Fight for life. Part 5, Middle years.

This is the fifth in a six-part series which uses cutting edge computer graphics and rare footage to show how the body fights for survival against the odds of trauma, illness and accident. This part focuses on the kind of things which can go wrong with the body when it reaches middle age and how surgery and the body itself fight to survive. 53-year-old Alan has a bulge in his aorta which, if left, will kill him within 18 months, but the surgery to repair his aorta is hugely traumatic and runs a high risk of mortality or of paralysis in his legs. We see detailed footage of the surgery. Christine has been a life-long smoker and her lungs are seriously damaged so a chest infection leaves her close to death - much footage is shown of how the lungs function. John has a pacemaker fitted using keyhole surgery and Nick has a stent fitted following a stroke.