Small bowel

Anatomy

Small bowel 75 % of the total length ofGI

Length: 260 cm by living persons

5 – 7 m post mortem

Parts: jejunum 2/5 lengthileum 3/5 length

Anatomy

Wall of small intestine:1. Serous layer

2. Muscular layer smooth muscle

3. Submucosa fibroelastic tissue, blood and lymphatic vessels

4. Mucosa

Microanatomy

Wall of small intestine:Circular plices - Kerkring-i enlarge 3 x the surface of mucosaVilli intestinales enlarge 10 x enlarge 3 x the

surface of mucosa

Microvilli enlarge 30 x surface of mucosa

total enlargement 900 x !!

Epithelium - enterocytes - absorb cell- goblet cells – mucin production

Anatomy

Blood supply:

a.mesenterica superior

a. pancreaticoduodenalis inferior - pancreas duodenum

aa. jejunales – one arcades- jejunum

aa. ileae – 2-4 arcades - ileum

a. ileocolica – colon ascendens and caecum

a. colica dextra – colon ascendens

a. colica media – colon transversum

Blood supply of small bowel

Bood supply of large bowel

Physiologydigestion:

1. Intraluminal phase:

chymus is mixed with enzymes from enterocytes, pancreas, bile, stomach

2. Absorb phase : in the wall of bowel

absorbtion of nutrients, water, minerals, vitamins

3. Transport phase

Physiology

Motility:1. Peristaltic

Circular contractions in distal direction

fr.= 10/min., transit time in small bowel is 1- 6 hr.

2. Segmental contractions:

to mix the content

Absorbtion

Absorbtion

Mesentery - functions

1. mechanical support for bowel2. blood supply

3. lymphatic drainage of nutrients

4. immunological barrier

Physiology

Functional disorder 1. :

Maldigestion – intraluminal disorder

lack of bile, stomach acid, or pancreatic intestinal juice

Malabsorbtion – disorder in the phase of absorbtion or transport

Physiology

Other functional disorders 2. :

Diarrhea ( osmotic, infection, )

Blind sac sy ( stasis of enteral content in a blind sac, what leads to bacterial contamination and deconjugation a of bile acids - diarrhea)

Short bowel sy ( after extent resections, leads to depletion of water, minerals, nutrients, vitamins) requires parenteral nutrition

Diagnostics specific

enteroclysis- „small bowel enema“

study

enteroscopy - double balloon - push

- on table

- capsule

Double balloon enteroscopy

Double balloon enteroscopy

Push enteroscopy

PILLCAM - hi-tech capsule enteroscopy

Capsule endoscopy

On table enteroscopy- bleeding from adenoma

Enteroscopy- A-V malformation

Enteroscopynecrotizing colitis, adenoma

Non specific

Laboratory

X-ray

Ultrasound

CT

MRI

Gastroscopy

Colonoscopy

AG, scintigraphy- bleeding

Plane X-ray

Plane X- ray , lateral

Barium enema

Barium enema study

Barium enema study- MC

Angiography

Exomphalos

Surgical treatment

Meckel´s diverticulum

remnant of omphaloenteteric duct, which did not obliterate

Pathology : 1-2%, situated on the antimesenterial site of bowel

Clinical presentation : inflammation, bleeding, torsion, ileocaecal invagination

Dg : not easyTherapy : resection of diverticulum

Meckel´s diverticulum

Ileocoecal invagination

Mesenterial cysts

Pathology :on the mesenterial site of bowel,

Symptoms : chronic pain, palpable mass, can be signs of compression

Dg : X-ray, ultrasound, CT, MRI

Therapy : resection of bowel and mesentery

Mesenterial cyst

Crohn´s disease- IBD

Granulomatous inflammation, which extends diffusely through the entire

thickness of the bowel wallCan affect whole GI, but most commonly in small

and large bowel ( skip lesions)

Etiology: not known

Pathology: a/acute inflammation

b/chronic inflammation

c/ complications

Clinical features

Acute- pain, diarrhea, fever

Chronic- malabsorbtion, extraintestinal

Complications: obstruction, fistulas, bleeding, perforation, perianal MC

Dg :History, examination, barium enema,

endoscopy (cobblestone surface), ultrasound, CT, biopsy

Ulcerative colitis

Crohn´s disease

Endoscopy

Endoscopy

Endoscopy

Small bowel enema

CT

Crohn´s disease

Crohn´s disease

Thickened wall by inflammatory oedema

Crohn´s disease

Fissured ulcers

Extraintestinal presentation

Treatment

Dietary : without fiber, avoiding malabsorbtion, elementary diet.

2. Parenteral nutrition:3. Drugs

- 5-ASA( sulphasalazine)- steroids- parenteral, p.o, topical- azathioprin ( IMURAN )- Metronidazol 0,5- 1,5 - monoclonal antibodies anti TNF alfa

(Remicade)

Surgical treatment

Urgent–perforation, toxic megacolon, bleeding, obstruction

elective –abscess, fistulas, chronic obstruction

Resection, anastomosis, stoma , stricturoplasty

Recurrent disease

Opening

Revision

Resection

Anastomosis

Benign tumors

Rare only 1.5 = of GI tumors

Mostly mesenchymal

Clinical presentation: obstruction, bleeding,

Dg: small bowel enema, endoscopy, ultrasound, CT, MRI

Therapy: surgical resection with anastomosis

Malignant tumors

Rare only 2% of GI tumors

adenocarcinoma – 50 %,

leiomyosarcoma – 33 %

carcinoid – semimalignant with metastatic potential

lymphoma

GIST – gastrointestinal stromal tumor

Clinical presentation: obstruction, bleeding,

Dg: small bowel enema, endoscopy, ultrasound, CT, MRI

Therapy: surgical resection with anastomosis

CARCINOID of small bowel

Carcinoma: source of bleeding

Ischemic small bowel

Gangrenous small bowel

Retroperitoneal anatomy