branches, forming a
longitudinal anastomosis on the ureteric
wall.
•Branches are small and relatively
delicate, and disruption may lead to
ischemia in spite of the continuous
anastomotic channel formed
•In operations in the posterior abdominal
region, surgeons pay special attention to
the location of ureters and are careful
not to retract them laterally or
unnecessarily.
Ureters: Blood Supply
Veins draining the abdominal part of the ureters drain into the
renal and gonadal (testicular or ovarian) veins.
Ureters: Lymphatic Drainage
•The lymphatic vessels of
the ureters join the renal
collecting vessels or pass
directly to right or left
lumbar (caval or aortic)
lymph nodes and the
common iliac lymph
nodes.
•Lymph drainage from
the pelvic parts of the
ureters is into the
common, external, and
internal iliac lymph
nodes.
Renal Arteries and Veins
•The renal arteries arise at the
level of the intervertebral disc
between the L1 and the L2
vertebrae.
•The longer right
renal artery passes
posterior to the
inferior vena cava.
Renal Arteries and Veins
Typically, each artery divides close
to the hilum into five segmental
arteries that are end arteries (i.e.,
they do not anastomose
significantly with other segmental
arteries, so that the area supplied
by each segmental artery is an
independent, surgically resectable
unit or renal segment).
Vascular Supply
Renal artery
 Interlobar arteries
 Arcuate arteries
 Interlobular arteries
 Afferent arteries
 Glomeruli
 Efferent arterioles
Peritubular plexus 
 Arcuate veins
Renal Veins
•Several renal veins drain each kidney and unite in a variable
fashion to form the right and left renal veins.
•The right and left renal veins lie anterior to the right
and left renal arteries.
Renal Veins
•The longer left renal vein receives the left suprarenal vein, the left gonadal
(testicular or ovarian) vein, and a communication with the ascending lumbar
vein, then passes anterior to the aorta.
•Each renal vein drains into the inferior vena cava.
Ascending lumbar
vein
Accessory Renal Vessels
•During their ascent to their final site, the embryonic kidneys receive their
blood supply and venous drainage from successively more superior vessels.
•Usually the inferior vessels degenerate as superior ones take over the blood
supply and venous drainage.
Accessory Renal Vessels
•Failure of these vessels to degenerate
results in accessory renal arteries and
veins (known as polar arteries and veins
when they enter/exit the poles of the
kidneys).
•Variations in the number and position
of these vessels occur in approximately
25% of people.
Congenital Anomalies of the Kidneys and Ureters
•Bifid renal pelvis and ureter are fairly common.
These anomalies result from division of the metanephric
diverticulum (ureteric bud), the primordium of the renal pelvis
and ureter.
Congenital Anomalies of the Kidneys and Ureters
•The extent of ureteral
duplication depends on the
completeness of embryonic
division of the metanephric
diverticulum.
•The bifid renal pelvis and/or
.
ureter may be unilateral or
bilateral; however, separate
openings into the bladder are
uncommon.
•Incomplete division of the
metanephric diverticulum
results in a bifid ureter;
complete division results in a
supernumerary kidney
Congenital Anomalies of the Kidneys and Ureters
•An uncommon anomaly is a retrocaval ureter, which
leaves the kidney and passes posterior to the inferior
vena cava.
Congenital Anomalies of the Kidneys and Ureters
•The embryonic kidneys are close together in
the pelvis.
•In approximately 1 in 600 fetuses, the inferior poles (rarely, the superior
poles) of the kidneys fuse to form a horseshoe kidney.
•This U-shaped kidney usually lies at the
level of L3 - L5 vertebrae because the
root of the inferior mesenteric artery
prevented normal ascent of the
abnormal kidney.
•Horseshoe kidney usually produces
no symptoms; however, associated
abnormalities of the kidney and renal
pelvis may be present, obstructing the
ureter.
Congenital Anomalies of the Kidneys and Ureters
•Sometimes the embryonic kidney on one or both sides fails to ascend to the
abdomen and lies anterior to the sacrum.
•Although uncommon, awareness of the
possibility of an ectopic pelvic kidney should
prevent it from being mistaken for a pelvic
tumor and removed.
•A pelvic kidney in a woman also can be
injured by or cause obstruction during
childbirth.
•Pelvic kidneys usually receive their blood supply from the
common iliac arteries.
Renal and Ureteric Calculi
•Calculi are composed of salts of
inorganic or organic acids or of other
materials.
•They may form and become located
in the calices of the kidneys, ureters,
or urinary bladder.
•A renal calculus (kidney stone) may pass from the
kidney into the renal pelvis and then into the ureter.
Renal and Ureteric Calculi
•If the stone is sharp, or it is
larger than the normal
lumen of the ureter
(approximately 3 mm)
causing excessive
distension of this muscular
tube, the ureteric calculus
will cause severe
intermittent pain (ureteric
colic) as it is gradually
forced down the ureter by
waves of contraction.
•The calculus may cause
complete or intermittent
obstruction of urinary flow.
Renal and Ureteric Calculi
•Depending on the level of obstruction, which changes, the pain may be
referred to the lumbar or inguinal regions, or the external genitalia
and/or testis.
•The pain is referred to the cutaneous areas innervated
by spinal cord segments and sensory ganglia, which also
receive visceral afferents from the ureter, mainly T11 - L2.
•The pain passes inferoanteriorly from the loin to the
groin as the stone progresses through the ureter (the loin
is the lumbar region, and the groin is the inguinal region).
•The pain may extend into the proximal anterior aspect
of the thigh by projection through the genitofemoral
nerve (L1, L2), the scrotum in males and the labia majora
in females.
•The extreme pain may be accompanied by marked alimentary upset (nausea,
vomiting, cramping, and diarrhea) and a generalized sympathetic response that
may to various degrees mask the more specific symptoms.
Suprarenal Glands
•The suprarenal (adrenal) glands, yellowish in living persons, are
located between the superomedial aspects of the kidneys and the
diaphragm, where they are surrounded by connective tissue
containing considerable perinephric fat.
Suprarenal Glands
•The glands are enclosed by renal fascia by which they are attached to the
crura of the diaphragm.
•They are separated from the kidneys by
a thin septum (part of the renal fascia).
Suprarenal Glands:
shape and relations
•differ on the two sides
•The pyramidal right gland is more apical (situated over the superior pole)
relative to the right kidney, lies anterolateral to the right crus of the
diaphragm, and makes contact with the inferior vena cava anteromedially and
the liver anterolaterally.
Suprarenal Glands:
shape and relations
•The crescent-shaped left gland is medial to the superior half of
the left kidney and is related to the spleen, stomach, pancreas,
and the left crus of the diaphragm.
Suprarenal Glands:
Size and Hilum
•Each gland has a hilum, where the veins and lymphatic vessels
exit the gland; whereas arteries and nerves enter the glands at
multiple sites.
•The medial borders of the
suprarenal glands are 4 - 5 cm
apart.
Suprarenal Glands:
•Each suprarenal
gland has two
parts: the
suprarenal cortex
and suprarenal
medulla; these
parts have
different
embryological
origins and
different functions.
Parts
Suprarenal Glands:
Cortex
•The suprarenal cortex derives from mesoderm and secretes corticosteroids
and androgens.
•These hormones cause the kidneys to retain sodium and water in response
to stress, increasing the blood volume and blood pressure.
•They also affect muscles and organs such as the heart and lungs.
Suprarenal Glands:
Medulla
•The suprarenal medulla is a mass of nervous tissue permeated with
capillaries and sinusoids that derives from neural crest cells associated with
the sympathetic nervous system.
•The chromaffin cells of the medulla are related
to sympathetic ganglion (postsynaptic) neurons
in both derivation (neural crest cells) and
function.
•These cells secrete catecholamines (mostly
epinephrine) into the bloodstream in response
to signals from presynaptic neurons.
•The powerful medullary hormones epinephrine (adrenaline) and
norepinephrine (noradrenaline) activate the body to a flight-or-fight status in
response to traumatic stress.
•They also increase heart rate and blood pressure, dilate the bronchioles, and
change blood flow patterns, preparing for physical exertion.
Suprarenal Glands:
Blood Supply
•The endocrine function of the suprarenal glands makes their
abundant blood supply necessary.
•The suprarenal
arteries branch
freely before
entering each gland
so that 50 - 60
arteries penetrate
the capsule
covering the entire
surface of the
glands.
Suprarenal Glands:
Blood Supply - Suprarenal arteries
•Suprarenal arteries arise from three sources:
1. Superior suprarenal
arteries from the
inferior phrenic
arteries.
2. Middle suprarenal
arteries from the
abdominal aorta near
the level of origin of
the superior
mesenteric artery.
3. Inferior suprarenal
arteries from the
renal arteries
Suprarenal Glands:
•The venous drainage
of the suprarenal
gland is into a large
suprarenal vein.
•The short right
suprarenal vein
drains into the
inferior vena cava,
whereas the longer
left suprarenal vein,
often joined by the
inferior phrenic vein,
empties into the left
renal vein.
Blood Supply - Veins