Objective-Brain arteriovenous malformations (bAVM) are an important cause of hemorrhagic stroke. The underlying mechanisms are not clear. No animal model for adult bAVM is available for mechanistic exploration. Patients with Hereditary Hemorrhagic Telangiectasia Type2 (HHT2) with activin receptor-like kinase 1 (ALK1; ACVRL1) mutations have a higher incidence of bAVM than the general population. We tested the hypothesis that VEGF stimulation with regional homozygous deletion of Alk1 induces severe dysplasia in the adult mouse brain, akin to human bAVM.Methods-Alk1 2f/2f (exons 4-6 flanked by loxP sites) and wild-type (WT) mice (8-10 weeks old) were injected with Ad-Cre (2×10 7 PFU, adenoviral vector expressing Cre recombinase) and AAV-VEGF (2×10 9 genome copies, adeno-associated viral vectors expressing VEGF) into the basal ganglia. At 8 weeks, blood vessels were analyzed.Results-Gross vascular irregularities were seen in Alk1 2f/2f mouse brain injected with Ad-Cre and AAV-VEGF. The vessels were markedly enlarged with abnormal patterning resembling aspects of the human bAVM phenotype, displayed altered expression of the arterial and venous markers (EphB4 and Jagged-1), and showed evidence of arteriovenous shunting. Vascular irregularities were not seen in similarly treated WT mice.Interpretation-Our data indicate that post-natal, adult formation of the human disease bAVM is possible, and that both genetic mutation and angiogenic stimulation are necessary for lesion development. Our work not only provides a testable adult mouse bAVM model for the first time, but also suggests that specific medical therapy can be developed to slow bAVM growth and potentially stabilize the rupture-prone abnormal vasculature.

Postmastectomy pain syndrome is common after surgical treatment for breast cancer and may be challenging to manage. Currently, there are a wide variety of approaches to treat this type of pain, including medications, physical therapy, and interventional procedures. However, because of the complexity of innervation of the breast, the serratus plane block may better target the web of nerves innervating the anterior chest wall including the breast. We present a case series of 8 patients who were successfully treated with serratus plane block for pain after treatment for breast cancer. We feel that this particular application for the serratus plane block deserves further investigation, as it is relatively easy to perform and has good clinical utility for this type of pain.

Background: Chronic pelvic pain (CPP) represents a group of poorly understood disorders that are often refractory to conventional treatment. Referral to pain management typically occurs later in the continuum of care; as such, many of the injections and nerve blocks commonly prescribed for such patients are potentially limited in efficacy. While neuromodulation is conventionally considered the next algorithmic step in the treatment of chronic pain after injections fail, there is a common perception that neuromodulation is largely ineffective for CPP conditions. However, there is evidence that suggests neuromodulation may in fact be a viable treatment option for this particular patient population when utilized properly. Objectives: To provide a basic overview of the pathophysiology of CPP and the relevant neuroanatomy as it pertains to various available treatment options, as well as the techniques and potential targets for neuromodulation. Study Design: Literature review. Setting: Private practice, academic and hospital setting. Methods: A comprehensive review of the available literature was performed targeting publications focused on CPP and various techniques for utilizing neuromodulation to treat it. Results: Neuromodulation is an established treatment modalities, however its usefulness as it relates to treating CPP has typically been drawn into question. In this literature review, we discuss the efficacy of various techniques for treating CPP with neuromodulation. Limitations: Evidence to support the various treatments, while encouraging, is based on small studies and case series. Large-scale randomized, placebo-controlled clinical trials are warranted to evaluate the clinical efficacy and safety of the different treatments described, particularly neuromodulation. Conclusions: In addition to the percutaneous, injection-based treatments described herein, neuromodulation remains a plausible option for recalcitrant cases that fail to respond to more conventional means. Key words: Chronic pelvic pain, neuromodulation, spinal cord stimulation, CRPS, complex regional pain syndrome, neuropathic pain.

Objectives Temporary, percutaneous peripheral nerve stimulation (PNS) has been shown to provide analgesia for acute postoperative pain, postamputation pain, and low back pain. The implanted device stimulates the neural target for up to 60 days at which point the leads are extracted. Patients have demonstrated prolonged analgesia continuing after extraction of the leads. The purpose of this case series is to demonstrate peripheral neural targets that could feasibly be used to treat various pain syndromes prevalent in the oncologic population. Materials and Methods A temporary, percutaneous PNS was implanted under ultrasound guidance in 12 oncologic chronic pain patients seen in an outpatient pain clinic who had failed medical and/or interventional management. The device was implanted for up to 60 days. Clinical progress of pain and functional capacity was monitored through regular clinical visits. Results The case series presents seven successful cases of implementation of the PNS to treat oncologic pain. Three of these cases demonstrate targeting of proximal spinal nerves to treat truncal neuropathic pain and lumbar radicular pain. The four remaining cases demonstrate successful targeting of other peripheral nerves and brachial plexus. We also share five failed cases without adequate pain relief with PNS. Conclusions PNS has potential uses in the treatment of oncologic pain. Further high‐quality studies should be designed to further elucidate use of the PNS to treat oncologic pain.

To compare aerosol clearance with and without negative pressure, the humidifier was turned off to simulate the end of an aerosol-generating procedure. Without negative pressure, 183 min was required for the particle count to decrease by 98%, compared with 5 min when negative pressure was applied (Supplementary Fig. 2). Whilst visual inspection correlated with the removal of large aerosolised particles (>10 mm), it was highly unreliable at determining the degree of removal of small aerosolised particles, as the hood appeared clear when particle count of particles greater than 0.5 mm was well above Access published on April 3 2020 3. Owen MK, Ensor DS, Sparks LE. Airborne particle sizes and sources found in indoor air. Atmos Environ Gen Top 1992; 26: 2149e62 4. Lindsley WG, Pearce TA, Hudnall JB, et al. Quantity and size distribution of cough-generated aerosol particles produced by influenza patients during and after illness. J Occup Environ Hyg 2012; 9: 443e9 5. Faulkner WB, Memarzadeh F, Riskowski GL, Kalbasi A, Chang AC. Effects of air exchange rate, particle size and injection place on particle concentrations within a reduced-scale room.

No abstract

Objective Breast cancer is the most common female malignancy worldwide. Breast surgery and adjuvant oncological therapies are often required to increase survival. Treatment-related pain may persist and evolve into postmastectomy pain syndrome (PMPS) in a significant subset of breast cancer survivors. In this retrospective investigation, we will present our experience in applying an interventional algorithmic approach to treat PMPS. Design A retrospective study. Setting An academic cancer hospital. Subjects Adult females with PMPS diagnosis. Methods We reviewed 169 records with the diagnosis of PMPS from 2015 to 2019 within our health system. Pre- and post-injection pain scores, relief duration, and medication usage changes were collected. The decision to perform each procedure was based on the anatomic location of the painful area with the corresponding peripheral sensory innervation. Decision-making flow diagrams were created to present our experience in managing PMPS beyond peripheral nerve blocks. Results Ultrasound-guided peripheral nerve block results (n=350) were analyzed. The mean baseline pain score was 7, compared with the post-treatment mean score of 3 (95% confidence interval: 3.58 to 3.98, P = 0.0001). Among the responders, the mean pain relief duration was 45 days, with a median of 84 days. Opioid medication consumption was reduced by 11% (t = 0.72, P = 0.47). Conclusions Ultrasound-guided nerve blocks of this area could be performed safely and effectively after breast surgeries. We also present our proposed algorithm to provide a stepwise application for selecting the appropriate therapies in the management of more complex PMPS.

No abstract