UROL_V3_No1_001_Editorial.qxd

O R I G I N A L A R T I C L E S

Endourology and Stone Diseases

Retrograde Flexible Ureteroscopic Approach for Pyelocaliceal

Calculi

Petrisor Geavlete, Seyed Abdulah Seyed Aghamiri,* Razvan Multescu

Department of Urology, St John Clinical Emergency Hospital, Bucharest, Romania

ABSTRACT

Introduction: Our goal was to investigate the efficacy of flexible ureteroscopy (FU)

in the treatment of pyelocaliceal calculi.

Materials and Methods: Between September 2002 and December 2004, a total of

41 patients with multiple (23 cases), pelvic (7 cases), and inferior caliceal (11 cases)

SWL-resistant calculi underwent FU. We used a 7.5-F flexible ureteroscope with

pressure irrigation and electro-hydraulic lithotripsy. The fragments were retrieved with

triradiate graspers or tipless baskets.

Results: A double J stent had been previously placed in 34% of the patients. Dilation

of the ureteral orifice was necessary in 9.8%. The location of the calculi was renal

pelvis, inferior calyx, and pelvis and calyxes in 7, 11, and 23 patients, respectively. The

median operative time was 64 minutes for pyelocaliceal, 46 minutes for pelvic, and 39

minutes for inferior caliceal calculi. Complete stone clearance or good fragmentation

(fragments less than 3 mm) was obtained in 71% of patients (57% for pyelocaliceal, 87%

for pelvic, and 71% for inferior caliceal calculi). A successful outcome was achieved in

78%, 72%, and 49% for calculi sized 10 mm or smaller, 11 mm to 20 mm, and greater

than 20 mm, respectively. Two or more procedures were required in 11 patients (27%).

The complication rate was 7.3% (hematuria, persistent renal colic, and hyperthermia).

Conclusion: Our experience shows that FU can be an effective approach in selected

patients, especially those with kidney calculi that are resistant to SWL. However,

percutaneous approach is a better alternative for calculi greater than 20 mm.

KEY WORDS: flexible ureteroscopy, kidney calculus, shock wave lithotripsy

Urology Journal

UNRC/IUA

Vol. 3, No. 1, 15-19 Winter 2006

Printed in IRAN

Introduction

The first flexible ureteroscopy (FU) was

performed for diagnostic purposes in 1964 by

Marshall.(1) He used a 9-F endoscope produced by

an American cystoscope manufacturer, without a

working channel or active deflection facilities.

At the beginning of the 1980s, Bagley and

colleagues(2,3) contributed significantly to the

development of FU by adding three essential

technical characteristics: the working channel, an

active deflection, and--by reducing the rigidity in

the distal portion of the sheath--a passive

deflection. By miniaturization of the endoscopes

and development of the optical system,

ureteroscopes became very useful tools in the

diagnosis and treatment of upper urinary tract

lesions.(4)

Although shock wave lithotripsy (SWL)

represents the first-line treatment of pyelocaliceal

Received November 2005

Accepted February 2006

*Corresponding author: Tel: +40 722 402 887,

Fax: +40 21 321 0507, E-mail: seyedag@yahoo.com

calculi smaller than 20 mm, other alternatives of

endourologic techniques for SWL-resistant calculi

are necessary. Since 2002, the use of FU in the

diagnostic and therapeutic arsenal at St John

Clinical Emergency Hospital in Bucharest has

substantially improved the diagnosis and

treatment of the upper urinary tract diseases,

especially kidney calculi. The purpose of this

study was to evaluate the efficacy, limits, and

complications of the FU in SWL-resistant

pyelocaliceal calculi.

Materials and Methods

Between September 2002 and December 2004,

a total of 41 patients with SWL-resistant

pyelocaliceal calculi underwent FU in our

department. The investigational protocol included

physical examination, routine blood tests,

abdominal ultrasonography, plain abdominal

radiography (kidney, ureter, and bladder),

intravenous urography (IVU), and, in selected

cases, retrograde ureteropyelography and CT

scan.

The characteristics of the calculi are

summarized in Table 1. In the patients with

multiple calculi, the location of calculi was either

concomitant pelvic and caliceal (inferior, middle,

or superior) or multiple caliceal. The maximum

dimensions were 25 mm for pelvic calculi and 12

mm for caliceal ones; the mean area was 328

mm2 (range, 175 mm2 to 610 mm2). In 14 patients

(34%) with obstructive pelvic calculi and

hydronephrosis, double J stenting had been

previously performed and the stent maintained

for 14 days before FU.

In all patients, SWL had been attempted and

the mean number of procedures was 2.9 (range,

1 to 4). They were treated using a 7.5-F Storz

flexible ureteroscope (Karl Storz, Tuttlingen,

Germany) with an active deflection, a secondary

passive deflection, and a 3.6-F working channel.

As an energy source, we used an electrohydraulic

lithotripter (Calcutript, Karl Storz, Tuttlingen,

Germany) with 1.6-F and 1.9-F flexible probes.

For irrigation, saline (0.9% NaCl) solution was

used. For retrieval of calculi fragments, we used

flexible triradiate graspers or Nitinol tipless

baskets. All interventions were performed under

fluoroscopic guidance using a mobile radiological

unit (Siemens, Erlangen, Germany).

Ureteral orifice dilation was necessary in 4

patients (9.8%). The insertion of the FU was

fluoroscopically controlled by sliding on a Nitinol

guide wire (Figure 1); no access ureteral sheath

was used.

In 33 patients (80.4%), ureteral stenting after

the procedure was not necessary. Stents were

used only in patients who needed meatal dilation

(4 cases) and those with significant renal

bleeding during lithotripsy (4 cases), which were

left in place for 14 days.

The procedure was considered successful if all

the calculi were extracted (Figures 2 to 4) or if

the resulted fragments were smaller than 3 mm,

small enough not to be considered as obstructive.

The follow-up protocol included abdominal

ultrasonography, plain abdominal radiography (in

patients with radio-opaque calculi), and in

selected cases (6 patients), IVU.

Flexible Ureteroscopy for Pyelocaliceal Calculi16

TABLE 1. Size and location of the kidney calculi

FIG. 1. Flexible uretroscopic approach to the middle

caliceal calculi (fluoroscopic aspect)

Number of calculi (%)

Size of the calculi

< 10 mm 45 (51.7)

10 mm to 20 mm 25 (28.7)

> 20 mm 17 (19.5)

Location of the calculi Number of patients (%)

Pelvic 7 (17)

Inferior calyx 11 (26.8)

Pyelocaliceal 23 (56.1)

Geavlete et al

Results

The median operative time was 64 minutes

(range, 41 to 215 minutes) for pyelocaliceal, 46

minutes (range, 28 to 89 minutes) for pelvic, and

39 minutes (range, 27 to 70 minutes) for inferior

caliceal calculi. The mean follow-up period was 7

months (range, 3 to 22 months).

Eleven patients (26.8%) required to repeat the

procedure. In 6 of them (54.5%), the initial

procedure was interrupted due to a low visibility

(bleeding in 5 and pyuria in 1) and lithotripsy

was performed in a secondary procedure. In the

other 5 patients (45.5%), the inferior caliceal

calculi could not be approached by flexible

retrograde ureteroscopy, requiring a second

procedure.

The overall success rate was 71%; it was 57% for

pyelocaliceal, 87% for pelvic, and 71% for inferior

caliceal calculi. Considering the calculi

dimensions, the success rate was 78% for calculi

sized 10 mm or smaller, 72% for calculi between

11 mm and 20 mm, and 49% for calculi larger

than 20 mm.

The causes of FU failure were the impossibility

of calculi approach (only in inferior caliceal

calculi), impossibility of fragmentation, or the

necessity of procedure interruption. In all cases,

percutaneous nephrolithotripsy (PCNL) was

performed thereafter. There were no major

complications or deaths. Complication rate was

7.3% (3 patients) presented as minor

complications including hematuria, persistent

lumbar pain, and pyelonephritis.

Discussion

The therapeutic options for pyelocaliceal calculi

are represented by SWL, FU, and PCNL, selected

according to the therapeutic strategy for each

patient.

Developed in the 1980s, SWL became the first

line treatment of calculi smaller than 20 mm.

Although the success rate of this method reaches

92% in selected patients, it is 33% to 65% for

calculi larger than 20 mm,(5,6) and only 41% for

inferior caliceal calculi.(7)

In all SWL-resistant calculi, other methods of

fragmentation and/or extraction are necessary.

Although it has very good results (90% stone-free

rate), PCNL is an invasive method with a high

morbidity rate.(8)

Allowing, at least theoretically, the access to

any upper urinary tract region, FU represents a

valuable alternative in the therapeutic arsenal for

kidney calculi. Flexible ureteroscopy offers the

advantages of direct visualization and extraction

of the calculi, followed by inspection of the

pyelocaliceal system for potential remnant

fragments.(7)

Parameters such as dimension, composition,

and multiplicity of the calculi influence the

success rate of the lithotripsy methods. The

success rate of SWL in lower caliceal calculi is

low (41% to 79%).(7,9,10) Large dimensions of the

calculi, higher concentration of cystine or calcium

monohydrate oxalate,(11) or anatomical particular-

ities of intrarenal ducts (inferior caliceal

infundibular length of more than 3 mm and/or a

diameter smaller than 5 mm, acute infundibulo-

pelvic angle) are associated with a poor SWL

success rate.(12) In the presence of these negative

factors, the FU could be a superior alternative.

FIG. 3. A stone-free inferior calyx (endoscopic and

fluoroscopic intra-operative aspect)

FIG. 4. Middle caliceal calculi (endoscopic and fluoroscopic

intra-operative aspect)

FIG. 2. Multiple caliceal calculi (endoscopic and

fluoroscopic intra-operative aspect)

Flexible Ureteroscopy for Pyelocaliceal Calculi

Grasso and Ficazzola have treated 90 cases of

lower pole calculi with a small diameter, actively

deflectable, flexible ureteropyeloscope and

reported a 94% success rate using FU for inferior

caliceal calculi smaller than 10 mm and a 95%

rate for those between 11 mm and 20 mm.(13)

Hollenbeck and colleagues have reported a 79 %

stone-free rate after one attempt, raised to 88%

after the second procedure.(14) The 71 % stone-

free rate for inferior caliceal calculi in our study—

lower than that in other reports—can be explained

by the patient selection (with SWL-resistant

calculi) and by the type of energy used to

fragment calculi (electrohydraulic lithotripter). In

a study on 81 patients with SWL-resistant kidney

calculi, Stav and associates have reported a 67 %

success rate.(7)

Hallenbeck have suggested that anatomical

particularities of intrarenal ducts associated with

a poor SWL success rate also makes the

endoscopic approach difficult.(14) Likewise,

Grasso and Ficazzola have indicated that

hydronephrosis, inferior caliceal duct stenosis,

and infundibular length of more than 3 mm are

most frequently associated with the failure of

intrarenal lithotripsy using FU.(13) Oxalate

calcium monohydrate calculi associated with a

low SWL success rate are frequently

electrohydraulic lithotripsy-resistant. The use of a

Holmium laser energy source would probably

improve the stone-free rate.(15)

The success rate of FU in patients with

pyelocaliceal calculi larger than 20 mm is less

than 50%; Grasso and Ficazzola have reported the

complete fragmentation of calculi of such

dimensions in 45% of patients,(13) and Robert and

colleagues have reported it in 47 %.(16) Shock

wave lithotripsy is also associated with poor

results for this type of calculi (average success

rate of 63%). The best therapeutic alternative for

this type of calculi remains PCNL.(5,6,17)

In 14 patients (35%) of our series with

obstructive pelvic calculi and hydronephrosis, a

double J stent was placed and FU was performed

14 days thereafter. The double J stent reduces the

hydronephrosis, enhancing the performances of

FU by offering the possibility of obtaining the

secondary passive deflection, which allows the

access to the inferior caliceal group.

The complication rate reported in literature is

between 0% and 13%--mostly due to minor

complications.(11) Only one major complication

was cited: retroperitoneal hematoma in a patient

with uncontrolled hemorrhagic diathesis.(18) Stav

and colleagues have reported a 10% rate of minor

complications and no major ones.(7)

Because of the reduced dimensions of the

flexible ureteroscope, the injury to the upper

urinary tract is minimal(19); this technical

particularity associated with an adequate

preoperative assessment makes FU a safe method

with a lower morbidity and practically no

mortality.

Conclusion

Flexible ureteroscopy can be an efficient

treatment alternative in kidney calculi, especially

in SWL-resistant calculi smaller than 20 mm.

This method provides a good approach for

inferior caliceal calculi (with a success rate higher

in selected cases than that obtained by SWL). For

calculi larger than 20 mm, the most efficient

method remains PCNL, despite its higher

morbidity rate.

Overall, respecting the anatomical urinary

tract, FU is a minimally invasive method with a

low morbidity rate.

References

1. Marshall VF. Fiber optics in urology. J Urol. 1964;91:110-4.

2. Bagley DH, Huffman JL, Lyon ES. Combined rigid and

flexible ureteropyeloscopy. J Urol. 1983;130:243-4.

3. Bagley DH, Huffman JL, Lyon ES. Flexible

ureteropyeloscopy: diagnosis and treatment in the upper

urinary tract. J Urol. 1987;138:280-5.

4. Grasso M. Ureteroscopy. eMedicine [cited 2002 May 29].

Available from:

http://www.emedicine.com/med/topic3079.htm

5. Tiselius HG, Ackermann D, Alken P, Buck C, Conort P,

Gallucci M; Working Party on Lithiasis, European

Association of Urology. Guidelines on urolithiasis. Eur

Urol. 2001;40:362-71.

6. Lingeman JE, Lifshitz DA, Evan AP. Surgical

management of urinary lithiasis. In: Walsh PC, Retik

AB, Vaughan ED Jr, et al, editors. Campbell's urology.

8th ed. Philadelphia: WB Saunders; 2002. p. 3361-436.

7. Stav K, Cooper A, Zisman A, Leibovici D, Lindner A,

Siegel YI. Retrograde intrarenal lithotripsy outcome

after failure of shock wave lithotripsy. J Urol.

2003;170:2198-201.

8. Kerbl K, Rehman J, Landman J, Lee D, Sundaram C,

Clayman RV. Current management of urolithiasis:

progress or regress? J Endourol. 2002;16:281-8.

9. Lingeman JE, Siegel YI, Steele B, Nyhuis AW, Woods

JR. Management of lower pole nephrolithiasis: a critical

analysis. J Urol. 1994;151:663-7.

10. Netto NR Jr, Claro JF, Lemos GC, Cortado PL. Renal

Geavlete et al

calculi in lower pole calices: what is the best method of

treatment? J Urol. 1991;146:721-3.

11. Busby JE, Low RK. Ureteroscopic treatment of renal

calculi. Urol Clin North Am. 2004;31:89-98.

12. Elbahnasy AM, Shalhav AL, Hoenig DM, et al. Lower

caliceal stone clearance after shock wave lithotripsy or

ureteroscopy: the impact of lower pole radiographic

anatomy. J Urol. 1998;159:676-82.

13. Grasso M, Ficazzola M. Retrograde ureteropyeloscopy

for lower pole caliceal calculi. J Urol. 1999;162:1904-8.

14. Hollenbeck BK, Schuster TG, Faerber GJ, Wolf JS.

Flexible ureteroscopy in conjunction with in situ litho-

tripsy for lower pole calculi. Urology. 2001;58:859-63.

15. Sofer M, Watterson JD, Wollin TA, Nott L, Razvi H,

Denstedt JD. Holmium:YAG laser lithotripsy for upper

urinary tract calculi in 598 patients. J Urol. 2002;167:31-4.

16. Robert M, Drianno N, Marotta J, Delbos O, Guiter J,

Grasset D. [The value of retrograde ureterorenoscopy in

the treatment of bulky kidney calculi]. Prog Urol.

1997;7:35-41. French.

17. Conort P, Dore B, Saussine C; Comite Lithiase de

l'Association Francaise d'Urologie. [Guidelines for the

urological management of renal and ureteric stones in

adults]. Prog Urol. 2004;14:1095-102. French.

18. Watterson JD, Girvan AR, Cook AJ, et al. Safety and

efficacy of holmium: YAG laser lithotripsy in patients

with bleeding diatheses. J Urol. 2002;168:442-5.

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Editorial Comment

Consistent with other reports, the success rate

of ureteroscopy in the treatment of calculi

greater than 2 cm and multiple pyelocaliceal

calculi was lower in this study. However, it should

be noted that the patients with such calculi

constituted a very smaller proportion of the

patients in this report. Thus, with a larger sample

size and increasing the surgeons' experience, a

different outcome may be achieved. Moreover, the

relatively low success rate in patients with

multiple calculi could be related to the total size

of the calculi.

The authors have mentioned that the energy

source was provided by an electrohydraulic

lithotripter. Nonetheless, using holmium laser is

nowadays a more recommended method as

electrohydraulic lithotripsy can lead to injuries to

the ureteral mucosa and damage to the

ureteroscope lens. This can explain the cause of

intra-operative bleeding in 5 out of 41 patients,

resulting in lithotripsy failure.

Abbas Basiri

Department of Urology, Shaheed

Labbafinejad Medical Center,

Shaheed Beheshti University of

Medical Sciences, Tehran, Iran

Reply by Author

Indeed, the electrohydraulic lithotripsy has

some disadvantages comparing with laser

lithotripsy: lower success rate in stone

fragmentation, higher risk of damaging the

pyelocaliceal mucosa, and the ureteroscope's

optical system. Nonetheless, electrohydraulic

lithotripsy presents some advantages: lower costs

and also a higher flexibility of the thin 1.6-F

electrohydraulic probes, in comparison with the

200-µm laser fiber. These flexible probes inserted

through the working channel have a reduced

influence on the maximum deflection angle of the

flexible ureteroscope, important when the access

to the inferior calyx is difficult.

Seyed Abdulah Seyed Aghamiri

Department of Urology, St John

Clinical Emergency Hospital,

Bucharest, Romania