Watertight dural closure! An in vitro study to explore the myth

Abstract

Aim

The watertight closure of the dura mater is fundamental to intracranial supratentorial procedures in neurosurgery. Controversies exist claiming the superiority of one closure technique over another. But is ‘Water-tight’ dural closure really achievable ? An in vitro study system was developed to test the pressures at which dural incisions, closed with sutures, leaked.

Materials and Methods

Bovine dura was secured to the lower end of an open ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a two 2 cm length of the dura without any incision. Similarly a 2 cm incision was made and closed with interrupted and continuous stitches. Cylinder was filled with colored saline gradually. Height of the water column at which sutured dura leaked was recorded. The tests were conducted with the dura both in lax and tense conditions. Inlay closure technique was also tested on the same model using a dural substitute.

Results

Even without an incision, needle puncture sites over a dura, leak, at a very low hydrostatic pressure (30 < mm of H2O), though a continuous interlocking suture performs slightly better than an interrupted suture technique. If the needle puncture sites are closed with glue, both the suture techniques can achieve a watertight closure against a hydrostatic pressure of 240 mm of H2O.

Conclusion

In the experimental model described, ‘Water-tight’ dural closure appears to be impossible with suture closure of a dural defect.

Key words

Dependent position - experimental model - watertight dural closure

• References

• 1 Megyesi JF, Ranger A, MacDonald W, Del Maestro RF. Suturing technique and the integrity of dural closures: An in vitro study. Neurosurgery 2004; 55: 950-954
• 2 Ozisik PA, Inci S, Soylemezoglu F, Orhan H, Ozgen T. Comparative dural closure techniques: A safety study in rats. Surg Neurol 2006; 65: 42-47