Pediatric Surgery and Urology
This domain mixes congenital anomalies, paediatric abdominal emergencies and common urological procedures. Paediatric stems reward attention to age, feeding history and fluid status; urology stems test the sequence of investigation and the cost of delay.
Neonatal and infant emergencies
- Hypertrophic pyloric stenosis: 3–6 weeks, first-born boys, projectile non-bilious vomiting, visible gastric waves, olive-shaped mass. Ultrasound shows pyloric muscle thickness over 3 mm and canal length over 14 mm. Biochemistry is hypochloraemic, hypokalaemic metabolic alkalosis with paradoxical aciduria. Correct fluids and potassium before Ramstedt pyloromyotomy.
- Intussusception: 6–36 months, colicky pain, drawing up legs, redcurrant stool, sausage-shaped mass; ultrasound shows a target sign. Air or contrast enema reduces it if the child is stable and there is no peritonitis.
- Malrotation with volvulus: bilious vomiting in a neonate is a surgical emergency; urgent laparotomy and Ladd procedure.
- Hirschsprung disease: delayed meconium, abdominal distension, transition zone on contrast enema, confirmed by rectal biopsy showing absent ganglion cells; definitive pull-through later.
Paediatric urology
- Testicular torsion: sudden pain, high testis, absent cremasteric reflex; Doppler is supportive but not exclusionary. Explore within 6 hours and fix both testes.
- Cryptorchidism: orchidopexy between 6 and 18 months to reduce infertility and malignancy risk.
- Hypospadias: never circumcise before repair, because the foreskin is used in reconstruction; repair at 6–18 months.
- Posterior urethral valves: male neonate with bilateral hydronephrosis and poor stream; catheterise, correct electrolytes, then ablate valves.
- Vesicoureteric reflux graded I–V; grade V needs surgical consideration.
Adult urology essentials
- Benign prostatic hyperplasia: IPSS symptom score, alpha blocker first, TURP for failed medical therapy or complications.
- Prostate cancer: PSA, digital examination, MRI and biopsy; Gleason score and grade group guide treatment.
- Renal stones under 10 mm are candidates for shockwave lithotripsy or ureteroscopy; obstruction with infection needs urgent decompression.
Worked example
A 6-week-old boy has projectile vomiting, a palpable olive and a chloride of 88 mmol/L with bicarbonate 34 mmol/L. This is pyloric stenosis with hypochloraemic alkalosis. Give 0.9% saline with potassium chloride until chloride and bicarbonate normalise and urine output is established, then perform pyloromyotomy; operating on the alkalotic infant risks postoperative apnoea.
Traps that lose marks
Circumcising a boy with hypospadias; delaying exploration for torsion; reducing an intussusception in an unstable child; operating before correcting pyloric stenosis biochemistry.