FRCS Applied Surgical Anatomy 2 — Questions and Answers
Question 1: Which layer is entered first when performing a McBurney's point incision for appendicectomy?
- Transversalis fascia
- External oblique aponeurosis (Correct answer)
- Internal oblique
- Peritoneum
Correct answer: External oblique aponeurosis
During open appendicectomy via a Gridiron incision at McBurney's point, the layers encountered are: skin → subcutaneous fat → Camper's fascia → Scarpa's fascia → external oblique aponeurosis → internal oblique (split in direction of fibres) → transversus abdominis → transversalis fascia → extraperitoneal fat → peritoneum.
Question 2: The portal vein is formed by the union of which two vessels?
- Inferior mesenteric vein and splenic vein
- Superior mesenteric vein and inferior mesenteric vein
- Superior mesenteric vein and splenic vein (Correct answer)
- Left gastric vein and splenic vein
Correct answer: Superior mesenteric vein and splenic vein
The portal vein is formed at the level of L1–L2 behind the neck of the pancreas by the union of the superior mesenteric vein and the splenic vein (which has already received the inferior mesenteric vein). This anatomy is critical in pancreatic surgery where the portal vein may be involved by tumour.
Question 3: During a Whipple's procedure (pancreaticoduodenectomy), which structure defines the plane of resection in assessing portal vein involvement?
- The hepatic artery
- The portal vein/superior mesenteric vein confluence (Correct answer)
- The common bile duct
- The gastroduodenal artery
Correct answer: The portal vein/superior mesenteric vein confluence
Resectability in pancreatic head cancer is determined by the relationship of the tumour to the superior mesenteric vein (SMV) and portal vein (PV). The SMV-PV confluence lies in the groove between the uncinate process and the neck of the pancreas; tumour involvement of this vessel indicates a technically demanding or borderline resection.
Question 4: The Triangle of Calot is defined by which three structures?
- Cystic duct, common hepatic duct, and right hepatic artery
- Cystic artery, cystic duct, and liver
- Common hepatic duct, cystic duct, and inferior edge of liver (Correct answer)
- Common bile duct, cystic duct, and gastroduodenal artery
Correct answer: Common hepatic duct, cystic duct, and inferior edge of liver
Calot's triangle is bounded by: the common hepatic duct medially, the cystic duct inferiorly, and the inferior surface of the right lobe of the liver superiorly. The cystic artery is found within this triangle, and the Critical View of Safety (CVS) must be achieved before any clipping in laparoscopic cholecystectomy.
Question 5: Which nerve is at risk during a modified radical mastectomy due to its course along the chest wall?
- Long thoracic nerve of Bell (Correct answer)
- Thoracodorsal nerve
- Medial pectoral nerve
- Lateral cutaneous branches of intercostal nerves
Correct answer: Long thoracic nerve of Bell
The long thoracic nerve of Bell (C5–C7) runs along the lateral chest wall supplying serratus anterior. Injury during axillary dissection causes 'winged scapula' (inability to protract the scapula, winging on pushing against a wall), a debilitating cosmetic and functional defect.
Question 6: The anatomical landmark for the femoral nerve during femoral vessel exposure in vascular surgery is its location relative to the femoral artery. Where does it lie?
- Medial to the femoral artery within the femoral sheath
- Posterior to the femoral vein
- Lateral to the femoral artery, outside the femoral sheath (Correct answer)
- Anterior to the femoral artery
Correct answer: Lateral to the femoral artery, outside the femoral sheath
The femoral nerve lies lateral to the femoral artery outside the femoral sheath, in the iliacus groove. The femoral sheath contains only the femoral artery, vein, and canal (lymphatics). Knowledge of this anatomy prevents femoral nerve injury during femoral artery exposure.
FRCS Applied Surgical Anatomy 2
Which layer is entered first when performing a McBurney's point incision for appendicectomy?