Hyperhidrosis (especially PH) significantly affects the social life and functional aspects of the affected individuals. Many scoring systems have been proposed for evaluation of the condition and the response to provided treatment . Some children have gross problems at their schools with many of them being bullied by their colleagues, schoolmates, and, even worse, their teachers. Hyperhidrosis has also major psychological effects over both patients and their parents. Many of them suffer from significantly lower self-esteem and self-confidence and sometimes force them to self-isolation and negative thoughts.
The appropriate time for surgical intervention has received some attention in recent years. Some studies have showed that the earlier this condition is addressed, the better is the outcome . Steiner et al. included 325 patients, 116 were children (8–14 years of age, median = 13), and 209 were adolescents and adults (15–41 years of age, median =18); they concluded that the children who underwent sympathectomies benefited of the effects the procedure on their daily lives  and that the incidence of side effects of the procedure (e.g., compensatory sweating) was significantly lower than that occurred in older adolescents and adults who underwent the same procedure (69.8% vs. 88.5%); in addition, satisfaction rates were also higher 92.2% vs. 80.7% .
In the majority of published TS procedures, a biportal approach was used with the first port for the scope and the second as a working port. We have successfully used the same approach in all procedures. There was no need for introducing a third port. Some of the studies however are in favor of introducing a second working port especially in recurrent cases or when adhesions are expected .
T2 ganglion has been viewed traditionally as the key pathway for the hands [6,7,8]. T2 interruption has been found to cause dry hands and denervation of the face. Drott suggested that turning off head and face sweating may be the main trigger for compensatory sweating on the trunk . Schmidt et al. found that avoiding T2 ganglion may limit compensatory sweating .
The most appropriate segment to be interrupted for the treatment of primary PH is still debatable. A previously published anatomic study showed that the preganglionic fibers to the arm originate mostly from the third to the sixth spinal segments, and the third and fourth segments were considered as main lesions . Lin and Wu reported that few or none of the fibers from T2 or T3 innervate the hands, whereas fibers from T4 to the skin of the palm definitely pass through T2 and T3 .
The current study showed that either T2-T3 or T4 sympathectomy produces resolution of the palmar symptoms with good satisfaction of the patients. Mild moisture hands occurred commonly in T4 TS group; this was well tolerated by the patients. Slight moistness occurred in hot weather mainly, and the satisfaction rate in patients with moist hands was even higher than those with dry hands. The occurrence of slight hand moistness was also reported by Liu et al., who compared T3 versus T4 sympathectomy and it was noted in 59.4% of patients who had T4 sympathectomy vs. 25.8% of those who had T3 sympathectomy. A high satisfaction rate (94.2%) was noted in the T4 TS group in his study .
Despite the good results regarding resolution of PH and cessation of sweating, TS has its potential side effects. Postoperative compensatory sweating or over dryness of hands occur in some cases. The incidence and severity of these side effects vary significantly in different published series [14, 15]. These postoperative unfavorable consequences are the main focus of current research.
Compensatory sweating after TS is a common side effect. In the current study, postoperative compensatory sweating developed in both groups (50% versus 45.4%). The incidence of this complication varies widely throughout the literature. Zacherl et al.  reported an incidence of 69% in a series of 352 patients. In another study by Fredman et al., 90% of patients had compensatory sweating postoperatively . This variability is probably due to the differences in surgical technique and classification of compensatory sweating. One of the topics that needs to be studied and researched is the mechanism of development of CH, since this is not fully understood till now. One of the interesting findings in our study is the onset of occurrence of compensatory sweating as it did not develop in any of the cases after operating on one side and only developed after operating on both sides of the patient. The group of patients who underwent unilateral sympathectomy did not develop any compensatory sweating. Despite the development of compensatory sweating in almost half of the patients, all of them were satisfied with the exception of one case, yet the patient did not regret having the procedure. The overall incidence of compensatory sweating in this study is much less than that in many other series. The impact of sequential bilateral TS rather than simultaneous bilateral TS on development of compensatory sweating was highlighted in a study conducted by Youssef et al. where sequential sympathectomy was found to be a more optimal technique for reduction of compensatory sweating . Confirming this finding needs further studies and prospective controlled randomized clinical trials.
Various techniques have been attempted to reduce the occurrence rates of compensatory sweating. The level and extent of resection of the sympathetic chain are thought to be the factors behind the frequency and severity of compensatory sweating by many authors [14, 15]. The more sympathetic segments excised, especially those including T2, the greater the incidence of severe compensatory symptoms.
In Liu et al.’s study, the overall occurrence rate of compensatory sweating was 66.4% with those in the T3 group being more affected than patients in T4 group. Sweating was found to be mild, and patients did not feel any discomfort in their daily activities .
Hand over dryness is a potential side effect of TS surgery. In the current study, this was not documented in any of the cases in T4 group but was common (35%) in group T2-T3. A similar high rate (35%) of over dryness of limbs was also observed in of cases following T2 sympathectomy for PH by Mahdy et al. .
The occurrence of Horner’s syndrome is one of the serious potential side effects following the operation. Injury to the sympathetic fibers in T1 (stellate ganglion) leads to its development. Such injury may occur during the operation resulting from transmitted heat via the diathermy or may be due to traction on the ganglion . This complication was reported by Wait et al. in 5% of 322 patients after sympathectomy and in only 0.9% when sympathicotomy (interruption of the sympathetic trunk by its complete transection) was used. This may point to sympathicotomy being a better option since it avoids extensive manipulation and traction on the sympathetic chain . A study of 85 T2-T3 TH procedures done in 44 children reported the occurrence of transient Horner’s syndrome in 18% of cases . Only one case of temporary Horner’s syndrome developed in our study among the T2-T3 group, and it resolved spontaneously within few weeks. The limited development of such side effect in our study could be owed to the limited number of cases in comparison with previous studies; also, much care was given during manipulation at T2 level during surgery. We believe that T4 TS away from stellate ganglion can obviate the occurrence of Horner’s syndrome. Also, the use of bipolar diathermy is always advocated when available rather than monopolar diathermy which is associated with more heat dispersion.
Although T4 ganglion is the main source of sympathetic innervation of the hand, some sympathetic fiber from T3 and T2 ganglions also add to hand innervation sequentially as impulses ascend along the sympathetic chain. Ablation at T2 level, therefore, blocks the impulse from T3 and T4 ganglions to the hand. Likely, ablation at T3 level blocks the impulse from T4 ganglions. T2 sympathectomy results in the most thorough sympathetic denervation of the hands; however, it induces the most common and severe side effects, which makes it a poor option.
T4 TS though theoretically means the least denervation of the hands, it produces resolution of the over-sweating of the hands, and the majority of patients would be satisfied by its results . For such reason, and because it is associated with less morbidity, T4 sympathectomy is recommended to be the operation of choice since the goal of the treatment of PH is to improve the QOL of the patients, rather than the full elimination of sweating function of hands.
Limitation of the study
We acknowledge the limitations of the current study; the number is relatively small in the subgroups of patients. The impact of performing bilateral TS at the same time instead of doing it sequentially on the compensatory sweating rate needs to be investigated.