Preclude MVP TM Synthetic Dural Substitute Applied as a Non-watertight ?Underlay? Graft for Craniotomies

E. Thomas Chappell, MD
University of California - Irvine

Introduction

While water-tight closure of the dura is often not possible. Many graft materials with various attributes and drawbacks have been in use for many years. A novel synthetic dural graft material called Preclude MVP TM (Gore, Inc., Flagstaff, AZ) is specifically designed to use as a dural underlay graft in a non-water-tight fashion. One surface of the primary Gortex TM (Gore, Inc., Flagstaff, AZ) material is modified to facilitate fibroblast in-growth so that its proximity to the underside of the dura will lead to rapid incorporation. In small rabbit craniotomies repaired with non-water-tight Preclude MVPTM underlay grafts, high experimental intracranial pressures can be achieved without leakage within days.

Methods

Preclude MVP TM is being used as a non-water-tight underlay graft in a series of cranial procedures. These are preliminary results from an ongoing post-release product evaluation. At least 3 months of follow-up data including cranial imaging is being accumulated on all subjects.


Results

To date, 25 subjects are part of the evaluation. The mean clinical and radiographic follow-up is 130 days (54 356). All subjects have had excellent outcomes related to use of the graft. There have been 2 presumably graft-related complications: a transient pseudomengocele in a markedly obese patient, and an infection in a patient with prior irradiation to the operative field. The latter required removal of the graft and bone flap, and delayed cranioplasty.

Fig. 1

Click to see full size image
Regenerated dura 6 weeks after non-watertight underlay graft using Preclude for duraplasty during hemicraniectomy noted at time of cranioplasty. Black line indicates where nacent dura ends, regenerated dura begins (incorporated graft material).


Conclusions

When this is not possible, Preclude MVP TM can be used as an underlay graft in a non-water-tight fashion. However, if used at the skull base, over large voids (relaxed brain or tumor bed), or in patients with raised CSF pressure, tacking (at a minimum) or water-tight suturing should be used. The non-water-tight underlay application of Preclude MVP TM is best applied over the convexities and is particularly well-suited to duraplasty after hemicraniectomy (Fig. 1).

Learning Objectives

1) discuss the attributes of Preclude MVP TM dural substitute. 2) dileneate the various modifications and uses of the "underlay" graft technique. 3) list the circumstances under which the material might not be used.