What is the recommended management of an impacted urethral stone in a male patient?

Management of Impacted Urethral Stone in Male Patients

In the absence of urethral stricture, the stone should be pushed back into the bladder using a urethral catheter after adequate urethral anesthesia, followed by definitive treatment of the stone in the bladder via either endoscopic lithotripsy or extracorporeal shock wave lithotripsy (ESWL).

Initial Management Approach

The primary strategy for impacted urethral stones without associated urethral pathology is retrograde manipulation back into the bladder 1, 2. This approach is both safe and effective, avoiding the need for immediate urethral surgery and its associated risks of urethral trauma.

Step-by-Step Technique:

• Urethral anesthesia: Instill 2% lidocaine jelly into the urethra and retain for 5 minutes 1, 2
• Catheter insertion: Gently advance a 16F urethral catheter to push the stone retrograde into the bladder 1
• Success rate: This technique successfully dislodges stones in nearly all cases without complications when no urethral stricture is present 1, 2

Critical caveat: This retrograde manipulation approach is only appropriate when there is no history or evidence of urethral stricture. The success depends entirely on adequate urethral anesthesia before catheter insertion 1.

Definitive Stone Treatment After Bladder Relocation

Once the stone is in the bladder, you have two primary options:

Option 1: Endoscopic Lithotripsy (Preferred for Most Cases)

Transurethral ultrasonic or laser lithotripsy should be the first-line definitive treatment 3, 4. This approach:

• Uses a 22-24F nephroscope with ultrasonic or Holmium laser fragmentation 3, 4
• Requires general anesthesia but causes minimal urethral trauma 4
• Allows simultaneous stone fragmentation and fragment removal 3
• Operative time typically 30 minutes 3
• No evidence of urethral stricture formation at 6-month follow-up 4

Option 2: ESWL (Alternative Approach)

For stones successfully pushed into the bladder, ESWL can be performed 1:

• Patient positioned prone with 15-degree tilt toward the stone side to minimize movement 1
• Mean 3600 shock waves (range 1200-6000) at 5-8 kV 1
• Success rate of 95% (19/20 patients) in one session 1
• Major advantage: No anesthesia or analgesia required 1
• Particularly valuable in pediatric patients 1

Option 3: Open Cystolithotomy

Reserved for situations where endoscopic equipment is unavailable 2. While effective, this is more invasive than endoscopic approaches.

Special Considerations

Stones That Cannot Be Pushed Back

If the stone is truly impacted and cannot be manipulated retrograde (rare in the absence of stricture):

• Direct endoscopic lithotripsy can be performed in situ using ultrasonic fragmentation through a nephroscope 4, 5
• Electrohydraulic lithotripsy is another option for endoscopically accessible stones 5

Associated Urethral Diverticulum

If imaging suggests a stone-containing diverticulum 3, 6:

• The diverticulum does NOT need to be resected if it resulted from dilation behind the calculus 3
• Stone removal alone is sufficient 3
• Ultrasound lithotripsy is preferred as it causes minimal mucosal harm 3

Giant Prostatic Urethral Stones

For very large stones (>4 cm) in the prostatic urethra 7, 8:

• TURP combined with Holmium laser lithotripsy for stones up to 4 cm 7
• Open prostatolithotomy may be necessary for giant stones (>7 cm) 8

Common Pitfalls to Avoid

1. Attempting manipulation without adequate urethral anesthesia - This is the most common cause of failure and patient discomfort 1

2. Forcing the catheter against resistance - If the stone won't move easily after proper anesthesia, consider underlying urethral pathology (stricture, diverticulum) 5, 6

3. Attempting in situ ESWL of posterior urethral stones - This is not feasible due to localization difficulties and pain 1

4. Overlooking predisposing factors - Always evaluate for bladder outlet obstruction, neurogenic bladder, urethral strictures, or concomitant bladder stones, as these are present in the majority of cases 5

5. Inadequate follow-up - Monitor for recurrence and urethral stricture formation, though the latter is rare with proper technique 4

Algorithmic Summary

1. Confirm no urethral stricture (history, imaging)
2. Instill lidocaine jelly and wait 5 minutes
3. Push stone to bladder with 16F catheter
4. If successful: Proceed to endoscopic lithotripsy (first choice) or ESWL (especially in children)
5. If unsuccessful: Direct endoscopic lithotripsy in situ
6. If giant stone (>7 cm): Consider open surgery