Recovery of glomerular and tubular function in autotransplanted dog kidneys preserved by hypothermic storage or machine perfusion. Relation of initial function to long-term function.

Sixteen male dogs had split renal function studies prior to unilateral nephrectomy and autotransplant. Kidneys were preserved for 24 hr by either simple hypothermic storage in Collins C2 solution (SHS) or machine-perfused (MP) on a Waters machine (MOX 100) with plasmanate perfusate. Renal function studies were repeated at 1 hr and at 7, 14, and 28 days, and the statistical relationship between initial and 1-month function was determined for a number of parameters. All MP kidneys functioned immediately, whereas 1/3 of SHS kidneys had delayed function. Recovery was more rapid in MP kidneys and was essentially complete by 14 days, at which time MP kidneys had higher rates of creatinine clearance and sodium reabsorption. However, by one month 3/7 MP kidneys (P = 0.15 compared with SHS) had lower creatinine clearance rates than at 2 weeks, and para-aminohippurate (PAH) clearance and fractional sodium reabsorption were significantly decreased. During the same period SHS kidneys either showed continued improvement or maintained stable function. Thus, by one month there were no differences between the groups in clearances of creatinine and PAH, plasma creatinine and blood urea nitrogen concentrations, or fractional reabsorption of sodium, potassium, and water. For SHS kidneys, the 1-hr creatinine clearance and the absolute rate of sodium reabsorption were strong predictors of the eventual function of the kidneys at one month (r = 0.93 and r = .83, P less than 0.05, respectively). No such correlations were found in MP kidneys (r = less than .01, P greater than 0.9 for both variables). The data show that MP results in significantly better function early after transplant, but this advantage does not persist, and that SHS kidneys early function is a good predictor of long-term recovery, but this is not true for MP kidneys.

Transplant immunity in hamsters treated with ultrasound.

Hamsters with subcutaneous fibrosarcomas were treated by excision and by exposure to 5-MHz ultrasound for six minutes at an intensity of 3 W/sq cm. Rates for successful elimination of the tumors were between 80% and 90% and were not significantly different for the two methods of treatment. After 30 days, the animals were challenged with the same tumor cells. Animals successfully treated with ultrasound or excision required at least 10 times as many cells to produce a tumor as controls, indicating that eradication of the tumor by ultrasound induced a level of transplant immunity at least as good as that resulting from surgical excision.

Twenty-four hour canine renal preservation by pulsatile perfusion, hypothermic storage, and combinations of the two methods.

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.

Unfocused ultrasound for localized tissue destruction in rabbit kidneys.

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.

Histomorphologic features of ultrasonic renal injury.

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.

Cadaver donor nephrectomy.

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.

Wallace method of ureteroileal anastomosis.

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.

Response of rat testis to localized induced hyperthermia.

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.