Endometriosis-related pneumothorax after F.I.V.E.T. procedure

Background: Catamenial pneumothorax is a unique entity occurring in ovulating women at the onset of menses. The video reports the case of spontaneous pneumothorax in a woman following hormonal treatment before Fertilization in Vitro Embryo Transfer (F.I.V.E.T.). Methods: A 32 years-old woman presented with right pneumothorax. She referred right back noise and cough every menses. She underwent unsuccessful F.I.V.E.T. two weeks before. At thoracoscopy we detected on dorsal pleura and diaphragm some tiny blue brown nodules of endometriosis, as confirmed by histology. No holes were present on diaphragm. Some open blebs were found in the apex of the inferior lobe and removed. No endometriosis was identified on this specimen. Endometrial foci were coagulated. Pleural abrasion was also performed. Results: No recurrence of pneumothorax or back noise occurred at a 22 months follow-up. The patient underwent a new successful F.I.V.E.T. 8 months after surgery. Conclusions: Different theories explain thoracic endometriosis: a retrograde menstruation with implantation on diaphragm, a coelomic metaplasia of endometrial tissue or a metastatic spread in the lungs. We found endometrial foci on diaphragm and parietal pleura supporting the implantation theory. Many hypothesis have been proposed for the relation between endometriosis and pneumothorax: trans-fallopian ascent air passing thorough diaphragmatic fenestrations, rupture of blebs due to the bronchial constrictor prostaglandins F2, or visceral pleura perforation due to subpleural endometriosis proliferating during menses. In our case no diaphragmatic fenestrations were found, so the blebs rupture, due to hormonal storm preparing the F.I.V.E.T., was the unique explanation for pneumothorax. Surgical blebs resection, endometriosis coagulation and pleural abrasion were appropriate to prevent relapse and control thoracic pain related to pleural endometriosis during menses. We conclude that there are different mechanisms for catamenial pneumotorax and, in some cases, blebs resection and pleural abrasion are enough to prevent relapses.