Question

Consider the following statements: thrombolytic therapy is contraindicated in 1. Irreversible ischaemia. 2. A potential source of haemorrhage. 3. Suprainguinal occlusion. 4. Critical ischaemia with neurological deficit. Which of these statements are correct?

• A. 1, 2 and 3
• B. 2, 3 and 4
• C. 1, 2 and 4
• D. 1, 3 and 4

Hint:

One of the four statements describes a limb that is already beyond saving, not a reason thrombolysis itself is unsafe.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
This question asks which clinical situations are recognised contraindications to using thrombolytic, clot-dissolving, therapy for acute arterial occlusion of a limb.

Step 2: Key Concept or Approach:
Thrombolytic therapy works by slowly dissolving clot over hours, so it is only appropriate when the limb can tolerate that delay and when the bleeding risk from the drug is acceptable. It is unsuitable whenever a patient has a bleeding risk, when the anatomical situation makes catheter-directed therapy unsafe or ineffective, or when the limb is under such immediate threat that waiting for lysis would risk permanent damage. This is a different situation from a limb that is already beyond salvage, where thrombolysis is simply pointless rather than contraindicated, because urgent amputation, not clot dissolution, is what is needed.

Step 3: Working Through the Options:
A potential source of haemorrhage, statement 2, is a straightforward contraindication, since the thrombolytic drug acts systemically and any bleeding-prone site, such as a recent wound, ulcer, or bleeding disorder, becomes dangerous once lysis begins. Suprainguinal occlusion, statement 3, is a recognised contraindication because thrombolysis above the inguinal ligament carries a higher risk of major haemorrhagic and embolic complications and is technically harder to manage by the catheter-directed route than more distal, infrainguinal occlusions. Critical ischaemia with a neurological deficit, statement 4, signals a limb that is still viable but under urgent threat, which needs immediate surgical revascularisation rather than the several hours a thrombolytic infusion takes to work, making it a contraindication to choosing thrombolysis as the initial strategy. Irreversible ischaemia, statement 1, describes a limb that is already non-viable; here the issue is not that thrombolysis is unsafe, but that there is no longer any tissue left to save, so the patient goes straight to amputation rather than being said to have a contraindication to a treatment that was never going to help.

Step 4: Conclusion:
The correct combination is statements 2, 3, and 4: a bleeding source, suprainguinal occlusion, and critical ischaemia with neurological deficit are the recognised contraindications to thrombolytic therapy, while irreversible ischaemia is a separate situation in which thrombolysis is simply not applicable because the limb is already unsalvageable.