Endobronchial valves in treatment of persistent air leaks: a systematic review of clinical evidence

Lung-Mimetic Hydrofoam Sealant to Treat Pulmonary Air Leak

Pulmonary air leak is the most common complication of lung surgery, contributing to post-operative morbidity in up to 60% of patients; yet, there is no reliable treatment. Available surgical sealants do not match the demanding deformation mechanics of lung tissue; and therefore, fail to seal air leak. To address this therapeutic gap, a sealant with structural and mechanical similarity to subpleural lung is designed, developed, and systematically evaluated. This "lung-mimetic" sealant is a hydrofoam material that has alveolar-like porous ultrastructure, lung-like viscoelastic properties (adhesive, compressive, tensile), and lung extracellular matrix-derived signals (matrikines) to support tissue repair. In biocompatibility testing, the lung-mimetic sealant shows minimal cytotoxicity and immunogenicity in vitro. Human primary monocytes exposed to sealant matrikines in vitro upregulate key genes (MARCO, PDGFB, VEGF) known to correlate with pleural wound healing and tissue repair in vivo. In rat and swine models of pulmonary air leak, this lung-mimetic sealant rapidly seals air leak and restores baseline lung mechanics. Altogether, these data indicate that the lung-mimetic sealant can effectively seal pulmonary air leak and promote a favorable cellular response in vitro.

ERS International Congress 2023: highlights from the Respiratory Intensive Care Assembly

Early career members of Assembly 2 (Respiratory Intensive Care) attended the 2023 European Respiratory Society International Congress in Milan, Italy. The conference covered acute and chronic respiratory failure. Sessions of interest to our assembly members and to those interested in respiratory critical care are summarised in this article and include the latest updates in respiratory intensive care, in particular acute respiratory distress syndrome and mechanical ventilation.

Predictors of reoperation after lung volume reduction surgery

OBJECTIVES

Lung volume reduction surgery (LVRS) has proven an effective treatment for emphysema, by decreasing hyperinflation and improving lung function, activity level and reducing dyspnoea. However, postoperative air leak is an important complication, often leading to reoperation. Our aim was to analyse reoperations after LVRS and identify potential predictors.

METHODS

Consecutive single-centre unilateral VATS LVRS performed from 2017 to 2022 were included. Typically, 3-5 minor resections were made using vascular magazines without buttressing. Data were obtained from an institutional database and analysed. Multivariable logistic regression was used to identify predictors of reoperation. Number and location of injuries were registered.

RESULTS

In total, 191 patients were included, 25 were reoperated (13%). In 21 patients, the indication for reoperation was substantial air leak, 3 patients bleeding and 1 patient empyema. Length of stay (LOS) was 21 (11-33) vs. 5 days (3-11), respectively. Only 3 injuries were in the stapler line, 13 within < 2cm and 15 injuries were in another site. Multivariable logistic regression analysis showed that decreasing DLCO increased risk of reoperation, OR 1.1 (1.03, 1.18, P = 0.005). Resections in only one lobe, compared to resections in multiple lobes, were also a risk factor OR 3.10 (1.17, 9.32, P = 0.03). Patients undergoing reoperation had significantly increased 30-day mortality, OR 5.52 (1.03, 26.69, P = 0.02).

CONCLUSIONS

Our incidence of reoperation after LVRS was 13% leading to prolonged LOS and increased 30-day mortality. Low DLCO and resections in a single lobe were significant predictors of reoperation. The air leak was usually not localized in the stapler line.

Hypoxemia After Endobronchial Valve Deployment for Persistent Air Leak

Endobronchial valves (EBVs) are a novel, minimally invasive bronchoscopic management technique for persistent air leaks that fail conservative therapy. Currently, 2 EBVs are available in the United States: the Spiration Valve System (Olympus, Redmond, WA) and the Zephyr Valve (Pulmonx, Redwood, CA). These valves are Food and Drug Administration-approved to reduce hyperinflation in emphysematous patients via bronchoscopic lung-volume reduction. However, more recently, the Spiration Valve has been granted a compassionate use exemption through the Food and Drug Administration for persistent postsurgical air leaks. Despite their popularity, these devices are not free from side effects. As an anesthesiologist, it is vital to be aware of the pathophysiology of this patient population so that safe and effective anesthetics may be provided during valve placement. Here, the use of EBVs is discussed in a patient who presented with a persistent air leak after a transthoracic needle aspiration that failed treatment due to persistent hypoxemia, warranting EBV removal.

Management of Complications Following Lung Resection

Lung resections are associated with a variety of potential postoperative complications. Not surprisingly, pulmonary complications are most frequent after lung surgery. Cardiac and thromboembolic complications are also important. It is essential that surgeons anticipate the possibility of these complications and take preventative measures whenever possible. When complications do occur, prompt recognition and treatment is required to assure optimal patient outcomes.

Intrathoracic negative pressure therapy and/or endobronchial valve for pleural empyema minimal invasive management: case series of thirteen patients and review of the literature

Introduction

Intrathoracic negative pressure therapy is an adjunct to standard methods of complex empyema management in debilitated patients. Nevertheless, the use of endoscopic one-way endobronchial valves to successfully close large bronchopleural fistulas in patients with advanced pleural empyema has been described in only a few case reports.

Aim

To present our experience in managing complex pleural empyema using thoracostomy with intrathoracic negative pressure therapy and/or endobronchial valve implantation.

Material and methods

We retrospectively analyzed data from 13 consecutive patients (11 men, mean age: 56 years, range: 38–80 years) who were treated for pleural empyema using thoracostomy with intrathoracic negative pressure therapy and/or endobronchial valve implantation between October 2015 and November 2017.

Results

The control of empyema was satisfactory in 12 patients; however, 1 patient died from sepsis-related multiorgan failure despite complete cessation of air leak on day 9 after endobronchial valve implantation. The overall success rate for the final closure of the chest wall was 9/12 patients (75%): in 5 patients, the wall closed spontaneously, and in 4, the wall was closed using thoracomyoplasty.

Conclusions

Thoracostomy with intrathoracic negative pressure therapy, endobronchial valve implantation with tube drainage, and a combination of the two could adequately manage patients with pleural empyema with or without a persistent air leakage fistula.

Management of air leaks post-surgical lung resection

Airleaks are one of the most common complications associated with elective lung resection. There have been many techniques and modern advancements in thoracic surgery, however airleaks persist. This review article will discuss several interventions ranging from conservative noninvasive to surgical management of the persistent airleak. These techniques include stopping of suction on the plueravac, fibrin patches, pleurodesis, use of endobronchial valves (EBVs), return to OR for operative intervention, and lastly to send patients home with mini pleuravacs.

An Innovative Solution for Prolonged Air Leaks: The Customized Endobronchial Silicone Blocker

BACKGROUND

Prolonged air leak (PAL) is a life-threatening condition that can present either as bronchopleural fistula, or alveolar-pleural fistula (APF). Although numerous bronchoscopic treatments are described, they are either expensive, not widely available in the developing world or have limited success. We describe our experience with a novel customized endobronchial silicone blocker (CESB) for PAL treatment.

METHODS

This is a retrospective study of PAL patients who underwent CESB placement. The air leak was localized using a balloon occlusion test. The CESB was uniquely designed by molding silicone stent pieces into a conical shape, deployed with rigid bronchoscopy into the appropriate segment, and reinforced with cyanoacrylate glue to prevent migration. In patients with APF, pleurodesis was performed after leak resolution to prevent recurrence. Following this, the CESB was removed after 6 weeks.

RESULTS

Forty-nine CESBs were placed in 31 patients (25 male individuals, 6 female individuals) with mean age of 49.7±19.7 years. The PALs included APF (n=16), bronchopleural fistula (n=14), and airway-mediastinal fistula (n=1). The average diameter of the CESB used was 7.9±2.9 mm. There was resolution of the PAL in 26 of 31 patients (84%). The CESB migrated in 5 patients with no adverse events. Pleurodesis was performed in 13 of 16 patients with APF, to prevent recurrence. No other significant complications were observed.

CONCLUSIONS

CESBs represent a safe, effective, and innovative approach in the management of PAL. They should be considered in patients who are not surgical candidates, fail surgery, or those who have a recurrence following surgery.

The Clinical Significance of Collateral Ventilation

Oxygen delivery and carbon dioxide removal being critical to cell survival, mammals have developed collateral vascular and ventilation systems to ensure tissue viability. Collateral ventilation, defined as ventilation of alveoli via pathways that bypass normal airways, is present in humans and many other species. The presence of collateral ventilation can be beneficial in certain disease states, whereas its relative absence can predispose to other diseases. These well defined anatomical pathways contribute little to ventilation in normal humans, but modulate ventilation perfusion imbalance in a variety of diseases, including obstructive diseases, such as asthma and emphysema. These pathways can be affected by pharmaceuticals and inhaled gas compositions. The middle lobe and lingula, constrained by their isolated, segmental anatomy, have reduced collateral ventilation, which predisposes them to disease. Recently, attempts to improve the quality of life of patients with emphysema, by performing nonsurgical lung volume reduction via use of endobronchial valves, have led to mixed results, because the role of collateral ventilation in the success or failure of the procedure was not initially appreciated. This review describes the anatomical pathways of collateral ventilation, their physiology and relationship to disease states, their modulatory effects on gas exchange, treatment considerations, and their effect on diagnostic procedures.

Endobronchial one-way valves for treatment of persistent air leaks: a systematic review

Persistent air leak (PAL) is associated with significant morbidity and mortality, prolonged hospitalization and increased health-care costs. It can arise from a number of conditions, including pneumothorax, necrotizing infection, trauma, malignancies, procedural interventions and complications after thoracic surgery. Numerous therapeutic options, including noninvasive and invasive techniques, are available to treat PALs. Recently, endobronchial one-way valves have been used to treat PAL. We conducted a systematic review based on studies retrieved from PubMed, EMbase and Cochrane library. We also did a hand-search in the bibliographies of relevant articles for additional studies. 34 case reports and 10 case series comprising 208 patients were included in our review. Only 4 patients were children, most of the patients were males. The most common underlying disease was COPD, emphysema and cancer. The most remarkable cause was pneumothorax. The upper lobes were the most frequent locations of air leaks. Complete resolution was gained within less than 24 h in majority of patients. Complications were migration or expectoration of valves, moderate oxygen desaturation and infection of related lung. No death related to endobronchial one-way valves implantation has been found. The use of endobronchial one-way valve adds to the armamentarium for non-invasive treatments of challenging PAL, especially those with difficulties of anesthesia, poor condition and high morbidity. Nevertheless, prospective randomized control trials with large sample should be needed to further evaluate the effects and safety of endobronchial one-way valve implantation in the treatment of PAL.

Persistent air leak after pulmonary transplantation

A 59-year-old man with bilateral apical emphysema underwent a double lung transplant for end-stagechronic obstructive pulmonary disease leaving remnant right apical native tissue due to pleural adhesions. Initial postoperative course was uneventful until the chest drains were removed. This revealed a small pneumomediastinum, which progressively increased in size causing gross surgical emphysema. Re-insertion of the chest drain stabilised the patient so that the cause could be identified and corrected. Two bronchoscopies excluded anastomotic dehiscence as a cause. Therefore the subcostal wound was refashioned under video-assisted thoracoscopic surgery in case there was a defect. Unfortunately this also failed to halt the air leak; therefore another cause was sought. A multidisciplinary team meeting review of the radiology revealed that the patient's native bullous tissue was still inflated. Subsequent bronchoscopy revealed a native bronchial communication, due to variant anatomy, proximal to the surgical anastomosis. This was subsequently occluded using a bronchial valve allowing the patient to make a swift recovery.

Bronchopleural Fistula Resolution with Endobronchial Valve Placement and Liberation from Mechanical Ventilation in Acute Respiratory Distress Syndrome: A Case Series

Patients who have acute respiratory distress syndrome (ARDS) with persistent air leaks have worse outcomes. Endobronchial valves (EBV) are frequently deployed after pulmonary resection in noncritically ill patients to reduce and eliminate bronchopleural fistulas (BPFs) with persistent air leak (PAL). Information regarding EBV placement in mechanically ventilated patients with ARDS and high volume persistent air leaks is rare and limited to case reports. We describe three cases where EBV placement facilitated endotracheal extubation in patients with severe respiratory failure on prolonged mechanical ventilation with BPFs. In each case, EBV placement led to immediate resolution of PAL. We believe endobronchial valve placement is a safe method treating persistent air leak with severe respiratory failure and may reduce days on mechanical ventilation.

[Absence of postoperative pulmonary impermeability in patients with spontaneous pneumothorax]

AIM

to improve treatment of patients with spontaneous pneumothorax who had not postoperative pulmonary impermeability.

MATERIAL AND METHODS

87 patients with spontaneous pneumothorax underwent videothoracoscopy (VTS), lung resection supplemented by pleurodesis (parietal pleurectomy or pleural abrasion). Absence of pulmonary impermeability was observed in 5 (5.7%) patients.

RESULTS AND DISCUSSION

Re-operation was performed in 2 patients (Vanderschuren 2 and 3) namely re-thoracoscopy and thoracotomy with additional ligation of air origins. Drainage tubes were removed in 4 and 17 days postoperatively in patient without/with emphysema respectively. In patient (Vanderschuren 1) who underwent thoracoscopic resection and parietal pleural abrasion valve bronchoblocation was performed in 9 days after VTS due to persistent pneumothorax. Pleural drainage tube was removed in 13 days (emphysema) after bronchial valve deployment. 2 patients (Vanderschuren 4) had heterogeneous pulmonary emphysema. One of them underwent video-assisted mini-thoracotomy, lung resection with reinforcement of seams with synthetic material. In other observation conversion to thoracotomy followed by atypical resection of bullous emphysema and manual suturing of lung was applied. In both cases bronchoblocation was performed intraoperatively with good results. Drainage tubes were removed in 13 and 17 days respectively. There were no complications.

CONCLUSION

Intraoperative endoscopic bronchoblocation is advisable if air leakage is considerable in operating theater and complicates lung smoothing. Such approach reduces hospital-stay and improves outcomes.