---

M.S. General Surgery - Paper III (April/May 2018)

---

Question 1 - Injuries to Male Urethra and Management (30 Marks)

Anatomy of Male Urethra (Brief)

• Posterior urethra: Prostatic urethra + Membranous urethra
• Anterior urethra: Bulbar urethra + Penile (spongy) urethra

---

Classification of Urethral Injuries

A. Posterior Urethral Injuries

• High-energy blunt trauma: road traffic accidents, motorcycle collisions, falls, industrial accidents
• Associated with disruption of the pelvic ring (anterior disruption - symphysis pubis and pubic rami fractures)

• Blood at the urethral meatus (most reliable sign)
• Inability to void
• Distended bladder
• High-riding prostate on digital rectal examination (DRE)
• Perineal/scrotal bruising and ecchymosis
• Signs of pelvic fracture

• Retrograde Urethrogram (RUG) is the definitive investigation
• Partial disruption: contrast enters the bladder
• Complete disruption: contrast does not reach the bladder, extravasates outside the urethra
• CT cystogram for associated bladder injuries

• Follow ATLS protocols (Airway, Breathing, Circulation)
• Primary surgical repair is NOT recommended - high rates of complications (incontinence 69%, erectile dysfunction ~50%)
• Suprapubic catheter (SPT) placement is the preferred initial treatment (AUA guidelines) - can be placed even in unstable patients undergoing ORIF of pelvic fracture
• SPT decompresses the bladder, avoids urethral manipulation, and can be placed quickly in unstable patients

• Can be considered for hemodynamically stable patients within the first week
• Performed by two urologists using cystoscopy and fluoroscopy
• Catheter maintained 4-6 weeks
• Even if successful, ~50-69% still develop urethral strictures, but these may be simpler to manage later

• Concurrent rectal or bladder neck injury (to prevent fistula)
• Female patients with PFUI should undergo early primary repair within 7 days

• Most patients develop urethral stricture
• Posterior urethroplasty - the definitive procedure, best performed by reconstructive specialists
• Risk of urethral stricture: 45-100%
• Erectile dysfunction: ~50% of cases
• Urinary incontinence: rare (~5%)

---

• Less common
• Usually associated with severe pelvic fractures or penetrating injuries
• May involve bladder neck

---

B. Anterior Urethral Injuries

• Direct blunt trauma to the perineum
• The bulbar urethra is compressed between the object (bicycle crossbar, fence, etc.) and the pubic arch
• Common in falls astride an object

• Blood at urethral meatus
• Perineal haematoma ("butterfly haematoma" - confined by Colles' fascia, spreading to scrotum, perineum, lower abdomen but NOT the thighs)
• Inability to void
• Swelling and bruising of the perineum

• RUG shows extravasation of contrast in the perineum

• If partial tear: suprapubic catheter + wait for healing + urethroplasty if stricture develops
• If complete tear: suprapubic catheter + delayed urethroplasty at 3 months
• Bulbar urethroplasty (end-to-end anastomosis) has excellent results

---

• Penetrating trauma (stab, gunshot)
• Iatrogenic: catheterization-related injuries (most common cause in hospital setting)
• Blunt trauma to erect penis

• Incidence: 3.2-6.7 injuries per 1000 male patients catheterized
• Risk factors: urethral stricture, prior surgery/radiation, benign prostatic hyperplasia, operator inexperience
• Mechanisms: inflation of catheter balloon within the urethra, creation of false passage, overzealous force
• Consequences: urethral stricture, haematuria, acute urinary retention

• Cystoscopic catheter placement under vision
• Suprapubic catheterization if cystoscopy fails
• Formal urethroplasty for significant injuries or resulting strictures

---

C. Iatrogenic/Intraoperative Urethral Injuries

• May occur during female pelvic reconstructive surgery, colorectal surgery, transurethral procedures
• Often associated with concomitant bladder/ureteral injury
• Managed by primary repair + catheter drainage

---

General Principles in Management

---

---

Question 2 - Wilms' Tumour (20 Marks)

Introduction

• Smith and Tanagho's General Urology, 19th Edition

---

Aetiology and Associations

• WT1 gene on chromosome 11p13 - associated with Wilms tumour and genitourinary abnormalities (mutated in only 5-10% of sporadic cases)
• Two-hit hypothesis (Knudson & Strong, 1972): sporadic form results from two postzygotic mutations; familial form arises from one prezygotic + one postzygotic mutation

• WAGR syndrome - Wilms, Aniridia, Genitourinary malformation, mental Retardation
• Beckwith-Wiedemann syndrome - overgrowth syndrome (IGF1, H19, p57 genes)
• Isolated hemihypertrophy
• Isolated aniridia
• Trisomy 18
• Genitourinary anomalies: hypospadias, cryptorchidism, renal fusion (4.5-13.4% of cases)
• Familial cases: ~1% of all Wilms' tumours

---

Pathology

• Generally large, multilobulated, grey or tan in colour
• Focal areas of haemorrhage and necrosis
• Fibrous pseudocapsule occasionally seen

1. Blastemal - small blue cells, densely packed, undifferentiated
2. Epithelial - tubular/glomeruloid structures (resembles developing kidney)
3. Stromal - spindle cells, fibromyxoid matrix

• Favorable histology (FH): majority, no anaplasia
• Unfavorable histology (UH): Anaplasia (focal or diffuse) - associated with WT1/p53 mutations; confers worse prognosis

• Perilobar NRs and Intralobar NRs
• Some remain dormant, others give rise to Wilms' tumours

• Direct extension through renal capsule
• Haematogenous via renal vein and inferior vena cava
• Lymphatic spread (regional nodes involved in 25%)
• Metastases at diagnosis in 10-15%: lungs (85-95%), liver (10-15%)

---

Clinical Features

• Painless abdominal mass (most common presentation) - discovered by parent while bathing child
• Abdominal distension
• Haematuria (gross or microscopic)
• Hypertension (due to renin secretion) - in ~25%
• Fever
• Anorexia, weight loss, malaise
• Varicocele (due to renal vein involvement)

• Smooth, firm, non-tender flank mass, does NOT cross midline (unlike neuroblastoma which often does)
• Signs of associated syndromes (hemihypertrophy, aniridia)

---

Investigations

1. Ultrasound abdomen - first line; shows solid intrarenal mass, renal vein/IVC thrombus
2. CT scan abdomen and pelvis - gold standard for staging; defines tumour, lymph nodes, contralateral kidney
3. Chest X-ray - initial screening for lung metastases
4. CT chest - in high-risk patients or if CXR abnormal
5. MRI - for IVC/intracardiac extension; distinguishes nephrogenic rests from Wilms' tumour
6. Urinalysis - microscopic haematuria
7. FBC, LFTs, renal function - baseline

---

Staging (NWTS System - Most Widely Used)

---

Management

• Standard is radical transabdominal nephrectomy via midline/flank incision
• The contralateral kidney must be explored
• Regional lymph node sampling is mandatory for staging
• Tumour thrombus from IVC requires careful extraction
• For bilateral tumours (Stage V): nephron-sparing surgery/partial nephrectomy to preserve renal function

• All stages receive chemotherapy (NWTS protocols)
• Standard agents: Vincristine, Actinomycin D (Dactinomycin)
• Advanced/high-risk (Stage III/IV or UH): add Doxorubicin
• Pre-operative chemotherapy is preferred in Europe (SIOP protocol) especially for large/unresectable tumours

• Stage III: Abdominal/flank irradiation
• Stage IV with lung mets: whole lung radiotherapy

• Overall 5-year survival: ~85%
• Stage I/II FH: >95%
• Stage IV: ~80%
• Unfavorable histology: poorer outcome

---

---

Question 3 - Investigations in Dysphagia + Management of Achalasia Cardia (20 Marks)

Part A: Investigations of a Patient with Dysphagia

History Points (Critical Before Investigations)

• Onset: sudden vs. gradual
• Progressive (suggests organic cause like carcinoma) vs. intermittent
• Solid food only vs. both solids and liquids (liquids alone = motility disorder)
• Location of sensation
• Associated symptoms: regurgitation, weight loss, heartburn, respiratory symptoms (aspiration), chest pain
• Nocturnal regurgitation (achalasia)

Classification of Dysphagia

• Oropharyngeal (Transfer) dysphagia: difficulty initiating swallowing
• Oesophageal dysphagia: food sticks after swallowing

---

Investigations

• FBC - anaemia (may suggest malignancy or iron deficiency from reflux-related stricture)
• ESR, CRP - inflammation/malignancy
• Serum albumin - nutritional status
• TFTs - hypothyroidism can cause dysphagia
• Autoantibodies - in suspected connective tissue diseases (scleroderma)

• First-line radiological investigation
• Identifies: strictures, carcinomas, pouches (pharyngeal pouch), webs, and motility disorders
• Achalasia: "rat-tail" or "bird-beak" appearance at the lower oesophageal sphincter with dilated oesophagus
• Shows anatomical and some motor disorders
• Safe, non-invasive, good for complex anatomical problems

• Investigation of choice for suspected mucosal/luminal pathology
• Allows direct visualisation, biopsy for histology
• Therapeutic: dilatation of strictures, removal of foreign bodies
• Can show: carcinoma, peptic stricture, oesophagitis, achalasia (baggy dilated oesophagus with food debris)

• Gold standard for oropharyngeal dysphagia
• Dynamic real-time assessment of swallowing
• Detects aspiration, penetration, residue
• Guides dysphagia therapy

• Equally effective to videofluoroscopy for oropharyngeal dysphagia
• Assesses anatomy, sensation, bolus clearance
• Suitable for bedside assessment; no radiation
• Both FEES and videofluoroscopy are first choices for oropharyngeal dysphagia

• Gold standard for oesophageal motility disorders
• Achalasia: high resting LOS pressure, failure of LOS relaxation, absent peristalsis
• Identifies candidates for myotomy or pneumatic dilatation
• Also diagnoses: diffuse oesophageal spasm, nutcracker oesophagus, scleroderma

• Staging of oesophageal carcinoma
• Assessment of extrinsic compression (lymph nodes, mediastinal masses, aortic aneurysm)
• CT neck + chest in suspected pharyngeal/hypopharyngeal tumours

• Staging of oesophageal carcinoma (T and N staging)
• Assesses depth of tumour invasion

• Confirms GORD causing peptic stricture
• Used before antireflux surgery

• Staging of oesophageal carcinoma, detecting distant metastases

---

Part B: Management of Achalasia Cardia

Definition and Pathophysiology

• Failure of relaxation of the lower oesophageal sphincter (LOS)
• Absent oesophageal peristalsis
• High resting LOS pressure

Clinical Features

• Dysphagia - starts with solids, progresses to liquids
• Regurgitation of undigested food (not acidic, unlike GORD)
• Nocturnal regurgitation and aspiration
• Chest pain (due to oesophageal spasm)
• Weight loss
• Respiratory symptoms: recurrent chest infections, aspiration pneumonia
• Bad breath (halitosis)

---

Management of Achalasia Cardia

• Limited role due to side effects and lack of sustained benefit
• Calcium channel blockers (Nifedipine), nitrates
• Used mainly in patients unfit for intervention
• In children: anticholinergics, calcium channel blockers, nitrates - all have limited benefit

• Most effective non-surgical option
• Graded dilatation under fluoroscopic/endoscopic guidance using a pneumatic balloon (30-40 mm)
• Disrupts LOS muscle fibres
• Success rates: 60-85%
• Repeated dilatations usually required
• Complications: oesophageal perforation (1-5%) - most serious; GORD
• Preferred in elderly, high surgical risk patients

• Endoscopic injection into the LOS
• Inhibits acetylcholine release from nerve terminals - temporarily reduces LOS pressure
• Success rates: 60-90% initially, but effect wears off within 6-12 months
• Suitable for elderly patients unfit for surgery
• May make subsequent myotomy more difficult

• Longitudinal myotomy of the lower oesophagus extended 2-3 cm onto the gastric cardia
• Divides the circular and longitudinal muscle fibres of the LOS
• Combined with a partial fundoplication (Dor or Toupet) to prevent GORD
• Laparoscopic Heller myotomy + partial fundoplication is now the gold standard surgical approach
• Success rate: 85-90%
• Complications: oesophageal perforation (intraoperative), GORD, dysphagia recurrence

• Newer endoscopic technique
• Submucosal tunnelling to access and divide the circular muscle of the oesophagus and LOS
• Comparable results to laparoscopic Heller myotomy
• Advantages: no external incision, shorter hospital stay
• Disadvantage: higher incidence of post-procedure GORD

• Mega-oesophagus with tortuous, dilated oesophagus
• Oesophagectomy may be required

Treatment Algorithm

1. Diagnosis confirmed by manometry + barium swallow
2. Young, fit patient: Laparoscopic Heller myotomy + partial fundoplication (first choice) OR POEM
3. Elderly/high surgical risk: Pneumatic balloon dilatation
4. Short-term/bridge: Botox injection
5. Failure of conservative measures: Surgery

---

---

Question 4 - Write in Brief (30 Marks - 10 marks each)

4(1) - Extradural Haematoma

• Results from rupture of an artery, vein, or venous sinus in association with a skull fracture
• Classical injury: fracture to the thin squamous temporal bone with associated damage to the middle meningeal artery (most common cause - arterial bleed)
• Venous extradural haematoma: from torn diploic veins or venous sinuses (less common)

• Arterial bleeding causes rapid haematoma expansion
• As volume increases, intracranial pressure (ICP) rises following Monro-Kellie doctrine
• Transtentorial herniation occurs when compensatory mechanisms are exhausted

1. Initial head injury with transient loss of consciousness
2. Lucid interval - patient apparently recovers, may have headache but no neurological deficit (minutes to hours)
3. Rapid deterioration - as haematoma expands:
   • Severe headache
   • Vomiting
   • Reduced conscious level (GCS falling)
   • Contralateral hemiparesis
   • Ipsilateral fixed dilated pupil (due to uncal herniation compressing CN III)
   • Cushing's response: bradycardia + hypertension + irregular breathing (late sign)

• CT scan (non-contrast) - investigation of choice
• Appearance: lentiform (biconvex/lens-shaped) hyperdense lesion between skull and brain
• Constrained by dural adherence to skull (does not cross suture lines)
• Mass effect with midline shift
• Areas of mixed density = active bleeding
• Skull fracture usually evident
• MRI: not preferred in acute setting (CT is faster)

• Small haematomas (<30 mL, <1 cm thickness, <5 mm midline shift, GCS >8) with neurologically intact patient
• Close observation with serial CT scans
• ICU monitoring

• All deteriorating or comatose patients
• Haematoma >30 mL or >1 cm thickness or >5 mm midline shift
• Urgent transfer to neurosurgical facility
• Burr hole craniotomy / Emergency craniotomy + haematoma evacuation
• Middle meningeal artery secured with cautery or ligature
• Post-operative ICP monitoring

• Excellent if promptly evacuated without associated primary brain injury
• Delay in diagnosis/treatment worsens outcome dramatically
• Mortality approaches zero with rapid surgical evacuation in good-grade patients

---

4(2) - Thyroglossal Cyst

• Thyroid gland originates as a diverticulum from the floor of the pharynx (foramen caecum)
• Descends through the neck via the thyroglossal duct
• Normally, the duct disappears as the gland reaches its final position
• Failure of involution leads to persistence of ductal remnants and cyst formation
• The tract passes through or around the hyoid bone

• Lined by pseudostratified columnar/squamous epithelium
• May contain mucus, serous fluid
• Thyroid tissue may be present in the cyst wall (~1-2%)
• May rarely undergo malignant transformation to papillary thyroid carcinoma

• Painless, midline neck swelling - most common presentation
• Characteristic sign: moves upward on protrusion of the tongue and on swallowing (pathognomonic - due to attachment to hyoid bone)
• Most common in children and young adults (paediatric patients predominantly)
• Location: most often just below the hyoid bone (~50%), but can be above (submental) or at the level of the hyoid
• Usually 1-4 cm in size, soft, fluctuant
• Can become infected - causing pain, redness, swelling, fistula formation
• Rarely: difficulty swallowing, breathing (large cysts)

• Primarily clinical - midline neck mass moving with tongue protrusion
• Ultrasound - confirms cystic nature, locates normal thyroid gland inferiorly (must confirm before surgery)
• CT scan - for large/infected cysts, to define anatomy
• FNA - to rule out malignancy or other pathology
• Thyroid scan - if thyroid not identifiable on ultrasound (to ensure remnant thyroid is not the only functioning thyroid tissue)

• Definitive treatment is surgical excision
• Sistrunk's Operation (standard operation):
  • Complete excision of the cyst
  • Removal of the central portion of the hyoid bone (mid-body)
  • Excision of the entire tract up to the base of the tongue (foramen caecum)
  • This complete excision is essential to prevent recurrence
  • Simple cystectomy alone has recurrence rate of ~40-50%; Sistrunk's operation reduces this to <5%

• Infection and abscess formation (commonest complication) - may need incision and drainage before definitive surgery
• Recurrence after incomplete excision
• Fistula formation (thyroglossal fistula) - usually secondary to rupture or inadequate drainage of infected cyst
• Malignant change (rare, ~1%) - usually papillary carcinoma, treated with total thyroidectomy + radioiodine

---

4(3) - Ectopic Testis

• Undescended testis: arrested along the normal pathway (intra-abdominal, inguinal canal, at deep ring, superficial ring)
• Ectopic testis: deviated to an abnormal site; the testis is usually well-developed (unlike undescended testis which is smaller and less developed)
• In both conditions, the scrotum on the affected side is empty

1. Scrotal tail - the main/strongest tail - normally directs testis into scrotum
2. Pubic tail - attached to pubic tubercle
3. Perineal tail - attached to perineum
4. Inguinal tail - attached to the front of the inguinal canal
5. Femoral tail - attached to the saphenous opening

1. Superficial inguinal pouch (most common site - superficial to external oblique aponeurosis, above and lateral to the superficial inguinal ring)
2. Root of penis (pubic ectopic testis)
3. Perineum (perineal ectopic testis)
4. Femoral triangle (upper and medial - femoral ectopic testis) - rarest

• Empty scrotum on affected side
• Palpable testis at one of the ectopic sites (most commonly in superficial inguinal pouch)
• Testis can be identified by its shape, feel, and "testicular sensation" on palpation
• Ectopic testis is usually well developed (unlike undescended)
• Rising test: determines whether testis is superficial or deep to abdominal muscles

• Clinical examination is usually diagnostic
• Ultrasound - for impalpable testes
• MRI or laparoscopy for intra-abdominal impalpable testes

• Undescended testis
• Retractile testis (most common mimic - testis is pulled into superficial inguinal pouch by cremasteric reflex; chair test helps differentiate - testis comes down to scrotum when child sits hugging knees to chest)
• Lymph node
• Inguinal hernia

• Orchidopexy - surgical fixation of testis in the scrotum
• Timing: Recommended between 6-18 months of age (before age 2 years) to:
  • Preserve fertility (prevent progressive germ cell damage)
  • Reduce risk of malignancy
  • Correct associated hernial sac (patent processus vaginalis is always present)
  • Psychological benefit
  • Reduce risk of torsion

• Infertility
• Increased risk of testicular malignancy (risk reduced but not eliminated by orchidopexy)
• Torsion
• Trauma (testis is in an unprotected position)
• Psychological distress

---

Summary Table for Quick Revision