All operated patients in our cohort were treated with microsurgical cyst fenestration. However, in the literature, a wide variety of surgical methods have been described with variable rates of success. These include microsurgical cyst excision [
6,
20], cyst fenestration [
16,
22], anti-inflammatory medication [
14], ultrasound-guided selective nerve root block [
12], epiduroscopic neural laser decompression [
10], CT-guided cyst aspiration [
19], percutaneous injection of fibrin sealant [
17], cyst-subarachnoid shunts [
15,
23], lumboperitoneal shunts, and cyst-peritoneal shunts [
3,
5]. In the largest cohort of treated perineural cysts to date, Murphy et al. reported clinical improvement in 82% of 213 patients treated with minimally invasive CT-guided two-needle cyst aspiration and fibrin sealant injection [
17]. While this minimally invasive method might have the advantage of shorter hospital stay and no post-operative surgical site symptoms, theoretical limitations include the risk of nerve damage, bleeding, and cyst recurrence. Supporting this view, many studies, including a recent meta-analysis, argue that the literature favors the use of microsurgery as it has the best long-term results [
5,
7,
9,
13,
21].
In a recent systematic review of patients surgically treated for symptomatic perineural cysts, 82% of 646 patients reported complete or partial alleviation of symptoms [
7]. In comparison, we found that 94% (
n = 16) of our surgically treated cohort sustained symptomatic improvement at the long-term follow-up (Table
1). Notably, the success rate for patients who showed clinical improvement following cyst aspiration (i.e., group A) was 100%. Furthermore, none of the patients developed complications that could be attributed to the surgical procedure. Thus, microsurgical cyst fenestration for symptomatic perineural cysts appears to be both safe and effective, and we report a somewhat higher success rate than previous studies.
Ten patients in our cohort were offered surgery but chose to be treated conservatively instead. Of these, four (40%) showed progression of symptoms at long-term follow-up, and the remaining six remained unchanged. Thus, conservative treatment was associated with poor outcome in patients who were deemed as candidates for surgery.