ABOHNS Plastic Surgery Within the Head and Neck cheat sheet

Aesthetic subunits of the nose: dorsum, tip, alae, soft triangles, columella, sidewalls; incisions placed at subunit borders hide scars best.

Nasal tip support derives from the lower lateral cartilages, medial crural footplate attachments, and the caudal septum; over-resection causes supratip deformity and Polly beak.

In rhinoplasty, 1 mm of cephalic dorsum resection approximates a visible profile change; the dorsum should parallel the septal angle to avoid a Polly beak.

Upper lid blepharoplasty: 8-10 mm supratarsal crease in women, 7-8 mm in men; preserve at least 10 mm of pretarsal skin and avoid the levator aponeurosis.

Lower lid blepharoplasty: transconjunctival approach avoids external scar and is preferred when no skin excision is needed; transcutaneous approach addresses skin laxity.

Facial nerve frontal branch runs within the superficial temporal fascia (SMAS layer); dissection deep to this plane protects it.

Marginal mandibular nerve lies deep to the platysma and superficial to the investing fascia after crossing the mandibular border near the facial vessels.

In facelift, the SMAS is elevated superficial to the facial nerve branches; the plane deep to SMAS is unsafe except at named nerve-safe zones.

Reconstructive ladder: healing by secondary intention, primary closure, skin graft, local flap, regional flap, free tissue transfer; choose based on defect size, vascularity, and donor morbidity.

Radial forearm free flap: thin, pliable, reliable; pedicle length 10-15 cm; donor site requires skin graft if fascia is exposed; Allen test required.

Anterolateral thigh flap: perforator-based, can be chimeric; useful for large through-and-through defects; perforators from descending branch of lateral circumflex femoral artery.

Fibula free flap: bone stock up to 25 cm; peroneal artery pedicle; requires preoperative vascular assessment (peroneal artery magna); skin paddle from septocutaneous perforators.

Jejunal free flap: used for circumferential pharyngoesophageal defects; requires laparotomy; risk of fistula and stricture; not for patients with short bowel.

Pectoralis major myocutaneous flap: pedicled on thoracoacromial artery; reliable for large head and neck defects; bulk can obscure neck contour and limit shoulder mobility.

Free flap monitoring: hourly for first 24 hours, then every 2-4 hours; signs of arterial failure are pale, cool, absent Doppler; venous failure is congested, dark, brisk bleeding.

Recipient vessels in head and neck: superior thyroid artery, facial artery, superficial temporal artery; venous drainage via internal or external jugular tributaries.

Cleft lip: embryologic failure of fusion of medial nasal and maxillary prominences at 5-7 weeks; cleft palate from failure of palatal shelf fusion at 7-12 weeks.

Cleft lip repair timing: rule of 10s (weight >10 lb, hemoglobin >10 g/dL, age >10 weeks); palate repair typically 9-18 months for speech development.

Cleft palate repair: von Langenbeck (bipedicle) and Furlow double-opposing Z-plasty; Furlow lengthens the palate and is used for submucous cleft or short palate.

Velopharyngeal insufficiency: hypernasal speech, nasal emission; evaluation with nasopharyngoscopy and videofluoroscopy; treatment with pharyngeal flap or sphincter pharyngoplasty.

Craniosynostosis: premature suture fusion; sagittal synostosis causes scaphocephaly; coronal causes plagiocephaly; metopic causes trigonocephaly.

Nonsyndromic craniosynostosis is usually isolated; syndromic forms include Apert, Crouzon, and Pfeiffer (FGFR mutations) with midface hypoplasia.

Pierre Robin sequence: micrognathia, glossoptosis, and cleft palate; airway management ranges from prone positioning to mandibular distraction or tracheostomy.

Hemifacial microsomia: first and second branchial arch derivatives; mandibular hypoplasia, ear anomalies; graded by Pruzansky-Kaban classification.

Basal cell carcinoma: most common cutaneous malignancy; subtypes include nodular, superficial, morpheaform; morpheaform has high recurrence and requires wide margins.

Squamous cell carcinoma: risk factors include UV exposure, immunosuppression, chronic wounds; high-risk features include perineural invasion, depth >2 mm, and poor differentiation.

Melanoma: Breslow thickness drives prognosis; margins are 0.5 cm for in situ, 1 cm for <1 mm, 1-2 cm for 1-2 mm, and 2 cm for >2 mm.

Sentinel lymph node biopsy for melanoma is indicated for tumors >1 mm Breslow thickness or >0.75 mm with ulceration or mitoses.

Nevus sebaceus: congenital hamartoma of sebaceous glands; may develop basal cell carcinoma; excision considered at puberty.

Keloid versus hypertrophic scar: keloid extends beyond original wound and recurs; hypertrophic scar remains within wound and regresses over time.

Cutaneous horn: hyperkeratotic lesion; underlying pathology may be actinic keratosis, SCC, or BCC; requires biopsy of the base.

Mohs micrographic surgery: indicated for recurrent tumors, cosmetically sensitive areas, and tumors with perineural invasion; provides complete margin control.

Ideal facial proportions: vertical thirds equal (trichion to glabella, glabella to subnasale, subnasale to menton); horizontal fifths based on intercanthal distance.

Nasolabial angle: 90-95 degrees in men, 95-110 degrees in women; defines tip rotation in rhinoplasty.

Rhinoplasty: dorsal augmentation with spreader grafts or onlay grafts; tip projection via columellar strut or tongue-in-groove technique.

Brow position: ideal brow apex at lateral limbus in women; men have flatter, lower brow; brow lift approaches include endoscopic, coronal, and temporal.

Cervicofacial rhytidectomy: superficial musculoaponeurotic system (SMAS) plication or imbrication; deep plane dissection elevates SMAS with skin.

Fat grafting: harvest with low-negative-pressure cannula; process by centrifugation or filtration; place in small aliquots for neovascularization.

Chemical peels: superficial (glycolic, salicylic), medium (trichloroacetic acid 35%), deep (phenol); depth depends on concentration and skin prep.

Laser resurfacing: ablative (CO2, erbium) versus nonablative; Fitzpatrick skin types IV-VI have higher risk of postinflammatory hyperpigmentation.

Le Fort I: transverse maxillary fracture above tooth roots; Le Fort II: pyramidal involving nasal bones and medial orbital walls; Le Fort III: craniofacial disjunction.

Zygomaticomaxillary complex fracture: displacement at zygomaticofrontal suture, zygomaticomaxillary suture, zygomatic arch, and orbital floor; treat with 2-3 point fixation.

Orbital floor blowout: inferior rectus entrapment causes diplopia and restricted upgaze; urgent repair if muscle entrapment or large defect >2 cm.

Mandibular angle fractures: most common mandibular fracture; treat with open reduction and internal fixation via intraoral approach; risk of infection and nerve injury.

Condylar fractures: most managed closed with early mobilization; open reduction indicated for displacement into middle cranial fossa or inability to restore occlusion.

Naso-orbitoethmoid fractures: assess telecanthus via intercanthal distance and bowstring test; repair with transnasal wire or plate fixation of medial canthus.

Frontal sinus fractures: anterior table fractures may be observed if no displacement; posterior table fractures with CSF leak may require cranialization or obliteration.

Facial nerve injury: immediate primary repair if laceration; nerve grafting for gaps; House-Brackmann scale grades facial function from I (normal) to VI (total paralysis).

Oral cavity SCC: most common site is tongue; risk factors include tobacco, alcohol, betel nut; margins of 1-1.5 cm recommended.

Laryngeal cancer: glottic tumors present early with hoarseness; supraglottic tumors present late with nodal metastasis; T1 glottic may be treated with radiation or laser excision.

Neck dissection levels: I submental/submandibular, II upper jugular, III mid jugular, IV lower jugular, V posterior triangle, VI anterior compartment.

N0 neck: elective neck dissection or sentinel node biopsy indicated when risk of occult metastasis exceeds 15-20%, as in oral cavity SCC >2-4 mm depth.

Thyroid carcinoma: papillary spreads via lymphatics, follicular via hematogenous; medullary from parafollicular C cells with calcitonin as marker.

Parotid tumors: superficial parotidectomy with facial nerve preservation for benign tumors; deep lobe tumors may require total parotidectomy.

Adenoid cystic carcinoma: perineural invasion is characteristic; late distant metastasis to lungs; long-term follow-up required.

Radiation therapy: xerostomia from parotid sparing; osteoradionecrosis risk after dental extraction; pre-radiation dental evaluation recommended.

Local flaps: rhomboid, bilobed, advancement, rotation, and transposition; choose based on defect size, laxity, and relaxed skin tension lines.

Bilobed flap: two lobes at 45-90 degrees each; total arc 90-180 degrees; used for nasal tip defects 1-2 cm.

Nasolabial flap: pedicled on angular artery and facial artery perforators; excellent color match for nasal ala and upper lip defects.

Paramedian forehead flap: pedicled on supratrochlear artery; staged procedure; used for large nasal defects; requires cartilage framework for structural support.

Deltopectoral flap: pedicled on perforators of internal mammary artery; useful for neck and lower face; staged division at 2-3 weeks.

Free flap failure rates: 1-5%; most failures from venous thrombosis; early reexploration improves salvage.

Perforator flaps: based on individual perforators; DIEP, ALT, and TAP flaps; require preoperative perforator mapping with CT angiography or Doppler.

Osteocutaneous free flaps: fibula, iliac crest, scapula, and radial forearm; fibula provides longest bone and reliable skin paddle.

Anterior cranial fossa approaches: transbasal, subcranial, and endoscopic endonasal; CSF leak risk requires meticulous dural repair.

Endoscopic endonasal skull base surgery: uses nasoseptal flap for reconstruction; pedicled on posterior septal artery; reliable for dural defects.

Le Fort I osteotomy: used for midface advancement; blood supply from descending palatine arteries; risk of ischemia with extensive dissection.

Craniofacial resection: combined neurosurgical and head and neck approach for anterior skull base tumors; complication rates higher in previously irradiated patients.

CSF leak management: lumbar drain, bed rest, and acetazolamide; persistent leaks require surgical repair with vascularized tissue.

Skull base osteomyelitis: often from malignant otitis externa; Pseudomonas most common; requires prolonged antibiotics and debridement.

Frontal sinus obliteration: fat or pericranial flap; indications include posterior table fracture with CSF leak or failed cranialization.

Transsphenoidal surgery: for pituitary tumors; risk of diabetes insipidus and CSF leak; nasoseptal flap reduces leak rates.

Venous thromboembolism prophylaxis: Caprini risk assessment; mechanical prophylaxis for all; pharmacologic for high-risk patients; head and neck surgery is moderate-high risk.

Free flap patients: avoid pressure on pedicle, maintain warm room, adequate hydration, and avoid vasoconstrictors; hematocrit 30% optimizes oxygen delivery.

Surgical site infection prevention: preoperative chlorhexidine, appropriate antibiotic prophylaxis within 60 minutes of incision, and normothermia.

Airway management: difficult airway algorithm; awake fiberoptic intubation for head and neck tumors; consider tracheostomy for anticipated prolonged ventilation.

Seroma prevention: closed suction drains, quilting sutures, and compression garments; seromas increase infection and flap compromise risk.

Hematoma: most common early complication of rhytidectomy; presents with swelling and pain; evacuate urgently to prevent skin necrosis.

Nerve injury prevention: identify and protect marginal mandibular nerve during neck dissection; use nerve monitoring for thyroid and parotid surgery.

Patient safety: time-out before incision, correct site marking, and DVT prophylaxis compliance reduce preventable complications.