Lessons learned from laser tissue soldering and fibrin glue pyeloplasty inan in vivo porcine model

Purpose: We compared sutured pyeloplasty to 2 newer techniques of tissue an astomosis, including laser soldered pyeloplasty using a diode laser with 50 % albumin solder mixed with indocyanine green and fibrin glue. Materials and Methods: We performed 53 pyeloplasties in 50 pigs using sutur e, laser or fibrin glue. In the immediate group anastomotic leak pressure w as measured immediately postoperatively, and then animals were euthanized. At 1, 3 and 4 weeks postoperatively a pressure flow study at 10 cc per minu te in cm. H2O was performed, and tissue was sent for histological and colla gen content analysis. Results: In the immediate studies laser soldering achieved a significantly higher mean anastomotic leak pressure (50.5 +/- 15.1 cm. H2O) than sutured (17.3 +/- 5.4) or fibrin glued (3.5 +/- 1.5) repairs. In the 1, 2 and 4-wee k studies animals in the sutured pyeloplasty group had no complications, an d all pressure flow studies except I were normal. However, in the laser sol dered groups we observed 8 urinomas in 19 animals, and most occurred during the first part of our study. This complication was prevented by stopping u rine flow at the anastomotic site at laser irradiation and by improving app lication of the solder. Of the 11 animals in which pressure flow studies we re performed only 2 were obstructed. Of the 7 chronic fibrin glue group 4 a nimals had urinomas and 2 had unobstructed pressure flow studies. Histologi cal studies and immunohistochemical staining for collagen showed no differe nces in collagen distribution among the 3 procedures. Conclusions: Laser soldering and fibrin glue pyeloplasties are not superior in the long-term compared to sutured pyeloplasty. Fibrin glue in our anima l model had the highest failure rate. Further improvements in the technical aspect of laser tissue welding need to be made to benefit from its theoret ical advantages in minimally invasive surgery.