New developments in percutaneous stone surgery

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy (PCNL) procedure in terms of indications and evolving techniques, and to identify the advantages and disadvantages of each modality. The data for this review were collected after a thorough PubMed search in core clinical journals in English language. The key words included “PCNL” and “PNL” in combination with “indications”, “techniques”, “review” and “miniaturized PCNL”. Publications relevant to the subject were retrieved and critically reviewed. Current European and American Urology Association Nephrolithiasis Guidelines were included as well. The indications for standard PCNL have been changed through the past decade. Despite evolution of the procedure, innovations and the development of new technical approaches, the indications for miniaturized PCNL have not been standardized yet. There is a need for well-constructed randomized trials to explore the indications, complications and results for each evolving approach. A continuous reduction of tract size is not the only revolution of the last years. There is constant ongoing interest in developing new efficient miniature instruments, intracorporeal lithotripters and sophisticated tract creation methods. We can summarize that, PCNL represents a valuable well-known tool in the field of endourology. We should be open minded to future changes in surgical approaches and technological improvements.

Device-Related Adverse Events During Percutaneous Nephrolithotomy: Review of the Manufacturer and User Facility Device Experience Database

INTRODUCTION AND OBJECTIVES

Percutaneous nephrolithotomy (PCNL) is an established technique for removal of large stones from the upper urinary tract. It is a complex multistep procedure requiring several classes of instruments that are subject to operator misuse and device malfunction. We report device-related adverse events during PCNL from the Manufacturer and User Facility Device Experience (MAUDE) database using a recently developed standardized classification system.

MATERIALS AND METHODS

The MAUDE database was queried for "percutaneous nephrolithotomy" from 2006 to 2016. The circumstances and patient complications associated with classes of devices used during PCNL were identified. We then utilized a novel MAUDE classification system to categorize clinical events. Logistic regression analysis was performed to identify associations between device classes and severe adverse events.

RESULTS

A total of 218 device-related events were reported. The most common classes included: lithotripter 53 (24.3%), wires 43 (19.7%), balloon dilators 30 (13.8%), and occlusion balloons 28 (12.8%). Reported patient complications included need for a second procedure 12 (28.6%), bleeding 8 (19.0%), retained fragments 7 (16.7%), prolonged procedure 4 (9.5%), ureteral injury 2 (4.8%), and conversion to an open procedure 3 (7.1%). Using a MAUDE classification system, 176 complications (81%) were Level I (mild/none), 26 (12%) were Level II (moderate), 15 (7%) were Level III (severe), and 1 (0.5%) was Level IV (life threatening). On univariate analysis, balloon dilators had the highest risk of Level II-IV complications compared with the other device classes [odds ratio: 4.33, confidence interval: 1.978, 9.493, p < 0.001]. The device was evaluated by the manufacturer in 93 (42.7%) cases, with 54.8% of reviewed cases listing the source of malfunction as misuse by the operator.

CONCLUSIONS

PCNL is subject to a wide range of device-related adverse events. A MAUDE classification system is useful for standardized, clinically-relevant reporting of events. Our findings highlight the importance of proper surgeon training with devices to maximize efficiency and decrease harm.

Use of Ultrasound in Pediatric Renal Stone Diagnosis and Surgery

Pediatric urolithiasis is on the rise globally and incidence rates have risen by 6-10% annually over the past couple of decades. Given the increasing incidence, high likelihood of recurrence, and long life expectancy of children, the use of ionizing radiation in the diagnosis, management, and follow up of pediatric urolithiasis has been scrutinized recently and many institutions and organizations have emphasized the use of non-ionizing imaging modality such as ultrasound. This review examines the use of ultrasound in the diagnosis and treatment of pediatric urolithiasis. Specifically, the role of ultrasound in shockwave lithotripsy, percutaneous nephrolithotomy, and, more recently, ureteroscopy will be examined.

Immediate versus delayed shockwave lithotripsy for inaccessible stones after uncomplicated percutaneous nephrolithotomy

Objective

To evaluate the efficacy and safety of immediate versus delayed shockwave lithotripsy (SWL) for inaccessible stones after uncomplicated percutaneous nephrolithotomy (PCNL).

Patients and methods

Between December 2011 and June 2014, patients with residual inaccessible stones after uncomplicated PCNL were prospectively randomised into two treatment groups; Group I, immediate SWL and Group II, delayed SWL at 1 week after PCNL. Patients with residual stones of ⩾1.5 cm, a stone density of >1000 Hounsfield units and body mass index of >40 kg/m² were excluded from the study. The following data were reported: patients’ demographics, stone characteristics after PCNL, hospital stay, perioperative complications, stent duration, and stone-free rate (SFR).

Results

In all, 84 patients (51 males and 33 females) with mean (SD) age of 39 (8.5) years were included in the study. Group I included 44 patients, whilst Group II included 40 patients. There was no statistically significant difference amongst the groups for patients’ demographics, stone characteristics, and perioperative complications. The hospital stay was significantly shorter in Group I, at a mean (SD) of 34 (3.7) vs 45 (2.9) h (P < 0.001). The duration of ureteric stenting was significantly lower in Group I as compared to Group II, at a mean (SD) of 12 (4.2) vs 25 (3.5) days (P < 0.001). The SFR was 93.2% and 95% in Groups I and II, respectively (P = 0.9).

Conclusions

Immediate SWL after PCNL is as effective and safe as delayed SWL with a lesser hospital stay and duration of ureteric stenting.