Which retractor features arms that curve outwardly?

The West retractor is specifically designed with arms that curve outwardly, which allows for effective retraction of tissue during surgical procedures. This curvilinear shape facilitates a broader exposure of the surgical field, making it particularly useful in areas where access is limited or where additional space is required to see and work on underlying tissues. The outwardly curved arms help to hold back the edges of incisions or flaps without causing undue strain on the surrounding tissue, thereby minimizing tissue trauma and promoting better surgical conditions.

The other instruments listed serve different purposes or have different shapes that do not feature outwardly curving arms. For instance, the Aln skin retractor typically has straight arms designed to hold skin edges apart rather than curve outward. The Senn retractor has one straight prong and one curved prong but does not have a continuously outwardly curving design. St. Martin dissecting forceps are primarily used for grasping and manipulating rather than retracting, thus lacking the characteristic of curved retractor arms altogether.