Part two - small bowel Flashcards
Causes of small bowel obstruction
Adhesions - 60%
Neoplasms - 20% - intrinsic and extrinsic
Hernias - 10% - external, internal, congenital
Inflammatory - Crohns, appendicitis, diverticulitis, pancreatits
Miscellaneous
- Congenital band
- Intussusception +/- tumour
- Gallstone ileus
- Post radiotherapy stricture
- Vascular - heamatoma, post-ischaemic stricture
- Ingested foreign bodies
How may Meckel’s diverticulum present?
Haemorrhage - 30% SBO - 25% Inflammation/diverticulitis - 15% Umbilical anomalies - 5% Neoplasia -2% Ulceration Perforation
Describe a Meckel’s diverticulum
A true diverticulum (all bowel wall layers) and its own artery. Persistence of the vitello-intestinal tract which usually obliterates in the 4th-6th week of gestation.
How is Meckel’s diverticulum commonly diagnosed?
Technetium-99m pertechnetate scan enhanced by pentagastrin before the scan but relies on gastric heterotopic mucosa
Coincidental or intentional finding at laparosocpy or laparotomy
What is the risk of symtpoms or complications from a Meckel’s diverticulum?
Estimated lifetime risk of 4% of which more than 50% will be in children under ten years of age
What features of a Meckel’s diverticulum suggest it may be more likely to become symtpomatic?
Length >2cm
Age t be palpated
Incidence of SBO requiring hospitalisation after surgery
15% and 2% requiring operation - open
2% and 2% - laparoscopic surgery
What is gastrograffin and how does it work?
A water soluble contrast agent with an osmolarity of 1900mosm/L.
Activates movement of water into SB lumen, resuces SB oedema and enhances smooth muscle contractilty.
Makes future CT difficult to intepret and contributes to a severe pneumonia if aspirated
Define early post-operative small bowel obstruction
Occurring within thirty days post-operatively after an initial temporary return of bowel function.
Deal to nutrition and try not to operate for at least one month. Often self resolving within two weeks.
Predictors of fistula non-closure
HIP FRIENDS H - high output I - infection P - proximal fistula F - foreign body R - radiation I - inflammation - Crohn E - established > 6 weeks N - neoplasia / nutritionally deplete D - distal obstruction S - steroids / immunosuppression
How to treat a fistula
S - skin S - sepsis S - surgeon, surgeries from previous N - nutrition A - anatomy P - prevent complications P - psychological P - pharmalogical P - pathology - treat Crohns etc P - plan definitive procedure
Small bowel tumours
Rare, 5% of GI neoplasms Theory of paucity - rapid transit - high cell turnover - alkalinity - increased IgA BENIGN - leiomyoma - GIST - CD117, CD34 (S100 and desmin negativity) - adenomas - FAP duodenum - lipoma - PJS hamartoma - (cancer SB, stomach, panc, ovary, breast, uterus, breast, colorectal) MALIGNANT - mets - carcinoid - adenocarcinoma
Ileal break
Presentation of fat to ileum reduces proximal gastric and SB motility causing reduced satiety mediated by GI hormones.
This is removed during an ileocolic resection.
Duodenal break
Nutrients presented to the duodenum decrease gastric secretions and emptying
