Endoscopic approach after failure of open sinus procedures

Surgeons need to be familiar with the external surgical approaches including the indications and techniques in order to perform revision cases safely. • Every effort should be made to obtain a detailed knowledge of the previous surgery. • Potential for complications is greater due to the disruption of normal anatomy and pathways and greater likelihood of osteoneogenesis, adhesions, and breech of sinus boundaries compared to endoscopic surgery. • Image guidance is useful but does not compensate for lack of preoperative planning. • Always operate from known to unknown and always be vigilant that significant surgical defects can be found behind normal anatomy.