What are the indications
for pancreas Tx
•
Patients
with type I
diabetes and ESRF may present prior to dialysis,
whilst on dialysis
or after KTx.
o
With
functioning Kidney transplant – patient may undergo pancreas
after kidney (PAK)
o
Without
functioning KTx :
§ Simultaneous
pancreas kidney Tx (SPK): this
is the most common option exceeding all other options combined.
Ouctomes are
superior to solitary pancreas Tx.
§ Pancreas
after kidney Tx (PAK): KTx is
from either a deceased or living (to reduce waiting time) donor.
Most of
benefit derives from Ktx. Ouctomes are inferior to SPK.
§ Simultaneous
living donor kidney and deceased donor pancreas (SPLK)
§ Living
donor kidney-pancreas Tx: the living donor
provides the tail of pancreas. Results are
comparable to SPK. Donor morbidity is significant
o
Most of
benefit derives from
kidney Tx. So patients are
advised to adopt which ever option produces quickest KTx when
the wait for SPK
is long.
•
Non-uremic
type I diabetic
patients
may be considered
for pancreas transplant alone (PTA). These are labile diabetics who have severe complications from diabetes
most commonly
brittle disease with severe hypoglycaemia. Whether it
results in mortality
benefit is unknown – the patient assumes the risks of
immunosuppression, which
in contrast to the uraemic patient is already assumed by virtue
of KTx.
•
In
both contexts pancreas transplantation
PTx is an
alternative to intensive insulin therapy which has risks of
severe recurrent
hypoglycaemia which may lead to neurological injury,
especially when combined
with hypoglycaemic unawareness.
What is the impact of
donor quality on outcome
•
Age, hypotension, vasopressor use and
hyperglycaemia are all of greater concern in potential
deceased donors.
•
Visual
inspection is most important – the
pancreas should be
soft and free of fibrosis
How can pancreas
transplants be implanted
•
Portal drainage or systemic drainage of
venous outflow
– portal drainage reduces systemic
hyperinsulinaeia. This has not been shown to improve outcome
•
Bladder or enteric drainage of exocrine
secretion –
the major advantage of bladder drainage
is ability to monitor unrinary amylase for assessing graft
function. This is
more important in solitary pancreas Tx as in PKTx the kidney
function is a
sensitive proxy for pancreas rejection. Bladder drainage is
associated with
recurrent UTI, haemorrhagic cystitis, bicarbonate wasting and
dehydration. Thus
enteric drainage is preferred.
•
Enteric
drainage is combined with portal venous drainage because of the
orientation of
pancreas.
What are the unique
complications of pancreas Tx
Immediate
•
Bleeding – common
Early
•
Graft
thrombosis – much more common than other transplants.
Most common cause of early graft loss. Anti-coagulation and
improved immunosuppressions
have improved the thrombosis rate.
•
Duodenal leak – 10%
usually 1-2 weeks after Tx. Treated by
re-operation. Can be treated by attempting to repair the leak
(usually from
closed end of duodenum), change to bladder drainage and
decompression of
duodenum using a foley catheter or removing the Tx. Drainage,
either open or
CT-guided may be used.
What is the outcome
•
SPK:
mortality benefit compared with dialysis or KTx alone
o
Reduces
recurrence of diabetic nephropathy
o
Diabetic
neuropathy is slowed and even reversed in some cases
o
Most
patients enjoy improved quality of life.
•
There
is no clear evidence that PTA contributes to reduced mortality
Arterial anastomosis: SMA
to external iliac Art
Venous Anastomosis: Portal
vein to external iliac vein
Enteric Anastomosis:
Duodeno-enteric side to side