A systematic review of viral transmission risk to healthcare staff comparing laparoscopic and open surgery.

BACKGROUND: Throughout the United Kingdom, there have been sweeping changes to the practice of medicine due to the COVID-19 pandemic. For the surgical speciality, there have been changes to both elective and emergency practice. Concern regarding potential aerosolisation during invasive procedures have been raised - including the use of pneumoperitoneum to facilitate laparoscopy. The aim of this study is to systematically review the data available to date regarding the potential risk posed to theatre staff by laparoscopy. METHOD: A systematic review and meta-analysis was carried out in accordance with PRISMA guidelines. Only publications in peer-reviewed journals were considered. PubMed, Ovid Embase, SCOPUS, and Cochrane Library were searched. The search period was between 1st January 1980 and 27th April 2020. Bias was assessed using the ROBINS-I tool. RESULTS: 4209 records were identified, resulting in 9 unique studies being selected. The included studies examined viral DNA aerosoliation generated by electrosurgery and CO2 laser ablation, with one study examining viral DNA aerosolisation following laparoscopy. Each of these demonstrated that viral DNA (Hepatitis B Virus and Human Papilloma Virus) was detectable in the surgical smoke plume. CONCLUSION: The data and analysis reported in this study reflect the most up-to-date evidence available for the surgeon to assess risk towards healthcare staff. It was constrained by heterogeneity of reporting for several outcomes and lack of comparable studies. There is currently insufficient data to recommend open or a minimally invasive surgical approach with regard to theatre team safety in the COVID-19 era.

Meta-analysis of patient-reported outcomes after laparoscopic versus open inguinal hernia repair.

BACKGROUND: Inguinal hernia repair is a common low-risk intervention. Patient-reported outcomes (PROs) are being used increasingly as primary outcomes in clinical trials. The aim of this study was to review and meta-analyse the PROs in RCTs comparing laparoscopic versus open inguinal hernia repair techniques in adult patients. METHODS: A systematic review and meta-analysis was carried out in accordance with PRISMA guidelines. Only RCTs in peer-reviewed journals were considered. PubMed, Ovid Embase, Scopus and the Cochrane Library were searched. In addition, four trial registries were searched. The search interval was between 1 January 1998 and 1 May 2018. Identified publications were reviewed independently by two authors. The review was registered in the PROSPERO database (CRD42018099552). Bias was assessed using the Cochrane Collaboration risk-of-bias tool. RESULTS: Some 7192 records were identified, from which 58 unique RCTs were selected. Laparoscopic hernia repair was associated with significantly less postoperative pain in three intervals: from 2 weeks to within 6 months after surgery (risk ratio (RR) 0·74, 95 per cent c.i. 0·62 to 0·88), 6 months to 1 year (RR 0·74, 0·59 to 0·93) and 1 year onwards (RR 0·62, 0·47 to 0·82). Paraesthesia (RR 0·27, 0·18 to 0·40) and patient-reported satisfaction (RR 0·91, 0·85 to 0·98) were also significantly better in the laparoscopic repair group. CONCLUSION: The data and analysis reported in this study reflect the most up-to-date evidence available for the surgeon to counsel patients. It was constrained by heterogeneity of reporting for several outcomes.

Distributed natural gas venting offshore along the Cascadia margin.

Widespread gas venting along the Cascadia margin is investigated from acoustic water column data and reveals a nonuniform regional distribution of over 1100 mapped acoustic flares. The highest number of flares occurs on the shelf, and the highest flare density is seen around the nutrition-rich outflow of the Juan de Fuca Strait. We determine ∼430 flow-rates at ∼340 individual flare locations along the margin with instantaneous in situ values ranging from ∼6 mL min-1 to ∼18 L min-1. Applying a tidal-modulation model, a depth-dependent methane density, and extrapolating these results across the margin using two normalization techniques yields a combined average in situ flow-rate of ∼88 × 106 kg y-1. The average methane flux-rate for the Cascadia margin is thus estimated to ∼0.9 g y-1m-2. Combined uncertainties result in a range of these values between 4.5 and 1800% of the estimated mean values.

Increase in antibiotic prescriptions in out-of-hours primary care in contrast to in-hours primary care prescriptions: service evaluation in a population of 600 000 patients.

OBJECTIVES: The objective of this study was to describe the frequency and nature of antibiotic prescriptions issued by a primary care out-of-hours (OOH) service and compare time trends in prescriptions between OOH and in-hours primary care. METHODS: We performed a retrospective audit of 496 931 patient contacts with the Oxfordshire OOH primary care service. Comparison of time trends in antibiotic prescriptions from OOH primary care and in-hours primary care for the same population was made using multiple linear regression models fitted to the monthly data for OOH prescriptions, OOH contacts and in-hours prescriptions between September 2010 and August 2014. RESULTS: Compared with the overall population contacting the OOH service, younger age, female sex and patients who were less deprived were independently correlated with an increased chance of a contact resulting in prescription of antibiotics. The majority of antibiotics were prescribed to patients contacting the service at weekends. Despite a reduction in patient contacts with the OOH service [an estimated decrease of 486.5 monthly contacts each year (95% CI -676.3 to -296.8), 5.0% of the average monthly contacts], antibiotic prescriptions from this service rose during the study period [increase of 37.1 monthly prescriptions each year (95% CI 10.6-63.7), 2.5% of the average monthly prescriptions]. A matching increase was not seen for in-hours antibiotic prescriptions; the difference between the year trends was significant (Z test, P = 0.002). CONCLUSIONS: We have demonstrated trends in prescribing that could represent a partial displacement of antibiotic prescribing from in-hours to OOH primary care. The possibility that the trends we describe are evident nationally should be explored.

Quantification of tumour and circulating vascular endothelial growth factor (VEGF) in patients with oesophagogastric cancer: a long-term follow-up study.

Vascular endothelial growth factor (VEGF) is an angiogenic cytokine that regulates tumour angiogenesis. The prognostic significance of VEGF expression remains incompletely investigated for patients with oesophagogastric cancer. This study assesses the significance of tumour VEGF (T-VEGF) and circulating VEGF (C-VEGF) expression in a 10-year follow-up of patients with oesophagogastric cancer. Patients undergoing surgical resection were prospectively recruited between February 1999 and August 2000. Circulating VEGF, derived both from plasma (P-VEGF) and serum (S-VEGF), and T-VEGF were assessed using a commercial enzyme-linked immunosorbent assay (ELISA). As platelet count may contribute to C-VEGF, pre-operative platelet levels were also recorded to exclude a confounding effect. Patients were followed up over a 10-year period using the Northern Ireland Cancer Registry. Sixty-one patients were recruited (men=45) with a mean age of 65.7 years. The 10-year survival was 19.7% (n=12) with a median follow-up of 808 days (inter-quartile range [IQR]: 349.5-2358.5). Union for International Cancer Control (UICC) tumour staging was Stage I=9 (14.8%), Stage II=15 (24.6%), Stage III=33 (54.1%) and Stage IV=4 (6.6%). The only significant relationship between clinicopathological features and the study variables was for S-VEGF, which was elevated in patients with advanced T-stage (P = 0.05). Circulating VEGF did not correlate with platelet count. Although a trend towards decreased survival was observed for patients who had positive lymph nodes (P = 0.08) and advanced UICC stage (P = 0.09) on univariate analysis, only lymphovascular invasion significantly predicted poor prognosis in this cohort (P = 0.05). Therefore, ELISA quantification of circulatory or tumour VEGF does not appear to be a significant predictor of mortality in patients with oesophagogastric cancer.

Bone marrow micrometastases in esophageal carcinoma: a 10-year follow-up study.

Detection of bone marrow micrometastases (BMMs) in patients with esophageal carcinoma may indicate a metastatic phenotype. We assessed if the presence of BMMs had adverse prognostic significance in a 10-year follow-up study. Patients undergoing surgery for esophageal cancer were prospectively recruited between February 1999 and August 2000. Bone marrow aspirates were obtained from the iliac crest of patients under general anesthesia at the time of surgery. Immunocytochemical analysis using anticytokeratin antibodies CAM 5.2 and AE1/AE3 was undertaken to determine the presence of BMMs. Union International Contre le Cancer staging was recorded for all patients. Patient follow-up was completed over a 10-year period through analysis of the Northern Ireland Cancer Registry. Forty-two patients (male = 35) were included, with a mean age of 67.2 years (range 39-83). BMMs were detected in 19 patients (45.2%). International Contre le Cancer tumor staging was stage I = 6, stage II = 10, stage III = 24, and stage IV = 2. BMMs were associated with lymphovascular invasion (P= 0.02) and advanced T stage (P= 0.02). Overall, 10-year survival was 21.4% (n= 9), with a median follow-up of 877.5 days (interquartile range 391.5-2546.3). There was no statistically significant difference between the survival of patients with or without BMMs (1451.4 vs. 1431.6 days, P= 0.99). Univariate analysis demonstrated a trend toward decreased survival for patients with positive lymph nodes (P= 0.07), an increased T stage (P= 0.06), and lymphovascular invasion (P= 0.07). Multivariate analysis demonstrated that none of the variables were significant predictors of mortality. Although the presence of BMMs correlates with recognized adverse tumor characteristics in patients with esophageal cancer, micrometastases detected in the bone marrow at time of surgery does not influence long-term survival.

Bone formation in a carbonate-substituted hydroxyapatite implant is inhibited by zoledronate: the importance of bioresorption to osteoconduction.

Carbonate-substituted hydroxyapatite (CHA) is more osteoconductive and more resorbable than hydroxyapatite (HA), but the underlying mode of its action is unclear. We hypothesised that increased resorption of the ceramic by osteoclasts might subsequently upregulate osteoblasts by a coupling mechanism, and sought to test this in a large animal model. Defects were created in both the lateral femoral condyles of 12 adult sheep. Six were implanted with CHA granules bilaterally, and six with HA. Six of the animals in each group received the bisphosphonate zoledronate (0.05 mg/kg), which inhibits the function of osteoclasts, intra-operatively. After six weeks bony ingrowth was greater in the CHA implants than in HA, but not in the animals given zoledronate. Functional osteoclasts are necessary for the enhanced osteoconduction seen in CHA compared with HA.

Differentiation of mononuclear precursors into osteoclasts on the surface of Si-substituted hydroxyapatite.

In healthy bone, resorption and synthesis are in perfect coordination. In previous studies we demonstrated that the incorporation of silicon into the hydroxyapatite (HA) lattice enhances the proliferation and differentiation of human osteoblasts. Therefore, the aim of this study was to demonstrate the effect of silicon-substituted HA (0.8 and 1.5 wt % Si-HA) on the differentiation of mononuclear cells into osteoclasts, using two different starting cultures, peripheral blood mononuclear cells (PBMC) and monocytes expressing the CD14 antigen (CD14+). Through this study, it was possible to demonstrate that Si-HA allows the differentiation of mononuclear cells into mature osteoclasts, independent of the starting culture, PBMC or CD14+. Most of the cells on the surface of the materials expressed osteoclastic markers: actin rings, several nuclei, positivity for tartrate-resistant acid phosphatase (TRAP), and vitronectin receptor. In the presence of osteoclasts, a higher release of calcium and phosphate into the medium from the 1.5 wt % Si-HA substrate was detected when compared to the HA substrate; therefore, these results indicate higher osteoclastic resorptive activity on the 1.5 wt % Si-HA surface. Si-HA can be resorbed by cellular mechanisms and have a stimulatory effect on osteoclasts, although the underlying mechanism is still poorly understood.

Decreased stability of methane hydrates in marine sediments owing to phase-boundary roughness.

Below water depths of about 300 metres, pressure and temperature conditions cause methane to form ice-like crystals of methane hydrate. Marine deposits of methane hydrate are estimated to be large, amassing about 10,000 gigatonnes of carbon, and are thought to be important to global change and seafloor stability, as well as representing a potentially exploitable energy resource. The extent of these deposits can usually be inferred from seismic imaging, in which the base of the methane hydrate stability zone is frequently identifiable as a smooth reflector that runs parallel to the sea floor. Here, using high-resolution seismic sections of seafloor sediments in the Cascadia margin off the coast of Vancouver Island, Canada, we observe lateral variations in the base of the hydrate stability zone, including gas-rich vertical intrusions into the hydrate stability zone. We suggest that these vertical intrusions are associated with upward flow of warmer fluids. Therefore, where seafloor fluid expulsion and methane hydrate deposits coincide, the base of the hydrate stability zone might exhibit significant roughness and increased surface area. Increased area implies that significantly more methane hydrate lies close to being unstable and hence closer to dissociation in the event of a lowering of pressure due to sea-level fall.

Vascular endothelial growth factor levels in serum and plasma following esophageal cancer resection--relationship to platelet count.

In patients with cancer circulating vascular endothelial growth factor (VEGF) may be tumor-derived and have prognostic significance. Activated platelets may also be a source of VEGF, releasing it in serum formation. Debate exists as to whether serum or plasma VEGF (S-VEGF, P-VEGF) is the most appropriate surrogate marker of tumor angiogenesis. As healing wounds produce VEGF that can spill over into the circulation, we aimed to investigate the potential confounding effects of cancer surgery on both perioperative S-VEGF and P-VEGF levels and to evaluate their relationship with platelet count. S-VEGF, P-VEGF and platelet counts were measured in 23 patients undergoing esophageal cancer resection. Samples were taken preoperatively and six weeks following surgery. Seven patients were also sampled on postoperative days 1, 5 and 10. VEGF was assayed using a commercial enzyme linked immunosorbent assay. S-VEGF and P-VEGF both rose after surgery (S-VEGF; day 5: 1017 [446-1224] pg/mL and day 10: 1231 [626-2046] pg/mL versus pre-op: 329 [189-599] pg/mL. P-VEGF; day 1: 55 [46-104] pg/mL and day 10: 58 [20-154] pg/mL versus pre-op: 23 [13-46] pg/mL), falling towards preoperative levels by six weeks. Platelet count correlated with S-VEGF (rho=0.281; p<0.05, Spearman's rank) and P-VEGF (rho=0.330; p<0.01, Spearman's rank). Platelets may contribute to VEGF levels in plasma as well as in serum. The effects of surgery on S-VEGF or P-VEGF levels are mainly transient. Care must be exercised when interpreting circulating VEGF levels in the early postoperative period.

Diagnosing slipped upper femoral epiphysis.

The key to diagnosing slipped upper femoral epiphysis is a high index of suspicion. This article summarizes the important clinical features of the disorder and points out the pitfalls in diagnosis.

Gastrointestinal infections presenting in general practice in Scotland.

OBJECTIVES: To determine the incidence of gastrointestinal infections (GII) presenting to general practitioners (GPs) in Scotland, To record the demographic and clinical characteristics of persons presenting with GII, To determine the proportion and characteristics of GII investigated in the laboratory, To report on the microbiological aetiology of the GII. DESIGN: Descriptive epidemiological study. SETTING: Twenty three general practices in Scotland serving a total practice population of 152,471. SUBJECTS: Patients consulting their GPs for a 'gastrointestinal infection' which met the study case definition. RESULTS: These are presented for the 3872 patient consultations for GII between April 1996 and December 31st 1997 which met the survey case definition. The crude annual rate of new consultations recorded was 1.7 per 100 person years. The crude monthly consultation rate for new cases ranged between 11 and 18 per 10,000 patients. GPs notified 9% of the cases as 'food poisoning'. A request for microbiological testing of samples at the local laboratory for clinical reasons was documented for 34% of cases with diarrhoea. The study laboratory received faecal samples by post from 66% of these cases. About one in five of the samples tested revealed evidence of infection with a common gastrointestinal pathogen. The pathogens most frequently reported were Campylobacter sp and Salmonella sp. CONCLUSION: The incidence of consultations for GII in Scotland is similar to that recorded in a recent survey in England. The very low notification rate by GPs means that statutory notification by telephone or post is a poor basis for early warning of outbreaks. It is recommended that a pilot study of electronic notification using the NHS net is set up.

Impaired delivery of hemodialysis prescriptions: an analysis of causes and an approach to evaluation.

Serial kinetic modeling is commonly used in hemodialysis to assess the adequacy of dialysis. A variety of problems lead to declining Kt/V in previously stable patients. These include noncompliance, vascular access recirculation, and dialyzer dysfunction. The purpose of this study was to find the relative frequencies of these problems in a group of patients undergoing routine hemodialysis. Simultaneous urea kinetic modeling and access recirculation were tested during 3 consecutive months. The baseline Kt/V was defined as the average of each patient's Kt/V values obtained during the previous 4 mo. A clinically important fall in Kt/V was defined as a decline of > or =0.2 if the baseline Kt/V was > or =1.2, or a decline of > or =0.1 if the baseline Kt/V was <1.2. Ninety-three of 375 (25%) sessions met the criteria for a significant decline in urea kinetic modeling. The baseline Kt/V in this group was 1.33 +/- 0.20 (mean +/- SEM) and declined to 1.02 +/- 0.18 in the abnormal month (P < 0.05). In 42% of instances with a decline of Kt/V, reduced blood processing due to a lower blood flow or shorter time than prescribed was responsible. Recirculation of >12% was found in 25% of sessions with a decrease in Kt/V. These patients most often had access dysfunction or reversed needles. The remaining one-third of patients with decreases in Kt/V had no problem identified, and subsequent monthly kinetic modeling results returned to baseline. These results suggest that analysis of falling urea kinetic modeling results should include a careful review of the dialysis record for reductions in prescribed time or blood flow rates followed by vascular access testing. If these evaluations are unrevealing, urea kinetic modeling results usually return to baseline in the next month.