Pilonidal disease is usually surgically managed by elliptical off-midline excision and primary closure. Other options (negative pressure wound dressings, packing with healing by secondary intention, injection of tracts with fibrin glue, etc) are also used. Recurrent (and sometimes primary) disease may require rotational flaps. Many options are available. One of the simpler options is a rhomboid flap. Recall that a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are non-right angled.
The Dufourmentel flap can be used to close a rhomboid with any acute angle from 60 to 90°. It is somewhat more complicated to construct than some other flaps, but when the rhomboid defect is tight – ie, has angles of less than 60°, the Dufourmentel flap is narrower than a Limberg flap, and therefore easier to close without as much tension.
Step 1: Extend imaginary lines (dotted lines) from the short diagonal and from one adjacent defect side.
Step 2: Bisect the angle formed by these lines with a line equal in length to one of the sides of the defect (solid line).
Step 3: Draw a line parallel to the long diagonal of the defect equal in length to a defect side (solid line on the right).
This flap is all communicating 60° equilateral triangles – every side of the defect and the flap are of equal length. Therefore the flap is the same size as the defect created. This flap leaves an elliptical donor site defect which is closed primarily after subdermal undermining.
Step 1: A parallelogram (angles of 60° and 120°) is drawn around the lesion.
Step 2: A line is extended from the short horizontal
Step 3: A second line (equal in length and parallel to one of the adjacent defect sides) from the distal end of the first line – this forms the apex of the rotation flap.