Lung Transplantation Flashcards
Lung transplant candidate selection
Advanced en-stage pulmonary disease
Predicted life expectancy of < 2 years
Failed medial managment
Sufficient nutritional status
Adequate cardiac function
Exclusin criteria (inelegibility) for lung transplant
- Age > 65
- Smoker (within prior 6 mo)
- Concomitant organ failure
- History of malignancy within prior 5 years
- High dose steroid (>20 mg prednisone QD) requirement
Preop evaluation for lung transplantation
- Cardiac screening:
- Echocardiogram
- Left- and right- cardiac catheterization (CAD and pul HTN)
- PFTs*
- Quantitative V/Q scan*
- High resolution chest CT*
*Help guide which lung to transplant in single lung recipients as well as the order of transplantation for bilateral lung recipients
Used to allocate donor lungs to individual transplant candidates
Lung Allocation Score (LAS)
based on the probability of death on the waitlist and the probability of posttransplant survival
COPD guidelines for lung transplantation
- Transplantation suitable for candidates with a high risk for COPD-related mortality who have failed maximal medical therapy with oxygen supplementation and bronchodilator therapy.
- LVRS should be considered before transplantation in suitable candidates
Current Guidelines:
- Postbronchodilator FEV1 < 20-25% predicted
- PaO2 < 55 mmHg at rest
- PaCO2 > 55 mmHg
- Trend toward bilateral lung transplant
IPF guidelines for lung transplantation
- Patients with IPF have worst survival rate among lung disease while on transplant waiting list
- IPF patients should be referred for tranplantation evaluation very early in disease course
- Patients with early severe lung restriction and hypoxemia should be considered for transplant
Cystic Fibrosis guidelines for transplantation
Cystic fibrosis with FEV1 < 30% predicted (~50% 2-year mortality)
Presence of hypoxemia, hypercapnea, weight loss
Primary cause of end-stage obstructive pulmonary disease in first 3 decades of life
Cystic fibrosis
Transplant strategy for cystic fibrosis
Bilateral lung transplantation
(prevents spread of infection from a colonized native lung to transplanted lung)
Primary pulmonary hypertension guidelines for transplantation
Progression of disease despite maximal medical therapy
Suggested Criteria:
Mean PAP > 50 mmHg
RA pressure > 10 mmHg
Cardiac index < 2.5 L/min/m2
NYHA Class III or IV
Syncope
Optimal donor characteristics for lung transplantation
- ABO compatibility
- Age < 55 years
- PaO2 > 300 on 100% FiO2 with PEEP 5
- Normal CXR
- Normal bronchoscopic exam
Access incisions for single lung transplant
Anterolateral or posterolateral thoracotomy
Access incision options for bilateral lung transplant
- bilateral anterolateral thoracotomy
- clamshell thoracotomy
If need for CPB expected during lung transplant, approach would include
Central cannulation via right thoracotomy
Femoral cannulation for single left sided transplant (left thoracotomy)
Immunosuppression primarily used after lung transplant
- Corticosteroids
- Calcineurin inhibitors (cyclosporine and tacrolimus)
- Cell-cycle inhibitors (MMF and azathioprine)
Immunosuppression MOA:
block expression of IL-2 with subsequent inhibition of T-lymphocytes
Calcinueurin inhibitors:
- Cyclosporin
- Tacrolimus
Immunosuppression MOA:
inhibit de novo purine synthis, resulting in T-cell and B-cell proliferation
Cell-cycle inhibitors
- MMF
- Azathioprine
MC technical complications during lung transplantation
- Bronchial anastomosis stricture or dehiscence
- Perform bronchoscopy at end of transplant to assess anastomosis
- PA anastomosis stricture
- Persistent pulmonary hypertension and unexplained hypoxia
- Dx:
- nuclear perfusion scan (unequal blood flow to lungs)
- angiogram (15-20 mmHg gradient across anastomosis
- Impaired venous drainage acorss atrail anastomosis
- elevated PA pressures and ipsilateral pulmonary edema
ID the complication:
persistentent pulmonary hypertension or unexplained hypoxia
PA anastomotic stricture
Dx w/u for suspected PA anastomotic stricture
Nuclear perfusion scan (unequal blood flow distribution)
Pulmonary angiogram (15-20 mmHg gradiant across anastomosis)
ID complication:
elevated PA pressure
ipsilateral pulmonary edema
Impaired venous drainage across atrial anastomosis
Dx w/u to evaluate suspected impaired venous drainage across atrial anasomosis
TEE
Leading cause of postoperative lung infections in transplant recipients
CMV
(infectious compications may be: bacterial, viral, or fungal)
Definition and mortality associated with Primary Graft Dysfunction (PGD)
Ischemia-reperfusion injury after lung transplantaiton
Mortality rate up to 30%
Signs and symptoms of acute rejection after lung transplant
- Low grade fever
- Dyspnea
- Fatigue
- Hypoxemia
- >10% decrease in FEV1 from baseline
- Pulmonary infiltrates on CXR
Incidene of PGD after lung tranplant
Up to 75% of lung transplant recipients
(within the first 3 months after transplant)
RF for developement of chronic rejection and bronchiolitis obliterans
Acute rejection
Definition and characteristics of Bronchiolitis Obliterans Syndrome (BOS)
Definition: decline in post-transplant FEV1 after other causes have been excluded
Irreversible
Modifications in immunosuppression may slow progression of disease.
ISHLT estimates of survival after lung transplantation
1-year survival: ~ 79%
5-year survival: ~ 52%
Preoperative diagnoses associated with worse prognosis after lung transplantation
- Primary pulmonary hypertension
- IPF
