Renal Tract and Retroperitoneum

Kidneys ~10-15cm, ~150g, T12-L3

  • LK usually 1.5cm longer and higher than R. Gradually increase in size until 20yo at 90-130mm before gradually reducing after 50yo.
  • upper pole/moiety (more medial and posterior), hilum (A>P v,a,pelvis), lower pole/moiety
  • Fibrous capsule, cortex (outer 1/3, contain glomeruli, proximal and distal convoluted tubules, vessels) and medulla (inner 2/3, collecting tubules, loops of Henle, * vesels). Peripheral cortex is immediately beneath capsule, septal cortex extends between medullary pyramids (with base, body, papilla) as columns of Bertin.
  • minor calyces
  • simple calyx = 1 papilla, compound/complex ≥ 2 (more common in UP, more prone to reflux)
  • major calyces (7 ventral, 7 dorsal [4UP, 3LP])
  • infundibula (calyces > pelvis; upper, lower pole ± middle)
  • renal pelvis
  • renal sinus (slit-like space between calices, outside pelvis; contain fat)


  • RK A=liver, D2, ascending colon, small intestine; LK A = stomach, spleen, jejunum, splenic flexure, pancreas
  • P = costodiaphragmatic recess, rib 12, diaphragm, psoas, quadrates lumborum, transverses abdominis
  • S = adrenal gland


  • nephrons (1 million per kidney, uriniferous tubule + glomerulus)
  • renal/Malpighian corpuscle (glomerulus + capsule)
  • glomerulus (loop of capillaries)
  • Bowman’s/glomerular capsule
  • proximal convoluted tubule
  • descending and ascending loops of Henle
  • distal convoluted tubule
  • junctional tubule
  • collecting ducts (~12 per papilla)

Renal arteries – L2, R posterior to IVC; branches to inferior suprarenal, proximal ureter, superior and middle capsular aa

  • anterior division (>apex, anterior UP, entire LP)
  • posterior division (post to pelvis, >post UP and mid)
  • segmental arteries (5, run adjacent to infundibula):
    • apical segment (<anterior division)
    • upper, middle and lower segments (<ant division)
    • posterior segment (<post division)
  • interlobar branches (medulla along pyramids>cortico-medullary junction)
  • arcuate arteries (base of pyramids, do not anastamose; may anast with capsular aa)
  • interlobular arteries >inner cortex)
  • afferent arterioles (>glomeruli)
  • efferent arterioles (>supply cortex and medulla; near capsule>convoluted tubules; inner >vasa recta)
  • vasa recta (accompany loop of Henle) > arcuate v
  • capsular arteries (sup < renal or inferior suprarenal aa; mid < renal a; inferior < gonadal a)


  • stellate venules (next to capsule) > interlobular > arcuate >interobar vv (5-6)
  • renal vein (ant to pelvis, L anterior to aorta and receives inferior phrenic, gonadal and suprarenal vv; L 5x longer than R)
  • capsular veins > suprarenal, gonadal and diaphragmatic veins

applied anatomy

  • nephrostomy should be performed through a calyx to minimise arterial injury
  • kidney may be perfused via anastamoses with capsular aa

Nerve Supply

  • sympathetic: thoracic and lumbar splanchnic nn>coeliac, renal and superior hypogastric plexuses
  • afferent fibres (T12-L2) travel with sympathetic nn



  • Persistent fetal lobulation (betw calyces, with infolding of columns within medulla; whole or mid and lower kidney)
  • Junctional cortical defect (sinus fat extending to cortex)
  • Extrarenal pelvis
  • Crossed fused renal ectopia – LP fuses with UP ectopic contralateral kidney. Renal aa always aberrant. Ureters enter correct sides.
  • Horseshoe kidney (1/700) – LP fuse, ascent usually arrested by IMA. Isthmus may be fibrous or contain functioning renal tisue. Kidneys usually malrotated with pelvises directed ant, lower pole calyces medial (usually directed lat). Renal aa commonly multiple and ectopic. Increased risk of traumatic injury, urinary stasis (stones, infection).
  • Pelvic kidney (1/1500; < internal iliac aa)
  • Agenesis of one kidney (1/2400)
  • Pancake kidney (completely fused pelvic kidneys)
  • Thoracic kidney (incomplete fusion of parts of diaphragm)
  • Dromedary/splenic hump (prominent midportion of lateral border left kidey)
  • Non-rotation, incomplete rotation or excessive rotation (usually 90° inward) of the kidneys with hilum facing other than ant-med


  • Apical segment < main renal a (25%), aorta (25%), or posterior division (10%)
  • Upper and middle segments < posterior division
  • Accessory renal arteries (25%, up to 4 each side; anterior or posterior to IVC; <aorta, inferior phrenic a, iliac a)
  • Superior and inferior polar arteries (main renal a or aorta > directly into parenchyma without through hilum)
  • Aberrant segmental renal a < SMA/gonadal a
  • Early bifurcation of renal artery


  • Retroaortic left renal vein
  • Circumaortic left renal vein (sup > ant, inferior with gonadal > post)
  • Supernumeray veins (10%)
  • Persistent left IVC > left renal v
  • Right gonadal v > renal v

Ureter ~25cm

  • abdominal, pelvic and intravesical (2cm) portions
  • 5mm dia above pelvic prim, 7mm in pelvis
  • Main ureteric narrowings include pelviureteric junction, mid-ureter (iliac vessels and pelvic brim), vesicoureteric junction.
  • turns anteromedial at ischial spines then posterior after crossing iliac vessels
  • adventitial (outer continous with renal capsule and bladder adventitia), smooth m (outer circular, inner longitudinal), inner mucosa (transitional epithelium) layers
  • upper ureter < ureteric branch of renal a
  • mid ureter < gonadal, common iliac aa
  • distal ureter < superior and inferior vesical, middle rectal, uterine aa
  • lymph>paraaortic nodes or internal iliac nodes


  • R A = D2, gonadal, right colic, ileocolic vessels, mesentery, terminal ileum
  • L A = gonadal, L colic aa, jejunum, sigmoid mesocolon
  • P = psoas mm, genitofemoral nn, pelvic brim, iliac vessels, seminal vesicles
  • S/A = round lig, uterine a, ductus deferens
  • med = IVC/aorta, IMV (L), uterus, cervis, rectum
  • lat = obturator internus


  • duplex kidney/ureter (4%)
    • incomplete duplication of ureter (unite midway with constriction)
    • complete duplication of ureter
    • Weigert-Meyer law: UP ureter drains fewer calyces and inserts below the normally inserted LP ureter
  • ectopic ureter (usually with duplex system; bladder neck, urethra, vestibule, posterior vaginal, seminal vesicle, vas deferens, ejaculary duct and rarely uterus, Wolffian duct remnant, rectum)
  • ureterocele (dilation of intramural ureter from stenosis of orifice, usually with ectopic ureter)
  • retro/circum-caval ureter (right ureter hooks around IVC)
  • vesicoureteric reflux (VUR, short or anomalous VUJ)

Suprarenal/Adrenal Glands ~T12, 5g

  • med-ant-sup aspect of kidneys, enclosed in perirenal fascia
  • 1/3 of kidney in infant; 1/30th in adult
  • R fixed to posterior IVC ,L fixed to L crus and higher
  • R suprarenal pyramidal, 2 limbs (med and lat)
  • L suprarenal crescent, 3 limbs (anterior, posteromedial, posterolateral)
  • limbs < 6.5mm or adjacent crus
  • outer cortex (zona glomerulosa [mineralocorticoid], zona fasciculate [glucocorticoid and androgens], zona reticularis [glucocorticoid and androgens])
  • inner medulla (catecholamines)


  • R A = IVC, right liver; L A lesser sac, cardia, spleen, splenic v, pancreas
  • P/med = crus
  • P/lat = perirenal fat, kidney
  • L medial = left coeliac ganglaion, left inferior phrenic and left gastric aa

Blood Supply

  • superior suprarenal a < inferior phrenic a
  • middle suprarenal a < suprarenal artery proper < aorta
  • inferior suprarenal a < renal a
  • suprarenal vein (single), R > IVC; L > L renal v

Nerve Supply

  • greater and lesser splanchnic nn > coeliac ganglion > supply aa to regulate flow and suprarenal medulla to secrete catecholamines


  • cortical bodies (islands of suprarenal cortical tissue found in broad lig, spermatic cord, epididymis)
  • superior adrenal artery < aorta or renal a
  • multiple middle adrenal aa (30%)
  • inferior adrenal a < superior capsular a
  • < gonadal a

Fascial Spaces

retroperitoneum lies between parietal peritoneum, transversalis fascia, liver/diaphragm and pelvic brim

perirenal fascia

  • anterior leaf = Gerota’s fascia (med>fascia around aorta and IVC; superior > diaphragm, bare area liver; inferior > debatable, fuses with posterior leaf around ureter as apex of inverted cone)
  • posterior leaf = Zuckerkandl’s fascia (med>fusion with transversalis, psoas and quadrates lumborum fascia; sup>psoas and quadrates lumborum fascia at lumbocostal arch; inferior > periureteric facia). Comprises anterior and posterior layers (post > lateroconal fascia, anterior > anterior leaf), may be separated by inflammation (eg pancreatitis) extending from anterior pararenal space.

lateroconal fascia (Gerota’s and Zuckerkandl’s fascias fuse lat, cont with parietal peritoneum)

anterior pararenal space

  • S = diaphgram posterior to oesophagus, cont with mediastinum
  • I = open, continuous with prevesical, perivescical and presacral spaces
  • medial = continous with contralateral side
  • pancreas, duodenum, ascending and descending colon, root SB mesentery, transverse mesocolon

perirenal space has septa extending between renal capsule and perirenal fascia.

  • medial = confluence of anterior and posterior perirenal fascia, continous with contralateral side in some
  • lateral = confluence of anterior and posterior perirenal fascia
  • S = bare area of liver (R), diaphragm and extraparietal subphrenic space (L)
  • I = debatable, fusion anterior and posterior perirenal fascia
  • kidney, renal vessels, collecting system, ureters, adrenal gland, perinephric/perirenal fat with septae/lamellae

posterior pararenal space

  • medial = muscular psoas fascia
  • lateral = transversalis fascia, cont with properitoneal space
  • S = fusion of posterior perirenal fascia with psoas fascia
  • I = open into pelvis
  • extraperitoneal fat, vessels lymphatics

space for aorta, IVC and psoas


  • variable extents of anterior pararenal and perirenal spaces across midline
  • variable inferior extent of perirenal space

Abdominal Aorta T12>L4, 2-3 x 12cm


  • A = coeliac axis and plexus, caudate lobe, pancreas, stomach, left renal v, SMA, SMV, D3, small bowel, IMA
  • P = L1-L4 (discs and ALL), left psoas, L lumbar vv
  • R = IVC, thoracic duct
  • L = SB, duodenum



  • inferior phrenic aa (T12, > superior suprarenal aa)
  • (middle) suprarenal aa (L1)
  • renal arteries (L1/L2)
  • gonadal arteries (L2)
  • lumbar arteries (4 pairs L1-L4, >dorsal [muscle, skin, joints] and spinal [cord, cauda equina] branches)
  • common iliac arteries (L4)


  • coeliac artery (T12/L1)
  • superior mesenteric artery (L1)
  • inferior mesenteric artery (L3)
  • median sacral artery (L4; >rectum, may >5th lumbar a)


  • retroaortic or circumaortic left renal v
  • superior suprarenal, left gastric or common hepatic from aorta
  • multiple renal or middle adrenal aa

Inferior Vena Cava (IVC) L5>RA

  • intraabdominal and intrathoracic (2cm) portions from T8
  • incomplete semilunar Eustachian valve at RA


  • A = aortic bifurcation, R CIA, SB, root mesentery, D3, head pancreas, CBD, D1, portal v, epiploic foramen, superior mesenteric vessels, liver
  • P = vertebrae, R adrenal gland, R inferior phrenic, R adrenal, R renal, R lumbar aa, R sympathetic trunk
  • L = aorta


  • right inferior phrenic vein (T8)
  • hepatic veins (T8; 3 main and multiple accessory)
  • capsular vv (sup, medial and inf; may >IVC, suprarenal or inferior phrenic vv)
  • right suprarenal v (L1)
  • renal vv (L1; L<suprarenal [<L inferior phrenic v] and gonadal)
  • right gonadal vein (L2)
  • 3rd and 4th lumbar veins
  • common iliac veins (L5)


  • double (infrarenal) IVC (2%; persistence of both supracardinal vv; > left renal v > right IVC)
  • left (infrarenal) IVC (0.5%; > left renal v > right sided suprarenal IVC)
  • azygos or hemiazygos continuation of IVC (0.6%, absent hepatic segment of IVC; drainage via azygos system, hepatic vv > RA)
  • double IVC with retroaortic right renal vein and hemiazygos continuation of IVC (persistent supracardianal vv and failed right subcardinal-hepatic anastomosis)
  • double IVC with retroaortic left renal vein and azygos continuation of IVC
  • circumaortic left renal vein = circumaortic cava (10%; superior crosses ant, inferior is post)
  • retroaortic left renal vein (2%)
  • circumcaval/retrocaval ureter (passes to the right of the aorta)

Veins of the Posterior Abdominal Wall

  • internal and external vertebral venous plexuses > (segmental) lumbar vv
    • 1st and 2nd lumbar vv > ascending lumbar v
    • 3rd and 4th > IVC
    • 5th > ileolumbar v
    • ascending lumbar vv (betw psaos and transverse processes) <(segmental) lumbar vv, branches from lateral sacral vv, ileolumbar vv, L renal
  • azygos/hemiazygos = ascending lumbar + subcostal vv; may arise from IVC or left renal v

Abdominal Lymphatics

Preaortic Nodes

  • efferent channels > right and left intestinal trunks > cysterna chyli

coeliac nodes

  • gastric group
    • left gastric group (lesser curve; <stomach and lower oesophagus)
    • gastroepiploic group (greater curve; R gastroepiploic a >pyloric nodes)
    • pyloric group (4-5 nodes at bifurcation of GDA @ D1/D2, <pylorus, D1, gastroepiploic nodes)
  • hepatic group (lesser omentum; <stomach, duodenum, BDs, liver, GB, pancreas)
    • cystic node (junction cystic and hepatic ducts)
  • pancreaticosplenic group (along splenic a; <stomach, spleen, pancreas)

superior and inferior mesenteric nodes

  • mesenteric nodes
    • mural group (terminal branches of aa)
    • intermediate group (mesenteric arcades)
    • juxtaarterial group (upper trunk SMA)
  • ileocolic nodes
    • ileal group
    • anterior ileocolic group (@ileocaecal fold)
    • posterior ileocolic (betw ileum, ascending colon, posterior to caecum)
  • colic nodes
    • epicolic group (wall/appendices epiploicae)
    • paracolic (mesenteric borders and medial asc/desc colon)
    • intermediate colic (colic aa)
    • preterminal colic (SMA/IMA)
  • perirectal/pararectal nodes (wall nodes > intermediate colic group [sup rectal a], some > internal and common iliac nodes)

Paraaortic nodes

  • sides of aorta, lateral and anterior to IVC
  • aortocaval nodes (betw aorta and IVC)
  • portocaval node (betw IVC and portal v)
  • retroaortic nodes
  • efferent channels > right and left lumbar trunks and preaortic nodes
  • < posterior abdo wall, diaphragm, kidneys, suprarenals, gonads, common, external, internal and circumflex iliac, inferior epigastric and sacral nodes

Iliac Nodes

  • common iliac nodes (CIA, L5/sacral promontory; > paraaortic nodes; medial, lateral and intermediate chains)
    • external iliac nodes (medial, lateral and anterior groups around a; inferior epigastric and circumflex iliac groups)
      • medial EI nodes < inguinal nodes, deep lower abdo wall, adductor comp thigh, glans penis, membr urethra, prostate, upper bladder, cervix, upper vagina
    • internal iliac nodes (<pelvic viscera, perineum, gluteal, posterior femoral mm; incl sacral nodes, obturator nodes)

Cisterna Chyli

  • <intestinal and lumbar trunks, descending intercostal trunks
  • 6mm x 6cm anterior to L1 and L2 > retrocural space > thoracic duct


  • L/A = aorta
  • R = right crus
  • P = L1-2

Sympathetic Trunk and Plexuses

  • thoracic sympathetic chain > medial arcuate lig > lumbar trunk > iliac vessels > sacral trunk
  • P = lumbar aa, vertebrae and discs; A = IVC, aorta
  • sympathetic trunks, splanchnic, vagus, phrenic nn > solar plexuses (ie efferents radiate out)
  • coeliac plexus (betw coeliac and SMA; >phrenic, hepatic, left gastric, splenic, suprarenal, renal, testicular, ovarian, superior mesenteric, intermesenteric and inferior mesenteric plexuses)
  • superior hypogastric plexus (@ bifurcation aorta; > right and left hypogastric nerves > inferior hypogastric plexus)
  • inferior hypogastric plexus (post to bladder; > middle rectal, vesical, prostatic plexuses, uterine and vaginal nn)

Posterior Abdominal Wall

  • 12th rib to pelvic brim
  • superior and inferior halves (iliac crest)


  • lumbar vertebrae (L1-L5)
  • transverse processes (L3 longest, L1-4 horizontal, L5 posterosuperior)

Muscles and Fascia

  • psoas major (T12-L5, central tendon > lesser trochanter; encompasses ventral rami L2-4, lumbar plexus; psoas fascia > medial arcuate ligament)
  • psoas minor (absent in 40%; anterior to major; T12-L1>innominate line ilium)
  • quadrates lumborum (T12-L5 transverse processes> iliac crest; fascia > lateral arcuate lig; iliolumbar lig [L5>crest])
  • transverses abdominis (aponeurosis >thoracolumbar fascia)
  • iliacus (iliac fossa>psoas tendon at level of inguinal lig forming iliopsoas)