Comparative stability of sodium tetradecyl sulphate (STD) and polidocanol foam: impact on vein damage in an in-vitro model.

OBJECTIVES: To compare the half-life of STD and polidocanol air-based foams and the damage they inflict upon human great saphenous vein in an in-vitro model. METHODS: The time for the volume of 3% STD and polidocanol foams to reduce by 10% (T(90)) and 50% (T(50)) was recorded in an incubator at 37 °C. Segments of proximal GSV harvested during varicose vein surgery were filled with foam for 5 or 15 min. Histological analysis determined percentage endothelial cell loss and depth of media injury. RESULTS: Median (±IQR) T(90) and T(50) for polidocanol were 123.3 s (111.7-165.6) and 266.3 s (245.6-383.1) versus 102.03 s (91.1-112) and 213.13 s (201-231.6) for STD (T(90)p = 0.008, T(50)p = 0.004). Median endothelial loss with polidocanol was; 63.5% (62.2-82.8) and 85.9% (83.8-92.5) versus 86.3% (84.8-93.7) and 97.64% (97.3-97.8) for STD after 5 and 15 min (p = 0.076 and p = 0.009). The median depth and % media thickness injured were 0 µm (0-0 µm) and 0% for both assessments with polidocanol versus 37.4 µm (35.3-45.8 and 43.4 µm (42.1-46.7) and 3.5% (3.1-3.6) and 5.3% (3.7-6.0) after 5 and 15 min for STD (p < 0.01 for all comparisons). CONCLUSION: Although polidocanol foam shows greater stability than STD foam perhaps remaining in the vein for longer, endothelial cell loss and damage to the media were significantly greater with STD.

The impact of different concentrations of sodium tetradecyl sulphate and initial balloon denudation on endothelial cell loss and tunica media injury in a model of foam sclerotherapy.

INTRODUCTION: Recanalisation rates (20-32%) 1-3 years after truncal vein foam sclerotherapy (FS) suggest thrombotic occlusion rather than irreversible vein wall injury. This study examines the injury inflicted by sodium tetradecyl sulphate (STD) foam before and after balloon endothelial denudation (BD). METHODS: In 20 patients undergoing great saphenous vein (GSV) stripping 1.5 cm proximal GSV were harvested (controls). The next 1.5 cm were harvested after in situ BD (n = 10) or no denudation (n = 10). These test segments were filled with 1% or 3% STD foam (5 min), flushed and fixed in formalin. Percentage endothelial cell loss (ECL) and tunica media injury were determined (H&E staining) and collagen structure assessed (transmission electron microscopy, TEM). RESULTS: Controls showed no injury. 1% and 3% STD foam caused 86.3% and 92.2% ECL (p < 0.001 versus controls; 1% versus 3%, p = 0.55). Endothelial cells persisted in all sections. BD increased ECL (1%: 96.9%, 3%: 98.1%, p = 0.01) Tunica media injury (smooth muscle vacuolation) was minimal (8.9% (1% STD) and 12% (3% STD) of its depth) and not enhanced by BD (1%: 8.7%, p = 0.93; 3%: 11.3%; p = 0.86). No collagen disruption occurred (TEM). CONCLUSIONS: Balloon denudation increased ECL but did not facilitate tunica media injury. Equivalent injury was inflicted by 1% and 3% STD.

Outcome following saphenopopliteal surgery: a prospective observational study.

OBJECTIVES: High recurrence rates following small saphenous varicose vein surgery have been reported. The aim of this study was to ascertain initial success rates following saphenopopliteal junction (SPJ) surgery using pre- and postoperative duplex scanning. METHODS: A prospective study was performed on patients with ultrasound-proven SPJ reflux. Patients underwent preoperative duplex skin marking and a postoperative quality assurance scan. RESULTS: Ninety procedures were performed in 88 patients. The SPJ was successfully ligated in 87 (96.7%) cases. Reflux was completely abolished in 51 (56.7%) cases, but persisted solely in the small saphenous vein (SSV) in 32.2%. Subsequently, 10 consecutive patients underwent 11 SPJ ligations with stripping of the SSV. Follow-up ultrasound scan demonstrated successful ligation of the SPJ and elimination of superficial venous reflux. CONCLUSION: This study demonstrates that preoperative duplex SPJ marking results in a high percentage of successful ligation. Given that residual persistent reflux was avoided in patients who underwent stripping of the SSV, we propose that patients who require SPJ surgery undergo duplex marking along with specific consideration with regard to treatment of the residual SSV.

Should cardiac troponins be used as a risk stratification tool for patients with chronic critical limb ischaemia?

OBJECTIVES: Cardiovascular mortality in patients with chronic critical lower limb ischaemia (CCLI) is high and early risk stratification in these patients may aid clinical management improving outcomes. Cardiac troponin I (cTnI) has prognostic significance in patients with unstable angina. The aim of this study was to evaluate the prognostic significance of cardiac troponins in CCLI patients who had no clinical evidence of unstable coronary heart disease. METHODS: Patients (n=152) admitted with CCLI to a single vascular unit over a two-year period were included prospectively in this study. Patients with clinical evidence of unstable coronary disease were excluded from the study. Patient demographics, clinical history, co-morbidity and risk factors for peripheral vascular disease were documented. Admission cTnI levels were recorded using a threshold, 0.1 ng/ml. The primary endpoint was mortality. RESULTS: Fifty-two patients (34.2%) had an elevated cTnI, whilst 100 (65.8%) had cTnI <0.1 ng/ml. Sixty-two patients died during the follow-up period, 38 with an elevated admission cTnI. Death rate in patients with cTnI >0.1 ng/nl was 73% compared with 24% in those with levels below the threshold (p<0.0001). Patients with elevated cTnI were significantly older than those with normal level (median age 76 years vs 71 years, p<0.001). An elevated cTnI was found to independently predict disease-specific mortality on Cox regression analysis (Hazard Ratio 4.2; 95% Confidence Interval 1.3-12.7). CONCLUSION: In this series of patients with CCLI the measurement of cTnI on admission was a significant independent predictor of survival. cTnI has potential as a prognostic test to stratify patients with a high cardiovascular risk and may enable further optimisation of these high-risk patients.