Transplants- Exam 2 Flashcards
What are the 3 types of transplants that perfusion is involvedin?
Heart transplants
Lung transplants
Liver transplants
Transplants can be performed individually or in combination often with what organ?
Kidney
Who described the first heterotropic transplant of a donor heart into the neck of a dog? When?
1905; Carrel and Guthrie
Describe the first heterotropic transplant of a donor heart into the neck of a dog.
Not a functional model, functioned together with the recipients heart; heart was not capable of supporting circulation, lasted 2 hours before the chambers clotted
Who won the Nobel Prize in Medicine and Physiology for work in this area? What year?
Carrell, 1912
What institution did Carrel and Guthrie create innovative surgical technique for vascular anastomoses?
University of Chicago
Describe the “Working Model” of the heterotopic transplant with circulatory unloading of the RV.
1933- Mann, et al. at Mayo Clinic
Lasted 4 days
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
1960- Lower and Shumway
Orthotopic heart transplant in dogs with CPB and topical hypothermia for donor heart preservation; survived 6-21 days; died of rejection
When was Pharmcologic immunosuppression introduced?
1960s
What happened not long after pharmacologic immunosuppresion was introduced?
first clinical transplantation occured (kidney)
When was the first human heart transplant? Where?
1967, South Africa; followed shortly by Shumway and colleagues at Stanford in 1968
Many centers initially rushed to perform transplants. How come this didn’t continue?
Realized post operative survival was limited
lots of opportunistic infections
graft rejections
When did most center discontinue doing transplants ?
in the 1970’s
When did cyclosporine based immunosuppresion get introduced?
1980’s; interest in transplantation re-emerged around this time
What patients are selected to get transplants?
Have to be in end stage CHF
Must be able to benefit from a transplant
How to determine 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, acute myocarditis)
ischemic heart disease
Contraindications of transplants?
Advanced age (should be less than 65 y/o)
Irreversible pulmonary hypertension
Active infection and malignancy
Obesity
Diabetes
Pulmonary fibrosis, emphysema, hepatic and renal dysfunction, cerebral vascular disease, peripheral vascular disease (relative)
Contrainidications of transplants: Age
Should be less than 65 y/o
Can be done in older patients
physiologic age is a better indicator than chronologic age
Contraindications of transplants: Pulmonary HTN
complication of CHF with elevated LVEDP
Can create irreversible changes to pulmonary vasculature
could cause RV failure in new organ
PA systolic above 50-60 mmHg is not good
Give inhaled nitric oxide to prevent pulmonary htn
Contraindications of transplants: Active Infection and malignancy
infections are exacerbated by immunosuppression required after transplanation
Hepatits B, C, HIV not usually done
Non-melanoma cutaneous cancers, primary cardiac tumors restricted to the heart, low grade prostate cancers
Contraindications: Obesity
Impacts infection rates, wound healing, and have an increased incidence of acute rejection
BMI less than 30 kg/m2
Contraindication: Diabetes
Relative contraindication
Control of blood sugars on steroids and immunosuppressants
Wound healing
Contraindications: Psychosocial
Substance abuse (tobacco, alcohol)
Compliance with medications
Frequency of social support
What is done prior to performing a transplant?
Lots of tests/ workups are done prior to transplantation
Must be approved by several committees and departments prior to listing the patient
What is looked at for organ matching?
ABO Blood Compatibility Overall body size (must be within 20% of body weight) HLA Cross match Priority on UNOS Registry Geographic distance from donor
HLA Cross match
some patients are sensitized to antigen due to pregnancy, prior transplant, or blood transfusion
Waiting List Criteria
Status code and time within the status code
Highest medical urgency and lowest short term survival are assigned higher codes
How Wait List 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.
Going out for Procurement
Donor heart is arrested with cardioplegia/ preservation solution
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
Heart is cooled topically
What is the ischemic time?
3-4 hours!! can do up for 5-6 hours- not idea
Recipient: Re-anastomosis of midatrial level
Start at atrial septum
Generous “cuff” of donor RA, so SA node will be included in transplant
Great vessels connected above the Semilunar valves
Recipient: Bi-atrial tehcnique modified lately
Leave donor atria in tact and make the anastomosis at the SVC and iVV and pulmonary veins (Bicaval techniques)
notice less distortion of the aortic valve
improved atrial and ventricular function
Less AI
less arrhythmias/heart block