Lower GI - Toronto Notes

Question 1

What are the most common sites for the tumours of the small intestine?

Answer 1

• Terminal ileum
• Proximal jejunum

Question 2

Outline the types of polyp disease

Answer 2

• Adenomas
• Hamartomas
• Familial adenomatous polyposis (FAP)
• Juvenile polyps
• Other
  
  • leiomyomas
  • lipomas
  • hemangiomas

Question 3

What are the risk factors for adenocarcinoma?

Answer 3

• FAP
• History of colorectal cancer
• HNPCC

Question 4

What are the clinical features of an adenocarcinoma?

Answer 4

• Early metastasis to lymph nodes
• 80% metastatic at time of operation
• Common - abdominal pain - general

Question 5

What are the clinical features of a carcinoid tumour?

Answer 5

• Nausea
• Vomiting
• Anaemia
• GI bleeding
• Jaundice
• Slow growing - usually asymptomatic, incidental finding
• Obstruction, bleeding, crampy abdominal pain, intussusception
• Specifically:
  
  • hot flashes, hypotension, diarrhea, bronchoconstriction, right heart failure
  • requires liver involvement - lesion secretes serotonin, kinins and vasoactive peptides directly to systemic circulation (normally inactivated by liver)

Question 6

What are the risk factors for small bowel lymphoma?

Answer 6

• Crohn’s
• Celiac
• Autoimmune disease
• Immunosuppression
• Radiation therapy
• Nodular lymphoid hyperplasia

Question 7

What are the clinical features of a small bowel lymphoma?

Answer 7

• Fatigue, weight loss, fever, malabsorption, abdominal pain
• Anorexia, vomiting ,constipation and mass
• Rarely:
  
  • perforation
  • obstruction
  • bleeding
  • intussusception

Question 8

What are the risk factors for metastatic disease in the small bowel?

Answer 8

• Melanoma
• Breast cancer
• Lung cancer
• Ovarian cancer
• Colon cancer
• Cervical cancer

Question 9

What are the key clinical features of metastatic disease in the small bowel?

Answer 9

• Obstruction
• Bleeding

Question 10

What are your investigations of choice for an adenocarcinoma?

Answer 10

• CT abdomen and pelvis
• Endoscopy

Question 11

What are your investigations of choice for a carcinoid tumour?

Answer 11

• Most are found incidentally at surgery for obstruction or appendectomy
• Chest thorax/abdo/pelvis CT
• Consider small bowel enteroclysis to look for primary
• Elevated 5-HIAA (break down product of serotonin) in urine or increased 5-HT in blood
• Radiolabelled octreotide or MIBG scans to locate tumour

Question 12

What are your investigations of choice for a lymphoma of the small bowel?

Answer 12

• CT abdo/pelvis

Question 13

What are your investigations of choice for metastatic disease of the small bowel?

Answer 13

• CT abdo/pelvis

Question 14

Outline brief plans for treatment of each of the four malignant pathologies the small intestine discussed so far.

Answer 14

• Adenocarcinoma
  
  • Surgical resection and chemotherapy
• Carcinoid
  
  • Surgical resection and chemotherapy
  • Carcinoid syndrome treated witih steroids, histamine, octreotide
• Lymphoma
  
  • Low grade - chemotherapy with cyclophosphamide
  • High grade - surgical resection, radiation
  • Palliative - somatostatin and doxorubicin
• Metastatic
  
  • Paliation

Question 15

Simply define a hernia.

Answer 15

• It is a fascial defect - in which there is a protrusion of a viscus into an area in which it is not normally contained.

Question 16

What are the risk factors for a hernia?

Answer 16

• Activities which increased intra-abdominal pressure
  
  • Obesity
  • Chronic cough
  • Pregnancy
  • Constipation
  • Straining on urination or defecation
  • Ascites
  • Heavy lifting
• Congenital abnormality
• Previous hernia repair

Question 17

What are the clinical features of a hernia?

Answer 17

• It is a mass of variable size
• Tenderness worse at end of the day, relieved by supine position or with reduction
• Abdominal fullness, vomiting and constipation
• Transmits palpable impulse with coughing or straining

Question 18

Outline some investigations for a hernia.

Answer 18

• Physical examination usually sufficient
• Ultrasound
  
  • With or without a CT
    
    • A CT is usually required for obturator hernias, internal abdominal hernias and Spigelian femoral hernias in obese patients

Question 19

What are the borders of Hesselbach’s Triangle?

Answer 19

• Lateral - inferior epigastric artery
• Inferior - inguinal ligament
• Medial - lateral margin of rectus sheath

Question 20

Outline a classification system for hernias.

Answer 20

• Complete
  
  • hernia sac and contents protrude through defect
• Incomplete
  
  • Partial protrusion through the defect
• Internal hernia
  
  • Sac herniating into or involving intra-abdominal structure
• External hernia
  
  • Sac protrudes completely through the abdominal wall
• Strangulated hernia
  
  • Vascular supply of protruded viscus is compromised ( ischemia)
    
    • Requires emergency repair
• Incarcerated hernia
  
  • Irreducible hernia, not necessarily strangulated
• Richter’s hernia
  
  • Only part of bowel circumference (usually anti-mesenteric border) is incarcerated or strangulated so may not be obstructed
    
    • A strangulated Richter’s hernia may self-reduce and thus be overlooked, leaving a gangrenous segment at risk of perforation
• Sliding hernia
  
  • Part of wall of hernia formed by protruding viscus (usually cecum)

Question 21

What are the different anatomical types of hernias?

Answer 21

• Groin
  
  • Indirect and direct inguinal, femoral
  • Pantaloon - combined direct and indirect hernias - peritoneum draped over epigastric vessels
• Epigastric
  
  • Defect in linea alba above umbilicus
• Incisional
  
  • Ventral hernia at site of wound closure - may be secondary to wound infection
• Other
  
  • Littre’s (involving Meckel’s diverticulum)
  • Amyand’s (containing appendix)
  • Lumbar
  • Obturator
  • Parastomal
  • Umbilical
  • Spigelian (ventral hernia through linea semilunaris)

Question 22

What are the complications of hernias?

Answer 22

• Incarceration - irreducible hernias
• Strangulation
  
  • irreducible with resulting ischemia
    
    • Small - new hernias more likely to strangulate
    • Femoral >>, indirect iinguinal > direct inguinal
    • Intense pain followed by tenderness
    • Intestinal obstruction, gangrenous bowel and sepsis
    • Surgical emergency

Question 23

What treatment options are available for a hernia?

Answer 23

• Surgical treatment (herniorrhaphy) is only to prevent strangulation and evisceration for symptomatic relief, for cosmesis - if asymptomatic can delay surgery
• Repair may be done open or laproscopic and may use mesh for tension free closure
• Most repairs are now done using tension-free techniques - a plug in the hernial defect and a patch over it or patch alone
• Observation is acceptable for small asymptomatic inguinal hernias

Question 24

What are the postoperative complications for hernia repair?

Answer 24

• Recurrence
  
  • Risk factors
    
    • Age greater than 50
    • BM greater than 25
    • Poor pre-op functional status
    • Associated medical conditions:
      
      • Type II DM
      • Hyperlipidemia
      • Immunosuppression
      • Any comorbid conditions increasing intra-abdominal pressure
      • Less common with mesh/tension free repair
• Scrotal hematoma
  
  • Painful scrotal swelling from compromised venous return of testes
  • Deep bleeding - may enter retroperitoneal space and not be initially apparent
  • Difficulty voiding
• Nerve entrapment
  
  • Ilioinguinal (causes numbness of inner thigh or lateral scrotum)
  • Genital branch of genitofemoral (spermatic cord)
• Stenosis/occlusion of femoral vein
  
  • Acute leg swelling
• Ischaemic colitis

Question 25

What are the contents of the spermatic cord?

Answer 25

* Vas deferens * Testicular artery/veins * Genital branch of gentiofemoral nerve * Lymphatics * Cremaster muscle * Hernia sac

Question 26

Describe the anatomical location of an inguinal hernia

Answer 26

MD's Don't LIe MD: Medial to: the inferior epigastric artery = Direct inguinal hernia LIe: Lateral to the inferior epigastric artery = Indirect inguinal hernia

Question 27

Describe the etiology of groin hernias.

Answer 27

* Direct inguinal * Acquired weakness of trasvrsalis fascia * Wear and tear * Increased abdominal pressure * Indirect inguinal * Congenital persistence of processus vaginalis in 20% of adults * Femoral * Pregnancy - weakness of pelvic floor musculature * Increased intra-abdominal pressure

Question 28

What is the anatomy of direct inguinal hernias?

Answer 28

* Through Hessellbach's triangle * Medial to inferior epigastric artery - usually does not descend into scrotal sac

Question 29

What is the anatomy of an indirect inguinal hernia?

Answer 29

* Originates in deep inguinal ring * Lateral to inferior epigastric artery * Often descends into scrotal sac (or labia majora)

Question 30

What is the anatomy of a femoral hernia?

Answer 30

* Into femoral canal, below inguinal ligament but may override it * Medial to femoral vein within femoral canal

Question 31

Describe the anatomy of the superficial inguinal ring.

Answer 31

* Opening in external abdominal aponeurosis; palpable superior and lateral to pubic tubercle * Medial border: * Medial crus of external abdominal aponeurosis * Lateral border * Lateral crus of external oblique aponeurosis * Roof * Intercrural fibres

Question 32

Describe the anatomy of the deep inguinal ring

Answer 32

* Opening in transversalis fascia - palpable superior to mid-inguinal ligament * Medial border: * Inferior epigastric vessels * Superior-lateral border: * Internal oblique and transversus abdominis muscles * Inferior: * Inguinal ligament

Question 33

Define the term ''bowel obstruction''

Answer 33

* Partial or complete blockage of the bowel resulting in failure of intestinal contents to pass through the lumen

Question 34

What is the pathogenesis of bowel obstruction?

Answer 34

* Disruption of the normal flow of intestinal contents - proximal dilatation + distal decompression * May tak 12-24 h to decompress, therefore passage of feces and flatus may occur after the onset of obstruction * Bowel ischaemia may occur if blood supply is strangulated or bowel wall inflammation leads to venous congestion * bowel wall edema and disrupton of normal bowel absorptive function - increased intraluminal fluid - transudative fluid loss into the peritoneal cavity - leading to electrolyte disturbances

Question 35

What are the clinical features of bowel obstruction?

Answer 35

* Must differentiate between obstruction and ileus - characterise obstruction as acute vs chronic, partial vs complete (constipation vs obstipation), small vs large bowel, strangulating vs non-strangulating, and with vs without perforation.

Question 36

What are the clinical features of a small bowel obstruction?

Answer 36

* Nausea, vomiting * Early, may be bilious * Abdominal pain * Colicky * Constipation * + * Other * May have visible peristalsis * Bowel sounds * Normal - increased * Absent if secondary ileus * AXR findings * Air-fluid levels * 'Ladder' pattern plicae circularis * Proximal distention (\>3cm) with no colonic gas

Question 37

What are the clinical features of a large bowel obstruction?

Answer 37

* Nausea, vomiting * Late and may be feculent * Abdominal pain * Colicky * Abdominal distention * ++ * Other * May present with visible peristalsis * Bowel sounds * Normal, increased (borborygmi) * Absent if secondary ileus present * AXR findings * Air-fluid levels * 'Picture frame' appearance * Proximal distention and distal decompression * No small bowel air if competent ileocecal valve * Coffee bean sign

Question 38

What are the clinical features of a paralytic ileus?

Answer 38

* Nausea and vomiting * Present * Abdominal pain * Minimal or absent * Abdominal distention * + * Constipation * + * Bowel sounds * Decreased or absent * AXR findings * Air throughout small bowel and colon

Question 39

What are the complications of total obstruction?

Answer 39

* Strangulating obstruction (10% of bowel obstructions) = surgical emergency * Cramping pain turns to continuous ache, hematemesis, melena (if infarction) * Fever, leukocytosis and tachycardia * Peritoneal signs, early shock * Other * Perforation - secondary to ischaemia and luminal distention * Septicemia * Hypovolemia (due to third spacing)

Question 40

What investigations will you consider in bowel obstruction?

Answer 40

* Radiological * Upright CXR or left lateral decubitus (LLD) to rule out free air; usually seen under the right hemidiaphragm * Abdominal x-ray (3 views) to determine SBO vs LBO vs ileus * If ischaemc bowel look for: * free air * pneumatosis * thickened bowel wall * air in portal vein * dilated small and large bowels * thickened or hose like haustra (normally finger like projections) * Other * Most used - CT provides information on level of obstruction, severity and cause * important to r/o closed loop obstruction - especially in the elderly * Less used - upper GI series/small bowel series for SBO (if no cause apparaent i.e. no pervious hernias or surgeries) * If suspect LBO - consider a rectal water soluble enema rather than a barium enema (can thicken and cause complete obstruction) * May consider ultrasound or MRI in pregnany patients * Laboratory studies * May be normal early in disease course * BUN, creatinine, hematocrt (hemoconcentration) to assess degree of hydration * fluid, electrolyte abnormalities * amylase elevated * metabolic alkalosis due to frequent emesis * if strangulation - leukocytosis with left shift, lactic acidosis, elevated LDH (late signs)

Question 41

What are the causes of SBO?

Answer 41

SHAVING Stricture Hernia Adhesions Volvulus Intussusception/IBD Neoplasm Gallstones

Question 42

What is the management plan for bowel obstruction?

Answer 42

* Stabilize vitals, fluids and electrolyte resuscitation (with normal saline/Ringer's first, then with added potassium after fluid deficits are corrected) * NG tube to relieve vomiting, prevent aspiration and decompress small bowel by prevention of further distention by swalloed air * Foley catheter to monitor in and outs

Question 43

What is the etiology of a small bowel obstruction?

Answer 43

* Intraluminal * Intussuscpetion * Gallstones * Intramural * Crohn's * Radiation stricture * Adenocarcinoma * Extramural * Adhesions * Incarcerated hernia * Peritoneal carcinomatosis

Question 44

What is the tratment of a small bowel obstruction?

Answer 44

* Consider whether complete or partial obstruction, ongoing or impending strangulation location and cause: * SBO with history of previous abdo/pelvic surgery - likely to resolve with conservative management - surgery if no resolution in 48-72 hours or complications * Complete SBO, strangulation - urgent surgery after stabilizing patient with fluid resuscitation * SBO with no previous surgery and no evidence of carcinomatosis - operate * Trial of medical management may be indicated with Crohn's, recurrent SBO, carcinomatosis * NGT decompression * GI rest * Serial abdominal exams * Special case: * Early postoperative SBO (within 30 days of abdominal surgery) - prolonged trial of conservative therapy may be appropriate, surgery is reserved for complications such as strangulation

Question 45

What is the etiology of large bowel obstruction?

Answer 45

* Intraluminal * constipation * Intramural * Adenocarcinoma * Diverticultis * IBD stricture * Radiation stricture * Extramural * Volvulus * Adhesions

Question 46

What are the clinical features of a large bowel obstruction?

Answer 46

* Open loop (10-20%) (safer): * Incompetent ileocecal valve allows relief of colonic pressure as contents reflux into the ileum, therefore clinical presentation similar to SBO * Closed loop (80-90%) (dangerous) * Competent ileocecal valve, resulting in proximal and distal occlusions * Massive colonic distention * Increased pressure in the cecum - leading to bowel ischaemia - necrosis and ultimately perforation

Question 47

What is the treatment of a LBO?

Answer 47

* Surgical correction of obstruction (usually requires resection and temporary diverting colostomy) * Volvulus requires sigmoidoscopic or endoscopic decompression followed by operative reduction if unsuccessful * If successful, consider sigmoid resection on same admission * Cecal volvulus can be a true volvulus or a cecal 'bascule' - both need surgical treatment

Question 48

What is the defintion of a colonic pseudo-obstruction?

Answer 48

* Condition with symptoms of intestinal blockage without any physical signs of blockage

Question 49

What is the differential diagnosis of a colonic pseudo-obstruction?

Answer 49

* Acute * toxic megacolon * trauama * postoperative (especially post orthopedic procedures with prolonged immoblization) * neurological disease * retroperitnoeal disease * medications (narcotic and psychiatric) * Chronic * Neurologic disease (enteric, central, peripheral nervous system) * Scleroderma

Question 50

What is the pathogenesis of toxic megacolon?

Answer 50

* Extension of inflammation into smooth muscle layer causing paralysis * Damage to myenteric plexus and electrolyte abnormalities are not consistently found

Question 51

What is the etiology of toxic megacolon?

Answer 51

* IBD * Infectious colitis * bacterial (c.diff, salmonella, shigella, campylobacter) * viral (cytomegalovirus) * parasitic (E.histolytica) * Volvulus * Diverticulitis * Ischaemic colitis * Obstructing colon cancer are rare causes

Question 52

What are the clinical features of toxic megacolon?

Answer 52

• infectious colitis usually present for \>1 wk before colonic dilatation • diarrhea ± blood (but improvement of diarrhea may portend onset of megacolon) • abdominal distention, tenderness, ± local/general peritoneal signs (suggest perforation) • triggers: hypokalemia, constipating agents (opioids, antidepressants, loperamide, anticholinergics), barium enema, colonoscopy

Question 53

What is the diagnostic criteria for toxic megacolon?

Answer 53

* Must have both colitis and sytemic manifestations for diagnosis * Radiologic evidence of dilated colon * Three of: * Fever * Hear rate (greater than 120) * WBC (greater than 10.5) * Anaemia * One of: * Fluid and electrolyte disturbances * Hypotension * Altered LOC *

Question 54

What are the investigations that form part of the work up for toxic megacolon?

Answer 54

* FBC * Look for leukocytosis * Anaemia from bloody diarrhea * Electrolytes * Elevated CRP and ESR * ABG * Metabolic alkalosis - due to volume contraction and hypokalemia * Hypoalbuminaemia * Although these are late findings * AXR * Dilated colon (greater than 6cm) (right\>transverse\>left), loss of haustra * CT * Useful in assessing underlying disease

Question 55

What is your management plan for a patient with toxic megacolon?

Answer 55

* NBM * NG Tube * Stop constipating agents * Correct fluid and electrolyte abnormalities and transfusion * Serial AXRs * Broad-spectrum antibiotics * reduce sepsis * anticipate perforation * Aggressive treatment of underlying disease * (steroids in IBD or metronidazole for C.difficile)

Question 56

What are the indications for surgery in a patient with toxic megacolon?

Answer 56

* Worsening or persisting toxicity or dilatation after 48-72 hours * Severe haemorrhage and perforation * High lactate and WBC specifically for C.difficile

Question 57

What is the surgical procedure indicated for toxic megacolon?

Answer 57

* Subtotal colectomy and end ileostomy (may be temporary, with second operation for re-anastamosis later)

Question 58

Briefly, what is the pathogenesis for paralytic ileus?

Answer 58

* Temporary paralysis of the myenteric plexus

Question 59

What are the associations with paralytic ileus?

Answer 59

* Postoperative * Intra-abdominal sepsis * Medications * Opiates * Anesthetics * Psychotropics * Electrolyte disturbances * Sodium * Potassium * Calcium * Microbiology * C.difficile * Inactivity

Question 60

What is the treatment for paralytic ileus?

Answer 60

* NG decompression * NBM * Fluid resuscitation * Correct causative abnormalities * Sepsis * Medications * Electrolytes * Consider TPN for prolonged ileus * Post-operatively - gastric and small bowel motility returns by 24-48 hours, colonic motility by day 3-5.

Question 61

What is the etiology of intestinal ischaemia?

Answer 61

* Acute * Arterio-occlusive mesenteric ischemia (AOMI) * thrombotic * embolic * extrinsic compression (e.g. strangulating hernia) * Non-occlusive mesenteric ischaemia (NOMI) * mesenteric vasoconstriction secondary to systemic hypoperfusion (preserves supply to vital organs) * Mesenteric venous thrombosis (MVT) * consider hypercoagulable state (ruling out malignancy) * DVT (prevents venous outflow) * Chronic * Usually due to atherosclerotic disease - look for CVD risk factors

Question 62

What are the clinical features of intestinal ischaemia?

Answer 62

* Acute * Severe abdominal pain out of proportion to physical findings * Vomiting * Bloody diarrhea * Bloating * Minimal peritoneal signs early in course * Hypotensive shock and sepsis * Chronic * Postprandial pain * Fear of eating * Weight loss * Common sites: * Superior mesenteric artery (SMA) supplied territory * 'Watershed' areas of the colon: * splenic flexure * left colon * sigmoid colon

Question 63

What are the investigations to be considered when diagnosing intestinal ischaemia?

Answer 63

* FBC * Leukocytosis * Bloods * Lactic acidosis (late finding) * Amylase * LDH * CK * ALP * Hypercoagulability workup if suspect venous thrombosis * AXR * Portal venous gas * Intestinal pneumatosis * Free air, if perforation * Contrast CT * thickened bowel wall * luminal dilatation * SMA or SMV thrombus, mesenteric/portal venous gas * pneumatosis * CT angiography is the gold standard for acute arterial ischaemia

Question 64

What is your management and treatment plan for intestinal ischaemia?

Answer 64

* Fluid resuscitation * Correct metabolic acidosis * NBM * NG decompression of stomach * Prophylactic broad spectrum antibiotics, avoid vasoconstrictors and digitalis * Exploratory laparotomy * Angiogram, embolectomy/thrombectomy, bypass graft and mesentric endarterectomy, anticoagulation therapy, percutaneous transluminal angioplasty with or without stent * Segmental resection of necrotic intestine: * assess extent of viability; if extent of bowel viability is uncertain, a second look laparotomy 12-24 hours later is mandatory.

Question 65

What is the modified Alvarado score for acute appendicitis?

Answer 65

1 point per: • Migratory right Iliac fossa pain (1 point) • Anorexia (1 point) • Nausea/vomiting (1 point) • Tenderness in right Iliac fossa (2 points) • Rebound tenderness in right Iliac fossa (1 point) * Fever \>37.5°C (1 point) * Leukocytosis (2 points) • 0-3 = low risk, discharge to return if no improvement • 4-6 = moderate risk, admit, observe, repeat examinations • Male 7-9 = appendectomy • Female (not pregnant) 7-9 = diagnostic laparoscopy ± appendectomy

Question 66

What is McBurney's sign?

Answer 66

Tenderness 1/3 the distance from the ASIS to the umbilicus on the right side

Question 67

What is the pathogensis of appendicitis?

Answer 67

* Luminal obstruction - bacterial overgrowth - inflammation/swellling - increased pressure - localised ischaemia - gangrene/perforation - localised abscess (walled off by omentum) or peritonitis

Question 68

What is the etiology of appendicitis?

Answer 68

* Children or young adult: * Hyperplasia of lymphoid follicces * Initiated by infection * Adult * Fibrosis/stricture * Fecolith * Obstructing neoplasm * Other causes: * parasites and foreign body

Question 69

What are the clinical features of appendicitis?

Answer 69

* Most reliable feature is progression of signs and symptoms * Low grade fever, rises with perforation * Abdominal pain then anorexia, nausea and vomiting * Classic pattern: * Pain initially periumbilical; constant, dull, poorly localised, then well localised pain over McBurney's point * Due to progression of disease from visceral irritation (causing referred pain from structures of the embryologic midgut - including the appendix) to irritation of parietal structures * McBurney's sign * Signs: * Inferior appendix - McBurney's sign, Rosving's sign (palpation presure to left abdomen causes McBurney's point tenderness) * Retrocecal appendix: * Psoas sign (pain on flexion of hip against resistance or passive hyperextension of hip) * Pelvic appendix: * Obturator sign (flexion then external or internal rotation about right hip causes pain) * Complications * Perforation * Abscess, phlegmon

Question 70

What investigations would you order for a case of appendicitis?

Answer 70

* Labs/Bloods: * Mild leukocytosis with left shift (normal WBC counts) * Higher leukoctye count with perforation * beta hCG to rule out pregnancy * urinalysis * Imaging: * upright CXR, AXR - usually nonspecific - free air if perforated (rarely), calcified fecolith, loss of psoas shadow, RLQ ileus * Ultrasound - may visualise appendix but also helps rule out gynecological causes * CT scan - thick wall, appendicolith, inflammatory changes

Question 71

What is your treatment plan for appendicitis?

Answer 71

* Hydration and correct electrolyte abnormalities * Surgery (gold standard, 20% mortality with perforation especially in the elderly) + antibiotic coverage * If localised abscess (palpable masses or large phlegmon on imaging and often pain \>4-5 days) * consider radiological drainage and antibiotics x 14 days + or - interval appendectomy in 6 weeks * Appendectomy * Laparoscopic or open * Complications * Spillage of bowel contents * Pelvic abscess * Enterocutaneous fistula * Perioperative antibiotics * cefazolin + metronidazole (no post-op antibiotics unless perforated) * other choices - 2nd or 3rd generation cephalosporin for aerobic gut organisms * Colonoscopy in the eldery to rule out other etiology (neoplasm)

Question 72

Compare laparoscopic and open appendectomy

Answer 72

* Laparoscopic * Wound infection less likely * Intra-abdominal abscesses 2 times more likely * Reduced pain on post-operative day 1 * Reduced hospital stay * Sooner return to normal activity, work and sport * Costs outside outside hospital are reduced * Open * Shorter duration of surgery * Lower operation costs

Question 73

What is: * A diverticulum * Diverticulosis * Diverticulitis * True diverticuli * False diverticuli

Answer 73

* Abnormal sac like protrusion from the wall of a hollow organ * Presence of multiple diverticula * Inflammation of diverticula * Contain all layers of the colonic wall, often right sided * False diverticuli - contain mucosa and submucosa - often left sided

Question 74

What is the pathogenesis of diverticulosis?

Answer 74

* Risk factors: * Lifestyle * Low fibre diet * Predispose to motility abnormalities and higher intraluminal pressure, inactivity and obesity * muscle wall weakness from aging and illness (Ehler-Danlos, Marfan's) * high intraluminal pressure causes outpouching to occur at point of greatest weakness, most commonly where vasa recta penetrates the circular muscle layer - therefore increasing the risk of haemorrhage.

Question 75

What are the clinical features of diverticulosis?

Answer 75

* Uncomplicated diverticulosis - asymptomatic * Episodic abdominal pain (often LLQ), bloating, flatulence, constipation and diarrhea * Absence of fever and leukocytosis * No physical exam findings or poorly controlled LLQ tenderness * Complicatoins * Diverticulitis * 25% of which are complicated (i.e. abscess, obstruction, perforation and fistula) * Bleeding (5-15%) - painless rectal bleeding, 30-50% of massive lower GI bleeds * Diverticular colitis (rare) - diarrhea, hematochezia, tenesmus, abdominal pain

Question 76

What is the treatment for diverticulosis?

Answer 76

* Uncomplicated diverticulosis: high fibre and education * Diverticular bleed * Initially work up and treat as any lower GI bleed * If haemorrhage does not stop, resect involved region

Question 77

What is the pathogenesis of diverticulitis ?

Answer 77

* erosion of the wall by increased intraluminal pressure or inspissated food particles leading to... * inflammation and focal necrosis gmicro or macroscopic perforation usually mild inflammation with perforation walled off by pericolic fat and mesentery; abscess, * fistula or obstruction can ensue * poor containment results in free perforation and peritonitis

Question 78

What are the clinical features of diverticulitis?

Answer 78

* depend on severity of inflammation and whether or not complications are present; hence ranges from asymptomatic to generalized peritonitis * LLQ pain/tenderness (2/3 of patients) often for several days before admission * constipation, diarrhea, nausea, vomiting, urinary symptoms (with adjacent inflammation) * complications (25% of cases): * ƒabscess: palpable tender abdominal mass * ƒfistula: colovesical (most common), coloenteric, colovaginal, colocutaneous * ƒcolonic obstruction: due to scarring from repeated inflammation * ƒperforation: generalized peritonitis (feculent vs. purulent) * Šrecurrent attacks rarely lead to peritonitis * low-grade fever, mild leukocytosis common, * occult or gross blood in stool rarely coexist with acute diverticulitis

Question 79

What are the investigations for diverticulitis?

Answer 79

* AXR, upright CXR * Localized diverticulitis (ileus, thickened wall, SBO, partial colonic obstruction) * Free air may be seen in 30% with perforation and generalized peritonitis * CT scan (test of choice) - very useful for assessment of severity and prognosis * 97%, sensitive; 99% specific * Increased soft tissue density within pericolic fat secondary to inflammation, diverticula secondary to inflammation, bowel wall thickening, soft tissue mass (pericolic fluid, abscesses), fistula * 10% of diverticulitis cannot be distinguished from carcinoma * Hypaque (water soluble) enema - safe (under low pressure) * Saw tooth pattern (colonic spasm) * May show site of perforation, abscess cavities or sinus tracts, fistulas * Elective evaluations: establish extent of disease and rule out other diagnoses (polyps, malignancies) after resolution of acute episode * Colonoscopy or barium enema and flexible sigmoidoscopy

Question 80

What are your treatment options for diverticulosis?

Answer 80

* Uncomplicated: * Conservative management * Outpatient: * Clear fluids only until improvement and antibiotics (e.g. ciproflxacin and metronidazole) 7-10 days to cover gram negative rods and anaerobes (e.g. B fragilis) * Hospitalize: if severe presentation, inability to tolerate oral intake, significant comorbidities, fail to improve outpatient management * Treat with NBM, IV fluids, IV antibiotics, (e.g. IV ceftriaxone + metronidazole, ampicillin, gentamicin) * Indications for surgery: * Unstable patient with peritonitis * Hinchey stage 3-4 * After 1 attack if: * Immunosuppressed * Abscess needing percutaneous