Characteristics of patients requiring Double-J placement because of urine leakage after percutaneous nephrolithotomy

Hydrostatic pressure of the renal pelvis as a radiation-free alternative to fluoroscopic nephrostogram following percutaneous nephrolithotomy

Background

We evaluated the hydrostatic pressure of the renal pelvis (RPP) as a radiation-free alternative to fluoroscopic nephrostogram to assess ureteral patency after percutaneous nephrolithotomy (PCNL).

Methods

Retrospective non-inferiority study analyzing 248 PCNL-patients (86 female (35%) and 162 males (65%)) between 2007 and 2015. Postoperatively, RPP was measured using a central venous pressure manometer in cmH2O. The primary endpoint was to assess RPP depending on the patency of the ureter and the nephrostomy tube removal. Secondary, the upper limit of normal RPP of $$\le$$ ≤ 20 cmH2O was assessed as an indicator of an unobstructed patency.

Results

The median procedure duration was 141 min (112–171.5) with a stone free rate of 82% (n = 202). RPP was significantly higher in patients with obstructive nephrostogram with 25.0 mmH2O (21.0–32.0) versus 20.0 mmH2O (16.0–24.0; p < 0.001). The pressure was lower in successful nephrostomy removal with 18 cmH2O (15–21) versus 23 cmH2O (20–29) in the leakage group (p < 0.001). The analysis of a cut-off of $$\le$$ ≤ 20 cmH2O showed a sensitivity of 76.9% (95% CI [60.7%; 88.9%]) and a specificity of 61.5% (95% CI [54.6%; 68.2%]). The negative predictive value was 93.4% (95% CI: [87.9%; 97.0%]) and the positive predictive value 27.3% (95% CI [19.2%; 36.6%]). The accuracy of the model showed an AUC = 0.795 (95% CI [0.668; 0.862]).

Conclusion

The hydrostatic RPP seems to allow a bedside evaluation of ureteral patency after PCNL.

Optimization of the outcome of percutaneous nephrolithotomy regarding urinary leakage, what should we do?

To evaluate the factors affecting urinary leakage post percutaneous nephrolithotomy. To define those at high risk in whom a double J stent for 4 weeks or external ureteral catheter fixation for at least 3 days is indicated at the end of procedure. A total of 140 patients who underwent single-stage Percutaneous Nephrolithotomy (PCNL) with single or multiple accesses were included between February 2014 and March 2019. A detailed history, laboratory and radiological investigations were performed on all patients. All patients were classified according to postoperative urinary leakage into three groups. We defined leakage as a leakage from percutaneous puncture site. Group 1 (90 patients), No leakage was defined as leakage < 12 hours. In group 2 (32 patients), short-term leakage was defined as leakage 12-48 hours, and in Group 3 (18 patients), prolonged urinary leakage > 48 hours. Patients with short-term and prolonged urinary leakage had a significantly shorter access tract. Most patients (93.8%) with short-term leakage had an access tract of 71-90 mm, while > 50% of patients (55.6) with prolonged leakage had an access tract of 51-70 mm (p <0.001). Multivariate ordinal regression revealed that Operative time, length of the access tract and parenchymal thicknesses significantly predict short-term and prolonged leakage. For predicting the prolonged urinary leakage, the length of access tract and parenchymalthickness showed significant areas under the curve (AUC); 78% (95% CI: 69 - 85, p = 0.002) and 94% (95% CI: 87 - 97, p <0.001), respectively. Operative time, length of the access tract and parenchymal thickness significantly predict short-term and prolonged leakage.

A novel nomogram and a simple scoring system for urinary leakage after percutaneous nephrolithotomy

Introduction:

The present study aimed to investigate the factors of prolonged urinary leakage (PUL) after percutaneous nephrolithotomy (PCNL) and develop a new and simple scoring system to predict it.

Patients and Methods:

We retrospectively reviewed patients with renal stones who underwent PCNL at the University of Health Sciences Izmir Bozyaka Training and Research Hospital between April 2011 and January 2020. The patients were divided into two groups according to the presence of PUL, and their preoperative and perioperative data were compared. A multivariate regression analysis was applied to examine the relationship between perioperative descriptors and PUL, and a nomogram was developed using significant predictors. Then, the individual components of the nomogram were assigned points to form a scoring system.

Results:

There were 92 and 840 patients in the groups with and without PUL, respectively. The results of the univariate logistic regression analysis showed that hydronephrosis grade, parenchymal thickness, duration of nephroscopy, and duration of nephrostomy catheter were significantly associated with PUL. Subsequently, a multivariate regression analysis was carried out with these four factors as possible independent risk factors of PUL after PCNL. Based on the results of this analysis, a nomogram prediction model was developed with an area under the curve value of 0.811, which was consequently used to develop a new simple score system consisting of three characteristics: parenchymal thickness (1–5 points), duration of nephroscopy (1–3 points), and hydronephrosis grade (1–3 points).

Conclusion:

A novel scoring system is a useful tool for predicting PUL in patients who have undergone percutaneous nephrolithotomy.

Stones hounsfield unit value and predictors of urinary leakage after PCNL

Background

To evaluate the predictive factors of urinary leakage (UL) following percutaneous nephrolithotomy (PNL) and to investigate the relationship between Hounsfield unit (HU) of stone and UL.

Methods

We retrospectively reviewed the data of 728 patients who underwent PNL between January 2012 and January 2017. In total, 396 patients were eligible for the study. Patient demographics, renal factors, stone properties and operative details were collected. The association between UL and these variables were assessed by univariate and multivariate analysis.

Results

There was no statistically significant correlation considering age, body mass index and the presence of hypertension. The presence of diabetes mellitus (DM) was significantly correlated with UL (p < 0.001). Kidney related factors such as parenchymal thickness, hydronephrosis grade (HN), previous stone treatment, and stone related factors, such as stone surface area, stone burden, stone localization and HU value of stone, were found to affect UL status significantly (p < 0.001). Operation time, fluoroscopy time, treatment outcome, j stent use, percutenous nephrostomy (PCN) catheter stay time and the hospitalization time also had significant effect on UL (p < 0.001). Multivariable logistic analysis showed that presence of DM, parenchymal thickness, HU values, HN, operation time, j stent use, and PCN catheter stay time are independently related with UL following PCNL. Moreover, we determined a HU cut-off value of 933 with ROC analysis, which demostrated 84.9% sensitivity and 67.1% specificity for predicting UL.

Conclusion

This study has shown that we are more likely to encounter postoperative UL in stones with higher HU values. Therefore, we suggest clinicians to inform patients with this type of kidney stones about the probable complication of UL.

Is it Necessary to Perform Nephrostography before Tube Removal after Percutaneous Nephrolithotomy

BACKGROUND

The aim of this study is the caparison of the complications rate among the patients which underwent nephrostomy removal with and without performing nephrostography.

MATERIALS AND METHODS

Between October 2010 and November 2011, 200 patients who underwent standard percutaneous nephrolithotomy (PCNL) procedures were included in this study. The patients were randomly assigned into two groups, Group A (n = 100) did not undergo the antegrade nephrostography on postoperative day 2 and the patients were discharged keeping the nephrostomy until postoperative day 3, while in Group B (n = 100) the nephrostomy tube was removed on postoperative day 3 after antegrade nephrostography demonstrating ureteral drainage down to the bladder. Postoperative complications in both groups were recorded and compared between two groups.

RESULTS

A total of 200 patients were treated with standard PCNL. The persistent leakage of urine after removal of the nephrostomy tube was encountered in 5 (5.0%) and 3 (3%) of patients in Groups 1 and 2, respectively. Urinary leakage was resolved with conservative management in 3 and 2 patients of Groups 1 and 2, respectively, but a double-J stent was inserted in 2 and 1 patients in each group because of persistent leakage of urine more than 1-week. The two groups show comparable complications such as prolonged urinary leakage which managed in a similar manner, however, postoperative hospital stay was lesser in Group 1.

CONCLUSION

Our results revealed postoperative performing nephrostogramy before tube removal changed the planning of complications such as prolonged urinary leakage and could be omitted in cases.

Study of predictive factors affecting the prolonged urinary leakage after percutaneous nephrolithotomy

Objective:

To evaluate the factors that may influence the prolonged urinary leakage following percutaneous nephrolithotomy (PCNL).

Materials and Methods:

A total of 936 consecutive patients underwent PCNL during the study period from April 2013 to December 2014 at our center, and data were recorded prospectively. Patients who required stage PCNL, chronic renal failure and diabetic patients, concurrent ureteric stone and patients in whom double-J stent was placed because of ureteropelvic injury, or pelvicalyceal extravasation were excluded from the study. After exclusion, 576 patients were included in the study. The predictive factors that may lead to prolonged urinary leakage after PCNL were broadly categorized into patient-related factors and procedure-related factors. Patients were divided into two groups: Group 1 (n = 32) – Required double-J stent placement due to prolonged urinary leakage (>48 h) after removal of the nephrostomy tube. Group 2 (n = 544) – Did not require double-J stent placement.

Results:

Patient-related factors such as stone complexity, grade of hydronephrosis, renal parenchymal thickness in access line, and intra-parenchymal renal pelvis were most important factors for prolonged urinary leakage (P < 0.05, P < 0.05, P < 0.05, and P < 0.05, respectively), while procedure-related factors such as multiple punctures, surgeon's experience, and residual stones were most important factors for prolonged urinary leakage (P < 0.05, P < 0.05, and P < 0.05, respectively).

Conclusion:

In the present study, several factors appear to affect post-PCNL prolonged urinary leakage. We suggest that patients who are at increased risk of prolonged urinary leakage double-J stent should be placed at the end of PCNL procedure.

Factors Influencing the Duration of Urine Leakage following Percutaneous Nephrolithotomy

Purpose. The duration of urine leakage following the removal of the nephrostomy tube after percutaneous nephrolithotomy (PCNL) shows significant variations depending on the techniques used. We aimed to assess the factors likely to influence the duration of urine leakage. Material and Methods. In total, 103 patients who underwent PCNL were reviewed retrospectively. DUL was evaluated regarding patient characteristics, thickness of the access line, presence of hydronephrosis, and residual stones. Results. DUL was significantly prolonged in accordance with a decrease in the thickness of parenchyma tissue (R = −0.716, P < 0.001). DUL was prolonged as the degree of hydronephrosis (R = 0.526, P < 0.001) and the number of patients with residual stones (R = 0.273, P = 0.005) increased. Median DUL was significantly longer in patients with residual stones than those without residual stones (P = 0.002). In the receiving operating curve analysis, the optimum cut-off value of parenchymal thickness for hospitalization ≤12 h was 17.2 mm (sensitivity, 90.2%; specificity, 69.4%; P = 0.001). Conclusions. We found that parenchymal thickness of the access line, hydronephrosis, and residual stones were the most influential factors determining DUL following PCNL, respectively.

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.

Re: totally tubeless percutaneous nephrolithotomy: a prospective randomized controlled study

The study is unique in terms of defining the safety of totally tubeless percutaneous nephrolithotomy (PNL). Furthermore, the authors state that the tubeless group has an advantage of less pain. However, we interpreted the results of pain-related comparisons different than that the authors had. In our opinion, the results gained show that there is no difference in terms of pain in both groups. The authors state that they have inserted a double J catheter to patients that were included in the tubeless group in addition to the nephrostomy as a conventional procedure. However, routine Double-J placement in addition to nephrostomy is not a common procedure. Additionally, the large-bore nephrostomy tube preferred is certain to cause pain, as stated in the previous studies. It has been shown that small-bore tubes cause less pain. It may have been more appropriate to compare the groups in such a manner. Even though we have stated our comments with respect to pain issues, it is evident that the study is unique in terms of defining the safety of a totally tubeless procedure.

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.

Diagnostic utility and clinical value of postpercutaneous nephrolithotomy nephrostogram

BACKGROUND AND PURPOSE

After percutaneous nephrolithotomy (PCNL), the current standard of care is to obtain a nephrostogram before removal of the nephrostomy tube to rule out distal ureteral obstruction. The aim of this study was to determine whether nephrostogram findings predict prolonged urinary drainage and postoperative ureteral stent insertion.

PATIENTS AND METHODS

Data for all patients who had nephrostomy tubes inserted post-PCNL between January and December 2006 were retrospectively reviewed. Patients with radiolucent stones, concomitant procedures, or caliceal diverticula were excluded. All nephrostograms were reviewed to identify distal ureteral obstruction without evidence of residual fragments. The Fisher's exact test was used.

RESULTS

Fifty patients who underwent 51 PCNLs were included in the study (one patient had bilateral PCNLs). Nephrostograms were performed on median postoperative day (POD) 2 (range POD 2-8), and tubes were removed on median POD 2 (range POD 2-10). In 14 (27%) patients who had distal ureteral obstruction without ureteral stones, the nephrostomy tube was removed on the same day of nephrostography. Eight (16%) patients experienced a prolonged urinary leak (>24 hours). While obstruction on the nephrostogram predicted prolonged urinary leak (36% vs 8%; P = 0.02), none of these obstructed patients needed postoperative ureteral stent placement. A patient with a horseshoe kidney without distal ureteral obstruction had his nephrostomy removed on POD 2. He presented on POD 7 with prolonged urinary leakage and needed readmission with ureteral stent placement and Foley catheterization.

CONCLUSION

While distal obstruction seems to predict prolonged urinary leakage (more than 24 hours), it may not necessitate ureteral stent placement or prolonged nephrostomy drainage because blood clot or ureterovesical junction edema resolve spontaneously with expectant management.

Which factors may effect urinary leakage following percutaneous nephrolithotomy?

OBJECTIVE

To evaluate the factors that may effect urinary leakage following percutaneous nephrolithotomy (PCNL).

METHODS

Four hundred and thirty-three patients who underwent PCNL were reviewed retrospectively. The factors that may lead to leakage after surgery were analyzed as categorized into four groups according to individual variables (age, sex, body mass index); renal factors (previous surgery, extracorporeal shock wave lithotripsy history, presence of hydronephrosis); stone burden; and surgical features (access number, type of dilatation, presence of nephrostomy catheter). These data were compared for the presence and duration of urinary leakage.

RESULTS

There was no statistically significant correlation between individual factors and both the presence of leak (POL) and the duration of leak (DOL) (P > 0.05). Among renal factors, only presence and degree of hydronephrosis was significantly correlated with POL (P < 0.001) and DOL (P < 0.001). The mean cumulative stone burden neither had impact on POL nor correlated with DOL (P > 0.05). Among surgical factors, dilatation with a Nephromax dilator significantly increased incidence of POL when compared with an Amplatz dilator (P < 0.001), yet did not change DOL. Using an internal ureteral stent significantly decreased incidence of POL and DOL (P < 0.001). DOL increased with catheter diameter and stay time (P < 0.05).

CONCLUSION

Several yet simple factors appear to be effective in postoperative urine leakage from the access sites after percutaneous stone surgery. Precautions may also be simple if these factors are considered preoperatively.