Bronchoscopy-Guided Placement of Petrolatum Gauze For Closure of Peripheral Bronchopleural Fistula in Humans

Summary

This protocol describes bronchoscopy-guided petrolatum gauze implantation as a minimally invasive, cost-effective endobronchial occlusion method to close peripheral bronchopleural fistulas in patients (≤5 mm) who are not candidates for surgical repair.

Abstract

Bronchopleural fistula (BPF), defined as a pathological communication between the bronchial airways and the pleural space, carries high mortality (18%–50%) due to complications like infection and respiratory failure. Current treatments, including conservative management and invasive surgery, face limitations such as variable efficacy, high trauma, and inapplicability to high-risk patients. An innovative bronchoscopy-guided petrolatum gauze occlusion protocol provides a minimally invasive, cost-effective solution for patients with small to medium-sized bronchopleural fistulas (≤5 mm) who are not candidates for surgery. Key steps included precise fistula localization via. methylene blue dilution injection, tailored gauze sizing, and bronchoscopic placement under direct visualization. Stability was ensured through forceps-guided positioning or supplemental metal stents in anatomically challenging cases. Post-procedure monitoring included chest X-ray, CT imaging, and clinical assessments at 1 day, 1 week, and 1 month. In a retrospective study of 19 patients with peripheral BPFs ≤ 5 mm who met predefined inclusion criteria (e.g., failed prior conservative therapy, high surgical risk) and exclusion criteria (e.g., untreated empyema, fistulas involving central airways), petrolatum gauze occlusion achieved 94.7% efficacy (18/19) at one week, with a low infection rate (15.8%). The observed efficacy, while promising, should be interpreted within the context of the study's limitations, including its small sample size (n = 19), single-center retrospective design, and potential for selection bias. Consequently, the generalizability of these findings to broader patient populations or other institutional settings may be limited. This cost-effective, adaptable technique demonstrates high success in sealing small-to-medium fistulas (≤5 mm), offering a safe alternative for high-risk populations, particularly in resource-limited settings. This article describes in detail the indications for this method, preoperative evaluation, intraoperative manipulation, and postoperative testing.

Introduction

Bronchopleural fistula (BPF) represents an aberrant communication between the pleural space and the bronchial system. Surgical interventions, particularly lobectomy and pneumonectomy, constitute the predominant etiological factors, with reported incidence rates of 0.4% and 1.9% respectively¹ and case-fatality rates ranging from 18% to 50%². Additional pathogenic contributors include infection, secondary to chemotherapy or radiotherapy-related impairments in lung cancer, refractory spontaneous pneumothorax, and, less frequently, mycobacterial tuberculosis infection³. Early detection and effective management of the fistula are the critical determinants of prognosis.

The management of BPF encompasses three principal therapeutic modalities: conservative management, which generally applied in post-lobectomy bronchopleural fistulas with small residual cavities and decreasing air leaks⁴ by avoiding surgery, whereas post-pneumonectomy fistulas exhibit substantially lower closure rates (approximately 30%)^5,6; Surgical repair is the primary treatment for post-pneumonectomy BPFs >8 mm^7,8, achieving anatomical closure^9,10, but risks include flap dehiscence, recurrent fistula formation, thoracic cage deformity, and significant cardiopulmonary compromise in patients with preexisting functional limitations; Lastly, endobronchial occlusion has emerged as a minimally invasive paradigm for peripheral fistulas originating from subsegmental bronchiolar or alveolar sources¹¹, utilizing bronchoscopic modalities such as deployable stents, embolization coils and bioadhesive sealant. These techniques demonstrate clinical efficacy in fistulas <8 mm or high-risk surgical candidates, while some studies suggest clinical efficacy in fistulas <8 mm¹², the optimal size threshold remains debated. In this approach, fistulas ≤5 mm are specifically targeted for petrolatum gauze occlusion, as smaller fistulas are more amenable to complete sealing with this technique. This cutoff is consistent with the inclusion criteria used in the retrospective study. Stent placement, while effective for fistulas >3 mm, is associated with a risk of migration. In one study, dislocation occurred in 2 of 6 patients (33%) with covered metallic stents¹². Other bronchoscopic techniques, such as coil embolization and Amplatzer devices, have been reported for BPF closure. Coils are primarily used for small fistulas (<5 mm) but carry a risk of displacement, particularly during coughing, and often require adjunctive use of occlusive agents. Amplatzer devices, though originally designed for cardiac defects, have been used off-label for BPF closure with reported success rates up to 95%, but their effectiveness depends on correct sizing, and complications such as device displacement, infection, and airway obstruction have been documented¹³. Bioadhesive sealants such as fibrin glue have been used for BPF closure, but may require multiple applications in complex cases, particularly when infection is present¹⁴. This study demonstrated a novel interventional technique, petrolatum gauze occlusion, designed to achieve reliable fistula closure through bronchoscopic deployment. This method was developed to address the limitations of existing endobronchial approaches (e.g., material migration, inflammatory reactions, and costs) by leveraging the unique properties of petrolatum gauze: its mechanical stability, hydrophobic anti-adhesion surface, and biocompatibility enable atraumatic, cost-effective sealing of small-to-moderate bronchial defects while minimizing tissue irritation^12,15.

Protocol

This study complied with the amended Declaration of Helsinki and was approved by the local independent ethics committees (Approval Number: EC.D(BG)025.04.0). All patients provided written informed consent for the off-label application of occlusive materials. The reagents and the equipment used are listed in the Table of Materials.

1. Inclusion criteria

1. Diagnose patients with BPF based on medical history, clinical presentation, radiological features, and endobronchial examination¹⁶, as mentioned below:
   1. Fistulas ≤5 mm in diameter located at or distal to the segmental bronchi (segmental, subsegmental, or more peripheral airways) where direct surgical repair or complex interventions like stent placement are technically challenging or unnecessary due to size, location, or patient factors.
   2. Post-lobectomy patients with fistulas in segmental or more distal bronchi, or post-pneumonectomy patients with localized proximal main bronchial stump fistulas that do not involve the carina or other central airways.
   3. Patients with compromised cardiopulmonary function, advanced age, or comorbidities (e.g., uncontrolled diabetes, immunocompromised states) who cannot tolerate extensive surgical procedures.
   4. Persistent BPF despite adequate thoracic drainage, antibiotics, or fibrin glue sealing. Recurrent air leaks or empyema refractory to standard therapies, necessitating mechanical occlusion to stabilize the pleural space.
   5. Temporary stabilization of the fistula to control infection and improve patient condition prior to definitive surgical repair (e.g., muscle flap transposition)

2. Exclusion criteria

1. Consider the following exclusion criteria as mentioned below:
   1. Fistulas >5 mm in diameter or those involving central airways (trachea, main carina, or main bronchi), due to higher risk of dislodgment and inadequate sealing with this technique, which require surgical closure (e.g., stapling, flap coverage) or stent placement due to higher risk of dislodgment and inadequate sealing.
   2. Presence of untreated empyema, necrotizing pneumonia, or sepsis, as packing may trap infected material and exacerbate systemic inflammation.
   3. Fistulas adjacent to major vascular structures or with extensive tissue necrosis, where mechanical packing risks vascular injury or incomplete sealing.
   4. Patients with uncorrected coagulopathy (e.g., platelet dysfunction, anticoagulant use) due to heightened bleeding risk during packing placement.
   5. Severe airway stenosis or obstruction.
   6. History of allergy to petrolatum or blocking materials.
   7. Pregnancy or inability to co-operate with the operation. Inability to adhere to postoperative care (e.g., chest tube management, follow-up bronchoscopy), which is critical for monitoring packing efficacy and preventing complications.

3. Procedure

1. Patient preparation
   1. Perform preoperative examinations, including high-resolution CT (HRCT) (enhanced chest CT if necessary); electrocardiogram, echocardiogram, pulmonary function tests; routine blood count, coagulation function, C-reactive protein (CRP), Procalcitonin (PCT), liver and kidney function; screening for sexually transmitted diseases, including HIV infection, hepatitis B, hepatitis C, and syphilis.
   2. Communicate with the participants about the necessity, benefits, and potential risks of surgery, and obtain the signed informed consent form from patients and families. Emphasize the need for close monitoring of chest drainage and respiratory status after surgery.
   3. Maintain NPO status 8 h preoperatively.
2. Equipment preparation
   CAUTION: Ensure all emergency airway equipment, resuscitation drugs, and defibrillators are checked and readily accessible before starting the procedure. Confirm that methylene blue is stored properly and not expired.
   1. Prepare laryngeal masks and general anesthesia equipment.
   2. Assemble the flexible bronchoscopes, light sources for real-time navigation and archiving, high-definition imaging systems, and video-recording equipment.
      NOTE: Use a flexible therapeutic bronchoscope with a working channel diameter of 3.0 mm and an outer diameter of 6.0 mm. Utilize the rotatable deflection mechanism controlled by a lever near the control section to angle the distal tip in multiple directions, thereby expanding the range of motion and minimizing blind spots during navigation.
   3. Ensure that the petrolatum gauze, methylene blue diluent (2.0% with 1 mL concentrate: 50 mL saline), sterile saline, sterile towel packs, hemostatic agents, syringes, and forceps are ready.
   4. Ensure that pulse oximeter, non-invasive blood pressure monitor, defibrillator, endotracheal intubation set, and emergency drugs (adrenaline, atropine) are accessible for immediate use by trained personnel per ACLS protocols.
3. Procedural steps
   1. Place the patient in the supine position.
   2. Administer general anesthesia via .laryngeal mask intubation by a qualified anesthesiologist.
   3. Continuously monitor vital signs (including ECG, SpO₂, blood pressure, and end-tidal CO₂).
   4. Ensure immediate access to emergency airway equipment and resuscitation equipment.
   5. Place the chest tube under CT or ultrasound guidance in areas where air leakage is routinely detected, in order to assess the severity of the fistula by monitoring air leakage and to help locate the fistula more precisely under bronchoscopy.
   6. Confirm the patient has no allergy to methylene blue and is not taking any serotonergic drugs (to avoid serotonin syndrome), then typically inject 20 mL of the diluted 2.0% methylene blue solution (prepared by mixing 1 mL concentrate with 50 mL saline) retrograde through the chest tube.
   7. Observe dye exudation through the bronchoscope to pinpoint the fistula location, noting potential pulse oximetry interference during administration (Figure 1A).
      NOTE: Before injection, confirm chest tube patency and infuse slowly to avoid high pressure.
      CAUTION: Use only diluted methylene blue (2.0%, 1 mL concentrate in 50 mL saline). Inject exclusively through the chest tube in the reverse direction. Confirm no allergy and exclude concurrent serotonergic drug use. Monitor for transient pulse oximetry interference.
   8. Determine the size of the fistula based on preoperative CT scan images, endobronchial observation, and indirectly by the leakage volume of methylene blue dye.
   9. Cut the petrolatum gauze to a length of approximately 12 cm and a width of 3 cm using a blade, then fold it into a tapered cone shape (conical configuration), facilitating the deployment through the working channel of the bronchoscope (Figure 1D).
      NOTE: For fistulas distal to subsegmental airways that are not directly visible, occlude the proximal subsegmental bronchus indicated by methylene blue effusion.
      CAUTION: Use strict aseptic technique when handling petrolatum gauze. Cut and fold the gauze on a sterile field using sterile instruments to prevent contamination and reduce infection risk.
   10. Insert a grasping forceps through the working channel of the bronchoscope and grasp the tip of the cone to preserve visualization. Under bronchoscopic guidance, advance the gauze into the target bronchus where the fistula is located. Subsequently, place additional layers of gauze sequentially until the fistula is completely sealed (Figure 1B).
       NOTE: During placement, ensure that the petrolatum gauze covers the fistula completely and fits snugly into the surrounding tissue to achieve a good seal.
       CAUTION: During forceps-guided placement, avoid excessive force to prevent airway trauma or bleeding. Ensure the gauze is securely positioned to minimize the risk of migration or dislodgment.
   11. After placement, inject methylene blue dye into the chest tube again and observe for spillage from the bronchus to verify seal success.
       NOTE: Confirm successful occlusion by absence of methylene blue efflux. Dispose of all contaminated materials in biohazard containers. Place sharps (needles, syringes, blades) in puncture-resistant sharps containers immediately. Segregate and discard residual solutions and consumables as regulated biohazardous waste.
       CAUTION: Dispose of all contaminated materials (syringes, gauze, gloves) in designated biohazard containers. Immediately place sharps in puncture-resistant sharps containers. Follow institutional protocols for hazardous waste management.
   12. Perform the following substeps for patients with suspected multifocal fistulas, persistent air leak despite single-site occlusion, and diffuse methylene blue efflux.
       1. After initial occlusion, reinject the methylene blue diluted solution (2.0% with 1 mL concentrate: 50 mL saline) through the chest tube in the reverse direction.
       2. Observe bronchoscopically for dye exudation in other segmental or subsegmental bronchi to identify additional fistulas.
       3. If methylene blue dye is visualized in other bronchi, repeat the occlusion procedure (Steps 3.3.8–3.3.10) for each newly identified fistula.
       4. Reassess by repeating Steps 3.3.12.1–3.3.12.2 until no further dye exudation is observed.
       5. Verify complete occlusion by confirming absence of air leakage from the chest tube and absence of methylene blue efflux from all bronchial segments.
   13. If gauze dislodgment is suspected, perform bronchoscopy promptly to retrieve the gauze and reassess the fistula. Replace a new gauze with appropriate sizing and consider temporary metal stent placement in anatomically challenging cases.
   14. Postoperatively, closely observe the patient's vital signs and clinical symptoms, such as dyspnea, cough, accelerated heart rate, fever and chest pain, etc., so as to promptly detect and deal with possible complications.
       CAUTION: Monitor closely for signs of respiratory distress, hypoxia, fever, or chest pain, which may indicate complications such as infection, pneumothorax, or material migration. Keep emergency airway equipment accessible at the bedside during the immediate postoperative period.
   15. Perform a bedside chest X-ray on the first postoperative day and a chest CT at the end of the first postoperative week to assess the effectiveness of the blockage and the presence of complications such as pulmonary atelectasis, material migration, and infection.
       NOTE: Performed immediately if patients develop acute respiratory distress, sudden increase in air leak, fever, or hemodynamic instability, suggesting pneumothorax, infection, or material migration. If occlusion is incomplete or complications are suspected, repeat bronchoscopy or CT is performed earlier than scheduled. 
   16. Follow up with the patient 1 month after the procedure, including evaluation of clinical symptoms, laboratory tests (complete blood count, CRP, PCT), and CT imaging to monitor the progress of fistula healing and to detect potential complications such as granulation tissue, persistent air leak, or infection (Figure 1C).
   17. If clinical and imaging findings are favorable, perform a second bronchoscopy to remove the gauze and visually confirm complete fistula closure.
       NOTE: “Favorable conditions” mean “Resolution of clinical symptoms (e.g., no cough, dyspnea, or fever); No air leakage from the chest tube at discharge or chest tube had been removed during the follow-up visit; Absence of subcutaneous emphysema; Chest CT confirming fistula closure and no complications”. During this repeated bronchoscopy, the gauze is gently removed using grasping forceps under direct visualization, and the fistula site is inspected to confirm complete healing. If healing is incomplete, the gauze may be left in place longer.

4. Common complications

1. Observe cough with or without sputum production, fever, irritation, and foreign body sensation during breathing.
2. Monitor for obstructive pneumonia, atelectasis, displacement of petrolatum gauze, bleeding, and infection.
3. Assess for residual fistula or incomplete closure, pneumothorax, or pneumomediastinum.
4. Identify signs of asphyxia, cardiovascular accidents, and other unpredictable complications.

5. Troubleshooting of common procedural issues

1. Occlusion failure
   1. If initial occlusion fails, re-evaluate the fistula size and shape using methylene blue dilution injection and bronchoscopic visualization.
   2. Trim and fold a new petrolatum gauze to a size slightly larger than the fistula, ensuring it can adapt to the fistula’s irregularities.
   3. Gently insert the gauze under bronchoscopic guidance, using forceps to manipulate it until it fits snugly and fills any gaps.
   4. Apply gentle but firm pressure with the forceps to secure the gauze, ensuring complete coverage; consider using additional layers or combining with fibrin glue if needed.
2. Dislodged gauze
   1. If the gauze becomes dislodged, promptly perform bronchoscopy to locate and remove the dislodged gauze using forceps.
   2. Reassess the fistula site and surrounding airway anatomy to identify potential causes of dislodgment.
   3. Re-prepare and insert the petrolatum gauze, paying close attention to proper placement and secure fixation.
   4. Consider using a temporary metal stent (position proximal segment in bronchial lumen, distal segment in pleural space, and center waist across fistula orifice) adjacent to the gauze for additional support in anatomically challenging cases and advise the patient to avoid vigorous coughing.
      CAUTION: Perform temporary metal stent placement only if the operator is an experienced bronchoscopist. Confirm stent size and position to avoid airway perforation or migration. Monitor for stent-related complications, such as granulation tissue formation or mucosal injury.
3. Postoperative complications
   1. For complications like cough, fever, or foreign body sensation, monitor vital signs and symptoms, and perform chest X-ray and CT to assess for issues such as infection or atelectasis.
   2. Administer empiric antibiotics based on the patient’s condition and microbial culture results.
   3. Use bronchoscopic techniques to clear secretions if obstructive pneumonia or atelectasis is identified.
   4. For severe complications like pneumothorax, provide appropriate medical or surgical interventions based on severity and clinical status.

6. Outcome assessment

1. Define outcome measures as demonstrated in Table 1.
2. Define complete resolution¹⁷ as closure of all related bronchial segments with significant improvement in clinical symptoms, including shortness of breath and subcutaneous emphysema, and absence of air leakage from the closed chest drainage system. Confirm that no complications occur during the hospital stay.
3. Define partial resolution as the presence of a residual fistula lesion, partially relieved symptoms, and/or complications such as atelectasis, infection, or dislocation of materials.
4. Define ineffectiveness as failure of fistula closure and absence of symptomatic improvement.
5. Classify complete and partial resolution as effective outcomes¹².

Results

Retrospectively, 19 patients (10 males, 9 females; mean age 46.9 years ± 19.46 years) diagnosed with bronchopleural fistulae (BPFs) who were not suitable for surgical repair and underwent endobronchial closure with petrolatum gauze occlusion in the Endobronchial Intervention Center of Shanghai East Hospital from May 2018 to May 2024 were included (Table 2). The results showed that the overall effective rate on postoperative day 1 was 94.7% (18/19), of which 9 cases (47.4%) were completely cured, 9 cases ...

Discussion

The success of petrolatum gauze occlusion for the treatment of peripheral BPFs relies on meticulous execution of key steps. Firstly, the precise location of the fistula by retrograde injection of methylene blue dilution through the chest tube is essential to identify the culprit subsegmental bronchus. This technique is particularly valuable when the fistula orifice itself is not directly visible under bronchoscopy, as the dye efflux pinpoints the responsible airway segment. Second, gauze preparation (cut and folded into ...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bronchoscopy equipment	Olympus Evis Lucera Elite	CV-290,CV-290SL
Carescape monitor	GE Healthcare Finland 0y	YZB/FIN 3498-2014
General anesthesia equipment	Dräger Medical GmbH	8606000-66
Laryngeal masks	TuoRen Medical	(21)000075 (91)001
Single-use  biopsy forceps	Changmei Medtech	FB-12C-B1
Underwater seal drainage (UWSD)	Tiantai County Kangsheng Medical	YY0583 sanqiang-1500
Ventilator	Mindray	SV350	2.8mm inner diameter