Normally 3cm of
oesophagus lies within abdomen; is retroperitoneal but
peritoneum invests anterior and L lateral aspects only (257) (runs to diaphragm on R as
uppermost lesser omentum).
Lies on L crus, with aorta behind that. (253); then comes to run to left of aorta as it enters stomach.
- anterior and posterior trunks of vagus are related to relative oesophageal surfaces.
L lobe of liver is anterior
(grooved), caudate lobe to R. (258); retract liver
cranially and to right to access.; may need to divide
the left triangular ligament. (not usually)
Enters stomach at
cardiac orifice, right margin continuous with lesser
Left makes an acute angle (of His = 30-70°); height of fundus above this angle = 2-5cm.
sphincter: no morphological
thickening to correspond with measurable zone of P.
Guarding against reflux assisted by i) R crus fibre contraction; ii) entry angle of oesophagus; iii) long folds of oesophageal mucosa; iv) high pressure zone in lower oesophagus, v) positive intra-abdominal pressure.
Outer longitudinal and inner circular (thicker).
Opinion is divided about whether there is an anatomical LOS; may have some distal thickening but not where LOS is manometrically.
Cardia & lower
oesophagus mainly from below by ³1
branch of L gastric and branches of splenic
artery (282-3) and posterior gastric artery (~most
proximal short gastric)
Lower thoracic oesophagus gets aortic branches. There is a rich intramural arterial anastomosis in the subcutaneous layer.
Vagal inhibitory fibres --> sphincter relaxation (swallow, belching, vomiting).
Vagal excitatory fibres --> resting sphincter tone.
- these supply branches run within the muscle layer so skeletonisation of lower oesophagus doesn’t disrupt LOS function.
Sympathetic adrenergic fibres --> relaxation, (?function).