Increased Apolipoprotein A1 Expression Correlates with Tumor-Associated Neutrophils and T Lymphocytes in Upper Tract Urothelial Carcinoma.

An increased neutrophil-to-lymphocyte ratio (NLR) is a poor prognostic biomarker in various types of cancer, because it reflects the inhibition of lymphocytes in the circulation and tumors. In urologic cancers, upper tract urothelial carcinoma (UTUC) is known for its aggressive features and lack of T cell infiltration; however, the association between neutrophils and suppressed T lymphocytes in UTUC is largely unknown. In this study, we examined the relationship between UTUC-derived factors and tumor-associated neutrophils or T lymphocytes. The culture supernatant from UTUC tumor tissue modulated neutrophils to inhibit T cell proliferation. Among the dominant factors secreted by UTUC tumor tissue, apolipoprotein A1 (Apo-A1) exhibited a positive correlation with NLR. Moreover, tumor-infiltrating neutrophils were inversely correlated with tumor-infiltrating T cells. Elevated Apo-A1 levels in UTUC were also inversely associated with the population of tumor-infiltrating T cells. Our findings indicate that elevated Apo-A1 expression in UTUC correlates with tumor-associated neutrophils and T cells. This suggests a potential immunomodulatory effect on neutrophils and T cells within the tumor microenvironment, which may represent therapeutic targets for UTUC treatment.

Oct4 and Hypoxia Dual-Regulated Oncolytic Adenovirus Armed with shRNA-Targeting Dendritic Cell Immunoreceptor Exerts Potent Antitumor Activity against Bladder Cancer.

Immunotherapy has emerged as a promising modality for cancer treatment. Dendritic cell immunoreceptor (DCIR), a C-type lectin receptor, is expressed mainly by dendritic cells (DCs) and mediates inhibitory intracellular signaling. Inhibition of DCIR activation may enhance antitumor activity. DCIR is encoded by CLEC4A in humans and by Clec4a2 in mice. Gene gun-mediated delivery of short hairpin RNA (shRNA) targeting Clec4a2 into mice bearing bladder tumors reduces DCIR expression in DCs, inhibiting tumor growth and inducing CD8+ T cell immune responses. Various oncolytic adenoviruses have been developed in clinical trials. Previously, we have developed Ad.LCY, an oncolytic adenovirus regulated by Oct4 and hypoxia, and demonstrated its antitumor efficacy. Here, we generated a Clec4a2 shRNA-expressing oncolytic adenovirus derived from Ad.LCY, designated Ad.shDCIR, aimed at inducing more robust antitumor immune responses. Our results show that treatment with Ad.shDCIR reduced Clec4a expression in DCs in cell culture. Furthermore, Ad.shDCIR exerted cytolytic effects solely on MBT-2 bladder cancer cells but not on normal NIH 3T3 mouse fibroblasts, confirming the tumor selectivity of Ad.shDCIR. Compared to Ad.LCY, Ad.shDCIR induced higher cytotoxic T lymphocyte (CTL) activity in MBT-2 tumor-bearing immunocompetent mice. In addition, Ad.shDCIR and Ad.LCY exhibited similar antitumor effects on inhibiting tumor growth. Notably, Ad.shDCIR was superior to Ad.LCY in prolonging the survival of tumor-bearing mice. In conclusion, Ad.shDCIR may be further explored as a combination therapy of virotherapy and immunotherapy for bladder cancer and likely other types of cancer.

Impact of pathological response on oncological outcomes in patients with upper tract urothelial cancer receiving neo-adjuvant chemotherapy.

PURPOSE: The purpose of this study is to evaluate the rates of pathological complete response (ypT0N0/X) and pathological response (ypT1N0/X or less) in patients with upper tract urothelial cancer who were treated with neo-adjuvant chemotherapy and to examine their impact on oncological outcomes. METHODS: This study is a multi-institutional retrospective analysis of patients with high-risk upper tract urothelial cancer who underwent neoadjuvant chemotherapy and radical nephroureterectomy between 2002 and 2021. Logistic regression analyses were used to investigate all clinical parameters for response after neoadjuvant chemotherapy. Cox proportional hazard models were performed to assess the effect of the response on the oncological outcomes. RESULTS: A total of 84 patients with UTUC who received neo-adjuvant chemotherapy were identified. Among them, 44 (52.4%) patients received cisplatin-based chemotherapy, and 22 (26.2%) patients had a carboplatin-based regimen. The pathological complete response rate was 11.6% (n = 10), and the pathological response rate was 42.9% (n = 36). Multifocal tumors or tumors larger than 3 cm significantly reduced the odds of pathological response. In the multivariable Cox proportional hazard model, pathological response was independently associated with better overall survival (HR 0.38, p = 0.024), cancer-specific survival (HR 0.24, p = 0.033), and recurrence-free survival (HR 0.17, p = 0.001), but it was not associated with bladder recurrence-free survival (HR 0.84, p = 0.69). CONCLUSION: Pathological response after neo-adjuvant chemotherapy and radical nephroureterectomy is strongly associated with patient survival and recurrence, and it might be a good surrogate for evaluating the efficacy of neo-adjuvant chemotherapy in the future.

Needle Tip Culture after Prostate Biopsy: A Tool for Early Detection for Antibiotics Selection in Cases of Post-Biopsy Infection.

PURPOSE: To investigate biopsy needle tip culture after prostate biopsies for bacteria prediction and antibiotics selection. MATERIALS AND METHODS: From May 2017 to April 2019, 121 patients who underwent a prostate biopsy were enrolled. All biopsy needle tips were sent for aerobic and anaerobic culture. Patients were divided into positive and negative culture groups. Perioperative data were recorded and compared between the two groups. The culture time and susceptibility of febrile patients were analyzed. Blood cultures were conducted for all patients who experienced fever after biopsy. The time and results of the needle and blood cultures were recoded for descriptive analysis. RESULTS: There were 59 (48.8%) positive needle cultures. Other than fever (p = 0.023), there were no statistical significances in clinical data between the two groups. Fever occurred in eight patients, and seven febrile patients had positive needle cultures, six of whom had positive blood cultures. These six needle and blood cultures were consistent with the susceptibility test results. As compared to the waiting time for blood cultures, target antibiotics were administered at an average of 48.0 h earlier based on needle cultures. None of the patients with positive anaerobic cultures developed a fever, while all eight febrile patients had negative anaerobic cultures. CONCLUSION: Fevers developed at statistically significant higher rate among those who had positive needle cultures. Needle and blood cultures were consistent with the susceptibility test results. Needle cultures can help us administer target antibiotics earlier to febrile patients without the need to wait for blood cultures.

Methylomics analysis identifies ZNF671 as an epigenetically repressed novel tumor suppressor and a potential non-invasive biomarker for the detection of urothelial carcinoma.

The molecular mechanism underlying the lethal phenomenon of urothelial carcinoma (UC) tumor recurrence remains unresolved. Here, by methylation microarray, we identified promoter methylation of the zinc-finger protein gene, ZNF671 in bladder UC tumor tissue samples, a finding that was independently validated by bisulphite pyrosequencing in cell lines and tissue samples. Subsequent assays including treatment with epigenetic depressive agents and in vitro methylation showed ZNF671 methylation to result in its transcriptional repression. ZNF671 re-expression in UC cell lines, via ectopic expression, inhibited tumor growth and invasion, in possible conjunction with downregulation of cancer stem cell markers (c-KIT, NANOG, OCT4). Clinically, high ZNF671 methylation in UC tumor tissues (n=96; 63 bladder, 33 upper urinary tract) associated with tumor grade and poor locoregional disease-free survival. Quantitative MSP analysis in a training (n=97) and test (n=61) sets of voided urine samples from bladder UC patients revealed a sensitivity and specificity of 42%-48% and 89%-92.8%, respectively, for UC cancer detection. Moreover, combining DNA methylation of ZNF671 and 2 other genes (IRF8 and sFRP1) further increased the sensitivity to 96.2%, suggesting a possible three-gene UC biomarker. In summary, ZNF671, an epigenetically silenced novel tumor suppressor, represents a potential predictor for UC relapse and non-invasive biomarker that could assist in UC clinical decision-making.

Bilateral ureteral complete obstruction with huge spontaneous urinoma formation in a patient with advanced bladder cancer.

Spontaneous rupture of the collecting system with extravasation of urine and urinoma formation is usually associated with urinary tract obstruction by a ureteral calculus. Tumor growth is an extremely rare cause of urinary extravasation. Here we report a case of bilateral obstructive uropathy with a huge spontaneous left retroperitoneal urinoma caused by advanced infiltrative transitional cell carcinoma of the urinary bladder. The point of leakage was located in the left renal pelvis. The urinary leakage ceased after percutaneous nephrostomy drainage, and the patient subsequently underwent radical cystoprostatectomy. Histopathology revealed a high-grade urothelial carcinoma of the urinary bladder with pelvic lymph node metastasis. The patient refused any adjuvant treatment and expired 6 months after the operation from disseminated metastasis from bladder cancer.

Distinct DNA methylation epigenotypes in bladder cancer from different Chinese sub-populations and its implication in cancer detection using voided urine.

BACKGROUND: Bladder cancer is the sixth most common cancer in the world and the incidence is particularly high in southwestern Taiwan. Previous studies have identified several tumor-related genes that are hypermethylated in bladder cancer; however the DNA methylation profile of bladder cancer in Taiwan is not fully understood. METHODS: In this study, we compared the DNA methylation profile of multiple tumor suppressor genes (APC, DAPK, E-cadherin, hMLH1, IRF8, p14, p15, RASSF1A, SFRP1 and SOCS-1) in bladder cancer patients from different Chinese sub-populations including Taiwan (104 cases), Hong Kong (82 cases) and China (24 cases) by MSP. Two normal human urothelium were also included as control. To investigate the diagnostic potential of using DNA methylation in non-invasive detection of bladder cancer, degree of methylation of DAPK, IRF8, p14, RASSF1A and SFRP1 was also accessed by quantitative MSP in urine samples from thirty bladder cancer patients and nineteen non-cancer controls. RESULTS: There were distinct DNA methylation epigenotypes among the different sub-populations. Further, samples from Taiwan and China demonstrated a bimodal distribution suggesting that CpG island methylator phentotype (CIMP) is presented in bladder cancer. Moreover, the number of methylated genes in samples from Taiwan and Hong Kong were significantly correlated with histological grade (P < 0.01) and pathological stage (P < 0.01). Regarding the samples from Taiwan, methylation of SFRP1, IRF8, APC and RASSF1A were significantly associated with increased tumor grade, stage. Methylation of RASSF1A was associated with tumor recurrence. Patients with methylation of APC or RASSF1A were also significantly associated with shorter recurrence-free survival. For methylation detection in voided urine samples of cancer patients, the sensitivity and specificity of using any of the methylated genes (IRF8, p14 or sFRP1) by qMSP was 86.7% and 94.7%. CONCLUSIONS: Our results indicate that there are distinct methylation epigenotypes among different Chinese sub-populations. These profiles demonstrate gradual increases with cancer progression. Finally, detection of gene methylation in voided urine with these distinct DNA methylation markers is more sensitive than urine cytology.

Safety and efficacy of tubeless percutaneous nephrolithotomy in patients on anti-platelet therapy and cirrhotic patients.

Without the temponade effect over nephrostomy tube, postoperative hemorrhage is a major concern to the safety of tubeless percutaneous nephrolithotomy (PCNL) in patients with bleeding tendency. In this study, we would like to report our experience of performing tubeless PCNLs in these patients. At the end of PCNL, we cauterized the bleeding points in access tract for hemostasis to facilitate the achievement of tubeless PCNL. We identified and reviewed 16 patients under antiplatelet agent therapy and 6 patients with liver cirrhosis from 598 tubeless PCNLs performed in a single institute. Among the 16 patients undergoing anti-platelet therapy, the average stone size was 2.8 cm. The average operation time was 84.7 min. The stone-free rate was 87.5%. The average postoperative hospital stay was 3.8 days. Two patients (12.5%) experienced urinary tract infections after operation. There was no uncontrolled hemorrhage during and after operation and only one patient needed postoperative blood transfusion. No patient experienced any thromboembolic complication. Of the six patients with liver cirrhosis, the average stone size was 3.3 cm. The average operation time was 77.5 min. The stone-free rate is 83.4%. The average postoperative hospital stay was 4.0 days. No patient received blood transfusion after operation. There was no patient experiencing urinary tract infection after operation. Our results suggest that with careful hemostasis, tubeless PCNL is a safety modality in the treatment of urinary stone disease in patients on chronic anti-platelet therapy and cirrhotic patients.

The correlation between TWIST, E-cadherin, and beta-catenin in human bladder cancer.

PURPOSE: Epithelial-to-mesenchymal transition (EMT)- related factors are known to contribute to the invasion and migration of multiple cancers. However, the expression levels of and the relationship between TWIST, E-cadherin, and beta-catenin in bladder cancer are not yet known. Therefore, this study investigated the relationship between TWIST, E-cadherin, and beta-catenin in tissue specimens and cell lines of bladder cancer. METHODS: Microarrays of bladder cancer tissue and bladder cancer cell lines were used to study the expression levels of TWIST, E-cadherin, and beta-catenin, with disease stage and grade using immunohistochemistry. Moreover, the siRNAs of TWIST, E-cadherin, and beta-catenin were transfected into the bladder cancer cell lines to study any relationship between these factors. RESULTS: The levels of TWIST and beta-catenin were upregulated with increasing grade of malignancy. In contrast, the corresponding results for E-cadherin were just the opposite. Furthermore, inhibition of the expression of TWIST elevated the expression of E-cadherin, but reduced the expression of beta-catenin. However, reduction of beta-catenin by siRNA had no influence on TWIST, but up-regulated the expression of E-cadherin. CONCLUSION: TWIST may act upstream of E-cadherin, which can indirectly regulate the expression levels of beta-catenin. The EMT factors TWIST, E-cadherin, and beta-catenin may be a cluster of biomarkers for the metastatic progression of bladder cancer.

Tubeless percutaneous nephrolithotomy for geriatric patients.

AIM: To evaluate the safety of tubeless percutaneous nephrolithotomy (PCNL) in geriatric patients. MATERIALS AND METHOD: This is a retrospective review of 401 patients who received tubeless PCNL in a single institute. Among these, 50 were performed in patients aged older than 70 years (group 1), while 351 were performed in the remaining younger patients (group 2). RESULTS: There was no significant difference in stone size between the 2 groups (3.6 +/- 1.9 vs. 3.5 +/- 2.0 cm). The average operative time was similar in both groups (92.8 +/- 34.5 vs. 86.6 +/- 32.0 min). The stone-free rate in groups 1 and 2 was 68.0% (34/50) and 83.8% (294/351), respectively, which was statistically significantly different. The average postoperative hospital stay was longer in group 1 (4.6 +/- 3.4 days) than in group 2 (3.9 +/- 2.5 days), but the difference was not statistically significant. There was no significant difference in postoperative urinary tract infection rate and blood transfusion rate in both groups (urinary tract infection: 18.0 vs. 8.8%; blood transfusion: 4 vs. 2.6%). Two patients in group 1 and 3 patients in group 2 experienced pulmonary complications. There was no other severe complication. CONCLUSION: Tubeless PCNL is a safe procedure for the treatment of geriatric patients with urolithiasis.

Hyperbaric oxygen therapy for cyclophosphamide-induced intractable refractory hemorrhagic cystitis in a systemic lupus erythematosus patient.

Hemorrhagic cystitis is a complication of systemic lupus erythematosus and is also a common side effect after cyclophosphamide therapy. Intractable hemorrhagic cystitis is not unusual and may be a life-threatening condition; it has no effective noninvasive treatment at present. We report a case of hemorrhagic cystitis with intractable refractory bleeding that occurred in a 40-year-old woman after cyclophosphamide treatment for systemic lupus erythematosus. The hemorrhage was resistant to various therapies but resolved after hyperbaric oxygen therapy. There was no recurrent hematuria after hyperbaric oxygen therapy during 6 months of follow-up.

Delayed pneumothorax after tubeless percutaneous nephrolithotomy.

Percutaneous nephrolithotomy is the treatment of choice for large urinary stone and staghorn stone. Supracostal access through the upper calyx provides a straight tract along the long axis of the kidney and is the optimal route for the treatment of staghorn stone. However, the supracostal access bears higher risk for pleural or lung injury resulting in hydrothorax or pneumothorax. Percutaneous nephrolithotomy induced pneumothorax usually occurs immediately after operation. We report a case of delayed pneumothorax after tubeless percutaneous nephrolithotomy for a complete staghorn stone.

Innovative metal dilators for percutaneous nephrostomy tract: report on 546 cases.

OBJECTIVES: A retrospective study was conducted to evaluate the efficacy and safety of creating a percutaneous nephrostomy tract for stone removal with innovative metal dilators. METHODS: A total of 546 percutaneous nephrolithotomies was performed at Chiayi Christian Hospital from January 2001 to December 2005. Innovative metal dilators were used to create 546 percutaneous nephrostomy tracts in 520 patients. Several patients had multiple percutaneous nephrostomy tracts. Patient age, stone burden, operative time, stone-free rate, postoperative hospital day, postoperative urinary tract infection rate, and blood transfusion rate were recorded using retrospective chart review. RESULTS: The dilation time was less than 15 minutes. The average patient age was 53.7 +/- 13.1 years, and the average stone size was 3.5 +/- 2.0 cm. The average operative time was 100 +/- 45 minutes. The average postoperative hospital stay was 4.4 +/- 2.6 days. The overall stone-free rate was 84.4% (461 of 546). The stone-free rate was 99% (142 of 143) for upper ureteral stones, 87% (268 of 305) for renal stones, and 52% (51 of 98) for complete staghorn stones. The blood transfusion rate was 2.5% (14 of 546). The postoperative urinary tract infection rate was 8.6% (47 of 546). Of the 520 patients, 6 had pleural effusion and 1 had pneumothorax. CONCLUSIONS: Our innovative metal dilators saved time, resulted in less bleeding, and successfully provided one-stage tract creation in 520 patients. The dilation system also allowed the use of a ureteroscope to check the entrance tract to reduce complications.

High-power holmium:yttrium-aluminum-garnet laser for percutaneous treatment of large renal stones.

OBJECTIVES: To assess the efficacy and safety of high-power holmium-yttrium-aluminum-garnet (YAG) laser lithotripsy for percutaneous nephrolithotomy in patients with large renal stones. METHODS: We retrospectively reviewed the charts of 87 patients who underwent 91 percutaneous nephrolithotomy procedures at our hospital from April 2004 to June 2005, during which a holmium-YAG laser with a self-made fiber guider was used for lithotripsy. Of the 91 procedures, 51 were performed with the maximal power output set at 3.0 J in patients with a renal stone size of 3 cm or larger (group 1). The other 40 procedures were performed with the maximal power set at 2.0 J in patients with a renal stone size of less than 3 cm or with ureteral stones (group 2). RESULTS: The average stone size was 5.4 cm in group 1, and the stone-free rate was 61.4% after a single procedure. The average operation time was 108 minutes in group 1 and 93 minutes in group 2. The average postoperative hospital stay was 5.7 days in group 1 and 5.9 days in group 2. Two patients in group 1 and one in group 2 required blood transfusions after the procedure. Seven patients (13.7%) in group 1 and two (5.0%) in group 2 experienced a urinary tract infection after the procedure. No statistically significant difference in procedure time, postoperative hospital stay, blood transfusion rate, or postoperative urinary tract infection rate was found between the two groups. CONCLUSIONS: The results of our study have shown that using a high-power holmium-YAG laser is safe and effective in the treatment of large renal stones.

Nephrostomy tube-free percutaneous nephrolithotomy for patients with large stones and staghorn stones.

OBJECTIVES: To perform a retrospective study to assess the outcome and safety of 64 nephrostomy tube-free percutaneous nephrolithotomies (PCNLs) in 62 patients with calculi 3 cm or greater. METHODS: Between March 2001 and June 2004, 365 consecutive patients underwent 389 PCNLs at our hospital. Electrocauterization of the access tract was performed at the end of the operation in every patient. No nephrostomy tube was inserted in the patient if a bloodless tract had been obtained. Of the 389 PCNLs, 154 were performed in patients with a stone size of 3 cm or greater. Of these 154 PCNLs, 64 were performed with the nephrostomy tube-free modification (group 1) and 90 were performed with insertion of the nephrostomy tube after the operation (group 2). The hospital course and complications were evaluated in both groups. RESULTS: No statistically significant differences in age, stone size, urinary tract infection rate, or blood transfusion rate were found between those with and without insertion of the nephrostomy tube. Fourteen patients in group 1 had complete staghorn stones. A shorter operative time, lower analgesic requirement, and shorter postoperative hospital stay were noted in the group with the nephrostomy tube-free modification (group 1). CONCLUSIONS: With adequate homeostasis, nephrostomy tube-free PCNL can be performed in patients with complicated urolithiasis without any increase in morbidity.

Percutaneous nephrolithotomy with holmium: Yttrium-aluminum-garnet laser and fiber guider--report of 349 cases.

OBJECTIVES: To assess the efficacy and safety of holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy for percutaneous nephrolithotomy in a cohort of 349 consecutive procedures. METHODS: We retrospectively reviewed the charts of 334 patients who had undergone 349 percutaneous nephrolithotomy (PCNL) procedures conducted at our hospital from January 2001 to March 2004 in which the holmium:YAG laser with a self-made fiber guider was used for lithotripsy. RESULTS: The average patient age was 54.1 years, and the average stone size was 3.3 +/- 1.8 cm. The average operative time was 99 +/- 38 minutes, and the average postoperative hospital stay was 4.0 +/- 2.3 days. The overall stone-free rate was 83.7%. The postoperative urinary tract infection rate was 7.2%. The postoperative transfusion rate was 2.0%. The holmium:YAG laser was effective against all kinds of stones, but sometimes it was time consuming to use the holmium:YAG laser to disintegrate a very large stone. Thirteen PCNLs (3.7%) to treat large complete staghorn stones were performed in combination with a pneumatic lithotriptor. Of the 349 procedures, 152 (43.6%) had bloodless tracts afterward, and all 152 procedures had been performed with the nephrostomy tube-free modification. CONCLUSIONS: The holmium:YAG laser is an effective and safe lithotriptor for most percutaneous stone surgery. However, in patients with a very large stone burden, the combination of this technology with another, more powerful, intracorporeal lithotriptor may be necessary.

Electrocauterization of bleeding points for percutaneous nephrolithotomy.

OBJECTIVES: To perform a retrospective study to assess the efficacy and safety of electrocauterization of bleeding points after stone extraction using the data from 249 percutaneous nephrolithotomies. METHODS: A total of 341 percutaneous nephrolithotomies in 324 patients were performed at the Chiayi Christian Hospital from July 2000 to July 2003. Electrocauterization of bleeding points with an elongated electrode probe was performed in 249 patients. The age, height, weight, preoperative hemoglobin level, stone burden, operating time, stone free rate, length of postoperative hospital stay, postoperative urinary tract infection rate, and blood transfusion rate were recorded by retrospective chart review. RESULTS: No statistically significant differences in age, height, weight, stone burden, operating time, stone free rate, or length of postoperative hospital stay were found between patients with or without electrocauterization. No increase occurred in the postoperative urinary tract infection rate in patients who received electrocauterization, and these patients had a statistically significant decrease in the transfusion rate. No nephrostomy tube was inserted at the completion of surgery in 84 (33.7%) of the 249 operations in which electrocauterization was performed. CONCLUSIONS: Electrocauterization of the bleeding points at the end of percutaneous renal surgery decreases the blood transfusion rate without causing an increase in morbidity. This procedure is safe and effective and may make more patients suitable for tubeless modification.

Cauterization of access tract for nephrostomy tube-free percutaneous nephrolithotomy.

BACKGROUND AND PURPOSE: Percutaneous nephrolithotomy (PCNL) is now a popular method for removal of renal and ureteral stones. Placement of a nephrostomy tube after the completion of PCNL has been considered a standard procedure by most urologists, but some authors have recently challenged this practice. Bleeding is one of the most prevalent problems after nephrostomy tube-free percutaneous renal surgery. To diminish the possibility of postoperative bleeding, we cauterized the PCNL tract to make it bloodless. The efficacy and safety of this procedure were reviewed in this study. PATIENTS AND METHODS: From March 2001 to March 2003, 51 patients underwent PCNL with a one-stage procedure and a single access tract. The stone size ranged from 1.0 to 7.0 cm (mean 2.7 +/- 1.4 cm). A holmium:YAG laser and pneumatic lithotripter were used. After stone extraction, a 6F double-J catheter was inserted antegrade. The access tract was checked, and the bleeding points were cauterized. No nephrostomy tube was inserted, but a Penrose drain was left overnight. Perforation of the collecting system was not a contraindication to tubeless PCNL. RESULTS: The stone-free rate was 80.4%, including five patients with complete staghorn stones. Twenty-one patients required postoperative analgesics. Only one patient had urine leakage for longer than 24 hours. Transient low fever was noted in five patients, but no patient experienced severe urinary tract infection. Delayed hemorrhage (1 week after the operation) secondary to irritation by the double-J ureteral stent was noted in one patient. The average postoperative hospital stay was 2.2 days (range 1-3 days). No patient required a blood transfusion. No urinoma was noted on the postoperative ultrasound follow-up. CONCLUSION: Nephrostomy tube-free percutaneous renal surgery is a safe and effective procedure for selected patients with minimal hemorrhage after PCNL. Cauterization of tract bleeding points may make this modification a more secure procedure and make it suitable for more patients.