One-shot Dilation Research Articles

What is the safe and effective dilator number during access in PCNL? Three-shot dilation versus classical sequential Amplatz dilation

BackgroundAlthough PCNL has been used for a long time to treat nephrolithiasis, there is still contradictory information concerning the use of the dilation method. In this study, we aimed to compare conventional sequential Amplatz dilatation (SAD) using ten dilators and a method using three dilators (12, 20, and 30 Fr), which we named “three-shot dilatation” (3SD), in terms of fluoroscopy time (FT), operation time, bleeding and stone-free rates.MethodsThe study included patients who underwent PCNL with the SAD and 3SD methods. A different surgeon with extensive endourology experience applied each technique. One of the surgeons operated on the patients using the SAD method with ten dilators, and the other surgeon performed the operations using the 3SD method involving three Amplatz dilators (12, 20, and 30 Fr).ResultsA total of 283 patients, 138 in the 3SD group and 145 in the SAD group, were included in the study. The mean age of the patients was 47.32 ± 13.71 years. There was no statistically significant difference between the two groups regarding preoperative characteristics (p > 0.05). The FTs of access 2, total access, and total operation were significantly shorter in the 3SD group (p = 0.0001). The decrease in hemoglobin was statistically significant in the 3SD group compared to the SAD group (p = 0.022), while the blood transfusion requirements of the groups were similar (p = 0.176). There was no statistically significant difference between the two groups regarding stone-free rates (p = 0.973). In four patients in the SAD group, re-access was necessary due to the loss of passage due to the guide wire slipping out of its place.ConclusionIntraoperative FT can be shortened using the described 3SD method without compromising surgical safety. However, this method can be used as an intermediate step in the transition to one-shot dilation by surgeons experienced in performing SAD.

Endoscopic dilation using two guidewires: a novel approach for establishing access tract during percutaneous nephrolithotomy under ultrasonographic guidance.

To evaluate the efficacy and safety of a novel endoscopic dilation (END) method during percutaneous nephrolithotomy under ultrasonographic guidance. We retrospectively reviewed the clinical records of 138 patients who underwent percutaneous nephrolithotomy from June 2020 to December 2021. The patients were divided into three groups based on the method of nephrostomy tract creation: those who underwent fascial Amplatz serial fascial dilation (AMD) (n = 45), one-shot dilation (OSD) (n = 45), and END (n = 48). For END, a 20-Fr dilator with sheath was accessed over the first guidewire. A second guidewire was inserted into the collecting system via the endoscope. The nephroscope was then accessed to enlarge the renal puncture point using both guidewires. Demographic variables and important intraoperative and postoperative findings were compared among the three groups. The preoperative characteristics were similar among the three groups. The END group had a significantly shorter access time than both the AMD and OSD groups and significantly less severe hemoglobin loss than the OSD group. There were no significant differences in the other important perioperative findings. Use of this novel END method with two guidewires may be associated with less blood loss and a reduced access time.

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

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

The feasibility and safety of one-shot dilatation compared to conventional sequential dilatation in tubeless percutaneous nephrolithotomy: a prospective randomized controlled study

To study the feasibility and safety of One-Shot Dilatation (OSD), versus serial sequential dilatation in tubeless Percutaneous Nephrolithotomy (PCNL). One Hundred and Fifty patients were randomised into two groups; Group A (One-Shot Dilatation), Group B (Serial Dilatation). Twenty-one patients were excluded from the study. Detailed history was taken and full physical examination was performed. Pre-operative routine laboratory investigations were done. Also, non-contrast Computed Tomography of the Urinary Tract (CTUT) and plain urinary tract x-ray were done. Intra-operative assessments of dilatation, total operative, total fluoroscopy and fluoroscopy during dilatation durations were recorded, as well as estimated blood loss. Post-operatively haemoglobin, creatinine levels and CTUT were performed for all patients. Complications, as urinary leakage time, analgesic requirements and hospitalization time were measured. There were statistically significant differences in the intraoperative durations, where Group A had shorter dilatation time, fluoroscopy time during dilatation and total operative time. Group B had a higher complications rate than Group A; 37.9%, 11.3%, respectively. Also, Group B showed haemoglobin drop by 0.44 mg/dl higher than Group A. More doses of analgesia were required for Group B. Hospitalization time and rate of urinary leakage were both in favour of Group A. For patients undergoing Tubeless PCNL, we have concluded that one-shot dilatation seems to be a safer and more feasible technique than Serial dilatation.

Serial dilation using alken dilators versus one-shot dilation technique for access in percutaneous renal surgery: a randomized prospective study

Serial dilation using alken dilators versus one-shot dilation technique for access in percutaneous renal surgery: a randomized prospective study

Single vs Serial Dilatation of Access Tract in Percutaneous Nephrolithotomy: A Randomised Control Study on Its Feasibility and Effects in Management of Renal Calculi

Introduction: Percutaneous Nephrolithotomy (PCNL) is the recommended treatment for renal calculi. The tract dilatation method has a significant effect on the surgical outcome. One- shot Dilatation (OSD) involves dilatation using the dilator and Amplatz of desired size, while Serial Dilatation (SD) involves increasing the dilator size progressively up to the desired size. Aim: To compare the success and complication rates of SD techniques and OSD technique using Amplatz dilators. Materials and Methods: This was a randomised control study, conducted in a Tertiary Care Centre, of Bharati Hospital, Pune, Maharashtra, India, from March 2020 to December 2021. A non-probability sampling technique was followed and hundred consecutive patients of renal calculus were included in the study. The patients were then randomly allocated using random number table to undergo PCNL via a One-shot Dilatation (OSD-group I) or Serial Dilatation (SD-group II) of access tract. After the initial work up, the patients underwent PCNL, tract dilated as per the group enrolled. The two groups were then compared for patient demographics, stone characteristics (size, number, location), dilatation type, access time, tract size, access quality, bleeding at entry, operative time, radiation time, postoperative analgesic requirement, tube or tubeless procedure, time for removal of the nephrostomy tube and double ‘J’ stent placement. The statistical inference was obtained by Analysis of Variance (ANOVA) , Kruskall- Wallis t-test, Fisher’s exact test or Chi-square test. Significance was termed as a p-value&lt;0.05. The analysis was performed on Pvalue.io. Results: In the patients from group I, there was lesser blood loss (Haemoglobin drop 0.9 vs 1.3 gm/dL), clot at entry( 6% vs 28%), and radiation exposure ( 60.9 sec vs 94.1 sec) as compared to group II patients. This was also reflected in reduced mean operative time (46.2 min vs 57.1 min) and lesser duration of hospital stay (3 vs 4 days) among group I patients. conclusion: The OSD was found to be superior to SD using Amplatz dilatation in PCNL in terms of having reduced blood loss and reduced exposure to radiation for the patient.

Feasibility of one-shot dilation access in the pediatric age group.

To compare sequential fascial dilation (SFD) versus one-shot dilation (OSD) in the pediatric patients undergoing percutaneous nephrolithotomy. The present study is an observational study. The study subjects were divided into two groups. In group 1, renal dilation was done using the SFD and in group 2, renal dilation was done using the OSD. The amount of time exposed to radiation during access to pelvicalyceal system was estimated. Complications, stone free rates, ancillary procedures for residual stones and hospital stay were compared. Modified Clavien-Dindo classification was used for grading the complications. Radiation exposure and operative time were less in OSD group (95% confidence interval (CI) 3.068 to 14.072, and 2.565 to 12.435, p<0.005). The mean drop of hematocrit was statistically less significant in OSD group (p=0.032). In both groups, complications, stone free rate and hospital stay were statistically insignificant. OSD is feasible in the children with reduced radiation exposure and shorter operative time. The outcome was similar to SFD.

One-Shot Dilatation vs Metal Dilator During Percutaneous Nephrolithotomy in Flank-Free Supine Position: A Randomized Controlled Study.

Background: The creation and dilatation of the nephrostomy tract is a fundamental step in percutaneous nephrolithotomy (PCNL). In one-shot dilatation (OSD), we used a single Amplatz dilator over a central Alken rod. PCNL in the supine position is as effective and safe as in the prone position. The Barts flank-free modified supine position sums several advantages of the different supine positions. We evaluated the efficacy and safety of OSD compared with metal telescopic dilator (MTD) during PCNL while the patient was in Barts flank-free modified supine position. Materials and Methods: Within 2.5 years, 150 patients with kidney stone candidates for PCNL were randomized into two equal groups according to the dilatation technique. In the OSD group, dilatation was performed using a single Amplatz dilator (30F) and in the MTD group dilatation was performed by sequential MTD (9-30F). All PCNL procedures were done with patients in Barts flank-free modified supine position. Patient characteristics, operative data, and results were collected for statistical analysis. Results: There are no statistically significant differences between both groups regarding patients' characters. The tracts were effectively dilated in all patients. Statistical analyses show a significant difference (p ˂ 0.05) between both groups regarding the time of dilatation (seconds; 68 ± 15 vs 147 ± 18), time of X-ray exposure (seconds; during dilatation; 36 ± 10 vs 61 ± 15 and the total; 157 ± 16 vs 181 ± 20), hemoglobin loss (mg/dL; 0.7 ± 0.2 vs 1.2 ± 0.3), and hospital stay (days; 3 ± 0.6 vs 3.7 ± 0.7) with favorable results to OSD. Complication rates were comparable between the two groups. Conclusions: OSD is efficient as MTD during PCNL while patients are in Barts flank-free modified supine position, with less dilatation time, X-ray exposure, blood loss, and hospital stay than MTD.

One-shot dilation versus metallic dilation technique for access in percutaneous nephrolithotomy: comparison of efficacy, access time and fluoroscopic time

Objective: The aim of this study was to compare the efficacy, access tract dilation time and fluoroscopic time between the one-shot dilation technique and telescopic metal dilatation technique in patients undergoing percutaneous nephrolithotomy in Nakornping Hospital. Materials and Methods: Sixty-six patients who underwent percutaneous nephrolithotomy from January 2020 to July 2021 were included in the study and they were randomly divided into two groups. In group 1 (32 patients), telescopic metal dilation was used, in group 2 (33 patients), the one-shot technique was used. Success rates of dilation, access tract dilation time and fluoroscopic time were evaluated. Results: The success rate of dilation was 100% in both groups. The access tract dilation time was 835.63 ± 309.68 seconds in group 1 and 569.42 ± 314.75 seconds in group 2 (p = 0.001). The fluoroscopic time was 48.16 ± 22.16 seconds in group 1 and 41.97 ± 23.99 seconds in group 2 (p = 0.29). The access tract dilation time of the one-shot dilation technique was statistically significantly shorter than that in the telescopic metal dilatation group. The mean fluoroscopic time of the one- shot dilation technique was shorter than in telescopic metal dilatation but was not statistically significant. Conclusion: One-shot dilation technique is as effective as telescopic metal dilatation, with a significant reduction in access tract dilation time.

A novel approach in creating nephrostomy using a double-lumen access sheath during endoscopic combined intrarenal surgery.

BackgroundThis study aimed to evaluate the safety and efficacy of an inner ureteral access sheath (i-UAS) with a double-lumen channel used in ureteroscopic lithotripsy (URS) as a dilator for the percutaneous tract in endoscopic combined intrarenal surgery (ECIRS).MethodsThis was a single-center cohort study conducted from January 2016 to April 2020. We used an i-UAS as a dilator and a double-lumen catheter to insert a safety guidewire during the creation of the nephrostomy tract in ECIRS. Univariate and multivariate analyses were performed to assess the association between the perioperative parameters and the use of i-UAS. The primary endpoint was perioperative complications, and secondary endpoints were stone-free rate (SFR), operative time, fluoroscopy time, and duration of hospitalization.ResultsIn total, 221 patients were enrolled during the study period. Patients were divided into an i-UAS dilation group (n=108) and a one-shot dilation group (n=113). No differences were observed between the two groups in terms of patient history. Univariate analyses indicated that, in the i-UAS dilation group, the operative time was shorter [105.50 (83.75–143.25) vs. 121.00 (90.00–155.00) min; P=0.02] and the modified Valdivia position was more frequently selected. Multivariate analyses showed no significant differences in the frequency of complications, such as urinary injury or postoperative pyelonephritis, but it showed a significantly shorter operative time as well as fewer tract creation troubles in the i-UAS dilation group.ConclusionsUsing an i-UAS as a dilator and a double-lumen catheter to insert a safety guidewire during ECIRS is a convenient and safe technical method for creating a nephrostomy tract that can reduce the operative time.

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

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

One Shot Dilatation (OSD) in Percutaneous Nephrolithotomy (PCNL) - A Safe and Feasible Technique

Objective: To evaluate the feasibility, safety and efficacy of one-shot dilation (OSD) in standard percutaneous nephrolithotomy (PCNL). Methods: This is a prospective, single -center study conducted between January 2017 to June 2019. Patients who underwent PCNL using one shot dilatation (21 – 24 Fr) for access in PCNL were included in the study. Access time, fluoroscopy time, successful dilation time, stone free rate, decrease hemoglobin level and transfusion rate, complication rate, length of post operative hospital stay, cost were recorded. Data was analyzed and reported using summary statistics. Results: A total of 30 patients were enrolled in this survey. 30 patients in one shot dilation (OSD) group.The mean age was 39.5 years. Control group of 30 patients were included in standard PCNL procedure where method of tract dilation was done by regid Amplatz dilators. Access time and fluoroscopy time in OSD group was approximately shorter. Statistically it was significant. Successful dilation and stone free rate were subsequently 98% and was significant. Data collected included patient access time, radiation exposure, total operating time, preoperative and postoperative hemoglobin concentrations, tract dilatation failures, complications and transfusions. Conclusion: The use of one shot and standard prone position under general anaesthesia combines the advantages of these both methods including less radiation exposure and shorter access and operative time. One shot dilation technique is safe, economical and feasible technique with added advantage,lesser radiation exposure and lesser chance of blood transfusion. Bangladesh Journal of Urology, Vol. 23, No. 2, July 2020 p.114-117

Single-Step Renal Dilatation Is a Novel Technique in Percutaneous Nephrolithotomy: A Prospective Randomised Study

Purpose: To evaluate the feasibility, safety and efficacy of one-shot dilation (OSD) in percutaneous nephrolithotomy (PCNL). Materials and Methods: In a prospective randomised study including 62 patients divided into two groups, the first had RD before PCNL using the standard metallic telescopic dilators (Alken), and the second had RD using the 30-F Amplatz dilator over the central Alken dilator. The operative duration, with X-ray exposure, was calculated. The procedure outcome in terms of complications, stone-free rates and hospital stay was evaluated statistically. Results : The tract was dilated correctly in all cases. The operative duration and X-ray exposure was shorter in patients undergoing single-step RD (P &lt; 0.05). There were perioperative complications, according to the Clavien grading system, in 15 (25%) patients but there was no statistically significant difference between the groups. The stone-free rates were comparable in both groups. Conclusion : A single-step RD during PCNL is feasible, with a shorter operative duration and X-ray exposure. The outcomes were comparable with those of a standard metallic telescopic RD Bangladesh Journal of Urology, Vol. 20, No. 2, July 2017 p.70-73

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.

One-shot dilation versus serial dilation technique for access in percutaneous nephrolithotomy: a systematic review and meta-analysis

ObjectiveThe purpose of this study was to systematically review the outcomes of the use of one-shot dilation (OSD) and serial tract dilation for percutaneous nephrolithotomy (PCNL).MethodsA systematic review and meta-analysis...

Randomized study comparing safety and efficacy of one shot versus serial metal telescopic dilation technique in percutaneous nephrolithotomy

Introduction: Dilation of the track can be achieved by multiple incremental flexible Amplatz type, Alken metal telescoping dilators, or balloon in Percutaneous Nephrolithotomy (PCNL). Balloon dilator is the most expensive method. Both of the incremental dilation techniques are more time consuming with higher failure rates. Hence, a prospective randomized study was conducted to compare the safety and efficacy of “single shot” dilation of the nephrostomy tract by amplatz dilator with serial alken metallic telescopic dilation technique in PCNL.&#x0D; Methods: Of the 138 renal stone patients who underwent PCNL from January 2015 to December 2015, 100 patients were randomized into two groups. Serial tract dilation with alken metallic dilators was used in group A (n=50), and one shot dilation technique in Group B (n=50). The access tract dilation time, success rate, blood loss and complications were evaluated.&#x0D; Results: Both the groups were comparable in terms of mean age, location and size (largest diameter) of the stone (p&gt;0.05). No difference was observed in the procedural success rate between groups A and B (96% v 94% respectively, p=0.64). Mean access time was similar in both groups (5.89+2.67 vs 4.98+2.0 mins, p=0.06). Complications between the groups were not significantly different. There were 6 patients with previous open stone surgery in both the groups. Previous open stone surgery did not impact procedural success rate, access time and complications in both groups.&#x0D; Conclusion: One-shot dilation technique is equally as effective, safe and well tolerated as metal telescopic dilation techniques even in patients with history of ipsilateral open stone surgery.

A novel percutaneous nephrolithotomy (PCNL) set: The ‘Economical One-shot PCNL Set’ (Ecoset)

ObjectivesTo suggest a novel disposable percutaneous nephrolithotomy (PCNL) set that we named the ‘Economical One-shot PCNL Set’ (Ecoset), which consists of a single 30-F dilator, 30-F sheath, and 8-F polyurethane dilator, as use of a ‘one-shot’ dilatation technique during PCNL is becoming widespread. Patient and methodsThe medical records of 42 patients with kidney stones who had undergone ‘one-shot’ PCNL from February 2014 to June 2016 were retrospectively reviewed and analysed. Demographic data, as well as the stone size, radiation exposure time, operation time, hospitalisation duration, rate of treatment success and complications, were recorded. ResultsThe mean (SD, range) age of the patients was 44.43 (16.54, 11–72)years. The mean (SD) stone size was 35.12 (17.53)mm. The mean (SD) operation time was 54.58 (22.24) min. The mean (SD) fluoroscopic screening time was limited to 154.72 (117.48) s. Treatment success was achieved in 32 (76%) patients. The mean (SD) hospital stay was 3.09 (0.75)days. None of the patients had any major complications. Bleeding requiring blood transfusion was required in three patients. The cost of a disposable dilatation set for a single PCNL operation with a balloon set, a standard Amplatz set, or an Ecoset is ∼$137, $120, or $27 (American dollars), respectively. ConclusionsThe one-shot dilatation technique using the Ecoset for PCNL can be feasibly, safely, and effectively performed in almost every adult patient. The Amplatz dilator set and balloon dilator set have the disadvantage of relatively high cost, whereas the Ecoset is the cheapest ‘disposable set’ that can be used during PCNL surgery.

A prospective randomized study comparing the four tract dilation methods of percutaneous nephrolithotomy.

To compare the one-shot dilation (OSD) technique with three other dilation techniques namely telescopic Alken, fascial Amplatz and balloon dilation (BD) in terms of safety efficacy and cost effectiveness. During a 3½year enrollment period, 480 patients who required PCNL surgery were equally randomized into four groups. All the cases were assessed preoperatively, intraoperatively as well as postoperatively till a period of 3months. Access time, X-ray exposure time, hemoglobin drop, complications, success rate, etc., were all assessed and recorded. Similar preoperative characteristics were observed in all the four study arms. X-ray exposure time during dilation was significantly reduced for both OSD and BD when compared to sequential Amplatz and telescopic Alken dilation (Group ALD=62.1+13, Group AMD=67.0+10, Group OSD=36.8+7, Group BD=38.1+6, p value=0.01, post hoc: G4=G3<G2=G1). There was no significant difference between the access time, hemoglobin drop, complication and success rates among the groups. BD was the most expensive dilation method when compared to the other three dilation techniques. All the four methods of dilation are equally safe and effective but both OSD and BD are advantageous in terms of lesser fluoroscopy time during dilation. OSD is much cheaper option when compared to BD, and therefore with more experience, it can become the preferable dilation method, especially in the developing countries.

Percutaneous nephrolithotomy with one-shot dilation method: Is it safe in patients who had open surgery before?

This study aimed to evaluate whether one-shot dilatation technique is as safe in patients with a history of open-stone surgery as it is in patients without previous open-stone surgery. Between January 2007 and February 2015, 82 patients who underwent percutaneous nephrolithotomy (PNL) surgery with one-shot dilation technique who previously had open-stone surgery were retrospectively reviewed and evaluated (Group 1). Another 82 patients were selected randomly among patients who had PNL with one-shot dilation technique, but with no history of open renal surgery (Group 2). Age, gender, type of kidney stone, duration of surgery, radiation exposure time, and whether or not there was any bleeding requiring perioperative and postoperative transfusion were noted for each patient. The stone-free rates, operation and fluoroscopy time, and peroperative and postoperative complication rates were similar in both groups (p>0.05). Our experience indicated that PNL with one-shot dilation technique is a reliable method in patients with a history of open-stone surgery.

Factors affecting complications according to the modified Clavien classification in complete supine percutaneous nephrolithotomy

An increase in percutaneous nephrolithotomy (PCNL) has been accompanied by an increase in complications. We identified the parameters affecting the severity of complications using the modified Clavien classification (MCC). From 2008 to 2013, 330 patients underwent complete supine PCNL using subcostal access, one-shot dilation, rigid nephroscopy, and pneumatic lithotripsy. We assessed the impact of the following factors on complication severity based on the MCC: age, gender, body mass index, hypertension, diabetes, previous stone surgery and extracorporeal shock wave lithotripsy, preoperative hemoglobin, renal dysfunction (creatinine >1.4 mg/dL), preoperative urinary tract infection, anatomic upper urinary tract abnormality (AUUTA), significant (moderate-severe) hydronephrosis, stone-related parameters (opacity, number, burden, location, staghorn, complex stones), anesthesia type, kidney side, imaging and calyx for access, tract number, tubeless approach, operative time, postoperative hemoglobin, and hemoglobin drop and stone-free results. The complication rate was 19.7% (MCC: 0=80.3%, I=6.4%, II=11.2%, ≥III=2.1%). On univariate analyses, only the following factors affected MCC: gender, preoperative hemoglobin, AUUTA, significant hydronephrosis, imaging for access, calyx for access, tract number, postoperative hemoglobin, hemoglobin drop and stone-free result. Renal dysfunction was accompanied by higher complications, yet the results were not statistically significant. Multivariate logistic regression analysis demonstrated renal dysfunction, absence of significant hydronephrosis, AUUTA, multiple tracts, lower postoperative hemoglobin, and higher postoperative hemoglobin drop as the significant parameters which affected MCC and predicted higher grades. The paper's limitations include a low number of cases in the higher Clavien grades and some subgroups of variables, and not applying some techniques due to surgeon preference. Many of the complete supine PCNL complications were in the lower Clavien grades and major complications were uncommon. Renal dysfunction, AUUTA, significant hydronephrosis, tract number, postoperative hemoglobin, and hemoglobin drop were the only factors affecting MCC.