Indigo carmine for the selective endoscopic intervertebral nuclectomy

Abstract

This study was undertaken to prove that the selectively infiltrated parts of nucleus pulposus with indigo carmine was degenerated parts of nucleus pulposus. This study was done, between August and October 2002, in 5 patients, who received endoscopic discectomy, due to intervertebral disc herniation. Discogram was done with mixture of indigo carmine and radioactive dye. Blue discolored part was removed through endoscope, and small undiscolored part was removed together for the control. The two parts were stained with hematoxylin and eosin and compared under the microscope. Undiscolored part was normal nucleus pulposus, composed of chondrocytes with a matrix of type II collagen and proteoglycan, mainly aggrecan. However, in discolored part, slits with destruction of collagen fiber array and ingrowth of vessel and nerve were observed. Using indigo carmine in endoscopic discectomy gives us selective removal of degenerated disc.

Fig. 1

Normal nucleus pulposus appears homogenous and pale lilac-blue and shows regular chondrocytes array with a matrix of type II collagen and proteoglycan, mainly aggrecan in undiscolored part on H&E stain. With the exception of the outer third of the AF, the normal adult IVD is avascular and aneural (×10).

Fig. 2

Degenerated nucleus pulposus shows some slits with destruction of collagen fiber array, vessel and nerve ingrowth, and irregular chondrocytes aggregation (H&E, ×200).