Risk Factors for Uroseptic Shock in Patients with Urolithiasis-Related Acute Pyelonephritis.

OBJECTIVES: To analyze the risk factors of uroseptic shock induced by calculous acute pyelonephritis (APN). METHODS: This study included 69 patients (41 were women and 28 were men) who were admitted to our hospital for APN treatment associated with urolithiasis during the period from January 2005 to December 2012. We reviewed the electronic medical records of these patients to analyze risk factors contributing to the development of uroseptic shock from APN in patients with urolithiasis. RESULTS: Urinary drainage with ureteral stent or nephrostomy was carried out in 62 cases. Septic shock requiring vasopressor infusion against circulatory collapse was observed in 25 patients, these patients showed significantly lower serum albumin levels and higher C-reactive protein (CRP) compared to patients who did not exhibit septic shock. Multivariate analysis revealed that serum albumin level and CRP were the significant risk factors for the development of uroseptic shock from calculous APN. CONCLUSIONS: Serum albumin level was the significant risk factor for the development of uroseptic shock from calculous APN. Emergency drainage to decompress the obstructed urinary tract is mandatory as an initial urological intervention for the patients with lower serum albumin level.

The Efficacy of a Transurethral Incision for Diurnal and Nocturnal Enuresis in Young Males.

INTRODUCTION: In this study, we investigated the effects of treatment with a transurethral incision (TUI) for congenital urethral stenosis, which was accompanied by diurnal and nocturnal enuresis. METHODS: We recruited 21 young males who presented to our department for the treatment of diurnal and nocturnal enuresis from January 2010 to March 2014. All patients underwent TUI due to urethral stricture found by a close investigation. We surveyed each case to evaluate the improvement of diurnal and/or nocturnal enuresis after TUI. RESULTS: One and a half years after TUI, an improvement in diurnal enuresis was observed in 17 of 21 cases (80.9%), whereas that of nocturnal enuresis was observe in only 7 of 21 cases (33.3%), showing the significant contribution of TUI to the improvement of diurnal enuresis (p = 0.001). In the case of diurnal enuresis, continual improvement was observed more than a year after surgery, whereas no improvement was observed in nocturnal enuresis at more than 6 months after surgery. CONCLUSION: TUI is more effective for diurnal enuresis than nocturnal enuresis. At postoperative 6 months, clinicians should thus consider other etiologies for unresponsive cases and start other treatment options.

Differential effects of adipose tissue stromal cells on the apoptosis, growth and invasion of bladder urothelial carcinoma between the superficial and invasive types.

OBJECTIVES: To clarify the interaction between adipose tissue stromal cells and bladder cancer cells. METHODS: Superficial (RT4) and invasive (EJ) urothelial carcinoma cells were cultured on adipose tissue stromal cell-embedded or non-embedded collagen gel. Cells were analyzed by immunohistochemistry, western blot and real-time reverse transcription polymerase chain reaction. RESULTS: Adipose tissue stromal cells inhibited growth of RT4, while they promoted the apoptosis. In contrast, adipose tissue stromal cells promoted growth of EJ, but they did not affect the apoptosis. Adipose tissue stromal cells slightly promoted expression of mitogen-activated protein kinase cascade in RT4 and EJ. Adipose tissue stromal cells promoted display of the molecular-targeted agent human epidermal growth factor receptor-2 in only RT4. In turn, RT4 and EJ enhanced α-smooth muscle actin (myofibroblast marker) and S-100 protein (adipocyte marker) expression of adipose tissue stromal cells, respectively. CONCLUSIONS: These findings suggest that: (i) adipose tissue stromal cells might suppress the progression of superficial-type cancer, whereas they might promote that of invasive type; (ii) adipose tissue stromal cell-activated mitogen-activated protein kinase pathway might play differential roles in both types of bladder cancer; (iii) human epidermal growth factor receptor-2 could represent a critical therapeutic agent for the superficial type under adipose tissue stromal cells-cancer interaction; and (iv) superficial bladder cancer might promote myofibroblast differentiation of adipose tissue stromal cells as a cancer-associate phenotype, whereas invasive bladder cancer might promote their adipocyte differentiation.

Non-inferiority of silodosin 4 mg once daily to twice daily for storage symptoms score evaluated by the International Prostate Symptom Score in Japanese patients with benign prostatic hyperplasia: a multicenter, randomized, parallel-group study.

OBJECTIVES: To compare the effect of treatment with silodosin 4 mg once daily versus that of silodosin 4 mg twice daily on storage symptoms in Japanese patients with benign prostatic hyperplasia. METHODS: A prospective, multicenter, 12-week, open-labeled study randomized a total of 268 men aged 50 years or older with benign prostatic hyperplasia and overactive bladder to silodosin 4 mg/day or 8 mg/day. Changes in the end-points of the average value of International Prostate Symptom Score, quality of life index in the International Prostate Symptom Score, Overactive Bladder Symptom Score and urodynamic parameters were evaluated. The change in the storage symptom subtotal score of the International Prostate Symptom Score was considered as the primary end-point. RESULTS: Silodosin 4 mg/day was not inferior to silodosin 8 mg/day in regard to the primary end-point. In contrast, the efficacy of treatment with silodosin 4 mg twice daily was greater than that of 4 mg once daily, based on both the quality of life index and the Overactive Bladder Symptom Score total score. There was a discrepancy between the scores evaluated using the International Prostate Symptom Score and Overactive Bladder Symptom Score questionnaires. CONCLUSIONS: Silodosin 4 mg once daily is not inferior to silodosin 4 mg twice daily in regard to storage symptoms score evaluated by the International Prostate Symptom Score. In contrast, silodosin 4 mg twice daily is more effective on storage symptoms evaluated by the Overactive Bladder Symptom Score than silodosin 4 mg once daily.

[PROCEDURE AND FEASIBILITY OF LAPAROSCOPIC RENAL BIOPSY].

OBJECTIVES: Recently, laparoscopic surgery is the standard procedure in urological field. We report the experience of laparoscopic renal biopsy for 4 patients who have contraindication of ultrasound-guided percutaneous renal biopsy. PATIENTS AND METHODS: We retrospectively reviewed the patients who underwent laparoscopic renal biopsy (LRB) from March 2010 to June 2013 in our hospital. Four female with mean age of 54.5 years old underwent LRB. Two patients had solitary kidney and the other 2 patients had bleeding tendency. All the biopsy was performed retroperitoneal approach. We used 18-gauge biopsy needle to take renal cortical tissue in all cases. In addition, one patient underwent small wedge biopsy with a cold knife. RESULTS: Mean operative time, pneumoperitoneal time, and estimated blood loss was 63.0 min (range 48-92 min), 37.5 min (range 22-75), and 11.25 ml (range 0-30 ml), respectively. No perioperative complication was observed. In all cases, we can diagnose pathologically by LRB. CONCLUSIONS: LRB is safe, effective, and feasible procedure for the patients in whom ultrasound-guided percutaneous renal biopsy is contraindication.

Is the eGFR formula adequate for evaluating renal function before chemotherapy in patients with urogenital cancer? A suggestion for clinical application of eGFR formula.

BACKGROUND: Accurate evaluation of renal function is required before cancer chemotherapy. Various kinds of formula have been developed for estimating creatinine clearance (Ccr) or glomerular filtration rate (GFR) conveniently. We retrospectively examined the reliability of the GFR estimating formula using the renal function data in cancer chemotherapy. METHODS: Clinical data of 12 patients with urogenital cancer from 1998 to 2013 in Saga University Hospital were reviewed. Patients were treated with 6-21 (median 10.5) courses of chemotherapy and those patients underwent 9-29 (median 14.5) times of 24hrCcr tests before and during chemotherapy. We compared estimated GFR (eGFR) with 24hrCcr. In addition, we developed a novel method to estimate the Ccr using the patient-inherent 24hrCcr/eGFR ratio, which is calculated from initial 3 or 4 determinations of 24hrCcr and the corresponding eGFR. Those estimated Ccrs were also compared with 24hrCcr. RESULTS: The dissociation between 24hrCcr and eGFR was not constant, and a large dissociation was observed in some cases. The newly devised estimated Ccr demonstrated less dissociation from 24hrCcr compared with eGFR. CONCLUSIONS: The eGFR formula is not adequate for the clinical use in cancer chemotherapy. The absolute value of eGFR is not reliable, but clinical use of eGFR as relative value seems to be acceptable. To avoid troublesome 24hrCcr measurement in long-term cancer chemotherapy, eGFR formula can be used for estimating Ccr in combination with the specific inherent 24hrCcr/eGFR ratio, which is obtained from 3 or 4 times of actual 24hrCcr measurements.

Usefulness of Blocksom vesicostomy in elderly men with chronic urinary retention and severe dementia.

AIM: In the present article, we present the usefulness of Blocksom vesicostomy in elderly men with chronic urinary retention. METHODS: We carried out Blocksom vesicostomy in four patients between January 2011 and September 2013. We followed up all patients over 6 months. We checked their general and urinary condition based on interviews with their family members. RESULTS: The etiology of urinary retention included prostate cancer and neurogenic bladder. All of the patients had severe dementia. We successfully managed the urinary treatment of all patients, although their general conditions gradually deteriorated. CONCLUSIONS: In general, this type of vesicostomy is not a popular urinary treatment; however, Blocksom vesicostomy can be useful for treating elderly men with chronic urinary retention and severe dementia.

Chronic urinary retention could decrease the number of suburothelial myofibroblasts in the rat bladder.

AIMS: To demonstrate changes in the number of suburothelial myofibroblasts in the rat bladder due to chronic urinary retention (CUR). METHODS: Bladder specimens were obtained from 12-week-old Wistar female rats that were divided into two groups: a CUR group and a sham-operated group. In the CUR rats, the urethra was intubated with a polyethylene catheter, and a double 4-0 silk ligature was placed around the proximal urethra, after which the catheter was removed. After 8 weeks, the cystometric findings and immunohistochemical staining of the suburothelial myofibroblasts were compared between the groups. RESULTS: The bladder weight of the control rats was 0.20 ± 0.01 g and that of CUR rats 1.6 ± 0.4 g. The bladder capacity of the control rats was 0.5 ± 0.3 ml and that of the CUR rats 12.9 ± 3.1 ml. The number of suburothelial myofibroblasts of the control rats was 417 ± 123 and that of the CUR rats 44 ± 42. The number of suburothelial myofibroblasts in the CUR rats was significantly less than that observed in the sham-operated rats (p < 0.01). CONCLUSIONS: In this study, we demonstrated that mechanical stress over a long period on the bladder wall can decrease the number of suburothelial myofibroblasts. The reduced expression of suburothelial myofibroblasts may be related to prolongation of the micturition interval by CUR.

Risk factors of postoperative urinary retention after hip surgery for femoral neck fracture in elderly women.

AIM: The aim of the present study was to evaluate risk factors for postoperative urinary retention (POUR) in female patients with femoral neck fractures. METHODS: We recruited 72 female patients (age 86.5 ± 6.7 years) from among 90 cases of hip surgery carried out between January and December 2011 at Goto Chuo Hospital. We evaluated the risk factors for POUR, including the administration of anticholinergic drugs, diabetes mellitus, preoperative dementia and/or delirium, neurological disorders, age, hypertension, overactive bladder, and the postoperative duration of the use of an indwelling urethral catheter using a multiple logistic regression analysis. RESULTS: In the present study, POUR occurred in eight out of 72 cases (11.1%). The multivariate analysis showed that the indwelling period of the urethral catheter (per 1-day increase; P = 0.04, OR 0.33 95% CI 0.11-0.96), and preoperative dementia and/or delirium (P = 0.03, OR10.4, 95%CI 1.21-89.2) correlated with the occurrence of POUR. Diabetes mellitus (P = 0.78), anticholinergic agents (P = 0.23), neurological disorders (P = 0.83), age (P = 0.86), hypertension (P = 0.76) and overactive bladder (P = 0.34) did not significantly correlate with the occurrence of POUR. CONCLUSIONS: The present study showed that the early removal of the urethral catheter, and preoperative dementia and/or delirium had significant correlations with POUR. The femoral neck fractures and the surgical procedure used for the hip surgery do not induce damage to the bladder and nerve system related to the voiding function, and the voiding function in all of the patients recovered after short-term intermittent catheterization. Physicians should not place permanent indwelling urethral catheters without carrying out urological assessments.

Suture Granuloma Showing False-Positive Findings on FDG-PET.

We report a case of a 33-year-old male with a mixed germ-cell testicular tumor. Postoperative follow-up FDG-PET revealed concentration of FDG in the left inguinal area which is not tumor metastasis or local recurrence but suture reactivity granuloma. In this paper, we reviewed suture granulomas associated with false-positive findings on FDG-PET after surgery. If FDG-PET will be used more frequently in the future, it will be necessary to refrain from using silk thread in order to prevent any unnecessary surgery.

Magnetic resonance imaging of large chromophobe renal cell carcinomas.

PURPOSE: The objective of this study was to clarify the magnetic resonance imaging (MRI) findings of large chromophobe renal cell carcinomas. MATERIALS AND METHODS: Five patients diagnosed pathologically with chromophobe renal cell carcinoma are included. MRI findings were retrospectively evaluated for the tumor contour, uniformity and hypointensity of the rim of the tumor on T2-weighted images, "microscopic fat," enhancement degree and pattern on dynamic study, and necrosis in the tumor, among other findings. RESULTS: The tumor size ranged from 4.8 to 13.7 cm (mean 7.9 cm). The tumor contour was well defined in four patients. All but one tumor showed a hypointensity rim, and all tumors had a heterogeneous appearance on T2-weighted images. "Microscopic fat" was detected in one case. All tumors demonstrated low enhancement compared to that of the renal cortex. All tumors showed heterogeneous enhancement on postcontrast images. Necrosis was seen in four. Hemorrhage and renal vein thrombosis was seen in one. CONCLUSION: Chromophobe renal cell carcinomas of large size tend to have a heterogeneous appearance on postcontrast and T2-weighted images, a well-defined tumor contour with a hypointensity rim on T2-wighted images, and lower enhancement than that of the renal cortex. Tumor necrosis is easily apparent, and "microscopic fat" may be observed.

Effects of adipocytes on the proliferation and differentiation of prostate cancer cells in a 3-D culture model.

OBJECTIVE: To investigate how the mechanism of adipocyte-prostate cancer cell interaction affects the proliferation and differentiation of prostate cancer cells. METHODS: An androgen-dependent cell line (LNCaP), two androgen-independent cell lines (PC-3, DU145), and mature adipocytes harvested from male Wistar rats were used. Cancer cells were co-cultured with the isolated mature adipocytes in 3-D collagen gel matrix culture. The morphology and proliferative ability of the prostate cancer cells were examined. With regard to the activation of the phosphatidylinositol 3-kinase (PI3K) pathway, the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN), Akt and Bad were determined by immunohistochemistry. RESULTS: LNCaP cells co-cultured with adipocytes formed larger clusters than those of the control. PC-3 cells co-cultured with adipocytes did not form larger clusters, but formed spherical and spindle-shaped cells. The phosphorylation of Akt in PC-3 cells was greater in the co-cultured group compared with the controls, but there were no significant differences in the phosphorylation of Akt with regard to LNCaP and DU145 cells. CONCLUSIONS: Adipocytes could modulate the proliferation and differentiation of prostate cancer cell lines. Activation of the PI3K pathway might be involved in the prostate cancer cell-adipocyte interaction.

Skeletal-related events in urological cancer patients with bone metastasis: a multicenter study in Japan.

OBJECTIVE: To investigate the incidence of skeletal-related events (SRE) in urological cancer patients with bone metastases in Japan. METHODS: Five hundred eleven patients with urological cancer and documented bone metastases treated from January 2003 to April 2008 in ten Japanese institutions were included in a retrospective analysis. Type and incidence of SRE (fracture, radiotherapy, spinal cord compression, surgery, hypercalcemia, and bone pain) were determined from patient medical records. RESULTS: The overall incidence of SRE, including 'pain', was 61%. The most common event was radiotherapy for bone metastases, with an incidence of 31%. The overall incidence of events seemed to be similar among Japanese and Western patients with prostate cancer and renal cell carcinoma when comparing data with previously published reports. Nevertheless, a much lower incidence of fracture (19.1%) was observed in Japanese renal cell carcinoma patients. CONCLUSIONS: The overall incidence of SRE in Japanese urological cancer patients with bone metastasis was similar to that in Western patients, but the incidence of fracture was lower in Japanese renal cancer patients.

Adipose tissue explants and MDCK cells reciprocally regulate their morphogenesis in coculture.

Adipokine-producing fatty tissues, composed of preadipocytes, adipocytes, and mesenchymal stem cells, surround the kidney. To study the interaction between renal tubular cells and adipose tissue, we cocultured adipose tissue fragments and MDCK cells. MDCK cells in the coculture showed a taller columnar shape with improved organization of their microvilli and basal lamina than that seen in MDCK cell monoculture. The adipose tissue-induced change in morphology was replicated when we added leptin to MDCK cells cultured alone. Adiponectin abolished the leptin effect. Adipose tissue fragments inhibited MDCK cell division and also the formation of single-stranded DNA, an indicator of apoptosis. The fragments promoted the expression of polarity-associated proteins, including the tight junction molecules, ZO-1, atypical protein kinase C, and Cdc42. Further, the fragments also accelerated the expression of pendrin, the chloride/iodide transporter in the MDCK cells. In turn, MDCK cells decreased the number of preadipocytes and CD44+/CD105+ mesenchymal stem cells in the fragments, and promoted adiponectin production from the fragments. Thus, our study shows that adipose tissue fragments promote the hypertrophy, polarization, and differentiation of MDCK cells by attenuating their growth and apoptosis through opposing endocrine or paracrine effects of leptin and adiponectin. Further, MDCK cells inhibit the regeneration of preadipocytes and mesenchymal stem cells in adipose tissue.

Microwave tissue coagulator induces renal apoptotic damage to preserved normal renal tissue following partial nephrectomy.

BACKGROUND: We assessed the extent of apoptotic damage induced by the microwave tissue coagulator (MTC) in the preserved normal renal tissue following partial nephrectomy. METHODS: Eleven patients who underwent nonischemic partial nephrectomy with MTC (group M) were enrolled in this study. The other 11 patients who underwent cold-ischemic partial nephrectomy without the use of MTC were enrolled as controls (group C). There were no significant differences in tumor size or age between the two groups. Renal damage was evaluated by counting apoptotic cells in the normal renal tissue surrounding the tumor tissue. Immunohistochemical staining with single-stranded DNA was carried out to investigate the apoptotic cells. RESULTS: The number of apoptotic cells in group M ranged from 275 to 508 per 1,000 cells, with a median value of 421. The number in group C ranged from 122 to 466 per 1,000 cells with a median value of 286. The number of apoptotic cells in group M was significantly greater than that in group C (p = 0.006). Blood loss in group C was significantly greater than that in group M (p < 0.0001). CONCLUSIONS: This study points out that renal damage induced by the use of MTC comprises not only necrosis but also apoptotic change. Although MTC is useful for controlling renal parenchymal bleeding during partial nephrectomy, we must consider that renal apoptotic damage caused by the MTC may spread beyond the coagulated necrosis area.

The effects of neoadjuvant chemotherapy and chemo-radiation therapy on MRI staging in invasive bladder cancer: comparative study based on the pathological examination of whole layer bladder wall.

OBJECTIVE: We evaluated the correlation of radiological findings obtained by MRI study with pathological diagnosis in invasive bladder cancer treated with neoadjuvant chemotherapy, with or without radiation. DESIGN, SETTING, AND PARTICIPANTS: Twenty-seven patients, who underwent total or partial cystectomy for invasive bladder tumors, were enrolled into the present study. Eight cases had received neoadjuvant chemotherapy following the staging biopsy (group A), ten cases had received chemo-radiation therapy following the staging biopsy (group B), and nine cases had received preoperative staging biopsy alone (group C). As a final treatment, 12 of the 27 patients underwent total cystectomy and the other 15 patients underwent partial cystectomy. MRI was conducted prior to total or partial cystectomy in each case. The pathological stage was assessed by histological examination of the entire layer of the bladder wall. RESULTS AND LIMITATIONS: Tumor stage assessed by MRI was consistent with pathological findings in 16 of the 27 cases (59.3%), while MRI produced over-staging in 7 cases and under-staging in 4 cases. The accuracy of staging was 75.0, 30.0, and 77.8% in groups A, B, and C, respectively. The accuracy of MRI staging in group B was lower than that in group C (P < 0.05). There was no difference in the accuracy of MRI staging between groups A and C. CONCLUSION: MRI is useful for the staging of bladder cancer. However, care needs to be taken when staging invasive bladder tumors treated with neoadjuvant chemo-radiation therapy, because inflammatory infiltrations and/or fibrous changes caused by the chemotherapy or chemo-radiation therapy make precise staging with MRI difficult.

Laparoscopic radical nephroureterectomy: a multicenter analysis in Japan.

BACKGROUND: Laparoscopic nephroureterectomy (LNUx) is prevalent in Japan and throughout the world, but long-term outcome data remain limited. OBJECTIVE: To understand the present state of LNUx in Japan, we conducted a multicenter analysis of clinical outcome and long-term cancer control for patients who underwent the procedure. DESIGN, SETTING, AND PARTICIPANTS: Between January 1995 and December 2005, 1003 patients with urothelial cancer in the upper urinary tract were treated with LNUx at 51 institutions in Japan, and patient data were collected retrospectively. MEASUREMENTS: Patient profiles were gathered and analyzed for survival, intravesical recurrence, and risk factors influencing them. RESULTS AND LIMITATIONS: Median operative time was 320 min. Median bleeding volume was 232 ml. Complications occurred in 93 cases (9.3%) intraoperatively and in 107 cases (10.7%) postoperatively. Overall survival rate was 70% at 5 yr. Grade 3, pT3 or pT4, multifocal tumor, lymph-node metastasis, and previous or coexistent bladder tumor were independent risk factors for overall survival. Intravesical recurrence rate was 43% at 5 yr. Intravesical recurrence occurred more frequently in males, in patients with multifocal tumors, in patients with previous or coexistent bladder tumors, and in patients who underwent the hand-assisted approach. CONCLUSIONS: Our report represents the largest multicenter analysis of LNUx reported to date. Male sex and the use of the hand-assisted approach were shown for the first time to be risk factors for recurrence-free survival and intravesical recurrence. To further analyze the effectiveness of LNUx, a long-term outcome comparison with risk stratification must be made between LNUx and open nephroureterectomy.

[Metachronous testicular seminoma with an interval of 14 years from the first nonseminomatous testicular tumor: a case report].

A 32-year-old man was admitted to our hospital with a complaint of right scrotal swelling. He had a past history of left testicular nonseminomatous germ cell tumor (NSGCT), stage IIB 14 years ago. He had undergone chemotherapy with 3 courses of PEP and retroperitoneal lymphnode dissection revealing pathological CR. He was diagnosed as having right testicular tumor. He underwent right high orchiectomy. Imaging studies and pathological studies revealed pure seminoma with spermatic cord invasion, stage I, pT3N0M0. He underwent chemotherapy with 3 courses of VIP. Herein we present a case of metachronous bilateral testicular germ cell tumor with a review of literatures.

Squamous cell carcinoma of the urachus.

A 64-year-old man was admitted with complaints of abdominal pain and pollakisuria. A soft mass was palpable under his navel. Magnetic resonance imaging (MRI) revealed a 9 x 6 cm tumor, which was composed of a cystic lesion arising from the urachus and a solid mass component at the urinary bladder dome. Urine cytology specimens showed squamous cell carcinoma (SCC). Serum SCC level was increased and the tumor was removed surgically. Histological examination detected well-differentiated SCC, which had invaded the urinary bladder and the peritoneum. The patient has been followed up without recurrence for 6 months.

Management of extrinsic malignant ureteral obstruction with urinary diversion.

OBJECTIVE: The effectiveness of urinary diversion for patients with renal insufficiency due to extrinsic ureteral obstruction was assessed. METHODS: Between 1990 and 2003, 30 males and 45 females, ranging 36-90 years of age (average, 62.7) who had secondary ureteral obstruction due to either a retroperitoneal or pelvic invasion of malignant disease, underwent nephrostomy or ureteral stenting using a double-J stent without side holes. RESULTS: Ureteral stenting was attempted as an initial procedure in 51 of the 75 cases. The remaining 24 cases had a nephrostomy at the first step. Of 51, 37 cases were successfully stented, while internal stenting was unsuccessful in the remaining 14 cases. These 14 cases were treated with nephrostomy at the second step following the unsuccessful internal stenting. Eight cases of the 37 successfully stented cases were eventually changed to a nephrostomy because of catheter trouble. As a result, 29 cases could be managed by internal ureteral stenting up until the end of their life. The follow-up period for the 75 cases who underwent urinary diversion ranged from 5 days to 19 months, averaging 5.7 months. The average period from diversion to death was 5.6 months in the internally stented group and 5.9 months in the nephrostomy group. CONCLUSION: The high patency rate of the internal ureteral stent in our cases might be due to our use of a stent without shaft vent holes.