To evaluate the association of right vs left single lung transplants (SLT) from split lung donors with long-term post-transplant recipient outcomes.

We performed a retrospective review of the Scientific Registry of Transplant Recipients data of split SLT adult recipients comparing right and left lung grafts between 2005 and 2021. We used a paired donor model to account for underlying differences between donors and evaluated post-transplant patient and graft survival with Cox proportional hazard models with robust variance estimates adjusted for recipient characteristics. We also used Wilcoxon signed-rank, McNemar's, and Bowker's tests to evaluate complication rates between donor pairs.

There were 5,180 recipients with 2,590 right and left split allografts. Left SLT had higher rates of mortality (hazards ratio [HR] = 1.17, 95% confidence interval [CI]: 1.08, 1.27) and graft failure (HR = 1.16, 95% CI: 1.06, 1.26) compared to right SLT in adjusted models. There were more early deaths (<13 days post-transplant) among left vs right SLT (n = 52 vs 31, p = 0.018). Estimated 5-year graft survival was 47.1% (95% CI: 45.1, 49.3) and 51.4% (95% CI: 49.4, 53.5) for left and right SLT, respectively. Right SLT was associated with longer length of stay (median 14 days vs 13 days, p = 0.016) and more prolonged ventilation (>5 days) (n = 319, 12.6% vs n = 270, 10.6%; p = 0.030).

Left SLT was associated with significantly worse mortality and graft failure while right SLT was associated with more short-term complications from split lung donors. Organ listing and acceptance decisions should consider donor lung laterality.

Careful donor quality assessment and size match can impact long-term survival in lung transplantation. With this article, we review the conceptual and practical aspects of the preoperative donor lung quality assessment and size matching.

Lung transplantation (LT) is a life-saving therapeutic procedure that prolongs survival in patients with end-stage lung disease. Furthermore, as a therapeutic option for high-risk candidates, single LT (SLT) can be feasible because the immediate morbidity and mortality after transplantation are lower compared to sequential single (double) LT (SSLTx). Still, the long-term overall survival is, in general, better for SSLTx. Despite the great success over the years, the early post-SLT period remains a perilous time for these patients. Patients who undergo SLT are predisposed to evolving early or late postoperative complications. This review emphasizes factors leading to post-SLT complications in the early and late periods including primary graft dysfunction and chronic lung allograft dysfunction, native lung complications, anastomosis complications, infections, cardiovascular, gastrointestinal, renal, and metabolite complications, and their association with morbidity and mortality in these patients. Furthermore, we discuss the incidence of malignancy after SLT and their correlation with immunosuppression therapy.

Although single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants.

Using the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival.

Lung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients.

In COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.

Lung perfusion scintigraphy (LPS) with (99m)Tc-MAA gives valuable information about patients who will undergo a single lung transplantation. This technique makes it possible to evaluate and quantify the relative function of both lungs to select the organ to be transplanted. Once the surgery has been performed, the LPS represents a diagnostic method to study the status of the transplanted organ. Two patients who underwent single lung transplantation were studied in our hospital. In both cases, a pre-operative LPS was performed before surgery for selection of the organ to be transplanted and the scintigraphy study was performed a few months after transplantation to establish the perfusion function of the transplanted lung.