Donor Total Lung Capacity Predicts Recipient Total Lung Capacity After Size-reduced Lung Transplantation

"Horses for courses" computed tomography or predicted total lung capacity for size matching in lung transplantation

Size-matching donors to recipients in lung transplantation continues to be a clinical challenge. Predicted total lung capacity equations, or more simply, donor and recipient heights, while widely used, are imprecise and may not be representative of the pool of donors and recipients. These inherent limitations may result in size discrepancies. The advent of easily accessible software and the widespread availability of computed tomography (CT) imaging in donor assessments have made it possible to directly measure lung volumes in donors and recipients. As a result, there is a growing interest in adopting personalized CT volumetry as an alternative. This article explores both methods and underscores the potential benefits and precision offered by CT.

Review of outcomes of delayed chest closure following lung transplantation: a meta-analysis

Purpose

The clinical outcomes of delayed chest closure (DCC) compared with primary chest closure (PCC) following lung transplantation, including perioperative outcomes and long-term survival, remained controversial. This was the first systematic review and meta-analysis aimed to identify the short- and long-term outcomes of DCC following lung transplantation.

Methods

We comprehensively searched electronic literature from 4 databases up to April 1st, 2022. Dichotomous data and continuous data were pooled with odds ratio and weighted mean difference, respectively. The quality of included studies was assessed with the Newcastle–Ottawa Scale.

Results

Ten studies were included in the systematic review and 4 studies were included in the meta-analysis. Pooled analysis showed that DCC was associated with an increased risk of surgical site infection, prolonged hospital stays, and higher risk of primary graft dysfunction compared to PCC. The 30 day and 5 year survival were higher in PCC cohort compared with DCC cohort while differences in survival at 6 months was insignificant.

Conclusion

Our findings do not support the aggressive application of DCC. DCC should be cautiously applied since its association with worse perioperative outcomes and higher mortality. But it remains the life-saving steps under dangerous circumstances.

Lung protective ventilation based on donor size is associated with a lower risk of severe primary graft dysfunction after lung transplantation

BACKGROUND

Mechanical ventilation immediately after lung transplantation may impact the development of primary graft dysfunction (PGD), particularly in cases of donor-recipient size mismatch as ventilation is typically based on recipient rather than donor size.

METHODS

We conducted a retrospective cohort study of adult bilateral lung transplant recipients at our center between January 2010 and January 2017. We defined donor-based lung protective ventilation (dLPV) as 6 to 8 ml/kg of donor ideal body weight and plateau pressure <30 cm H₂O. We calculated the donor-recipient predicted total lung capacity (pTLC) ratio and used logistic regression to examine relationships between pTLC ratio, dLPV and PGD grade 3 at 48 to 72 hours. We used Cox proportional hazards modelling to examine the relationship between pTLC ratio, dLPV and 1-year survival.

RESULTS

The cohort included 373 recipients; 24 (6.4%) developed PGD grade 3 at 48 to 72 hours, and 213 (57.3%) received dLPV. Mean pTLC ratio was 1.04 ± 0.18. dLPV was associated with significantly lower risks of PGD grade 3 (OR = 0.44; 95% CI: 0.29-0.68, p < 0.001) and 1-year mortality (HR = 0.49; 95% CI: 0.29-0.8, p = 0.018). There was a significant association between pTLC ratio and the risk of PGD grade 3, but this was attenuated by the use of dLPV.

CONCLUSIONS

dLPV is associated with decreased risk of PGD grade 3 at 48 to 72 hours and decreased 1-year mortality. Additionally, dLPV attenuates the association between pTLC and both PGD grade 3 and 1-year mortality. Donor-based ventilation strategies may help to mitigate the risk of PGD and other adverse outcomes associated with size mismatch after lung transplantation.

Long-Term Outcomes of Cadaveric Lobar Lung Transplantation: An Important Surgical Option

BACKGROUND

Cadaveric lobar lung transplantation (L-LTx) is developed to overcome donor-recipient size mismatch. Controversial short- and long-term outcomes following L-LTx have been reported compared to full-sized lung transplantation (F-LTx). This study reports long-term outcomes after L-LTx.

METHODS

We reviewed patients undergoing lung transplantation (LTx) between 2000 and 2016. The decision to perform L-LTx was made based mainly on donor-recipient height discrepancy and visual assessment of donor lungs. Predicted donor-recipient total lung capacity (TLC) ratio was calculated more recently. Primary outcome was overall survival.

RESULTS

In all, 370 bilateral LTx were performed during the study period, among those 250 (67%) underwent F-LTx and 120 (32%) underwent L-LTx, respectively. One- and 5-year survival rates were 85% vs. 90% and 53% vs. 63% for L-LTx and F-LTx, respectively (p = 0.16). Chronic lung allograft dysfunction (CLAD)-free survival at 5 years was 48% in L-LTx vs. 51% in F-LTx recipients (p = 0.89), respectively. Age, intraoperative extracorporeal membrane oxygenation (ECMO) use, intensive care unit (ICU) stay, and postoperative renal replacement therapy (RRT) were significant prognostic factors for survival using multivariate analysis.

CONCLUSIONS

Overall survival and CLAD-free survival following L-LTx were comparable to F-LTx. Given the ongoing donor organ shortage, cadaveric L-LTx remains as an important resource in LTx.

The feasibility of CT lung volume as a surrogate marker of donor-recipient size matching in lung transplantation

Donor-recipient size matching in lung transplantation (LTx) by computed tomography lung volume (CTvol) may be a reasonable approach because size matching is an anatomical issue. The purpose of this study is to evaluate the feasibility of CTvol as a surrogate marker of size matching in LTx by comparing CTvol and predicted total lung capacity (pTLC) to reference total lung capacity (TLC) values.From January to December 2014, data from 400 patients who underwent plethysmography, pulmonary function testing (PFT), and chest computed tomography scans were reviewed retrospectively. Enrolled 264 patients were divided into 3 groups according to PFT results: Group I, obstructive pattern; Group II, restrictive pattern; Group III, normal range. The correlations between pTLC and TLC and between CTvol and TLC were analyzed, and the linear correlation coefficients were compared. The percentage error rates of pTLC and CTvol were calculated and absolute error rates were compared.The correlation coefficient between CTvol and TLC in Group I was larger than that of pTLC and TLC (0.701 vs 0.432, P = 0.002). The absolute percentage error rate between CTvol and pTLC was lower than that of pTLC in Group II (15.3% ± 11.9% vs 42.2% ± 28.1%, P < 0.001).CTvol showed similar or better correlation with TLC compared to the pTLC in normal participants and patients with obstructive or restrictive pulmonary diseases. CTvol showed a smaller error rate in patients with restrictive disease. The results suggest that CTvol may be a feasible method for size matching in LTx.

Comparison of Predicted Total Lung Capacity and Total Lung Capacity by Computed Tomography in Lung Transplantation Candidates

PURPOSE

Lung size mismatch is a major cause of poor lung function and worse survival after lung transplantation (LTx). We compared predicted total lung capacity (pTLC) and TLC measured by chest computed tomography (TLC(CT)) in LTx candidates.

MATERIALS AND METHODS

We reviewed the medical records of patients on waiting lists for LTx. According to the results of pulmonary function tests, patients were divided into an obstructive disease group and restrictive disease group. The differences between pTLC calculated using the equation of the European Respiratory Society and TLC(CT) were analyzed in each group.

RESULTS

Ninety two patients met the criteria. Thirty five patients were included in the obstructive disease group, and 57 patients were included in the restrictive disease group. pTLC in the obstructive disease group (5.50±1.07 L) and restrictive disease group (5.57±1.03 L) had no statistical significance (p=0.747), while TLC(CT) in the restrictive disease group (3.17±1.15 L) was smaller than that I the obstructive disease group (4.21±1.38 L) (p<0.0001). TLC(CT)/pTLC was 0.770 in the obstructive disease group and 0.571 in the restrictive disease group.

CONCLUSION

Regardless of pulmonary disease pattern, TLC(CT) was smaller than pTLC, and it was more apparent in restrictive lung disease. Therefore, we should consider the difference between TLC(CT) and pTLC, as well as lung disease patterns of candidates, in lung size matching for LTx.

New predictive equation for lung volume using chest computed tomography for size matching in lung transplantation

PURPOSE

Lung size matching is important in lung transplantation (LT). With advances in computed tomography (CT) technology, multidetector row CT can accurately measure the thoracic cage and lung volumes. The objective of this study was to generate a new regression equation using demographic data based on the measured CT lung volume in a healthy population to predict the CT lung volume of the donor in LT size matching.

MATERIALS AND METHODS

The medical records of healthy subjects who underwent chest CT scans to screen for lung cancer were retrospectively reviewed. CT lung volume was semi-automatically measured using a threshold-based auto-segmentation technique. New regression equations for CT lung volume were generated by multiple linear regression analysis using demographic data including height (H, cm), weight (W, kg), and age (A, years). The percentage error rate (%) of the equations were calculated as ([Estimated CT lung volume--Measured CT lung volume]/Measured CT lung volume × 100). A percentage error rate within ± 20% was considered acceptable.

RESULTS

A total of 141 men aged 27 to 55 years (mean, 46.7 ± 6.2 years) and 128 women aged 20 to 55 years (mean, 45.4 ± 7.2 years) were enrolled. The final regression equations for CT lung volume were (-5.890 + 0.067 H - 0.030 W + 0.020 A) in men and (-6.698 + 0.072 H - 0.024 W) in women. The mean absolute error rate was 10.9 ± 9.0% and 11.0 ± 8.5% in men and women, respectively. Percentage error rates were within ± 20% in 121 of 141 (85.8%) men and 113 of 128 (88.3%) women.

CONCLUSION

These equations could predict the CT lung volume of healthy subjects using demographic data. Using these equations, the predicted CT lung volume of donors could be matched to the measured CT lung volume of recipients in lung transplantation.

Current State of Pediatric Lung Transplantation

Cardiothoracic transplantation has significantly impacted the lives of pediatric patients with advanced cardiopulmonary failure. The current state of lung transplantation in children as well as its ongoing and future challenges are discussed.

Lobar lung transplantation--is it comparable with standard lung transplantation?

Lobar lung transplantation is used mainly for urgent small recipients who are less likely to obtain size matched lungs in due time. Only limited numbers have been published, and we herewith report the largest series of lobar-LuTX. We analyzed our LuTX database from 1/2001 to 12/2012 and compared the outcome of lobar-LuTX recipients with those receiving standard LuTX. Seven hundred and seventy-eighty LuTX (group 1) were performed either in standard technique by implanting the whole lungs (n = 539) or with downsizing by wedge resection of the right middle lobe and/or the left lingula (n = 239). One hundred and thirty-eight LuTX were performed in lobar technique (group 2) to overcome more pronounced size discrepancies. Patients in group 1 had a different spectrum of diagnoses and were less frequently bridged to LuTX (P < 0.001). Intubation time, ICU stay, and hospital stay were shorter in group 1 (P < 0.001). One-year survival was 84.8% vs. 65.1%, and 5-years survival 69.9% vs. 54.9% (P < 0.001). In multivariate analyzes, procedure, diagnosis, and pre-operative bridging were shown to be significant prognostic factors in survival. Early postoperative outcome in Lobar LuTX was significantly inferior to standard LuTX recipients. However, survival rates of successfully dismissed patients were comparable with standard LuTX (P = 0.168); thereby, Lobar-LuTX remains an important option in the management of urgent small recipients.

Practical guidelines: lung transplantation in patients with cystic fibrosis

There are no European recommendations on issues specifically related to lung transplantation (LTX) in cystic fibrosis (CF). The main goal of this paper is to provide CF care team members with clinically relevant CF-specific information on all aspects of LTX, highlighting areas of consensus and controversy throughout Europe. Bilateral lung transplantation has been shown to be an important therapeutic option for end-stage CF pulmonary disease. Transplant function and patient survival after transplantation are better than in most other indications for this procedure. Attention though has to be paid to pretransplant morbidity, time for referral, evaluation, indication, and contraindication in children and in adults. This review makes extensive use of specific evidence in the field of lung transplantation in CF patients and addresses all issues of practical importance. The requirements of pre-, peri-, and postoperative management are discussed in detail including bridging to transplant and postoperative complications, immune suppression, chronic allograft dysfunction, infection, and malignancies being the most important. Among the contributors to this guiding information are 19 members of the ECORN-CF project and other experts. The document is endorsed by the European Cystic Fibrosis Society and sponsored by the Christiane Herzog Foundation.

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.

Techniques and results of lobar lung transplantations

OBJECTIVES

We report our experience of lobar lung transplantations (LLTs) in patients with small thoracic volume.

METHODS

Since 1988, 50 LLTs were done for cystic fibrosis (n=35), fibrosis (n=7), bronchiectasis (n=3), emphysema (n=3) and lymphangiomyomatosis (n=2). There were 44 females and 6 males (mean age 31±13 years, mean size 155±5.5 cm and mean predicted total lung capacity (TLC) 4463±598 ml). Mean ratio between donor and recipient-predicted TLC was 1.65±0.26. Six patients were listed in high emergency, 2 of them on ECMO as a bridge to transplantation. Forty middle/lower right lobe with left lower LLT, four bilateral lower LLT and six split left lung LLT were performed through a clamshell incision (n=12) or a bilateral antero-lateral thoracotomy (n=38), with epidural analgesia in 17 cases. Thirty-two patients were transplanted under circulatory support (CPB n=16, veno-arterial ECMO n=16). In 11 cases, the right venous anastomosis was enlarged by a pericardial cuff. Ischaemic time was 4.4±1.2 h for the first lobe and 6.1±1.3 h for the second.

RESULTS

Median mechanical ventilation weaning time was 10.5 (1-136) days. Four patients were extubated in the operating room. Ten patients needed ECMO for primary graft dysfunction. In-hospital mortality was 28% related to sepsis (n=6), PGD (n=3), haemorrhage (n=2), broncho-vascular fistula (n=1), and multiorgan failure (n=2). Eight patients required endoscopic treatments for airway complications. Mean best FEV1 was 72±16% of the theoretical value. The actuarial 3-year and 5-year survival rates were 60 and 46%, respectively.

CONCLUSIONS

LLTs are a reliable solution and can be performed with satisfactory functional results and survival rates.

Long-term outcomes of bilateral lobar lung transplantation

OBJECTIVES

Lobar lung transplantation is an option that provides the possibility of transplanting an urgent listed recipient of small size with a size-mismatched donor lung by surgically reducing the size of the donor lung. We report our short- and long-term results with bilateral lobar lung transplantation (BLLT) and compare it with the long-term outcomes of our cohort.

METHODS

Retrospective analyses of 75 lung transplant recipients who received downsized lungs with a special focus on 23 recipients with BLLT performed since January 2000. Postoperative surgical complications, lung function tests, late complications and survival were analyzed. The decision to perform lobar transplantation was considered during allocation and finally decided prior to implantation.

RESULTS

Cystic fibrosis was the most common indication (43.5%) followed by pulmonary fibrosis (35%). Median age at transplantation was 41 (range 13-66) years. Fifteen were females. Nineteen of the transplantations (83%) were done with extracorporeal membrane oxygenation (ECMO) support; 3 of them were already on ECMO prior to transplantation. There was no 30-day or in-hospital mortality. No bronchial complications occurred. The most common early complication was haematothorax (39%), which required surgical intervention. The rate of postoperative atrial arrhythmias was 30%. Forced expiratory volumes in 1 s (% predicted) at 1 and 2 years were 76 ± 23 and 76 ± 22, respectively (mean ± standard deviation). By 2-year follow-up, bronchiolitis obliterans syndrome was documented in 3 patients with a median follow-up of 1457 days. Overall survivals at 1 and 5 years were 82 ± 8 and 64 ± 11%, respectively and were comparable with those of 219 other recipients who received bilateral lung transplantation during the same period (log rank test, P = 0.56).

CONCLUSIONS

This study demonstrates that BLLT has short- and long-term outcomes comparable with those of standard bilateral lung transplantation. The limitation of lung transplantation due to size-mismatch, particularly in smaller recipients, could be overcome by utilizing lobar lung transplantation.

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.

Lung transplantation

PURPOSE OF REVIEW

To describe recent advances in lung transplantation relevant to anesthesiologists.

RECENT FINDINGS

There is recent literature describing medical, surgical, anesthetic and critical care of lung transplant recipients.

SUMMARY

There have been substantial changes in preoperative selection and preparation of lung transplant recipients; these include donation after cardiac death, and improved lung-preservation solutions. Newer immunosuppression regimens have been successfully evaluated in clinical trials. Particular advances in anesthesia include endorsement of fluid restriction in thoracic surgery, greater use of transesophageal echocardiography, and postoperative extracorporeal membrane oxygenation.