1. Management of Small renal tumors
Dr. NGAI Ho Yin
Division of Urology
Department of Surgery
United Christian Hospital

2. Differential Dx of solid renal mass
Most common:
Renal cell carcinoma
Less common:
Oncocytoma
Renal cortical adenoma
AML
Rare:
Neoplasm:
Transitional cell carcinoma
Metastatic tumors
Infection:
Renal abscess
Vascular
Infarct
Vascular malformation

3. Natural history of small renal tumor
Meta-analysis from Uzzo et al. (2006)
234 enhancing renal masses
From 9 series
Mean follow-up: 34 months
Mean initial size: 2.60cm
Mean growth rate 0.28cm/yr
Uzzo et al. The natural history of observed enhancing renal masses: Meta-analysis and review of the world literature. J Urol 175: Feb 2006

4. Analysis of Histology related to Tumor size ( Mayo clinic, from 1970-2000, n=2935 )
% of Tumors that were RCC
% of RCC that were G3/G4
<1 cm (n=80)
54% 2%
1-4 cm (n=867)
79%
16%
4-7 cm (n=923)
90%
30%
>7 cm (n=1065)
94%
57%
Frank I et al. Solid Renal Tumors: an analysis of pathological features related to tumor size.　J Urol 170: Feb 2003

5. Natural history of small renal tumor
For single, small solid renal tumor
Almost 50% are benign if <1cm
Most will grow slowly, ~0.28cm/yr
 size =  chance of RCC & high grade disease
Aggressive potential of RCC increase after 3cm

6. What are the available options in dealing with small renal tumors ?
Management strategy
What are the available options in dealing with small renal tumors ?

7. Options Observation Radical Nephrectomy Nephron-Sparing Surgery
Tumor Excision
Open partial nephrectomy
Laparoscopic partial nephrectomy
Tumor Ablation
Laparoscopic cryoablation
Radiofrequency ablation (RFA)

8. Observation

9. Radical nephrectomy

10. Radical nephrectomy Gold Standard curative operation
Described by Robson 1963
Surgical Principles
Early ligation of the renal artery & vein
Removal of the kidney outside Gerota’s fascia
+/- Removal of ipslateral adrenal gland
+/- Complete lymphadenectomy from the crus of diaphragm to aortic bifurcation

11. Radical nephrectomy
5 yr survival ( organ-confined ) ~ 95%

12. Nephron Sparing Surgery

13. Nephron Sparing Surgery
Goal of NSS:
Complete oncological excision of tumor with minimal technical complications
Optimal functional preservation for renal remnant
Indication

14. Nephron Sparing Surgery
1. Open partial nephrectomy
Principles

15. Nephron Sparing Surgery Open partial nephrectomy
Data from 3 major centers including:
Cleveland clinic Hafez KS, Novick AC, Butler BP. Management of small solitary unilateral renal cell carcinomas: impact of central versus peripheral tumor location. J Urol 1998;159:1156–60
Mayo clinic Lerner SE, Hawkins CA, Blue ML, et al. Disease outcome in patients with low stage renal cell carcinoma treated with nephron sparing or radical surgery. J Urol 2002;167:884–9.
Memorial Sloan-Kettering Cancer Center Lee CT, Katz J, Shi W, Thaler HT, Reuter VE, Russo P. Surgical management of renal tumors 4 cm or less in a contemporary cohort. J Urol 2000;163:730–6.
NSS and radical nephrectomy provide equally effective curative treatment for single, small (<=4cm) localized RCC

16. Nephron Sparing Surgery Open partial nephrectomy
Novick AC. Laparoscopic and partial nephrectomy. Clin Cancer Res 2004; 10:6322S-7S
Review of 1262 patients with open NSS for RCC since 1990
Mean Cancer-specific survival for all patients undergoing open NSS for localized RCC
 88% to 97.5% at Mean Follow-up 4-6 years

17. Nephron Sparing Surgery Open partial nephrectomy
Benefit in decreasing risk of progression to chronic renal insufficiency and ESRF
Memorial Sloan-Kettering Cancer Center McKiernan J, Simmons R, Katz J, Russo P. Natural history of chronic renal insufficiency after partial and radical nephrectomy. Urology 2002;59:816–20.
Mayo clinic Lau WK, Blute ML, Weaver AL, Torres VE, Zincke H. Matched comparison of radical nephrectomy vs nephron-sparing surgery in patients with unilateral renal cell carcinoma and a normal contralateral kidney. Mayo Clin Proc 2000;75:1236–42.
Renal insufficiency (Increase in Serum Cr >2mg/dl)
At 10 years time :
12.4% in radical nephrectomy group
2.3% in NSS group

18. Nephron Sparing Surgery Open partial nephrectomy
Gold standard in nephron-sparing surgery
Comparable efficacy, morbidity & mortality as radical nephrectomy
Additional benefit in renal preservation

19. Nephron Sparing Surgery
2. Laparoscopic partial nephrectomy
Principle

20. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Largest single institutional report of LPN by Gill et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200 patients. Journal of Urology. 170(1):64-8, 2003 Jul.
Patients with solitary renal tumor (<=7cm) in size ( clinical T1 RCC )
LPN (n=100) : Sept 1999 to Jan 2002
OPN (n=100) : Apr 1998 to May 2001

21. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Lap PN
Open PN
Blood loss
125ml
250ml
p<0.001
Morphine equivalent
20.2mg
252.5mg
Hospital stay
2 days
5 days
Convalescence
4 weeks
6 weeks

22. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Intra-op Complications
Lap PN
Open PN
Renal haemorrhage 3
Ureteral resection 1
Post-op Complications
Urine leakage
Perirenal haematoma
Renal haemorrhage,
Embolization
Nephrectomy
Haematuria
Ureteropelvic obstruction
Total 11 2
p=0.01

23. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Oncological efficacy of LPN by Allaf et al.
( John Hopkins Medical institution – 3-year follow-up)
48 patients with RCC (Mean tumors size 2.4cm) treated by LPN
Intra-op FS margin : all negative
Mean FU 37.7 months
Final pathology:
42 patients : pT1
6 patients : pT3a
Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome. Journal of Urology. 172(3):871-3, 2004 Sep.

24. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Results :
No recurrence in 46 patients
1 patient with VHL locally recurred at 18th months
1 patient recurred at new location of same kidney at 4 yrs time

25. Nephron Sparing Surgery Laparoscopic partial nephrectomy
Benefits from LPN:
Less blood loss
Less analgesic requirement
Shorter hospital stay
Shorter convalescence
Short term data suggesting promising survival outcomes
Problems of LPN:
Longer warm ischaemic time
More major intra-op & post-op urological Cx
No long term data concerning the oncological efficacy
Laparoscopic NSS is an effective treatment for clinically small localized RCC despite long term result needed.

26. Nephron Sparing Surgery
3. Laparoscopic Cryoablation

27. Nephron Sparing Surgery Laparoscopic Cryoablation
Method:
Usage of a liquid nitrogen-cooled cryoprobe
At temperature of –40 ‘C
By dual freeze-thaw cycle
Direct cellular injury &
Indirect damage to microvasculature
To ablate normal and cancerous tissues
Problems :
No histopathology to assume clearance
May Need extra biopsy for margin clearance

28. Nephron Sparing Surgery Laparoscopic Cryoablation
Gill et al. Renal cryoablation: outcome at 3 years. Journal of Urology. 173(6):1903-7, 2005 Jun.
3 yrs results
56 patients with small renal tumors
75% reduction in mean cryolesion size at 3 years
38% (17 lesions) completely disappeared
Post-op needle biopsy: residual tumor in 2 patients
3 years Cancer-specific survival ( unilateral sporadic renal tumor ) = 98%

29. Nephron Sparing Surgery Laparoscopic Cryoablation
Technically safe and intermediate results are encouraging
Longer term follow-up needed for oncological efficacy of cryoablation

30. Nephron Sparing Surgery
4. Radio Frequency Ablation

31. Nephron Sparing Surgery Radio Frequency Ablation
Using a RFA needle (Percutaneous> open / laparoscopic)
Deliver high-frequency alternating current to cancerous tissue
Induce ionic agitation  frictional heat
 intracellular temperature ( ํC)
Desiccation, Cellular protein denaturation and membrane disintegration

32. Nephron Sparing Surgery Radio Frequency Ablation
Rendon et al.
11 renal tumors
RFA  Immediate / Delayed nephrectomy
Found viable cancer cells in specimen :
4/5 (80%) [immediate group]
3/6 (50%) [delayed group]

33. Nephron Sparing Surgery Radio Frequency Ablation
Michaels et al.
20 renal tumors (mean 2.4cm) in 15 pts
RFA  Open Partial Nephrectomy
Results:
All 20 specimens had evidence of morphologically unchanged tumors

34. Nephron Sparing Surgery Radio Frequency Ablation
Current RFA regimens:
Ineffective for total destruction of renal tumor tissue in a significant number of patients.
Still experimental in treatment of RCC

35. Conclusion For small solid renal tumor <= 4cm Most are RCC
Evidence suggested NSS is equally effective as radical nephrectomy
NSS with better preservation of renal functions in long term
OPN is the gold standard among choices of NSS
LPN is promising technique with its potential advantages

36. Thank you