Screening for prostate cancer in a city in Japan: age-specific prostate-specific antigen cutoff thresholds.

PURPOSE: Older men have higher prostate-specific antigen levels than younger men. However, the current Japanese Urological Association guidelines recommend secondary screening at a cutoff value of 4.0 ng/mL, even in older men. Here, we reexamined the cutoffs for older men using a prostate screening cohort in Japan and first performed an analysis to determine the indication cutoffs for detecting positive biopsies. METHODS: Data from 68,566 prostate cancer screenings in the city in 2018 were combined with cancer registration data. The optimal prostate-specific antigen levels to predict prostate cancer in different age groups were calculated using receiver operating characteristic curves after determining whether a cancer was registered within one year of screening. RESULTS: At the conventional prostate-specific antigen threshold of 4.0 ng/mL, the sensitivity, specificity, and negative predictive value were 94.9%, 91.7%, and 91.7%, respectively. The optimal prostate-specific antigen cutoff values for patients aged 50-59 years, 60-69 years, 70-79 years, and over 80 years were 3.900 ng/mL, 4.014 ng/mL, 4.080 ng/mL, and 4.780 ng/mL, respectively. CONCLUSIONS: The sensitivity and specificity of prostate cancer screening in the city were high, indicating a highly accurate screening. The prostate-specific antigen threshold was 4.78 ng/mL in patients older than 80 years. A higher prostate-specific antigen threshold may be useful in men over 80 years of age to avoid excess biopsy and reduce costs. Our results suggest that the current Japanese method of using PSA 4.0 ng/mL as a cutoff regardless of age may not be preferable for older men.

MMP1, IL-1ß, sTNFR-1, and IL-6 are prognostic factors for patients with unresectable or metastatic renal cell carcinoma treated with immune checkpoint inhibitors.

BACKGROUND: Few studies have reported reliable prognostic factors for immune checkpoint inhibitors (ICIs) in renal cell carcinoma (RCC). Therefore, we investigated prognostic factors in patients treated with ICIs for unresectable or metastatic RCC. METHODS: We included 43 patients who received ICI treatment for RCC between January 2018 and October 2021. Blood samples were drawn before treatment, and 73 soluble factors in the plasma were analyzed using a bead-based multiplex assay. We examined factors associated with progression-free survival (PFS), overall survival (OS), and immune-related adverse events (irAE) using the Chi-squared test, Kaplan-Meier method, and the COX proportional hazards model. RESULTS: Patients exhibited a median PFS and OS of 212 and 783 days, respectively. Significant differences in both PFS and OS were observed for MMP1 (PFS, p < 0.001; OS, p = 0.003), IL-1ß (PFS, p = 0.021; OS, p = 0.008), sTNFR-1 (PFS, p = 0.017; OS, p = 0.005), and IL-6 (PFS, p = 0.004; OS, p < 0.001). Multivariate analysis revealed significant differences in PFS for MMP1 (hazard ratio [HR] 5.305, 95% confidence interval [CI], 1.648-17.082; p = 0.005) and OS for IL-6 (HR 23.876, 95% CI, 3.426-166.386; p = 0.001). Moreover, 26 patients experienced irAE, leading to ICI discontinuation or withdrawal. MMP1 was significantly associated with irAE (p = 0.039). CONCLUSION: MMP1 may be associated with severe irAE, and MMP1, IL-1ß, sTNFR-1, and IL-6 could serve as prognostic factors in unresectable or metastatic RCC treated with ICIs. MMP1 and IL-6 were independent predictors of PFS and OS, respectively. Thus, inhibiting these soluble factors may be promising for enhancing antitumor responses in patients with RCC treated with ICIs.

[A Case of Solitary Metastasis of Renal Cell Carcinoma to the Thyroid Gland].

A case of solitary metastasis of renal cell carcinoma to the thyroid gland is presented. The patient was a 82-year-old man found to have an abnormal mass in his neck. He had a past history of renal clear cell carcinoma of the left kidney (pT1aN0M0, G1>2, alveolar type, clear cell subtype), which had been resected 12 years previously. Ultrasonography revealed a tumor mass in the right hemithyroid gland. This time fine needle biopsy of the thyroid tumor suggested metastatic thyroid carcinoma. Right hemithyroidectomy was performed last year. The histopathological findings were suggestive of clear cell carcinoma, thus metastatic renal carcinoma was diagnosed. This is the 26th case of thyroid solitary metastasis of clear cell renal cell carcinoma reported in Japan to date.

Increased neutrophil-to-lymphocyte ratio is associated with disease-specific mortality in patients with penile cancer.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR), a simple marker of the systemic inflammatory response, has been demonstrated to correlate with patient outcomes for various solid malignancies. We investigated the utility of the pretreatment NLR as a prognosticator in patients who presented with penile cancer. METHODS: A total of 41 patients who underwent complete blood count with differential and subsequent radical penectomy from 1988 to 2014 were analyzed. We assessed the correlation between the NLR and the prognosis of penile cancer. RESULTS: The median and mean (± SD) NLRs in 41 penile cancer patients were 3.42 and 5.03 ± 4.99, respectively. Based on the area under receiver operator characteristic curve, the cut-off value of NLR was determined to be 2.82. Patients with a high NLR (≥2.82) showed a significantly poorer cancer-specific survival (p = 0.023) than those with a low NLR. CONCLUSIONS: The pretreatment NLR may function as a biomarker that precisely predicts the prognosis in patients with penile cancer.

Developing a preoperative predictive model for ureteral length for ureteral stent insertion.

BACKGROUND: Ureteral stenting has been a fundamental part of various urological procedures. Selecting a ureteral stent of optimal length is important for decreasing the incidence of stent migration and complications. The aim of the present study was to develop and internally validate a model for predicting the ureteral length for ureteral stent insertion. METHODS: This study included a total of 127 patients whose ureters had previously been assessed by both intravenous urography (IVU) and CT scan. The actual ureteral length was determined by direct measurement using a 5-Fr ureteral catheter. Multiple linear regression analysis with backward selection was used to model the relationship between the factors analyzed and actual ureteral length. Bootstrapping was used to internally validate the predictive model. RESULTS: Patients all of whom had stone disease included 76 men (59.8%) and 51 women (40.2%), with the median and mean (± SD) ages of 60 and 58.7 (±14.2) years. In these patients, 53 (41.7%) right and 74 (58.3%) left ureters were analyzed. The median and mean (± SD) actual ureteral lengths were 24.0 and 23.3 (±2.0) cm, respectively. Using the bootstrap methods for internal validation, the correlation coefficient (R2) was 0.57 ± 0.07. CONCLUSION: We have developed a predictive model, for the first time, which predicts ureteral length using the following five preoperative characteristics: age, side, sex, IVU measurement, and CT calculation. This predictive model can be used to reliably predict ureteral length based on clinical and radiological factors and may thus be a useful tool to help determining the optimal length of ureteral stent.

Retrograde intrarenal surgery for urinary stone disease in patients with solitary kidney: A retrospective analysis of the efficacy and safety.

OBJECTIVES: To compare outcomes of retrograde intrarenal surgery for urolithiasis between patients with solitary kidneys and patients who have single-side urolithiasis with bilateral kidneys. METHODS: We retrospectively analyzed outcomes of retrograde intrarenal surgery in solitary kidney patients (group A) carried out during 2007-2014, and in patients with bilateral kidneys with comparable stone burdens (group B). Stone-free status was defined as no residual fragment on computed tomography 1 month later. RESULTS: There were 19 patients in group A (mean age 62.5 ± 18.4 years, range 14-76 years). The mean stone diameter and burden were 6.0 mm (range 3-24 mm) and 10.42 ± 6.92 mm, respectively. The stone-free rate was 94.7%, and no repeat procedure was required. The glomerular filtration rate tended to rise post-surgery (postoperative day 1: 48.67 ± 15.92 mL/min, 100.2%, P = 0.940; postoperative month 1: 51.32 ± 16.90 mL/min, 105.7%, P = 0.101) compared with preoperative rates. The stone-free rate and surgery time were not significantly different between the two groups, although post-surgical hospitalization time was longer for group A (4.05 vs 3.08 days, P = 0.037). The change in glomerular filtration rate was not significantly different between groups A and B (postoperative day 1: +0.101 vs +0.547 mL/min, respectively, P = 0.857; postoperative month 1: +2.749 vs 3.161 mL/min, respectively, P = 0.882). No significant difference was found in terms of complication rate. CONCLUSIONS: Retrograde intrarenal surgery in solitary kidney patients is as safe and effective as in bilateral kidney patients.

Risk factors of systemic inflammation response syndrome after endoscopic combined intrarenal surgery in the modified Valdivia position.

OBJECTIVE: To identify risk factors of developing systemic inflammation response syndrome after endoscopic combined intrarenal surgery in the modified Valdivia position for renal stone treatment. METHODS: We retrospectively analyzed 370 consecutive patients who underwent endoscopic combined intrarenal surgery procedures in the modified Valdivia position to treat renal stones. Antibiotic therapy based on preoperative urine cultures was administered to all patients from induction of anesthesia until at least postoperative day 3. Postoperative systemic inflammation response syndrome was diagnosed if the patient met two or more systemic inflammation response syndrome criteria. A multivariate logistic regression model with backward selection was used to evaluate the relationships between the incidence of systemic inflammation response syndrome after endoscopic combined intrarenal surgery and other clinical factors. RESULTS: Of the 370 patients, 61 patients (16.5%) were diagnosed with systemic inflammation response syndrome after endoscopic combined intrarenal surgery. Significant differences were found between the non-systemic inflammation response syndrome and systemic inflammation response syndrome groups with regard to female sex (29.8% vs 44.3%, P = 0.027), history of febrile urinary tract infection (16.5% vs 32.8%, P = 0.015) and number of involved calyces (2.68 vs 4.1, P < 0.001). Multivariate analysis found three independent predictors of postoperative systemic inflammation response syndrome: the number of involved calyces (P = 0.017), stone surface area (P = 0.021) and history of febrile urinary tract infection (P = 0.005). CONCLUSIONS: The number of involved calyces larger than four, stone surface area >500 mm(2) and a history of febrile urinary tract infection independently predicted the development of systemic inflammation response syndrome after endoscopic combined intrarenal surgery. This is the first study to identify the independent predictors of systemic inflammation response syndrome after endoscopic combined intrarenal surgery in the modified Valdivia position.

Development and internal validation of a nomogram for predicting stone-free status after flexible ureteroscopy for renal stones.

OBJECTIVE: To develop and internally validate a preoperative nomogram for predicting stone-free status (SF) after flexible ureteroscopy (fURS) for renal stones, as there is a need to predict the outcome of fURS for the treatment of renal stone disease. PATIENTS AND METHODS: We retrospectively analysed 310 fURS procedures for renal stone removal performed between December 2009 and April 2013. Final outcome of fURS was determined by computed tomography 3 months after the last fURS session. Assessed preoperative factors included stone volume and number, age, sex, presence of hydronephrosis and lower pole calculi, and ureteric stent placement. Multivariate logistic regression analysis with backward selection was used to model the relationship between preoperative factors and SF after fURS. Bootstrapping was used to internally validate the nomogram. RESULTS: Five independent predictors of SF after fURS were identified: stone volume (P < 0.001), presence of lower pole calculi (P = 0.001), operator with experience of >50 fURS (P = 0.026), stone number (P = 0.075), and presence of hydronephrosis (P = 0.047). We developed a nomogram to predict SF after fURS using these five preoperative characteristics. Total nomogram score (maximum 25) was derived from summing individual scores of each predictive variable; a high total score was predictive of successful fURS outcome, whereas a low total score was predictive of unsuccessful outcome. The area under the receiver operating characteristics for nomogram predictions was 0.87. CONCLUSION: The nomogram can be used to reliably predict SF based on patient characteristics after fURS treatment of renal stone disease.

[Tubeless Percutaneous Nephrolithotomy].

We assessed our initial experience with tubeless percutaneous nephrolithotomy (PCNL). Between February 2011 and December 2013, we performed 155 tubeless PCNL and 54 standard PCNL in which nephrostomy tubes were used postoperatively. Tubeless PCNL was performed when the presence of residual fragments, bleeding, and extravasation were excluded intraoperatively. The incidence of complications, hospital stay duration, analgesic requirements, visual analog scale score, decrease in hemoglobin levels, and stone-free rates were compared between the two groups. The mean hospital stay after tubeless PCNL was shorter (5.1 days) than that after standard PCNL (6.8 days, P＜0.05). Transient fever was seen in 20 patients (13.8%) in the tubeless PCNL group and 12 patients (25.5%) in the standard PCNL group. Tubeless PCNL is a safe and effective procedure, and hospital stay is shorter with tubeless PCNL than with standard PCNL.

C-reactive Protein Is a Prognostic Factor for Survival in Metastatic Upper Tract Urothelial Carcinoma Patients Receiving Pembrolizumab.

BACKGROUND/AIM: The number of available treatment options for urothelial carcinoma has increased recently. Upper tract urothelial carcinoma (UTUC) is relatively rare compared with bladder cancer. There are few reports on the efficacy of immune checkpoint inhibitors (ICIs) for metastatic UTUC, and ICIs may occasionally show less efficacy and cause severe side effects. Therefore, it is important to predict the treatment response and change the treatment strategy as appropriate. We investigated the prognostic factors for treatment response in patients with metastatic UTUC treated with pembrolizumab at our hospital. PATIENTS AND METHODS: Patients who received pembrolizumab for UTUC between January 2018 and June 2023 were analyzed. Patients who presented with bladder cancer complications at initial diagnosis were excluded. The primary endpoints assessed were overall survival (OS) and progression-free survival (PFS). Statistical analyses were conducted using laboratory values obtained before and after pembrolizumab administration. The relationship between cancer and inflammation is important. Therefore, we analyzed this relationship using prognostic factors for urothelial carcinoma as previously reported. Specifically, pretreatment C-reactive protein (CRP) level, neutrophil-to-lymphocyte ratio (NLR), and NLR/albumin values were examined. RESULTS: Forty-seven patients were analyzed. The median PFS was 66 days (24-107 days), and the median OS was 164 days (13-314 days). A CRP level <1 before the first cycle was a useful factor in the multivariate analysis for both OS and PFS [OS: p=0.004, hazard ratio (HR)=3.244, 95% confidence interval (CI)=1.464-7.104; PFS: p=0.003, HR=2.998, 95%CI=1.444-6.225]. CONCLUSION: CRP level is a prognostic factor for pembrolizumab treatment response in patients with UTUC.

Ramelteon combined with an α1-blocker decreases nocturia in men with benign prostatic hyperplasia.

BACKGROUND: Nocturia is defined as waking one or more times during the night due to the urge to void. Recently, the effectiveness of several sedatives and analgesics for nocturia has been reported. We herein investigated the effects of ramelteon, an antioxidant and sleep inducer, on nocturia unresponsive to α1-blocker monotherapy in males with lower urinary tract symptoms (LUTS) as a pilot study. METHODS: Subjects were 19 patients who had LUTS suggestive of benign prostate hyperplasia, received α1-blockers (tamsulosin, silodosin, or naftopidil), and continued to have two or more episodes of nocturia per night before starting ramelteon. Ramelteon at 8 mg once daily for one month was added to the α1-blocker. A self-administered questionnaire including the International Prostate Symptom Score (IPSS), quality of life (QoL) index, Overactive Bladder Symptom Score (OABSS), and Nocturia Quality-of-Life Questionnaire (N-QOL) were assessed before and one month after starting ramelteon. RESULTS: The mean score on IPSS question 7 (nocturia) decreased significantly from 2.88 before starting ramelteon to 2.41 one month after starting the medication (P = 0.03). The mean total OABSS decreased significantly from 6.31 to 5.38 (P = 0.03), and the mean for OABSS question 2 (nighttime frequency of nocturia) also significantly decreased from 2.63 to 2.13 (P = 0.01). The mean total N-QOL score did not change significantly. Two patients had dizziness; the remaining patients had no adverse drug-related events. CONCLUSIONS: Ramelteon in combination with an α1-blocker could be a treatment option for reducing nocturia in men with BPH.

Use of Sotrovimab for COVID-19 in a Patient with International Germ Cell Consensus Classification Poor Prognosis Testicular Germ Cell Tumor.

A 35-year-old man was diagnosed with stage IIIC non-seminoma with paralysis of the lower half of his body due to 8th thoracic spine metastasis. The patient received bleomycin, etoposide, and cisplatin (BEP) therapy. On day 4 of the second course of BEP, the patient developed a fever and was diagnosed with coronavirus disease (COVID-19). COVID-19 was suspected to worsen because of cancer and chemotherapy-induced immunosuppression. However, the benefits of continuing BEP therapy outweighed these risks. After obtaining fully informed consent, BEP therapy was continued from day 5, while sotrovimab (anti-COVID-19 drug) was administered. The second course of BEP was completed without worsening severe COVID-19 or bleomycin-induced lung injury. The patient completed four courses of BEP, with normalization of tumor markers, partial response on imaging, and improvement in lower body paralysis. In this case, we successfully treated a patient with testicular germ cell tumor with chemotherapy while having COVID-19 without treatment delay. During the COVID-19 pandemic, concomitant chemotherapy and COVID-19 treatment are warranted because delaying treatment will decrease the efficacy of highly curative diseases such as germ cell tumors.

Localized amyloidosis of the ureter: a case report.

BACKGROUND: Amyloidosis is a collection of disorders characterized by the extracellular deposition of amyloid, a specialized fibrous protein, in diverse tissues, leading to functional impairments. CASE PRESENTATION: A 70-year old Asian-Japanese female was referred to our department for further examination of her left hydronephrosis come from lower ureteral obstruction. Contrast enhanced CT and retrograde pyelo-nephrography revealed left ureteral tumor. Though ureteroscropic biopsy did not show malignant pathological findings, ureteroscopic image suspected malignant disease, thus nephroureterectomy was performed. Pathological findings revealed localized ureteral amyloidosis. Whole body examination including gastro endoscopy and cardio ultrasonography could not reveal amyloidosis except ureter. She was free from recurrence 9 months postoperatively. CONCLUSION: We herein report a rare case of localized ureteral amyloidosis.

Review of the Developing Landscape of Prostate Biopsy and Its Roles in Prostate Cancer Diagnosis and Treatment.

Prostate cancer remains a significant global health challenge. Traditionally anchored by the Gleason score/Grade Group (GS/GG), the landscape of prostate cancer diagnosis is undergoing transformative steps, particularly in the domain of biopsy procedures. GS/GG continues to be pivotal in malignancy grading, but recent technological strides have augmented the diagnostic relevance of biopsies. Integral to this progression is the adoption of advanced imaging techniques, especially magnetic resonance imaging, which has refined biopsy accuracy and efficiency. A deep understanding of prostate cancer pathology reveals a cribriform pattern and intraductal carcinoma of the prostate as independent forms of malignancy, suggesting a potentially aggressive disease course. Furthermore, the distinct behaviour of ductal adenocarcinoma and small cell carcinoma of the prostate, compared with acinar adenocarcinoma, necessitates their accurate differentiation during biopsy. The genomic era ushers in a renewed emphasis on tissue samples obtained from prostate biopsies, especially as mutations in genes, such as BRCA1/2, and paves the way for precision medicine. This review encapsulates the evolving dynamics of prostate biopsy, from technological advancements to the profound implications on prostate cancer management and therapy.

Ureteroscopy assisted retrograde nephrostomy: a new technique for percutaneous nephrolithotomy (PCNL).

UNLABELLED: Study Type - Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? Retrograde nephrostomy was first developed by Lawson et al. in 1983, and Hunter et al. reported 30 cases of retrograde nephrostomy in 1987. This procedure uses less radiation exposure and has a shorter duration compared with the previous percutaneous nephrostomy techniques. Retrograde nephrostomy using Lawson's procedure was reported in the late 1980s by several authors. But since then, few studies have been reported about this procedure due to the development of ultrasonography assisted percutaneous nephrostomy. With the arrival and development of the flexible ureteroscope (URS) both observation and manipulation in the renal pelvis are now easily achieved. The present procedure provides less radiation exposure, less bleeding, and a shorter procedure than previous percutaneous nephrostomy techniques. Using this procedure, after the needle has exited through the skin, no further steps are required in preparation for dilatation. In the present study, we continuously visualised from puncture to inserting the nephron-access sheath with the URS. OBJECTIVE: • To describe a technique for ureteroscopy assisted retrograde nephrostomy. PATIENTS AND METHODS: • Under general and epidural anaesthesia, the patient is placed in a modified-Valdivia position. Flexible ureteroscopy is carried out, and a Lawson retrograde nephrostomy puncture wire is placed in the ureteroscope (URS). • After the needle has exited through the skin, no further steps are required in preparation for dilatation. RESULTS: • After informed consent was obtained, two patients (a 43-year-old man with left renal stones and a 57-year-old woman with right renal stones) underwent this procedure. • The URS was positioned in the middle posterior calyx and punctured toward the skin. CONCLUSIONS: • This procedure involves less radiation exposure and shorter surgery than the previous percutaneous nephrostomy technique. • Our technique represents another new option for percutaneous nephrolithotomy in patients with a non-dilated intrarenal collecting system.

Changing to a loop-type ureteral stent decreases patients' stent-related symptoms.

The first indwelling ureteral splint was described in 1967. A ureteral stent can cause unpleasant side effects, such as urinary frequency, urgency, incontinence, hematuria, bladder pain and flank pain, which have a negative impact on a patient's quality of life. It is necessary to minimize the amount of material in the bladder in order to decrease stent-related symptoms. This study investigated the stent-related symptoms after changing from a double pigtail to a loop-type ureteral stent in the same patient group. This study followed 25 patients who underwent ureteral stent exchange from double pigtail to loop-type ureteral stent between September 2009 and February 2010. Ureteral stents were exchanged using topical, conscious sedation and general anesthesia for the various procedures including stent exchange, before/after shock wave lithotripsy and before/after ureteroscopy. The stent length was selected to be the same as whole ureteral length and the caliber based on the previous stent. A self-administered stent-related symptom questionnaire was used to assess stent-related symptoms in comparison to the previous double-pigtail stents. A total of 25 patients with a median age of 56.5 years underwent ureteral stent exchange. All patients had stone disease except two patients who had ureteral stricture. Almost all of stent-related symptoms without nocturia showed a significantly lower score with the loop-type ureteral stent than in double-pigtail stent. None of the patients experienced urinary tract infection either before or after undergoing ureteral stent exchange. Changing to loop-type ureteral stent significantly decreased ureteral stent-related symptoms.

Stone area and volume are correlated with operative time for cystolithotripsy for bladder calculi using a holmium: yttrium garnet laser.

OBJECTIVE: This study investigated the correlation between the operation time and the stone size as determined by multiple modalities and the computed tomography (CT) densities of bladder calculi using holmium: yttrium garnet (Ho:YAG) laser lithotripsy. MATERIAL AND METHODS: A total of 68 patients underwent cystolithotripsy from March 2010 to October 2011. Thirty-six of these patients underwent cystolithotripsy using a Ho:YAG laser for bladder calculi by a single surgeon. The stone size was assessed by six modalities: sum of the stones' diameters: stone burden; maximum stone's diameter; number of stones; sum of the area using axial CT; sum of area using kidney-ureter-bladder (KUB) films; and volume using CT. In addition, the stone's CT density was measured by: the mean CT density of the maximum stone's whole area; maximum CT density of the maximum stone's whole area; and mean CT density of the maximum stone's center area. Correlations between the operation time and the stone size and the stone CT density were assessed. RESULTS: A total of 36 patients (30 male and six female) who underwent cystolithotripsy using a Ho:YAG laser for bladder calculi were enrolled in this study. Spearman correlation showed that the area and volume were strongly correlated with the operative time. The multipliers between the stone size and stone CT density showed no advantages based on the stone area or volume alone. CONCLUSION: The area and volume of the stones correlated more closely with the operation time than the stone burden for bladder calculi lithotripsy using a Ho:YAG laser.

Choosing an appropriate length of loop type ureteral stent using direct ureteral length measurement.

PURPOSE: The ureteral stent is now a fundamental part of many urological procedures. To decrease ureteral stent-related symptoms, loop type ureteral stent was developed. However the most important factor to decrease urinary symptoms is choosing the optimal length of a ureteral stent. We investigated the relationship between the actual ureteral length and the loop type ureteral stent position. MATERIALS AND METHODS: A total of 226 loop type polyurethane ureteral stents (156 patients) were inserted with four options for stent length (20, 22, 24 and 26 cm). The ureteral length was measured using a ruled 5-Fr ureteral catheter. The appropriateness of stent position was defined into three groups based on kidney-ureter-bladder films. RESULTS: Nine stents (3.9%) migrated, 171 stents (75.7%) were in the appropriate position and 46 stents (19.5%) were overlong. The rate of migration rate and overlong stents closely correlated with the ureteral length when the proximal end of the stent was in the renal pelvis. CONCLUSIONS: It is appropriate to choose a loop type ureteral stent that is the same or 1 cm less than the length of the ureter when the proximal end of the stent will be in the renal pelvis.

Ureteral stent exchange under fluoroscopic guidance using the crochet hook technique in women.

PURPOSE: We developed a method for ureteral stent exchange in female patients under fluoroscopic guidance using a crochet hook technique (CHEX). PATIENTS AND METHODS: A total of 45 female patients (51 stents) underwent exchange of ureteral stents. In these patients, 21 ureteral stents were exchanged using CHEX. All procedures were carried out with the patients under conscious sedation. At the time of the procedures, we extracted the ureteral stent from the external urethral orifice using CHEX under fluoroscopic guidance and inserted the new stent under fluoroscopic guidance without cystoscopy. RESULTS: 20 of the 21 stents (95.2%) were successfully exchanged. Ureteral stent exchange using CHEX was unsuccessful in 1 patient, including migration to the ureter. CONCLUSIONS: Ureteral stent exchange using a crochet hook is easy, safe and cost-effective. This technique was also easy to learn.

Which is the best method to estimate the actual ureteral length in patients undergoing ureteral stent placement?

OBJECTIVES: To define the best modality for estimating ureteral length in patients undergoing ureteral stent placement. METHODS: This study enrolled 151 patients (169 ureters) undergoing stent insertion. In all of them, an intravenous urography and non-contrast computed tomography were carried out. The actual ureteral length was determined by direct measurement using a 5-Fr ureteral catheter. A multivariate analysis evaluated the association between the ureteral length and each of the following parameters: body height, body surface area, ureteral trace by intravenous urography, linear distance (liner distance 1) from the ureteropelvic junction to the ureterovesical junction by intravenous urography, linear distance (liner distance 2) from the mid kidney to the ureterovesical junction by intravenous urography, and the distance from the level of the renal vein to the ureterovesical junction by axial computed tomography (axial computed tomography distance). RESULTS: The mean actual ureteral length was 23.2 cm (median 24 cm, range 16-29 cm). The Spearman correlation coefficients for body height, body surface area, ureteral trace, liner distance 1, liner distance 2 and axial computed tomography distance were 0.3126, 0.3076, 0.4541, 0.5230, 0.4796 and 0.6168, respectively. Axial computed tomography distance showed the best correlation with the actual ureteral length. CONCLUSION: The axial computed tomography distance as calculated by the axial computed tomography can more reliably predict the actual ureteral length than other parameters. Further studies are required to show the best method for estimating the actual ureteral length in patients undergoing ureteral stent placement.