Developing and validating an implantable suture tension sensor.

Introduction: Suture tension has a direct influence on the sutured tissue. For abdominal wall closure, suture tension should be optimal without causing tissue necrosis, which can result in surgical site infection or incisional hernia. The purpose of the present study is to evaluate a device that can measure suture tension in-situ and in real-time. Materials and methods: A cheap, commercially available analog-to-digital converter was used, in conjunction with a force sensing resistor. A sensor probe housing was designed and 3D-printed. In order to test the sensor, a mechanical, computer controlled human abdominal wall model called the AbdoMAN was used. Results: An implantable suture tension sensor was developed, keeping cost-effectiveness in mind. This sensor can translate tension in the suture into a downward force, applied to the force sensing resistor. The sensor's raw readout was characterized using a set of weights, from which a formula correlating the readout to a specific force, was derived. Preliminary validation was successfully performed using the AbdoMANmodel, which showed a progressive rise in suture tension when the intra-abdominal pressure was artificially increased over time. Conclusion: The implantable suture tension sensor appeared to be capable of recording real time changes in suture tension, and the. validation process of this sensor has been initiated. With the information from devices like this, a much better understanding of the issues at play in the development of incisional hernia can be gained.

Strength of small-bites abdominal wall closure using different suturing methods and materials in an experimental animal model.

PURPOSE: Using small instead of large bites for laparotomy closure results in lower incidence of incisional hernia, but no consensus exists on which suture material to use. This study aimed to compare five different closure strategies in a standardized experimental setting. METHODS: Fifty porcine abdominal walls were arranged into 5 groups: (A) running 2/0 polydioxanone; (B) interlocking 2/0 polydioxanone; (C) running size 0 barbed polydioxanone; (D) running size 0 barbed glycolic acid and trimethylene carbonate; (E) running size 0 suturable polypropylene mesh. The small-bites technique was used for linea alba closure in all. The abdominal walls were divided into a supra- and infra-umbilical half, resulting in 20 specimens per group that were pulled apart in a tensile testing machine. Maximum tensile force and types of suture failure were registered. RESULTS: The highest tensile force was measured when using barbed polydioxanone (334.8 N ± 157.0), but differences did not reach statistical significance. Infra-umbilical abdominal walls endured a significantly higher maximum tensile force compared to supra-umbilical (397 N vs 271 N, p < 0.001). Barbed glycolic acid and trimethylene carbonate failed significantly more often (25% vs 0%, p = 0.008). CONCLUSION: Based on tensile force, both interlocking and running suture techniques using polydioxanone, and running sutures using barbed polydioxanone or suturable mesh, seem to be suitable for abdominal wall closure. Tensile strength was significantly higher in infra-umbilical abdominal walls compared to supra-umbilical. Barbed glycolic acid and trimethylene carbonate should probably be discouraged for fascial closure, because of increased risk of suture failure.

Athletes treated for inguinal-related groin pain by endoscopic totally extraperitoneal (TEP) repair: long-term benefits of a prospective cohort.

PURPOSE: Inguinal-related groin pain (IRGP) in athletes is a multifactorial condition, posing a therapeutic challenge. If conservative treatment fails, totally extraperitoneal (TEP) repair is effective in pain relief. Because there are only few long-term follow-up results available, this study was designed to evaluate effectiveness of TEP repair in IRGP-patients years after the initial procedure. METHODS: Patients enrolled in the original, prospective cohort study (TEP-ID-study) were subjected to two telephone questionnaires. The TEP-ID-study demonstrated favorable outcomes after TEP repair for IRGP-patients after a median follow-up of 19 months. The questionnaires in the current study assessed different aspects, including, but not limited to pain, recurrence, new groin-related symptoms and physical functioning measured by the Copenhagen Hip and Groin Outcome Score (HAGOS). The primary outcome was pain during exercise on the numeric rating scale (NRS) at very long-term follow-up. RESULTS: Out of 32 male participants in the TEP-ID-study, 28 patients (88%) were available with a median follow-up of 83 months (range: 69-95). Seventy-five percent of athletes were pain free during exercise (p < 0.001). At 83 months follow-up, a median NRS of 0 was observed during exercise (IQR 0-2), which was significantly lower compared to earlier scores (p <0.01). Ten patients (36%) mentioned subjective recurrence of complaints, however, physical functioning improved on all HAGOS subscales (p <0.05). CONCLUSION: This study demonstrates the safety and effectivity of TEP repair in a prospective cohort of IRGP-athletes, for whom conservative treatment had failed, with a follow-up period of over 80 months.

Relationship between in feed drugs, antibiotics and organic enrichment in marine sediments at Canadian Atlantic salmon aquaculture sites.

The presence of in-feed anti-sea lice drugs and their relationship with organic enrichment is poorly understood in sediment surrounding salmon farms. Using data from an aquaculture monitoring program (2018-2020), we describe this relationship at ten sites in four Canadian provinces. Three anti-sea lice pesticides (lufenuron, teflubenzuron, emamectin benzoate and metabolite desmethyl emamectin benzoate), and one antibiotic (oxytetracycline) were detected. Concentrations were often below limits of quantification. Values are also lower than those reported in other aquaculture salmon-producing countries. Highest concentrations, along with organic enrichment, were observed ~200 m of cages with lower concentrations detected up to 1.5 km away. Most samples had at least two drugs present: 75.2 % (British Columbia), 91.4 % (Newfoundland), and 54.8 % (New Brunswick/Nova Scotia) highlighting the potential for cumulative effects. Emamectin benzoate and oxytetracycline were detected four and three years respectively after last known treatments, demonstrating the need for research on overall persistence of compounds.

Feasibility of a smartphone application for inguinal hernia care: a prospective pilot study.

The Inguinal Hernia Application (IHAPP) is designed to overcome current limitations of regular follow-up after inguinal hernia surgery. It has two goals: Minimizing unnecessary healthcare consumption by supplying patient information and facilitating registration of patient-reported outcome measures (PROMs) by offering simple questionnaires. In this study we evaluated the usability and validity of the app. Patients (≥18 years) scheduled for elective hernia repair were assessed for eligibility. Feasibility of the app was evaluated by measuring patient satisfaction about utilization. Validity (internal consistency and convergent validity) was tested by comparing answers in the app to the scores of the standardized EuraHS-Quality of Life instrument. Furthermore, test-retest reliability was analyzed correlating scores obtained at 6 weeks to outcomes after 44 days (6 weeks and 2 days). During a 3-month period, a total of 100 patients were included. Median age was 56 years and 98% were male. Most respondents (68%) valued the application as a supplementary tool to their treatment. The pre-operative information was reported as useful by 77% and the app was regarded user-friendly by 71%. Patient adherence was mediocre, 47% completed all questionnaires during follow-up. Reliability of the app was considered excellent (α > 0.90) and convergent validity was significant (p = 0.01). The same applies to test-retest reliability (p = 0.01). Our results demonstrate the IHAPP is a useful tool for reliable data registration and serves as patient information platform. However, further improvements are necessary to increase patient compliance in recording PROMs.

Determinants of label non-adherence to non-vitamin K oral anticoagulants in patients with newly diagnosed atrial fibrillation.

Aims: To evaluate the extent and determinants of off-label non-vitamin K oral anticoagulant (NOAC) dosing in newly diagnosed Dutch AF patients. Methods and results: In the DUTCH-AF registry, patients with newly diagnosed AF (<6 months) are prospectively enrolled. Label adherence to NOAC dosing was assessed using the European Medicines Agency labelling. Factors associated with off-label dosing were explored by multivariable logistic regression analyses. From July 2018 to November 2020, 4500 patients were registered. The mean age was 69.6 ± 10.5 years, and 41.5% were female. Of the 3252 patients in which NOAC label adherence could be assessed, underdosing and overdosing were observed in 4.2% and 2.4%, respectively. In 2916 (89.7%) patients with a full-dose NOAC recommendation, 4.6% were underdosed, with a similar distribution between NOACs. Independent determinants (with 95% confidence interval) were higher age [odds ratio (OR): 1.01 per year, 1.01-1.02], lower renal function (OR: 0.96 per ml/min/1.73 m2, 0.92-0.98), lower weight (OR: 0.98 per kg, 0.97-1.00), active malignancy (OR: 2.46, 1.19-5.09), anaemia (OR: 1.73, 1.08-2.76), and concomitant use of antiplatelets (OR: 4.93, 2.57-9.46). In the 336 (10.3%) patients with a reduced dose NOAC recommendation, 22.9% were overdosed, most often with rivaroxaban. Independent determinants were lower age (OR: 0.92 per year, 0.88-0.96) and lower renal function (OR: 0.98 per ml/min/1.73 m2, 0.96-1.00). Conclusion: In newly diagnosed Dutch AF patients, off-label dosing of NOACs was seen in only 6.6% of patients, most often underdosing. In this study, determinants of off-label dosing were age, renal function, weight, anaemia, active malignancy, and concomitant use of antiplatelets.

Significant factors influencing chronic postoperative inguinal pain: A conditional time-dependent observational cohort study.

BACKGROUND: Inguinal hernia (IH) repair is a common surgical procedure. Focus has shifted from recurrences to chronic postoperative inguinal pain (CPIP). To assess the natural course of CPIP and identify patient factors influencing the onset of CPIP, an observational registry-based study was performed. MATERIALS AND METHODS: Data prospectively collected from the Club-Hernie national database was retrieved from 2011 until 2021. Patients who underwent elective surgery for inguinal hernia were divided in an irrelevant pain group and relevant pain group. Relevant pain at one year and two years were compared with patients with irrelevant pain at all-time points (preoperatively, one month, one year and two years). Quality of life questions were compared between relevant pain at one year and two years. RESULTS: 4.016 patients were included in the analysis. Mean age was 65.1 years, 90.3% of patients was male. Factors correlated with CPIP onset were age, gender, ASA, recurrent surgery, surgical technique, nerve handling and fixation type. Relevant pain at one month was a greater risk for CPIP than preoperative pain (12.3% vs 3.6%). In the majority of patients (83.2%) CPIP was ameliorated at two years. Hernia related complaints differed significantly between CPIP at one year and two years. CONCLUSION: Postoperative pain after one month was a greater risk factor for CPIP development than preoperative pain. CPIP at one year seems to have a different pain etiology than CPIP at two years. Patient and surgical factors influence the onset of CPIP at one year, however the natural course of these complaints shows great decline at two years, largely without reinterventions.

Minimally Invasive Tensiometry: A New Modality for Per-Operative Measurement of Medialization and Tension During Laparoscopic Hernia Surgery.

Background: Newly developed techniques for minimally invasive abdominal wall reconstruction (AWR) for complex ventral hernia are continuously evolving. In order to achieve hernia defect closure, the aponeurotic edges of the hernia defect need to be approximated. Currently, surgeons have no way to objectively measure and quantify the traction required to approximate these edges. This study presents minimally invasive tensiometry (MINT), a novel technology for measuring fascial tension, as well as initial experiences and results using it. Methods: The MINT device was designed using rapid prototyping principles. It was designed as an add-on tool for any existing laparoscopic instrument, enabling objective assessment of abdominal wall tension by the use of a manually operated linear spring. Pre-clinical measurements of medialization at 10 and 20 N of tension during AWR were performed on fresh-frozen Post-Mortem Human Specimens (PMHS). Results: Three specimens were included, and a total number of 36 measurements of medialization at three different levels of the abdominal wall were performed under structured and similar circumstances. Median total medialization with 20 Newton (N) of applied tension was 25 mm (mm) cranially, 37.5 mm at the umbilicus and 27.5 mm at the caudal level. The highest rate of medialization was seen at the umbilical level (2.25 mm/N). Conclusion: MINT is a novel non-invasive technique, which allows surgeons to intraoperatively measure fascial tension when performing AWR. The MINT device is easy to use and reproduce. The next step is to start performing clinical measurements applying MINT during AWR.

Differences in biomechanics of abdominal wall closure with and without mesh reinforcement: A study in post mortem human specimens.

INTRODUCTION: Small bites for the closure of the abdominal wall after midline laparotomy result in significantly less incisional hernias in comparison with large bites. However, fundamental knowledge of underlying biomechanical phenomena remains sparse. The objective of this study was to develop a digital image correlation-based method to compare different suturing techniques in terms of strain pattern after closure of a midline laparotomy in a passive model just after the time of surgery. METHODS: A digital image correlation (DIC)-based method was used for the comparison of strain fields on the external surface of the myofascial abdominal wall (skin and subcutaneous fat removed) among six configurations, including an intact linea alba in five post mortem human specimens. The second configuration comprised primary mass closure with small bites (five mm between two consecutive stitches and five mm distance from the incision, 5x5 mm). The third configuration was primary mass closure with large bites (ten mm by ten mm, 10x10 mm). The fourth, fifth and sixth configuration comprised primary mass closure with large bites and the placement of a mesh in onlay position with two different overlaps and the use of glue to simulate the integration of the mesh within the soft tissue. RESULTS: No visible difference was observed between 5x5 and 10x10 mm closure configurations. However, the use of mesh as suture line reinforcement highlighted a stiffer behavior of the midline area for similar intra-abdominal pressure, which was amplified when a larger mesh overlap was used. However, the whole abdominal wall showed quite similar shapes for the various configurations, except for the configuration with mesh reinforcement and the use of glue. CONCLUSION: Mesh reinforcement incited lower opening tension profiles in the midline area of the abdominal wall. following closure of the linea alba in median laparotomy. The next step should be to investigate the impact of mesh location (e.g. retromuscular) and different time points after surgery.

Evaluation of a new suture material (Duramesh™) by measuring suture tension in small and large bites techniques for laparotomy closure in a porcine model.

PURPOSE: After closure of laparotomies, sutures may pull through tissue due to too high intra-abdominal pressure or suture tension, resulting in burst abdomen and incisional hernia. The objective of this study was to measure the suture tension in small and large bites with a new suture material. METHODS: Closure of the linea alba was performed with small bites (i.e., 5 mm between two consecutive stitches and 5 mm distance from the incision) and large bites (i.e., 10 mm × 10 mm) with Duramesh™ size 0 (2 mm) and PDS II 2-0 in 24 experiments on six porcine abdominal walls. The abdominal wall was fixated on an artificial computer-controlled insufflatable abdomen, known as the 'AbdoMan'. A custom-made suture tension sensor was placed in the middle of the incision. RESULTS: The suture tension was significantly lower with the small bites technique and Duramesh™ when compared with large bites (small bites 0.12 N (IQR 0.07-0.19) vs. large bites 0.57 N (IQR 0.23-0.92), p < 0.025). This significant difference was also found in favour of the small bites with PDS II 2-0 (p < 0.038). No macroscopic tissue failure was seen during or after the experiments. CONCLUSION: Closure of the abdominal wall with the small bites technique and Duramesh™ was more efficient in dividing suture tension across the incision when compared to large bites. However, suture tension compared to a conventional suture material was not significantly different, contradicting an advantage of the new suture material in the prevention of burst abdomen and incisional hernia during the acute, postoperative phase.

Perioperative surgical outcome of conventional and robot-assisted total laparoscopic hysterectomy.

BACKGROUND: To evaluate surgical outcome in a consecutive series of patients with conventional and robot assisted total laparoscopic hysterectomy. METHODS: A retrospective cohort study was performed among patients with benign and malignant indications for a laparoscopic hysterectomy. Main surgical outcomes were operation room time and skin to skin operating time, complications, conversions, rehospitalisation and reoperation, estimated blood loss and length of hospital stay. RESULTS: A total of 294 patients were evaluated: 123 in the conventional total laparoscopic hysterectomy (TLH) group and 171 in the robot TLH group. After correction for differences in basic demographics with a multivariate linear regression analysis, the skin to skin operating time was a significant 18 minutes shorter in robot assisted TLH compared to conventional TLH (robot assisted TLH 92m, conventional TLH 110m, p0.001). The presence or absence of previous abdominal surgery had a significant influence on the skin to skin operating time as did the body mass index and the weight of the uterus. Complications were not significantly different. The robot TLH group had significantly less blood loss and lower rehospitalisation and reoperation rates. CONCLUSIONS: This study compares conventional TLH with robot assisted TLH and shows shorter operating times, less blood loss and lower rehospitalisation and reoperation rates in the robot TLH group.

On the potential of personal networks for hospitals.

OBJECTIVE: Today, there are many barriers that prevent seamless electronic voice and data communication with remote content and services that the user wants to access at a certain time and place. This is especially the case in hospitals, where the communication needs are very complex and context dependent, and where strict privacy and safety conditions apply. Personal network (PN) technology is expected to enable the various private networks of a single person to communicate seamlessly with each other, hiding underlying network complexity from the user. We have analyzed the usefulness of PNs in hospitals. METHODS: We studied the use case of a medical emergency surgery, and built a demonstrator by integrating models of the specialists' personal area networks, home networks, office networks, and a hospital network into a single virtual network. We performed user studies in various hospitals, using a combination of individual context interviews, scenario and requirements verification, guided experimenting with the demonstrator and concluding workshops. RESULTS: We show that, in case of medical emergencies, PNs can provide a means to enlist remote assistance from peers wherever they are in the world at a particular moment. It can also ease the communication between the operating theatre and the outside world, e.g. for educational purposes.

Personal networks enabling remote assistance for medical emergency teams.

Personal Networks provide the technology that is needed to interconnect the various private networks of a single user (home network, car network, office network, Personal Area Network, and others) seamlessly, at any time and at any place. This can be useful in many business sectors. In case of medical emergencies, it can provide a means to enlist remote assistance from peers wherever they are in the world at that particular moment. To illustrate this, we have analyzed the use case of a medical emergency surgery and have built a demonstrator.

Patient satisfaction with occupational health physicians, development of a questionnaire.

AIMS: To develop a questionnaire that measures specific aspects of patient satisfaction with occupational health physicians. METHODS: General patient satisfaction questionnaires, a literature survey, and interviews with patients were used. An initial questionnaire was distributed among sick listed patients (n = 432) of occupational physicians (n = 90) from different occupational health services. To reduce items and to develop scales exploratory factor analysis and reliability analysis was used. A linear regression model was used to predict satisfaction ratings from the scales of the questionnaire. RESULTS: Questions about independence of the occupational physician were difficult to ask unambiguously. The factor analysis revealed five relevant factors which were named "being taken seriously as a patient", "attitude towards occupational health services", "trust and confidentiality", "expectations", and "comfort and access". All scales could be reduced to a maximum of five items without reducing the scale reliability too much. In the regression analysis, 71% of the variance of satisfaction ratings was explained by the first four scales and most by the first scale. "Comfort and access" did not contribute significantly to the model. CONCLUSIONS: A short questionnaire was developed to measure different aspects of patient satisfaction specific for occupational health. Whether the questionnaire can effectively lead to quality improvement in occupational health services should be investigated.

Locating liquid and gas interfaces behind a steel hull: a neutron backscatter tool in action.

Monte Carlo simulations were performed to prove that a neutron backscatter tool can detect liquid (hydrocarbon or water) and gas levels behind steel casings, even when used under water. Consequently such a tool can be applied to the detection of fluid levels in wrecked vessels, which is important for environmentally safe retrieval of oil in these vessels. These simulations enable the efficient optimisation of the experimental conditions, without having to resort to expensive mock-ups.

Pravastatin in acute ischaemic syndromes: results of a randomised placebo-controlled trial.

Therapy with individual 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has been shown conclusively to diminish coronary event rates and mortality in both primary and secondary prevention. To date, scant attention has been paid to whether initiation of such regimens in the hospital phase of acute coronary syndromes might confer cardioprotective benefits. The purpose of this study was to determine the safety and tolerability of early initiation of statin therapy in patients with acute coronary syndromes. In this randomised, double-blind, three-month, pilot study, 100 patients with acute myocardial infarction or unstable angina and low-density lipoprotein cholesterol > 3.5 mmol/l were randomly assigned to pravastatin 40 mg daily or placebo initiated within 48 hours of hospital admission. Pravastatin proved safe and well tolerated in these patients, who were well matched at baseline. No statistically significant differences in death, MI and drug-related adverse events were observed in the pravastatin group compared with control subjects. This pilot study shows that therapy with pravastatin early after an acute coronary event is safe and well tolerated. Larger, long-term studies are needed to confirm these findings.

A comparison of the efficacy and tolerability of titrate-to-goal regimens of simvastatin and fluvastatin: a randomized, double-blind study in adult patients at moderate to high risk for cardiovascular disease.

BACKGROUND: Use of cholesterol-lowering regimens has been shown to reduce the risk of coronary heart disease (CHD), both in primary and secondary prevention. However, there have been few studies of the relative benefits and risks of the various cholesterol-lowering agents in patient groups with specific risk factors for CHD. OBJECTIVE: The primary goal of this study was to compare the proportions of adult patients with primary hypercholesterolemia and a moderate to high risk for CHD achieving National Cholesterol Education Program low-density lipoprotein cholesterol (LDL-C) goals with titrate-to-goal regimens of simvastatin and fluvastatin. METHODS: This was a multicenter, prospective, randomized, double-blind, parallel-group study enrolling adult patients with type IIa or IIb primary hypercholesterolemia, LDL-C levels <6.0 mmol/L (<232.0 mg/dL), and triglyceride levels <4.5 mmol/L (<398.6 mg/dL), and either CHD or other atherosclerotic disease (the CHD, or high-risk, group), or multiple risk factors for CHD (the MRF, or moderate-risk, group). After a 6-week washout period, patients were randomized to 18 weeks of treatment at an initial dosage of simvastatin 10 mg once daily or fluvastatin 20 mg once daily. At 6- and 12-week titration visits, the dosage in patients who had not acheived the LDL-C goal could be increased to simvastatin 20 mg once daily and then 40 mg once daily, or to fluvastatin 40 mg once daily and then 40 mg twice daily. Lipid profiles were obtained at each titration visit and at the end of treatment. In addition to the comparison between treatments, secondary comparisons were made between the CHD and MRF subgroups within each treatment group. Statistical significance was assessed using analysis of variance. RESULTS: A total of 478 patients were enrolled, 237 in the simvastatin group and 241 in the fluvastatin group. There were no significant between-group differences in patients' characteristics at baseline. At the end of the study, 60.8% (135/222) of patients in the simvastatin group had reached target LDL-C goals, compared with 35.1% (76/216) in the fluvastatin group (P < 0.001). In the simvastatin CHD and MRF subgroups, 49% and 73%, respectively, reached the LDL-C target, compared with 19% and 50% in the corresponding fluvastatin subgroups (P < 0.001). The proportion of patients requiring titration was higher in the fluvastatin group than in the simvastatin group (87.1% and 64.1%, respectively; P = 0.001). The incidence of adverse events was similar between groups. CONCLUSION: In this study, more patients with primary hypercholesterolemia and CHD or multiple risk factors for CHD reached LDL-C goals with simvastatin treatment and required less titration than those who received fluvastatin treatment.

Differential induction of systemic resistance in Arabidopsis by biocontrol bacteria.

Selected nonpathogenic, root-colonizing bacteria are able to elicit induced systemic resistance (ISR) in plants. To elucidate the molecular mechanisms underlying this type of systemic resistance, an Arabidopsis-based model system was developed in which Pseudomonas syringae pv. tomato and Fusarium oxysporum f. sp. raphani were used as challenging pathogens. In Arabidopsis thaliana ecotypes Columbia and Landsberg erecta, colonization of the rhizosphere by P. fluorescens strain WCS417r induced systemic resistance against both pathogens. In contrast, ecotype RLD did not respond to WCS417r treatment, whereas all three ecotypes expressed systemic acquired resistance upon treatment with salicylic acid (SA). P. fluorescens strain WCS374r, previously shown to induce ISR in radish, did not elicit ISR in Arabidopsis. The opposite was found for P. putida strain WCS358r, which induced ISR in Arabidopsis but not in radish. These results demonstrate that rhizosphere pseudomonads are differentially active in eliciting ISR in related plant species. The outer membrane lipopolysaccharide (LPS) of WCS417r is the main ISR-inducing determinant in radish and carnation, and LPS-containing cell walls also elicit ISR in Arabidopsis. However, mutant WCS417rOA-, lacking the O-antigenic side chain of the LPS, induced levels of protection similar to those induced by wild-type WCS417r. This indicates that ISR-inducing bacteria produce more than a single factor that trigger ISR in Arabidopsis. Furthermore, WCS417r and WCS358r induced protection in both wild-type Arabidopsis and SA-nonaccumulating NahG plants without activating pathogenesis-related gene expression. This suggests that elicitation of an SA-independent signaling pathway is a characteristic feature of ISR-inducing biocontrol bacteria.