Baseline chronic kidney disease does not predict long-term renal functional decline after percutaneous nephrolithotomy

Percutaneous Nephrolithotomy in Patients with Chronic Kidney Disease: A Systematic Review

BACKGROUND

Renal calculi in chronic kidney disease (CKD) are not uncommon. Percutaneous nephrolithotomy (PCNL) is a standard treatment for large renal calculi. PCNL in CKD has been a subject of debate as it may improve the renal function with stone clearance but may be associated with an increased complication rate. Studying the impact of PCNL in CKD patients is of utmost significance.

OBJECTIVE

The aim of the study was to evaluate the efficacy and safety of PCNL in patients with renal insufficiency in order to provide clinicians expected outcomes to effectively counsel patients.

METHODS

We performed a systematic review of clinical trials reporting the outcomes of PCNL in CKD patients. The search was performed in MEDLINE, EMBASE, Cochrane Library, CINAHL, Google Scholar, and Web of Science. All studies with a minimum of 15 patients carried out in the last 20 years were selected. A total of 13 studies involving 2,192 patients were included for final analysis. The pre-operative and post-operative renal function was compared. Post-procedure complications were analysed. Evidence Analysis: The majority of patients in all studies except one had either improvement or stabilization in renal function. The complication rate was 31.9%, which was more than that in patients with normal renal function.

CONCLUSION

Our review suggested that the majority of the patients of renal calculus with renal insufficiency are benefitted with PCNL in improving or preserving the renal function. But the post-operative complications are more in CKD and increases as the severity of renal insufficiency increases.

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.

Is multiple tract percutaneous nephrolithotomy a safe approach for staghorn calculi?

PURPOSE

To explore the safety of multiple tract percutaneous nephrolithotomy (PNL) in terms of complication and draw a nomogram to predict the possibility of significant renal function decline (SRFD).

MATERIALS AND METHODS

Patients with complex renal calculi appropriate for PNL at our institution between August 2016 and February 2018 were included in the study. The outcome of single and multiple tract PNL was analyzed retrospectively. A nomogram was created to predict the probability of SRFD.

RESULTS

793 (88.4%) patients were treated with single tract PNL (Group 1) and 104 patients (11.6%) treated with multiple tract PNL (Group 2). Group 2 had a significantly greater hemoglobin reduction (16.0 ± 12.5 vs. 11.4 ± 11.8 g/L, p < 0.001), higher rate of postoperative fever (19.2% vs. 11.9%, p = 0.034) and longer duration of the operation (110.6 ± 39.6 vs. 97.8 ± 34.5 min, p < 0.001). A nomogram for predicting the probability of SRFD was constructed based on identified risk factors: patients' age, positive urine culture (UC +), hemoglobin reduction and embolization. The area of receiver operating characteristic (ROC) curve was 70%. Bootstrapping technique utilized to make the calibration plot showed a high reliability of the nomogram.

CONCLUSIONS

Multiple tract PNL had a higher risk of hemoglobin reduction and postoperative fever than single tract PNL. Multiple tracts had no effect on SRFD, but old age, UC + , hemoglobin reduction and embolization were risk factors for SRFD. A nomogram with the aim of predicting the probability of SRFD based on these parameters demonstrated good uniformity in internal validation.