Transrectal high-intensity focused ultrasound as focal therapy for posterior deep infiltrating endometriosis

Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

Diagnostic Performances of Tridimensional Rectosonography and Magnetic Resonance Imaging in Rectosigmoid Endometriosis: A Prospective Cohort Study on 101 Patients

Tridimensional rectosonography (3-D RSG) is a transvaginal ultrasonography procedure combining intrarectal contrast with tridimensional technology. The objectives of this study were to assess the diagnostic performances of 3-D RSG in deep infiltrating rectosigmoid endometriosis using surgery and pathology as the gold standard, and to compare its results with those of magnetic resonance imaging (MRI). Patients referred for endometriosis with symptoms suggesting deep infiltrating intestinal endometriosis (DIE) were included if they agreed to undergo a 3-D RSG and MRI and if there was a surgical indication related to endometriosis. The study was a non-randomized monocentric prospective cohort study (Canadian task force classification Level II-2). From May 2012 to May 2017, 101 patients were included. Sixty patients (59.4%) had bowel involvement of the rectum (n = 21, 20.8%) or of the sigmoid (n = 39, 38.6%) confirmed in surgery and/or in pathologic testing. In the diagnosis of rectosigmoid DIE, 3-D RSG sensitivity, specificity, positive predictive value, negative predictive value, accuracy and κ index were 93%, 95%, 97%, 91%, 94% and 0.88, respectively. For MRI they were 87%, 90%, 93%, 82%, 88% and 0.76, respectively. The accuracy was not significantly different between 3-D RSG and MRI (p = 0.181). In conclusion, 3-D RSG is an effective technique to diagnose rectosigmoid endometriosis and seems to have similar diagnostic performances to MRI for this indication.

Endometriosis treatment with shock waves: A novel approach

Endometriosis affects 10-15% of women. When medication is unsatisfactory, not well tolerated or unwanted, surgery remains the sole option. There is a need for a less invasive treatment. We suggest the application of shock wave therapy (SWT) to endometriotic nodules (including deep infiltrating endometriosis), endometriomas and adenomyosis. We hypothesize pain relief via an antiinflammatory effect, an antioxidant effect and neural pathways modulation, as well as a direct effect on the lesions by the energy thus delivered. Questions to be answered before a clinical application is tested include route of administration (external versus internal transducers), dose regimen, optimal duration of treatment and type of shock waves used (focalised versus radial).