Superior Hypogastric Plexus Block and Pulsed Radiofrequency on Dorsal Root Ganglia of Sacral Nerves for Chronic Pelvic Cancer Pain

pelvic cancer is a broad term encompassing malignant tumors of the bladder, prostate, cervix, endometrium, ovaries, and uterus, among others. Pain associated with pelvic cancer is one of the most debilitating symptoms experienced by affected patients. Multiple studies demonstrate that the prevalence of pain in patients with pelvic cancer is >50%, and can be upwards of 60% to 70% in patients with advanced or metastatic disease . Cancer patients with extension of tumor into the pelvis may experience severe pain. Oral or parenteral opioids may not only fail to provide relief, but may cause excessive sedation and other side effects. More invasive approaches may thus be needed to control pain and improve the quality of life. Since pelvic cancer pain is visceral in most cases, this could be achieved with percutaneous chemical neurolytic block of the superior hypogastric plexus . The superior hypogastric plexus is located at the anterior aspect of the L5 and S1 vertebrae, and traverses the disk between these levels. It is an extension of the aortic plexus below the aortic bifurcation, and contains almost exclusively sympathetic fibers and visceral afferents . Afferent pain fibers innervating pelvic organs travel with sympathetic nerves, trunks, ganglia, and rami; thus, interrupting the sympathetic chain at this level can be used to treat pelvic cancer pain. Several studies examined the use of superior hypogastric plexus block in the treatment of pelvic cancer pain. Although the authors reported a mean reduction in pain of 70%, neither the follow-up period nor the proportion with a successful prognostic block were noted. Radiofrequency utilizes a high-frequency alternating current that is passed from the needle electrode into the surrounding tissue, resulting in frictional heating and necrosis. Due to the accuracy of lesions produced by radiofrequency ablation, there has been growing interest in the use of this technique for neurolysis of nerves as it offers the potential of accurate nerve destruction ablation, with a predictable and controlled ablative lesion. Another advantage of radiofrequency ablation is that it has an immediate effect unlike alcohol and phenol, which may take up to 1 week or 10 days to achieve neurolysis .