The holmium:YAG laser was used successfully to fragment human urinary stones of various sizes and compositions. At an energy level of 0.5 J/pulse and at a frequency of 5 Hz, lithotripsy resulted in minimal ureteral wall injury. However, increasing the amount of energy or frequency level often caused significant damage to surrounding tissue. We conclude, therefore, that when used at low power settings with care to avoid direct ureteral wall contact, holmium:YAG laser lithotripsy appears to be an effective procedure. Additional studies are necessary to accurately assess its clinical safety.
Hematuria may be of glomerular or nonglomerular origin. Dysmorphic erythrocytes are found in the urine of patients with glomerular bleeding, whereas isomorphic erythrocytes characterize nonglomerular or urological hematuria. Urine specimens from 100 patients with microscopic hematuria were collected: 50 had a known glomerular pathological condition and 50 had urological disease. Scanning electron microscopy of the urine specimens showed a marked difference in morphology between dysmorphic and isomorphic red blood cells. This differentiation can be made with a simpler instrument, the standard Coulter counter. Accurate prediction of glomerular versus nonglomerular hematuria was made in 97 of the 100 patients by Coulter counter analysis. The test is rapid, simple and readily reproducible. A permanent graphic record of the red blood cell morphology can be obtained for each patient. Identification of glomerular versus nonglomerular hematuria can be of practical use in the clinical management of patients.
Laser photoirradiation has been delivered encloscopically for the treatment of both benign prostatic hyperplasia and early localized pmstatic carcinoma. In treating carcinoma, aggressive iransurethral resection of the prostate has been followed with laser irradiation to the remnants of malignant capsular disease. No attempt has been made heretofore to completely destroy the glandular prostate using laser irradiation alone. We performed a two-stage endoscopic laser prostatectomy in 6 adult mongrel dogs in an attempt to completely destroy the glandular prostate. Although no complications developed, histologic evaluation of the prostate revealed viable glandular elements in the midst of necrosis and atrophy. We conclude that in order to accomplish total ablation of the glandular prostate using laser photoirradiation, more precise thermal telemetry is needed.
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