Study of predictive factors for complications after percutaneous nephrolithotomy according to the Clavien classification

Is Guy's stone score useful for predicting outcomes in percutaneous nephrolithotomy?

INTRODUCTION

Percutaneous Nephrolithotomy (PCNL) is currently the treatment of choice in large kidney stones. Guy's stone score was developed to predict treatment outcomes. The aim of this study was to evaluate the relationship between Guy's score and outcomes in our institution.

MATERIALS AND METHODS

The medical records of patients diagnosed with urolithiasis and treated by PCNL were retrospectively evaluated between January 2017 and December 2018. Analyzed data included: age, sex, Guy's score based on preoperative findings, transfusion, stone-free rate and requirement of auxiliary procedures. Chi-square test was used for the comparison of proportions. Odds ratios (OR) with confidence intervals (CIs) of 95% were calculated by logistic regression.

RESULTS

A total of 386 patients, 53.89% female, mean age of 45.59 ± 15 years were analyzed. Guy's score was as follows: 112 patients (29.04%) were classified as Guy I, 92 patients (23.82%) as Guy II, 94 patients (24.34%) as Guy III, and 88 patients (22.80%) as Guy IV. There were no differences between groups in terms of blood transfusions. Stone-free rate was 96.43% (n = 108) for patients Guy I; 84.78% (n = 72) for Guy II; 76.59% (n = 72) for Guy III and 50% (n = 44) for Guy IV categories (p < 0.0001). Taking as a reference Guy I group, the OR to require new treatment for residual stones were: Guy II 4.85 (CI = 0.95 to 24.60, P = 0.05) to Guy III 8.25 (CI = 1.73 to 39.44, P = 0.008) and Guy IV 27 (CI = 5.84 to 124.70; p < 0.0001).

CONCLUSION

There was a statistically significant association between Guy's Score and stone-free rates following PCNL. Guy's score was useful to predict results of PCNL in our group.

Application of Clavien-Dindo Classification System for Complications of Minimally Invasive Percutaneous Nephrolithotomy

Objective

To investigate the clinical applications of the Clavien-Dindo classification system (CDCS) in the assessment of perioperative complications in minimally invasive percutaneous nephrolithotomy (MPCNL).

Methods

Totally, 390 patients with renal stones in our hospital from March 2015 to March 2020 were included for this study and then were divided into observation group (complication group, 78 cases) and control group (noncomplication group, 312 cases) according to the incidence of perioperative complications in CDCS. Single factor analysis and multivariate logistic regression analysis were used to analyze the risk factors of the perioperative complications of MPCNL.

Results

The total incidence of complication in the 390 cases with MPCNL was 20.00% (78 cases) according to CDCS, among which the incidence of complications at grades I, II, III, IV, and V was 6.92% (27 cases), 8.21% (32 cases), 2.82% (11 cases), 1.79% (7 cases), and 0.26% (1 case), respectively. The proportion of patients, that aged >60 years, complicated with comorbidities, sophisticated calculi, the preoperative albumin level (<35 g/L), the operation time (>180 minutes), intraoperative bleeding volume (>300 mL), and hospitalization time (>7 days) in the observation group was significantly higher than that in the control group ((75.64% vs. 61.86%, 38.46% vs. 24.36%, 83.33% vs. 69.55%, 83.33% vs. 69.55%, 70.51% vs. 30.76%, 53.85% vs. 36.54%, and 60.26% vs. 43.27%), all P < 0.05). Multivariate logistic regression analysis showed that gender, associated comorbidities, preoperative albumin level, calculus complexity, operation time, and intraoperative bleeding volume (>300 mL) were correlated with the occurrence of complications (P ≤ 0.001, 0.001, 0.001, 0.001, 0.003, and 0.001 respectively).

Conclusion

The CDCS can give standard and more comparative criteria for the assessment of perioperative complications, which will provide reference data for reducing complications and ensuring safety profiles in these high-risk patients.

Complications of percutaneous nephrolithotomy: classification, management, and prevention

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PCNL) provides the highest stone-free rate after one session and low morbidity rates in cases of large or multiple renal calculi. The classification, management, and prevention of complications of PCNL are reviewed.

RECENT FINDINGS

PCNL is a well tolerated and very effective procedure for the management of renal stones. Specific complications limit the surgical outcome of PCNL whereas the majority of the complications are resolving with conservative or minimally invasive management. Experience with the technique is important for minimizing complications. There is an ongoing effort to classify the complications and to achieve a consensus in reporting the complications and surgical outcome of the procedure.

SUMMARY

The knowledge of risk factors, complications, and their management is important for every endourologist. Establishing of a PCNL-specific classification system for reporting outcomes and complications could set the basis for further improvement of the PCNL technique and outcomes.

Can Activities of Daily Living Predict Complications following Percutaneous Nephrolithotomy?

PURPOSE

Activities of daily living provide information about the functional status of an individual and can predict postoperative complications after general and oncological surgery. However, they have rarely been applied to urology. We evaluated whether deficits in activities of daily living could predict complications after percutaneous nephrolithotomy and how this compares with the Charlson comorbidity index and the ASA(®) (American Society of Anesthesiologists(®)) classification.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients who underwent percutaneous nephrolithotomy between March 2013 and March 2014. Those with complete assessment of activities of daily living were included in analysis. Perioperative outcomes, complications and hospital length of stay were examined according to the degree of deficits in daily living activities.

RESULTS

Overall 176 patients underwent a total of 192 percutaneous nephrolithotomies. Deficits in activities of daily living were seen in 16% of patients, including minor in 9% and major in 7%. Complications developed more frequently in those with vs without deficits in daily living activities (53% vs 31%, p = 0.029) and length of stay was longer (2.0 vs 4.5 days, p = 0.005). On multivariate logistic regression activities of daily living were an independent predictor of complications (OR 1.11, p = 0.01) but ASA classification and Charlson comorbidity index were not.

CONCLUSIONS

Activities of daily living are easily evaluated prior to surgery. They independently predict complications following percutaneous nephrolithotomy better than the Charlson comorbidity index or the ASA classification. Preoperative assessment of daily living activities can help risk stratify patients and may inform treatment decisions.

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

INTRODUCTION

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).

METHODS

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.

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.

INTERPRETATION

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.

Analysis of the factors affecting blood loss in percutaneous nephrolithotomy: a registry of the Spanish Association of Urology in the supine position

OBJECTIVE

Percutaneous nephrolithotomy (PCNL) is the minimally invasive procedure of choice for removing renal stones larger than 2 cm. This study has aimed to identify the different variables that might influence decrease of hemoglobin during the surgery performed in supine position.

MATERIAL AND METHODS

A prospective, multicenter, observational study of supine PCNL, based on the Spanish Association of Urology database, was analyzed. The different preoperative and postoperative factors that might affect the decrease of hemoglobin were assessed: demographics and anthropometric data, comorbidities, size and location of the stones, anatomical variants and technical aspects of the procedure.

RESULTS

From September 2008 to December 2012, 397 supine PCNL procedures performed in 15 Spanish centers were registered. Mean hemoglobin decrease was 2.3±1.5 g/dl and overall blood transfusion rate was 5.5%. No statistically significant differences were found between genders, body mass index (BMI) and age in terms of blood loss. There were also no differences between patients with cardiovascular, hypertensive, diabetic and anticoagulant treatment background. Blood loss was not significantly influenced by stone size and location. Technical aspects of the procedure as operative time (> 120 min ≤), access to the pelvi-caliceal system (ultrasound, fluoroscopy), percutaneous tract dilation technique (Alken, balloon or Amplatz) or placement of nephrostomy (tube versus tubeless) were not associated with differences in pre-op/post-op hemoglobin. Only multiple percutaneous tracts (≥2) and middle calix access were statistically significantly (P=.03 and P=.01) related with less blood loss.

CONCLUSIONS

PCNL in supine position is a minimally invasive procedure for removal of large (≥2 cm) and multiple renal stones, with a low incidence of blood loss and minimal transfusion rate. Multiple percutaneous tracts and middle calix puncture were the only statistically significant variables associated with decrease in hemoglobin levels.