Endovascular Denervation: a new approach for cancer pain relief
The authors sought out toe evaluate the feasibility of patients Endovascular denervation (EDN) to treat pain caused by pancreatic cancer, cervical cancer, cholangiocarcinoma and esophageal cancer. The authors included patients with abdominal cancer that had a VAS >6, ages 25-75 and had a greater than 1 month survival expectation. The primary end point was pain relief as measured with VAS, secondary end points included, QOL assesment, narcotic intake and safety. During the procedure the patient has a surface electrode placd on the back, an aortogram is performed and through an 8 French sheath a 6 electrode catheter is placed proximal to the celiac artery and close to the SMA. The procedure was done under moderate anesthesia, and the denervation was performed for 120 seconds and 60 degrees. Six different points of ablation were treated in that region.
The seven patients included had a VAS score greater than 7 and experienced pain relief at 1, 2 , 4, 8 and 12 weeks. The average VAS score was reduced by greater than 3 points in all patients. The average QOL score increased by 25, with improvement in sleep and more enjoyment in activities. Narcotic use also decreased after EDN, and no major complications were observed.
The authors hypothesize that the radiofrequency energy delivered through the aorta may cause celiac plexus block and improve abdominal pain. The authors mention that the results are similar to CT or EUS guided CPL and quote pain relief in 10-24% when used alone and 80-90% when used in combination with other options. In the group presented by the authors pain relief lead to significant increase in QOL scores, with decreased narcotic use and improved sleep, with no major complications.
The study is limited by the small sample size, the lack of a control group and the difficulty in quantifying a subjective measure like pain.
Figure- Anortogram showing the origin of the celiac and SMA(a), followed by deployment of the electrode near the celiac (b) and the SMA (c)
The authors show that endovascular CPN might be an alternative to CT CPL and potentially technically easier and with less complications. Technically the procedure seems straight forward and the results promising. Patients had a decrease in pain scores, improved QOL scores and decreased narcotic intake. The discussion mentions similar outcomes when compared to CT and EUS CPN, however the data presented for the other studies (pain relief efficacy) is not similar to what the authors presented, similar to the pain relief duration. The study could benefit from a longer follow up, and to compare it to a group of patients that were treated either with CT or EUS CPN.
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Zhang Q, Guo JH, Zhu HD, Zhong YM, Pan T, Yin HQ, Dong YH, Teng GJ. Endovascular Denervation: A New Approach for Cancer Pain Relief? J Vasc Interv Radiol. 2018 Nov 7. pii: S1051-0443(18)31415-5. doi: 10.1016/j.jvir.2018.08.008. [Epub ahead of print] PubMed PMID: 30414719.
Carlos J. Guevara, MD
Department of Radiology, Interventional Radiology Division
University of Texas Health Sciences, Houston