~ Omental appendices/ epiploic appendices: peritoneal-covered accumulations of fat / Pocket/tags of peritoneum containing fat, present on the surface of the colons.~ Taeniae coli: the segregation of longitudinal muscle in its walls into three narrow bands ~ Haustra: One of a series of saccules or pouches, so called because of a fancied resemblance to the buckets on a water wheel. Formed due to shortening of the longitudinal muscular coat than to the circular muscular coat
Large bowel obstruction
• Distal end of Ileum anus (about 1.5 m)– Smallest diameter: Sigmoid colon (where the diverticulosisis most common to form here due to the high pressure especially duringstraining.)• Primary function of the large intestine1. Completion of absorption, esp. final absorption of water2. Normal flora manufacture certain vitamins (B complex, K)3. Formation, storage and expulsion of feces
• General characteristics– larger internal diameter– Presence of epiploic appendices– Presence of taeniae coli– Presence of the haustraHaustra
Caecum~ A blind-ended pouchsituated in the RIF~ Rest on iliacus muscle.~ 6 cm long~ Completely coveredwith peritoneum.~ No mesentery butquite mobile~ Teniae coli convergeon the base of theappendix.Ascending colon~ 13 cm long~ Peritoneumcoverage: front & sides~ adhered to abd wallRight colic/HepaticflexureLeft colic/ Splenicflexure~ higher than theright colic flexure~ suspended fromthe diaphragm bythe phrenicocolicligamentTransverse colon~ About 38 cm long(suspended by the transversemesocolon from the pancreas- mobile)Descending colon~ About 25 cm long~ Smaller diameter than asc.~ Peritoneum coverage: thefront and the sides~ adhered to abd wallSigmoid colon~ 25 – 38 cm long~ Continuous with therectum in front of S3~ Extremely mobile~ Attached to theposterior pelvic wall bythe fan-shapedsigmoid mesocolon.
• Abdominal Pain– Sudden Severe Colicky Pain– Large Bowel – Lower abdominal pain• Vomiting– The higher the obstruction the earlier itappears and more profuse it is.– The nature of the vomitus depend on the levelof the obstruction.
• Constipation– Earlier in large Bowel Obstruction• Abdominal Distension• Dehydration• Signs & Symptoms Of Peritonism• Low Grade Fever
• Abdominal X-ray– distended bowel loops– Multiple air fluid level• CT Gastrograffin– Level of obstruction– Cause of obstruction(intraluminal, intramural, extraluminal)• USG Abdomen• Colonoscope
LARGE BOWEL OBSTRUCTIONThe large bowelcan be identifiedby the haustraand is distendedfrom theascending colonthrough thesigmoid. There isa definite paucityof air in therectum caused byimpacted fecesleading to abuildup of fecalmaterial and gas.
Suspected large bowel obstruction on clinical features and plainabdominal radiograph (supine)↓INITIAL RESUSCITATION1. Fluid resuscitation2. Nil per oral3. Consider nasogastric decompression (RT Insertion) especially if it isassociated with small bowel dilatation and replace losses withHartmann solution4. Draw blood and send for FBC, BUSE, ABG, RBS and GSH5. Correction of any electrolytes imbalances6. Oxygen, Analgesic and Antibiotic therapy7. CBD and strict I/O chart8. Consider CVL insertion9. Frequent and regular monitoring of the parameters ( pulse rate,urine output, CVP, blood pressure ) to ensure adequateresuscitation10.Regular abdominal assessment to look for peritoneal signsindicating ischaemia , strangulation or perforation
Any peritoneal signs (tender,guarding,rebound tenderness)Yes No↓ ↓Surgery Gastrograffin enema study (preferred)or colonoscopyMechanical obstruction Pseudo-obstruction↓Surgery Expandable metal Initial conservative management↓ stenting for distal - treat underlying causecolorectal tumours - discontinued all anti-motility- correct electrolyte imbalances- nasogastric decompression- Syp erythromycin 125-250mg qid- Enemas and flatus tube- Colonoscopy decompression- Consider IV neostigmine 2.5 mg slowbolus if above fails ( should be given undercardiac monitoring due to risk of bradycardia)Indication for surgery:- fails expectant management- grossly distended caecum (>10cm widestdiameter) with signs of impending perforation- PeritonitisRight-sided obstruction- Right hemicolectomy with primaryanastomosis- Right hemicolectomy with exteriorizationof both endsLeft –sided obstruction- three stage procedures ; defunctioningcolostomy followed later by resection ofthe tumour and closure of colostomy- Two-stage or Hartmann’s procedure- One-stage procedure ; primaryresection of the tumour withanastomosis
Reference1. J M Villar, A P Martinez. Surgical Optionfor Malignant Left-Sided ColonicObstruction. Surg Today (2005) 35: 275-2812. H Markogiannakis, A Messaris. AcuteMechanical Bowel Obstruction. World JGastroenterol 2007 ; 13(3):432-4373. The Management of Malignant LargeBowel Obstruction : ACPGBI PositionStatement . Colorectal disease 2007; 9(Suppl 4) 1-17