After the demise of Mervyn's, in 2005, the mall had a hulking vacant anchor store along its west-facing front. A plan was drawn up to replace it with an outdoor plaza and pedestrian Skybridge, which would traverse Gessner Road. Above, we see an early conceptualization.
Drawing from http://www.memorialcity.com

The western Skybridge segment was completed in 2009. The pedestrian walkway linked MEMORIAL CITY MALL with the Memorial Hermann Memorial Medical Center. The Memorial Hermann Tower, one of the components of the gargantuan healthcare facility, was also finished in 2009.
Drawing from http://www.memorialcity.com

In 2012, an eastern Skybridge section was extended from the mall's Dillard's parking garage over to the Forum Energy Technologies Corporate Campus high rise. Since then, elevated walkways have also linked into the Air Liquide Houston Hub building and new Hotel Zaza, seen above.
Photo from https://www.hotelzaza.com