The pelvic floor muscles comprised of piriformis, coccygeus, levator ani, internal anal sphincter, and perineal body provide support to the pelvic organs. The contraction of these muscles plays an important role in maintaining continence, while the abdominal pressure increases with forceful activity (
3). The sacroiliac joint and pelvic ring provide stability to the pelvis. Pain in the pelvic area occurs with loss of stability and reduced load transferability between the trunk and lower extremity, and myofascial dysfunction of the pelvic floor (
3). Problems originating either from the disc, joint, muscles, or nervous system can be important pain generator sources. Referred pain to the pelvis can occur from pathology in the nearby musculoskeletal system. Sympathetic innervation via hypogastric plexi from sacral and pelvic regions innervate the pelvic organs. These visceral afferents reach the upper lumbar and lower thoracic spinal cord similar to those visceral afferents from lower lumbar disc level-transmission of information from autonomic afferents projects as somatic symptoms. Nerve entrapment due to stretching, compression, fibrosis or suture, and injury due to prolonged second stage of labor, laser treatment to perineal structures could be an important source of origin of pelvic pain (
3). Infection, trauma, or surgery can stimulate the production of bradykinin, leukotrienes, histamine, substance P, K+, H+, which in turn activate the nerve endings and transmission of these impulses to the dorsal horn of the spinal cord lowers the pain threshold (
18). Oxidative stress, neurogenic inflammation, and smooth muscle cell proliferation contribute to chronicity of pain (
6,
19).
A case report by Rosenberg et al. described complete pain relief immediately following superior hypogastric plexus block in a patient with severe penile pain after transurethral resection of the prostate. The patient continued to be pain-free at 1, 2, 4, and 8 months follow-up (
20).
The superior hypogastric plexus innervate the pelvic structures, including the bladder, urethra, perineum, prostate, penis, testis, descending colon, rectum, perineum, vulva, and internal genitalia except the ovary and fallopian tubes (
21). The superior hypogastric plexus is retroperitoneal, located bilaterally at the lower third of the fifth lumbar vertebral body and upper third of the first sacral vertebral body proximity to the bifurcation of common iliac vessels. Axial computed tomography (CT) scanning aids in the visualization of vascular and soft tissue structures. Targeted superior hypogastric plexus blocks can be utilized for pelvic pain secondary to endometriosis. A disadvantage of this technique is intestinal perforation and radiation exposure (
22). Wechsler et al. performed these blocks for patients with endometriosis and chronic pelvic pain using 20-gauge, 15 cm needles via the classic posterior approach in four patients and the anterior approach for the fifth patient. one patient experienced mild pain relief, three patients had considerable pain relief, the fifth patient had complete midline pain relief without any change in lateral pain and the sixth patient was totally pain-free. They abandoned the procedure on the seventh patient as the medication was accidentally injected into the peritoneal cavity. They concluded that CT-guided superior hypogastric block can be easily performed and could be used to assess whether chronic pelvic pain can be attenuated by blocking the superior hypogastric plexus (
23).