OPERATION-DAY BLOOD-TRANSFUSION AND RENAL TRANSPLANTATION

OPERATION-DAY BLOOD-TRANSFUSION AND RENAL TRANSPLANTATION

494 ’ Letters to the Editor OPERATION-DAY BLOOD-TRANSFUSION AND RENAL TRANSPLANTATION SiR,—Dr Stiller and his colleagues (Jan. 28, p. 169) presen...

291KB Sizes 0 Downloads 53 Views

494 ’

Letters

to

the Editor

OPERATION-DAY BLOOD-TRANSFUSION AND RENAL TRANSPLANTATION

SiR,—Dr Stiller and his colleagues (Jan. 28, p. 169) present insufficient data to justify their conclusion that peroperative blood-transfusion in renal transplantation confers increased graft survival. Indeed their summary stating that peroperative transfusion proved to have been beneficial contradicts the statistical evidence presented. In their four groups of patients, totalling 56, no significant effect of peroperative transfusions was seen at 1 year when previously transfused and non-transfused groups were considered separately. The group of patients most crucial to their hypothesis, those transfused for the first time at the time of transplantation, numbers only 7. The quotation of percentage graft survival figures in a group of this size is meaningless. Only by combining groups and ignoring other factors affecting graft survival has it been possible to produce "significant" evidence of apparent benefit. No mention is made of the obstetric history of the recipients, though the U.K. Transplant Report for 1976/77 has shown parity to be associated with a 13% improvement in 1-year graft survival irrespective of transfusion. Other factors to be mentioned in the same context are HLA matching,’ steroid/cytotoxic donor pre-treatment/.3 and previous failed transplants. Without such information to ensure comparability between very small groups of patients the validity of the conclusions cannot be assessed. J. K. CRUICKSHANK M. H. SIMMS A. R. DE BOLLA

Renal Unit, Queen Elizabeth Hospital, Birmingham B15 2TH

***This letter has been shown whose reply follows.-ED.L.

to

Dr Stiller and his

colleagues,

SIR,-Unfortunately the statistical evidence that Dr Cruickcolleagues request was omitted from our paper during preparation for the printer. The footnotes to table II should have indicated that graft survivors in group C (no transfusions prior, but transfusions on the day of transplant) and group D (no transfusions prior or during) were significant shank and his

at

3, 6, and 12 months. In full, the table should have been: TABLE II-TRANSFUSION BEFORE AND ON DAY OF

I

I

*AvsBatlmo,r<001. A vs D at 1 mo, p
I

I

at

3 mo, r<00001;

SURGERY*

i

at

,

6 mo,

p<0.0001;

12 mo, P
The statistical evidence presented suggests that transfusion the day of surgery gives a benefit to those patients never having received transfusions before surgery and that graft suron

1. 2. 3.

Opelz, G., Mickey, M. R., Terasaki, P. I. Transplant. Proc. 1977, 9, 22. Guttman, R. D., and others ibid. 1975, 7, 117. Zincke, H., Woods, J. E. Surgery Gynec. Obstet. 1977, 145, 183.

vival in this group is indistinguishable from that in patients who had received prior transfusions but no transfusions peroperatively. More important, the effect of transfusion either before or at surgery obscures the effect of the other (group A vs B and group A vs.C). Studies on the effect of preoperative transfusions have shown significant benefit when pooled data are analysed. We have confirmed this (71% vs. 40% 1-year graft survival). Our central point is that peroperative transfusions confer the same benefit (79% vs. 44% 1-year graft survival). The factors mentioned by Cruickshank et al. do not seem different between our groups, and none of our patients were recipients of donor pretreated organs or had had previous grafts. Other factors were examined and found not to explain the differences observed. Confirmation or refutation of these observations can only be provided by multifactorial analysis of a large group of patients studied prospectively, as Terasaki has

proposed. University Hospital, London, Ontario N6A 5A5, Canada.

C. R. STILLER N. R. STC. SINCLAIR B. LOCKWOOD

SIR,-Stiller et al. claim to have shown that transfusion on the day of operation improved the survival-rate of human cadaver renal allografts. The observations were made on a small group of patients who were selected to some extent by their blood-transfusion history being "on record". The conclusion that in previously untransfused patients "transfusion on the day of operation seems to have been beneficial" was drawn from a study of just 7 patients. Whilst I agree that there are hazards in transfusing patients before transplantation and that it might be better to transfuse at the time of operation, our results have failed to show this to be of benefit. We have analysed the outcome of all first cadaver renal transplants done in the years 1972-76, and in untransfused patients (N=47) the one-year graft-survival rate was 40%. A separate group of 7 patients received their first blood-transfusion at the time of transplantation and far from being better, the results were worse, 6 of the 7 grafts being rejected within the year. This group again is small, but until a greater number of such patients have been reported the beneficial effect of operationday blood-transfusion must remain in doubt. Renal Transplant Unit, Cardiff Royal Infirmary, Cardiff CF2 1SZ

JOHN R. SALAMAN

SIR,-Blood-transfusions given before transplantation improve renal-allograft survival.1-8 Dr Stiller and his colleagues are the first to report the beneficial effect of intraoperative blood-transfusions, although the Advisory Committee to the Renal Transplant Registry suggested this in its 1977 report.9 Because our studies,5.6 done retrospectively, showed no beneficial effect of intraoperative transfusions, or at least much less benefit than preoperative transfusions, we would like to comment on the paper by Stiller et al. Although no data were available to suggest prior sensitisation to blood and blood products, it has been our experience that such information is often inaccurate. Extra care must be taken to ensure exclusion of this variable. Leucocyte antibodies are one such objective indi1. Opelz, G., Sengar, D. P. S., Mickey, M. R., Terasaki, P. I. Transplant. Proc., 1973, 5, 523. 2. Opelz, G., Terasaki, P. I. Lancet, 1974, ii, 696. 3. Festenstein, H., Sachs, J. A., Pans, A. M. I., Pegrum, G. D., Moorhead, J. F. ibid. 1976, i, 157. 4. Opelz, G., Terasaki, P. I. Transplantation, 1976, 22, 380. 5. van Hooff, J. P., Kalff, M. W., van Poelgeest, A. E., Persijn, G. G., van Rood, J. J. ibid. 1976, 22, 306. 6. Persijn, G. G., van Hooff, J. P., Kalff, M. W., Lansbergen, Q., van Rood, J. J. Transplant. Proc. 1977, 9, 503. 7. Fuller, T. C., Delmonico, F. L., Cosimi, A. B., Huggins, C. E., King, M., Russell, P. S. ibid. p. 117. 8. Sirchia, G., Mercuriali, F., Scalamogna, M., Rossi di San Secondo, V., Pizzi, C., Poli, F. Transplantation, 1977, 23, 391. 9. American College of Surgeons/National Institutes of Health. Transplant. Proc., 1977, 9, 9.

495 table we have compared the chance of having an affected fetus Stiller et al. give no information about their presence or of the and women who have positive results after being screened for of sex the An indication absence. patients pregnancy to exclude and would be useful also neural-tube defects with that in four other common groups for would help another z, history whom amniocentesis is currently accepted. source of error. The small numbers of patients on which Stiller Of the women in the five groups, those with high serumet al. based their conclusions make this information essential. A.F.P. levels (>2.5 x median at 16-18 weeks gestation after We found an 18% one-year graft survival in 33 patients receivin transfusions contrast to the have been excluded by ultrasound) have 71% intraoperative only,6 multiple pregnancies ing the highest chance of having an affected fetus. When ultra(5 out of 7) survival reported by Stiller et al. Patients who had been pregnant and those with leucocyte sound is used as an additional check on gestational age some women in this group will be found to have normal levels, and antibodies in their serum were excluded in our study. We believe that only preoperative blood-transfusions have the risk of an affected fetus in the remaining women will be even greater-about 13% on the basis of our own preliminary been shown to have a beneficial effect on renal surresults in Oxford. (The risk of spina bifida alone will be about vival. Our concern is that that practice will be abandoned in favour of the perhaps simpler, but yet unproved, intraopera7%.) In addition, A.F.P. screening can be expected to identify tive transfusion. Our policy of giving at least one blood-transabout 84% of all infants with open neural-tube defects,3 fusion to patients awaiting a renal transplant will remain unwhereas in the other four groups no more than about a third of all affected fetuses will be identified. changed. While the decision to perform an amniocentesis on an indiEurotransplant Foundation, vidual patient will depend on many considerations, the risks c/o Bloodbank, G. G. PERSIJN shown in the table are likely to be an important influence. In University Hospital, Leiden, Netherlands J. J. VAN ROOD the light of these figures it would seem to be inconsistent to regard amniocentesis as unacceptable in women with high serum-A.F.p. levels but acceptable in the other groups. SCREENING FOR NEURAL-TUBE DEFECTS cator.

in

allograft

,

SIR,--Your editorial of Feb. 11 asks if neural-tube defect

screening by measurement of maternal serum alpha-fetoprotein (A.F.P.) should be introduced. The aim of such screening is to identify a group of women with a high enough risk of having an affected fetus to justify amniocentesis. While the risks RISK IN BRITAIN OF HAVING A FETUS WITH A NEURAL-TUBE

D.H.S.S. Cancer Epidemiology and Clinical Trials Unit, Department of Regius Professor of Medicine, Radcliffe Infirmary, Oxford OX2 6HE

NICHOLAS WALD HOWARD CUCKLE

Nuffield Department of Obstetrics and Gynæcology, John Radcliffe Hospital, Oxford

GORDON STIRRAT

DEFECT OR A CHROMOSOMAL ABNORMALITY AMONG FIVE GROUPS ’ OF WOMEN FOR WHOM AMNIOCENTESIS MIGHT BE CONSIDERED

CORONARY-ARTERY BYPASS SURGERY

SIR,-The Veterans Administration paper’ has serious flaws. The survival curves in fig. 2 are labelled wrongly, as comparison with previous V.A. reports shows:2.3 the medical and surgical curves are interchanged until the point of crossover at 30 months (after which the curves are identified correctly) and the medical and surgical curves in fig. 3 are inter-

changed. consideration of the subsets of two and as a single subset on the basis of simiobstruction three-artery lar survival. Addition of the two-artery obstructions to the three-artery group in table IV improves the prognosis for medically treated patients but worsens the outlook for the surgical group. Calculation of the apparent medical and surgical mortality for obstruction of two arteries and an abnormal left ventricle does not conform to survival previously reported at 36 months.2 The numbers presented in the paper refer to randomised but not to compliant patients. Many problems in the V.A. reports would be clarified by a statement giving the numbers of medical and surgical deaths at various specific intervals (e.g., 24 and 48 months) and the numbers of compliant patients eligible to have survived the stated time, both for the whole study and for specific subsets. Reduction of the number of operative deaths would affect survival. During 1973 (the middle year of the V.A. study) our operative mortality for 1400 patients, excluding left-main coronary-artery obstructions, was 0.6%. There was a perioperative infarction-rate of about 4% and graft patency of 87% durThe

*

Serum-A.F.p. >2.5 x median at 16-18 weeks gestation after multiple pregnancy has been excluded by ultrasound; the figures in parentheses, based on our unpublished data, relate to pregnancies which still have high A.F.P. levels after gestational age has been checked by ultrasound. t The 84% comprises an average of 79% relating to open spina bifida only and 88% relating to anencephaly, assuming that each is equally common at birth. t These percentages are based on the frequency of chromomal abnormatmes found in mid-trimester amniotic fluid samples; the other percentages m the table are based on data at birth.

of amniocentesis are still not precisely known they do not appear to be great,I,2 and the procedure is already established clinical practice in several situations. In the accompanying 1. N.I.C.H.D. National

Registry for Amniocentesis Study Group J. Am. med. Ass. 1976, 236, 1471. 2. Simpson, N. E., Dallaire, L., Miller, J. R., Simonovich, L., Hamerton, J. L., Miller, J., McKeen, C. Can. med. Ass. J. 1976, 115, 739. 3. U.K. Collaborative Study Lancet, 1977,i, 1323. 4. Carter, C. O., David, P. A., Laurence, K. M. Med. Genet. 1968, 5, 81. 5. Galjaard, H. Cytogenet. Cell Genet. 1976, 16, 453.

ing

text

that

justifies

period.

V.A.

figures

were

5-6% operative mortality,

Registrar General’s Statistical Review for England and Wales, 1973: part I (A), tables, medical. H.M. Stationery Office. 7. Office of Population Censuses and Surveys Medical Division. Personal com-

6.

munication. 8. Griffith, G. W. Hlth Trends, 1973, 5, 59. 1. Detre, K., Murphy, M. L., Hultgren, H. Lancet, 1977, ii, 1243. 2. Murphy, M. L., Hultgren, H. N., Petre, K. M., Thomsen, J., Takaro, T.

New Engl. J. Med. 1977, 297, 621. 3. Read, R. C., Detre, K. M., Murphy, M. L., thorac. cardiovasc. Surg. 1978, 75, 1.

Hultgren,

H.

N., Takaro, T. J.