Efficacy and safety of tibial nerve stimulation using a wearable device for overactive bladder

OBJECTIVE

To evaluate the efficacy and safety of a wearable, smartphone-controlled, rechargeable transcutaneous tibial nerve stimulation (TTNS) device in patients with overactive bladder (OAB).

PATIENTS AND METHODS

This multicentre, prospective, single-blind, randomised clinical trial included eligible patients with OAB symptoms who were randomly assigned to the stimulation group or sham group. The primary efficacy outcome was change from baseline in voiding frequency/24 h after 4 weeks of treatment. The secondary efficacy outcomes included changes in bladder diary outcomes (urgency score/void, nocturia episodes/day, micturition volume/void, and incontinence episodes/day), questionnaires on Overactive Bladder Symptom Score (OABSS), Patient Perception of Bladder Condition (PPBC), and American Urological Association Symptom Index Quality of Life Score (AUA-SI-QoL) at baseline and after 4 weeks of treatment. Device-related adverse events (AEs) were also evaluated.

RESULTS

In the full analysis set (FAS), the mean (sd) change of voiding frequency/24 h in the stimulation group and sham group at 4 weeks were -3.5 (2.9) and -0.6 (2.4), respectively (P < 0.01). Similar results were obtained in the per-protocol set (PPS): -3.5 (2.9) vs -0.4 (2.3) (P < 0.01). In the FAS and PPS, micturition volume/void significantly improved at 4 weeks (P = 0.01 and P = 0.02). PPBC improvement almost reached significance in the FAS (P = 0.05), while it was significant in the PPS (P = 0.02). In the FAS and PPS, AUA-SI-QoL significantly improved at 4 weeks in the two groups (P < 0.01 and P < 0.01), whereas there were no significant differences in urgency score/void, nocturia episodes/day or OABSS between the groups. Also, no device-related serious AEs were reported.

CONCLUSIONS

The non-invasive neuromodulation technique using the novel ambulatory TTNS device is effective and safe for treating OAB. Its convenience and easy maintenance make it a new potential home-based treatment modality. Future studies are warranted to confirm its longer-term efficacy.

Transcutaneous Hitching Sutures in Paediatric Minimally Invasive Surgery: A Novel Technique of "Assistant Without Port"

BACKGROUND

Transcutaneous hitching sutures in paediatric minimally invasive surgery (MIS) is a unique and rare technique. This technique has been used previously in adult patients undergoing gastric resections and laparoscopic cholecystectomy; however, its use in paediatric population has never been reported in the world literature. The primary objective of this study was to bring out the advantages and feasibility of this technique in minimally invasive gastrointestinal, hepatobiliary, urological and thoracoscopic surgeries on paediatric patients.

MATERIALS AND METHODS

This retrospective observational study was conducted on 167 paediatric patients who underwent MIS surgery for different indications between April 2016 and March 2020 at two paediatric surgery tertiary care centres.

RESULTS

A total of 167 patients, including 91 boys and 76 girl patients between the age group of new-born period to 12 years were operated. The mean hospital stay was 4 days. Five out of 167 cases (3%) had post-operative surgical emphysema, which resolved spontaneously. At 6-month follow-up, parental satisfaction was 100%, and in 99% of patients, scars were imperceptible.

CONCLUSION

This versatile technique is of exemplary utility, especially in paediatric patients where there is a paucity of working space at low intra-abdominal pressure, and eases the dissection even in narrow and closed spaces with a better functional and cosmetic outcome.

Efficacy of Vagal nerve stimulation on anxiety among elderly retired teachers during COVID-19 pandemic

BACKGROUND

Excessive fear, worry and behavioral disturbances define anxiety, with particular significance attributed to vagal nerve, a crucial transmitter of information to the brain regions governing anxiety. Highlighting the importance of vagal nerve, transcutaneous auricular vagal nerve stimulation (TaVNS) emerges as a tolerable and safe technique. The success of non-invasive vagal nerve stimulation in alleviating anxiety underscores the pivotal role of the vagal nerve.

OBJECTIVES

The purpose of this study was to assess the effectiveness of physiotherapy interventions in mitigating anxiety among retired teachers during the COVID-19 pandemic, emphasizing the relevance of targeting the vagal nerve for improved mental well-being.

METHODS

60 retired teachers diagnosed with anxiety were chosen through random allocation. Participants were divided into two groups: Group A (Experimental group) received transcutaneous auricular vagal nerve stimulation (TaVNS), and Group B (Control group) underwent the Jacobson relaxation technique. Intervention period spanned 4 weeks, with four sessions per week, lasting 30 minutes. The outcome measures included Generalized Anxiety Disorder-7 (GAD-7) questionnaire and salivary cortisol levels.

RESULTS

Following the 4-week intervention, both groups exhibited a significant reduction in Generalized Anxiety Disorder-7 (GAD-7) scores and salivary cortisol levels (P <  0.001). Notably, Group A demonstrated a significantly higher effectiveness rate compared to Group B.

CONCLUSION

The study concludes that transcutaneous auricular vagal nerve stimulation (TaVNS) is effective in reducing anxiety among retired teachers. Transcutaneous auricular vagal nerve stimulation (TaVNS) proves to be a powerful and effective intervention in alleviating anxiety among retired teachers, emphasizing its potential significance in enhancing mental well-being.

The Precision Between Transcutaneous Carbon Dioxide Versus PaCO2 in Infants Undergoing Therapeutic Hypothermia

BACKGROUND

Infants with hypoxic-ischemic encephalopathy are often treated with therapeutic hypothermia and high-frequency ventilation. Fluctuations in PaCO2 during therapeutic hypothermia are associated with poor neurodevelopmental outcomes. Transcutaneous CO2 monitors offer a noninvasive estimate of PaCO2 represented by transcutaneously measured partial pressure of carbon dioxide (PtcCO2 ). We aimed to assess the precision between PtcCO2 and PaCO2 values in neonates undergoing therapeutic hypothermia.

METHODS

This was a retrospective chart review of 10 neonates who underwent therapeutic hypothermia requiring respiratory support over 2 y. A range of 2-27 simultaneous PtcCO2 and PaCO2 pairs of measurements per neonate were analyzed via linear mixed models and a Bland-Altman plot for multiple observations per neonate.

RESULTS

A linear mixed-effect model demonstrated that PtcCO2 and PaCO2 (controlling for sex) were similar. The 95% CI of the mean difference ranged from -2.3 to 5.7 mm Hg (P = .41). However, precision was poor as the PtcCO2 ranged from > 18 mm Hg to < 13 mm Hg than PaCO2 values for 95% of observations.

CONCLUSIONS

The neonates' PtcCO2 was as much as 18 mm Hg higher to 13 mm Hg lower than the PaCO2 95% of the time. Transcutaneous CO2 monitoring may not be a good trending tool, nor is it appropriate for estimating PaCO2 in patients undergoing therapeutic hypothermia.

Skin temperature influence on transcutaneous carbon dioxide (CO2) conductivity and skin blood flow in healthy human subjects at the arm and wrist

Objective: present transcutaneous carbon dioxide (CO2)-tcpCO2-monitors suffer from limitations which hamper their widespread use, and call for a new tcpCO2 measurement technique. However, the progress in this area is hindered by the lack of knowledge in transcutaneous CO2 diffusion. To address this knowledge gap, this study focuses on investigating the influence of skin temperature on two key skin properties: CO2 permeability and skin blood flow. Methods: a monocentric prospective exploratory study including 40 healthy adults was undertaken. Each subject experienced a 90 min visit split into five 18 min sessions at different skin temperatures-Non-Heated (NH), 35, 38, 41, and 44°C. At each temperature, custom sensors measured transcutaneous CO2 conductivity and exhalation rate at the arm and wrist, while Laser Doppler Flowmetry (LDF) assessed skin blood flow at the arm. Results: the three studied metrics sharply increased with rising skin temperature. Mean values increased from the NH situation up to 44°C from 4.03 up to 8.88 and from 2.94 up to 8.11 m·s-1 for skin conductivity, and from 80.4 up to 177.5 and from 58.7 up to 162.3 cm3·m-2·h-1 for exhalation rate at the arm and wrist, respectively. Likewise, skin blood flow increased elevenfold for the same temperature increase. Of note, all metrics already augmented significantly in the 35-38°C skin temperature range, which may be reached without active heating-i.e. only using a warm clothing. Conclusion: these results are extremely encouraging for the development of next-generation tcpCO2 sensors. Indeed, the moderate increase (× 2) in skin conductivity from NH to 44°C tends to indicate that heating the skin is not critical from a response time point of view, i.e. little to no skin heating would only result in a doubled sensor response time in the worst case, compared to a maximal heating at 44°C. Crucially, a skin temperature within the 35-38°C range already sharply increases the skin blood flow, suggesting that tcpCO2 correlates well with the arterial paCO2 even at such low skin temperatures. These two conclusions further strengthen the viability of non-heated tcpCO2 sensors, thereby paving the way for the development of wearable transcutaneous capnometers.

Towards a Miniaturized Photoacoustic Sensor for Transcutaneous CO2 Monitoring

A photoacoustic sensor system (PAS) intended for carbon dioxide (CO2) blood gas detection is presented. The development focuses on a photoacoustic (PA) sensor based on the so-called two-chamber principle, i.e., comprising a measuring cell and a detection chamber. The aim is the reliable continuous monitoring of transcutaneous CO2 values, which is very important, for example, in intensive care unit patient monitoring. An infrared light-emitting diode (LED) with an emission peak wavelength at 4.3 µm was used as a light source. A micro-electro-mechanical system (MEMS) microphone and the target gas CO2 are inside a hermetically sealed detection chamber for selective target gas detection. Based on conducted simulations and measurement results in a laboratory setup, a miniaturized PA CO2 sensor with an absorption path length of 2.0 mm and a diameter of 3.0 mm was developed for the investigation of cross-sensitivities, detection limit, and signal stability and was compared to a commercial infrared CO2 sensor with a similar measurement range. The achieved detection limit of the presented PA CO2 sensor during laboratory tests is 1 vol. % CO2. Compared to the commercial sensor, our PA sensor showed less influences of humidity and oxygen on the detected signal and a faster response and recovery time. Finally, the developed sensor system was fixed to the skin of a test person, and an arterialization time of 181 min could be determined.

The effect of transcutaneous auricular vagus nerve stimulation on cycling ergometry and recovery in healthy young individuals

BACKGROUND

It is aimed to examine the potential benefits and effects of the use of transcutaneous auricular vagus nerve stimulation (VNS) for sporting purposes on recovery, fatigue, and sportive performance level.

METHODS

In this study, 90 people between the ages of 18-23 were participated. They were randomly divided into three groups as bilateral sham, unilateral left, and bilateral VNS. A 4-day protocol was applied to the participants. Cycling exercise was performed with maximum performance for 30 min under the same watt load. Pulse, systolic and diastolic blood pressure, distance, pain, fatigue, lactic acid level, and autonomic nervous system were evaluated.

RESULTS

Within the groups, there was a statistically significant difference between the data (p < .05) except for the distance covered parameter. When we compare the groups, in addition to the distance traveled in all groups, there is no statistically significant difference in the 1st day 1st measurement and 2nd measurement data of all parameters (p > .05 When we compared the data according to days, there was a statistically significant difference between bilateral stimulation (BS) and unilateral stimulation, only pain and fatigue levels (p < .05).

CONCLUSION

In our study, we saw that BS application gave positive results in reducing pain and fatigue due to cycling exercise compared to other applications. Similar results were obtained when we evaluated the data on a daily basis. We believe that VNS will be beneficial in reducing pain and fatigue, especially during and after the competition halftime.

Trans-jugular transcutaneous closure of atrial septal defects with an adjustable curved sheath under echocardiography guidance

INTRODUCTION AND OBJECTIVES

Traditional transcatheter closure of atrial septal defect (ASD) via the femoral vein carries risk of radiation damage. Transcutaneous closure of ASD under echocardiography guidance avoids radiation exposure and can be gradually applied. An alternative is to transcutaneous closure of ASD trans-jugular with an adjustable curved sheath under echocardiography guidance.

METHODS

We retrospectively studied all cases of trans-jugular transcutaneous closure of ASD with an adjustable curved sheath under echocardiography guidance in the Heart Center of Henan Province People's Hospital between 2016 and December 2022.

RESULTS

A total of 156 patients were included, 74 males and 82 females. Mean age was 6.9 ± 7.4 years and weight 23.7 ± 14.6 kg. Mean sizes of the ASD and occluder were (9.7 ± 4.7) mm and (14.1 ± 5.7) mm. The mean operation time was (49.6 ± 29.2) min. No complications such as atrioventricular block, reoperation, or pericardial effusion occurred. There are 3 patients had a residual shunt. All patients were followed-up for (38.7 ± 11.0) months. The three patients with residual shunt had self-closed at the 3-6-12 months follow-up. There was no complication at follow-up.

CONCLUSION

Trans-jugular transcutaneous closure of ASD with adjustable curved sheath under echocardiography guidance is safe, effective and minimally invasive.

Urethral Hair Bezoar Management With Transcutaneous Neodymium-Doped Yttrium Aluminum Garnet Laser Post-hypospadias Repair: A Clinical Case

Post-hypospadias repair, hair growth within the urethra, and subsequent hair bezoar formation can lead to significant complications, including urinary tract infections (UTIs) and urinary flow obstruction. Using hair-bearing skin in hypospadias repair can cause these complications. We report a 55-year-old male who underwent two-stage penile hypospadias repair at age three, presenting with recurrent UTIs and lower urinary tract obstruction symptoms. Urethroscopy identified a hair bezoar in a wide-mouth diverticulum of the penile urethra. Post-extraction of the hair bezoar using a rigid cystoscope, transcutaneous neodymium-doped yttrium aluminum garnet (ND:YAG) laser epilation was employed to ablate urethral diverticular hair follicles. Hair bezoars in the urethra, although rare in modern practice, may obstruct urine flow and act as a nidus for UTIs. Transcutaneous ND:YAG laser has emerged as a minimally invasive technique, offering a simple, effective solution for urethral hair removal with minimal complications. Transcutaneous ND:YAG laser epilation serves as a viable first-line treatment for urethral hair follicles following hypospadias repair, emphasizing its significance in preventing recurrent complications in such patients.

Non-Invasive Vaccines: Challenges in Formulation and Vaccine Adjuvants

Given the limitations of conventional invasive vaccines, such as the requirement for a cold chain system and trained personnel, needle-based injuries, and limited immunogenicity, non-invasive vaccines have gained significant attention. Although numerous approaches for formulating and administrating non-invasive vaccines have emerged, each of them faces its own challenges associated with vaccine bioavailability, toxicity, and other issues. To overcome such limitations, researchers have created novel supplementary materials and delivery systems. The goal of this review article is to provide vaccine formulation researchers with the most up-to-date information on vaccine formulation and the immunological mechanisms available, to identify the technical challenges associated with the commercialization of non-invasive vaccines, and to guide future research and development efforts.

Reinterpreting published tDCS results in terms of a cranial and cervical nerve co-stimulation mechanism

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation method that has been used to alter cognition in hundreds of experiments. During tDCS, a low-amplitude current is delivered via scalp electrodes to create a weak electric field in the brain. The weak electric field causes membrane polarization in cortical neurons directly under the scalp electrodes. It is generally assumed that this mechanism causes the observed effects of tDCS on cognition. However, it was recently shown that some tDCS effects are not caused by the electric field in the brain but rather via co-stimulation of cranial and cervical nerves in the scalp that also have neuromodulatory effects that can influence cognition. This peripheral nerve co-stimulation mechanism is not controlled for in tDCS experiments that use the standard sham condition. In light of this new evidence, results from previous tDCS experiments could be reinterpreted in terms of a peripheral nerve co-stimulation mechanism. Here, we selected six publications that reported tDCS effects on cognition and attributed the effects to the electric field in the brain directly under the electrode. We then posed the question: given the known neuromodulatory effects of cranial and cervical nerve stimulation, could the reported results also be understood in terms of tDCS peripheral nerve co-stimulation? We present our re-interpretation of these results as a way to stimulate debate within the neuromodulation field and as a food-for-thought for researchers designing new tDCS experiments.

Neuromodulation of the Autonomic Nervous System in Chronic Low Back Pain: A Randomized, Controlled, Crossover Clinical Trial

Chronic pain is a societal concern influencing the autonomic nervous system. This system can be captured with automated pupillometry. The direct connection between the epidermal cells and the brain is presented as part of the central nervous system, reflecting the modulation of the autonomic system. This study's aim was to investigate if tape containing magnetic particles (TCMP) has an immediate effect on the autonomic nervous system (ANS) and influences chronic low back pain. Twenty-three subjects completed this study. Subjects were randomized to either receive the control tape (CT) or TCMP first. Each subject underwent a pain provocative pressure test on the spinous process, followed by the skin pinch test and automated pupillometry. Next, the TCMP/control tape was applied. After tape removal, a second provocative spinous process pressure test and skin pinch test were performed. Subjects returned for a second testing day to receive the other tape application. The results demonstrate that TCMP had an immediate significant effect on the autonomic nervous system and resulted in decreased chronic lower back pain. We postulate that this modulation by TCMP s has an immediate effect on the autonomic system and reducing perceived pain, opening a large field of future research.

Skin-Based Vaccination: A Systematic Mapping Review of the Types of Vaccines and Methods Used and Immunity and Protection Elicited in Pigs

The advantages of skin-based vaccination include induction of strong immunity, dose-sparing, and ease of administration. Several technologies for skin-based immunisation in humans are being developed to maximise these key advantages. This route is more conventionally used in veterinary medicine. Skin-based vaccination of pigs is of high relevance due to their anatomical, physiological, and immunological similarities to humans, as well as being a source of zoonotic diseases and their livestock value. We conducted a systematic mapping review, focusing on vaccine-induced immunity and safety after the skin immunisation of pigs. Veterinary vaccines, specifically anti-viral vaccines, predominated in the literature. The safe and potent skin administration to pigs of adjuvanted vaccines, particularly emulsions, are frequently documented. Multiple methods of skin immunisation exist; however, there is a lack of consistent terminology and accurate descriptions of the route and device. Antibody responses, compared to other immune correlates, are most frequently reported. There is a lack of research on the underlying mechanisms of action and breadth of responses. Nevertheless, encouraging results, both in safety and immunogenicity, were observed after skin vaccination that were often comparable to or superior the intramuscular route. Further research in this area will underlie the development of enhanced skin vaccine strategies for pigs, other animals and humans.

Comparison of Antera 3D® and TcPO2 for Evaluation of Blood Flow in Skin

Background

There is a need for quick skin blood flow tests that can be performed in the wound healing field. Antera 3D® is a compact scanner using multispectral imaging. It can perform quick assessment of skin conditions. The purpose of the present study was to investigate the ability of the Antera 3D® to assess skin blood flow in comparison with transcutaneous partial pressure of oxygen (TcPO2) measurements.

Methods

This study was conducted on 13 patients with a history of lower extremity ulcers. Measurements of hemoglobin average level (hereafter, Hb score) measured by Antera 3D® and TcPO2 measured by a transcutaneous blood gas monitor were obtained at the same sites on the dorsal foot and lower leg. Differences in Hb score and TcPO2 were analyzed by t-test for each measurement site and for the presence of peripheral arterial disease (PAD). The correlation between TcPO2 and Hb score was analyzed by Pearson's correlation coefficient.

Results

Twenty-four limbs were tested. Hb score was higher (P < 0.001) and TcPO2 was lower (P = 0.056) in the dorsal foot compared to the lower leg. In the dorsal foot, Hb score was higher (P = 0.023) and TcPO2 was lower (P = 0.046) in patients with PAD compared to those without PAD. A significant negative correlation (r = -0.68; 95% confidence interval -0.85 to -0.38, P < 0.001) between TcPO2 and Hb score was observed in the dorsal foot.

Conclusion

The negative correlation between TcPO2 and Hb score may reflect compensatory peripheral vasodilation due to occlusion or stenosis of central arteries. This study showed that Hb score measured by Antera 3D® may be related to skin blood flow.

Optimization of Transspinal Stimulation Applications for Motor Recovery after Spinal Cord Injury: Scoping Review

Spinal cord injury (SCI) is a debilitating condition that can significantly affect an individual's life, causing paralysis, autonomic dysreflexia, and chronic pain. Transspinal stimulation (TSS) is a non-invasive form of neuromodulation that activates the underlying neural circuitries of the spinal cord. Application of TSS can be performed through multiple stimulation protocols, which may vary in the electrodes' size or position as well as stimulation parameters, and which may influence the response of motor functions to the stimulation. Due to the novelty of TSS, it is beneficial to summarize the available evidence to identify the range of parameters that may provide the best outcomes for motor response. The PubMed and Google Scholar databases were searched for studies examining the effects of TSS on limb motor function. A literature search yielded 34 studies for analysis, in which electrode placement and stimulation parameters varied considerably. The stimulation protocols from each study and their impact on limb motor function were summarized. Electrode placement was variable based on the targeted limb. Studies for the upper limbs targeted the cervical enlargement with anatomical placement of the cathode over the cervical vertebral region. In lower-limb studies, the cathode(s) were placed over the thoracic and lumbar vertebral regions, to target the lumbar enlargement. The effects of carrier frequency were inconclusive across the studies. Multisite cathodal placements yielded favorable motor response results compared to single-site placement. This review briefly summarized the current mechanistic evidence of the effect of TSS on motor response after SCI. Our findings indicate that optimization of stimulation parameters will require future randomized controlled studies to independently assess the effects of different stimulation parameters under controlled circumstances.

Methemoglobinemia Secondary to Inhalation of Automobile Emissions with Suicide Motivations

BACKGROUND

Methemoglobinemia (MetHb) is a rare and potentially severe dyshemoglobinemia that can be induced by exposure to oxidizing agents, decreasing the functional capacity of the hemoglobin molecule to transport and release oxygen into the tissues. MetHb can originate from gases with oxidizing capacity generated by internal combustion engines, although since the universalization of catalyst converters in automobiles, a tiny proportion of MetHb poisoning is due to exposure to engine gases and fumes. Within this group, only two cases due to suicidal motivations have been reported in the last 30 years.

CASE PRESENTATION

Here, we expose the case of a patient with MetHb levels of 25.2% (normal 0-1.5%) who with suicidal motivations had attached and locked a hose to the exhaust pipe of her vehicle with electrical tape, becoming exposed to a sustained concentration of the vehicle's exhaust. Upon her arrival at the emergency department, the presence of generalized greyish cyanosis with alterations of the sensorium, dissociation between saturation measured by arterial blood gas analysis and pulse oximetry (98% vs. 85%), no response to high-flow oxygen therapy, and an excellent response to intravenous methylene blue treatment were highlighted.

CONCLUSIONS

This report illustrates an original case of acute toxic acquired MetHb due to inhalation of oxidizing substances originating from the bad ignition of an internal combustion engine. When evaluating a patient with suspected gas intoxication, we usually consider poisoning by the most common toxins, such as carbon monoxide or cyanide. In this context, we propose an algorithm to assist in the suspicion of this entity in patients with cyanosis in the emergency department. MetHb poisoning should be suspected, and urgent co-oximetry should be requested when there is no congruence between cyanosis intensity and oxygen saturation measured by pulse oximetry, if there is discordance between the results of oxygen saturation measured by arterial blood gas and pulse oximeter, and if there is no response to oxygen treatment. This algorithm could be useful to not delay diagnosis, improve prognosis, and limit potential sequelae.

Noninvasive Stimulation of Peripheral Nerves using Temporally-Interfering Electrical Fields

Electrical stimulation of peripheral nerves is a cornerstone of bioelectronic medicine. Effective ways to accomplish peripheral nerve stimulation (PNS) noninvasively without surgically implanted devices are enabling for fundamental research and clinical translation. Here, it is demonstrated how relatively high-frequency sine-wave carriers (3 kHz) emitted by two pairs of cutaneous electrodes can temporally interfere at deep peripheral nerve targets. The effective stimulation frequency is equal to the offset frequency (0.5 - 4 Hz) between the two carriers. This principle of temporal interference nerve stimulation (TINS) in vivo using the murine sciatic nerve model is validated. Effective actuation is delivered at significantly lower current amplitudes than standard transcutaneous electrical stimulation. Further, how flexible and conformable on-skin multielectrode arrays can facilitate precise alignment of TINS onto a nerve is demonstrated. This method is simple, relying on the repurposing of existing clinically-approved hardware. TINS opens the possibility of precise noninvasive stimulation with depth and efficiency previously impossible with transcutaneous techniques.

The Baha® Attract System Implantations Significantly Improve the Quality of Life of Hearing-Impaired Patients in Long-Term Observations

BACKGROUND

The aim of this study was to assess the impact of the Baha® Attract system implantation on the quality of life of hearing-impaired patients, who were qualified for surgery due to various audiological indications.

METHODS

A total of 96 patients implanted with the Baha® Attract system were asked to fill in the set of questionnaires: the Glasgow Benefit Inventory, the Abbreviated Profile of Hearing-Aid Benefit, and the BAHA Aesthetic, Hygiene, and Use. Totally 79 patients responded and were then analyzed. Patients were divided into 4 groups: A: with bilateral mixed or conductive hearing loss, B: with single-sided deafness, C: with unilateral mixed or conductive hearing loss, and D: others.

RESULTS

There was a significant improvement in quality of life measured by the Glasgow Benefit Inventory in all the analyzed groups, with a mean total score of 29.4 points (P < .001). Similarly, the evaluation by the Abbreviated Profile of Hearing Aid Benefit questionnaire showed a significant improvement in terms of the global score in all the analyzed groups, with a mean gain of 38.6% (P < .001). There were no differences between the groups. More than 90% of patients found the Baha® Attract system easy to place on their heads and maintain good hygiene. Of all the implant users, 81% were satisfied with the final aesthetic effect.

CONCLUSION

The implantation of the Baha® Attract system significantly improves the quality of life of hearing-impaired patients in all subjec- tive scales used. The system is effective for all audiological indications when strictly adhered to. The majority of patients are very satisfied with the aesthetic, hygienic, and utility aspects of the device.

A retrospective review of transcutaneous and transconjunctival dual approach-A technique for mini-invasive double eyelid blepharoplasty with blepharoptosis correction

BACKGROUND

Many Oriental eyes feature single eyelid fold and ptotic eyelid. Performing the double eyelid blepharoplasty (DEB) in a minimally invasive manner with simultaneous blepharoptosis correction (BPC) is important to achieve an aesthetic pleasing outcome.

OBJECTIVE

To demonstrate an effective mini-invasive transcutaneous and transconjunctival dual approach technique for simultaneous DEB and BPC. Furthermore, to compare the outcome of BPC in dual approach, transcutaneous procedure and transconjunctival procedure.

METHODS

This is a retrospective study reviewing 159 eyelids that underwent mini-invasive DEB with BPC from November 2018 to May 2019, including the technical description and the surgical outcomes. To investigate the efficacy, the pre- and postoperative margin reflex distance 1 (MRD1) and levator function (LF) corresponding to the different surgical procedures and preoperative severity was analyzed.

RESULTS

Statistically, the dual approach group has significant improvement in MRD1 and LF (47 eyelids, p<0.05) corresponding to patients with ptosis of any severity. Under the same tucking amount, dual approach can achieve 1.6±0.7 mm of MRD1 improvement, which is nearly twice the amount compare with transconjunctival approach alone. No revision nor complication noted in the dual approach group by 6-month follow-up.

CONCLUSION

The dual approach technique is a method with a wide range of applications, effective, and low revision rate that simultaneously correct blepharoptosis and create a double eyelid.

Influence of Spine Curvature on the Efficacy of Transcutaneous Lumbar Spinal Cord Stimulation

Transcutaneous spinal cord stimulation is a non-invasive method for neuromodulation of sensorimotor function. Its main mechanism of action results from the activation of afferent fibers in the posterior roots-the same structures as targeted by epidural stimulation. Here, we investigated the influence of sagittal spine alignment on the capacity of the surface-electrode-based stimulation to activate these neural structures. We evaluated electromyographic responses evoked in the lower limbs of ten healthy individuals during extension, flexion, and neutral alignment of the thoracolumbar spine. To control for position-specific effects, stimulation in these spine alignment conditions was performed in four different body positions. In comparison to neutral and extended spine alignment, flexion of the spine resulted in a strong reduction of the response amplitudes. There was no such effect on tibial-nerve evoked H reflexes. Further, there was a reduction of post-activation depression of the responses to transcutaneous spinal cord stimulation evoked in spinal flexion. Thus, afferent fibers were reliably activated with neutral and extended spine alignment. Spinal flexion, however, reduced the capacity of the stimulation to activate afferent fibers and led to the co-activation of motor fibers in the anterior roots. This change of action was due to biophysical rather than neurophysiological influences. We recommend applying transcutaneous spinal cord stimulation in body positions that allow individuals to maintain a neutral or extended spine.

Algorithms for Automated Calibration of Transcutaneous Spinal Cord Stimulation to Facilitate Clinical Applications

Transcutaneous spinal cord stimulation (tSCS) is a promising intervention that can benefit spasticity control and augment voluntary movement in spinal cord injury (SCI) and multiple sclerosis. Current applications require expert knowledge and rely on the thorough visual analysis of electromyographic (EMG) responses from lower-limb muscles to optimize attainable treatment effects. Here, we devised an automated tSCS setup by combining an electrode array placed over low-thoracic to mid-lumbar vertebrae, synchronized EMG recordings, and a self-operating stimulation protocol to systematically test various stimulation sites and amplitudes. A built-in calibration procedure classifies the evoked responses as reflexes or direct motor responses and identifies stimulation thresholds as recommendations for tSCS therapy. We tested our setup in 15 individuals (five neurologically intact, five SCI, and five Parkinson’s disease) and validated the results against blinded ratings from two clinical experts. Congruent results were obtained in 13 cases for electrode positions and in eight for tSCS amplitudes, with deviations of a maximum of one position and 5 to 10 mA in amplitude in the remaining cases. Despite these minor deviations, the calibration found clinically suitable tSCS settings in 13 individuals. In the remaining two cases, the automatic setup and both experts agreed that no reflex responses could be detected. The presented technological developments may facilitate the dissemination of tSCS into non-academic environments and broaden its use for diagnostic and therapeutic purposes.

Effect of Transcutaneous Radial Artery Photobiomodulation on Continuous Measures of Interstitial Glucose in a Single Subject: A Brief Report

Background: Intravenous blood irradiation with light is purported to reduce blood sugar levels in people with diabetes mellitus (DM). Transcutaneous light emitting devices are marketed for use in modulating glucose levels, yet evidence of effectiveness is scarce. Materials and methods: In a single subject (nondiabetic woman with significant family history of DM), transcutaneous photobiomodulation (PBM) at various wavelengths was applied to the radial artery immediately after a standardized meal, or at the peak glucose after the standardized meal. Data were compared with a "no intervention" control period. Interstitial glucose was measured every 5 min until return to baseline. Results: A single transcutaneous application of PBM at wavelength and dose combinations tested and when applied immediately after a test meal or at peak glucose postprandially did not affect interstitial glucose levels in a woman without DM. Conclusions: Future studies could include testing additional subjects, using repeated PBM applications and monitoring using blood glucose.

Experience of orbital floor fractures in a UK level one trauma centre: a focus on the surgical approach and lid-related complications

The two surgical approaches to access orbital fractures are transconjunctival and transcutaneous. The aim of this study was to assess the outcomes of orbital repairs with a focus on lid-related complications and their management. A retrospective analysis was carried out over a five-year period (January 2015 to January 2020) to assess all consecutive orbital repairs in our unit. Data were collected for variables including demographics, fracture pattern, surgical approach, and details of postoperative complications. A total of 111 patients were included in the study, 94 were male (85%), the majority being between 16 and 45 years of age. A total of 46 (41%) had isolated orbital floor fractures, 31 (28%) zygomaticomaxillary complex, and 18 (16%) Le Fort pattern fractures. Eighty per cent (n = 91) received a transconjunctival approach as first choice. In the transconjunctival group, six (6.6%) had entropion and increased scleral show, four (4.4%) had ectropion, and none had canthal malposition. In the transcutaneous group (n = 20) there was a higher rate of ectropion (25%, n = 5), a lower rate of entropion (n = 1, 5%) and higher rate of increased scleral show (n = 2, 10%). Factors associated with a higher rate of complications included complex fractures, use of conjunctival sutures, and increased length of time to surgery. Seventy-two per cent of patients who suffered entropion required further surgical treatment. The most common complication of the transconjunctival approach was entropion, and clinicians should have a low threshold for early surgical management. We feel that this should be part of the consenting process, especially in high-risk cases.

Retrosigmoidal placement of an active transcutaneous bone conduction implant: surgical and audiological perspectives in a multicentre study

Introduction

The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system.

Methods

A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system.

Results

Audiological assessment concerning the measurement of the functional and effective gain by pure-tone audiometry (28 dB HL and -12.25 dB HL, respectively) and speech audiometry (24.7 dB HL and -21 dB HL, respectively) was conducted. A high overall subjective improvement of quality of life was recorded with the Glasgow Benefit Inventory questionnaire. No major complications, such as device extrusions or other conditions requiring revision surgery, were reported during the follow-up period (median: 42 months).

Conclusions

In our study, which has one of the largest cohort of patients reported in the literature, RS placement of the BB system was safe and effective. Our functional results showed comparable hearing outcomes with presigmoidal placement. The effective gain, rarely investigated in this field, may be the object of further research to improve our understanding of bone conduction mechanisms exploited by bone conduction hearing implants.

A direct transcutaneous approach to infraorbital nerve biopsy

Purpose: To describe a novel transcutaneous infraorbital nerve biopsy technique which can be performed to aid in the diagnosis of perineural invasion (PNI) of facial cutaneous squamous cell carcinoma (SCC).Methods: A single-center retrospective chart review was performed. Patients diagnosed with SCC with PNI via an infraorbital nerve biopsy between February 2019 and February 2020 were included. Data collected consisted of patient demographics, medical history, clinical presentation and exam, histologic and radiographic findings, treatment, and outcomes.Results: Four patients (3 male, 1 female) met inclusion criteria. The mean age at diagnosis was 79.5 years (range 66-85 years). Three of the four patients had a history of facial skin lesions, including actinic keratosis and SCC, involving the nose, cheek, or ear. One patient had no history of cutaneous malignancy. All patients presented with cranial neuropathies, including total V2 hypoesthesia. The most common presenting symptom was facial pain, followed by diplopia, unilateral facial weakness, and hypoesthesia in the V1 and/or V2 distribution. Transcutaneous infraorbital nerve biopsy in all patients revealed squamous cell carcinoma with no biopsy complications.Conclusion: Definitive diagnosis of PNI can be challenging but is important to minimize tumor-related morbidity. Infraorbital nerve biopsy can establish this diagnosis, especially in the context of negative or indeterminate imaging findings. This work comprises the first description of a transcutaneous approach to infraorbital nerve biopsy, which is a minimally invasive technique that can be performed in an outpatient procedure suite with limited to no sedation.

Transcutaneous Spinal Cord Stimulation Enhances Walking Performance and Reduces Spasticity in Individuals with Multiple Sclerosis

Gait dysfunction and spasticity are common debilitating consequences of multiple sclerosis (MS). Improvements of these motor impairments by lumbar transcutaneous spinal cord stimulation (tSCS) have been demonstrated in spinal cord injury. Here, we explored for the first time the motor effects of lumbar tSCS applied at 50 Hz for 30 min in 16 individuals with MS and investigated their temporal persistence post-intervention. We used a comprehensive protocol assessing walking ability, different presentations of spasticity, standing ability, manual dexterity, and trunk control. Walking ability, including walking speed and endurance, was significantly improved for two hours beyond the intervention and returned to baseline after 24 h. Muscle spasms, clonus duration, and exaggerated stretch reflexes were reduced for two hours, and clinically assessed lower-extremity muscle hypertonia remained at improved levels for 24 h post-intervention. Further, postural sway during normal standing with eyes open was decreased for two hours. No changes were detected in manual dexterity and trunk control. Our results suggest that transcutaneous lumbar SCS can serve as a clinically accessible method without known side effects that holds the potential for substantial clinical benefit across the disability spectrum of MS.

Transcutaneous PCO2 -based dead space ventilation at submaximal exercise accurately discriminates healthy controls from patients with chronic obstructive pulmonary disease

BACKGROUND

Increased physiological dead space ventilation (V_D /V_T ) at exercise reflects pulmonary gas exchange impairment and is a sensitive marker of cardio-respiratory disease. V_D /V_T is typically not measured during routine cardiopulmonary exercise testing (CPET) because its calculation requires arterial blood gas analysis for determination of PaCO₂ . Instead, dead space ventilation is indirectly evaluated as a determinant of the ventilation (VE)/VCO₂ relationship, which also depends on the PaCO₂ set point. We hypothesized that V_D /V_T calculations based on non-invasive transcutaneous PCO₂ (PtcCO₂ ) measurement had better diagnostic characteristics than the VE/VCO₂ slope for the discrimination of healthy subjects from patients with COPD, a common disease associated with impaired pulmonary gas exchange.

METHODS

Retrospective study of 19 healthy controls and 24 COPD patients who underwent CPET with continuous PtcCO₂ monitoring. Areas under receiver operating characteristics curves (AUC) were calculated to assess diagnostic accuracy of CPET measurement for the discrimination of COPD and Controls.

RESULTS

The AUC for PtcCO₂ -based V_D /V_T at VT1 (0.977) was significantly higher than for the VE/VCO₂ slope (0.660), SpO₂ at peak exercise (0.913), decrease in inspiratory capacity (0.719), and ventilatory reserve (0.708). At a threshold of 0.24, the sensitivity and specificity of PtcCO₂ -based V_D /V_T for the discrimination of COPD patients and healthy Controls were 100% and 84%, respectively. All Control subjects had PtcCO₂ -based V_D /V_T  ≤ 0.25.

CONCLUSIONS

PtcCO₂ -based V_D /V_T was the most accurate measurement to discriminate healthy controls from subjects with COPD, a chronic lung disease associated with altered pulmonary gas exchange. Non-invasive monitoring of PtcCO₂ may be useful for routine CPET.

Incidence of Dacryocystorhinostomy (DCR) in France: A Nationwide Study over the 2010-2019 Period

BACKGROUND

To assess the annual incidence, surgical technique preferred (i.e. external versus endonasal) and the characteristics of patients undergoing a Dacryocystorhinostomy (DCR) in France over a 10-year-period.

METHODS

A national observational cohort study was conducted in France between January 2010 and December 2019. Data were collected from the national PMSI (Programme de Médicalisation des Sytèmes d'Information) database provided by the CNAM (Caisse Nationale de l'Assurance Maladie). All patients undergoing a DCR were included.

RESULTS

Twenty-one thousand one hundred ninety-nine patients, with a mean age of 70.4 years, were included. A female predominance (78%) was noted. The mean annual number of DCRs was 2481 (2366-2633), corresponding to a mean incidence of 3.8 per 100,000 person-years. This number remained stable over the study period (p = .966). Of the 24,808 DCRs, external DCRs were more prevalent compared to endonasal procedures (70.8% vs. 29.2%, p = .0001). Six hundred and fifteen (2.5%) associated acts were performed intraoperatively, mainly during endonasal DCR (96.3%). A total of 10,857 (43.8%) silicone stents were placed intraoperatively. Bicanalicular silicone stenting was preferred over the monocanalicular stenting. All the regions performed more likely external DCR except the Île-de-France area where endonasal DCR was performed in 75.6% of procedures. DCRs were mainly performed by an ophthalmologist (80%).

CONCLUSION

The mean annual incidence of external and endonasal DCRs remained stable over the study period. Endonasal DCR was more likely performed by the otorhinolaryngologists, emphasizing the need to develop personalized endonasal training in the ophthalmology residency program.

Validation of transcutaneous carbon dioxide monitoring using an artificial lung during adult pulsatile cardiopulmonary bypass

Measurements of transcutaneous carbon dioxide (tcCO₂) have been used in multiple venues, such as during procedures utilizing jet ventilation, hyperbaric oxygen therapy, as well as both the adult and neo-natal ICUs. However, tcCO₂ measurements have not been validated under conditions which utilize an artificial lung, such cardiopulmonary bypass (CPB). The purpose of this study was to (1) validate the use of tcCO₂ using an artificial lung during CPB and (2) identify a location for the sensor that would optimize estimation of PaCO₂ when compared to the gold standard of blood gas analysis.tcCO₂ measurements (N = 185) were collected every 30 min during 54 pulsatile CPB procedures. The agreement/differences between the tcCO₂ and the PaCO₂ were compared by three sensor locations. Compared to the earlobe or the forehead, the submandibular PtcCO₂ values agreed best with the PaCO₂ and with a median difference of -.03 mmHg (IQR = 5.4, p < 0.001). The small median difference and acceptable IQR support the validity of the tcCO₂ measurement. The multiple linear regression model for predicting the agreement between the submandibular tcCO₂ and PaCO₂ included the SvO₂, the oxygenator gas to blood flow ratio, and the native perfusion index (R² = 0.699, df = 1, 60; F = 19.1, p < 0.001).Our experience in utilizing tcCO₂ during CPB has demonstrated accuracy in estimating PaCO₂ when compared to the gold standard arterial blood gas analysis, even during CO₂ flooding of the surgical field.

Soft-tissue spectral subtraction improves transcutaneous Raman estimates of murine bone strength in vivo

Transcutaneous determination of a bone's Raman spectrum is challenging because the type I collagen in the overlying soft tissue is spectroscopically identical to that in bone. In a previous transcutaneous study of murine tibiae, we developed a library-based model called SOLD to unmix spatially offset Raman measurements into three spectra: a bone estimate, a soft tissue estimate, and a residual. Here, we demonstrate the value of combining the bone estimate and the residual to produce a "top layer subtracted" (tls) spectrum. We report superior prediction of two standard bone metrics (volumetric bone mineralization density and maximum torque) using partial least squares regression models based upon tls spectra rather than SOLD bone estimates, implying that the spectral residuals contain useful information. Simulations reinforce experimental in vivo findings. This chemometric approach, which we denote as SOLD/TLS, could have broad applicability in situations where comprehensive spectral libraries are difficult to acquire.

Vaccination into the Dermal Compartment: Techniques, Challenges, and Prospects

In 2019, an 'influenza pandemic' and 'vaccine hesitancy' were listed as two of the top 10 challenges to global health by the WHO. The skin is a unique vaccination site, due to its immune-rich milieu, which is evolutionarily primed to respond to challenge, and its ability to induce both humoral and cellular immunity. Vaccination into this dermal compartment offers a way of addressing both of the challenges presented by the WHO, as well as opening up avenues for novel vaccine formulation and dose-sparing strategies to enter the clinic. This review will provide an overview of the diverse range of vaccination techniques available to target the dermal compartment, as well as their current state, challenges, and prospects, and touch upon the formulations that have been developed to maximally benefit from these new techniques. These include needle and syringe techniques, microneedles, DNA tattooing, jet and ballistic delivery, and skin permeabilization techniques, including thermal ablation, chemical enhancers, ablation, electroporation, iontophoresis, and sonophoresis.

Comparative effects of unilateral and bilateral bone conduction hearing devices on functional hearing and sound localization abilities in patients with bilateral microtia-atresia

Background: Various amplification options are available for patients with congenital bilateral conductive hearing loss. Unilateral bone conduction hearing device (BCHD) is widely used for these patients, whereas benefits of bilateral BCHDs in certain subgroups of patients require further exploration.Objectives: To evaluate functional and directional hearing in patients with unilateral Bonebridge (MEDEL) and contralateral ADHEAR (MEDEL) devices.Materials and methods: This study included 32 patients (20 males, 12 females), of mean age 11.8 years (range 7-27 years). Hearing thresholds, speech perception and sound localization were tested three months after activation of the Bonebridge under three conditions: unaided, unilateral BHCD (Bonebridge) and bilateral BHCDs (Bonebridge plus contralateral ADHEAR). Patient acceptance of these devices in daily life was evaluated by questionnaire.Results: Compared with unaided, the mean hearing thresholds (0.5, 1, 2, and 4 kHz) and speech perception with unilateral BCHD and bilateral BCHDs were improved significantly (p < .05 each). Markers of directional hearing ability, including percentages of accurate responses, bias angles and RMS errors, were significantly better with bilateral BCHDs than unilateral BHCD (p < .05 each). Questionnaire revealed high patient satisfaction with both unilateral and bilateral devices.Conclusions: Functional hearing and sound localization abilities were better with bilateral BCHDs than unilateral BCHD.

Critical Review of Transcutaneous Vagus Nerve Stimulation: Challenges for Translation to Clinical Practice

Several studies have illustrated that transcutaneous vagus nerve stimulation (tVNS) can elicit therapeutic effects that are similar to those produced by its invasive counterpart, vagus nerve stimulation (VNS). VNS is an FDA-approved therapy for the treatment of both depression and epilepsy, but it is limited to the management of more severe, intervention-resistant cases as a second or third-line treatment option due to perioperative risks involved with device implantation. In contrast, tVNS is a non-invasive technique that involves the application of electrical currents through surface electrodes at select locations, most commonly targeting the auricular branch of the vagus nerve (ABVN) and the cervical branch of the vagus nerve in the neck. Although it has been shown that tVNS elicits hypo- and hyperactivation in various regions of the brain associated with anxiety and mood regulation, the mechanism of action and influence of stimulation parameters on clinical outcomes remains predominantly hypothetical. Suppositions are largely based on correlations between the neurobiology of the vagus nerve and its effects on neural activity. However, tVNS has also been investigated for several other disorders, including tinnitus, migraine and pain, by targeting the vagus nerve at sites in both the ear and the neck. As most of the described methods differ in the parameters and protocols applied, there is currently no firm evidence on the optimal location for tVNS or the stimulation parameters that provide the greatest therapeutic effects for a specific condition. This review presents the current status of tVNS with a focus on stimulation parameters, stimulation sites, and available devices. For tVNS to reach its full potential as a non-invasive and clinically relevant therapy, it is imperative that systematic studies be undertaken to reveal the mechanism of action and optimal stimulation modalities.

Feasibilty of Transcutaneous pCO2 Monitoring During Immediate Transition After Birth-A Prospective Observational Study

Background: According to recommendations, non-invasive monitoring during neonatal resuscitation after birth includes heart rate (HR) and oxygen saturation (SpO₂). Continuous transcutaneous monitoring of carbon dioxide partial pressure (tcpCO₂) may further offer quantitative information on neonatal respiratory status. Objective: We aimed to investigate feasibility of tcpCO₂ measurements in the delivery room during immediate neonatal transition and to compare the course of tcpCO₂ between stable term and preterm infants. Methods: Neonates without need for cardio-respiratory intervention during immediate transition after birth were enrolled in a prospective observational study. In these term and preterm neonates, we measured HR and SpO₂ by pulse oximetry on the right wrist and tcpCO₂ with the sensor applied on the left hemithorax during the first 15 min after birth. Courses of tcpCO₂ were analyzed in term and preterm neonates and groups were compared. Results: Fifty-three term (gestational age: 38.8 ± 0.9 weeks) and 13 preterm neonates (gestational age: 34.1 ± 1.5 weeks) were included. First tcpCO₂ values were achieved in both groups at minute 4 after birth, which reached a stable plateau after the equilibration phase at minute 9. Mean tcpCO₂ values 15 min after birth were 46.2 (95% CI 34.5-57.8) mmHg in term neonates and 48.5 (95%CI 43.0-54.1) mmHg in preterm neonates. Preterm and term infants did not show significant differences in the tcpCO₂ values at any time point. Conclusion: This study demonstrates that tcpCO₂ measurement is feasible during immediate neonatal transition after birth and that tcpCO₂ values were comparable in stable term and preterm neonates.

Simple Defocused Fiber Optic Volume Probe for Subsurface Raman Spectroscopy in Turbid Media

We investigated the ability to perform deep subsurface Raman spectroscopy in turbid media using a simple fiber optic volume probe. Being able to collect Raman signals from regions deep within a biological sample provides the ability to noninvasively study underlying living tissue and tissue engineered constructs with high chemical specificity. Spatially offset Raman spectroscopy has shown great potential for obtaining subsurface Raman signals in biological samples. The applicability of the method for in vivo studies depends on the system complexity and small size probes are often desirable. Most real-time studies on human patients utilizing Raman spectroscopy have been performed with easy-to-handle miniaturized probes. Here we show both experimentally and theoretically that the sampling depth from a simple volume probe can be controlled by changing the probe to sample distance effectively suppressing Raman and fluorescence contributions from shallow sample layers while favoring the collection of signals from deeper layers. Relative spectral intensities as function of probe to sample distance were investigated for layered phantoms of poly(methyl methacrylate) and trans-stilbene and compared with theory. The volume probe was then utilized for the collection of spectra from phantoms mimicking in vivo transcutaneous measurement configurations of bone and engineered scaffold as well as from an ex vivo sample of bone and soft tissue. Together the results show that Raman fiber optic volume probes can be utilized for subsurface Raman spectroscopy in turbid media, providing a simple alternative to spatially offset Raman systems for, e.g., noninvasive monitoring and studying mineralized tissue and implanted scaffolds in vivo.

The Safety and Immunogenicity of GTU®MultiHIV DNA Vaccine Delivered by Transcutaneous and Intramuscular Injection With or Without Electroporation in HIV-1 Positive Subjects on Suppressive ART

Previous studies have shown targeting different tissues via the transcutaneous (TC) and intramuscular injection (IM) with or without electroporation (EP) has the potential to trigger immune responses to DNA vaccination. The CUTHIVTHER 001 Phase I/II randomized controlled clinical trial was designed to determine whether the mode of DNA vaccination delivery (TC+IM or EP+IM) could influence the quality and function of induced cellular immune responses compared to placebo, in an HIV positive clade B cohort on antiretroviral therapy (ART). The GTU^®MultiHIV B DNA vaccine DNA vaccine encoded a MultiHIV B clade fusion protein to target the cellular response. Overall the vaccine and regimens were safe and well-tolerated. There were robust pre-vaccination IFN-γ responses with no measurable change following vaccination compared to placebo. However, modest intracellular cytokine staining (ICS) responses were seen in the TC+IM group. A high proportion of individuals demonstrated potent viral inhibition at baseline that was not improved by vaccination. These results show that HIV positive subjects with nadir CD4+ counts ≥250 on suppressive ART display potent levels of cellular immunity and viral inhibition, and that DNA vaccination alone is insufficient to improve such responses. These data suggest that more potent prime-boost vaccination strategies are likely needed to improve pre-existing responses in similar HIV-1 cohorts (This study has been registered at http://ClinicalTrials.gov under registration no. NCT02457689).

Transcutaneous Ultrasound-Mediated Nonviral Gene Delivery to the Liver in a Porcine Model

Ultrasound (US)-mediated gene delivery (UMGD) of nonviral vectors was demonstrated in this study to be an effective method to transfer genes into the livers of large animals via a minimally invasive approach. We developed a transhepatic venous nonviral gene delivery protocol in combination with transcutaneous, therapeutic US (tUS) to facilitate significant gene transfer in pig livers. A balloon catheter was inserted into the pig hepatic veins of the target liver lobes via jugular vein access under fluoroscopic guidance. tUS exposure was continuously applied to the lobe with simultaneous infusion of pGL4 plasmid (encoding a luciferase reporter gene) and microbubbles. tUS was delivered via an unfocused, two-element disc transducer (H105) or a novel focused, single-element transducer (H114). We found applying transcutaneous US using H114 and H105 with longer pulses and reduced acoustic pressures resulted in an over 100-fold increase in luciferase activity relative to untreated lobes. We also showed effective UMGD by achieving focal regions of >10⁵ relative light units (RLUs)/mg protein with minimal tissue damage, demonstrating the feasibility for clinical translation of this technique to treat patients with genetic diseases.

Comparison of transcutaneous and serum bilirubin before, under, and after phototherapy in term and late-preterm infants

This study aimed to determine the correlation of transcutaneous bilirubin (TcB) with total serum bilirubin (TSB) in infants receiving phototherapy and the accuracy of TcB for deciding the time to discontinue phototherapy. Paired TcB and TSB levels were assessed in 52 term and 56 late-preterm infants receiving phototherapy. TcB was measured in the unexposed skin of the middle forehead using a noninvasive bilirubin analyzer, BiliChek. TSB was measured every morning, and TcB was measured 2 hours after TSB measurements. Bland-Altman plots, linear regression, multivariate pair wise correlation, and receiver operating characteristic curve (ROC) analyses were performed. Bland-Altman plots before, under, and 24 hours after phototherapy in term and late-preterm infants revealed that TcB and TSB have higher consistency. TcB and TSB showed positive linear correlation before, under, and after phototherapy in both infant groups. In the multivariate pair wise correlations, differences between TcB and TSB were negatively correlated with phototherapy duration in term (correlation coefficient = -0.233, P value = .001) and late-preterm (correlation coefficient = -0.198, P value = .002) infants. Cutoff levels of TcB for discontinuing phototherapy based on the ROC analysis were 13.8 (sensitivity of 90%, specificity of 84%, area under the curve [AUC] 0.94) and 11.8 mg/dL (sensitivity of 84%, specificity of 88%, AUC 0.92) in term and late-preterm infants, respectively. TcB and TSB before, under, and after phototherapy in both term and late-preterm infants showed good correlation and higher consistency with jaundice. To reduce repetitive blood sampling for TSB, TcB measurement may be a reliable method for term and late-preterm infants undergoing phototherapy.

Transcutaneous Spinal Cord Stimulation Induces Temporary Attenuation of Spasticity in Individuals with Spinal Cord Injury

Epidural spinal cord stimulation (SCS) is currently regarded as a breakthrough procedure for enabling movement after spinal cord injury (SCI), yet one of its original applications was for spinal spasticity. An emergent method that activates similar target neural structures non-invasively is transcutaneous SCS. Its clinical value for spasticity control would depend on inducing carry-over effects, because the surface-electrode-based approach cannot be applied chronically. We evaluated single-session effects of transcutaneous lumbar SCS in 12 individuals with SCI by a test-battery approach, before, immediately after and 2 h after intervention. Stimulation was applied for 30 min at 50 Hz with an intensity sub-threshold for eliciting reflexes in lower extremity muscles. The tests included evaluations of stretch-induced spasticity (Modified Ashworth Scale [MAS] sum score, pendulum test, electromyography-based evaluation of tonic stretch reflexes), clonus, cutaneous-input-evoked spasms, and the timed 10 m walk test. Across participants, the MAS sum score, clonus, and spasms were significantly reduced immediately after SCS, and all spasticity measures were improved 2 h post-intervention, with large effect sizes and including clinically meaningful improvements. The effect on walking speed varied across individuals. We further conducted a single-case multi-session study over 6 weeks to explore the applicability of transcutaneous SCS as a home-based therapy. Self-application of the intervention was successful; weekly evaluations suggested progressively improving therapeutic effects during the active period and carry-over effects for 7 days. Our results suggest that transcutaneous SCS can be a viable non-pharmacological option for managing spasticity, likely working through enhancing pre- and post-synaptic spinal inhibitory mechanisms, and may additionally serve to identify responders to treatments with epidural SCS.

Outcomes of the Baha Attract System combined with auricle reconstruction in mandarin speaking patients with bilateral microtia-atresia

BACKGROUND

A transcutaneous bone-conduction hearing device (tBCHD), the Baha Attract System has been recently introduced to China, and very few studies have assessed the efficacy of this system in speakers of mandarin.

OBJECTIVES

This study aims to analyze the functional and cosmetic outcomes of this system.

MATERIALS AND METHODS

This prospective study included 11 patients (nine males, two females), of mean age 16 years (range 9-32 years). Seven patients were conducted the implantation simultaneously with auricle reconstruction, and the other four were before it. Auditory results were compared between unaided patients and implanted patients. Subjective satisfaction was analyzed using three questionnaires.

RESULTS

The mean sound field thresholds were 65.9 ± 5.1 dB SPL unaided and 30.9 ± 4.7 dB SPL with an implanted Baha Attract System, resulting in a mean hearing gain of 35.0 ± 6.7 dB. The mean WRS scores were 47.8 ± 8.7% unaided and 92.1 ± 2.0% with the Baha Attract System, resulting in a mean improvement of 47.8 ± 8.7%. No adverse events were reported and questionnaires showed good patients satisfaction.

CONCLUSIONS

The transcutaneous Baha Attract System is effective in mandarin speaking patients, and the combination of hearing rehabilitation and auricle reconstruction surgery is promising for patients with bilateral microtia-atresia.

Real-Time Light-Guided Vocal Fold Injection: Ex Vivo Feasibility Study in a Canine Model

OBJECTIVE

The transcricothyroid (CT) membrane approach is a good option for office-based vocal fold injection (VFI). However, because the needle tip is invisible during injection using the CT approach, precise localization requires a high level of experience, and mastering this approach involves a steep learning curve. To overcome current limitations, we conceptualized a novel technique: real-time light-guided VFI (RL-VFI), which enables simultaneous VFI under direct visualization of the lighted needle tip. Herein, we aimed to verify the feasibility of RL-VFI in cadaveric canine model, simulating the setting of office-based VFI, as well as to explore its clinical usefulness.

STUDY DESIGN

Animal study.

METHODS

A customized prototype device was developed. It consisted of three parts: light source, controller, and injector. Light source comprised laser diodes of two wavelengths (635 nanometers [nm], red; 532 nm, green). Four types of injector were developed using 40-mm needles of 23- and 25-gauge and optic fibers of 50 and 100 μm. ex vivo canine larynx was prepared for the experiment. Flexible laryngoscopy system was used to examine canine vocal folds.

RESULTS

Various routes from three insertion points (3 mm, 10 mm, and 17 mm from the midline) were validated using the device. Regardless of the injection routes, the location of the needle tip was accurately indicated by light. RL-VFI was feasible under light guidance without difficulties. Moreover, precise and simultaneous re-injection could be performed at the intended point using the device.

CONCLUSION

We introduced RL-VFI using our customized prototype device in an ex vivo canine larynx, simulating the setting of office-based VFI. Clinical application of RL-VFI will improve safety and precision of CT approach, as well as expand its applications in laryngology.

LEVEL OF EVIDENCE

NA. Laryngoscope, 129:935-942, 2019.

The rise of transcutaneous drug delivery for the management of alopecia: a review of existing literature and an eye towards the future

Introduction: Fractional lasers and microneedling devices are increasingly used with topical drugs to treat various conditions, including alopecia, as they grant access to dermal structures such as hair follicles and cutaneous vasculature. Objective: To perform a comprehensive review on transcutaneous drug delivery for the management of alopecia. Methods: PubMed, Embase, and Ovid Medline databases were searched using terms including: alopecia, microneedling, lasers, androgenetic alopecia (AGA), alopecia areata (AA), drug delivery. Articles were examined for inclusion criteria: diagnosis of alopecia regardless of type, use of fractional laser or microneedling devices, and subsequent administration of topical medication. Results: 8 studies, 6 prospective clinical trials and 2 case series, examining either AA or AGA were identified. For AA, five studies examined microneedling together with topical triamcinolone in three of these, while two studies used photodynamic therapy. Regarding AGA, two studies used topical minoxidil plus microneedling, and one examined topical finasteride with fractional erbium glass laser. Improvement was seen in 6 of the 8 studies. Discussion: Transcutaneous drug delivery via fractional laser and microneedling is a promising modality with preliminary evidence for increased hair regrowth over topical therapy alone. Further studies are needed to elucidate treatment parameters and appropriate device selection for drug delivery.

Noninvasive vaccination against infectious diseases

The development of a successful vaccine, which should elicit a combination of humoral and cellular responses to control or prevent infections, is the first step in protecting against infectious diseases. A vaccine may protect against bacterial, fungal, parasitic, or viral infections in animal models, but to be effective in humans there are some issues that should be considered, such as the adjuvant, the route of vaccination, and the antigen-carrier system. While almost all licensed vaccines are injected such that inoculation is by far the most commonly used method, injection has several potential disadvantages, including pain, cross contamination, needlestick injury, under- or overdosing, and increased cost. It is also problematic for patients from rural areas of developing countries, who must travel to a hospital for vaccine administration. Noninvasive immunizations, including oral, intranasal, and transcutaneous administration of vaccines, can reduce or eliminate pain, reduce the cost of vaccinations, and increase their safety. Several preclinical and clinical studies as well as experience with licensed vaccines have demonstrated that noninvasive vaccine immunization activates cellular and humoral immunity, which protect against pathogen infections. Here we review the development of noninvasive immunization with vaccines based on live attenuated virus, recombinant adenovirus, inactivated virus, viral subunits, virus-like particles, DNA, RNA, and antigen expression in rice in preclinical and clinical studies. We predict that noninvasive vaccine administration will be more widely applied in the clinic in the near future.

Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation

BACKGROUND

The current standard for pelvic intraoperative neuromonitoring (pIONM) is based on intermittent direct nerve stimulation. This study investigated the potential use of transcutaneous sacral nerve stimulation for non-invasive verification of pelvic autonomic nerves.

METHODS

A consecutive series of six pigs underwent low anterior rectal resection. For transcutaneous sacral nerve stimulation, an array of ten electrodes (cathodes) was placed over the sacral foramina (S2 to S4). Anodes were applied on the back, right and left thigh, lower abdomen, and intra-anally. Stimulation using the novel method and current standard were performed at different phases of the experiments under electromyography of the autonomic innervated internal anal sphincter (IAS).

KEY RESULTS

Transcutaneous stimulation induced increase of IAS activity could be observed in each animal under specific cathode-anode configurations. Out of 300 tested configurations, 18 exhibited a change in the IAS activity correlated with intentional autonomic nerve damage. The damage resulted in a significant decrease of the relative area under the curve of the IAS frequency spectrum (P<.001). Comparison of the IAS spectra under transcutaneous and direct stimulation revealed no significant difference (after rectal resection: median 5.99 μV•Hz vs 7.78 μV•Hz, P=.12; after intentional nerve damage: median -0.27 μV•Hz vs 3.35 μV•Hz, P=.29).

CONCLUSIONS AND INFERENCES

Non-invasive selective transcutaneous sacral nerve stimulation could be used for verification of IAS innervation.

Factors which influence concordance among measurements obtained by different pulse oximeters currently used in some clinical situations

AIMS AND OBJECTIVES

To evaluate both concordance among those measurements obtained by three different pulse oximeters currently used by nursing professionals in hospital units and the factors which can influence this concordance.

BACKGROUND

Many models of wireless pulse oximeters in the present market do not offer possibility of calibration and, therefore, they do not ensure patients' safety in daily clinical practice.

DESIGN

This is a descriptive and cross-sectional study. The sample of patients (140) was selected from such hospital units, and all of them had to fulfil inclusion and exclusion criteria for participation.

METHODS

The instruments used to carry out this research were a monitor (calibrated), two models of portable wireless pulse oximeters (used for 3 years by the nursing staff, without being calibrated), a tympanic thermometer and a weather meter. The concordance correlation coefficient (CCC) was used to establish the concordance, whereas the Landis-Koch criteria were used to interpret the results.

RESULTS

The concordance among the three devices was considered as "good" (CCC: 0.925 and 0.974 (95%)). The CCC (0.925) for saturation measures was regarded as "very good"/"almost perfect," and the pulse measure was considered as "very good" CCC 0.974, providing in both cases a high level of concordance (CCC > 0.91).

CONCLUSIONS

The overall concordance as regards pulse and oxygen saturation among the three pulse oximeters analysed is considered as "very good" according to the Landis-Koch criteria.

RELEVANCE TO CLINICAL PRACTICE

There exists a "very good" concordance among two wireless oximeters which have been used by the health staff for 3 years and which did not offer any possibility of calibration and one monitor which belongs to the healthcare institution. This aspect is of crucial importance in daily clinical practice, and it is also relevant to ensure patient's safety.

Non-invasive Vagal Nerve Stimulation Effects on Hyperarousal and Autonomic State in Patients with Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury: Preliminary Evidence

Posttraumatic stress disorder (PTSD) is a reaction to trauma that results in a chronic perception of threat, precipitating mobilization of the autonomic nervous system, and may be reflected by chronic disinhibition of limbic structures. A common injury preceding PTSD in veterans is mild traumatic brain injury (mTBI). This may be due to the vulnerability of white matter in these networks and such damage may affect treatment response. We evaluated transcutaneous vagal nerve stimulation (tVNS), a non-invasive, low-risk approach that may alter the functions of the limbo-cortical and peripheral networks underlying the hyperarousal component of PTSD and thus improve patient health and well-being. In this single visit pilot study evaluating the impact of tVNS in 22 combat veterans, we used a between-subjects design in people with either PTSD with preceding mTBI or healthy controls. Participants were randomized into stimulation or sham groups and completed a posturally modulated autonomic assessment and emotionally modulated startle paradigm. The primary measures used were respiratory sinus arrhythmia (high-frequency heart rate variability) during a tilt-table procedure derived from an electrocardiogram, and skin conductance changes in response to acoustic startle while viewing emotional images (International Affective Picture System). The stimulation was well tolerated and resulted in improvements in vagal tone and moderation of autonomic response to startle, consistent with modulation of autonomic state and response to stress in this population. Our results suggest that tVNS affects systems underlying emotional dysregulation in this population and, therefore, should be further evaluated and developed as a potential treatment tool for these patients.

Continuous non-invasive PCO2 monitoring in weaning patients: Transcutaneous is advantageous over end-tidal PCO2

BACKGROUND AND OBJECTIVE

Continuous partial pressure of carbon dioxide (PCO₂ ) assessment is essential for the success of mechanical ventilation (MV). Non-invasive end-tidal PCO₂ (PetCO₂ ) and transcutaneous PCO₂ (PtcCO₂ ) measurements serve as alternatives to the gold standard arterial PCO₂ (PaCO₂ ) method, but their eligibility in critical care is unclear.

METHODS

The present study therefore performed methodological comparisons of PaCO₂ versus PetCO₂ and PtcCO₂ , respectively, in weaning patients receiving invasive MV via tracheal cannulas. PetCO₂ and PtcCO₂ were recorded continuously, while PaCO₂ was analysed at baseline, and after 30 and 60 min. Using the Bland-Altman analysis, a clinically acceptable range was defined as a mean difference of ±4 mm Hg between PaCO₂ and non-invasive strategies.

RESULTS

A total of 60 patients (COPD (n = 30) and non-COPD (n = 30)) completed the protocol. Mean PCO₂ values were 42.4 ± 8.6 mm Hg (PaCO₂ ), 36.5 ± 7.5 mm Hg (PetCO₂ ) and 41.7 ± 8.7 mm Hg (PtcCO₂ ). Mean differences between PtcCO₂ and PaCO₂ were -0.7 ± 3.6 mm Hg (95% CI: -1.6/0.3 mm Hg; 95% limits of agreement: -7.8 to 6.4 mm Hg), and between PetCO₂ and PaCO₂ -5.9 ± 5.3 mm Hg (95% CI: -7.2/-4.5 mm Hg; 95% limits of agreement: -16.2 to 4.5 mm Hg). Underestimation of PaCO₂ by PetCO₂ was most pronounced in COPD patients.

CONCLUSION

Our data therefore support PtcCO₂ as a suitable means for monitoring PCO₂ in patients undergoing invasive MV. This is in contrast to PetCO₂ , which clearly underestimated PaCO₂ , especially in patients with COPD.

[Pediatric hearing rehabilitation with the Baha® Attract implant system]

INTRODUCTION

Baha^® Attract is a new transcutaneous bone-conduction hearing aid, which is more preferable in childhood than the conventional percutaneous systems.

AIM

Our aim was to demonstrate the possibilities of application in childhood.

METHOD

Eight children have undergone surgeries (mean age of 13.2 ± 3.2 years; "posterosuperior" incision technique, 5 mm implants). The thickness of the skull bone was determined in 72 children (1-8 years old) at the recommended implant site, based on CT scans.

RESULTS

The average duration of surgeries was 30 minutes. There were no intra- and postoperative complications observed. Sound processors were fitted at the postoperative 4th week. Hearing measurements proved 51.58±11.22SD dBHL gain in warble tone thresholds, and 43.3 ± 16.02 SD dB in speech discrimination thresholds. The skull bone thickness was measured as 3.39 ± 1.05 SD mm.

CONCLUSION

The Baha Attract system is a new tool for hearing rehabilitation in pediatric population. Preoperative CT provides valuable knowledge about skull bone thickness. Orv. Hetil., 2017, 158(8), 304-310.

Improved kinetic model for the transcutaneous measurement of glomerular filtration rate in experimental animals

Transcutaneous measurement of the glomerular filtration rate (_tGFR) is now frequently used in animal studies. _tGFR allows consecutive measurements on the same animal, including multiple measurements on a daily basis, because no blood sampling is required. Here we derive and validate a novel kinetic model for the description of transcutaneously measured FITC-Sinistrin excretion kinetics. In contrast to standard 1- to 3-compartment models, our model covers the complete kinetic, including injection and distribution of the tracer in the plasma compartment. Because the model describes the complete progression of the measurement, it allows further refinement by correcting for baseline shifts observed occasionally during measurement. Possible reasons for shifts in the background signal include photo bleaching of the skin, autofluorescence, changes of physiological state of the animals during the measurements, or effects arising from the attachment of the measurement device. Using the new 3-compartment kinetic model with modulated baseline (_tGFR_3cp.b.m), _tGFR measurements in rats can reach comparable precision as those from GFR measurements assessed using a gold standard technique based on constant infusion of a tracer. Moreover, the variability of simultaneous (parallel) measurements, as well as repeated _tGFR measurements in the same animals, showed higher precision when _tGFR_3cp.b.m was compared with the 1-compartment _tGFR_1cp model.