VT Venous Mapping & Preoperative Assessment 1 — Questions and Answers
Question 1: What minimum diameter of the great saphenous vein (GSV) is typically required for use as a bypass conduit?
- 1.5 mm
- 2.0 mm
- 3.0 mm (Correct answer)
- 4.5 mm
Correct answer: 3.0 mm
A GSV diameter of at least 3.0 mm is generally required for use as a bypass conduit to ensure adequate flow and long-term patency.
Question 2: Which patient position best demonstrates GSV diameter during preoperative vein mapping?
- Supine with legs flat
- Prone with feet elevated
- Standing or reverse Trendelenburg (Correct answer)
- Trendelenburg with legs elevated 30°
Correct answer: Standing or reverse Trendelenburg
A standing or reverse Trendelenburg position uses gravity to distend the veins, giving the most accurate diameter measurements for surgical planning.
Question 3: In the CEAP classification system for chronic venous disease, what does the letter 'C' represent?
- Chronic venous disease stage
- Clinical signs (Correct answer)
- Compression therapy class
- Collateral vessel grading
Correct answer: Clinical signs
In CEAP, 'C' stands for Clinical signs, ranging from C0 (no visible disease) to C6 (active venous ulcer).
Question 4: Which CEAP clinical class specifically describes an active venous ulcer?
- C4b
- C5
- C6 (Correct answer)
- C3
Correct answer: C6
CEAP C6 is defined as an active venous ulcer that has not healed, while C5 indicates a healed venous ulcer.
Question 5: At which anatomical junction does the small saphenous vein (SSV) typically terminate?
- Saphenofemoral junction in the groin
- Superficial femoral vein in the mid-thigh
- Saphenopopliteal junction in the popliteal fossa (Correct answer)
- Anterior tibial vein at the ankle
Correct answer: Saphenopopliteal junction in the popliteal fossa
The SSV most commonly terminates at the saphenopopliteal junction (SPJ) in the popliteal fossa, although anatomic variants are common.
Question 6: Which imaging modality is the standard of care for preoperative GSV mapping prior to coronary artery bypass grafting (CABG)?
- CT angiography
- MR venography
- Duplex ultrasound (Correct answer)
- Conventional contrast venography
Correct answer: Duplex ultrasound
Duplex ultrasound is the standard for GSV mapping because it provides real-time diameter assessment, compressibility testing, and skin-marking of the vein course without radiation or contrast.
Question 7: Which duplex ultrasound finding indicates an incompetent perforating vein?
- Inward flow lasting >1.0 second during calf compression
- Absent flow at rest in the perforator
- Outward flow lasting >0.5 seconds upon release of calf compression (Correct answer)
- Bidirectional flow synchronous with respiration
Correct answer: Outward flow lasting >0.5 seconds upon release of calf compression
Outward (deep-to-superficial) flow lasting more than 0.5 seconds following release of calf compression indicates perforator incompetence.
VT Venous Mapping & Preoperative Assessment 1
What minimum diameter of the great saphenous vein (GSV) is typically required for use as a bypass conduit?