Project description:BackgroundA variety of endovascular and open surgical interventions exist to treat great saphenous vein reflux. However, comparisons of treatment outcomes have been inconsistent.MethodsA systematic review and network meta-analysis of RCTs was performed to compare rates of incomplete stripping or non-occlusion of the great saphenous vein with or without reflux (anatomical failure) at early, mid- and long-term follow-up; and secondary outcomes (reintervention and clinical recurrence) among intervention groups. The surface under the cumulative ranking curve (SUCRA) method was used to estimate the probability of the intervention with the lowest anatomical failure rates.ResultsSome 72 RCTs were included. Comparisons of endothermal techniques with open surgery were mostly not significantly different, except for endovenous laser ablation (EVLA), which had higher long-term anatomical failure rates (pooled risk ratio (RR) 1.87, 95 per cent c.i. 1.14 to 3.07). Mechanochemical ablation had higher anatomical failure rates than radiofrequency ablation (RFA) (pooled RR 2.77, 1.38 to 5.53), and cyanoacrylate closure (CAC) had a RR 0.56 (0.34 to 0.93) times lower than either RFA or EVLA at the early term. Ultrasound-guided foam sclerotherapy had a higher risk of anatomical failure and reintervention than open surgery, with the lowest SUCRA value, and CAC was ranked first, third and first for best intervention for anatomical failure at early, mid and long term respectively. However, clinical recurrence rates were not significantly different between all comparisons.ConclusionMechanochemical ablation and ultrasound-guided foam sclerotherapy performed poorly, with higher anatomical failure rates in the long term. The other treatment modalities had similar rates of anatomical failure in the short and mid term.
Project description:A curious hemodynamic phenomenon emerging as a consequence of the treatment of varicose veins can offer a reasonable explanation why varicose vein and reflux recurrences occur tenaciously irrespective of the applied therapeutic procedure. Saphenous reflux is the most important hemodynamic factor in varicose vein disease: it is responsible for the hemodynamic disturbance, ambulatory venous hypertension, clinical symptoms, and chronic venous insufficiency. Abolition of saphenous reflux eliminates the hemodynamic disturbance and restores physiological hemodynamic and pressure conditions, but at the same time it unavoidably evokes a pressure difference between the femoral vein and the incompetent superficial veins in the thigh during calf pump activity. The pressure difference increases flow and enhances fluid shear stress on the endothelium in pre-existing minor communicating channels between the femoral vein and the saphenous system in the thigh, which triggers release of biochemical agents nitride oxide and vascular endothelial growth factor; the consequence is enlargement (vascular remodeling) of the communicating channels, and ultimately reflux recurrence. Hence, the abolition of saphenous reflux creates preconditions for the comeback of the previous pathological situation. This phenomenon-starting the same trouble while fixing the problem-has been called hemodynamic paradox; is explains why varicose vein and reflux recurrence can occur after any mode of therapy.
Project description:PurposeThe maxillary vein is associated with major hemorrhage, an intraoperative risk factor during mandibuloplasty. Our objectives in this study were to identify the anatomical course of the maxillary vein relative to the mandible, and to ascertain the relationship of its course with that of the maxillary artery.MethodsThirteen sides of 13 cadavers in the possession of the Department of Anatomy of Tokyo Dental College were used. The maxillofacial region was first dissected, after which the upper part of the mandibular ramus was removed and the maxillary artery, maxillary vein, and pterygoid venous plexus were identified. The length of the maxillary vein and its height from the mandibular plane were then measured, and its anatomical course was recorded.ResultsThe maxillary vein ran downward along the inner aspect of the temporal muscle, then from the base of the coronoid process it ran horizontally near the bone surface of the inner aspect of the mandibular ramus. After joining the inferior alveolar vein, it joined the superficial temporal vein to form the retromandibular vein. The mean length of the maxillary vein was 22.2 ± 3.2 mm. At the posterior margin of the mandibular ramus, its mean height above the mandibular plane was 34.2 ± 5.4 mm. From the posterior margin of the mandibular ramus to the lowest point of the mandibular notch, the maxillary vein was located within the areolar connective tissue directly above the periosteum adjoining the inner aspect of the mandibular ramus.ConclusionsIn the wide area from the center of the maxillary notch to the posterior margin of the mandibular ramus, the maxillary vein runs extremely close to the periosteum on the inner aspect of the mandibular ramus, suggesting that it may pose a risk of hemorrhage in various oral surgical procedures.
Project description:Suprapubic varicose veins are usually indicative of unilateral iliac vein occlusion and venous collateralisation. We report two cases of suprapubic varicose veins following pelvic vein embolisation and subsequent pregnancy; both presented without residual pelvic venous reflux or pelvic venous obstruction. In both cases, there was no significant flow in the suprapubic veins indicating that they were not acting as a collateral post-pregnancy. One patient had this venous abnormality treated successfully with TRansluminal Occlusion of Perforators, followed by foam sclerotherapy to the main part of the suprapubic vein. This patient has since completed the reminder of her lower limb varicose vein treatment. We suggest that pregnancy may have caused prolonged intermittent compression of the left common iliac vein, and that this, together with the physiological impact of previous embolisation procedures, obstructed venous drainage from the left leg resulting in collateral vein formation within the 9-month gestation period.
Project description:Compliant elastomer tubing with a fabric "jacket" has been essential in various applications as soft robotic actuators, such as in biomedical exomuscles and massage therapy implements. Here, our study shows that a similar design concept can be an effective strategy in realizing passive regulation in the tube's distension, as well as in preventing aneurysm-like asymmetric rupture of the tube. A custom hydraulic pressure testing rig was built to perform experiments. The jacketed tubes initially deform rapidly as pressure increases, but a self-regulation behavior suppresses the tube's continued distension by strain-stiffening of the "jacket". In addition, highly asymmetric distension, common to elastomeric tubes due to imperfection in fabrication, is prevented dramatically by the "jacket". A three-dimensional finite element model predicts the distension of all tested tubes quantitatively across the entire experimental pressure ranges and beyond. Incorporating custom-designed kirigami relief patterns in the "jackets" expands the potential of the elastomeric tubes.
Project description:Three-dimensional computed tomography venography is a useful tool to identify increased saphenous vein diameter and provides a complementary road map for surgery in patients with varicose veins. In this study, we investigated the correlation between saphenous vein diameter on computed tomography venography and venous reflux detected on duplex ultraonography. We enrolled 152 patients (213 extremities) who underwent endovenous laser ablation therapy, following high ligation of the saphenofemoral junction between January 2014 and December 2019. All patients underwent preoperative computed tomography venography evaluation. The saphenous vein diameter was measured on computed tomography venography, and venous reflux was evaluated in the operating room using Doppler ultrasonography. Among the 152 patients included in the study, 61 showed varicose veins affecting the bilateral extremities. Among the 213 extremities investigated, 165 (77.5%) and 48 (22.5%) extremities showed varicosities involving the greater and lesser saphenous veins, respectively. Among all extremities, venous reflux was detected in 172 (80.8%). The mean diameter of the greater saphenous vein measured 5 cm distal to the saphenofemoral junction was 8.07±1.82 mm in patients with reflux and 5.11±1.20 mm in patients without reflux (p < .05). The small saphenous vein diameter measured 5 cm distal to the saphenopopliteal junction was 7.65±1.74 mm in patients with reflux and 5.04±1.80 mm in patients without reflux (p < .05). Based on the receiver operating characteristic curve, the greater saphenous vein threshold diameter of 5.880 mm measured 5 cm distal to the saphenofemoral junction was the optimal cut-off value to predict reflux (sensitivity 91.4%, specificity 81.8%). The lesser saphenous vein diameter of 5.285 mm measured 5 cm distal to the saphenopopliteal junction was the optimal cut-off value to predict reflux (sensitivity 94.9%, specificity 75.0%). Vein diameter cannot be used as an absolute reference for venous reflux; however, it may have predictive value in patients with varicose veins. Computed tomography venography based measurements of vein diameter may serve as a useful diagnostic tool to predict venous reflux and recommend treatment.
Project description:ObjectiveThe aim of this work was to estimate cost-effectiveness of five common procedures for varicose vein surgery (high ligation and stripping, radiofrequency ablation, endovenous laser ablation, steam vein sclerosis and cyanoacrylate glue) in a Norwegian setting from both a societal and a healthcare payer perspective.DesignCost-effectiveness analysis using decision tree modelling.MethodsA structured literature search was conducted to estimate the clinical effectiveness and the rate of complications in the five methods. Data on costs and health-related quality of life associated with varicose vein disease were also collected. With the aid of an expert panel, a structured decision tree was developed. A 1-year perspective was modelled, and a variety of common complications were included. Monte Carlo simulation was used for probabilistic sensitivity analyses.ResultsThe laser ablation strategy was the most cost-effective option from a societal perspective, with an incremental cost-effectiveness ratio of €8448 compared to a no-treatment alternative, and had a 42% probability of being cost-effective using the Norwegian willingness-to-pay threshold of €59,880. From a healthcare payer perspective, however, the steam vein sclerosis strategy was the most cost-effective with an incremental cost-effectiveness ratio of €4072 compared to a no-treatment alternative, and this strategy had a 50% probability of being cost-effective.ConclusionResults from this study did depend upon the perspective chosen for analyses. Although recent endovenous surgical procedures (including laser ablation and steam vein sclerosis) provide clinically effective treatment for advanced, symptomatic varicose vein disease, availability of high-level data is currently limiting the cost-effectiveness analyses.