Histopathological examination of chemo-sympathectomy in cats

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“…This anteriorly located segment is very difficult to reach via a posterior percutaneous approach with either an electrical or a chemical method (2). The only viable route is to approach this segment through the intercostal space where the intercostal nerve and vessels are located.…”

“…They are also influenced by the central neural mechanism. Therefore, PST fluctuates within a large range in different intraoperative situations while the patient is under local anesthesia (2,3). PST markedly decreases during emotional tension or surgical manipulation because of increased sympathetic tone, and it increases gradually only when a sufficient interruption of the sympathetic segment has been induced by phenol injection.…”

“…In fact, the thumb skin temperature of patients with PH is approximately 1°C colder than that of a healthy individual; after sympathectomy, however, it becomes approximately 2°C warmer than that of a healthy person. Consequently, PST is not useful or reliable as a guide for localizing the precise sympathetic target for phenol injection; it is useful only to indicate the final effect of a satisfactory phenol sympathicolysis procedure (2,3).…”

“…Consequently, it is difficult to perform an adequate sympathectomy via the posterior percutaneous approach, and multiple blind injections by trial and error or electrocoagulation with fluoroscopic guidance at the expected anatomic location are often required to obtain sufficient denervation to lead to a definite therapeutic effect. The risk of injuring the intercostal nerve and vessels during such procedures is very high (2), which is why the surgeon must remove a part of the rib and the bony costovertebral junction during the open dorsal sympathectomy before reaching the sympathetic segment and then resecting it.…”

“…Furthermore, the sympathetic trunk is almost impossible to localize exactly with a C-arm fluoroscope because it is so thin that it is not radiologically visible. Also, it varies greatly from patient to patient (2). Intraoperative monitoring of palmar skin temperature (PST) is an important and useful aid in confirming that an adequate sympathectomy is performed for the treatment of patients with PH (5).…”