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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4479_Библиотеки_им_академика_М_И_Перельмана.pdf
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outow system option. The radial venae comitantes lumen diameter is generally
1.5mm, while the cephalic vein diameter is often 3mm or larger. The cephalic vein
is simple to harvest and is most commonly employed as a single venous drainage
system. The downside of single cephalic venous drainage is the risk of vessel thrombosis and possible OCRFFF failure [25, 26]. Venae comitantes join into a single
larger caliber vein just before draining into the medial cubital vein at the bifurcation
point of the brachial artery. The length of the coalesced vein is about 0.25–1.5cm.
Employing a large diameter coalesced vein gives effective venous drainage from the
hemodynamically superior deep venous system as well as an appropriate lumen
width for microanastomosis [27].
In general, there are multiple options for ap venous outow designs, including
the deep or supercial system alone or dual combination congurations. Prior studies have reported similar outcomes using supercial venous drainage systems compared to the deep alone or dual combination systems and ultimately may be selected
per reconstructive surgeon preference and/or prior experience [28, 29].
F. Mirzamohammadi et al.
Preoperative Planning
Preoperative planning for the OCRFFF is both integral and critical for achieving a
successful reconstructive outcome. This investigation includes thorough patient history and comprehensive clinical exam, complemented with diagnostic imaging
as needed.
Medical andSocial History
The patient history establishes hand dominance and occupation, if applicable, as
this will contribute to selecting the appropriate donor site arm. It is important to
determine if the patient has had any prior surgery on the upper extremity that could
jeopardize the vascularity of the ap.
Clinical Exam
Following identication of the patient’s preferred or dominant hand, the contralateral limb is evaluated for quality of skin, tissue bulk and consistency, as well as the
presence of any prior scars or surgical interventions. The continuity of the palmar
arch is assessed by employing Allen’s test. A modied version of Allen’s test can
also be performed, utilizing either Doppler evaluation of the radial palmar arch or a
pulse-oxygen monitor for evaluation of saturation throughout the study. This evaluation can identify if the ulnar artery is robust enough to perfuse the hand through the
palmar arch after ap harvest radial artery sacrice.
In our experience, we have found a combined approach of using an in-ofce
Allen’s test with an ultrasound duplex exam improves our accuracy of arterial ow
15 The Osteocutaneous Radial Forearm Free Flap
203
dominance, thereby eliminating the need for intraoperative treatment of hand ischemia related to ulnar artery insufciency. Furthermore, this more thorough preoperative workup minimizes the need for intraoperative preap harvest tourniquet
deation (i.e., to assess radial hand perfusion prior to denitive donor radial artery
ligation), thereby minimizing operative eld bleeding and shortening our subsequent surgical times.
Imaging
Image-based investigation is not a mandatory portion of the preoperative workup
with a stable clinical evaluation, but it can certainly augment the clinical exam ndings and provide clarication when clinical ndings are equivocal. For example, if
Allen’s test lacks brisk hand reperfusion, an arterial duplex scan can objectively
elucidate functional extremity vasculature and conrm whether radial artery harvest
is safe.
Instrumentation/Requirements
Positioning/Prep
• Split or universal draping system
• Betadine or ChloraPrep
• Supine positioning with arm accessible via arm table
Pharmacy
• Preoperative antibiotic per surgeon preference
• “Tsai solution” (vessel lumen irrigation) in 10cc aliquots
– 250cc lactated ringers with 30cc 1% lidocaine without epinephrine and
3000units of heparin
• 0.5% marcaine or Ropivicaine for postoperative pain control
• Consider analgesic catheter placement in the forearm (i.e., On-Q pain pump;
Avanos Medical, Inc., Alpharetta, Georgia)
• Heparin available
• Bone wax available
Instruments
• Microinstrument tray
– Two sets available: one opened and one emergency backup tray.
• Head and neck/plastics tray
• Hand set
• Osteotomes
• Sagittal and reciprocating saw
• Dermatome
• Wound vacuum-assisted closure device
Suture
• Monocryl 4-0
204
• Vicryl 3-0 and 4-0
• Ethilon 8-0 BV (2815G)
• 2-0 Silk sutures for drains
Drains
• 10 at JP, fully uted or Blake round drain
Requests
• High-denition microscope, 250 lenses, preferably with monitor screen for
the staff to follow along
• Maintain 70–75F degree room temperature
• Two operative scrub teams—donor and recipient site assistance
• Bilateral lower extremity sequential compression devices (SCDs)
• Pressure point padding
• Foley catheter placement
• Arterial line placement peranesthesia assessment
F. Mirzamohammadi et al.
Design/Technique
Patient Positioning
The patient is placed in a supine position with the head slightly over the upper edge
of the bed. Belt and extremity straps are employed to secure the patient to the OR
table. Sequential compression devices are placed on the bilateral lower extremities
for DVT prophylaxis. The patient’s neck is extended with a shoulder roll and a gel
or polyfoam cushion under the head. The upper extremity from which the OCRFFF
will be harvested is placed on a hand surgery side table or extended arm board, with
attention paid to shoulder positioning to avoid excessive shoulder abduction/extension that could potentially cause a traction injury to the brachial plexus. An Allen
test can be repeated prior to initiating harvest in a modied fashion with a pulse
oximeter, or alternatively, an intraoperative Allen test can be performed when the
radial artery has been isolated prior to ligation.
Prepping andDraping
The entire donor limb is prepped from the axilla to the ngertips. An extremity
drape, or two split drapes, is placed up to the axilla, and then a well-padded sterile
tourniquet is placed to the root of the extremity/upper arm, leaving the antecubital
fossa well exposed.
Flap Design andHarvest
A template of the recipient site head and neck defect is created using a spare sterile
surgical glove, sterile glove paper, or a piece of the sterile Esmarch elastic bandage.
15 The Osteocutaneous Radial Forearm Free Flap
205
The template is then transposed over the donor radial artery while ensuring the capture of the cephalic vein radially. Prior to making the incision, donor site closure is
preplanned, whether by a skin graft or adjacent perforator ap, to guide the proximal forearm incision toward the antecubital fossa. Local ap reconstruction techniques often include the proximal ap harvest incision in the ap design, usually
requiring a more radially positioned forearm access incision to allow recruitment of
more ulnar artery-based tissues for donor site reconstruction. If a skin graft is
selected to reconstruct the donor defect, a curvilinear incision is marked from the
proximal marking of the template to the antecubital fossa.
The limb is partially exsanguinated with manual occlusion of the brachial artery
at the elbow and elevation of the limb for approximately 60s. This allows gravity to
partially exsanguinate the limb while leaving enough blood in the vessels to aid in
visual identications of all key structures during the subsequent dissection.
Alternatively, the tourniquet can be inated to 250 mmHg for exsanguination
as well.
The skin paddle incision is then carried down through the skin and the subcutaneous tissue where fascia of the muscles of the forearm is identied, taking extreme
care to avoid injuring the cephalic vein and radial sensory nerve, both of which run
subcutaneously above the antebrachial forearm fascia in the distal forearm. The
radial artery is identied at the wrist and isolated with delicate dissection and vessel
loops. The distal venae comitantes and other small veins are clipped and divided.
The cephalic vein is dissected for an additional 1–2cm distally and then clipped and
divided. Axially oriented fascial incisions made over the brachioradialis (radially)
and the exor carpi radialis (ulnarly) tendons will allow safe en bloc elevation of the
radial septum connecting the skin ap with the radial artery and its venae comitantes—the fascial incisions should not violate the radial septum. Care must be taken
to preserve deep periosteal branches of the radial artery to the radius bone—these
are the perforating vessels that will nourish the vascularized bone graft of the
OCRFFF.The cephalic vein is also raised en bloc with the ap to provide a secondary drainage system for the ap as a backup or dual combination.
Identication of the supercial branch of the radial sensory nerve (RSN) as it
courses close to the cephalic vein at the wrist is paramount. Meticulous preservation
of the RSN branches prevents debilitating future painful neuromata and chronic
pain syndromes; of note, the RSN runs in the deeper layer of subcutaneous fat, in a
plane just deep to the cephalic vein. In contrast, the lateral antebrachial cutaneous
(LABC) nerve runs in the same plane as the cephalic vein, closely following the
path of this vein.
The proximal incision is then made through the skin and subcutaneous tissue
taking care to identify and preserve the supercial venous system as well as the
sensory nerves. The LABC nerve is located adjacent to the cephalic vein, and the
medial antebrachial cutaneous nerve is adjacent to the basilic vein. The supercial
drainage system generally runs supercial to the brachioradialis. It is isolated and
followed proximally, where it is commonly seen converging with the deep venous
system near the antecubital fossa. The radial artery and its venae commitantes run
206
F. Mirzamohammadi et al.
proximally under the brachioradialis muscle belly and are exposed by retracting the
plane between the brachioradialis and exor carpi radialis muscles.
Next, the skin island of the ap can be elevated off of the muscles of the forearm.
If desired, the tourniquet can now be released to evaluate hand perfusion. Meticulous
hemostasis is achieved. Microvascular clamps are applied to the distal radial artery,
and hand perfusion can be observed to conrm intact ulnar circulation of the hand.
The distal radial artery and cephalic vein should be divided no less than 1cm beyond
the skin paddle. With the vascular pedicle included with the skin paddle, the radial
and ulnar aspects of the distal skin island are elevated off the tendons of the brachioradialis and exor carpi radialis, taking care to maintain the integrity of the overlying paratenon in an effort to prevent them from adhering to the skin graft
postoperatively. Alternatively, a suprafascial skin paddle harvest may provide an
additional vascularized fascial soft tissue gliding barrier between the tendons and
the overlying soft tissue coverage or skin graft.
Radius Osteotomy
The brachioradialis muscle is retracted with careful preservation of the deep tissue
of the muscle belly containing fascio-osseous perforator branches of the radial
artery. Care must also be taken to preserve the deep course of the supercial branch
of the radial nerve. The exor digitorum supercialis is then released along the
ulnar aspect of the radius and retracted to visualize the exor pollicis longus. The
pronator quadratus is transected at its insertion to the radius. The periosteum and the
exor pollicis longus are longitudinally dissected down over the radius.
Following exposure of the radius, the next step is planning the osteotomy. The
length of the bone to be harvested is delineated following close evaluation and measurement of the defect to be reconstructed. The radius bone is generally harvested
in the middle and distal one third of the forearm, between the pronator teres and
brachioradialis tendon insertions (Fig.15.5). The distal osteotomy must be made at
least 2.5 cm proximal to the radius styloid process to allow a minimum of two
Fig. 15.5 Intraoperative
photograph showing radius
bone following harvest of
osteocutaneous free ap.
Note the thickness of bone
remaining and the beveled
cut at the proximal
osteotomy site, which is a
commonly utilized
osteotomy angle
15 The Osteocutaneous Radial Forearm Free Flap
207
screws to be inserted during prophylactic plating. Proximally, the bone can be harvested even beyond the pronator teres (PT) muscle insertion. In this case, the PT
tendon would require reattachment to the remaining radius or suture directly to the
plate. Figure15.6 demonstrates the radius bone following the harvest of the free ap.
A reciprocating saw is used to rst make the proximal and distal transverse osteotomy cuts, which are subsequently connected longitudinally with a sagittal saw.
Up to 50% of the radius’ thickness can be successfully and safely harvested. It is
best to initiate the cut beginning proximally on the radius, followed by advancing
distally. Extreme care must be taken to avoid injuring adjacent neurovascular and
musculotendinous structures. This proximal-to-distal technique approach can minimize the risk of an overly thickened bone harvest where the radius diameter is anatomically smaller. Irrigating the saw blade prevents thermal necrosis of the peripheral
margins of the bone ap and is essential to maintaining osteocyte viability within
the ap. The periosteum is preserved over the bone graft and incised dorsally, completing the vascularized bone graft harvest. Extreme care must be taken to avoid
separating the bone graft from the vascular pedicle.
Proximal Donor Vessel Preparation
Once the osteotomies are complete, the ap is then elevated distal to proximal. The
proximal venous and arterial anatomy is carefully evaluated and dened prior to
ligation. The deep and supercial venous systems often come together to create a
single large-caliber vein ideal for anastomosis. If this large caliber vein is traced
proximal to the antecubital fossa, it may branch into two large outows if a dual
drainage ap is desired. The radial artery is followed distal to proximal. The most
distal bifurcation observed is most likely found at the location of the radial artery
and the recurrent radial artery. Labeling the pedicle’s artery and veins in situ prior
to ap harvest (we recommend using microvascular clamps of differing sizes for
artery vs. vein) simplies subsequent vessel identication and preparation for anastomosis (Fig.15.7). Once the ap is ready to be transferred, the donor vein and
Fig. 15.6 Intraoperative
photograph showing
completed proximal
pedicle dissection
following harvest of radius
bone. Note dual drainage
system utilizing deep and
supercial venous outow
208
Fig. 15.7 Intraoperative
photograph showing
prophylactic radius plating
following harvest of
osteocutaneous radial
forearm free ap
F. Mirzamohammadi et al.
artery are ligated, the ap is transferred to the recipient site and inset, bony xation
is performed (thereby dening pedicle orientation and length), and microvascular
anastomosis is performed.
Prophylactic Plating oftheRadius
Forearm fracture following bone-harvesting radius osteotomy carries signicant
morbidity [30]. The incidence of pathologic fracture of the radius after radial osteotomy in older series reporting conventional approaches without radius reinforcement is reported between 20% and 67% [12, 30–33]. Biomechanical studies on
cadaveric radii have demonstrated even small osteotomies, up to one-third of the
radius diameter, may result in up to 24% loss of cortical integrity and radius strength
[34]. In an animal bone-based biomechanical study, removal of 25%, 33%, and 50%
of the cross-section area of the bone resulted in a 70%, 80%, and 85% decrease in
bone tensile strength, respectively [35].
The use of prophylactic internal xation of the radius after OCRFFF harvest to
strengthen the donor site was rst described in 1999; it has been shown to restore
75% of the bone strength of an intact radius and decrease the overall fracture rate to
0.5–2.6% [6, 12, 36–38]. With prophylactic plating, the amount of bone that can
safely be harvested may increase to as much as 50% of the radial circumference [8,
12, 37].
Various plates have been used for radius prophylactic internal xation. A straight
3.5mm stainless steel dynamic compression plate (DCP), applied in neutral mode
as a neutralizing tension band, is the most commonly used plate that has been
described. This specic plate design is bridged over the osteotomized radius surface
with bicortical screw xation to redistribute tensile and torsion forces and avoid
their stress concentration on the fulcrum otherwise created by the bone harvest osteotomy. Recently, low prole and anatomically contoured titanium or stainless steel
plates have been introduced and secured by unicortical locking screw systems; these
can be T-shaped or straight and vary in thickness from 2.4 or 3.5mm [39, 40]. A
15 The Osteocutaneous Radial Forearm Free Flap
209
biomechanical study of various prophylactic plates applied in sheep tibia found the
straight 3.5mm stainless DCP plate with bicortical screw xation demonstrated the
highest dened strain criteria, as compared to unicortical locking systems [38].
In our experience, we routinely use 3.5mm stainless DCP plates for internal
xation of the radius following osteocutaneous harvest via anterior approach
(Fig.15.8). The plate is placed on the anterior surface of the radius over the bony
defect and adapted in place with bicortical screw xation with a minimum of two
screws at each end of the osteotomy defect. Usually, an 8- to 14-hole plate is
required depending on the length of the osteotomy defect. The plate’s screws are
applied in neutral mode (i.e., non-compressive) and act as neutralizing tension
bands to provide bridging reinforcement and prevent tensile forces from stress concentrating on the intact radius cortex (i.e., prevent hinging on the intact cortex of the
radius that would otherwise produce a pathologic fracture). This technique also
increases our safe bone harvest limit up to 50% of the radial circumference [8, 12].
Distally, extreme care must be taken to ensure that the tips of the screws engaging
the dorsal radius cortex do not impinge upon the extensor tendons, as this can risk
tendon ruptures. The anterior approach is simple and effective [41].
Posterior plate positioning can also be employed by retracting the extensor tendons to allow dorsal radius plating opposite the donor site defect. Distally, the radial
wrist extensors are retracted, and two to three standard bicortical screws are placed.
Proximally, the supinator muscle is subperiosteally elevated, and the plate is placed
beneath it. Care must be taken in this step to protect the posterior interosseous nerve
(PIN), which pierces the supinator muscle; injury to the PIN can cause nger and
thumb extensor paralysis. No screws are placed in the defect cavity because it is
shown to increase the rate of fracture at the screw site. The soft tissue coverage over
a posterior plate is relatively thin, and there is a higher chance of extensor tendon
rupture.
Both anterior and posterior approaches have been successfully used in a number
of clinical series with an overall fracture rate decrease to 2.6% [11, 38, 42, 43].
However, posterior plate xation can be more demanding compared to the anterior
Fig. 15.8 Intraoperative
photograph showing
preoperative forearm
markings planning for
local ulnar ap closure of
ap donor site
210
F. Mirzamohammadi et al.
approach and increase risks of extensor tendon-related complications. Because of
this, we prefer the anterior method of xation in our practice.
Closure oftheDonor Site
In order to optimize closure of the forearm donor site, vascularized soft tissue,
including underlying muscle, should be reapproximated over the xation plate to
prevent plate extrusion. The exor pollicis longus is sutured over the plate, and the
exor digitorum supercialis is brought over the exor carpi radialis tendon to the
radial skin edge. This provides a second muscular layer over the plate and bony
donor site and facilitates skin graft take should one be used. The pronator quadratus
can also be repaired to the radial edge of the brachioradialis tendon to provide an
interposed vascularized muscle layer to separate the plate from the exor tendons to
decrease the risk of tendon rupture.
Multiple different techniques for the closure of the OCRFFF donor site have
been described. Direct closure may be possible in certain scenarios, but generally
not performed as the size of skin paddles typically harvested precludes this [44, 45].
Preexpansion of the OCRFFF donor site is another technique that can facilitate the
primary closure of the donor site [46]. However, preexpansion requires an additional surgical procedure and delays the treatment of oncologic patients requiring
immediate surgery and reconstruction. Furthermore, tissue expanders are not without the risk of implant infection or extrusion.
Secondary OCRFFF donor site closure techniques can be divided into two major
categories: nonvascularized versus vascularized soft tissue based closure.
Nonvascularized Donor Site Reconstruction Techniques
Split-thickness skin grafts (STSG) have conventionally been used to close OCRFFF
donor sites. They are technically simple to apply, but associated complications
reported include partial loss of the skin graft, tendon exposure with poor skin graft
bed preparation, and suboptimal aesthetic results.
The purse-string suturing technique or cross-suturing technique have been
described and used to partially close the donor site, reducing the size of the donor
site defect, ultimately requiring a smaller skin graft [47, 48]. Care must be taken to
avoid applying undue tension to the wrist crease, as this can risk causing subsequent
loss of wrist motion.
Another alternative or adjunct to STSG is the use of dermal substitutes for donor
coverage [49, 50]. Selected studies that compared STSG-alone versus dermal matrix
combined with STSG reported aesthetic and functionally favorable results in the
dermal matrix augmentation group.
Full-thickness skin graft (FTSG) reconstruction is another alternative to
STSG.The FTSG provides thicker wound coverage compared to STSG, reducing
the rate of wound breakdown in addition to providing a superior aesthetic result
15 The Osteocutaneous Radial Forearm Free Flap
211
[51]. FTSGs can be harvested from multiple locations, including the abdomen,
groin, inner arm, or neck [52–55]. Harvest of an FTSG adjacent to the OCRFFF
donor has also been described in an attempt to improve secondary donor-related
outcomes and better skin color match [51, 56–58]. However, the size of donor site
defects that can be covered with this technique is limited. FTSG techniques also
depend on a robust and well-vascularized recipient site wound bed capable of supporting the skin graft.
Few studies have described the innovative use of local tissue rearrangement and
skin grafting to be able to close a larger donor defect in the forearm. In a series of
100 patients with OCRFFF donor reconstruction using local FTSG, Morino Sanchez
etal. describe a graft technique using between two and four local FTSG triangles in
a geometric model for the reconstruction of large donor site defects up to 70cm2 [59].
Vascularized Soft Tissue Donor Site Reconstruction Techniques
OCRFFF donor site reconstruction by local aps may achieve primary closure of
the donor site without an additional limb donor site (as seen with skin grafts), provide the optimally matched soft tissue for forearm donor site closure (often with
superior aesthetics), and provide the optimal soft tissue gliding barrier over exposed
tendons and the underlying reconstruction plate. These local ap techniques can be
performed in a single stage but are limited by the amount of tissue required and
available for defect closure and can be complicated by issues such as dehiscence/
partial tip ap loss.
Since 1988, when Elliot et al. used the ulnar artery perforator ap to close a
radial forearm donor defect, multiple modications have been introduced to optimize the RFFF tissue coverage based on this technique [60, 61]. The ulnar artery is
radial to the exor carpi ulnaris muscle. Dominant perforators of the ulnar artery
emerge approximately at the distal one-third of the forearm. One or two perforators
of the ulnar artery are consistently observed 8–10cm proximal to the pisiform [62].
By preserving these perforating vessels of the ulnar artery, the remaining forearm
fasciocutaneous tissue can be lifted off the underlying musculature and advanced
forward to close the radial forearm free ap donor defect.
If a V-to-Y advancement ap is selected for donor site reconstruction, the radial
forearm ap is better to be elevated with its long axis parallel to the wrist crease
rather than the anatomical design along the radial artery to facilitate closure using
proximal forearm local tissues. However, this approach may decrease radial forearm
ap viability. The ulnar perforator ap closure is not without risk. It has been associated with the risk of sensory decit or marginal necrosis because of extensive undermining required for advancement closure.
A variety of different local tissue rearrangements based on the fasciocutaneous
perforators of the ulnar artery have been described, facilitating anatomical long-axis
harvest of the radial forearm ap and the ability to cover a larger donor defect size.
These techniques include using a bilobed ap, a double-opposing rhomboid transposition ap, and z-plasty [63–66]. The Keystone ap is also a feasible alternative