RHOMBOID FLAP

Rhombus: A parallelogram which is equilateral but not right angled.

Rhomboid: A parallelogram which is neither equilateral nor right angled.

INTRODUCTION:

Rhomboid flaps don’t reflect the shape of the flap but literally the shape of the defect.

Full thickness local flaps with random pattern blood supply relying on dermal-subdermal plexus of vessel

A rhomboid flap pivots and also advances towards the defect requiring extensive undermining of the of the skin at the base of the flap.

Mostly used in head and neck areas.

HISTORY:

Limberg, in 1946, first described this technique to close a 60 degree rhombus defect e transposition flap.

Dufourmental, in 1962, modified the technique to close any acute angle.

Webster, in 1978, modified it further using a 30 degree angulation of distal flap end along with an M-Plasty closure at the base of defect thus preventing dog-ear or standing cone effect.

RHOMBOID FLAP DESIGN AND PLANNING:

AC= Short diagnol, BD= Long diagnol

ABCD represents a 60 degree rhombic defect.

AC is extended by its length to E, and EF is then drawn parallel and equal to CD.

When planning a reconstruction with a rhomboid flap, every rhombus can be closed with one of 4 distant flaps.

Three important aesthetic and functional considerations must be balanced in flap design and choice:

Using RSTLs

Preserving integrity of neighboring fixed anatomical landmarks like lip, eyelid margin, nasal alae.

Observing aesthetic subunits.

LIMBERG FLAP: A classical limberg flap is a parallelogram with angles of 60 &120 drawn around lesion to be excised.

DUFOURMENTAL FLAP: Used to close any acute angle.

An imaginary line is extended from short diagnol and one adjacent side defect.

Angle formed by these lines bisected with a line equal in length to one of sides of defect.

A line is drawn parallel to long diagnol of defect equal in length to one of sides of defect.

WEBSTER or 30 degree FLAP: 30 angulation of distal flap end along with M-plasty spares tissue and prevents Dog-ear appearance. It creates smaller donor site to be closed and also reduces the tension required to close the defect.

INDICATIONS:

Rhombic flaps like transposition flaps are useful when the size or shape of a lesion does not permit direct closure using a standard fusiform or elliptical incision.

Used in reconstruction of cheek, temple, lips, ear, nose, chin, eyelids and neck.

Since much of the scar of the rhomboid flap does not align with the RSTLs, the aesthetic and mechanical properties of these flaps make them especially useful for reconstruction of lower cheek, mid cheek and upper lip as these areas have less prominent skin tension lines.

Though mostly used in head and neck areas, these flaps can also be used elsewhere;

Mid Foot Coverage: For defects on the non-weight bearing area on medial aspect of sole.

Skin defects of Perineum and Vagina: Defects typically result from resection of in-situ & invasive malignancies

Due to laxity of skin in these areas, small defects are closed primarily but for moderate sized defects, Rhomboid flaps provide excellent choice of closure as they allow for early mobilization & less heavy dressing.

CONTRAINDICATIONS:

Heavy Smokers and IDDM patients have higher complication rates due to MICROVASCULAR PATHOLOGY.

Since donor site is closed primarily, these flaps should not be considered for extreamly larger lesions or in instances where the resulting tension distorts the neighbouring fixed anatomical landmarks e.g: Nasal alae, lip, eyelid margin.

The natural parallel, horizontal wrinkles of central forehaead prevent good aesthetic result with these flaps, therefore, rhomboid flaps are generally avoided in these areas.

COMPLICATIONS: FLAP FAILURE IS UNCOMMON.

Partial necrosis of the distal flap end can occur if the angle is too tight.

Standing cones or widened scars result from transposition of such flaps.

OUTCOME & PROGNOSIS:

PIN CUSHIONING/ TRAP DOOR Deformities (Contraction of the base of defect) may be related to inadequate incision of wound edges, incomplete undermining or post operative scar thickening.

(Thickened scar may be managed by intralesional corticosteroid injections, scar revision and dermabrasion).

A poorly planned rhomboid flap my disturb the neighboring fixed anatomical landmarks and leave a poorly oriented scar.