LASER-TISSUE WELDING IN GENITOURINARY RECONSTRUCTIVE SURGERY - ASSESSMENT OF OPTIMAL SUTURE MATERIALS

Objectives. Laser tissue welding in genitourinary reconstructive surge ry has been shown in animal models to decrease operative time, improve healing, and decrease postoperative fistula formation when compared w ith conventional suture controls. Although the absence of suture mater ial is the ultimate goal, this has not been shown to be practical with current technology for larger repairs. Therefore, suture-assisted las er tissue welding will likely be performed. This study sought to deter mine the optimal suture to be used during laser welding.Methods. The i ntegrity of various organic and synthetic sutures exposed to laser irr adiation were analyzed. Sutures studied included gut, clear Vicryl, cl ear polydioxanone suture (PDS), and violet PDS. Sutures were irradiate d with a potassium titanyl phosphate (KTP)-532 laser or an 808-nm diod e laser with and without the addition of a light-absorbing chromophore (fluorescein or indocyanine green, respectively). A remote temperatur e-sensing device obtained real-time surface temperatures during lasing . The average temperature, time, and total energy at break point were recorded. Results. Overall, gut suture achieved significantly higher t emperatures and withstood higher average energy delivery at break poin t with both the KTP-532 and the 808-nm diode lasers compared with all other groups (P < 0.05). Both chromophore-treated groups had higher av erage temperatures at break point combined with lower average energy. The break-point temperature for all groups other than gut occurred at 91 degrees C or less. The optimal temperature range for tissue welding appears to be between 60 degrees and 80 degrees C. Conclusions. Gut s uture offers the greatest margin of error for KTP and 808-nm diode las er welding with or without the use of a chromophore.