Miniaturized percutaneous nephrolithotomy (PCNL) techniques like super mini-PCNL (SMP) provide safe and effective alternatives to conventional PCNL for treating kidney stones. SMP uses an irrigation-suction sheath system that maintains a clear endoscopic view and actively removes stone fragments through continuous suction. This allows for high stone-free rates comparable to conventional PCNL but with lower complication rates and shorter hospital stays. SMP is particularly well-suited for pediatric patients and for treating stones less than 3 cm in adults.

1. Super Mini PCNL for
Renal Stones
Dr Zamari Noori
MD Urolgy and Endourology

3. Pros and Cons for PCNL
Pros
• High stone-free rate
Cons
• High complications（Bleeding，
Urosepsis…)

4. Miniaturized percutaneous
nephrolithotomy
• miniaturized PCNL techniques appear to be
• safe and effective
• alternatives to conventional PCNL for both
• adult and pediatric patients.
They aim to reduce percutaneous tract size in order to
lower complication rates,
high stone-free rates.

5. . mini-PCNL, minimally invasive PCNL (MIP)
• Chinese mini-PCNL (MPCNL),
• ultra-mini-PCNL (UMP),
• micro-PCNL,
• mini-micro-PCNL, and
• super-mini-PCNL (SMP).

7. How to decrease bleeding
following PCNL
• Always make a puncture - From fornix
• Never from infundibulum
8% vein injury
No artery injury
8% vein injury
No artery injury

8. How to decrease bleeding
following PCNL
• Small size access
• Different mini-perc techniques were
developed
Mircro-Perc(Fr 4.85)
UMP(Fr 11-13)
SMP(Fr 10-14)

9. New problems for Mini-Perc
• Lower irrigation flow
• Small size access-miniature endoscopes -Small size irrigation
channel
• Increased difficulty in stone extraction
• Passive egress of the stone fragments with pressure pump
• Compromised endoscopic view
• Lower irrigation flow, specially insertion of laser fiber and
basket…
• High intra-renal pressure
• Pressure pump
• How to deal with all problems?

11. Irrigation-suction sheath system
• This system consists of 2 parts:
straight sheath and handle part.
• Sheath consists of 2 layers metal
sheath, which form a tiny gap in
between for irrigation .
• 8 tiny holes are located at the tip
of sheath for fluid outflow.
• There is a vent on the handle
part ,which controls negative
pressure by it’s opening or closure.

12. Irrigation-suction sheath system
• Good entry and exit of the irrigation fluid
Irrigation inflow is from sheath, and not from irrigation
Channel in endoscope, irrigation outflow with the suction sheath
• Clear endoscopic view
Continuous suction and good irrigation flow
• Effective evacuation of stone fragments
One-way suction-active removal of stone fragments
Mostly no need any forcep and basket

13. outflow
inflow
Nephroscope
Irriga
tion
pum
p
Irrigation-suction sheath
SMP system
Traditional mini-PCNL
outflow
inflow
Nephroscope
Irrigation
pump
Sheath
inflow
outflow
stone fragments
The hydrodynamic mechanisms for retrieval fragments in new generation
SMP system and traditional mini-PCNL SMP system

14. RPP in new-generation SMP
• Basic RPP (mmHg) 8.94±3.58
• Intraoperative RPP (mmHg) 20.02±3.58
• Number of patients who had one episode of RPP ≥ 30 mmHg 81.5%
• Accumulated time of RPP ≥ 30 mmHg (s) 114.89±132.65
Irrigation Pressure: 200-250mmHg
Suction Pressure: 150-200mmHg
Lower intra-renal pressure: less than 30mmHg
Good space for operation

15. Indications for SMP
• Stone size less than 3cm
• Failed SWL or RIRS
• Especially for pediatric patients resistant
to SWL

16. SMP for adult nephrolithiasis
22 years old male, solitary right functioning kidney, multiple stones
located in lower calyx and upper ureter, anuria, the DJ stent was left for
40 days.
How to manage it?
First choice: SWL? RIRS? PCNL?

17. Multiple-tracts SMP - totally
tubeless
Multiple-tracts SMP - totally tube
RIRS failed

18. SMP (n=2012) vs. mini-PCNL (n=1513) for ≥
2cm renal stones

19. SMP could be a safer and more efficacious option for the treatment of renal
stones of 2–3 cm, with the advantage of a shorter hospital stay.

20. SMP for pediatric nephrolithiasis
Girl, 2 years old, right kidney stone 2cm, SWL failure, stone composition
analysis :cystine stone
How to manage it?
First choice: RIRS? PCNL?

22. SMP for pediatric patients
• Patients data (111 cases)
• Gender: 71 boys and 41 girls
• Age: 3.90± 3.53 yrs (0.5~15).
• Stone burden (cm)：1.4±0.6 (0.8-4.8)
• Stone location, n (%)
Upper ureter 33 (29.7%)
Pelvis 26 (23.4%)
Upper calyx 14 (12.6%)
Middle calyx 9 (8.1%)
Lower calyx 21 (18.9%)
Multiple 8 (7.2%)
• Positive preoperative urine culture 16 (14.4%)
• HU value: 735.2±329.1 (288-1378)

23. Results
• Single tract: 111 (100%)
• Operative time: 39.4±26.2 mins （7~105)
• SFR (1 day after procedure) : 101 (91.0%)
• SFR (3 months after procedure) : 106
(95.5%)
• Hb dropped (g/L) : 10.2±7.1 (0~25)
• Access size: 10F 2(1.8%), 12F
94(84.7%),14F 15(13.5%)
• Puncture site:

24. Results
• Complications: fever (>38.5 °C) 7 (6.3%)
• Transfusion：0%.
• Total tubeless PCNL: 95 (85.6%)
• Hospital stay (days): 2.7±1.5
• Stone composition (84 cases available):
Calcium phosphate 4 (4.8%)
Magnesium ammonium phosphate 6 (7.1%)
Carbonate apatite 1 (1.2%)
Uric acid 10 (11.9%)
Calcium oxalate 25 (29.8%)
Ammonium urate 37 (44.0%)
Cystine 1 (1.2%)
For pediatric stones of 10–20 mm, SMP could be an ideal choice with
a high stone-free rate and minimal invasiveness.

25. Half-day surgery SMP
SMP under paravertebral block anesthesia
• Fast recovery
– Totally “tubeless”, short hospital stay and no need to come back for
stent removal.
– Discharged post-operative 5-6 hours.
• Low risk of cross-infection of COVID-19
– Safe for doctors: No need to use ventilators
– Safe for patients: One-day surgery, no need to stay overnight in the
hospital
• Comfortable and cost-effective

26. Summary
SMP-another definition
Safe………...............S
Meaningful……....…M
Practical…………......P

27. Conclusion
• New SMP solve all drawbacks in Mini-Perc
• Achieve an excellent clinical outcome
 High SFR
 High total tubeless or tubeless rate
 Short hospital stay
 Less complications
 Less(0.5%) Blood transfusion
Best
Culmination
New
SMP