Topic 9: Transplants Flashcards
Perfusion is involved in what 3 types of transplants?
Heart Transplants
Lung Transplants
Liver Transplants
Can be performed individually or in combo
Often along with a kidney
Who described first heterotopic transplant of a donor heart into the neck of a dog?
1905–Carrel and Guthrie
Not a functional model, functioned together with the recipient’s heart
Heart was not capable of supporting circulation
Lasted 2 hours before the chambers clotted
Created innovative surgical technique for vascular anastomoses?
Carrel and Guthrie
Heterotopic transplant with circulatory unloading of the RV
Working model
1933–Mann, et al. at Mayo Clinic
Observed–failure of the transplanted heart was not always caused by faulty surgical technique, but to “some biologic factor which is probably identical to that which prevents survival of other homotransplanted tissues and organs”
Described acute allograft rejection
Described acute allograft rejection?
1933–Mann, et al. at Mayo Clinic
Orthotopic heart transplant in dogs with CPB
and topical hypothermia for donor heart preservation?
1960–Lower and Shumway
Survived 6-21 days
Died of rejection
1967–First human heart transplant was performed where?
South Africa
in the 1980s –Interest in transplantation re-emerged?
cyclosporine-based immunosuppression introduced
Patient selection for a heart transplant criteria?
Patients have to be in end stage CHF
NYHA function class III or IV
Symptomatic refractory to management with medications, electrophysiology devices (pacemakers/AICD) and surgical intervention.
LVEF < 35%
Cardiogenic shock (Acute MI or Myocarditis)
Ischemic heart disease
Must be able to benefit from a transplant
Patient selection for a heart transplant criteria, must be what NYHA functional class?
NYHA function class III or IV
Patient selection for a heart transplant criteria, LVEF % has to be what?
LVEF < 35%
Contraindications for transplant?
Advanced age Irreversible pulmonary hypertension Active Infection and malignancy Obesity Diabetes Pulmonary Fibrosis, Emphysema, Hepatic and renal dysfunction, Cerebral vascular disease, Peripheral vascular disease Psychosocial
Contraindications for transplant?
Advanced age:
Should be less than 65 years old
Can be done in older patients
Physiologic age is a better indicator than chronologic age.
Contraindications for transplant?
Irreversible pulmonary HTN
complication of what? PA mmHg? give what?
Pulmonary htn is a complication of CHF with elevated LVEDP.
Can create irreversible changes to pulmonary vasculature
Could cause RV failure in new organ
PA systolic above 50-60mmHg is not good!
Give inhaled nitric oxide to prevent pulmonary htn.
Contraindications for transplant?
Active Infection and malignancy
fever free?
Infections are exacerbated by immunosuppression required after transplantation.
-Need to be fever free for 72 hours
-Normal white cell count
-Negative blood cultures
Hepatitis B, C, HIV not usually done
-HIV is becoming more acceptable to transplant due to improvement in drug therapy.
Non-melanoma cutaneous cancers, primary cardiac tumors restricted to the heart, low grade prostate cancers
-Ok to transplant
Contraindications for transplant?
Obesity?
why, BMI
Impacts infection rates, wound healing, and have an increased incidence of acute rejection.
BMI less than 30 kg/m2
Contraindications for transplant?
Psychosocial - what and why?
Substance abuse (tobacco, alcohol) Compliance with medications Frequency of social support Lots of tests/ workups are done prior to transplantation. Must be approved my several committees and departments prior to listing the patient
Organ matching - what do they look at?
- ABO Blood Compatibility
- Overall body size
- Match must be within 20% of body weight
- HLA Cross match
- Some patients are sensitized to antigens due to pregnancy, prior transplant, or blood transfusion.
- Priority on UNOS Registry
- Geographic distance from donor
Organ matching -Waiting List Criteria
Status code and time within the status code
Highest medical urgency and lowest short term survival are assigned higher codes
Organ matching - how it works?
Offered to local status 1 patients first, Status 1A before Status 1B.
No match? Offered to Status 1 patients within 500 mile radius.
No match? Offered to Status 2 local patients.
Repeat at 1000 mile radius, and 1500 mile radius.
Organ transplant -
how is heart arrested
Donor heart is arrested with a cardioplegia/ preservation solution.
Heart is cooled topically.
Organ transplant - how is it transected?
Atria are transected at the midatrial level
Leave multiple pulmonary venous connections to the LA intact.
Transect the aorta and PA just above the semilunar valves
Organ Transplant – Ischemic time?
–3-4 hours!! (can do up to 5-6 hours–not ideal!!)
Organ Transplant - Re-anastomosis of midatrial level – how is it done?
Start at atrial septum
Generous “cuff” of donor RA, so SA node will be included in transplant
Great vessels connected above the Semilunar valves.
Organ Transplant – Recently, bi-atrial technique has been modified
how is it done? Less what found?
(Called Bicaval technique)
Leave donor atria in tact and make the anastomosis at the SVC and IVC and Pulmonary Veins
Notice less distortion of the aortic valve
Improved atrial and ventricular function
Less AI
Less arrhythmias/ heart block.
Heart/Organ transplant – post op course?
Same as a normal cardiac case
Patient will be on immunosuppression drugs
Will require pacing for a few days
Takes 2-3 days for the SA node to come back and “reset”
Transplanted Heart - response to drugs?
Don’t respond to drugs that work via the
parasympathetic pathway.