TO THE EDITOR:
In the article "Acute Tubular Necrosis of an Allograft Kidney following Total Hip Replacement. A Case Report" (79-A: 1402—1403, Sept. 1997), Cable et al. urged proper protection of an allograft kidney when a total hip replacement is performed with the patient in the lateral decubitus position. This advice is consistent with the recommendation that Zimmerman and I made in 1982, when we reported infarction of a renal transplant during total hip arthroplasty performed with the patient in this position1. We, too, believed that intraoperative pressure from the positioning devices compressed the renal artery. Four days after the operation on our patient, flow to the kidney was occluded because of a clot in the renal artery.
I agree with the points made in the Discussion section of the article by Cable et al., except for the statement that their patient is the first reported case of this complication. The case reported by those authors differs from the one reported by Zimmerman and me in that their patient recovered renal function and ours did not1. Our patient had a second, successful transplantation of a cadaveric kidney four years later.
Harris S. Yett, M.D.: Beth Israel Deaconess Medical Center,
330 Brookline Avenue, Boston, Massachusetts 02215
Dr. Cable, Dr. Sloan, and Dr. Kaufer reply:
The earlier report of infarction of a renal transplant due to occlusion of the renal artery, by Zimmerman and Yett1, adds strength to our recommendation regarding careful positioning of the patient in the lateral decubitus position, with adequate padding of the pelvic kidney, when the patient has an allograft kidney.
As Dr. Yett states, there are several apparent differences between the two cases. First, Zimmerman and Yett1 admitted that the precise mechanism of the infarction in their patient remained conjectural. The firm conclusion of our case report was that the etiology of the acute tubular necrosis was direct trauma to the pelvic kidney. Second, the renal failure in our patient developed intraoperatively, whereas the renal failure in their patient developed four days postoperatively. Third, our patient recovered renal function and did not require prolonged dialysis, whereas their patient required chronic dialysis and eventually had a second, successful transplantation of a cadaveric kidney.
We appreciate the case report by Zimmerman and Yett1. However, we believe that our case report of acute tubular necrosis related to operative positioning in a patient who had an allograft kidney is, without reservation, the first such report. Our conclusion that the operative team must vigilantly monitor urinary output both intraoperatively and postoperatively in a patient with a renal transplant who is having a hip replacement is new and important information.
Todd D. Cable, M.D.: 403 Tates Creek Road, Lexington, Kentucky 40517
Paul A. Sloan, M.D.; Herb Kaufer, M.D.: Departments of Anesthesiology (P. A. S.) and Surgery (H. K.), University of Kentucky Hospital, 800 Rose Street, Lexington, Kentucky 40536