**Region:** Head and Neck # Karapandzic Flap ## Anatomy - Pedicle: facial artery → superior and inferior labial arteries; venae comitantes not specified in source. - Course: the facial artery branches into superior and inferior labial arteries approximately 1.5 cm lateral to the oral commissures; these labial arteries supply the lips and the Karapandzic flap. The superior labial artery is generally found within 1 cm of the upper-lip vermilion border. The inferior labial artery is usually located 4–13 mm from the lower-lip vermilion border. - Typical diameter/length: not reported in the provided text. - Perforator pattern / type: specific number, location, and whether perforators are intramuscular versus septocutaneous are not detailed in the source. Choke vessels and adjacent angiosome connections are not described. - Nerves: - Motor: branches of the facial nerve (CN VII) supplying the perioral musculature; motor innervation to most perioral muscles is on their deep surfaces (except the mentalis, buccinators, and levator labii superioris, which are exceptions noted in the source). - Sensory: infraorbital nerve (V2) and mental nerve (V3) provide cutaneous sensation to the lip regions relevant to flap harvest and sensate reconstruction. - Clinical implication from source: preservation of the neurovascular supply to the orbicularis oris is a core principle of the flap (sensate and functional outcome depends on intact innervation). - Included tissues: - Full-thickness circumoral rotation-advancement flap design that includes skin, subcutaneous tissue, orbicularis oris muscle (pars marginalis and pars peripheralis described), and mucosa (mucosal advancement performed via partial-thickness incisions on the deep surface). - Thickness profile: the flap is full-thickness circumoral tissue, with muscle released at the periphery of orbicularis oris; specific thickness measurements are not provided. - Arc of rotation: rotation-advancement around the circumoral region permitting closure of central and lateral defects; numeric arc/rotation degrees not reported. - Common variants/anomalies: not specifically enumerated in the source; the flap may be performed unilaterally or bilaterally depending on defect size. ## Dissection Steps 1. Positioning, markings, landmarks. - Position: patient supine. If general anesthesia is used, nasal intubation is recommended to avoid interference with the operative field. - Landmarks and primary markings: - Square off the defect so a right angle is created at the lip margin and continued to the base of the flap. - From these initial marks draw the flap border perpendicular to the initial marks and parallel to the lip margin. - To capture the labial artery, mark the flap border at least 1 cm superior to the upper lip or 1.3 cm inferior to the lower lip (source-specified distances). - For lower-lip defects, attempt to place the incision in the mental crease. For upper-lip defects, place it in the alar-facial groove. - Mark the incisions to extend around the oral commissure and into the melolabial crease, maintaining equal distance from the lip margin throughout. - Anticipate dog-ears; mark potential Burow’s triangles on the outer circle (these may be excised during inset as needed). 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Initial incision: carried through the skin and soft tissue but not made full-thickness at first to preserve neurovascular supply. - Muscle plane: progressive incision of muscle (orbicularis oris) until neurovascular structures are identified and preserved. Incisions are carried through or at the periphery of the orbicularis oris to allow release and advancement. - Mucosa: make separate partial-thickness incisions through the mucosa on the deep surface to permit mucosal advancement. - Perforator identification: the source emphasizes marking to ensure capture of the labial arteries (distances above). No specific handheld or intraoperative Doppler protocol is provided in the text. 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Exposure/control: - Progressively incise orbicularis oris at its periphery to free the flap while actively identifying and preserving the neurovascular supply to the muscle. - Other perioral muscles may be divided where they are tethered to the orbicularis oris to allow adequate mobilization. - Division: - The Karapandzic flap is designed as a neurovascularly pedicled rotation-advancement flap; the labial neurovascular pedicles are preserved rather than divided. - The source does not describe routine ligation or division of named pedicle branches for transfer. - Transfer and inset: - Rotate/advance unilateral or bilateral flaps into the defect; bilateral flaps are preferable for larger defects and improved symmetry. - Approximate tissues with minimal tension and perform multilayered closure: careful vermilion border approximation and reconstitution of the oral sphincter. - Reattach divided perioral muscles to the orbicularis oris in appropriate anatomic positions when possible. - Perfusion checks: - The text does not provide a protocol for intraoperative perfusion checks (e.g., fluorescein or Doppler); clinical assessment and preservation of labial arteries are emphasized. 4. Donor-site closure techniques. - Close the donor site in layers, approximating mucosa, muscle, and skin. - Excise Burow’s triangles as needed to eliminate dog ears and achieve a smooth contour. - Reapproximate and reattach muscles of facial expression divided from orbicularis oris to restore anatomy and function. ## Indications and Contraindications - Indications (as stated in source): - Full-thickness lip defects. - Upper-lip defects of approximately one-half to two-thirds of lip width. - Lower-lip defects up to approximately three-fourths of lip width. - Central or lateral defects. - Defects involving the oral commissure. - Contraindications (from source or implied by content): - Compromise or absence of the labial neurovascular supply (for example prior injuries or resections that have damaged the labial arteries or facial nerve branches) — the source specifically warns that if nerves have been compromised one should not expect a functional repair. - Relative contraindication: if expected microstomia is unacceptable to patient (source emphasizes careful preoperative assessment of microstomia risk; the lips will stretch with time, so some microstomia may be tolerated). - Other absolute or relative contraindications (e.g., severe peripheral vascular disease, irradiated tissue) are not explicitly discussed in the provided text. ## Postoperative Care - The provided source does not supply a detailed postoperative care protocol. The following points are stated or directly implied in the source: - Expect progressive improvement in oral aperture over time (widening of oral aperture may occur postoperatively). - Plan for possible secondary procedures if required (a secondary Abbe flap can restore lip balance in the presence of significant microstomia or asymmetry). - Specific monitoring schedule/methods (clinical checks, Doppler, implantable probes), warming, antithrombotic practice, positioning/splinting, drain management, mobilization, diet, analgesia, or precise return-to-OR thresholds/time windows are not described in the source material. ## Complications (rates & management) - Rates/frequencies: the source does not provide numeric complication rates. - Complications mentioned in the source and recommended management: - Microstomia: - Recognized risk; lips generally stretch over time so some degree of microstomia may be acceptable. - If unacceptable, secondary procedures such as an Abbe flap can be used to restore lip balance and aperture. - Dog ears and contour issues: - Anticipate and treat with excision of Burow’s triangles during the primary closure or in a staged fashion as needed. - Functional failure when nerves compromised: - If preoperative or intraoperative nerve compromise exists, a purely functional repair should not be expected; plan reconstruction and counseling accordingly. - Other complications such as venous congestion, arterial thrombosis, partial/total flap loss, infection, fat necrosis, seroma, hematoma, hernia or weakness at donor site are not quantified or specifically discussed in the text; no explicit management algorithms (re-exploration, leeching, thrombolysis) are provided in the source. - Management algorithms: - The only explicit secondary-management item in the source is use of a secondary Abbe flap for restoration of lip balance/mouth opening when microstomia or imbalance remains problematic. - For dog ears/contour deformities: simple excision of Burow’s triangles is recommended. ## Key Clinical Pearls - Preserve the neurovascular supply to the orbicularis oris — the Karapandzic flap’s functional advantage is maintenance of the labial arteries and motor innervation. - Mark to capture the labial artery: place incisions at least 1 cm superior to the upper-lip vermilion or at least 1.3 cm inferior to the lower-lip vermilion (source-specified distances) to ensure inclusion of the labial artery. - Know the branching landmark: the facial artery branches into superior and inferior labial arteries approximately 1.5 cm lateral to the oral commissures — plan your lateral extent accordingly. - Expect microstomia and counsel the patient preoperatively; lips often stretch and oral aperture commonly widens with time. - For lower-lip incisions, utilize the mental crease; for upper-lip incisions, utilize the alar-facial groove to place scars in natural creases. - Perform progressive, partial-thickness incisions through skin and soft tissue first, then incrementally through muscle until the neurovascular structures are identified and preserved — do not perform abrupt full-thickness cuts that risk dividing the pedicle. - Reapproximate mucosa, muscle (including reattachment of facial-expression muscles to orbicularis oris), and skin in multilayered closure with precise vermilion-border alignment to restore sphincter continuity and cosmesis. - Anticipate dog ears and have plans to excise Burow’s triangles; bilateral flaps provide better symmetry for larger defects and allow closure of defects that may initially appear larger once the orbicularis is released.