Impact of Anterior Kidney Calyx Involvement of Complex Stones on Outcomes for Patients Undergoing Percutaneous Nephrolithotomy

Comparative Analysis of Safety and Efficacy Between Anterior and Posterior Calyceal Entry in Supine Percutaneous Nephrolithotomy

Introduction: One advantage of supine percutaneous nephrolithotomy (sPCNL) is the ability to access anterior as well as posterior calyces, but the safety and efficacy of anterior calyceal entry has never been investigated to our knowledge. We prospectively evaluated patients scheduled for sPCNL comparing anterior and posterior calyceal access. Materials and Methods: After Institutional Review Board approval, we prospectively enrolled 100 consecutive patients undergoing sPCNL from February to September 2023. Primary outcomes included intraoperative complications, blood transfusions, 30-day complication rates, and emergency department (ED) visits or readmissions. Secondary outcomes included stone-free rates (SFR). Results: Seventy-six patients had anterior calyceal entry and 24 had posterior. No significant differences were found in terms of baseline demographics (age, body mass index), stone characteristics (location, density, complexity), or intraoperative features (operative time, location of access). Safety outcomes, including intraoperative complications (1% vs 4%), blood transfusions (3% vs 8%), 30-day complication rates (17% vs 21%), and ED visits (1% vs 0) or readmissions (11% vs 21%) were comparable between groups. Overall SFRs were equivalent (86% vs 90%). Conclusion: We found that anterior and posterior accesses in sPCNL offer similar safety and efficacy, with no significant differences in complications or SFRs. Surgeons can select either approach based on patient anatomy and surgical needs without concern for increased complications. Further research is necessary to confirm these findings and guide best practices for calyx selection in sPCNL.

What should the optimal access site be for percutaneous treatment of anterior lower pole calyx stones?

OBJECTIVES

Compared to other stone groups, anterior calyx stones are more challenging for endourologists to treat. This study aims to evaluate the differences between our latest technique and conventional techniques for treating anterior calyx stones in the lower pole.

MATERIALS AND METHODS

Patients with isolated anterior lower pole calyx or complex lower pole stones with anterior calyx branching were included in the study. The first group included lower pole access, while the second group included percutaneous treatment through the middle or upper pole. In the first group, the posterior calyx or direct anterior calyx approach was utilised depending on whether the stone was isolated calyx, complex structure or calyx anatomy, while in the second group, percutaneous nephrolithotomy was performed through the middle or upper pole posterior calyx access.

RESULTS

There were 37 patients in Group 1 and 25 patients in Group 2. Both groups were similar regarding patient age, sex, stone burden, and stone localisation (p > 0.05). When comparing operative and post-operative data between groups, it was found that the stone clearance rate, number of accesses, and haematocrit decrease were statistically superior in the second group (p: 0.003, p: 0.002, p: 0.018), with no significant difference in mean operative time, length of hospital stay, fluoroscopy time and pain score (p > 0.05).

CONCLUSIONS

Percutaneous surgery utilising an access from a calyx distal to the stone may offer better clearance and lower morbidity rates for lower pole stones involving the anterior calyx.

Thulium fiber laser vs Ho:YAG in RIRS: a prospective randomized clinical trial assessing the efficacy of lasers and different fiber diameters (150 µm and 200 µm)

INTRODUCTION

The aims of the study: (1) to compare the Super Pulse Thulium Fiber Laser (SP TFL) and the holmium: yttrium-aluminium-garnet (Ho:YAG) lasers in retrograde intrarenal surgery (RIRS); (2) to compare the efficacy of SP TFL laser fibers of different diameters (150 μm and 200 μm).

METHODS

A prospective randomized single-blinded trial was conducted. Patients with stones from 10 to 20 mm were randomly assigned RIRS in three groups: (1) SP TFL (NTO IRE-Polus, Russia) with fiber diameter of 150 μm; (2) SP TFL with 200-μm fiber; and (3) Ho:YAG (Lumenis, USA) with 200-μm fiber.

RESULTS

Ninety-six patients with kidney stones were randomized to undergo RIRS with SP TFL using a 150-μm fiber (34 patients) and a 200-μm fiber (32 patients) and RIRS with Ho:YAG (30 patients). The median laser on time (LOT) in the 200-μm SP TFL group was 9.2 (6.2-14.6) min, in 150-μm SP TFL-11.4 (7.7-14.9) min (p = 0.390), in Ho:YAG-14.1 (10.8-18.1) min (p = 0.021). The total energy consumed in 200-μm SP TFL was 8.4 (5.8-15.2) kJ; 150-μm SP TFL - 10.8 (7.3-13.5) kJ (p = 0.626) and in Ho:YAG-15.2 (11.1-25.3) kJ (p = 0.005).

CONCLUSIONS

Irrespective of the density, RIRS with SP TFL laser has proven to be both a safe and effective procedure. Whilst the introduction of smaller fibers may have the potential to reduce the duration of surgery, SP TFL results in a reduction in the LOT and total energy for stone ablation in RIRS compared with Ho:YAG.

Anatomical approach to PCNL: concept of ideal puncture zone in a 3D perspective

To describe a concept of ideal 'puncture zone' as against any single ideal 'puncture tract' for percutaneous nephro-lithotomy (PCNL) and present our results. Through this narrative, we aim to reduce the gaps in inter-understanding of an erstwhile description of ideal tract and real-life puncture making. The puncture zone principle was applied for our novel puncture making technique during PCNL. The largest imaginary cone that can fit into a respective calyx, with its tip in the pelvis defines the 'puncture zone' for that calyx. This concept allows fine-tuning of the ideal puncture tract based upon the desired corresponding manipulation zone and also shifts the focus of puncture making to infundibulum anatomy from the tip of calyx. The surgical technique and retrospective review of 136 cases done between 2015 and 2021 using this concept are presented. Primary outcome included stone-free rate, pseudo-aneurysm and blood transfusion at 3 months of follow-up. 33 cases had multiple (> 3) stones, 21 only calyceal/infundibular stones, eight partial staghorn and 12 were complete staghorn stones. Mean stone size was 29 ± 15 (Range: 5-53) mm. Complete clearance was achieved in 127 cases, four of which required two tracts. Blood transfusion was required in one case. No pseudo-aneurysms were encountered. The puncture zone concept has provided good results in our hands. It may help easier understanding of PCN puncture making and provides a background for reconciliation between description of an ideal tract and practical puncturing techniques used by different surgeons.

Effect of Percutaneous Nephrolithotomy Combined with Needle Nephrolithotomy on Renal Function and Complication Rate in Patients with Complex Renal Calculi

Objective

To investigate the effect of percutaneous nephrolithotomy combined with needle nephrolithotomy on renal function and incidence of complications in patients with complex renal calculi.

Methods

From March 2020 to March 2022, 88 patients with complex renal calculi were enrolled and divided into two groups. Percutaneous nephrolithotomy (PCNL) was performed in the control group, and percutaneous nephrolithotomy combined with needle nephrolithotomy was performed in the study group. Perioperative conditions, renal function parameters such as blood urea nitrogen (BUN), serum creatinine (Scr), and cystatin C (CysC) levels, inflammatory factors such as C-reactive protein (CRP) and procalcitonin (PCT) levels before surgery and 1 day after surgery were determined. The incidence of complications was statistically analyzed between two groups.

Results

There was no significant difference in stone clearance rate between the two groups. The operation time and hospital stay in the study group were shorter than those in the control group. The intraoperative blood loss was less than that in the control group. The VAS score was lower than that in the control group. BUN, Scr, and CysC in the study group were not significantly different from those in the control group. CRP and PCT in the two groups at 1 d after surgery were higher than those before surgery, but CRP and PCT in the study group were lower than those in the control group. The incidence of complications in the study group was lower than that in the control group.

Conclusion

Percutaneous nephrolithotomy combined with needle nephrolithotomy is effective and safe in the treatment of complex renal calculi.

Needle-perc-assisted endoscopic surgery for patients with complex renal stones: technique and outcomes

Our aim was to investigate the safety and efficacy of needle-perc-assisted percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS), namely, needle-perc-assisted endoscopic surgery (NAES), in a series of patients with large and/or complex renal stones. From May 2018 to August 2021, a total of 119 patients underwent NAES at our institute. Among them, 94 patients underwent needle-perc-assisted standard PCNL in prone position and 25 underwent needle-perc-assisted RIRS in the Galdakao-modified supine Valdivia position or prone split-leg position. Clinical factors including age, sex, medical history, and stone characteristics were collected. Intraoperative and postoperative outcomes were retrospectively evaluated. The patients' mean age ± standard deviation was 50.3 ± 14.3 years. The mean stone size was 7.6 ± 3.7 and 1.7 ± 0.8 cm for needle-perc-assisted PCNL and RIRS, respectively. Of the 119 patients, 51 had staghorn stones, 16 had solitary kidneys, 17 had a history of ipsilateral renal surgery, and 6 had calyceal diverticular stones. The mean operative time was 83.4 ± 25.9 min for needle-perc-assisted PCNL and 66.3 ± 21.8 min for needle-perc-assisted RIRS. The stone-free rate (SFR) for needle-perc-assisted PCNL was 77.7% after the first treatment and 88.3% after auxiliary treatments. The SFR for needle-perc-assisted RIRS was 88.0% and no auxiliary treatments were carried out in this group. Eleven (11.7%) patients who underwent needle-perc-assisted standard PCNL developed Clavien-Dindo grade I or II complications. Three (12.0%) patients who underwent needle-perc-assisted RIRS developed a fever (grade I). The overall complication rate for NAES was 11.8%, with no urosepsis, angioembolization, or other grade III to V complications. In conclusion, NAES is a safe and effective procedure for one-step complete resolution of large and/or complex renal stones with no additional procedure-related complications.

Double-Sheath Vacuum Suction Minimally Invasive Percutaneous Nephrolithotomy for Management of Large Renal Stones

OBJECTIVES

This study aimed to describe a novel double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (mini-PCNL) to overcome the deficiencies of the conventional procedure.

PATIENTS AND METHODS

Between March 2019 and December 2019, 65 patients (37 males and 28 females) with a mean age of 41 years (range 23-69) underwent mini-PCNL with double-sheath vacuum suction. It consisted of an F20 Y-shaped sheath as an outer sheath and an F16 Y-shaped sheath as an inner sheath, in which the inner sheath was longer than the outer sheath. The oblique arm of the outer sheath and the inner sheath was connected to the perfusion inflow and the vacuum suction, respectively. A 550-μm holmium-YAG laser was introduced for stone fragmentation through the working channel of the mini-nephroscope, which was no longer connected to the perfusion fluid.

RESULTS

All procedures were successful. Mean operation time was 50.2 min (range 39-83). Mean hemoglobin decrease was 5.2 g/L (range 1.0-15.5), and no patient needed a blood transfusion. One patient (1.5%) with low fever (<38°C) at day 1 had returned to normal at day 2 without administration of antibiotics. There were no Clavien grade 2-4 complications. Mean postoperative hospital stay was 2.4 days (range 2-6). The initial stone-free rate of PCNL was 81.53% (53 of 65 patients). One month after surgery, the final stone-free rate increased to 90.77% (59/65 patients).

CONCLUSIONS

The double-sheath vacuum suction mini-PCNL is a safe and effective modality for large renal stones, which might increase the efficiency of stone extraction with low intrapelvic pressure.

The impact of anterior calyceal stones on the outcomes of percutaneous nephrolithotomy for complex kidney stones: a comparative study

BACKGROUND

This study aimed to evaluate the possible effect of anterior calyceal stones on the surgical outcomes of percutaneous nephrolithotomy.

METHODS

Consecutive patients with complex kidney stones from 2012 to 2020 were evaluated retrospectively. In total, 219 patients were divided into 2 groups based on the presence of anterior calyceal stones (group 1; N.=89) or not (group 2; N.=130). The groups were compared in terms of surgical outcomes (i.e., stone-free rate [SFR], operation time, and hemoglobin drop) and complications.

RESULTS

The patient demographics and stone characteristics were similar between the groups. Multiple access was more frequently done in group 1 than it was in group 2 (47.2% vs. 30.8%; P=0.014), and the SFR was lower in group 1 (51.7%) than it was in group 2 (67.7%; P=0.017). Of the anterior calyceal stones in group 1, 42.6% could not be cleaned. However, when excluding patients who have only anterior residual stones from the statistical analysis, the groups had similar SFRs (68.5% vs. 67.7% for group 1 and group 2, respectively).

CONCLUSIONS

The presence of complex kidney stones with anterior calyceal extension are associated with higher residual stones rates in the anterior calyx. Also, it increases multiple access, the operation time, and level of hemoglobin drop.