transplants Flashcards
Perfusion is involved in 3 types of transplants:
Heart Transplants Lung Transplants Liver Transplants
Can be performed individually or in combination Often along with a kidney
1905 – Carrel and Guthrie
Described first heterotopic transplant of a donor heart
into the neck of a dog
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 won the Nobel Prize in Medicine and Physiology in 1912 for his work in this area.
1933 – Mann, et al. at Mayo Clinic
Heterotopic transplant with circulatory unloading of the
RV Working model
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
1960s – Pharmacologic immunosuppression introduced.
Not long after – First clinical transplantation occurred Kidney
1967
First human heart transplant was performed in South Africa
Followed shortly by Shumway and colleagues at Stanford in 1968.
1970s.
Most centers discontinued doing transplants in the
1980s
cyclosporine-based immunosuppression introduced
Interest in transplantation re-emerged.
Patient Selection
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.
patients for transplants have to have EF <
35%
patients that have cardiogenic shock like _________ may benefit from a transplant
Acute MI
Acute Myocarditis Ischemic heart disease
Must be able to benefit from a transplant
Contraindications 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 Irreversible pulmonary hypertension
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
Active Infection and malignancy
Infections are exacerbated by immunosuppression required
after transplantation. Need to be fever free for 72 hours Normal white cell count Negative blood cultures
Contraindications Hepatitis B, C, HIV
not usually done HIV is becoming more acceptable to transplant due to
improvement in drug therapy.
contraindications Non-melanoma cutaneous cancers
primary cardiac tumors restricted to the heart, low grade prostate cancers
Ok to transplant
contraindications obesity
Impacts infection rates, wound healing, and have an increased incidence of acute rejection.
BMI less than 30 kg/m2
contraidications
Diabetes Relative contraindication Control of blood sugars on steroids and immunosuppressant’s Wound healing
relative contraindications
Pulmonary Fibrosis, Emphysema, Hepatic and renal dysfunction, Cerebral vascular disease, Peripheral vascular disease
Contraindications
Psychosocial
Substance abuse (tobacco, alcohol) Compliance with medications Frequency of social support
Organ Matching
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.
transplant technique
Go out for procurement Donor heart is arrested with a 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.
Ischemic time – 3-4 hours!! (can do up to 5-6 hours – not ideal!!)
Technique
Recipient: bi atrial technique
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.
Recently, bi-atrial technique has been modified
Leave donor atria in tact and make the anastomosis at the SVC and IVC and Pulmonary Veins
Called Bicaval technique
bicaval technique advantages
Notice less distortion of the aortic valve Improved atrial and ventricular function Less AI Less arrhythmias/ heart block.
Post operative 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
Physiology of Transplanted Heart
Completely denervated
Faster resting heart rate (95-100 beats per min) Intrinsic rate of SA node No parasympathetic down regulation
Slower to increase HR in response to exercise
Slower to recover after exercise
transplanted heart response to injury
No angina with ischemia Will have silent MIs. Will present with CHF, Silent MI or
Sudden death.
Don’t respond to drugs that work via the parasympathetic pathway.
donor heart iscemic time
Write down donor cross clamp time. This is the start of the ischemic period of the donor organ. to cross clamp off after sutures or hot shot
type of incision for heart transplant
median sternotomy. if its a redo you will go fem-fem
drift or cool to _____ when transplanting
32 C and cross clamp immediately
cardioplegia during transplant
not usually given
after sutures are complete some institutions will give
“hot shot” type dose of “cardioplegia”. Use Glutamate Aspartate Solution. Full of nutrients for that ischemic heart. Other places don’t.
after hot shot is in or suture are done
Cross Clamp off Pacing wires placed Fill up heart Wean from CPB. Close
First beating heart transplant
May 2007
system that kept first beating heart alive
Maintained at normal body temperature and hooked up to
the Transmedics Organ Care System.
Transmedics Organ Care System advantages
Beats with warm, oxygenated blood inside a sterile box
Can monitor parameters of the heart and blood.
Prolongs time between removal of the heart and transplantation.
Decreases injury while ischemic.
Can allow for the right patient to get the right organ, despite distance.
irst human lung transplant
was done over 35 years ago at the University of Mississippi Patient with severe emphysema and carcinoma of L. Bronchus
Died 18 days later of renal failure
First heart-lung transplant
1986 Stanford
first single lung transplant
1986 toronto
amount of lung transplants annually
1000
wait time for a single and double lung transplant
24,36
Indications for a lung transplant
Irreversible, progressively disabling, end-stage pulmonary disease
Usually life expectancy is less than 18 months Oxygen dependent Exercise intolerance Less than 65 years old
Poor quality of life.
lung transplant Patient is evaluated in the following areas:
History
Respiratory exam Past medical history Family history Psychosocial and cultural history
Things affecting eligibility lung transplant
Osteoporosis Musculoskeletal disease Use of corticosteroids (>20mg/day) Malnutrition 130% ideal body weight Substance abuse/ addiction Smoking within 4 months of activation on the transplant list Psychosocial problems – high risk of poor outcome Mechanical ventilation Colonization of fungi Previous thoracotomy, sternotomy, scarring, etc.
Types of Transplants lung
Single Lung Transplant : Right,
Left
Double lung transplant : En Bloc, Bilateral sequential Heart-lung block Ex-Vivo Lung Transplant
reasons for single lung transplant
COPD/ Emphysema Idiopathic Interstitial Pulmonary Fibrosis Sarcoidosis Eosinophilic Granuloma Lymphangiolyomyomatosis Primary Pulmonary Hypertension Eisenmengers Syndrome with cardiac repair
which side is easier for single lung transplant
Left side is easier
is cpb necessary for single lung
No CPB is necessary – usually Depends on patient’s tolerance to unilateral support during
cross clamp.
incision type for single lung
Posterolateral thoracotomy through bed of excised 5th rib.
how to asses stability of patient for single lung transplant
Main PA is encircled and temporarily clamped Assess the impact on hemodynamic stability and gas
exchange
If not tolerated, femoral cannulation is used, and patient placed on CPB
cooling for single lung
stay warm
single native lung is excised then …
Left Atrium is clamped
Pulmonary veins are attached to LA Cuff.
PA is anastomosed
End to end anastomosis of the donor and recipient bronchus
Atrial clamp is remove
reasons for Bilateral Sequential Double Lung
Cystic Fibrosis Bronchiectasis Emphysema Primary Pulmonary Hypertension Eisenmenger’s Syndrome with cardiac repair
Double lung transplant – gives patients
a better pulmonary reserve
Double Lung Transplant
Used to be done
en bloc where each lung was implanted separately through a pleural-pericardial window while on CPB.
en bloc utilizes
Clamshell incision BIG PAIN from a perfusion standpoint!!
Now, common to do
bilateral sequential.
Like 2 single lung transplants.
Ventilate the native lung, while the first goes in. Then ventilate the new lung while the second goes in.
Ex Vivo Lung Perfusion
Therapy applied to donor lungs outside the body before transplantation
Improves organ quality Allows lungs that were previously unsuitable for
transplantation – safe for transplantation. Expands donor pool
Ex Vivo Lung Perfusion lasts for
3-4 hour
ex vivo maintained at
normal body temps.
EX VIVO treated with
a bloodless solution that contains nutrients, proteins, oxygen
Reverse lung injury Remove excess water
First human liver transplant was done in
1963 by Thomas Starz in Denver, CO.
But 1967, marked
the first time a liver transplant patient lived to 1 year post surgery.
Liver Transplants
General Guidelines
Any patient with a chronic or acute liver disease who is unable to sustain normal quality of life or patients with serious complications related to the underlying liver pathology should be considered.
liver transplants evaluation of severity
Encephalopathy Ascites Recurrent GI Bleeding Severe Fatigue
Early stage primary liver tumor Others.
liver transplant questions before transplant
Do they need the
transplant?
Can they sustain the operation?
Is there a risk of recurrence?
test clamp for liver
est Clamp is performed. If patient remains stable – can do it
without V-V bypass. If not, V-V bypass is initiated.
New Liver is sewn in:
Suprahepatic IVC Infrahepatic IVC Portal Vein
Hepatic Artery Clamps are removed – Bypass is discontinued Bile Duct
Less than 5% of liver transplants use
V-V Bypass.
liver can use a partial occlusion
clamp on the IVC without cross clamping the entire IVC
liver Need to monitor lots of parameters:
EKG
HR Core Temp Pulse Ox Arterial BP PA Catheter SvO2 Cardiac Output
Liver Transplant – V-V bypass
First used by
Marshall, Et al in 1970. Managed a patient with renal cell carcinoma extending into
the IVC and RA
Liver Transplant – V-V bypass 1960s – realized
that they needed a shunt that could train blood from the lower extremities and portal system
First looked at utilizing bypass without a pump Unsuccessful – circuit clotted, and created embolism
Tried anticoagulation Increased bleeding too much
liver transplant 1980s
V-V Bypass came into practice with the use of heparin bonded circuits and a centrifugal pump.
Liver Transplant – V-V Bypass perfusion
No oxygenator
Less flows than on CPB
Flows from 1-2 liters most common Flow what you can get
Femoral vein is cannulated and advanced to the bifurcation of the IVC
2nd cannula placed in the portal vein to drain the portal system.
Wyed into the venous line. Centrifugal pump Return to axillary vein or internal jugular vein.
Liver Transplant – V-V Bypass
No heparin
is used Flows adequate unless less than 1 liter per minute
and cardiac preload is maintained Need to maintain flow to prevent clot Preload dependent.
Closed system, so no volume can be added.
To avoid pulmonary hypertension give
Inhaled NO
