GC203 The Child Needs An Operation Common Emergencies And Surgery In Childhood
An overview of common pediatric surgical emergencies and elective procedures, covering the recognition, initial management, and referral of conditions such as appendicitis, intussusception, pyloric stenosis, hernias, and undescended testes in childhood.
The Child Needs an Operation: Common Emergencies and Surgery in Childhood
This GC 203 lecture by Prof. Kenneth Wong covers the breadth of paediatric surgery — both elective and emergency conditions — that a medical student must know for the Fourth Summative Exam. The lecture is structured in two halves:
- Elective paediatric surgical conditions: Phimosis/circumcision, inguinal hernia & hydrocele, undescended testes, common benign and malignant solid tumours.
- Common emergency paediatric operations: Testicular torsion, foreign body ingestion, acute appendicitis, scald/burn, and intussusception.
Why this matters: Paediatric surgery questions appear frequently in MCQ, SAQ, and minicase formats. The 2023 Fourth Summative Minicase was an entire intussusception case (Case Two, all 4 sections). Understanding the first-principles embryology (patent processus vaginalis, testicular descent) and pathophysiology (vascular compromise in torsion, telescoping in intussusception) is what separates a pass from a distinction.
Learning Objectives (inferred from slides):
- Understand indications and complications of circumcision
- Differentiate inguinal hernia from hydrocele and manage appropriately
- Know the reasons, timing, and approach to orchidopexy
- Classify and manage benign and malignant paediatric tumours
- Recognize and manage the five key paediatric surgical emergencies
Part 1: Elective Paediatric Surgical Conditions
Non-retractable foreskin is common: ~50% at 5 years, decreasing by ~10% per year. Circumcision is rarely needed before 4 years of age. [1]
Why is phimosis normal in young children? At birth, the foreskin is naturally adherent to the glans (physiological phimosis). As the child grows, spontaneous separation occurs through intermittent erections and keratinization. This is why you should NOT force retraction in a toddler — it causes pain, tearing, and scarring, potentially converting physiological phimosis into pathological phimosis (cicatricial).
Indications for circumcision: [1]
- Recurrent balanitis (repeated infection under the foreskin → scarring → worsening phimosis cycle)
- Balanitis xerotica obliterans (BXO) (white, sclerotic ring at the prepuce tip — the paediatric equivalent of lichen sclerosus; progressive and will NOT resolve spontaneously)
- Religious (relative indication)
High Yield – BXO
BXO is a pathological phimosis that will not resolve with steroid cream or time. It is the one absolute indication for circumcision in children. Look for a white, thickened, non-retractile foreskin tip on exam descriptions.
What about topical steroids? Not explicitly mentioned in the lecture slides, but in current practice, a trial of topical betamethasone 0.05% for 4–6 weeks is often tried for physiological phimosis before considering surgery. For BXO, topical steroids may temporarily soften but do not cure — circumcision is definitive.
Complications of circumcision: [1]
- Bleeding (most common immediate complication)
- Infection (rare)
- Meatal stenosis (loss of protective foreskin → chronic meatal irritation → stenosis; more common in neonatal circumcision)
- Excessive removal (too much skin removed → painful erections later, buried penis)
Why meatal stenosis? The foreskin protects the meatus from ammonia in wet nappies. After circumcision, chronic chemical irritation leads to meatal narrowing. This is why meatal stenosis is more common with neonatal circumcision (longer exposure period in nappies).
Both have the same aetiology — patent processus vaginalis (PPV). [1]
Embryology first-principles: During fetal development, the testis descends from the posterior abdominal wall through the inguinal canal into the scrotum, dragging a diverticulum of peritoneum (the processus vaginalis) with it. Normally, the processus vaginalis obliterates after birth. If it remains patent:
- Wide PPV → bowel/omentum can enter → inguinal hernia (indirect)
- Narrow PPV → only peritoneal fluid tracks down → communicating hydrocele
- Closed PPV with residual fluid → non-communicating hydrocele
Hernias are common in neonates (30% in premature babies). Bilateral hernias increase with decreasing age. Bowel strangulation is a potential complication. [1]
Why more common in prematurity? The processus vaginalis closes late in gestation (typically around 36–40 weeks). Premature babies are delivered before this closure, so the processus remains patent.
Why bilateral hernias are more common in younger children? In very young infants, both processus vaginalis may not have had time to close. As the child ages, one side may close spontaneously, making unilateral presentation more likely.
Natural History and Treatment: [1]
| Inguinal Hernia | Hydrocele | |
|---|---|---|
| Natural history | Persists; risk of incarceration | Most resolve spontaneously |
| Treatment | Herniotomy (early) | Observe; high ligation if persists |
High Yield – Hernia vs Hydrocele Management
Inguinal hernia = operate early (herniotomy) because of the risk of incarceration/strangulation. A strangulated hernia in a neonate can rapidly lead to bowel necrosis and testicular ischaemia.
Hydrocele = observe until 1–2 years because most communicating hydroceles resolve as the PPV obliterates. If it persists beyond 2 years or is symptomatic, perform high ligation of the PPV (same principle as herniotomy).
Key exam discriminator: In paediatric inguinal hernia, the operation is herniotomy (ligation and division of the hernial sac at the internal ring) — NOT herniorrhaphy (mesh repair). Children have strong tissues and do NOT need mesh. Using "herniotomy" in your answer is a clear signal you know the difference between paediatric and adult hernia repair.
Clinical differentiation:
- Hernia: reducible inguino-scrotal swelling that increases with crying/straining; you can get above it; does NOT transilluminate (if contains bowel)
- Hydrocele: non-tender, transilluminant scrotal swelling; you CANNOT get above a communicating hydrocele that extends to the inguinal canal
Incidence: 3% of male neonates; higher in premature babies. Presents with empty and hypoplastic scrotum. [1]
Why is the scrotum hypoplastic? The scrotum develops in response to the presence of the testis. Without the testis descending into the scrotum, it lacks the trophic stimulus for normal development.
Location classification: [1]
- Undescended: intra-abdominal, inguinal (along the normal path of descent but arrested)
- Ectopic: perineal, femoral (deviated from the normal path)
Important distinction: An undescended testis is along the normal descent pathway but stopped early. An ectopic testis has left the normal pathway entirely. This matters because ectopic testes are usually palpable but in unexpected locations, while truly intra-abdominal undescended testes may be impalpable.
Retractile testis (not on slide but commonly tested): A normally descended testis that is pulled up by an overactive cremasteric reflex. It can be manually brought to the scrotum and stays there. This does NOT need surgery — just reassurance and follow-up.
Reasons for orchidopexy (around 1 year of age): [1]
- Improve possible sub-fertility (heat damage to germ cells begins early)
- Improve tumour detection (palpable testis is easier to examine)
- Reduce risk of physical injury (testis against pubic bone is vulnerable)
- Reduce risk of torsion (abnormal attachment predisposes to torsion)
High Yield – Why Operate at 1 Year?
Germ cell degeneration begins as early as 6 months in an undescended testis due to the higher intra-abdominal/inguinal temperature compared to the scrotum (which is 2–3°C cooler than core body temperature). Operating around 1 year balances allowing time for spontaneous descent against preventing irreversible germ cell damage. Orchidopexy does NOT eliminate the malignancy risk — it merely makes the testis palpable for self-examination.
Management: [1]
- Palpable testis → orchidopexy
- Impalpable testis → ? Absence ? Intra-abdominal → further investigations needed
- Ultrasound, MRI
- Laparoscopy (gold standard for impalpable testis — diagnostic AND therapeutic)
Why laparoscopy for impalpable testis? Ultrasound and MRI have limited sensitivity for intra-abdominal testes. Diagnostic laparoscopy directly visualizes whether the testis is intra-abdominal (and can proceed to orchidopexy, possibly staged Fowler-Stephens) or whether blind-ending vessels indicate testicular absence/vanishing testis.
4. Benign Tumours
Types: [1]
- Cystic hygroma (lymphatics)
- Haemangioma (blood vessels)
- Dermoid / Epidermoid (soft tissue)
- Vascular Malformations
Maldevelopment of lymphatics. Cervical 70%, Axillary 20%. [1]
First principles: Cystic hygromas (now often called lymphatic malformations) arise from failure of the primitive lymphatic system to connect with the venous system. Lymph accumulates in dilated lymphatic channels, forming multiloculated cystic masses. The head/neck is the most common site because the jugular lymph sacs (which should drain into the jugular veins) are the largest.
Complications: Infection, Haemorrhage, Pressure (on airway/vessels) [1]
Treatment depends on type — macrocystic vs microcystic: [1]
- Surgical excision
- Sclerotherapy (e.g. OK-432, tetracycline, bleomycin)
- Sirolimus? (emerging therapy — mTOR inhibitor with anti-lymphangiogenic properties)
Why does type matter? Macrocystic lesions respond well to sclerotherapy because the sclerosant can fill and ablate the large cysts. Microcystic lesions are difficult to inject and typically require surgical excision. Mixed lesions often need a combined approach.
Common condition. Examples: [1]
- Salmon patch (naevus simplex — flat, pink, midline; fades spontaneously)
- Port-wine stain (naevus flammeus — flat, dark red, does NOT fade; associated with Sturge-Weber syndrome if in V1 distribution)
- Strawberry naevus (infantile haemangioma — raised, red, appears in first weeks of life; proliferates then involutes)
Important Classification Note
The lecture groups these together, but for accuracy: Salmon patch and port-wine stain are actually vascular malformations (present at birth, do not proliferate), while strawberry naevus (infantile haemangioma) is a true vascular tumour (not present at birth, proliferates then involutes). For exam purposes, follow the GC slide grouping, but be aware of this distinction if a question probes deeper.
Complications: Trauma, Haemorrhage, Cardiac failure (can lead to hydrops in utero) [1]
Why cardiac failure? Large haemangiomas act as arteriovenous shunts, increasing venous return to the heart. If the shunt volume is large enough, it causes high-output cardiac failure. In utero, this manifests as hydrops fetalis (fluid overload).
Treatment: [1]
- Conservative — most resolve after puberty (except venous malformation)
- Steroids or vincristine
- Propranolol — blocks VEGF
- Excision
- Sclerotherapy
- Laser
High Yield – Propranolol for Infantile Haemangioma
Propranolol is now the first-line medical therapy for problematic infantile haemangiomas (those threatening vision, airway, or causing ulceration/disfigurement). It works by vasoconstriction (immediate effect), inhibition of VEGF/bFGF expression (anti-angiogenesis), and triggering apoptosis of endothelial cells. The GC slide says it "blocks VEGF" — this is the mechanism to quote in exams.
5. Malignant Tumours
General principles: Diagnosis → Neoadjuvant Chemotherapy → Surgery [1]
This is a critical concept: most paediatric solid tumours are chemo-sensitive. The strategy is often to biopsy/confirm histology first, shrink the tumour with chemotherapy, then perform definitive surgical resection. This is different from many adult cancers where surgery is the primary treatment.
Usually seen antenatally. Mostly benign when diagnosed but can turn malignant. High AFP. Large tumours can cause hydrops. CT scan post-natal to delineate tumour. Surgical excision with coccyx usually cures. [1]
Why excise the coccyx? SCTs arise from totipotent cells at the Hensen's node (coccyx area). If the coccyx is left behind, residual totipotent cells can give rise to recurrence, with potential for malignant transformation (yolk sac tumour/endodermal sinus tumour). The malignancy risk increases with age at diagnosis — neonatal SCTs are overwhelmingly benign, but those diagnosed later have higher malignancy rates.
AFP as a tumour marker: AFP is normally very high in neonates (physiological) and falls to adult levels by ~8 months. In SCT, a persistently elevated or rising AFP indicates malignant elements (yolk sac tumour component).
Most common solid childhood tumour. Arises from adrenal gland or sympathetic chain. Clinical picture: mass, weight loss, anorexia. Can secrete HVA and VMA. Associated with n-myc oncogene. [1]
First principles: Neuroblastoma arises from neural crest cells (which form the sympathetic nervous system and adrenal medulla). Because neural crest cells are distributed along the entire sympathetic chain, neuroblastoma can arise anywhere from the neck to the pelvis, but ~40% arise in the adrenal gland.
HVA and VMA: Homovanillic acid and vanillylmandelic acid are catecholamine metabolites. Since neuroblastoma cells produce catecholamines (like their normal adrenal medullary counterparts), elevated urinary HVA/VMA are diagnostic markers. This is a classic "which tumour marker" exam question.
n-myc amplification: This is the most important prognostic factor. n-myc amplification indicates aggressive biology, poor prognosis, and need for intensive therapy — regardless of stage.
Treatment: Surgery, Chemotherapy. Prognosis depends on stage and age. Overall 5-year survival ~60%. [1]
Age matters: Children < 18 months have significantly better prognosis. Stage 4S (a special stage unique to neuroblastoma in infants < 12 months with specific metastatic pattern to skin, liver, and bone marrow) can spontaneously regress.
Presents as abdominal mass. May have haematuria, weight loss, anaemia. 5% bilateral. Associated with WT1, WT2 genes. [1]
Classic presentation: A mother notices her child's belly is getting bigger during bath time. On examination, there is a smooth, non-tender flank mass that does NOT cross the midline (unlike neuroblastoma which often crosses midline).
Treatment: Surgical resection. Good response to chemotherapy. 5-year survival now > 90%. [1]
WT1 and WT2 genes: These are tumour suppressor genes on chromosome 11. WT1 mutations are also associated with WAGR syndrome (Wilms, Aniridia, Genitourinary malformations, mental Retardation) and Denys-Drash syndrome. WT2 is associated with Beckwith-Wiedemann syndrome (macroglossia, omphalocele, macrosomia, hemihypertrophy).
| Feature | Neuroblastoma | Wilms' Tumour |
|---|---|---|
| Origin | Neural crest (adrenal/sympathetic chain) | Metanephric blastema (kidney) |
| Peak age | < 2 years | 3–4 years |
| Tumour marker | Urinary HVA/VMA | None specific (but check renal function) |
| Crosses midline? | Often yes | Rarely (unless bilateral) |
| Calcification on imaging | Common (90%) | Uncommon |
| Genetics | n-myc amplification (poor prognosis) | WT1, WT2 genes |
| 5-year survival | ~60% overall | > 90% |
| Key exam tip | "Most common solid tumour of childhood" | "Presents as abdominal mass in a toddler" |
Commonest malignant liver tumour in children. Good response to chemotherapy. Presents as hepatomegaly. Raised AFP in serum. [1]
Associated with Beckwith-Wiedemann syndrome. Tumour marker is AFP. Overall survival 70%; Stage 1 > 90%, Stage 4 20%. Complete resection is critical; pre-op chemo can convert an unresectable tumour to resectable. [1]
Liver transplantation for hepatoblastoma: Primary LTx 82% 6-year survival, rescue LTx 30%. Total hepatectomy and liver transplant is a very good therapeutic option for selected patients with hepatoblastoma. [1]
High Yield – Hepatoblastoma Key Facts
- AFP is the tumour marker (same as SCT — both have yolk sac tumour elements)
- Beckwith-Wiedemann syndrome association (also associated with Wilms')
- Complete resection is the key to cure — neoadjuvant chemo shrinks tumour
- Liver transplantation is an option for unresectable tumours with excellent outcomes (82% at 6 years for primary LTx)
Part 2: Common Emergency Paediatric Operations
The testicle twists upon the spermatic cord, leading to arterial occlusion. Presents as sudden onset testicular pain. Incidence 1:4000 males < 25 years. [1]
Pathophysiology: The "bell-clapper" deformity (horizontal lie of testis with inadequate fixation to the tunica vaginalis) allows the testis to rotate freely within the tunica. Torsion occludes first the venous outflow (causing congestion and oedema), then progresses to arterial occlusion (causing ischaemia and infarction). The degree and duration of torsion determine salvageability.
Time window:
| Duration | Salvage Rate |
|---|---|
| < 6 hours | ~90–100% |
| 6–12 hours | ~50% |
| > 24 hours | ~10% or less |
Differential diagnosis: [1]
- Epididymo-orchitis
- Torsion of testicular appendages (appendix testis or appendix epididymis — "blue dot sign")
- Traumatic haematoma
Key clinical signs differentiating torsion from epididymo-orchitis:
- Torsion: sudden onset, absent cremasteric reflex, high-riding testis with abnormal lie, negative Prehn's sign (lifting scrotum does NOT relieve pain)
- Epididymo-orchitis: more gradual onset, positive cremasteric reflex, positive Prehn's sign (pain relieved by elevation), may have dysuria/urethral discharge
Confirming diagnosis: Doppler and nuclear scan may help. Clinical findings are the mainstay of diagnosis due to the relatively short time window (6 hours). Always explore if clinically suspicious. [1]
Critical Principle
Never delay surgical exploration for imaging if clinical suspicion is high. A normal Doppler does NOT rule out intermittent torsion or early partial torsion. If in doubt, explore. The worst outcome is a negative exploration (minor morbidity). The worst outcome of NOT exploring is testicular loss.
Surgical management (not explicitly on slide but essential knowledge):
- Bilateral fixation (orchidopexy): Even if only one side is torted, the bell-clapper deformity is usually bilateral. Both testes must be fixed to the dartos fascia with non-absorbable sutures.
- Orchidectomy: If the testis is non-viable at exploration.
Very common problem in children worldwide (4% of children have history). Peak incidence 9 to 24 months. More common in boys than girls. Fish bones and coins most common in HK. [1]
Why 9–24 months? This is the "oral phase" of development — children explore their environment by putting things in their mouths. They have enough motor coordination to pick up small objects but insufficient judgement to avoid swallowing them.
Management: [1]
- Most foreign bodies will pass
- Initial conservative management
- Endoscopy if symptoms persist or specific FB sensation
- Laparotomy only needed rarely
When is urgent endoscopy needed? (not on slide but high-yield)
- Button/disc batteries in oesophagus: Can cause liquefactive necrosis within 2 hours → oesophageal perforation → mediastinitis. This is a TRUE emergency.
- Sharp objects (open safety pins, needles): Risk of perforation
- Magnets (≥ 2 magnets or magnet + metal): Can attract through bowel walls → pressure necrosis → perforation/fistula
- Oesophageal impaction with complete obstruction (drooling, unable to swallow)
Conservative management specifics: Serial abdominal X-rays to track progress. Most coins in the stomach will pass within 1–2 weeks. If a coin is stuck in the oesophagus, it should be removed endoscopically.
Most common acute paediatric surgical condition. Peak age between 4 and 15 years. "Closed loop" obstruction as aetiology? [1]
Pathophysiology: Luminal obstruction (by faecolith, lymphoid hyperplasia, or rarely parasites) → continued mucus secretion → increased intraluminal pressure → venous congestion → bacterial invasion of the wall → transmural inflammation → perforation. The "closed loop" concept explains why the appendix is particularly vulnerable — it has a single opening, so any obstruction creates a closed space.
Clinical presentation — VAGUE!! Central abdominal pain, anorexia, shifting pain. [1]
Why vague in children? Young children cannot localize or articulate their pain well. The classic migratory pain (periumbilical → RIF) relies on the patient being able to describe the progression. In young children, you may only see irritability, refusal to eat, and drawing up of legs.
Signs: pyrexia, guarding, localised tenderness (no rebound), Rovsing's sign, psoas and obturator signs. [1]
Why 'No Rebound' on the Slide?
The slide says "no rebound" — this likely means rebound tenderness is NOT a reliable sign in children (they tense up with any palpation, making it difficult to interpret). Some interpret this as the slide advising against testing for rebound tenderness in children due to its poor specificity and the distress it causes. Focus on guarding and localised tenderness as more reliable signs.
Clinical signs explained:
- Rovsing's sign: Pain in the RIF when palpating the LIF (peritoneal irritation transmitted)
- Psoas sign: Pain on extension of right hip (retrocaecal appendix lying on psoas muscle)
- Obturator sign: Pain on internal rotation of flexed right hip (pelvic appendix near obturator internus)
Investigations: Leucocytosis, plain XR (rarely), USG, CT (beware of high radiation). [1]
Why USG first in children? No ionizing radiation! Children are more susceptible to radiation-induced cancers (longer remaining lifespan for cancer to develop). USG has good sensitivity in experienced hands and can show a non-compressible, dilated (>6mm) appendix. CT is reserved for equivocal cases and should be used judiciously — the GC slide explicitly warns about high radiation.
Differential diagnosis: mesenteric adenitis, cholecystitis, Henoch-Schönlein purpura… [1]
Key DDx in children:
| Condition | Differentiating Feature |
|---|---|
| Mesenteric adenitis | Often follows viral URTI; diffuse rather than localised tenderness; fever may be higher than expected for degree of abdominal signs |
| Henoch-Schönlein purpura | Purpuric rash on buttocks/legs; joint pain; haematuria; abdominal pain from vasculitis of bowel wall |
| Intussusception | Younger age (< 2 years); colicky pain; "red currant jelly" stools |
| Meckel's diverticulitis | Clinically indistinguishable from appendicitis; found at operation |
| Urinary tract infection | Dysuria, frequency; positive urinalysis |
Scalding is the most common form of burn. Increased incidence in toddlers due to newfound mobility. Rarely due to non-accidental cause. [1]
Why toddlers? They can now reach up and pull things (hot cups, pots) down onto themselves but lack understanding of danger. The typical scenario: child pulls a cup of hot tea off a table, spilling it over face/chest/arm.
Admission criteria: [1]
- > 10% burn
- Facial burn
- ? Non-accidental injury (NAI)
Non-Accidental Injury — Red Flags
Always consider NAI in paediatric burns. Red flags include:
- Pattern burns: glove/stocking distribution (forced immersion), cigarette burns (circular, uniform depth), iron-shaped burns
- Delay in presentation: parents waited hours/days before seeking help
- Inconsistent history: story doesn't match the burn pattern or the child's developmental stage
- Other signs of abuse: bruises of different ages, fractures, failure to thrive The slide uses "?" before NAI — this means it should be a consideration in every paediatric burn case.
Additional admission criteria (standard practice, not on slide): burns to hands, feet, perineum, genitalia, major joints; circumferential burns; inhalational injury; electrical/chemical burns; burns in children with significant comorbidities.
Hospital management: [1]
- Fluid replacement — intravenous or oral
- Daily dressing via aseptic technique
- Regular wound swab — treat infection
- ? Skin grafting
Fluid resuscitation in paediatric burns: The Parkland formula (4 mL × body weight in kg × % TBSA burned) is commonly used, with half given in the first 8 hours and the rest over the next 16 hours. Importantly, children also need maintenance fluids on top of the burn resuscitation fluid (unlike adults). The modified Lund and Browder chart should be used for TBSA estimation in children (the "Rule of Nines" overestimates head surface area and underestimates leg surface area in young children).
Invagination of a portion of intestine into adjacent portion. Male > female. Peak incidence 4 to 24 months. May be preceded by viral infection. [1]
Pathophysiology: A lead point (often hypertrophied Peyer's patches from a preceding viral infection in children) gets caught by peristalsis and drags the proximal bowel (intussusceptum) into the distal bowel (intussuscipiens). As the bowel telescopes, the mesentery is dragged in too → venous congestion → oedema → arterial compromise → ischaemia → necrosis → perforation.
Why "red currant jelly" stool? The venous congestion and mucosal sloughing produce a mix of blood and mucus that has the characteristic appearance. This is a LATE sign indicating significant bowel compromise.
Clinical presentation: [1]
- Colicky abdominal pain
- Vomiting
- Crying baby
- "Red currant jelly" per rectum
- Abdominal mass
Classic triad to remember: Colicky pain + vomiting + bloody stools. But the full triad is present in only ~20% of cases. The most consistent finding is paroxysmal crying/pain (the child draws up legs, screams, then has a pain-free interval and may even fall asleep — then the cycle repeats).
"Sausage-shaped mass": Typically palpable in the right upper quadrant (because ileocolic intussusception progresses along the colon). The RIF may feel "empty" (Dance's sign — absence of normal caecal fullness).
Investigations: [1]
- AXR — may show dilated small bowels and a mass
- Ultrasound — usually diagnostic in experienced hands
- Contrast enema — rarely done now
USG findings: The classic "target sign" (donut sign) on transverse section — concentric rings of bowel-within-bowel. On longitudinal section, the "pseudo-kidney sign". USG sensitivity and specificity approach 100% in experienced hands.
Why is contrast enema rarely done now? USG has largely replaced contrast enema for diagnosis. Contrast enema is now mainly therapeutic (hydrostatic reduction) rather than diagnostic.
Management: [1]
- Resuscitation — NPO, IV replacement, nasogastric tube decompression
- Hydrostatic reduction under USG / fluoroscopy
- Surgery for open reduction / laparoscopic reduction
High Yield – Intussusception Management Algorithm
- Resuscitate first: IV access, fluid bolus, NGT for decompression, NPO
- Non-operative reduction (first-line if no contraindications): Hydrostatic (saline) or pneumatic (air) under USG or fluoroscopy guidance
- Contraindications to non-operative reduction: Peritonitis, perforation, prolonged duration with hemodynamic instability, shock
- Surgery if non-operative reduction fails or is contraindicated: Open or laparoscopic manual reduction; resection + primary anastomosis if non-viable bowel or pathological lead point found
- Post-reduction: Observe 12–24 hours for recurrence (~5–10% recurrence rate)
Recurrence and pathological lead points [3]: In the 2023 minicase, the parents asked about recurrence and pathological lead points. Key points:
- Recurrence rate after successful non-operative reduction is ~5–10%
- In children < 2 years with typical presentation, pathological lead points are uncommon (~5%)
- In children > 2 years (especially > 5 years), pathological lead points are more common and should be actively sought (Meckel's diverticulum, polyps, lymphoma, HSP) [2]
Exam Intelligence
| Trap | Correct Approach |
|---|---|
| "Herniotomy" vs "herniorrhaphy" for paediatric hernia | Herniotomy (no mesh in children) |
| Confusing hydrocele with hernia management | Hydrocele: observe first. Hernia: operate early |
| Ordering CT for paediatric appendicitis as first-line | USG first (radiation concern in children) |
| Delay exploration for testicular torsion to get a Doppler | Never delay — clinical diagnosis, explore immediately |
| Thinking circumcision is needed for all phimosis < 4 years | No — physiological phimosis resolves spontaneously |
| Forgetting to fix BOTH testes in torsion surgery | Bell-clapper deformity is bilateral → bilateral orchidopexy |
| Mixing up neuroblastoma and Wilms' tumour markers | Neuroblastoma = HVA/VMA. Wilms' = no specific tumour marker. Hepatoblastoma/SCT = AFP |
| Forgetting coccyx excision in SCT resection | Must remove coccyx to prevent recurrence |
| Applying Rule of Nines to a child's burn | Use Lund and Browder chart in children |
| Assuming all haemangiomas need treatment | Most involute spontaneously; treat only if complicated |
Neuroblastoma vs Wilms' tumour: See table above — this is a perennial exam favourite.
Hernia vs Hydrocele in an infant:
- Both = inguinoscrotal swelling
- Hernia: irreducible or changes size with crying; get above it is difficult; risk of strangulation
- Hydrocele: transilluminant; non-tender; fluctuates slowly with communicating type
Past Paper Questions
Stem: A 7-year-old boy with fever and increasing abdominal pain for two days. No vomiting or diarrhoea. Diffuse abdominal tenderness and guarding in the RLQ. Temperature 39°C. WCC 15 × 10⁹/L.
(a) Most likely diagnosis? (2 marks) Answer: Acute appendicitis (with possible perforation given 2-day history and high fever)
(b) Most appropriate imaging modality (1 mark) + three reasons (3 marks) Answer: Ultrasound abdomen
- No ionizing radiation (important in a child)
- Can visualize inflamed appendix (non-compressible, > 6mm diameter)
- Can identify complications (abscess, free fluid)
- Can exclude other DDx (mesenteric adenitis, ovarian pathology)
(c) Two possible imaging findings (2 marks) Answer: (i) Non-compressible, dilated appendix > 6 mm; (ii) Appendicolith; (iii) Periappendiceal fluid collection; (iv) Target sign on cross-section
(d) Alternative cross-sectional imaging especially in an obese child (2 marks) Answer: CT abdomen with contrast (better penetration through adipose tissue; GC slide cautions about high radiation — mention this awareness)
This was a full 4-section minicase on a 20-month-old baby girl with vomiting, RIF tenderness, vague RIF mass, and red currant jelly stool on DRE = Intussusception.
Section 1, Q1: List five possible GI disorders for vomiting in a 20-month-old. Markscheme: Intussusception, acute appendicitis, incarcerated inguinal hernia, gastroenteritis, intestinal obstruction (adhesions/malrotation), Meckel's diverticulum, Hirschsprung's disease
Section 1, Q2: Five specific history questions. Markscheme: Nature of vomiting (bilious?), character of pain (colicky? intermittent?), stool colour/consistency (bloody? mucoid?), preceding viral illness, fever, passage of flatus, previous similar episodes, oral intake
Section 1, Q3: Four clinical features of moderate-severe dehydration. Markscheme: Sunken eyes, sunken anterior fontanelle, dry mucous membranes, decreased skin turgor, reduced urine output, tachycardia, prolonged capillary refill, lethargy
Section 2, Q4: Most likely diagnosis. Answer: Intussusception
Section 2, Q5: Management including relevant investigations. (21 marks) Markscheme: Resuscitation (NPO, IV fluids, NGT decompression); blood tests (FBC, U&E, group & save); abdominal X-ray (may show dilated loops/soft tissue mass); ultrasound abdomen (confirm diagnosis — target sign); hydrostatic or pneumatic reduction under USG/fluoroscopy guidance; prepare for surgery if non-operative reduction fails; inform parents
Section 3, Q8: Most appropriate management now (USG confirmed intussusception). Answer: Hydrostatic (or pneumatic) reduction under USG/fluoroscopy guidance
Section 3, Q9: Two potential adverse outcomes of the procedure. Answer: (i) Failure of reduction (requiring surgery); (ii) Perforation during reduction
Section 4: Parents ask about recurrence and pathological lead points. Key points: Recurrence rate ~5–10%; pathological lead points uncommon at this age (20 months) but more common if > 2–3 years or recurrent episodes; examples of lead points include Meckel's diverticulum, polyps, lymphoma
GC 205 (Neonatal GI emergencies) [5]: Complements this lecture by covering neonatal conditions (pyloric stenosis, intestinal atresia, malrotation with volvulus, Hirschsprung's disease, NEC). Key overlap: malrotation can present in older children as bilious vomiting — a surgical emergency requiring Ladd's procedure [2].
GC 145 (Critically ill child) [6]: Emphasizes that in children, cardiac output depends on heart rate (low stroke volume due to stiff cardiac muscle) — bradycardia is ominous in a child. This is relevant when managing any paediatric surgical emergency with haemodynamic compromise [7].
Adrian Lui Pediatrics Notes [7]: Provides detailed vital sign norms and PEWS scoring. Key point: children compensate well haemodynamically until they suddenly decompensate (hypotension is a LATE sign in paediatric shock). Always look for tachycardia, prolonged capillary refill, and altered consciousness BEFORE blood pressure drops.
Case 6 - Paediatric Abdominal Pain [8]: Study guide specifically on intussusception with HKU references, including Wong et al. (2015) on the HKU experience with childhood intussusception and predictors for bowel resection.
High Yield Summary
Elective conditions: (1) Phimosis — circumcision rarely needed < 4 years; indications are recurrent balanitis, BXO, religious. (2) Inguinal hernia/hydrocele — both from PPV; hernia = herniotomy early, hydrocele = observe. (3) Undescended testes — orchidopexy at ~1 year for fertility, tumour detection, injury prevention, torsion risk. (4) Benign tumours — cystic hygroma (cervical 70%), haemangioma (propranolol for infantile type). (5) Malignant tumours — neuroblastoma (HVA/VMA, n-myc), Wilms' (WT1/WT2, > 90% survival), hepatoblastoma (AFP, Beckwith-Wiedemann, liver transplant option), SCT (excise with coccyx).
Emergency conditions: (1) Testicular torsion — 6-hour window, always explore if suspicious. (2) Foreign body — most pass; endoscopy if symptomatic; button batteries are urgent. (3) Appendicitis — most common acute paediatric surgical condition; USG first (not CT); vague presentation in children. (4) Scald/burn — admit if > 10%, facial, or ?NAI; use Lund-Browder in children. (5) Intussusception — peak 4–24 months; colicky pain + vomiting + red currant jelly; USG diagnosis (target sign); hydrostatic reduction first, surgery if fails.
Active Recall - Lecture Notes
[1] Lecture slides: GC 203. The child needs an operation Common emergencies and surgery in childhood.pdf (all pages) [2] Senior notes: MBBS Final MB (Pediatrics) (Felix PY Lai).pdf (pp. 348–367) [3] Past papers: 2023 Fourth Summative Minicase.pdf (Case Two, pp. 10–15) [4] Past papers: 2016 Fourth Summative SAQ.pdf (Q9, p. 5) [5] Lecture slides: GC 205. The newborn baby is vomiting repeatedly Neonatal intestinal obstruction and other GI emergencies.pdf [6] Lecture slides: GC 145. A critically ill child childhood medical emergencies.pdf (p. 48) [7] Senior notes: Adrian Lui Pediatrics Notes.pdf (p. 487) [8] Case 6 - Abd-Pain (Paediatric).pdf (p. 9)
GC202 Surgery May Cure Your Cancer Surgical Oncology - Notes
Surgical oncology is the branch of surgery dedicated to the diagnosis, staging, and curative or palliative resection of solid tumors, often integrated with multimodal cancer therapies.
GC204 The Newborn Baby Cannot Breathe Oesophageal Atresia, Diaphragmatic Hernia, And Other Surgery Of Lung
Neonatal respiratory distress caused by congenital surgical conditions such as oesophageal atresia, congenital diaphragmatic hernia, and other thoracic anomalies that obstruct or compromise the airway and lung function, requiring urgent surgical intervention.