Calculi In Horseshoe Kidneys Research Articles

Tailored minimally invasive management of complex calculi in horseshoe kidney.

Complex calculi in horseshoe kidney (HK) present a significant management challenge. Here, we report the clinical efficacy of extracorporeal shock wave lithotripsy (ESWL), minimally invasive percutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS), combined with holmium laser lithotripsy, in the treatment of calculi in HK. From January 2005 to May 2014, 62 HK patients with renal calculi were reviewed in terms of medical history, treatment modality and therapeutic outcome in a single tertiary care hospital. Among the patients, 11 with a solitary stone ≤ 1.5 cm in diameter received ESWL, leading to overall stone-free rate of 72.7%; 18 with stone diameter ≤ 2-3 cm received retrograde flexible ureteroscopy, with a recorded mean digitized surface area (DSA) of 339.6 ± 103.9 mm2, mean operation time of 93.1 ± 11.5 minutes and overall stone-free rate of 88.9%; and 33 with staghorn or complex calculi (d ≥ 2 cm) had MPCNL or MPCNL-FURS, with a recorded mean DSA of 691.0 ± 329.9 vs. 802.9 ± 333.3 mm2, mean operation time of 106.4 ± 16.6 vs. 124.4 ± 15.1 min and overall stone-free rate of 89.5% vs. 92.9%. For complex calculi (d ≥ 2 cm), MPCNL combined with antegrade FURS was superior in terms of reducing number of tracts, controlling mean hemoglobin drop, but required longer operation time, comparing with MPCNL alone. As minimally invasive treatments, a combination of MPCNL and antegrade FURS provides a safe and effective modality in the management of staghorn or complex calculi (d ≥ 2 cm) in HK with significantly reduced blood loss comparing to MPCNL alone, and retrograde FURS alone is favorable for stones with a diameter ≤ 2-3 cm. ESWL is effective for viable small solitary stones (d ≤ 1.5 cm). Treatment modality should be tailored based on individual condition.

Safety and Efficacy of Minimally Invasive Percutaneous Nephrolithotomy in Treatment of Calculi in Horseshoe Kidneys

To evaluate the safety and efficacy of minimally invasive percutaneous nephrolithotomy (MPCNL) in horseshoe kidneys (HKs) with calculi. From 2006 to 2012, 35 renal units in 32 patients with calculi in HKs underwent MPCNL. Patients and stone characteristics, stone-free rates (SFR), and complications were evaluated. The composition of the stones obtained from operation was also analyzed by infrared spectroscopy. The average age of patients was 38.2±7.3 years (range 14-72). The mean stone burden was 657±510.9 mm(2) (range 134.7-2460.1). The mean operative time was 93.4±17.6 minutes (53-152). The most popular access site was upper pole access (35/42, 83.3%). The SFR after initial MPCNL was 82.9% (29/35 renal units). Second-stage MPCNL was performed in 5 renal units, with a 91.4% (32/35 renal units) final SFR. Minor complications (Clavien grades I and II) were seen in six patients, and urosepsis requiring intensive care unit management in one (Clavien grade IVa). All were treated successfully. MPCNL is a safe and effective treatment modality in HK stones with acceptable results, which was compatible to a normal anatomy kidney. However, further studies with a larger sample size are required.

English

Horseshoe kidney (HSK) is the most common renal anomalies. Bilateral staghorn calculi in HSK are rare and management is challenging. Anatomic consideration is important in choosing treatment modality. We report a case of bilateral staghorn calculus and its management. We report a case of bilateral staghorn calculus due to its rarity and challenge associated with its management.

Staghorn Calculus in a Horseshoe Kidney = حصاة مرجانية في كلية حدوة الحصان

A 52-year-old male patient presented with bilateral loin pain of four months’ duration. Twenty years before, he had had surgery for kidney stone disease. An abdominal examination revealed a scar from the previous surgery on his left side. Investigations showed microscopic haematuria with no growth on urine culture. His serum creatinine and haemoglobin were normal. A plain abdominal X-ray of the kidneys, ureter, and bladder (KUB) [Figure 1] showed bilateral renal stones. The detailed renal anatomy and the extent of renal stones were delineated by computed tomography (CT). The patient underwent an open pyelonephrolithotomy [Figure 2] and a staghorn stone was extracted [Figure 3]. The post-operative course was smooth and the residual stones were managed by extracorporeal shock wave lithotripsy (ESWL). Figure 1: Plain X-ray showing staghorn calculus in a horseshoe kidney (black arrows). Figure 2: Intra-operative view of the horseshoe kidney (vessel loop around renal artery). Figure 3: The staghorn calculus extracted from the horseshoe kidney. The horseshoe kidney is the most common of all renal fusion anomalies. It occurs in 0.25% of the population (1 in 400 persons). The horseshoe kidney, even though it produces no symptoms, is frequently found in association with other congenital anomalies including genital anomalies: hypospadias - 4%, undescended testes - 4%, bicornuate uterus - 7% and septate vagina - 7%; urinary collecting system anomalies: ureteral duplication - 10%, ureteropelvic junction obstruction - 20%, vesicoureteral reflux -50%; renal parenchymal abnormalities: multicystic dysplasia - 1%, autosomal recessive polycystic kidney - 1%, and metabolic derangements in patients with stones in 50%: hypercalciuria, hyperoxaluria, hypocitraturia, hypouricuria.1 The association of horseshoe kidneys with staghorn calculus formation is rare. The reported cases in the literature of a staghorn calculi in a horseshoe kidneys were 19,2 3,3 8,4 and 35 cases. Percutaneous extraction of stones from horseshoe kidneys has been done safely and is considered the standard of care. Prado et al. treated 8 patients with staghorn calculi in a horseshoe kidney by percutaneous nephrolithotomy (PCNL).4 Complete stone clearance was achieved in all the patients. Only one patient suffered a long-term urinary tract infection of three months’ duration, and temporary deterioration in renal function. It was concluded that PCNL, performed after an imaging study and careful assessment of the renal anatomy and related structures, can be a safe and effective monotherapy for patients with staghorn calculi in horseshoes kidney. Liatsikos et al., in a study of 15 patients with 17 staghorn calculi in horseshoe kidneys who were treated by PCNL, reported an overall stone-free rate of 82%, with a major and minor complication rate of 20 and 46.6%, respectively.6 Raj et al. used PCNL for the treatment of 37 patients with renal calculi in a horseshoe kidney (3 staghorn) and concluded that PCNL is an effective means of kidney stone management in this complex patient population.3 However, PCNL is technically challenging, usually requiring upper pole access and flexible nephroscopy due to the altered anatomical relationships of the fused renal units. The present case was managed by open surgery rather than PCNL due to the surgeon’s preference. In addition, it has been shown that staghorn calculi are associated with a lower stone-free rate after percutaneous nephrolithotomy.2 A patient with staghorn calculi in a horseshoe kidney was 45 times more likely to have a lower stone-free rate after percutaneous nephrolithotomy than a patient without staghorn calculi in the horseshoe kidney. Therefore, open surgery still has a role in the treatment of horseshoe kidneys with staghorn calculus when indicated.

Ureteroscopy-assisted retrograde nephrostomy for lower calyx calculi in horseshoe kidney: two case reports

IntroductionWe previously reported on the effectiveness of ureteroscopy-assisted retrograde nephrostomy during percutaneous nephrolithotomy and report two cases of lower calyx calculi in horseshoe kidney that were successfully treated with ureteroscopy-assisted retrograde nephrostomy. During the ureteroscopy-assisted retrograde nephrostomy procedure, a ureteroscope is advanced in the desired calyx and a Lawson retrograde nephrostomy puncture wire is inserted. The wire is advanced through the calyx to exit the skin. The wire is then used for the percutaneous dilation.Case presentationCase 1 was a 68-year-old man who was shown on radiography to have left lower calyx calculi (19 × 15mm, 7 × 5mm, and 7 × 3mm) in horseshoe kidney. Case 2 was a 36-year-old woman shown on radiography to have a left lower calyx calculus (10 × 8mm) in horseshoe kidney.ConclusionsBoth patients were stone-free after ureteroscopy-assisted retrograde nephrostomy during percutaneous nephrolithotomy. Ureteroscopy-assisted retrograde nephrostomy is a promising procedure for safely and effectively treating lower calyx stones in horseshoe kidney.

Minimally invasive and standard percutaneous nephrolithotomy for treatment of calculi in horseshoe kidney: an analysis of clinical effectiveness

Minimally invasive and standard percutaneous nephrolithotomy for treatment of calculi in horseshoe kidney: an analysis of clinical effectiveness

Percutaneous Nephrolithotomy in Horseshoe Kidneys: Factors Affecting Stone-Free Rate

We report a 2-center study of factors affecting the stone-free rate after percutaneous nephrolithotomy in horseshoe kidneys. The postoperative stone-free rate after percutaneous nephrolithotomy was evaluated in 47 male and 11 female patients with horseshoe kidneys. All data were collected prospectively. Patient and procedure related factors predicting the stone-free rate were analyzed by univariate and multivariate tests. The mean ± SD stone burden was 7.62 ± 7.18 cm(2) (range 1 to 45) and the stone was larger than 10 cm(2) in 14 patients (24.1%). Complex stones and staghorn stones were present in 21 (36.2%) and 19 patients (32.7%), respectively. The overall stone-free rate was 65.5%. Complex stones (p = 0.01), stone burden greater than 5 cm(2) (p = 0.013), stone burden greater than 10 cm(2) (p = 0.012), multiple stones (p = 0.006) and staghorn stones (p <0.001) were related to adverse outcomes on univariate analysis. Logistic regression analysis revealed that staghorn calculi was the only factor that significantly predicted the stone-free rate (p = 0.002). A patient with staghorn calculi in the horseshoe kidney was 45 times more likely to have a lower stone-free rate after percutaneous nephrolithotomy than a patient without staghorn calculi in the horseshoe kidney. Stone parameters are important when treating calculi in horseshoe kidneys. Staghorn calculi are associated with a lower stone-free rate after percutaneous nephrolithotomy.

Percutaneous Management of Staghorn Calculi in Horseshoe Kidneys: A Multi-Institutional Experience

Percutaneous nephrolithotomy (PNL) is a first-line management technique for staghorn stones and stones located in a horseshoe kidney (HK). We present our multi-institutional experience on the management of staghorn calculi within HKs. The study included 15 patients with 17 staghorn calculi in HKs who were treated by PNL in six academic institutions. All PNL procedures were performed in a standard one-session technique with fluoroscopic guidance. The following information was assessed: Number of access dilations, renal access location, blood loss, blood transfusion, stone-free rate, length of hospitalization. Intraoperative and postoperative complications as well as secondary procedures (second-look PNL, ureteroscopy, and shockwave lithotripsy) were reviewed. Mean patient age was 50 years (range 24-72 y) years old. Subcostal (n = 16) or intercostal (n = 1) puncture was performed. The average anesthesia time was 126 minutes (93-200 min). The average blood loss was 450 mL, and transfusions were deemed necessary in 20% of the cases. Single skin incisions were made for the management of 11 renal units, and multiple incisions were made in 6. The average number of tract dilations per renal unit was 2.11 (range 1-4). The overall stone-free rate was 82%. The average length of hospital stay was 4.4 days (range 3-7). The average duration of nephrostomy tube drainage was 80 hours with a range of 72 to 96 hours. Major and minor complication rate was 20% and 46.6%, respectively. The performance of PNL is a safe and effective method to manage staghorn calculi in HKs.

Percutaneous nephrolithotomy in horseshoe Kidneys: is rigid nephroscopy sufficient tool for complete clearance? a case series study

Backgroundthis study represents a case series to evaluate how successful is the rigid percutaneous nephroscopy as a tool for clearance of all stones in various locations in horseshoe kidneys.MethodsBetween 2005 and 2009, we carried out PCNL (percutaneous nephrolithotomy) for calculi in horseshoe kidneys in 21 renal units (17 patients) in our department. The indications were large stone burden in 18 units and failed SWL(shock wave lithotripsy) in 3 renal units. All procedures were done under general anesthesia; using fluoroscopic guidance for localization and standard alkan dilatation followed by rigid nephroscopy and stone extraction with or without stone disintegration. We analyzed our results regarding the site and number of the required access, the intra and postoperative complications, the presence of any residual stones, as well as their location.ResultsThe procedure was completed, using a single access tract in 20 renal units, with the site of puncture being the upper calyx in nine units and the posterior middle calyx in eleven units. Only in one renal unit, two access tracts (an upper and a lower calyceal) were required for completion and a supracostal puncture was required in another case. There was no significant intraoperative bleeding and no blood transfusion was required in any patient. A pelvic perforation occurred in one case, requiring longer PCN (percutaneous nephrostomy) drainage. One patient with infection stones suffered urosepsis postoperatively which was successfully managed. Three cases had residual stones, all located in the renal isthmus, all residuals were un approachable with the rigid instrument; resulting in a overall stone-free rate of 85.7% at discharge.ConclusionPercutaneous nephrolithotomy is generally safe and successful in the management of stones in horseshoe kidneys. However, location of the stones in these patients is crucial to decide the proper tool for optimal stone clearance result.

Percutaneous Management of Urinary Calculi in Horseshoe Kidneys

Urolithiasis in horseshoe kidney presents a unique challenge in decision-making and technical aspects of calculus treatment. We present our experience with a group of patients with symptomatic calculi in their horseshoe kidneys. We had 8 patients with 9 horseshoe kidneys bearing calculi. They all underwent percutaneous nephrolithotomy. The median size of the calculi was 21 mm (range, 12 to 45 mm). Auxiliary therapeutic procedures were required in 2 patients who had residual calculi on control imaging. The stone-free status was observed in 6 patients (75.0%) at discharge, and in 7 (87.5%) after 3 months of follow-up. Surgical complications included bleeding in 2 patients that was controlled with complete bed rest and blood transfusion, and pleural injury in 1 which was managed conservatively.

Percutaneous Nephrolithotomy in Patients with Kidney Malformations

Percutaneous nephrolithotomy (PCNL) for complex calculi within malformed kidneys can be challenging because of the abnormal anatomy. We present our 7-year experience with PCNL in such patients. We performed PCNL on 16 patients with complex calculi and anomalous kidneys, including 7 with horseshoe kidneys, 5 with rotation anomalies, 3 with ectopic kidneys, and 1 with a small kidney. After appropriate preoperative evaluation, the procedure was performed by choosing either anterior or posterior approaches depending on the kidney anomaly. When required, ultrasonography, laparoscopy, or both were used, as well as fluoroscopy to control the procedures. A single-stage PCNL resulted in complete clearance in 13 patients (81%). A second-look procedure, alone or followed by shockwave lithotripsy, conferred stone clearance in one patient with a malrotated kidney and two with staghorn calculi in horseshoe kidneys. More than one tract was needed in two patients. The procedure was guided by laparoscopy in two patients with calculi in ectopic left kidneys. Serious complications were not encountered. Patients with malformed kidneys and complex calculi can be managed safely and effectively with PCNL when they are properly selected and appropriately assessed before operation.

Percutaneous nephrolithotomy of kidney calculi in horseshoe kidney.

The aim of this study was to evaluate percutaneous nephrolithotomy (PCNL) in horseshoe kidneys with calculi. Between 1995 and 2005, we performed PCNL in 9 patients with horseshoe kidney. In 3 of them, there was a single calculus and the rest had multiple calculi in the pelvis and at least 1 in the calyxes. Ultrasonography, plain abdominal radiography, and intravenous urography (IVU) were performed in all patients. We used fluoroscopy for entering the system and then, pneumatic or ultrasonic lithotripsy was used. In all except 1 patient (88.9%) we could access the system. Single calculi in 3 patients were removed. In 5 patients with multiple calculi, the calculus causing obstruction was removed, and in 3, the calculi located in the calyxes were removed too. Consequently, 66.7% were stone-free at the end of the procedure. In 2 patients, there were residual calculi in the calyxes and they underwent candidates for extracorporeal shockwave lithotripsy. Percutaneous nephrolithotomy can be used in patients with horseshoe kidney if the patient selection is appropriate and the surgeon is experienced enough. The success rate and complications are the same as the patients with normal anatomy. However, access to the lower calyx is more difficult due to its anatomic status.

Metabolic abnormalities associated with renal calculi in patients with horseshoe kidneys.

Horseshoe kidneys are a complex anatomic variant of fused kidneys, with a 20% reported incidence of associated calculi. Anatomic causes such as high insertion of the ureter on the renal pelvis and obstruction of the ureteropelvic junction are thought to contribute to stone formation via impaired drainage, with urinary stasis, and an increased incidence of infection. In this multi-institutional study, we evaluated whether metabolic factors contributed to stone development in patients with horseshoe kidneys. A retrospective review of 37 patients with horseshoe kidneys was performed to determine if these patients had metabolic derangements that might have contributed to calculus formation. Stone compositions as well as 24-hour urine collections were examined. Specific data points of interest were total urine volume; urine pH; urine concentrations of calcium, sodium, uric acid, oxalate, and citrate; and number of abnormalities per patient per 24-hour urine collection. These data were compared with those of a group of 13 patients with stones in caliceal diverticula as well as 24 age-, race-, and sex-matched controls with stones in anatomically normal kidneys. Eleven (9 men and 2 women) of the 37 patients (30%) with renal calculi in horseshoe kidneys had complete metabolic evaluations available for review. All patients were noted to have at least one abnormality, with an average of 2.68 abnormalities per 24-hour urine collection (range 1-4). One patient had primary hyperparathyroidism and underwent a parathyroidectomy. Low urine volumes were noted in eight patients on at least one of the two specimens (range 350-1640 mL/day). Hypercalciuria, hyperoxaluria, hyperuricosuria, and hypocitraturia were noted in seven, three, six, and six patients, respectively. No patients were found to have gouty diathesis or developed cystine stones. Comparative metabolic analyses of patients with renal calculi in caliceal diverticula or normal kidneys revealed a distinct profile in patients with horseshoe kidneys, with a higher incidence of hypocitraturia. All patients with renal calculi in horseshoe kidneys were noted to have metabolic abnormalities predisposing to stone formation. In this initial series of 11 patients, hypovolemia, hypercalcuria and hypocitraturia were most common metabolic defects. These findings suggest that metabolic derangements play a role in stone formation in patients with a horseshoe kidney. Patients with calculi in anatomically abnormal kidneys should be considered for a metabolic evaluation to identify their stone-forming risk factors in order to initiate preventative selective medical therapy and reduce the risk of recurrent calculus formation.

Current management of calculi in horseshoe kidneys.

To assess treatment options for calculi in horseshoe kidneys and the impact of extracorporeal shockwave lithotripsy (ESWL) on the management of renal stones. From June 1971 to January 1998, 52 patients with horseshoe kidneys and calculi received treatment at our Urologic Stone Unit. There were 40 men (77%) and 12 women (23%). Average patient age was 41 years (range: 10-70 years). Clinical onset, treatment received and outcome were evaluated retrospectively. A successful outcome was defined as a patient without residual calculi or with fragments <0.4 cm in size. Clinical onset was mainly low back pain in 37 patients (71%). Eighty-nine stones were treated, i.e. an average of 1.7 treatments per patient. Before the ESWL era (May 1987), we performed two heminephrectomies, 16 pyelolithotomies, 12 pyelolithotomies combined with ureteropyeloplasty and one percutaneous nephrolithotomy. Since the advent of ESWL, seven pyelolithotomies and three pyelolithotomies combined with ureteropyloplasty have been done. ESWL was used to treat 48 calculi. In three cases the patient was placed in the prone position due to difficulties in stone focusing. In 37 cases (77%) patients were either rendered stone-free or had residual fragments <0.4 cm in size. Urinary diversion for obstruction was carried out in two cases (4%). At present ESWL is the first-choice treatment for calculi in horseshoe kidneys. It involves no significant focusing difficulties and is associated with a low incidence of obstructive complications. Open surgery is indicated in cases of stone-related pyeloureteral stenosis and in the presence of calculi >2-2.5 cm in size.

PERCUTANEOUS STONE REMOVAL IN HORSESHOE KIDNEYS

Purpose We review our experience with percutaneous nephrolithotomy for stones in horseshoe kidneys when extracorporeal shock wave lithotripsy was unsuccessful or inappropriate because of stone burden. Materials and Methods Stone burden, nephrostomy and percutaneous surgical techniques, and clinical outcome of 12 consecutive patients undergoing percutaneous nephrolithotomy for calculi in horseshoe kidneys between 1988 and 1997 were reviewed. Results Complete stone removal was achieved by percutaneous methods alone in 9 patients (75%). More than 1 nephrostomy tract was required in 5 patients and additional intraoperative nephrostomies were necessary in 4. Flexible nephroscopy was essential in achieving complete stone removal in 9 of 11 patients (82%). Second look procedures for stone removal were required in 3 patients. No sepsis occurred and no transfusions were needed. Conclusions Percutaneous nephrolithotomy is a safe and effective method of stone removal in patients with calculi in horseshoe kidneys. Multiple nephrostomy tracts, the use of flexible nephroscopy and second look procedures may be necessary to achieve optimum stone removal.

Anatomical bases of percutaneous surgery for calculi in horseshoe kidney.

Horseshoe kidney is a renal fusion which combines three anatomic abnormalities: ectopia, malrotation and vascular changes. These anomalies can be recognised separately to varying degrees in unfused kidneys. Necessary modifications of the standard technique for percutaneous nephrolithotomy (PNL) are directly deducible from analysis of the anatomic data of the imaging of horseshoe kidneys. We report our experience with 5 patients (7 kidneys) who underwent PNL for calculi in horseshoe kidneys. The percutaneous approach was performed under ultrasound and fluoroscopic monitoring. In situ disintegration by ultrasonic lithotripsy and nephrostomy drainage were necessary in all cases. Modifications of the standard PNL procedure are related to the anatomic changes. The lower abdominal position of a horseshoe kidney necessitates upper or middle calyceal puncture, while the malrotation necessitates a more posterior puncture. Monitoring of the puncture needle by fluoroscopy as it is advanced postero-anteriorly is more difficult and the risk of the surgeon's hand entering the radiation path is increased. The renal pelvis is deep and a long endoscope may be required. Aberrant segmental vessels may create potential hazards. The majority of problems in location can be avoided by use of an ultrasonically guided needle. Percutaneous nephrolithotomy is the treatment of choice for calculi in horseshoe kidneys for the following reasons: the high incidence of recurrent lithiasis in horseshoe kidney and the complexity of repeated surgical approaches diminish the acceptable results of open surgery; difficulties in focussing on the calculi and drainage problems militate against the success of extracorporeal shock wave lithotripsy (ESWL); PNL has a good success rate and the least morbidity.

Which Method Is Best for Stone Localization in Horseshoe Kidneys?

Seven patients with calculi in horseshoe kidneys were treated with extracorporeal shock wave lithotripsy on a Dornier MPL 9000-X lithotripter. Ultrasound localization of stones proved more difficult than the X-ray technique because of the anatomic abnormality and the difficulties in targeting stones located in anterior renal calices. When treatment success was judged by stone fragmentation and clearance, there was no difference between treatments given under X-ray or ultrasonic imaging. However, fluoroscopic targeting was accomplished more easily. The longer focal distance of the Dornier X-155 electrode, together with shock wave entry via the anterolateral abdominal wall, were particularly advantageous. For third-generation lithotripters with fluoroscopic and ultrasound imaging modalities, we recommend fluoroscopic imaging as the best method for localization of stones in horseshoe kidneys.

Percutaneous Nephrolithotomy for Calculi in Horseshoe Kidneys

Between 1983 and 1988, 15 patients (18 kidneys) underwent percutaneous nephrolithotomy at this unit for calculi in horseshoe kidneys. A standard 1-stage percutaneous access technique with minor modifications was used. In situ disintegration with ultrasound or electrohydraulic lithotripsy was necessary in 15 moieties (83.3%) and nephrostomy drainage was required in 12 (66.7%). Percutaneous access was not a problem and there were minimal perioperative problems. Blood transfusion was required postoperatively in 2 patients. A total of 14 kidneys (77.8%) were rendered free of stone with percutaneous nephrolithotomy alone and 2 kidneys were left with asymptomatic stone fragments of 2mm. or less. Another 2 kidneys became free of stone after extracorporeal shock wave lithotripsy, thus giving an over-all stone clearance rate of 88.8%. We conclude that percutaneous nephrolithotomy is an acceptable treatment for stones in horseshoe kidneys and it is the treatment of choice for patients in whom imaging is difficult or impossible

Extracorporeal shock-wave lithotripsyin horseshoe kidneys

Using the Dornier HM-3 lithotriptor, 10 patients (11 renal units) with calculi in horseshoe kidneys were treated with extraeorporeal shock-wave lithotripsy (ESWL) and ancillary procedures. Six renal units (55 %) underwent pre-ESWL manipulation consisting of a Double J stent, ureteral catheter, or percutaneous nephrostomy. The “blast path” was employed to treat five renal units which could not be positioned at F2. Good initial stone fragmentation was obtained in eight renal units (73 %). There were two episodes of post-ESWL obstruction requiring intervention; both occurred in the same patient. A total of seven post-ESWL procedures were performed on two renal units. After all procedures, eight renal units (73 %) were rendered stone: free, six (55 %) with ESWL alone. The average follow-up interval was twelve months (range 1–28 months). ESWL can be used effectively to treat some patients with calculi in horseshoe kidneys. The ectopic location of these renal units may make it difficult to position calculi at F 2, thus necessitating treatment on the blast path or placement of the patient in prone position. Multiple ancillary procedures may be necessary.

Extracorporeal Shock Wave Lithotripsy Treatment of Calculi in Horseshoe Kidneys

From June 1985 to November 1986, 17 patients with calculi in horseshoe kidneys presented to our hospital for evaluation and possible treatment with extracorporeal shock wave lithotripsy. Of these patients 14 were treated with extracorporeal shock wave lithotripsy; the calculi in 2 could not be localized and focused at the F2 focal point, and 1 was asymptomatic and has been followed conservatively. Four patients required repeat extracorporeal shock wave lithotripsy. Adjunctive procedures included preoperative retrograde catheter placement (5 patients), postoperative percutaneous nephrostolithotomy (1), ureteroscopy for ureteral fragments (2) and placement of a double pigtail stent (1). Of 14 patients 11 (79 per cent) have been rendered free of fragments with extracorporeal shock wave lithotripsy and adjunctive measures as needed. We conclude that most patients with calculi in a horseshoe kidney can be managed primarily with extracorporeal shock wave lithotripsy.