Invasive pulmonary fungal infection (IPFI) refers to bronchopulmonary infections caused by fungi, involving invasion of the trachea, bronchi, and lungs. This condition leads to airway mucosal inflammation and pulmonary granulomas, and in severe cases, results in necrotizing pneumonia. It excludes bronchopulmonary changes caused by fungal colonization or fungal-induced allergic reactions.
Fungi are classified into pathogenic fungi and opportunistic fungi based on their pathogenicity. Pathogenic fungi include Histoplasma, Coccidioides, Paracoccidioides, and Sporothrix species, which primarily cause exogenous infections. These fungi exhibit specific geographic distributions and can infect hosts with normal immune functions.
Opportunistic fungi, including Candida, Aspergillus, Cryptococcus, and Mucor species, are responsible for most cases of IPFI. These fungi are not typically pathogenic or exhibit low pathogenicity but can cause fungal lung infections in individuals with compromised immunity. Clinically, opportunistic fungal infections are the most common type of IPFI, often associated with significant underlying conditions such as chronic obstructive pulmonary disease (COPD), tuberculosis, malignancies, HIV infection, AIDS, organ transplantation, diabetes, and prolonged ICU stays.
In recent years, the incidence of IPFI has been increasing, largely as a result of the extensive use of broad-spectrum antibiotics, cancer therapies, glucocorticoids, and immunosuppressive agents, as well as the rise in organ transplantation and the prevalence of immunodeficiency diseases such as AIDS. IPFI has become a significant cause of mortality in organ transplant recipients, cancer patients, individuals with immunodeficiency diseases, and critically ill patients. Although the use of modern broad-spectrum antifungal drugs has improved treatment outcomes, localized IPFI may still require combined surgical and pharmacological therapy in some cases during the course of standard treatment.
Indications
Indications for surgery include:
- Lesions that are localized but show no significant improvement after 3 to 6 months of standardized antifungal treatment, or cases in which the disease progresses, forming lung abscesses or cavities.
- Pulmonary lesions that cannot be definitively diagnosed and cannot be differentiated from lung tumors or tuberculosis.
- Conditions involving the pleura or chest wall, such as empyema, chest wall abscesses, or fistulas, which necessitate surgical drainage or debridement.
- Recurrent respiratory symptoms such as hemoptysis or blood-streaked sputum, which are unresponsive to pharmacological treatment.
- Pulmonary lesions located near major blood vessels, where surgical resection is necessary to prevent massive hemoptysis.
- Prevention of recurrence of pulmonary lesions prior to chemotherapy in patients with hematologic malignancies.
Surgical Approaches
Patients with IPFI often have a prolonged disease course and may present with other comorbidities such as diabetes or hematologic diseases, along with compromised immune function. Preoperative assessment of the patient’s overall condition, along with appropriate preoperative treatment, is critical.
Surgical approaches are determined by the location and extent of the lesions and may include wedge resection, segmentectomy, lobectomy, or even pneumonectomy. For cases involving the pleura or chest wall, drainage or expanded excision is performed. For chest wall fistulas, debridement is indicated.
Postoperative Complications and Management
The main postoperative complications include empyema, bronchopleural fistula, recurrence, pulmonary infection, and incision site infections. The incidence and mortality of these complications are higher in IPFI surgeries compared to standard pulmonary resections.
Preventive measures during the perioperative period include the administration of antifungal drugs and appropriate antibiotics, strict adherence to aseptic surgical techniques, and careful management of bronchial stumps. Postoperative measures include maintaining clear respiratory and thoracic drainage pathways to facilitate early and full re-expansion of the remaining lung. Rigorous oral hygiene is also recommended. These measures are essential for reducing and preventing postoperative complications.