Influence of technique of percutaneous tract creation on incidence of renal hemorrhage

Factors associated to hemoglobin decrease after percutaneous nephrolithotomy: a retrospective study

OBJECTIVE

This study aims to determine the preoperative and perioperative risk parameters associated with a decrease in hemoglobin (Hb) in patients undergoing percutaneous nephrolithotomy (PCNL).

METHODS

We collected prospective data of consecutive patients who underwent PCNL from January 2018 to December 2022. The median decrease in post-operative hemoglobin levels compared to pre-operative was found to be 1.5 g/dl. This value was the cut-off value that divided the sample into two groups. Group 1 has a decrease in Hb levels that is higher or equal to the cutoff, group 2 has a decrease in Hb levels that is lower than the cut-off. All preoperative, stone characteristics and perioperative factors were recorded.

RESULTS

A total of 273 patients were included in the study, 141 in Group 1 and 132 in Group 2. The mean age of Group 1 was significantly higher (55.48 ± 8.73 vs 45.9 ± 10.75 years, p < 0.05). The mean bleeding of Group 1 was significantly higher (285.85 ± 113.68 vs 135 ± 77.54 ml, p < 0.05). There was a significant difference in mean operation time between groups (86.35 ± 32.05 vs 64.89 ± 27.83 min, p < 0.05). Multivariate analysis showed that the variables age, comorbid diabetes mellitus, intraoperative bleeding amount, and operation time had a significant relationship with Hb reduction in patients undergoing PCNL (p < 0.05).

CONCLUSIONS

Older age, comorbid diabetes mellitus, large amounts of intraoperative bleeding, and longer operating time are factors associated with PCNL-related postoperative hemoglobin decrease.

Comparison of safety and efficacy of one shot dilation vs. gradual dilation technique in supine percutaneous nephrolithotomy

PURPOSE

To compare the efficacy and safety of gradual dilation (GD) and one-shot dilation (OSD) techniques in patients who underwent supine percutaneous nephrolithotomy (PCNL).

METHODS

The data of 176 patients who underwent supine PCNL were reviewed. Eighty-seven patients who underwent OSD were defined as group 1, and 89 patients who underwent GD were defined as group 2. Both surgical techniques were compared with each other in terms of various parameters. Then, regression analysis of factors predicting stone-free status and complications in patients who underwent supine PNL were performed. Then, regression analysis of factors predicting success rate and complications in patients who underwent supine PNL were performed.

RESULTS

No statistical difference was found in terms of stone-free rate, Clavien-Dindo complication grade and operation time. No statistical difference was found in terms of success rate, Clavien-Dindo complication grade and operation time. However, the fluoroscopy time was found to be significantly shorter in group 1 (p < 0.001). In the analysis of factors predicting stone-free status, the presence of calyceal stones, increased stone size and number were associated with a decrease in stone-free rate. In the analysis of factors predicting success, the presence of calyceal stones, increased stone size and number were associated with a decrease in success rate. Increased fluoroscopy and operation time, increased complication rates were found to be significantly associated with residual stone. Analysis of factors predicting complications found a higher complication rate in patients with low BMI and severe hydronephrosis. Increased complication was associated with increased time to nephrostomy removal and hospital stay, decrease in stone-free rate, decrease in Hb and increase in Cre value at the postoperative 24th hour.

CONCLUSION

When comparing OSD and GD in patients undergoing supine PCNL, both techniques have similar stone-free and complication rates. When comparing OSD and GD in patients undergoing supine PCNL, both techniques have similar success and complication rates. Compared to GD, the OSD technique can be preferred primarily due to its shorter fluoroscopy time.

Effects of severe hydronephrosis on the outcomes of percutaneous nephrolithotomy with one-shot dilation method

OBJECTIVE

To investigate the effect of the presence of severe hydronephrosis on percutaneous nephrolithotomy (PNL) outcome in patients who underwent PNL operation with one-shot dilatation technique.

MATERIALS AND METHODS

Medical data of 989 patients underwent PNL operation in our clinic between 2012 and 2018 were retrospectively reviewed. We included 373 of the patients underwent PNL operation due to renal pelvic stone, who were older than 18 years of age, who did not have any urinary tract abnormality, and had no previous history of open renal stone operation. Patients were divided into two groups according to the presence of severe hydronephrosis and absence of hydronephrosis. These two groups were compared in terms of age, gender, body mass index (BMI), number of stones, stone burden, operation duration, fluoroscopy time, hospitalization time, hemoglobin and creatinine change, complications, and stone free rate.

RESULTS

There was no statistically significant difference between the groups in terms of age, gender, BMI, stone number, stone size, stone density, operation duration, fluoroscopy time, and hospitalization duration. The mean change in hemoglobin was 1.5 g/dL in group 1 and 1.1 g/dL in group 2. This difference was statistically significant (p = 0.006). Postoperative blood transfusion was required for 3 patients (2.1%) in group 1 and 12 patients (5.1%) in group 2. This difference was statistically significant (p < 0.001).

CONCLUSION

Only the presence of severe hydronephrosis was found to be associated with the change in hemoglobin and postoperative blood transfusion.

Balloon versus Amplatz for tract dilation in fluoroscopically guided percutaneous nephrolithotomy: a systematic review and meta-analysis

OBJECTIVE

To compare the safety and efficacy of balloon and Amplatz for tract dilation in fluoroscopically guided percutaneous nephrolithotomy (PCNL).

METHOD

EMBASE, PUBMED, MEDLINE and the Cochrane Central Register of Controlled Trials were searched for pertinent studies up until 30 October 2019. Pooled effects were calculated as ORs with 95% CIs or mean differences (MD) with 95% CIs. Endpoints included postoperative decrease in haemoglobin, transfusion rate, complication rate, successful dilation rate, stone-free rate, fluoroscopy time, access time, total operation time and length of postoperative hospitalisation (LPH). Bonferroni's correction was intercalated to reduce the likelihood of making a meta-analytical false positive.

RESULTS

One randomised controlled trial and five controlled clinical trials were included, which involved 1317 patients in total. We found a lower drop in postoperative haemoglobin for patients receiving balloon dilation compared with those in the Amplatz group (MD=-0.21, 95% CI -0.33 to 0.09, p=0.0005; Bonferroni correction a=0.005). Access time in the balloon group was also, on average, 2.61 min shorter than the Amplatz group (MD=-2.61, 95% CI -4.20 to 1.01, p=0.001; Bonferroni correction a=0.005). No significant differences were identified between the two dilation methods in terms of transfusion rate, complication rate, successful dilation rate, stone-free rate, fluoroscopy time, total operation time and LPH.

CONCLUSION

Balloon dilation is a safe and effective tract dilation technique for access creation during fluoroscopically guided PCNL. Both of methods have similar success rates although balloon dilation is associated with significantly less postoperative haemoglobin decline and shorter access time. Therefore, balloon dilation appears to be the superior tract dilation technique, but further confirmatory research is required to confirm these findings.

Four dilation techniques in percutaneous nephrolithotomy: a single-institute comparative analysis

BACKGROUND

The aim of this study was to compare four renal access techniques in percutaneous nephrolithotomy (PCNL).

METHODS

A total of 437 patients who underwent PCNL at our center from January 2015 to December 2019 were included in the analysis. Telescopic metallic coaxial dilation (TMD) was used in 146 patients, single step balloon dilation (BD) in 98 patients, one-shot dilation with 30F Amplatz (OS 30F) in 106 patients, and one-shot dilation with 16F Amplatz (OS 16F) in 87 patients. Primary endpoints were perioperative outcomes and complications of the procedures.

RESULTS

Similar baseline characteristics were observed in the four groups. Fluoroscopy time was significantly shorter in OS 30F and OS 16F groups (P<0.0001). The drop in hemoglobin level was not significantly different between TMD and BD groups, but it was significantly lower in OS 16F group versus the OS 30F group and lower in OS 30F group versus the BD Group (P<0.0001). Despite this, the rate of blood transfusion was similar across groups (P=0.837). Moreover, a smaller tract was associated with reduced postoperative morbidity including time to nephrostomy removal (P=0.001), hospital stay (P<0.0001), VAS scale (P<0.0001). There were no significant differences in postoperative complications (P=0.683), and Clavien-Dindo grade ≥3 complication rates (P=0.486) among the groups. Stone-free rates and number of auxiliary procedures required to achieve stone-free status were also similar among all groups (P=0.964 and 0.988, respectively). Multinomial logistic regression analysis showed that BMI (P=0.002), stone size (P=0.002) and previous PCNL (P=0.038) were predictive factors associated with the choice of OS 16 approach.

CONCLUSIONS

Different dilation methods are equally effective and safe to use in a PCNL procedure for kidney stone treatment, allowing similar stone free rates and risk of complications. The OS dilation techniques seem to allow a shorter X-ray exposure time, which might be beneficial for both patients and operators. The use of a 16 F dilator can reduce the postoperative morbidity. Risk of sepsis should be always kept in mind.

Endoscopic nephrolithotomy for the removal of complicated nephroliths in dogs and cats: 16 kidneys in 12 patients (2005-2017)

OBJECTIVE

To describe techniques and outcomes for dogs and cats undergoing endoscopic nephrolithotomy (ENL) for the removal of complicated nephroliths.

ANIMALS

11 dogs and 1 cat (n = 16 renal units) with complicated nephroliths that underwent ENL via a surgically assisted ENL approach (12 renal units) or a percutaneous nephrolithotomy approach (4 renal units) between December 2005 and June 2017.

PROCEDURES

Data were obtained from the medical records regarding preoperative, operative, and postoperative findings. Follow-up information on complications and outcomes was also collected.

RESULTS

Indications for nephrolith removal included massive calculi displacing parenchyma (n = 7), recurrent urinary tract infections (5), and ureteral outflow obstruction (4). Median nephrolith diameter was 2.5 cm (range, 0.5 to 5.7 cm). Nephrolith composition differed among patients; calcium oxalate was the most common type (n = 7 [including 2 mixed nephroliths containing ≥ 60% calcium oxalate]). Following ENL (median duration, 180 minutes), 15 of 16 renal units were completely nephrolith free. Procedure-related complications included renal puncture-associated hemorrhage requiring a blood transfusion (n = 1), renal capsule tear (1), and ureteral puncture (1); all were managed without adverse consequence. Five of 12 patients remained alive at the final follow-up (median, 557 days after ENL), and none died from the procedure.

CONCLUSIONS AND CLINICAL RELEVANCE

ENL as performed was safe and effective in removing complicated nephroliths in a renal-sparing manner for the patients in this study. This procedure requires technical training and could be considered for the treatment of complicated nephrolithiasis in dogs and possibly cats.

Effectiveness and safety of four tract dilation methods of percutaneous nephrolithotomy: A meta-analysis

Percutaneous nephrolithotomy (PCNL) has become a routine surgical procedure for treating patients with large kidney stones; the fundamental step in this process is the creation of the nephrostomy tract. In the present study, a meta-analysis was performed to compare the effectiveness and safety of different tract dilation techniques for PCNL. Databases were searched from inception to 1 April 2019 to identify relevant randomized controlled trials. The X-ray exposure time, hemoglobin decrease, stone-free rate, transfusion rate, hospital stay and the complication rate associated with the various techniques were analyzed. A total of 11 studies comprising 1,415 cases were enrolled in the meta-analysis. Significant differences in X-ray exposure time [weighted mean difference (WMD), 30.67; 95% confidence interval (CI), 20.08-41.26; P<0.001] and hemoglobin decrease (WMD, 0.19; 95%CI, 0.15-0.23; P<0.001) were identified between metal telescopic dilation (MTD) and one-shot dilation (OSD). A significantly lower hemoglobin decrease was observed in the balloon dilation (BD) vs. fascial Amplatz dilation (AD) group [WMD, -0.65; 95%CI, -(0.77-0.52); P<0.001]. The transfusion rate was similar between these techniques. The MTD had an obviously higher successful dilation rate compared with that of the OSD, but no significant differences in stone-free rate and transfusion rate were obtained. The present study determined that, compared with other methods, OSD was safer in almost every adult patient, including those that had previously undergone renal surgery; though it is recommended that this should be performed by experienced surgeons. BD was reported to be effective and safer in patients without a history of renal surgery compared to other methods. The present study proposed AD and MTD as safer methods of dilation for patients who have previously undergone kidney surgery.

The Analysis of Risk Factors for Hemorrhage Associated with Minimally Invasive Percutaneous Nephrolithotomy

Objective

This study investigated the risk factors for bleeding during minimally invasive percutaneous nephrolithotomy, so as to prevent the occurrence of bleeding and improve the surgical effect.

Patients and Methods

The data of 396 patients who underwent percutaneous nephrolithotomy by an experienced surgeon between May 2014 and December 2017 were retrospectively analyzed. To identify the risk factors for bleeding during percutaneous nephrolithotomy, each group was stratified according to the decrease in median hemoglobin. Age, gender, body mass index, stone size, operation time, stone type, degree of hydronephrosis, number of accesses, puncture guidance, underlying disease (diabetes; hypertension), and previous surgical history were evaluated. Univariate analysis was performed to calculate the potential factors. In order to determine the independence of each factor, we finally selected stone size, staghorn stone, degree of hydronephrosis, and operation time. Multivariate logistic regression analysis was used to identify the risk factors for bleeding during minimally invasive percutaneous nephrolithotomy.

Results

A total of 396 patients were successfully treated with percutaneous nephrolithotomy. The univariate analysis demonstrated that the potential risk factors for bleeding during percutaneous nephrolithotomy included stone size, type of stone, operative time, and degree of hydronephrosis. According to the previous studies, stone size, staghorn stone, degree of hydronephrosis, and operation time were ultimately selected. Multivariate logistic regression analysis was used to identify the risk factors for bleeding during percutaneous nephrolithotomy. According to the outcome of logistic regression analysis, stone size, staghorn stone, operation time, and degree of hydronephrosis were the risk factors for bleeding during minimally invasive percutaneous nephrolithotomy.

Conclusions

Percutaneous nephrolithotomy is an effective method for the treatment of upper urinary calculi with few complications. According to the results achieved by an experienced surgeon, the size of stone, staghorn stone, operation time, and degree of hydronephrosis were associated with the bleeding during minimally invasive percutaneous nephrolithotomy.

Amplatz versus Balloon for Tract Dilation in Ultrasonographically Guided Percutaneous Nephrolithotomy: A Randomized Clinical Trial

Purpose

To compare balloon with Amplatz for tract dilation in totally ultrasonographically guided PCNL (UPCN).

Methods

We randomized 66 patients candidate for sonographically guided PCNL in the flank position in two study groups. In the first group, we used single step Amplatz dilation (AG) technique in which the 28- or 30-French Amplatz dilator is used for tract dilation. In the other group, we dilated the tract using balloon dilator (BG). We compared procedure time, success rate of dilation, and postoperative clinical outcomes and cost between two groups.

Results

The rate of short dilation was higher in the Amplatz group (57.6%) compared with Balloon group (36.4%) (P=0.08). When using Amplatz for lower pole access, short dilation occurred in 81% of cases compared with 44% in the BG (P=0.02). Overall operation was longer in the AG (80±21 versus 65±20 minutes P=0.02). Stone free rate was 87.9% in the AG compared with 72.7% in the BG (p=0.12). Mean cost of the surgery was 603±85 USD and 718±78 USD in the AG and BG, respectively (P=0.0001). Hemoglobin drop, transfusion rate, renal function alteration, duration of hospitalization, and complication rate based on Clavien classification were similar in both groups.

Conclusions

AG showed a higher rate of short dilation compared with BG; consequently, overall operating time was significantly longer in the AG whereas BG was significantly more expensive than AG. Bleeding and other complications were similar in two groups. We observed an advantage for balloon dilation over Amplatz when approaching the lower pole calyxes.

Percutaneous nephrolithotomy: complications and how to deal with them

Percutaneous nephrolithotomy is a common surgical treatment for large and complex stones within the intrarenal collecting system. A wide variety of complications can result from this procedure, including bleeding, injury to surrounding structures, infection, positioning-related injuries, thromboembolic disease, and even death. Knowledge of the different types of complications can be useful in order to prevent, diagnose, and treat these problems if they occur. This review describes the diversity of complications with the goal of improving their avoidance and treatment.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm

INTRODUCTION

The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS).

OBJECTIVE

To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time.

MATERIAL AND METHODS

We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL.

RESULTS

The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate.

CONCLUSIONS

The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

A double-blind, placebo-controlled randomized clinical trial to evaluate the efficacy of tranexamic acid in irrigant solution on blood loss during percutaneous nephrolithotomy: a pilot study from tertiary care center of North India

PURPOSE

To evaluate the efficacy and safety of 0.1% tranexamic acid in irrigant fluid in reducing blood loss during PCNL.

MATERIALS AND METHODS

The study involved 400 patients who were planned for PCNL and were prospectively randomized into two equal groups. In tranexamic group, 0.1% tranexamic acid was given in irrigant fluid, while in placebo group, distilled water was added to irrigant fluid during surgery. Operative data were recorded which included fall in hemoglobin, total blood loss, operative time, irrigation fluid, length of stay in hospital, requirement of blood transfusion, complications related to PCNL and adverse events of tranexamic acid.

RESULTS

Baseline parameters were comparable between two groups. The fall in hemoglobin and total blood loss in the tranexamic group was significantly lower than placebo group (1.71 vs. 2.67 gm/dL, 154.55 vs. 212.61 mL, respectively, p < 0.0001). Operative time, amount of irrigation fluid used and hospital stay of tranexamic group were significantly less compared to placebo (p < 0.05). Complete stone clearance rate was 88% in tranexamic group versus 82% in placebo (p = 0.12). The blood transfusion requirement was significantly lower in the tranexamic group versus placebo (5 vs. 12.5%, p = 0.012), as was the complication rate (19 vs. 28%, p = 0.044). The requirement of angioembolization in the tranexamic group was significantly less as compared to placebo (0.5 vs. 4%, p = 0.03). No adverse events related to administration of tranexamic acid were noted.

CONCLUSIONS

0.1% tranexamic acid in irrigant fluid is safe and significantly reduces perioperative blood loss and requirement of blood transfusion during percutaneous nephrolithotomy. It is associated with lower perioperative complication rates.

Ultrasonography-guided percutaneous nephrolithotomy with Chinese one-shot tract dilation technique based on stimulated diuresis: A report of 67 cases

The safety and effectiveness of a novel Chinese one-shot dilation technique based on stimulated diuresis for percutaneous nephrolithotomy (PCNL) were investigated. After the feasibility of the Chinese one-shot dilation based on stimulated diuresis was verified by an animal study, this technique was applied in the clinical practice. A total of 67 patients in our department underwent the modified PCNL from July 2014 to June 2015. After the renal infundibulum was distended by stimulated diuresis, the kidney was punctured under the ultrasonographic guidance via the fornix of the target calyx. The working channel was dilated using a special designed pencil-shaped fascial dilator. The successful access rate, nephrostomy tract creation time, pre- and postoperative hemoglobin values and serum creatinine concentrations, stone-free rate and complications were recorded and analyzed. The renal infundibulum was successfully distended in all of the patients by the diuresis treatment. Under the ultrasonographic guidance, the successful access rate was 100% and the mean tract creation time was 2.0 min (range: 1.5-5.0 min). The stone-free rate right after surgery was 91.0%. Although the postoperative hemoglobin was significantly reduced (P<0.01), transfusion was not clinically necessary. There was no significant difference in serum creatinine concentrations before and after operation (P>0.05). No severe complication occurred during or after the PCNL. It was suggested that this Chinese one-shot dilation technique based on stimulated diuresis is an efficient and safe innovation for PCNL, and is even helpful for those patients with non-dilated pelvicaliceal systems.

Balloon dilator versus telescopic metal dilators for tract dilatation during percutaneous nephrolithotomy for staghorn stones and calyceal stones

Objective

To compare the results of balloon dilatation (BD) vs. telescopic metal dilators (TMDs) in establishing the tract for percutaneous nephrolithotomy (PCNL) in patients with calyceal stones or staghorn stones, but with no hydronephrosis.

Patients and methods

Data from selected patients over 4 years were recorded retrospectively. Patients with complex staghorn stones, an undilated targeted calyx, or the stone filling the targeted calyx, were included in the study. In all, 97 patients were included, of 235 undergoing PCNL between March 2010 and March 2014, and were divided into two groups according to the technique of primary tract dilatation. Group A included patients who had BD and group B those treated using TMDs.

Results

In group A (BD, 55 patients) dilatation was successful in 34 (62%). The dilatation failed or there was a need for re-dilatation using TMD in 21 patients (38%). In one of these 21 patients the dilatation failed due to extravasation. In group B (TMD, 42 patients) dilatation was successful in 38 (90%) patients, with incomplete dilatation and a need for re-dilatation in four (10%) patients, and no failed procedures. Group A had a significantly higher failure rate than group B (P < 0.001). Differences in operative duration, blood loss, stone-removal success rate and complication rate were statistically insignificant.

Conclusion

BD has a higher failure rate than TMD when establishing access for calyceal stones or staghorn stones that have little space around them.

Fluoroscopy guided percutaneous renal access in prone position

Percutaneous nephrolithotomy is a very commonly done procedure for management of renal calculus disease. Establishing a good access is the first and probably the most crucial step of this procedure. A proper access is the gateway to success. However, this crucial step has the steepest learning curve for, in a fluoroscopy guided access, it involves visualizing a three dimensional anatomy on a two dimensional fluoroscopy screen. This review describes the anatomical basis of the renal access. It provides a literature review of all aspects of percutaneous renal access along with the advances that have taken place in this field over the years. The article describes a technique to determine the site of skin puncture, the angle and depth of puncture using a simple mathematical principle. It also reviews the common problems faced during the process of puncture and dilatation and describes the ways to overcome them. The aim of this article is to provide the reader a step by step guide for percutaneous renal access.

Lessons learned from the CROES percutaneous nephrolithotomy global study

PURPOSE

The purpose of the study was to give an overview of the data derived from the CROES PCNL Global Study published previously in 25 articles.

METHODS

A comprehensive overview of the outcome of the CROES PCNL Global Study was made, analysed and compared with the current literature and guidelines.

RESULTS

Percutaneous nephrolithotomy (PCNL) was predominately performed in prone position. Although the supine position claims to be favourable over the prone approach, the present study showed a longer operation time and lower stone-free rate (SFR). This might be explained by differences in definition in operation time and methods in the evaluation of residual stones. Ultrasound (US)-guided access proves beneficial in lowering puncture time and radiation exposure. Renal anomalies can safely be treated by PCNL and have similar outcomes to a normal situation. In patients with a solitary kidney, however, there is a lower SFR and more bleeding. Also, severe chronic kidney disease (CKD) patients have less favourable outcome. Morbidity and complications following PCNL are dominated by fever (10.5%) and bleeding (7.8%). A matched control analysis confirmed that antibiotic prophylaxis gives a threefold lower post-operative fever rate. In a multivariate analysis, it was elegantly demonstrated that bleeding was directly related to the size of the dilatation: the larger the bore, the higher the chance for bleeding. Elderly patients are at higher risk of complications and longer hospital stay. Overall, obese patients have similar outcome as the general population; however, super-obese (BMI > 40) patients have a higher chance of more severe complications. For the first time, this database illustrated a significant relationship between results and complications of PCNL, and caseload volume. The optimal case volume per centre appears to be 120 PCNL's/year. Finally, a nomogram has been developed that enables better patient counselling and decision-making.

CONCLUSION

The CROES PCNL Global Study is the largest real-life study providing new insights into general and special conditions. Because of the vast number of patients included, rare conditions including renal anomalies, solitary kidneys and patient characteristics like severe CKD, super obesity and old age could be analysed. Besides this information, a nomogram was developed. And for the first time, the influence of caseload volume was established.

The surgical management of kidney stone disease: a population based time series analysis

PURPOSE

We evaluate population based trends in the use of extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy during the last 20 years, as well as assess the re-treatment rate and morbidity from treatment over time.

MATERIALS AND METHODS

Using administrative databases in the province of Ontario, Canada, a population based cross-sectional time series analysis was performed between July 1, 1991 and December 31, 2010. All extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy procedures were identified, along with all hospital readmissions and emergency department visits within 7 days of treatment. The primary outcome was treatment use, and secondary outcomes were the need for ancillary treatment and hospital readmission or emergency department visit after treatment. Exponential smoothing and autoregressive integrated moving average (ARIMA) models were used to assess trends over time.

RESULTS

We identified 194,781 kidney stone treatments performed during the study period. Time series modeling revealed a significant increase in the use of ureteroscopy over time (25% to 59% of all procedures, p <0.0001) and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy (69% to 34% of all procedures, p <0.0001). A corresponding significant decrease in the need for ancillary treatment over time (23% to 15%, p <0.0001) and increase in the need for hospital readmission (7% to 11%, p <0.0001) or emergency department visit (7% to 11%, p=0.0024) after treatment were also demonstrated.

CONCLUSIONS

Our population based study demonstrates a shift in the treatment paradigm with increased use of ureteroscopy over time and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy. We also observed a corresponding decrease in ancillary treatment and increase in posttreatment morbidity over time.

A comparison among four tract dilation methods of percutaneous nephrolithotomy: a systematic review and meta-analysis

The purpose of this study was to evaluate the efficacy and safety of the Amplatz dilation (AD), metal telescopic dilation (MTD), balloon dilation (BD), and one-shot dilation (OSD) methods for tract dilation during percutaneous nephrolithotomy (PCNL). Relevant eligible studies were identified using three electronic databases (Medline, EMBASE, and Cochrane CENTRAL). Database acquisition and quality evaluation were independently performed by two reviewers. Efficacy (stone-free rate, surgical duration, and tract dilatation fluoroscopy time) and safety (transfusion rate and hemoglobin decrease) were evaluated using Review Manager 5.2. Four randomized controlled trials and eight clinical controlled trials involving 6,820 patients met the inclusion criteria. The pooled result from a meta-analysis showed statistically significant differences in tract dilatation fluoroscopy time and hemoglobin decrease between the OSD and MTD groups, which showed comparable stone-free and transfusion rates. Significant differences in transfusion rate were found between the BD and MTD groups. Among patients without previous open renal surgery, those who underwent BD exhibited a lower blood transfusion rate and a shorter surgical duration compared with those who underwent AD. The OSD technique is safer and more efficient than the MTD technique for tract dilation during PCNL, particularly in patients with previous open renal surgery, resulting in a shorter tract dilatation fluoroscopy time and a lesser decrease in hemoglobin. The efficacy and safety of BD are better than AD in patients without previous open renal surgery. The OSD technique should be considered for most patients who undergo PCNL therapy.

Predictive factors for bleeding during percutaneous nephrolithotomy

Purpose

Although 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 Methods

The 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.

Results

The 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.

Conclusions

On 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.

Reliability of percutaneous nephrolithotomy in pediatric patients: comparison of complications with those in adults

PURPOSE

To assess the reliability of percutaneous nephrolithotomy (PNL) in pediatric patients by comparing complications between pediatric patients and adults by use of the modified Clavien grading system.

MATERIALS AND METHODS

The data of 74 pediatric (0 to 16 years) and 535 adult (17 years and older) patients who underwent PNL owing to kidney stone disease between January 2005 and December 2011 were analyzed retrospectively. The complications in the pediatric and adult patients were classified in five grades according to the modified Clavien system.

RESULTS

The most frequent cause of grade I complications was fever requiring antipyretics, which was seen in 4 pediatric patients (5.4%) and 30 adult patients (5.6%). Grade II complications (blood transfusions, <12 hours urinary leakage) were observed in 11 pediatric patients (14.8%) and 80 adult patients (14.9%). Grade III complications were also seen in 6 pediatric patients (8.1%) (grade IIIb; D-J catheter implantation under general anesthesia) and 78 adult patients (14.5%) (grade IIIa; D-J catheter implantation and angio-embolization under local anesthesia). There was no statistically significant difference between the two groups in terms of grade I, II, or III complications (p>0.05). Colonic injury occured in one patient (1.3%) in the pediatric group (grade IVa). In the adult group, one patient (0.2%) died as the result of myocardial infarction (grade V).

CONCLUSIONS

Thanks to technological developments and minimalization of the equipment used, when indicated, pediatric patients can be safely treated with PNL with low complication rates similar to those in adult patients.

Parenchymal thickness: does it have an impact on outcomes of percutaneous nephrolithotomy?

OBJECTIVE

To evaluate whether renal parenchymal thickness (RPT) has an effect on the outcomes of percutaneous nephrolithotomy (PNL).

METHODS

We performed a retrospective analysis of 144 patients with lower pole and/or renal pelvic stones who underwent PNL. The relationship between RPT and peri- and postoperative measures was evaluated.

RESULTS

The average age was 45.94 ± 14.47 (15-76) years. The mean BMI was calculated as 27.47 ± 4.73 (16.9-44.9) kg/m(2). The mean stone burden was 293 ± 126 (150-800 mm(2)). The mean RPT was measured as 17.33 ± 5.32 (6-35) mm. No correlation was detected between the RPT and the operation or fluoroscopy times or the duration of hospitalization (p = 0.63, 0.52, 0.08, respectively). The mean drop in hemoglobin level was 1.45 ± 1.25 (0-9) g/dl. A negative correlation was detected between hemoglobin drop and RPT (p = 0.01, r = -0.23). However, the RPT was similar in patients who did or did not require a blood transfusion (p = 0.09). The RPT was found to have no impact on success rate (p = 0.4).

CONCLUSION

The postoperative hemoglobin drop increases in parallel with the increase in RPT. However, no relationship was detected between the RPT and blood transfusion, overall success rate or any other perioperative parameters.

Percutaneous nephrolithotomy in patients on chronic anticoagulant/antiplatelet therapy

Percutaneous nephrolithotomy (PCNL) is an integral component in the management of large volume renal stone disease either as monotherapy or in combination with shock wave lithotripsy. Stone disease in patients on chronic anticoagulation/antiplatelet therapy, however, poses a difficult scenario. Bleeding is a major concern for any patient undergoing PCNL. We retrospectively analyzed our series of patients with renal calculi who were on chronic anticoagulant therapy and who underwent PCNL. We reviewed the case records of patients undergoing PCNL during the period from January 2005 to December 2011. We analyzed the changes in preoperative and postoperative hemoglobin, serum creatinine, and clotting parameters, as well as intraoperative and postoperative bleeding and thromboembolic complications. During the 5-year study period, a total of 36 patients (30 males and 6 females) with a mean age of 46.33±9.96 years (range, 29-61 years) who were on chronic anticoagulant/antiplatelet therapy underwent PCNL for urolithiasis. The mean size of the stone was 6.40±1.98 cm² (range, 2.8-9 cm²). The mean operating time was 62.08±10.10 min. The bleeding was successfully managed in all patients and the anticoagulant/antiplatelet agents were restarted after an appropriate duration. The mean rise in serum creatinine at discharge was 0.05±0.03 mg/dl and the mean fall in serum hemoglobin was 1.63±0.77 g/dl. At 3 months after surgery, the stone-free rate was 100%. With careful preoperative care and regulation of anticoagulation/antiplatelet therapy and appropriate intraoperative management, PCNL can be performed safely and successfully in properly selected patients with renal calculi who are on chronic anticoagulant/antiplatelet therapy.

Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in children with moderate-size kidney stones: results of multi-institutional analysis

OBJECTIVE

To compare the outcomes of miniaturized percutaneous nephrolithotomy (mini-perc) and retrograde intrarenal surgery (RIRS) in children for 10- to 30-mm renal calculi by evaluating operative data, stone-free rates, and associated complications.

METHODS

The records of 201 pediatric patients who underwent mini-perc (n = 106) or RIRS (n = 95) for intrarenal stones of 10- to 30-mm size were reviewed retrospectively. The χ(2) test was applied to compare the success rates, postoperative complications, and blood transfusion rates, and the Mann-Whitney U test was used to compare the means of hospital stay, fluoroscopy, and operative time for mini-perc and RIRS.

RESULTS

The stone-free rate was 84.2% for the RIRS group and 85.8% for the mini-perc group after a single procedure (P = .745). These percentages increased to 92.6% and 94.3% with adjunctive therapies for RIRS and mini-perc, respectively. Minor complications classified as Clavien I or II occurred in 17% and 8.4% in mini-perc and RIRS, respectively. No major complications (Clavien III-V) occurred in either group. Overall complication rates in mini-perc were higher, but the differences were not statistically significant (P = .07). However, 7 patients in the mini-perc group received blood transfusions, whereas none of the children in the RIRS group were transfused (P = .015). The mean hospital stay, fluoroscopy, and operation times were significantly longer in the mini-perc group.

CONCLUSION

This study demonstrates that RIRS is an effective alternative to mini-perc in pediatric patients with intermediate-sized renal stones. Operative time, radiation exposure, hospital stay, and morbidities of percutaneous nephrolithotomy (PNL) can be significantly reduced with the RIRS technique.

Percutaneous nephrolithotomy in the United kingdom: results of a prospective data registry

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is commonly used in the management of large upper renal tract stones. It is highly effective but carries a greater risk of significant morbidity than less invasive treatment options such as ureteroscopy or extracorporeal shock wave lithotripsy.

OBJECTIVE

Evaluate the current practice and outcomes of PCNL using a national prospective data registry.

DESIGN, SETTING, AND PARTICIPANTS

All surgeons undertaking PCNL in the United Kingdom were invited to submit data to an online registry.

MEASUREMENTS

Effectiveness was assessed by stone-free rates and safety according to complications including blood transfusion, fever, and sepsis rates.

RESULTS AND LIMITATIONS

Since January 2010, data on 987 patients who had 1028 PCNL procedures were collected. A total of 299 of 1012 procedures (30%) were for staghorn calculi, 299 (30%) for stones >2 cm, 329 (33%) for stones 1-2 cm, and 89 (9%) for stones <1cm. There were no significant differences in rates of failed access or complications according to whether a urologist or radiologist obtained renal access. There was a nonsignificant trend to a higher transfusion rate with balloon dilatation (7 of 222 [3.2%]) compared with serial dilatation (2 of 245 [0.8%]) of the renal tract (p = 0.093). Totally tubeless procedures were not associated with higher complication rates but did lead to a significant reduction in median length of stay (3 d vs 1.5 d; p<0.0001). Intraoperatively, 78% of patients were believed to be stone free, which was confirmed in 68% with postoperative imaging. Blood transfusion was required in 24 of 968 patients (2.5%). The incidence of postoperative fever was 16% and of sepsis was 2.4%.

CONCLUSIONS

The PCNL data registry is a unique resource providing vital information on current practice and critical outcome data. Using the registry, endourologists can audit their practice against national outcome data for this benchmark procedure. It will help surgeons counsel patients during consent for this complex endourologic procedure about the possible outcome in their hands.

A comparison of metal telescopic dilators and Amplatz dilators for nephrostomy tract dilation in percutaneous nephrolithotomy

BACKGROUND AND PURPOSE

Nephrostomy tract dilation is one of the important steps in percutaneous renal surgery. We present our experiences with using Amplatz and metal telescopic dilators (Alken) to create a percutaneous tract and compare the advantages and risk factors of both procedures.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 173 patients who had undergone 188 percutaneous nephrolithotomy procedures between April 2007 and December 2010. The nephrostomy tracts had been created by using Amplatz (67 cases) or Alken dilators (121 cases). Total operative time, scope time, tract formation time, decrease in hemoglobin concentrations, blood transfusion rates, tract dilation failures, and the cost of both systems were compared between the groups.

RESULTS

There were no statistically significant differences in total operative time (103.3 ± 46.5 vs 99.1 ± 44.4 min, P=0.583), scope time (5.23 ± 3.06 vs 5.28 ± 2.52 min, P=0.732), decrease in hemoglobin concentration (-1.5 ± 1.2 vs-1.3 ± 1.1 mg/dL, P=0.230), blood transfusion rates (13.4% vs 11.6%, P=0.709), and tract dilation failure rates (6.0% vs 1.7%, P=0.107) for Amplatz and Alken dilation groups, respectively. A shorter tract formation time (6.56 ± 3.04 vs 5.42 ± 3.07 min, P<0.001) was observed in the Alken dilation group. The approximate costs per each case were $220 and $7.25 for Amplatz and Alken dilation groups, respectively.

CONCLUSIONS

The Alken dilation technique produces similar results to the Amplatz dilators in terms of efficiency, safety, and total operative time. Notwithstanding, it is more cost-effective in comparison.

Percutaneous nephrolithotomy in children

The surgical management of pediatric stone disease has evolved significantly over the last three decades. Prior to the introduction of shockwave lithotripsy (SWL) in the 1980s, open lithotomy was the lone therapy for children with upper tract calculi. Since then, SWL has been the procedure of choice in most pediatric centers for children with large renal calculi. While other therapies such as percutaneous nephrolithotomy (PNL) were also being advanced around the same time, PNL was generally seen as a suitable therapy in adults because of the concerns for damage in the developing kidney. However, recent advances in endoscopic instrumentation and renal access techniques have led to an increase in its use in the pediatric population, particularly in those children with large upper tract stones. This paper is a review of the literature focusing on the indications, techniques, results, and complications of PNL in children with renal calculi.

Comparison of supracostal versus infracostal percutaneous nephrolithotomy using the novel prone-flexed patient position

BACKGROUND AND PURPOSE

Percutaneous nephrolithotomy (PCNL) is considered standard therapy for large and complex renal calculi. The optimal patient position and puncture site for collecting system access remains controversial. This purpose of this retrospective review is to analyze our PCNL series with respect to puncture tracts, success, and complications using our novel prone-flexed position.

PATIENTS AND METHODS

Perioperative data were collected on consecutive PCNL cases for renal calculi performed in the prone-flexed position from 2004 to 2009. Patient demographic, stone, operative, postoperative, and follow-up data were collected. Successful treatment was defined as stone free or sandlike (≤1  mm) particles visible on CT scan at 3 months.

RESULTS

A total of 318 patients, with a mean age of 52.9 years and body mass index of 27.8  kg/m(2), underwent PCNL in the prone-flexed position (57.9% male). Sixteen tracts were above the 11th rib, 138 were above the 12th rib, and 164 were infracostal. Multiple tracts were used in 16 patients. There were no significant differences between patients undergoing supracostal vs infracostal puncture with respect to side, stone area, number of tracts, number of stones, or the presence of staghorn or struvite calculi. Success in the supracostal group (89.8%) was not statistically different from the infracostal group (94.1%), P>0.05. Overall complication rates across groups was low (11.6%), with a significant difference in complications between the supracostal and infracostal puncture groups across Clavien grades, P<0.01. No patients needed blood transfusions or angioembolization.

CONCLUSION

Regardless of supracostal or infracostal renal access, our novel prone-flexed position assists with percutaneous renal access and ease of nephrolithotomy, while maintaining excellent success rates and minimizing procedural morbidity.

Operating times and bleeding complications in percutaneous nephrolithotomy: a comparison of tract dilation methods in 5,537 patients in the Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study

PURPOSE

The study investigated factors that affect operating times and bleeding complications associated with percutaneous nephrolithotomy (PCNL) in the PCNL Global Study.

PATIENTS AND METHODS

All patients who underwent PCNL for primary or secondary treatment of kidney stone indications during the study period (November 2007-December 2009) were eligible for inclusion. PCNL procedures were performed according to local clinical guidelines and practices. Nephrostomy tract dilation was performed using balloon dilation, metal telescopic dilation, or Amplatz serial dilation. Hematologic complications assessed included bleeding rates, transfusion rates, and preoperative and postoperative hematocrit values.

RESULTS

The median operating time with balloon dilation (n=2277) was significantly longer than with telescopic/serial dilation (n=3260) at 94.0 vs 60.0 minutes, respectively (P<0.0001). In the balloon dilation group, there was significantly more bleeding (9.4% vs 6.7%, respectively; P<0.0001) and more transfusions (7.0% vs 4.9%, respectively; P=0.001) compared with the telescopic/serial dilator group. Univariate analysis showed that the probability of bleeding complications was higher with balloon vs telescopic/serial dilation (odds ratio [OR] 1.75; P=0.0001) and larger sheath size (OR 1.42; P=0.0001). By multivariate analysis, sheath size but not dilation method was predictive of bleeding complications. Other significant predictive factors included operating time, stone load, and caseload.

CONCLUSION

This study shows that in PCNL, factors that are associated with bleeding/transfusion include sheath size, operating time, stone load, and caseload.

Renal parenchymal damage after percutaneous nephrolithotomy with one-stage tract dilation technique: a randomized clinical trial

PURPOSE

To compare the effects of one-stage vs gradual dilation techniques during percutaneous nephrolithotomy (PCNL) on postoperative renal scar formation and overall renal function.

PATIENTS AND METHODS

Of 152 adult patients who underwent surgery during the study period, 48 were randomized into two groups. In group 1 (n=19), gradual tract dilation with Alken metallic dilators was used, and in group 2 (n=29), one-stage tract dilation was used. We compared patient demographics, intraoperative and preoperative parameters, postoperative overall renal function, and renal scar formation on the target renal pole.

RESULTS

Access time (P=0.001; 95% confidence interval [CI]: 3.19-6.30) and radiation exposure during access (P=0.03; 95% CI: 0.03-0.66) were significantly shorter in group 2. In group 1, the decrease in mean technetium-99m dimercaptosuccinic acid (99m-Tc DMSA) uptake from 44.1±20.1% to 43.4±19.6% 4 weeks postoperatively (-0.7%±0.5%; P=0.27; 95% CI: -0.56-1.93) was not significant. In group 2, however, there was a significant decrease in post-PCNL 99m-Tc DMSA uptake 2 (-2.4±0.3%, from 50.1±13.5% to 47.7±13.8%; P=0.001; 95% CI: 1.13-3.66). Four weeks after surgery, new scar formation or progression of the preoperative scar at the site of access were seen in 14 of 29 (48.3%) patients who were treated with one-stage dilation whereas only 2 of 19 (11.0%) patients who were treated with gradual dilation developed new scarring at the access site (P=0.007).

CONCLUSION

Although the one-stage tract dilation technique reduced radiation exposure and access time, in the short term, it may cause more parenchymal damage than the gradual dilation technique.

Effect of simple malrotation on percutaneous nephrolithotomy: a matched pair multicenter analysis

PURPOSE

In this multicenter study we compared the outcome of percutaneous nephrolithotomy in patients with and without malrotated kidneys.

MATERIALS AND METHODS

A total of 44 patients (group 1) at 6 institutions who underwent percutaneous nephrolithotomy for kidneys with simple malrotation were enrolled in our study. Attending physicians in our group also provided the same number of cases of percutaneous nephrolithotomy done for nonmalrotated (normal) kidneys (group 2). Group 2 patients were selected by match pairing. Operative and postoperative data on the 2 groups were compared using the chi-square, Student t and Fisher exact tests.

RESULTS

As a result of match pairing, the 2 groups were similar in age, gender, body mass index, and stone size and site. Mean ± SD stone size was 5.9 ± 3.5 cm(2) in group 1. Multiple access attempts were required in 9 (20.5%) and 7 cases (15.9%) in groups 1 and 2, respectively (p >0.05). Mean fluoroscopy time was 7.0 ± 3.9 minutes in the malrotated kidney group and 7.3 ± 4.5 minutes in the nonmalrotated kidney group (p >0.05). The mean hemoglobin decrease after percutaneous nephrolithotomy was significantly higher in group 1 (-1.9 vs -1.3 gm/dl, p = 0.008) but the blood transfusion rate was similar in the 2 groups. The procedure success rate in groups 1 and 2 was 77.3% and 79.5%, respectively (p >0.05).

CONCLUSIONS

Percutaneous nephrolithotomy is safe and effective even in patients with larger kidney stones and malrotated kidneys.

The efficacy and safety of tubeless percutaneous nephrolithotomy: a systematic review and meta-analysis

The objective of this study was to conduct a systematic review and meta-analysis to evaluate the efficacy and safety of tubeless versus standard percutaneous nephrolithotomy (PCNL). Relevant randomized or quasi-randomized controlled trials studies were identified from electronic database (Cochrane CENTRAL, Medline and EMBASE et al.). The retrieval time ended in August 2010. The quality of the included trials was assessed and the data were extracted independently by two reviewers. We divided the participants who received standard PCNL into two subgroups: small tube (4-10 F) group and big tube (14-24 F) group to reduce heterogeneity and bias. Efficacy (hospital stay time, operative time, stone-free rate) and safety (postoperative pain and analgesia requirement, postoperative fever, blood transfusion, urine leakage) were explored by using review manager v5.0. Fourteen randomized controlled trials comprising 776 subjects met the inclusion criteria. Our meta-analysis showed that there were statistically significant differences in hospital stay, postoperative analgesic requirement and urine leakage between tubeless and standard PCNL. In operative time, significant difference was found between tubeless and big tube group. No statistically significant differences were found in stone-free rate, postoperative fever, and blood transfusion between tubeless and standard PCNL. In conclusion, Tubeless PCNL was an effective and safe procedure for treatment of renal stones in selected patients, with shorter hospital stay, less analgesic requirement, lower urine leakage and without increased complications. Patients can receive great benefit from tubeless PCNL and it will become more palatable to patients as well as more cost-effective than standard PCNL in the future.

Factors affecting bleeding during percutaneous nephrolithotomy: single surgeon experience

PURPOSE

To investigate variables that affect bleeding during percutaneous nephrolithotomy (PCNL), focusing on the experience of a single surgeon.

PATIENTS AND METHODS

The records of 649 PCNL procedures that were performed by the same surgeon were reviewed retrospectively. The effect of surgical experience; patient and stone-related factors, including age, sex, hypertension, and diabetes, serum creatinine level, history of ipsilateral renal procedures, stone surface area and type, degree of hydronephrosis, preoperative hemoglobin level; operative factors, such as the calix of puncture, number of accesses, operative time; and intraoperative complications, such as pelvicaliceal system perforation on bleeding (described as decrease in hemoglobin level and need for blood transfusion), were investigated. For statistical assessment, univariate analyses and multivariate stepwise regression analyses were used.

RESULTS

A 92.3% success rate was achieved after one session PCNL. The overall blood transfusion rate was 10.8%. The number of accesses, stone type, diabetes, preoperative hemoglobin level, and operative time were the most important factors for blood transfusion requirement. In the receiver operating characteristic curve, the best cutoff point of operative time was 58 minutes for the blood transfusion requirement. Multivariate stepwise regression analyses showed that there was an association between diabetes, operative time, number of accesses, and stone type with the decrease in hemoglobin levels. No correlation between surgical experience and decrease in hemoglobin level as well as blood transfusion necessity was found.

CONCLUSIONS

Depending on the results achieved by a single surgeon, multiple access tracts, staghorn calculi, presence of diabetes, and prolonged operative time, but not surgical experience, significantly increased blood loss during PCNL.

Effect of percutaneous nephrolithotomy and tract dilatation methods on renal function: assessment by quantitative single-photon emission computed tomography of technetium-99m-dimercaptosuccinic acid uptake by the kidneys

OBJECTIVES

The aim of this study was to determine the impact of percutaneous nephrolithotomy (PCNL) and tract dilatation methods on global and regional renal function using quantitative single-photon emission computed tomography (QSPECT) of technetium-99m-dimercaptosuccinic acid ((99m)Tc-DMSA).

METHODS

Seventy-five patients undergoing PCNL between May 2008 and April 2009 were included in this randomized study. Of the 75 patients, 50 were evaluated by QSPECT of (99m)Tc-DMSA examinations before and at 3 to 6 months after surgery. This group of patients were categorized into three groups according to the dilatation technique used: group I (balloon dilator, n = 12 [24%] patients), group II (metal dilator, n = 14 [28%] patients), and group III (Amplatz dilator, n = 24 [48%] patients).

RESULTS

Of 50 renal units, new focal cortical defects on (99m)Tc-DMSA scan were seen in nine patients (18%). In six of these kidneys the site of focal defect corresponded to the access site for tract formation during PCNL (two in group II and four in group III). Total relative uptake and total area of treated kidney, for the entire group, increased from 42.2% and 42.3% preoperatively to 44.12% and 43.9% postoperatively. There was no statistically significant differences between the groups for total uptake and area of the treated kidneys before and after the procedure (p > 0.05 for each parameter).

CONCLUSIONS

QSPECT of (99m)Tc-DMSA confirms that renal function is preserved or often improved after percutaneous stone removal, and nephrostomy tract dilatation methods have similar effects on renal function.

Hemostatic sandwich to control percutaneous nephrolithotomy tract bleeding

BACKGROUND AND PURPOSE

Significant bleeding necessitating use of a tamponade balloon, embolization, or renal exploration is a rare but catastrophic complication after percutaneous nephrolithotomy (PCNL). The purpose of this study is to review the success of a novel, minimally invasive technique for controlling percutaneous tract bleeding that is refractory to conventional measures.

MATERIALS AND METHODS

A retrospective review was performed on four patients with refractory tract hemorrhage that was managed with a novel gelatin matrix hemostatic sandwich technique. In this technique, a 5F angiographic reentry catheter was placed through the kidney into the bladder and a 22F Councill-tip catheter balloon was passed over this catheter and positioned so that the inflated balloon would occlude the inner surface of the nephrostomy tract. Next, a 16F Councill-tip catheter was placed over a second wire so that the uninflated balloon was just underneath the skin surface. Gelatin matrix hemostatic sealant was then injected to fill the tract. Inflation of the outer balloon completely sealed the tract, completing the hemostatic sandwich.

RESULTS

This technique was successfully applied to four patients with tract bleeding that would not stop with pressure or a conventional nephrostomy tube alone. The average estimated blood loss was 562 mL, and three of four patients avoided transfusion. All postoperative hemoglobin values stabilized within 2 days of surgery. There were no major or minor complications after use of this technique. No patients needed angioembolization or renal exploration.

CONCLUSIONS

This novel hemostatic sandwich technique should be considered as an option for the control of refractory tract hemorrhage after PCNL.

Comparison of percutaneous nephrolithotomy using pneumatic lithotripsy (lithoclast®) alone or in combination with ultrasonic lithotripsy

PURPOSE

Percutaneous nephrolithotomy (PCNL) is the procedure of choice for treating large renal stones. Pneumatic lithotripsy (Lithoclast®) is effective regardless of the stones' composition, and ultrasonic lithotripsy allows the aspiration of small debris during lithotripsy. We investigated the efficacy and safety of PCNL via Lithoclast® alone or combined with ultrasonic lithotripsy.

MATERIALS AND METHODS

Thirty-five (group A) and 39 (group B) patients underwent Lithoclast® PCNL and combination therapy, respectively, from May 2001 to March 2010, and the two groups were compared in terms of stone size, location, and composition; operative time; average number of treatments; hospital days; hemoglobin loss; ancillary procedures; rate of device failure; and initial and total stone-free rates.

RESULTS

The two groups did not differ significantly in preoperative stone size, location, or composition; the average number of treatments; or the initial and overall stone-free rates. However, combination therapy was associated with a significantly lower operative time (181±50 vs. 221±65 min, respectively, p=0.004), number of hospital days (11.6±3.8 vs. 14.2±4.4 days, respectively, p=0.009), and average hemoglobin loss (1.12±0.61 vs. 1.39±1.02 g/dl, respectively, p=0.013). Transfusions were required in 6 patients (4 and 2 in each group, respectively), but there were no significant complications related to percutaneous access. There were 2 (5.7%) mechanical failures (Lithoclast® probe fracture) in the group A and 5 (12.8%) in the group B (2 cases of suction tube obstruction, 3 cases of overheating).

CONCLUSIONS

The combination of ultrasonic lithotripter and Lithoclast® is more effective than Lithoclast® alone because it significantly decreases operative time, hemoglobin loss, and the hospital stay. This may reflect the superior power of Lithoclast® and the ability to aspirate the debris during ultrasonic lithotripsy.

Factors affecting blood loss during percutaneous nephrolithotomy using balloon dilation in a large contemporary series

OBJECTIVE

Renal hemorrhage is a common and worrisome complication of percutaneous nephrolithotomy (PNL). We review factors affecting blood loss and transfusion requirements in a large contemporary series of patients undergoing PNL utilizing balloon dilation.

METHODS

We retrospectively reviewed all patients undergoing PNL at one institution from July 2000 to January 2008. Demographics, stone parameters, perioperative factors, complications, and stone-free rates were evaluated. Hemorrhage was estimated using hematocrit and blood transfusion requirement. Various factors were assessed for their association with blood loss using univariate models.

RESULTS

The 225 patients reviewed had a mean stone size of 3.5 +/- 1.8 cm (range, 0.6-9.0 cm), with 54 (23.4%) staghorn and 93 (40.3%) partial staghorn calculi. One hundred and seventy-five (75.8%), 173 (74.9%), and 80 (34.6%) had pelvic, lower pole, and upper pole calculi, respectively. Multiple access tracts were used in 12 (5.2%) patients, with overall stone-free and complication rates of 80.4% and 14.1%. Complications included postoperative fever in 15 patients (6.4%), clinically insignificant pleural effusion in 8 patients (3.4%), 2 (0.8%) renal artery pseudoaneurysms requiring angioembolization, and 1 (0.4%) urinoma requiring stent placement. Mean hematocrit decrease was 6.1 +/- 4.3%, with three (1.3%) patients receiving blood transfusions. On univariate analysis no other statistically significant differences were found between hematocrit decrease and stone size or location, presence of partial or complete staghorn calculi, diabetes, or number of access tracts.

CONCLUSIONS

We report a comparable stone-free rate and a lower incidence of blood transfusion among patients undergoing PNL using balloon dilation.

Two contemporary series of percutaneous tract dilation for percutaneous nephrolithotomy

Dilation of the tract for percutaneous nephrolithotomy can be performed with three different basic techniques. A retrospective outcome analysis of two techniques-metal telescoping dilation and balloon dilation-in a contemporary series of two European departments shows no significant difference in morbidity related to the dilation procedure. A literature survey that concentrates on publications with a focus on tract dilation shows that balloon dilation is the most frequently performed, but the morbidity reported for the different techniques appears identical. The three standard techniques have been developed more than 20 years ago. Very few new techniques have been added.

Percutaneous nephrolithotomy: tubeless or not tubeless?

The objective of this study is to evaluate the safety and outcomes of tubeless PCNL in comparison with standard PCNL. Since June 2002, we have performed 99 tubeless PCNL. Tubeless technique involves antegrade placement of a 6Fr double-J stent without nephrostomy tube at the end of the procedure. This series has been compared with a total of 110 patients in which revision of operative reports ruled out the presence of intraoperative conditions necessary to candidate a patient to tubeless procedure but standard PCNL was performed because prior to its introduction or because of surgeon's attitude afterward. Mean stone burden was 5.4 for standard group and 4.9 cm(2) for tubeless group, respectively. Mean BMI was 24.1 in the first group and 23.6 in the second one. In this retrospective study, complications rate, postoperative pain, length of hospitalization and convalescence were evaluated by chart review. Hematocrit drop did not differ significantly between tubeless PCNL and standard PCNL (5.5 vs. 5.9%). Conversely, there was statistically significant difference between tubeless and standard PCNL in terms of the amount of analgesics (49.5 vs. 84.2 mg), immediate postoperative patients' discomfort, hospitalization (2.2 vs. 5.3 days) and time to resume normal activities (11.0 vs. 16.5 days). In conclusion, in our series, tubeless approach did not determine increase in complication rate. Conversely, tubeless PCNL reduced analgesics' requirement, patients' discomfort, hospitalization and time to recovery. As such, at our institution, tubeless PCNL has become routine procedure that actually is feasible in almost two-third of renal calculi suitable for percutaneous treatment.