Emergency- Septic stone

Question 1

A 44F presents with a 6 month hx of rUTIs and left loin pain. CTKUB shows a staghorn calculus.
Define a staghorn calculus

Answer 1

renal stone that branches into more than one calyces

Question 2

What further investigations would you perform for a nonseptic staghorn calculi ?

Answer 2

Urinalysis- C&S, HCG for all women of child bearing age.
Bloods: FBC, U&Es, CRP, Bone profile, uric acid, Coag
Imaging: DMSA to check split renal function

Question 3

What is the difference between DMSA and MAG3 scan

Answer 3

DMSA= A form of static renal imaging that uses 2,3 dimercaptosuccinic acid with a radioactive isotope Technecium 99m and is injected and protein is attached to the renal tubules. images are taken with a gamma ray camera after 2-3 hours of the tracer.
indicated for assessing renal cortex and morphology as well as split renal function

MAG3= A form of dynamic renal imaging that uses mercaptoacetyltriglycerine with technecium 99m which undergoes tubular and glomerular excretion. Gamma ray camera takes a series of images every 2 sec for 1 minute, the every 30s for approx 30mins to create almost like a video.
indicated for assessing for renal obstruction as well as split renal function

Question 4

What surgical options are there for renal stones

Answer 4

Upper and mid pole stones
>2cm= 1st PCNL, 2nd URS/ESWL
1-2cm= PCNL/URS/ESWL
<1cm= 1st URS/ESWL, 2nd PCNL

Lower pole stones
>2cm=1st PCNL, 2nd URS/ESWL
1-2cm= if not good for SWL--> URS/PCNL
             if good for SWL--> 1st SWL, 2nd URS, PCNL
<1cm= 1st ESWL/ URS, 2nd PCNL

Question 5

What are signs of ureteric stone on a CTKUB?

Answer 5

hydonephrosis, perinephric stranding, periureteric wall oedema, periureteric stranding

Question 6

How would you consent for a ureteroscopy and stone fragmentation?

Answer 6

Confirm patient name, DOB, clarify side and mark
Explain indications and alternatives- PCNL or nephrostomy
Explain procedure but presume would have had BAUS leaflet before consent
Explain risks
-Bleeding, infection, failure to locate UO and need nephrostomy, failure to get to stone and stent only inserted, need for further procedure. damage to bladder, ureter or kidney that may require open surgery to repair, Stent symptoms, GA risks, blood clots [PE/DVT]

Question 7

When would you consider a nephrostomy over a ureteric stent?

Answer 7

If the patient is unstable for a GA and there is a interventional radiologist available.
If the patient is pregnant and to avoid a GA.

There is no evidence to suggest which intervention is better

Question 8

What are the possible risk factors for stone formation?

Answer 8

General:

• poor fluid intake and diet
• Obesity

Associated conditions:

• short gut syndrome
• IBD: Crohn’s disease
• Neurogenic bladder

Genetics:

• Cystic Fibrosis
• Cystinuria

Anatomical:

• PUJ obstruction
• Ureteric stricture
• Medullary Sponge kidney