Level IV dissection is possible by gaining the same access as recommended for levels I to III; please be aware of the thoracic duct on the left side as there is limited access in the caudal region.

The horizontal access to levels I to III generally allows two variations for extended access to level IV and V nodes: MacFee and a modified Schobinger approach (Fig. 2.27).

Irradiated neck: the MacFee approach leads to less wound healing disturbances.

Modified Schobinger incision: better access to the posterior triangle and the complete course of the accessory nerve.

Modified Schobinger incision: angle of the cranioposterior tip has to be at least 90°; therefore, take care that the posterior incision for the level I to III dissection is not extended cranially to the mastoid/ear lobe region—otherwise, tip necrosis may occur. Downward incision follows the anterior border of the trapezius muscle.

Recommendation: use modified Schobinger approach, but discuss MacFee incision in irradiated patients and patients with a short neck.

The leading landmark for dissection of level V is the greater auricular nerve.

The most severe malpractice that can occur during dissection of level V is injury of the SAN.

Location of the SAN: 1 cm cranial of the point where the greater auricular nerve fades away behind the posterior border of the SCM muscle (Fig. 2.28).