The lack of a clear definition of PGD in many large series of lung transplantation, including the ISHLT registry data, hampers the identification of recipient-related risk factors. Concomitant donor-related variables further confound these analyses. Based on the current body of literature, recipient-related risk factors that would require further study before any association can be stated include the type of procedure, the presence of hepatic dysfunction, and pleural adhesions and/or prior surgery, which increase the risk of post-operative bleeding. Additional factors that may confound the clinical picture or possibly contribute to the severity of the manifestations of PGD include renal impairment, left heart disease, elevated anti-HLA antibodies and secondary pulmonary hypertension. Secondary pulmonary hypertension may increase the risk of peri-operative mortality, but this may or may not be related to an increased incidence of PGD. Studies have tended to include all etiologies of secondary pulmonary hypertension (congenital heart disease, thromboembolic disease, obstructive lung disease and interstitial lung disease), which limits the ability to determine the effect of pulmonary hypertension on PGD. In addition, most studies include data from screening right-heart catheterization at the time of listing. This limits the ability to accurately define the sub-groups of patients with and without pulmonary hypertension at the time of transplantation. Presently, there is no conclusive evidence to strongly recommend single vs bilateral transplant for patients with secondary pulmonary hypertension. Significant data support the safe use of cardiopulmonary bypass for lung transplantation. Possible deleterious effects on primary graft function have been documented, but do not appear to significantly impair short- and long-term outcomes. Refinements in the methods and techniques of cardiopulmonary bypass, including the use of leukocyte filters and modified ultrafiltration, will likely continue to diminish potential deleterious effects. Although there is no strong evidence to support the elective use of cardiopulmonary bypass in the absence of hemodynamic or intra-operative factors, its use should not be deferred secondary to fear of graft dysfunction. Beyond the issue of PGD, other concerns, such as bleeding with increased need of blood and/or blood products as well as overall resource utilization, may support the role of primary lung transplant without cardiopulmonary bypass. Presently, the strongest and most clearly established recipient risk factor for primary graft dysfunction is the diagnosis of PPH. Further research into the mechanism of PPH-associated PGD could well lead to advances in preventing or treating this syndrome in all patients after lung transplantation. The other strong recipient-related factor appears to be the technique utilized for lung reperfusion. Based on the early series of clinical experience utilizing modified reperfusion, this extremely promising method may greatly decrease the incidence of PGD. It may also allow the use of non-standard donor criteria lungs in a safer fashion. Finally, all studies of recipient-related risk factors for PGD need to be analyzed in the context of concomitant donor-related risk factors.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Cardiology and Cardiovascular Medicine