Selective Recruitment of Large Lower Lobe Atelectasis on Donor Back Table in Rejected Donor Lungs

Abstract

Background: Large atelectatic areas in donor lungs are frequently resistant to standard recruitment maneuvers, producing a tenaciously low PO₂/FiO₂ ratio. The aim of this study is to investigate the optimal protocol for the recruitment of large atelectatic areas in the context of ex vivo lung perfusion (EVLP).

Methods: Seventeen rejected lungs with large lower lobe atelectasis (≥40%) were divided into 2 groups: manual resuscitation (n = 5) and selective recruitment (n = 12). Transplant suitability was then evaluated in cellular EVLP. In the manual resuscitation group, following bronchoscopy, if the conventional recruitment maneuver was not successful, a bagging technique was utilized to resolve atelectasis in EVLP. In the selective recruitment group, a pediatric endotracheal tube was introduced to the lower lobe bronchus on the back table of the donor hospital. Selective recruitment of the lower lobe was accomplished while keeping peak inspiratory pressure <30 cm H₂O for 30 seconds.

Results: The average atelectasis size and lung weight in 17 donor lungs was 75.4 ± 20.6% and 960 ± 221 g, respectively. There were no significant differences between the 2 groups in all donor variables, except cold ischemic time (P = 0.001, 5.2 ± 0.5 versus 6.4 ± 0.7 hours). The selective recruitment group was associated with better transplant suitability (P = 0.035, 75% versus 20%), better PO₂/FiO₂ ratio (P = 0.186, 324 ± 89 versus 258 ± 87 mm Hg), lower lung weight (P = 0.057, 997.9 ± 229.2 versus 1377.2 ± 452.9 g), and better pathological score (P < 0.05, 1.0 ± 1.3 versus 2.8 ± 0.8) than the manual resuscitation group.

Conclusion: A selective recruitment procedure is a safe and effective method of eliminating large atelectasis before EVLP.

FIGURE 1.

Three possible outcomes of high PEEP recruitment in bilateral total lower lobe atelectasis through the trachea. (1) Lower lobes are fully expanded. (2) Upper and middle lobes are overexpanded, whereas lower lobes are not expanded. (3) Blood pressure drops. EVLP, ex vivo lung perfusion; PEEP, positive end-expiratory pressure.

FIGURE 2.

Study layout. In the manual resuscitation group (n = 5), donor lungs with large atelectasis were preserved in cold lung preservation solution. Following no success of opening atelectasis by conventional recruitment maneuvers (high PEEP and high tidal volume) in EVLP, atelectatic lesions were opened by using bagging procedure. In the selective recruitment group (n = 12), following lung procurement, atelectasis was completely eliminated by selective recruitment procedure in the back table of the donor hospital as shown in Figure 3. Then, lungs were stored in cold lung preservation solution. Transplant suitability was evaluated according to physiological parameters at 2 h of EVLP. EVLP, ex vivo lung perfusion; PEEP, positive end-expiratory pressure.

FIGURE 3.

Selective recruitment procedure of large lower lobe atelectasis on the back table. A, Selective recruitment procedure in back table of the donor hospital. Pediatric tracheal tube (5.5 mm ID) was introduced to the lower lobe bronchus, and balloon cuff was inflated. The tracheal tube was connected to Ambu bag with a manometer. Selective recruitment of the lower lobe was done with the maximum airway pressure <30 cm H₂O for 30 s. Then, the trachea was clamped at approximately 50% of total lung capacity. B, The backside view of rejected donor lung with large lower lobe atelectasis in the back table of the donor hospital. Atelectasis size was 80% in the left lower lobe and 100% in right lower lobe. C, In the selective recruitment procedure, both sides of atelectasis were completely opened up using the pressure of <30 cm H₂O in the lower lobe bronchus.

FIGURE 4.

Pathological evaluation of lung tissue. A, Pathological score was significantly lower in the selective recruitment group than in the manual resuscitation group (1.0 ± 1.3 vs 2.8 ± 0.8, P = 0.033). B, Typical finding of the selective recruitment group (hematoxylin and eosin; ×40): predominantly unremarkable alveolated lung parenchymal with focal mild congestion (right upper). C, Typical finding of the manual resuscitation group (hematoxylin and eosin; ×40): diffusely congested alveolated lung parenchyma with reactive pneumocytes and early acute lung injury.