Nephrostomy

A total of 155 consecutive sPCNL cases were included from January 2004 through July 2012 at Seoul National University Bundang Hospital. Percutaneous renal access was routinely obtained by 2 experienced uro-radiologists 1 day before or on the operative day. If the patient previously had a percutaneous nephrostomy, this nephrostomy was used as an access. sPCNL was performed in a prone position by 1 of 4 faculty professors. A rigid nephroscope was used in combination with a ballistic lithotripter, stone forceps, and a suction tube. If needed, a flexible nephroscope and/or ureteroscope were also used for collecting systems that were inaccessible with a rigid nephroscope. In this setting, a Holmium laser and stone basket were used. Temporary drainage was usually maintained with a 14-F nephrostomy catheter.
All patients were evaluated with pre- and post-operative computed tomography (CT). The evaluated preoperative stone parameters included the number, largest diameter, total stone volume, renometry (complete, partial staghorn, or other), average Hounsfield units, and degree of hydronephrosis (normal, mild, moderate, or severe). A complete staghorn stone was defined as a renal pelvic calculi extending into all major calyceal groups filling at least 80% of the renal collecting system, and a partial staghorn stone was defined as a renal pelvic calculi extending into at least two calyceal groups. Stone volume was calculated by length×width×depth×π×0.52. The total stone volume was the sum of all stone volumes. The average Hounsfield unit was measured using the elliptical region of interest incorporated into the largest stone area in a non-contrast axial image [9] (link). “Stone-free” was defined as no evidence of residual stones on postoperative images for 1 month.

According to our internal protocol, uncomplicated procedures were managed as follows: the bladder catheter was removed on postoperative day one and the nephrostomy tube was closed; on postoperative day two a percutaneous pyelography was performed to assess ureteral canalization and the presence of residual stones. If ureteral canalization was confirmed, the nephrostomy tube was removed. Patients were discharged on postoperative day three.
The Guy’s stone score was used to grade the complexity of vamPCNL [25 (link)]. Postoperative complications were graded according to the PCNL-adjusted Clavien Score [26 (link), 27 (link)]. Patients were evaluated within 3 months after surgery with non-contrast enhanced CT scan to identify residual stones. The CT-based postoperative stone-free rate (ctSFR) was defined as the absence of residual fragments [17 (link)]. Patients with residual fragments were offered, according to stone dimension, observation or auxiliary procedures including second-look PCNL, extracorporeal shockwave lithotripsy, or retrograde intrarenal surgery.
We excluded patients with renal or skeletal anomalies (N = 21); scheduled staged procedures for large stone burden (N = 42); endoscopic combined intrarenal surgery procedures (N = 3). A final cohort of 235 patients who underwent vamPCNL for kidney stones was considered for statistical analysis.
Data collection adheres to the principles of the Declaration of Helsinki. All patients signed an informed consent agreeing to share their own anonymous information for future studies. The study was approved by the Foundation IRCCS Ca’ Granda, Ospedale Maggiore Policlinico Ethical Committee (Prot. 25508).

The primary efficacy outcome was overall survival, defined as time from randomisation to death from any cause. Failure-free survival was the primary activity outcome measure for interim analyses and was defined as time from randomisation to first evidence of at least one of: biochemical failure; progression either locally, in lymph nodes, or in distant metastases; or death from prostate cancer. Biochemical failure was based on a rise above the lowest PSA value reported within 24 weeks after enrolment of 50% and to at least 4 ng/mL; patients without a fall of 50% were considered to have biochemical failure at time zero. Secondary outcomes were progression-free survival (defined as failure-free survival but without biochemical events) and metastatic progression-free survival (defined as time from randomisation to new metastases or progression of existing metastases or death). Cause of death was determined by the site investigator, with some causes reclassified as prostate cancer according to predefined criteria that indicated prostate cancer to be the likely cause. Symptomatic local events were defined as any of the following: urinary-tract infection, new urinary catheterisation, acute kidney injury, transurethral resection of the prostate, urinary-tract obstruction, ureteric stent, nephrostomy, colostomy, and surgery for bowel obstruction. Patients without the event of interest were censored at the time last known to be event-free.

This single-centre, retrospective, observational and comparative study was exempted from further review by the Institutional Review Board (Bioethical Committee) of the Pomeranian Medical University, Szczecin, Poland, and was conducted in accordance with the regulations set forth by the Declaration of Helsinki. Patients included in this study routinely consented to participate in the study, specifically to allow the use of their anonymised treatment data for scientific purposes. We analysed consecutively admitted patients who were treated in the Department of Urology and Urological Oncology in Szczecin for an acute episode of urolithiasis during the first peak of SARS-CoV-2 infection in Poland (October–December 2020; Study group A). We compared them with patients admitted between October–December, 2019 (pre-COVID-19 era; Control group). In addition, to observe a changing pattern in the admission of patients with acute renal colic during the pandemic, we analysed the medical records of patients admitted consecutively during the second peak of COVID-19 cases in Poland (February–April 2021; Study group B). The selection of the analysed periods was based on the daily incidence of new SARS-CoV-2 cases in Poland. During the first peak of infection, the highest daily number of new cases was up to 30,000, whereas the highest recorded daily incidence during the second peak of the COVID-19 pandemic in Poland was 35,000 cases [10 (link)]. Throughout the pandemic, urological healthcare in Szczecin was significantly reorganised. The department that served as the focus of the present study was the only one to deal with emergency urological patients who did not suffer from COVID-19. Other urological departments in Szczecin were closed, and only one urological department was dedicated to hospitalising SARS-CoV-2-positive patients requiring emergency urological care.
For the present study, we only included patients who presented with symptoms of renal colic and required subsequent admission to the urological department. Indications for hospital admission included renal colic of a solitary kidney, bilateral renal colic, kidney injury, infected renal colic, intractable pain or nausea, and urinary extravasation. Before hospitalisation, each patient was examined by a urologist. Additionally, laboratory tests and urinary tract ultrasonography were performed to establish hydronephrosis. Finally, unenhanced computed tomography (CT) was performed to identify the location and size of the stones and to provide information regarding other potential aetiologies of pain. CT was also used to guide further management of the condition.
Data extracted from the medical records included age, gender, sex, body mass index (BMI), duration of symptoms, presence of fever, inflammatory markers, glomerular filtration rate (GFR), urinalysis, and urine and blood cultures. In addition, variables related to the presence of deposits on unenhanced CT, such as the size, location, and degree of hydronephrosis, were collected. Depending on the clinical presentation and images acquired, patients were qualified for further treatment: medical expulsive therapy (MET), urinary drainage (nephrostomy or double J stent implantation) with delayed definitive stone removal after the infection was cleared, or emergency removal of the deposit. Finally, all three analysed periods were compared to determine changing patterns in the clinical presentation of patients and management options chosen for acute episodes of urolithiasis after the reorganisation of emergency urological care due to the COVID-19 pandemic.

A total of 196 patients with ureteral stricture underwent balloon dilation between January 2012 and August 2022 at the Peking University First Hospital, Miyun Hospital, Emergency General Hospital, and Jian Gong Hospital. Baseline data and follow-up data were complete for 127 patients, including 97 patients with balloon dilation and 30 patients with balloon dilation combined with endoureterotomy (Figure 1 and Table 1). The patient’s phone number was empty and wrong, and the patient or his family members refused to follow up and lost contact. Clinical data, including general clinical data, perioperative data, balloon parameters at the time of surgery, and follow-up results, were collected in our Reconstruction of the Urinary Tract: Epidemiology and Result (RECUTTER) database [18 (link)].
Postoperative results of ureteral stenosis patients were collected at 3 months, 6 months, and 1 year after surgery, and the results of balloon dilatation treatment were evaluated at different periods and patients in each period were divided into two groups (failure group and non-failure group). One of the following conditions resulted in patients being allocated to the failure group: the reappearance of ureteral stricture and worsening of hydronephrosis on routine imaging (intravenous pyelogram, renal scan, retrograde pyelogram, ultrasound); the need for the repositioning of the DJ tube/nephrostomy tube; or surgical treatment. The remaining patients were allocated to the non-failure group.
The risk factor analysis included the following criteria: (a) patients with ureteral strictures detected through ureteroscopy or imaging. Imaging examinations include intravenous urography, computed tomography urogram, and magnetic resonance urography; (b) treatment with balloon dilation only and with technical success. Technical success is defined as the ability of the ureteroscope and guidewire to pass through the balloon-dilated ureteral stricture and successful retention of a double J ureteral stent. Exclusion criteria: (a) contraindication to surgery; (b) combined pregnancy; (c) conditions that the investigator needed to exclude; (d) incomplete data; and (e) a combined history of malignancy. The surgical outcome 3 months postoperatively was considered as the endpoint. In an analysis of risk factors for the failure of balloon dilatation alone, data from 97 patients were considered valid.
To compare the efficacy of balloon dilation versus balloon dilation combined with endoureterotomy in the treatment of lower segment ureteral stricture, patients with multi-segmental strictures were excluded.
The endpoint was clarified by a telephone follow-up, and the true validity of the clinical data was verified in 127 patients. The information collected included gender, age, BMI, preoperative renal function (preoperative creatinine, preoperative urea nitrogen, preoperative blood eGFR), ureteral stricture length, ureteral stricture site, whether there was a history of urologic surgery, balloon circumference, balloon pressure, and duration of dilation. The risk factors for recurrence after the balloon dilation of ureteral stricture were investigated according to whether the patients’ surgical outcome had failed or been successful, as of the endpoint.
A total of 127 patients with complete data after follow-up were included in this study. There were 97 patients with balloon dilatation alone and 30 patients with balloon dilatation combined with endoureterotomy. There were 67 patients with lower segment ureteral stricture, of which 30 received balloon dilatation combined with endoureterotomy and 37 received balloon dilatation alone. Among 97 patients who underwent balloon dilatation alone, 10 patients had multiple ureteral stenosis, 4 patients had middle ureteral stenosis, and 83 patients had upper and lower ureteral stenosis.
This study was designed and conducted in accordance with the principles of the Declaration of Helsinki (revised 2013) and was approved by the Ethics Committee of Peking University First Hospital. Individual consent was waived due to the retrospective nature of this study.