The inguinal canal is an oblique passage through the lower abdominal wall. In males it transmits the spermatic cord and ilioinguinal nerve; in females the round ligament and ilioinguinal nerve. ^[1]

Why this matters: Direct hernias push through the posterior wall (transversalis fascia weakness). Indirect hernias enter through the deep inguinal ring (a defect in the transversalis fascia laterally). Understanding walls = understanding hernia types. ^[1]

The spermatic cord contains: vas deferens, artery to the vas, gonadal artery, cremasteric artery and vein, gonadal vein (pampiniform plexus), genital branch of genitofemoral nerve, ilioinguinal nerve, sympathetic nerves, lymphatics. The coverings are: internal spermatic fascia, cremasteric fascia and muscle, external spermatic fascia. ^[1]

Male: opening in the transversalis fascia through which the vas deferens enters on its course from the pelvis. Female: transmits the round ligament and the genital branch of the genitofemoral nerve. ^[1]

Surface marking: The deep inguinal ring lies at the midpoint of the inguinal ligament (midpoint between ASIS and pubic tubercle). This is different from the mid-inguinal point (midpoint between ASIS and pubic symphysis), which marks the femoral artery pulse. Confusing these is one of the most common exam mistakes. ^[1]

First described by Henri Fruchaud in 1956. An area of weakness in the pelvic region not reinforced by muscle layers. All groin hernias (inguinal and femoral) emerge through this single orifice. Prone to progressive bulging from repetitive increases in intra-abdominal pressure. ^[1]

Borders of the MPO:

• Superior: Arching fibres of internal oblique and transversus abdominis
• Medial: Rectus abdominis and its fascial sheath
• Inferior: Cooper's (pectineal) ligament
• Lateral: Iliopsoas muscle

Why this matters clinically: The laparoscopic posterior approach (TEP/TAPP) repairs the entire MPO with a single mesh — covering both potential inguinal AND femoral defects. This is why laparoscopic repair is recommended for females (to avoid missing a femoral hernia) and for bilateral hernias (one operation, both sides). ^[1]

Triangle of Doom: bounded by vas deferens (medially) and gonadal vessels (laterally) — contains external iliac vessels. Triangle of Pain: lateral to the gonadal vessels — contains lateral femoral cutaneous nerve, femoral branch of genitofemoral nerve, and femoral nerve. ^[1]

These are danger zones during laparoscopic hernia repair. Tacking or stapling in the Triangle of Doom → vascular injury. Tacking in the Triangle of Pain → chronic neuropathic pain. ^[1]

Painful groin lumps: tender lymph nodes, strangulated inguinal hernia, strangulated femoral hernia. Painless groin lumps: skin swelling, non-tender lymph nodes, inguinal hernia, femoral hernia, undescended testis, femoral artery aneurysm, saphena varix. ^[1]

Painful scrotal lumps: torsion of testis, torsion of appendage, epididymo-orchitis, strangulated inguinal hernia, haematocele/haematoma. Painless scrotal lumps: inguinal hernia, hydrocele, epididymal cyst, spermatocele, varicocele, testicular tumour, skin swelling. ^[1]

^[1][4]

Indirect hernia: lateral to the inferior epigastric vessels, due to recannulation of the obliterated vaginal process (processus vaginalis). Direct hernia: medial to the inferior epigastric vessels, due to insufficient transversalis fascia. Pantaloon hernia: presence of both direct and indirect hernia. Sliding hernia: an internal organ forming part of the hernia wall, usually the sigmoid colon. ^[1]

^[1][4][5]

Hesselbach's Triangle (site of direct hernia):

• Inferior: Inguinal ligament
• Lateral: Inferior epigastric vessels
• Medial: Lateral border of rectus sheath ^[5]

Amyand's hernia: hernia sac containing the appendix (named after Claudius Amyand who performed the first successful appendectomy in 1735 on an 11-year-old boy with appendix in his inguinal hernia). Richter's hernia: only one sidewall (anti-mesenteric border) of the bowel is trapped — causes ischaemia but NOT obstruction (no complete luminal compromise). Littre's hernia: contains Meckel's diverticulum. Maydl's hernia: W-loop of bowel in the hernia sac. ^[1][4]

Reducible groin mass → Hernia. Painful scrotal swelling → epididymo-orchitis/torsion. Painless scrotal enlargement → Hydrocele/Testicular tumour. Fullness/"bag of worms" → Varicocele. ^[1]

Intrinsic: family history, previous contralateral hernia, gender (male), age, abnormal collagen metabolism. Acquired: prostatectomy, obesity, chronic constipation, pulmonary disease (chronic cough). ^[1]

Why prostatectomy? During radical prostatectomy, the transversalis fascia and posterior inguinal canal structures can be disrupted. Also, post-prostatectomy patients may strain during voiding recovery. ^[1]

This is OSCE-critical material.

Start with the patient STANDING. Inspect: describe the mass, visible cough impulse, scars. Palpate: describe the mass, can you get above it (scrotal vs. groin extending to scrotum?), palpable cough impulse, unilateral or bilateral. ^[1]

Then SUPINE. Inspect. Palpate. Identify the pubic tubercle and ASIS. Relationship of swelling to pubic tubercle? Reducible? Occlusion test. Examine abdomen for mass. Examine testes. ^[1]

Examination checklist (combined from lecture + clinical demonstration): ^[1][6][3]

1. Consent + Exposure (nipple to mid-thigh)
2. Standing:
   • Inspect both groins and scrotum
   • Ask patient to cough → visible cough impulse?
   • Look for scars (previous repair?)
   • Palpate the lump: site, size, shape, consistency, tenderness
   • Can you get above it? (If no → inguinoscrotal = hernia or communicating hydrocele)
   • Ask patient to cough → palpable expansile cough impulse
   • Check both sides (20% bilateral)
3. Supine:
   • Identify pubic tubercle (first bony prominence lateral to pubic symphysis)
   • Determine relationship: above & medial (inguinal) vs. below & lateral (femoral)
   • Attempt gentle reduction
   • Occlusion test: Reduce hernia → place finger firmly over deep ring (midpoint of inguinal ligament) → ask patient to stand and cough → if hernia stays reduced = indirect; if it reappears = direct
   • Examine abdomen (mass? ascites causing ↑IAP?)
   • Examine both testes (undescended? tumour?)
4. Complete: Contralateral groin, genital examination, PR if indicated

Occlusion test accuracy for indirect inguinal hernia: 86%. For direct inguinal hernia: 35%. ^[1]

Why the difference? The test works by blocking the deep ring. If the hernia comes through the deep ring (indirect), blocking it works well. But direct hernias don't come through the deep ring, so the test is not designed to "catch" them — you can only infer a direct hernia when the test fails to control the bulge.

Physical examination alone is the primary diagnostic method. Ultrasound if uncertain. CT for complex cases. MRI or herniography less commonly used. ^[1]

Symptomatic hernia → Surgery. Asymptomatic hernia → Watchful waiting (but 70% will need surgery within 5 years). ^[1]

Herniotomy: excision of the hernia sac after reduction of contents. Herniorrhaphy: herniotomy + strengthening of posterior wall WITHOUT mesh. Hernioplasty: herniotomy + strengthening of posterior wall WITH mesh. ^[1]

Well-accepted alternative to open repair. Advantages: less early postoperative pain, less chronic pain. European Hernia Society guideline recommends endoscopic repair for both unilateral and bilateral hernias. Preferred approach for recurrent hernia after previous open repair. ^[1]

TEP vs. TAPP

TEP (Total Extraperitoneal Repair): directly dissects into the preperitoneal plane without perforating the peritoneum. TAPP (Transabdominal Preperitoneal Repair): enters the peritoneal cavity first (diagnostic laparoscopy), then incises peritoneum to enter the preperitoneal plane. ^[1]

TAPP and TEP have comparable outcomes. Choice depends on surgeon's skills and experience. TEP has a longer learning curve than TAPP. TAPP → more visceral injuries. TEP → more vascular injuries. ^[1]

Laparo-endoscopic repair is recommended in females to decrease chronic pain risk and avoid missing a femoral hernia. In pregnant women: watchful waiting → self-limiting round ligament varicosities. ^[1]

Why laparoscopic for females? Femoral hernias are more common in females. Open anterior repair only addresses the inguinal defect and can miss a concurrent femoral hernia. Laparoscopic posterior repair with mesh covers the entire MPO, addressing both inguinal and femoral defects simultaneously. ^[1]

For recurrence after anterior repair → use posterior repair (laparoscopic). For recurrence after posterior repair → use anterior repair. The principle is to avoid scar tissue by switching approach. ^[1]

Patient characteristics, local/national resources, surgical expertise, logistics all influence the choice of operation. ^[1]

Poor surgical technique, low surgical volume, and surgical inexperience are the main preoperative risk factors for recurrence. ^[1]

Low risk of complications (pain and recurrence), easy to learn, fast recovery, reproducible result, cost effective. ^[1]

Classification designed for the posterior approach based on size of the internal ring and integrity of the posterior wall. Type 1: indirect hernia, normal internal ring. Type 2: indirect hernia, enlarged internal ring. Type 3a: direct inguinal hernia. Type 3b: indirect hernia causing posterior wall weakness. Type 3c: femoral hernia. Type 4: all recurrent hernias. ^[1]

Primary vs. Recurrent. Location: Lateral (Indirect) / Medial (Direct) / Femoral. Size: 0, 1 (≤ 1 finger), 2 (1–2 fingers), 3 (≥ 3 fingers), x. Example: Primary L2 = Primary indirect hernia, 1–2 finger breadths. ^[1]

Affects 10–12% of inguinal hernia repair patients. Defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively. Risk factors: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia, open repair. ^[1]

Nociceptive pain: caused by activation of nociceptors by nociceptive molecules due to tissue injury/inflammation, transmitted via A-delta and C-fibres. Neuropathic pain: caused by direct nerve injury — contact with mesh, nerve entrapment by sutures, staples, tacks, folded mesh, or meshoma. ^[1]

The three nerves at risk during open inguinal hernia repair:

1. Ilioinguinal nerve (L1) — most commonly injured
2. Iliohypogastric nerve (L1)
3. Genital branch of genitofemoral nerve (L1-2)

Paediatric emergency. Unilateral scrotal pain often associated with vomiting. Surgical emergency. ^[1]

Key points from supporting notes: ^[7]

• Two peak ages: neonatal and adolescent (12–18 years)
• Bell-clapper deformity: tunica vaginalis attaches high on the spermatic cord → testis hangs freely like a clapper in a bell → prone to torsion
• Examination: High-riding testis, horizontal lie, absent cremasteric reflex, negative Prehn's sign
• Time is testis: Irreversible damage after ~6 hours of warm ischaemia (salvage rate > 90% if < 6h, drops to < 10% after 24h)
• Management: Emergency scrotal exploration + detorsion ± orchidopexy (bilateral fixation — because bell-clapper is usually bilateral)

Fluid in the tunica vaginalis. Can get above it. Transillumination positive. Fluctuant. Testis not palpable (surrounded by fluid). USG to examine the testis (must rule out underlying testicular tumour causing secondary/reactive hydrocele). Primary vs. secondary hydrocele. ^[1]

Types: ^[1][7]

• Communicating (congenital): Patent processus vaginalis → changes size with activity/Valsalva → most resolve by age 1–2 years
• Non-communicating: Vaginal hydrocele (most common adult type), infantile hydrocele, encysted hydrocele of the cord

Management:

Needle aspiration or Jaboulay procedure (eversion of tunica vaginalis). ^[1]

• Aspiration: temporary (recurs), risk of infection — mainly for elderly/unfit patients
• Lord's plication or Jaboulay procedure: definitive surgery — sac is opened, fluid drained, tunica everted and sutured behind the cord

Abnormal enlargement of the pampiniform venous plexus in the scrotum. Occurs in ~15% of men. Left side more common than right (because left gonadal vein drains into left renal vein at right angles → higher hydrostatic pressure). May lead to fertility issues. ^[1]

"Bag of worms" felt on standing. Must rule out renal mass causing venous congestion. Nutcracker syndrome (left renal vein compressed between SMA and aorta). ^[1]

Why left > right?

• Left gonadal vein → left renal vein (longer, enters at 90°, compressed by SMA = nutcracker)
• Right gonadal vein → IVC (shorter, enters at acute angle, better drainage)

Risk factors: 20–45 years old, undescended testis, family/personal history, white, HIV. Presentation: enlarged, firm, non-tender testis. Tumour markers: AFP, hCG, LDH-1. Treatment: inguinal radical orchidectomy ± RPLND (retroperitoneal lymph node dissection). ^[1]

Why inguinal (not scrotal) orchidectomy? To avoid disrupting scrotal lymphatic drainage (scrotum drains to superficial inguinal nodes; testis drains to para-aortic nodes). A scrotal incision could alter lymphatic drainage patterns and upstage the tumour. ^[1]

WHO Classification: Germ cell tumours (seminoma, embryonal carcinoma, teratoma, choriocarcinoma, yolk sac tumour) and sex cord stromal tumours (Leydig cell, Sertoli cell, granulosa cell, mixed). ^[1]

Chemotherapy regimens: BEP (bleomycin, etoposide, cisplatin) is the standard. Carboplatin for stage I pure seminoma only. ^[1]

The "25/M with testicular swelling and haemoptysis" vignette on slide 80 is a classic presentation of testicular choriocarcinoma with lung metastases (choriocarcinoma is highly vascular and spreads haematogenously). ^[1]

1. "Cannot get above it" does NOT automatically mean hernia — a communicating hydrocele also cannot be gotten above, but it transilluminates
2. Femoral hernia in exam = emergency — always think strangulation (exam rarely shows a non-urgent femoral hernia)
3. Indirect hernia CAN occur in elderly — don't assume indirect = always young/congenital
4. Sliding hernia — sigmoid colon (left) or caecum (right) forms part of the wall → careful not to injure viscera during dissection
5. Testicular torsion is a clinical diagnosis — do NOT delay surgery for ultrasound if clinical suspicion is high

Q1: "Occurs over previous incision or trauma sites."

• Answer: D. Incisional hernia
• Rationale: By definition, incisional hernia occurs at the site of a previous surgical incision where the fascia has failed to heal.

Q2: "Hernia ring above and medial to pubic tubercle."

• Answer: E. Inguinal hernia
• Rationale: Both direct and indirect inguinal hernias emerge above and medial to the pubic tubercle. The inguinal ligament attaches to the pubic tubercle, and the inguinal canal lies above it.

Q3: "Hernia ring inferior to the inguinal ligament."

• Answer: C. Femoral hernia
• Rationale: Femoral hernia passes through the femoral canal, which is below the inguinal ligament and lateral to the pubic tubercle.

Q4: "Usually occurs at epigastrium but not considered as true hernia."

• Answer: A. Divarication of recti (Diastasis recti)
• Rationale: Divarication of recti is a stretching/separation of the linea alba — there is no true fascial defect (no hernial ring), so it is not a true hernia. The abdominal wall bulges but the fascial layer is intact (just attenuated). ^[4]

Q5: "Occurs at a defect above or below the umbilicus."

• Answer: H. Para-umbilical hernia
• Rationale: Para-umbilical hernia occurs through the linea alba around (above or below) the umbilicus, not through the umbilical scar itself (which would be an umbilical hernia). ^[4]

Q13: "80-year-old female vegetarian, history of gastrectomy, vomiting and abdominal pain for 3 days, dehydrated, poor denture, dilated small bowels with multiple fluid levels."

• Answer: B. Bezoar obstruction
• Rationale: Vegetarian diet + poor denture (inadequate chewing of fibrous food) + gastrectomy (loss of pyloric grinding function) → phytobezoar causing small bowel obstruction. Not a hernia question, but tests DDx of IO.

Q14: "50-year-old man, vomiting and abdominal distension, history of laparotomy + appendectomy, dilated small bowel with multiple fluid levels."

• Answer: A. Adhesive bowel obstruction
• Rationale: Two previous abdominal operations → adhesions → most common cause of small bowel obstruction. Note: femoral hernia (option E) is also a cause of IO but the history of multiple surgeries makes adhesions far more likely.