Biomedical Engineering Reference
In-Depth Information
demonstrated the feasibility of laser-assisted end-to-side anastomosis in bypass
surgery, which - to our knowledge - had never been tested before in vivo and
presents peculiar technical features. In fact, beside a more complex geometry
of the junction, it requires the accomplishment of an effective welding between
the artery and the vein graft, which exhibit different wall structures. More-
over, surgical advantages were observed in laser-assisted when compared with
conventionally sutured anastomoses, such as a simplification of the procedure,
a reduction or suppression of bleeding, and a shortening of the operative time,
which may be potentially reduced by up to a factor of three. Again, histolog-
ical, ultrastructural and immunohistochemical analyzes confirmed the occur-
rence of lesser inflammation and of better preservation of the endothelium and
of the inner wall structures of both artery and vein in laser-treated segments.
This is expected to reduce the occurrence of thrombosis and favor an optimal
restoration process.
15.4 Potentials in Other Surgical Fields
15.4.1 Laser Welding of the Gastrointestinal Tract
Repair of the gastrointestinal tract by means of laser welding has been found to
be a technique that is much easier, faster, and yielding better healing response
and no stone formation, when compared with suturing closure techniques. The
first published study regarding laser bowel welding was reported in 1986 by
Sauer et al. They used a CO
2
laser to repair longitudinal transmural incisions
in an otherwise-intact rabbit ileum, producing strong hermetic closures [84].
The same authors later proposed the use of a biocompatible, water-soluble, in-
traluminal stent in conjunction with India ink as an exogenous chromophore,
to perform a suture-free end-to-end small bowel anastomosis [85]. In 1994
Rabau et al. described the healing process of CO
2
laser intestinal welding
in a rat model, which evidenced a higher probability of dehiscence in the
first 10 postoperative days compared with control sutured repairs [86]. More-
over, comparable healing response among argon and Ho:YAG laser-welded
and control-sutured anastomoses have been found by using a temperature-
controlled laser system [87]. Oz et al. investigated the feasibility of using a
pulsed THC:YAG and a cw argon laser for the welding of biliary tissue. They
found better histological response and higher pressure prior to breaking in the
latter case [30]. Lastly, laser soldering with ICG-doped liquid albumin-solder
in conjunction with a diode laser was successfully evaluated for the purpose
of sealing liver injuries with minimal heat damage [88].
15.4.2 Laser Welding in Gynaecology
Laser welding was experimented in 1978 for reconstructive surgery in the
fallopian tubes, using a CO
2
laser with good results [89]. Contrasting results
