To The Editor:
We were surprised to read "Acute Tubular Necrosis of an Allograft
Kidney following Total Hip Replacement. A Case Report" (79-A: 1402-1403,
Sept. 1997), by Cable et al., as previous reports in the world literature,
from both sides of the Atlantic, have described acute renal failure in
renal transplant patients following hip replacement and the dangers
of pressure on the transplant when the procedure is performed with the
patient in the lateral position.
In addition to the case report by Zimmerman and Yett3, we reported
one case of acute renal failure in a series of twenty-five transplant
patients who had a total of thirty-four hip replacements1. In that
study, we noted that renal transplant patients need special consideration
during corrective surgery. It is essential to monitor the urinary output,
to avoid hypotensive anesthesia and nephrotoxic agents, and to ensure
that there is no pressure on the renal transplant during surgery. In
addition, we recommended that aspirin be given as prophylaxis to
help to reduce the risk of renal vein thrombosis.
Cable et al. commented that the case of their patient was different
from the case described by Zimmerman and Yett, but both patients
seem to have had acute renal failure, as did our patient. Therefore,
this complication does seem to have been reported previously. In
their reply to the letter from Dr. Yett2, Cable et al. stated that
their firm conclusion was that pressure was the cause of acute tubular
necrosis, but they presented no firm evidence; thus, their explanation
is simply a plausible conjecture (although one with which we agree).
Since the case report by Zimmerman and Yett was published, we
have routinely avoided use of the lateral position. Our patient,
in whom acute tubular necrosis developed one hour postoperatively,
was in the supine position during the procedure. She was well hydrated
throughout and, apart from a momentary episode of hypotension, maintained
an excellent blood pressure. She did not receive any nephrotoxic
agents, and an ultrasound ruled out renal vein thrombosis.
We previously reported the need for vigilant monitoring of urinary
output both intraoperatively and postoperatively and the need to
ensure that there was no pressure on the graft. Thus, we must agree
with Zimmerman and Yett that the case described by Cable et al.
is not the first such report and that this information is not new
as the authors reasserted in their reply to Dr. Yett's letter2.
Max Gibbons, M.A., F.R.C.S.
Hamish Simpson, D.M., F.R.C.S.
Corresponding author: Max Gibbons, M.A., F.R.C.S.,
Nuffield Department of Orthopaedic Surgery,
University of Oxford, Nuffield Orthopaedic Centre,
Headington, Oxford OX3 7LD, United Kingdom
Dr. Sloan and Dr. Kaufer reply:
Acute renal failure following anesthesia and surgery is an uncommon
event; however, it may be more prevalent in patients who have had
a previous renal transplantation. Our case report highlighted the
dangers associated with the use of positioning devices such as the
Montreal Hip Positioner during orthopaedic surgery. Gibbons and
Simpson referred to their previous article concerning total hip
replacement in patients who have had a renal transplantation1. In
that study, the one patient who had acute tubular necrosis had development
of this complication postoperatively and had been in the supine
position during the procedure. Thus, the complication was unrelated
to operative positioning and pressure on the transplanted kidney.
These findings differ considerably from those in our patient, in
whom anuria developed intraoperatively with the onset of acute tubular
necrosis.
We believe that the complication described in our study - acute
tubular necrosis occurring intraoperatively in a patient with a
transplanted kidney - is related to operative positioning and has
not been previously reported. The need for surgeons and anesthesiologists
to be vigilant in monitoring urinary output intraoperatively is important
information.
Paul A. Sloan, M.D.
Herb Kaufer, M.D.
Corresponding author: Paul A. Sloan, M.D.,
Department of Anesthesiology,
University of Kentucky Hospital,
800 Rose Street, Lexington, Kentucky 40536