Central Venography: Superior Vena Cavagraphy

Study Notes

Central venography includes superior and inferior vena cavography for assessing the central venous system.

Indications:
- Identifies occlusion or stenosis of central veins.
- Serves as a preliminary examination for transvenous interventional techniques.
- Detects congenital venous abnormalities, e.g., left-sided superior vena cava.
Contrast Medium:
- Low Osmolar Contrast Medium (LOCM) with concentration 370 mg I mL−1, 60 mL volume.
Equipment:
- Requires a C-arm with digital subtraction angiography.
Patient Preparation:
- No specific preparation needed.
Technique:
- Patient positioned supine; 18G butterfly needles inserted into median antecubital veins of both arms.
- Contrast medium (30 mL per side) injected simultaneously by two operators, recorded via rapid serial radiography.
- Image acquisition starts after about two-thirds of the contrast medium is injected.
- For congenital abnormalities, a 5-F catheter may be used if initial opacification is inadequate.
Imaging:
- Captured at 1 frame/s for 10 seconds.
Aftercare:
- None required unless a catheter is used.
Complications:
- Mild: Nausea, vomiting, urticaria.
- Moderate: Tachycardia, mild bronchospasm, vasovagal reaction, diffuse erythema.
- Severe: Seizures, cardiovascular collapse, moderate/severe bronchospasm, laryngeal edema, loss of consciousness.

Indications:
- Demonstrates site of venous obstruction, displacement, or infiltration.
- Serves as a preliminary examination for transvenous interventional techniques.
- Identifies congenital venous system abnormalities.
Contrast Medium:
- Low Osmolar Contrast Medium (LOCM) with concentration 370 mg I mL−1, 40 mL volume.
Technique:
- Patient positioned supine; sheath placed into the femoral vein using standard vascular access techniques.
- Valsalva maneuver may facilitate venipuncture by distending the femoral vein.
- Puncture should ideally be performed under ultrasound guidance; blind puncture may be done targeting the medial side of the common femoral artery pulse.
- Obstruction during catheter passage can indicate thrombosis or incorrect catheter placement; fluoroscopy and hand injection help clarify.
- For injection, 40 mL of contrast medium is administered at 20 mL/s using a pump injector, recorded by rapid serial radiography or digital subtraction at 2 frames/s.
Aftercare:
- Pressure applied at the venipuncture site, with routine observations for 2 hours.
Complications:
- Similar to superior venography: mild nausea, vomiting, urticaria; moderate tachycardia, mild bronchospasm, vasovagal reactions; severe reactions include similar risks as mentioned.