Radial Forearm Free Flap

Preoperative Considerations

Consent:

Flap failure
Donor site morbidity (including sensory loss, weakness, or cosmetic concerns in the forearm)
Possibility of requiring additional surgeries.‍
Functional Implications: changes in sensation, strength, and mobility in the forearm and hand. Patients should understand how the procedure may impact their ability to perform certain activities.‍
Cosmetic Outcome: Discuss the anticipated cosmetic outcome of both the reconstructed area and the donor site on the forearm. Manage expectations regarding scarring and potential differences in appearance between the two sites.

Anesthesia/Positioning:

OK for paralysis

Other:

Allen test prior to surgery
Hang "No IV" sign in preop until final surgeon assessment

Armamentarium:

Scalpel, scissors, and dissecting instruments for tissue dissection and preparation.
Microsurgical instruments, including microforceps, microscissors, and microneedle holders, for precise microvascular anastomosis.
Bipolar cautery or diathermy for hemostasis.
Vessel loops or vessel clamps for temporary occlusion of blood vessels.
Microvascular clamps for vessel occlusion during anastomosis.
Suture materials, such as 8-0 or 9-0 nylon or polypropylene sutures for microvascular anastomosis and 4-0 or 5-0 absorbable sutures for wound closure.

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Doppler Probe: Used for identifying and assessing blood flow in vessels during dissection and anastomosis.
Tourniquet: A pneumatic tourniquet may be used to achieve bloodless surgical fields during the procedure.
Flap Harvesting Instruments: Dermatome for harvesting skin grafts from the forearm. Tissue retractors and elevators for exposing and dissecting tissue layers. Hemostatic agents, such as surgical clips or electrocautery, for controlling bleeding during flap harvesting.
Microvascular Anastomosis Equipment: Operating microscope with appropriate lighting. Microsurgical instruments mentioned earlier. Loupes or magnifying glasses for surgeons who do not use a microscope. Microvascular anastomosis couplers (optional), which can facilitate faster anastomosis in some cases.

Technique

The defect is measured in order to estimate the flap dimensions and configuration prior to the elevation.
The donor site can be designed in a rectangular or ellipsoid fashion in the distal aspect of the forearm with course of the radial artery and cephalic vein coursing through it.
Next, exsanguination is achieved with a tourniquet raised to 250 mmHg for approximately 60-90 minutes. A lazy S connects the marked donor site with the proximal forearm and allows access for vascular dissection. Of note, the incision surrounding the skin paddle is performed carefully to preserve the subcutaneous veins

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The dissection can begin proximally (pictured) or distally depending on surgeon preference. Beginning proximally may aid the surgeon in early identification of cephalic vein, radial artery, and venae comitantes.
Skin Incision beginning proximally in ACF

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Elevation and incision of the fascial layer

The fascia is then identified in the subcutaneous plane and is sharply incised at the anticipated juncture between the brachioradialis and flexor carpi radialis (FCR) muscle
Dissection is continued deeper between FCR and brachioradialis till the pedicle (radial artery & venae comitantes) is identified

Muscle bellies with intervening fascia identified

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Continuation of dissection towards pedicle

The radial artery and vena comitantes are dissected between the brachioradialis and the flexor carpi radialis. The dissection is continued proximally until the surgeon is satisfied with the pedicle length for the anastomosis. Furthermore, the tissue between the pedicle and cephalic vein is maintained to preserve the vascular channels between the superficial and deep vascular systems. At this point, the radial artery, vena comitantes, cephalic vein, and lateral cutaneous nerve of the forearm (if dissected) should be clearly identified.

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FCR and bracioradialis muscles are separated and the pedicle is visualized

Once the vessels are identified within the intermuscular septum, the dissection continues distally till the skin paddle. During this process, multiple deep muscular and bony vascular branches are divided and ligated to allow ease of flap elevation.

The radial artery can be seen within the intermuscular septum.

Attention is then directed towards the elevation of the distal flap and skin paddle.
Distal incision is made through skin ONLY with electrocautery or blade. Ensure the underlying superficial branches of radial nerves and vessels are not violated.

Attention is then directed toward identification and isolation of the distal venae comitantes, cephalic vein, and radial artery.

Demonstration and protection of a superficial branch of radial nerve (gives sensation to dorsal thumb surface)

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Cephalic vein is identified distally between the two superficial radial nerve braches

Note that some surgeons elevate the flap without cephalic vein (venae comitantes only), however, harvest of cephalic vein may allow for additional venous drainage and better vein size matching during the inset

Cephalic vein is identified distally between branches of superficial radial nerve (preserved)

The cephalic vein is identified, dissected, ligated and is kept attached to the flap.

The skin paddle is then carefully elevated in a subfascial plane taking care to protect the radial nerve branches
Note that a subfascial (rather than suprafascial) dissection allows for capture of majority of perforators

During the elevation it is also critical to ensure the pedicle remains connected to the skin paddle.

Radial dissection completed, Note the two branches of superficial radial nerve join as single trunk

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Cephalic ven, radial artery, venae comitantes

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The ulnar dissection is now implemented and the flap is elevated off the superficial flexor tendons ensuring the paratenon remains intact.
Preservation of paratenon will protect the tendon from dessication and helps with success of skin graft

Ulnar side dissection and elevation of the flap

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Radial artery is kept intact til the dissection is completed from both radial and ulnar sides

Completion of the ulnar end of the dissection in a subfascial plane

Separating flap in subfascial plane from tendon of palmaris longus

Distal end of radial artery and venae comitantes are identified
Keeping the radial artery intact until immediately prior to flap disconnect will maintain vascularity to the hand in case there is an intraoperative change in reconstructive plan

Finally, the radial artery and vena comitantes are ligated and transected in preparation for harvest completion.

The vessels are separated at the distal end and the flap is carefully elevated towards the proximal takeoff, taking care to avoid damage to the main vessels as they are dissected away from deeper branches.

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Dissection is continued proximally to ACF till the cephalic vein connects with the venae comitantes so there is a common connection which allows for single venous anastomosis . This also provides larger caliber vessel for anastomosis.
Hemostasis is now achieved and the flap can be ligated and transposed to the recipient site.
Closure for donor sites options:
- Primary split or full-thickness skin graft (with wound vac or xeroform or compressive/bolster dressing such as an ace bandage)
- Staged closure- tissue matrix such a Integra (1 week of wound vac then 5 weeks of xeroform/ kerlix) followed by secondary skin grafting. (Pictured). This allows granulation tissue growth over tendons and gives a higher success rate of secondary skin graft.
Drain placement per surgeon preference

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Integra secured with 4-0 chromic gut, proximal incision closed with subcutaneous 4-0 monocryl

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Postoperative Considerations

Immediate:

Short arm volar splint

Follow Up:

Examining donor + inset sites for color, temperature, sensation, and capillary refill. Any changes in these parameters may indicate potential complications such as flap compromise or vascular insufficiency.

Operative Note

Surgeon(s): ***

‍Assistant Surgeon(s): ***

‍Preoperative Diagnosis: ***

‍Postoperative Diagnosis: Same

‍Procedure(s): ***

‍Anesthesia: General

‍Implants: None

‍Specimen:***

‍Drains: None

‍Fluids: See anesthesia record

‍EBL: Minimal

‍Complications: None

‍Counts: Correct x2

‍Indications: ***

‍Findings: As expected

‍Procedure in Detail:

‍The patient was seen in the preoperative holding area with a H&P was updated, consents were verified, surgical site marked, and all questions and concerns related to the proposed procedure were discussed in detail. The patient was transferred to the operating room by the anesthesia team. The patient underwent general anesthesia with endotracheal intubation. Tegaderms were placed over the eyes. The patient was prepped and draped in the standard fashion for maxillofacial procedures. A time-out was performed and the procedure began.

The upper extremity was inflated to 250 mmHg with a tourniquet. A releasing incision was made from the antecubital fossa to the planned skin only. The muscle bellies of the FCR and brachioradialis were separated and the pedicle was identified. This was then traced proximally to the bifurcation of the brachial artery and the ulnar artery was identified and preserved. Radial VC convergent to a large system suitable for microvascular anastomosis. The cephalic vein was clipped and divided. The skin island was then raised in a subfascial plane, taking care to identify and preserve the superficial branch of the radial nerve. From the ulnar direction the S and FPL muscles were identified in order to stay underneath the pedicle. Pedicle was then suture ligated and divided distally and the flap was raised in a distal to proximal direction. At this point, the tourniquet was released and the extremity was allowed to perfuse demonstrating excellent return of color, warm with a cap refill to the 4 fingers and thumb with good pulsatile flow to the flap and bleeding from the cut edges.

Radial vessels were then clipped, divided and flushed with heparinized saline. He was transferred to the neck for insetting anastomosis. Skin paddle was inset and transferred appropriately in a tension-free manner into the left neck. A sterile operating microscope was then brought into the field and the radial artery was sutured to the branch off the facial artery using 8-0 nylons in a running continuous fashion. Vein was secured to the common facial using a 4 mm coupler. Release of the vascular clamps demonstrated excellent flow across the anastomosis with return of color, warmth and cap refill to the flap. Forearm donor site was irrigated and repaired by first harvesting a split thickness skin graft from the _____ power dermatome. This was used to cover the volar surface defect and pie crusted. Releasing incision was then closed in layer and a bolster dressing with a negative pressure wound vacuum device was placed. Short arm volar splint was also applied.

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The patient's face was then cleaned and the posterior pharynx was suctioned. An OG tube was used to suction out the contents of the stomach. Tegaderms were removed from the eyes. Dressings were placed. The patient was then transferred back to the care of the anesthesia team for extubation and recovery.

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Coding

15758 Radial Forearm free flap (soft tissue)
15757 Radial Forearm free flap
29125 Application of short arm splint, forearm to hand; static.
97605 Wound vac application < 50cm SQ
21244: Reconstruction of mandible - extraoral approach, with plate application
35701: Exploration of Neck / Carotid vessels
41155: Composite procedure with resection of floor of mouth, mandibular resection, and neck dissection
20245: Deep bone open biopsy (bone deep to muscular tissue)
31600: Tracheotomy
21209: Osteoplasty of facial bone with reduction Incision and repair of bony defect of cheek bone including bony segment reduction
69990: Microsurgical techniques, requiring use of operating microscope
88331: Pathology consultation during surgery
14041: Local tissue rearrangement
97605: Wound vac application < 50cm SQ
64400: Local anesthesia block
76377: 3D post-processing images are reconstructed on an independent workstation with concurrent physician supervision.