Lung Transplantation

Question 1

Lung transplant candidate selection

Answer 1

Advanced en-stage pulmonary disease

Predicted life expectancy of < 2 years

Failed medial managment

Sufficient nutritional status

Adequate cardiac function

Question 2

Exclusin criteria (inelegibility) for lung transplant

Answer 2

• 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

Question 3

Preop evaluation for lung transplantation

Answer 3

• 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

Question 4

Used to allocate donor lungs to individual transplant candidates

Answer 4

Lung Allocation Score (LAS)

based on the probability of death on the waitlist and the probability of posttransplant survival

Question 5

COPD guidelines for lung transplantation

Answer 5

• 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

Question 6

IPF guidelines for lung transplantation

Answer 6

• 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

Question 7

Cystic Fibrosis guidelines for transplantation

Answer 7

Cystic fibrosis with FEV1 < 30% predicted (~50% 2-year mortality)

Presence of hypoxemia, hypercapnea, weight loss

Question 8

Primary cause of end-stage obstructive pulmonary disease in first 3 decades of life

Answer 8

Cystic fibrosis

Question 9

Transplant strategy for cystic fibrosis

Answer 9

Bilateral lung transplantation

(prevents spread of infection from a colonized native lung to transplanted lung)

Question 10

Primary pulmonary hypertension guidelines for transplantation

Answer 10

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

Question 11

Optimal donor characteristics for lung transplantation

Answer 11

• ABO compatibility
• Age < 55 years
• PaO2 > 300 on 100% FiO2 with PEEP 5
• Normal CXR
• Normal bronchoscopic exam

Question 12

Access incisions for single lung transplant

Answer 12

Anterolateral or posterolateral thoracotomy

Question 13

Access incision options for bilateral lung transplant

Answer 13

• bilateral anterolateral thoracotomy
• clamshell thoracotomy

Question 14

If need for CPB expected during lung transplant, approach would include

Answer 14

Central cannulation via right thoracotomy

Femoral cannulation for single left sided transplant (left thoracotomy)

Question 15

Immunosuppression primarily used after lung transplant

Answer 15

• Corticosteroids
• Calcineurin inhibitors (cyclosporine and tacrolimus)
• Cell-cycle inhibitors (MMF and azathioprine)

Question 16

Immunosuppression MOA:

block expression of IL-2 with subsequent inhibition of T-lymphocytes

Answer 16

Calcinueurin inhibitors:

• Cyclosporin
• Tacrolimus

Question 17

Immunosuppression MOA:

inhibit de novo purine synthis, resulting in T-cell and B-cell proliferation

Answer 17

Cell-cycle inhibitors

• MMF
• Azathioprine

Question 18

MC technical complications during lung transplantation

Answer 18

• 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

Question 19

ID the complication:

persistentent pulmonary hypertension or unexplained hypoxia

Answer 19

PA anastomotic stricture

Question 20

Dx w/u for suspected PA anastomotic stricture

Answer 20

Nuclear perfusion scan (unequal blood flow distribution)

Pulmonary angiogram (15-20 mmHg gradiant across anastomosis)

Question 21

ID complication:

elevated PA pressure

ipsilateral pulmonary edema

Answer 21

Impaired venous drainage across atrial anastomosis

Question 22

Dx w/u to evaluate suspected impaired venous drainage across atrial anasomosis

Answer 22

TEE

Question 23

Leading cause of postoperative lung infections in transplant recipients

Answer 23

CMV

(infectious compications may be: bacterial, viral, or fungal)

Question 24

Definition and mortality associated with Primary Graft Dysfunction (PGD)

Answer 24

Ischemia-reperfusion injury after lung transplantaiton

Mortality rate up to 30%

Question 25

Signs and symptoms of acute rejection after lung transplant

Answer 25

• Low grade fever
• Dyspnea
• Fatigue
• Hypoxemia
• >10% decrease in FEV1 from baseline
• Pulmonary infiltrates on CXR

Question 26

Incidene of PGD after lung tranplant

Answer 26

Up to 75% of lung transplant recipients

(within the first 3 months after transplant)

Question 27

RF for developement of chronic rejection and bronchiolitis obliterans

Answer 27

Acute rejection

Question 28

Definition and characteristics of Bronchiolitis Obliterans Syndrome (BOS)

Answer 28

Definition: decline in post-transplant FEV1 after other causes have been excluded

Irreversible

Modifications in immunosuppression may slow progression of disease.

Question 29

ISHLT estimates of survival after lung transplantation

Answer 29

1-year survival: ~ 79%

5-year survival: ~ 52%

Question 30

Preoperative diagnoses associated with worse prognosis after lung transplantation

Answer 30

• Primary pulmonary hypertension
• IPF