Biomedical subjects

Shuji Nishizawa

Publications and source records attributed to Shuji Nishizawa.

3 recordsLinked to original sources

PubMed2006

[Novel NMP22 quick qualitative analysis (BladderChek NMP22) for the diagnosis of urothelial tumor].

PURPOSE: The BladderChek NMP22 test was studied to determine whether it could be a useful diagnostic tool for urothelial tumor. MATERIALS AND METHODS: During the period from April to May 2004, a total of 50 patients who visited Nagano Municipal Hospital were subjected to analysis with the BladderChek NMP22 test. They consisted of 25 patients with microscopic or gross hematuria and 25 patients with urothelial tumor who were being followed after surgery. The clinical diagnosis was made by cystoscopy, abdominal CT scanning, ultrasonography or intravenous urography. BladderChek NMP22 was used in all of the patients and the test was judged to be positive when a line appeared on the glass at 30 minutes after a drop of urine was added to the sample well. Cytological examination of the urine was also done. It was defined as negative if the result was I, II or III, while it was positive if the result was IV or V. RESULTS: Seven patients who were not eligible were excluded and the remaining 43 patients were studied. Eleven of the 43 patients were diagnosed as having urothelial tumor. The sensitivity, specificity, and accuracy of BladderChek NMP22 for making a correct diagnosis was 63.6%, 62.5%, and 62.7%, respectively (p = 0.1703). As for urine cytology, the sensitivity, specificity, and accuracy was 36.3%, 100%, and 83.7%, respectively (p = 0.0027). BladderChek NMP22 was positive in all the patients whose urine cytology was positive and in three patients with low-grade, low-stage, and small tumors, although urine cytology was negative. On the other hand, false-positive BladderChek NMP22 results were obtained in patients undergoing follow-up after removal of urothelial carcinoma and in patients with urinary stones. The sensitivity of BladderChek NMP22 was superior to that of urine cytology, but its specificity was inferior. CONCLUSION: The combined use of BladderChek NMP22 and cystoscopy may be useful for the diagnosis and follow-up of urothelial tumor. On the other hand, the results obtained with BladderChek NMP22 need to be interpreted carefully because the test can yield a false-positive outcome in the presence of marked hematuria, pyuria or cytolysis of normal urotherium. When the result of BladderChek NMP22 in the monitoring of recurrent urotherial tumor following surgery was positive in spite of negative findings of cystoscopy, it is necessary to consider the presence of a tumor in the upper urinary tract or a high tendency toward tumor recurrence. In such a case, careful followup may be necessary.

Adult↗

PubMed2003

[Non-ischemic partial nephrectomy using microwave tissue coagulator].

PURPOSE: The indications and the safety of non-ischemic partial nephrectomy using a microwave tissue coagulator were studied. MATERIALS AND METHODS: Non-ischemic partial nephrectomy was performed on 17 kidneys of 16 patients using a microwave tissue coagulator. The diagnosis was renal tumor and renal stones in eleven and five patients, respectively. Renal tumors were less than 4 centimeters in diameter, while the stones were associated with a caliceal diverticulum or secondary cortical atrophy. Excision of the tumors was done via the retroperitoneal approach through an oblique lumbar incision. The needle of the microwave tissue coagulator was inserted around the tumor (stone) 10 to 20 times, and the coagulator was activated. Then the tumor (stone) was excised with a sharp knife or scissors. Patients were encouraged to walk on the first postoperative day. RESULTS: Vascular clamping was necessary in one patient to reduce bleeding. Nephrectomy was done after partial nephrectomy in one patient because it was difficult to close the urinary collecting system after it was widely exposed. Although urine leakage was seen postoperatively in two patients, it ceased spontaneously at 14 and 23 days after surgery. Postoperative complications developed in one of seven patients (14%) with protruding renal tumor, in three of five patients (60%) with non-protruding renal tumor and in two patients with renal stone. Allogenic or autologous blood transfusion was not necessary, nor was any bleeding noticed post-operatively. In one patient, atrophy of the renal parenchyma occurred gradually after surgery and function was eventually lost. However, renal function was well preserved and recurrence of the problem was not observed in the other 15 patients, excluding one who died of esophageal cancer. CONCLUSIONS: The microwave tissue coagulator is a useful surgical instrument for non-ischemic partial nephrectomy, not only in patients with renal tumors but also in patients with complicated kidney stones. However, non-protruding renal tumor in a patient with solitary kidney should be avoided for this surgery. Thermal injury to the renal parenchyma or large vessels should be avoided and urine leakage from the collecting system should be meticulously treated during the operation.

Adult↗

PubMed2002

De-serosalized muscle layer covering method for antireflux ureteroileostomy: a new operative technique and pressure study with ureterometry at the ureteroileal anastomotic site in dogs.

PURPOSE: In pursuit of a more effective antireflux ureteroileostomy with a lower postoperative complication rate we performed a new operative technique and evaluated intraureteral pressure with ureterometry to examine the mechanism of antireflux function. MATERIALS AND METHODS: A total of 11 beagle dogs were used in this study. A 3 x 2 cm. section of the ileal serosa was removed, the severed ureter was directly anastomosed to the de-serosalized area and 1 cm. of terminal ureter and the direct anastomotic site were covered with the de-serosalized ileal wall. The bladder was augmented with the ileum containing the ureter. Postoperative evaluations were performed monthly and ureterometry of the reimplanted ureter was done 6 months postoperatively. RESULTS: Complete reflux prevention and a low stricture rate were achieved with this procedure. Direct ureteroileal anastomosis caused stricture in 1 of the 11 ureters but the covering procedure to prevent ureteral reflux caused no ureteral strictures. When the bladder was empty, ureteral closure pressure at the intramural portion of the ureter was low. At the phase of high intravesical pressure ureteral closure pressure at the intramural ureter was as high as intravesical pressure. CONCLUSIONS: The de-serosalized muscle layer covering method prevented ureteral reflux completely with a low stricture rate. The antireflux function of this method seems to depend on the flexibility of the terminal ureter covered with the de-serosalized ileal wall. Reflux prevention in the low intravesical pressure phase seems to be due to extension of the ileal wall.

Anastomosis, Surgical↗