Laser activation of tissue sealant in hand-sewn canine esophageal closure
Auteri, J.S.; Oz, M.C.; Jeevanandam, V.; Sanchez, J.A.; Treat, M.R.; Smith, C.R.
Journal of Thoracic and Cardiovascular Surgery 103(4): 781-783
1992
ISSN/ISBN: 0022-5223 PMID: 1548921 Document Number: 392103
Dehiscence rates of esophageal are between 5% and 20%. Because small leaks betwen sutures might promote microabscess formation and lead to dehiscence, we postulated that a better initial physical seal might be beneficial. Reinforcement with laser activation of tissue sealant (LATS) is a new technique that has been shown to increase the bursting strength of anastomoses in other tissues. The tissue sealant is composed of 0.4 ml of hyaluronic acid and 0.2 ml of albumin, to which 3 drops of indocyanine green dye are added to give the sealant a peak absorbance of 805 nm, matching the wavelength (808 nm) of a small, hand-held diode laser. Since tissues do not absorb at this wavelength, laser energy is focused in the sealant, minimizing collateral thermal damage. To extend this concept, we assessed LATS in a canine model of esophageal closure. The esophagus was exposed via a right thoracotomy in 20 dogs, and two transverse incisions, 2 cm in length, were made in each esophagus (n = 40 closures). Both sites were closed with a single layer of interrupted 4-0 polyglycolic acid suture. Either the proximal or distal incision was randomly chosen to receive laser activation of tissue sealant. Tissue sealant was applied to the reapproximated edges of the hand-sewn closure, which was then exposed to diode laser energy. The end point was visible shrinking and desiccation of the sealant, which required about 2 minutes. Each esophagus was recovered at 0, 2, or 7 days postoperatively (n = 10, 5, and 5 dogs, respectively), bursting pressure was measured, and the closures were examined histologically. At all three time points LATS closures had significantly higher bursting pressures than control closures (time 0: 251 .+-. 87 versus 105 .+-. 46, p < 0.0001; time 2 days: 296 .+-. 36 versus 121 .+-. 14, p < 0.0013; time 7 days: 318 .+-. 72 versus 197 .+-. 60, p < 0.0021). Histologic study revealed trace thermal injury, with regeneration of intact mucosal lining by 7 days. Conclusion: laser activation of tissue sealant is a simple technique that significantly increases the strength of esophageal closure and may reduce the prevalence of dehiscence.