Ultrasonic treatment of tumors: I. Absence of metastases following treatment of a hamster fibrosarcoma.
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Biomedical subjects
Publications and source records attributed to C W Fridd.
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A comparison of the effectiveness of two renal preservation techniques was studied in 30 cannine renal pairs. In the absence of warm ischemia, 24-hr preservation by pulsatile perfusion was not significantly superior to hypothermic storage. When 15 min of warm ischemia was added as an additional insult, pulsatile perfusion afforded significantly better early function than cold storage. Combinations of pulsatile perfusion and hypothermic storage following 15 min of warm ischemia were superior to hypothermic storage alone, but inferior to pulsatile perfusion. Kidneys initially perfused for 6 hr and then cold-stored functioned slightly better than kidneys perfused for 18 hr after initial cold storage.
The rabbit kidney was subjected to exposure from an unfocused ultrasound source in an effort to create a relatively large volume of ultrasound-damaged tissue in the rabbit kidney. The results of this exposure were followed for 1 year. An insignificant change in blood pressure was noted up to 1 month after exposure to ultrasound and no persistent hypertension was noted thereafter. Marked gross, histologic, and vascular changes were found in the area of exposure culminating in marked absorption of renal substance (in excess of 25 per cent of total kidney weight). Calcific stones formed in the pelvis of the kidney in virtually all animals observed from 6 months to 1 year after ultrasound exposure. These stones appeared to be related to the calcification within the transitional epithelium of tubules at the junction of normal and ultrasound-damaged tissue. The marked ability of the absorptive processes to ablate large volumes of physically damaged tissue is demonstrated.
Fifteen-second exposure of rabbit kidneys to 2 MHz focused ultrasound with approximately 900 w/sq cm acoustic power consistently produced localized parenchymal destruction. Evolution of the lesions was followed histologically over a one-year period. The lesions were sharply delineated from outlying renal tissue and had a concentric multizonal structure. Resorption of the damaged tissue with scarring was completed in 6 to 12 months following intermediate phases characterized by cellular infiltration. The lesions are compared to other models of renal injury, particularly with respect to cellular infiltration. A combination of mechanical, thermal, and ischemic factors seem to be responsible for development of ultrasonic lesions. The sharply circumscribed nature and ultimate complete scarring of the lesions suggest the feasibility of ultrasound in achieving selective complete destruction of renal parenchyma.
A method is presented in which the rat testis is extensively mobilized through a low abdominal incision, but in which its blood supply is carefully preserved. Localized hyperthermia is induced in this mobilized testis by water bath immersion. The tissue temperature is measured during and after immersion by means of a thermocouple inserted into the tissue. The relative sensitivity of spermatogenic tissue to increased temperature is confirmed and the relative resistance of Sertoli and Leydig cells is noted. Minimal or absent inflammatory reaction to thermal destruction of testicular cells is found as long as the tubule is intact. A marked peritesticular inflammatory response is noted when the total testicular tissue is destroyed at the highest temperature tested.
The Wallace technique for ureteroileal anastomosis was used in 28 consecutive patients requiring urinary diversion. Details of the surgical technique are reported. The method is found to be appropriate for children and adults, for primary ureteroileal anastomosis, or for revision of previous ureteroileal anastomosis done by other techniques, and for patients with one or two ureters. Its continued use appears to be indicated.
Optimal preservation of renal and ureteral structure and function is attempted by maintenance of renal circulation during heart-beating cadaver nephrectomy. Modifications of Ackermann's en bloc procedure for removal of cadaver kidneys are suggested to adapt this procedure to the heart-beating cadaver situation.