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282
D. Copson et al.
29.1.1.3 Fascia-Only Reverse PIA Flap
Fascia-only variant of the reverse PIA ap. The original article highlights an improved cosmesis of the donor site as no
graft is required; it is a super-thin and very pliable fascial
ap, well suited to dorsal hand coverage. The ap is raised in
much the same manner at the reverse PIA ap [3].
29.1.1.4 Extended PIA Flap
The extended PIA ap is a variant described to extend the
reach of the reverse PIA ap to reach the ngertips. Instead
of using the PIA’s communication with the AIA to perfuse
the reverse-ow ap, the dorsal intercarpal arch, originating
from the radial artery, is used and the AIA communication
divided. The dorsal intercarpal arch communicates with the
PIA via the fth extensor compartment artery. This moves
the pivot point of the ap to the level of the carpus, rather
than 2cm proximal to the DRUJ, greatly extending the reach
of the ap [4].
29.2 Anatomy
The PIA ap is a fasciocutaneous ap, based on the septocutaneous perforators coming off the posterior interosseous
artery; a detailed knowledge of the arterial anatomy is
important.
The common interosseous artery arises from the ulnar
artery and branches into the anterior and posterior interosseous arteries in the proximal volar forearm. The PIA passes
dorsally between the radius and ulna at a point just distal to
the chorda obliqua ligament, through the proximal aspect of
the interosseous membrane; this point lies approximately
6cm distal to the lateral epicondyle.
When viewed from the extensor aspect, the PIA enters
into the extensor compartment between the distal edge of
supinator and the proximal origin of APL; this point is at the
junction of the upper and middle thirds of the forearm. Just
after entering the extensor compartment, the interosseous
recurrent artery is given off, from which a large proximal
cutaneous perforator may arise; the PIA lies on the septum
between ECU and EDM and passes distally in the forearm. It
reduces in size and becomes more supercial in the middle
third of the forearm, lying just under the deep fascia rather
than near the interosseous membrane. At a point 2cm proximal to the DRUJ, a communication exists between the PIA
and AIA; this communication is the basis of the distally
based posterior interosseous artery ap. Distal to the PIAAIA communicating branch, the PIA also has a communication with the dorsal carpal arch, which is the basis of the
extended PIA ap [2, 5].
Along its course the PIA gives off muscular, osseous and
fasciocutaneous perforators. These fasciocutaneous perforators provide the cutaneous supply on which the ap relies.
The PIA perforators are divided into proximal, middle
and distal third perforators. The most common perforator
relied upon in a classic PIA ap is in the middle third of the
forearm, just distal to the mid-axial point.
Use of the proximal perforators for reverse PIA aps has
been described to extend the reach of the ap, but this comes
with the added risk to the posterior interosseous nerve (PIN)
as there exists a closer relationship between the PIA and
branches of the PIN in the proximal third of the forearm.
The posterior interosseous nerve is of utmost importance
as the sole motor innervation to the extensor compartment of
the forearm and must, therefore, be preserved. The PIN
enters the dorsal compartment between the two heads of
supinator and lies on the radial side of the artery giving off
multiple branches. The nerve branch of the PIN to ECU
commonly passes just proximal to the large proximal perforator but can pass between the proximal perforator and the
remainder of the perforators in the septum, necessitating
division of this perforator.
29.2.1 Anatomical Variations
• Origin of the PIA may be from the ulnar artery directly
instead of the common interosseous branch in up to 10%
of cases. This does not affect the reliability of the PIA
ap.
• There is a large proximal perforator which has a degree of
anatomical variability as its source vessel may be the pos-
terior interosseous artery or the posterior interosseous
recurrent artery.
• The motor branch of the PIN to ECU may cross the recur-
rent PIA or the PIA proper in the proximal third of the
dorsal forearm. In these cases care must be taken to pre-
serve the nerve branch. This may limit which proximal
perforators may be harvested with the ap.
29.3 Preoperative Investigation
Preoperative assessment begins with a thorough history of
prior injury or surgical intervention to the dorsal forearm and
wrist. The current mechanism of injury must also be taken
into account and zone of injury assessed as to whether it
encroaches on the territory of the ap.
Preoperative imaging is not strictly necessary although
CT angio and Doppler investigations can offer additional
information. Handheld Doppler assessment can be used to
localise septocutaneous perforators as well as localise the
communication between the PIA and the AIA [6].
With a good-quality, high-resolution CT angiogram, it is
possible to visualise the posterior interosseous artery.
29 Posterior Interosseous Artery Flap
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29.4 Flap Design andMarkings
1. With the forearm in a pronated position, mark a line
between the lateral epicondyle of the humerus and DRUJ.
(This is the axis of intermuscular septum between ECU
and EDM.)
2. Mark a point 2cm proximal to the DRUJ (this is the location of the communication between the AIA and PIA
which acts as the vascular supply and pivot point when
performing a reverse PIA ap).
3. Template the defect and plan the ap in reverse based
around the pivot point:
– In our practice the proximal extent of the ap should
not extend above a point 6cm below the lateral epicondyle of the humerus. More proximal skin paddle
locations have been described up to the level of the
elbow but in our view come with increased risk of distal ap complications.
– For dorsal hand defects, template the defect after
debridement and with the hand in exion as not to
underestimate the size of the defect.
– Flaps with a width greater than 4cm will likely require
grafting of the donor site which should be taken into
consideration.
– The size and shape of the skin paddle may be varied to
include only the skin required to reconstruct the defect
or, in addition, a thin strip of skin over the septum as
advocated by some authors in a racquet-shaped skin
paddle [7]. In our view the latter is unnecessary,
because the septum, which is always raised with the
ap, is both slender and robust.
283
Fig. 29.1 Markings for PIA ap to cover MCPJ.With the forearm in a
pronated position, mark a line between the lateral epicondyle of the
humerus and DRUJ. (This is the axis of intermuscular septum between
ECU and EDM)
29.5 Flap Raise/Elevation: AStep-by-Step
Guide
Step 1: Markings
(See Previous Section and Fig.29.1)
Step 2: Patient Positioning
Surgery is performed under general or regional anaesthetic
with the patient supine. A padded hand table and arm tourniquet are used as well as loupe magnication, typically 2.5x
or similar. The arm is not exsanguinated before ination of
the tourniquet to aid identication of the vessels.
Step 3: Locating the Septum (Fig.29.2 and 29.3)
Dissection commences in the distal third of the forearm; the
little nger may be exed and extended to identify EDM
muscle belly and tendon through the translucent deep fascia
(Video 29.1). The forearm fascia is incised radial to the 5/6
septum and EDM muscle retracted to visualise the septum
Fig. 29.2 Dissection starts in the distal third of the forearm– note a
perforator emerging between the ECU and EDM septum
and PIA that lies against it. Once the septum and PIA are
clearly identied, a second parallel incision is made on the
ulnar side of the septum, which continues proximally to the
level of the ap itself.
Step 4: Centring the Flap on the Septum
(Fig.29.4 and 29.5)
Provisional ap markings are then checked to ensure that the
ap/skin paddle is actually centred over 5/6 septum; this is
particularly important when raising narrow aps, where
there is little margin for error. An incision around the ulnar
border of the ap is then made, and fascia over ECU is harvested with the ap.
284
Fig. 29.3 The forearm fascia is incised radial to the 5/6 septum and
EDM muscle retracted to visualise the septum and PIA that lies against
it. Note the perforators going into the skin paddle of the PIA ap
D. Copson et al.
Fig. 29.5 Location of multiple perforators going into PIA skin paddle– the ap axis is centred on the basis of these perforators
Fig. 29.4 Flap is centred over the 5/6 septum and the fascial strip over
ECU is harvested to protect the PIA pedicle
Step 5: Pedicle/Septum Dissection (Fig.29.6)
The ap is raised in a proximal to distal fashion once the
septum has been identied. The PIA is divided proximally
with the use of ligaclips. Muscle perforators are similarly
clipped or divided after cautery with ne bipolar forceps, and
the PIA and venae comitantes are harvested with the intermuscular septum preserving branches of the PIN.
Step 6: Flap Inset (Fig.29.7a, b)
A supercial tunnel is created to allow for compression-free
delivery of the ap to the primary defect; any tunnel wide
Fig. 29.6 The PIA is divided proximally with the use of ligaclips and
islanded for skin coverage of the hand
enough to allow easy passage of the skin paddle will easily
accommodate the narrow vascular pedicle. The ap is inset,
and the donor site closed either primarily or by split thickness skin graft.
Note
If raising an anterograde PIA ap, the dissection is carried
out in a similar fashion, with the location of the septum being
initially identied distally, by incising the fascia over
EDM.The dissection in an anterograde PIA ap progresses
from distal to proximal, ligating the PIA at the level of the
communication with the AIA [8].
ab
29 Posterior Interosseous Artery Flap
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Fig. 29.7 (a) PIA ap inset. (b) Outcome at 2weeks
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29.6 Core Surgical Techniques inFlap
29.7 Clinical Scenario
Dissection
29.7.1 Scenario A(Dorsum oftheHand/MCPJ):
Step 1: Markings (See Previous Section and Fig.29.1)
The markings act as a guide but may need to be adjusted
based on the location of the intermuscular septum. It is
important to not commit to the ap borders until the septum
is identied.
Steps 3 and 4: Locating the Septum and Centring the
Flap on the Septum (Figs.29.2, 29.3, 29.4, and 29.5)
As mentioned in the previous section, moving the little nger
through its range of motion can aid in the identication of
EDM tendon and muscle belly as demonstrated in Video
29.1.
Step 5: Pedicle/Septum Dissection (Fig.29.6)
Pedicle dissection is relatively straightforward once the
septum is identied. We nd retraction of the muscle best
performed by an assistant rather than a self-retainer. Care
must be taken at the proximal extent of the dissection,
where the PIA and PIN are in close proximity, and the
proximal nerve branch to ECU is most at risk as it may
cross the artery.
The most common scenario which lends itself to the PIA ap
is a dorsal hand defect with exposed tendon or bone in an
otherwise uninjured upper limb.
29.7.1.1 Case 1: Video 29.1: Surgeon Dariush
The associated images 1–7 and Video 29.1 show the right
hand of a gentleman with an exposed right middle nger
MCPJ.Tendon and an open joint were at the base of the wound
after debridement of an infected wound and septic MCPJ.In
this scenario a reverse PIA ap is used to cover the defect.
29.7.1.2 Case 2: Video 29.2: Surgeon Mark
A gentleman presented with a large SCC of the right thumb
necessitating amputation. Video 29.1 demonstrates a reverse
PIA ap being used to cover the defect.
Surgeon Dariush Nikkhah
Nikkhah
Pickford
29.7.2 Scenario B (Dorsum oftheHand Free
Step 6: Flap Inset (Fig.29.7a, b)
As with all pedicled aps, it is important to avoid venous
compression. The best technique to avoid compression will
depend on the specic case but may, occasionally, involve
dividing the overlying skin.
A 57-year-old man sustained a circular saw injury to his left
hand which resulted in open fractures and signicant soft tissue loss over the dorsum of the hand (Fig.29.8). Under axillary block we performed osteosynthesis rst and second
PIA Flap): Surgeon Petr Vondra
286
D. Copson et al.
Fig. 29.9 Harvest of a free PIA ap under regional anaesthetic
Fig. 29.8 Circular saw injury to his left hand which resulted in open
fractures and signicant soft tissue loss over the dorsum of the hand
metacarpal bones with plate xation. A vein graft was used
to repair a segmental defect in the radial artery.
At second stage we performed a free ipsilateral PIA ap,
anastomosed end to side to the vein graft and local veins
(Fig.29.9). The secondary defect was partially sutured under
tension and skin grafted. Final result on photo is after 6
(Fig.29.10) months from injury, the patient regained good
two-point sensation and excellent range of motion
(Fig.29.11).
Fig. 29.10 Long-term result
Fig. 29.11 Patient able to achieve near full exion
29 Posterior Interosseous Artery Flap
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287
29.8 Pearls andPitfalls
Pearls
• When identifying the septum between EDM and
ECU, moving the little nger and visualising the
tendons through the translucent deep fascia can aid
accurate identication of EDM.Looking for arterial
branches travelling in the fascia can also help locate
the septum [9].
• Harvest a strip of fascia over EDM and ECU, as
well as the 5/6 septum. This protects the underlying
ap pedicle and avoids unnecessary and risky dissection of the vessels off the septum.
• Do not attempt to skeletonise the pedicle or dissect
out the perforating vessel between the AIA and the
PIA.Both manoeuvres risk damage to the pedicle.
Pitfalls
• Unnecessary Proximal Dissection: Dissection of
the most proximal perforator is possible but
increases risk to the PIN.If the defect can be closed
using a middle third septocutaneous perforator,
then base the ap on this perforator.
• Underestimating the Size of the Defect: The
defect should be debrided before the defect size is
measured and the nal skin paddle designed. Dorsal
hand defects should also be measured with the hand
exed into a st as to not underestimate the size of
the defect [10].
• This paper is an early anatomical and clinical study of the
PIA ap. In this paper two anterograde and ten reverse
PIA aps are described.
• Zaidenberg EE, Zancolli P, Farias Cisneros E, Miller AG,
Moreno R. Antegrade Posterior Interosseous Flap for
Nonhealing Wounds of the Elbow: Anatomical and
Clinical Study. Plast Reconstr Surg Glob Open. 2018 Nov
7;6(11):e1959. doi: 10.1097/GOX.0000000000001959.
PMID: 30881783; PMCID: PMC6414117.
• This paper published in 2018 provides detail on the vas-
cular anatomy pertinent to the less frequently used anterograde posterior interosseous artery ap.
• Zaidenberg EE, Farias-Cisneros E, Pastrana MJ,
Zaidenberg CR.Extended Posterior Interosseous Artery
Flap: Anatomical and Clinical Study. J Hand Surg Am.
2017 Mar;42(3):182–189. doi: 10.1016/j.
jhsa.2017.01.004. PMID: 28259275.
• This CME style article published in the Journal of Hand
Surgery outlines the anatomical basis and surgical technique for the extended PIA ap and provides a more
detailed description of this less common variant than can
be entered into in this chapter.
• Techniques to enable identication and safe elevation of
the posterior interosseous artery ap: Part 1 and 2.
Nikkhah D, Pickford M.J Plast Reconstr Aesthet Surg.
2019 Jun;72 [4]:1030–1048. doi: 10.1016/j.
bjps.2019.02.006. Epub 2019 Mar 5. PMID: 30871942
No abstract available.
• Short communication detailing technical steps in safe
elevation of this ap and identifying the pedicle.
29.9 Selected Readings
• Posterior Interosseous Island Forearm Flap. J Hand Surg.
2 May 1988; 13-B.
• This paper is the original description, in the English lan-
guage, of the reverse posterior interosseous artery ap, as
described by Zancolli and Argrigiani in 1988. The same
authors published a description of the ap in Spanish
medical literature 2years previously (1986). It should be
the starting point for anyone considering performing this
ap as it provides a good description of the anatomy and
surgical technique and gives case examples.
• Penteado CV, Masquelet AC, Chevrel JP. The anatomic
basis of the fascio-cutaneous ap of the posterior interosseous artery. Surg Radiol Anat. 1986;8(4):209–15. doi:
10.1007/BF02425069. PMID: 3107143.
References
1. Zancolli EA, Angrigiani C.Posterior interosseous island forearm
ap. J Hand Surg. 1988;13B:130–5.
2. Penteado CV, Masquelet AC, Chevrel JP. The anatomic basis
of the fascio-cutaneous ap of the posterior interosseous artery.
Surg Radiol Anat. 1986;8(4):209–15. https://doi.org/10.1007/
BF02425069. Original French publication: Masquelet AC,
Penteado CV. Le Lambeau interosseux postérieur. Ann Chir Main
(sous presse). 1986
3. Jakubietz RG, Bernuth S, Schmidt K, Meffert RH, Jakubietz
MG. The fascia-only reverse posterior interosseous artery ap. J
Hand Surg Am. 2019;44(3):249.e1–5. https://doi.org/10.1016/j.
jhsa.2018.06.012. Epub 2018 Jul 19
4. Zaidenberg EE, Farias-Cisneros E, Pastrana MJ, Zaidenberg
CR. Extended posterior interosseous artery ap: anatomical and
clinical study. J Hand Surg Am. 2017;42(3):182–9. https://doi.
org/10.1016/j.jhsa.2017.01.004.
5. Costa H, Soutar DS. The distally based island posterior interosseous ap. Br J Plast Surg. 1988;41(3):221–7. https://doi.
org/10.1016/0007- 1226(88)90104- x.
6. Puri V, Mahendru S, Rana R. Posterior interosseous artery ap,
fasciosubcutaneous pedicle technique: a study of 25 cases. J
288
D. Copson et al.
Plast Reconstr Aesthet Surg. 2007;60(12):1331–7. https://doi.
org/10.1016/j.bjps.2007.07.003. Epub 2007 Aug 23
7. Acharya FNB, Bhat MS, Bhaskarand MS. The posterior interosseous artery ap technical considerations in raising an easier and
more reliable ap. J Hand Surg. 2012;37A:575–82.
8. Zaidenberg EE, Zancolli P, Farias Cisneros E, Miller AG, Moreno
R. Antegrade posterior interosseous ap for nonhealing wounds
of the elbow: anatomical and clinical study. Plast Reconstr
Surg Glob Open. 2018;6(11):e1959. https://doi.org/10.1097/
GOX.0000000000001959. PMID: 30881783; PMCID:
PMC6414117.
9. Nikkhah D, Pickford M. Techniques to enable identication and
safe elevation of the posterior interosseous artery ap: part 1 and
2. J Plast Reconstr Aesthet Surg 2019 Jun;72(6):1030–1048. doi:
https://doi.org/10.1016/j.bjps.2019.02.006. Epub 2019 Mar 5.
PMID: 30871942.
10. Shibata M, Iwabuchi Y, Kubota S, Matsuzaki H. Comparison of
free and reversed pedicled posterior interosseous cutaneous aps.
Plast Reconstr Surg. 1997;99:791–802.
Venous Flaps
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ChristopherDeutsch andJamilMoledina
30
30.1 Introduction
Venous aps—cutaneous free aps raised on a venous plexus
alone—are a unique subset of free aps, which have specic
characteristics ideally suiting them to reconstruction of the
upper limb and, in particular, the hand and digits.
The technique was originally described in animal models
by Nakayama [1] and subsequently translated into clinical
practice for reconstruction of skin defects in digital replantation [2, 3]. The early aps in humans were based solely on
venous inow, through the venous ap, with blood then
returned to the venous system as a true “ow-through” ap.
Anastomosis of an artery to the inow of the venous ap has
been used to enhance oxygen delivery to the transposed tissue, to increase the size and versatility of these aps [4]. As
such, venous aps can be classied according to both their
recipient inow and outow:
• V-V-V (vein-to-vein-to-vein). Venous inow passes
through the veins of the ap into an outow vein as a true
ow-through ap. This is most commonly useful on the
dorsum of the hand where recipient veins are readily
accessible and metabolic demands are relatively low.
• A-V-A (artery-to-vein-to-artery). As another ow-through
ap, arterial inow passes into the ap and is drained
back into a distal artery. This technique is particularly
useful in reconstructing a segmental arterial defect, thus
perfusing both ap and tissue beyond, in addition to pro-
viding soft tissue cover, as may be required in complex
digital revascularization.
• A-V-V (artery-to-vein-to-vein). Arterialized venous
aps are more similar to conventional free aps, where
the ap is designed in such a way as to restore vascular
anatomy approximating a normal artery-to-venous sys-
tem through a capillary bed. They are a useful option
C. Deutsch (*) · J. Moledina
Department of Plastic Surgery, St George’s University Hospitals
NHS Foundation Trust, London, UK
where reconstruction of the artery in continuity is not
required for distal digital reperfusion, such as at the ngertip or elsewhere on the hand. The authors recommend
the use of arterialized, as opposed to ow-through, aps
wherever possible, given the ap survival benets of
restoring a capillary bed.
30.2 Anatomy
Venous aps are not dened by an anatomical donor site, but
rather are united by the absence of an anatomical arterialcapillary- venous ow pattern. The ap can be raised on any
subcutaneous venous network where an inow and outow
vein can be selected and where the network is closely associated with the overlying skin; this is most commonly the dorsum of the foot, the volar forearm, and the medial leg.
The physiological mechanism for survival of these aps is
debated. It is certainly true that non-arterialized venous aps
will be required to survive on a lower PaO2 than is normal
and that for such aps in particular, neovascularization is
likely to be key to their long-term survival. The low PaO2
may indeed be a signicant driver in neovascularization.
Even in the case of arterialized venous aps, ow studies
have shown that where blood ow passes through the ap in
a straightforward anterograde manner (i.e., in the natural
direction of ow-through venous valves), the peripheral ap
is largely bypassed. A solution to this problem of shunting
has been to divert the ow around the ap in a retrograde
manner [5], so that resistance provided by the valves pushes
blood out to the peripheries. More recently, this has been
superseded by in-ap ligation of vessels, known as shunt
restriction, to encourage one vessel to act as an afferent
“artery” and one as an efferent “vein,” rather than relying on
one vein to do both and thus forcing blood into the peripheries of the ap [6]. This technique drives blood through a capillary system between the main afferent and efferent vessels
and signicantly improves the survival of these aps.
© Springer Nature Switzerland AG 2023
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289
290
30.3 Preoperative Investigation
The venous ap donor site is usually planned to be readily
expendable, and as such no specic preoperative investigation is required beyond standard preoperative planning for
any microsurgical procedure. As these aps are usually very
thin, the supercial venous plexus can be easily assessed clinically, and indeed this is the most appropriate way to design
the ap accurately. Handheld vein visualization devices may
have a role when supercial veins are hard to see.
30.4 Flap Design andMarkings
1. The venous networks of the volar forearm and dorsal
foot make excellent donors for venous aps (Fig.30.1).
2. Numerous tributaries to the basilic and cephalic veins of
the forearm are readily identied under the pliable skin
of the volar forearm; compression of the forearm or
upper arm may improve their visibility (Fig.30.2).
3. The defect can be templated and superimposed over visible veins, with a note made of the position of the recipient artery and veins (Fig.30.3).
4. The inow vessel needs to be positioned in the ap to
allow for anastomosis to the recipient vessel.
5. For an arterialized ow-through ap (A-V-A), a suitable
vein should be selected to act as the inow to the ap,
paying attention to ensure an anterograde direction of
ow. The vessel should run through the ap and then
anastomosed to a distal artery in the defect.
6. For an arterialized venous ap (A-V-V), the inow artery
should enter the ap, ideally centrally, and run only for a
short distance in the ap before being terminated by
ligation or distally anastomosed to an outow artery if
an arterial defect needs to be bridged. The authors sug-
Fig. 30.1 The venous plexus comprising tributaries to the cephalic and
basilic veins of the forearm
C. Deutsch and J. Moledina
Fig. 30.2 Manual compression of the forearm distends the veins and
makes them easily visible for ap planning
Fig. 30.3 The defect can be templated and superimposed over the
venous network for ap design
gest that approximately one quarter to one third, but certainly less than half, of the surface of the ap overlies the
arterialized vein, with the rest of the ap dedicated to
outow vein(s) (Fig.30.4).
7. Outow veins must also be selected in an appropriate
position for anastomosis to the outow recipient vessels
(Fig.30.5).
8. In arterialized venous aps, in-ap ligations should be
planned to be prevent all large connections between
inow and outow vessels; this shunt restriction recreates a capillary bed and reduces the problem of direct
shunt between the inow and outow systems.
9. The ap design can be adjusted to t a wide range of
defects. Design features such as concatenation of two skin
paddles (to resurface adjacent digits), or the inclusion of
additional structures such as the tendon of the palmaris
longus, allow reconstruction of complex defects (Fig.30.6).
10. The donor venous plexus must t with the recipient vessels, and if it does not, then a different donor site must be
explored.
30 Venous Flaps
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a
291
b
Fig. 30.4 (a, b) The arterialized inow to the ap should be ideally
positioned centrally, and terminated by ligation after running for a short
distance within the ap (marked in red)
a
b
Fig. 30.5 (a, b) The outow veins (marked in blue) are positioned to
match the position of recipient veins. [Alternative Figure—The outow venous network (highlighted) is positioned to match the position
of the recipient veins.]
Fig. 30.6 Tendon (highlighted), such as palmaris longus, can be
included within the ap for reconstruction of composite defects
30.5 Flap Raise/Elevation: AStep-by-Step
Guide
1. Design
In venous aps, design is a critical phase. The inow and
outow vessels must be carefully selected to match up to
the intended recipient vessels (Fig.30.7).
2. Tourniquet ination
Inate an upper arm tourniquet.
3. Ulnar skin incision
Begin on the ulnar border of the ap, closest to the operating surgeon. Incise carefully just through the dermis as
the veins are very supercial and can easily be damaged.
Once the veins are identied, they can be followed away
from the ap to obtain an adequate pedicle length, usually
up to 2cm, and then ligated and divided (Fig.30.8).
4. Radial skin incision
Repeat the process for the radial border of the ap, again
taking care not to injure the supercial venous network.
Preserve some length even on veins that have not been
identied for anastomosis as backup vessels (Fig.30.9).
5. Complete sub-ap dissection
Once the vessels have been dissected and ligated circumferentially around the ap, the ap can be raised relatively easily, by simply freeing it from the underlying
forearm fascia with sharp dissection (Fig.30.10).
6. Raise completed
The ap is ready for inset after performing in-ap ligation
on the underside using microvascular ligation clips or
suture ties. Here the ap has been raised with paratenon
and tendon for vascularized tendon reconstruction
(Fig.30.11).
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