Biomedical Engineering Reference
In-Depth Information
stays supporting the anastomosis was progressively reduced, to minimize for-
eign body reaction, and eventually to achieve simpler and faster operation.
In conventional suturing procedures of microvascular anastomosis, a number
of suture stays from 8 to 12 are applied to support the anastomosis. On the
other hand, laser-assisted procedures to weld the vessel edges were first accom-
plished with the support of four conventional stays; then successful LAMAs
were performed with only two sutures stays, and lastly with no permanent
stays at all. These results demonstrated experimentally that diode laser weld-
ing alone could withstand both blood pressure and vessel tensile strength,
providing mechanical and functional support to the anastomosis. Moreover,
the most significant result of these studies emerged from histological exami-
nation on longer follow-up times (up to three months), by comparison of the
healing of laser-welded and conventionally sutured vessels. Specimens from
both arteries and veins yielded unquestionable evidence of faster and superior
healing induced by the laser treatment, very similar to a “
restitutio ad inte-
grum
” of vessel structures (Fig. 15.8). The repair mechanism of vessel walls
in LAMAs seemed significantly favored by reduction or absence of suture ma-
terial, which limited the occurrence of foreign body reaction, granulomas and
inflammation, and ultimately resulted in a more effective and faster restora-
tion of the architecture of the vessel walls.
In a more recent study, diode laser welding was experimentally tested to
perform end-to-side anastomosis in carotid bypass surgery [11]. This appli-
cation may be particularly important in neurosurgery in order to minimize
the occlusion time of the carotid artery during the application of a venous
bypass graft, thus reducing the risk of post-operative brain damages. With
regards to technical aspects of the laser-assisted welding procedure, the study
Fig. 15.8.
Left
: aspect of femorary artery of a Wistar rat after end-to-end LAMA
performed by staining the vessel edges with ICG and then welding them by using a
low power diode laser emitting at 810 nm, without conventional stitches.
Right
:his-
tological section of the artery wall 3 months after the surgery showing the complete
restoration of the wall architecture (Wiegert elastica-Van Gieson stain,
×
250)
