Question

During surgical exploration for a hydatid cyst of the liver, any of the following agents can be used as a scolicidal agent EXCEPT

• A. Hypertonic sodium chloride
• B. Formalin
• C. Cetrimide
• D. Povidone iodine

Hint:

Consider which agent needs the longest contact time to reliably kill protoscolices.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question is about intraoperative scolicidal agents instilled into a hepatic hydatid cyst before it is opened, to kill any protoscolices and prevent spillage-related recurrence or anaphylaxis.

Step 2: Key Concept or Approach:
An effective scolicidal agent needs adequate concentration and contact time to kill the protoscolices reliably, without causing serious local or systemic toxicity if a small amount leaks into the biliary tree or peritoneal cavity.

Step 3: Working Through the Options:
Formalin, cetrimide and povidone iodine have all been instilled into hydatid cysts intraoperatively and act as effective scolicidal agents within a relatively short exposure time. Hypertonic sodium chloride is scolicidal only at high concentration and when left in contact for a prolonged period (roughly 15-20 minutes); a brief exposure, which is what is practical during surgery, makes it a less dependable option compared to the other three agents listed, which is why it is picked as the exception here.

Step 4: Conclusion:
Hypertonic sodium chloride is the option that stands apart as the least reliable scolicidal agent among those listed for intraoperative use.