Small Intestine

1
Small Intestine

• James Taclin C. Banez, MD

2
Small Intestine

• one of the most important organs for immune
  defense
• largest endocrine organ of the body
• Starts from the pylorus and ends at the cecum
• 3 parts
• Duodenum (20cm)
• Jejunum (100 to 110cm)
• Ileum (150 to 160 cm)

3
Anatomy

• Has plicae circulares or valves of Kerkring
• Duodenum
• Retro-peritoneal
• Supplied by the celiac artery
• Jejunum
• Occupies upper left of the abdomen
• Thicker wall and wider lumen than the ileum
• Mesentery has less fat and forms only 1-2 arcades
• Ileum
• Occupies the lower right has more fat and forms
  more arcades
• Contains Payers patches
• Ileum jejunum is supplied by the SMA

4
Function

• Digestion Absorption
• Endocrine Function
• Secretes numerous hormones involved in GIT
  function.
• Secretin
• Cholecystokenin
• Gastric inhibitory peptide
• Enteroglucagon
• Vasoactive intestinal peptide
• Motilin
• Bombesin
• Somatostatin
• Neurotensin

5
Function

• Immune function
• Major source of IgA
• Integrity of the GUT wall prevents bacterial
  translocation into the wall of the intestine and
  abdominal cavity which can lead to sepsis
• Gut associated lymphoid tissue part of the
  immune defense system which clears the abdominal
  cavity of pathogenic bacteria found in Peyers
  patches

6
Small Bowel Surgical Lesions

• Small bowel obstruction
• Mechanical
• Ileus
• Small bowel infection
• Chronic inflammation
• Neoplasm
• Diverticula
• Short bowel syndrome

7
Small Bowel Obstruction

• Causes of Mechanical Obstruction
• Post-operative adhesion (75)
• Hernias
• Crohns disease
• Neoplasm (primary or extrinsic compression or
  invasion)
• Superior mesenteric artery syndrome (compression
  of transverse duodenum)

8
Pathophysiology

• Accdg. to its anatomical relationship to the
  intestinal wall
• Intraluminal ( foreign bodies, gallstone, and
  meconium)
• Intramural (neoplasm, Crohns, hematomas)
• Extrinsic (adhesion, hernias carcinomatosis)

9
Pathophysiology

• Air-fluid level
• Gas due to swallowed air
• Fluid a) swallowed fluid
• b) gastrointestinal
• secretion
• (increase epithelial water
• secretion).
• Bowel distention / elevated intramural pressure
  ---gt ischemia ------gt necrosis.
• (strangulated bowel obstruction)

10
Pathophysiology

• Partial small-bowel obstruction passage of gas
  and fluid.
• Complete small-bowel obstruction (obstipation)
• Closed loop obstruction (obstructed proximal and
  distal) ex. volvulus

11
Manifestation

• colicky abdominal pain
• nausea / vomiting
• obstipation
• abdominal distention
• hyperactive bowel sound
• signs of dehydration (sequestration of fluid in
  bowel wall and lumen as well as poor oral intake)
• lab. findings
• hemoconcentration
• fluid electrolyte imbalance
• leucocytosis

12
Manifestation

• Features of Strangulated obstruction
• tachycardia
• localized abd. tenderness
• fever
• marked leucocytosis
• acidosis
• lab result
• - elevated serum amyase, lipase, LDH,
• phosphate and potassium

13
Diagnosis

• Focus on the following goals
• distinguish between mechanical obstruction from
  ileus
• determine the etiology
• whether it is partial or complete obstruction
• differentiate between simple and strangulating
  obstruction

14
Diagnosis

• Clinical history PE
• Radiological examination
• FPA (supine and upright)
• Triad 1. dilated small bowel (gt3cm )
• 2. air-fluid levels seen in upright
• 3. paucity of air in the colon
• Sensitivity of 70-80 but with low specificity
  for ileus and colonic obstruction mimics
• False (-) - proximal small bowel obstruction
• - bowel lumen filled with fluid (cant see
• air-fluid level)

15
Diagnosis

• CT scan (90 sensitive / 90 specific)
• Findings of small bowel obstruction
• Discrete transition zone
• Intra-luminal contrast unable to passed beyond
  the transition zone
• Colon containing little gas or fluid
• Strangulation is suggested
• Thickening of the bowel wall
• Pneumatosis intestinalis
• Portal venous gas
• Mesentery haziness
• Poor uptake of intravenous contrast into the wall
  of the affected bowel
• Limitation unable to detect partial intestina
• obstruction (lt50
  sensitivity)

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Diagnosis

• Small bowel series (barium / gastrografin)
• Enteroclysis
• 200 to 250 ml of barium followed by 1 to 2 L of
  methylcellulose in water is instilled into the
  proximal jejunum via a long naso-enteric tube

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Treatment

• Correct fluid electrolyte imbalance
• Isotonic fluid
• Monitor resuscitation (foley catheter/CVP)
• NPO / TPN
• Broad spectrum antibiotic (due to bacterial
  translocation)
• Placed NGT to decompress the stomach and decrease
  nausea, distention and risk of aspiration
• Expeditious celiotomy (to minimize risk of
  strangulation).
• Type of operation based on operative finding
  causing intestinal obstruction

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Ileus / Pseudo-Obstruction

• Impaired intestinal motility
• Most common cause of delayed discharge following
  abdominal operations
• Temporary and reversible

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Ileus / Pseudo-Obstruction

• Etiologies
• Abdominal surgery
• Infection inflammation (sepsis/peritonitis)
• Electrolyte imbalance (Hypo K, Mg Na)
• Drugs (anticholinergic, opiates)
• Visceral myopathies (degeneration/fibrosis of
  smooth muscle)
• Visceral neuropathies (degenerative disorders of
  myenteric submucosal plexuses)

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Symptoms

1. Inability to tolerate solid liquid by mouth
2. Nausea/vomiting
3. Lack of flatus bowel movements
4. Diminished or absent bowel sound
5. Abdominal pain and distention

21
Diagnosis

1. History of recent abdominal surgery
2. Discontinue opiates
3. Serum electrolyte determination
4. CT scan better than FPA in postoperative setting
   to exclude presence of abscess or mechanical
   obstruction

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Therapy

1. NPO, if prolong TPN is required
2. NGT to decompress the stomach
3. Correct fluid electrolyte imbalance
4. Give ketorolac and reduce the dose of opioids

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CROHNS DISEASE

• Regional, transmural, granulomatous enteritis).
• Chronic, idiopathic inflammatory dse
• Ethnic groups ---gt East Europe (Ashkenazi Jewish)
  
• Female predominance, 2x higher smokers
• Familial association (30x in siblings / 13 x in
  1st degree relatives).
• Higher socioeconomic status
• Breast feeding is protective

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Etiology

• Unknown
• Hypothesis
• Infectious - Chlamydia / Pseudomonas /
  Mycobacterium paratuberculosis / Listeria
  monocytogenesis / Measles / Yersinia
  enterocolitica
• Immunologic abnormalities
• Humeral cell-mediated immune reactions against
  gut cells.
• Genetic factors
• Chromosome 16 (IBD1 --gt NOD2)

25
Pathology

• Affect any portion of GIT
• Small bowel alone (30)
• Ileocolitis (55)
• Colon alone (15)
• Hallmark focal, transmural inflammation of the
  intestine
• Earliest sign --gt aphthous ulcers surrounded by
  halo erythema over a non-caseating granuloma.

26
Pathology

• As the aphthous ulcer enlarge and coalesce
  transversely forming cobblestone appearance.
• Advanced dse ---gt transmural inflammation. This
  results to
• adhesions to adjacent bowel,
• stricture formation (fibrosis),
• intra-abdominal abscesses,
• fistula or free perforation (peritonitis)
• Skip lesions and w/ fat wrapping (encroachment of
  mesenteric fat onto the serosal surface) --gt
  pathognomonic for Crohns.

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Clinical Manifestation

• Most common symptom
• Abdominal pain
• Diarrhea
• Weight loss
• Other symptoms depends on type of complications
• obstruction (fibrosis)
• perforation (peritonitis, fistula, intraabdominal
  abscess)
• toxic megacolon (marked colonic dilatation, adb.
  tenderness, fever leukocytosis)
• cancer (6x greater/more advanced---gt poor
  prognosis)
• perianal dse (fissure, fistula, stricture or
  abscess)
• Extra-intestinal manifestation
• erythema nodosum peripheral arthritis are
  correlated w/ severity of intestinal inflammation.

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Diagnosis

1. Endoscopy (esophagogastroduodenoscopy (EGD)
   /colonoscopy) w/ biopsy.
2. Barium enema / intestinal series
3. Enteroclysis (small bowel) more accurate
4. CT scan to reveal intra-abd. abscesses

29
Treatment

• Medical
• Intravenous fluids
• NGT to rest GIT (elemental diet/TPN)
• Medications
• to relieve diarrhea
• relieve pain
• control infection (antibiotic)
• Anti-inflammatory ( aminosalicylates,
  corticosteroid, immunomodulators azathioprime
  6-mercaptopurine and cyclosporine
• Infliximab chimeric monoclonal
  anti-tumor-necrosis-factor antibody inducing
  remission and in promoting closure of
  enterocutaneous fistulas

30

• Surgical
• Indicated if
• with complications
• Medication-induced complications arise
• Cushingoid features, cataract, glaucoma, systemic
  hypertension, compression fracture or aseptic
  necrosis
• Types
• Segmental resection w/ primary anastomosis
• Microscopic evidence of the dse at the resection
  margin does not compromise a safe anastomosis,
  hence, a frozen section is unnecessary.
• Stricturoplasty
• Bypass procedures (gastrojejunostomy)

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Prognosis

• High recurrence rate (most common proximal to the
  site of previous resection).
• 70 recur w/in 1 yr and 85 w/in 3 yrs.
• Most common complication
• Wound infection
• Postoperative intra-abdominal abscess
• Anastomotic leaks
• 60-300 x more frequent to develop CA

32
Tuberculous Enteritis

• In developing and under develop countries
• Resurgence in develop countries due to
• AIDS epidemic
• Influx of Asian migrants
• Use of immunosuppressive agents
• Forms
• Primary infection (caused by M. tuberculosis
  bovine from ingested milk)
• Secondary infection (swallowing bacilli from
  active pulmonary) TB

33
Tuberculous Enteritis

• Patterns
• Hypertrophic causes stenosis or obstruction
• Ulcerative diarrhea and bleeding
• Ulcero-hypertrophic
• Treatment
• Chemotherapy (given 2 wks prior to surgery up to
  1 yr).
• Rifampicin
• Isoniazid
• Ethambutol
• Surgery (perforation, obstruction, hemorrhage).

34
Typhoid enteritis

• Caused by Salmonella typhi
• Diagnosis
• Culture from blood or feces
• Agglutinins against O and H antigen
• Treatment
• Medical
• Chloramphenicol / trimethropin-sulfamethoxazole /
  amoxycillin / quinolones
• Surgical
• perforations / hemorrhage
• Segmental resection (w/ primary anastomosis or
  ileostomy)

35
Neoplasm

• Rare
• Rapid transit time
• Local immune system of the small bowel mucosa
  (IgA)
• Alkaline pH
• Relatively low concentration of bacteria low
  concentration of carcinogenic products of
  bacterial metabolism.
• Presence of mucosal enzymes (hydrolases) that
  destroy certain carcinogens
• Efficient epithelial cellular apoptotic
  mechanisms that serve to eliminate clones
  harboring genetic mutation

36
Neoplasm

• 50 60 y/o
• Risk factors
• Red meat
• Ingestion of smoked or cured foods
• Crohns dse
• Celiac sprue
• Hereditary nonpolyposis colorectal cancer (HNPCC)
• Familial adenomatous polyposis (FAD) 100 to
  develop duodenal CA
• Peutz-Jeghers syndrome

37
Neoplasm

• Symptoms
• Most are asymptomatic
• Symptoms
• Vague abdominal pain (epigastric discomfort, N/V,
  abd. pain, diarrhea).
• Bleeding (hematochezia or hematemesis)
• Obstruction (intussuception, circumferencial
  growth, kinking of the bowel, intramural growth).
• Most common mode of presentation is ---gt crampy
  abd. pain, distention, nausea / vomiting
• Hemorrhage usually indolent 2nd common mode of
  presentation

38
Neoplasm

• Diagnosis
• For most are asymptomatic it is rarely diagnosed
  preoperatively
• Serological examination
• Serum 5-hydroxyindole acetic acid (HIAA) for
  carcinoid.
• CEA associated w/ small intestinal adenocarcinoma
  but only if w/ liver metastasis.

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Neoplasm

• Diagnosis
• Radiological examination
• Enteroclysis (test of choice 90 sensitivity)
• UGIS w/ intestinal follow through
• CT scan
• Angiography / RBC scan --gt bleeding lesions
• Endoscopy
• EGD (esophagus, gastric, and duodenum)
• Colonoscopy

40
Benign tumors

• Adenomas (most common benign neoplasm
  duodenum)
• True adenomas
• Associated w/ bleeding and obstruction
• Usually seen in the ileum
• Majority are asymptomatic
• Villous adenoma
• Most common in the duodenum
• soap bubble appearance on contrast radiography
• No report of secretory diarrhea
• Brunners gland adenoma
• In the duodenum
• No malignant potential
• Mimic PUD

41
Benign tumors

• Leiomyoma
• Most common symptomatic benign lesion
• Associated w/ bleeding
• Diagnosed by angiography and commonly located in
  the jejunum
• 2 growth pattern
• Intramurally ----gt obstruction
• Both intramural and extramural (Dumbbell shaped)

42
Benign tumors

• Lipoma
• Most common in the ileum
• Causes obstruction (lead point of an
  intussusception)
• Bleeding due to ulcer formation
• No malignant degeneration

43
Benign tumors

• Peutz-Jeghers Syndrome
• Inherited syndrome of
• Mucocutaneous melatonic pigmentation (face,
  buccal mucosa, palm, sole, peri-anal area)
• Gastrointestinal polyp (enteric jejunum and
  ileum are most frequent part of GIT followed by
  colon, rectum and stomach).
• Symptoms
• colicky abd. pain (due to intermittent
  intussuception)
• Hemorrhage
• Treatment
• Segmental resection of the bowel causing
  obstruction or bleeding.
• Cure impossible due to widespread intestinal
  involvement

44
Malignant neoplasm

• Histologic types

Tumor type Cell of origin Frequency Predominant Site
adenocarcinoma Epithelial cell 35 50 Duodenum
carcinoid Enterochromaffin cell 20 40 Ileum
lymphoma lymphocyte 10 15 Ileum
GIST (gastrointestinal stromal tumors) ? Interstitial cell of Cajal 10 15 -
45
Malignant neoplasm

• Adenocarcinoma
• Most common CA of small bowel
• Most common in duodenum and proximal jejunum
• Half involve the ampulla of Vater.

46
Malignant neoplasm

• Carcinoid
• From enterochromaffin cells or Kultchitsky cells
• Arise from foregut, midgut hindgut
• Appendix (46) gt Ileum (28) gt Rectum (17)

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Malignant neoplasm

• Carcinoid
• Aggressive behavior than the appendiceal
  carcinoid.
• appendix 3 metastasize Ileum 35
  metastasize
• Appendix solitary Ileum 30 multiple
• 25-50 w/ carcinoid tumor with liver metastasis
  develops carcinoid syndrome.
• Secretes serotonin, bradykinin and substance P
• Diarrhea
• Flushing
• Hypotension
• tachycardia
• fibrosis of endocardium and valves of the right
  heart.

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Malignant neoplasm

• Lymphomas
• Most common intestinal neoplasm in children under
  10y/o.
• In adult 10-15 of small bowel malignant tumors
• Most common presentation
• intestinal obstruction
• Perforation (10)

49
Malignant neoplasm

• Lymphomas
• Criteria of primary lymphomas of the small bowel
• Absence of peripheral lymphadenopathy
• Normal chest x-ray w/o evidence of mediastinal LN
  enlargement.
• Normal WBC count and differential
• At operation, the bowel lesion must predominate
  and the only nodes are associated w/ the bowel
  lesion
• Absence of disease in the liver and spleen

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Malignant neoplasm

• GISTs (gastrointestinal stromal tumors)
• Most common mesenchymal tumors arising in the
  small bowel
• 70 arises from the stomach followed by the small
  bowel
• 15 of small bowel malignancies
• Formerly classified as
• Leiomyomas
• Leiomyosarcomas
• Smooth muscle tumors of small bowel
• Associated w/ overt hemorrhage
• Has its expression of the receptor tyrosine
  kinase KIT (CD117). There is pathological KIT
  signal transduction

51
Treatment

• For Benign lesions
• All symptomatic benign tumors should be
  surgically resected or removed endoscopically
  (EGD / colonoscopy).
• Duodenal tumors
• 1 cm. ----gt endoscopic polypectomy
• 2cm. ----gt surgically resected (Whipples
  located near the ampulla of Vater).
• Duodenal adenomas w/ FAP shd undergo Whipples for
  it is usually multiple and sessile and has 100
  degenerate to CA.

52
Treatment

• Malignant lesions
• Adenocarcinoma
• Wide local resection w/ its mesentery to achieve
  regional lymphadenectomy
• Chemotherapy has no proven efficacy in the
  adjuvant or palliative treatment of
  small-intestinal adenoCA.
• Small intestinal lymphoma
• For localized segmental resection w/ adjacent
  mesentery
• If w/ diffused involvement --gtchemotherapy
  rather than surgery, is primary therapy

53
Treatment

• Carcinoid
• Segmental intestinal resection regional
  lymphadenectomy.
• lt 1cm rarely has LN metastases
• gt 3cm 75 to 90 LN metastases
• 30 are multiple, hence entire small bowel shd be
  examined prior to surgery.

54
Treatment

• Carcinoid
• Is w/ metastatic lesions---gt debulking,
  associated w/ long-term survival amelioration
  of symptoms of carcinoid syndrome
• Chemotherapy ---gt 30 -50 response
• Doxorubicin
• 5-fluorouracil
• Streptozocin
• Octreotide - most effective for management of
  symptoms of carcinoid syndrome

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Treatment

• Small-intestine GISTs
• Segmental resection
• If was preoperatively diagnosed, lymphadenectomy
  shd not be done, for rarely associated w/ LN
  metastases.
• Resistant to conventional chemotherapy
• IMATINIB (Gleevec)
• Formerly known as ST1571
• 80 of pt w/ unresectable lesions showed clinical
  benefits
• 50 60 showed evidence of reduction in tumor
  volume
• Role as neoadjuvant and adjuvant tx under
  investigation

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Treatment

• Metastatic cancers
• Melanoma associated w/ propensity for metastasis
  to the small bowel.
• Palliative resection / bypass procedure
• Systemic therapy depends on the responds of the
  primary site.

57
Meckels Diverticulum

• Most prevalent congenital anomaly of GIT
• 32 (malefemale)
• True diverticula
• 60 contains heterotopic mucosa
• Gastric mucosa (60)
• Pancreatic acini
• Brunners gland
• Pancreatic islets
• Colonic mucosa
• Endometriosis
• Hepatobiliary tissues

58
Meckels Diverticulum

• Rules of Twos
• 2 prevalence
• 21 female predominance
• Location 2 feet proximal to the ileocecal valve
  in adults.
• Half of those are asymptomatic are younger than 2
  years of age.
• Complications
• Bleeding (most common) due to ileal mucosal
  ulceration.
• Obstruction
• Volvulus of the intestine
• Entrapment of intestine by the mesodiverticular
  band
• Intussuception
• Stricture due to diverticulitis
• As Littres hernia found in inguinal or femoral
  hernia sac.

59
Meckels Diverticulum

• Clinical manifestation
• Asymptomatic
• 4 symptomatic due to complication
• 50 are younger than 10y/o
• Symptomatic (Bleeding gt obstruction gt
  diverticulitis)
• bleeding is 50 in children and pt younger 18y/o
• bleeding is rare in pt older than 30y/o
• intestinal obstruction most common in adult
• diverticulitis is indistinguishable to
  appendicitis
• Neoplasm seen ---gt Carcinoid

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Meckels Diverticulum

• Diagnosis
• For asymptomatic usually discovered as an
  incidental findings in radiographic imaging,
  endoscopy, or intraoperatively.
• Enteroclysis has 75 accuracy but not applicable
  during acute cases.
• Radionuclide scans (99m Tc-pertechnate) for
  ectopic gastric mucosa or in active bleeding
• Angiography to localize site of bleeder

61
Meckels Diverticulum

• Management
• Diverticulectomy
• diverticulitis
• obstruction (w/ removal of associated band)
• Segmental resection for
• Bleeding
• If with tumor

62
Acquired Small Bowel Diverticula

• Epidemiology
• False diverticula
• Increases w/ age seldom seen lt 40y/o (50-70y/o)
• Duodenum
• Most common usually adjacent to ampulla
• Called periampullary, juxtapapillary, or
  peri-Vaterian diverticula
• 75 arise in the medial wall
• Jejunoileal
• 80 - jejunum (tends to be large and multiple)
• 15 - ileum (tends to be small and solitary)
• 5 - both ileum and jejunum

63
Acquired Small Bowel Diverticula

• Pathophysiology
• Abnormalities of intestinal smooth muscle or
  dysregulated motility leading to herniation.
• Associated w/
• Bacterial overgrowth vit B12 deficiency,
  megalobalstic anemia, malabsorption steatorrhea
• Periampullary duodenal diverticula
• Obstructive jaundice
• Pancreatitis
• Intestinal obstruction due to compression of
  adjacent bowel

64
Acquired Small Bowel Diverticula

• Diagnosis
• Best diagnosed w/ enteroclysis
• Treatment
• Asymptomatic ---gt left alone
• Bacterial overgrowth --gt antibiotics
• Bleeding and obstruction ---gt segmental resection
  for jejunoileal diverticula.

65
Acquired Small Bowel Diverticula

• Treatment
• Diverticulectomy if located in the duodenum
• For medial duodenal diverticula ---gt do lateral
  duodenotomy and oversewing of the bleeder
• May invaginate the diverticula into the duodenal
  lumen then excised
• If related to the ampulla ---gt extended
  sphincterotoplasty
• If perforated ----gt excised and closed w/ omental
  patch if to inflammed ---gt placed
  gastrojejunostomy

66
Mesenteric Ischemia

• Clinical Syndrome
• Acute mesenteric ischemia
• Pathophysiology
• Arterial embolus (most common-50 heart
  usually lodge distal to origin of the middle
  colic
• Arterial thrombosis occlusion occurs at proximal
  near its origin.
• Vasospasm (nonocclusive mesenteric ischemia
  NOMI) usually in critically-ill pt. receiving
  vasopressors.
• Venous thrombosis (5-15) and 95 SMA
• Primary no etiologic factor identified
• Secondary heritable or acquired coagulation
  disorder

67
Mesenteric Ischemia

• Clinical Syndrome
• Chronic Mesenteric Ischemia
• Develops insidiously allows for collateral
  circulation to develop
• Rarely leads to infarction.
• Usually due to arteriosclerosis
• Usually two mesenteric arteries are involved
• Chronic mesenteric venous thrombosis can lead to
  portal hypertension

68
Mesenteric Ischemia

• Manifestation
• Acute mesenteric ischemia
• Severe abdominal pain out of proportion to the
  degree of abd. tenderness (hallmark)
• Colicky at the mid-abdomen.
• Nausea / vomiting, diarrhea
• On PE, early ischemia char. Absent
• onset of bowel necrosis abd.
  distention,
• peritonitis, passage bloody stool
• Chronic mesenteric ischemia
• Postprandial abd. pain food-fear, (most common)

69
Mesenteric Ischemia

• No laboratory test sensitive for the detection of
  acute mesenteric ischemia prior to the onset of
  intestinal infarction.
• The presence of its hallmark sign, is an
  indication for immediate celiotomy.

70
Mesenteric Ischemia

• Angiography most reliable 74 100
  sensitivity and 100 specificity
• It is gold standard for the diagnosis of Chronic
  arterial mesenteric ischemia.
• CT scanning is used to
• Disorder other abd. condition causing abd. pain
• Evidence of occlusion or stenosis of mesenteric
  vasculature.
• Evidence of ischemia in the intestine mesentery
• Test of choice for acute mesenteric venous
  thrombosis

71
Mesenteric Ischemia

• Treatment
• Therapeutic option for acute mesenteric ischemia
  is based on
• Presence or absence of signs of peritonitis
• Presence or absence of ischemic but viable
  intestine
• General condition of the patient
• Specific vascular lesion causing mesenteric
  ischemia
• w/ signs of peritonitis --gt celiotomy check for
  viability of the bowel
• Necrotic ----gt segmental resection
• Questionable viability ----gt second look
  laparotomies

72
Mesenteric Ischemia

• Surgical revascularization (embolectomy /
  thrombectomy / mesenteric bypass).
• Not done if
• segment is necrotic
• is too unstable patient
• Done pt diagnosed w/ emboli or thrombus-induced
  acute mesenteric ischemia w/o signs of
  peritonitis.
• May give thrombolysis (streptokinase, urokinase,
  recombinant tissue plasminogen activator). Useful
  only in partially occluded vessels and has given
  w/in 12 hrs. after onset of symptoms.

73
Mesenteric Ischemia

• NOMI std tx. Is infusion of vasodilator
  (papavarine hydrochloride) into the SMA. If w/
  signs of peritonitis --gt immediate celiotomy and
  resect necrotic segment.
• Acute mesenteric venous thrombosis
• Std tx. anticoagulant (heparin / warfarin).
• Signs of peritonitis --gt explore and resects if
  needed
• For chronic arterial mesenteric ischemia
• Surgical revascularization
• Aortomesenteric bypass grafting
• Mesenteric endarterectomy
• Percutaneous transluminal mesenteric angioplasty
  alone or w/ stent.

74
Short Bowel Syndrome

• Presence of less than 200cm of residual small
  bowel in adult pts.
• Functional definition - insufficient intestinal
  absorptive capacity results in the clinical
  manifestations of
• Diarrhea
• Dehydration
• malnutrition

75
Short Bowel Syndrome

• Etiologies (adult)
• Acute mesenteric ischemia
• Malignancy
• Crohns disease
• Etiologies (pediatric)
• Intestinal atresias
• Volvulus
• Necrotizing enterocolitis

76
Short Bowel Syndrome

• Factors predictive of achieving independence from
  TPN
• Presence or absence of an intact colon (capacity
  to absorb fluid electrolytes and absorb
  short-chain FA).
• Intact ileocecal valve
• A healthy, rather disease, residual small
  intestine is associated w/ decreased severity of
  malabsorption
• Resection of jejunum is better tolerated than the
  ileum, due to bile salt and vit B12 absorption
  capacity of the ileum.

77
Short Bowel Syndrome

• Medical therapy
• Mx of primary condition causing intestinal
  resection
• Correct fluid electrolyte imbalance due to
  severe diarrhea
• TPN, enteral nutrition is gradually introduced,
  once ileus is resolved

78
Short Bowel Syndrome

• Medical therapy
• H2 receptor antagonist --gt to reduce gastric acid
  secretion
• Antimotility agents (loperamide HCL or
  diphenoxylate)
• Octreotide to reduce volume of
  gastrointestinal secretion
• TPN complication
• Catheter sepsis
• Venous thrombosis
• Liver and kidney failure
• osteoporosis

79
Short Bowel Syndrome

• Surgical Therapy
• Non-transplant
• Goal is to increase nutrient and fluid absorption
  by either slowing intestinal transit or
  increasing intestinal length
• Slow intestinal transit
• Segmental reversal of the small bowel
• Interposition of a segment of colon
• Construction of small intestinal valves
• Electrical pacing of the small bowel
• Limited case report
• Frequently associated w/ intestinal obstruction

80
Short Bowel Syndrome

• Surgical Therapy
• Non-transplant
• Intestinal lengthening operation
• Longitudinal Intestinal lengthening and tailoring
  (LILT)
• Serial transverse enteroplasty procedure (STEP)
• Intestinal transplant

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