It was hypothesized that the amount of adjacent tissue would affect the contraction of vessel segments; it was thought that less of the surrounding tissue would induce greater contraction response in the vessel segments.
Einnig var skoðað hvort að magn aðlægs vefs hefði áhrif á samdrátt æðarbútanna, en talið var að því minna sem væri af aðliggjandi vef því meiri yrði samdráttarsvörun æðarbútanna.