The Appendix - According to Bailey and Love's Short Practice of Surgery (28th Edition)

1. ANATOMY

General

Gross Anatomy

Figure 76.1 - The various positions of the appendix (after Sir C. Wakeley)

Positions of the Appendix (Wakeley's Classification)

Microscopic Anatomy / Function

2. ACUTE APPENDICITIS

Historical Note

Incidence

• Incidence rose greatly in the first half of the 20th century (up to 16% of the population underwent appendicectomy)
• The past 30 years have seen a dramatic fall in incidence in Western countries
• Lifetime risk of appendicectomy: 8.6% in males, 6.7% in females
• Rare in infants; peaks in teens and early twenties
• Equal sex incidence before puberty; male:female ratio rises to 3:2 at age 25, then declines

Aetiology

• Low dietary fibre / refined carbohydrate diet - parallels the geography of incidence; lowest incidence in high-fibre societies
• Luminal obstruction - the most widely held initiating mechanism:
  • Faecolith (appendicolith) - inspissated faecal material, calcium phosphates, bacteria, and epithelial debris. CT scan demonstration:

Figure 76.5 - CT of inflamed appendix with multiple radiopaque appendicoliths

• Fibrotic stricture (previous resolved appendicitis)
• Caecal carcinoma obstructing the appendiceal orifice (in middle-aged/elderly)
• Intestinal parasites (e.g., Enterobius vermicularis/pinworm)
• Bacterial proliferation - mixed aerobic and anaerobic organisms; no single organism responsible
• Viral infection - occasional clustering in children/young adults and seasonal variation (May-August in northern Europe) suggests a viral initiating factor

Pathology

1. Lymphoid hyperplasia narrows the appendix lumen
2. Obstruction → continued mucus secretion → raised intraluminal pressure → obstructed lymphatic drainage
3. Oedema and mucosal ulceration develop → bacterial translocation to submucosa
4. Resolution may occur spontaneously or with antibiotics at this stage
5. If it progresses → further distension → venous obstruction and ischaemia of the appendix wall
6. Bacterial invasion through the muscularis propria and submucosa (gangrene)
7. Perforation → faecal peritonitis or localised abscess formation

Symptoms

• Central abdominal (periumbilical) pain initially - colicky or continuous, due to appendix distension (visceral pain, T10)
• Pain migrates to the right iliac fossa (RIF) - as parietal peritoneum becomes involved (somatic pain)
• Anorexia - almost universal; if the patient is hungry, appendicitis is unlikely
• Nausea and vomiting - occur after the onset of pain (important: if vomiting precedes pain, consider gastroenteritis)
• Fever - low grade (37.5-38°C); high fever suggests perforation or alternative diagnosis
• Constipation is common; diarrhoea may occur if inflamed appendix is in contact with bowel

Clinical Signs

• Retrocaecal appendix: Tenderness may be more lateral/posterior; psoas sign positive; flank/loin tenderness
• Pelvic appendix: Tenderness may be minimal anteriorly; rectal/vaginal examination reveals tenderness; diarrhoea and urinary symptoms more common
• Pre-ileal/post-ileal: May cause diarrhoea due to proximity to small bowel

Differential Diagnosis

• Acute gastroenteritis (most common mimic - but vomiting/diarrhoea precede pain)
• Mesenteric lymphadenitis (colicky pain, cervical lymph nodes)
• Meckel's diverticulitis (clinically identical but may be central/left-sided)
• Intussusception (age <2 years, palpable mass)
• Henoch-Schönlein purpura (ecchymotic rash, normal platelets, microscopic haematuria)
• Right basal pneumonia (high fever, pleural signs, chest X-ray diagnostic)

• Terminal ileitis (Crohn's / Yersinia - history of cramping, weight loss, diarrhoea)
• Perforated peptic ulcer
• Right ureteric colic
• Acute cholecystitis (high, more lateral)
• Psoas abscess

• Ruptured ectopic pregnancy (ALWAYS exclude - do hCG)
• Mittelschmerz (mid-cycle, resolves quickly)
• Torsion/rupture of ovarian cyst
• Acute salpingitis/PID (bilateral, vaginal discharge, cervical excitation)
• Endometriosis

Scoring Systems

Investigations

• WBC: Leucocytosis (10,000-18,000) with neutrophilia is typical. Normal WBC does not exclude appendicitis
• CRP: Elevated; more sensitive than WBC in later presentations
• Urine dipstick: 20-30% may show mild pyuria or haematuria (inflamed appendix near ureter/bladder) - does NOT exclude appendicitis
• Pregnancy test (hCG): Mandatory in all women of childbearing age
• Ultrasound: Operator-dependent; useful to exclude gynaecological pathology. Shows non-compressible tubular structure >6 mm in diameter
• CT scan (gold standard for adults): Sensitivity ~95%, specificity ~95%. Shows enlarged, enhancing appendix, periappendiceal fat stranding, faecolith. Preferred when diagnosis is uncertain
• MRI: Preferred in pregnancy (no radiation), useful in children

Risk Factors for Perforation

• Extremes of age (young children, elderly)
• Delay in presentation / diagnosis
• Faecolith present
• Immunocompromise
• Pelvic or retrocaecal position (delayed diagnosis)

3. MANAGEMENT

Preoperative

• IV fluids, NBM, analgesia (opiates do not mask signs and should not be withheld)
• IV antibiotics (reduce wound infection and intra-abdominal sepsis)
• Anti-emetics, DVT prophylaxis

Non-operative (Antibiotic) Treatment

• Increasingly supported by evidence for uncomplicated appendicitis
• Short-term resolution in ~70% of adults and ~90% of children
• Failure rate is high (~30% at 1 year requiring appendicectomy); patients must be fully counselled
• Patients >40 years treated conservatively must be followed up to exclude underlying malignancy

Appendicectomy (Surgical Treatment)

Open (Conventional) Appendicectomy

• Gridiron (McArthur) incision - at right angles to the spinoumbilical line, centred on McBurney's point
• Lanz (transverse/skin crease) incision - 2 cm below umbilicus, centred on midclavicular-midinguinal line; better cosmesis, easier extension

Figure 76.11 - Lanz (transverse) incision for appendicectomy

• Rutherford Morison incision - extends the gridiron by splitting internal oblique and transversus muscles in the line of the incision; used for retrocaecal appendix or when more access is needed
• Lower midline incision - when diagnosis is in doubt, particularly if peritonitis is present

Laparoscopic Appendicectomy

• Better diagnostic accuracy (especially in women)
• Reduced wound infection and hospital stay
• Faster return to work
• Superior visualisation of the peritoneal cavity

Figure 76.13 - Laparoscopic appendicectomy steps

4. COMPLICATIONS

Postoperative Complications Checklist (Bailey and Love's Summary Box 76.7)

• Examine wound and abdomen for wound abscess
• Perform rectal examination to exclude pelvic abscess
• Examine lungs for pneumonitis or collapse
• Examine legs for deep vein thrombosis
• Check conjunctivae/liver for jaundice and ask about rigors (pyelophlebitis - portal vein thrombosis)
• Examine urine for organisms (pyelonephritis)
• Suspect subphrenic abscess

5. APPENDIX MASS

• Forms when the inflamed appendix becomes walled off by omentum and adjacent bowel
• Standard treatment is the Ochsner-Sherren conservative regime
  • Premise: inflammation is already localised; operating is difficult and may be dangerous
  • IV antibiotics, IV fluids, 4-hourly temperature and pulse, mark mass extent on skin
  • CT scan to identify abscess (drain radiologically if found)
  • Clinical improvement expected in 24-48 hours (~90% resolve)
  • Failure to resolve should raise suspicion of carcinoma or Crohn's disease

• Rising pulse rate
• Increasing or spreading abdominal pain
• Increasing size of the mass
• → Proceed to early laparotomy

6. APPENDICITIS IN SPECIAL SITUATIONS

Appendicitis in Pregnancy

• Most common surgical emergency in pregnancy
• Diagnosis is difficult as the caecum and appendix migrate upward with the uterus
• Pain may be in the right upper quadrant in later pregnancy
• Perforation risk is higher due to delayed diagnosis
• Immediate surgery is indicated (no conservative approach)
• Laparoscopic approach is safe in any trimester (use open Hasson technique)
• Obstetric complications occur in ~5% of pregnant women undergoing abdominal surgery

7. RECURRENT ACUTE APPENDICITIS

• Rare; presents as chronic recurrent lower abdominal pain
• Arises from incomplete, self-limiting obstruction of the appendix lumen
• Attacks every few months; majority culminate in severe acute appendicitis
• Appendix shows thickening and fibrosis from previous inflammation

8. NEOPLASMS OF THE APPENDIX

Classification

1. Neuroendocrine tumours (NETs) - ~30% of appendix neoplasms
   • Slightly more common in females
   • Incidence: 0.15-0.6 per 100,000/year
   • Arise from subepithelial neuroendocrine cells
   • 70% located at the appendix tip
   • Average age at presentation: 40-50 years
   • Mostly asymptomatic; carcinoid syndrome is extremely rare
   • Diagnosed by immunohistochemistry for synaptophysin and chromogranin A; graded 1-3 by Ki-67 index and mitotic rate
   • Treatment: Simple appendicectomy for tumours <2 cm (cured in >95%); right hemicolectomy for tumours >2 cm or with mesoappendiceal invasion
2. Epithelial tumours - most of the remainder
   • Range from low-grade appendiceal mucinous neoplasm (LAMN) to high-grade invasive adenocarcinoma with signet ring features
   • Perforation of a mucinous appendix tumour causes Pseudomyxoma Peritonei (PMP) - dissemination of epithelial cells and mucin production throughout the peritoneum
   • Treatment ranges from appendicectomy (low-grade, confined) to cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP
3. Mesenchymal tumours - rare
   • Lymphoma, neuroma, GIST, Kaposi's sarcoma, granular cell tumour

Management of Unexpected Appendix Tumour at Surgery

• If tumour is <2 cm and resection margins are clear, appendicectomy is sufficient
• If tumour is >2 cm, patient should be referred for right hemicolectomy after histological confirmation

Umbilical Hernia - According to Bailey and Love's Short Practice of Surgery (28th Edition)

DEFINITION

A hernia is an abnormal protrusion of an organ or tissue through an opening in the layer that normally confines it.

ANATOMY AND PATHOGENESIS

• Pregnancy
• Obesity
• Liver disease with cirrhosis and ascites

• Directly through the umbilicus
• In the linea alba immediately adjacent to (most often above) the true umbilicus - these are commonly called paraumbilical hernias; however, under current guidelines, any hernia in the immediate vicinity of the umbilicus can now be called 'umbilical'

UMBILICAL HERNIA IN CHILDREN

Epidemiology

• Occurs in up to 10% of infants
• Higher incidence in premature babies
• Sexes equally affected
• Incidence in black infants is up to 8 times higher than in white infants

Clinical Features

• Appears within a few weeks of birth
• Often symptomless
• Increases in size on crying; assumes a classic conical shape
• Obstruction and/or strangulation is extremely uncommon below the age of 3 years

Treatment

• Common in infants; most resolve spontaneously
• Rarely strangulate

Surgery (in Children)

UMBILICAL HERNIA IN ADULTS

Clinical Features

• Commonly seen in overweight men with a thinned and attenuated midline raphe
• Also in postpartum women with a weakened abdominal wall
• Women are affected more than men
• The bulge is typically slightly to one side of the umbilical depression, creating a crescent-shaped appearance to the umbilicus

Figure 64.18 - A small adult umbilical hernia

Contents

• Small hernias often contain extraperitoneal fat or omentum
• Larger hernias can contain small or large bowel

Why Adult Umbilical Hernias are Dangerous

• Irreducible (incarcerated)
• Obstructed
• Strangulated

Symptoms

• Pain due to tissue tension
• Symptoms of intermittent bowel obstruction
• In large hernias, the overlying skin may become very thin; overlying skin irritation and ulceration may occur
• Spontaneous rupture is extremely rare

TREATMENT IN ADULTS

OPEN UMBILICAL HERNIA REPAIR

• Simple suture repair, provided the fascia is not closed under tension
• Alternative: darn suture technique - a non-absorbable monofilament suture is criss-crossed across the defect and anchored firmly to the fascia all around

• A transverse incision is made over the hernia
• Hernia sac dissected, opened, contents reduced
• Peritoneum closed
• The defect in the linea alba is extended transversely
• Fascial edges closed in an overlapping style with the superior flap on top - the "waistcoat over trousers" technique
• Non-absorbable sutures used
• Redundant skin may need to be excised for cosmesis

• The Mayo repair remains popular for defects up to 2 cm, but the larger the defect the more tissue tension
• Current evidence advises the use of mesh even in small defects, and certainly for all defects larger than 2 cm, due to high likelihood of recurrence

Figure 64.19 - A massive umbilical hernia, intraoperative view

LAPAROSCOPIC UMBILICAL HERNIA REPAIR

• A camera port and two working ports are placed laterally on the abdominal wall, well away from the defect
• Contents of the hernia are reduced by traction and external pressure
• The falciform ligament above and the median umbilical fold below may need to be taken down to create a smooth, firm surface for mesh placement

Figure 64.20 - Umbilical defect: laparoscopic view before the falciform ligament has been taken down

• A disc of non-adherent mesh designed for intraperitoneal use is introduced and positioned on the undersurface of the abdominal wall, centred on the defect
• Fixed to the peritoneum and posterior rectus sheaths using staples, tacks, or sutures

• Fewer wound complications than open repair
• Allows large pieces of mesh
• Should be considered for obese patients, those with concomitant rectus divarication, and those with multiple ventral hernia defects

• Requires specialised equipment and expensive tissue-separating mesh
• Risk of bowel adhesion, erosion, and fistulation
• Intraperitoneal meshes can cause severe pain lasting 24-48 hours post-op that can mimic peritonitis
• Tacks/sutures used to fix the mesh can be a source of chronic pain

SPECIAL CIRCUMSTANCES

• Women often develop umbilical hernias during pregnancy; may present in the early postpartum period
• There is often a degree of rectus divarication
• Advised to exercise, lose weight, and increase abdominal muscle tone before surgery is considered
• These may resolve completely within a few months
• Strongly recommended to avoid surgery for umbilical hernia repair before or during pregnancy

• Patients with liver cirrhosis have extremely high mortality and morbidity after primary ventral hernia repair, especially with Child's B and C disease
• Patient selection is very important, with appropriate hepatology support if surgery is contemplated
• Fascial repair is best done with fine continuous sutures to minimise the risk of postoperative ascites leakage

EMERGENCY REPAIR OF UMBILICAL HERNIA

• Large hernias are often multiloculated - there may be strangulated bowel in one component while other areas appear clinically soft and non-tender
• Most emergency repairs are performed by open surgery
• In the presence of established strangulation, mesh should be avoided (risk of infection is too high)
• The focus of the emergency operation is to deal with the strangulated tissue
• A suture repair is advised, with a more definitive repair to be performed at a later date if necessary

SUMMARY TABLE