Oral & Maxillofacial
Microvascular Reconstruction
A comprehensive surgical summary of workhorse flaps utilized in maxillofacial reconstructive surgery, detailing vascular anatomy, indications, and harvest design.
Fibula Free Flap (FFF)
Vascular Anatomy
- Artery: Peroneal Artery (Branch of tibioperoneal trunk)
- Vein(s): Peroneal Venae Comitantes (usually 2, join to form common peroneal vein)
- Pedicle Length: 5-8 cm (Can be extended by harvesting more proximal bone and discarding it)
- Vessel Diameter: Artery 1.5-2.5mm, Veins 2.0-3.0mm
Indications
- Large mandibular defects (>6 cm).
- Maxillary reconstruction (Brown Class II-IV).
- Requirements for osseointegrated dental implants (provides excellent cortical bone stock).
- Composite defects requiring bone and moderate soft tissue (skin paddle).
Flap Design & Harvest
Pre-op: CTA/MRA or lower extremity angiogram to confirm 3-vessel runoff to the foot.
Bone Harvest: Lateral aspect of lower leg. Up to 25cm of bone available. Crucial rule: Must preserve 6-8 cm of distal fibula (ankle stability) and proximal fibula (knee stability/fibular nerve).
Skin Paddle: Designed over the posterolateral intermuscular septum. Relies on septocutaneous perforators (usually lower 1/3 to middle 1/3 of leg).
Included Muscle(s): A 1-2 cm cuff of the Flexor Hallucis Longus (FHL) and Tibialis Posterior is typically retained along the posterior/medial aspect of the bone to protect the peroneal vessels. A larger segment of the Soleus or FHL can be included if extra soft-tissue bulk is required.
Modification: Can be osteotomized multiple times (closing wedges) to perfectly mimic the mandibular curve.
Anatomical Landmarks & Design Diagram
SchematicRadial Forearm Free Flap (RFFF)
Vascular Anatomy
- Artery: Radial Artery
- Vein(s): Cephalic Vein (superficial system) and Radial Venae Comitantes (deep system). Usually both are harvested.
- Pedicle Length: Exceptionally long, up to 15-20 cm.
- Vessel Diameter: Artery 2.0-3.0mm, Veins 2.5-4.0mm (Cephalic).
Indications
- Intraoral soft tissue defects (tongue, floor of mouth, buccal mucosa).
- Defects requiring thin, pliable, hairless tissue for excellent functional mobility.
- Facial skin resurfacing.
- Can be innervated (lateral antebrachial cutaneous nerve) for sensate reconstructions.
Flap Design & Harvest
Pre-op: Allen's test is absolutely mandatory to ensure ulnar artery collateral perfusion to the hand.
Harvest: Volar aspect of the non-dominant forearm. Designed over the course of the radial artery between the brachioradialis and flexor carpi radialis (FCR).
Dissection: Subfascial plane, ensuring paratenon over flexor tendons is preserved to allow for split-thickness skin graft (STSG) take.
Included Muscle(s): None (Strictly fasciocutaneous). The flap is elevated off the underlying Brachioradialis and Flexor Carpi Radialis muscles, which are preserved in the donor bed.
Note: Donor site morbidity includes aesthetic defect, potential decreased grip strength, and need for STSG.
Anatomical Landmarks & Design Diagram
SchematicOsteocutaneous Radial Forearm
Vascular Anatomy
Identical to standard RFFF. The bone is perfused via periosteal branches from the radial artery traveling in the lateral intermuscular septum.
Indications
- Small, non-load-bearing composite defects.
- Mandibular defects < 3-4 cm combined with large soft tissue requirement.
- Palate and maxillectomy defects (Class I-II).
Flap Design & Bone Harvest
Same soft tissue design as RFFF. Include a segment of the radius along the intermuscular septum.
Included Muscle(s): None (Minimal). Only a very small cuff of the Flexor Pollicis Longus (FPL) and Pronator Quadratus muscular attachments are retained specifically to preserve the periosteal blood supply to the harvested bone segment.
Critical Constraint:
Bone harvest is limited to a maximum of 10-12 cm in length and strictly no more than 40% of the cross-sectional circumference of the radius.
Post-op: Prophylactic plating of the radius (keel shape cut preferred) and prolonged immobilization are often required to prevent pathological fracture.
Anatomical Landmarks & Design Diagram
SchematicIliac Crest Bone Flap (DCIA)
Vascular Anatomy
- Artery: Deep Circumflex Iliac Artery (DCIA), branch of external iliac.
- Vein(s): Deep Circumflex Iliac Vein (DCIV), drains into external iliac vein.
- Pedicle Length: Short (5-7 cm). Often requires vein grafts if neck vessels are depleted.
Indications
- Defects requiring massive vertical bone height (native crest provides 12-16mm, ideal for osseointegrated implants).
- Mandibular angle and ascending ramus reconstruction (naturally mimics the curve).
- Large maxillary (Brown Class III-IV) composite defects.
Flap Design & Bone Harvest
Bone Harvest: Taken from the anterior ilium starting ~2cm posterior to the Anterior Superior Iliac Spine (ASIS). Can be harvested as an inner table block or a full-thickness bicortical segment.
Included Muscle(s): The Internal Oblique muscle is frequently co-harvested (based on the ascending branch of the DCIA) to provide bulky, reliable, mucosalized soft tissue coverage for the oral cavity. A small cuff of Transversus Abdominis and External Oblique is retained over the inner crest to protect the pedicle.
Donor Site Note: High morbidity risk. Requires meticulous multilayer abdominal wall closure to prevent hernia formation. Patients may experience temporary lateral femoral cutaneous nerve neuropraxia and gait disturbances.
Anatomical Landmarks & Design Diagram
SchematicAnterolateral Thigh (ALT)
Vascular Anatomy
- Artery: Descending branch of the Lateral Circumflex Femoral Artery (LCFA).
- Vein(s): Venae comitantes to LCFA.
- Perforators: Relies on musculocutaneous perforators (80%) through vastus lateralis or septocutaneous (20%).
- Pedicle Length: 8-16 cm.
Indications
- Massive soft tissue defects (total glossectomy, skull base, large scalp/neck).
- Through-and-through cheek defects (can be folded or bipaddled).
- When primary closure of donor site is preferred (unlike RFFF).
Flap Design & Harvest
Design: Axis is a line drawn from ASIS to superolateral patella. Perforators usually found within a 3cm radius of the midpoint of this line.
Harvest: Subfascial or suprafascial dissection. Identifying and tracing perforators through the vastus lateralis muscle requires meticulous microsurgical technique.
Included Muscle(s): Variable. Can be harvested as a pure fasciocutaneous flap (no muscle) by meticulously dissecting perforators free, or as a myocutaneous/chimeric flap including a portion or the entirety of the Vastus Lateralis muscle for dead space obliteration.
Versatility: Can be thinned primarily (microdissection of subcutaneous fat) or harvested as a chimeric flap (skin paddle + separate vastus lateralis muscle block on same pedicle for dead space obliteration).
Donor site generally closed primarily if width is < 8-10 cm.
Anatomical Landmarks & Design Diagram
SchematicLateral Upper Arm Flap (LAF)
Vascular Anatomy
- Artery: Posterior Radial Collateral Artery (PRCA), a terminal branch of the profunda brachii artery.
- Vein(s): Venae comitantes to the PRCA.
- Pedicle Length: Moderate (6-8 cm).
Indications
- Small to moderate oral cavity defects (tongue, floor of mouth, buccal mucosa).
- Excellent substitute for the RFFF when Allen's test is abnormal or to avoid cosmetically obvious forearm scarring.
- Can provide a slightly thicker and more robust skin paddle than the distal forearm.
Flap Design & Harvest
Design: The flap is centered over the lateral intermuscular septum of the arm. The axis is a line drawn from the deltoid insertion down to the lateral epicondyle of the humerus.
Included Muscle(s): None (Strictly fasciocutaneous). The flap is elevated off the triceps posteriorly and the brachialis/brachioradialis anteriorly. A very thin rim of triceps fascia is sometimes preserved around the septum to protect the perforating vessels.
Donor Site: Widths up to 6-8 cm can usually be closed primarily. If primary closure is achieved, the resulting linear scar is easily hidden beneath short sleeves.
Anatomical Landmarks & Design Diagram
SchematicPedicled Pectoralis Major (PMF)
Vascular Anatomy
- Dominant Pedicle: Pectoral branch of the Thoracoacromial Artery and Vein.
- Course: Exits clavipectoral fascia deep to the muscle, courses medial to the coracoid process, descending inferomedially on the undersurface of the muscle.
Indications
- "Workhorse" for salvage reconstruction or vessel-depleted necks (post-radiation/failed free flaps).
- Patients medically unfit for prolonged free flap surgery.
- Carotid blowout prophylaxis (muscle coverage).
- Oral cavity, oropharynx, and neck skin defects.
Flap Design & Harvest
Design: Skin paddle drawn inferomedially to the nipple/areola complex (to capture random musculocutaneous perforators). Muscle is released from humeral, clavicular, and sternal attachments.
Included Muscle(s): Pectoralis Major. The muscle itself acts as the vascular carrier for the overlying skin paddle and provides significant bulk to cover neurovascular structures in the neck.
Arc of Rotation: Rotated up to 180 degrees into the neck/face over the clavicle. Clavicle can act as a fulcrum and compress the pedicle; occasionally a portion of clavicle is removed or the flap is tunneled beneath it.
Drawbacks: Bulky (especially in women with breast tissue), creates neck tethering, significant chest wall deformity, gravity pulls flap down over time.
Anatomical Landmarks & Design Diagram
SchematicLatissimus Dorsi (LD)
Vascular Anatomy
- Dominant Pedicle: Thoracodorsal Artery & Vein (continuation of subscapular system).
- Pedicle Length: Up to 10-12 cm.
- Vessel Diameter: Large caliber (2.5 - 3.5mm), very reliable.
Indications
- Massive soft tissue defects requiring tremendous surface area (e.g., near-total scalp defects).
- Can be utilized as a Free Flap (microsurgical) or Pedicled Flap.
- Pedicled used for lower neck or posterior scalp reconstruction.
Flap Design & Harvest
Design: Extremely large skin paddles (e.g., 10x20 cm) can be harvested safely. Can also harvest muscle alone and cover with STSG.
Harvest (Pedicled): Muscle detached from spine/iliac crest. Pedicle isolated in the axilla. Flap is tunneled through the axilla to the neck.
Included Muscle(s): Latissimus Dorsi. Often harvested as a large myocutaneous flap or a muscle-only flap. (The Serratus Anterior muscle can occasionally be co-harvested based on the subscapular system for chimeric needs).
Logistical Note: Requires patient to be placed in lateral decubitus position during surgery, which can complicate simultaneous two-team approaches (ablative + reconstructive) compared to ALT or forearm.
Anatomical Landmarks & Design Diagram
SchematicLocal & Regional Flaps
When microvascular free tissue transfer is contraindicated, or for smaller defects (< 4-5 cm) where free flaps would provide excessive bulk, local and regional flaps offer highly reliable, tissue-matched reconstructive solutions with minimal donor site morbidity.
Buccal Fat Pad (BFP)
Buccal / Deep Temporal Art.
Easily harvested via a small mucosal incision superior to the maxillary molars. Excellent for closing moderate Oroantral Communications (OAC) or posterior palatal defects.
FAMM Flap
Facial Artery/Vein
Facial Artery Musculomucosal flap. Can be pedicled superiorly (retrograde flow) or inferiorly (anterograde flow). Ideal for floor of mouth, alveolar ridge, and soft palate.
Nasolabial Flap
Facial Art. Perforators
Harvested from the nasolabial fold and tunneled through the cheek (transbuccal) for anterior intraoral defects. Scar is easily hidden in the natural facial crease.
Palatal Island Flap
Greater Palatine Art.
A robust mucoperiosteal flap based on the descending palatine vessels exiting the greater palatine foramen. Rotated to reconstruct soft palate or maxillary defects.
Submental Flap
Submental Art. (Facial Br.)
Tissue from the submental space tunneled to the face or oral cavity. Excellent color match for facial skin defects.
TPFF
Superficial Temporal Art.
Temporoparietal Fascia Flap. An ultra-thin, highly vascularized regional flap. Used for orbital floor, skull base, or as coverage over auricular frameworks.
Rhomboid (Limberg)
Transposition Flap
A classic transposition flap designed around a rhombic defect with 60° and 120° angles. Uses adjacent tissue laxity to close defects with minimal tension.
Bilobed Flap
Double Transposition
Utilizes two adjacent lobes. The primary lobe reconstructs the main defect, while the smaller secondary lobe reconstructs the primary donor site.
Cervicofacial Flap
Rotation-Advancement
A massive skin flap mobilizing tissue from the preauricular, cheek, and cervical regions. Provides excellent color and texture match for large facial defects.
Local Skin Flap Design Principles
Geometric SchematicOral Cavity SCC Staging
Critical Updates in 8th Edition
The AJCC 8th Edition introduced two major paradigm shifts for oral cavity cancer: Depth of Invasion (DOI) replaced tumor thickness as a primary T-stage modifier, and Extranodal Extension (ENE) was incorporated as a primary N-stage modifier, profoundly impacting prognosis and staging.
Primary Tumor (T) Staging
- T1 Tumor ≤ 2 cm AND DOI ≤ 5 mm
- T2 Tumor ≤ 2 cm AND DOI > 5 mm to ≤ 10 mm
OR
Tumor > 2 cm to ≤ 4 cm AND DOI ≤ 10 mm - T3 Tumor > 4 cm
OR
Any size tumor with DOI > 10 mm - T4a Moderately Advanced: Invades cortical bone, deep/extrinsic muscle of tongue, maxillary sinus, or skin of face.
- T4b Very Advanced: Invades masticator space, pterygoid plates, skull base, or encases internal carotid artery.
Clinical Nodal (cN) Staging
- N1 Single ipsilateral node ≤ 3 cm, ENE(-)
- N2a Single ipsilateral node > 3 cm but ≤ 6 cm, ENE(-)
- N2b Multiple ipsilateral nodes, none > 6 cm, ENE(-)
- N2c Bilateral or contralateral nodes, none > 6 cm, ENE(-)
- N3a Any node > 6 cm, ENE(-)
- N3b Any node with clinical ENE(+)
(invasion of skin, muscle, nerve, or tethering)
Depth of Invasion (DOI) vs. Thickness
Histological ConceptNeck Dissection (ND)
Classification Types
- Radical Neck Dissection (RND): Removal of all ipsilateral lymph node groups (Levels I-V) along with the Spinal Accessory Nerve (SAN), Internal Jugular Vein (IJV), and Sternocleidomastoid muscle (SCM).
- Modified Radical (MRND): Removal of Levels I-V with preservation of one or more non-lymphatic structures.
- Type I: Preserves SAN.
- Type II: Preserves SAN & IJV.
- Type III: Preserves SAN, IJV & SCM (Functional).
- Selective (SND): Preservation of one or more lymphatic groups that are routinely removed in RND (e.g., Supraomohyoid SND commonly removes I-III for oral cavity cancers).
- Extended: RND plus additional lymph nodes (e.g., Level VI) or non-lymphatic structures (e.g., Carotid, Vagus).
Cervical Lymph Node Levels
Level I: Submental (Ia) and Submandibular (Ib). Bounded by the anterior/posterior bellies of the digastric muscle and the mandible.
Level II: Upper Jugular. Skull base down to the carotid bifurcation (clinical landmark: hyoid bone). Anterior to posterior border of SCM.
Level III: Middle Jugular. Carotid bifurcation down to the omohyoid muscle (clinical landmark: cricoid cartilage).
Level IV: Lower Jugular. Omohyoid muscle down to the clavicle.
Level V: Posterior Triangle. Posterior boundary of SCM to anterior boundary of trapezius.
Level VI: Anterior Compartment. Hyoid bone to suprasternal notch, bounded laterally by medial borders of carotid sheaths.
Sentinel Lymph Node Biopsy (SLNB)
Concept: The identification and excision of the first lymph node(s) in the lymphatic basin that drains a primary tumor. If the sentinel node is negative for metastasis, the rest of the nodal basin is presumed disease-free.
Primary Indication: Early-stage (T1-T2) Oral Cavity Squamous Cell Carcinoma (OCSCC) with a clinically and radiologically negative neck (cN0).
Technique: Involves preoperative peritumoral injection of a radiotracer (e.g., Technetium-99m) and/or intraoperative blue dye. The sentinel node is localized during surgery using a handheld gamma probe.
Significantly reduces morbidity associated with an elective neck dissection (e.g., shoulder dysfunction, contour defects, prolonged drainage) in patients who do not actually harbor occult metastases.
Anatomical Neck Levels Diagram
Lateral View
Supplemental Flaps
Gracilis Flap
Medial Circumflex Femoral
Muscle-only free flap heavily utilized for dynamic facial reanimation (treating facial paralysis). A small, consistent muscle belly that can be innervated by the masseteric or cross-facial nerve graft.
Scapular System
Circumflex Scapular / Thoracodorsal
Osteocutaneous or chimeric free flap. Excellent for complex 3D defects with independent skin and bone paddles (parascapular/scapular skin + lateral border scapula bone). Drawback: Requires repositioning (lateral/prone).
Supraclavicular (SCAIF)
Transverse Cervical Art.
Thin, pliable regional fasciocutaneous flap harvested from the shoulder/supraclavicular region. An excellent alternative to free tissue transfer for vessel-depleted necks, tracheostoma defects, or patients with severe medical comorbidities.
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