Technical aspects to maximize the hyperaccuracy three-dimensional (HA3D™) computed tomography reconstruction for kidney stones surgery: a pilot study

The aim of the current prospective pilot study was to describe a hyperaccuracy three-dimensional (HA3D^™) model reconstruction technique, specifically developed to maximize the visualization of the renal collecting system's anatomy, and its relationship with the stones, vessels and renal parenchyma, and to compare the HA3D^™ virtual models with the intraoperative findings. The image acquisition was performed using a CT scanner (Toshiba, Aquilion Prime) and included the unenhanced, arterial, venous and excretory phases. The DICOM format CT images were processed by MEDICS Srl ( www.medics3d.com , Turin, Italy). In total, study included three patients with renal stone scheduled for non-papillary prone percutaneous nephrolithotomy (PCNL). The median age and BMI were 51 (range 49-54) and 25.5 (range 25.0-32.7), respectively. The median stone size was 1170 mm² (range 830-1520) and median stone density was 1130 HU (range 600-1340). In all cases, the quality of the CT images acquired with our protocol was adequate to perform the HA3D^™ reconstruction. Median operative and puncture time were 39.4 (range 35.2-44.0) and 1.9 (range 1.8-2.1) mins, respectively. The success rate for the first attempt of the percutaneous puncture was 100%, and only one PCNL tract was sufficient to complete the surgery. All three patients were stone-free on the third postoperative day. A dedicated imaging acquisition protocol and a tailored 3D model reconstruction process specifically developed for kidney stones treatment allow obtaining HA3D^™ highly relevant models to greatly match intraoperative findings during PCNL with the potential of minimizing bleeding and organ injury complications.

Percutaneous antegrade management of large proximal ureteral stones using non-papillary puncture

Objective

To evaluate the feasibility and the safety of medial non-papillary percutaneous nephrolithotomy (npPCNL) for the management of large proximal ureteral stones.

Methods

We evaluated prospectively collected data of 37 patients with large proximal ureteral stones more than 1.5 cm in diameter treated by prone npPCNL. Depending on stone size, in-toto stone removal or lithotripsy using the Lithoclast® Trilogy (EMS Medical, Nyon, Switzerland) was performed. Perioperative parameters including operative time (from start of puncture to the skin suturing), stone extraction time (from the first insertion of the nephroscope to the extraction of all stone fragments), and the stone-free rate were evaluated.

Results

Twenty-one males and 16 females underwent npPCNL for the management of large upper ureteral calculi. The median age and stone size of treated patients were 58 (interquartile range [IQR]: 51-69) years and 19.3 (IQR: 18.0-22.0) mm, respectively. The median operative time and stone extraction time were 25 (IQR: 21-29) min and 8 (IQR: 7-10) min, respectively. One case (2.7%) of postoperative bleeding and two cases (5.4%) of prolonged fever were managed conservatively. The stone-free rate at a 1-month follow-up was 94.6%.

Conclusion

The npPCNL provides a straight route to the ureteropelvic junction and proximal ureter. Approaching from a dilated portion of the ureter under low irrigation pressure with larger diameter instruments results in effective and safe stone extraction within a few minutes.

Non-papillary prone percutaneous nephrolithotomy for renal abnormalities: single-institution experience

PURPOSE

To evaluate the effectiveness and safety of non-papillary prone PCNL for the treatment of patients with renal abnormalities.

METHODS

An observational retrospective cohort study including PCNL cases of patients with renal abnormalities was performed. The following inclusion criteria were applied: renal stones > 1.5 cm with maximal diameter, anatomical malformations of affected kidney (malrotated kidneys, horseshoe kidneys and kidneys with complete duplicated systems, medullary sponge kidney), patients treated with standard (30Fr) PCNL or mini-PCNL (22Fr). The lithotripsy was performed using the Lithoclast Master or the Lithoclast^® Trilogy (EMS Medical, Nyon, Switzerland).

RESULTS

Overall, 57 patients, 35 males, and 22 females with any renal malformation underwent non-papillary prone PCNL. Our study included 25 patients with horseshoe kidneys, 21 with malrotated kidneys, 9 with kidneys with duplicated pelvicalyceal systems and 2 with medullary sponge kidneys. The mean cumulative stone size was 36 ± 1.4 mm and most of the stones were in the lower calyceal group (36.9%) and in the pelvis (27.2%). The stone-free rate (SFR) was 84.2% and the mean hospitalization time was 2.7 ± 0.7 days. In total, postoperative complications were developed in six patients (10.5%), half of them presenting fever and the other half requiring blood transfusion (Grade II).

CONCLUSION

The PCNL is the method of choice for treating large stones in anomalous kidneys. The generally accepted panacea that only a papillary puncture is safe is questioned by our results. Based on our experience, a non-papillary puncture proved to be a safe and effective procedure.