Reproduced from the International Society for Heart and Lung Transplantation, Registries;
http://www.ishlt.org/registries/slides.asp?slides=heartLungRegistry
Reproduced from the International Society for Heart and Lung Transplantation;
http://www.ishlt.org/registries/slides.asp?slides=heartLungRegistry
Benefits of Lung Transplantation
Figure 3 depicts the functional status of patients following lung transplantation at 1, 3, and 5 years post-transplant. As you know, patients who are eligible for lung transplant are often at the end stages of pulmonary hypertension with severely limited functional capacity. As you can see in the figure, more than 80% of recipients exhibit no activity limitations following lung transplantation.
Reproduced from the International Society for Heart and Lung Transplantation;
http://www.ishlt.org/registries/slides.asp?slides=heartLungRegistry
Patient Qualification for a Lung Transplant: a patient is considered to qualify if their projected life expectancy is greater than two years due to lung disease. According to the WHO, proceeding to a transplantation depends on:
- The patient’s wishes and medical status
- Insurance coverage
- Current lung transplantation guidelines
- United Network for Organ Sharing (UNOS) lung allocation score (LAS) (go to http://www.unos.org for additional information)
UNOS Lung Allocation Scoring: established in 2005, the formula for LAS estimates medical urgency pre-transplant and the probability for prolonged post-transplant survival. Scoring and eligibility are based on the greatest “net benefit”. LAS scoring has not provided an advantage to PAH patients as
compared to, for example, fibrotic lung disease. For more information about UNOS and allocation scoring, go to http://www.unos.org
Contraindications to Transplant
- Absolute Contraindications
- Patient is not compliant with medical therapy and office follow-up
- Patient diagnosed with an untreatable psychiatric or psychological condition associated with the inability to cooperate or comply with medical therapy
- Substance addiction (e.g. alcohol, tobacco or drugs) in the last 6 months
- Malignancy in the last two years, with the exception of skin squamous and basal cell tumors. In general, a five-year disease-free interval is prudent for all other malignancies
- Untreatable advanced dysfunction of another major organ system (e.g. heart, liver or kidney disease)
- Untreatable chronic extrapulmonary infection including HIV, active hepatitis B and C
- Relative Contraindications
- Age: Lung transplantation is “generally not recommended” above age 65
- Colonization with pan-resistant bacteria, drug resistant fungi or atypical mycobacteria
- Severe or symptomatic osteoporosis
- Morbid obesity
- Significant chest wall or spinal deformity
- Mechanical ventilation/ECMO (“heart-lung bypass”)
- Other medical conditions (e.g. diabetes mellitus, hypertension, gastroesophageal reflux, coronary artery disease) that have not resulted in end-organ damage potentially impacting on long-term outcome that are not well controlled
Survival With and Without Transplant
Without treatment for PAH, survival projections are poor. Within this scenario, there is only a 34% survival at 5 years following diagnosis. In patients who fail medical therapies, transplantation can improve survival. Survival rates, however, depend on the preexisting disease; PAH (idiopathic) has an overall lower survival even after transplantation.
Summary
Patients with rapidly worsening PAH in the face of combination therapy should be considered for referral to atrial septostomy or lung transplantation. Atrial septostomy must be viewed in a risk-benefit scenario as it reduces right heart loading but reduces blood oxygenation at the same time. Double lung transplant
is the most common surgical procedure utilized, although single lung and heart-lung procedures are options. Post-transplant survival warrants that every medical intervention be pursued before transplantation is considered. Although a relatively small number of patients ultimately require transplantation or septostomy, these are viable options once the patient has shown rapid decline while on medical therapy.
References
1. McLaughlin VV, Archer SL, Badesch DB, et al. JACC, 2009; 53:1573-1619.
2. Rashkind WJ, Miller WW. JAMA 1966;196(11):991-992.
3. Boehm W, Emmel M, Sreeram N. Images Paediatr Cardiol. 2006 Jan-Mar; 8(1): 8–14.
4. The Registry of the International Society for Heart and Lung Transplantation: 29th Official Adult Heart Transplant Report. J Heart Lung Transplant. 2012 Oct; 31(10): 1045-1095.
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