transplantation Flashcards
organs: explain which organs can be transplanted, why, and where the transplanted organs come from
when are organs transplanted
when they are failing/have failed, or for reconstruction and improving life quality
when are life-saving transplants conducted
when other life-supportive methods have reached end of their use
3 examples of life-saving transplants
liver, heart (e.g. left ventricular assist device), small bowel (total parenteral nutrition)
when are life-enhancing transplants conducted
when other life-supportive methods are less good, or when organ is not vital but improves quality of life
2 examples of life-enhancing transplants when other life-supportive methods are less good
kidney (dialysis), pancreas (selected cases when better than insulin injection)
2 examples of life-enhancing transplants when organ is not vital but improves quality of life
cornea, reconstructive surgery
when does cornea fail (these are not required - principle is different organs fail for different reasons)
degenerative disease, infections, trauma
when does skin/composite fail
burns, trauma, infections, tumour
when does bone marrow fail
tumour, hereditary diseases
when does kidney fail
diabetes, hypertension, glomerulonephritis, hereditary conditions
when does liver fail
cirrhosis (viral hepatitis, alcohol, auto-immune, hereditary conditions), acute liver failure (paracetamol)
when does heart fail
coronary artery or valve disease, cardiomyopathy (viral, alcohol), congenital defects
when do lungs fail
COPD, emphysema (smoking, environmental), interstitial fibrosis/interstitial lung disease (idiopathic, autoimmune, environmental), cystic fibrosis (hereditary), pulmonary hypertension
when does pancreas fail
type 1 diabetes
when does small bowel fail
mainly children with volvulus, gastroschisis, necrotising enteritis related to prematurity; in adults with Crohn’s, vascular disease, cancer
5 types of transplantation
autografts, isografts, allografts, xenografts, prosthetic graft
what is an autograft between
same individual
what is an isograft between
between genetically identical individuals of same species
what is an allograft between
between different individuals of same species
what is an xenograft between
between indivuals of different species
what can a prosthetic graft be made from
plastic, metal
long term target for autograft transplanation
forming organs from stem cells
examples of xenografts
heart valves (pig/cow), skin
allograft transplantation options
solid organs (kidney, liver, heart, lung, pancreas); small bowel; free cells (bone marrow, pancreas islets); temporary e.g. blood, skin (burns); privileged sites e.g. cornea; framework e.g. bone, cartilage, tendons, nerves; composite e.g. hands, face, larynx
2 types of allograft donor
dead, living
examples of living donor organs in allograft
bone marrow, kidney, liver
who can be used as a living donor in allograft
genetically related or unrelated (e.g. spouse, altruistic)
in dead donors, what is DBD and how is this confirmed
donor after brain stem death (majority of donors), confirmed using neurological criteria
in donor after brain stem death, what does brain injury cause death before
terminal apnoea has resulted in cardiac arrest and circulatory standstill (circulation established through resuscitation)
example of death causing donor after brain stem death
intracranial haemorrhage, road traffic accident
how is ischaemic damage minimised in DBD
organs harvested and cooled
in dead donors, what is DCD and how is this confirmed
donor after circulatory death, with death diagnosed and confirmed using cardio-respiratory criteria (5 minute observation of irreversible cardiorespiratory arrest)
describe controlled DCD
generally patients with catastrophic brain injuries who, while not fulfilling neurological criteria for death, have injuries of such severity as to justify withdrawal of life-sustaining cardiorespiratory treatments on grounds of best interests
describe uncontrolled DCD
no or unsucessful resuscitation
feature of ischaemia time in DCD
longer period of warm ischaemia time
what is neurological criteria of death based on
irremediable structural brain damage of known cause
what does neurological criteria of death rule out
apnoeic coma due to other things e.g. cardiovascular instability, depressant drugs, metabolic/endocrine disturbance, hypothermia, neuromuscular blockers
what does neurological criteria of death demonstrate
absence of brain stem reflexes (light, touch, cold caloric, orbital pressure, cough and gag reflex, lastly apnoea test on disconnection from ventilator)
what dead donors must be excluded
viral infection; malignancy; drug abuse, overdose or poison; disease of transplanted organ
what is absolute maximum cold ischaemia time for kidney before perfusion
60h (ideally <24h, with other organs being much shorter)
