Lumbar sympathetic chain: anatomical variation and clinical perspectives

Lumbar Sympathetic Block Leading to Increased Arterial Diameter and Blood Flow: A Mechanism of Therapeutic Benefit

Lumbar sympathetic blocks (LSBs) have long been used for the treatment of chronic lower extremity pain and for conditions such as complex regional pain syndrome (CRPS). With a better understanding of the autonomic nervous system and its function, these blocks have grown in their utility. Through this growth, however, our understanding of sympathetic-mediated pain is still vaguely understood. Here, we present a case of a patient who underwent a point-of-care ultrasound (POCUS) before and after an LSB, and we were able to show significant dilation of the posterior tibial artery (PTA) following the block. We propose that this arterial dilation plays a mechanistic role in providing pain relief to patients who undergo LSB. This increased blood flow can not only enhance healing properties to surrounding tissues but also allow for nitric oxide to play potential regulatory roles in pain pathways. Here, we also review potential mechanisms of the amelioration of sympathetic-mediated pain as well as the potential utilization of LSBs and neuromodulation in treating visceral pathologies through a better understanding of visceral somatic relationships.

Evaluation of combined radiofrequency and chemical blockade of multi-segmental lumbar sympathetic ganglia in painful diabetic peripheral neuropathy

Background

Painful diabetic peripheral neuropathy (PDPN) is one of the most common complications of diabetes. PDPN seriously affects the quality of life and is difficult to treat; therefore, there is an urgent need for new cost-effective treatment methods for PDPN.

Objective

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

Study design

Retrospective comparative study.

Setting

Shengjing Hospital of China Medical University.

Methods

Ninety patients diagnosed with PDPN were enrolled in this study. The patients were randomly divided into AE group (A, n=30), RF group (B, n=30), and RF+ AE group (C, n=30). The follow-up included preoperative basic conditions, visual analog scale (VAS), the total remission rate (TRR), skin temperature (ST) and the improvement of numbness and hyperalgesia in the lower extremities, complications, and degree of satisfaction (DOS) before and after surgery.

Results

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. TRR in group A, group B and group C at 1Y after operation was 66.7%, 73.3% and 93.3%, respectively; TRR in group C was statistically different compared to groups A and B (P<0.05). 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. In addition, 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.

Conclusion

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.