Whole lung lavage and GM-CSF use for pulmonary alveolar proteinosis in an infant with lysinuric protein intolerance: a case report.

BACKGROUND: Lysinuric protein intolerance (LPI) is a multi-organ metabolic disorder characterized by the imbalance in absorption and excretion of cationic amino acids like lysine, ornithine and arginine. Infants with LPI typically present with recurrent vomiting, poor growth, interstitial lung disease or renal impairment. The early onset of pulmonary alveolar proteinosis (PAP) has been reported to be associated with a severe form of LPI. Treatment of PAP most commonly consists of whole-lung lavage (WLL) and in autoimmune PAP, granulocyte-macrophage colony stimulating factor (GM-CSF) administration. Nevertheless, GM-CSF therapy in LPI-associated PAP has not been scientifically justified. CASE PRESENTATION: We describe the case of an 8-month-old infant presenting with respiratory failure due to LPI associated with PAP, who was twice treated with WLL; firstly, while on veno-venous ECMO assistance and then by the use of a selective bronchial blocker. After the two treatments with WLL, she was weaned from daytime respiratory support while on initially subcutaneous, then on inhaled GM-CSF therapy. CONCLUSIONS: This case supports the notion that GM-CSF therapy might be of benefit in patients with LPI-associated PAP. Further studies are needed to clarify the exact mechanism of GM-CSF in patients with LPI-associated PAP.

Role of rituximab as neoadjuvant therapy in a difficult case of relapsing pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease which involves the accumulation of insoluble lipoproteinaceous material in the alveoli leading to impaired gas exchange and even respiratory failure. Autoimmune PAP is the most common type and is characterized by the presence of anti-granulocyte-monocyte colony stimulating factor (anti GM-CSF) antibody. Whole lung lavage has been traditionally used as first-line management of PAP but there is a lack of clarity especially in the treatment of relapsing cases of PAP. Rituximab is an anti Cluster of Differentiate 20 (CD 20) monoclonal antibody that has been tried as salvage therapy for relapsing cases of PAP. We present a case of 35 years old female patient who was diagnosed as a case of relapsing PAP who was managed initially with neoadjuvant rituximab. This is a retrospective observational report showing novel use of neoadjuvant rituximab in a difficult case of relapsing PAP.

Cytokine profiles associated with disease severity and prognosis of autoimmune pulmonary alveolar proteinosis.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is characterized by an abnormal accumulation of surfactants in the alveoli. Most cases are classified as autoimmune PAP (APAP) because they are associated with autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). However, GM-CSF autoantibody levels are unlikely to correlate with the disease severity or prognosis of APAP. METHODS: We collected clinical records and measured 38 serum cytokine concentrations for consecutive patients with APAP. After exclusion of 21 cytokines because of undetectable levels, 17 cytokine levels were compared between low and high disease severity scores (DSSs). We also compared whole lung lavage (WLL)-free survival with cut-off values defined by receiver operating characteristic (ROC) curves of cytokine levels and WLL administration at 11 months. RESULTS: Nineteen patients with APAP were enrolled in the study. Five were classified as DSS 1 or 2, while the others were classified as DSS 4 or 5. Comparison between DSS 1-2 and 4-5 revealed that the concentrations of IP-10 and GRO increased in the latter groups (p < 0.05). Fifteen patients underwent WLL. Comparison between those who underwent WLL within 11 months and the others showed that IP-10 and TNF-α were tended to be elevated in the former group (p = 0.082 and 0.057, respectively). The cut-off values of IP-10, 308.8 pg/mL and TNF-α, 19.1 pg/mL, defined by the ROC curves, significantly separated WLL-free survivals with log-rank analyses (p = 0.005). CONCLUSIONS: The concentrations of IP-10 and GRO may reflect the DSSs of APAP. A combination of IP-10 and TNF-α levels could be a biomarker to predict WLL-free survival.

Coexistence of Autoimmune Pulmonary Alveolar Proteinosis With Small Cell Lung Cancer in a Man Presenting With Acute Onset Respiratory Failure.

A 60-year-old man was referred to our Respiratory Department with progressive dyspnea on exertion and productive cough over the past two months. High-resolution computed tomography showed diffuse ground glass opacities with superimposed interlobular and intralobular septal thickening mainly in the middle and lower lobes, compatible with crazy paving pattern. Serology tests revealed positive antibody transcriptional intermediary factor-γ1 (TIF-1γ) in myositis panel and bronchoalveolar lavage revealed milky appearance and positive periodic acid-Schiff (PAS) stain. Pulmonary function tests showed moderate reduction in diffusing capacity for carbon monoxide. The working diagnosis of autoimmune pulmonary alveolar proteinosis was established by high detectable levels of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies. Despite clinical and radiological improvement following treatment with whole lung lavage and inhaled sargramostim, patient's follow-up chest computed tomography revealed an enlargement of lower left paratracheal lymph node 4L. Endobronchial ultrasound bronchoscopy (EBUS) biopsy was compatible with small cell lung cancer (SCLC). Chemotherapeutic agents were promptly administrated, with no adverse events up until now.

Impact of Whole Lung Lavage on Pneumoconiosis Patients - China, 2018-2022.

What is already known about this topic?: The application of whole lung lavage (WLL) for the clinical treatment of pneumoconiosis is prevalent in China. Several scholars have reported success in the treatment of early-stage pneumoconiosis. Nonetheless, the overall efficacy of WLL in the management of pneumoconiosis remains ambiguous. What is added by this report?: The preliminary evaluation of the effects of WLL on pneumoconiosis patients was conducted using follow-up data from 2020 to 2022, after controlling for confounding factors via propensity score matching. While the study found that WLL may improve some pneumoconiosis symptoms, no significant enhancements were observed in overall health status or quality of life. What are the implications for public health practice?: The findings of this research indicate limited efficacy of WLL in treating patients with pneumoconiosis, thereby suggesting that it should not be utilized as a standard treatment procedure for this condition.

A complicated case of whole-lung lavage: a case report.

Introduction: We report a life-threatening case of severe respiratory failure due to a pulmonary alveolar proteinosis (PAP) secondary to lysinuric protein intolerance (LPI), complicated by a pre-existing right pneumothorax, which we treated using a rescue whole-lung lavage (WLL). To date, in the literature, there are no cases of WLL performed in this condition. Clinical condition: Patient was referred to our center because of rapidly worsening dyspnea and deterioration of gas exchange, caused by a secondary form of PAP which required an immediate therapeutic option such as the one offered by WLL. On physical examination, bilateral crackles were present, and peripheral blood oxygen saturation was 78% on oxygen with a FiO2 of 40%. Interventions: After stabilizing the clinical conditions with oxygen therapy erogated through a high-flow nasal cannula, shortly after admission, we performed a rescue WLL among two procedures. The procedure was very effective, and the patient was later discharged without oxygen therapy and in good clinical condition. Conclusion: Our case report represents a chance to help fill the gap of knowledge relative to secondary forms of PAP. The patient we presented suffers from a very rare genetic condition (LPI) that only has a few reported cases in the literature and has a very low prevalence which makes it difficult to produce the affected people:newborns ratio. We believe that difficult and rare cases like this one can improve our understanding of the disease and, most importantly, of how much the only therapeutic option we had, a rescue WLL, is effective to improve gas exchange and radiological features, despite being performed in these severe respiratory conditions.

Whole lung lavage decreases physiological dead space in patients with pulmonary alveolar proteinosis: two case reports.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by progressive accumulation of the alveolar surfactant. Whole lung lavage (WLL) using a high volume of warmed saline remains the standard therapy. However, no established bedside monitoring tool can evaluate the physiological effect of WLL in the perioperative period. Indirect calorimetry, which is generally used to measure resting energy expenditure, can detect carbon dioxide (CO2) production and mixed-expired partial pressure of CO2 breath by breath. In this physiological study, we calculated CO2 elimination per breath (VTCO2,br) and Enghoff's dead space using indirect calorimetry and measured the extravascular lung water index to reveal the effect of WLL. CASE PRESENTATION: We measured VTCO2,br, Enghoff's dead space, and the extravascular lung water and cardiac indices before and after WLL to assess the reduction in shunt by washing out the surfactant. A total of four WLLs were performed in two PAP patients. The first case involved an Asian 62-year-old man who presented with a 3-month history of dyspnea on exertion. The second case involved an Asian 48-year-old woman with no symptoms. VTCO2,br increased, and the Enghoff's dead space decreased at 12 h following WLL. An increase in the extravascular lung water was detected immediately following WLL, leading to a transient increase in Enghoff's dead space. CONCLUSION: WLL can increase efficient alveolar ventilation by washing out the accumulated surfactant. However, the lavage fluid may be absorbed into the lung tissues immediately after WLL and result in an increase in the extravascular lung water.

A Case of Pulmonary Alveolar Proteinosis in a 15-Year-Old Female Patient.

Pulmonary alveolar proteinosis (PAP) is an extremely rare pulmonary disease that can be classified into primary, secondary, or congenital types. It typically presents with a pattern of interstitial lung disease. This rare condition is even rare in the adolescent or pediatric age group, making this case particularly rare and interesting. We report a case of a 15-year-old girl who presented with a four-month history of dry cough and exertional dyspnea. After performing a high-resolution computed tomography (HRCT) scan and bronchoalveolar lavage (BAL) with analysis of the BAL fluid, she was eventually diagnosed with PAP. She was then referred to a higher qualified center, where a whole lung lavage (WLL) was performed, resulting in significant improvement of her symptoms.

Post-COVID-19 Pulmonary Alveolar Proteinosis Treated Successfully with Whole Lung Lavage: A Rare Case Report.

Pulmonary alveolar proteinosis (PAP) is an uncommon disease and its diagnosis remains challenging. During the COVID-19 pandemic, it has been difficult to distinguish between PAP and post-COVID-19 pulmonary sequelae. Here we present a case of a 44-year-old male patient who experienced exertional dyspnea after recovering from COVID-19. He was initially diagnosed with post-COVID-19 syndrome and treated with systemic corticosteroid without improvement. Chest computed tomography (CT) showed crazy-paving pattern with ground-glass opacities. Fibreoptic bronchoscopy with bronchial lavage fluid (BLF) analysis confirmed the final diagnosis of PAP. The patient underwent left lung lavage in combination with conventional therapy and experienced significant improvement in his respiratory condition and overall health during follow-up. Hence, PAP could occur after a COVID-19 infection. This case highlights the importance of considering PAP as a potential diagnosis in patients with persistent respiratory symptoms after COVID-19. The high suspicion indicators of PAP revealed by chest-CT and BLF may be a key to differentiating PAP from post-COVID-19 pulmonary sequelae. Moreover, it is plausible that SARS-CoV-2 plays a role in the development of proteinosis, either by inducing a flare-up or by directly causing the condition.

Pulmonary alveolar proteinosis in Taiwan.

BACKGROUND/PURPOSE: Pulmonary alveolar proteinosis (PAP) is rare disease manifested as alveolar macrophage dysfunction and abnormal accumulation of surfactant protein in the alveoli. In this nationwide, population-based study, we investigated the epidemiology of PAP in Taiwan, and discovered the comorbidities and prognostic factors of PAP. METHODS: From the National Health Insurance Research Database (NHIRD), we obtained comprehensive information about all patients of PAP in Taiwan between 1995 and 2013. The incidence, baseline characteristics comorbidities, and prognostic factors of PAP were investigated. RESULTS: The annual incidence rate of PAP was around 0.79 (range: 0.49-1.17) patients per million people after 2000, and the prevalence rate was 7.96 patients per million people by the end of 2013. In total, 276 patients of PAP were identified, including 177 (64%) and 99 (36%) patients with primary and secondary PAP, respectively. The median age of diagnosis was 53.8 years. The median survival was 9.6 years after the initial PAP diagnosis, and the 5-year survival rate was 65.96%. Twenty (7%) patients received whole lung lavage (WLL) within three months after the diagnosis had significantly better survival compared to the others. Multivariable Cox regression analyses showed that elder age, secondary PAP, and malignancy were associated with poorer survival, while WLL within 3 months of diagnosis might greatly improve the survival. CONCLUSION: We demonstrated the epidemiology of PAP in Taiwan, showing several poor prognostic factors and the potential effectiveness of WLL. Further prospective studies based on registry are warranted to improve the diagnosis and treatment of PAP.

Association between one-session bilateral whole-lung lavage and periprocedural complications in patients with pulmonary alveolar proteinosis: a retrospective cohort study.

BACKGROUND: Whole lung lavage (WLL) has been recognized as the most effective therapy of severe pulmonary alveolar proteinosis (PAP). Most centers perform the lavage of each lung in two sessions under general anesthesia at an interval of several days to weeks. Compared with two-session WLL, one-session bilateral sequential WLL only requires general anesthesia once. However, the safety of one-session WLL in PAP patients has not been assessed by large cohort studies. In this study, we aimed to investigate the association between the mode of WLL procedure (one-session or two-session) and the risk of periprocedural complications in PAP patients. METHODS: In this single-center retrospective cohort study, we included adult patients who were diagnosed as PAP and had undergone WLL procedures under general anesthesia from 2000 to 2022. Patients requiring extra-corporeal oxygenation during WLL were excluded. Since some patients received multiple WLL procedures, we considered each procedure in one-session or two-session group as a unique unit in our analysis. The primary outcome was the occurrence of any complications during hospitalization, including termination of WLL procedure due to fluid leakage or refractory hypoxemia, bronchospasm, delayed endotracheal extubation, cardiovascular event, pneumothorax, and fever. RESULTS: We included a total of 175 WLL procedures (118 patients), with 48 in the two-session group and 127 in the one-session group. Periprocedural complications occurred in 17 (35.4%) and 39 (30.7%) procedures in the two-session and the one-session groups, respectively. The risk of periprocedural complications did not differ significantly between groups, after adjusting the unbalanced confounders in a multivariable model (odds ratio 0.95, 95% confidence interval 0.34 to 2.69, P 0.929) or by inverse probability of treatment weighting (odds ratio 0.70, 95% confidence interval 0.30 to 1.54, P 0.379). Compared with the two-session WLL group, the one-session WLL group had a shorter postprocedural length of hospitalization and comparable decrease in alveolar-arterial oxygen tension gradient from baseline. CONCLUSIONS: One-session bilateral WLL was not associated with an increased risk of periprocedural complications compared with two-session WLL in PAP patients. Experienced physicians may consider performing one-session WLL in view of the comparable safety and efficacy and potential advantages of saving time.

Updated severity and prognosis score of pulmonary alveolar proteinosis: A multi-center cohort study in China.

Background: The high-resolution computed tomography (HRCT) score is an important component of the severity and prognosis score of pulmonary alveolar proteinosis (SPSP). However, the HRCT score in SPSP only considers the extent of opacity, which is insufficient. Methods: We retrospectively evaluated HRCT scores for 231 patients with autoimmune pulmonary alveolar proteinosis (APAP) from three centers of the China Alliance for Rare Diseases. The SPSPII was created based on the overall density and extent, incorporating the SPSP. The severity of APAP patients was assessed using disease severity scores (DSS), SPSP, and SPSPII to determine the strengths and weaknesses of the different assessment methods. We then prospectively applied the SPSPII to patients before treatment, and the curative effect was assessed after 3 months. Results: The HRCT overall density and extent scores in our retrospective analysis were higher than the extent scores in all patients and every original extent score severity group, as well as higher related to arterial partial oxygen pressure (PaO2) than extent scores. The mild patients accounted for 61.9% based on DSS 1-2, 20.3% based on SPSP 1-3, and 20.8% based on SPSPII 1-3. Based on SPSP or SPSPII, the number of severe patients deteriorating was higher in the mild and moderate groups. When applied prospectively, arterial PaO2 differed between any two SPSPII severity groups. The alveolar-arterial gradient in PaO2 (P[A-a]O2), % predicted carbon monoxide diffusing capacity of the lung (DLCO), and HRCT score were higher in the severe group than in the mild and moderate groups. After diagnosis, mild patients received symptomatic treatment, moderate patients received pure whole lung lavage (WLL) or granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy, and severe patients received WLL and GM-CSF therapy. Importantly, the SPSPII in mild and severe groups were lower than baseline after 3 months. Conclusion: The HRCT density and extent scores of patients with APAP were better than the extent score. The SPSPII score system based on smoking status, symptoms, PaO2, predicted DLCO, and overall HRCT score was better than DSS and SPSP for assessing the severity and efficacy and predicting the prognosis. Trial registration: ClinicalTrial.gov, identifier: NCT04516577.

Anesthetic Challenges During Whole Lung Lavage: A Case Report.

Pulmonary alveolar proteinosis is an uncommon lung disease characterized by the accumulation of surfactant in the lungs. Treatment is done by whole lung lavage. One-lung ventilation in diseased lungs is a challenge to anesthesiologists due to the rapid desaturation and hemodynamic fluctuations encountered during the procedure. A 24-year-old female, a known patient of pulmonary alveolar proteinosis, who had undergone previous lung lavage presented with a dry cough and shortness of breath. Our management of the case included complete lung isolation with a double-lumen tube (DLT), one-lung ventilation, and an appropriate hemodynamic management strategy during the procedure.

Utilization and influencing factors of whole lung lavage for patients with pneumoconiosis in Chinese mainland from 2018 to 2021 / 中国职业医学

Objective: To evaluate the utilization and influencing factors of whole lung lavage (WLL) for patients with pneumoconiosis. Methods: A total of 10 524 pneumoconiosis patients who sought medical treatment from 2018 to 2021 were selected as the research subjects using a combination of stratified random sampling and non-random sampling methods. The patients were from 27 provincial administrative regions of Chinese mainland (excluding Shanghai City, Tianjin City, Hainan Province and Tibet Autonomous Region). The effects of demographic and sociological characteristics, disease-related factors, and economic and social security status on WLL utilization were analyzed. Results: The WLL rate of pneumoconiosis patients was 17.8% (1 871/10 524). The main reason for promoting WLL in pneumoconiosis patients was “doctor's advice”, accounting for 65.4%； followed by “known-pneumoconiosis-patients had WLL” and “patient's recommendation”, accounting for 24.1% and 18.1%, respectively. Multivariate logistic regression analysis showed that age, body mass index, smoking index, education level, survey area, source of patients, current employment status, nature of dust-exposed unit, stage of pneumoconiosis, type of pneumoconiosis, pneumoconiosis symptoms (coughing up phlegm, chest pain, dyspnea, joint pain), contraindications to WLL (tuberculosis, pulmonary heart disease), family annual income, medical insurance for urban employees, proportion of medical insurance reimbursement, disability benefits, and social assistance were the influencing factors of WLL utilization in pneumoconiosis patients (all P<0.05). Conclusion: A large proportion of pneumoconiosis patients used WLL. The influencing factors of WLL utilization included demographic and sociological characteristics, disease-related factors, economic and social security status, and more. It is necessary to protect the interests of pneumoconiosis patients, strengthen occupational health education and health promotion for pneumoconiosis patients, standardize the use of WLL in medical institutions, and make rational use of WLL.

A case of autoimmune pulmonary alveolar proteinosis with severe respiratory failure treated with segmental lung lavage and oral statin therapy.

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease characterized by the accumulation of alveolar surfactants due to dysfunction of granulocyte-macrophage colony-stimulating factor-dependent cholesterol clearance. Whole-lung lavage is the current standard of care for PAP, but it can lead to the exacerbation of hypoxia. A medication targeting cholesterol homeostasis is a promising therapy for refractory PAP. We present a case of autoimmune PAP with severe hypoxia that was successfully treated with segmental lung lavage (SLL). Following SLL for disease relapse, statin treatment for dyslipidemia was started. After initiating statin treatment, the patient did not require bronchoalveolar lavage for 10 months.

Lung injury induced by different negative suction pressure in patients with pneumoconiosis undergoing whole lung lavage.

BACKGROUND: Pneumoconiosis is a diffuse interstitial fibronodular lung disease, which is caused by the inhalation of crystalline silica. Whole lung lavage (WLL) is a therapeutic procedure used to treat pneumoconiosis. This study is to compare the effects of different negative pressure suction on lung injury in patients with pneumoconiosis undergoing WLL. MATERIALS AND METHODS: A prospective study was conducted with 24 consecutively pneumoconiosis patients who underwent WLL from March 2020 to July 2020 at Emergency General Hospital, China. The patients were divided into two groups: high negative suction pressure group (group H, n = 13, negative suction pressure of 300-400 mmHg) and low negative suction pressure group (group L, n = 11, negative suction pressure of 40-50 mmHg). The arterial blood gas, lung function, lavage data, oxidative stress, and inflammatory responses to access lung injury were monitored. RESULTS: Compared with those of group H, the right and left lung residual were significantly increased in the group L (P = 0.04, P = 0.01). Potential of hydrogen (pH), arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), lactic acid (LAC) and glucose (GLU) varied from point to point in time (P < 0.01, respectively). There was statistical difference in the trend of superoxide dismutase (SOD) and interleukin-10 (IL-10) over time between the two groups (P < 0.01, P = 0.02). In comparison with the group H, the levels of IL-10 (P = 0.01) and SOD (P < 0.01) in WLL fluid were significantly increased in the group L. There was no statistical difference in the trend of maximal volumtary ventilation (MVV), forced vital capacity (FVC), forced expiratory volume in one second (FEV1%), residual volume (RV), residual volume/total lung capacity (RV/TLC), carbon monoxide dispersion factor (DLCO%), forced expiratory volume in one second/ forced vital capacity (FEV1/FVC%) over time between the two groups (P > 0.05, respectively). CONCLUSION: Low negative suction pressure has the potential benefit to reduce lung injury in patients with pneumoconiosis undergoing WLL, although it can lead to increased residual lavage fluid. Despite differing suction strategies, pulmonary function parameters including FEV1%, RV and DLCO% became worse than before WLL. Trial Registration Chinese Clinical Trial registration number ChiCTR2000031024, 21/03/2020.

Unilateral Autoimmune Pulmonary Alveolar Proteinosis with Polymyositis-related Interstitial Lung Disease.

A 61-year-old patient with cystic bronchiectasis and bronchial artery hyperplasia in the left lung was diagnosed with polymyositis-related interstitial lung disease. After nine months of immunosuppressive therapy, he developed unilateral autoimmune pulmonary alveolar proteinosis (APAP) in the right lung with respiratory failure. After bronchial artery embolization to prevent massive hemoptysis, whole-lung lavage was performed using veno-venous extracorporeal membrane oxygenation. His respiratory condition improved, and he was discharged from the hospital with supplemental oxygen. Three reported cases of APAP with polymyositis-related interstitial lung disease, including the present case, were all positive for anti-glycyl tRNA synthetase antibody and were under immunosuppressive treatment.

Dilutional acidosis during whole lung lavage under general anesthesia due to excessive absorption of normal saline.

BACKGROUND: Whole lung lavage (WLL) is an effective therapy for pulmonary alveolar proteinosis. We report a rare dilutional acidosis following WLL in a female patient. CASE PRESENTATION: Under general anesthesia, a left-sided double-lumen tube was inserted with its bronchial lumen connected to the saline delivery system. Preoperatively, arterial blood gases were within normal limits. During 14 l of fluid was instilled into the lung for 2.5 hours, a decrease in pH, K+, and base excess, alongside an increase in Na+ and Cl-, indicated a strong ion difference; the diagnosis was dilutional hyperchloremic metabolic acidosis. Although she remained hemodynamically stable and had no indicators of massive absorption, she stayed in the ICU for mechanical ventilation for one night out of concern of pulmonary edema. CONCLUSIONS: Inappropriate irrigating fluid pressure might lead to absorption of normal saline. Continuous monitoring and careful observation during WLL can help prevent intraoperative dilutional acidosis.

A mini-whole lung lavage to treat autoimmune pulmonary alveolar proteinosis (PAP).

BACKGROUND: PAP is an ultra-rare respiratory syndrome characterized by the accumulation of surfactant within the alveoli. Whole lung lavage (WLL) is the current standard of care of PAP, however it is not a standardized procedure and the total amount of fluid used to wash each lung is still debated. Considering ICU hospitalization associated risks, a "mini-WLL" with anticipated manual clapping and reduced total infusion volume and has been proposed in our center. The aim of the study is to retrospectively analyze the efficacy of mini-WLL compared to standard WLL at the Pavia center. METHODS: 13 autoimmune PAP patients eligible for WLL were included: 7 patients were admitted to mini-WLL (9 L total infusion volume for each lung) and 6 patients underwent standard WLL (14 L of infusion volume). Functional data (VC%, FVC%, TLC%, DLCO%) and alveolar-arterial gradient values (A-aO2) were collected at the baseline and 1, 3, 6, 12, 18 months after the procedure. RESULTS: A statistically significant improvement of VC% (p = 0.013, 95%CI 3.49-30.19), FVC% (p = 0.016, 95%CI 3.37-32.09), TLC% (p = 0.001, 95%CI 7.38-30.34) was observed in the mini-WLL group in comparison with the standard WLL group, while no significant difference in DLCO% and A-aO2 mean values were reported. CONCLUSION: Mini-WLL has demonstrated higher efficacy in ameliorating lung volumes, suggesting that a lower infusion volume is sufficient to remove the surfactant accumulation and possibly allows a reduced mechanical insult of the bronchi walls and the alveoli. However, no statistically significant differences were found in terms of DLCO% and Aa-O2.