Factors Affecting Residual Stone Rate, Operative Duration, and Complications in Patients Undergoing Minimally Invasive Percutaneous Nephrolithotomy

Risk factors of stone residual after retrograde intrarenal surgery: A prospective cohort study

BACKGROUND

Complete removal of renal stones is crucial for optimal patient outcomes, but recent studies have reported residual stones after retrograde intrarenal surgery (RIRS). This study aimed to identify the associated risk factors to improve patient management and treatment selection.

METHODS

This cohort study was conducted over 18 months at two hospitals and recruited adult patients with renal stones less than 3 cm. Preoperative assessment included medical history, physical examination, laboratory tests, and radiological imaging. Intraoperative and postoperative data collection and follow-up were conducted to evaluate surgical success and potential complications.

RESULTS

A total of 100 patients were included, with a mean age of 45.3 ± 10.7 years and a mean BMI of 26.2 ± 1.4 kg/m2. Approximately 19% of the patients had residual stones after the RIRS procedure. The RUSS score showed good diagnostic performance with an AUC of 0.843, and the optimal cut point was ⩾2.0 with a sensitivity of 52.6% and specificity of 95.1%. Independent predictors of residual stones were multiple sites (OR = 24.98; p = 0.002), multiple stones (OR = 13.62, p = 0.002), stone size of 21-30 mm (OR = 4.91, p = 0.038), lower calyx site (OR = 4.85, p = 0.033), and surgeon experience of fewer than 50 cases (OR = 6.82, p = 0.020).

CONCLUSIONS

This study identifies several factors associated with residual stones after RIRS for renal stones, including stone size, location, number, and surgeon experience. The study suggests that the RUSS score can be used as a reliable tool for predicting the likelihood of residual stones, which can help clinicians in patient selection and treatment planning.

Effects of severe hydronephrosis on surgical outcomes of minimally invasive percutaneous nephrolithotomy (MPCNL)

Introduction

The impact of severe hydronephrosis on the outcomes of minimally invasive percutaneous nephrolithotomy (MPCNL) remains controversial; it is still a subject well worth exploration.

Aim

To investigate the effects of severe hydronephrosis on surgical outcomes of MPCNL, especially on operative time (OT) and stone-free rate (SFR).

Material and methods

In total, 301 patients who underwent MPCNL were included in this study and divided into 4 groups according to the degree of hydronephrosis (nil, mild, moderate, and severe hydronephrosis, respectively). Univariate analyses and multivariate logistic analyses were used to determine the risk factors affecting OT and SFR.

Results

Patients with severe hydronephrosis had a longer OT (p < 0.001), a decreased SFR (p < 0.001), and a higher postoperative haemoglobin drop and blood transfusion rate compared to the other 3 cohorts (p = 0.011 and p = 0.043, respectively). Univariate analyses determined that severe hydronephrosis, calyx for access, stone location, stone type, stone size, and number of tracts significantly correlated with OT, while severe hydronephrosis, stone location, stone type, and stone size showed a strong association with SFR (all p < 0.05). Multivariate analyses further identified that severe hydronephrosis (OR = 3.496, p = 0.013), stone location (≥ 4 calyces: OR = 3.024, p = 0.017), stone type (staghorn: OR = 5.204, p = 0.002), and stone size (≥ 1600 mm2: OR = 12.669, p < 0.001; 800-1599 mm2: OR = 5.194, p < 0.001) were significant risk factors affecting OT, while SFR was independently influenced by stone type (staghorn: OR = 4.377, p = 0.039; multiple: OR = 3.778, p = 0.044), stone location (≥ 4 calyces: OR = 4.413, p = 0.020; 2-3 calyces: OR = 3.617, p = 0.034), and severe hydronephrosis (OR = 7.093, p = 0.001).

Conclusions

Severe hydronephrosis is a significant risk factor that can lead to longer OT and lower SFR, and correlates with increased risk of bleeding and blood transfusion rate in some cases during MPCNL. Accordingly, severe hydronephrosis is an influential factor that should not be ignored when performing MPCNL.

Robotic gastrointestinal stromal tumors surgery - initial results

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) usually present as an exophytic mass localized in stomach. Years ago, conventional surgery was the only option. Laparoscopic and robotic procedures have risen to prominence in recent decades as technology and surgical techniques have advanced.

Percutaneous Nephrolithotomy Combined Antegrade Flexible Ureteroscope for Complete Staghorn Stones: A Case Report of a New Concept of Stone Surgery

Percutaneous nephrolithotomy (PCNL) is the treatment of choice for staghorn stones. However, residual stones in calyces remain a challenge due to the limited angle which makes the approach difficult. The new operative technique of endoscopic combined intrarenal surgery (ECIRS), which integrates the advantages of PCNL and retrograde intrarenal surgery (RIRS), was developed to overcome this difficulty. However, two experienced urologists are required to perform ECIRS, and the patient has to be placed in the Galdakao-modified supine Valdivia position or modified prone split-leg position which cannot be achieved in the elderly or patients with ankylosing arthritis, as it may cause harm due to abnormal traction of the joints. In addition, it is difficult for surgeons to create an ideal access tract to perform PCNL in this position. We report the case of a 72-year-old female patient with left staghorn stone. We performed RIRS first and then placed the patient in the decubitus position for PCNL with antegrade flexible ureteroscopy. This method allows patients to be placed in an easier position, with the use of flexible ureteroscopy through a nephroscope to find previously unreachable stones. Moreover, in addition to the more comfortable position both for surgeons and patients, this procedure can also deal with large complex renal stones as with ECIRS. We also created a brand-new definition for stone clearance rate, namely, stone reduction efficiency (SRE). There was a high stone reduction efficiency of 12.64 (mm²/min) in our patient, and no complications occurred. We suggest that this procedure is an ideal alternative treatment for a huge staghorn stone instead of PCNL or ECIRS.