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TREATMENT OF COMPLETE STAGHORN STONES: A PROSPECTIVE RANDOMIZED COMPARISON OF OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY
0022-5347/05/1732-0469/0 THE JOURNAL OF UROLOGY® Copyright © 2005 by AMERICAN UROLOGICAL ASSOCIATION
Vol. 173, 469 – 473, February 2005 Printed in U.S.A.
DOI: 10.1097/01.ju.0000150519.49495.88
Urolithiasis/Endourology TREATMENT OF COMPLETE STAGHORN STONES: A PROSPECTIVE RANDOMIZED COMPARISON OF OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY KHALED M. AL-KOHLANY, AHMED A. SHOKEIR,* AHMED MOSBAH, TAREK MOHSEN, AHMED M. SHOMA, IBRAHIM ERAKY, MAHMOUD EL-KENAWY AND HAMDY A. EL-KAPPANY From the Urology and Nephrology Center, Mansoura University, Mansoura, Egypt
ABSTRACT
Purpose: We studied the role of open surgery versus percutaneous nephrolithotomy (PCNL) in the treatment of complete staghorn stones in a prospective randomized manner. Materials and Methods: A total of 79 patients with 88 complete staghorn stones, defined as filling the entire collecting system or at least 80% of it, were prospectively randomized for PCNL (43) or open surgery (45). Intraoperative and postoperative morbidity, operative time, hospital stay, and stone clearance at discharge home and followup were compared for both methods. Patients with significant residuals in both groups were subjected to extracorporeal shock wave lithotripsy (Dornier Medical Systems, Inc., Marietta, Georgia) on an outpatient basis. Followup was completed for all cases with a mean duration ⫾ SD of 4.9 ⫾ 2.5 months (range 3 to 14). Renal function was evaluated by 99mTc-mercaptoacetyltriglycine renogram before and after treatment in both groups. Results: Intraoperative complications in terms of bleeding requiring blood transfusion, and pleural, vascular or ureteral injuries were recorded in 7 patients (16.3%) in the PCNL and 17 (37.8%) in the open surgery groups, a difference of significant value (p ⬍0.05). Major postoperative complications including massive hematuria requiring blood transfusion, septicemia, urinary leakage and wound infection were observed in 8 patients (18.6%) in the PCNL group and in 14 (31.1%) in the open surgery group, a difference of no significant value. PCNL was associated with shorter operative time (127 ⫾ 30 vs 204 ⫾ 31 minutes, p ⬍0.001), shorter hospital stay (6.4 ⫾ 4.2 vs 10 ⫾ 4.2 days, p ⬍0.001) and earlier return to work (2.5 ⫾ 0.8 vs 4.1 ⫾ 1 weeks, p ⬍0.001). On the other hand both treatment groups were comparable in regard to stone-free rates at discharge home (49% vs 66%) and at followup (74% vs 82%). At followup renal function improved or remained stable in 91% and 86.7% in the PCNL and open surgery groups, respectively. Conclusions: PCNL is a valuable treatment option for complete staghorn stones with a stonefree rate approaching that of open surgery. Moreover, it has the advantages of lower morbidity, shorter operative time, shorter hospital stay and earlier return to work. KEY WORDS: kidney, kidney calculi; surgical procedures, operative; nephrostomy, percutaneous; lithotripsy
Staghorn stones represent a troublesome therapeutic challenge to urologists. Because of the lack of consensus on how to define the stones and how to assess the burden, treatment recommendations and reported results are highly variable. Based on the definition of Rassweiler et al1 and the classification of Di Silverio et al,2 staghorn stones are classified into 4 groups as borderline which occupies the renal pelvis and branches only into 1 calix, partial which involves the renal pelvis and branches into 2 calices or more, complete which fills the entire collecting system or at least 80% of it, and giant which fills a hugely dilated system completely. Currently most borderline and partial staghorn stones are treated with percutaneous nephrolithotomy (PCNL) alone or with extracorporeal shock wave lithotripsy (ESWL). ESWL
alone may be recommended for selected cases of staghorn stones with a small stone burden in a nondilated collecting system while most giant stones are treated with open surgery. There is no consensus regarding treatment of complete staghorn stones. Some studies have compared open surgery versus new treatment modalities. Nevertheless, all these previous studies were retrospective, and the results are controversial and inconclusive.3–5 In this study we examined the role of open surgery versus PCNL in the treatment of complete staghorn stones in a prospective randomized manner. To our knowledge this is the first prospective randomized study in this regard. MATERIALS AND METHODS
Submitted for publication May 26, 2004. Between September 2001 and September 2003, 145 * Correspondence: Urology & Nephrology Center, Mansoura University, Mansoura, Egypt (FAX: 20 50-2263717; e-mail: ahmedshokeir@ patients with staghorn stones were treated at our center. Patients with borderline and partial staghorn stones (54) hotmail.com or [email protected]). 469
470
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES
were treated with PCNL and subsequent ESWL for any significant residual fragments. Patients with giant staghorn stones (24) were treated with open surgery. Those with complete staghorn stones (filling the entire collecting system or at least 80% of it) are the subject of the present study. This group included 79 patients (88 renal units) randomly treated with PCNL (43) or open surgery (45). Randomization was done on the day of intervention using the closed envelope method. Significant stone residuals were treated with ESWL in both treatment groups. Of the 79 patients 88 renal units were treated since 9 patients had bilateral disease. Exclusion criteria included children, patients with end stage renal disease, those with congenital, acquired urinary or skeletal abnormalities, and patients with uncorrectable coagulopathies. Patients with borderline, partial and giant staghorn stones were not included in this study. The characteristics of the patients, stones and urinary tract of both treatment groups are summarized in table 1. Preoperative evaluation. In addition to history, clinical examination and routine laboratory investigations, radiological evaluation included plain abdominal radiography (KUB) and gray-scale ultrasonography (US). Excretory urography (IVP) was performed if serum creatinine was 1.5 mg/dl or less. In patients with higher serum creatinine the configuration of the upper tract was evaluated with magnetic resonance urography. Quantitative assessment of the stone burden was done with 3-dimensional computerized tomography (3D-CT) through measurement of stone volume.6 Split renal function was assessed using 99mTc-mercaptoacetyltriglycine radioisotope renography through measurement of the glomerular filtration rate (GFR) of both kidneys. Urinary tract infection (UTI) was treated in all patients according to urine culture sensitivity. Stone analysis was done in 50 cases with x-ray diffraction.7 Operative techniques. A standard PCNL was performed with the patient under hemispinal anesthesia. Access to the kidney was achieved through 1 puncture in 7 units (lower caliceal in 3 and upper in 4), 2 punctures in 21 units (lower calix and middle in 15, and lower and upper in 6) and 3 punctures (lower and middle and upper) in the remaining 15 kidneys. A combination of ultrasonic and pneumatic lithotripsy was used for stone fragmentation in all cases. Flexible nephroscopy was used in all cases for visualization and extraction of any stones not reached by rigid nephroscope. At the end of the procedure an 18Fr nephrostomy tube was left in each puncture. Mean operative time was 127 ⫾ 30 minutes (range 70 to 180). The procedure was completed in 1 session
in 16, 2 sessions in 23 and more than 2 sessions in 4 kidneys. Radiological evaluation for residual stones was done by KUB with or without nephrostogram. In faint opaque and lucent stones noncontrast spiral CT was performed. Postoperative course, stone-free rate at discharge home and hospital stay were recorded. Patients who were completely cleared of stones were considered stone-free. Patients with clinically insignificant residual fragments (CIRFs) were those with nonsymptomatic, nonobstructing and noninfected fragments of less than 4 mm in diameter. Open surgery was performed through the standard supracostal flank incision without rib resection. The kidney was fully mobilized and the renal artery was selectively dissected, controlled by a bulldog clamp, and surface cooling was applied. The stones were retrieved via extended pyelolithotomy in 18 kidneys, combined pyelolithotomy and nephrolithotomy in 20, anatrophic nephrolithotomy in 5 and pyelocalicotomy in the remaining 2 kidneys. Control films were done intraoperatively. A 10Fr nephroureterostomy stent was left in all patients. Mean operative time was 204 ⫾ 31 minutes (range 150 to 270) and mean ischemia time was 37.8 ⫾ 16 minutes (range 10 to 65). In both groups patients who were discharged home with clinically significant residual fragments were scheduled for ESWL which was performed as an outpatient procedure without the patient under anesthesia. The machine used for ESWL has an electromagnetic generator with the possibility of x-ray and US localization of stones (Dornier Lithotriptor S, Dornier MedTech, Kennesaw, Georgia). Evaluation at followup. All patients in both groups were regularly followed up every 3 months during the first year and every 6 months thereafter. At each visit patients were asked about the time required to return to normal activities. Urinalysis, culture, serum creatinine, KUB and abdominal US were performed. If stone recurrence was diagnosed IVP was performed. Noncontrast spiral CT was performed for radiolucent stones. Renal scans using 99mTc-mercaptoacetyltriglycine for selective determination of GFR were performed in all patients at least once during followup, which ranged from 3 to 14 months with a mean of 4.9 ⫾ 2.5 months. Data were processed using SPSS-10 for Windows (SPSS, Inc., Chicago, Illinois). Statistical analysis of the means of continuous variables was performed with the unpaired Student’s t test. Analysis of the significance of categorical variables was performed using the chi-square test with differences resulting in p ⬍0.05 considered statistically significant.
TABLE 1. Preoperative characteristics of both treatment groups Characteristics No. pts No. kidneys Mean pt age ⫾ SD (range) Sex (male/female) Mean mg/dl serum creatinine ⫾ SD (range) Mean ml/min selective GFR ⫾ SD (range) No. pts with UTI (%) Dilatation of upper tract (No. kidneys): No Mild Moderate Marked Mean cm3 stone vol ⫾ SD (range) Nature of stone (No. kidneys): De novo Recurrent Radiopacity (No. kidneys): Opaque Faint opaque Lucent None of the studied variables had statistical significance.
PCNL
Open
40 43 48.6 ⫾ 8.5 (27–65) 17/26 1 ⫾ 0.3 (0.6–2.1) 40.9 ⫾ 12.1 (11–57) 7 (16.3)
44 45 48.7 ⫾ 10.9 (26–75) 23/22 1.1 ⫾ 0.5 (0.6–3.6) 35.8 ⫾ 13.7 (13–74) 8 (17.7)
2 21 16 4 18.7 ⫾ 6.9 (8.3–37)
0 20 19 6 18.8 ⫾ 8.1 (9–39.9)
31 12
36 9
21 16 6
31 12 2
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES RESULTS
Both groups were comparable regarding age, sex, serum creatinine, GFR of the corresponding kidney, incidence of UTI, stone characteristics and status of the upper urinary tract (table 1). Loin pain was the most common clinical presentation seen in 38 patients (88.4%) in the PCNL and 41 (91%) in the open surgery group. Hematuria was the presenting symptom in 4 (9.3%) and 3 (6.7%) in PCNL, and in open surgery groups, respectively. Only 1 patient in each group was asymptomatic and was discovered accidentally. Intraoperative complications in terms of bleeding requiring blood transfusion, or pleural, renal vein or ureteropelvic junction injuries were recorded in 7 patients (16.3%) in PCNL and 17 (37.8%) in open surgery groups, a difference of significant value (p ⬍0.05, table 2). Ureteropelvic junction injury was managed with adequate repair and Double-J stent (Medical Engineering Corp., New York, New York). Major postoperative complications including massive hematuria requiring blood transfusion, septicemia, urinary leakage and wound infection were observed in 8 patients (18.6%) in the PCNL group and in 14 (31.1%) in the open surgery group, a difference of no significant value (table 2). The mean operative time of the PCNL group (127 ⫾ 30 minutes) was significantly lower than that of the open surgery group (204 ⫾ 31 minutes, p ⬍0.001). Similarly hospital stay was significantly shorter in the PCNL group (6.4 ⫾ 4.2 vs 10 ⫾ 4.2 days, p ⬍0.001). Return to work was also faster in the PCNL group (2.5 ⫾ 0.8 vs 4.1 ⫾ 1 weeks, p ⬍0.001). Stone analysis was done for 50 cases from both groups and revealed uric acid stones in 14 (28%), calcium oxalate monohydrate in 12 (24%), mixed calcium oxalate and uric acid in 6 (12%), struvite in 5 (10%), cystine in 2 (4%), and mixed stones in 11 (22%). Stone clearance at discharge home including stone-free rate, and the frequency of insignificant and significant residuals were not significantly different among patients of both treatment groups (table 3). Similarly during followup the stone clearance rate and the recurrence rate were not significantly different (table 3). Of 12 patients 7 (59%) and of 8 patients 5 (60%) discharged home with insignificant residual fragments became stone-free at followup in the PCNL and open surgical groups, respectively. Patients with significant residuals in the PCNL (10) and in the open surgery group (7) were subjected to ESWL (27 sessions in PCNL and 18 sessions in open surgery). One patient in the open surgery group refused ESWL. Of patients with significant residuals 6 (60%) in the PCNL and 3 (50%) in the open surgery group became stone-free. The remaining patients had stones disintegrated to insignificant residuals. Collecting system dilation, stone volume and composition had no significant impact on the stone-free rate or complications. Morphological and functional results at followup are summarized in table 4. Most renal units showed no dilatation in both treatment groups. Mean serum creatinine was not significantly different between the groups. Moreover, the ma-
TABLE 2. Intraoperative and postoperative complications in both groups No. intraop complications (%): Bleeding Pleural injury Renal pelvis injury Vascular injury Ureteral injury No. postop complications (%): Septicemia Massive hematuria Urinary leakage Wound infection
PCNL
Open Surgery
p Value
7 (16.3) 5 (11.6) 0 2 (4.7) 0 0 8 (18.6) 3 (7) 3 (7) 2 (4.7) 0
17 (37.8) 11 (24.5) 4 (8.9) 0 1 (2.2) 1 (2.2) 14 (31.1) 3 (6.7) 4 (8.9) 6 (13.3) 1 (2.2)
0.047
0.432
471
jority of cases in both groups showed stable or improved GFR of the corresponding kidney in comparison to baseline values (table 4, see figure). Improvement or deterioration of renal function was defined as a change of split function greater than 10% of total value at followup compared to baseline.8 DISCUSSION
Although treatment recommendations for staghorn stones have been proposed, the preferred treatment option for such stones remains unsettled.9 Complete staghorn stones are a heterogeneous group between partial and giant classifications. Lack of strict definition causes overlap among these 3 groups. One may consider a partial staghorn to be complete or complete to be giant, etc. Studies comparing open surgery with endourological procedures for the treatment of complete staghorn stones are lacking in the literature.3, 5 The available reports are retrospective comparing these 2 treatment options in different periods with different followup. In a retrospective study Snyder and Smith compared anatrophic nephrolithotomy with endourological procedures for the treatment of staghorn stones, and reported on the superiority of the latter procedure.3 However, in a similar and more recent retrospective study Assimos et al showed contradictory results in favor of anatrophic nephrolithotomy.5 To our knowledge the present study is the first prospective randomized work comparing open surgery versus endourological procedures in the treatment of large staghorn stones. In the PCNL group our target was to remove the maximum bulk of the stone burden with the minimum number of punctures and with the aid of a flexible nephroscope. For peripheral nontargeted stones we preferred ESWL rather than additional punctures. Using this policy we achieved a stonefree rate of 74.4% and good functional results as documented by renal scan. Winfield et al advocated the liberal use of multiple punctures (up to 4) and multiple sessions (up to 5) as well as other auxiliary tools to render the patient stone-free before discharge home.10 With this approach they achieved a stone-free rate of 86%. Nevertheless, the authors did not report on the impact of this approach on kidney function. For preservation of renal function principles of minimal invasiveness have been recommended by many authors in the last 2 decades.1, 11 However, this approach was associated with low stone-free rates at discharge home11 as well as after 6 months.12 For improvement in the results of PCNL some authors reported that the supracostal approach is more suitable for reaching most of the stone bulk with an acceptable rate of chest complications.13 Others believe that the lower caliceal approach is the most appropriate and that supracostal puncture is valuable when stones branch into the upper calix.10 We found that it is difficult to suggest a fixed role regarding the puncture site. Being branching and complex, each staghorn stone should be approached individually. After endourological procedures our stone-free rates at discharge home (49%) and at followup (74%) were close to those reported in the literature.4, 14 Schulze et al reported that 66% of patients with CIRFs became stone-free at 3 months of followup.14 In the present study 59% of patients (7 of 12) discharged home with CIRFs became stone-free at followup. Moreover, 60% of those with clinically significant residual fragments (6 of 10) were rendered stone-free after ESWL therapy. In the open surgery group we extracted stones via the renal pelvis whenever possible. We tried to avoid nephrotomy as much as possible and when it was inevitable we used the least possible ischemia time to avoid extensive renal damage in the already compromised kidneys. Thus, extended pyelolithotomy alone or in combination with nephrotomy or calicotomy was the preferred operation in 89% of cases. Anatrophic nephrolithotomy was necessary in only 5 cases (11%),
472
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES TABLE 3. Stone clearance rate at discharge home and followup Stone Clearance
No. kidneys at discharge home (%): Stone-free Insignificant residuals Significant residuals No. kidneys at followup (%): Stone-free Insignificant residuals Significant residuals Recurrence
PCNL
Open
21 (48.8) 12 (27.9) 10 (23.3)
30 (66.7) 8 (17.8) 7 (15.5)
32 (74.4) 9 (20.9) 0 2 (4.7)
37 (82.2) 5 (11.2) 2 (4.4) 1 (2.2)
p Value 0.238
0.284
TABLE 4. Morphology and function of corresponding kidney at followup Followup Parameters Dilatation of upper tract (No. kidneys): None Mild Moderate Marked Split function (No. kidneys): Improvement Stabilization Deterioration Mean mg/dl serum creatinine ⫾ SD (range) Mean ml/min selective GFR ⫾ SD (range)
PCNL
Open
p Value 0.246
40 2 1 0
44 0 0 1 0.413
2 37 4 1.1 ⫾ 0.3 (0.6–2.1) 37.5 ⫾ 12.9 (12–71)
5 34 6 1.2 ⫾ 0.9 (0.6–6.8) 34.6 ⫾ 14.5 (9–60)
0.272 0.327
Comparison between baseline split renal function of corresponding kidney and value at followup for each individual kidney in PCNL group (A) and open surgery group (B). Values are calculated as percentage of total.
and was indicated when the renal pelvis was completely intrarenal and could not be dissected. For significant residuals we used ESWL. Using this approach the stone-free rate at followup (82%) was similar to that of some recent studies using modified anatrophic nephrolithotomy.15 Older reports before the era of endourology achieved higher stone-free rates because of the greater use of anatrophic nephrolithotomy and liberal nephrotomy.16 Although the safety of anatrophic nephrolithotomy under cold ischemia has been reported,17 the opponents of this operation believe that extended pyelolithotomy is safer.18, 19 With the development of new treatment modalities, especially ESWL, the popularity of the concept of complete stone clearance during the open surgical procedure subsided. Moreover, it was recognized that some peripheral untargeted stones can be left without further intervention if they are in a closed calix and are noninfected. A noteworthy observation is that 28% of patients in whom stone analysis was performed had pure uric acid stones. Medical treatment was not tried in such patients because of the large stone burden which required a long treatment time. Such a line of therapy was not accepted by the patients who had frequent attacks of pain due to obstruction. However, posttreatment prophylaxis was used to avoid stone recurrence. In our study there were significantly more intraoperative complications in the open surgery group (38%) compared to the PCNL group (16%), p ⬍0.05. The most significant com-
plication in both groups was bleeding requiring blood transfusion (33% for open and 14% for PCNL, p ⬍0.05). In a recent report rates of major complications were nearly similar in open surgery and endourological groups but the blood transfusion rate was higher in the open surgery group (37% versus 10%).20 The reported mean operative time, mean hospital stay and mean time required for return to normal daily activities are in accordance with those reported in the literature.3 In general these are in favor of the endourological method except for 1 report.5 In the current work we used 3D-CT for stone burden assessment. This technique gives precise information about the shape of the stone, and size, number and direction of branches, allowing for better planning of PCNL.6 Moreover, 3D-CT is beneficial in the visualization of faint opaque and lucent stones, especially when such stones are not clearly visible by IVP or when the corresponding kidney has poor dye excretion. Retrograde study, which has the risk of provocation of septicemia, was thereby avoided and in none of our cases was this procedure necessary. In our patients the split GFR of the treated kidneys improved or remained stable in 91% of PCNL and in 86.7% of the open surgery group, a difference of no significant value. Previous studies showed that open and endourological procedures caused no significant changes in preoperative renal function measured by dimercapto-succinic acid scan15 or conventional renogram.8
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES CONCLUSIONS
PCNL is a valuable treatment option for complete staghorn stones. Although it has a lower stone-free rate at discharge home, compared to open surgery it approaches similar results at followup. Moreover, it has the advantages of lower morbidity, shorter operative time and early return to work. REFERENCES
1. Rassweiler, J., Gumpinger, R., Miller, K., Holzermann, F. and Eisenberger, F.: Multimodal treatment (extracorporeal shock wave lithotripsy and endourology) of complicated renal stone disease. Eur Urol, 12: 294, 1986 2. Di Silverio, F., Gallucci, M. and Alpi, R.: Staghorn calculi of the kidney: classification and therapy. Br J Urol, 65: 449, 1990 3. Snyder, J. A. and Smith, A. D.: Staghorn calculi: percutaneous extraction versus anatrophic nephrolithotomy. J Urol, 136: 351, 1986 4. Kahnoski, R. J., Lingeman, J. A., Coury, T. A., Steele, R. E. and Mosbaugh, P. J.: Combined percutaneous and extracorporeal shock wave lithotripsy for staghorn calculi: an alternative to anatrophic nephrolithotomy. J Urol, 135: 679, 1986 5. Assimos, D. G., Wrenn, J. J., Harrison, L. H., McCullough, D. L., Boyce, W. H., Taylor, C. L. et al: A comparison of anatrophic nephrolithotomy and percutaneous nephrolithotomy with and without extracorporeal shock wave lithotripsy for management of patients with staghorn calculi. J Urol, 145: 710, 1991 6. Hubert, J., Blum, A., Cormier, L., Claudon, M., Regent, D. and Mangin, P.: Three-dimensional CT-scan reconstruction of renal calculi. A new tool for mapping-out staghorn calculi and follow-up of radiolucent stones. Eur Urol, 31: 297, 1997 7. Sutor, D. J. and Wooley, S. E.: Composition of urinary calculi by X-ray diffraction. Collected data from various localities. XV– XVII. Royal Navy; Bristol, England; and Dundee, Scotland. Br J Urol, 46: 229, 1974 8. Tasca, A., D’Angelo, A., Zattoni, F., Ferrarese, P., Calo, L., Bui, F. et al: Short-term and stabilized effects of percutaneous nephrolithotomy on the kidney. Eur Urol, 14: 120, 1988 9. Segura, J. W., Preminger, J. M., Assimos, D. G., Dretler, S. P.,
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Kahn, R. I., Lingeman, G. E. et al: Nephrolithiasis clinical guidelines panel summary report on the management of staghorn calculi. J Urol, 151: 1648, 1994 Winfield, H. N., Clayman, R. V., Chaussy, C. G., Weyman, P. J., Fuchs, G. J. and Lupu, A. N.: Monotherapy of staghorn renal calculi: a comparative study between percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. J Urol, 139: 895, 1988 Eisenberger, F., Rassweiler, J., Bup, P., Kallert, B. and Miller, K.: Differentiated approach to staghorn calculi using extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy: an analysis of 151 consecutive cases. World J Urol, 5: 248, 1987 Segura, J. W., Patterson, D. E. and LeRoy, A. J.: Combined percutaneous ultrasonic lithotripsy and extracorporeal shock wave lithotripsy for struvite staghorn calculi. World J Urol, 5: 245, 1987 Munver, R., Delvecchio, F. C., Newman, G. E. and Preminger, G. M.: Critical analysis of supracostal access for percutaneous renal surgery. J Urol, 166: 1242, 2001 Schulze, H., Hertle, L., Graff, J., Funke, P.-J. and Senge, T.: Combined treatment of branched calculi by percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. J Urol, 135: 1138, 1986 Morey, A. F., Nitahara, K. S. and McAninch, J. W.: Modified anatrophic nephrolithotomy for management of staghorn calculi: is renal function preserved. J Urol, 162: 670, 1999 Smith, M. J. V. and Boyce, W. H.: Anatrophic nephrotomy and plastic calyrhaphy. J Urol, 99: 521, 1968 Stubbs, A. J., Resnick, M. I. and Boyce, W. H.: Anatrophic nephrolithotomy in the solitary kidney. J Urol, 119: 457, 1978 Libertino, J. A., Newman, H. R., Lytton, B. and Weiss, R. M.: Staghorn calculi in solitary kidneys. J Urol, 105: 753, 1971 Woodhouse, C. R., Farrell, C. R., Paris, A. M. and Blandy, J. P.: The place of extended pyelolithotomy (Gil-Vernet Operation) in the management of renal staghorn calculi. Br J Urol, 53: 520, 1981 Rassweiler, J. J., Renner, C. and Eisenberger, F.: The management of complex renal stones. BJU Int, 86: 919, 2000
Vol. 173, 469 – 473, February 2005 Printed in U.S.A.
DOI: 10.1097/01.ju.0000150519.49495.88
Urolithiasis/Endourology TREATMENT OF COMPLETE STAGHORN STONES: A PROSPECTIVE RANDOMIZED COMPARISON OF OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY KHALED M. AL-KOHLANY, AHMED A. SHOKEIR,* AHMED MOSBAH, TAREK MOHSEN, AHMED M. SHOMA, IBRAHIM ERAKY, MAHMOUD EL-KENAWY AND HAMDY A. EL-KAPPANY From the Urology and Nephrology Center, Mansoura University, Mansoura, Egypt
ABSTRACT
Purpose: We studied the role of open surgery versus percutaneous nephrolithotomy (PCNL) in the treatment of complete staghorn stones in a prospective randomized manner. Materials and Methods: A total of 79 patients with 88 complete staghorn stones, defined as filling the entire collecting system or at least 80% of it, were prospectively randomized for PCNL (43) or open surgery (45). Intraoperative and postoperative morbidity, operative time, hospital stay, and stone clearance at discharge home and followup were compared for both methods. Patients with significant residuals in both groups were subjected to extracorporeal shock wave lithotripsy (Dornier Medical Systems, Inc., Marietta, Georgia) on an outpatient basis. Followup was completed for all cases with a mean duration ⫾ SD of 4.9 ⫾ 2.5 months (range 3 to 14). Renal function was evaluated by 99mTc-mercaptoacetyltriglycine renogram before and after treatment in both groups. Results: Intraoperative complications in terms of bleeding requiring blood transfusion, and pleural, vascular or ureteral injuries were recorded in 7 patients (16.3%) in the PCNL and 17 (37.8%) in the open surgery groups, a difference of significant value (p ⬍0.05). Major postoperative complications including massive hematuria requiring blood transfusion, septicemia, urinary leakage and wound infection were observed in 8 patients (18.6%) in the PCNL group and in 14 (31.1%) in the open surgery group, a difference of no significant value. PCNL was associated with shorter operative time (127 ⫾ 30 vs 204 ⫾ 31 minutes, p ⬍0.001), shorter hospital stay (6.4 ⫾ 4.2 vs 10 ⫾ 4.2 days, p ⬍0.001) and earlier return to work (2.5 ⫾ 0.8 vs 4.1 ⫾ 1 weeks, p ⬍0.001). On the other hand both treatment groups were comparable in regard to stone-free rates at discharge home (49% vs 66%) and at followup (74% vs 82%). At followup renal function improved or remained stable in 91% and 86.7% in the PCNL and open surgery groups, respectively. Conclusions: PCNL is a valuable treatment option for complete staghorn stones with a stonefree rate approaching that of open surgery. Moreover, it has the advantages of lower morbidity, shorter operative time, shorter hospital stay and earlier return to work. KEY WORDS: kidney, kidney calculi; surgical procedures, operative; nephrostomy, percutaneous; lithotripsy
Staghorn stones represent a troublesome therapeutic challenge to urologists. Because of the lack of consensus on how to define the stones and how to assess the burden, treatment recommendations and reported results are highly variable. Based on the definition of Rassweiler et al1 and the classification of Di Silverio et al,2 staghorn stones are classified into 4 groups as borderline which occupies the renal pelvis and branches only into 1 calix, partial which involves the renal pelvis and branches into 2 calices or more, complete which fills the entire collecting system or at least 80% of it, and giant which fills a hugely dilated system completely. Currently most borderline and partial staghorn stones are treated with percutaneous nephrolithotomy (PCNL) alone or with extracorporeal shock wave lithotripsy (ESWL). ESWL
alone may be recommended for selected cases of staghorn stones with a small stone burden in a nondilated collecting system while most giant stones are treated with open surgery. There is no consensus regarding treatment of complete staghorn stones. Some studies have compared open surgery versus new treatment modalities. Nevertheless, all these previous studies were retrospective, and the results are controversial and inconclusive.3–5 In this study we examined the role of open surgery versus PCNL in the treatment of complete staghorn stones in a prospective randomized manner. To our knowledge this is the first prospective randomized study in this regard. MATERIALS AND METHODS
Submitted for publication May 26, 2004. Between September 2001 and September 2003, 145 * Correspondence: Urology & Nephrology Center, Mansoura University, Mansoura, Egypt (FAX: 20 50-2263717; e-mail: ahmedshokeir@ patients with staghorn stones were treated at our center. Patients with borderline and partial staghorn stones (54) hotmail.com or [email protected]). 469
470
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES
were treated with PCNL and subsequent ESWL for any significant residual fragments. Patients with giant staghorn stones (24) were treated with open surgery. Those with complete staghorn stones (filling the entire collecting system or at least 80% of it) are the subject of the present study. This group included 79 patients (88 renal units) randomly treated with PCNL (43) or open surgery (45). Randomization was done on the day of intervention using the closed envelope method. Significant stone residuals were treated with ESWL in both treatment groups. Of the 79 patients 88 renal units were treated since 9 patients had bilateral disease. Exclusion criteria included children, patients with end stage renal disease, those with congenital, acquired urinary or skeletal abnormalities, and patients with uncorrectable coagulopathies. Patients with borderline, partial and giant staghorn stones were not included in this study. The characteristics of the patients, stones and urinary tract of both treatment groups are summarized in table 1. Preoperative evaluation. In addition to history, clinical examination and routine laboratory investigations, radiological evaluation included plain abdominal radiography (KUB) and gray-scale ultrasonography (US). Excretory urography (IVP) was performed if serum creatinine was 1.5 mg/dl or less. In patients with higher serum creatinine the configuration of the upper tract was evaluated with magnetic resonance urography. Quantitative assessment of the stone burden was done with 3-dimensional computerized tomography (3D-CT) through measurement of stone volume.6 Split renal function was assessed using 99mTc-mercaptoacetyltriglycine radioisotope renography through measurement of the glomerular filtration rate (GFR) of both kidneys. Urinary tract infection (UTI) was treated in all patients according to urine culture sensitivity. Stone analysis was done in 50 cases with x-ray diffraction.7 Operative techniques. A standard PCNL was performed with the patient under hemispinal anesthesia. Access to the kidney was achieved through 1 puncture in 7 units (lower caliceal in 3 and upper in 4), 2 punctures in 21 units (lower calix and middle in 15, and lower and upper in 6) and 3 punctures (lower and middle and upper) in the remaining 15 kidneys. A combination of ultrasonic and pneumatic lithotripsy was used for stone fragmentation in all cases. Flexible nephroscopy was used in all cases for visualization and extraction of any stones not reached by rigid nephroscope. At the end of the procedure an 18Fr nephrostomy tube was left in each puncture. Mean operative time was 127 ⫾ 30 minutes (range 70 to 180). The procedure was completed in 1 session
in 16, 2 sessions in 23 and more than 2 sessions in 4 kidneys. Radiological evaluation for residual stones was done by KUB with or without nephrostogram. In faint opaque and lucent stones noncontrast spiral CT was performed. Postoperative course, stone-free rate at discharge home and hospital stay were recorded. Patients who were completely cleared of stones were considered stone-free. Patients with clinically insignificant residual fragments (CIRFs) were those with nonsymptomatic, nonobstructing and noninfected fragments of less than 4 mm in diameter. Open surgery was performed through the standard supracostal flank incision without rib resection. The kidney was fully mobilized and the renal artery was selectively dissected, controlled by a bulldog clamp, and surface cooling was applied. The stones were retrieved via extended pyelolithotomy in 18 kidneys, combined pyelolithotomy and nephrolithotomy in 20, anatrophic nephrolithotomy in 5 and pyelocalicotomy in the remaining 2 kidneys. Control films were done intraoperatively. A 10Fr nephroureterostomy stent was left in all patients. Mean operative time was 204 ⫾ 31 minutes (range 150 to 270) and mean ischemia time was 37.8 ⫾ 16 minutes (range 10 to 65). In both groups patients who were discharged home with clinically significant residual fragments were scheduled for ESWL which was performed as an outpatient procedure without the patient under anesthesia. The machine used for ESWL has an electromagnetic generator with the possibility of x-ray and US localization of stones (Dornier Lithotriptor S, Dornier MedTech, Kennesaw, Georgia). Evaluation at followup. All patients in both groups were regularly followed up every 3 months during the first year and every 6 months thereafter. At each visit patients were asked about the time required to return to normal activities. Urinalysis, culture, serum creatinine, KUB and abdominal US were performed. If stone recurrence was diagnosed IVP was performed. Noncontrast spiral CT was performed for radiolucent stones. Renal scans using 99mTc-mercaptoacetyltriglycine for selective determination of GFR were performed in all patients at least once during followup, which ranged from 3 to 14 months with a mean of 4.9 ⫾ 2.5 months. Data were processed using SPSS-10 for Windows (SPSS, Inc., Chicago, Illinois). Statistical analysis of the means of continuous variables was performed with the unpaired Student’s t test. Analysis of the significance of categorical variables was performed using the chi-square test with differences resulting in p ⬍0.05 considered statistically significant.
TABLE 1. Preoperative characteristics of both treatment groups Characteristics No. pts No. kidneys Mean pt age ⫾ SD (range) Sex (male/female) Mean mg/dl serum creatinine ⫾ SD (range) Mean ml/min selective GFR ⫾ SD (range) No. pts with UTI (%) Dilatation of upper tract (No. kidneys): No Mild Moderate Marked Mean cm3 stone vol ⫾ SD (range) Nature of stone (No. kidneys): De novo Recurrent Radiopacity (No. kidneys): Opaque Faint opaque Lucent None of the studied variables had statistical significance.
PCNL
Open
40 43 48.6 ⫾ 8.5 (27–65) 17/26 1 ⫾ 0.3 (0.6–2.1) 40.9 ⫾ 12.1 (11–57) 7 (16.3)
44 45 48.7 ⫾ 10.9 (26–75) 23/22 1.1 ⫾ 0.5 (0.6–3.6) 35.8 ⫾ 13.7 (13–74) 8 (17.7)
2 21 16 4 18.7 ⫾ 6.9 (8.3–37)
0 20 19 6 18.8 ⫾ 8.1 (9–39.9)
31 12
36 9
21 16 6
31 12 2
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES RESULTS
Both groups were comparable regarding age, sex, serum creatinine, GFR of the corresponding kidney, incidence of UTI, stone characteristics and status of the upper urinary tract (table 1). Loin pain was the most common clinical presentation seen in 38 patients (88.4%) in the PCNL and 41 (91%) in the open surgery group. Hematuria was the presenting symptom in 4 (9.3%) and 3 (6.7%) in PCNL, and in open surgery groups, respectively. Only 1 patient in each group was asymptomatic and was discovered accidentally. Intraoperative complications in terms of bleeding requiring blood transfusion, or pleural, renal vein or ureteropelvic junction injuries were recorded in 7 patients (16.3%) in PCNL and 17 (37.8%) in open surgery groups, a difference of significant value (p ⬍0.05, table 2). Ureteropelvic junction injury was managed with adequate repair and Double-J stent (Medical Engineering Corp., New York, New York). Major postoperative complications including massive hematuria requiring blood transfusion, septicemia, urinary leakage and wound infection were observed in 8 patients (18.6%) in the PCNL group and in 14 (31.1%) in the open surgery group, a difference of no significant value (table 2). The mean operative time of the PCNL group (127 ⫾ 30 minutes) was significantly lower than that of the open surgery group (204 ⫾ 31 minutes, p ⬍0.001). Similarly hospital stay was significantly shorter in the PCNL group (6.4 ⫾ 4.2 vs 10 ⫾ 4.2 days, p ⬍0.001). Return to work was also faster in the PCNL group (2.5 ⫾ 0.8 vs 4.1 ⫾ 1 weeks, p ⬍0.001). Stone analysis was done for 50 cases from both groups and revealed uric acid stones in 14 (28%), calcium oxalate monohydrate in 12 (24%), mixed calcium oxalate and uric acid in 6 (12%), struvite in 5 (10%), cystine in 2 (4%), and mixed stones in 11 (22%). Stone clearance at discharge home including stone-free rate, and the frequency of insignificant and significant residuals were not significantly different among patients of both treatment groups (table 3). Similarly during followup the stone clearance rate and the recurrence rate were not significantly different (table 3). Of 12 patients 7 (59%) and of 8 patients 5 (60%) discharged home with insignificant residual fragments became stone-free at followup in the PCNL and open surgical groups, respectively. Patients with significant residuals in the PCNL (10) and in the open surgery group (7) were subjected to ESWL (27 sessions in PCNL and 18 sessions in open surgery). One patient in the open surgery group refused ESWL. Of patients with significant residuals 6 (60%) in the PCNL and 3 (50%) in the open surgery group became stone-free. The remaining patients had stones disintegrated to insignificant residuals. Collecting system dilation, stone volume and composition had no significant impact on the stone-free rate or complications. Morphological and functional results at followup are summarized in table 4. Most renal units showed no dilatation in both treatment groups. Mean serum creatinine was not significantly different between the groups. Moreover, the ma-
TABLE 2. Intraoperative and postoperative complications in both groups No. intraop complications (%): Bleeding Pleural injury Renal pelvis injury Vascular injury Ureteral injury No. postop complications (%): Septicemia Massive hematuria Urinary leakage Wound infection
PCNL
Open Surgery
p Value
7 (16.3) 5 (11.6) 0 2 (4.7) 0 0 8 (18.6) 3 (7) 3 (7) 2 (4.7) 0
17 (37.8) 11 (24.5) 4 (8.9) 0 1 (2.2) 1 (2.2) 14 (31.1) 3 (6.7) 4 (8.9) 6 (13.3) 1 (2.2)
0.047
0.432
471
jority of cases in both groups showed stable or improved GFR of the corresponding kidney in comparison to baseline values (table 4, see figure). Improvement or deterioration of renal function was defined as a change of split function greater than 10% of total value at followup compared to baseline.8 DISCUSSION
Although treatment recommendations for staghorn stones have been proposed, the preferred treatment option for such stones remains unsettled.9 Complete staghorn stones are a heterogeneous group between partial and giant classifications. Lack of strict definition causes overlap among these 3 groups. One may consider a partial staghorn to be complete or complete to be giant, etc. Studies comparing open surgery with endourological procedures for the treatment of complete staghorn stones are lacking in the literature.3, 5 The available reports are retrospective comparing these 2 treatment options in different periods with different followup. In a retrospective study Snyder and Smith compared anatrophic nephrolithotomy with endourological procedures for the treatment of staghorn stones, and reported on the superiority of the latter procedure.3 However, in a similar and more recent retrospective study Assimos et al showed contradictory results in favor of anatrophic nephrolithotomy.5 To our knowledge the present study is the first prospective randomized work comparing open surgery versus endourological procedures in the treatment of large staghorn stones. In the PCNL group our target was to remove the maximum bulk of the stone burden with the minimum number of punctures and with the aid of a flexible nephroscope. For peripheral nontargeted stones we preferred ESWL rather than additional punctures. Using this policy we achieved a stonefree rate of 74.4% and good functional results as documented by renal scan. Winfield et al advocated the liberal use of multiple punctures (up to 4) and multiple sessions (up to 5) as well as other auxiliary tools to render the patient stone-free before discharge home.10 With this approach they achieved a stone-free rate of 86%. Nevertheless, the authors did not report on the impact of this approach on kidney function. For preservation of renal function principles of minimal invasiveness have been recommended by many authors in the last 2 decades.1, 11 However, this approach was associated with low stone-free rates at discharge home11 as well as after 6 months.12 For improvement in the results of PCNL some authors reported that the supracostal approach is more suitable for reaching most of the stone bulk with an acceptable rate of chest complications.13 Others believe that the lower caliceal approach is the most appropriate and that supracostal puncture is valuable when stones branch into the upper calix.10 We found that it is difficult to suggest a fixed role regarding the puncture site. Being branching and complex, each staghorn stone should be approached individually. After endourological procedures our stone-free rates at discharge home (49%) and at followup (74%) were close to those reported in the literature.4, 14 Schulze et al reported that 66% of patients with CIRFs became stone-free at 3 months of followup.14 In the present study 59% of patients (7 of 12) discharged home with CIRFs became stone-free at followup. Moreover, 60% of those with clinically significant residual fragments (6 of 10) were rendered stone-free after ESWL therapy. In the open surgery group we extracted stones via the renal pelvis whenever possible. We tried to avoid nephrotomy as much as possible and when it was inevitable we used the least possible ischemia time to avoid extensive renal damage in the already compromised kidneys. Thus, extended pyelolithotomy alone or in combination with nephrotomy or calicotomy was the preferred operation in 89% of cases. Anatrophic nephrolithotomy was necessary in only 5 cases (11%),
472
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES TABLE 3. Stone clearance rate at discharge home and followup Stone Clearance
No. kidneys at discharge home (%): Stone-free Insignificant residuals Significant residuals No. kidneys at followup (%): Stone-free Insignificant residuals Significant residuals Recurrence
PCNL
Open
21 (48.8) 12 (27.9) 10 (23.3)
30 (66.7) 8 (17.8) 7 (15.5)
32 (74.4) 9 (20.9) 0 2 (4.7)
37 (82.2) 5 (11.2) 2 (4.4) 1 (2.2)
p Value 0.238
0.284
TABLE 4. Morphology and function of corresponding kidney at followup Followup Parameters Dilatation of upper tract (No. kidneys): None Mild Moderate Marked Split function (No. kidneys): Improvement Stabilization Deterioration Mean mg/dl serum creatinine ⫾ SD (range) Mean ml/min selective GFR ⫾ SD (range)
PCNL
Open
p Value 0.246
40 2 1 0
44 0 0 1 0.413
2 37 4 1.1 ⫾ 0.3 (0.6–2.1) 37.5 ⫾ 12.9 (12–71)
5 34 6 1.2 ⫾ 0.9 (0.6–6.8) 34.6 ⫾ 14.5 (9–60)
0.272 0.327
Comparison between baseline split renal function of corresponding kidney and value at followup for each individual kidney in PCNL group (A) and open surgery group (B). Values are calculated as percentage of total.
and was indicated when the renal pelvis was completely intrarenal and could not be dissected. For significant residuals we used ESWL. Using this approach the stone-free rate at followup (82%) was similar to that of some recent studies using modified anatrophic nephrolithotomy.15 Older reports before the era of endourology achieved higher stone-free rates because of the greater use of anatrophic nephrolithotomy and liberal nephrotomy.16 Although the safety of anatrophic nephrolithotomy under cold ischemia has been reported,17 the opponents of this operation believe that extended pyelolithotomy is safer.18, 19 With the development of new treatment modalities, especially ESWL, the popularity of the concept of complete stone clearance during the open surgical procedure subsided. Moreover, it was recognized that some peripheral untargeted stones can be left without further intervention if they are in a closed calix and are noninfected. A noteworthy observation is that 28% of patients in whom stone analysis was performed had pure uric acid stones. Medical treatment was not tried in such patients because of the large stone burden which required a long treatment time. Such a line of therapy was not accepted by the patients who had frequent attacks of pain due to obstruction. However, posttreatment prophylaxis was used to avoid stone recurrence. In our study there were significantly more intraoperative complications in the open surgery group (38%) compared to the PCNL group (16%), p ⬍0.05. The most significant com-
plication in both groups was bleeding requiring blood transfusion (33% for open and 14% for PCNL, p ⬍0.05). In a recent report rates of major complications were nearly similar in open surgery and endourological groups but the blood transfusion rate was higher in the open surgery group (37% versus 10%).20 The reported mean operative time, mean hospital stay and mean time required for return to normal daily activities are in accordance with those reported in the literature.3 In general these are in favor of the endourological method except for 1 report.5 In the current work we used 3D-CT for stone burden assessment. This technique gives precise information about the shape of the stone, and size, number and direction of branches, allowing for better planning of PCNL.6 Moreover, 3D-CT is beneficial in the visualization of faint opaque and lucent stones, especially when such stones are not clearly visible by IVP or when the corresponding kidney has poor dye excretion. Retrograde study, which has the risk of provocation of septicemia, was thereby avoided and in none of our cases was this procedure necessary. In our patients the split GFR of the treated kidneys improved or remained stable in 91% of PCNL and in 86.7% of the open surgery group, a difference of no significant value. Previous studies showed that open and endourological procedures caused no significant changes in preoperative renal function measured by dimercapto-succinic acid scan15 or conventional renogram.8
OPEN SURGERY VERSUS PERCUTANEOUS NEPHROLITHOTOMY FOR STAGHORN STONES CONCLUSIONS
PCNL is a valuable treatment option for complete staghorn stones. Although it has a lower stone-free rate at discharge home, compared to open surgery it approaches similar results at followup. Moreover, it has the advantages of lower morbidity, shorter operative time and early return to work. REFERENCES
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