Renal-tissue damage induced by laparoscopic partial nephrectomy using microwave tissue coagulator.

BACKGROUND AND PURPOSE: The microwave coagulator is a useful instrument that enables surgeons to perform partial nephrectomy without vascular clamping. The extent of postoperative thermal damage in surgically spared renal tissue has not been well examined. The present study was conducted to evaluate the tissue damage caused by microwave coagulation in laparoscopic partial nephrectomy (LPN) for small renal tumors. MATERIALS AND METHODS: Seven cases of LPN with a microwave tissue coagulator were entered in the present study. The median tumor diameter was 1.5 cm, and the median size of the resected specimen was 2.2 cm. Postoperative tissue damage was evaluated by contrast-enhanced CT 1 month after surgery. Surgically spared renal-tissue volume and functioning renal-tissue volume were estimated from the images by NIH Image 1.62 software. RESULTS: Postoperative CT revealed unenhanced renal tissue adjacent to the surgical margin. The median estimated volumes of surgically spared and functioning renal tissue were 96.1% (range 74.3%-99.8%) and 88.4% (range 68.0%-92.7%) of preoperative normal renal tissue, respectively. The percentile volume of functioning to surgically spared renal tissue ranged from 89.9% to 96.0% (median 92.8%). CONCLUSIONS: The microwave coagulator enables us to carry out partial nephrectomy without vascular clamping. Although 96% of normal renal tissue was surgically spared, 4% to 10% of this tissue was nonfunctioning as a result of microwave-induced thermal damage.

[A modified retroperitoneal approach to the kidney in patients with a highly deformed thorax: obtaining a wide operative field through subperiosteal resection of the 10th, 11th and 12th ribs].

We herein report a technique which facilitates a retroperitoneal approach to the kidney in cases of highly deformed thorax due to kyphoscoliosis. The operation consists of a lumbar oblique incision with removal of the 11th rib, combined with the additional removal of the 12th and 10th ribs. Resection of the upper two ribs was performed subperiosteally, leaving the periosteum of the deep side untouched. However, the deep side periosteum of the 12th rib was incised caudal from the pleural margin in order to facilitate exposure of the diaphragm. The retroperitoneal space was entered through the tip of the 11th rib bed. The diaphragm was incised dorso-medially at a level 1 cm caudal from the lower margin of the pleura, to an extent necessary to enable the pleura together with the cranial diaphragm to be manoeuvred in an upward direction. Two cases with renal tuberculosis associated with high-grade kyphosis and one case with staghorn calculi accompanied with lordosis were operated on utilizing this technique. In the former two cases, the thoracic cage was in direct contact with the iliac bone and there was practically no space between the rib border and the iliac crest. This was also true of the third case, but the grade of deformity was not as extensive as in the former two cases. Removal of the 10th, 11th and 12th ribs could be achieved without injuring the pleura and a satisfactorily large operating field could thus be developed which enabled a simple nephrectomy to be performed without difficulty. The characteristic feature of the described approach is that resection of the 10th and 11th ribs is simply to facilitate manoevrability of the wound margin, without going through the rib bed. The technique could be advantageous in selected cases where there is a highly deformed thorax.

Significant reduction of WT1 gene expression, possibly due to epigenetic alteration in Wilms' tumor.

WT1 at 11p13 is a tumor suppressor gene, an aberration of which causes Wilms' tumor (WT). Since WT1 expression is reduced in a certain proportion of WTs and its mutation is found only in 10-20% of WTs, we examined WT1 gene silencing due to epigenetic alteration in a total of 22 WTs. WT1 expression was significantly reduced in half of WTs without any mutation in the WT1 gene itself, suggesting that the reduction of expression was possibly epigenetic. We found promoter hypermethylation in one WT with loss of heterozygosity (LOH) and showed that promoter methylation reduced reporter gene activity by a reporter assay. These data suggested that methylation was an epigenetic mechanism leading to WT1 silencing and that the expression-reduced allele by hypermethylation combined with LOH was consistent with the revised two-hit model. In addition, as the beta-catenin mutation is frequently associated with the WT1 mutation, the association of WT1 silencing with the beta-catenin mutation was also investigated. beta-catenin mutated in only one WT without WT1 silencing, suggesting that the beta-catenin mutation was not associated with the reduction of WT1 expression.

Nonionic contrast media are less nephrotoxic than ionic contrast media to rat renal cortical slices.

BACKGROUND: Nephrotoxicity induced by contrast media (CM) is well recognized. Nonionic CM with lower osmolality than that of conventional ionic CM have been developed in an effort to reduce toxicity. However, the nephrotoxic effects of nonionic CM have not been well evaluated. Although our previous experiments using rat renal cortical slices indicated that the direct cellular toxicity of nonionic CM is less than that of ionic CM, it was suggested that the less toxic effects of nonionic CM on the metabolic function of renal epithelial cells were in part attributable to the lower osmolality of nonionic CM. In the present experiment, the direct toxicity of nonionic CM on renal epithelial cells was compared with that of ionic CM under equiosmolar conditions, where the effects of osmotic pressure were excluded. METHODS: Rat renal cortical slices were incubated with several kinds of CM at 37 degrees C for 120 min. Diatrizoate and iothalamate were employed as ionic CM. Iopamidol and iohexol were employed as nonionic CM. The activities of N-acetyl-beta-D-glucosaminidase (NAG), gamma-glutamyltransferase (GGTP), and lactate dehydrogenase (LDH) released from the renal slices into the incubation buffer were determined in order to evaluate renal epithelial damage caused by CM. Gluconeogenesis, p-aminohippuric (PAH) acid accumulation and ATP content in rat renal slices were determined with a view to examine the inhibitory effects of CM on the metabolic function of renal epithelial cells. The toxic effects of nonionic CM were compared with those of ionic CM under equiosmolar conditions, where mannitol was added to the experimental groups containing nonionic CM in order to exclude the effects of osmotic pressure. RESULTS: A significant difference was generally not found with regard to enzyme release between ionic CM and nonionic CM plus mannitol. The inhibition of gluconeogenesis and PAH accumulation in rat renal slices by nonionic CM with mannitol was less than that by ionic CM. Although the ATP content was reduced by both ionic CM and nonionic CM plus mannitol, there was no significant difference between these two groups. CONCLUSIONS: The present experiments demonstrated that nonionic CM were less nephrotoxic than ionic CM with regard to the function of renal epithelial cells, including gluconeogenesis and PAH accumulation, under equiosmolar conditions. These differences in nephrotoxicity between ionic and nonionic CM cannot be fully attributable to differences in osmotic pressure.

Hand-assisted retroperitoneoscopic nephroureterectomy for upper urinary-tract urothelial tumors.

PURPOSE: We report our experience with hand-assisted retroperitoneoscopic nephroureterectomy for upper urinary-tract urothelial cancer. PATIENTS AND METHODS: Our initial 10 cases of clinical stage T(1)N(0)M(0) renal pelvic and ureteral tumors treated with hand-assisted retroperitoneoscopic nephroureterectomy are included in the present report. Nephrectomy was conducted retroperitoneoscopically with hand assistance via a lower-abdominal midline incision. Resection of the lower ureter together with the bladder cuff was performed as open surgery and the specimen was removed en bloc via the same incision. RESULTS: Hand-assisted retroperitoneoscopic nephroureterectomy was completed successfully in all 10 cases. The mean operating time was 456 +/- 90 minutes, and the mean estimated blood loss was 462 +/- 364 mL. The times to oral intake and walking were 1.5 +/- 0.5 days and 2.3 +/- 0.7 days, respectively. One case of renal vein injury, one case of pulmonary embolism, and three cases of wound infection were the complications. CONCLUSION: This is the first report of hand-assisted endoscopic nephroureterectomy using the retroperitoneal approach. The surgical technique seems quite reasonable because the lower-abdominal incision can be utilized, not only as a route for hand assistance, but also as a window for open surgery when resecting the distal ureter as well as for extracting the surgical specimen.

Expression of hypoxia-inducible factor 1alpha in human normal, benign, and malignant prostate tissue.

OBJECTIVE: To investigate hypoxia-inducible factor 1alpha (HIF-1alpha) protein expression in normal prostates (NP), benign prostatic glandular hyperplasia (BPH), and prostate adenocarcinoma (Pca). METHODS: HIF-1alpha protein expression was determined by immunohistochemistry in formalin-fixed and paraffin-embedded specimens obtained from 13 cases of NP, 28 cases of BPH, and 34 cases of Pca. In cases of Pca, the relationship between HIF-1alpha protein expression and certain clinicopathological factors, such as clinicopathologic stage and Gleason score, was evaluated. RESULTS: NP manifested no immunoreactivity, whereas Pca and BPH showed significantly increased HIF-1alpha protein expression. A significantly higher expression was observed in Pca specimens compared with BPH samples. In Pca, no significant relationship between HIF-1alpha protein expression and clinicopathological factors was found. CONCLUSION: Our findings of increased HIF-1alpha protein expression in BPH and Pca specimens suggests the potential role of this protein in BPH and Pca.

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.

Experimental study of renal disorder caused by oxaliplatin in rat renal cortical slices.

BACKGROUND: Oxaliplatin is a newly developed antitumor platinum complex that is known to have low nephrotoxicity. The inhibitory effects of oxaliplatin on several tubular functions were compared with those of cisplatin and carboplatin, using a renal cortical slice system. METHODS AND RESULTS: Rat renal cortical slices were incubated with 0.25 mM to 2.0 mM of oxaliplatin, cisplatin, on carboplatin at 37 degrees C for 120 min. Para-amino hippuric acid (PAH) accumulation, gluconeogenesis, and ATP content in the rat renal slices were determined. PAH accumulation was not inhibited by carboplatin, but it was significantly inhibited by oxaliplatin and cisplatin. Inhibition of PAH accumulation by cisplatin was greater than that by oxaliplatin. Gluconeogenesis was not decreased by carboplatin, but it was suppressed by oxaliplatin and cisplatin in a dose-dependent manner. The decrease in gluconeogenesis induced by oxaliplatin was significantly greater than that induced by cisplatin. ATP content in the renal slices was decreased by oxaliplatin, cisplatin, and carboplatin to almost the same extent. As an in vivo experiment, 21.6 mmole/kg of oxaliplatin, cisplatin, or carboplatin was injected into rats; then blood urea nitrogen (BUN) and serum creatinine were determined on day 4. Significantly elevated levels of BUN and serum creatinine were observed only in the rats injected with cisplatin. CONCLUSIONS: Oxaliplatin did not cause nephrotoxicity in the in vivo study; however, the nephrotoxic pattern of oxaliplatin observed in the renal cortical-slice system resembled that of cisplatin. The reason why oxaliplatin is less nephrotoxic than cisplatin in vivo could not be fully elucidated in the present experiment using the renal cortical-slice system.

Annual PSA tests are not necessary for men with a PSA level below 2 ng/mL: findings of the Imari prostate cancer screening program.

BACKGROUND: Annual changes in prostate specific antigen (PSA) levels detected by the Imari prostate cancer screening program were evaluated to establish a more efficient and cost-saving screening system, especially for men with low PSA levels. METHODS: Prostate specific antigen-based annual mass screenings for prostate cancer were conducted for men aged 60-69 in the Imari district, Saga, Japan. Between 1992 and 2000, 1822 men had their PSA levels tested. A total of 4661 PSA tests were conducted. Changes in PSA levels over the following 1 to 5 years were analyzed in men with PSA levels of 3 ng/mL or less, a range in which the detection rate of prostate cancer would seem to be negligibly low. RESULTS: The overall detection rate of prostate cancer between 1992 and 2000 was 0.73%. The detection rate in men with a PSA level between 3.1 and 3.9 ng/mL, and between 4 and 9.9 ng/mL was 1.6% and 8.3%, respectively. Of 4661 determinations of PSA, 2553 (54.8%) were found to be < or = 1 ng/mL, 1273 (27.3%) were between 1.1 and 2 ng/mL, and 401 (8.6%) were between 2.1 and 3 ng/mL. Four hundred and thirty-four men (9.3%) had PSA levels > or = 3.1 ng/mL, with possible indications for prostate biopsy. Of the men tested, 1.4% with an initial PSA level of < or = 2 ng/mL and 22.3% with an initial level between 2.1 and 3 ng/mL had a PSA level of > or = 3.1 ng/mL after 1 year. Almost the same rate of PSA increase was observed between the two PSA tests conducted at 2 to 5-year intervals. Of the men tested, 2.2% with an initial PSA level of < or = 2 ng/mL, and 21.9% with an initial level between 2.1 and 3 ng/mL, had a level of > or = 3.1 ng/mL after 5 years. CONCLUSION: Levels of PSA in men with an initial level below 2 ng/mL remained stable for up to 5 years. Levels of PSA in 97.8- 98.8% of men remained below 3 ng/mL after 1 to 5 years. In contrast, 18-35.3% of men with an initial PSA level between 2.1 and 3 ng/mL showed PSA progression to 3.1 ng/mL or more within 5 years. Our present data suggest that annual PSA testing is not necessary for men with a PSA level below 2 ng/mL. Prostate specific antigen testing could therefore be conducted at longer intervals in such individuals.

Device to promote pelvic floor muscle training for stress incontinence.

AIM: Many patients with stress urinary incontinence do not have enough motivation to continue pelvic floor muscle training (PFMT) by themselves. Therefore, a device was created to support PFMT, and its effect was examined. METHODS: Forty-six women with stress urinary incontinence were assigned to a control group or a device group in order of presentation. A pamphlet on PFMT was given to control patients, while the same pamphlet plus the device and instructions on its use were given to patients in the device group. The device had a chime that was set to sound three times a day when exercise sessions were scheduled. PFMT consisted of fast and slow pelvic floor muscle contraction exercises that were performed for 2 min and followed a rhythm set by the device. RESULTS: After 8 weeks, 20 patients from the control group and 21 patients from the device group could be evaluated. In the control group, only the quality of life (QOL) index improved significantly. In the device group, however, the daily number of incontinence episodes, the number of pads used daily, the QOL index, and the pad weight in the pad test improved significantly. Patients in the device group said that they felt obligated to perform PFMT when the chime sounded. Forty-eight percent of patients from the device group were satisfied with the outcome of PFMT, while only 15% were satisfied in the control group. CONCLUSION: This device may be useful to support the management of stress urinary incontinence.