**Region:** Lower Extremity # Profunda Artery Perforator (PAP) Flap ## Anatomy - Pedicle: profunda femoris (deep femoral) artery perforator(s) with venae comitantes. Typical vessel metrics reported: - artery diameter at profunda origin ~2.2 mm; mean accompanying vein diameter ~2.8 mm; pedicle length commonly ~10 cm (reported range 7–13 cm). (Hanasono et al.; Azoury et al.) - Course: - Source: profunda femoris artery (branch of common femoral) gives off perforating branches that course posteriorly along the adductor magnus insertion and supply the posterior/medial thigh skin. - Perforators commonly emerge through or alongside adductor magnus and/or between adductor magnus and semimembranosus; many are musculocutaneous (muscle-traversing) but septocutaneous perforators are also present. (Azoury et al.; Haddock series) - Most common proximal perforator location: ≈5 cm inferior (caudal) to the inferior gluteal crease and ≈3–4 cm posterior to the medial thigh midline (posterior to gracilis). A sizeable perforator in this region reported in ~85% of thighs. (Hanasono et al.; Haddock et al.) - Number: at least 2 perforators are typical (reported range 2–5); ~25% may arise from a common trunk. (Hanasono et al.; Azoury et al.) - Intramuscular segment length (when musculocutaneous): reported mean ~5.7 cm in some series. (Azoury et al.; Haddock et al.) - Perforator pattern: - Variable; both musculocutaneous and septocutaneous perforators found. Preoperative imaging (CTA/MRA) and Doppler correlate strongly with intraoperative anatomy (high detection rates reported). Mean perforator number ~3.3 and mean perforator caliber ~1.9 mm in imaging series. (Haddock et al.) - Perforators give ascending/descending branches forming interperforator collateral channels (perforasomes). - Nerves: - Posterior femoral cutaneous nerve supplies sensory fibers to posterior thigh skin; a branch can be included for a sensate PAP. (Azoury et al.; Dayan & Allen) - Avoid injury to posterior femoral cutaneous nerve when harvesting transverse/posterior incisions to prevent donor-site paresthesia. - Included tissues: - Skin ± subcutaneous fat; muscle usually spared (adductor magnus territory) — option to include small cuff of adductor magnus if bulk or dead-space filling required (chimeric design). - Thickness: posteromedial/posterior thigh adipose tends to be firmer/malleable and can provide 300–400 g typical flap weight for breast work (reported typical 300–400 g; range 150–900 g; series report up to ≈800 g). (Hanasono et al.; Allen et al.) - Arc of rotation: for free transfer pedicle length and recipient vessel choice (commonly internal mammary in breast reconstruction) determine inset; pedicle length often limits reach without vein/arterial grafts. - Common variants/anomalies: - Skin paddles: transverse (tPAP), vertical (vPAP), diagonal/fleur-de-lis (dPAP/fleur-de-PAP) — each captures different perforator distribution and donor-site trade-offs. (Hanasono et al.; Allen et al.) - Perforator location and number are variable; preoperative CTA/MRA recommended to identify and choose optimal perforator(s). (Haddock et al.; Azoury et al.) ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine with frog-leg or lithotomy; split-leg table or split-leg position facilitates two-team approach (donor harvest between legs) and avoids prolonged prone positioning. (Azoury; Allen/Hanasono) - Landmarks to mark standing then confirm supine: inferior gluteal crease (IGC), posterior border of gracilis/adductor line, candidate perforators (preop CTA/MRA and handheld Doppler). Mark anterior border ~along posterior gracilis and posterior border along Langer’s lines for diagonal designs. (Hanasono et al.; Azoury et al.) - Skin-paddle choices: - tPAP: superior margin at/≈1 cm below IGC; inferior margin commonly ~7 cm below (width limited by closure tension). Hidden scar in gluteal crease. (Hanasono) - vPAP: vertical paddle parallel to gracilis; useful when larger distal perforators preferred. (Rivera‑Serrano; Scaglioni) - dPAP: diagonal along Langer’s lines to capture posteromedial fat and permit wider paddle with lower closure tension. (Azoury; Allen) 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Preop mapping: CTA or MRA three‑dimensional mapping strongly advised to localize perforators, assess intramuscular course, length and caliber; handheld audio Doppler used intraop to confirm. (Haddock; Hanasono) - Incise anterior border first; enter suprafascial/subfascial plane over gracilis and dissect posteriorly to expose adductor magnus fascia. Proceed subfascially posterior/lateral until perforators visible. (Azoury; Allen) - When perforator identified, trace suprafascially back to planned skin paddle to confirm territory. If perforator inadequate, plan bailout (e.g., TUG) or select alternate perforator. (Hanasono; Azoury) 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Dissect perforator intramuscularly toward profunda femoris / perforating branch; ligate small muscular branches as encountered to gain pedicle length (avoid muscle transection — spread fibers if necessary). (Azoury et al.; Haddock) - Goal: adequate pedicle length (commonly ~10 cm) and vessel caliber for microanastomosis. If pedicle length insufficient, plan recipient site accordingly (internal mammary vessels commonly used for breast reconstruction). (Hanasono et al.) - Divide pedicle when ready; complete flap harvest and transfer for microvascular anastomosis. Use intraoperative fluorescence angiography (ICG/SPY) to assess perfusion if available. (Perforator chapter; Hanasono) - For breast inset, cone flap to create breast mound; perform nipple reconstruction as indicated (immediate nipple reconstruction possible at apex of cone in immediate reconstruction). (Hanasono; Allen) 4. Donor-site closure techniques. - Undermine superior/inferior flaps as needed but avoid excessive undermining that distorts inferior gluteal fold. Approximate Scarpa’s fascia meticulously (layered closure) and place at least one closed‑suction drain. Quilting sutures may reduce dead space. Apply compression dressing; instruct compression garment postoperatively. (Azoury; Allen; Haddock) - For wide paddles, diagonal or fleur-de-lis design helps reduce closure tension and donor-site morbidity. ## Indications and Contraindications - Indications: - Autologous breast reconstruction when abdominal donor site inadequate or undesired (primary alternative to TUG; can be stacked/paired for larger volume). Typical single-flap weights commonly 300–400 g (range reported 150–900 g); series report achievable weights up to ≈800 g. (Hanasono; Allen) - Head/neck reconstruction (vertical paddle offers thinner, pliable tissue suitable for partial glossectomy). (Hanasono; Scaglioni) - Perineal and locoregional reconstructions as pedicled flap (V‑Y or propeller). (Hanasono) - Secondary option in prior failed abdominal reconstructions or when abdominal surgery/risk precludes DIEP/msf-TRAM. (Allen/Hanasono) - Contraindications (relative/absolute): - Prior posterior/medial thigh surgery or scarring in donor region (may disrupt perforators). - Significant peripheral vascular disease / iliofemoral atherosclerotic disease compromising profunda axis. - Preexisting lower‑extremity lymphedema or active infection in donor limb (avoid dissection near lymphatics; tPAP designs with superior extension near inguinal lymphatics increase risk). (Hanasono; Azoury) - Insufficient local tissue volume for patient’s reconstructive goal (consider stacked flaps or alternate donor). (Allen; Haddock) ## Postoperative Care - Monitoring schedule/method: - Routine clinical monitoring (hourly-then-spaced per institutional protocol); handheld Doppler checks; consider implantable Doppler or continuous monitoring per unit protocol. - Intraoperative and immediate postoperative use of ICG/SPY fluorescence angiography for perfusion assessment (reported use). (Perforator chapter; Hanasono) - Warming: maintain normothermia; use warming blankets as per routine free-flap protocols. - Antithrombotic practice: - Per institutional microsurgery protocols (several authors emphasize standard VTE prophylaxis and early ambulation); chemical prophylaxis for VTE recommended as per patient risk. (Azoury; Haddock) - Positioning/splinting: - Early ambulation encouraged postoperative day 1; avoid prolonged sitting on donor site initially; compression garment for donor limb recommended for ~3 weeks. (Azoury; Hanasono) - Drains: - Closed-suction drains in donor thigh; remove when output meets institutional criteria. - Mobilization: - Ambulate early; avoid strenuous lower‑extremity exertion for ~4–6 weeks (institutional practice and series describe activity limits). (Azoury; Allen) - Diet/analgesia: standard multimodal analgesia and ERAS pathways as available reduce opioids and length of stay. (ERAS mentions in literature; see Hanasono/Perforator texts) - Return-to-OR thresholds and time windows: - Any suspected vascular compromise (loss of Doppler signal, progressive flap pallor/cyanosis) mandates urgent assessment and typically immediate return to OR for exploration; reconstructive series report re‑exploration as primary salvage method. (Allen; Haddock) - Local salvage adjuncts reported: chemical leeching (heparin injections) has been used intra/postoperatively for marginal ischemia in delayed territory reperfusion (case reports/illustrations). (Taylor chapter; Hanasono) ## Complications (rates & management) - Perfusion-related: - Total flap loss: pooled literature ~1% (systematic review); single‑series reports 1.9–3% flap loss in large PAP cohorts. (Systematic review; Haddock series) - Partial flap loss / fat necrosis: reported ~2–7% in series (fat necrosis ~7% in one series). (Allen et al.; systematic review) - Arterial/venous thrombosis: reported but uncommon; re-exploration indicated immediately on clinical signs. - Donor-site issues: - Seroma: reported rates variable — series report 2–6% (Haddock 4.5%; Allen series 6%). (Haddock; Allen) - Hematoma: 1–3% in reports (Haddock 2.6%; Allen 1.9% reported in some series). - Wound dehiscence / donor wound problems: reported ≈2–6–7% depending on series; risk increased with wider transverse paddles and higher BMI. (Systematic review; Cho et al.; Haddock) - Infection: reported ~4–5% in some series. (Haddock) - Sensory disturbance: posterior thigh paresthesia if posterior cutaneous nerve injured; sensate flap possible if nerve coapted. (Azoury; Dayan & Allen) - Lymphedema: uncommon but transient cases reported; avoid femoral triangle dissection and respect lymphatic drainage to reduce risk. (Hanasono; Allen) - Management algorithms: - Vascular compromise: immediate return to OR for exploration and revision of anastomosis; rule out technical causes (kinking, compression, thrombosis); revise, thrombectomy, heparin irrigation, revise anastomosis as indicated. (Standard microsurgery approach in texts) - Venous congestion: if early and reversible — explore for venous outflow obstruction; options include anastomotic revision, conversion to two‑vein drainage, temporary medicinal/chemical leeching, or medicinal leech therapy for superficial congestion if re‑exploration not feasible (authors note ICG/clinical eval guides management). (Perforator/clinical chapters) - Partial distal ischemia / marginal zones: intraop SPY/ICG to delineate; chemical leech (local heparin) reported successful in some delayed marginal territories (case example). (Taylor; Hanasono) - Donor wound problems: wound care, negative pressure therapy, revision/closure for dehiscence; seroma management with drainage ± sclerotherapy if recurrent. (Haddock; Cho) - Frequencies (selected series; use only numbers reported above): - Pooled total flap loss ~1% (systematic review of 516 PAP flaps). - Fat necrosis ~7% (one institutional series). - Seroma 2–6% (series variability; Haddock 4.5%). - Donor wound issues requiring intervention ~6–7% in some series. (Allen; Haddock; systematic review) ## Key Clinical Pearls - Preoperative imaging (CTA or MRA) plus handheld Doppler is strongly recommended — imaging correlates >98% with intraoperative perforator identification and provides perforator course, length, and caliber for planning. (Haddock; Azoury) - Most consistent proximal perforator lies ~5 cm inferior to the inferior gluteal crease and ~3–4 cm posterior to medial midline (posterior to gracilis); expect at least 2 perforators (range 2–5). (Hanasono; Haddock) - Choose skin-paddle design to match donor laxity and goals: tPAP hides scar in gluteal crease but limits width; dPAP (diagonal) follows Langer’s lines and allows larger, lower‑tension harvest; vPAP useful when distal perforators preferred or for extremity/head‑neck work. (Hanasono; Allen; Azoury) - Expect pedicle length commonly ~10 cm (range 7–13 cm) and plan recipient vessels accordingly (internal mammary system commonly used for breast reconstructions). (Hanasono; Azoury) - Intramuscular perforator dissection is common (mean intramuscular length reported ≈5.7 cm); dissect carefully through muscle fibers (spread, do not indiscriminately transect). (Azoury; Haddock) - Avoid dissection in femoral triangle and respect lymphatic drainage to minimize donor-site lymphedema; if donor closure is tight, use diagonal/fleur designs or staged revisions rather than forcing wide transverse closure. (Hanasono; Allen) - Use intraoperative perfusion adjuncts (ICG/SPY) when available to define viable tissue and guide trimming of marginal zones; have plan for urgent re-exploration for vascular compromise. (Perforator chapter; Hanasono) - Counsel patients on donor-site trade-offs (hidden vs visible scar, sitting discomfort in tPAP, potential need for secondary contouring/fat grafting) and on the learning-curve–related nature of early complication risk. (Allen; Haddock)