Large Renal Stones Research Articles

Comparative study of laparoscopic pyelolithotomy versus percutaneous nephrolithotomy in the management of large renal pelvic stones.

The aim of the study is to investigate whether laparoscopic pyelolithotomy (LPL) could be used to manage large renal pelvic stones, generally considered excellent indications for percutaneous nephrolithotomy (PNL). This study was performed from May 2009 to March 2012 at Al-Azhar University Hospitals (Assiut and Cairo), Egypt. It included two groups of patients with large renal pelvic stones; only patients with stones 2.5 cm(2) or greater were included. Group 1 included 40 patients treated by PNL and Group 2 included 10 patients treated by LPL. The differences between the two procedures were compared and analyzed. There was no difference between the two groups regarding patient demographics and stone size. There was a statistically significant difference between the groups regarding mean estimated blood loss (65 ± 12.25 [range: 52.75-77.25] vs. 180 ± 20.74 [range: 159.26-200.74] mL, p ≤ 0001), mean hospital stay (2.3 ± 0.64 [range: 1.66-2.94] vs. 3.7 ± 1.4 [range: 2.3-5.1] days, p ≤ 0.006), rate of postoperative blood transfusion (0% vs. 4.8%, p ≤ 0.0024), and stone-free rate (80% vs. 78.6%, p ≤ 0.23). The mean operative time was significantly longer in Group 2 (LPL) (131 ± 22.11 [range: 108.89-153.11) vs. 51.19 ± 24.39 [range: 26.8-75.58] min, p ≤ 0001), respectively. Although PNL is the standard treatment in most cases of renal pelvic stones, LPL is another feasible surgical technique for patients with large renal pelvic stones.

Laparoscopic Pyelolithotomy: Comparison of Surgical Outcomes in Relation to Stone Distribution Within the Kidney

Abstract Purpose: To evaluate surgical outcomes of laparoscopic pyelolithotomy (LP) in relation to stone distribution within the kidney. Between August 2008 and February 2012, 77 patients underwent LP as first-line treatment for renal stone(s). Cases were classified into four groups, depending on stone location: Group I (located in only renal pelvis), Group II (located only in renal calyx), Group III (located in renal pelvis and in one calyx), and Group IV (located in renal pelvis and in multiple calyces). Patient and stone characteristics, surgical outcomes, and complications were evaluated. Sixty-seven (81.8%) cases were stone-free after LP for large renal stones. Stone-free rates in a single session significantly decreased with greater stone dispersion (p<0.001). Mean hospital stay in group IV was significantly longer than in other groups (p=0.038). However, there were no significant differences in mean operation times (p=0.214), mean change in serum hemoglobin (p=0.709), postoperative analgesics usages (p=0.153), and number of analgesics used on an as-needed basis (p=0.079). There were no complications of grade IIIb or of greater severity. One patient in group II received blood transfusion, and 1 in group III required percutaneous drainage due to perirenal urine collection. LP is an effective and safe modality for managing renal stones diseases. Distribution of stone burden, and total stone burden, is an important predictor of surgical outcome of LP in renal stone diseases.

Percutaneous nephrolithotomy in the supine position: Safety and outcomes in a single-centre experience

ObjectivesTo assess the feasibility of performing percutaneous nephrolithotomy (PCNL) with the patient supine. Although PCNL with the patient prone is the standard technique for treating large (>2cm) renal stones including staghorn stones, we evaluated the safety and efficacy of supine PCNL for managing large renal stones, with special attention to evaluating the complications. Patients and methodIn a prospective study between January 2010 and December 2011, 54 patients with large and staghorn renal stones underwent cystoscopy with a ureteric catheter inserted, followed by puncture of the collecting system while they were supine. Tract dilatation to 30F was followed by nephroscopy, stone disintegration using pneumatic lithotripsy, and retrieval using a stone forceps. All patients had a nephrostomy tube placed at the end of the procedure. The results were compared with those from recent large series of supine PCNL. ResultsThe median (range) operative duration was 130 (90–210) min, and the mean (SD) volume of irrigant was 22.2 (3.7) L. One puncture was used to enter the collecting system in 51 renal units (94%), while three units (6%) with a staghorn stone needed two punctures. The stone clearance rate was 91%, and five patients had an auxiliary procedure. There were complications in 15 patients (28%). All patients were stone-free at a 3-month follow-up. ConclusionSupine PCNL is technically feasible; it has several advantages to patients, urologists and anaesthesiologists. It gives stone-free rates and a low incidence of organ injury comparable to those in standard prone PCNL.

Minimally Invasive Percutaneous Nephrolithotomy: A Comparative Study of the Management of Small and Large Renal Stones

To compare the safety and efficacy of minimally invasive percutaneous nephrolitholapaxy (MIP) between small (<2 cm) and large (>2 cm) renal calculi, because although MIP has proved its efficacy in small lower caliceal stones, the efficacy in large renal calculi has been questioned. The data from 191 consecutive minimally invasive percutaneous nephrolithotomy (MIP) procedures at a single institution from January 2007 to March 2011 were reviewed retrospectively. All stone sizes and complexity were included (98 were <2 cm and 93 were ≥ 2 cm). We performed a comparative analysis of procedures for calculi <2 cm and ≥ 2 cm regarding the stone-free rate, the need for auxiliary procedures, and complications. The Student t test for parametric continuous variables and the chi-square test or Fischer's exact test for nominal variables were applied. The primary stone-free rate was significantly lower for the large than for the small stones (76.3% vs 90.8%, P = .007), and the secondary stone-free rate after one auxiliary procedure (second-look percutaneous nephrolithotomy, ureterorenoscopy, or shock wave lithotripsy) was not significantly different between the 2 groups (94.6% vs 98.9%, P = .1). The total complication rate was not significantly different (26.9% vs 19.4%, P = .2) between the 2 groups either. Grade III complications occurred in 5.2% of all patients, and no grade IV or V complications were observed. Using MIP, the total stone-free rate was greater for the small than for the large calculi; however, most patients could be rendered stone-free with the use of one auxiliary procedure. The high success rate and low rate of higher grade complications justify the application of MIP for large stones.

Semirigid Laser Ureterolithotripsy for Single Large Renal Pelvic Stones

Background and purpose: Large stones located at the renal pelvis are usually managed with Percutaneous Nephrolithotomy (PCNL); however this procedure carries both a substantial morbidity and a considerable risk for complications. Our objective was to assess the safety and efficacy of semirigid ureteroscopy (S-URS) and laser lithotripsy for the treatment of single large (>1.5 cm) pelvic stones. Patients and methods: Twenty patients (12 women and 8 men, aged 54-72 years) with isolated renal pelvic stone (mean size: 2.1 cm, range: 1.5-3 cm) underwent S-URS under general anaesthesia, over a 2-year period (January 2010 to January 2012). Holmium:yttrium-aluminum-garnet (Ho:YAG) laser was used for the stone fragmentation. In all cases the ureters were stented following completion of the operation. Preoperative data as well as stone-free rate, operative time and associated complications were retrospectively evaluated. Results: In 17 patients (18%; 12 women and 5 men) the stones were accessible with S-URS. The mean operative time was 69.4 min (37.2-94.5). There were no major complications, however 2 female patients developed fever due to Urinary Tract Infection (UTI) in the early postoperative period. The stone-free rate (assessed with X-ray) following S-URS was 70.6% on the 1st postoperative day and increased to 82.3% after 1 month. The mean hospitalization period was 1.4 (1.1-4.3) days. Adjuvant Extracorporeal Shockwave Lithotripsy (ESWL) was performed in 3 patients with residual stones (mean number of ESWL sessions: 1.5). Multivariate analysis revealed that only sex (female vs. male) significantly influenced the results, in favor of the females. Conclusions: S-URS is an effective and safe alternative treatment for single large (>1.5 cm) renal pelvic stones, especially in female patients.

Predictive Factors for Bleeding During Percutaneous Nephrolithotomy

PurposeAlthough percutaneous nephrolithotomy (PCNL) has been accepted as a standard method for the management of large renal stones, the incidence of renal hemorrhage is relatively high. This study investigated the variables that affect bleeding during PCNL.Materials and MethodsThe medical records of 370 patients who underwent PCNL by a single surgeon from January 2005 to December 2010 were reviewed retrospectively. All patients were divided into two groups according to median blood loss (lesser bleeding group and higher bleeding group). Various clinical and perioperative factors including age, sex, stone size and position, degree of hydronephrosis, operative time, underlying disease, history of anticoagulant medication, presence of previous nephrostomy catheter, stone composition, and thickness of the renal cortex were assessed. For statistical assessment, univariate and multivariate logistic regression analyses were used.ResultsThe mean patient age was 48.8 years (range, 22 to 75 years). Forty-three patients (11.6%) received a transfusion and 9 patients (2.4%) underwent angioembolization after surgery. The mean blood loss was 511.8±341.3 mL. Body mass index (BMI), stone size, stone position, operation time, and degree of preoperative hydronephrosis were predictive factors for severe bleeding during PCNL.ConclusionsOn the basis of the results achieved by a single surgeon, staghorn stones, high BMI, large stones, prolonged operation time, and absence of hydronephrosis were significantly associated with the risk of severe bleeding during PCNL.

Neurologic Complications in Percutaneous Nephrolithotomy

PurposePercutaneous nephrolithotomy (PCNL) has been the preferred procedure for the removal of large renal stones in Iran since 1990. Recently, we encountered a series of devastating neurologic complications during PCNL, including paraplegia and hemiplegia. There are several reports of neurologic complications following PCNL owing to paradoxical air emboli, but there are no reports of paraplegia following PCNL.Materials and MethodsWe retrospectively reviewed the medical records of patients who had undergone PCNL in 13 different endourologic centers and retrieved data related to neurologic complications after PCNL, including coma, paraplegia, hemiplegia, and quadriplegia.ResultsThe total number of PCNL procedures in these 13 centers was 30,666. Among these procedures, 11 cases were complicated by neurologic events, and four of these cases experienced paraplegia. All events happened with the patient in the prone position with the use of general anesthesia and in the presence of air injection. There were no reports of neurologic complications in PCNL procedures performed with the patient under general anesthesia and in the prone position and with contrast injection.ConclusionsIt can be assumed that using room air to opacify the collecting system played a major role in the occurrence of these complications. Likewise, the prone position and general anesthesia may predispose to these events in the presence of air injection.

Effectiveness of Ureteroscopy-Assisted Retrograde Nephrostomy (UARN) for Percutaneous Nephrolithotomy (PCNL)

ObjectiveTo determine the impact of ureteroscopy-assisted retrograde nephrostomy (UARN) during percutaneous nephrolithotomy (PCNL).Materials and MethodsFrom April 2009 to September 2011, a total of 50 patients underwent PCNL for large renal stones (stone burden >2 cm). We performed UARN in the Galdakao-modified Valdivia position for 27 patients (UARN PCNL) and ultrasonography-assisted percutaneous nephrostomy in the prone position for 23 patients (prone PCNL).ResultsUARN PCNL significantly improved the stone-free rate (81.5% vs 52.2%) and the rate of residual stones (<4 mm, 92.6% vs 65.2%, P<0.05). The median length of the operation was significantly shorter for UARN PCNL, at 160 min, compared to 299 min for prone PCNL (P<0.001). There was one intraoperative complication in prone PCNL, namely a hemorrhage that resulted in stopping the initial treatment, but it was cured conservatively. The postoperative complications included a high grade fever that persisted for three days in two UARN PCNL patients (7.4%) and six prone PCNL patients (26.1%). The Clavien grading scores showed significantly lower postoperative complications for UARN PCNL compared to prone PCNL.ConclusionUARN is associated with a higher stone-free rate, shorter operation time, and fewer complications during PCNL than prone PCNL.

Percutaneous nephrolithotomy in adult patients with spina bifida, severe spinal deformity and large renal stones

To present our experience in patients with spina bifida with severe spinal abnormality undergoing percutaneous nephrolithotomy (PCNL) for large stone burden. A retrospective review identified five spina bifida patients with abnormal spinal curvature who had a PCNL for large kidney stones. The mean age was 28 years. In two patients, stones were on the concave side of the scoliotic spine further limiting percutaneous access. Mean stone burden was 940 mm2. All patients were paraplegic, three patients had symptomatic stone disease. We performed initial percutaneous renal access in radiology department and staged nephrolithotomy in operating room. Tract dilatation was accomplished using Amplatz dilators and a 24 Ch or 26 Ch nephroscope was used. Fragmentation and stone removal were accomplished in all patients using pneumatic and or ultrasound lithotripter and a retrieval grasper. No anaesthetic complications were recorded. One patient required multiple percutaneous tracts, four had single tract to access stones. Three patients were stone free after PCNL. One required second PCNL through the same tract and another patient had multiple adjunctive ESWL. All five patients were stone clear after the final procedure. Two patients required blood transfusion. No patient had major complication or admission to intensive care unit. Percutaneous nephrolithotomy in patients with spina bifida is challenging but safe. Detailed pre-operative anaesthetic assessment and precise uroradiological evaluation of renal anatomy is essential. Second-look PCNL and additional ESWL/URS treatment may be required to completely clear stones.

Percutaneous stone surgery using a tubeless technique with fibrin sealant: report of our first 107 cases

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Small case series support the safety and efficacy of tubeless PCNL with fibrin sealant. However, there is a paucity of data from larger case series supporting this approach. To our knowledge, this is among the largest tubeless PCNL series. We found the use of fibrin sealant for tubeless PCNL was associated with excellent stone-free rates (approaching 90%), short hospitalisation, and low complication rates. Tubeless PCNL with nephrostomy tract fibrin sealant appears to be viable option for appropriately select patients. • To report on our first 107 cases of tubeless percutaneous nephrolithotomy (PCNL) using fibrin sealant as a haemostatic agent within the access tract. PCNL is the preferred treatment for patients with large renal stones, and the tubeless technique with the use of fibrin sealant has recently gained popularity. • We performed a retrospective review of single-access, PCNL cases performed without a nephrostomy tube from January 2002 to July 2008. • Nephrostomy tracts were sealed at the conclusion of each procedure with fibrin-containing haemostatic agents. • We evaluated demographic variables, tracked complications, and compared pre- and postoperative haemoglobin, haematocrit and creatinine levels. • On postoperative day 1 computed tomography was used to determine stone-free rates. • Student's t-test calculations were used to determine statistical significance at P ≤ 0.05. • In all, 59 men and 48 women with a mean age of 43 years were included in the analysis of 107 cases. The mean stone size was 2.9 cm(2) and the average hospital stay was 1.07 days. • Pre- and postoperative changes in serum haemoglobin and serum creatinine were not statistically different. Postoperative haematocrit declined by a mean of 4.5% (P ≤ 0.05), but no patients required a transfusion. • Stone-free rates were 72% overall, and 90% when excluding patients with residual fragments of <4 mm. • Complications included seven asymptomatic subcapsular haematomas, one pseudoaneurysm requiring selective embolization, one urine leak, and five return visits to the emergency room for pain. • The use of fibrin sealant in this large tubeless PCNL series was associated with favourable stone-free rates, short hospital stays, and low complication rates with no significant bleeding. • Tubeless PCNL with nephrostomy tract fibrin sealant appears to be a viable option for appropriately selected patients, but future randomised trials are warranted.

EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY;

Objective: To determine the efficacy of Alpha blocker as adjunctive medical therapy , which increases the stone clearance afterextracorporeal shock wave lithotripsy (ESWL) to treat renal stones. Design: Quasi Experimental study. Setting: Department of Urology,Liaquat National Hospital, Karachi. Period: September 2010 to March 2011. Materials &amp; Method: Ultrasound guided Dornier Alpha Impactlithotripter was used for shock wave lithotripsy. Study was carried out on 60 patients who underwent single session of ESWL for renal calculus.Patients were divided in two groups, Group A (n=30) received conventional treatment and Group B (n=30) received Alpha-1 Blocker in additionto conventional treatment. All patients were evaluated with X-ray and Ultrasound (KUB) after 2 weeks and repeated at the end of month. Failureis defined as unsuccessful expulsion after 4 weeks and patient desire to remove the stone before day 30. Result: Out of 60 patients, 45(75%)were males and 15(257%) were females with male to female ratio was 3:1. The average age of the patients was found 36.32 ± 14.8 (Rangingfrom 15 to 75) years. Complete clearance was achieved in 76.7% of those receiving Alpha-1 Blocker and in 46.7% of controls at 1 month (P =0.001). This difference was statistically significant. Conclusions: The results of my study demonstrate that Alpha-1 Blocker therapy, as anadjunctive medical therapy after ESWL is more effective than lithotripsy alone for the treatment of patients with large renal stones and is equallysafe.

Flexible Ureteroscopy and Laser Lithotripsy for Stones &gt;2 cm: A Systematic Review and Meta-Analysis

Urinary stones >2 cm are traditionally managed with percutaneous nephrolithotomy (PCNL). Recently, flexible ureteroscopy and laser lithotripsy) (FURSL) has been used to manage them with comparable results. In a comparative study of renal stones between 2 and 3 cm, FURSL was reported to need less second-stage procedures and be just as effective as PCNL. Our purpose was to review the literature for renal stones >2 cm managed by ureteroscopy and holmium lasertripsy. A systematic review and quantitative meta-analysis was performed using studies identified by a literature search from 1990s (the first reported large renal stones treated ureteroscopically) to August 2011. All English language articles reporting on a minimum of 10 patients treated with FURSL for renal stones >2 cm were included. Two reviewers independently extracted the data from each study. The data of studies with comparable results were included into a meta-analysis. In nine studies, 445 patients (460 renal units) were reportedly treated with FURSL. The mean operative time was 82.5 minutes (28-215 min). The mean stone-free rate was 93.7% (77%-96.7%), with an average of 1.6 procedures per patient. The mean stone size was 2.5 cm. An overall complication rate was 10.1%. Major complications developed in 21 (5.3%) patients and minor complications developed in 19 (4.8%) patients. A subgroup analysis shows that FURSL has a 95.7% stone-free rate with stones 2-3 cm and 84.6% in those >3 cm (P=0.01), with a minor complication rate of 14.3% and 15.4%, respectively, and a major complication rate of 0% and 11.5%, respectively. In experienced hands, FURSL can successfully treat patients with stones >2 cm with a high stone-free rate and a low complication rate. Although the studies are from high-volume experienced centers and may not be sufficient to alter everyday routine practice, this review has shown that the efficacy of FURSL allows an alternative to PCNL.

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

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

Minimally Invasive Surgical and Medical Management of Urinary Calculi

Management of urinary calculi has changed from open pyelolithotomy and ureterolithotomy to predominantly non-invasive procedures such as extracorporeal shockwave lithotripsy (ESWL) as well as endourological such as ureterorenoscopy (URS) and percutaneous nephrolithotripsy (PCNL). Technology has advanced rapidly allowing stone disease to be treated with minimally invasive techniques that have lower morbidity than the open operations of the past. Newer semi-rigid ureteroscopes of size 7 to 9 F allow visualisation of the ureter without traumatic dilatation. There is the flexible ureteroscope developed with smaller fibre optics, the addition of the working channel that allows the use of laser fibres for stone fragmentation and a greater deflection of the tip that enables all parts of the pelvicalyceal system to be inspected for stones. New generation lithotripters for ESWL deliver shockwave to a smaller focal zone so as to minimise damage to surrounding soft tissue but as a result, there are higher failure rates. PCNL, though more invasive than ESWL and URS, is the procedure of choice for large renal stones. It is highly efficient in such situations as newer equipment to disintegrate stone and newer techniques for percutaneous access has been developed. In addition to all these minimally invasive surgical techniques, there is medical therapy available to allow the expulsion of distal ureteric stones as well as alkalinising agents to dissolve uric acid stones. Metabolic evaluation is necessary for patients with recurrent stones. Dietary adjustments may help prevent recurrent stone formation in selected patients depending on the results. With all these techniques currently available, management of urinary calculi has to be tailored according to the size, location of stone as well as patient preference.

Impact of body mass index on clinical outcomes associated with percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is the preferred treatment for patients with large renal calculi or stones that have not responded to extracorporeal shock wave lithotripsy (ESWL). The objective of this study was to compare outcomes and complications of PCNL in patients of various body mass indices (BMI) to determine the safety of this procedure in patients with elevated BMI. A retrospective chart review of 114 patients who underwent PCNL between 2006 and 2009 was performed. Patients were separated into 4 groups with respect to their BMI: (1) ideal body weight (BMI <25 kg/m(2)), (2) overweight (BMW 25-29 kg/m(2)), (3) obese (BMI 30-39 kg/m(2)) and (4) morbidly obese (BMI ≥40 kg/m(2)). One-way ANOVA and univariate logistic regression analysis were used to assess the association between BMI (classified into 4 levels) and variables including age, sex, stone size, length of stay, incidence of complications and stone-free rates. The distribution of the 114 patients in each BMI category was: ideal body weight 39 (34%), overweight 24 (21%), obese 41 (36%), morbidly obese 10 (9%). There was no difference in the composition of groups with respect to age, sex, pharmacologically treated comorbidities or stone size. Mean length of stay in days, intra- and postoperative complication rates were not statistically different. Stone-free rates showed no significant difference between groups: 90% ideal body weight; 87% overweight; 90% obese; 80% morbidly obese (p = 0.83). Outcomes of PCNL were statistically independent of BMI. PCNL is a safe and efficacious treatment of stone disease in patients of all sizes.

Preoperative stenting for ureteroscopic lithotripsy for a large renal stone

A large renal stone can be treated ureteroscopically, but the treatment often requires more than one procedure. The use of stenting before ureteroscopy was recently reported. The present study investigated the effectiveness of preoperative stenting before ureteroscopic lithotripsy for large (>15 mm) renal stones. A ureteral stent was intentionally inserted in 25 patients undergoing ureteroscopic surgery. A group of 36 non-prestented patients was used as control. Median stone diameter was 21 mm in both groups. Pre-ureteroscopy stenting significantly improved the stone-free rate, defined as stones <2 mm and <4 mm (P < 0.05), whereas it did not significantly improve the stone-free rate defined as 0 mm (P = 0.12). The uretereoscopy success rate was 72.0% in the stented and 55.6% in the control group (P = 0.09). A 14/16-Fr ureteral access sheath was successfully inserted in 94.7% of the stented patients, and 74.2% of the non-stented patients (P < 0.05). Our findings showed that preoperative stenting is effective for dilation of the ureter, and also to facilitate the insertion of a ureteral access sheath in patients undergoing ureteroscopic lithotripsy for large renal stones.

Treatment of renal stones in infants: comparing extracorporeal shock wave lithotripsy and mini-percutaneous nephrolithotomy

The objective of the study is to compare the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and mini-percutaneous nephrolithotomy (MPCNL) in treating renal stones sizing 15-25 mm in infants <3 years. Forty-six infants with renal stones sizing 15-30 mm were treated by either ESWL (22 renal units in 22 infants) using Dornier compact delta lithotripter or MPCNL (25 renal units in 24 infants) using 14F-18F renal access under general anesthesia. The operation time, stone-free rate, re-treatment rate, and complications between the two groups were compared with the χ(2), Mann-Whitney U, and Student's t tests. No significant differences in mean age and stone size were observed between the two groups. The 1- and 3-month postoperative stone-free rates were 84 and 96% in MPCNL group and were 31.8 and 86.4% in ESWL group. The re-treatment and complication rates were significantly higher in ESWL group than in MPCNL group (50 vs. 12%, P = 0.004; 16.0 vs. 45.5%, P = 0.028). The stone recurrence rate was similar between the two groups. No significant changes of serum creatinine (Cr) level and glomerular filtration rate were observed in both groups. In conclusion, MPCNL is an effective and feasible alternative monotherapy for large renal stones (15-25 mm) in infants, with a higher stone-free rate and a lower complication rate when compared with ESWL.

Editorial Comment

The American Urological Association Guidelines recommend percutaneous nephrolithotomy (PCNL) as the standard of care for patients with staghorn or large renal stones because of the high stone-free rates (SFRs) with minimal morbidity. 1 Preminger G.M. Assimos D.G. Lingeman J.E. et al. AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations. J Urol. 2005; 173: 1991-2000 Abstract Full Text Full Text PDF PubMed Scopus (725) Google Scholar Before the advent of flexible fiberoptic instruments and Holmium laser lithotripters, it was not unusual for PCNL to require multiple access tracts directly on calyces containing stones to achieve stone-free status. Some authors even suggested performing auxiliary procedures, such as shock wave lithotripsy (SWL) as combination or “sandwich” therapy with PCNL to fragment stones that could not be reached using rigid instruments. However, SFRs were lower when SWL was not followed with PCNL to remove stone fragments. With the invention of flexible nephroscopes and ureteroscopes in addition to the availability of flexible miniaturized lithotripters, such as Holmium laser using 200- or 365-μm fibers, PCNL through a single incision and a single tract (sPCNL) becomes possible for large renal stones and even staghorns. In the above manuscript, the authors present a retrospective series of 351 patients who underwent sPCNL from 2000 to 2010. 2 Shahrour K, Tmoaszewski J, Ortiz T, et al. Predictors of immediate post-operative outcome of single-tract percutaneous nephrolithotomy. Urology. 17057. Google Scholar Although this method was first proposed by Wong and Leveillee, 3 Wong C. Leveillee R.J. Single upper-pole percutaneous access for treatment of ≥ 5-cm complex branched staghorn calculi: is Shock wave lithotripsy necessary?. J Endourol. 2002; 16: 477-481 Crossref PubMed Scopus (84) Google Scholar the authors should be commended for their meticulous collection of data over the 10-year period. In addition to limiting the incision to a single site (laparo-endoscopic single site [LESS), they also used a flexible ureteroscope through a natural orifice (urethra) during second-look nephroscopy to access calyces inaccessible using a flexible nephroscope; thus combining LESS with natural orifice transurethral endoscopic surgery (NOTES). Predictors of Immediate Postoperative Outcome of Single-tract Percutaneous NephrolithotomyUrologyVol. 80Issue 1PreviewTo evaluate the efficacy of single tract percutaneous nephrolithotomy (sPCNL) and investigate the preoperative predictive factors associated with stone clearance after sPCNL. Full-Text PDF

Minimally invasive percutaneous nephrolitholapaxy (PCNL) as an effective and safe procedure for large renal stones

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? The minimally invasive percutaneous nephrolitholapaxy (MIP) has shown high efficacy and safety for the management of small renal stones. It was initially developed to overcome a gap between the minimally invasive extracorporeal shockwave lithotripsy and invasive conventional percutaneous nephrolitholapaxy (PCNL) in the management of low stone burden but there is debate as to whether the MIP is also effective for larger stones. The present study shows the high efficacy and safety of MIP, which is comparable to conventional PCNL in the treatment of stones of >20 mm, including complex staghorn stones. • To evaluate the safety and efficacy of minimally invasive percutaneous nephrolitholapaxy (MIP) in the management of large and complex renal calculi. • From January 2007 to March 2011, 73 patients with 83 renal units with large renal stones (>20 mm in diameter) were retrospectively evaluated. • Stones were classified into simple (isolated renal pelvis or isolated calyceal stones) or complex (partial or complete staghorn stones, renal pelvis stones with accompanying calyceal stones). • Stone-free rate, complications according to the modified Clavien system, decrease in haemoglobin, creatinine level, operative duration and hospital stay were compared for simple and complex renal calculi. • The mean (sd) stone size was 36.7 (23.37) mm and mean operative duration was 99.2 (48.3) min. • In all, 65 cases (78.3%) were stone-free after the first procedure and another 14 needed an auxiliary procedure (four second-look percutaneous nephrolitholapaxy, nine ureterorenoscopy, and one extracorporeal shockwave lithotripsy) to become stone-free, resulting in a 95.2% stone-free rate. • Complications occurred in 22 procedures (26.5%), 17 of them were Clavien Grade 1 or 2 (20.5%), five were Grade 3 (6%). There were no Grade 4 or 5 complications. • The only significant difference between complex and simple stones was the stone-free rate (96.9% vs 66.7%, P = 0.001). • The MIP technique is effective and safe for larger stones with low morbidity, good success rate and reasonable operative duration.

1707 URONET™: A NOVEL DEVICE FOR MANAGING PATIENTS WITH BLADDER AND RENAL STONES

INTRODUCTION AND OBJECTIVES: For patients treated for large bladder and renal stones, open lithotomy, percutaneous approach and transurethral cystolithalapaxy have been the standard of care. Complete removal of these stones is paramount to eliminate stone burden and to help prevent stone recurrence. We describe our experience with a new device for evacuation of large bladder stones by percutaneous cystolithalapaxy and staghorn renal stone(s) removal by percutaneous nephrolithotomy (PCNL). METHODS: We treated 20 patients who presented with bladder stones (10) and/or renal stones (12). The mean stone burden was 6 cm and 3 cm for bladder and renal stones, respectively. The mean age of patients was 56 years with male predominance of 9:1 in the bladder stone group and parity of gender with 5:5 ratio for renal stones. Extraction of stones following cystoscopy/laser lithotripsy (7), percutaneous cystolithalapaxy (2) or stone manipulation (1) of bladder stones and percutaneous nephrolithotomy (12) for renal stones were performed with the UroNetTM (US Urology, Cleveland, Ohio). Stones were extracted using the 5.4F or 9.6F UroNetTM mesh (3.0cm x 1.25cm) device for percutaneous cystolithalapaxy or PCNL, respectively. RESULTS: The smaller UroNetTM device was ideal for removal of bladder stones and the larger device successfully removed stones within the kidney. The UroNetTM was ideal for removal of stones between 2-10mm in size and the softer, sludge-like stones. In one patient undergoing a PCNL procedure, extraction of 108 renal stones was completed with 25 passages of the UroNetTM. Smaller particles were extracted by aspiration techniques. All patients had successful treatment of stones without any complications. Stone composition included Calcium Oxalate (9), Calcium Phosphate (5), Struvite (2), Uric Acid Stones (3) and mixed type stones (3). CONCLUSIONS: The UroNetTM is a safe, reliable and efficient disposable device to remove multiple stone fragments with each passage of the device. The limited passage of instruments helps minimize trauma to the bladder, urethra and kidney during cystolithalapaxy and PCNL procedures. More efficient stone extraction also decreased operative and anesthesia times. Prospective studies are currently underway to compare classic stone baskets to the UroNetTM.