The relationship between apposition pressure during welding and tensile strength of the acute weld

P. J. Wu*, Jay Walsh

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


Dye-assisted photothermal welding is a technique used to close wounds by thermally cross-linking collagen across apposed tissue edges. For a successful weld, not only do laser parameters have to be optimized, but also apposition of the incision has to be consistent and controlled. The objective of this study was to quantify the relationship between the applied apposition pressure (i.e., the compressive force holding the wound closed during the welding procedure divided by the area of the skin-to-skin interface) and the tensile strength of the wound following the welding procedure. By using a clamping device made of two complementary pieces, each 3 cm wide with a row of 10 equally spaced blunt wire mesh tips, the apposition pressure along a 2-cm-long incision in each albino guinea pig was quantified using a 127-μm-thick load cell and varied from 0-1.8 kgf/cm2. A continuous wave, Nd:YAG laser emitting 10.0 W of 1.06-um radiation from a 600-μm-diameter fiber irradiating a 5-mm-diameter spot size was scanned across the incision in order to deliver 300 J of total energy. As the apposition pressure of the incisions was increased, the resulting tensile strength of welded skin increased in a sigmoidal manner. For this welding technique, an apposition pressure of at least 1.2 kgf/cm2 is necessary to obtain maximum weld strength of the skin (2.56 ± 0.36 kg/cm2).

Original languageEnglish (US)
Pages (from-to)175-179
Number of pages5
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Jan 1 2001
EventLaser in Surgery: Advanced Characterization, Therapeutics, and Systems XI - San Jose,CA, United States
Duration: Jun 20 2001Jun 23 2001


  • Apposition pressure
  • Laser tissue welding
  • Tensile strength

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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