Unrecognized durotomy after lumbar discectomy: a report of four cases associated with the use of ADCON-L.

STUDY DESIGN: This report describes four cases of symptomatic cerebral spinal fluid leak after lumbar microdiscectomy where ADCON-L was used. OBJECTIVES: To report that ADCON-L may exacerbate cerebral spinal fluid leak from unrecognized, small dural tears after lumbar discectomy. SUMMARY OF BACKGROUND DATA: ADCON-L is a porcine-derived polyglycan that is used with increasing frequency in spinal surgery. It is advocated to reduce postoperative peridural fibrosis and adhesions. METHODS: Four cases of symptomatic cerebral spinal fluid leak after lumbar microdiscectomy were identified. Information on these patients was obtained by chart review. RESULTS: Three patients had small, inadvertent durotomies that were not appreciated at surgery even with the aid of a microscope. The dural violation in the fourth patient occurred at the previous epidural steroid injection site located on the contralateral side of the laminotomy. CONCLUSION: ADCON-L may inhibit dural healing and exacerbate cerebral spinal fluid leak from microscopic durotomies not recognized at the time of surgery.

Hereditary resistance to 1,25-dihydroxyvitamin D: clinical and radiological improvement during high-dose oral calcium therapy.

A 6-year-old boy, of consanguinous parents, presented with severe rickets and alopecia; he was found to have hypocalcaemia and elevated circulating 1,25-dihydroxyvitamin D [1,25-(OH)2D] levels. He showed no calcaemic response to 1,25-(OH)2D3 or ergocalciferol given for 3 or more months in daily doses as high as 48 micrograms and 6 X 10(6) IU, respectively. Analyses with cultured skin fibroblasts revealed a normal capacity and affinity for 1,25-(OH)2D3 in soluble extracts ('cytosol') and in nuclei of intact cells but no detectable response of 25-(OH)D3 24-hydroxylase to 1,25-(OH)2D3 in high concentration. Treatment with high doses of calcium (3-4 g elemental calcium orally per day) produced a striking clinical and radiological improvement. We conclude that high oral doses of calcium can replace many of the actions of calciferols. Therapy with high doses of calcium should be tried in similarly affected cases that appear totally or partially unresponsive to calciferols.