Question 6

The dermal fibres of the anterior abdominal wall are predominantly transverse and curve upwards. A vertical skin incision crosses these fibres and therefore generates greater tension across the wound, which can result in a wider scar. A transverse incision is more closely aligned with the predominant orientation of the dermal fibres and is therefore less prone to this effect. This anatomical principle is distinct from the deeper orientation of the abdominal-wall muscles, although both skin and deeper layers contribute to the practical advantages of transverse lower abdominal incisions. Because a vertical incision crosses the predominantly transverse dermal fibre orientation, it is exposed to greater wound tension and is more likely to produce a wider scar.

A) A vertical incision crosses the predominantly transverse dermal fibres and generates greater tension.

C) A midline longitudinal incision remains vertically orientated and does not follow the predominant dermal fibre direction.

D) A paramedian longitudinal incision is also vertical rather than aligned with the transverse dermal fibres.

E) A vertical infraumbilical incision retains the same unfavourable relationship to the transverse dermal fibres.

Part 1 MRCOG Revision Notes and Sample SBAs. Cambridge University Press, 2020. Section 1: Anatomy, Chapter 1. https://doi.org/10.1017/9781108644396