Kidney Stones - Surgical

Question 1

What are favorable conditions for a SWL on CT?

Answer 1

HU < 1000
skin to stone distance < 10cm

Question 2

What are necessary preoperative labs?

Answer 2

U/A, w/ reflex to urine cx - an absolute!

If there is concern for hemmorhage - PCNL, robotic pyelolithotomy, etc: CBC, INR/PT, T&S

If concern of kidney function - BMP

Key it is personalized

Question 3

Patient with uncomplicated stone </= 10mm

Answer 3

offer trial of passage
for distal stones - offer tamsulosin (this is where all the studies are at - but can still optionally offer to patients with stone more prox)

Question 4

What is timeline for MET?

Answer 4

The recommendation is no more than 6 weeks

Question 5

Outline how to counsel on SWL vs URS

Answer 5

Same UTI, sepsis, ureteral stricture, avulsion rate
Ureteral perforation is higher in URS
overall lower complication rate with SWL

Stone free rate for less than 10mm: URS 90% vs 72% SWL
STONE FREE RATE FOR > 10MM in PROX URETER rather equivalent. for stone sizes bigger than this in mid and distal - still URS better

Also counsel usually only need one procedure with URS vs SWL

Question 6

Which stones are not great for SWL?

Answer 6

cystine (resistant to frag) and uric acid (radiolucent)

Question 7

What are reasons to leave a stent?

Answer 7

anatomical impedance to stone drainage (significant manipulation causing ureteral wall edema), large stone burden (>1.5cm), solitary kidney, poor renal function, going to do another ipsilateral URS

Question 8

What are alternatives if complex ureteral stone?

Answer 8

antegrade URS (PCNL), robotic ureterolithotomy

Question 9

Why is EHL not recommended in ureter?

Answer 9

b/c of increased chance of ureteral perforation

Question 10

Total non-lower renal stone burden </= 20mm

Answer 10

SWL or URS or PCNL

SWL and URS less morbidity than PCNL

Question 11

Total non-lower renal stone burden > 2cm

Answer 11

PCNL
more superior stone free rate in less procedures, but increased morbidity

SWL is not first line - as need multiple procedures, increased chance for steinstrasse

Question 12

What to do if residual stone fragments?

Answer 12

Offer ENDOSCOPIC removal. Especially if infection stone.

shown to lead back to stone growth, reintervention, as well as recurrent UTI

Question 13

What is treatment for asymptomatic non obstructing calyceal stone?

Answer 13

may offer AS - but need to do annual imaging

Question 14

Lower pole renal stone </= 1 cm

Answer 14

SWL or URS

Question 15

Lower pole renal stone > 1cm

Answer 15

URS or PCNL

PCNL has higher stone free rate, but more morbidity

Question 16

Are nephrostomy tubes absolutely necessary post PCNL?

Answer 16

No.

Need if planning a second procedure or BLEEDING. Infection should also consider

Question 17

Do you need to do flexible nephroscope?

Answer 17

Yes

Question 18

What irrigation to use?

Answer 18

saline only

Question 19

When are two situations where a safety wire can be omitted?

Answer 19

Impacted stone (place safety wire just distal to stone)
Ureteral access sheath right at pelvis

Question 20

Is antibiotic prophylaxis required for SWL?

Answer 20

No, only if UTI

Yes for PCNL and URS. Remember, stones can contain infection with them

Question 21

You get purulent urine during endoscopic procedure, what do you do?

Answer 21

Stop procedure, place stent or nephrostomy tube, GET URINE CX, start on broad spectrum, antibiotics

Question 22

Can you perform URS on patients that are anti coagulated or on anti platelet?

Answer 22

Yes - increase chance for hematuria / clot formation

Question 23

What are some common sentiments for complex stones that you are doing URS?

Answer 23

Use low pressure as possible, use ureteral access sheath

otherwise increased chance of hemmorhage, sepsis, collecting system perforation, fluid absorption

Question 24

What to remind patients when they ask about using alpha blocker for stone passage?

Answer 24

OFF LABEL

Question 25

When is there an absolute contraindication to SWL?

Answer 25

when there is a distal obstruction

Question 26

What is treatment for diverticular stone?

Answer 26

PCNL, robotic, laparoscopic, or URS

Question 27

Pedi patient with ureteral stone

Answer 27

observation or MET

Question 28

What is treatment for pedi patient with ureteral stone?

Answer 28

SWL or URS

Question 29

What imaging for pedi patient prior to PCNL?

Answer 29

low dose CT

Question 30

Pedi renal stone burden

Answer 30

SWL or URS

Question 31

Pedi renal stone burden > 2cm

Answer 31

PCNL or SWL

Question 32

Which kind of surgeries to avoid in pedi?

Answer 32

robotic and open ureterlithotomy unless with anatomic abnormality

Question 33

Can you observe stones in pedi patients?

Answer 33

Yes, non obstructing asymptomatic renal stones

Question 34

What is first line treatment for pregnant woman with ureteral stone ?

Answer 34

observation - as long as symptoms well controlled

Question 35

What happens if symptomatic?

Answer 35

URS or ureteral stent and nephrsotomy tube - frequent changes

Question 36

Detail what you would do if you encountered arterial and venous bleeding during a PCNL. What about stone outside the renal pelvis. What about irrigant mismatch?

Answer 36

Venous bleeding: stop procedure - place nephrostomy tube and inflate balloon to tamponade Arterial bleeding: stop procedure - place nephrostomy tube, inflate balloon, consider embolization Stone outside pelvis - forget about it If irrigant is more than 1000ml difference - STOP