The "Poiseuille formula" which is given by [tex]\\\begin{aligned} \small Q& = \small \frac{\pi r^4}{8 \eta}.\frac{\Delta P}{\Delta L}\\\end{aligned}[/tex] describes the volumetric flow rate ([tex]\small Q[/tex]) through tubular sections.
Here, [tex]\Delta P,\,\, \Delta L,\,\, r,\,\, \eta[/tex] represent the injection pressure difference, the length of the section, the radius of the section and the viscosity index of the fluid that flows through the section respectively.
With this, one can confirm that all the factors except the vessel side holes affect the flow rate.
Side holes, however, are a factor that could give a measure of how much volume would flow to a particular location. In such a situation the flow rate remains unchanged and one location would receive a lower volume (not the whole) as some volume would spill out at the side holes.
