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INTRODUCTION
Finding a suitable kidney is of prime importance for the success of
a renal transplant programme. The transplanted
kidney has to adjust itself to new surroundings and the recipient’s
body has to accept the new kidney. And undoubtedly the matchmakers play
a very important role in this alliance. Kidney transplantation operation
defines the laws of nature to
a certain degree and is trying to .nd some loopholes in these laws to
make the operation a success.
The donated kidneys can be obtained from a living donor or from a cadaver
donor. Until 1980’s the morbidity and mortality after transplant
were high. With the advent of newer immunosuppressive medicines the
morbidity and mortality rates have
reduced considerably, and the rate of success and comfort would now
almost match a live unrelated donor in the short term. Living donors
remain the main source of the kidneys in the transplant programme in
our country.
Amongst the most important reasons for continuing of live donor programme
is the more favourable results that can be achieved with a physiologically
perfect kidney that is also biologically matched. Living related donor
grafts have an 80% .ve year survival which is 10 to 12% better than
the cadaver grafts.
Another reason is that the operation can be planned, limiting time on
the dialysis. This is important for economic reasons as a transplanted
patient can be better rehabilitated, and is one third as expensive as
a prolonged dialysis. Of greater
importance is that the operation can be performed when the recipient
is in optimal medical condition.
Also there is risk of development of antibody to HLA antigen during
prolonged dialysis, especially if intermittent blood transfusion is
required. As a result of this allosensitisation a negative cross match
donor kidney becomes difficult to find.
Getting cadaver donor kidneys is difficult and the demand for kidneys
is high, but this is changing.
EVALUATION OF DONOR
It is nature’s gift to mankind to have provided us with two kidneys.
Each of these kidneys has tremendous reserve capable of providing four
to .ve times the minimal required function. However before taking out
a kidney we should check if it is suitable to the recipient and by removing
one kidney we do not in any way jeopardize the physical health of the
donor.
All donors are first screened for emotional stability and motivation.
The unrelated but emotionally attached donors are questioned by a third
party to rule out any financial gains for the donor.
Next the blood groups of the recipient and donor are checked and if there
is a blood group mismatch them another donor is looked for.
Potential donors after the initial screening process are evaluated meticulously
and repeatedly to confirm excellent general and good bilateral renal function.
The tests done are listed in the table below.
It must be made certain that the non-donated kidney is normal. This is
especially relevant when the potential donor’s relative has renal
failure due to a hereditary cause e.g. polycystic kidneys. In case of
a related donor in these circumstances is considered he should be beyond
35 years of age, non hypertensive and with no evidence of any cysts.
Family conference with transplant-dialysis team ABO blood group, tissue
typing, leukocyte crossmatch, ± mixed lymphocyte culture History,
physical examinations, serial blood pressure determinations Full blood
count, coagulation pro.le, blood urea nitrogen, serum creatinine an
clearance, fasting blood sugar glucose, cytomegalovirus antibody,
human immunode.ciency virus antibody, hepatitis B and C testing, cholesterol,
triglycerides, calcium, phosphorus, urine analysis, urine culture,
24-hour urine protein Chest radiograph, intravenous pyelogram or ultrasound
Electrocardiogram
Aortogram or digital subtraction angiography and/or. in the kidneys.
The final selection of the donor is made on the basis of histocompatibility
testing. An HLA identical sibling being the ideal choice. If this
is not possible then the serological testing identifies other compatible
members, the person whose cells
produce the least stimulation of host cells in mixed lymphocyte culture
may be preferred for renal donation.
Throughout this selection the physicians should ensure that the decision
for donation is voluntary and under no duress.
Once the potential donor has been isolated it is important to study
the vasculature of the renal system. Despite the increasing availability
of non invasive modalities, inadequate definition of the exact status
of the renal arteries makes an angiogram necessary.
Based on intravenous pyelography, both the kidneys should have good
and equal function. There should be no evidence of scarring and there
should be a single ureter on the donor side.
Based on the angiogram, it is preferable to have a single artery.
If there are double arteries on both sides then the kidney whose vessels
are sufficiently big and equal is chosen. Care is taken to avoid a
kidney which has a double vessel, with a small lower polar vessel.
In general the left side kidney is preferred over the right, because
the left renal vein is long and this makes the venous anastomosis
easy. The right renal vein is short, the posterior wall of the vein
is thin and so it necessitates removal of cuff of the inferior vena
cara (IVC). This makes the task a bit more challenging.
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CADAVER
KIDNEY DONOR
If a suitable living donor is not available, patients should be
considered for cadaver renal transplantation. Though the results
do not match the living donor, the graft survival rates have been
improving.
The procurement of a cadaver kidney has raised new moral and legal
issues, the most important of which is to establish brain death.
To avoid any conflict of interest, the declaration of death must
be the primary responsibility of the patient’s physician.
It is done with the full understanding of the patient’s family.
The transplant team is not involved with the decision regarding
the donor’s treatment or chances of recovery.
The ideal donor should typically be a young, previously healthy
individual who has sustained a fatal head injury or a cerebrovascular
accident.
Maintenance of renal blood .ow and function with adequate hydration
is important. A major concern for the donor team is the transmission
of infection. Particularly important are the infections that antedate
the terminal illness viz. hepatitis B,
HIV, encephalitis of unknown cause and TB.
The more difficult category of infections to evaluate are the
ones that complicate the donor’s terminal care. Any donor
with unequivocal sepsis is ruled out for transplant. In contrast
patients with catheter related infections or patients with central
venous line infections have not found to transmit the infections
of treated appropriately with antibiotics.
Attempts should also be made to rule out significant organ contamination
by culturing perfusate and transport media. On occasions Staph.
Aureus, Candida or Pseudomonas have been isolated. These kidneys
should be discarded.
Donor evaluation needs maturity and responsibility. All the precautions
should be taken to make sure that donor remains mentally and physically
fit and can lead normal life with a satisfaction of helping somebody
lead a new life..
| SHOULD
ALL PATIENTS WITH CORONARY DISEASE RECEIVE ANGIOTENSIN-CONVERTING-ENZYME
INHIBITORS?
Angiotensin-converting-enzyme inhibitors (ACEIs) have been
shown to have the broadest impact of any drug in cardiovascular
medicine, reducing the risk of death, myocardial infarction,
stroke, diabetes, and renal impairment.
However, these studies have provided strong evidence that,
regardless of left ventricular function, all patients with
coronary artery disease (and without contraindications against
ACEIs) should now be treated with an ACEI in addition to
aspirin, a b blocker, a statin and aggressive risk-factor
modi.cation.
Lancet, 2003; 362 : 755-56.]
HATS-OFF
TO HANDS-ON
"Is expertise in physical examination still important
in clinical medicine?"
Little is known about the clinical relevance of physical
examination in the care of patients in hospital. Brendan
M Reilly,
together with an adjudication panel, systematically reviewed
the hospital records of 100 general medical in patients
to
investigate whether .ndings discovered by the attending
physician by physical examination led to important changes
in clinical management. In 26 patients, diagnosis and treatment
changed substantially as a result of physical examination.
These findings, although preliminary, suggest that physical
examination improves timeliness and quality of care and
can affect treatment decisions, and that the importance
of maintaining physicians' traditional clinical skills should
be emphasised.
Lancet Oncol, 2003; 1100
CHILDHOOD ASTHMA FOLLOWED TO ADULTHOOD
These investigators followed a large birth cohort with the
use of questionnaires, lung-function tests, and allergy
skin tests
from the age of 3 to 26 years. Almost three quarters of
the study participants had wheezing at one point in the
follow-up, and 15 per cent had wheezing at all points in
the follow-up.
These data show that asthma begins in childhood and persists
in many cases. Interventions to modify asthma may
need to target the very young.
N Engl J Med 2003; 349 : 1414.
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