DURAL CLOSURE WITH LASER-TISSUE WELDING

This study investigates the use of tissue-soldering techniques to subs titute or reinforce traditional suture closure of dural incisions, Fre sh human cadaveric dura was incised and subsequently closed by use of three techniques: (1) conventional interrupted suture with 4-0 silk (n = 25), (2) laser solder reinforced suture closure (n = 25), and (3) l aser solder closure alone (n = 25), Anastomosis tensile strength and h ydrostatic leak pressures were measured, Dural repair was also perform ed in 15 live Lewis rats. Dural closure was accomplished with 9-0 Prol ene sutures (n = 5), laser-reinforced suture closure (n = 5), and lase r solder closure alone (n = 5), Histologic examination of the closure immediately after soldering and 2 weeks later was performed, Suture cl osure alone had the lowest leak pressure, 9.4 +/- 1.7 mm Hg, and an in termediate break point, 13.3 +/- 2.1 Kgf/cm(2). Measurements with lase r solder alone revealed a mean leak pressure of 26.2 +/- 3.7 mm Hg and a break point of 4.6 +/- 1.4 Kgf/cm(2), Solder-reinforced suture clos ure leak pressure measured 64.0 +/- 6.7 mm Hg and 21.4 +/- 2.4 Kgf/cm( 2). There was a statistically significant increase in leak pressure an d tensile strength in the closures performed with laser weld reinforce ment of traditional suture technique (p = 0.0001), Dural closure with laser tissue welding alone provided an immediate leak-free closure, bu t with poor tensile strength, Histologic examination of welded dura an d underlying brain tissue showed no evidence of thermal injury in four of five animals studied. Laser welding may significantly decrease the incidence of cerebrospinal fluid leak after dural closure. In additio n, laser tissue welding also makes dural closure possible where space constraints make traditional suture closure difficult.