Microvasculature, blood flow, and vasoreactivity in rabbit sinus mucosa after surgery

To study the circulatory integrity of the sinus mucosa following surgery, the vascular anatomy, blood flow, and vasoconstrictor response of the regenerated microcirculatory network were analyzed.

Forty-six New Zealand White rabbits were operated on unilaterally with either a modified radical operation (MRO) or middle meatal antrostomy (MMA), using the nonoperated sinus for control purposes. After surgery, the animals were left to heal for 1 month.

Vascular casts were prepared with a low-viscosity methyl methacrylate resin and studied by scanning electron microscopy. Blood flow was measured by means of radiolabeled microspheres (tin 113 [113Sn]). The vasoconstrictor response to oxymetazoline at increasing concentrations was measured with laser Doppler flowmetry.

The number of vessels increased significantly in the regenerated mucosa. The vascular casts displayed a rich microcirculation with local signs of angiogenesis. However, there was no difference in blood flow between the operated cavities and their control sides. Following MRO the regenerated mucosa was more sensitive to the vasoconstrictor effect of oxymetazoline, compared with the control side. This difference was not evident in the MMA-operated sinuses.

In this model, surgery does not seriously interfere with the sinus blood flow, although the regenerated mucosa did display an altered vasoreactivity. These findings should be considered in relation to the effects of surgery intended to limit local inflammation and to ensure the ventilation of the sinuses.