**Region:** Head and Neck # Supratrochlear and Supraorbital Artery Flap ## Anatomy - Pedicle: supratrochlear artery and/or supraorbital artery with small accompanying veins (venae comitantes); both arteries are terminal branches of the ophthalmic artery. - Supratrochlear artery: average diameter ~1.0 mm; exits the orbit around the supratrochlear notch/medial rim, then courses cephalad between corrugator and frontalis, becoming superficial as it traverses the frontalis and subcutaneous tissue (emergence reported ≈ 15–50 mm above the supraorbital rim with wide variation) (Paramedian Forehead Flap; Supratrochlear & Supraorbital chapter). - Supraorbital artery: average diameter ~1.0 mm; exits via supraorbital foramen/ notch and runs deep to frontalis then pierces it to reach subcutaneous plane; foramen localized ~10.8 ± 4.9 mm lateral to medial canthal vertical and ~22.1 ± 2.6 mm superior to the medial canthal palpebral plane (Supratrochlear & Supraorbital chapter). - Venae comitantes: small veins accompany the arteries; supraorbital vein runs anterior to corresponding artery; ascending glabellar veins connect to angular veins and can be important for venous drainage (Supratrochlear & Supraorbital chapter; Vascular Anatomy). - Course (origin → skin paddle): - Ophthalmic artery → supraorbital / supratrochlear branches exit the orbit (pierce orbital septum or pass over rim) → pass between corrugator and frontalis or deep to frontalis → perforate frontalis → run in subcutaneous plane to mid-forehead and hairline where they anastomose with frontal branch of superficial temporal and contralateral vessels (Paramedian Forehead Flap; Vascular Anatomy). - Perforator pattern: - These vessels act as perforators after they enter the superficial facial fascia and muscle layer: they give superficial perforating branches through corrugator/procerus/orbicularis/frontalis (intramuscular/septocutaneous components depending on location), then continue subdermally supplying forehead skin (Supratrochlear & Supraorbital chapter; Vascular Anatomy). - Anatomical variability: deep branch of supratrochlear artery absent in up to ~45% in one series; supratrochlear emergence height shows wide range (multiple reports) (Supratrochlear & Supraorbital chapter). - Extensive anastomotic network across midline and with adjacent angiosomes (angular, dorsal nasal, superficial temporal frontal branch) — allows long paramedian / extended forehead flaps (Vascular Anatomy). - Nerves: - Supratrochlear nerve accompanies the supratrochlear vessels as they exit the orbit; frontal branch of facial nerve lies deep to superficial temporal fascia and crosses zygomatic arch (relevant to deep dissection) (Paramedian Forehead Flap; Ascending Helical Rim chapter for facial nerve relation). - Sensory branches (supratrochlear / supraorbital) run with vessels — preserve if sensate reconstruction desired (Paramedian Forehead Flap). - Included tissues: - Skin, subcutaneous tissue, frontalis muscle and galea/subgaleal plane as required; when raised as paramedian/axial flap often includes frontalis and variable thickness of subcutaneous fat. - Typical flap depth/planes by vertical third (paramedian technique): upper third — subcutaneous; middle third — submuscular/subgaleal (beneath frontalis) protecting vessels; lower third — subperiosteal (to preserve vessel through corrugator region) (Paramedian Forehead Flap). - Thickness profile: forehead skin is thicker than eyelid/nasal skin; expanded forehead flaps can be thinner for better contouring (Supratrochlear & Supraorbital chapter; Vascular Anatomy). - Arc of rotation / reach: - Supratrochlear-based paramedian/perforator flaps reach nasal, periorbital, and midface defects; supraorbital-based flaps suited for supraorbital–forehead and lower periorbital coverage. Pre-expansion increases available surface and reach (Supratrochlear & Supraorbital; Vascular Anatomy). - Common variants/anomalies: - Absent supratrochlear artery reported; substitute paracentral/angular branches may supply region (Kleintjes). Deep supratrochlear branch absent in a significant proportion (Supratrochlear & Supraorbital chapter). - Variable emergence height of supratrochlear; variability in venous anatomy (glabellar ascending veins) (Supratrochlear & Supraorbital; Vascular Anatomy). ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine with head slightly extended and turned to expose forehead and recipient site (Supratrochlear & Supraorbital chapter). - Mark Doppler-confirmed course of supratrochlear and supraorbital arteries from orbital rim to planned flap territory; mark midline, hairline, medial canthus, nasolabial folds and defect template. - If using tissue expansion, expand and re-map arteries/veins (indocyanine green useful after expansion to map arterial and venous phases) (Supratrochlear & Supraorbital chapter). - Template: transfer defect template to forehead and enlarge ~2–3 mm to account for inset (Supratrochlear & Supraorbital chapter). - Avoid injecting local anesthetic with epinephrine into the flap itself (blanching will hinder vascular assessment) (Paramedian Forehead Flap). 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Incise through skin and subcutaneous to superficial fascia; elevate in subfascial/subgaleal plane from superior to inferior, leaving periosteum intact. - Identify corrugator attachments — vessels are intimately associated here; use loupe magnification. - Use handheld Doppler to confirm perforator location and path; expanded flaps: indocyanine green angiography can visualize arterial and venous flow (Supratrochlear & Supraorbital chapter). - For paramedian flap: dissect upper third subcutaneous, middle third submuscular/subgaleal beneath frontalis, inferior third subperiosteal (Paramedian Forehead Flap). 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Expose the perforator where it pierces muscle/fascia; carefully free vessel from surrounding corrugator/frontalis to permit rotation without kinking; ligate small side branches. - Dissect pedicle proximally to required length; stay subperiosteal at orbital rim to avoid inadvertent vessel transection (Paramedian Forehead Flap). - For propeller/perforator island flaps: simulate rotation (clockwise and counterclockwise) and check for twisting/kinking; protect pedicle with surrounding tissue during rotation if tunneling. - Transfer by direct inset or via subcutaneous tunnel; check capillary refill, color, Doppler signal. For staged paramedian flaps: allow 3–4 weeks for neovascularization, then temporarily occlude pedicle (vessel loop) to test perfusion prior to division (Paramedian Forehead Flap). - If pedicle length insufficient for reach, consider alternative recipient vessels or interpositional vein graft (Ascending Helical Rim chapter; Supratrochlear & Supraorbital chapter). 4. Donor-site closure techniques. - Wide subgaleal undermining toward temporalis bilaterally increases mobility; galeal scoring can add advancement for primary closure (Paramedian Forehead Flap). - Primary closure if laxity permits; small residual areas can be left to heal secondarily or grafted (split‑thickness) but avoid exposing dry calvarial bone — keep periosteum moist or graft/cover to avoid delayed healing (Paramedian Forehead Flap). - Pretransfer expansion reduces need for graft and produces thinner flap for contouring (Supratrochlear & Supraorbital chapter). ## Indications and Contraindications - Indications: - Reconstruction of nasal skin (external cover) including partial and complete nasal defects (paramedian supratrochlear-based flaps remain workhorse) (Paramedian Forehead Flap). - Single-stage or staged reconstruction of periorbital, medial cheek, forehead, and nasal lining/ala (supratrochlear and supraorbital perforator flaps can be designed as propeller islands for one-stage repair in selected cases) (Supratrochlear & Supraorbital chapter). - Pre-expanded flaps for larger surface-area needs or when thinner tissue is required (Supratrochlear & Supraorbital chapter). - Size limits / tissue character: - Flap length limited by forehead height and vascular territory; superior extensions into hairline beyond ~1–1.5 cm are less reliable without delay/expansion (Supratrochlear & Supraorbital chapter). - Forehead flaps are thicker than nasal skin—defatting may be staged; expansion thins flap. - Sensate reconstruction: - Potential to preserve sensory nerves (supratrochlear/supraorbital) when required, but flaps are most commonly non‑innervated transfers (Paramedian Forehead Flap; Supratrochlear & Supraorbital chapter). - Contraindications: - Prior trauma/surgery/radiation to the frontal donor site or loss/ligation of the source vessels at the orbit (contraindication for reliable perforator flap) (Supratrochlear & Supraorbital chapter). - Very low hairline (may introduce hair-bearing skin into recipient), absent or tiny perforator on Doppler, or significant vascular disease — consider alternate donor or staged/delayed approaches (Paramedian Forehead Flap; Supratrochlear & Supraorbital chapter). ## Postoperative Care - Monitoring schedule / method: - Early frequent clinical checks: color, temperature, capillary refill and bleeding characteristics; use handheld Doppler to confirm arterial signal as needed (Supratrochlear & Supraorbital chapter). - For expanded flaps and when available, indocyanine green angiography can assist in assessing arterial and venous fill patterns (Supratrochlear & Supraorbital chapter). - For staged paramedian forehead flap: allow 3–4 weeks for neovascularization; prior to pedicle division temporarily occlude pedicle (vessel loop) and observe distal flap perfusion (Paramedian Forehead Flap). - Warming, antithrombotic practice: - Use standard local protocols for free/pedicled flap warming and anticoagulation as per institutional microvascular guidelines (no specific numeric regimen mandated in source texts). - Positioning / splinting / drains / mobilization / diet / analgesia: - Avoid pressure on pedicle/tunnel; drain placement at surgeon discretion — remove when output low (example threshold cited: remove when <5 mL to reduce hematoma risk in one chapter) (Supratrochlear & Supraorbital chapter). - Early mobilization as permitted by overall patient condition; standard analgesia and diet protocols. - Return-to-OR thresholds and time windows: - Immediate return to OR for clear signs of arterial insufficiency or progressive venous thrombosis (source case series stress importance of re-exploration in microvascular reconstructions and use of vein grafts when needed) (Ascending Helical Rim; Supratrochlear & Supraorbital chapter). - For pedicled paramedian flap: delay pedicle division if flap shows pallor or congestion at test occlusion; re-evaluate after further interval rather than immediate division (Paramedian Forehead Flap). ## Complications (rates & management) - Typical complications (reported in the source material in narrative form; explicit numeric complication rates generally not provided for supratrochlear/supraorbital flaps in the supplied chapters): - Venous congestion — recognition by bluish discoloration, slow capillary refill; management: urgent assessment, consider releasing sutures, remove compressing dressings/tunnels, and for microvascular transfers proceed to immediate re-exploration for venous thrombosis/thrombectomy/repair or additional venous anastomosis/ leech therapy only if described in specific series (Ascending Helical Rim and Vascular Anatomy note venous valve issues in reverse-flow constructs and recommendation for separate venous anastomosis in some reverse-flow flaps) (Ascending Helical Rim; Vascular Anatomy). - Arterial thrombosis / ischemia — sudden pallor and loss of Doppler signal: immediate return to OR for exploration, thrombectomy or revision of anastomosis; consider interpositional vein graft if pedicle length is inadequate (Ascending Helical Rim; Supratrochlear & Supraorbital). - Partial distal necrosis — small distal tips may necrose with tension or marginal perfusion: conservative wound care or debridement and local revision; paramedian flap strategy includes delay of division if distal pale or congested (Paramedian Forehead Flap). - Infection and wound dehiscence — treat with local wound care and antibiotics; debride if necessary. - Fat necrosis or bulky flap contour — may require secondary debulking or staged defatting; aggressive primary thinning over perforator may risk pedicle injury and is discouraged in initial operation (Supratrochlear & Supraorbital; Paramedian Forehead Flap). - Donor‑site issues: - Forehead donor: conspicuous scarring, wound-healing problems if periosteum/calvarium exposed — avoid drying periosteum; secondary healing or skin graft may be necessary (Paramedian Forehead Flap). - Hair-bearing transfer into non-hair-bearing recipient: consider later laser hair removal (Supratrochlear & Supraorbital chapter). - If primary closure impossible, tissue expansion or staged reconstructions recommended. - Management algorithms (from source guidance): - Pedicled forehead flap (staged): allow 3–4 weeks, perform temporary pedicle occlusion test; if healthy → divide; if pale/congested → delay/divide later (Paramedian Forehead Flap). - Microvascular / free-perforator / helical rim flaps: prepare for immediate re-exploration for arterial/venous compromise; be prepared to use vein grafts or alternate recipient vessels if pedicle reach inadequate (Ascending Helical Rim; Supratrochlear & Supraorbital). - Reverse-flow constructs: be mindful of venous valves; consider separate venous anastomosis for reliable drainage (Vascular Anatomy; Ascending Helical Rim). ## Key Clinical Pearls - Map the artery with Doppler preoperatively and mark the emergence point; supratrochlear perforator often exits medially ≈1.7–2.2 cm from midline and ~1.2 cm superior to medial canthus in reported series — expect wide variation (Supratrochlear & Supraorbital chapter; Paramedian Forehead Flap). - Respect the three-zone dissection plan for paramedian flaps: upper third subcutaneous; middle third submuscular/subgaleal beneath frontalis; lower third subperiosteal to protect the vessel as it comes around the orbital rim (Paramedian Forehead Flap). - Do not inject epinephrine-containing local anesthetic into the flap skin paddle — it obscures perfusion assessment intraoperatively (Paramedian Forehead Flap). - When greater length or thinner tissue is required, pre-expansion is effective: it enlarges surface area, thins flap, and permits indocyanine green mapping of arterial/venous phases (Supratrochlear & Supraorbital chapter). - Simulate rotation of perforator propeller flaps before dividing pedicle; ensure pedicle is freed sufficiently and not kinked with 180° rotation — always protect pedicle with surrounding tissue during transfer (Supratrochlear & Supraorbital chapter). - If Doppler fails to detect supratrochlear or supraorbital perforators, do not proceed with a narrow single-stage perforator flap — instead consider a paramedian forehead design with broad base, delay procedure, or alternate donor (Paramedian Forehead Flap; Supratrochlear & Supraorbital chapter). - Avoid aggressive primary thinning of the flap over the perforator — defer contouring to a secondary procedure to reduce risk of damaging intramuscular perforators. - Preserve periosteum and avoid leaving exposed calvarium to heal secondarily — maintain moisture or cover promptly to prevent prolonged donor-site morbidity (Paramedian Forehead Flap).