Thoracic Sympathectomy - Sympathetic Block

Endoscopic transthoracic sympathetic surgery (ETS) is a collective term for a series of procedures that may differ significantly from each other.

Indications

Sympathetic surgery should be reserved to patients with severe forms of the following disorders, for which no satisfactory result was obtained by conventional measures:

• Palmar Hyperhidrosis (sweaty hands)
• Craniofacial hyperhidrosis (facial sweating)
• Facial Blushing (Sympathicogenic Erythema) with Erythrophobia

NB: isolated Axillary Hyperhidrosis (armpit sweating) should be treated by other treatment options. ETS should only be considered in exceptional cases (severe distress and total failure of botulinum toxin therapy and local surgical procedures).

Choice of procedure

The type of surgery and the way it is carried out has a significant impact on the result, both regarding the effect and, in particular, regarding the side effects.

• Palmar hyperhidrosis: T3 ganglionectomy (alt. periganglionic neuro-compression = Clamping)
  

  The exclusion of the T3 ganglion produces reliable results for excessive hand sweat. Cardiocirculatory side effects (slower heart rate and lower blood pressure) are almost absent and the risk for reactive (compensatory) hyperhidrosis is very low. Under no circumstances should the ganglion T2 be involved at a first operation, nor should the sympathetic chain be interrupted above this ganglion, because of a more pronounced risk of developing intense compensatory sweating and side effects involving heart function and blood pressure.

  
  
• Craniofacial hyperhidrosis: interganglionic neuro-compression (clamping) between the ganglia Th1-T2
  

  The compression is performed by applying a single clip just above the ganglion T2. This usually corresponds to the lower edge of the second rib, which ensures a safe distance to the stellate ganglion (Th1).

  
  
• Facial Blushing - Erythrophobia: Same procedure as for craniofacial hyperhidrosis.

Unfortunately, the terminology that describes the level is not uniform, sometimes even misleading. Today we still lack a generally accepted, univocal and precise nomenclature. Many surgeons dedicated to sympathetic surgery refer to the ribs when determining the level of interruption, without closer look to the targeted ganglion/nerve segment or analysis of its relationship to the rib, and often without exactly specifying the interruption level (e.g. mid rib, upper or lower margin of the rib). However, since the topography of the ganglion may vary widely from individual to individual (especially for the ganglion T3), published results are often difficult to evaluate due to the foggy nomenclature.close

Surgical Technique

• Anesthesia
  The procedure is performed under general anesthesia.

  We prefer the single-lumen intubation, a double-lumen intubation carries virtually no benefits and extends the duration of the surgery unnecessarily.

• Positioning
  Supine position with arms abducted at right angles.

  The lateral position seems more awkward because it requires the patient to be repositioned under anesthesia.

• Unilateral or bilateral surgery?
  From the patient's perspective, arguments for an operation in two temporally distinct phases are hardly justifiable. The patient looses twice as much working hours and has to undergo an extra anesthesia, although both sides can be operated easily in one session. Only in case of unexpected complications or special anatomical difficulties it may be justifiable to opt for a two stage procedure.

  Two-stage procedures are almost always chosen in order to get double reimbursements from the health insurance or because the surgeon is not yet familiar with the procedure.

• The procedure
  The approach through the armpit has the advantage of producing hardly visible scars and should therefore be preferred. Usually, for videothoracoscopic ETS, 2 ports are sufficient. Two small incisions of 7-8 mm in the armpit, at a distance of 3-4 cm, are performed. With a special cannula carbon dioxide is insufflated into the pleural space (between lung and pleura). This reduces the volume of the lung and creates free space in the chest cavity which allows introducing the instruments without damaging the lung. After positioning two thin tubes, the optical system and a the dissector electrode is inserted in either tube. Now, the nerve is identified and the exact level for the interruption is determined. After opening a tiny window in the pleura, the sympatcahetic trunk is severed or clamped. Eventually, the initially inflated gas is re-aspirated and the instruments are simultaneously removed under direct vision. A suction drain is only needed when a lesion of the lung is suspected (very rare occurrence); some surgeons, however, place a drain routinely. The two wounds are closed with an airtight suture. Subsequently, the same procedure is carried out on the opposite chest cavity.
  

  Alternative techniques include the 1-port method in which only one incision is required. For this purpose, either a special instrument with integrates both the optical system and an electrode (resectoscope), similar to devices used in urology for prostatic surgery, or an even thinner endoscope provided with a coagulation electrode is employed. Clamping is not possible with 1-port systems. In rare cases with extreme adhesions between the pleura and lung, the one-port method may be the only way to approach the nerve.
  Exceptional events may require a third port, e.g. in the presence of particularly difficult anatomy or when copious bleeding occurs.

Results

After proper interruption of the nervous signal flow, the effect is already apparent immediately upon awakening from anesthesia, and with special measuring devices even in the course of surgery. After a few months, a certain degree of moisture on the palms or in the face may become gradually noticeable in some patients, but it hardly ever reaches a cumbersome level and practically never the original intensity of hyperhidrosis. This phenomenon is generally caused by a redirection of nervous impulses via parallel pathways, thus bypassing the block, rarely by reconnection of the nerve fibers at the point of interruption.
Recurrence of facial blushing is more frequent (> 10%) and appears to be caused by the same mechanism.

Risks