Urolithiasis DOI 10.1007/s00240-013-0615-2
ORIGINAL PAPER
Comparison of shock wave lithotripsy, flexible ureterorenoscopy and percutaneous nephrolithotripsy on moderate size renal pelvis stones Okan Bas • Hasan Bakirtas • Nevzat Can Sener • Ufuk Ozturk • Can Tuygun • H. N. Goksel Goktug M. Abdurrahim Imamoglu
•
Received: 26 August 2013 / Accepted: 15 October 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract To compare success and complication rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) according to modified clavien grading system of renal pelvis stones between 1 and 2 cm. The results of 149 patients were evaluated retrospectively. Patients were divided into three groups as 52 for SWL, 47 for F-URS and 50 for PNL. Complications were evaluated by modified Clavien grading system. In the first group, stone-free rates after a mean of 2, 6 sessions was 86 % (45/52). In Group 2, this ratio was 91.4 % (43/47), and in Group 3, it was 98 % (49/50). The success rate in Group 3 was significantly higher than other groups. Complication rates for Group 1, 2 and 3 were 7.6 % (4/52), 6.3 % (3/47) and 12 % (6/50), respectively. Although PNL was the most successful technique compared with other techniques, complications were also higher in this group. Even though PNL is the most successful, it should be performed for selected patient groups and indications should be carefully evaluated. Keywords Moderate size renal pelvis stones SWL F-URS PNL
O. Bas (&) Department of Urology, Abdurrahman Yurtaslan Oncology Training and Research Hospital, Ankara, Turkey e-mail: [email protected] H. Bakirtas U. Ozturk C. Tuygun H. N. G. Goktug M. A. Imamoglu Department of Urology, Ministry of Health, Diskapi Yildirim Beyazid Training and Research Hospital, Ankara, Turkey N. C. Sener Department of Urology, Ministry of Health, Numune Training and Research Hospital, Adana, Turkey
Abbreviations SWL Shock wave lithotripsy F-URS Flexible ureterorenoscopy PNL Percutaneous nephrolithotripsy KUB Kidney–ureter–bladder
Introduction Urolithiasis is one of the most painful diseases and although prevalence varies according to demographic changes, a lifetime prevalence of 10 % has been reported [1]. It may be present throughout the entire urinary tract but the kidney is the most common site. Treatment options include surveillance, medical treatment, extracorporeal shock wave lithotripsy (SWL), percutaneous nephrolitotomy (PNL), mini-PNL, flexible ureterorenoscopy (F-URS), laparoscopy and open surgery. As a result of advancements in endourologic technology, only 1–2 % of kidney stones are treated by open surgery [2]. Although urolithiasis can be treated with great success, high recurrence rates make it an important health issue requiring additional techniques. Without further medical treatment, there is a 50 % chance of recurrence [3]. Which highlights the importance of endoscopic and minimal invasive treatments [4]. It has been recommended that kidney stones bigger than 2 cm are treated by PNL, stones smaller than 1 cm by SWL or F-URS and there is a gray zone for stones between 1 and 2 cm. In recent guidelines [5], there is no clear recommendation for the treatment of moderate size renal pelvis stones. Therefore, in this study it was aimed to compare the success and complication rates of SWL, F-URS and PNL for renal pelvis stones between 1 and 2 cm in size.
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Urolithiasis
Patients and methods Patients A retrospective evaluation was made of 149 patients treated with SWL, F-URS or PNL at our clinic between January 2008 and August 2012. Treatment method was chosen according to the surgeons’ and patient’s preference. Patients with a single renal pelvis opaque stone of diameter between 1 and 2 cm were included the study. Patients with semi-opaque or non-opaque stones, anomalous kidneys, ureteropelvic junction obstruction, a history of open or percutaneous interventions to the ipsilateral kidney or having a solitary kidney were excluded. A total of 149 patients met these criteria and were divided into three groups according to the procedure performed; Group 1 (SWL) n = 52, Group 2 (F-URS) n = 47, Group 3 (PNL) n = 50. In the F-URS Group, three patients continued their antiagregant therapy as an advantage of this method, whilst it was stopped for all patients in the other groups. Also, for patients undergoing PNL, only subcostal access was included. Methods SWL technique SWL treatment was performed as an outpatient procedure using an electrohydraulic extracorporeal lithotripter (Multimed Classic; Elmed, Ankara, Turkey) by a team consisted of an experienced urologist and technician. Before treatment, an intramuscular non-steroidal anti-inflammatory drug was administered. No sedation and/or general anesthesia was needed. Stone targeting was done by fluoroscopy. Therapy was started at 16 kV and then increased gradually to 18 kV. A maximum of 3,000 shocks were delivered for each session (100–120 shocks/min) or until complete fragmentation of the stone had occurred. Patient coupling was done by membrane (dry coupling) and a water cushion was used. The patients were evaluated for fragmentation assessment by kidney–ureter–bladder (KUB) radiography, 1 week after the SWL session. When inadequate fragmentation of the stone was observed, treatment was repeated after 2 weeks. If there was no breakage of the stone after three sessions, the case was considered a SWL failure. F-URS technique F-URS procedures were performed under general anesthesia with the patient placed in the lithotomy position on
123
an endoscopy table with fluoroscopic imaging capability. Rigid ureteroscopy was routinely performed before flexible ureteroscopy in all patients for dilation of the ureter and to place a hydrophilic guidewire into the renal pelvis. A 0.035/0.038 in. safety guidewire was inserted into the renal pelvis under fluoroscopic guidance. Thereafter, a ureteral access (11/13F) sheath was passed over the hydrophilic guidewire as far as the ureteropelvic junction. When the rigid/flexible ureteroscope could not be advanced easily, the stent was left for 2 weeks before repeating the procedure. The flexible ureterorenoscope (Flex-X2, Karl Storz, Tuttlingen, Germany) was inserted through the ureteral access sheath. The stones were fragmented with a 200-lm holmium laser probe (Ho YAG Laser; Dornier MedTech; Munich, Germany) until they were deemed small enough to be passed spontaneously. A JJ stent was put into place at the end of the procedure and removed approximately 7–14 days postoperatively. PNL technique With the patient in the lithotomy position, rigid cystoscopy was performed to place a ureteral catheter. After catheter insertion, the patient was placed in the prone position, and percutaneous access was achieved under C-arm fluoroscopy guidance using an 18-gauge needle and guidewire. Amplatz dilators were used for tract dilatation up to 12F– 30F. Removal of stone fragmentation was accomplished using a pneumatic lithotripter (Lithoclast; EMS, Nyon, Switzerland) and retrieval graspers through a rigid nephroscope (26F, Karl StorzÒ). A nephrostomy tube was placed in all the patients at the end of the procedure. This nephrostomy was removed on postoperative days 1–2 and the patient was discharged the following day. All patients were evaluated by medical history, physical examination, complete blood count, plasma urea and creatinine values, coagulation profiles, intravenous urography, urinalysis and urine cultures. A preoperative negative urine culture was required before surgery so any positive urine cultures were adequately treated with appropriate antibiotics. Stone length was measured on KUB radiography. Stone clearance was assessed with postoperative KUB radiography at day 7 for SWL and with intraoperative and postoperative 1st day KUB radiography for F-URS and PNL. All patients were assessed with urinary ultrasound at postoperative 1 month. The groups were compared for success and complication rates by the modified clavien grading system as developed by Clavien et al. [6] and modified in 2004 for standardization [7] (Table 1). Patients who were stone-free 1-month after the operation were considered successful.
Urolithiasis Table 1 Classification of surgical complications based on the modified Clavien system Grade
Subgrade
Definition
I
Any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions. Allowed therapeutic regimens are drugs as antiemetics, antipyretics, analgesics, diuretics, electrolytes and physiotherapy. This grade also includes wound infections opened at the bedside
II
Complications requiring pharmacological treatment with drugs other than such allowed for grade I complications. Blood transfusions and total parenteral nutrition are also included
III
Complications requiring surgical, endoscopic or radiological intervention a
Intervention not under general anesthesia
b
Intervention under general anesthesia
IV
Fig. 1 Comparison of success rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) groups. *p \ 0.05, statistically different from other groups
used for comparisons of variables between categorical data. A value of p \ 0.05 was considered statistically significant.
Life-threatening complications (including CNS complications) requiring IC/ICU management a
Single organ dysfunction (including dialysis)
b
Multiorgan dysfunction
V
Death
Suffix ‘‘d’’
If the patient suffers from a complication at the time of discharge, the suffix ‘‘d’’ (for disability) is added to the respective grade of complication. This label indicates the need for a follow-up to fully evaluate the complication
Table 2 Comparison of patient demographics Group I (n = 52)
Group II (n = 47)
Group III (n = 50)
P
Male (%)
53.84 (n = 28)
63.82 (n = 30)
58 (n = 29)
[0.05
Female (%)
46.15 (n = 24)
36.17 (n = 17)
42 (n = 21)
[0.05
Sex
Stone localization (%) Right
44.23 (n = 23)
40.42 (n = 19)
40 (n = 20)
[0.05
Left
55.76 (n = 29) 15.3 ± 2.1
59.57 (n = 28) 14.8 ± 2.3
60 (n = 30)
[0.05
15.9 ± 2.9
[0.05
Stone size (mm)
Statistical analysis Statistical analyses were performed using the Statistical Package for Social Sciences version 20.0 software (SPSS Inc, Chicago, IL, USA). In addition to the frequency and percentage distributions of the data, Student’s t test was used for in-group comparisons, and Chi Square test was
Results The mean age of the patients was 46.4 years (±15.1 years), 47.2 years (±14.2 years) and 45.5 years (±13.1 years) for Groups 1, 2 and 3, respectively. There was no significant demographic difference between the groups (Table 2). The mean number of sessions for SWL group was 2.6 (2–3). Nineteen patients were treated in two sessions and 33 patients were treated in three sessions. After a mean of 2.6 sessions, the stone-free rate was 86 % (45/52) (Fig. 1). In Group 2, the mean stone-free rate was 91.4 % (43/47) (Fig. 1). The main reason for residual stones was the migration of stones to the lower pole in three patients. No additional interventions were planned for those patients. The other patient with an unsuccessful operation was because of the perforation of the collective system by the guidewire. The patient was treated by placing a JJ tube in the same session. In Group 3, the mean stone-free rate was 98 % (49/50) (Fig. 1). The main reason for the unsuccessful patient was because vision was lost due to hemorrhage. Groups 1 and 2 did not differ significantly according to operation success, but Group 2 had the highest success rates (p \ 0.05) (Fig. 1). The mean complication rate for Group 1 was 7.6 % (4/ 52) (Fig. 2). Two patients suffered from renal colic following SWL treatment. One patient had to undergo ureteroscopy for steinstrasse. One patient had a perirenal hematoma treated conservatively. The complication rate for Group 2 was 6.3 % (3/47) (Fig. 2). One patient was treated by a JJ stent because of collective system perforation and two patients were treated medically for postoperative fever. Six patients in Group 3 (6/50) suffered from
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Urolithiasis
Fig. 2 Comparison of complication rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) groups. *p \ 0.05, statistically different from other groups
Table 3 Complications according to modified clavien system Grade
SWL (n = 52)
F-URS (n = 47)
PNL (n = 50)
I
2
2
2
NS
II
1
–
2
NS
A
–
–
2
B
1
1
0
IV
–
–
–
–
V Total
– 4 (7.6 %)
– 3 (6.3 %)
– 6 (12 %)
– \0.05
III
p
NS
complications (Fig. 2). Two patients had postoperative hemorrhage which required blood transfusion. One patient suffered from prolonged urine leakage ([24 h). Examination did not reveal any residual stones or obstruction but the patient was treated by a JJ stent on postoperative day 4. Two patients had postoperative fever treated medically. Hematuria was detected in 1 patient on postoperative day 10 and the arteriovenous fistula revealed by Doppler Ultrasound was treated by selective arterial embolization. When the complications were re-evaluated by the modified clavien system, there was no statistical difference between Groups 1 and 2, but the PNL group had the most complications (p \ 0.05) (Fig. 2). The distribution of complications among the groups is summarized in Table 3.
Discussion When the methods used in this study were compared, SWL and F-URS had similar success and complication rates. PNL has the most successful outcomes but this success rate comes with highest complication rates. However, the study had limitations, such as the retrospective method, a
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relatively low patient number, the lack of randomized controlled studies concerning the same patient group, the assessment of patients only with KUB radiography and ultrasound, the lack of patient body mass index values and information about the HU of the stones. There are no clear recommendation guidelines for treatment of moderatesized pelvis stones, because no previous study has specifically examined and compared the clinical outcomes of treatment approaches in this cohort of patients and selecting the optimal treatment for these stones can be challenging because each treatment modality has unique advantages and disadvantages. The European Association of Urology guidelines for the treatment of renal calculi \2 cm recommend SWL or endourology [5]. SWL has advantages such as its noninvasive nature, low complication rate and high level of patient acceptance [8–10]. A variety of factors can affect the success rate of SWL, and those patients who are more likely to have an unsuccessful outcome have been described in several studies [11–15]. It has been demonstrated that stone size, stone location, stone shape, number of stones, patient age, renal morphology and congenital anomalies are important factors for the success rate [11, 12, 15, 16]. SWL has a success rate between 60 and 90 %, but the ratio is around 80 % for renal pelvis stones [17, 18]. The SWL group of the current study had a success rate of 86 %, which is parallel to rates in the literature. To date, F-URS has generally been reserved for morbid obese patients, patients with musculoskeletal abnormalities, patients in need of complete stone removal (such as pilots) and kidney stones with failed SWL. Convenient for both urologist and patient, the method has disadvantages such as high cost and the need of expensive repairs especially during the learning curve. Afane et al. [19, 20] reported repairs in 12 cases, whereas Hollenbeck reported 21 cases. Even though there is a lack of randomized prospective studies concerning isolated renal pelvis stones treated by F-URS, the available data show success rates of around 90 %. Similar to our cohort, Atis et al. [21] aimed to treat renal pelvis stones of 47 patients with semi-rigid ureteroscope, but 22 patients had to be treated with holmium YAG laser. Success rates were determined as 76 % in the first month and 86.4 % in the second month. Geavlete et al. [22] performed F-URS on 47 patients with pyelocayxeal stones. A success rate of 87 % success rate was reported for isolated pelvis stones. When the results were sorted according to stone size, a success rate of 72 % was determined for stones between 1 and 2 cm regardless of stone location. In the current study, stone-free rate for pelvis stones between 1 and 2 cm for F-URS group was 91.4 %. That this success rate is higher than that in the literature is believed to be because of the selection criteria. The JJ stent placement in
Urolithiasis
the procedure of F-URS is a disadvantage because of the need for a second procedure. Also, ureteroscopy may have important long-term complications, such as ureteral stenosis and persistent vesicoureteral reflux. Various authors reported about 0.1 % rates of these complications [23, 24]. We did not encounter such complications in our relatively short follow-up. The success rate for PNL has been reported between 72 and 98 % regardless of stone localization [25–28] and at 82–93 % when renal pelvis stones are considered [29, 30]. In the current study, a success rate of 98 % was determined in the PNL group and this high rate is believed to be due to the selection of patients with a relatively low stone burden and opaque stones. F-URS is a new technique, which requires new technology and expensive devices [31]. Even though PNL is a more cost effective method for kidney stone treatment, relatively higher complication rates make PNL more expensive [32]. There are no clear guideline recommendations for renal pelvis stones between 1 and 2 cm. This may be because of the lack of randomized controlled studies concerning SWL, F-URS and PNL methods. Even though SWL is easy to apply and relatively non-invasive, the current study reveals the same outcomes even from the most convenient place, such as the renal pelvis. Complication rates may suggest consideration of its non-invasiveness. PNL seems to be the most successful technique but as it has the highest complication rates, it should be reserved for selected cases.
Conclusions With improving experience and advancements in technology, F-URS may considered to be the superior method to be with high success rates and relatively low complications. The results of the current study reveal data supporting this hypothesis but prospective randomized trials on larger cohorts are required to confirm these findings. Conflict of interest
No competing financial interests exist.
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4. Cohen J, Cohen S, Grasso M (2013) Ureteropyeloscopic treatment of large, complex intrarenal and proximal ureteral calculi. BJU Int 111:E127–E131 5. Turk C, Knoll T, Petrik A, Sarica K (2013) Guidelines on urolithiasis. European Association of Urology. http://www.uroweb. org/publications/eau-guidelines/ 6. Clavien PA, Sanabria JR, Strasberg SM (1992) Proposed classification of complications of surgery with examples of utility in cholecystectomy. Surgery 111:518–526 7. Dindo D, Demartines N, Clavien PA (2004) Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 240:205–213 8. Deem S, Defade B, Modak A, Emmett M, Martinez F, Davalos J (2011) Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate sized kidney stones. Urology 78:739–743 9. Preminger GM, Tiselius HG, Assimos DG, Alken P, Buck C, Gallucci M, Knoll T, Lingeman JE, Nakada SY, Pearle MS, Sarica K, Turk C, Wolf JS Jr (2007) 2007 guideline for the management of ureteral calculi. J Urol 178:2418–2434 10. Wiesenthal JD, Ghiculete D, D’A Honey RJ, Pace KT (2011) A comparison of treatment modalities for renal calculi between 100 and 300 mm2: are shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy equivalent? J Endourol 25:481–485 11. Al-Ansari A, As-Sadiq K, Al-Said S, Younis N, Jaleel OA, Shokeir AA (2006) Prognostic factors of success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal stones. Int Urol Nephrol 38:63–67 12. Elkoushy MA, Hassan JA, Morehouse DD, Anidjar M, Andonian S (2011) Factors determining stone-free rate in shock wave lithotripsy using standard focus of Storz Modulith SLX-F2 lithotripter. Urology 78:759–763 13. Kanao K, Nakashima J, Nakagawa K, Asakura H, Miyajima A, Oya M, Ohigashi T, Murai M (2006) Preoperative nomograms for predicting stone-free rate after extracorporeal shock wave lithotripsy. J Urol 176:1453–1456 14. Lingeman JE, Siegel YI, Steele B, Nyhuis AW, Woods JR (1994) Management of lower pole nephrolithiasis: a critical analysis. J Urol 151:663–667 15. Wiesenthal JD, Ghiculete D, D’A Honey RJ, Pace KT (2010) Evaluating the importance of mean stone density and skin-tostone distance in predicting successful shock wave lithotripsy of renal and ureteric calculi. Urol Res 38:307–313 16. Wang LJ, Wong YC, Chuang CK, Chu SH, Chen CS, See LC, Chiang YJ (2005) Predictions of outcomes of renal stones after extracorporeal shock wave lithotripsy from stone characteristics determined by unenhanced helical computed tomography: a multivariate analysis. Eur Radiol 15:2238–2243 17. Abe T, Akakura K, Kawaguchi M, Ueda T, Ichikawa T, Ito H, Nozumi K, Suzuki K (2005) Outcomes of shockwave lithotripsy for upper urinary-tract stones: a large-scale study at a single institution. J Endourol 19:768–773 18. Egilmez T, Tekin MI, Gonen M, Kilinc F, Goren R, Ozkardes H (2007) Efficacy and safety of a new-generation shockwave lithotripsy machine in the treatment of single renal or ureteral stones: experience with 2670 patients. J Endourol 21:23–27 19. Afane JS, Olweny EO, Bercowsky E, Sundaram CP, Dunn MD, Shalhav AL, McDougall EM, Clayman RV (2000) Flexible ureteroscopes: a single center evaluation of the durability and function of the new endoscopes smaller than 9Fr. J Urol 164:1164–1168 20. Hollenbeck BK, Spencer SL, Faerber GJ (2000) Use of a working channel catheter during flexible ureteroscopic laser lithotripsy. J Urol 163:1808–1809
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28. Streem SB, Lammert G (1992) Long-term efficacy of combination therapy for struvite staghorn calculi. J Urol 147:563–566 29. Meria P, Milcent S, Desgrandchamps F, Mongiat-Artus P, Duclos JM, Teillac P (2005) Management of pelvic stones larger than 20 mm: laparoscopic transperitoneal pyelolithotomy or percutaneous nephrolithotomy? Urol Int 75:322–326 30. Resorlu B, Unsal A, Tepeler A, Atis G, Tokatli Z, Oztuna D, Armagan A, Gurbuz C, Caskurlu T, Saglam R (2012) Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in children with moderate-size kidney stones: results of multi-institutional analysis. Urology 80:519–523 31. Collins JW, Keeley FX Jr, Timoney A (2004) Cost analysis of flexible ureterorenoscopy. BJU Int 93:1023–1026 32. Hyams ES, Matlaga BR (2013) Cost-effectiveness treatment strategies for stone disease for the practicing urologist. Urol Clin North Am 40:129–133
ORIGINAL PAPER
Comparison of shock wave lithotripsy, flexible ureterorenoscopy and percutaneous nephrolithotripsy on moderate size renal pelvis stones Okan Bas • Hasan Bakirtas • Nevzat Can Sener • Ufuk Ozturk • Can Tuygun • H. N. Goksel Goktug M. Abdurrahim Imamoglu
•
Received: 26 August 2013 / Accepted: 15 October 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract To compare success and complication rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) according to modified clavien grading system of renal pelvis stones between 1 and 2 cm. The results of 149 patients were evaluated retrospectively. Patients were divided into three groups as 52 for SWL, 47 for F-URS and 50 for PNL. Complications were evaluated by modified Clavien grading system. In the first group, stone-free rates after a mean of 2, 6 sessions was 86 % (45/52). In Group 2, this ratio was 91.4 % (43/47), and in Group 3, it was 98 % (49/50). The success rate in Group 3 was significantly higher than other groups. Complication rates for Group 1, 2 and 3 were 7.6 % (4/52), 6.3 % (3/47) and 12 % (6/50), respectively. Although PNL was the most successful technique compared with other techniques, complications were also higher in this group. Even though PNL is the most successful, it should be performed for selected patient groups and indications should be carefully evaluated. Keywords Moderate size renal pelvis stones SWL F-URS PNL
O. Bas (&) Department of Urology, Abdurrahman Yurtaslan Oncology Training and Research Hospital, Ankara, Turkey e-mail: [email protected] H. Bakirtas U. Ozturk C. Tuygun H. N. G. Goktug M. A. Imamoglu Department of Urology, Ministry of Health, Diskapi Yildirim Beyazid Training and Research Hospital, Ankara, Turkey N. C. Sener Department of Urology, Ministry of Health, Numune Training and Research Hospital, Adana, Turkey
Abbreviations SWL Shock wave lithotripsy F-URS Flexible ureterorenoscopy PNL Percutaneous nephrolithotripsy KUB Kidney–ureter–bladder
Introduction Urolithiasis is one of the most painful diseases and although prevalence varies according to demographic changes, a lifetime prevalence of 10 % has been reported [1]. It may be present throughout the entire urinary tract but the kidney is the most common site. Treatment options include surveillance, medical treatment, extracorporeal shock wave lithotripsy (SWL), percutaneous nephrolitotomy (PNL), mini-PNL, flexible ureterorenoscopy (F-URS), laparoscopy and open surgery. As a result of advancements in endourologic technology, only 1–2 % of kidney stones are treated by open surgery [2]. Although urolithiasis can be treated with great success, high recurrence rates make it an important health issue requiring additional techniques. Without further medical treatment, there is a 50 % chance of recurrence [3]. Which highlights the importance of endoscopic and minimal invasive treatments [4]. It has been recommended that kidney stones bigger than 2 cm are treated by PNL, stones smaller than 1 cm by SWL or F-URS and there is a gray zone for stones between 1 and 2 cm. In recent guidelines [5], there is no clear recommendation for the treatment of moderate size renal pelvis stones. Therefore, in this study it was aimed to compare the success and complication rates of SWL, F-URS and PNL for renal pelvis stones between 1 and 2 cm in size.
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Urolithiasis
Patients and methods Patients A retrospective evaluation was made of 149 patients treated with SWL, F-URS or PNL at our clinic between January 2008 and August 2012. Treatment method was chosen according to the surgeons’ and patient’s preference. Patients with a single renal pelvis opaque stone of diameter between 1 and 2 cm were included the study. Patients with semi-opaque or non-opaque stones, anomalous kidneys, ureteropelvic junction obstruction, a history of open or percutaneous interventions to the ipsilateral kidney or having a solitary kidney were excluded. A total of 149 patients met these criteria and were divided into three groups according to the procedure performed; Group 1 (SWL) n = 52, Group 2 (F-URS) n = 47, Group 3 (PNL) n = 50. In the F-URS Group, three patients continued their antiagregant therapy as an advantage of this method, whilst it was stopped for all patients in the other groups. Also, for patients undergoing PNL, only subcostal access was included. Methods SWL technique SWL treatment was performed as an outpatient procedure using an electrohydraulic extracorporeal lithotripter (Multimed Classic; Elmed, Ankara, Turkey) by a team consisted of an experienced urologist and technician. Before treatment, an intramuscular non-steroidal anti-inflammatory drug was administered. No sedation and/or general anesthesia was needed. Stone targeting was done by fluoroscopy. Therapy was started at 16 kV and then increased gradually to 18 kV. A maximum of 3,000 shocks were delivered for each session (100–120 shocks/min) or until complete fragmentation of the stone had occurred. Patient coupling was done by membrane (dry coupling) and a water cushion was used. The patients were evaluated for fragmentation assessment by kidney–ureter–bladder (KUB) radiography, 1 week after the SWL session. When inadequate fragmentation of the stone was observed, treatment was repeated after 2 weeks. If there was no breakage of the stone after three sessions, the case was considered a SWL failure. F-URS technique F-URS procedures were performed under general anesthesia with the patient placed in the lithotomy position on
123
an endoscopy table with fluoroscopic imaging capability. Rigid ureteroscopy was routinely performed before flexible ureteroscopy in all patients for dilation of the ureter and to place a hydrophilic guidewire into the renal pelvis. A 0.035/0.038 in. safety guidewire was inserted into the renal pelvis under fluoroscopic guidance. Thereafter, a ureteral access (11/13F) sheath was passed over the hydrophilic guidewire as far as the ureteropelvic junction. When the rigid/flexible ureteroscope could not be advanced easily, the stent was left for 2 weeks before repeating the procedure. The flexible ureterorenoscope (Flex-X2, Karl Storz, Tuttlingen, Germany) was inserted through the ureteral access sheath. The stones were fragmented with a 200-lm holmium laser probe (Ho YAG Laser; Dornier MedTech; Munich, Germany) until they were deemed small enough to be passed spontaneously. A JJ stent was put into place at the end of the procedure and removed approximately 7–14 days postoperatively. PNL technique With the patient in the lithotomy position, rigid cystoscopy was performed to place a ureteral catheter. After catheter insertion, the patient was placed in the prone position, and percutaneous access was achieved under C-arm fluoroscopy guidance using an 18-gauge needle and guidewire. Amplatz dilators were used for tract dilatation up to 12F– 30F. Removal of stone fragmentation was accomplished using a pneumatic lithotripter (Lithoclast; EMS, Nyon, Switzerland) and retrieval graspers through a rigid nephroscope (26F, Karl StorzÒ). A nephrostomy tube was placed in all the patients at the end of the procedure. This nephrostomy was removed on postoperative days 1–2 and the patient was discharged the following day. All patients were evaluated by medical history, physical examination, complete blood count, plasma urea and creatinine values, coagulation profiles, intravenous urography, urinalysis and urine cultures. A preoperative negative urine culture was required before surgery so any positive urine cultures were adequately treated with appropriate antibiotics. Stone length was measured on KUB radiography. Stone clearance was assessed with postoperative KUB radiography at day 7 for SWL and with intraoperative and postoperative 1st day KUB radiography for F-URS and PNL. All patients were assessed with urinary ultrasound at postoperative 1 month. The groups were compared for success and complication rates by the modified clavien grading system as developed by Clavien et al. [6] and modified in 2004 for standardization [7] (Table 1). Patients who were stone-free 1-month after the operation were considered successful.
Urolithiasis Table 1 Classification of surgical complications based on the modified Clavien system Grade
Subgrade
Definition
I
Any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions. Allowed therapeutic regimens are drugs as antiemetics, antipyretics, analgesics, diuretics, electrolytes and physiotherapy. This grade also includes wound infections opened at the bedside
II
Complications requiring pharmacological treatment with drugs other than such allowed for grade I complications. Blood transfusions and total parenteral nutrition are also included
III
Complications requiring surgical, endoscopic or radiological intervention a
Intervention not under general anesthesia
b
Intervention under general anesthesia
IV
Fig. 1 Comparison of success rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) groups. *p \ 0.05, statistically different from other groups
used for comparisons of variables between categorical data. A value of p \ 0.05 was considered statistically significant.
Life-threatening complications (including CNS complications) requiring IC/ICU management a
Single organ dysfunction (including dialysis)
b
Multiorgan dysfunction
V
Death
Suffix ‘‘d’’
If the patient suffers from a complication at the time of discharge, the suffix ‘‘d’’ (for disability) is added to the respective grade of complication. This label indicates the need for a follow-up to fully evaluate the complication
Table 2 Comparison of patient demographics Group I (n = 52)
Group II (n = 47)
Group III (n = 50)
P
Male (%)
53.84 (n = 28)
63.82 (n = 30)
58 (n = 29)
[0.05
Female (%)
46.15 (n = 24)
36.17 (n = 17)
42 (n = 21)
[0.05
Sex
Stone localization (%) Right
44.23 (n = 23)
40.42 (n = 19)
40 (n = 20)
[0.05
Left
55.76 (n = 29) 15.3 ± 2.1
59.57 (n = 28) 14.8 ± 2.3
60 (n = 30)
[0.05
15.9 ± 2.9
[0.05
Stone size (mm)
Statistical analysis Statistical analyses were performed using the Statistical Package for Social Sciences version 20.0 software (SPSS Inc, Chicago, IL, USA). In addition to the frequency and percentage distributions of the data, Student’s t test was used for in-group comparisons, and Chi Square test was
Results The mean age of the patients was 46.4 years (±15.1 years), 47.2 years (±14.2 years) and 45.5 years (±13.1 years) for Groups 1, 2 and 3, respectively. There was no significant demographic difference between the groups (Table 2). The mean number of sessions for SWL group was 2.6 (2–3). Nineteen patients were treated in two sessions and 33 patients were treated in three sessions. After a mean of 2.6 sessions, the stone-free rate was 86 % (45/52) (Fig. 1). In Group 2, the mean stone-free rate was 91.4 % (43/47) (Fig. 1). The main reason for residual stones was the migration of stones to the lower pole in three patients. No additional interventions were planned for those patients. The other patient with an unsuccessful operation was because of the perforation of the collective system by the guidewire. The patient was treated by placing a JJ tube in the same session. In Group 3, the mean stone-free rate was 98 % (49/50) (Fig. 1). The main reason for the unsuccessful patient was because vision was lost due to hemorrhage. Groups 1 and 2 did not differ significantly according to operation success, but Group 2 had the highest success rates (p \ 0.05) (Fig. 1). The mean complication rate for Group 1 was 7.6 % (4/ 52) (Fig. 2). Two patients suffered from renal colic following SWL treatment. One patient had to undergo ureteroscopy for steinstrasse. One patient had a perirenal hematoma treated conservatively. The complication rate for Group 2 was 6.3 % (3/47) (Fig. 2). One patient was treated by a JJ stent because of collective system perforation and two patients were treated medically for postoperative fever. Six patients in Group 3 (6/50) suffered from
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Urolithiasis
Fig. 2 Comparison of complication rates of shock wave lithotripsy (SWL), flexible ureterorenoscopy (F-URS) and percutaneous nephrolithotripsy (PNL) groups. *p \ 0.05, statistically different from other groups
Table 3 Complications according to modified clavien system Grade
SWL (n = 52)
F-URS (n = 47)
PNL (n = 50)
I
2
2
2
NS
II
1
–
2
NS
A
–
–
2
B
1
1
0
IV
–
–
–
–
V Total
– 4 (7.6 %)
– 3 (6.3 %)
– 6 (12 %)
– \0.05
III
p
NS
complications (Fig. 2). Two patients had postoperative hemorrhage which required blood transfusion. One patient suffered from prolonged urine leakage ([24 h). Examination did not reveal any residual stones or obstruction but the patient was treated by a JJ stent on postoperative day 4. Two patients had postoperative fever treated medically. Hematuria was detected in 1 patient on postoperative day 10 and the arteriovenous fistula revealed by Doppler Ultrasound was treated by selective arterial embolization. When the complications were re-evaluated by the modified clavien system, there was no statistical difference between Groups 1 and 2, but the PNL group had the most complications (p \ 0.05) (Fig. 2). The distribution of complications among the groups is summarized in Table 3.
Discussion When the methods used in this study were compared, SWL and F-URS had similar success and complication rates. PNL has the most successful outcomes but this success rate comes with highest complication rates. However, the study had limitations, such as the retrospective method, a
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relatively low patient number, the lack of randomized controlled studies concerning the same patient group, the assessment of patients only with KUB radiography and ultrasound, the lack of patient body mass index values and information about the HU of the stones. There are no clear recommendation guidelines for treatment of moderatesized pelvis stones, because no previous study has specifically examined and compared the clinical outcomes of treatment approaches in this cohort of patients and selecting the optimal treatment for these stones can be challenging because each treatment modality has unique advantages and disadvantages. The European Association of Urology guidelines for the treatment of renal calculi \2 cm recommend SWL or endourology [5]. SWL has advantages such as its noninvasive nature, low complication rate and high level of patient acceptance [8–10]. A variety of factors can affect the success rate of SWL, and those patients who are more likely to have an unsuccessful outcome have been described in several studies [11–15]. It has been demonstrated that stone size, stone location, stone shape, number of stones, patient age, renal morphology and congenital anomalies are important factors for the success rate [11, 12, 15, 16]. SWL has a success rate between 60 and 90 %, but the ratio is around 80 % for renal pelvis stones [17, 18]. The SWL group of the current study had a success rate of 86 %, which is parallel to rates in the literature. To date, F-URS has generally been reserved for morbid obese patients, patients with musculoskeletal abnormalities, patients in need of complete stone removal (such as pilots) and kidney stones with failed SWL. Convenient for both urologist and patient, the method has disadvantages such as high cost and the need of expensive repairs especially during the learning curve. Afane et al. [19, 20] reported repairs in 12 cases, whereas Hollenbeck reported 21 cases. Even though there is a lack of randomized prospective studies concerning isolated renal pelvis stones treated by F-URS, the available data show success rates of around 90 %. Similar to our cohort, Atis et al. [21] aimed to treat renal pelvis stones of 47 patients with semi-rigid ureteroscope, but 22 patients had to be treated with holmium YAG laser. Success rates were determined as 76 % in the first month and 86.4 % in the second month. Geavlete et al. [22] performed F-URS on 47 patients with pyelocayxeal stones. A success rate of 87 % success rate was reported for isolated pelvis stones. When the results were sorted according to stone size, a success rate of 72 % was determined for stones between 1 and 2 cm regardless of stone location. In the current study, stone-free rate for pelvis stones between 1 and 2 cm for F-URS group was 91.4 %. That this success rate is higher than that in the literature is believed to be because of the selection criteria. The JJ stent placement in
Urolithiasis
the procedure of F-URS is a disadvantage because of the need for a second procedure. Also, ureteroscopy may have important long-term complications, such as ureteral stenosis and persistent vesicoureteral reflux. Various authors reported about 0.1 % rates of these complications [23, 24]. We did not encounter such complications in our relatively short follow-up. The success rate for PNL has been reported between 72 and 98 % regardless of stone localization [25–28] and at 82–93 % when renal pelvis stones are considered [29, 30]. In the current study, a success rate of 98 % was determined in the PNL group and this high rate is believed to be due to the selection of patients with a relatively low stone burden and opaque stones. F-URS is a new technique, which requires new technology and expensive devices [31]. Even though PNL is a more cost effective method for kidney stone treatment, relatively higher complication rates make PNL more expensive [32]. There are no clear guideline recommendations for renal pelvis stones between 1 and 2 cm. This may be because of the lack of randomized controlled studies concerning SWL, F-URS and PNL methods. Even though SWL is easy to apply and relatively non-invasive, the current study reveals the same outcomes even from the most convenient place, such as the renal pelvis. Complication rates may suggest consideration of its non-invasiveness. PNL seems to be the most successful technique but as it has the highest complication rates, it should be reserved for selected cases.
Conclusions With improving experience and advancements in technology, F-URS may considered to be the superior method to be with high success rates and relatively low complications. The results of the current study reveal data supporting this hypothesis but prospective randomized trials on larger cohorts are required to confirm these findings. Conflict of interest
No competing financial interests exist.
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