IDEAS AND INNOVATIONS
Hydrodissection of the neurovascular pedicle with lignocaine
T. C. Teo
Received: 1 November 2005 / Accepted: 14 July 2006 / Published online: 7 October 2006
The technique of hydrodissection is not new. It is
commonly used to aid surgical dissection. It involves
pressure insufflation of fluid into an anatomical space with
a consequent increase in hydrostatic pressure that separates
the tissue planes.
Recently, hydrodissection has been proposed as a
method for harvesting the internal thoracic artery .
We have been using a similar method at our institution
for a number of years when harvesting free flaps for
microsurgical reconstruction. It is not uncommon when
raising certain free flaps (e.g., thoracodorsal artery perfora-
tor flap, anterolateral thigh flap) to dissect the motor nerve
from the neurovascular pedicle in order to avoid denerva-
tion of the remaining muscle. We have found that our
technique of hydrodissection greatly aids this process in
terms of speed and ease of dissection with no untoward
The technique involves the use of 5 ml of 2% lignocaine.
This is delivered in a 5-ml syringe via an 18-gauge flat
blunt cannula (BD™ drawing up needle; Fig. 1).
The tip of the cannula is placed into the sheath of the
neurovascular pedicle of the flap, next to the nerve (Fig. 2).
The solution is then gently injected into the sheath. It
insufflates the entire sheath (Fig. 3). With a pair of non-
toothed forceps and tenotomy scissors, the sheath can be
easily split (Fig. 4). The nerve is then delivered effortlessly
away from the vascular pedicle (Fig. 5). The dissection
proceeds from distal to proximal until the entire nerve is
This technique has the added advantage of sparing the
vasa nervosum from trauma, as it is easily visualized
adherent to the nerve. The nerve therefore remains
vascularized throughout its length.
We have also been using the same technique to
effectively dissect the artery of the pedicle from the
venae commitantes in preparation for microvascular
We have found the use of lignocaine for hydrodissection of
the neurovascular pedicle to be an invaluable aid to
microsurgical dissection. Its use is advantageous over
normal saline because of a dilatation of the vessels .
This does not only greatly speeds their dissection but also
allows their branches to be easily seen and ligated as
necessary. Lignocaine also acts directly on the motor end
plates of the surrounding muscles, which reduces the
twitching that inevitably occurs when the motor nerve and
muscle are directly stimulated.
We feel that the use of a narrow blunt-tip cannula affords
no risk of trauma to the pedicle and that the dissection time
is greatly reduced. We have seen no complications from the
use of this technique to date.
Eur J Plast Surg (2006) 29:201–202
V. Rose (*)
T. C. Teo
The Queen Victoria Hospital,
East Grinstead, West Sussex, UK
31 Heathfield Gardens,
Chiswick, London W4 4JU, UK