Anatomic Landmarks for Interventional Procedures

Vascular Access Landmarks - Vessel Ventures

• Femoral Artery & Vein:
  • Landmark: Mid-inguinal point (ASIS to pubic symphysis). Artery palpated 1-2 cm below inguinal ligament.
  • Access: Needle at 45° to skin, cephalad. Ideal: over femoral head.
  • 📌 NAVEL (Lateral to Medial): Nerve, Artery, Vein, Empty space, Lymphatics.

  ⭐ Femoral artery is lateral to femoral vein (NAVEL: Nerve, Artery, Vein, Empty space, Lymphatics from lateral to medial).

• Internal Jugular Vein (IJV):
  • Landmark: Sedillot's triangle (SCM heads & clavicle).
  • Access: Apex of triangle, needle caudally to ipsilateral nipple (30-45°). Ultrasound guidance standard.
  • Relation: Carotid artery medial & deep.
• Subclavian Vein:
  • Landmark: Junction of medial & middle thirds of clavicle.
  • Access: Needle 1 cm inferior/posterior to clavicle, aim for suprasternal notch.
  • ⚠️ High pneumothorax risk.
• Radial Artery:
  • Landmark: 1-2 cm proximal to radial styloid, lateral to flexor carpi radialis tendon.
  • Pre-procedure: Allen's test for ulnar patency.

Body Cavity Landmarks - Drain Game

• Core Aim: Safe fluid aspiration/drainage; USG guidance preferred.
• Thoracentesis (Pleural Effusion)
  • Position: Sitting, leaning forward.
  • Landmarks:
    • Triangle of Safety: Latissimus dorsi (post.), Pectoralis major (ant.), 5th ICS (inf.), Axilla (apex).
    • Or: Mid-scapular/posterior axillary line.
  • 

  ⭐ For thoracentesis, needle insertion is 1-2 ICS below fluid level (mid/post-axillary line), above the rib to avoid neurovascular bundle.

• Paracentesis (Ascites)
  • Position: Supine.
  • Landmarks:
    • LLQ: 2-4 cm medial & superior to ASIS. (📌 Left = Less caecum risk)
    • Midline: ~2 cm below umbilicus (linea alba); avoid if veins/scars.
  • Technique: Z-track insertion (prevents leak).
• Key: Asepsis, local anesthesia.

Organ & Spine Landmarks - Point Perfect

• Liver Access (e.g., Biopsy, Drainage):
  • Mid-axillary line: 8th-11th Intercostal Space (ICS).
  • Subcostal approach: Angle superiorly & posteriorly.
  • Guidance: Ultrasound (US) / Computed Tomography (CT).
• Native Kidney Biopsy:
  • Position: Prone; Left lower pole preferred.
  • Landmark: 2-3 cm below 12th rib, 8-10 cm lateral to midline.
  • Guidance: US/CT.
• Spleen Access:
  • Posterior axillary line: 9th-11th ICS.
  • High bleeding risk; consider transarterial route for embolization.
• Lumbar Puncture (LP):
  • Position: Lateral decubitus or sitting, flexed spine.
  • Needle insertion: L3-L4 or L4-L5 interspace, angled slightly cephalad.

  ⭐ Tuffier's line (joining highest points of iliac crests) usually crosses L4 spinous process or L4-L5 interspace, a key landmark for lumbar puncture.

• Vertebral Interventions (e.g., Vertebroplasty, Kyphoplasty):
  • Target: Pedicles for transpedicular approach.
  • Guidance: Fluoroscopy/CT.
• Celiac Plexus Block:
  • Target level: T12-L1, anterior to aorta around celiac artery origin.
  • Approach: Paravertebral at L1 (CT-guided).

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High‑Yield Points - ⚡ Biggest Takeaways

• Celiac trunk typically arises at T12-L1, vital for hepatic interventions.
• SMA originates ~1 cm below celiac trunk (L1), key for mesenteric procedures.
• Renal arteries usually branch at L1-L2, important for renal interventions.
• Aortic bifurcation is commonly at L4-L5, guiding lower limb access.
• Femoral artery puncture: CFA over femoral head, below inguinal ligament.
• Internal jugular vein access: Between SCM heads, lateral to carotid artery.
• IVC filter placement: Ideally below renal veins to preserve renal outflow.