From the Guidelines
Catamenial pneumothorax is primarily characterized by the presence of endometrial tissue implants on the diaphragm or pleural surfaces, which respond to hormonal fluctuations during the menstrual cycle, leading to small perforations in the diaphragm and air leakage into the pleural space. The pathophysiology of catamenial pneumothorax involves a complex interplay of hormonal and anatomical factors, as described in the British Thoracic Society guideline for pleural disease 1. The condition typically presents with chest pain, dyspnoea, and haemoptysis occurring within 72 hours before or after menstruation in young women.
Key Mechanisms
- The most accepted theory is that of aspiration of air from the abdomen and genital tract via the diaphragmatic fenestrations, which are often found on the pleural diaphragmatic surface at thoracoscopy 1.
- The appearance of endometrial deposits on the visceral pleural surface raises the possibility that erosion of the visceral pleura might be an alternative mechanism 1.
- The condition is often associated with pelvic endometriosis, and patients typically have a history of recurrent pneumothoraces, with the associated pneumothorax usually being right-sided 1.
Clinical Considerations
- The true incidence of catamenial pneumothorax is unknown, but it may be relatively underdiagnosed, and should be suspected in female patients who have recurrent pneumothoraces 1.
- Management of catamenial pneumothorax should be multidisciplinary and include hormonal treatment or surgery by VATS, with medical therapy to achieve ovarian rest often advocated in the postoperative period 1.
- Understanding the pathophysiology of catamenial pneumothorax is crucial for proper management, which typically involves hormonal therapy to suppress menstruation, combined with surgical approaches to address diaphragmatic defects when necessary.
From the Research
Pathophysiology of Catamenial Pneumothorax
- Catamenial pneumothorax (CP) is defined as a recurrent spontaneous pneumothorax occurring in females of reproductive age, typically within 72 hours before or after the onset of menstruation 2, 3, 4, 5.
- The exact etiology of CP is unknown, but it is often associated with thoracic endometriosis, which can cause pneumothorax during the intermenstrual period (TER non-CP) 2.
- Diaphragmatic defects, such as fenestrations, are commonly found in patients with CP and are thought to contribute to the development of pneumothorax 3, 4.
- The pathophysiology of CP is not fully understood, but it is believed to involve the cyclical growth and regression of endometrial tissue in the thorax, leading to the formation of diaphragmatic defects and the subsequent development of pneumothorax 2, 5.
Clinical Presentation and Diagnosis
- The clinical presentation of CP is often nonspecific, with symptoms such as chest pain and shortness of breath 2, 3.
- Imaging studies, such as computed tomography (CT) scans and magnetic resonance imaging (MRI), may show evidence of endometriosis or diaphragmatic lesions, but these findings are not always present 2, 3.
- A thorough menstrual history and temporal relation to pneumothorax onset should be assessed in every woman presenting with recurrent pneumothorax, and intraoperative exploration of the diaphragmatic surface should be performed in patients with high suspicion of CP 3.
Treatment and Management
- Surgical treatment, including diaphragmatic plication and resection of visible endometriosis-related lesions, is often effective in managing CP 2, 3, 4, 5.
- Hormonal therapy, such as hormonal blockade, may also be effective in sustaining the effects of surgical treatment and preventing recurrence 2, 5.
- Talc pleurodesis and other forms of chemical pleurodesis may also be used to prevent recurrence 2, 3.