Stomas

• Stomas:

  • Surgically created opening in the body between the skin and a hollow viscus
  • Abdominal stomas divert faeces or urine outside the body where they drain into a bag on the skin
  • Allow the bypass of distal portions of the bowel or urinary tract
  • Three common types: colostomy, ileostomy and urostomy
  • Can be permanent or temporary
• Colostomy:

  • Made using the large bowel
  • Found in left iliac fossa
  • Contents should be solid or semisolid - faeces have travelled through the colon, undergoing water absorption
  • Flush to the skin (non spout) because the enzymes present in large bowel contents are less alkali and therefore less irritating to the skin
  • Permanent end colostomy - often after resection of lower rectal or anal cancers leading to the removal or the entire rectum
  • Temporary end colostomies - allow distal bowel to rest e.g. Hartmann's procedure for diverticulitis
• Loop colostomy:

  • To protect distal anastomoses
  • Can also be performed to decompress distal bowel obstruction
  • A loop of bowel will be brought to the skin's surface and half-opening (two lumens)
  • No need for a mucus fistula (in end colostomies, the bypassed bowel still produces mucus and this can continue to leak out of the anus)
• Ileostomy:

  • Small bowel
  • Located in right iliac fossa
  • Contents tends to have a liquid or mushy consistency due to less water being absorbed in the small bowel
  • Spouted - enzymes in small bowel can irritate the skin
  • Permanent ileostomies are typically created after a panproctocolectomy (removal entire colon, rectum and anal canal) for conditions such as ulcerative colitis
• Urostomies:

  • Created after a cystectomy (removal of bladder)
  • Located in right iliac fossa
  • An ileal conduit is used to route the urine out of the abdomen into the bag. This involves a piece of ileum being resected then attached to the skin with a spout protruding.
  • The ureters are then attached to the other end of the bowel.
  • The urine then drains via the piece of ileum into the stoma bag.
• Options for surgery where a section of large bowel is removed:

  •Sew the two ends together (anastomosis) and close up with no stoma

  •Sew the two ends together, but to allow the anastomosis to heal bring out some proximal bowel temporarily e.g. ileum- as a loop ileostomy. Then a few weeks later reverse the ileostomy and close everything up

  •If you can’t sew the two ends together bring out bowel permanently – end ileostomy or end colostomy. NB if there’s lots of large bowel left beyond this point may also need to make a mucus fistula
• Surgery where most/all large bowel is removed:

  •Bring out an end ileostomy which will either be permanent, or at a later date can be joined to remaining bowel

  •If sigmoid/ rectum left join it to that

  •If only anus left create a J pouch (surgically made rectum) and join that to anus
• Colorectal operations that might need a stoma:

  • Right hemicolectomy: remove ascending colon
  • Left hemicolectomy: remove descending colon and a portion of the sigmoid colon
  • High anterior resection: remove part of sigmoid colon and upper part of rectum
  • Low anterior resection: remove part of sigmoid colon and all of rectum
  • Abdomino-perineal resection: remove rectum and anus
  • Subtotal colectomy: remove ascending, transverse and descending colon
  • Total colectomy: remove entire colon and rectum
  • Hartmann's procedure: emergency removal of part of descending/sigmoid colon/rectum
• Complications:

  • Psycho-social impact
  • Local skin irritation
  • Parastomal hernia
  • Loss of bowel length leading to high output, dehydration and malnutrition
  • Constipation (colostomies)
  • Stenosis
  • Obstruction
  • Retraction
  • Prolapse
  • Bleeding
  • Granulomas causing raised red lumps around the stoma
• Parastomal hernia:

  • Type of incisional hernia
  • Abdominal contents protrudes though an abdominal wall defect related to the stoma
  • More common with colostomies
  • Features - enlargement of the stoma, bulging of an area behind or around the stoma, cough impulse, reducible
  • Rarely a loop of bowel can become strangulated causing ischaemic injury to the bowel
  • Management - stoma support garment, repair or re-siting the stoma
• Stoma prolapse:

  • Elongation of the stoma when the patient stands, coughs or strains
  • Reduces when the patient lies dies
  • If the stoma remains prolapsed for long periods of time, venous drainage can be impaired causing congestion and secondary ischaemia
  • Management: specialist pouches, reduce swelling, support garments or surgery
• Stoma retraction:

  • stoma sinks below the level of the skin
  • Has a concave, bowl-shaped appearance
  • Results in poor stoma bag attachment causing leakage and frequent peristomal skin complications
  • Management: specialist bags, ostomy belts or surgery
• Stoma haemorrhage:

  • Small amount of bleeding from stomal mucosa is not uncommon, normally due to mild trauma during a stoma bag change
  • Large amounts/pulsatile bleeding needs urgent review
  • Bleeding can also be a sign of pathology within the GI tract e.g. malignancy
• Stoma ischaemia/infarction:

  • Caused by inadequate arterial blood supply
  • Causes - operative tissue trauma, damage to arterial supply, venous outflow obstruction
  • Symptoms - pain at the stoma site, necrosis of the stoma