Sympathectomy limits blood flow to a vital organ like the brain

1. Acta Physiol Scand. 2000 Sep;170(1):33-8.

Middle cerebral artery blood velocity during exercise with beta-1 adrenergic and unilateral stellate ganglion blockade in humans.

Ide K, Boushel R, Sørensen HM, Fernandes A, Cai Y, Pott F, Secher NH.

Department of Anaesthesia, The Copenhagen Muscle Research Centre, University of Copenhagen, Rigshospitalet, Denmark.

A reduced ability to increase cardiac output (CO) during exercise limits blood flow by vasoconstriction even in active skeletal muscle. Such a flow limitation may also take place in the brain as an increase in the transcranial Doppler determined middle cerebral artery blood velocity (MCA V(mean)) is attenuated during cycling with beta-1 adrenergic blockade and in patients with heart insufficiency. We studied whether sympathetic blockade at the level of the neck (0.1% lidocaine; 8 mL; n=8) affects the attenuated exercise - MCA V(mean following cardio-selective beta-1 adrenergic blockade (0.15 mg kg(-1) metoprolol
i.v.) during cycling. Cardiac output determined by indocyanine green dye dilution, heart rate (HR), mean arterial pressure (MAP) and MCA V(mean) were obtained during moderate intensity cycling before and after pharmacological intervention. During control cycling the right and left MCA V(mean) increased to the same extent (11.4 1.9 vs. 11.1 1.9 cm s(-1)). With the
pharmacological intervention the exercise CO (10 1 vs. 12 1 L min(-1); n=5), HR (115 4 vs. 134 4 beats min(-1)) and delta MCA V(mean) (8.7 2.2 vs. 11.4 1.9 cm s(-1) were reduced, and MAP was increased (100 5 vs. 86 2 mmHg; P < 0.05).

However, sympathetic blockade at the level of the neck eliminated the beta-1 blockade induced attenuation in delta MCA V(mean) (10.2 2.5 cm s(-1)). These results indicate that a reduced ability to increase CO during exercise limits blood flow to a vital organ like the brain and that this flow limitation is likely to be by way of the sympathetic nervous system.

PMID: 10971220 [PubMed - indexed for MEDLINE]

Parallels between effects of spinal cord injury and sympathectomy on cardiac function

Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and neuroanatomy and pathophysiology of autonomic nervous system, sympathetic and parasympathetic. SCI causes disruption of descendent pathways from central control centers to spinal sympathetic neurons, originating into intermediolateral nuclei of T1-L2 spinal cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant cardiac dysfunction. Impairment of autonomic nervous control system, mostly in patients with cervical or high thoracic SCI, causes cardiac dysrrhythmias, especially bradycardia and, rarely, cardiac arrest, or tachyarrhytmias and hypotension. Specific complication dependent on the period of time after trauma like spinal shock and autonomic dysreflexia are also reviewed. Spinal shock occurs during the acute phase following SCI and is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe bradycardia and hypotension. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life-threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5-T6). Besides all this, additional cardiac complications, such as cardiac deconditioning and coronary heart disease may also occur.
http://www.ncbi.nlm.nih.gov/pubmed/20108532


Neurogenic shock is shock caused by the sudden loss of the autonomic nervous system signals to the smooth muscle in vessel walls. This can result from severe central nervous system (brain and spinal cord) damage. With the sudden loss of background sympathetic stimulation, the vessels suddenly relax resulting in a sudden decrease in peripheral vascular resistance (vasodilation)^[1] and decreased blood pressure.

Signs and symptoms

• hypotension
• bradycardia
• warm, dry extremities
• peripheral vasodilation
• venous pooling
• Poikilothermia
• Priapism Due to PNS stimulation
• decreased cardiac output (with cervical or high thoracic injury)

Mayo Clinic investigates the same disorder as the one resulting from the elective surgical sympathectomy

Autoimmune autonomic ganglionopathy is characterized by impairment of multiple autonomic domains of which sudomotor function is among the most common. Many patients with this disorder have difficulties with thermoregulation and anhidrosis.

Sudomotor dysfunction in autoimmune autonomic ganglionopathy

http://www.ncbi.nlm.nih.gov/pubmed/19884578

Other alternative more selective methods, rather than cutting the main trunk should be studied

Compensatory sweating remains the most common, and most disabling complication of video-assisted thoracoscopic sympathectomy. Other alternative more selective methods, rather than cutting the main trunk should be studied thoroughly to assess their efficacy in reducing the complication of compensatory sweating.
http://www.ncbi.nlm.nih.gov/pubmed/18521466

Evidence: sympathectomy created imbalance of autonomic activity and functional changes of the intrathoracic organs

Surgical thoracic sympathectomy such as ESD or heart transplantation can result in an imbalance between the sympathetic and parasympathetic activities and result in functional changes
in the intrathoracic organs.
Therefore, the procedures affecting sympathetic nerve functions, such as epidural anesthesia, ESD, and heart transplantation, may cause an imbalance between sympathetic and parasympa-
thetic activities (1, 6, 16, 17). Recently, it has been reported that ESD results in functional changes of the intrathoracic organs.


In conclusion, our study demonstrated that ESD adversely affected lung function early after surgery and the BHR was affected by an imbalance of autonomic activity created by bilateral ESD in patients with primary focal hyperhidrosis.
Journal of Asthma, 46:276–279, 2009

T2 procedure results in a complete sympathectomy

Sympathectomy of the upper extremity. Evidence that only the second dorsal ganglion need be removed for complete sympathectomy.

Hyndman OR,Wolkin J

Arch Surg. 1942 45:145–155

Sympathectomy and parasympathectomy leads to the hyperfunction of the serotoninergic system and pathology

We studied the balance of activity of sympathetic, parasympathetic, and serotoninergic divisions of the autonomic nervous system in the regulation of the heart function in rabbits. High activities of the sympathetic and parasympathetic system are associated with antagonistic interactions between them. Moderation of activity of these systems could be accompanied by activation of the serotoninergic system. Physiological sympathectomy and parasympathectomy lead to hyperfunction of the serotoninergic system and pathology.
Bulletin of Experimental Biology and Medicine, Vol. 140, No. 5, 2005 PHYSIOLOGY

Disturbances in brain serotonergic systems result in a range of phenotypes such as depression, suicide and anxiety disorders.
http://www.biomedcentral.com/1471-2202/10/50