Video-assisted thoracoscopic surgery for catamenial pneumothorax: Insights from a single-centre experience

Introduction: Catamenial pneumothorax (CP) is a rare cause of recurrent spontaneous pneumothorax in women of reproductive age, typically linked to endometriosis. It usually occurs 24 h before or within 72 h of the onset of menstruation, along with hormonal changes leading to lung collapse. Patients and Methods: This retrospective study analysed the data from 11 patients who underwent video-assisted thoracoscopic surgery (VATS) for CP at a tertiary care centre from March 2012 to December 2023. Pre-operative assessment included detailed history, physical examination, imaging and haematological investigations. Surgery was performed using a three-port VATS technique and involved resection of diaphragm (all 11 patients) along with diaphragmatic plication and wedge resection of the lung in 1 patient each. This was followed by talc pleurodesis in all the patients. Post-operative care included adequate pain relief, early mobilisation, active physiotherapy and monitoring air leaks.

The mean patients’ age was 18.9 years. Seven patients had pneumothorax within 24 h before menstruation and four within 72 h after. At surgery (VATS), diaphragmatic fenestrations were found in all the patients, with five having diaphragmatic endometriosis also. One patient had multiple blebs and another one exhibited visceral pleural endometriosis. The average surgery duration was 154 min, with minimal blood loss. All patients had uneventful recovery and no recurrences were observed during a median follow-up of 54 months.

VATS is an effective, minimally invasive approach for the management of CP, with excellent surgical outcomes, shortened convalescence and no recurrence in our study.

Catamenial pneumothorax (CP) is a rare cause of recurrent spontaneous pneumothorax in women of reproductive age group without the presence of concomitant respiratory disease. The term ‘catamenial’ is derived from the Greek word for menstruation, reflecting the fact that the episodes of pneumothorax generally occur 24 h before or within 72 h of the onset of menstruation. Although considered rare, recent literature suggests that 3%–6% of spontaneous pneumothorax in women is CP.[1] The exact cause of CP is still not fully understood; however, several theories indicate the role of menstrual hormonal changes (particularly oestrogen) in onset of CP.[2-4] Oestrogen influences the pleural membrane and the diaphragm, inducing certain changes that make the lung more prone to collapse. In a number of cases, the condition is associated with the development of endometrial tissue outside the uterus, in areas such as the diaphragm or the pleura, wherein, it may lead to inflammation and rupture. Women with CP often experience recurrent episodes of pneumothorax, characterised by sharp chest pain, difficulty in breathing and a feeling of tightness in the chest.[5] These episodes particularly occur around the time of menstruation, and are therefore, an important indication for the doctors to diagnose the condition. Clinical diagnosis of CP requires a thorough imaging comprising of chest X-ray and CT scan of the chest. Treatment of this condition generally involves the management of the pneumothorax with a chest tube and surgery to prevent future relapses; however, some women may also experience the alleviation of symptoms from hormonal treatment. In cases of recurrent CP, surgical intervention is required. Video-assisted thoracoscopic surgery (VATS) allows both the diagnosis and treatment of CP. Despite its rare occurrence, CP is an important medical condition and requires immediate intervention in females presenting with recurrent spontaneous pneumothorax, especially with a history of endometriosis or unexplained lung collapses. The current study presents learnings from our experience in the successful management of 11 cases of CP using video-assisted thoracoscopic surgery (VATS). PATIENTS AND METHODS This study is a retrospective analysis of prospectively maintained data of patients who underwent surgery for CP at a tertiary care centre in India from March 2012 to December 2023. A total of 11 patients were included in the analysis. Ethical approval for the study was obtained from the institutional ethics committee before data collection. Demographic data, clinical history, pre-operative, intraoperative and post-operative variables were recorded and analysed. Pre-operative evaluation consisted of a detailed history, physical examination, imaging and haematological investigations. Radiological assessment included Chest X-ray and contrast-enhanced computed tomography (CECT) of the chest for all the patients. CECT chest was utilised to assess lung parenchyma for any abnormality, determine unilateral or bilateral involvement, assessment of the extent of lung collapse and identification of any diaphragmatic rupture or presence of abdominal contents in the thoracic cavity. Surgical details All the procedures were performed under general anaesthesia with single lung ventilation, achieved with a double-lumen tube placed under bronchoscopic guidance. The patients were placed in the lateral decubitus position with the affected side facing upwards. A three-port technique was employed for all VATS cases. The patients were placed in a lateral decubitus position, using axillary rolls for support, with the affected side up. The intercostal space on the ipsilateral side was widened by adjusting the table to move the hip away from the operating field and ensure the upper arm was positioned away from the operative site. We performed all the cases with 10 mm, 30° telescope. A diagnostic thoracoscopy was performed initially to rule out any unexpected pathology. We proceeded further with VATS thereafter by creating a utility port initially, which made it easier and safer to take down all adhesions under vision by blunt and sharp dissection. Detailed inspection of the pleural, pericardial, pulmonary and diaphragmatic surfaces was performed to identify ectopic endometrial deposits, diaphragmatic fenestrations, bullae or the blebs. Fenestrated diaphragm as well as diaphragmatic endometrial deposits was resected with endoscopic staplers and diaphragmatic plication was also performed in one patient for multiple small diaphragmatic fenestrations. For lung parenchyma involvement in the form of endometrial deposits or presence of blebs, endoscopic staplers were used to resect the lesions ensuring a sufficient healthy lung margin. An air leak test was conducted at the end of the procedure to rule out any active air leak on table. Pleurodesis using medicated steritalc was done in all the cases to prevent future recurrence. Two chest tubes were placed, one in the apical area and another one in the basal area, both connected to a digital negative suction device after ensuring complete lung expansion. All patients were extubated on the operating table and shifted to ICU for overnight observation. Post-operative care and follow-up All the patients were assessed the following morning and subsequently transferred to the ward for continued management. Adequate analgesics were administered to keep the patients pain free, which ensured active participation of the patients for aggressive chest physiotherapy to promote complete lung expansion. Chest tubes were removed when lung was fully expanded without air leak and the drainage was non-purulent/non-haemorrhagic with amount 7 days), duration of chest tube placement, wound infection, other complications and duration of hospital stay were analysed. All patients were closely monitored during the follow-up visits in the outpatient department at weekly intervals for the 1st month and subsequently every 3 months for the initial 6 months.

A total of 11 patients were included in this study. The mean age of the patients was 18.9 years, with a range of 16–25 years. These patients had initially received conservative or procedural management, including chest tube insertions, for their CP. They were referred to our centre after experiencing multiple episodes, with an average of 3.2 episodes before referral. Of the 11 patients, seven experienced pneumothoraxes within 24 h before the onset of menstruation, and four experienced it within 72 h after the onset. None of these patients had previously been diagnosed with pelvic endometriosis, nor were they on any hormonal therapy. Ten patients presented with spontaneous pneumothorax, while 1 had haemopneumothorax. In our series, 8 patients had pneumothorax on the right side and 3 on the left side [Table 1]. Pre-operative evaluation included a thorough assessment of the chest using CECT, which was performed on all patients to identify abnormalities. Thereafter, all the patients were managed with video-assisted thoracoscopic surgery (VATS). Intraoperative findings varied. The most common was the presence of the diaphragmatic abnormalities in all the cases [Figures 1 and 2]. Specifically, diaphragmatic fenestrations were found in all the 11 patients, while 5 of them had diaphragmatic endometriosis also. Notably, only one patient had visceral pleural endometriosis. One patient had multiple blebs on the lung surface [Table 2]. Surgical intervention consisted of diaphragmatic resection in all 11 patients, a combination of diaphragmatic resection and plication in one patient (multiple fenestrations) and diaphragmatic resection with wedge resection of the lung parenchyma affected by blebs in one patient. Talc pleurodesis was performed in all cases to prevent recurrence [Table 3]. Histopathological examination of the resected specimens confirmed the presence of thoracic endometriosis in five patients. Three of these patients were diagnosed with pelvic endometriosis also by the gynaecologist, and this was managed conservatively. Multiple diaphragmatic fenestration identified during video-assisted thoracoscopic surgery in patients with catamenial pneumothorax: Thoracoscopic images (a-c) demonstrate multiple diaphragmatic fenestrations, followed by surgical management with endoscopic stapling of the diaphragm Single large diaphragmatic defect identified during video-assisted thoracoscopic surgery in patients with catamenial pneumothorax: Thoracoscopic images (a-c) demonstrate single large diaphragmatic defect, followed by surgical management with suturing of the diaphragm Surgical procedure done by video-assisted thoracoscopic surgery The average duration of the surgery was 154 min and the average blood loss was 58 ml. There were no intraoperative complications and none required conversion to open surgery. There were no post-operative complications or mortality. The chest tubes were removed after an average of 4 days, and the average hospital stay was 4.4 days. The median follow-up period was 54 months with the range of 3–144 months. During follow-up, no recurrence was observed in any of the patients [Figure 3]. A succinct overview of the study showing pathophysiology of catamenial pneumothorax with study details, key study findings, surgical procedure and the conclusion

CP is a rare and under-recognised cause of spontaneous pneumothorax in women of reproductive age. It usually occurs 24 h before or within 72 h of the onset of menstruation, typically linked to the presence of underlying thoracic and pelvic endometriosis.[6] In our cohort of 11 patients, the clinical features were consistent with the previously described criteria for CP, with 7 of the patients experiencing pneumothorax within 24 h before menstruation and 4 within 72 h after the onset. Our study population had a mean age of 18.9 years, which was younger than the reported typical age of onset for CP, which is around 30 years.[7-9] This may be due to the small sample size of our cohort. Nevertheless, CP can occur in younger women, as demonstrated in many studies with patients in their teens and early twenties.[10,11] In complete coherence with previous studies, CP in our study was pre-dominantly right-sided, with 8 out of 11 patients presenting with right-sided pneumothorax and only 3 patients showing left-sided involvement.[12,13] Although bilateral involvement has also been described in the literature,[14,15] none of our patients had bilateral disease. The clinical presentation of CP is typically spontaneous pneumothorax, sometimes occurring with catamenial haemoptysis or catamenial haemothorax. Spontaneous pneumothorax was found to be the most common presentation in our series, with 10 out of 11 patients presenting with this condition. However, one patient presented with haemopneumothorax, which highlights the variability in the clinical presentation. These findings are consistent with previously published studies.[16] Endometriosis, particularly diaphragmatic endometriosis, has been reported to play a pivotal role in the pathogenesis of CP. One of the most common findings in CP is the presence of ectopic endometrial tissue in the thoracic cavity, often triggering the induction of diaphragmatic defects.[17] Histopathological examination of the patients in our study confirmed the presence of thoracic endometriosis in five patients, which is in coherence with the previously published literature.[18,19] A number of theories have been proposed to explain the pathogenesis of CP, such as: High-dose prostaglandin production leading to increased diaphragm contractility and subsequent change in intra-thoracic pressure, leading to pre-disposition of women with endometriosis to develop spontaneous pneumothorax. In addition, high levels of prostaglandins may trigger inflammation in the pleura as well as the diaphragm, leading to rupture of pulmonary blebs or bullae[2] Migration of endometrial tissue to the thoracic cavity followed by response of the migrated tissue to hormonal changes during menstruation, such as its proliferation and bleeding, triggering pleural inflammation and subsequent formation of pneumothorax[3] Air passage through diaphragmatic defects or fenestrations during increased intra-abdominal pressure in menstruation.[4] Five patients in our study group had diaphragmatic deposits, and all these endometrial deposits were resected using thoracoscopic staplers. One of the patients showed the presence of multiple lung blebs, which were resected by wedge resection. The presence of thoracic endometriosis in CP underscores the importance of careful examination of the diaphragm as well as the lung parenchyma during surgery.[20] The diagnosis of CP is primarily based on the clinical symptoms, which are supported by radiological findings as well as intraoperative findings. Previous studies have highlighted the importance of CECT in the identification of diaphragmatic abnormalities, lung parenchymal lesions and potential involvement of abdominal organs in the thoracic cavity.[21] Therefore, in our series, all patients were subjected to CECT chest pre-operatively, which enabled effective surgical planning while also ensuring addressal of all the involved thoracic lesions. Diaphragmatic lesions, especially defects, should be dealt by complete resection, and in our series, these defects were resected by endoscopic staplers. Lesions, which are suspicious of being endometrial deposits, should be taken for biopsy. All other parenchymal lesions such as blebs or bullae should be resected with the help of endoscopic staplers. We were able to do all these procedures with VATS in our series. Surgical treatment, particularly video-assisted thoracoscopic surgery (VATS), is considered the gold standard for managing CP. A number of previously published studies have demonstrated the advantages of VATS in both diagnosis and the treatment of CP, owing to increased visualisation of the pleural cavity, diaphragm, as well as lung parenchyma in comparison to traditional open thoracotomy.[22] The results of our study align with the findings of previously published literature, since VATS enabled both precise identification and resection of diaphragmatic defects and lung lesions, including blebs, bullae and endometrial deposits.[23] Talc pleurodesis was performed in all the patients to reduce the chances of future recurrence, a practice followed in a number of previously published studies that advocate for pleurodesis as the part of the surgical management of CP.[17,24,25] Talc pleurodesis aids in achieving a permanent adhesion between the pleural layers, curtailing the probability of occurrence of future pneumothorax episodes. The findings of our study support the efficacy of VATS in the treatment of CP, since the surgical procedure was completed successfully without the need for conversion to open surgery. The mean duration of surgery was 154 min and the average blood loss was minimal (58 ml), reinforcing the evidence of the minimally invasive nature of VATS. The chest tubes were removed after an average of 4 days and average hospital stay was only 4.4 days, which is in accordance with the accelerated healing rate and expedited recovery reported in other studies advocating VATS for CP. No major complications were encountered, and no recurrence of pneumothorax was observed during the follow-up period, showcasing high success and low recurrence rates following VATS for CP.[26,27] Our research group has previously demonstrated the efficacy of video-assisted thoracoscopic surgery (VATS) in the management of primary spontaneous pneumothorax, based on the outcomes observed in 110 consecutive cases.[28]

VATS is an effective and minimally invasive approach for the management of CP, offering excellent surgical outcomes, shortened convalescence and a low risk of recurrence. The findings of the current study substantiate the growing body of evidence supporting VATS as the treatment of choice for CP. VATS provides a promising approach for the long-term management of this rare and challenging condition. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

We would like to express our sincere gratitude to Dr. Deepika Bhardwaj for her invaluable assistance in the writing and refinement of this article.

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