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Abstract Background Although median sternotomy is standard during cardiac surgery, the procedure is associated with a risk of injury to mediastinal organs. Here, we discuss two cases of tracheal injury following median sternotomy during cardiac surgery. Case presentation Ventilation failure occurred in a 78-year-old Japanese man and a 71-year-old Japanese man after median sternotomy, and tracheal injury was identified. The sites of injury were directly repaired and covered with mediastinal fat tissue, following which ventilation was successful. The burn-like deposits observed at the site of tracheal injury and on the removed endotracheal tube support the notion that the injuries in our patients were caused by electrocautery prior to median sternotomy. In one case, short sternotracheal distance may have contributed to tracheal injury during post-sternal manipulation. In both cases, the relative inexperience of both surgeons also supports the suspected cause of injury. Conclusions Tracheal injury represents a potential complication following median sternotomy, especially when performed by inexperienced surgeons or in cases of short sternotracheal distance. Anesthesiologists should consider this rare yet potentially lethal complication.

The cytochrome P450 enzyme RosC catalyzes a two-step, hydroxylation and alcohol oxidation, oxidation reaction to form the C-20 formyl group in the biosynthesis of a 16-membered macrolide antibiotic rosamicin produced by Micromonospora rosaria IFO13697. RosC is presumed to be involved in the formation of 20-carboxyrosamicin because it has been isolated from the culture broth of M. rosaria. Here, we confirmed that RosC has catalytic activity, with E. coli expressing RosC converting rosamicin into 20-carboxyrosamicin. Therefore, it was revealed that RosC is a multifunctional P450 that catalyzes a three-step oxidation reaction that leads to the formation of the hydroxyl group, formyl group and carboxyl group at C-20 on the macrolactone ring in the rosamicin biosynthetic pathway. Moreover, the cytochrome P450 enzyme TylI, which is involved in formation of the formyl group of a 16-membered macrolide antibiotic tylosin produced by Streptomyces fradiae ATCC 19609, also converted rosamicin into 20-carboxyrosamicin. [ABSTRACT FROM AUTHOR]

A 56-year-old woman presented with general fatigue, dyspnea on exercise, and hepatomegaly subsequent to secondary implantation of a pacemaker. On admission, cardiac echo examination showed tricuspid valve regurgitation due to a migrated looped lead. At surgery, there was evidence of severe stenosis at both orifices of the superior and inferior vena cavae due to fibrous tissue around the leads. We removed the fibrous tissue, pacing leads, and generator. New leads were anchored onto the epicardium and a generator was inserted under the rectus muscle. The postoperative course was satisfactory and the symptoms disappeared. [ABSTRACT FROM AUTHOR]