Bedform characteristics and biofilm community development interact to modify hyporheic exchange

The physical and biological attributes of riverine ecosystems interact in a complex manner which can affect the hydrodynamic behaviour of the system. This can alter the mixing characteristics of a river at the sediment-water interface. Research on hyporheic exchange has increased in recent years driven by a greater appreciation for the importance of this dynamic ecotone in connecting and regulating river systems. An understanding of process-based interactions driving hyporheic exchange is still limited, specifically the feedbacks between the physical and biological controlling factors. The interplay between bed morphology and sediment size on biofilm community development and the impact on hyporheic exchange mechanisms, was experimentally considered. Purpose built recirculating flume systems were constructed and three profiles of bedform investigated: i) flat, ii) undulating λ = 1 m ii) undulating λ = 0.2 m, across two different sized sediments (0.5 mm and 5 mm). The influence of biofilm growth and bedform interaction on hyporheic exchange was explored, over time, using discrete repeat injections of fluorescent dye into the flumes. Hyporheic exchange rates were greatest in systems with larger sediment sizes (5 mm) and with more bedforms (undulating λ = 0.2). Sediment size was a dominant control in governing biofilm growth and hyporheic exchange in systems with limited bedform. In systems where bedform was prevalent, sediment size and biofilm appeared to no longer be a control on exchange due to the physical influence of advective pumping. Here, exchange rates within these environments were more consistent overtime, despite greater microbial growth. As such, bedform has the potential to overcome the rate limiting effects of biotic factors on hyporheic exchange and sediment size on microbial penetration. This has implications for pollutant and nutrient penetration; bedforms increase hydrological connectivity, generating the opportunity to support microbial communities at depth and as such, improve the self-purification ability of river systems

Twelve-year outcomes of watchful waiting versus surgery of mildly symptomatic or asymptomatic inguinal hernia in men aged 50 years and older:a randomised controlled trial

Background: Inguinal hernia belongs to the most common surgical pathology worldwide. Approximately, one third is asymptomatic. The value of watchful waiting (WW) in patients with asymptomatic or mildly symptomatic inguinal hernia has been established in a few randomised controlled trials (RCTs). The aim of this study was to assess long-term outcomes of a RCT comparing WW and elective surgery.Methods: In the original study, men aged ≥50 years with an asymptomatic or mildly symptomatic inguinal hernia were randomly assigned to WW or elective repair. In the present study, the primary outcome was the 12-year crossover rate to surgery, secondary outcomes were time-to-crossover, patient regret, pain, quality of life and incarceration. Dutch Trial Registry: NTR629. Findings: Out of 496 originally analysed patients, 488 (98.4%) were evaluable for chart review (WW: n = 258, surgery: n = 230), and 200 (41.0%) for telephone contact (WW: n = 106, surgery: n = 94) between November 2021 and March 2022 with a median 12 years follow-up (IQR 9–14). After 12 years, the estimated cumulative crossover rate to surgery was 64.2%, which was higher in mildly symptomatic than in asymptomatic patients (71.7% versus 60.4%, HR 1.451, 95% CI: 1.064–1.979). Time-to-crossover was longer in asymptomatic patients (50% after 6.0 years versus 2.0 years, p = 0.019). Patient regret was higher in the WW group (37.7 versus 18.0%, p = 0.002), as well as pain/discomfort (p = 0.031). Quality of life did not differ (p = 0.737). In the WW group, incarceration occurred in 10/255 patients (3.9%). Interpretation: During 12-year follow-up, most WW patients crossed over to surgery, significantly earlier with mildly symptomatic hernia. Considering the relatively low incarceration rate, WW might still be an option in asymptomatic patients with a clear preference and being well-informed about pros and cons.</p

Twelve-year outcomes of watchful waiting versus surgery of mildly symptomatic or asymptomatic inguinal hernia in men aged 50 years and older:a randomised controlled trial

Background: Inguinal hernia belongs to the most common surgical pathology worldwide. Approximately, one third is asymptomatic. The value of watchful waiting (WW) in patients with asymptomatic or mildly symptomatic inguinal hernia has been established in a few randomised controlled trials (RCTs). The aim of this study was to assess long-term outcomes of a RCT comparing WW and elective surgery. Methods: In the original study, men aged ≥50 years with an asymptomatic or mildly symptomatic inguinal hernia were randomly assigned to WW or elective repair. In the present study, the primary outcome was the 12-year crossover rate to surgery, secondary outcomes were time-to-crossover, patient regret, pain, quality of life and incarceration. Dutch Trial Registry: NTR629. Findings: Out of 496 originally analysed patients, 488 (98.4%) were evaluable for chart review (WW: n = 258, surgery: n = 230), and 200 (41.0%) for telephone contact (WW: n = 106, surgery: n = 94) between November 2021 and March 2022 with a median 12 years follow-up (IQR 9–14). After 12 years, the estimated cumulative crossover rate to surgery was 64.2%, which was higher in mildly symptomatic than in asymptomatic patients (71.7% versus 60.4%, HR 1.451, 95% CI: 1.064–1.979). Time-to-crossover was longer in asymptomatic patients (50% after 6.0 years versus 2.0 years, p = 0.019). Patient regret was higher in the WW group (37.7 versus 18.0%, p = 0.002), as well as pain/discomfort (p = 0.031). Quality of life did not differ (p = 0.737). In the WW group, incarceration occurred in 10/255 patients (3.9%). Interpretation: During 12-year follow-up, most WW patients crossed over to surgery, significantly earlier with mildly symptomatic hernia. Considering the relatively low incarceration rate, WW might still be an option in asymptomatic patients with a clear preference and being well-informed about pros and cons. Funding: The initial trial was funded by the Netherlands Organisation for Health Research and Development (ZonMW). This long-term study did not receive funding.</p

Risks to human and animal health related to the presence of deoxynivalenol and its acetylated and modified forms in food and feed

Peer reviewedPublisher PD

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

The incidence of extraction site incisional hernia after minimally invasive colorectal surgery: a systematic review and meta-analysis

Aim: Minimally invasive colorectal surgery reduces surgical trauma with better preservation of abdominal wall integrity, but the extraction site is still at risk of incisional hernia (IH). The aim of this study was to determine pooled incidence of IH for each type of extraction site and to compare rates of IH after midline, nonmidline and Pfannenstiel extraction. Method: A systematic review and meta-analysis was conducted using the PRISMA guidelines. Single-armed and multiple-armed cohort studies and randomized controlled trials regarding minimally invasive colorectal surgery were searched from five databases. Outcomes were pooled and compared with random-effects, inverse-variance models. Risk of bias within the studies was assessed using the Cochrane ROBINS-I and RoB 2 tool. Results: Thirty six studies were included, with a total 11,788 patients. The pooled extraction site IH rate was 16.0% for midline (n = 4081), 9.3% for umbilical (n = 2425), 5.2% for transverse (n = 3213), 9.4% for paramedian (n = 134) and 2.1% for Pfannenstiel (n = 1449). Nonmidline extraction (transverse and paramedian) showed significantly lower odds ratios (ORs) for IH when compared with midline extraction (including umbilical). Pfannenstiel extraction resulted in a significantly lower OR for IH compared with midline [OR 0.12 (0.50–0.30)], transverse [OR 0.25 (0.13–0.50)] and umbilical (OR 0.072 [0.033–0.16]) extraction sites. The risks of surgical site infection, seroma/haematoma or wound dehiscence were not significantly different in any of the analyses. Conclusion: Pfannenstiel extraction is the preferred method in minimally invasive colorectal surgery. In cases where Pfannenstiel extraction is not possible, surgeons should avoid specimen extraction in the midline

The incidence of extraction site incisional hernia after minimally invasive colorectal surgery: a systematic review and meta-analysis

Aim: Minimally invasive colorectal surgery reduces surgical trauma with better preservation of abdominal wall integrity, but the extraction site is still at risk of incisional hernia (IH). The aim of this study was to determine pooled incidence of IH for each type of extraction site and to compare rates of IH after midline, nonmidline and Pfannenstiel extraction. Method: A systematic review and meta-analysis was conducted using the PRISMA guidelines. Single-armed and multiple-armed cohort studies and randomized controlled trials regarding minimally invasive colorectal surgery were searched from five databases. Outcomes were pooled and compared with random-effects, inverse-variance models. Risk of bias within the studies was assessed using the Cochrane ROBINS-I and RoB 2 tool. Results: Thirty six studies were included, with a total 11,788 patients. The pooled extraction site IH rate was 16.0% for midline (n = 4081), 9.3% for umbilical (n = 2425), 5.2% for transverse (n = 3213), 9.4% for paramedian (n = 134) and 2.1% for Pfannenstiel (n = 1449). Nonmidline extraction (transverse and paramedian) showed significantly lower odds ratios (ORs) for IH when compared with midline extraction (including umbilical). Pfannenstiel extraction resulted in a significantly lower OR for IH compared with midline [OR 0.12 (0.50–0.30)], transverse [OR 0.25 (0.13–0.50)] and umbilical (OR 0.072 [0.033–0.16]) extraction sites. The risks of surgical site infection, seroma/haematoma or wound dehiscence were not significantly different in any of the analyses. Conclusion: Pfannenstiel extraction is the preferred method in minimally invasive colorectal surgery. In cases where Pfannenstiel extraction is not possible, surgeons should avoid specimen extraction in the midline