Gastric pathology
Key points
Gastric anatomy and physiology
Muscularis propria has three layers - innermost oblique layer, middle circular layer and outer longitudinal layer
Gastro-oesophageal junction - lies at T10
Transplyoric plane - L1
Fundus + body - oxyntic gland - mucus cells, parietal (oxyntic - HCl) cells and chief cells (pepsinogen)
Antrum - pyloric glands - neck mucus cells + G-cells (gastrin) + some chief cells
Enterochromaffin-like cells (ECL) stimulated by acetylcholine, gastrin and adrenaline - produce histamine
Acid production inhibited by somatostatin - released from D-cells in the fundus and antrum in response to gastrin and acid luminal contents. Directly inhibits release of gastrin from G-cells and histamine from ECL cells
H+/K+-ATPase pump in the parietal cell inhibited by PPI
Zollinger-Ellison syndrome - gastrin from G-cell neuroendocrine tumours (gastrinoma)
Neonatal gastric perforation
Aetiology -
Possible gaps in neonatal circular muscle
NG tube perforation
Can be due to NSAID/Steroid use
Tracheo-oesophageal fistula + ventilation
NEC
Most commonly fundus + greater curvature
Presents with sudden deterioration with large volume pneumoperitoneum. As opposed to slow deterioration (NEC), or well patient with pneumoperitoneum (SIP)
Operation
2 layer closure
Should make sure stomach is decompressed - use malecot catheter. If unwell, can close and use NG to save time, but NG can get blocked
Pyloric atresia
1:100,000
Polyhydramnios + distended stomach my be seen on antenatal scans
50% have associated anomalies - malrotation, cardiac defects, OA/TOF, other atresias in 10%
25% have Epidermolysis Bullosa - presents in 48 hours - possible autosomal recessive
Different to gastric antral web -which is normal tissues built up around pylorus
Types:
A: Thin pyloric membrane
B: Complete stenosis
C: Stomach and duodenum not connected
Treat A + B with resection of diaphragm and pyloroplasty - possibly endoscopy
C with anastomosis
Gastric heterotopic pancreas
Usually in submucosa
Secretion of enzymes causes bleeding
All diseases of normal pancreas also possible
Manage with endoscopy - if fails, needs resection
Congenital Microgastria
Very rare - less than 100 cases worldwide
Small stomach with normal mucosa
Presents with diarrhoea, oesophagitis and dilated oesophagus
Polyhydramnios and small stomach on antenatal scans
Can be isolated or associated with:
VACTERL association
Tracheo-oesophageal cleft
Malrotation/heterotaxy
Asplenia
UGI contrast shows small saccular/tubular structure where stomach should be
Management:
Start with continuous NG feeds
If fails - Hunt-Lawrence pouch - Roux-en-Y with J pouch anastomosed to oesophagus
Divide jejunum 30cm from DJ. Y anastomosis 20cm away from pouch
Start PN, contrast in 7 days
Dumping syndrome/Afferent loop syndrome are complication
Gastric diverticula
Symptoms of gastritis and peptic ulcer
Visible on lateral UGI contrast views
Can be excised if symptomatic
Gastroparesis
Causes: Idiopathic, autonomic neuropathy, diabetes in older children
Gastric pacemaker if medical management fails
Laparoscopy or laparotomy - place 2 leads in seromuscular layer between antrum and body
Tunnel into subcutaneous pouch with generator
Gastric volvulus
Primary: Laxity of the gastric ligaments
Secondary: Diaphragmatic hernia, splenic disorder
Right atrial isomerism (Ivemark syndrome): Asplenia, heterotaxy, cardiac abnormalities
Organoaxial: Rotation on the longitudinal axis through the pylorus and gastro-oesophageal junction (GOJ)
Mesenteroaxial: Rotation on an imaginary line through the lesser and greater curvatures
Presentation with Borchardt’s triad:
Inability to vomit
Severe epigastric distension
Inability to pass a nasogastric tube
Investigations
XR signs: Mesenteroaxial - pylorus/antrum higher than GOJ
Organoaxial - greater curvature lies higher than the lesser curvature
CT to confirm
Management
Resuscitation
Decompression of stomach if possible
Laparotomy and gastropexy or gastrostomy insertion
References
Vacek, Jonathan, and Mary E Fallat. "Congenital Gastric Anomalies." Pediatric Surgery NaT, American Pediatric Surgical Association, 2020. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829497/all/Congenital_Gastric_Anomalies.
Brahmamdam, Pavan, et al. "Gastric Disorders." Pediatric Surgery NaT, American Pediatric Surgical Association, 2021. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829525/all/Gastric_Disorders.
Lopez PP, Megha R. Gastric Volvulus. [Updated 2022 Nov 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507886/