Intestinal obstruction can be classified as dynamic or adynamic. Dynamic obstruction occurs when peristalsis works against a mechanical obstruction, while adynamic obstruction features no mechanical obstruction and lack of peristalsis. Causes include intraluminal, intramural, or extramural factors. Pathophysiology involves dilation of bowel proximal to obstruction and later fluid accumulation. Investigations include abdominal x-rays and CT scans. Treatment involves supportive care like NPO and IV fluids as well as surgical interventions like laparotomy, adhesiolysis, and resection depending on the specific cause and viability of the bowel.
4. Pathophysiology
Bowel proximal to obstruction dilates
↓
Distal bowel - normal peristalsis & absorption→later empty &collapses
Initially proximal peristalsis increased→later reduction in peristaltic strength
↓
flaccidity and paralysis
Proximal distention is caused by 1. gas
2.fluid
5. gas
Significant overgrowth of both aerobic
and anaerobic bacteria
Reabsorption – oxygen & corbondioxide
Nitrogen and hydrogen sulphide
fluid
24 hrs
Saliva -500ml, bile- 500ml ,pancreatic secretion -
500ml ,gastric secretion-1L
Accumulates & absorption –retarded
Dehydration & electrolyte loss
Reduced oral intake
Defective absorption
Vomiting
Sequestration in the bowel lumen
Transudation of fluid in to peritoneal cavity
6. Strangulation – Blood supply is
compromised and the bowel becomes
ischaemic
CAUSES
DIRECT PRESSURE ON THE BOWEL WALL
Hernial orifices
Adhesions / Bands
INTERRUPTED MESENTERIC BLOOD FLOW
Volvulus
Intussuseption
INCREASED INTRALUMINAL PRESSURE
Closed loop obstruction
7. Closed loop obstruction
Bowel is obstructed at both the proximal and distal points
Malignant stricture of the colon with a competent ileocaecal valve
↓
Inability of distended colon to decompress itself in to the small bowel
↓
Increase in luminal pressure
↓
necrosis and perforation
8. Internal hernia
Portion of small intestine becomes entrapped in one of the retroperitoneal fossae
or in a congenital mesenteric defect
SITES OF INTERNAL HERNIA
the foramen of winslow
a defect in the mesentery / transverse mesocolon/ broad ligament
congenital or acquired diaphragmatic hernia
Duodenal retro peritoneal fossae- left paraduodenal and right duodenojejunal
Caecal /appendiceal retroperitonel fossae- sup, inf, and retrocaecal
Intersigmoid fossa
9. Obstruction from enteric strictures
Small bowel – secondary to TB / Crohns disease
Subacute or chronic presentation
Mx- resection and anastomosis
11. Gallstone ileus
60 cm proximal to ileo-caecal valve
Rigler’s triad
Small bowel obstruction
Pneumobilia
Atypical metallic shadow on abdominal x ray
16. Common causes of intra-abdominal
adhesins
Acute inflammation Sites of anastomoses,
of raw areas, trauma, ischaemia
Foreign material Talc ,starch ,gauze, silk
infection Peritonitis, TB
Chronic inflammatory condditions Crohn’s disease
Radiation enteritis
17. Prevention of adhesions
Good surgical technigue
Washing of the peritonela cavity with saline to remove clots
Minimising contact with gauze
Covering anastomosis and raw peritoneal surfaces
19. Bands
Usually only one band is culpable
Congenital, e.g. obliterated vitellointestinal duct;
A string band following previous bacterial peritonitis
A portion of greater omentum, usually adherent to the parietes
20. Acute intussusception
One portion of the gut invaginate in to an immediately adherent segment;
Almost invariably-proximal in to the distal
MC in children ( 5-10 months ; peak incidence)
Hyperplasia of Peyer’s patches in the terminal ileum
Weaning – loss of passively acquired maternal immunity
Common viral pathogens
24. 3 parts
The Entering or inner tube- intussusceotum
The returning or middle tube
The sheath or outer tube – intussuscipiens
The part that advances apex, the mass- intussusception and neck is the junction
of entering layer with the mass
25. Volvulus
Twisting or axial rotation of a portion of bowel abouts its mesentery
Causes obstruction ( > 180 degree tortion)
If tight – vasocular occlusion in the mesentery( 360 degree)
Primary or secondary
May involve small intestine, caecum or sihmoid colon
Neonatal midgut volvulus sec to midgut malrotation is life threatening
Commonest spontaneous type in adult – SIGMOID
Sigmoid volvulus – relieved by decompression per anum
Surgery – to prevent or relieve ischaemia
45. Surgical management
INDICATION FOR EARLY SURGICAL INTERVENTION
Obstructed external hernia
Clinical features s/o strangulation
Obstruction in a ‘virgin’ abdomen
46. In complete obstruction with out evidence of intestinal ischaemia, surgery may be
deferred until the patient is fully resuscitated
In adhesive obstruction conservative management may be adviced for up to 72
hrs
55. Rx of recurrent intestinal obstructiom
caused by adhesions
Noble’s plication
Child Philips transmesenteric plication
Intestinal intubation
56. Rx of intussusception
Non operative reduction- air or barium enema
CONTRA-INDICATIONS
Signs of perforation/ peritonitis
Known pathological lead point
Profound shock
57. Surgery - when radiological reduction is failed or contra –indicated
Reduction- gently compressing the most distal part of the intussusception
towards its origin
Resection and anastomosis- irreducible or one complicated by infarction or
pathological lead point
58. Rx of acute large bowel obstruction
Emergency right hemicolectomy
Removal of lesion in the caecum, ascending colon, hepatic flexure, proximal
transverse colon
If the lesion is irremovable – proximal stoma or ileo- transverse bypass
59. For lesion in the left colon or recto sigmoid- resection should be done followed by
a) anastomosis
b)paul mikulicz procedure
c)hartmann’s peocedure
60.
61.
62. Rx of sigmoid colon
Sigmoidoscopy +insertion
of flatus tube
detortion of sigmoid and
fixation to anterior
abdominal wall
sigmoidectomy