Lower GI - Toronto Notes Flashcards
(80 cards)
1
Q
What are the most common sites for the tumours of the small intestine?
A
- Terminal ileum
- Proximal jejunum
2
Q
Outline the types of polyp disease
A
- Adenomas
- Hamartomas
- Familial adenomatous polyposis (FAP)
- Juvenile polyps
- Other
- leiomyomas
- lipomas
- hemangiomas
3
Q
What are the risk factors for adenocarcinoma?
A
- FAP
- History of colorectal cancer
- HNPCC
4
Q
What are the clinical features of an adenocarcinoma?
A
- Early metastasis to lymph nodes
- 80% metastatic at time of operation
- Common - abdominal pain - general
5
Q
What are the clinical features of a carcinoid tumour?
A
- 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)
6
Q
What are the risk factors for small bowel lymphoma?
A
- Crohn’s
- Celiac
- Autoimmune disease
- Immunosuppression
- Radiation therapy
- Nodular lymphoid hyperplasia
7
Q
What are the clinical features of a small bowel lymphoma?
A
- Fatigue, weight loss, fever, malabsorption, abdominal pain
- Anorexia, vomiting ,constipation and mass
- Rarely:
- perforation
- obstruction
- bleeding
- intussusception
8
Q
What are the risk factors for metastatic disease in the small bowel?
A
- Melanoma
- Breast cancer
- Lung cancer
- Ovarian cancer
- Colon cancer
- Cervical cancer
9
Q
What are the key clinical features of metastatic disease in the small bowel?
A
- Obstruction
- Bleeding
10
Q
What are your investigations of choice for an adenocarcinoma?
A
- CT abdomen and pelvis
- Endoscopy
11
Q
What are your investigations of choice for a carcinoid tumour?
A
- 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
12
Q
What are your investigations of choice for a lymphoma of the small bowel?
A
- CT abdo/pelvis
13
Q
What are your investigations of choice for metastatic disease of the small bowel?
A
- CT abdo/pelvis
14
Q
Outline brief plans for treatment of each of the four malignant pathologies the small intestine discussed so far.
A
- 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
15
Q
Simply define a hernia.
A
- It is a fascial defect - in which there is a protrusion of a viscus into an area in which it is not normally contained.
16
Q
What are the risk factors for a hernia?
A
- Activities which increased intra-abdominal pressure
- Obesity
- Chronic cough
- Pregnancy
- Constipation
- Straining on urination or defecation
- Ascites
- Heavy lifting
- Congenital abnormality
- Previous hernia repair
17
Q
What are the clinical features of a hernia?
A
- 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
18
Q
Outline some investigations for a hernia.
A
- 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
- With or without a CT
19
Q
What are the borders of Hesselbach’s Triangle?
A
- Lateral - inferior epigastric artery
- Inferior - inguinal ligament
- Medial - lateral margin of rectus sheath
20
Q
Outline a classification system for hernias.
A
- 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
- Vascular supply of protruded viscus is compromised ( ischemia)
- 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
- Only part of bowel circumference (usually anti-mesenteric border) is incarcerated or strangulated so may not be obstructed
- Sliding hernia
- Part of wall of hernia formed by protruding viscus (usually cecum)
21
Q
What are the different anatomical types of hernias?
A
- 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)
22
Q
What are the complications of hernias?
A
- 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
- irreducible with resulting ischemia
23
Q
What treatment options are available for a hernia?
A
- 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
24
Q
What are the postoperative complications for hernia repair?
A
- 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
- Risk factors
- 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
25
What are the contents of the spermatic cord?
* Vas deferens
* Testicular artery/veins
* Genital branch of gentiofemoral nerve
* Lymphatics
* Cremaster muscle
* Hernia sac
26
Describe the anatomical location of an inguinal hernia
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
27
Describe the etiology of groin hernias.
* 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
28
What is the anatomy of direct inguinal hernias?
* Through Hessellbach's triangle
* Medial to inferior epigastric artery - usually does not descend into scrotal sac
29
What is the anatomy of an indirect inguinal hernia?
* Originates in deep inguinal ring
* Lateral to inferior epigastric artery
* Often descends into scrotal sac (or labia majora)
30
What is the anatomy of a femoral hernia?
* Into femoral canal, below inguinal ligament but may override it
* Medial to femoral vein within femoral canal
31
Describe the anatomy of the superficial inguinal ring.
* 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
32
Describe the anatomy of the deep inguinal ring
* 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
33
Define the term ''bowel obstruction''
* Partial or complete blockage of the bowel resulting in failure of intestinal contents to pass through the lumen
34
What is the pathogenesis of bowel obstruction?
* 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
35
What are the clinical features of bowel obstruction?
* 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.
36
What are the clinical features of a small bowel obstruction?
* 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
37
What are the clinical features of a large bowel obstruction?
* 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
38
What are the clinical features of a paralytic ileus?
* 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
39
What are the complications of total obstruction?
* 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)
40
What investigations will you consider in bowel obstruction?
* 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)
41
What are the causes of SBO?
SHAVING
Stricture
Hernia
Adhesions
Volvulus
Intussusception/IBD
Neoplasm
Gallstones
42
What is the management plan for bowel obstruction?
* 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
43
What is the etiology of a small bowel obstruction?
* Intraluminal
* Intussuscpetion
* Gallstones
* Intramural
* Crohn's
* Radiation stricture
* Adenocarcinoma
* Extramural
* Adhesions
* Incarcerated hernia
* Peritoneal carcinomatosis
44
What is the tratment of a small bowel obstruction?
* 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
45
What is the etiology of large bowel obstruction?
* Intraluminal
* constipation
* Intramural
* Adenocarcinoma
* Diverticultis
* IBD stricture
* Radiation stricture
* Extramural
* Volvulus
* Adhesions
46
What are the clinical features of a large bowel obstruction?
* 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
47
What is the treatment of a LBO?
* 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
48
What is the defintion of a colonic pseudo-obstruction?
* Condition with symptoms of intestinal blockage without any physical signs of blockage
49
What is the differential diagnosis of a colonic pseudo-obstruction?
* 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
50
What is the pathogenesis of toxic megacolon?
* Extension of inflammation into smooth muscle layer causing paralysis
* Damage to myenteric plexus and electrolyte abnormalities are not consistently found
51
What is the etiology of toxic megacolon?
* IBD
* Infectious colitis
* bacterial (c.diff, salmonella, shigella, campylobacter)
* viral (cytomegalovirus)
* parasitic (E.histolytica)
* Volvulus
* Diverticulitis
* Ischaemic colitis
* Obstructing colon cancer are rare causes
52
What are the clinical features of toxic megacolon?
• 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
53
What is the diagnostic criteria for toxic megacolon?
* 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
*
54
What are the investigations that form part of the work up for toxic megacolon?
* 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
55
What is your management plan for a patient with toxic megacolon?
* 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)
56
What are the indications for surgery in a patient with toxic megacolon?
* Worsening or persisting toxicity or dilatation after 48-72 hours
* Severe haemorrhage and perforation
* High lactate and WBC specifically for C.difficile
57
What is the surgical procedure indicated for toxic megacolon?
* Subtotal colectomy and end ileostomy (may be temporary, with second operation for re-anastamosis later)
58
Briefly, what is the pathogenesis for paralytic ileus?
* Temporary paralysis of the myenteric plexus
59
What are the associations with paralytic ileus?
* Postoperative
* Intra-abdominal sepsis
* Medications
* Opiates
* Anesthetics
* Psychotropics
* Electrolyte disturbances
* Sodium
* Potassium
* Calcium
* Microbiology
* C.difficile
* Inactivity
60
What is the treatment for paralytic ileus?
* 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.
61
What is the etiology of intestinal ischaemia?
* 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
62
What are the clinical features of intestinal ischaemia?
* 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
63
What are the investigations to be considered when diagnosing intestinal ischaemia?
* 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
64
What is your management and treatment plan for intestinal ischaemia?
* 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.
65
What is the modified Alvarado score for acute appendicitis?
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
66
What is McBurney's sign?
Tenderness 1/3 the distance from the ASIS to the umbilicus on the right side
67
What is the pathogensis of appendicitis?
* Luminal obstruction - bacterial overgrowth - inflammation/swellling - increased pressure - localised ischaemia - gangrene/perforation - localised abscess (walled off by omentum) or peritonitis
68
What is the etiology of appendicitis?
* Children or young adult:
* Hyperplasia of lymphoid follicces
* Initiated by infection
* Adult
* Fibrosis/stricture
* Fecolith
* Obstructing neoplasm
* Other causes:
* parasites and foreign body
69
What are the clinical features of appendicitis?
* 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
70
What investigations would you order for a case of appendicitis?
* 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
71
What is your treatment plan for appendicitis?
* 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)
72
Compare laparoscopic and open appendectomy
* 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
73
What is:
* A diverticulum
* Diverticulosis
* Diverticulitis
* True diverticuli
* False diverticuli
* 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
74
What is the pathogenesis of diverticulosis?
* 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.
75
What are the clinical features of diverticulosis?
* 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
76
What is the treatment for diverticulosis?
* 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
77
What is the pathogenesis of diverticulitis ?
* 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
78
What are the clinical features of diverticulitis?
* 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):
* abscess: palpable tender abdominal mass
* fistula: colovesical (most common), coloenteric, colovaginal, colocutaneous
* colonic obstruction: due to scarring from repeated inflammation
* perforation: generalized peritonitis (feculent vs. purulent)
* recurrent attacks rarely lead to peritonitis
* low-grade fever, mild leukocytosis common,
* occult or gross blood in stool rarely coexist with acute diverticulitis
79
What are the investigations for diverticulitis?
* 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
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What are your treatment options for diverticulosis?
* 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
