Question

Chief Complaint: 52-year-old male with abdominal pain and nausea.  

History: The patient was woken up by abdominal pain located in his right lower quadrant, in the right groin and radiating into his right testicle. He was transported to the hospital. He reports that his pain is a “10” on a 1 to 10 scale. He is nauseated but has not vomited. The patient is normal weight and otherwise healthy. Upon palpation his abdomen is soft with mild tenderness in the right lower quadrant. Following the discovery of blood in his urine he is diagnosed with a ureteral obstruction, a computed tomography scan shows a calcified stone in the right ureter at the ureterovesical junction.

Answer the questions below.

1. The ureterovesical junction (where the ureter passes through the wall of the bladder) is a common site for kidney stones to become impacted. Can you propose two additional sites within the ureter where kidney stones are likely to become impacted based on the anatomy of the ureters?

2. This patient was advised to increase his water intake to prevent subsequent kidney stones. Why would an increased fluid intake lower his chances for a repeat incident?

3. Assume that the kidney stone in question has reached the bladder. What is the pathway of exit for this stone (i.e. what anatomic structures must the stone still pass through)? Based on the anatomy of those structures, do you predict this to be difficult or easy? Defend your answer.

4. Propose a possible treatment for the patient in this case study. How does this treatment improve conditions for the patient? Are these improvements seen at the cellular, tissue, organ or systemic level?

Answer 1

1) The ureteric stones are present most commonly in the ureterovesical junction as it is the narrowest part of ureter. Apart from this area, ureteric stones are also seen in pelviureteric junction and at the site of crossing of iliac artery in the mid ureter.

2) Increased water intake will dilute the urine and will decrease the probability of sediment formation (calculi) in renal tissues.

3) Once the calculi reach the bladder, it has to get pass through internal vesical sphincter, urerhra and external vesical sphincter. These structures can dilate to a maximum of 6 mm. This passage will be difficult if the size of stone is greater than 6 mm.

4) The calculus can be removed by cutaneous distal ureterostomy. This will remove the obstruction to urinary flow caused by calculus and therefore relieves pain.