Astronomer: In most cases in which a planet has been detected orbiting a distant star, the planet' s orbit is distinctly oval, whereas the orbits of Earth and several other planets around our sun are approximately circular  However, many comets orbiting our sun have been thrown into oval orbits by close encounters with planets orbiting our sun
So some of the planets in oval orbits around distant stars were probably thrown into those orbits by close encounters with other planets orbiting the same stars
There is no indication that the orbit of any planet orbiting our sun has been affected by a close encounter with another planet orbiting our sun.