Urolithiasis in the horseshoe kidney: a single-centre experience

Unfavorable factors in accessing the pelvicalyceal system during retrograde flexible ureteroscopy (fURS)

Flexible ureteroscopy (fURS) is a well-established procedure for treating multiple upper-urinary tract pathologies, particularly renoureteral lithiasis. Endoscopes have undergone significant advancements, including miniaturization, improved optics, and increased maneuverability. In addition, advancements in accessory instruments, such as the performance of laser fibers, guidewires, and extraction probes, have played a significant role in improving the overall performance of flexible ureteroscopy procedures. However, despite these advancements, unique circumstances can make achieving optimum results during flexible ureteroscopy challenging. These include congenital renal anomalies (horseshoe kidneys, ectopic kidneys, rotation anomalies), as well as the unique intrarenal anatomy (infundibulopelvic angle, infundibular length) or the specifications of the endoscope in terms of maneuverability (active and passive deflection). This review explored challenging scenarios during flexible ureteroscopy procedures in the pyelocaliceal system.

Percutaneous nephrolithotomy in horseshoe kidney: comparing ultrasound-guided access in flank position with conventional fluoroscopic-guided in prone position

We conducted this study to compare radiation-free US-guided percutaneous nephrolithotomy (PNL) in the flank position with conventional PNL in the prone position for the treatment of renal stones in patients with horseshoe kidneys. In a retrospective study, 14 HSK patients that were treated with conventional fluoroscopy-guided PNL in the prone position (group A) were compared with twenty-four HSK patients that were treated US-guided PNL in the flank position (group B). Data on baseline characteristics, percentage of successful entries, stone-free rate, duration of admission and complication rate were obtained from data registry. The average duration of the operation was 57.6 min in group B, which was statistically less than group A with 65.9 min (P = 0.001). Access time varied from 10 to 32.4 min (mean = 17.1 min) in group A and 5-29.5 min (mean = 10.9 min) in group B (P < 0.001). Access length had a significant relation to the surgery method so PNL with US-guided had less access length (P = 0.002). There was no significant relationship between the surgery guide and the residual stone rate (P = 0.6). Hemoglobin decrease (P = 0.5), hospitalization duration (P = 0.5) and need for blood transfusion (P value = 0.6) were not statistically different between the two groups. PNL with US guidance in flank position is a safe and effective technique in HSK patients and is associated with fewer complications than the traditional approach as well as reduced operating time, radiation exposure, and its complications.

Comparison of the Efficacy and Safety of Extracorporeal Shock Wave Lithotripsy and Flexible Ureteroscopy for Treatment of Urolithiasis in Horseshoe Kidney Patients: A Systematic Review and Meta-Analysis

Background: Urolithiasis is the most common complication of horseshoe kidney (HK), which can be treated by extracorporeal shock wave lithotripsy (ESWL), flexible ureteroscopy (FURS), and percutaneous nephrolithotomy (PCNL). When comparing treatments of ESWL and FURS, it is unclear which is more efficient and safe. The objective of this study was to compare the efficacy and safety of FURS and SWL for the treatment of urolithiasis in HK patients. Methods: A systematic search of the Web of Science, PubMed, and EMBASE was performed in February 2021. Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias in each study. Results: Five studies published between 2008 and 2018 were synthesized in the present meta-analysis. The study revealed that FURS compared with SWL had greater initial and overall stone-free rates (SFRs). Risk ratios (RRs) were 2.46 (P < 0.00001) in initial SFRs, 1.36 (P = 0.02) in overall SFRs. No differences were found in the retreatment ratio, RRs were 0.49 (P = 0.43). In addition, no major complications were encountered, and all the complications were mild to moderate. Conclusion: The study demonstrated that FURS and SWL are effective and safe treatments for patients with HK with stones (<20 mm). Moreover, FURS has greater clearance rates and lower complication rates than SWL.

Bilateral hematoma after tubeless percutaneous nephrolithotomy for unilateral horseshoe kidney stones: A case report

BACKGROUND

Bilateral perirenal hematoma is rarely reported in endoscopic management of horseshoe kidney stones, and there are few studies reporting the formation of bilateral hematoma following tubeless percutaneous nephrolithotomy (PCNL) for unilateral horseshoe kidney calculi.

CASE SUMMARY

A 32-year-old man was admitted to our hospital because of repeated intermittent hematuria for 10 years. Plain abdominal computed tomography (CT) scan revealed calculi in the horseshoe kidney; the largest being 2 cm in diameter. Tubeless PCNL was performed to remove the stones. Three days after the operation, the patient was discharged in a stable situation. Three days after discharge, the patient presented to our emergency department because of right low back pain and vomiting. Emergent CT scan revealed subcapsular and perirenal hematocele and exudates in both kidneys. Ultrasound-guided puncture and drainage of perirenal effusion were performed. After the temperature stabilized, the patient received low-pressure injection of urokinase 100000 U for 3 d. His routine blood indexes and the renal function returned to normal in 3 wk. CT re-examination 3 mo after lithotripsy showed that the subcapsular and perirenal hematoma and exudates in both kidneys were significantly absorbed as compared with those before. The patient was followed up for 1 year, during which no flank pain or hematuria recurred.

CONCLUSION

This is the first case report on the formation of bilateral hematoma following tubeless PCNL for unilateral horseshoe kidney calculi.

Real-world Global Outcomes of Retrograde Intrarenal Surgery in Anomalous Kidneys: A High Volume International Multicenter Study

OBJECTIVE

To analyze the trends and outcomes of retrograde intrarenal surgery for treatment of urolithiasis in anomalous kidneys in a large international multicenter series.

MATERIALS AND METHODS

We designed a multicentric retrospective study. Nineteen high-volume centers worldwide were included. Pre-, peri- and postoperative data were collected, and a subgroup analysis was performed according to renal anomaly.

RESULTS

We analyzed 414 procedures: 119 (28.7%) were horseshoe kidneys, 102 (24.6%) pelvic ectopic kidneys, 69 (16.7%) malrotated kidneys and 50 (12.1%) diverticular calculus. The average size (SD) of the stone was 13.9 (±6) millimeters and 193 (46.6%) patients had a pre-operative stent. In 249 cases (60.1%) a disposable scope was used. A UAS (ureteral access sheath) was used in 373 (90%) patients. A Holmium laser was used in 391 (94.4%) patients. The average (SD) operating time was 65.3 (±24.2) minutes. Hematuria, caliceal perforation and difficulty in stone localisation were mostly seen in diverticular stones and difficulty in UAS placement and lithotripsy in the cases of renal malrotation. The overall complication rate was 12%. Global stone-free rate was 79.2%. Residual fragments (RF) were significantly lesser in the pre-stented group (P <.05). Diverticular calculi was the group with more RF and needed ancillary procedures (P <.05).

CONCLUSION

Retrograde intrarenal surgery in patients with anomalous kidneys is safe and effective with a high single-stage stone-free rate and low complication rate. There is a trend toward using smaller and disposable scopes and smaller UAS. Diverticular stones can still be challenging with higher rates of intraoperative hematuria, caliceal perforation and RF.

Single-use ureteroscopes in ectopic pelvic kidney stones

We analyzed the results of single-use flexible ureteroscopy (su-fURS) with the holmium laser in treating renal stones associated with ectopic pelvic kidney (EPK). The study retrospectively analyzed data of 11 patients diagnosed with EPK and stone disease who underwent su-fURS between May 2017 and November 2019. The analyzed surgical data included the mean operation time, stone-free and complication rates, as well as hospitalization period. Disposable digital flexible ureteroscopes were exclusively used. The mean age was 55, with a 1.2:1 male to female ratio. The mean stone burden was 30±9 mm (ranging from 17 to 49 mm). The mean calculi digitized surface area (DSA) was 299±56 mm² (ranging from 170 to 597 mm²). A ureteral access sheath was used in all 11 patients, and holmium laser lithotripsy was performed (dusting mode parameters: low energy – 0.5J, high frequency – 50 Hz, long pulse; pop-corn mode: high energy >1 J, medium frequency– 10–50 Hz, long pulse; fragmenting mode: high energy >1 J, low frequency <10 Hz, short pulse). The average operative time was 78±19 minutes (ranging from 68 to 144 minutes). The stone-free status (residual fragments <3 mm) after one session was 60.1%, 84.1% after the second session, and 94.4% after the third session. The hospitalization period was 29 hours (ranging from 17 to 39 hours). The overall complications rate (according to the Clavien-Dindo system) was 19.7%. Therefore, su-fURS represents an effective therapeutic approach characterized by a remarkably high stone-free rate and few complications in EPK-associated calculi.

Retroperitoneal vs transperitoneal laparoscopic lithotripsy of 20-40 mm renal stones within horseshoe kidneys

BACKGROUND

Horseshoe kidney (HK) with renal stones is challenging for urologists. Although both retroperitoneal and transperitoneal laparoscopic approaches have been reported in some case reports, the therapeutic outcome of retroperitoneal compared with transperitoneal laparoscopic lithotripsy is unknown.

AIM

To assess the efficacy of laparoscopic lithotripsy for renal stones in patients with HK.

METHODS

This was a retrospective study of 12 patients with HK and a limited number (n ≤ 3) of 20-40 mm renal stones treated with either retroperitoneal or transperitoneal laparoscopic lithotripsy (June 2012 to May 2019). The perioperative data of both groups were compared including operation time, estimated blood loss, postoperative fasting time, perioperative complications and stone-free rate (SFR).

RESULTS

No significant difference was observed for age, gender, preoperative symptoms, body mass index, preoperative infection, hydronephrosis degree, largest stone diameter, stone number and isthmus thickness. The mean postoperative fasting time of the patients in the retroperitoneal group and the transperitoneal group was 1.29 ± 0.49 and 2.40 ± 0.89 d, respectively (P = 0.019). There was no significant difference in operation time (194.29 ± 102.48 min vs 151.40 ± 39.54 min, P = 0.399), estimated blood loss (48.57 ± 31.85 mL vs 72.00 ± 41.47 mL, P = 0.292) and length of hospital stay (12.14 ± 2.61 d vs 12.40 ± 3.21 d, P = 0.881) between the retroperitoneal and transperitoneal groups. All patients in both groups had a complete SFR and postoperative renal function was within the normal range. The change in estimated glomerular filtration rate (eGFR) from the preoperative stage to postoperative day 1 in the retroperitoneal group and the transperitoneal group was -3.86 ± 0.69 and -2.20 ± 2.17 mL/(min·1.73 m²), respectively (P = 0.176). From the preoperative stage to the 3-mo follow-up, the absolute change in eGFR values for patients in the retroperitoneal group and the transperitoneal group was -3.29 ± 1.11 and -2.40 ± 2.07 mL/(min·1.73 m²), respectively (P = 0.581).

CONCLUSION

Both retroperitoneal and transperitoneal laparoscopic lithotripsy seem to be safe and effective for HK patients with a limited number of 20-40 mm renal stones.

Management of staghorn stones in special situations

Staghorn stones have always been a challenge for urologists, especially in some special situations, such as horseshoe kidney, ectopic kidney, paediatric kidney, and solitary kidney. The treatment of these staghorn stones must be aggressive because they can lead to renal function loss and serious complications. The gold-standard management for staghorn stones is surgical treatment with the aim of clearing the stones and preserving renal function. Treatment methods for staghorn stones have developed rapidly, such as extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy and laparoscopy and open surgery. Whether the standard procedures for staghorn stones can also apply to these stones in special situations is still not agreed upon. The decision should be made individually according to the circumstances of the patient. In this review, we evaluates the previous studies and comments on the management of staghorn stones under special situations in the hope of guiding the optimal choice for urologists.

Outcomes of ureteroscopy for stone disease in anomalous kidneys: a systematic review

Introduction

Treatment of stone disease in anomalous kidneys can be challenging. As ureteroscopy (URS) has advanced, the number of studies reporting on outcomes of URS for stone disease in anomalous kidneys has increased. Our objective was to perform a systematic review of the literature to evaluate the outcomes of URS for stone disease in this group of patients.

Methods

A Cochrane style review was performed in accordance with the PRISMA guidelines using Medline, EMBASE, CINAHL, Cochrane Library, Scopus and individual urologic journals for all English language articles between inception and June 2018.

Results

Fourteen papers (413 patients) with a mean age of 43 years and a male to female ratio of 285:128 were included. The underlying renal anomaly was horseshoe kidney (n = 204), ectopic kidney (n = 117), malrotation (n = 86), cross fused ectopia (n = 2) and others (n = 2). With a mean stone size of 16 mm (range 2–35 mm), the majority of stones were in the lower pole (n = 143, 34.6%) or renal pelvis (n = 128, 31.0%), with 18.9% (n = 78) having stones in multiple locations. Treatment modality included the use of flexible ureteroscope in 90% of patients and ureteral access sheath used in 11 studies. With a mean operative time of 61.3 min (range 14–185 min), the initial and final SFR was 76.6% (n = 322) and 82.3% (n = 340), respectively. The overall complication rate was 17.2% (n = 71), of which 14.8% were Clavien I/II and the remaining 2.4% were Clavien ≥ III complications.

Conclusion

Although ureteroscopy in patients with anomalous kidneys can be technically challenging, advancements in endourological techniques have made it a safe and effective procedure. In these patients the stone-free rates are good with a low risk of major complications.

Changing trends in the endourological management of urolithiasis in anomalous kidneys

OBJECTIVES

To present our single-centre experience of urolithiasis management in anomalous kidneys, highlighting the need for an algorithm-based approach in deciding the appropriate treatment method for each type.

PATIENTS AND METHODS

We retrospectively reviewed the data of all the patients who presented to our renal unit with urolithiasis in an anomalous kidney between January 1990 and July 2014. The peri-operative characteristics of all the patients, along with management approach, were studied.

RESULTS

Percutaneous nephrolithotomy (PCNL) was the most common surgical technique used, followed by flexible ureterorenoscopy (URS). Pain was the most common presentation in these patients. The overall stone clearance rate associated with PCNL and flexible URS was 85.8% in cases of anomalous kidneys in this series. The stone clearance rates in ectopic kidneys, horseshoe kidneys, malrotated kidneys and autosomal dominant polycystic kidneys associated with PCNL and flexible URS were similar: 86%, 88%, 76% and 83%, respectively, and 81.2%, 80%, 92% and 100%, respectively . Based on our results, we developed a stone management algorithm.

CONCLUSION

The management of renal calculi in patients with renal anomalies may vary based on the stone size, location, density, pelvicalyceal system anatomy and drainage. An algorithm-based approach could help surgeons decide the appropriate treatment in this population.

Different managements of horseshoe kidney stones, any difference in the outcome?

Purpose

The aim is to assess the outcomes of different approaches for the management of renal stones associated with horseshoe kidneys (HSKs) in our institution over a 12-year period.

Methods

A retrospective review of 144 patients with HSKs who presented from 2000 to 2012 was performed. Twenty-eight patients (19.4%) were found to have renal stones. Demographic data were collected; the method of treatment and the outcomes of stone management were reviewed. We excluded patients with non-functioning moieties and associated genitourinary anomalies, and those with incomplete data.

Results

We included 25 patients, of which 16 males (64%) and 9 females (36%), with a mean age of 37 years. Mean serum creatinine level was 66 mmol/L. Eleven patients with a stone size <8 mm were treated expectantly with medical treatment, with only one patient requiring endoscopic intervention. Six patients (24%) with a stone size between 1 cm and ≤2 cm were treated with extracorporeal shock wave lithotripsy (ESWL) with the placement of double J stents, and seven patients (28%) with a stone size of >2 cm were treated with percutaneous nephrolithotomy. One patient with a 10 mm stone was treated using flexible ureteroscopy. No significant perioperative complications were encountered.

Conclusions

Indications, methods of treatment, and outcomes of management of stones associated with HSKs were comparable to those for stones associated with normal kidneys. Tailored approach based on stone size is highly recommended. ESWL accompanied with ureteric stenting is a promising strategy for the management of stones associated with HSKs in selected patients requiring intervention.

Nephrolithiasis in a 17-Year-Old Male With Seckel Syndrome and Horseshoe Kidneys: Case Report and Review of the Literature

We report the case of a 17-year-old male with Seckel syndrome and horseshoe kidneys which had a 7 mm kidney stone in the lower pole calyx of the right moiety. The patient had a history of rotoscoliosis with 60° dextroconvex curvature and hepatic steatosis. Attempted ureteroscopy was unsuccessful due to stone location and anatomy. Percutaneous nephrolithotomy was ultimately required. This case highlights the difficulties of endoscopic treatments of renal calculi in patients with abnormal renal anatomy and dysmorphia. To our knowledge, this is the first reported case of nephrolithiasis in a patient with Seckel syndrome and horseshoe kidneys.

Percutaneous nephrolithotomy of horseshoe kidney: Our institutional experience

Purpose

To review our success in PCNL for managing large horse shoe kidney stones as primary treatment.

Method

Between 2012 and 2016, a total of 23patients (24 renal units) underwent percutaneous renal surgery for stone dieses in horseshoe kidneys. Indications were HSK with stone more than 1 cm in size and failed ESWL.

Results

Mean age was 35.60 ± 10.10 years out of which 18 were males and 5 females. One patient had stone in both kidneys. Mean stone size was 22.03 ± 10.33 mm. Access site was upper calyceal and subcostal in all patients. In 2 patients an extra middle calyceal puncture were used for total clearance (8.69%). Mean operation time was 67.22 ± 7.63 minutes. One patient with staghorn stone was converted to open surgery because of inaccessibility of the stone and complexity of the renal calyceal system. Post operatively, 2 renal units with residual stone more than 8mm were cleared with ESWL. Complete clearance was achieved in 21 renal units with PCNL (87.50%). There was no significant intra operative complication. Post operatively 2 patients developed fever which was treated conservatively(clavien grade I).

Conclusion

PCNL can be recommended as first line of management in the treatment of horseshoe kidneys with large stone burden considering its higher clearance rate and minimal complications.

Incidence and characteristics of kidney stones in patients with horseshoe kidney: A systematic review and meta-analysis

Introduction

The horseshoe kidney (HSK) is the most common type of renal fusion anomaly. The incidence and characteristics of kidney stones in patients with HSK are not well studied. The aim of this meta-analysis was to evaluate the incidence and types of kidney stones in patients with HSK.

Methods

A systematic literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases' inception through November 2016. Studies assessing the incidence and types of kidney stones in patients with HSK were included. We applied a random-effects model to estimate the incidence of kidney stones. The study protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052037).

Results

A total of 14 observational studies with 943 patients (522 adults and 421 pediatric) with HSK were enrolled. The estimated pooled incidence of kidney stones was 36% (95% confidence interval [CI], 15%-59%) in adults with the HSK. Kidney stones were less common in pediatric patients with HSK with an estimated pooled incidence of 3% (95% CI, 2%-5%). The mean age of adult stone formers with HSK was 44.9 ± 6.2 years, and 75% were males. Within reported studies, 89.2% of kidney stones were calcium-based stones (64.2% calcium oxalate [CaOx], 18.8% calcium phosphate [CaP], and 6.2% mixed CaOx/CaP), followed by struvite stones (4.2%), uric acid stones (3.8%), and others (2.8%).

Conclusions

Kidney stones are very common in adult patients with HSK with an estimated incidence of 36%. Calcium-based stones are the most prevalent kidney stones in adults with HSKs. These findings may impact the prevention and clinical management of kidney stones in patients with HSK.

Flexible ureterorenoscopy in position or fusion anomaly: Is it feasible?

OBJECTIVE

To analyze the results of flexible ureterorenoscopy (F-URS) with holmium laser in the treatment of kidney stones with ectopic and fusion anomalies (horseshoe kidney and rotation anomalies).

METHOD

We reviewed data from 13 patients with fusion and ectopic renal anomalies that underwent F-URS from April 2011 to April 2017. We analyzed demographic and clinical data (age, gender, BMI, anatomical abnormality, location and dimension of the renal calculi) and perioperative data (method of treatment, stone-free rate, number of days with DJ catheter and perioperative complications).

RESULTS

The mean stone size was 12.23 +/- 5.43 mm (range 6-22mm), located in the inferior (58.33%) and middle (16.76%) calyceal units, renal pelvis (16.67%) and multiple locations (8.33%). All 13 patients were treated with Ho-Yag laser, using dusting technique (25%), fragmentation and extraction of the calculi (58.33%) and mixed technique (16.67%). We did not have any severe perioperative complication. After 90 days, nine patients (75%) were considered stone free.

CONCLUSION

Our data suggest that F-URS is a safe and feasible choice for the treatment of kidney stones in patients with renal ectopic and fusion anomalies.

Comparison of shock wave lithotripsy (SWL) and retrograde intrarenal surgery (RIRS) for treatment of stone disease in horseshoe kidney patients

Objectives

In this study it is aimed to compare the success and complication rates of SWL and RIRS in treatment of HSK stone disease.

Materials and methods

In this retrospective study data of 67 patients treated with either SWL (n=44) or RIRS (n=23) for stone disease in HSK between May 2003 to August 2014 was investigated. age, gender, stone size and multiplicity, stone free status, renal colic episodes and complication rates of the SWL and RIRS groups were compared.

Results

Mean age of the population was 42.5±8.2 (range: 16-78) years and mean stone size was 16.9±4.1 mm. SWL and RIRS groups were similar with regard to demographic characteristics and stone related characteristics. SFR of the SWL and RIRS groups were 47.7%(21/44 patients) and 73.9% (17/23 patients) respectively (p=0.039).Renal colic episodes were observed in 3 and 16 patients in the RIRS and SWL groups respectively (p=0.024). No statistically significant complications were observed between the SWL (8/44 patients) and RIRS (4/23) groups (p=0.936).

Conclusions

In HSK patients with stone disease, both SWL and RIRS are effective and safe treatment modalities. However RIRS seems to maintain higher SFRs with comparable complication rates.

Flexible Ureteroscopic Management of Horseshoe Kidney Renal Calculi

PURPOSE

To evaluate the clinical efficacy of flexible ureteroscope (F-URS) combined with holmium laser lithotripter in treating renal calculi in horseshoe kidney.

MATERIALS AND METHODS

From November 2010 to December 2013, the medical history and charts of sixteen patients (mean age 42.9 ± 11.6 years, range 26-66 years), including 13 males and 3 females were analyzed retrospectively. Mean stone burden was 29 ± 8 mm (range 17-42 mm2). Mean stone digitized surface area (DSA) was 321 ± 94 mm2 (range 180-538 mm2). Under spinal anesthesia in a modified lithotomy position with the head down, rigid ureteroscope was placed firstly into the ureter to reach the level of the pelvis, a zebra guide wire was inserted and following the removal of the rigid ureteroscope, an ureteral access sheath was positioned along the guide wire, then passed the URF P-5 flexible ureteroscope into the renal cavities over the guidewire. After locating the stones, holmium laser lithotripsy was performed.

RESULTS

The average operative time was 92 ± 16 minutes (range 74-127 min.). No major complications were encountered. Ten patients obtained stone-free status with one session, four obtained stone-free status after two sessions. Single session stone-free rate was 62.5%, overall stone-free rate was 87.5%. Two patients have small residual stones in the lower pole.

CONCLUSIONS

F-URS combined with holmium laser lithotripter and nitinol basket, is safe and effective in dealing with moderate stone diameter (<30 mm) in HSKs with high clearance rates and low complication rates.

Do Outcomes of Percutaneous Nephrolithotomy in Horseshoe Kidney in Children Differ from Adults? A Single-Center Experience

OBJECTIVE

To compare the efficacy, outcome, and safety of percutaneous nephrolithotomy (PCNL) for stones in horseshoe kidney (HSK) in children compared with adults.

METHODS

We retrospectively reviewed data of 18 renal units in children (<15 years) and 26 renal units in adult patients with HSKs who underwent PCNL between March 2008 and June 2015.

RESULTS

Mean age of the study group was 25.92 ± 15.79 with adults having 36.12 ± 11.84 (range 20-65) and children having 10.32 ± 2.88 (range 5-15). Mean stone burden was 311.20 ± 203.99 (104-1080 mm(2)) with children of 211.13 ± 130.21 (104-500 mm(2)) and adults of 382.68 ± 219.27 (114-1080 mm(2)). Success rate is defined as either complete stone free or with asymptomatic and clinical insignificant residuals fragment of <3 mm on postoperative imaging. Initial success rate was 79.54% (86.61% in adults vs 72.22% in children). After auxiliary procedure, the final success rate is 93.18% (adults: 92.30% vs children: 94.44%). Overall complications noted in 12 cases with 23.07% in adults and 33.33% in children, most of them were minor complications.

DISCUSSION

There was no significant difference in initial and final success rate. Complication is slightly higher in children although statistically not significant. The outcomes and complications are similar to those reported in other studies of pediatric PCNL.

CONCLUSIONS

Outcomes in child and adult HSKs do not differ significantly with respect to success rate and complications. Children have a relatively smaller stone burden compared with adults with a similar distribution. We found that most of the puncture can be made infracostal in children as well as adults.

Endoscopic Management of Urolithiasis in the Horseshoe Kidney

OBJECTIVE

To assess the endourologic outcomes of patients diagnosed with a horseshoe kidney (HK) and symptomatic urolithiasis.

METHODS

A retrospective review was performed of patients diagnosed with an HK who underwent endoscopic management from 2002 to present.

RESULTS

We identified 45 patients with 64 stone-bearing moieties who underwent 56 procedures, of which 31 (69%) were male. Mean age was 49.4 years (23-78) and mean stone size was 1.6 cm (0.2-5.7). Of the 64 moieties, 37 (58%) underwent percutaneous nephrolithotomy (PCNL), 25 (39%) underwent ureteroscopy (URS), and 2 (3%) underwent extracorporal shockwave lithotripsy (SWL). More than one access was utilized in 2 (5.7%) moieties undergoing PCNL. Additional procedures were required in 10 (28.5%) PCNL patients, of which 7 were URS, 2 were secondary PCNL, and 1 sandwich therapy with SWL and PCNL. Stone-free rate by moiety was 81.1% for PCNL, 84% for URS, and 50% for SWL. Postoperative complications occurred in 3 patients in the PCNL group, including readmission for pain and complicated urinary tract infection. With a mean follow-up of 20.5 months (range 0-118 months), stone recurrence was noted in 7 (16%) patients with a total of 11 events. Calcium oxalate was the most common stone type and 20/24 (83%) of patients with metabolic evaluations were found to have at least one abnormality.

CONCLUSION

After careful consideration of the anatomy, individuals with HK and symptomatic urolithiasis can be managed safely by a variety of endoscopic approaches with excellent outcomes; however, secondary procedures and recurrence are common.

Safety and efficacy of minimally invasive percutaneous nephrolithotomy in treatment of calculi in horseshoe kidneys

OBJECTIVE

To evaluate the safety and efficacy of minimally invasive percutaneous nephrolithotomy (MPCNL) in horseshoe kidneys (HKs) with calculi.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Laparoscopic management in stone disease

PURPOSE OF REVIEW

While most renal and ureteral stones can be efficiently managed using endourologic techniques, the use of laparoscopy for the management of urolithiasis is increasing. The application of laparoscopy for stone removal will further reduce the need for open stone surgery.

RECENT FINDINGS

Laparoscopic ureterolithotomy, pyelolithotomy, and anatrophic nephrolithotomy are highly successful techniques with regard to their one-session, high stone-free rates. These procedures could be considered as the preferred approaches when endourologic procedures are not available or have failed. Laparoscopic stone surgery (LSS) in patients with urinary tract anomalies offers a reliable minimally invasive procedure as an alternative to a complex endourologic technique.

SUMMARY

Although laparoscopy still has a limited role in the urologist's armamentarium for the surgical management of urolithiasis, it can further reduce the need for open stone surgery in complex circumstances. LSS duplicates its open counterpart and offers a high one-session, stone-free rate in most patients with a lower morbidity and quicker convalescence. More comparative studies are needed to define the role and indications of LSS in relation to endourologic and open techniques, especially in complex circumstances.

Management of stones in abnormal situations

Stones in abnormal situations present a management conundrum to the urologist. Many of these situations are relatively rare and literature is scanty on the appropriate management. We review the current literature on the management of stones in the setting of pregnancy, calyceal diverticulum, urinary diversions, pelvic kidneys, transplant kidneys, autosomal dominant polycystic kidney disease, horseshoe kidneys, and other renal anomalies. The aims of treatment are complete stone-free status. The modality of treatment should be individualized to the size and location of stone and type of abnormal situation confronted.

Retrograde intrarenal surgery in patients with horseshoe kidneys

Retrograde intrarenal surgery (RIRS) in patients with horseshoe kidneys (HSKs) remains poorly studied. The present study aimed to assess clinical success and stone-free rates in HSK patients with renal stones treated with flexible ureteroscopy. RIRS was attempted in 20 patients with 25 renal stones in HSK from December 2008 to January 2012. The patients were evaluated with imaging studies including plain abdominal radiography, intravenous urogram, abdominal ultrasonography or non-contrast tomography scan. Success rate was defined as stone-free or residual fragment less than 4 mm. Pre-operative, operative and postoperative data were retrospectively analyzed. A total of 20 patients were included in the present study (12 males, 8 females). 9 of 25 renal stones (36 %) were located in the lower calyx of the kidney, whereas 7 (28 %) in the middle calyx, 5 (20 %) in the renal pelvis and 4 (16 %) in the upper calyx. The mean stone size was 17.8 ± 4.5 mm. The stone-free rate was 70 % after a single procedure. 6 patients required shock wave lithotripsy and two of these were completely stone-free. Average hospital stay was 1.4 ± 0.7 days. Minor complications as classified by Clavien I or II occurred in 25 %. No major complications (Clavien III-V) occurred in the study group. RIRS is an effective and safe treatment modality for renal stones in patients with HSK. The procedure has minimal morbidity and high success rate.

[Surgical therapy of lithiasis in horseshoe kidney]

OBJECTIVE

To present our centre's experience in the surgical treatment of lithiasis in patients with horseshoe kidney.

MATERIAL AND METHODS

From October 2007 to March 2011 we treated 10 patients with renal lithiasis in their horseshoe kidneys. Retrospectively, we reviewed the symptoms, medical and surgical history, the characteristics of the stones (size, location, composition) and treatments that were carried out. In all the cases, the study was carried out by CT, with volume reconstruction and with an angiographic study. A percutaneous nephrolithotomy (PCNL) or an endoscopic retrograde intrarrenal surgery (RIRS) was carried out, depending on the size and location of the stone.

RESULTS

Three percutaneous nephrolithotomies were carried out (2 on staghorn lithiasis stones, 1 pseudocoraliform stone) with a combined rigid and flexible single-access nephroscopy. In one case there was haemorrhage that required treatment by selective embolization. In the rest, RIRS was carried out, all with stones < 30 mm in their greatest diameter without any complications. The mean surgical times were 120 (60-180) minutes for the percutaneous route and of 105 (65-160) minutes for the retrograde route. In all the cases the treatment achieved a complete elimination of the stones or remains of less than 5 mm.

CONCLUSIONS

The treatment of renal lithiasis in horseshoe kidneys is complex, given their peculiar anatomy. The usual surgical techniques can be reproduced in these cases with good results. We opt for PCNL in complete staghorn stone and pseudocoraiform stones, whereas RIRS is a valid option in cases with stones < 3 cm.

Management of Clinically Insignificant Residual Fragments following Shock Wave Lithotripsy

Clinically insignificant residual fragments (CIRFs) are small fragments (less than 5 mm) that are present in upper urinary tract at the time of regular post-SWL followup. The term is controversial because they may remain silent and asymptomatic or become a risk factor for stone growth and recurrence, leading to symptomatic events, and need further urologic treatment. Although a stone-free state is the desired outcome of surgical treatment of urolithiasis, the authors believe that the presence of noninfected, nonobstructive, asymptomatic residual fragments can be managed metabolically in order to prevent stone growth and recurrence. Further urologic intervention is warranted if clinical indications for stone removal are present.

The comparison of laparoscopic pyelolithotomy and percutaneous nephrolithotomy in the treatment of solitary large renal pelvic stones

The aim of the study is to investigate whether laparoscopic pyelolithotomy (LPL) could find a place in the management of large renal pelvic stones which are generally considered as excellent indications for percutaneous nephrolithotomy (PNL). Between 2006 and 2009, 26 consecutive patients with large (>4 cm(2)) renal pelvic stones were treated by LPL and their charts were compared to 26 match-paired patients treated with PNL during the same period. The patients were matched for age, BMI, stone size and location as well as presence of congenital anomalies. Perioperative and postoperative findings were compared. The mean age, mean stone size, rate of congenital anomalies, history open renal surgery and shock wave lithotripsy were similar in both groups (p > 0.05). The mean operation time was 138.40 ± 51.19 (range 70-240) min in LPL group as compared to 57.92 ± 21.12 (range 40-110) min in PNL group (p < 0.0001). There was one (3.8%) open conversion in the LPL group due to dense perirenal adhesions making the dissection difficult. The ureteropelvic junction (UPJ) obstruction concomitant to pelvic stones was successfully repaired laparoscopically in two cases. The mean drop in postoperative hemoglobin level was 0.9 ± 0.6 (range 0-2) g/dl in LPL group and 1.7 ± 1.1 (range 0-4) g/dl in PNL group (p = 0.024). Hospitalization was significantly shorter in PNL than LPL group (p = 0.0001). Stone-free rates were similar. Laparoscopic pyelolithotomy is associated with a longer operation time, is more invasive, and requires more skills when compared to PNL. However, LPL is associated with less blood loss. Laparoscopic pyelolithotomy is indicated for congenitally anomalous kidneys and especially in patients with concomitant UPJ.

Incidence, prevention, and management of complications following percutaneous nephrolitholapaxy

CONTEXT

Incidence, prevention, and management of complications of percutaneous nephrolitholapaxy (PNL) still lack consensus.

OBJECTIVE

To review the epidemiology of complications and their prevention and management.

EVIDENCE ACQUISITION

A literature review was performed using the PubMed database between 2001 and May 1, 2011, restricted to human species, adults, and the English language. The Medline search used a strategy including medical subject headings (MeSH) and free-text protocols with the keywords percutaneous, nephrolithotomy, PCNL, PNL, urolithiasis, complications, and Clavien, and the MeSH terms nephrostomy, percutaneous/adverse effects, and intraoperative complications or postoperative complications.

EVIDENCE SYNTHESIS

Assessing the epidemiology of complications is difficult because definitions of complications and their management still lack consensus. For a reproducible quality assessment, data should be obtained in a standardized manner, allowing for comparison. An approach is the validated Dindo-modified Clavien system, which was originally reported by seven studies. No deviation from the normal postoperative course (Clavien 0) was observed in 76.7% of PNL procedures. Including deviations from the normal postoperative course without the need for pharmacologic treatment or interventions (Clavien 1) would add up to 88.1%. Clavien 2 complications including blood transfusion and parenteral nutrition occurred in 7%; Clavien 3 complications requiring intervention in 4.1.%; Clavien 4, life-threatening complications, in 0.6%; and Clavien 5, mortality, in 0.04%. High-quality data on complication management of rare but potentially debilitating complications are scarce and consist mainly of case reports.

CONCLUSIONS

Complications after PNL can be kept to a minimum in experienced hands with the development of new techniques and improved technology. A modified procedure-specific Clavien classification should be established that would need to be validated in prospective trials.

Percutaneous nephrolithotomy in horseshoe kidneys: factors affecting stone-free rate

PURPOSE

We report a 2-center study of factors affecting the stone-free rate after percutaneous nephrolithotomy in horseshoe kidneys.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

Stone parameters are important when treating calculi in horseshoe kidneys. Staghorn calculi are associated with a lower stone-free rate after percutaneous nephrolithotomy.

[Renal position and fusion anomalies]

OBJECTIVES

To analyse kidney position and fusion anomalies, as well as associated urinary tract and extra-renal pathologies in a cohort from a tertiary hospital.

MATERIALS AND METHODS

The medical records of 84 children with renal ectopia (RE) and horseshoe kidney (HK) in our hospital from 1999 to 2010 were retrospectively reviewed.

RESULTS

Prenatal diagnosis was made in 53 patients (63.09%). Of the 84 patients surveyed 35 had unilateral simple renal ectopia (SRE), 1 had bilateral SRE; 2 had crossed renal ectopia (CRE) without fusion, 17 had CRE with fusion, and 29 had HK. Average age was 30 days at diagnosis (IQR: 0-12 months). In the individuals with renal ectopia (RE), the incidence of associated urinary tract pathologies was 20.23% in the ectopic kidney (EK) (17 out of 84) and 17.85% in the contralateral kidney (CK) (15 out of 84). The most frequent urological pathology was vesico-ureteral reflux (VUR), 4 individuals had multicystic dysplastic kidneys (MCDK). In 4 patients renal agenesis was detected in the CK. In patients with HK, the incidence of associated urinary tract pathologies was 16.66% (14 out of 84), and the most frequent associated urological anomaly was also VUR. Of the 84 patients 21(25.45%) had extra-renal pathology. Anomalies of the skeletal system were detected in 9/84(10.71%), genital anomalies 5/84 (5.95%), cardiac anomalies 3/84 (3.57%), and digestive disease 1/84 (1.19%). Facial malformations were noted in 3/84 patients (3.57%), endocrine disorders 2/84 (2.38%), and 8/84 children (9.52%) suffered from polymalformative syndrome. During follow-up, the most frequent complication of the urinary tract was infection, observed in 10/84 patients (11.91%).

CONCLUSIONS

When renal ectopia or horseshoe kidney is detected, associated renal and urinary anomalies and structural extra-renal malformations should be evaluated. Patients need long-term follow-up and should be examined regularly for potential complications.

[Horseshoe kidney stones: benefit of flexible ureterorenoscopy with holmium laser]

OBJECTIVES

We aim to assess the outcome of the flexible ureterorenoscopy (F-URS) with holmium laser in treating horseshoe kidney (HSK) stones.

PATIENTS AND METHODS

We reviewed retrospectively the records of 18 patients with HSK stone (18 renal units) who underwent F-URS using holmium laser from December 2004 to October 2009. The mean age was 37.7±6.9 years. The F-URS used after the extracorporeal shock wave lithotripsy (ESWL) failure in eight patients (44.4%) and four patients (22.2%) had PCNL failure. The follow up visit range were between 4 and 6 weeks with plain radiograph (KUB) and renal ultrasound or non contrast computed tomography scan (NCCT). Success rate was defined as stone free or residual fragment less than 3 mm. Use of auxiliary procedures like ESWL were considered as treatment failure.

RESULTS

Eighteen patients, three females and 15 males with mean age was 37.7±6.9 years with HSK calculi underwent ureteroscopic management. The presenting symptoms were renal colic, urinary tract infection or hematuria. We found different HSK stone location (11 mixed calyceal, three mixed pelvic and calyceal and four pelvic). The average stone burden was 15.5±7.3 mm and the mean operative time was 112±9.4 minutes. All over procedures were 27, with mean average of 1.5 procedures per patient. The success rate was 89%.

CONCLUSION

The F-URS with holmium laser is an efficient minimal invasive procedure in treating HSK stones.

Giant renal calculus in a horseshoe kidney presenting as an abdominal lump

We report a case of giant renal calculus of 14 × 10.5 × 9 cm in size and weighing 790 g, in a horseshoe kidney, along with two large calculi on the opposite side. Patient presented with unusual complaint of an abdominal lump only. Physical examination revealed a stony hard mass on the left side of the abdomen, extending from the subcostal region to just above the iliac crest. A giant renal calculus on the left and two large calculi on the right side of a horseshoe kidney were diagnosed on computed tomography (CT) scan. Percutaneous nephrolithotomy, followed after 5 days by open pyelolithotomy was done for the stones on the right and left side, respectively. Analysis revealed a calcium phosphate stone. This case is worth reporting as it was not only the 8th heaviest renal stone reported in the English literature, but also the first giant stone to be reported in a horseshoe kidney.

Flexible ureterorenoscopy with holmium laser in horseshoe kidneys

OBJECTIVES

To assess the outcome of flexible ureterorenoscopy (F-URS) with the holmium laser in treating stones in the horseshoe kidney (HSK).

METHODS

We retrospectively reviewed the records of 17 patients with a HSK stone (17 renal units) who had undergone F-URS with the holmium laser from December 2004 to May 2009. The presenting symptoms were renal colic, urinary tract infection, or hematuria. F-URS was used in as an alternative after the failure of shock wave lithotripsy in 8 patients (47%) and percutaneous nephrolithotomy failure in 4 patients (23.5%). Follow-up examination was performed after 4-6 weeks with plain radiography and either renal ultrasonography or noncontrast computed tomography. Success was defined as stone-free status or residual fragments <3 mm. The use of auxiliary procedures was considered to indicate treatment failure.

RESULTS

A total of 17 patients were included in the present study (3 females and 14 males). Their age was 16-52 years (mean age ± SD 34.7 ± 6.3). The HSK stone location was 7 mixed caliceal, 3 mixed pelvic and caliceal, and 7 pelvic. The average stone burden was 16 mm (range 7-35). The overall number of procedures was 25 (mean 1.5 procedures/patient). Of the 17 patients, 15 (88.2%) were rendered stone free.

CONCLUSIONS

The results of our study have shown that F-URS with the holmium laser is an efficient minimal invasive procedure for treating HSK stones.

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

Background

this 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.

Methods

Between 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.

Results

The 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.

Conclusion

Percutaneous 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.