Saphenous hypoplasia occurs in varicose limbs more frequently than in healthy ones (p= >0.001). It greatly influences the path of the reflux and the anatomy of the varicose veins. GSV segmental hypoplasia can be detected preoperatively by duplex ultrasonography. Its occurrence may influence surgical management for two main reasons: in about 68% of varicose limbs with segmental hypoplasia, the distal GSV is competent. If the distal GSV is varicose, its size and flow direction is normalised by treating the accessory vein that bypasses the hypoplastic segment.

WHAT THIS PAPER ADDS? Measuring great saphenous vein (GSV) diameter is standard in pre-interventional assessment of varicose disorders, but has never been properly validated. This work assessed the relative value of measuring GSV diameter at the most often used sites: the sapheno-femoral junction and the proximal thigh. We found a better correlation of the latter with reflux and both higher sensitivity and specificity for clinical disease severity. A conversion factor was calculated and used to revise published data. The conversion factor enabled comparison of venous disease severity of patients included in 10 interventional series with preoperative GSV measurements taken either at the sapheno-femoral junction or at the proximal thigh. Background: Great saphenous vein (GSV) incompetence is involved in the majority of cases of varicose disease. Standardised pre-interventional assessment is required to analyse the relative merit of treatment modalities. We weighed GSV diameter measurement at the sapheno-femoral junction (SFJ) against measurement at the proximal thigh 15 cm distal to the groin (PT), established a conversion factor and applied it to selected literature data. Methods: Legs with untreated isolated GSV reflux and varices limited to its territory and control legs were studied clinically, with duplex ultrasound and photoplethysmography. GSV diameters were measured at both the SFJ and the PT. A conversion factor was calculated and used to compare published data. Results: Of 182 legs, 60 had no GSV reflux (controls; group I), 51 had above-knee GSV reflux only (group II) and 71 had GSV reflux above and below knee (group III). GSV diameters in group I measured 7.5 mm (AE1.8) at the SFJ and 3.7 mm (AE0.9) at the PT. In groups II and III, they measured 10.9 mm (AE3.9) at the SFJ and 6.3 mm (AE1.9) at the PT (p < 0.001 each). Measurement at the PT revealed higher sensitivity and specificity to predict reflux and clinical class. Good correlation between sites of measurement (r ¼ 0.77) allowed a conversion factor (SFJ ¼ 1.767 * PT, PT ¼ 0.566*SFJ) to be applied to pre-interventional data of published studies. Conclusions: GSV diameter correlates with clinical class, measurement at the PT being more sensitive and more specific than measurement at the SFJ. Applying the conversion factor to published data suggests that some studies included patients with minor disease.

ImportanceGreater than 20% of cases and 0.4% of deaths from COVID-19 occur in children. Following demonstration of the safety and efficacy of the adjuvanted, recombinant spike protein vaccine NVX-CoV2373 in adults, the PREVENT-19 trial immediately expanded to adolescents.ObjectiveTo evaluate the safety, immunogenicity, and efficacy of NVX-CoV2373 in adolescents.Design, Setting, and ParticipantsThe NVX-CoV2373 vaccine was evaluated in adolescents aged 12 to 17 years in an expansion of PREVENT-19, a phase 3, randomized, observer-blinded, placebo-controlled multicenter clinical trial in the US. Participants were enrolled from April 26 to June 5, 2021, and the study is ongoing. A blinded crossover was implemented after 2 months of safety follow-up to offer active vaccine to all participants. Key exclusion criteria included known previous laboratory-confirmed SARS-CoV-2 infection or known immunosuppression. Of 2304 participants assessed for eligibility, 57 were excluded and 2247 were randomized.InterventionsParticipants were randomized 2:1 to 2 intramuscular injections of NVX-CoV2373 or placebo, 21 days apart.Main Outcomes and MeasuresSerologic noninferiority of neutralizing antibody responses compared with those in young adults (aged 18-25 years) in PREVENT-19, protective efficacy against laboratory-confirmed COVID-19, and assessment of reactogenicity and safety.ResultsAmong 2232 participants (1487 NVX-CoV2373 and 745 placebo recipients), the mean (SD) age was 13.8 (1.4) years, 1172 (52.5%) were male, 1660 (74.4%) were White individuals, and 359 (16.1%) had had a previous SARS-CoV-2 infection at baseline. After vaccination, the ratio of neutralizing antibody geometric mean titers in adolescents compared with those in young adults was 1.5 (95% CI, 1.3-1.7). Twenty mild COVID-19 cases occurred after a median of 64 (IQR, 57-69) days of follow-up, including 6 among NVX-CoV2373 recipients (incidence, 2.90 [95% CI, 1.31-6.46] cases per 100 person-years) and 14 among placebo recipients (incidence, 14.20 [95% CI, 8.42-23.93] cases per 100 person-years), yielding a vaccine efficacy of 79.5% (95% CI, 46.8%-92.1%). Vaccine efficacy for the Delta variant (the only viral variant identified by sequencing [n = 11]) was 82.0% (95% CI, 32.4%-95.2%). Reactogenicity was largely mild to moderate and transient, with a trend toward greater frequency after the second dose of NVX-CoV2373. Serious adverse events were rare and balanced between treatments. No adverse events led to study discontinuation.Conclusions and RelevanceThe findings of this randomized clinical trial indicate that NVX-CoV2373 is safe, immunogenic, and efficacious in preventing COVID-19, including the predominant Delta variant, in adolescents.Trial RegistrationClinicalTrials.gov Identifier: NCT04611802

Manoeuvres using APG on a tilt-table have the potential to quantify the contributions of global obstruction and reflux (mL/second) in patients with venous disease.

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