What are the most common sites for the tumours of the small intestine?
- Terminal ileum
- Proximal jejunum
Outline the types of polyp disease
- Adenomas
- Hamartomas
- Familial adenomatous polyposis (FAP)
- Juvenile polyps
- Other
- leiomyomas
- lipomas
- hemangiomas
What are the risk factors for adenocarcinoma?
- FAP
- History of colorectal cancer
- HNPCC
What are the clinical features of an adenocarcinoma?
- Early metastasis to lymph nodes
- 80% metastatic at time of operation
- Common - abdominal pain - general
What are the clinical features of a carcinoid tumour?
- 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)
What are the risk factors for small bowel lymphoma?
- Crohn’s
- Celiac
- Autoimmune disease
- Immunosuppression
- Radiation therapy
- Nodular lymphoid hyperplasia
What are the clinical features of a small bowel lymphoma?
- Fatigue, weight loss, fever, malabsorption, abdominal pain
- Anorexia, vomiting ,constipation and mass
- Rarely:
- perforation
- obstruction
- bleeding
- intussusception
What are the risk factors for metastatic disease in the small bowel?
- Melanoma
- Breast cancer
- Lung cancer
- Ovarian cancer
- Colon cancer
- Cervical cancer
What are the key clinical features of metastatic disease in the small bowel?
- Obstruction
- Bleeding
What are your investigations of choice for an adenocarcinoma?
- CT abdomen and pelvis
- Endoscopy
What are your investigations of choice for a carcinoid tumour?
- 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
What are your investigations of choice for a lymphoma of the small bowel?
- CT abdo/pelvis
What are your investigations of choice for metastatic disease of the small bowel?
- CT abdo/pelvis
Outline brief plans for treatment of each of the four malignant pathologies the small intestine discussed so far.
- 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
Simply define a hernia.
- It is a fascial defect - in which there is a protrusion of a viscus into an area in which it is not normally contained.
What are the risk factors for a hernia?
- Activities which increased intra-abdominal pressure
- Obesity
- Chronic cough
- Pregnancy
- Constipation
- Straining on urination or defecation
- Ascites
- Heavy lifting
- Congenital abnormality
- Previous hernia repair
What are the clinical features of a hernia?
- 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
Outline some investigations for a hernia.
- 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
What are the borders of Hesselbach’s Triangle?
- Lateral - inferior epigastric artery
- Inferior - inguinal ligament
- Medial - lateral margin of rectus sheath
Outline a classification system for hernias.
- 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)
What are the different anatomical types of hernias?
- 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)
What are the complications of hernias?
- 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
What treatment options are available for a hernia?
- 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
What are the postoperative complications for hernia repair?
- 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
What are the contents of the spermatic cord?
- Vas deferens
- Testicular artery/veins
- Genital branch of gentiofemoral nerve
- Lymphatics
- Cremaster muscle
- Hernia sac
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
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
What is the anatomy of direct inguinal hernias?
- Through Hessellbach’s triangle
- Medial to inferior epigastric artery - usually does not descend into scrotal sac
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)
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
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
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
Define the term ‘‘bowel obstruction’’
- Partial or complete blockage of the bowel resulting in failure of intestinal contents to pass through the lumen
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
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.
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
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
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
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)
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)
- If ischaemc bowel look for:
- 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
- Most used - CT provides information on level of obstruction, severity and cause
- 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)
What are the causes of SBO?
SHAVING
Stricture
Hernia
Adhesions
Volvulus
Intussusception/IBD
Neoplasm
Gallstones
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
What is the etiology of a small bowel obstruction?
- Intraluminal
- Intussuscpetion
- Gallstones
- Intramural
- Crohn’s
- Radiation stricture
- Adenocarcinoma
- Extramural
- Adhesions
- Incarcerated hernia
- Peritoneal carcinomatosis
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
What is the etiology of large bowel obstruction?
- Intraluminal
- constipation
- Intramural
- Adenocarcinoma
- Diverticultis
- IBD stricture
- Radiation stricture
- Extramural
- Volvulus
- Adhesions
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
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
What is the defintion of a colonic pseudo-obstruction?
- Condition with symptoms of intestinal blockage without any physical signs of blockage
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
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
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
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
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
*
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
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)
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
What is the surgical procedure indicated for toxic megacolon?
- Subtotal colectomy and end ileostomy (may be temporary, with second operation for re-anastamosis later)
Briefly, what is the pathogenesis for paralytic ileus?
- Temporary paralysis of the myenteric plexus
What are the associations with paralytic ileus?
- Postoperative
- Intra-abdominal sepsis
- Medications
- Opiates
- Anesthetics
- Psychotropics
- Electrolyte disturbances
- Sodium
- Potassium
- Calcium
- Microbiology
- C.difficile
- Inactivity
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.
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)
- Arterio-occlusive mesenteric ischemia (AOMI)
- Chronic
- Usually due to atherosclerotic disease - look for CVD risk factors
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
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
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.
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
What is McBurney’s sign?
Tenderness 1/3 the distance from the ASIS to the umbilicus on the right side
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
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
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
- Pain initially periumbilical; constant, dull, poorly localised, then well localised pain over McBurney’s point
- 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
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
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)
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
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
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.
- Low fibre diet
- Lifestyle
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
- Diverticulitis
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
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
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
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
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