Shizuka Iida

Holmium: yttrium-aluminum-garnet laser for endoscopic lithotripsy

OBJECTIVES To evaluate the holmium:yttrium-aluminum-garnet (Ho:YAG) laser for endoscopic lithotripsy on patients diagnosed with urinary tract calculi. METHODS Thirty-eight procedures utilizing transurethral ureterolithotripsy or percutaneous nephroureteral lithotripsy were evaluated: 5 renal calculi, 31 ureteral calculi (most in the upper ureter), 1 ureteropelvic junction calculus, and 1 bladder calculus. These were mainly in cases that, after being treated with extracorporeal shock-wave lithotripsy (ESWL), were contraindicated for further ESWL. Laser parameters included energy of 0.5 to 1.0 J/pulse and pulse rate of 5 to 10 Hz. RESULTS Composition of calculi was determined in 26 procedures. The Ho:YAG laser was effective for fragmenting all types of calculi. Patient outcome evaluated at 6 weeks after treatment showed that 33 of 38 procedures (87%) were effective. Residual calculi in 4 of the 5 unsuccessful procedures were less than 5 mm in size and judged to be able to pass spontaneously. In the remaining procedure, the calculus was passed spontaneously 3 months after treatment. No severe damage to tissues or adverse effects to the body were observed due to the Ho:YAG laser. CONCLUSIONS On the basis of these results, we determine that this wavelength is effective for lithotripsy in addition to its previously reported usefulness for soft tissue applications, and, thus, is a cost-effective and highly useful clinical device.

Transurethral holmium laser resection of the prostate.

PURPOSE We evaluated the efficacy of the holmium:YAG laser for transurethral endoscopic prostatectomy for benign prostatic hyperplasia (BPH). MATERIALS AND METHODS We treated 103 patients with BPH with holmium:YAG laser resection of the prostate. A high power holmium laser generating a maximum of 60 or 81 W. was used in a pulsed mode, applying energy directly to prostatic tissue via a forward firing 550 micron. fiber transurethrally under direct vision. Treatment outcome was evaluated by the International Prostate Symptom Score, quality of life score, maximum flow rate and post-void residual urine volume. We also compared holmium laser surgery and transurethral resection of the prostate for operative factors, such as surgical duration, bleeding volume and catheterization time. RESULTS Average symptom score, quality of life score, peak flow rate and post-void residual significantly improved at 1 week, 1 month and 3 months postoperatively, with improvement maintained up to 36 months postoperatively in the holmium:YAG group. Intraoperative bleeding volume was significantly lower and catheterization time was significantly shorter for holmium:YAG than for transurethral prostatic resection. Use of the holmium laser caused no complications. CONCLUSIONS Because of its effectiveness and safety holmium:YAG resection is a viable potential surgical alternative for symptomatic BPH. The holmium:YAG laser has been verified to be useful for many purposes in urology.

Primary carcinoid of the testis associated with carcinoid syndrome

Abstract Testicular carcinoid is a rare disease accounting for less than 1% of all testicular neoplasms. It rarely manifests symptoms of carcinoid syndrome. Recent reports have noted that only 1.1–3.1% of testicular carcinoid tumors are complicated by carcinoid syndrome. In general, large tumor size and the presence of carcinoid syndrome are features associated with a malignant course. In the present case, pathological findings revealed pure carcinoid of the testis without metastasis. Moreover, watery diarrhea due to carcinoid syndrome disappeared and the serum serotonin level normalized following orchiectomy. The patient was followed up for 12 months with whole body computed tomography scan and assessment of serotonin levels. To date, there is no evidence of tumor recurrence. These findings suggest that monitoring serum serotonin levels may be useful as a marker during follow up of this type of tumor.

Endoscopic lithotripsy with the holmium:YAG laser.

The holmium:YAG (Ho:YAG) laser can be used not only for soft tissue but also for hard tissue such as urinary calculi. The objective of this study was to assess the usefulness of the Ho:YAG laser for endoscopic lithotripsy in patients with urinary tract stone.

Protective role of heparin/heparan sulfate on oxalate-induced changes in cell morphology and intracellular Ca2+

Alterations in intracellular Ca2+ ([Ca2+]i) are generally associated with cellular distress. Oxalate-induced cell injury of the renal epithelium plays an important role in promoting CaOx nephrolithiasis. However, the degree of change in intracellular free calcium ions in renal epithelial cells during oxalate exposure remains unclear. The aim of this study is to determine whether acute short-term exposure to oxalate produces morphological changes in the cells, induces a change in cytosolic Ca2+ levels in renal tubular epithelial cells and whether the application of extracellular glycosaminoglycans (GAGs) prevents these changes. Cultured Mardin-Darby canine kidney cells were exposed to oxalate, and changes in cytosolic Ca2+ were determined under various conditions. The effect of heparin and heparan sulfate (HS) during oxalate exposure was examined. The change in the GAG contents of the culture medium was also determined. Transmission electron microscopy (TEM) was performed for morphological analysis. The degree of change in cytosolic Ca2+ strongly correlated with oxalate concentration. Cytosolic Ca2+ levels decreased in parallel with an increase in the concentration of oxalate. However, this decrease was strongly inhibited by pretreatment with heparin or HS. TEM revealed cytoplasmic vacuolization, the appearance of flocculent material and mitochondrial damage after oxalate exposure. On the other hand, pretreatment with heparin or HS completely blocked these morphological changes. The present data suggest that acute exposure to a high concentration of oxalate challenges the renal cells, diminishes their viability and induces changes in cytosolic Ca2+ levels. Heparin and HS, which are known as potent inhibitors of CaOx crystallization, may also prevent oxalate-induced cell changes by stabilizing the cytosolic Ca2+ level.

Calcium nephrolithiasis and distal tubular acidosis in type 1 glycogen storage disease

A 36‐year‐old man was admitted to hospital due to right flank pain as a result of ureteral stones. He had been followed up for type 1 glycogen storage disease since the age of 11 years. He had four episodes of spontaneous stone birth during the previous 2 years, and each stone was composed mainly of calcium oxalate. Intravenous pyelography showed right hydronephrosis due to ureteral stones and bilateral multiple renal stones. We carried out transurethral ureterolithotripsy (TUL) on the right ureteral stones. The composition was a mixture of calcium oxalate and calcium phosphate. Laboratory evaluation demonstrated the association of distal renal tubular acidosis (RTA). These observations suggest that hypocitraturia and distal RTA are strongly correlated to recurrence of calcium nephrolithiasis. The patients serum uric acid and urinary citrate excretion levels normalized after allopurinol and potassium citrate administration.

EXPRESSION OF HEPARAN SULFATE PROTEOGLYCAN MRNA IN RAT KIDNEYS DURING CALCIUM OXALATE NEPHROLITHIASIS

This study used reverse transcription polymerase chain reaction (RT-PCR) to examine heparan sulfate proteoglycan (HS-PG) mRNA expression levels during stone formation in the rat kidney. Total RNA in kidneys was extracted and converted to cDNA. PCR products were resolved by electrophoresis on 1.5% agarose gel and visualized with ethidium bromide. Fragment intensity and area were measured using an image analyzer. Control cyclophilin and HS-PG mRNAs were expressed in all samples examined as 235 by and 506 bp bands, respectively. Cyclophilin expression in the normal group was not significantly different from expression in the group that formed stones. However, the level of HS-PG mRNA expression apparently increased in calcium oxalate (CaOx) microlith. The findings suggest an association between CaOx nephrolithiasis and expression of HS-PG in the rat kidney.

Epidermoid cyst of the ureter: A case report

Abstract:  Epidermal cysts of the upper urinary tract are extremely rare. Only three cases have been reported in the published work written in English, Italian or German. We encountered a case of an epidermoid cyst in the ureter of a 72‐year‐old male. Findings on urine analysis and radiological examination were useful for establishing a correct diagnosis of epidermoid cyst of the urinary tract.