Gareth Clark's spine was missed by millimeters (fractions of an inch) when a branch went into his neck last week after his friend lost control of a car and hit a clump of trees, local media reported Wednesday.
A branch tore one neck jugular vein and passed millimeters (fractions of an inch) away from his vertebrae and spinal cord, esophagus, larynx, carotid arteries and a second vein, surgeon Andrew Currie said.
The badly bleeding 16-year-old stumbled out of the car onto the roadside where the unnamed nurse, who was traveling past with her young children, helped him.
"She just ran up to me and put the nappies on my neck to absorb the blood and tied (a) jumper around my neck to hold them in place," Clark told the "New Zealand Herald" on Wednesday.
"I would have definitely bled to death without her," he was quoted as saying from his Waikato Hospital bed on North Island.
The teen defied death a second time when he coughed while waking from surgery, causing a break in a jugular vein.
"He lost two liters of blood within seconds," Currie said. But being on the operating table meant he got immediate treatment.
Had he coughed anywhere else it was unlikely he would have survived, the surgeon added.
"The stick passed between his vertebrae and spinal column, and all the important structures at the front of the neck and back of the neck, including the larynx and esophagus, without injuring them at all," he said.
"Incredible, it's a miracle," Currie said. "I can't get over it and I said to him, 'Someone's looking out for you."'
Police Sergeant Graham McGurk said the driver of the car told police he had lost control while attempting to round the corner at 150 kilometers (94 miles) an hour.
Police have charged him with dangerous driving causing injury.