Pleural Space Problems After Living Lobar Transplantation

Changes in Thoracic Cavity Volume After Bilateral Lung Transplantation

Purpose

End-stage lung diseases result in anatomical changes of the thoracic cavity. However, very few studies have assessed changes in the thoracic cavity after lung transplantation (LTx). This study aimed to evaluate the relationships between thoracic cavity volume (TCV) changes after LTx and underlying lung disease.

Methods

We reviewed 89 patients who underwent a pre-LTx pulmonary function test (PFT), chest computed tomography (CT) scan, and 1-year follow-up CT after LTx. These patients were classified into two groups according to pre-LTx PFT as follows: obstructive group [forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio < 70%] and restrictive group (FEV1/FVC ratio > 70%). We measured TCV using CT scan before and at 1 year after LTx and compared the TCV change in the two groups.

Results

In the restrictive group, TCV increased after LTx (preop: 2,347.8 ± 709.5 mL, 1-year postop: 3,224.4 ± 919.0 mL, p < 0.001). In contrast, in the obstructive group, it decreased after LTx (preop: 4,662.9 ± 1,296.3 mL, 1-year postop: 3,711.1 ± 891.7 mL, p < 0.001). We observed that restrictive lung disease, taller stature, lower body mass index, and larger donor lung were independently associated with increased TCV after LTx.

Conclusion

The disease-specific chest remodeling caused by restriction and hyperinflation is at least, in part, reversible. After LTx, the chest remodeling appears to occur in the opposite direction to the disease-specific remodeling caused by the underlying lung disease in recipients.

Unilateral lung transplantation using right and left upper lobes: an experimental study

OBJECTIVE

The shortage of organ donors is a serious problem in Japan. The right and left upper lobes of rejected extended-criteria lungs have the potential to be used for downsized lung transplantation; however, the 2 upper lobes are too small for a size-matched recipient. The present study investigated the feasibility of unilateral transplantation using the right and left upper lobes.

METHODS

After harvesting the heart-lung block from donor swine, a left lung graft was created using the right and left upper lobes and transplanted into the left thoracic space of the recipient swine (group A, n = 5). We then evaluated graft function for 6 hours and compared these results with those of a control group (group B, n = 5), in which orthotopic left lung transplantation had been performed.

RESULTS

The mean partial pressure of oxygen in the arterial blood gas after reperfusion was 507 mm Hg in group A and 463 mm Hg in group B (P = .2). The mean pulmonary arterial pressure was 30.3 mm Hg in group A and 27.5 mm Hg in group B (P = .4). The mean airway pressure was 6.4 mm Hg in group A and 6.2 mm Hg in group B (P = .7).

CONCLUSIONS

Our results suggest that unilateral left lung transplantation using the right and left upper lobes is technically and functionally feasible for size-matched recipients. In addition, this technique enables the use of rejected lungs if the upper lobes are still intact.

Evidence-based suggestions for management of air leaks

The management of postoperative alveolar air leaks (AALs) continues to challenge thoracic surgeons. AALs increase length of stay and health care costs, and likely lead to other postoperative complications. Staple line buttresses, topical sealants, pleural tents, pneumoperitoneum, and modifications of traditional chest tube management (ie, reduced suction) have all been proposed to help reduce AAL. However, the cost of some of the commercial products being marketed may outweigh their relative effectiveness, and some of these techniques and products have not been adequately studied to date. This article provides a review of the available evidence-based literature that addresses the efficacy of the options currently available to prevent and manage AALs. Management suggestions based on this literature are presented.

Management of alveolar air leaks after pulmonary resection

Air leaks are a common problem after pulmonary resection and can be a source of significant morbidity and mortality. Air leaks are associated with prolonged hospital stays, and infectious and cardiopulmonary complications, and they occasionally require reoperation. Despite reasonably robust literature on the topic, the optimal approaches to manage postoperative air leaks remain controversial. We used available literature and expert consensus to formulate suggestions regarding the preferred approaches to both routine and prolonged alveolar air leaks. This review summarizes our findings.

Computed tomography measurement of lung volume in preoperative assessment for living donor lung transplantation: volume calculation using 3D surface rendering in the determination of size compatibility

The objective of this study was to describe the use of CT volume quantification assessment of candidates for LLDLT. Six pediatric candidates for LDLLT and their donors were investigated with helical chest CT, as part of the preoperative assessment. The CT images were analyzed as per routine and additional post-processing with CT volume quantification (CT densitovolumetry) was performed to assess volume matching between the lower lobes of the donors and respective lungs of the receptors. CT images were segmented by density and region of interest, using post-processing software. Size matching was also assessed using the FVC formula. Compatible volumes were found in three cases. The other three cases were considered incompatible. All three recipients with compatible sizes survived the procedure and are alive and well. One patient with incompatible size was submitted to the procedure and died because of complications attributed to the incompatible volumes. One patient with incompatible size has subsequently grown and new measurements are to be taken to check the current volumes. Different donors are being sought for the remaining patient whose lung volumes were considered too big for the prospective transplant donor lobes. Under FVC formula criteria, all cases were considered compatible. CT volume quantification is an easy to perform, non-invasive technique that uses CT images for the preassessment of candidates for LDLLT, to compare the volume of the lower lobes from the donors with volume of each lung in the prospective recipients. Size matching based on CT densitovolumetry and FVC may differ.

Matching donor to recipient in lung transplantation: How much does size matter?

OBJECTIVE

The impact of size matching between donor and recipient is unclear in lung transplantation. Therefore, we determined the relation of donor lung size to 1) posttransplant survival and 2) pulmonary function as measured by forced expiratory volume in 1 second.

METHODS

From 1990 to 2006, 469 adults underwent lung transplantation with lungs from donors aged 7 to 70 years. Donor and recipient total lung capacities were calculated using established formulae (predicted total lung capacity), and actual recipient lung size was measured in the pulmonary function laboratory. Disparity between donor and recipient lung size was expressed as a ratio of donor predicted total lung capacity to recipient predicted total lung capacity-the predicted total lung capacity ratio-and predicted donor total lung capacity to actual recipient total lung capacity-the actual total lung capacity ratio. Survival was measured by multiphase hazard methodology and repeated measures of National Health and Nutrition Examination Survey-normalized forced expiratory volume in 1 second analyzed by temporal decomposition.

RESULTS

Predicted total lung capacity ratio and actual total lung capacity ratio ranged widely, from 0.55 to 1.59 and 0.52 to 4.20, respectively. Overall survival was unaffected by predicted total lung capacity ratio (P = .3) or actual total lung capacity ratio (P = .5). Patients with emphysema and an actual total lung capacity ratio of 0.67 or less or 1.03 or greater had higher predicted mortality (P = .01). During the first posttransplant year, forced expiratory volume in 1 second increased and then gradually declined. Predicted total lung capacity ratio and actual total lung capacity ratio had a small impact on forced expiratory volume in 1 second, primarily in the late phase after transplant in a disease-specific manner.

CONCLUSION

Size matching between donor and recipient using predicted total lung capacity ratio and actual total lung capacity ratio is an effective technique. Wide discrepancies in lung sizing do not affect overall posttransplant survival or pulmonary function. Therefore, a greater degree of lung size mismatch can likely be accepted, thereby improving patients' odds of undergoing transplantation.

Decortication after lung transplantation

BACKGROUND

Compromise of a pulmonary allograft by restrictive or infectious pleural-space pathology may be amenable to surgical intervention; however, the role of decortication in this patient population has not yet been substantiated. To address this issue, indications and outcomes of decortication after lung transplantation were examined at our institution.

METHODS

From February 1990 to December 2006, 553 patients underwent lung transplantation; postoperative decortications were performed 27 times in 24 patients (4.3%).

RESULTS

Indications for decortication included presumed empyema (15), loculated effusion (7), hemothorax (3), and fibrothorax (2). Decortication was performed at a median of 81 days after transplantation (range, 12 days to 7.8 years). Complete lung reexpansion was achieved after 19 of 27 decortications (70%). Infection was cleared from the pleural space in 9 of 15 empyema patients (64%). Survivals at 1, 3, 6, and 12 months after decortication were 85%, 73%, 65%, and 60%, respectively. Operative mortality (30-day or in-hospital) was 23%, and median length of stay was 19 days.

CONCLUSIONS

Decortication may alleviate the compromise of a transplanted lung by restrictive or infectious pleural-space disease, but operative risk is substantial.

Long-term Improvement in Pulmonary Function After Living Donor Lobar Lung Transplantation

BACKGROUND

As an alternative to cadaveric transplantation, living donor lobar lung transplantation (LDLLT) has been applied in critical patients with end-stage pulmonary disease because of the mismatch between the supply and demand of lungs for transplantation. However, it is unclear whether two pulmonary lobes can provide adequate long-term pulmonary function and satisfactory clinical outcome in recipients.

METHODS

Between October 1998 and September 2004, 28 females and 3 males, including 5 children, underwent LDLLT at Okayama University Hospital. Their mean age was 31.8 years, and the mean observation period was 53.8 months. One patient who underwent single-lung transplantation and another who died peri-operatively were excluded from further analyses.

RESULTS

The most common indication for transplantation was pulmonary arterial hypertension (32.3%). The overall survival rate was 93.6%. Seven recipients (22.6%) developed bronchiolitis obliterans syndrome after LDLLT. The mean percent predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) improved between 12 and 24 months after transplantation (71.8 +/- 12.9% and 65.8 +/- 17.2% at 12 months vs 77.4 +/- 16.6% and 72.8 +/- 14.6% at 24 months; p < 0.005 and p < 0.05, respectively). The actual recipient FVC ultimately reached 123.0% of the estimated graft FVC of two donor lobes (calculated based on the donor FVC and number of segments implanted) at 36 months after LDLLT.

CONCLUSIONS

Although LDLLT may be associated with the limitation of size mismatch, it holds promise for providing well-functioning pulmonary lobar grafts to critically ill patients with poor life expectancy.

Bilateral native lung–sparing lobar transplantation in a canine model

OBJECTIVE

Bilateral living-donor lobar lung transplantation has become an accepted approach in response to the cadaveric lung donor shortage. Because only one lobe is implanted in each chest cavity, this procedure is usually confined to patients of small size. The purpose of this study was to develop a technique of bilateral native lung-sparing lobar transplantation that can be applied to large adult patients.

METHODS

Bilateral native lung-sparing lobar transplantation was performed in 12 pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the natural anatomic position with sparing native right upper, left upper, and middle lobes. In an acute study (n = 6), transplanted graft function was assessed for 3 hours after ligation of the pulmonary artery branches to the native spared lobes. In a chronic study (n = 6) the immunosuppressed recipients were observed for 3 weeks to assess the quality of bronchial healing and long-term pulmonary function.

RESULTS

Morphologic adaptation of the 2 grafts was found to be excellent. All 6 animals in the acute study showed excellent pulmonary function. Five of 6 animals in the chronic study survived for 3 weeks, with excellent pulmonary function and satisfactory bronchial healing.

CONCLUSION

Bilateral native lung-sparing lobar transplantation was technically possible and associated with excellent pulmonary function and good bronchial healing in a canine experimental model.