Radiofrequency thermocoagulation combined with AE chemical blockade of the LSG was safe and effective. Nevertheless, the details underlying analgesic mechanisms still need to be investigated. 

As the comforts of life increased, the incidence of diabetes also increases per year. researchers are estimated that the global incidence of diabetes will reach 552 million by 2030. the most severe and common complication of diabetes is peripheral diabetic peripheral neuropathy (PDPN). As PDPN seriously affects the quality of life and is difficult to treat, there is an urgent need for new cost-effective treatment methods for PDPN.

There are 2–6 pairs of lumbar sympathetic ganglia (LSG). The blocking of L2 and L3 LSG blocks the sympathetic fibres of the lower extremities and dilates blood vessels; L2 ganglia have an essential role in this process. Besides, the position of LSG varies; the L2 sympathetic ganglia are mainly found in the lower one-third of the L2 vertebrae and upper one-third of the L3 vertebrae, therefore, a multi-segment treatment is required when targeting these regions. Radio-frequency therapy comprises two methods: radio-frequency thermocoagulation and pulsed radio-frequency. Radio-frequency thermocoagulation lumbar sympathectomy, which focuses the nerve tissue by increasing the temperature, has been shown to be another effective treatment approach.

Rationale behind research:

Currently, there are several studies on single chemical or single radiofrequency treatment methods for destroying LSG, while there are no studies investigating the combination of chemicals and radiofrequency for PDPN.

This article examines the combination of radiofrequency thermocoagulation and anhydrous ethanol (AE) chemical blockade of LSG for the treatment of PDPN.

Objective:

To investigate the efficacy and safety of radio-frequency thermocoagulation (RF) combined with anhydrous ethanol (AE) chemical blockade of lumbar sympathetic ganglia (LSG) in patients with PDPN using computed tomography (CT) 

Study outcomes:

• Pain: For pain scoring, the following visual analog scale (VAS) was used: 0 (no pain) to 10 (the most unbearable pain)
• Analgesic effect: Analgesic effect was analyzed according to the WHO evaluation criteria for pain relief; the efficacy was formulated using four grades: Complete remission (CR), Partial remission (PR), Mild remission (MR), and No response (NR)
• Remission rate: The total remission rate was analyzed using the following formula: total remission rate (%) = [(CR+ PR+ MR)/n]×100%
• Skin temperature (ST) and the improvement of numbness and hyperalgesia in the lower extremities, complications, and degree of satisfaction (DOS) before and after surgery

Time period: 1 week (1W), 1 month (1M), 3 months (3M), 6M and 1 year

• Pain: Postoperative VASs were significantly decreased compared to preoperative VASs in all groups (P<0.05). The VAS in group A began to increase 3 months (3M) after surgery; VAS scores at 3M, 6 months (6M) and 1 year (1Y) were significantly different compared to group B and C (P<0.05); VAS in group B began to increase after 6M; VAS scores at 6M and 1Y were significantly different compared to group C (P<0.05); Moreover, group C maintained relatively long duration of pain relief
• Total remission rate: the total remission rates in groups A, B, and C were 66.7%, 73.3%, and 93.3%, respectively (Table 2). The total remission rate in group C was statistically different compared to groups A and B (P<0.05)
• Skin temperature: Higher ST in the lower extremities was observed after surgery in all groups compared to peroration (P<0.05); nonetheless, the difference was not statistically significant
• The numbness and hyperalgesia improved in all three groups after surgery compared to preoperational time, the numbness in group C was significantly higher compared to groups A and B
• No severe complications were observed. At 6M and 1Y after surgery, the degree of satisfaction in patients from group C was significantly higher compared to groups A and B

PDPN is a frequent and severe type of diabetic peripheral neuropathy. It is mainly manifested as burning pain and numbness, deep dull pain and stabbing pain in the lower limbs. The pattern of pain can vary, and spontaneous allodynia and hyperalgesia with various forms of pain can occur in the affected area. The pain is continuous and persistent with unclear aetiology and mechanisms. Previously the spinal cord stimulation method is used to remit the pain, but this method is expensive.

In conclusion, the study demonstrated that a combination of radiofrequency thermocoagulation and AE chemical blockade of the lumbar sympathetic ganglia was more effective compared to the single use of chemical or radiofrequency blockade for the treatment of PDPN. The results of this study also showed that this method is safe, effective and significantly alleviated the symptoms of PDPN and improved the patients’ degree of satisfaction.