In the current issue of Mayo Clinic Proceedings, Atkinson et al1 report on a 10-year experience with thoracoscopic sympathectomy treatment of hyperhidrosis (HH). Also called video-assisted thoracic sympathectomy or endoscopic thoracic sympathectomy, this procedure is most commonly performed for primary HH but is also performed for other indications, including complex regional pain syndrome type I (formerly known as reflex sympathetic dystrophy), upper extremity ischemia, and Raynaud disease.2
I commend Atkinson et al for their excellent short-term and long-term results. Their moderately sized series of approximately 15 patients per year adds to the general literature on a procedure that has been used and refined during the past 70 years. First described by Kux et al3 in the 1940s, sympathectomy for HH was “resurrected” in the late 1980s and early 1990s with the advent of video endoscopic surgery techniques.4 Several single-institution studies with large cohorts of patients have made this approach the single best technique for curing patients with palmar, axillary, or plantar HH.5,6 “Ideal candidates” for endoscopic thoracic sympathectomy have onset of HH at an early age ( 55 beats/min). As such, only a small percentage of patients wtih HH should be considered for surgical treatment.
Particularly interesting is that the series of Atkinson et al is one of the larger ones reported by a neurosurgical group; most previous large-scale reports have been described by thoracic, vascular, and general surgeons. The number of female patients in their report is lower than that previously reported; generally the incidence of clinically significant HH is approximately 1% (or slightly more) of the general population, depending on geography and ethnicity, with a predominance of females.7 The failure rate and the overall complication rate in the Atkinson et al report were appropriately low.
There are several different approaches to both the technique for sympathetic division and the choice of the level of division. Nerve resection, ablation, and division have all been described in the literature.8-10 In addition, less invasive techniques using only ramicotomy have been attempted to minimize the incidence of perioperative complications and particularly to reduce the prevalence of severe compensatory sweating (CS).11
Recent consensus statements from the Society of Thoracic Surgeons Sympathectomy Taskforce12 and the International Society of Sympathetic Surgery13 have attempted to standardize the performance and reporting of results after thoracoscopic sympathectomy. Both groups have recommended that the definition of sympathectomy procedures rely on a “rib-based” terminology. Thus, R2 sympathicotomy by any technique is a division of the chain overlying the second rib. This decision was based on the fact that too many patients have mediastinal fat that can obscure clear identification of the specific ganglia and because the ganglion anatomy has many anatomical variations. In describing the surgical procedure in an operative note, the surgeon may add to the rib-based terminology the actual ganglia that were interrupted. In addition, the committees agreed that a description of the type of interruption is required, denoting whether the chain was clipped, cut, or cauterized or whether a segment was removed. This terminology allows for easier comparison of different approaches and techniques reported in the literature worldwide.
The choice of Atkinson et al to cut the nerve high on the chain, although yielding good results, goes against the current consensus recommendations. Their use of a Doppler sonography flow probe to confirm the completion of sympathetic nerve division at the desired location and use of a uniportal incision approach with a modified thoracoscope for this procedure are helpful advances in the field. Finally, I14 and others have also advocated the division of all parallel nerve fibers to eliminate the risk of recurrence. We have used carbon dioxide insufflation within the thorax as a simple means of allowing better visibility,15 an addition that may have utility with the author's single small portal approach. However, their overall success rate suggests that this addition be reserved for only the more difficult cases. Similar to the experience of Atkinson et al, we generally discharge patients within 23 hours after the completion of surgery (Typically, we perform the surgery early in the morning, and patients can go home by noon the day of surgery).
The use of sympathicotomy vs resection or ablation may result in fewer cases of severe CS. Likewise, the division of the chain below the R2 level for hand sweating and even below that (R4) for axillary sweating probably has contributed to this significant decrease in CS as well. Current recommendations regarding the optimal level of division suggest either an R2 or an R3 division for hand sweating and an R4 division for axillary sweating.16 Improvements in plantar sweating have been reported to be approximately 50% using this approach.
It would be interesting to see the authors' approach to management of cases of severe CS. Do they administer routine medications? Have they ever offered a surgical approach to revision or neurosurgical nerve grafting? Connery et al17 have described an experimental robot-assisted model for graft transfer to reverse rare cases of severe CS. Overall, the literature suggests only a 50% correction rate using these types of reversal techniques.
Another interesting issue arising from the Atkinson et al report concerns the possible use of combined surgical teams for the thoracoscopic approach. If there are complicated anatomical findings or in the case of reoperations or clinically significant intrathoracic adhesions, have the authors benefitted from thoracic surgery input during the procedures?
One of the most exciting findings of the Atkinson et al series is the well-described cardiovascular physiology before and after the procedure. The drop in resting and maximal bicycle exercise heart rate in the subset of 22 study patients was not associated with a decrease in maximal oxygen uptake or duration of maximal exercise. There was both an increased parasympathetic component to the heart rate decrease and a decreased sympathetic cardiac tone. This may be in addition to the expected decrease in peripheral vasomotor tone. Although intriguing, these data need to be confirmed in a large-scale study and compared carefully to previous data, particularly from the thoracic and vascular surgery literature.18 Obviously, great caution should still be exercised in cases in which there is a clinically significant irregularity in heart beat from the beginning. In higher-risk patients, cardiology consultation before undertaking sympathectomy is still probably the safest approach.
Thoracoscopic sympathectomy is by far the best curative alternative for patients with clinically significant idiopathic HH. Topical creams containing aluminum hydroxide, use of iontophoresis, and use of off-label botulinum toxin type A (Botox, Allergan, Irvine, CA) injections are all less successful, time-consuming, and often costly. Use of a standardized surgical approach, including technical modifications as recommended by Atkinson et al, has become the criterion standard for treating HH. Although severe incapacitating CS can occur, it is rare (<2% of cases) and can often be avoided by using approaches that target the sympathetic chain lower than the T2 ganglion and by careful patient preparation. Finally, universal adoption of standard nomenclature will allow future research in this field to be performed across disciplines and allow for more precise comparison of results from centers around the globe.
