Question

Pelviureteric obstruction on the left side in a 33 year old male who presents with fever and infection. All the following are correct EXCEPT

• A. Dismembered pyeloplasty is the treatment of choice
• B. Endoscopic pyeloplasty is contraindicated
• C. Most common cause is an aberrant vessel
• D. Tuberculosis can be a cause

Hint:

Recall whether an intrinsic narrow segment or an outside vessel is the more common cause of PUJ obstruction.

Answer 1

The Correct Option is C

Step 1: Understand pelviureteric junction (PUJ) obstruction.
PUJ obstruction is a block at the point where the renal pelvis narrows into the ureter, so urine cannot drain freely from the kidney. It can be congenital, present from birth, or acquired later from stones, tumors, or infection.

Step 2: Analyze option (A), dismembered pyeloplasty.
The Anderson-Hynes dismembered pyeloplasty is the gold standard operation for PUJ obstruction. The narrow segment is cut out, the pelvis is trimmed, and a fresh wide anastomosis is made to the ureter. This statement is true.

Step 3: Analyze option (B), endoscopic pyeloplasty being contraindicated.
Endoscopic treatment (endopyelotomy) cuts the narrow segment from inside, without removing it or repositioning nearby vessels. It needs a clean, uninfected urinary tract to heal safely, since cutting through infected, inflamed tissue raises the risk of bleeding and urosepsis.
This patient has an obstructed kidney with active fever and infection, so the endoscopic approach is not safe as a first step here, and calling it contraindicated in this setting is a true statement.

Step 4: Analyze option (C), aberrant vessel as the most common cause.
The most common cause of PUJ obstruction is actually an intrinsic problem, an abnormal, poorly contractile (aperistaltic) segment of muscle at the PUJ that fails to push urine forward, present from birth in most congenital cases.
A crossing or aberrant lower pole vessel pressing on the PUJ from outside is a well recognized cause, and it matters because it changes how the pyeloplasty is done, but it is not the single most common cause overall.
So the claim that an aberrant vessel is the most common cause is false, and this is the statement that does not fit with the rest.

Step 5: Analyze option (D), tuberculosis as a cause.
Genitourinary tuberculosis can scar and narrow the ureter at the PUJ as it heals, causing a secondary, acquired PUJ obstruction. This statement is true.

Step 6: Final answer.
Note on the source key: the original answer key for this question was left blank or unclear in the source paper. Working through each statement on current medical grounds, the one that is NOT correct is that an aberrant vessel is the most common cause of PUJ obstruction, since an intrinsic aperistaltic segment is actually the more common cause.
\[ \boxed{\text{Most common cause is an aberrant vessel - INCORRECT statement}} \]