It is presented a further refinement in palmar hyperhidrosis's surgical treatment to improve results and reduce side effects, mainly compensatory hyperhidrosis. It seems that a more selective sympathetic system lesion, namely a selective T3 and T4 gray rami communicantes lesion, allows retaining some residual sweating in the hands without inducing compensatory sweating in the abdomen, thighs, and feet. The result is greater patient satisfaction. There has been a long journey since Wittmosser et al. suggested the technique of gray and white ramicotomy in 1992. In this way, the attending physicians have refined the surgical procedure progressively. The two last research groups reporting their results with selective gray ramicotomy (the idea now is not to lesion the white rami communicantes) entailed extensive lesions (T2 to T4/T5). This study shows that a more selective T3 and T4 selective gray ramicotomy achieves excellent results with fewer side effects. Thus, it is a further step toward improving outcomes, reducing side effects, and increasing patients' satisfaction.

Additionally, the present work has concentrated on objective ways to measure compensatory hyperhidrosis by measuring the sweat production in milliliters of water and the temperature changes in degrees Celsius. This accurate measurement removes the subjectivity induced when we base the results on the treating physicians' opinions or the patients themselves.

The objective measurement of the sweat production in milliliters of water and temperature rise in degrees Celsius has allowed the research group to reach conclusions independent of opinions both from treating physicians and patients themselves. Also, a more selective gray rami communicantes lesion can achieve better results with less compensatory hyperhidrosis and with better patient's satisfaction

Ever since the introduction of thoracic sympathectomy in the treatment of palmar and axillary hyperhidrosis, there has been a continuous quest to find a way to reduce its most unpleasant side effect: compensatory hyperhidrosis (CH). Following the idea of minimizing the surgically induced damage to the sympathetic chain, Wittmoser introduced in 1992, the ramicotomy technique. It entailed the selective lesion of the rami communicantes, both white and gray, from T2 to T4-T5. This surgical technique was not as selective as expected because it damaged the sympathetic input for the lungs and heart, and the head and face. Wittmoser described this surgical technique but never published any results. Gossot4 in 1997 compared this technique with the sympathectomy of the same ganglia in 54 patients. He found that CH's incidence was the same in both groups, but the severity was less in the ramicotomy than in the sympathectomy group. The recurrence rate was more prominent in the first than in the second group (5% ramicotomy versus 0% sympathectomy). Other researchers have confirmed these results.

More studies compared the sympathectomy with the ramicotomy in the following years, confirming that ramicotomy has a lower incidence of CH5-10, with less dry hands but with some recurrences.

In a step forward, Coveliers et al.11 lesioned only the T2 T3 and T4 gray rami communicantes, not touching the sympathetic chain or the white rami communicantes, with CH dropping to 7.2% and no recurrences. Akil et al.12 reported the lesion of the T2-T5 gray rami communicantes with no CH and again with no recurrences. Both studies entail a more extensive lesion, including T2, and one of those studies, T5. There is an agreement to avoid lesioning T2 in many previous reports to reduce the incidence and severity of CH.

Inclusion Criteria:

• palmar HH with or without axillary HH refractive to conservative treatments
• or reluctant to continue with them after six months and willing to undergo surgical treatment,
• Hyperhidrosis Disease Severity Score grade D

Exclusion Criteria:

• previous thoracic pathology (lung infections, particularly pulmonary empyema, pneumothorax, hemothorax, rib fractures, neoplasms)
• heart failure
• hypothyroidism
• tuberculosis
• bradycardia (40 pulsations/min)
• alcoholism
• drug addiction
• BMI >30
• pregnancy
• generalized HH or related to any health disorder
• comorbidities
• or medication intake that induces excessive sweating
• patients with primary facial or plantar HH
• patients not complying with follow-ups

Patients distributed in a prospective randomized fashion between two groups. We calculated the sample size based on previous research and used a block randomization model. We took eight blocks of four and two blocks of five patients with a random distribution of two patients from each group. This project was blind.