title: Horner syndrome after carotid sheath surgery in a pig: anatomic study of cervical sympathetic chain.
abstract: In an experimental model, iatrogenic Horner syndrome developed after a right carotid sheath surgery in an infant pig (Sus scrofa). Horner syndrome is a classic clinical triad consisting of ipsilateral eyelid ptosis, pupil miosis, and facial anhydrosis. This syndrome results from  cervical sympathetic chain (CSC) paresis and usually is acquired in humans. To determine whether the development of Horner syndrome in this situation could be attributed to pig anatomy, we compared the anatomy of the CSC in pigs and humans, by using 10 infant (age, 1 to 3 wk) pig cadavers.  The CSC and cranial cervical sympathetic ganglion (CCG) were dissected bilaterally under a surgical microscope. These structures were consistently within the carotid sheaths of the pigs. In contrast, the CSC and CCG are outside the carotid sheath in humans. Awareness of the anatomic variation  of the CSC and CCG within the carotid sheath in the pig and the possibility of the same variation in humans may help surgeons to identify and preserve important structures while performing cervical surgery in pigs and humans. Furthermore, this knowledge can aid in the diagnosis and prognosis  of schwannoma.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. pding3@jhmi.edu
authors.forename: Peng
authors.initials: P
authors.lastname: Ding
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Tufano
authors.forename: Regina
authors.initials: R
authors.lastname: Campbell-Malone
authors.forename: Wallace
authors.initials: W
authors.lastname: Feng
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Kim
authors.forename: Rebecca Z
authors.initials: RZ
authors.lastname: German
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D000831:Animals, Newborn; D003238:Connective Tissue / Q000601:surgery*; D004210:Dissection / Q000662:veterinary; D005728:Ganglia, Sympathetic / Q000033:anatomy & histology / Q000293:injuries* / Q000601:surgery; D006732:Horner Syndrome / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D006801:Humans; D007049:Iatrogenic Disease / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000209:etiology* / Q000473:pathology