Kuntz nerves most commonly are of small caliber measuring 0.3 to 0.5 mmin diameter. This makes it extremely challenging to identify them and requires a special technique to do so. For instance, the angle of approach of the endoscope is in and of itself very important in most accurately being able to find them.

They commonly cross the 3rd and 2nd ribs at a variety of diverging angles as they travel in a cephalad direction on their way to the fingers and face. They bypass the ganglia that they travel by and can actually travel up to several inches (4 to 6 inches) away from the main sympathetic nerve as they cross the second rib. However, Kuntz nerves commonly travel 1 to 5 cm lateral to the main sympathetic nerve. Less commonly, Kuntz nerves may travel medial to the main sympathetic nerve making their identification extremely difficult.

Intact Kuntz nerves is the most common reason I find for persistent symptoms after a patient has undergone bilateral sympathectomy. Much less commonly, persistent symptoms is due to misidentifying the T3 as the T2 level and therefore leaving the T2 level completely untouched and free to carry sympathetic nerve signal to the fingers and face.