Vascular Supply of the GI Tract

Inferior Phrenic Arteries (T12)

  • right (post to IVC) and left (post to oesophagus) inferior phrenic aa
    • ascending/anterior branch (R>IVC and diaphragmatic branches; L>oesophageal and accessory splenic branches) > anast with IMA, intercostal, pericardiophrenic aa
    • descending/posterior branch > anast with posterior intercostal and musculophrenic aa
    • superior suprarenal aa > renal capsular branches
  • branches to liver and spleen

Variants

  • <aorta/CT/L gastric/left renal artery
  • common trunk (33%)

Coeliac Trunk/Axis (CT, T12/L1, ~1-2cm)

Relations

  • A = lesser sac
  • S = L liver, median arcuate lig of diaphragm
  • I = pancreas, splenic v
  • L = stomach cardia

Left Gastric Artery

  • >gastric cardia
  • oesophageal branches (1-3)
  • posterior branch>lesser curve>right gastric artery
  • anterior branch (>ant stomach)
  • anast with right gastric, short gastric aa, gastroepiploic aa, cardio-oesophageal branches (<inferior phrenic a)

Splenic Artery ~13-32cm

  • sup-post pancreas > leinorenal lig
  • dorsal pancreatic artery (<splenic a in 37%)
    • transverse/inferior pancreatic a (>body and tail cont as caudal pancreatic a; >posterior epiploic a)
    • pancreatic head branch ( > between head and uncinate process, anast with ASPD, GDA or right gastroepiploic a)
    • uncinate process branch
  • short pancreatic arteries
  • arteria pancreatica magna = greater pancreatic a (>body; anast with transverse pancreatic a and caudal pancreatic a)
  • caudal pancreatic a = artery of the pancreatic tail (> tail)
  • left gastroepiploic artery (<terminal splenic a; anterior division of greater omentum)
    • arcus arteriosus ventriculi inferiori of Hyrtl (left>right gastroepiploic aa; branches>L&R gastric arcade)\
    • left epiploic artery (ant>post layer of greater omentum)
    • arcus epiploicus magnus of Barkow (post left>right epiploic aa; posterior greater omentum)
  • accessory left gastric artery (<mid/distal splenic a)
  • short gastric arteries (4-10; > greater curve)
  • superior, inferior ± middle terminal splenic aa (hilum; >4-6 intrasplenic arteries)
  • superior polar artery (65%, <superior terminal/splenic a)
  • inferior polar artery (82%, <left gastroepiploic a/distal splenic/inferior terminal a)

Common Hepatic Artery

  • >right hepatopancreatic fold>hepatoduodenal ligament
  • proper hepatic artery
    • P = portal vein, R = CBD
    • supraduodenal artery of Wilkie (<proper hepatic/right gastric/retroduodenal/GDA; >1st inch of duodenum)
    • right gastric artery (<proper[40%]/L hepatic aa[40%] or GDA/middle hepatic/right hepatic aa; >pylorus)
    • right hepatic artery (cross posterior to duct>cystohepatic angle>anterior segmental [V&VIII] and posterior segmental [VI&VII±I&GB] arteries)
      • cystic artery(s) (1 or 2 [20%]; <R hepatic [45%], OR common hepatic/ L hepatic/ middle hepatic/ GDA/ retroduodenal aa; >superficial and deep branches
    • left hepatic artery (inf to duct; >II&III±IV±I)
    • middle hepatic artery (<R&L hepatic[45%] or proper hepatic/GDA/CT; >IV±I)
  • gastroduodenal artery (GDA)
    • A = D1; P = pancreas; R = CBD
    • posterior superior pancreaticoduodenal artery = retroduodenal artery (crosses anterior then runs along CBD; >posterior inferior pancreaticoduodenal artery)
      • posterior pancreaticoduodenal arcade(s) (>vasa recta to duodenum, part of head)
    • anterior superior pancreaticoduodenal artery (ASPD; posterior D1>head>anterior inferior pancreatico-duodenal artery)
      • anterior pancreaticoduodenal arcade(s) (inferior to posterior arcade)
    • right gastroepiploic artery (>pylorus, anterior layers of greater omentum)
      • right epiploic artery (ant>post layer of greater omentum)

Variants

  • left gastric artery from aorta (3%)
  • arc of Bühler (2%, proximal CT/common hepatic/splenic>prox SMA)
  • coeliacomesenteric trunk (0.5%, CT and SMA)
  • lienohepatomesenteric trunk (0.25%, splenic, hepatic, SMA with separate left gastric a)
  • median arcuate lig compression of CT
  • hepatic arteries
    • (full) replacement artery
    • partial replacement = accessory artery
    • common hepatic artery from SMA (4.5%, posterior to portal v and lateral to CBD) or aorta
    • proper hepatic artery from left gastric (0.5%)
    • replaced (11%) or accessory (7%) right hepatic artery from proximal R SMA (post to pancreas, between portal v and IVC)
    • replaced (10%) or accessory (8%) left hepatic artery from left gastric a
    • cystic artery from left hepatic a (10%), common hepatic, GDA
    • early division or trifurcation of common hepatic a
  • gastroduodenal and pancreatic arteries
    • GDA from right (7%) or left (4-11%) hepatic aa, or trifurcation of common hepatic a
    • dorsal pancreatic a from CT (33%), SMA (21%), common hepatic (8%), or 1st jejunal branch
    • transverse pancreatic from splenic a or ASPD a (10%)
    • caudal pancreatic a < L gastroepiploic a
    • retroduodenal a < common hepatic, proper hepatic, R hepatic, R gastric aa

Superior Mesenteric Artery (SMA)

  • ~L1 1cm distal to CT
  • inferior pancreaticoduodenal artery (IPDA, posterior to SMV; > anterior and posterior IPDAs)
  • middle colic artery (right and left branches)
  • jejunal arteries (4-6; > marginal a of Dwight)
  • right colic artery (<SMA in 20-40%) > ascending and descending branches
  • ileal arteries (9-13)
    • SB arcades (4-7 levels, branches divide into 2 and anastamose with adjacent aa)
    • marginal artery of the small bowel/of Dwight (<arcades; >vasa rectae)
    • vasa rectae (>anterior and posterior branches)
  • ileocolic artery (ant to right gonadal a)
    • superior division/(ascending) colic branch (anast with right colic a)
    • inferior division/ileal branch
    • ascending branch
    • anterior and posterior caecal branches
    • appendicular branch (>recurrent artery anast with posterior caecal)
    • terminal ileal branch
  • terminal branch (>ileum, anast with ileal br of ileocolic)

Relations

  • A = pancreatic head/body, splenic vein
  • P = uncinate process, left renal vein, D3, aorta, renal aa
  • R = SMV

Variants

  • arc of Riolan = meandering mesenteric a of Moskowitz (middle colic a>left colic a)
  • IPDA or branches from 1st/2nd jejunal branch (>50%) or right hepatic a that arises from SMA
  • anterior and posterior IPDA separate origins (60%)
  • coelicomesenteric trunk
  • dorsal pancreatic a from SMA
  • right colic/middle colic trunk (53%)
  • right colic < arcade between ileocolic and middle colic
  • middle colic a < CT, splenic a, dorsal pancreatic, or replaced/accessory hepatic a from SMA
  • absent middle colic artery (large branch from left colic)
  • absent right colic artery (2%)
  • accessory right colic artery from ileocolic a (8%)
  • persistent vitellointestinal a (<6th/7th ileal a; >Meckel\’s diverticulum = embryological end point of SB)
  • proximal anastamotic arcade (ileocolic>distal SMA)

Applied Anatomy

  • Griffith’s point (relative arterial insufficiency in splenic flexure, junction of SMA and IMA supply)
  • Sudeck’s point (arterial insufficiency at junction sigmoid and superior rectal aa)

Anastamoses

  • left colic > arch of Riolan/marginal a of Drummond > middle and right colic
  • inferior > superior pancreaticoduodenal a > GDA
  • internal iliac aa > inferior and middle rectal aa > superior rectal > right colic

Inferior Mesenteric Artery (IMA)

  • ~L3, 3-4cm above bifurcation from ant-left of aorta
  • left colic artery (ascending and descending branches)
    • marginal artery of the large bowel/of Drummond (may be absent/tenuous at splenic flexure)
  • sigmoid arteries (2-3)
  • superior rectal/haemorrhoidal artery (terminal IMA; left and right branches split into 2)

Portal Vein ~8cm

  • < splenic + SMV @ L1/2
  • valves in utero and infant, but not adult

Relations

  • A = pancreatic neck, hepatoduodenal lig, D1; R/A = CBD; L/A = hepatic a
  • P = portocaval space (epiploic foramen between portal v and IVC), IVC
  • L = stomach
  • R = liver

Intrahepatic Portal Vein

  • right portal vein (2-3cm) > anterior(RA> RAS, RAI) and posterior (RP> RPS, RPI) branches
  • left portal vein (2-8cm) > proximal/transverse/medial (>LMS, LMI) and distal/umbilical/lateral (LLS, LLI) branches
  • caudate < left and right branches
  • obliterated umbilical vein (umbilical portion left portal vein in falciform lig>abdo wall)
  • paraumbilical vv (around ligamentum teres) > left branch of portal v
  • cystic vein anterior (1) and posterior (2) branches (2)>cystic v>liver or right or main portal v
  • I, GB bed and around falciform lig aberrant portal venous drainage directly into subsegmental hepatic parenchyma (V, causing portal perfusion defects, focal fatty infiltration or focal sparing)

Extrahepatic Portal Vein

  • bifurcation @porta
  • right gastric vein
  • left gastric v = coronary v (< lower oesophagus)
  • posterior superior pancreaticoduodenal v
  • splenic and SMV

Superior Mesenteric Vein (SMV) – P = D3, uncinate process, IVC, right psoas, right ureter; L = SMA

  • gastrocolic trunk (right gastroepiploic, middle colic and ASPD veins)
  • inferior pancreaticoduodenal veins (>SMV or 1st jejunal v)
  • right colic v (>SMV at D3; anast with ileocolic, middle colic)
  • ileocolic v (<ant and posterior caecal, appendicular, last ileal, coliv vv)
  • jejuno-ileal veins

Splenic Vein – A = pancreas; P = aorta; S = splenic a

  • inferior mesenteric vein (IMV; R = IMA; >splenic vein in 40%)
    • left colic vein
    • sigmoid veins
    • superior rectal/haemorrhoidal veins
  • dorsal pancreatic vein
    • transverse pancreatic v (or > splenic or confluence of splenic and SMV)
  • great and short pancreatic vv
  • left gastroepiploic vein
    • left epiploic vein (<venous arcade of Barkow < R epiploic v [<R gastroepiploic] in posterior omenutum)
  • short gastric vv

Variants

intrahepatic

  • trifurcation of main portal (11% >RA, RP and L)
  • RP from main portal (5%)
  • RA from L portal (4%)
  • absence of horizontal segment left portal (0.2%, br from right posterior > left)
  • absence of right portals
  • patent ductus venosus

extrahepatic

  • prepancreatic portal v
  • right gastric v > left or intrahepatic portal v (10%, causing ‘flow defect’ in I/IV)
  • left gastric v > confluence of splenic and SMV (60%), main portal vein (25%), or splenic v (15%)
  • ASPD v > portal v
  • posterior superior pancreaticoduodenal v > splenic v
  • IMV > triple confluence with splenic and SMV (30%, forming a trifurcation) or SMV (30%)
  • middle colic v or right gastroepiploic direct > SMV
  • double portal v (non-union SMV and splenic v)
  • superior polar (splenic) v > splenic v

Portasystemic Anastomoses

  • oesophageal (in wall) or paraoesophageal branches of left gastric > azygos vv
  • IMV > superior > middle and inferior and middle rectal veins
  • left portal v >paraumbilical portal vv = inferior veins of Sappey> caput medusa>superficial epigastric vv
  • left hepatic lobe>superior veins of Sappey >diaphragm>sup epigastric and internal thoracic vv
  • retroperitoneal anastomoses > veins of Retzius > retroperitoneal, renal, lumbar and phrenic vv
  • spontaneous splenorenal shunt