Piezoelectric lithotripsy monotherapy for partial or total staghorn lithiasis and calculi larger than thirty millimeters

Thirty patients with partial or total staghorn lithiasis or calculi larger than 30 mm were treated by piezoelectric lithotripsy (PEL) monotherapy using an EDAP LT-01 lithotripter with ultrasound guidance. Nineteen of these patients had a pelvic stone; the other 11 had partial (nine) or total (two) staghorn lithiasis. All patients first underwent an initial lithotripsy session. No anesthesia or intravenous sedation was required in any case. If stone fracturization was achieved after this first session, a double J stent was inserted before the second lithotripsy session. Prior to the first session, 18 of 30 patients had a sterile urine culture; 12 of 30 presented major distention of the excretory tract. Results were analyzed to determine those factors influencing the outcome of this therapy. Three months after the first session, patients were considered cured if their stone had completely disappeared on abdominal plain films (14/30 = 46%). In seven patients (23.3%), fracturization had occurred but residual fragments remained (1-3 fragments less than or equal to 4 mm). No fracturization was obtained after the first session in nine patients (30.7%) (one total staghorn lithiasis, eight pelvic stones). The mean number of treatment sessions was five (range 1-15). Complications occurred in only 10% of patients (3/30): two steinstrasse and one acute pyelonephritis. Eighty-three percent of patients without major excretory tract distention and 55% of patients whose initial urine culture was sterile, achieved a stone-free state.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fiberoptic transurethral lithotripsy prefers smaller impacted ureteral calculi rather than large renal stones

A total of 30 patients with urolithiasis underwent 35 sessions of fiberoptic transurethral lithotripsy (f-TUL) involving electrohydraulic lithotripsy. There were 11 patients with nephrolithiasis including 4 with staghorn calculi and 19 patients with ureterolithiasis which were all located above the pelvic brim. A fiberoptic nephroureteroscope (URF-P) was successfully introduced up to the stone in all but 2 cases (93.3%). Of the 28 patients with successful introduction, 21 received a single session of f-TUL for complete fragmentation of their stones, which measured less than 16 x 9 mm by radiography. Three patients with larger renal stones (greater than or equal to 17 x 9 mm) underwent 2 sessions of f-TUL for complete fragmentation. The remaining 4 patients who had staghorn calculi (greater than or equal to 38 x 33 mm) received 1 session of f-TUL with partial fragmentation; then 3 were sent to an ESWL clinic with good results, while the other patient received 2 more sessions of f-TUL and formed a stone street. Attempts were subsequently made to destroy the latter by ESWL but were unsuccessful. In conclusion, f-TUL appears to be most suitable for smaller impacted ureteral calculi above the pelvic brim.     

Clinical experience of extracorporeal shock wave lithotripsy for cystine calculi

Thirty patients (16 men and 14 women) with cystine urinary stones were treated by extracorporeal shock wave lithotripsy (Dormer HM-3) from December 1984 through October 1989. The average patient age was 35.2 years with a range of 14 to 59 years. Seventy per cent of these subjects had had previous open surgical operations for stones. The cases consisted of 7 ureteral stones and 37 renal stones, including 15 staghorn calculi. An average of 1.3 session of ESWL was carried out to treat ureteral stones. Thirty-seven renal units with renal stone required 96 sessions of lithotripsy (average 2.6 sessions per unit). Seven patients with ureteral stones required auxiliary procedures, i.e., one transurethral lithotripsy (TUL), two percutaneous nephrostomies (PNS) and one open surgery. Thirty-seven renal stones, including staghorn calculi was treated by ESWL and auxiliary treatment of 21 TUL procedures, one PNS, 16 PNL procedures and one chemical chemolysis. Successful fragmentation (residual debris less than or equal to 4 mm) was achieved in 85.7% of ureteral stones, 90.9% of renal stones and 73.3% of staghorn calculi. The stone free rates of patients with ureteral stones, renal stones and staghorn calculi were 71.4%, 50.0% and 53.5%, respectively, at 3 months after ESWL. No serious complications were seen in this series. Fever above 38.5 degrees C was the most common complications (13.5%). Ureteral perforation was encountered once in TUL procedures. Transfusion and selective arterial embolization were needed for one case treated by PNL procedures. Although cystine stone is harder to be fragmented by ESWL than other stone composition, ESWL and endourology may be effective and safe procedures for cystine stone patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of staghorn calculi by extracorporeal shock-wave lithotripsy in children]

To evaluate the efficacy of monotherapy with extracorporeal shock-wave lithotripsy (ESWL) for staghorn calculi in children. Material and methods: Between September 1987 and December 1998, 27 children (18 boys and 9 girls) with a mean age of 5.2 years (9 months to 147 years) were managed in our department for staghorn or pseudo-staghorn calculi. They were treated with a Lithostar Siemens-Ultra lithotriptor ith ultrasound detection. The "Puigvert method", which starts with low energy which is then gradually increased, allows satisfactory painless fragmentation, avoiding the need for general anaesthesia. RESULTS: the success rate was 70% with two sessions (37% with a single session). In one case, lithotripsy was not indicated and percutaneous nephrolithotomy was necessary. Two cystine stones ina girl (probably longstanding stones) could not be fragmented and open surgery was required. The other five systine staghorn calculi ere treated successfully. Ureteral catheterization was not required and only one double J stent was placed preventively in a girl with a solitary kidney. No major complication was detected. CONCLUSION: ESWL with the Siemens-Ultra lithotriptor is a safe and effective first-line method for the treatment of staghron calculi in children.     

Treatment for residual stones using flexible ureteroscopy and holmium laser lithotripsy after the management of complex calculi with single-tract percutaneous nephrolithotomy

This study validated the effectiveness and safety of the treatment for residual stones using flexible ureteroscopy (fURS) and holmium laser (0.6–1.2 J, 20–30 Hz) lithotripsy via a fiber with a 200-μm core diameter and 0.22 numerical aperture (NA) after the management of complex calculi with single-tract percutaneous nephrolithotomy (PCNL). Between January 2014 and June 2016, 27 consecutive patients with complex calculi underwent fURS and holmium laser lithotripsy after a planned single-tract PCNL. Among the 27 patients with complex calculi, 9 had full staghorn calculi, 7 had partial staghorn calculi, and 11 had multiple calculi. After the first single-tract PCNL session, the mean stone size and mean stone surface area were 18.0?±?10.7 mm and 181.9?±?172.2 mm², respectively. Treatment for residual stones with fURS and holmium laser lithotripsy was successfully completed and was performed without intraoperative complications. The mean operative time of the fURS procedure was 69.1?±?23.6 min, and the mean hospital stay was 5.3?±?2.4 days. The mean decrease in the hemoglobin level was 7.3?±?6.5 g/l. After the fURS procedure, the overall stone-free rate was 88.9%. The overall postoperative complication rate was 14.8% (Clavien grade I 11.1%; Clavien grade II 3.7%). The current approach tested here combines the advantages of both PCNL and fURS and effectively manages complex calculi with a high stone-free rate (SFR) (88.9%). This approach also reduced the number of treatment sessions, the number of percutaneous access tracts, and the blood loss and potential morbidity associated with multiple tracts.     

Shock wave monotherapy of staghorn calculi

From June 1987 to October 1988, 52 staghorn calculi were treated without anesthesia by shock wave lithotripsy with the second-generation lithotriptor, Lithostar Siemens. 36 calculi were evaluated. Multiple sessions (n = 1-6) were necessary according to the size of the stone. The mean hospital stay for complete treatment was 7 days. Double-J stenting was used in 45% of the patients with calculi of less than 40 mm and in 81% of the patients with calculi of greater than 40 mm. After 3 months, 50% of the patients with calculi of less than 40 mm were free of stones, as were 43% of the patients with calculi greater than 40 mm. After 9 months, the stone-free rate rose to 75%. At 3 months, the success rate (stone free or residual fragments of less than 4 mm) is 87.5% and rose to 92% at 9 months. Two severe complications were observed: one patient with acute infected hydronephrosis with sepsis and one with perirenal hematoma. Shock wave lithotripsy monotherapy of staghorn calculi is possible in multiple treatment sessions. Double-J stenting is mandatory in most of the cases but, even in this condition, anesthesia is not necessary.     

微创经皮肾镜碎石取石术治疗鹿角形肾结石52例分析

目的:探讨微创经皮肾镜碎石取石术(mPCNL)治疗鹿角形肾结石的疗效和安全性。方法:应用PCNL治疗52例鹿角形肾结石,采用实时彩色多普勒超声引导穿刺、扩张建立F16微通道,钬激光粉碎结石。统计结石清除率以及手术并发症等。结果:52例均一期建立通道。一次治疗结石清除率71.2%,总清除率84.7%,术后2例出现发热,未发生脏器损伤和感染性休克病例。结论:mPCNL治疗鹿角形肾结石效率高、出血量少,是治疗鹿角形肾结石的安全、有效方法。     

Current strategy in the treatment of urinary calculi since the introduction of the EDAP lithotripter

The extracorporeal lithotripter has radically changed the treatment of urinary stones. Three-hundred and seventy-four stones in 356 patients were treated over an eight-month period. Extracorporeal lithotripsy (262 cases) is mainly indicated in pelvic and calyceal stones measuring less than 2.5 cm, stones located in the lumbar ureter and previously flushed, and some stones of the pelvic ureter. Analysis of results showed that extracorporeal lithotripsy achieved fragmentation in 80% of cases and complete elimination 3 months after the procedure in 70% of cases. Repeat procedures were needed in 23% of patients. Complementary procedures were required to relieve obstruction in 4% of patients. Percutaneous nephrolithotomy now has very few indications but remains useful in large pelvic stones, failures of EDAP (7 cases), and some staghorn stones with few ramifications. Open surgery (24 cases) is still useful for complex staghorn stones, soft stones in febrile patients, calyceal stones with destruction of the neighboring renal parenchyma, incarcerated lumbar stones, and stones associated with an obstructive malformation of the urinary tract. Ureteroscopy (69 cases) proved highly reliable in stones located in the pelvic ureter. An improvement, therefore, but no miracle.     

气压弹道碎石术治疗肾鹿角状结石30例

目的：总结术中利用气压弹道碎石术治疗肾鹿状结石的临床疗效。方法：采和术中直视下气压弹道碎石术治疗肾鹿角状结石30例。结果：结石碎成小块较易取出，成功率90.0%（27/30）；并发症发生率为16.7%（5/30），主要是结石残留及出血。结论：此方法安全、损伤小、疗效确切。     

Percutaneous nephroscopic with holmium laser and ultrasound lithotripsy for complicated renal calculi

The aim of this work is to validate the clinical efficacy of the high-power holmium:YAG laser with percutaneous nephrolithotripsy (PCNL) in combination with ultrasound lithotripsy for complicated renal calculi. From November 2006 to December 2007, 60 patients with complicated renal calculi were treated with PCNL, where an F24 standard renal access tract was established by percutaneous renal puncture under the guidance of B-mode ultrasound, and stones were fragmented and cleared by high-power holmium laser in combination with ultrasound under an F20.8 nephroscope. Of the 60 patients with complicated renal calculi, 20 were complete staghorn calculi and 30 were partial staghorn calculi, of which six patients were accompanied with renal insufficiency; two were solitary calculi, and eight were caliceal diverticular calculi. Calculi were removed by one attempt in 49 patients and by two attempts in 11 patients; through one tract in 50 patients and through two and three tracts in ten patients. The stone-free rate was 81.7%. No injury to the pleura and abdominal organs occurred during the intraoperative puncture. No postoperative blood transfusion was needed in any patient, nor did fever and secondary hemorrhage occur. The mean operation duration was 98 min (range, 60–150 min), and the mean lithotripsy time was 45 min (range, 30–85 min). Additional postoperative extracorporeal shock wave lithotripsy (ESWL) was performed on six patients. High-power holmium laser PCNL in combination with ultrasound lithotripsy is safe, effective, and minimally invasive, with a high stone-free rate, especially for complicated renal calculi.     

Extracorporeal lithotripsy of ureteral calculi using the Dormier HM3 device. A series of 176 calculi]

In a series gathered over 5 years (November 1984 to November 1989), we have treated 356 patients with ureteral lithiasis. Out of these, 170 (134 men and 36 women) were treated with extracorporeal shock-wave lithotrity with a Dornier HM3 system, in situ and as a first intention. The calculi (176 stones) were regularly distributed along the ureter: their location was subpyelic in 44 cases, lumboiliac in 59, upper pelvic in 42 and lower pelvic in 32. The average diameter of the calculi was 10 mm for subpyelic stones and 8 mm for the others. A preliminary urine drainage was required for 24 calculi causing acute obstructive pyelonephritis (32 ureteral drains surrounding the stone, and 2 percutaneous nephrostomies). Radioscopic localization required intravenous pyelography during lithotrity in 52 cases (30%). On radiographs without preparation taken the next day, 170 stones were regarded as fragmented (96%). After some time the 6 patients whose calculus had not been fragmented underwent another treatment (4 ureterotomies and 2 ureteroscopies). Five patients had an additional treatment because of a painful and/or febrile episode (3 drain insertions and 2 ureterotomies) and 2 patients required a second session of lithotrity because fragmentation was not sufficient; 4 patients were lost to follow-up. A total of 153 patients (90%) got rid of their fragments, 146 during the first months and the remaining 7 before the sixth month. No severe complication was noted. Besides the 5 patients who had required additional treatment, 11 patients suffering from pain and/or fever had a medical treatment. These treatments lead us to proposing first-intention "in situ" extracorporeal shock wave lithotrity for all ureteral lithiases requiring a treatment.     

大功率钬激光经皮肾镜取石术治疗肾结石

目的探讨大功率钬激光经皮肾镜取石术治疗肾结石的有效性和安全性。方法应用大功率(60W:3·0J×20Hz)钬激光经皮肾镜治疗单纯肾盏或肾盂结石52例(平均结石直径3·1cm),肾盂肾盏多发结石36例(平均直径2·8cm),鹿角状结石24例(平均直径6·8cm)。记录碎石取石时间、结石取净率以及手术并发症。结果平均每次手术碎石取石时间44min,一次经皮肾镜取石术结石取净率为66%(74/112),总的取净率为89%(100/112);术后3例患者出现高热,无其他并发症。结论经皮肾镜下大功率钬激光治疗能快速粉碎结石,缩短手术时间,是治疗肾结石的安全、有效方法。     

Extracorporeal shockwave lithotripsy of 2000 urinary calculi with the modulith SL-20: success and failure according to size and location of stones

PURPOSE: We analyzed the successes and failures of SWL in the treatment of 2016 urinary calculi stratified according to size and position in the urinary tract. METHODS: All the patients were treated with a Modulith SL-20 (Storz Medical). RESULTS: The overall stone-free rate, regardless of the size and position of the stone, was 87.4%. The rate was different for kidney and ureteral stones. The stone-free rate observed for the different positions of the calculi within the kidney was upper calix 89.2%, middle calix 90.5% lower calix 84.8%, and renal pelvis 86.0%. For staghorn calculi, the stone-free rate was 60.0%. The stone-free rate for the different positions of calculi within the ureter was: upper ureter 84.3%, iliac ureter 82.4%, and pelvic ureter 91.0%. For calculi >24 mm, the retreatment rate increased, and the success rate dropped sharply. CONCLUSION: Extracorporal shockwave lithotripsy should be the first therapeutic option for urinary calculi of <24 mm regardless of their position in the urinary tract.     

Extracorporeal lithotripsy of ureteric calculi using the Dornier HM-3 lithotriptor.

Over a 5-year period (November 1984-November 1989), we treated 356 patients with ureteric calculi; 170 were treated by extracorporeal shock wave lithotripsy (ESWL) on a Dornier HM-3 lithotriptor. The calculi (n = 176) were uniformly distributed along the length of the ureter: 44 were just below the pelviureteric junction, 59 were lumbo-iliac, 42 were in the upper bony pelvis and 32 in the lower bony pelvis. The mean diameter of the upper ureteric calculi was 10 mm and for the others it was 8 mm. Thirty-four patients with acute obstructive pyelonephritis required pre-ESWL drainage of the urine. X-ray localisation required intravenous urography during lithotripsy in 52 cases (30%). On plain X-ray the following day 170 stones (96%) were judged to have disintegrated. The 6 patients whose stones were not fragmented received further treatment (ureterotomy (4) and ureteroscopy (2)). Five patients required additional treatment because of pain or fever (catheterisation (3) and ureterotomy (2)) and 2 patients had a second lithotripsy owing to insufficient fragmentation. Four patients were lost to follow-up. In 153 patients (90%) the fragments were eliminated completely, 146 in the first month and the remainder before the sixth month. No serious sequelae were observed. In addition to the 5 patients who required supplementary treatment. 11 patients with pain or fever needed medical treatment. We recommend first intention in situ ESWL for all ureteric calculi.     

Clinical experiences of renal and ureteral stones by extracorporeal shock-wave lithotripsy (ESWL). IV: 3-year clinical experience of cases treated with ESWL

We report our 3-year experience with extracorporeal shock wave lithotripsy (ESWL) since we first used it for upper urinary tract stones on September 1st, 1984. A total of 1,225 patients (1,320 cases) underwent 1,647 sessions with ESWL; They consisted of 855 males (70%) and 370 females (30%). Treated stone locations were 593 renal stones, which contained 112 complete staghorn calculi, 504 ureteral stones, 110 renoureteral stones, and 1 bladder stone. ESWL monotherapy was performed on 90% of cases with renal and ureteral stones, and 46% of cases with complete staghorn calculi. In all the cases so far observed for more than 12 weeks after ESWL, 84.9% of the former showed complete discharge of the stones, and 0.7% showed no change. Only 48.9% of the later showed the complete discharge of the stones, 43.3% of which had residual stones, and 7.8% had fragments of the size of small beans. Complications, which were fever and pain, were noticed in 33.6% of the cases with renal and ureteral stones, and 64.3% of the cases with complete staghorn calculi. After ESWL, hematuria was noticed in almost cases, but the average volume of hemorrhage was 28 +/- 33 ml/day. The only contraindication of ESWL was severe obesity, and in the cases in which spontaneous stone discharge can be expected.     

Characteristics of patients with staghorn calculi in our experience

PURPOSE: To elucidate the factors contributing to staghorn stone formation in patients. MATERIALS AND METHODS: The records of 82 patients (44 men and 38 women) with complete staghorn calculi were reviewed retrospectively for clinical presentation, metabolic disturbances and anatomical abnormalities. RESULTS: There were 79 unilateral and three bilateral cases. The patient performance of the activities of daily life was assessed with the modified Rankin scale (MRS) and it was found that 69 patients were functionally independent (84.1%, MRS 0-1) and 10 patients had a severe disability (12.2%, MRS 4-5). Seven patients had chronic indwelling catheters (8.5%). A positive urine culture was found in 24.4% of patients. Analysis of stone composition revealed magnesium ammonium phosphate and mixed calcium oxalate-phosphate were the most frequently identified types of stone (32.1% and 22.2%, respectively). Urinary pH was low in patients with uric acid stones (mean 5.4). Hyperuricemia, cystinuria and hypercalciuria were found in 14.6%, 2.4% and 37.8%, respectively. Hypercalciuria was found more frequently in calcium-stone cases. Eleven patients (13.4%) showed structural abnormalities of the kidney. CONCLUSIONS: Our data show that the patients with severe disability, urinary tract infection and hypercalciuria could be recognized more frequently in staghorn calculi compared with common urolithiasis. However, in Western countries, the frequency of both urinary tract infection and struvite stones is much higher than in our data. Other Japanese authors have also reported the low frequency of struvite stones in staghorn calculi, suggesting that various factors other than urinary tract infection possibly contribute to the formation of staghorn calculi in Japan.     

Electromagnetic extracorporeal shock wave lithotripsy in children

Extracorporeal shock wave lithotripsy (ESWL) was performed for the treatment of urinary tract calculi in 28 children. All treatments were done with the standard Siemens Lithostar device in situ: no special adaptations for adequate positioning of children are required to target the stone precisely. A total of 42 calculi in 30 renal units was treated, requiring 50 ESWL sessions. The mean energy used was 16.4 kv. and the number of shock waves averaged 3,188. Mean fluoroscopy time per session was 1.5 minutes. In 26 of 50 sessions (52%) general anesthesia was needed for the child to remain perfectly still. A complete stone-free rate was achieved in 38 of 42 calculi (90.5%): after 1 session in 30 (71.4%), after 2 sessions in 6 (13.7%) and after 3 sessions in 2 (4.8%). Five staghorn calculi were treated with ESWL monotherapy. A complete stone-free result was obtained after 3 treatments in 2 patients, while 2 had residual fragments in the lower pole (5 mm. after 6 sessions and 11 months of followup in 1, and 7 mm. after 3 sessions and 3 months of followup in 1). A cystine staghorn stone necessitated open nephrolithotomy after 3 sessions without any fragmentation. One impacted sacroiliac ureteral stone required endoscopic laser lithotripsy. Except for these 2 failures no adjuvant procedures were needed. There were no intraoperative or postoperative complications and minor skin bruising at the coupling site after 3 treatments did not require any therapy. We conclude that electromagnetic ESWL with the standard Lithostar unit is a safe and effective method to treat calculi throughout the urinary tract in children.     

Pediatric staghorn calculi: the role of extracorporeal shock wave lithotripsy monotherapy with special reference to ureteral stenting

PURPOSE: Treatment for staghorn calculi in children represents a unique challenge. We assessed the efficacy of extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia) monotherapy for the management of staghorn calculi in children with special reference to ureteral stenting. MATERIALS AND METHODS: From June 1992 to January 2001 we treated 42 children 9 months to 12 years old with staghorn stones using the Piezolith 2501 (Richard Wolf GmBH, Knittlingen, Germany) lithotriptor. The initial group of 19 patients underwent ESWL without prophylactic ureteral stenting, while in the latter group of 23 a Double-J (Medical Engineering Corp., New York, New York) ureteral stent was inserted immediately before the first ESWL session. Mean patient age, stone size, number of shock waves and ESWL sessions, hospital stay, stone-free rate and major complications were compared in the 2 groups. RESULTS: Overall 33 children (79%) were stone-free after 3 months. The 2 groups were comparable in regard to patient age, stone size, number of shock waves and ESWL sessions, and stone-free rates. Major complications developed in 21% of the unstented group, whereas none were observed in stented cases. This difference was statistically significant (p = 0.035). Seven post-ESWL auxiliary procedures were required in the unstented group to manage complications. Hospital stay was significantly longer in the unstented compared with the stented group (p = 0.022). At a followup of 9 to 102 months (mean 47) stones recurred in 2 children, who were treated with further ESWL. CONCLUSIONS: ESWL monotherapy was an efficient and safe modality for the treatment of staghorn calculi in children. Stented patients had fewer major complications and a shorter hospital stay. Prophylactic ureteral stenting is advisable before ESWL for staghorn calculi in children.     

Unenhanced computerized axial tomography to detect retained calculi after percutaneous ultrasonic lithotripsy.

PURPOSE: We report our experience with unenhanced computerized axial tomography (CT) after percutaneous ultrasonic lithotripsy in patients thought to be at high risk for retained calculi. MATERIALS AND METHODS: CT was obtained in 121 patients (124 kidneys) within 12 to 36 hours of percutaneous ultrasonic lithotripsy for staghorn or large nonstaghorn renal calculi. Cases were grouped according to the CT findings as no retained calculi, insignificant retained calculi (fragments 1 to 3 mm.), retained calculi amenable to shock wave lithotripsy and retained fragments requiring second look percutaneous ultrasonic lithotripsy or flexible nephroscopy. RESULTS: No calculi were seen in 73 kidneys (59%) and retained calculi were identified in 51 (41%). Shock wave lithotripsy was used to treat 8 patients and another percutaneous ultrasonic lithotripsy or flexible nephroscopy was performed in 23 to remove retained stones. Insignificant calculi were noted in the remaining 21 patients. CONCLUSIONS: We believe that postoperative unenhanced CT is superior to plain renal tomography and is the best method to determine if a patient is stone-free after percutaneous ultrasonic lithotripsy. It helps to locate precisely those stones requiring a second percutaneous ultrasonic lithotripsy or nephroscopic extraction. An unenhanced renal CT devoid of calculi obviates routine postoperative second look flexible nephroscopy. We encourage others to consider this technique to define more accurately kidney stone status after percutaneous ultrasonic lithotripsy for large staghorn calculi or in any patient at high risk for retained calculi after percutaneous ultrasonic lithotripsy.     

Staghorn calculi: analysis of treatment results between initial percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy monotherapy with reference to surface area.

Treatment recommendations and results reported for the management of staghorn calculi are highly variable. In an attempt to provide a more objective means to compare treatment results for staghorn renal calculi, stone burden as measured by stone surface area was used. Stone surface area was determined by computer analysis. A total of 380 cases of staghorn calculi treated at the same institution was evaluated. Treatment consisted of initial percutaneous nephrostolithotomy with or without extracorporeal shock wave lithotripsy (ESWL*) in 298 cases and ESWL monotherapy in 82. When considered as a group, the overall stone-free rate for initial percutaneous nephrostolithotomy (mean surface area 1,378.3 mm.2) was 84.2% compared to 51.2% (p less than 0.0001) for ESWL monotherapy (mean surface area 693.4 mm.2). For staghorn calculi smaller than 500 mm.2 a stone-free rate of 94.4% was achieved in the percutaneous nephrostolithotomy with or without ESWL group compared to 63.2% for ESWL monotherapy (p = 0.0214). For calculi of 501 to 1,000 mm.2 the stone-free rates were 86% and 45.7%, respectively (p less than 0.0001). When stone surface area exceeded 1,000 mm.2 the stone-free rate for percutaneous nephrostolithotomy with or without ESWL was 82.4% but it was only 22.2% for ESWL monotherapy (p = 0.0002). Overall, when adjusted for stone surface area the odds of being stone-free were more than 8 times higher for initial percutaneous nephrostolithotomy versus ESWL monotherapy (odds ratio = 8.36, p less than 0.0001). While percutaneous nephrostolithotomy with or without ESWL appears to be the procedure of choice for most staghorn stones, ESWL monotherapy may have a role for some stones smaller than 500 mm.2. In 12 such cases associated with a nondilated renal collecting system (mean surface area 380.5 mm.2) a stone-free rate of 91.7% was achieved. The number of procedures required to complete therapy was higher in the initial percutaneous nephrostolithotomy group (2.8 versus 2.1, p less than 0.0001). Although complications were more common in the ESWL monotherapy group (manifested as obstruction in 30.5%), bleeding requiring blood transfusion was more frequent in the initial percutaneous nephrostolithotomy group (9.4%).