A physical simulation to investigate the effect of anorectal angle on continence

This paper investigates the effect of the anorectal angle on continence using a physical model of the anatomical system. A method to fabricate, measure and control a physical model for the simulation of human faecal continence is presented. A model rectum and associated soft tissues, based on geometry from an anonymised CT dataset, was fabricated from silicone and showed behavioural realism to ex vivo tissue. Simulated stool matter with similar rheological properties to human faeces was developed. Instrumentation and control hardware are used to regulate injection of simulated stool into the system, define the anorectal angle and monitor stool flow rate, intra-rectal pressure and puborectalis force. A study was then conducted in which simulated stool was introduced to the system for anorectal angles between 80° and 100°. Results obtained from the study give insight into the effect of the anorectal angle on continence. Stool leakage was reduced as the angle became more acute. Conversely, intra-rectal pressure increased. These data demonstrate that the anorectal angle is fundamental in maintaining continence. This work is valuable in helping improve our understanding of the physical behaviour of the faecal system. It has particular relevance facilitating improved technologies to treat or manage severe faecal incontinence

A novel multiple electrode direct current technique for characterisation of tissue resistance during surgery

Electrochemical and electrical characteristics have the potential to help differentiate between, and assess the health state of, different biological tissues. However, measurement and interpretation of these characteristics is non-trivial. We propose a new DC galvanostatic sensing method for application to laparoscopic cancer surgery. This presents a simple and cost-effective measurement coupled with straightforward data interpretation. This paper describes the electrochemical and electrical theory underpinning the technique. Additionally, we describe a measurement system employing this technique and present an investigation into the feasibility of using it for measuring the resistance of different tissue types. Measurements were performed on ex vivo porcine liver, colon and rectum tissues. Outputs were consistent with theory and showed a significant difference between the resistance of the different tissue types, (one-way ANOVA, F(2, 28) = 1369, p < 0.01). These findings indicate that this novel technique may be viable as a low cost method for the discrimination and health assessment of tissues in clinical scenarios

Wearable devices for remote vital signs monitoring in the outpatient setting: an overview of the field

Early detection of physiological deterioration has been shown to improve patient outcomes. Due to recent improvements in technology, comprehensive outpatient vital signs monitoring is now possible. This is the first review to collate information on all wearable devices on the market for outpatient physiological monitoring. A scoping review was undertaken. The monitors reviewed were limited to those that can function in the outpatient setting with minimal restrictions on the patient’s normal lifestyle, while measuring any or all of the vital signs: heart rate, ECG, oxygen saturation, respiration rate, blood pressure and temperature. A total of 270 papers were included in the review. Thirty wearable monitors were examined: 6 patches, 3 clothing-based monitors, 4 chest straps, 2 upper arm bands and 15 wristbands. The monitoring of vital signs in the outpatient setting is a developing field with differing levels of evidence for each monitor. The most common clinical application was heart rate monitoring. Blood pressure and oxygen saturation measurements were the least common applications. There is a need for clinical validation studies in the outpatient setting to prove the potential of many of the monitors identified. Research in this area is in its infancy. Future research should look at aggregating the results of validity and reliability and patient outcome studies for each monitor and between different devices. This would provide a more holistic overview of the potential for the clinical use of each device

Systematic Review and Meta-analysis of Nonsteroidal Anti-inflammatory Drugs to Improve GI Recovery After Colorectal Surgery

BACKGROUND: The management of delayed GI recovery after surgery is an unmet challenge. Uncertainty over its pathophysiology has limited previous research, but recent evidence identifies intestinal inflammation and activation of µ-opioid receptors as key mechanisms. Nonsteroidal anti-inflammatory drugs are recommended by enhanced recovery protocols for their opioid-sparing and anti-inflammatory properties. OBJECTIVES: The purpose of this study was to explore the safety and efficacy of nonsteroidal anti-inflammatory drugs to improve GI recovery and to identify opportunities for future research. DATA SOURCES: MEDLINE, Embase, and the Cochrane Library were systematically searched from inception up to January 2018. STUDY SELECTION: Randomized controlled trials assessing the effect of nonsteroidal anti-inflammatory drugs on GI recovery after elective colorectal surgery were eligible. MAIN OUTCOME MEASURES: Postoperative GI recovery, including first passage of flatus, stool, and oral tolerance, were measured. RESULTS: Six randomized controlled trials involving 563 participants were identified. All of the participants received patient-controlled morphine and either nonsteroidal anti-inflammatory drug (nonselective: n = 4; cyclooxygenase-2 selective: n = 1; either: n = 1) or placebo. Patients receiving the active drug had faster return of flatus (mean difference: –17.73 h (95% CI, –21.26 to –14.19 h); p < 0.001), stool (–9.52 h (95% CI, –14.74 to –4.79 h); p < 0.001), and oral tolerance (–12.00 h (95% CI, –18.01 to –5.99 h); p < 0.001). Morphine consumption was reduced in the active groups of 4 studies (average reduction, 12.9–30.0 mg), and 1 study demonstrated significantly reduced measures of systemic inflammation. Nonsteroidal anti-inflammatory drugs were not associated with adverse events, but 1 study was temporarily suspended for safety. LIMITATIONS: The data presented are relatively outdated but represent the best available evidence. CONCLUSIONS: Nonsteroidal anti-inflammatory drugs may represent an effective and accessible intervention to improve GI recovery, but hesitancy over their use after colorectal surgery persists. Additional preclinical research to characterize their mechanisms of action, followed by well-designed clinical studies to test safety and patient-reported efficacy, should be considered

An in vivo analysis of safe laparoscopic grasping thresholds for colorectal surgery

Background Analysis of safe laparoscopic grasping thresholds for the colon has not been performed. This study aimed to analyse tissue damage thresholds when the colon is grasped laparoscopically, correlating histological changes to mechanical compressive forces. Methods An instrumented laparoscopic grasper was used to measure the forces applied to porcine colon, with data captured and plotted as a force–time (f–t) curve. Haematoxylin and eosin histochemistry of tissue subjected to 10, 20, 40, 50 and 70 N for 5, 30 and 60 s was performed, and the area of colonic circular and longitudinal muscle was compared in grasped and un-grasped regions. The area under the f–t curve was calculated as a measure of the accumulated force applied, known as the force–time product (FTP). Results FTP ranged from 55.7 to 3793 N.s. Significant differences were observed between the muscle area of the grasped and un-grasped regions in both longitudinal and circular muscle at 50 N and above for all grasping times. For the longitudinal muscle, significant differences were observed between grasped and un-grasped areas at 20 N force for 30 s (mean difference = 59 mm2, 95% CI 41–77 mm2, P = 0.04), 20 N force for 60 s (mean difference = 31 mm2, 95% CI 21.5–40.5 mm2, P = 0.006) and 40 N force for 30 s (mean difference 37 mm2, 95% CI 27–47 mm2, P = 0.006). Changes in histology correlated with mechanical forces applied to the longitudinal muscle at a FTP over 300 N s. Conclusions This study characterizes the grasping forces that result in histological changes to the colon and correlates these with a mechanical measurement of the applied force. The findings will contribute to the development of smart laparoscopic graspers with active constraints to prevent excessive grasping and tissue injury

A Review on the Scope of Photothermal Therapy–Based Nanomedicines in Preclinical Models of Colorectal Cancer

Oncologic thermal ablation involves the use of hyperthermic temperatures to damage and treat solid cancers. Thermal ablation is being investigated as a method of treatment in colorectal cancers and has the potential to complement conventional anticancer treatments in managing local recurrence and metastatic disease. Photothermal therapy utilizes photosensitive agents to generate local heat and induce thermal ablation. There is growing interest in developing nanotechnology platforms to deliver such photosensitive agents. An advantage of nanomedicines is their multifunctionality, with the capability to deliver combinations of chemotherapeutics and cancer-imaging agents. To date, there have been no clinical studies evaluating photothermal therapy–based nanomedicines in colorectal cancers. This review presents the current scope of preclinical studies, investigating nanomedicines that have been developed for delivering multimodal photothermal therapy to colorectal cancers, with an emphasis on potential clinical applications

Global academic response to COVID ‐19: Cross‐sectional study

This study explores the response to COVID‐19 from investigators, editors, and publishers and seeks to define challenges during the early stages of the pandemic. A cross‐sectional bibliometric review of COVID‐19 literature was undertaken between 1 November 2019 and 24 March 2020, along with a comparative review of Middle East respiratory syndrome (MERS) literature. Investigator responsiveness was assessed by measuring the volume and type of research published. Editorial responsiveness was assessed by measuring the submission‐to‐acceptance time and availability of original data. Publisher‐responsiveness was assessed by measuring the acceptance‐to‐publication time and the provision of open access. Three hundred and ninety‐eight of 2,835 COVID‐19 and 55 of 1,513 MERS search results were eligible. Most COVID‐19 studies were clinical reports (n = 242; 60.8%). The submission‐to‐acceptance [median: 5 days (IQR: 3–11) versus 71.5 days (38–106); P < .001] and acceptance‐to‐publication [median: 5 days (IQR: 2–8) versus 22.5 days (4–48·5‐; P < .001] times were strikingly shorter for COVID‐19. Almost all COVID‐19 (n = 396; 99.5%) and MERS (n = 55; 100%) studies were open‐access. Data sharing was infrequent, with original data available for 104 (26.1%) COVID‐19 and 10 (18.2%) MERS studies (P = .203). The early academic response was characterized by investigators aiming to define the disease. Studies were made rapidly and openly available. Only one‐in‐four were published alongside original data, which is a key target for improvement

The role of ABCG2 in modulating responses to anti-cancer photodynamic therapy

The ATP-binding cassette (ABC) superfamily G member 2 (ABCG2) transmembrane protein transporter is known for conferring resistance to treatment in cancers. Photodynamic therapy (PDT) is a promising anti-cancer method involving the use of light-activated photosensitisers to precisely induce oxidative stress and cell death in cancers. ABCG2 can efflux photosensitisers from out of cells, reducing the capacity of PDT and limiting the efficacy of treatment. Many studies have attempted to elucidate the relationship between the expression of ABCG2 in cancers, its effect on the cellular retention of photosensitisers and its impact on PDT. This review looks at the studies which investigate the effect of ABCG2 on a range of different photosensitisers in different pre-clinical models of cancer. This work also evaluates the approaches that are being investigated to address the role of ABCG2 in PDT with an outlook on potential clinical validation

Assessment of electrochemical properties of a biogalvanic system for tissue characterisation

Biogalvanic characterisation is a promising method for obtaining health-specific tissue information. However, there is a dearth of understanding in the literature regarding the underlying galvanic cell, electrode reactions and their controlling factors which limits the application of the technique. This work presents a parametric electrochemical investigation into a zinc-copper galvanic system using salt (NaCl) solution analogues at physiologically-relevant concentrations (1.71, 17.1 & 154. mM). The potential difference at open cell, closed cell maximum current and the internal resistance (based on published characterisation methods) were measured. Additionally, independent and relative polarisation scans of the electrodes were performed to improve understanding of the system.Our findings suggest that the prominent reaction at the cathode is that of oxygen-reduction, not hydrogen-evolution. Results indicate that cell potentials are influenced by the concentration of dissolved oxygen at low currents and maximum closed cell currents are limited by the rate of oxygen diffusion to the cathode. Characterised internal resistance values for the salt solutions did not correspond to theoretical values at the extremes of concentration (1.71 and 154. mM) due to electrode resistance and current limitation. Existing biogalvanic models do not consider these phenomena and should be improved to advance the technique and its practical application