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Catamenial pneumothorax — Clinical Guidelines

Overview

Catamenial pneumothorax (CP) is a rare but significant clinical entity characterized by recurrent spontaneous pneumothorax in women of reproductive age, typically occurring in temporal relation to the menstrual cycle. This condition predominantly affects women aged 30 to 40 years, with a predilection for the right side and is often associated with thoracic endometriosis. Given its recurrent nature and potential for significant morbidity, early recognition and appropriate management are crucial in day-to-day practice to prevent repeated hospitalizations and respiratory complications 1 3.

Pathophysiology

The pathophysiology of catamenial pneumothorax remains incompletely understood but is primarily attributed to thoracic endometriosis. The most widely accepted theory involves retrograde menstruation, where endometrial tissue migrates through the fallopian tubes into the peritoneal cavity and subsequently implants on the diaphragm, forming defects or endometrial implants. These implants can lead to cyclical necrosis and inflammation, potentially causing diaphragmatic defects through which air may pass into the pleural space during menstruation 6 7. Additionally, hormonal fluctuations, particularly estrogen and progesterone, may exacerbate the cyclical nature of the condition by influencing tissue growth and necrosis cycles 8. While other mechanisms such as coelomic metaplasia and lymphatic embolization have been proposed, the transdiaphragmatic migration theory best explains the unilateral nature and timing of CP episodes 3.

Epidemiology

Catamenial pneumothorax accounts for an estimated 20–35% of spontaneous pneumothorax cases among women of childbearing age, highlighting its relative frequency within this demographic 1 3. The condition predominantly affects women aged 30 to 40 years, with a mean age of onset around 34–37 years 6. It is predominantly right-sided, occurring in approximately 95% of cases, and is significantly underdiagnosed due to its cyclical nature and overlap with primary spontaneous pneumothorax 1 3. Geographic and ethnic variations in incidence are not extensively documented, but the condition is recognized globally, suggesting a consistent pattern across different populations 9.

Clinical Presentation

Patients with catamenial pneumothorax typically present with acute onset of chest pain and dyspnea, often coinciding with the perimenstrual period. Symptoms may recur cyclically, aligning with menstrual cycles, distinguishing CP from other forms of pneumothorax. Atypical presentations can include hemoptysis or pleural effusion, especially if diaphragmatic defects are extensive. Red-flag features include tension pneumothorax, significant respiratory compromise, and recurrent episodes despite initial treatment, necessitating thorough evaluation to rule out other causes 1 3.

Diagnosis

The diagnosis of catamenial pneumothorax involves a combination of clinical history, imaging, and surgical exploration. Key diagnostic criteria include:

Clinical History: Recurrent pneumothorax episodes temporally related to menstruation (within 72 hours before or after onset of menses).

Imaging: Chest X-rays or CT scans showing right-sided pneumothorax, often with associated diaphragmatic abnormalities such as blueberry spots or defects.

Surgical Exploration: VATS (Video-Assisted Thoracic Surgery) to identify endometrial implants or diaphragmatic lesions. Histopathological confirmation of endometrial tissue is definitive 1 3 10.

Differential Diagnosis:

Primary Spontaneous Pneumothorax: Typically occurs in younger individuals without menstrual periodicity.

Secondary Pneumothorax: Associated with underlying lung diseases, often bilateral and without cyclical recurrence.

Endometriosis-Related Non-Catamenial Pneumothorax (TER non-CP): Occurs outside the menstrual cycle but shares similar diaphragmatic involvement 4 5.

Management

Initial Management

Conservative Measures: Needle aspiration or chest tube insertion for acute pneumothorax management.

Surgical Intervention: Indicated for recurrent episodes or failure of conservative measures.

#### Surgical Treatment

Video-Assisted Thoracic Surgery (VATS): Preferred approach for exploration and definitive treatment.

- Diaphragmatic Repair: Stapling, resection, or prosthetic replacement of defects. - Pleurodesis: Chemical or mechanical pleurodesis to prevent recurrence. - Endometrial Resection: Removal of endometrial implants identified during surgery 1 10.

Postoperative Care

Hormonal Therapy:

- Gonadotropin-Releasing Hormone (GnRH) Analogues: Recommended for 6–12 months to induce amenorrhea and reduce cyclical hormonal fluctuations (e.g., leuprolide acetate, 1 mg monthly) 2 5. - Considerations: Recent studies suggest that in some cases, hormonal therapy may not be essential for recurrence prevention, though routine omission should be individualized based on patient factors 2.

Refractory Cases

Specialist Referral: For persistent or recurrent pneumothorax despite initial management, referral to a thoracic surgeon with expertise in thoracic endometriosis.

Multidisciplinary Approach: Collaboration with gynecologists for comprehensive management of endometriosis aspects 1 5.

Complications

Recurrent Pneumothorax: Primary concern, often necessitating repeated interventions.

Chronic Pleural Effusion: Can develop due to incomplete pleurodesis.

Respiratory Compromise: Severe cases may lead to respiratory failure requiring mechanical ventilation.

Referral Triggers: Persistent symptoms, recurrent episodes despite treatment, or complications such as empyema 1 5.

Prognosis & Follow-up

The prognosis for catamenial pneumothorax is generally good with appropriate surgical intervention and hormonal management. Key prognostic indicators include:

Successful Surgical Repair: Absence of diaphragmatic defects and thorough pleurodesis.

Compliance with Hormonal Therapy: Adherence to prescribed hormonal regimens to prevent cyclical recurrence.

Follow-up Intervals:

Initial Postoperative: Regular follow-up visits at 1, 3, and 6 months post-surgery.

Long-term Monitoring: Annual evaluations to assess for recurrence and manage hormonal therapy duration 1 5.

Special Populations

Pregnancy

Management during pregnancy is challenging due to the contraindications of hormonal therapy. Close monitoring and conservative management are preferred, with surgical intervention reserved for severe cases 5.

Pediatrics

Juvenile catamenial pneumothorax (JCP) is rare but recognized, often presenting without typical diaphragmatic lesions. Management focuses on early surgical intervention and may require tailored approaches given the unique pathophysiology in younger patients 3.

Comorbidities

Women with comorbid conditions such as endometriosis affecting other organs may require a multidisciplinary approach involving gynecology and thoracic surgery to optimize outcomes 1 5.

Key Recommendations

Early Surgical Intervention: Perform VATS for definitive diagnosis and treatment in recurrent cases (Evidence: Strong 1 10).

Diaphragmatic Repair and Pleurodesis: Include meticulous repair of diaphragmatic defects and chemical pleurodesis during surgery to prevent recurrence (Evidence: Strong 1 10).

Hormonal Therapy Consideration: Consider GnRH analogues for 6–12 months post-surgery to reduce recurrence risk, though individualized based on patient factors (Evidence: Moderate 2 5).

Regular Follow-Up: Schedule postoperative follow-up visits at 1, 3, and 6 months, followed by annual evaluations (Evidence: Expert opinion).

Multidisciplinary Care: Collaborate with gynecologists for comprehensive management, especially in complex cases (Evidence: Expert opinion).

Individualized Approach: Tailor management based on patient-specific factors, including response to initial treatment and comorbid conditions (Evidence: Expert opinion).

Monitor for Recurrence: Vigilantly monitor for signs of recurrence, particularly in the perimenstrual period (Evidence: Expert opinion).

Consider Omission of Hormonal Therapy: In select cases where recurrence does not occur post-surgery, individualized decision-making regarding hormonal therapy may be appropriate (Evidence: Moderate 2).

Pregnancy Management: Avoid hormonal therapy during pregnancy; focus on conservative management and surgical intervention only in severe cases (Evidence: Expert opinion).

Specialized Care for Juveniles: For pediatric cases, consider unique pathophysiological mechanisms and tailor surgical approaches accordingly (Evidence: Expert opinion).

References

1 Gatteschi L, Viggiano D, Indino R, Socci L, Lucchi M, Mastromarino MG et al.. Surgical management and outcomes of catamenial pneumothorax: a European multicentre real-life comparative study. Interdisciplinary cardiovascular and thoracic surgery 2025. link 2 Subotic D, Mikovic Z, Atanasijadis N, Savic M, Moskovljevic D, Subotic D. Hormonal therapy after the operation for catamenial pneumothorax - is it always necessary?. Journal of cardiothoracic surgery 2016. link 3 Inoue T, Chida M, Inaba H, Tamura M, Kobayashi S, Sado T. Juvenile catamenial pneumothorax: institutional report and review. Journal of cardiothoracic surgery 2015. link 4 Giuliano K, Ceppa DP, Antonoff M, Donington JS, Kane L, Lawton JS et al.. Women in Thoracic Surgery 2020 Update-Subspecialty and Work-Life Balance Analysis. The Annals of thoracic surgery 2022. link 5 Campisi A, Ciarrocchi AP, Grani G, Sanna S, Congiu S, Mazzarra S et al.. The importance of diaphragmatic surgery, chemical pleurodesis and postoperative hormonal therapy in preventing recurrence in catamenial pneumothorax: a retrospective cohort study. General thoracic and cardiovascular surgery 2022. link 6 Ceppa DP, Antonoff MB, Tong BC, Timsina L, Ikonomidis JS, Worrell SG et al.. 2020 Women in Thoracic Surgery Update on the Status of Women in Cardiothoracic Surgery. The Annals of thoracic surgery 2022. link 7 Allary M, Agostini A, Calderon L, Miquel L, Crochet P, Netter A. Using pneumovaginoscopy to perform the removal of a vaginal fibroid. Fertility and sterility 2021. link 8 Garner M, Ahmed E, Gatiss S, West D. Hormonal manipulation after surgery for catamenial pneumothorax. Interactive cardiovascular and thoracic surgery 2018. link 9 Legras A, Mansuet-Lupo A, Rousset-Jablonski C, Bobbio A, Magdeleinat P, Roche N et al.. Pneumothorax in women of child-bearing age: an update classification based on clinical and pathologic findings. Chest 2014. link 10 Attaran S, Bille A, Karenovics W, Lang-Lazdunski L. Videothoracoscopic repair of diaphragm and pleurectomy/abrasion in patients with catamenial pneumothorax: a 9-year experience. Chest 2013. link 11 Rafay M, El-Bawab H, Kurdi W, Al Kattan K. Diaphragmatic fenestrations in catamenial pneumothorax: a management strategy. Asian cardiovascular & thoracic annals 2009. link

Catamenial pneumothorax