Journal of Applied Sciences Research, 6(6): 659-664, 2010 © 2010, INSInet Publication The Nerve of Kuntz: Incidence, Location and Variations Zeenat F. Zaidi M.B.B.S, D.Phil., Arifa Ashraf M.B.B.S Department of Anatomy, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia Abstract: Nerve of Kuntz is considered to be one of the causes of recurrence of symptoms following endothoracic sympathectomy. This study was designed to explore the anatomic variations in the location and course of the intrathoracic nerve of Kuntz (INK). Bilateral dissection of the sympathetic chain and somatic nerves of the upper 5 intercostal spaces was undertaken in 25 adult cadavers. The total sample size comprised 25 cadavers (50 sides). The incidence of any connection between the first and second thoracic nerves (INK), the diameter of the INK, the distance from the arising point of the INK from the second thoracic nerve to the sympathetic trunk were noted. The presence and/or absence of stellate ganglion, location of second thoracic ganglion, occurrence of any connection from the lower thoracic nerves with the first thoracic nerve, and occurrence of subpleural vein and collateral artery were also recorded. All measurements were made with digital calipers. The intrathoracic nerve of Kuntz was observed in 33 (66%) sides (54.5% left, 45.5% right) and was present bilaterally in 78.9% of 19 cadavers. The diameter of the intrathoracic nerve was 1.32±0.10 mm on the left and 1.29±0.12 mm on right side. The arising point of the intrathoracic nerve from the second thoracic nerve was 9.0±0.06 mm on left side and 1.06±0.06 mm on right side from the sympathetic trunk. In 80% of cases a collateral artery was present in relation to INK. It is concluded that second thoracic nerve contributes fibers to the brachial plexus that do not ascend in sympathetic trunk. These nerve fibers, the Nerve of Kuntz, pass up over the second rib level on their way to join the first thoracic nerve. To achieve successful results of endothoracic sympathectomy it is imperative that all the sympathetic nerve fibers crossing the second rib level should be divided. Key words: Sympathectomy, stallate ganglion, sympathetic chain, nerve of Kuntz. INTRODUCTION Endoscopic thoracic sympathectomy (ETS) is a surgical procedure, used to relieve the symptoms of craniofacial, palmar, or axillary hyperhidrosis, [1,2,3,4] facial blushing, [5] Raynaud’s disease, [6,7] and reflex sympathetic dystrophy. [8,9] There are reports of ETS being used to achieve cerebral revascularization for patients with moyamoya disease [10] and to treat headaches, hyperactive bronchial tubes [11] , long QT syndrome [12,13] , causalgic pain [8,14] , erythromelalgia [15] , Burger’s disease [16] , Prinzmetal’s angina [17] , migraine [18] and in the treatment of chronic non-infectious rhinitis [19]. Sympathectomy is also effective in ameliorating the effects of frostbite injury, especially if performed within 36-72 hours of cold exposure [20] . Sympathectomy physically destroys sympathetic fibers anywhere in either of the two sympathetic trunks. The most common area targeted is the upper thoracic region, the part of the sympathetic trunk lying between the first and fifth thoracic vertebrae. The procedure has shown some failure rate and the symptoms may recur in a small proportion of patients, months or even years after surgery [7,21,22,23,24,25,26] . The second thoracic nerve is not generally regarded as contributory to the brachial plexus. However, an inconsistent intrathoracic ramus joining the 2nd intercostal nerve to the ventral ramus of the 1st thoracic nerve, proximal to the point where the latter gave a large branch to the brachial plexus, was found by Kuntz [27] and named after him. This nerve was considered to be carrying sympathetic fibers to the brachial plexus without passing through the sympathetic trunk [27, 28, 29] and was held responsible for the recurrence of symptoms following sympathectomy. However, the detailed anatomy of the intrathoracic nerve including variations have not been well documented. The aim of this study was to determine the incidence, location and variations in the neural connections of the intrathoracic nerve of Kuntz (INK). Corresponding Author: Dr. Zeenat F. Zaidi, Department of Anatomy Faculty of Medicine King Saud University P.O.Box 22452 Riyadh 11495 Saudi Arabia Tel: +966-1-4781995 Mobile: +966502151924 Fax: +966-1-4781995 E-mail: zeenatzaidi@hotmail.com zzaidi@ksu.edu.sa 659