1.Association between preoperative hydronephrosis and perioperative outcomes among patients undergoing percutaneous nephrolithotomy: A single-center prospective cohort study.
Dainiel Edgar A. Reyes ; Albert T. Aquino
Philippine Journal of Urology 2026;36(1):21-28
BACKGROUND
Staghorn calculi are complicated renal stones that are frequently linked to hydronephrosis, a parameter that can have a major impact on the results of surgery. Percutaneous nephrolithotomy (PCNL) is widely recognized as the gold standard for treating large kidney stones and staghorn calculi. Data on the effect of preoperative hydronephrosis on PCNL perioperative outcomes is still limited.
OBJECTIVEThis study aimed to investigate the association between preoperative hydronephrosis and perioperative outcomes among patients undergoing PCNL in a tertiary government hospital in Manila.
METHODSA single-center prospective cohort study was conducted, involving 90 patients diagnosed with staghorn calculi and scheduled for elective PCNL. Patients were categorized into two groups based on the presence or absence of moderate-to-severe hydronephrosis as determined by preoperative imaging. Perioperative outcomes, including total operative time, access time, lithotripsy time, and perioperative complications such as bleeding and sepsis, were evaluated. Data were analyzed using linear and logistic regression models to assess associations between hydronephrosis and perioperative outcomes.
RESULTSThe presence of hydronephrosis was associated with a statistically significant reduction in access time (p = 0.036), likely due to the dilation of renal structures facilitating easier entry. However, hydronephrosis was linked to a borderline significant reduction in lithotripsy rate (p = 0.051), indicating potential challenges in stone fragmentation. No significant association was found between hydronephrosis and total operative time or perioperative complications, such as bleeding and sepsis.
CONCLUSIONWhile hydronephrosis may make kidney access and other technical aspects of PCNL easier, it may also make stone fragmentation more difficult. Larger stone size and stone location were significant predictors of longer operative times and slower lithotripsy rates, underscoring their critical role in surgical outcomes.
Human ; Staghorn Calculi ; Nephrolithotomy, Percutaneous ; Kidney Calculi ; Hydronephrosis
2.Analysis of risk factors for developing sepsis in patients who underwent percutaneous nephrolithotomy at the National Kidney and Transplant Institute: A retrospective study.
Martin Joseph L. Alcaraz ; Arturo P. Castro Jr.
Philippine Journal of Urology 2026;36(1):29-39
OBJECTIVE
This study aimed to identify the different risk factors for developing sepsis in patients undergoing percutaneous nephrolithotomy
METHODSThis is a case-control study of all patients who underwent percutaneous nephrolithotomy in the National Kidney and Transplant Institute from 2017 to 2021. Demographic, stone characteristics, perioperative data and post-operative parameters were recorded. The association of clinical variables and sepsis was determined using logistic regression analysis.
RESULTSA total of 536 patients who underwent percutaneous nephrolithotomy were included in the study with 58 of them suffering from sepsis with a prevalence rate of 9.9%. The majority [392 (67.82%)] of the patients were 31-59 years old. Majority of patients suffering from sepsis also belonged to the same age group were predominantly male [33 (56.9%)], mostly diabetic [15 (26.32%)] and hypertensive [14 (24.56%)] and underwent previous PCNL [49 (8.45%)]. Imaging of patients who had sepsis showed staghorn calculi [30 (51.72%)] with mild [20 (34.48%)] and moderate [23 (39.66%)] seen on imaging. Patients who were requiring transfusion post operatively (Grade II Clavien-Dindo Classification) were seen to have sepsis.
CONCLUSIONThe following factors are contributory to the development of sepsis: a high Guy's stone score, high degree of obstruction or hydronephrosis, previous stone surgery and a higher volume of blood loss.
Human ; Nephrolithotomy, Percutaneous ; Sepsis ; Hydronephrosis
3.The use of artificial intelligence machine learning models to predict stone-free status after percutaneous nephrolithotomy: A meta-analysis
Rajiv H. Kalbit ; Enrique Ian S. Lorenzo ; Karl Marvin M. Tan
Philippine Journal of Urology 2025;35(2):97-106
OBJECTIVE
This meta-analysis aimed to evaluate the diagnostic capability of machine learning (ML) models in predicting stone-free status following percutaneous nephrolithotomy (PCNL).
METHODSA comprehensive literature search was conducted across MEDLINE, Embase, Scopus, Cochrane, Google Scholar and supplementary databases was undertaken until June 2023. Inclusion criteria were English publications assessing the sensitivity and specificity of ML in predicting post PCNL stone-free status. Studies on non-human subjects or with incomplete data sets were excluded. Quality assessment utilized the Cochrane Risk of Bias Tool. Pooled sensitivity, specificity, and other diagnostic metrics were calculated using Meta-Disc 1.4 software.
RESULTSOf the 65 initial articles, 5 met the inclusion criteria, representing a total of 1,773 participants. The accuracy of ML models ranged from 44% to 94.8%. The pooled sensitivity and specificity were 0.60 (95% CI [0.57, 0.63]) and 0.87 (95% CI [0.84, 0.89]), respectively. The pooled positive likelihood ratio was 4.69 (95% CI [3.82, 5.77]) and the negative likelihood ratio was 0.45 (95% CI [0.41, 0.48]). The diagnostic odds ratio was 10.93 (95% CI [8.35, 14.33]). The area under the curve (AUC) stood at 0.9372, signifying an excellent diagnostic performance.
CONCLUSIONMachine learning models demonstrate significant potential in accurately predicting stone-free status post-PCNL. However, the small number of included studies, retrospective designs, and heterogeneity in ML approaches limit generalizability. Standardized definitions, larger multicenter datasets, and prospective validation are required before routine clinical adoption.
Human ; Male ; Female ; Meta-analysis ; Artificial Intelligence ; Machine Learning ; Nephrolithotomy, Percutaneous
4.Analysis of the clinical efficacy and safety of a single upper pole access (SUPA-PCNL) for staghorn calculi: A prospective single center descriptive study
Lester Anthony H. Florencio ; Jose Benito A. Abraham
Philippine Journal of Urology 2025;35(1):1-8
INTRODUCTION AND OBJECTIVE
The endoscopic management of staghorn calculi is very challenging owing to its complex anatomical configuration. The authors analyzed the clinical efficacy and safety of a single upper pole access PCNL (SUPA-PCNL) for Guy Stone Score (GSS) 3-4 staghorn calculi.
METHODSProspective data collection was done on 56 consecutive patients who with GSS 3-4 staghorn calculi. All cases were treated with a standardized technique of a single upper pole access PCNL in the prone position. The patient demographics, stone characteristics, perioperative and postoperative outcomes were analyzed.
RESULTSThe cohort exhibited diversity in age (51.7+12), gender (male to female ratio of 5.5:4.5) comorbidities, and stone burden (4.82+1.96 cm). SUPA-PCNL demonstrated a high median stonefree rate (99.5%, IQR 90-100) with minimal complications, low blood loss with a of 200cc (IQR 100-300), and median hospital stay of 3.5 days (IQR 3-5). Stone characteristics did not significantly influence outcomes. A subset required secondary treatments (12%, n=7), but overall morbidity was low (16%, n=9): (7% n=4) of which required blood transfusion, and (9% n=5) due to sepsis. The following factors were associated with increased odds of perioperative morbidity: preoperative creatinine >3 mg/dl (OR 4.19 95% Cl 0.59 – 29.71 p=0.152) and a history of endoscopic surgery (OR 7.33 95% Cl 1.20-44.96 p=0.031).
CONCLUSIONSUPA-PCNL is effective and safe for the treatment of staghorn calculi. In select patients, this approach obviates the need for a multi-tract access or an endoscopically-combined intrarenal surgery (ECIRS).
Human ; Nephrolithotomy, Percutaneous ; Morbidity ; Staghorn Calculi
5.Laparoscopically assisted ureterocystoplasty on a solitary functioning kidney: A novel technique for urinary bladder augmentation
Kurt Roland A. Asperas ; Jose Benito Abraham ; Ernesto L. Gerial jr.
Philippine Journal of Urology 2025;35(1):32-36
Augmentation intestinal cystoplasty is usually the preferred method. However, this is complicated by mucus production, recurrent infection and cystolithiasis. In this report, the authors present a unique case of laparoscopically-assisted ureterocystoplasty and describe the operative technique and its advantages.
A 68-year-old female with a contracted urinary bladder and a solitary functioning kidney was diverted with a percutaneous nephrostomy tube for the past ten years. She consulted for a possible reconstructive procedure.
After a comprehensive preoperative evaluation, she underwent laparoscopically-assisted ureterocystoplasty. The operative time was 265 minutes with minimal blood loss. She had an unremarkable postoperative course. On follow-up, a voiding diary revealed urine volume of around 300 milliliters at 3 hour intervals, preservation of renal function, and no evidence of urinary infection.
Ureterocystoplasty was done using a combination of minimally invasive and open techniques. This procedure spared the patient a lifelong diversion with a nephrostomy tube and provided a better quality of life.
Human ; Female ; Aged: 65-79 Yrs Old ; Nephrostomy, Percutaneous
6.Comparative analysis of blood loss and transfusion requirements among patients with Staghorn Calculus undergoing Percutaneous Nephrolithotomy versus Open Stone Surgery in National Kidney and Transplant Institute: 2018-2019.
Rosa Jea A. Llanos ; Jose Benito A. Abraham
Philippine Journal of Urology 2023;33(1):12-18
BACKGROUND:
Percutaneous nephrolithotomy (PCNL) is the standard of care for the treatment of renal
stones >2cm and staghorn calculi. This minimally invasive procedure however has intraoperative
hemorrhage as one of its most dreaded complications.
OBJECTIVE:
To analyze the rate of hemorrhage and transfusion requirements among patients undergoing
either PCNL or open stone surgery (OSS).
METHODS:
This was a retrospective study conducted at the National Kidney and Transplant Institute
Medical Records Department. Data were collected for the period of January 2018 to December 2019.
RESULTS:
One hundred forty cases were included, 102 patients in the PCNL group and 38 in the OSS.
The mean age 50.84±11.89 vs. 50.50±10.09 with male to female ratio of 1.2:1 for PCNL and open
surgery, respectively. The most common comorbidity was hypertension (89, 63.6%). As regards stone
size, majority had >4 cm stone size (61; 43.9%). In PCNL, there was no significant change noted in the
hemoglobin (14.69±13.3 vs 12.03±1.91, p= 0.099) as compared to OSS, where there was significant
decline (12.77±2.64 vs. 11.06±2.52; = .000. The number of packed red cell units for transfusion was
also significantly higher in OSS compared to PCNL group (.526±.861 vs. 159±.502, p .020.)
CONCLUSION
In the treatment of staghorn calculi, PCNL incurs less blood loss and lower transfusion
requirements compared to open stone surgery.
percutaneous nephrolithotomy
;
blood transfusion
;
hemorrhage
7.Analysis of the clinical efficacy and safety of percutaneous nephrolithotomy in patients with anatomical variations: A single center retrospective study
Donnel Guenter Rubio ; Jose Benito A. Abraham
Philippine Journal of Urology 2023;33(2):47-51
Introduction and Objective:
Percutaneous Nephrolithotomy (PCNL) is the standard of care for renal stones >2cm. Kidneys with anatomical disparities resulting from fusion (horseshoe), malrotation, ectopic location (allografts) and bifid collecting systems present as a challenge because variations in vasculature, calyceal rotation and intervening viscera may make percutaneous access treacherous. Reported here is the authors’ experience with PCNL in these types of kidneys.
Methods:
A chart review was done on all patients who underwent PCNL at the National Kidney and Transplant Institute (NKTI) from 2012-2016. Those with anatomical variations were identified and analyzed. Patient demographics (age, gender, co-morbidity) and stone characteristics (Guy’s stone score, laterality) were summarized. Intraoperative parameters such as location of puncture site (upper, mid, inferior calyces), number of tracts (single vs. multiple), operative time, estimated blood loss (EBL), and length of hospital stay (LOS) were analyzed. The primary endpoints were stone-free and complication rates according to the Clavien-Dindo (CD) classification.
Results:
A total of 1,657 PCNLs were performed during the study period, of which 42 had anatomical variants. The mean age was 45.2±8.8 (R= 28-65) with a male to female ratio of 3:1. There were 18 horseshoe (42.9%), 15 bifid (35.7%), 7 malrotated (16.7%) and 2 renal allografts (4.8%.); Laterality- wise, 28 (67%) were left-sided, 12 (29%) were right-sided and 2 (5%) had right-sided pelvic kidneys (allografts). The Guy stone scores were 3 and 4 in 13 (30%) and 29 (70%) patients, respectively. The mean stone diameter was 3.8±0.6 cms. (R=2.5-5.5). Majority, n=37 (88%) were treated with an upper pole access. Thirty-six (86%) needed a single tract and while six (14%) required multiple tracts (bifid pelvis). The mean operative time was 111.5±28.1 mins. (R=65-188), EBL was 461±278.4 cc (R=200-1300). LOS was 3.6±0.94 days (R=2-7). The stone-free rate was 95%. Twenty-five (59.5%) complications were documented. Fifteen (35.7%) had fever: Grade I CD, and 10 (23.8%) required transfusion: Grade II CD. There was no mortality.
Conclusion
PCNL still persists as the treatment of choice for nephrolithiasis in kidneys with variations in anatomy or position. A high stone clearance rate can be achieved while minimizing complications.
Nephrolithotomy, Percutaneous
8.Bacteriology and antibiotic sensitivity pattern of isolates in patients who underwent Percutaneous Nephrolithotripsy (PCNL) at the Philippine General Hospital: A retrospective cohort study.
Joan Marie S. FLOR ; Marie Carmela M. LAPITAN
Acta Medica Philippina 2022;56(6):87-94
Background. Despite being a clean-contaminated procedure, performed only in patients with sterile urine preoperatively, percutaneous nephrolithotripsy (PCNL) is associated with significant infectious perioperative complications. A local antibiogram is of paramount importance in optimizing antibiotic prophylaxis in PCNL because of the substantial variation in bacterial distribution and antibiotic sensitivity worldwide.
Objectives. The incidence of post-PCNL infectious complications, microorganism distribution, and antibiotic sensitivities from patients admitted for PCNL was determined. The risk factors associated with positive cultures and the development of fever and bacteremia were also analyzed.
Methods. A retrospective study of 102 patients who underwent PCNL under a surveillance protocol was done. The susceptibility of isolates from different specimens was evaluated against the most common antibiotics in the hospital. Chi-square and Student's t-test were used to determine differences in the frequencies and means for other risk factors for those who developed fever and urosepsis and those who did not.
Results. The incidence of fever and urosepsis was 25% and 4%, respectively. The most common organism on urine specimens was Escherichia coli which showed high sensitivity to aminoglycosides. The most common isolate on stones was Pseudomonas aeruginosa, which showed higher sensitivities to the fluoroquinolones. The isolates showed nearly consistent resistance to ceftriaxone. No significant association was found between the clinical variables studied and the occurrence of infectious complications.
Conclusion. There are comparable rates of infectious complications to published literature. A change in antibiotic prophylaxis was warranted, given the high resistance to ceftriaxone and the predominance of Pseudomonas aeruginosa on stone isolates. Further surveillance is required to identify significant risk factors for the development of post-PCNL infectious complications.
Nephrolithotomy, Percutaneous ; Bacteriology ; Microbial Sensitivity Tests ; Nephrolithiasis
9.Comparison of mini-percutaneous nephrolithotomy and retroperitoneal laparoscopic ureterolithotomy for treatment of impacted proximal ureteral stones greater than 15 mm.
Guo-Liang LU ; Xiao-Jin WANG ; Bao-Xing HUANG ; Yang ZHAO ; Wei-Chao TU ; Xing-Wei JIN ; Yuan SHAO ; Da-Wei WANG
Chinese Medical Journal 2021;134(10):1209-1214
BACKGROUND:
The optimal treatment for large impacted proximal ureteral stones remains controversial. The aim of this study was to evaluate the efficacy, safety, and potential complications of mini-percutaneous nephrolithotomy (MPCNL) and retroperitoneal laparoscopic ureterolithotomy (RPLU) in the treatment of impacted proximal ureteral stones with size greater than 15 mm.
METHODS:
A total of 268 patients with impacted proximal ureteral stones greater than 15 mm who received MPCNL or RPLU procedures were enrolled consecutively between January 2014 and January 2019. Data on surgical outcomes and complications were collected and analyzed.
RESULTS:
Demographic and ureteral stone characteristics found between these two groups were not significantly different. The surgical success rate (139/142, 97.9% vs. 121/126, 96.0%, P = 0.595) and stone-free rate after 1 month (139/142, 97.9% vs. 119/126, 94.4%, P = 0.245) of RPLU group were marginally higher than that of the MPCNL group, but there was no significant difference. There was no significant difference in the drop of hemoglobin between the two groups (0.8 ± 0.6 vs. 0.4 ± 0. 2 g/dL, P = 0.621). The mean operative time (68.2 ± 12.5 vs. 87.2 ± 16.8 min, P = 0.041), post-operative analgesics usage (2/121, 1.7% vs. 13/139, 9.4%, P = 0.017), length of hospital stay after surgery (2.2 ± 0.6 vs. 4.8 ± 0.9 days, P < 0.001), double J stent time (3.2 ± 0.5 vs. 3.9 ± 0.8 days, P = 0.027), time of catheterization (1.1 ± 0.3 vs. 3.5 ± 0.5 days, P < 0.001), and time of drainage tube (2.3 ± 0.3 vs. 4.6 ± 0.6 days, P < 0.001) of MPCNL group were significantly shorter than that of the RPLU group. The complication rate was similar between the two groups (20/121, 16.5% vs. 31/139, 22.3%, P = 0.242).
CONCLUSIONS
MPCNL and RPLU have similar surgical success and stone clearance in treating impacted proximal ureteral stones greater than 15 mm, while patients undergoing MPCNL had a lower post-operative pain rate and a faster recovery.
Humans
;
Laparoscopy
;
Length of Stay
;
Nephrolithotomy, Percutaneous/adverse effects*
;
Retroperitoneal Space/surgery*
;
Treatment Outcome
;
Ureteral Calculi/surgery*
10.Percutaneous nephrolithotomy with X-ray free technique in morbidly obese patients.
Bo XIAO ; Xue ZENG ; Gang ZHANG ; Song JIN ; Wei-Guo HU ; Jian-Xing LI
Chinese Medical Journal 2021;134(20):2500-2502


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