**Region:** Head and Neck # Temporoparietal Artery Perforator Flap ## Anatomy - Pedicle: superficial temporal artery (STA) (parietal or frontal branch) with accompanying superficial temporal vein(s). Key numeric facts: STA origin diameter described variably (text: 2.5–3.2 mm at origin; terminal branch diameters: frontal ≈1.1 mm, parietal ≈1.3 mm), main trunk courses ≈6.7 cm before bifurcation; pedicle length measured from tragus ≈2–3 cm. The temporoparietal fascia (TPF) vascular territory can be harvested to ~12 × 14 cm; average free flap commonly ~12 × 8 cm and can be extended to ~17 × 12 cm (if margins viable) (Ch.13; Ch.12). - Course: STA runs anterior to the ear, crosses the zygomatic arch and pierces the temporoparietal fascia ~4–5 mm in front of the tragus, then bifurcates into frontal and parietal branches ~2–4 cm above the zygomatic arch and ascends within the TPF toward the vertex; branches give off superficial perforators that pierce frontalis/cutaneous layers approximately two‑thirds of the distance between zygomatic arch and midline (Ch.13; Ch.12). - Perforator pattern: perforators run within the temporoparietal fascia and become subdermal approximately in the upper forehead; the TPF is a direct (septocutaneous) axial fascial territory overlying the temporalis fossa nourished by STA branches (Ch.13; Ch.12). - Venous drainage: superficial temporal veins accompany the artery but may be variable (single, duplicate, or absent) and can lie posterior to the artery by several centimeters; posterior auricular and occipital veins contribute to drainage (Ch.13). - Choke vessels/angiosomes: robust anastomoses exist anteriorly with supraorbital/supratrochlear (ophthalmic) branches and posteriorly with posterior auricular/occipital territories—allows some extensions and composite designs (Ch.12; Ch.13). - Nerves: - Sensory: auriculotemporal nerve (V3) branches course posterior to the STA and provide sensory innervation to temporal scalp; these lie in/near the TPF and may be encountered during dissection (Ch.13). - Motor: frontal (temporofrontal) branch of facial nerve lies deep to the TPF on a line from 0.5 cm below the tragus to 1.5 cm above the lateral eyebrow (Pitanguy’s line). This line marks the anteroinferior safe limit for dissection—the nerve courses on the deep surface of the TPF and must be preserved to avoid brow ptosis (Ch.13). - Included tissues: - Tissue layers typically harvested: temporoparietal fascia (thin fascial layer), optionally overlying skin (hair-bearing if indicated), subdermal plexus, and with modifications may include deep temporal fascia (via middle temporal artery) and outer table calvarial bone (vascularized outer table) or hair-bearing scalp—allows composite flaps (Ch.13). - Thickness profile: TPF thickness ranges about 2–4 mm; very thin and pliable, excellent for gliding surfaces and for graft take on either side (Ch.13). - Arc of rotation: large for a local pedicled flap—pivot in the preauricular fold allows reach to ipsilateral hemiface, orbit/periorbital region, auricle, and via tunnel to oral cavity; as free flap it is versatile for extremity and head & neck coverage (Ch.13). - Variants/anomalies: STA and STV anatomical variability (number, diameter, course); middle temporal artery (MTA) can supply deep temporal fascia enabling two-layered (double) fascial flaps; STV may be posterior to arterial pedicle or duplicated/absent—leave base wide if venous anatomy uncertain (Ch.12; Ch.13). ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine, slight reverse Trendelenburg; head turned away from donor side; head supported on donut (Ch.13). - Markings: - Palpate/mark STA trajectory anterior to tragus; mark bifurcation and frontal/parietal branches with handheld Doppler (useful in atypical anatomy such as hemifacial microsomia) (Ch.13). - Draw a line from tragus to vertex to center flap; outline superior temporal line, zygomatic arch, preauricular fold, and Pitanguy’s line (0.5 cm below tragus → 1.5 cm above lateral eyebrow) as the anteroinferior safety boundary to protect frontal branch of facial nerve (Ch.13). - Plan flap size (TPF can be harvested up to about 12 × 14 cm routinely; free flap average 12 × 8 cm; extensions possible with caution) (Ch.13). 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Skin handling: shaving not required; prep hair out of field. Infiltrate subcutaneous tissue with dilute epinephrine avoiding area over pedicle markings (to avoid local vasoconstriction of target vessels) (Ch.13). - Skin incision: preferred horizontal or modified incision in hair direction (authors prefer horizontal to minimize alopecia); "T" or "Y" raw incisions increase alopecia risk—if vertical limbs used, zigzag/lazy‑S reduces scar contracture and alopecia (Ch.13). - Superficial elevation: elevate anterior scalp flaps in a plane immediately deep to hair follicles (subcutaneous/subdermal) to preserve superficial veins and include them if possible; coagulate small emergent superficial vessels cautiously with bipolar energy to avoid follicle damage and skin necrosis (Ch.13). - Fascial plane: expose temporoparietal fascia then incise flap edges and elevate deep surface in avascular plane (Merkel’s space) from superior → inferior (subfascial/sub‑temporoparietal fascia plane); this plane is smooth and is placed superficial in recipient bed (Ch.13). - Perforator identification: use handheld Doppler to mark STA branches preop; identify vessel where it emerges near corrugator/orbicularis region—expect vessel to be closely associated with corrugator muscle and pierce frontalis ~1.5–2.5 cm above supraorbital rim (Ch.13; Ch.19 provides allied forehead perforator anatomy). 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Pedicle exposure: ligate frontal branch if not required (commonly ligated ~3–4 cm distal to division from parietal branch). Dissect pedicle from surrounding tissue; options: - Wide pedicle with surrounding tissue preserved for reliable venous drainage, or - Skeletonize artery/vein for maximal length if free transfer is planned (Ch.13). - Follow pedicle inferiorly to origin near parotid if additional length needed; ligate zygomaticoorbital and transverse facial branches if needed to lengthen pivot point (Ch.13). - For composite designs preserve middle temporal artery if harvesting deep temporal fascia on same pedicle (two‑layer flap) (Ch.13). - Transfer: - Pedicled inset: rotate flap into defect or pass through adequately sized subcutaneous tunnel (large enough to avoid compression of pedicle). Secure flap, avoid kinking or torsion. Monitor with Doppler of pedicle for viability (Ch.13). - Free transfer: divide pedicle, perform microvascular anastomoses—artery typically STA branch; accompanying superficial temporal vein(s) used when present. Skeletonization of pedicle and careful separation of artery/vein required to permit microvascular anastomosis (Ch.13). - Perfusion checks: intraoperative handheld Doppler for arterial flow; clinical assessment of flap color/bleeding; indocyanine green angiography has been used in expanded forehead/perforator mapping (Ch.19) but not mandated for standard TPFF (Ch.13; Ch.19). 4. Donor-site closure techniques. - Primary closure is preferred: flap widths up to ~4 cm (or smaller depending on local laxity) commonly closed primarily; wide undermining and galeal scoring facilitate closure (Ch.13). - If primary closure not possible, options: - skin graft to donor scalp (cosmetic consequences), or - preoperative tissue expansion (expand under TPF/loose areolar plane) to permit primary closure and thin flap and reduce alopecia (Ch.13). - Drains: small suction drains may be placed when extensive elevation performed; close in layers and conceal scar in hair-bearing scalp (Ch.13). ## Indications and Contraindications - Indications: - Pedicled TPFF: auricular reconstruction (coverage of cartilage frameworks in microtia), orbital/periorbital reconstruction, forehead/scalp and brow reconstruction, coverage of cartilage grafts, thin pliable vascularized coverage for contracture release, lining or vascular carrier for mucosa (Ch.13). - Free TPFF: thin, vascularized fascial coverage in extremity reconstruction (hand dorsum, tendon coverage, tenolysis), coverage of osteomyelitis or devascularized bone, vascular carrier for composite reconstructions (e.g., trachea, pharynx, mucosal grafts), and small vascularized calvarial bone segments for bony reconstruction (Ch.13). - Composite options: include outer table calvarium, hair-bearing scalp, deep temporal fascia (with middle temporal artery) depending on defect needs (Ch.13). - Contraindications: - Prior surgery, trauma, or radiation to the temporoparietal donor region that compromises STA/STV territory or scalp viability (relative/absolute depending on severity) (Ch.13). - Severe hairline concerns where hair-bearing transfer would be unacceptable without prior planning (use tissue expansion or alternate donor) (Ch.13). - When larger soft-tissue volume is required (flap limited in maximal safe size) — consider alternative flaps (Ch.13). ## Postoperative Care - Monitoring schedule/method: - Pedicled TPFF: clinical checks and handheld Doppler for pedicle flow as needed; routine clinical assessment for color/temperature/bleeding (Ch.13). - Free TPFF: standard free flap monitoring per institutional protocols (clinical checks, Doppler/implantable probes if used) — the chapter notes no specific additional donor-site care unique to TPFF donor site (Ch.13). - Warming/positioning: standard measures to optimize perfusion; avoid compression at tunnel sites/pedicle course. - Antithrombotic practice: no specific regimen described in the chapter—adhere to institutional microvascular protocols. - Drains: small closed‑suction drains may be placed at donor site when extensive undermining performed (Ch.13). - Mobilization/diet/analgesia: standard postoperative care according to recipient site and patient status. - Return-to-OR thresholds/time windows: - Chapter does not provide numeric thresholds for re‑exploration; use general microvascular principles—significant arterial/venous flow loss, progressive ischemia or congestion, or loss of Doppler signal warrants urgent review/re-exploration per local policy (not specified in source). ## Complications (rates & management) - Reported/common complications (qualitative): - Alopecia at donor site—most common; associated with thermal injury to hair follicles or excessive skin undermining; management: prevention with careful bipolar coagulation, minimal cautery, tissue expansion for closure, or corrective procedures later (Ch.13). - Brow ptosis—due to injury to frontotemporal facial nerve; prevent by staying posterior/superior to Pitanguy’s line and careful dissection (Ch.13). - Sensory loss in temporal region—injury to auriculotemporal nerve if included or sacrificed (Ch.13). - Partial flap edge necrosis (tips) when extended beyond vascular limit; manage conservatively (debridement, secondary healing, or local revision) (Ch.13). - Venous congestion—possible because STV anatomy variable; leaving a wider pedicle or incorporating available veins reduces risk; if congestion occurs in free flap setting, consider urgent return to OR for exploration of venous anastomosis (general microvascular principle; specific algorithm not provided in chapter). - Donor-site contour deformity or need for skin graft when primary closure not possible; tissue expansion recommended to avoid grafts (Ch.13). - Quantitative rates: specific percentage rates not reported in the TPFF chapter; avoid speculative figures (Ch.13). - Management algorithms (as described/implicit in sources): - Prevention is emphasized: protect frontal branch of facial nerve by respecting Pitanguy’s line; avoid excessive bipolar coagulation to prevent alopecia; preserve venous outflow by leaving adequate pedicle width or including STV where present (Ch.13). - If venous/arterial compromise suspected in free flap: standard microvascular re-exploration for thrombosis/technical issues (chapter advises microvascular technique and pedicle care but does not provide stepwise re-exploration protocol) (Ch.13). - For partial skin necrosis at tip: conservative wound care, debridement when necessary, secondary revision once healed (Ch.13). ## Key Clinical Pearls - Protect the frontal branch of the facial nerve by keeping dissection posterior/superior to Pitanguy’s line (0.5 cm below tragus → 1.5 cm above lateral brow) (Ch.13). - Expect the STA to pierce the TPF ~4–5 mm anterior to the tragus; bifurcation into frontal/parietal branches commonly ~2–4 cm above the zygomatic arch—mark with Doppler preop (Ch.13; Ch.12). - Typical harvested TPF dimensions: routinely up to 12 × 14 cm; free flap commonly ~12 × 8 cm and extendable to ~17 × 12 cm with caution (Ch.13). - TPF is very thin (≈2–4 mm) and pliable—ideal when minimal bulk and a gliding vascular surface are required (e.g., tendon coverage, thin resurfacing) (Ch.13). - Venous anatomy is variable—when venous anatomy uncertain leave a wider pedicle (include adjacent tissue) rather than skeletonize fully; if planning free transfer, identify and preserve any accompanying STV during harvest (Ch.13). - Middle temporal artery preservation enables a two‑layered flap (TPF + deep temporal fascia) or composite designs; include calvarial outer table when bone is required—elevate en bloc with galea/periosteum (Ch.13). - For improved donor closure and to reduce alopecia, preoperative tissue expansion in the deep plane (under TPF/loose areolar tissue) is an effective strategy (Ch.13). - Use a horizontal or bevelled incision in the hair-bearing scalp and minimize use of cautery at hair follicles to decrease scar alopecia; consider endoscopic assisted harvest to reduce visible donor scarring in selected patients (Ch.13).