Reduced radiation exposure with the use of an air retrograde pyelogram during fluoroscopic access for percutaneous nephrolithotomy

Radiation exposure of patients during endourological procedures

PURPOSE

Considering the existing gaps in the literature regarding patient radiation dose (RD) and its associated risks, a systematic review of the literature on RD was conducted, focusing on percutaneous nephrolithotomy (PCNL), extracorporeal shock wave lithotripsy (SWL), and ureteroscopy (URS).

METHODS

Two authors conducted a literature search on PubMed, Web of Science, and Google Scholar to identify studies on RD during endourological procedures. Two thousand two hundred sixty-six articles were screened. Sixty-five publications met the inclusion criteria using the PRISMA standards.

RESULTS

RD was generally highest for PCNL, reaching levels up to 33 mSv, 28,700 mGycm2, and 430.8 mGy. This was followed by SWL, with RD reaching up to 7.32 mSv, 13,082 mGycm2, and 142 mGy. URS demonstrated lower RD, reaching up to 6.07 mSv, 8920 mGycm2, and 46.99 mGy. Surgeon experience and case load were inversely associated with RD. Strategies such as optimizing fluoroscopy settings, implementing ultrasound (US), and following the ALARA (As Low As Reasonably Achievable) principle minimized RD.

CONCLUSIONS

This is the first systematic review analyzing RD, which was generally highest during PCNL, followed by SWL and URS. There is no specific RD limit for these procedures. Implementation of strategies such as optimizing fluoroscopy settings, utilizing US, and adhering to the ALARA principle proved effective in reducing RD. However, further research is needed to explore the factors influencing RD, assess their impact on patient outcomes, and establish procedure-specific reference levels for RD.

Ultrasound-Guided PCNL - Why Are We Still Performing Exclusively Fluoroscopic Access?

PURPOSE OF REVIEW

While urologists are traditionally taught to perform percutaneous nephrolithotomy (PCNL) utilizing exclusively fluoroscopy, ultrasound has emerged as a safe alternative. This article showcases the major reasons why ultrasound-guided access should be considered the first-line approach for performing access for PCNL.

RECENT FINDINGS

There continues to be a need to further reduce radiation exposure in the management of kidney stone patients. This review showcases how performing ultrasound-guided PCNL has been associated with a shorter learning curve, increased patient safety, and the ability to perform x-ray free PCNL. Ultrasound-guided PCNL is not only an achievable skill for urologists to learn but provides multiple advantages over traditional fluoroscopic access. As every effort should be given to help reduce radiation exposure for kidney stone patients as well as performing surgeons and operating theater personnel, endourologists should strive to add this technique to their armamentarium.

New contrast agents for photoacoustic imaging and theranostics: Recent 5-year overview on phthalocyanine/naphthalocyanine-based nanoparticles

The phthalocyanine (Pc) and naphthalocyanine (Nc) nanoagents have drawn much attention as contrast agents for photoacoustic (PA) imaging due to their large extinction coefficients and long absorption wavelengths in the near-infrared region. Many investigations have been conducted to enhance Pc/Ncs' photophysical properties and address their poor solubility in an aqueous solution. Many diverse strategies have been adopted, including centric metal chelation, structure modification, and peripheral substitution. This review highlights recent advances on Pc/Nc-based PA agents and their extended use for multiplexed biomedical imaging, multimodal diagnostic imaging, and image-guided phototherapy.

Air vs contrast pyelogram for initial puncture access in percutaneous nephrolithotomy: a randomized controlled trial

Percutaneous nephrolithotomy (PCNL) is a standard procedure for large renal stones. Contrast (traditionally) as well as air is being used to delineate pelvi-calyceal system (PCS) to perform initial puncture. Contrast, when used has certain disadvantages including poor differentiation of anterior and posterior calyces. In this interim analysis of 122 patients of a prospective study subjects were stratified in two groups: in group 1, contrast was used while in group 2, air was used to delineate PCS. Out of 122,103 patients underwent puncture by contrast or air exclusively while 19 patients required mix of contrast and air (14 patients failed puncture using contrast while 5 using air). Mean dosage of radiation exposure (8.43 vs. 14.26 mGy), duration of radiation exposure (0.66 vs. 1.02 min), access time (3.72 vs. 5.84 min), were less in group 2 as compared to group 1. 84.5% of patients underwent puncture in single attempt in group 2 as compared to 56.25% in group 1. Five patients had post-operative fever and one had trans-pleural tract dilation. Complete stone clearance was seen in 94.8% of patients using air to only 75% of patients using contrast. Conclusion: Air pyelogram is a feasible, safe, cost effective and efficient access alternative to contrast pyelogram and in difficult situation a mixture of both is better than using one.

Air embolism during percutaneous nephrolithotomy using air pyelogram during initial access: Does it really occur?

INTRODUCTION

In the present era, percutaneous nephrolithotomy (PCNL) is the standard treatment for large (>2 cm) renal or staghorn renal stones. Both air and iodinated contrast has been used to opacify the pelvicalyceal system (PCS) before the dilatation of the tract. There are rare reports of air embolism following air pyelogram on mere presumptions.

MATERIALS AND METHODS

This is a prospective observational study. A total of 164 patients underwent PCNL in which air was used to opacify the PCS by placing a ureteric catheter for initial access.

RESULTS

None of our patients developed any complication during the procedure or in the postoperative period, which could be attributed to air embolism.

CONCLUSIONS

The present study ascertains that using air for opacification of PCS for initial puncture access is a safe and acceptable alternative to iodinated contrast.

Radiation-free flexible ureteroscopy for kidney stone treatment

Objectives: To evaluate the safety and effectiveness of flexible ureterorenoscopy (fURS) with holmium laser lithotripsy for treating kidney stones without fluoroscopy as method of best practice for patients and endourologists.

Patients and Methods: All patients treated for kidney stones by fURS with holmium laser lithotripsy from February 2016 to February 2017 were retrospectively evaluated. The patients’ demographic characteristics, stone features (size, number, and location), surgical variables (use of fluoroscopy, operative and fluoroscopy time), complications, and success rate (employing stone-free rate [SFR]), were included in the analysis.

Results: In all, 100 patients met the inclusion criteria: 33 fURS were performed under fluoroscopy (Group 1) and 67 without it (Group 2). The mean operating time was 94.33 vs 98.29 min (P = 0.888), respectively. The mean stone volume was 78.5 vs 82.4 mL (P = 0.885), respectively. The SFR was 63.6% and 64.2% (P = 0.771), the perioperative complications rate was 18.2% vs 11.9% (P = 0.285), and the postoperative complications rate was 24.2% and 10.4%, in groups 1 and 2 respectively (P = 0.174).

Conclusions: fURS with holmium laser lithotripsy without fluoroscopy was a feasible and safe treatment for kidney stones. There was no difference between the use of fluoroscopy or not regarding complications or SFR. Thus, we can reduce the risks of radiation exposure to patients and medical staff whilst maintaining surgical success. However, multicentre randomised controlled studies are necessary to evaluate fluoroless URS further and to confirm our present results.

Abbreviations: PTFE: polytetrafluoroethylene; SFR: stone-free rate; (f)URS: (flexible) ureterorenoscopy/ureterorenoscopies; US: ultrasonography

Radiation Mitigation Techniques in Kidney Stone Management

Patients with nephrolithiasis are exposed to significant quantities of ionizing radiation with the potential to cause secondary malignancy. This risk is magnified by the high recurrence rate of nephrolithiasis. In this article, we identify the risks of ionizing radiation as they pertain to patients with nephrolithiasis. We then identify evidence-based techniques for mitigating patient radiation exposure in the preoperative, intraoperative, and postoperative settings. Key factors include limiting the use of computed tomographic imaging, appropriate modulation of fluoroscopy settings, and minimizing rates of stone recurrence.

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.

A Comparative Study of Antegrade Air Pyelogram and Retrograde Air Pyelogram for Initial Puncture Access during Percutaneous Nephrolithotomy

INTRODUCTION

Access into the collecting system is considered to be the most critical step for Percutaneous Nephrolithotomy (PCNL).

AIM

The present study provides a comparative view into antegrade air pyelography and retrograde air pyelography procedures for percutaneous renal access.

MATERIALS AND METHODS

A cross-sectional study was conducted on 100 patients with radiopaque renal calculi indicated for PCNL procedure. These patients were randomly assigned to two groups namely antegrade air pyelogram group (Group I) and retrograde air pyelogram group (Group II). In antegrade air pyelogram group, the collecting system was delineated by targeting the renal stone using a 22 gauge spinal needle where the patients were in the prone position. In another group, the collecting system was delineated by retrograde air pyelogram under fluoroscopy guidance. The method of tract dilatation and stone extraction were the same in both groups for comparison of outcome and complication.

RESULTS

The mean age of patients was 41.7±13 and 41.4±13.6 years in Group-I and Group-II respectively. The male to female ratio in Groups I and II was 35/15 (70.00%) and 38/12 (76.00%) respectively. In Group-I the average duration of access was 2.66±1.0 minutes after prone positioning whereas it was recorded to be 19.48±5.0 minutes in Group-II, after lithotomy followed by prone positioning of the patient. Duration of radiation exposure was almost similar in both groups. Additional procedural cost was significantly higher in Group II.

CONCLUSION

Our study indicated that access for PCNL using antegrade air pyelogram can be a cost-effective and acceptable alternative to retrograde air pyelogram with decreased access time.

A novel dosimeter for measuring the amount of radiation exposure of surgeons during percutaneous nephrolithotomy: Instadose™

Introduction

The aim of this study was to demonstrate the efficacy of Instadose™, a novel dosimeter designed for radiation workers to provide a measurement of the radiation dose at any time from any computer; to determine the amount of radiation exposure during percutaneous nephrolithotomy (PNL); and to evaluate the factors that affect the amount of radiation exposed.

Material and methods

Two experienced surgeons wore Instadose™ on the outer part of their lead aprons during the PNL procedures performed between December 2013 and July 2014. Patient demographics and stone characteristics were noted. Factors affecting radiation dose were determined. Fluoroscopic screening time was compared with the amount of radiation in order to validate the measurements of Instadose™.

Results

Overall, 51 patients with a mean age of 43.41 ±18.58 (range 1–75) years were enrolled. Male to female ratio was 35/16. The amount of radiation was greater than 0.01mSv in only 19 (37.25%) cases. Stone location complexity (p = 0.380), dilation type (p = 0.584), stone size (p = 0.565), dilation size (p = 0.891) and access number (p = 0.268) were not associated with increased radiation exposure. Instadose™ measurements were correlated with fluoroscopic screening time (r = 0.519, p = 0.001).

Conclusions

Instadose™ is a useful tool for the measurement of radiation exposure during PNL. The advantage of measuring the amount of radiation exposure after each PNL operation is that it may aid urologists in taking appropriate precautions to minimize the risk of radiation related complications.

Management of anterior caliceal stones >15 mm

Anterior caliceal stones represent a challenge to endourologist to select the best modality of management with the least morbidity. To study different treatment modalities of management of anterior caliceal stones >15 mm. It is an observational prospective study of patients with anterior caliceal stones more than 15 mm. Inclusion criteria were patients with isolated anterior caliceal stones, or branched anterior caliceal stones with posterior caliceal extension. Patients were evaluated using non-contrast CT preoperatively. They were divided into three groups: group 1 underwent PCNL through posterior caliceal puncture in cases with wide anterior calyx infundibulum or obtuse infundibulopelvic pelvic, group 2 underwent PCNL through anterior caliceal access in cases with narrow infundibulum or acute infundibulopelvic angel and group 3 underwent flexible ureteroscopy and laser lithotripsy. Intraoperative and postoperative findings were recorded and compared. Eighty eight patients were included in this study, Group 1 (44 patients) group 2 (28 patients), and group 3 (16 patients). Operative time was not significantly different across the three groups (68 ± 11.5, 72 ± 9 and 74 ± 11 min in group 1, 2 and 3, respectively, P = 0.053). Fluoroscopy time was significantly shorter for group 3 (2 ± 0.5 m, P = 0.0001) compared to group 1 and 2 (5.6 ± 4.6 and 4.5 ± 1.4 min), respectively. There were no significant differences in stone-free rates after initial treatment between the three groups; 84, 82, and 69 %, in groups 1, 2 and 3, respectively (P = 0.4). Postoperative hemoglobin drop was noted to be highest for group 2 and lowest for group 3 which was significantly different (1.7 ± 0.8, 2.2 ± 1.1, and 0.3 ± 0.3 g/dl, for patients in groups 1, 2 and 3 respectively, P = 0.0001). Group 2 showed the highest post-operative complication rate (21 %) in comparison to group 1 (11 %) and group 3 (6 %), however, differences were not statistically significant (P = 0.3). PCNL through posterior or anterior caliceal puncture is an excellent modality to treat anterior caliceal stones with high stone clearance rate. Despite the higher chance of bleeding with anterior caliceal puncture, it is still inevitably needed in difficult anterior caliceal stones with unfavorable anatomy. RIRS is a good alternative to PCNL with the advantage of less radiation exposure and less bleeding.

Evaluating Parameters Affecting Fluoroscopy Time During Percutaneous Nephrolithotomy: Focus on the Predictive Role of Guy's, S.T.O.N.E., and CROES Scoring Systems

OBJECTIVE

To identify parameters predicting prolonged fluoroscopy time (FT) during percutaneous nephrolithotomy (PCNL) and to evaluate the predictive ability of Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram.

PATIENTS AND METHODS

We evaluated 153 consecutive patients who underwent a PCNL by a single experienced surgeon. Several preoperative, intraoperative, and postoperative parameters, including the three scoring systems, were assessed for their ability to predict FT.

RESULTS

FT was significantly associated with stone burden, stone location, number of stones, number of punctures, and number of tracts. It was also significantly associated with all scoring systems. Fluoroscopy use was significantly higher in patients who were effectively treated in these with longer hospitalization, probably reflecting case complexity. No association was found with postoperative complications.

CONCLUSIONS

FT during PCNL can be affected by several parameters. Identifying the ones that can affect FT can lead to fluoroscopy and radiation exposure decrease. Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram can all predict complexed cases and the need for increased FT.

Dose and image quality of cone-beam computed tomography as compared with conventional multislice computed tomography in abdominal imaging

OBJECTIVES

Recent technical developments have facilitated the application of cone-beam computed tomography (CBCT) for interventional and intraoperative imaging. The aim of this study was to compare the radiation doses and image quality in CBCT with those of conventional multislice spiral computed tomography (MSCT) for abdominal and genitourinary imaging.

METHODS

Different CBCT and MSCT protocols for imaging soft tissues and hard-contrast objects at different dose levels were investigated in this study. Local skin and organ doses were measured with thermoluminescent dosimeters placed in an anthropomorphic phantom. Moreover, the contrast-to-noise ratio, the noise-power spectrum, and the high-contrast resolution derived from the modulation transfer function were determined in a phantom with the same absorption properties as those of anthropomorphic phantom.

RESULTS

The effective dose of the examined abdominal/genitourinary CBCT protocols ranged between 0.35 mSv and 18.1 mSv. As compared with MSCT, the local skin dose of CBCT examinations could locally reach much higher doses up to 190 mGy. The effective dose necessary to realize the same contrast-to-noise ratio with CBCT and MSCT depended on the MSCT convolution kernel: the MSCT dose was smaller than the corresponding CBCT dose for a soft kernel but higher than that for a hard kernel. The noise-power spectrum of the CBCT images at tube voltages of 85/90 kV(p) is at least half of that of images measured at 103/115 kV(p) at any arbitrarily chosen spatial frequency. Although the pixel size and slice thickness of CBCT were half of those of the MSCT images, high-contrast resolution was inferior to the MSCT images reconstructed with a hard convolution kernel.

CONCLUSIONS

As compared with MSCT using a medium-hard convolution kernel, CBCT produces images at medium noise levels and, simultaneously, medium spatial resolution at approximately the same dose. It is well suited for visualizing hard-contrast objects in the abdomen with relatively low image noise and patient dose. For the detection of low-contrast objects at standard tube voltages of approximately 120 kV(p), however, MSCT should be preferred.

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.

Limiting radiation exposure during percutaneous nephrolithotomy

BACKGROUND AND PURPOSE

An increase in the prevalence of urologic stone disease and the refinement of endourologic techniques has seen a concomitant rise in the use of fluoroscopy during surgery. As such, there has been increasing concern in regard to the intraoperative radiation exposure to both clinicians and patients. The objective of the study was to audit contemporary data on radiation exposure during percutaneous nephrolithotomy (PCNL), in comparison with published series, and demonstrate that relatively low levels are achievable with clinical vigilance and attention to technique Methods: A retrospective analysis was performed of all PCNLs undertaken between July 2005 and December 2011. The primary outcome measure was fluoroscopy times and associated radiation exposure, measured as dose area product (DAP). No statistical analysis was undertaken.

RESULTS

Between July 2005 and October 2011, 376 PCNLs were performed. Data were available on 348 patients including 16 pediatric patients. Mean DAP and screening time (ST) over the whole study period were 45 cGy/cm(2) and 96s, respectively. On a year by year basis, the ST and DAP reduced from 917 to 375 and from 180 to 65, respectively. We acknowledge the limitation of this being a retrospective case series.

CONCLUSIONS

This study represents the largest series to date on radiation exposure during PCNL and compares favorably with other published series, including those purporting novel techniques. Subtle changes in surgical technique and experience over time can lead to low screening times and can be potentially achieved by all operators performing PCNL within a high throughput center. It is now recognized that surgical outcome in stone surgery is related to caseload. The radiation dose the patient receives during PCNL is increasingly recognized to be an important factor and can be reduced by careful technique and experience.

Assessing radiation exposure during endoscopic-guided percutaneous nephrolithotomy

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) may be associated with significant ionizing radiation exposure for patients and operating room staff. Endoscopic-guided PCNL (ePCNL) is a technique that may be associated with less radiation exposure. This study examines ePCNL-related radiation exposure (fluoroscopy time, effective dose) and investigates variables that may predict increased exposure.

METHODS

A retrospective review of all consecutive ePCNLs performed at our institution, by a single surgeon, was conducted between November 2011 and November 2013. Patient demographics, stone characteristics and perioperative details were recorded, including radiation exposure. Pearson and Spearman correlation were used to assess variables correlated with radiation exposure.

RESULTS

In total, 55 ePCNL cases were included in the study. The mean age was 60 ± 15 years, mean body mass index (BMI) 30.0 ± 6.4 kg/m(2) and mean stone size 3.2 × 2.1 cm. Seven cases (13%) involved complete staghorn stones, and 69% involved supracostal punctures. The mean fluoroscopy time was 3.4 ± 2.3 minutes, mean ED 2.4 ± 1.9 mSv. The treatment success rate, assessed 1-week postoperatively, was 87.3% and 7.3% of cases required ancillary procedures. The overall complication rate was 29%, but only 3 cases (5.5%) were Clavien ≥3. Longer fluoroscopy time correlated with increased stone size (p < 0.01), longer operative time (p < 0.01) and lower treatment success rates (p < 0.01); higher effective dose correlated with longer fluoroscopy time (p < 0.01) and increased skin-to-stone distance (p < 0.01). BMI did not correlate with fluoroscopy time or effective dose.

CONCLUSIONS

Outcomes of ePCNL are comparable to traditional PCNL techniques and may be associated with lower radiation exposure, particularly beneficial for patients with higher BMI.

As low as reasonably achievable: Methods for reducing radiation exposure during the management of renal and ureteral stones

Imaging for urolithiasis has evolved over the past 30 years. Currently, non-contrast computed tomography (NCCT) remains the first line imaging modality for the evaluation of patients with suspected urolithiasis. NCCT is a dominant source of ionizing radiation for patients and one of its major limitation. However, new low dose NCCT protocols may help to reduce the risk. Fluoroscopy use during operating room (OR) surgical procedures can be a substantial source of radiation for patients, OR staff and surgeons. It is important to consider the amount of radiation patients are exposed to from fluoroscopy during operative interventions for stones. Radiation reduction can be accomplished by appropriate selection of imaging studies and multiple techniques, which minimize the use of fluoroscopy whenever possible. The purpose of this manuscript is to review common imaging modalities used for diagnosing and management of renal and ureteral stones associated with radiation exposure. We also review alternatives and techniques to reduce radiation exposure.

Evaluation of a novel fascial dilator modified with scale marker in percutaneous nephrolithotomy for reducing the X-ray exposure: a randomized clinical study

OBJECTIVE

To evaluate the role of the fascial dilators modified with a scale marker in reducing fluoroscopy time during percutaneous nephrolithotomy (PCNL).

METHOD

In a randomized clinical trial, eligible 100 consecutive patients anticipated to undergo single-tract PCNL were randomly assigned into two groups by the closed envelope method, to compare the efficacy and safety of the modified scale fascial dilator (group 1, n=50) and traditional nonscale fascial dilator (group 2, n=50) with respect to the X-ray exposure duration as well as the outcome of PCNL.

RESULTS

There was no significant difference between group 1 and group 2 regarding to the initial successful access rate (100% v 96%), operative time (79.4 v 83.7 minutes), the initial stone-free rate (82% v 81.3%), complications (24% v 20%), and bleeding required blood transfusion (4% v 6%) (all p>0.05). The mean operative duration and fluoroscopic time for tract dilation in group 1 and group 2 were 164.4 ± 19 seconds v 168.3 ± 14 seconds, and 3.2 ± 0.9 seconds v 22.2 ± 4.6 seconds, (p=0.250 and p<0.001), respectively.

CONCLUSIONS

Compared to the use of nonscaled dilators, using the scaled fascial dilators for a percutaneous access in PCNL was found to be associated with less radiation hazards along with similar stone-free rate and complications.

Preoperative evaluation of pediatric kidney stone prior to percutaneous nephrolithotomy: is computed tomography really necessary?

The objective of the study was to investigate the precise role of computed tomography (CT) in preoperative radiologic evaluation and surgical planning of kidney stone in children prior to percutaneous nephrolithotomy (PNL). A total of 113 pediatric patients (aged ≤18 years) undergoing PNL for renal stone(s) in three referral hospitals between March 2010 and August 2012 were retrospectively evaluated. Depending on the preoperative radiologic evaluation, patients were divided into two groups. Those evaluated with CT were classified as group-1 (n = 50) and the remaining cases undergoing intravenous urography (IVU) examination were classified as group-2 (n = 63). Patient- and procedure-related variables and perioperative measures were compared between the groups. The mean age, stone size and localization were similar in both groups (p = 0.07, p = 0.57, p = 0.6, respectively). Although the postoperative hemoglobin drop was found to be significantly higher in group-2 (1.5 ± 1.3 vs. 0.9 ± 0.6 g/dL, p = 0.005), the mean operation time, fluoroscopic screening time, access number, overall success and complication rates were comparable (p = 0.06, p = 0.94, p = 0.75, p = 041, and p = 0.41, respectively). However, the mean hospitalization time was significantly prolonged in group-2 than in group-1 (p = 0.03). Our findings clearly demonstrate that, despite the key role of preoperative CT in particular patients with anatomically abnormal kidneys, IVU is a valuable alternative imaging modality with comparable radiation doses in children.

Prospective evaluation of complications using the modified Clavien grading system, and of success rates of percutaneous nephrolithotomy using Guy's Stone Score: A single-center experience

INTRODUCTION AND OBJECTIVES

To prospectively document the perioperative complications of percutaneous nephrolithotomy (PCNL) using the modified Clavien grading system. Evaluation of complications and clearance rates according to stone complexity using the validated Guy's Stone Score (GSS) was also done.

MATERIALS AND METHODS

A total of 221 renal units underwent 278 PCNL procedures at a urology resident training center between September 2010 and September 2011 and data were recorded prospectively in our registry. Patients with co-morbidities like diabetes, renal failure, hypertension and cardiopulmonary diseases were excluded. Stone complexity was classified according to the GSS while peri-operative complications were recorded using the modified Clavien grading system.

RESULTS

Two hundred and forty-five complications were encountered in 278 PCNL procedures involving 116 renal units (41.72%). Complications of Grades 1, 2, 3a, 3b, 4a, 4b and 5 were seen in 52 (18.7%), 122 (43.8%), 42 (15.1%), 18 (6.4%), 6 (2.1%), 4 (1.4%) and 1 (0.3%) renal units respectively. There were 68, 98, 50 and 5 renal units in GSS I, II, III and IV groups, respectively. All grades of complications were more common in GSS III and IV (P<0.05). For GSS I, II, III and IV 100%, 74%, 56% and 0% of renal units, respectively, were stone-free after one session and 0%, 24%, 44% and 60% respectively needed two sessions to be stone-free.

CONCLUSION

Although the complication rates were higher most were of low grade and self-limiting. Complications were significantly more common with higher GSS and the GSS effectively predicted stone-free rates.

Is the Percutaneous Nephrolithotomy Procedure Complicated in Patients with Anterior Caliceal Stones?

<b><i>Objectives:</i></b> It was the aim of this study to evaluate and compare the outcomes of percutaneous nephrolithotomy (PNL) for the treatment of posterior and anterior caliceal stones. <b><i>Patients and Methods:</i></b> We performed a retrospective analysis of 86 patients with isolated caliceal stones who underwent PNL between 2011 and 2012. The patients were classified into two groups according to the localization of the stone, either in the anterior (group 1, n = 41) or posterior (group 2, n = 45) calyx, on axial plane computed tomography. <b><i>Results:</i></b> The mean age, male/female ratio and stone size and location were similar in both groups. Fluoroscopy, operation time and duration of hospitalization were also similar between groups. Patients in group 1 had a greater postoperative hemoglobin drop than patients in group 2. Blood transfusion was required for 5 patients in group 1 and for 4 patients in group 2. In addition, open conversion was required for 2 patients in group 1 during the early postoperative period because of extensive bleeding. Hemodynamics were stabilized with angioembolization in 2 patients with prolonged hematuria in group 1. The overall success and complication rates were similar in both groups. <b><i>Conclusion:</i></b> Although the postoperative hemoglobin drop did not significantly differ between groups, hemorrhaging was more severe in patients with anterior caliceal stones than in those with posterior caliceal stones.

Imaging techniques for stone disease and methods for reducing radiation exposure

Imaging plays a critical role in the evaluation of patients with urolithiasis. It is essential for the diagnosis of stones and provides important information to aide in determining the appropriate treatment of renal or ureteral calculi. Imaging for urolithiasis has evolved over the past 30 years. Currently, noncontrast computed tomography remains the first-line imaging modality for the evaluation of patients with suspected urolithiasis. Proper imaging modality selection helps to minimize radiation exposure. Following the principles of As Low As Reasonably Achievable in the operating room can help reduce the amount of radiation patients are exposed to from fluoroscopy.

Risk reduction strategy for radiation exposure during percutaneous nephrolithotomy

PURPOSE OF REVIEW

To discuss the risk of radiation exposure to patients with nephrolithiasis. To review the risk factors for increased radiation exposure to patients during percutaneous nephrolithotomy (PNL) from fluoroscopy. To review the techniques to reduce patient radiation doses during PNL.

RECENT FINDINGS

Patients with nephrolithiasis are at risk for significant radiation exposure from diagnostic imaging. Fluoroscopy used during surgical treatment of nephrolithiasis also contributes to patient radiation exposure. On average, PNL with fluoroscopy exposes patients to more radiation than a noncontrast computed tomography of the abdomen and pelvis. Risk factors for increased radiation during PNL include obesity, larger stone size and increased access tracts. Following the principles of As Low As Reasonably Achievable, use of air instead of contrast for retrograde pyelogram and use of ultrasound all reduce radiation exposure during PNL.

SUMMARY

It is important to be aware of the amount of radiation patients with nephrolithiasis receive. These patients are at risk for multiple imaging studies and multiple procedures during their lifetime. Whenever possible, the techniques outlined in this review should be implemented to reduce the amount of radiation to which patients are exposed during PNL.

Impact of percutaneous renal access technique on outcomes of percutaneous nephrolithotomy

BACKGROUND AND PURPOSE

Percutaneous nephrolithotomy (PCNL) is regarded as the gold standard for the treatment of patients with renal stones larger than 2 cm in diameter. Creating a percutaneous renal access is the initial and probably the most important step in performing a PCNL. Two primary methods of obtaining proper percutaneous renal access under fluoroscopic guidance are described: The "triangulation" and the "eye of the needle" techniques. In this article, we compare these two techniques in terms of success and complication rates.

PATIENTS AND METHODS

From October 2010 to May 2011, 80 patients with simple renal stones were prospectively randomized into two groups according to the percutaneous renal access technique used for PCNL. Patients in group 1 (n=40) were assigned to the eye of the needle technique, and patients in group 2 (n=40) were assigned to the triangulation method. Patients needing multiple access points were excluded from the study. The preoperative, operative, and postoperative follow-up findings were thereafter analyzed and compared.

RESULTS

No significant difference between the two groups was detected in terms of patient demographics (mean patient age, body mass index, stone size, or stone location). The operation time, fluoroscopic screening time (FST), and duration of hospitalization were similar in both groups (P=0.52, P=0.32, P=0.26, respectively). Patients in group 1 had a larger drop in hematocrit postoperatively than patients in group 2 (7.6 ± 3.7 vs 4.8 ± 2.1, P=0.001). The blood transfusion rate (7.5%) was similar in both groups, however. Although the complication rate was higher in group 1 than group 2, no significant difference was detected (20% vs 15%, P=0.76).

CONCLUSIONS

The present study demonstrates that PCNL can be performed safely using two different percutaneous access techniques. The two techniques studied in this trial had similar FSTs, operation and hospitalization times, success rates, and complication rates.

ECIRS (Endoscopic Combined Intrarenal Surgery) in the Galdakao-modified supine Valdivia position: a new life for percutaneous surgery?

BACKGROUND

Percutaneous nephrolithotomy (PNL) is still the gold-standard treatment for large and/or complex renal stones. Evolution in the endoscopic instrumentation and innovation in the surgical skills improved its success rate and reduced perioperative morbidity. ECIRS (Endoscopic Combined IntraRenal Surgery) is a new way of affording PNL in a modified supine position, approaching antero-retrogradely to the renal cavities, and exploiting the full array of endourologic equipment. ECIRS summarizes the main issues recently debated about PNL.

METHODS

The recent literature regarding supine PNL and ECIRS has been reviewed, namely about patient positioning, synergy between operators, procedures, instrumentation, accessories and diagnostic tools, step-by-step standardization along with versatility of the surgical sequence, minimization of radiation exposure, broadening to particular and/or complex patients, limitation of post-operative renal damage.

RESULTS

Supine PNL and ECIRS are not superior to prone PNL in terms of urological results, but guarantee undeniable anesthesiological and management advantages for both patient and operators. In particular, ECIRS requires from the surgeon a permanent mental attitude to synergy, standardized surgical steps, versatility and adherence to the ongoing clinical requirements. ECIRS can be performed also in particular cases, irrespective to age or body habitus. The use of flexible endoscopes during ECIRS contributes to minimizing radiation exposure, hemorrhagic risk and post-PNL renal damage.

CONCLUSIONS

ECIRS may be considered an evolution of the PNL procedure. Its proposal has the merit of having triggered the critical analysis of the various PNL steps and of patient positioning, and of having transformed the old static PNL into an updated approach.

Incidence, prevention, and management of complications following percutaneous nephrolitholapaxy

CONTEXT

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

OBJECTIVE

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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