Axon regeneration and vascularisation of nerve grafts. An experimental study.

An experimental model has been designed to assess the effect of vascularisation on axon regeneration in nerve grafts. The vascular status of the grafts has been demonstrated by microangiography and histology. Rat sciatic nerve grafts in which the vascular pedicles were left intact retained a normal vascular pattern which was not adversely affected by wrapping the graft in a polythene sleeve. In devascularised grafts, revascularisation commenced at three days and was complete at nine days. If the devascularised grafts were wrapped in a polythene sleeve, revascularisation was impeded and at fifteen days the middle segment of the graft was avascular and infarcted. The rate of axon regeneration was measured electrophysiologically in the above four groups of nerve grafts. There was a linear relationship between the rate of axon regeneration with time post-graft, axon growth proceeding at a mean rate of 1.150mm/day (S.E. +/- 0.084) after a mean delay of 4.85 days. There was no significant difference in the rate of axon regeneration in the four groups.

The radiology of stillbirths and neonatal deaths.

Whole body radiographs were made in a consecutive series of 488 infants who were either stillborn or died within the first month of life; autopsies were done in 378. The radiographs were considered to have been useful, or diagnostic in 16% overall, in 100% of infants with dwarfism, in 40% where there were external malformations; and in 9% where there were no external malformations.