Sympathicotomy for Palmar Hyperhidrosis: The Association between Intraoperative Palm Temperature Change and the Curative Effect

Abstract

Purpose: To investigate the association between intraoperative palm temperature change and the curative effect of sympathicotomy.

Methods: 49 patients with palmar hyperhidrosis were treated with bilateral endoscopic sympathicotomy. Ipsilateral palm temperature was monitored before and at 3–5 min increments after the sympathetic trunk was transected. The maximum temperature elevation (Tmax) was calculated and used to evaluate the effect on postoperative cure rates.

Results: Forty-nine patients underwent 98 sympathicotomies. There were 77 T4 sympathicotomies, 15 T4 + T5 sympathicotomies, and six T3 sympathicotomies due to pleural adhesions or neurovascular proximity. The Tmax was ≤1°C in 49 (50.0%), 1–1.5°C in 17 (17.3%), and >1.5°C in 32 (32.7%) palms. Ninety-two palms of 46 patients were followed with complete efficacy, and three patients were lost to follow up. Cure was achieved in 86 palms (93.4%). Of the 71 palms which underwent T4 sympathicotomy, cure was achieved in 67 palms (94.3%). In those palms which did not achieve cure, the Tmax was less than 1°C in each case, while in palms with a Tmax ≤1°C, 32 of 36 (88.9%) were cured.

Conclusion: There is an association between intraoperative palmar temperature change and curative effect. However, palmar temperature change cannot be used to predict cure or guide surgical approach.

Introduction

Thoracic sympathicotomy is currently the standard procedure to treat palmar hyperhidrosis. However, some patients develop severe compensatory sweating postoperatively, which is the most troublesome complication impeding the development of this procedure. Recent years according to a number of randomized controlled studies, T4 sympathicotomy has been regarded as the preferred approach. It has the lowest rate of compensatory hyperhidrosis (CH).^1–4) However, some patients have mild hand moistness, while a few patients fail T4 sympathicotomy. Why the same procedure produces different effects in different patients remains unclear? Intraoperative palmar temperature change was widely deemed to be associated with the curative effect. So some authors propose the use of temperature monitoring to guide surgical approach. Patients without obvious increases in palm temperature receive transection of the sympathetic chain at a higher level.⁵⁾ Actually there are no studies which determine whether palmar temperature change really associates with the treatment efficacy.

Based on our former study, we routinely performed T4 sympathicotomy to treat palmar hyperhidrosis.²⁾ In this study we monitored ipsilateral palm temperature change of the patient, and investigated its correlation with cure during the follow-up period.

Materials and methods

Approval for the study was obtained from the Ethics Committee of the Hospital, and informed consent was obtained from each patient.

Patients and operations

Between July 2012 and April 2013 49 patients (30 males, 19 females, average age: 23.4 years) with palmar hyperhidrosis underwent bilateral endoscopic sympathicotomy in the Department of Thoracic Surgery of the Peking University People’s Hospital and Beijing Haidian Hospital. Palmar hyperhidrosis was combined with axillary hyperhidrosis in 12 cases, and foot hyperhidrosis in 31 cases. All patients received a detailed preoperative consultation. The diagnosis of primary palmar hyperhidrosis was made according to published criteria.⁶⁾ Tuberculosis, tuberculous pleurisy, suspicious pleural dense adhesions, and secondary hyperhidrosis due to hyperthyroidism and diabetes were considered contraindications to surgery. All patients underwent routine preoperative screening, including chest X-ray, electrocardiograph (ECG), and laboratory blood tests including hematologic, electrolyte, coagulation, hepatic, and liver profiles.

After the patient entered the thermostat laminar flow operating room (temperature set to 23°C), the left lower extremity was used for intravenous infusion. ECG, blood pressure, and oxygen saturation monitoring were performed. After routine induction of anesthesia, single-lumen endotracheal intubation (23 cases), or laryngeal mask airway (26 cases) ventilation was maintained.

A single incision was made in the third intercostal place at the midaxillary line. T4 sympathicotomy was performed as described previously.²⁾ The sympathetic chain was transected at the level of the fourth rib by electrocoagulation, and extended for a distance of 2 cm to ensure a complete result. T4 + T5 sympathicotomy was employed if axillary hyperhidrosis was present. Palm temperature measurement was performed with a thermometer (Microlife Company model FR1DZ1, China, calibration error ± 0.1°C). Ipsilateral palm temperature was monitored before sympathicotomy, and 3, 5, 7, 10, 15, and 20 min after sympathetic trunk transection.

Follow-up

Patients were followed postoperatively, to document improvement of palmar sweating, side effects and severity of compensatory hyperhidrosis (CH). With regards to improvement of palmar sweating, categories of dry, slightly damp, and wet were used. “Dry” was defined as the palm being completely without sweat in any condition. “Slightly damp” was defined as the palm being slightly damp under excessive heat or anxiety, but without visible sweat, obvious discomfort, and still having achieved patient’s satisfaction. “Wet” was defined as significant sweating, or no significant improvement compared with preoperative levels. During follow-up, both palms of the same patient were evaluated separately.

Results

General information

Forty-nine patients underwent 98 sympathicotomies, including 77 T4 sympathicotomies, 15 T4 + T5 sympathicotomies, and six T3 sympathicotomies. Among the T3 sympathicotomies, three cases were due to pleural adhesions, adhesions below the third intercostal place were difficult to separate. The other three cases were due to the fact that the sympathetic chain was obscured by intercostal vessels at the T4 level. All surgeries were successful, without postoperative complications or surgery-related death. All patients were discharged 1–2 days postoperatively.

Intraoperative palm temperature change

After transecting the sympathetic chain, of the six measurements of ipsilateral palm temperature, at least one temperature rise was detected in 87 palms (88.8%), and no rise or decreased temperature in 11 palms (11.2%). We selected the maximum rise in palm temperature (Tmax) from six data points after nerve transection and used it for the final evaluation. A Tmax of >1.5°C was observed in 32 palms (32.6%), 1–1.5°C in 17 palms (17.3%), and ≤1°C in 49 palms (50%). Tmax statistics of different surgical procedures are shown in Table 1.

Table 1.

Tmax in different surgical approaches

Surgical approaches	Cases (n)	>1.5°C	1.0–1.5°C	≤1.0°C
T3 sympathicotomies	6	5 (83.3%)	0	1 (16.7%)
T4 sympathicotomies	77	25 (32.5%)	16 (20.8%)	36 (46.7%)
T4+T5 sympathicotomies	15	2 (13.3%)	1 (6.7%)	12 (80.0%)
Total	98	32 (32.6%)	17 (17.3%)	49 (50%)

Curative effect postoperative

Postoperative follow-up was achieved via telephone, email, QQ Chat Tools or outpatient referral. The average follow-up period was 24.6 months. Three patients (6.1%) were lost in follow up and 46 patients with 92 palms had complete data.

In accordance with the classification criteria mentioned earlier, 47 palms (51%) were “dry,” 39 palms (42.4%) were “slightly damp,” and six palms (6.6%) were “wet.” The overall effect was good (“dry” + “slightly damp”) in 86 palms, accounting for 93.4%. Postoperative efficacy of different surgical procedures is shown in Table 2.

Table 2.

Improvement in palmar hyperhidrosis with different surgical approaches

Surgical approach	Cases (n)	Dry	Slightly damp	Wet
T3 sympathicotomies	6	5 (83.3%)	1 (16.7%)	0
T4 sympathicotomies	71	38 (53.5%)	29 (40.8%)	4 (5.7%)
T4+T5 sympathicotomies	15	4 (26.6%)	9 (60.1%)	2 (13.3%)
Total	92	47 (51.0%)	39 (42.4%)	6 (6.6%)

Nineteen (41.3%) patients had certain degrees of CH, often in back, chest, buttocks and thighs; slight in 15 (32.6%), and moderate in 4 (8.7%). No severe CH was reported.

Correlation analysis of intraoperative palm temperature change and cure

In the cases with follow-up data, improvement in palmar sweating is shown in Table 3. Of the 6 “wet” palms, Tmax levels were all ≤1°C. However, in palms with a Tmax ≤1°C, 87.6% of patients achieved cure.

Table 3.

The relationship between Tmax and cure in all palms

Tmax	Cases	Dry	Slightly damp	Wet
≤1°C	49	22 (44.8%)	21 (42.8%)	6 (12.4%)
1–1.5°C	14	8 (57.1%)	6 (42.9%)	0
>1.5°C	29	16 (55.0%)	13 (44.8%)	0
Total	92	46 (50%)	40 (43.5%)	6 (6.5%)

T4 sympathicotomies are the focus of this study. The relationship between Tmax and cure in T4 sympathicotomy palms is shown in Table 4. In this group, four palms had poor results, they all had Tmax values less than 1°C. However, satisfied palms with a Tmax ≤1°C accounted for 88.9%.

Table 4.

The relationship between Tmax and cure in T4 sympathicotomy palms

Tmax	Cases	Dry	Slightly damp	Wet
≤1°C	36	20 (55.6%)	12 (33.3%)	4 (11.1%)
1–1.5°C	13	7 (53.8%)	6 (46.2%)	0
>1.5°C	22	11 (50.0%)	11 (50.0%)	0
Total	71	38 (53.5%)	29 (40.8%)	4 (5.6%)

Correlation analysis of change in intraoperative palm temperature and CH

CH is equal in two sides whereas temperature change is not equal in some patients, so this analysis applied only to patients whose change in palm temperature in both palms were in the same segment. Twenty five patients were suitable. There was no significant difference in the relationship between Tmax and CH among different temperature groups (Fisher exact probability, P >0.05, shown in Table 5).

Table 5.

The relationship between Tmax and CH

	Cases	Compensatory hyperhidrosis	Mild	Moderate
≤1°C	17	10 (58.8%)	6 (35.3%)	4 (23.5%)
>1.0°C	8	2 (25.0%)	1 (12.5%)	1 (12.5%)
Total (side)	25	12 (48.0%)	7 (28.0%)	5 (20.0%)

Discussion

CH is the most common long-term side effect following sympathicotomy, and has remained the most troublesome complication impeding the development of this procedure.⁷⁾ In 2001, Lin and Wu first reported a significant reduction in compensatory sweating when T4 thoracic sympathicotomy was employed to treat palmar hyperhidrosis.⁸⁾ Several studies later confirmed that T4 sympathicotomy avoided compensatory sweating, patients were highly satisfied, and that this approach was preferred in the treatment of palmar hyperhidrosis.^1–4,9) In some patients, however, improvement in palmar sweating was less defined and its efficacy was incomplete. How to screen these particular patients in the preoperative or intraoperative setting? Thus tailor surgical approach is a valuable research topic.

When sympathetic nerves to the palms are stimulated, sweat glands secrete and capillaries contract. A decrease in palmar sweating and rise in palmar temperature are concomitant effects of thoracic sympathicotomy. In the early development of the operation, many surgeons monitored palm temperature intraoperatively to verify nerve transection. Later, as the understanding of sympathetic regional anatomy and surgical experience improved, it became easier to recognize sympathicotomy was successful and the former approach was gradually abandoned. But many authors deemed that Intraoperative palmar temperature is associated with the curative effect. Some authors used palm temperature change to guide surgical procedure options. For example, Kao et al. proposed 3°C as the cutoff point. For those whose palm temperature rise did not reach 3°C, extending the resection was recommended¹⁰⁾. In 2009, Li proposed that a rise in palm temperature of less than 1.5°C in T4 sympathicotomy required extension to T3 sympathicotomy, and even T2 sympathicotomy if the temperature rise was not obvious.⁵⁾ Is rise in palm temperature indeed directly related to the degree of sweating elimination? Is this method scientifically valid for guiding surgical approach? Further research is required.

From the data of this study cohort, after T4 sympathicotomy, four of the 71 palms failed to demonstrate cure, and they all had a change in palmar temperature of less than 1°C. If a temperature change ≤1°C or ≤1.5°C was chosen as the threshold for predicting efficacy, the sensitivity could be up to 100%. But in both temperature ranges, the probability of good results was 88.9% (32/36) and 91.8% (45/49), respectively. That is, the specificity was only 11.1% and 8.2%. This means that if a temperature rise of less than 1.5°C was selected as a reference point for changing the surgical procedure, 91.8% of patients would undergo T3 or T2 sympathicotomy, which may lead to additional unnecessary side-effects. Apparently, despite a correlation between palm temperature change and cure, it was unscientific to determine surgical approach based on this factor alone.

Lu et al. reported that in approximately 10% of patients, palmar temperature did not change after sympathicotomy.¹¹⁾ In our study, the temperature of nine palms did not rise or decrease after T4 sympathicotomy, accounting for 11.7%. Could 0°C be the threshold to predict efficacy? Our follow-up results demonstrated that of these nine cases, two had poor results, accounting for 50% of all four ineffective cases, with a sensitivity of 50% (2/4) and a specificity of 22.2% (2/9). As a result, even with 0°C as the threshold, the predictive value was also far from ideal.

As can be seen from the anatomy of the thoracic sympathetic nerves, compared with T2 or T3 sympathicotomy, T4 sympathicotomy had the least degree of denervation theoretically, so its impact on the palm temperature should also be the least. Palmar temperature change may be small and difficult to capture. On the other hand, intraoperative palm temperature could be affected by many factors that may be hard to control. These include ambient temperature of the operating room, depth of anesthesia, the cooling effect of alcohol after sterilization, the warming effect after application of drapes, the entry of cold air after opening of the pleural cavity, and so on. The temperature can fluctuate at different stages during the operation (from skin incision to nerve section). This may be the root reason why it is ineffective to predict the curative effect based upon intraoperative palm temperature change.

In summary, there is an association between intraoperative palmar temperature change and postoperative curative effect. Nevertheless, palmar temperature change cannot be used to predict curative effect or to guide surgical procedure options.

The limitation of the study is limited number of cases, and lack of comparative statistical analysis with regard to different section levels and different types of hyperhidrosis: palmar, palmar-axillary, plantar, etc.

Disclosure Statement

We confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.