In Vitro Effects of Detergent Sclerosants on Clot Formation and Fibrinolysis

Clinical outcomes and predictors of bleomycin polidocanol foam sclerotherapy treatment response in venous malformations

OBJECTIVE

To evaluate the safety and efficacy of bleomycin polidocanol foam (BPF) sclerotherapy for venous malformations (VMs) and analyze the associated clinical outcomes and predictors.

METHODS

We retrospectively assessed BPF sclerotherapy outcomes in 138 patients with VMs. We analyzed pain levels, lesion volume reduction, and subjective perception of response. Logistic regression analysis was performed to identify potential predictors of treatment outcome. Additionally, we carefully monitored and recorded complications.

RESULTS

There was a notable average reduction in lesion volume by 78.50% ± 15.71%. The pain numerical rating scale (NRS) score decreased from 4.17 ± 2.63 prior to treatment to 1.05 ± 1.54 afterward, and 70.3% of the patients experienced effective relief after a single BPF treatment. Multivariate analysis revealed that a high baseline NRS (odds ratio [OR]:  4.026) and elevated activated partial thromboplastin time (APTT, OR: 1.200) were positive predictors of pain reduction. Additionally, a high baseline NRS score (OR: 1.992) and elevated thrombocytocrit (PCT, OR: 2.543) were positive predictors of incomplete postoperative pain relief. Minor complications occurred in 31 (22.46%) patients.

CONCLUSION

BPF sclerotherapy is safe and effective for VMs, resulting in significant reduction in lesion volume, improved symptoms, and minimal complications. APTT and PCT levels are important predictors of pain outcomes following BPF treatment.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

Polidocanol: A Review of Off-Label Dermatologic Uses

BACKGROUND

Polidocanol is an FDA-approved treatment of incompetent great saphenous veins, accessory saphenous veins, and visible varicosities of the great saphenous vein system, but numerous other off-label dermatological applications have been reported.

OBJECTIVE

To describe the various off-label dermatological clinical uses of polidocanol, as well as efficacy and adverse effects.

METHODS

The review of studies searchable on PubMed from 2004 to 2021 describing clinical uses of polidocanol to determine efficacy and adverse effects associated with various dermatologic applications.

RESULTS

Polidocanol has shown efficacy in the treatment of mucocele of minor salivary gland, hemangioma, upper extremity veins, reticular veins of the chest, facial veins, pyogenic granuloma, lymphangioma circumscriptum, digital mucous cyst, mixed skin ulcers, cutaneous focal mucinosis, seromas, glomuvenous malformations, acne cysts, lymphocele, and dissecting cellulitis. Commonly reported side effects include pain, erythema, swelling, ecchymosis, and ulceration. Most sources were case reports and small prospective studies, as such the strength of data supporting many uses is limited by small sample sizes and lack of controls.

CONCLUSION

Although polidocanol is currently only FDA approved for incompetent great saphenous veins, accessory saphenous veins, and visible varicosities of the great saphenous vein system, the use of polidocanol has been selected for a variety of off-label clinical applications.

The Non-Activated Thromboelastometry (NATEM) Assay's Application among Adults and Neonatal/Pediatric Population: A Systematic Review

The non-activated thromboelastometry (NATEM) assay is a point-of-care assay that can provide a comprehensive insight into the actual hemostatic mechanism. However, there are very limited data about its use in clinical practice. The aim of this study was to systematically review the literature for any data regarding the use of NATEM in several clinical settings. A systematic review of PubMed and Scopus databases was conducted through 20 January 2022 for studies evaluating the use of the NATEM assay in different clinical settings. The literature search yielded a total of 47 publications, 30 of which met the eligibility criteria for this review. Evaluation of NATEM’s detecting ability for hemostasis disorders is limited in the literature. The results of the included studies indicate that NATEM seems to be a sensitive method for the detection of hyperfibrinolysis and may have an advantage in the diagnosis of hemostatic disorders. It could be more informative than the other ROTEM assays for detecting changes in coagulation parameters in patients who receive anticoagulants. However, the reported outcomes are highly varying among the included studies. NATEM has a high sensitivity to detect hypo- or hypercoagulability and provides a detailed insight into the whole hemostatic process from clot formation to clot breakdown. It could be a useful technique in variable fields of medicine, not only in adults, but also in pediatric and neonatal populations, to guide different hemostatic treatments and predict coagulation disorders or mortality/morbidity; this issue remains to be further investigated.

Strain Ultrasound Elastography of Aneurysm Sac Content after Randomized Endoleak Embolization with Sclerosing and Non-sclerosing Chitosan-based Hydrogels in a Canine Model

PURPOSE

To compare the mechanical properties of aneurysm content after endoleak embolization with a chitosan hydrogel (CH) versus a chitosan hydrogel with sodium tetradecyl sulphate (CH-STS) using strain ultrasound elastography (SUE).

MATERIALS AND METHODS

Bilateral common iliac artery type Ia endoleaks were created in nine dogs. Per animal, one endoleak was randomized to blinded embolization with CH, and the other, with CH-STS. Brightness mode ultrasound, Doppler ultrasound, SUE radiofrequency ultrasound, and computed tomography were performed for up to six months until sacrifice. Radiological and histopathological studies were co-registered to identify three regions of interest: embolic agent, intraluminal thrombus (ILT), and aneurysm sac. SUE segmentations were performed by two blinded, independent observers. Maximum axial strain (MAS) was the primary outcome. Statistical analysis was performed using Fisher's exact test, multivariable linear mixed-effects models, and intraclass correlation coefficients (ICCs).

RESULTS

Residual endoleaks were identified in 7/9 (78%) and 4/9 (44%) aneurysms embolized with CH and CH-STS, respectively (p=0.3348). CH-STS had 66% lower MAS (p<0.001) than CH. The ILT had 37% lower MAS (p=0.01) than CH and 77% greater MAS (p=0.079) than CH-STS. There was no significant difference in ILT between treatments. Aneurysm sacs embolized with CH-STS had 29% lower MAS (p<0.001) than those embolized with CH. Residual endoleak was associated with 53% greater aneurysm sac MAS (p<0.001). The ICC for MAS was 0.807 (95% confidence interval: 0.754-0.849) between segmentations.

CONCLUSION

CH-STS confers stiffer intraluminal properties to embolized aneurysms. Persistent endoleaks are associated with increased sac strain, an observation which may help guide management.

A Novel Drug Self-Delivery System from Fatty Alcohol Esters of Tranexamic Acid for Venous Malformation Sclerotherapy

Venous malformation (VM), which causes severe damage to patients' appearance and organ function, is one of the most common vascular malformations. At present, many drugs in clinical treatment cause various adverse reactions. Herein, we synthesized cationic amphiphilic gelators (TA6, TA8, and TA9) by introducing saturated carbon chains of different lengths to tranexamic acid (TA), which could self-assemble into low-molecular-weight gels (LMWGs) as drug delivery carriers by hydrogen bonds, van der Waals forces, and hydrophobic interactions. The rheological properties, gelation driving force and drug release profiles of TA6, TA8, and TA9 hydrogels were characterized, and the results indicated that the hydrogels prepared in this study possessed the typical characteristics of a gel and could release drugs slowly. More importantly, the TA9 gelator showed significant pharmacological activity, in that it served as both an active drug compound and a drug carrier. The in vitro experiments demonstrated that TA9 induced HUVECs death and hemolysis by destroying cell membranes in a dose-dependent manner, and caused cell death and hemolysis at a concentration of 0.09 µM/mL. Meanwhile, we found TA9 could interact not only with fibrinogen, but also with other endogenous molecules in the blood. After the administration of TA9 hydrogel for 15 days, macroscopic imaging and histological evaluation in mice and rabbits displayed obvious thrombi, inflammatory reactions, and venous embolization, indicating that the mechanism of the TA9 hydrogel in treating VM was involved in two processes. Firstly, the TA9 hydrogel relied on its mechanical strength to physically block veins and continuously release TA9, in situ, for targeted therapy. Then, TA9 destroyed endothelial cells and damaged venous walls critically, causing thrombi. Most excitingly, TA9 was hydrolyzed to TA by enzymes that inhibited the degradation of thrombi by plasmin to prolong the embolization time and to promote venous fibrosis. Compared with other clinically available sclerosants, the degradation of TA9 also empowered a better biocompatibility and biodegradability for the TA9 hydrogel. In conclusion, we synthesized a potentially safe and effective derivative of TA and developed a low-molecular-weight gel as a self-delivery system for TA in treating VM.

LIPIODOL reduces the lytic activity of detergent sclerosants in vitro

OBJECTIVES

Contrast agents are used widely in the interventional setting and in particularly in the management of vascular anomalies and have also been used in combination with sclero-embolic agents. There is limited information on the interaction of contrast agents with sclerosant agents when used as mixtures. The aim of this study was to determine the effect of mixing radiological contrast agents with detergent sclerosants and measuring the effect on change in lytic activity of detergent sclerosants in vitro and by proxy the change in potency.

METHODS

Red blood cell lysis was assessed following the incubation of two commonly used contrast agents, LIPIODOL® and ULTRAVIST®, mixed with detergent sclerosants, FIBROVEIN®, sodium tetradecyl sulfate (STS), and AETHOXYSKLEROL®, polidocanol (POL).

RESULTS

The density of both contrast agents was higher than STS and POL and neither of the detergent sclerosants were miscible in LIPIODOL. LIPIODOL on its own caused cell lysis (1.01%, p < 0.05) whereas ULTRAVIST did not. Fifty per cent cell lysis for sclerosant and LIPIODOL mix occurred at concentrations of: 0.041% (2.4 times greater than the control, p < 0.05) and 0.08% (3.6 times greater than the control, p = 0.06) for STS and POL, respectively.

CONCLUSIONS

LIPIODOL, when mixed with sclerosant detergents (ratio 1:1) causes a reduction in the lytic activity of sclerosants and this effect was statistically significant and most prominent in lower sclerosant concentration mixtures.

Reducing hyperpigmentation after sclerotherapy: A randomized clinical trial

OBJECTIVE

Sclerotherapy for the treatment of varicose veins is one of the most common medical procedures performed in the Western world, and hyperpigmentation is one of the most frequent, dreaded, minor adverse events. There has recently been some interest in investigating the inflammatory response of the local endothelium after sclerotherapy and the possible benefits of venoactive drugs because of their pleiotropic properties. The aim of this study was to evaluate whether adding a venoactive drug (sulodexide) to the standard sclerotherapy treatment protocol for patients with varicose veins can reduce the occurrence of postsclerotherapy hyperpigmentation.

METHODS

We carried out a prospective, multicenter, randomized controlled trial with a parallel group design. It included 720 patients with telangiectasia, reticular veins, or varicose veins who were candidates for sclerotherapy. Patients with reflux in deep system or saphenous veins were excluded. Group A consisted of 354 patients who received an oral dose of sulodexide twice a day for 7 days before scheduled sclerotherapy; the treatment then continued for 3 months. Group B consisted of 366 patients who received the standard sclerotherapy protocol. Polidocanol was used as the sclerosing agent, and 20 to 30 mm Hg compression stockings were used in both groups for 7 days. Control photographs were taken, and a follow-up examination took place after 1 month and 3 months. Computer software was used to analyze the treated area for incidence of hyperpigmentation, total area of hyperpigmentation, skin tone increase in the hyperpigmented area, vein disappearance, and incidence of major bleeding. The sample size was calculated to give a statistical power of 80%. Student t-test and the χ² test were used for comparative analyses, as appropriate. The level of significance was set at P < .05.

RESULTS

A total of 609 patients completed the 3-month follow-up: 312 in group A and 297 in group B. After 1 month, the incidence of hyperpigmentation was 8.7% in group A and 14.8% in group B (P = .01). Group A developed an average area of hyperpigmentation of 10.7% compared with 18.2% in group B (P = .01), and the skin tone of the hyperpigmented area was lower in group A than in group B (P = .02). However, the latter difference was not significant after 3 months. The overall vein disappearance rate was similar in both groups.

CONCLUSIONS

Our analysis shows that by adding a venoactive drug (sulodexide) to the standard sclerotherapy protocol, the occurrence of hyperpigmentation is reduced without affecting the desired therapeutic vein elimination response.

Deep vein sclerosis following sclerotherapy: Ultrasonic and d-dimer criteria

Objectives

The aim of sclerotherapy is to induce fibrosclerosis of superficial veins. We postulated that inadvertent entry of sclerosants into deep veins can result in sclerotic occlusion, deep vein sclerosis, a non-thrombotic process distinct from spontaneous deep vein thrombosis. The aim of this study was to assess the role of d-dimer in differentiating between deep vein sclerosis and deep vein thrombosis.

Methods

Proximal trunks of great and small saphenous veins were treated with endovenous laser ablation. Venous tributaries and perforators were treated with foam ultrasound guided sclerotherapy. Ultrasound studies of lower limb deep veins were performed before and one week after the procedures, to detect deep vein occlusions (DVOs). d-dimer levels were measured for DVOs and long-term ultrasound studies monitored the recanalisation rates.

Results

In a six-year period, 9143 procedures were performed in 1325 patients for bilateral varicose veins. This included 1124 endovenous laser ablation and 8019 foam ultrasound guided sclerotherapy procedures. A total of 259 DVOs (2.83%) were identified on ultrasound which included 251 deep vein sclerosis (2.74%), seven deep vein thrombosis (0.07%) and one endovenous heat-induced thrombosis (EHIT, 0.08%). d-dimer values <0.5 µg/mL excluded deep vein thrombosis s, 0.5–1.0 µg/mL were more likely to be associated with deep vein sclerosis and >1.0 µg/mL were a more likely to be associated with deep vein thrombosis. Lower sclerosant concentrations and higher foam volumes were associated with increased risk of DVO ( p <  .0001). No significant relationship was found between DVO and gender or thrombophilia. Deep vein thrombosis and EHIT cases but not deep vein sclerosis patients were anticoagulated. None had thromboembolic complications. Patients were followed up for a median of 299 days (37–1994 days). Recanalisation rates were 71.1% for deep vein sclerosis (92.3% competent) and 71.4% for deep vein thrombosis (60.0% competent).

Conclusions

Deep vein sclerosis is a relatively benign clinical entity distinct from deep vein thrombosis and does not require anticoagulation. Majority of affected veins on long-term follow-up regain patency and competence. d-dimer can be used to assist in differentiating deep vein sclerosis from deep vein thrombosis.

Circulating blood cells influence the fibrinolytic capacity of clots generated in the presence of detergent sclerosants

Objectives

To investigate the effects of sodium tetradecyl sulphate and polidocanol on fibrinolytic potential of sclerosant-incubated clots.

Methods

Serial dilutions of sodium tetradecyl sulphate and polidocanol were incubated with platelet poor plasma and whole blood samples. Rotational thromboelastometry was used to determine the lysis of sclerosant-incubated clots in whole blood. Fibrin generation and fibrinolysis were quantified using an overall haemostatic potential assay on platelet poor plasma.

Results

Rotational thromboelastometry analysis of whole blood revealed increased maximum lysis in the presence of sodium tetradecyl sulphate but decreased maximum lysis at low concentrations of polidocanol. Clots generated using platelet poor plasma in the overall haemostatic potential assay demonstrated no significant change in fibrinolysis for both sclerosants at all concentrations measured.

Discussion

Sodium tetradecyl sulphate and polidocanol produce differing effects on the fibrinolytic potential depending on sample type and concentration. In whole blood, sodium tetradecyl sulphate produces clots more sensitive to lysis while polidocanol produced fibrinolytic-resistant clots.

In vitro and ex vivo evaluation of the biological performance of sclerosing foams

Since the first reports on foam sclerotherapy, multiple studies have been conducted to determine the physical properties and behavior of foams, but relatively little is known about their biological effects on the endothelial cells lining the vessel wall. Moreover, a systematic comparison of the biological performance of foams produced with different methods has not been carried out yet. Herein, a 2D in vitro method was developed to compare efficacy of commercially available polidocanol injectable foam (PEM, Varithena) and physician-compounded foams (PCFs). Endothelial cell attachment upon treatment with foam was quantified as an indicator of therapeutic efficacy, and was correlated with foam physical characteristics and administration conditions. An ex vivo method was also developed to establish the disruption and permeabilisation of the endothelium caused by sclerosing agents. It relied on the quantitation of extravasated bovine serum albumin conjugated to Evans Blue, as an indicator of endothelial permeability. In our series of comparisons, PEM presented a greater overall efficacy compared to PCFs, across the different biological models, which was attributed to its drainage dynamics and gas formulation. This is consistent with earlier studies that indicated superior physical cohesiveness of PEM compared to PCFs.

Comparison of tetradecyl sulfate versus polidocanol injections for stabilisation of joints that regularly dislocate in an Ehlers-Danlos population

OBJECTIVES

To determine whether there is similarity between tetradecyl sulfate and polidocanol in stabilising a joint from dislocating in patients with Ehlers-Danlos syndrome (EDS).

METHOD

A retrospective analysis of patients with EDS in a sole-practice clinic in New Zealand. Patients must have had the diagnosis of EDS, had easily dislocatable joints, had treatment and at least 3 months' follow-up. 0.11% tetradecyl sulfate solution, or 0.25% polidocanol solution, was injected to ligament attachments (enthesis) on the side of the joints where they dislocated. Patients were deemed successfully treated if their affected joints were no longer dislocated over a minimum of 3 months' follow-up (out to 3 years).

RESULTS

Of 250 patients at the time of the study, 46 fitted the criteria. There were 37 treated with tetradecyl sulfate and nine with polidocanol. For the tetradecyl group there were a total of 305 injections around 97 joints: mean 3.1, range 1-22, median 2. For the polidocanol group there were 36 injections around 19 joints: mean 1.9, range 1-8, median 2. The difference of means between group 1 (tetradecyl) and group 2 (polidocanol) is 1.2, CIs 0.34 to 2.98. All patients had no further dislocations of treated joints unless they had a major new injury (two patients).

CONCLUSION

There was no difference between the two groups for stabilising joints from dislocating. These two agents appear promising for treating patients with recurrent joint dislocations in the setting of EDS. Prospective multicentre randomised controlled trials are needed to confirm these data.

Novel developments in foam sclerotherapy: Focus on Varithena® (polidocanol endovenous microfoam) in the management of varicose veins

Scope Varithena® is a recently approved commercially available drug/delivery unit that produces foam using 1% polidocanol for the management of varicose veins. The purpose of this review is to examine the benefits of foam sclerotherapy, features of the ideal foam sclerosant and the strengths and limitations of Varithena® in the context of current foam sclerotherapy practices. Method Electronic databases including PubMed, Medline (Ovid) SP as well as trial registries and product information sheets were searched using the keywords, 'Varithena', 'Varisolve', 'polidocanol endovenous microfoam', 'polidocanol' and/or 'foam sclerotherapy/sclerosant'. Articles published prior to 20 September 2016 were identified. Results Foam sclerosants have effectively replaced liquid agents due to their physiochemical properties resulting in better clinical outcomes. Medical practitioners commonly prepare sclerosant foam at the bedside by agitating liquid sclerosant with a gas such as room air, using techniques as described by Tessari or the double syringe method. Such physician-compounded foams are highly operator dependent producing inconsistent foams of different gas/liquid compositions, bubble size, foam behaviour and varied safety profiles. Varithena® overcomes the variability and inconsistencies of physician-compounded foam. However, Varithena® has limited applications due to its fixed sclerosant type and concentration, cost and lack of worldwide availability. Clinical trials of Varithena® have demonstrated efficacy and safety outcomes equivalent or better than physician-compounded foam but only in comparison to placebo alone. Conclusion Varithena® is a promising step towards the creation of an ideal sclerosant foam. Further assessment in independent randomised controlled clinical trials is required to establish the advantages of Varithena® over and above the current best practice physician-compounded foam.

Interaction of detergent sclerosants with cell membranes

Commonly used detergent sclerosants including sodium tetradecyl sulphate (STS) and polidocanol (POL) are clinically used to induce endovascular fibrosis and vessel occlusion. They achieve this by lysing the endothelial lining of target vessels. These agents are surface active (surfactant) molecules that interfere with cell membranes. Surfactants have a striking similarity to the phospholipid molecules of the membrane lipid bilayer. By adsorbing at the cell membrane, surfactants disrupt the normal architecture of the lipid bilayer and reduce the surface tension. The outcome of this interaction is concentration dependent. At high enough concentrations, surfactants solubilise cell membranes resulting in cell lysis. At lower concentrations, these agents can induce a procoagulant negatively charged surface on the external aspect of the cell membrane. The interaction is also influenced by the ionic charge, molecular structure, pH and the chemical nature of the diluent (e.g. saline vs. water). The ionic charge of the surfactant molecule can influence the effect on plasma proteins and the protein contents of cell membranes. STS, an anionic detergent, denatures the tertiary complex of most proteins and in particular the clinically relevant clotting factors. By contrast, POL has no effect on proteins due to its non-ionic structure. These agents therefore exhibit remarkable differences in their interaction with lipid membranes, target cells and circulating proteins with potential implications in a range of clinical applications.

Development of an in vitro fibrin clot model to evaluate fibrinolytic agents for wound care application

OBJECTIVE

To describe an in vitro fibrin clot model that could reliably assess the fibrinolytic activity of enzymatic debriding agents for wound care application.

METHOD

A model of a fibrin clot was reconstructed in vitro by mixture of human fibrinogen and (alpha)-thrombin supplemented with factor XIII. These clots were then treated with enzymatic ointments. Fibrinolytic activity was investigated by measuring D-dimer levels, using an automated immunoturbidimetric Liatest D-dimer assay.

RESULTS

Collagenase and papain-urea ointments demonstrated fibrinolytic activity which was macroscopically visible. Their effect was identical on the in vitro reconstructed fibrin clot and ex vivo collected wound fibrin clot; collagenase and papain-urea both induced a complete degradation and dissolution of both fibrin clots after 24 hours of treatment. This was associated with an increase in D-dimer concentration.

CONCLUSION

This reconstructed fibrin clot in vitro model has the potential to predict the efficacy of fibrinolytic agents and therefore appears to be a suitable model for in vitro assays.

DECLARATION OF INTEREST

This study was supported by a grant from URGO Laboratory.

In vivo effects of foam sclerotherapy on coagulation

OBJECTIVE

The aim of this study was to evaluate whether foam sclerotherapy (FS) induces changes in CAT (calibrated automated thrombinography) and other coagulation parameters which could indicate an increased risk of thrombotic events.

METHODS

Blood samples from eight patients treated with FS were taken before treatment and 30 minutes, one and four hours and one week after treatment. CAT parameters (ETP1n, Peak1n, Lag time 1), thrombin antithrombin complexes (TAT), d-dimers, fibrinogen, Von Willebrand (vWf Ag) factor and platelet-derived microparticles (MIPAs) were measured.

RESULTS

Significant changes over time for Peak1n, fibrinogen, d-dimers, vWfAg and TAT complexes were observed. CAT parameters decreased over time, except for Lag time 1. D-dimers and TAT complexes increased and fibrinogen, vWf Ag, MIPA's decreased during the first hours.

CONCLUSION

The findings in this study support the hypothesis that FS initiate coagulation pathways, but there is no evidence that this activation results in an increased thrombosis risk.

Non-involuting congenital haemangioma of the eyelid: successful treatment with fluroscopic ultrasound guided sclerotherapy and surgical excision

We present a case of non-involuting congenital haemangioma (NICH) of the right eyelid which was present at birth as a purpuric macule but increased in size to cause significant obstruction of vision. At four years of age the lesion was treated with fluroscopic ultrasound-guided sclerotherapy using 0.5% sodium tetradecyl suphate foam and surgically debulked 16 days later. Histopathology was negative for glucose transporter-1 stain confirming the diagnosis. The residual segments were subsequently treated in three further sessions of sclerotherapy in the ensuing three years. This treatment approach resulted in a good cosmetic and functional outcome with no associated complications. To our knowledge, this is the first published case of a histologically confirmed NICH treated primarily with sclerotherapy.

Comparison of whole blood fibrin-based clot tests in thrombelastography and thromboelastometry

BACKGROUND

Fibrin-based clot firmness is measured as maximum amplitude (MA) in the functional fibrinogen (FF) thrombelastographic assay and maximum clot firmness (MCF) in the FIBTEM thromboelastometric assay. Differences between the assays/devices may be clinically significant. Our objective was to compare clot firmness parameters through standard (FF on a thrombelastography device [TEG®]; FIBTEM on a thromboelastometry device [ROTEM®]) and crossover (FF on ROTEM®; FIBTEM on TEG®) analyses.

METHODS

Whole-blood samples from healthy volunteers were subjected to thrombelastography and thromboelastometry analyses. Samples were investigated native and following stepwise dilution with sodium chloride solution (20%, 40%, and 60% dilution). Samples were also assessed after in vitro addition of medications (heparin, protamine, tranexamic acid) and 50% dilution with hydroxyethyl starch, gelatin, sodium chloride, and albumin.

RESULTS

FF produced higher values than FIBTEM, regardless of the device, and TEG® produced higher values than ROTEM®, regardless of the assay. With all added medications except heparin 400 U/kg bodyweight, FF MA remained significantly higher (P < 0.05) than FIBTEM MCF, which was largely unchanged. FF MA was significantly reduced (P = 0.04) by high-dose heparin and partially restored with protamine. Fifty percent dilution with hydroxyethyl starch, albumin, and gelatin decreased FIBTEM MCF and FF MA by >50%.

CONCLUSIONS

These results demonstrate differences when measuring fibrin-based clotting via the FF and FIBTEM assays on the TEG® and ROTEM® devices. Point-of-care targeted correction of fibrin-based clotting may be influenced by the assay and device used. For the FF assay, data are lacking.

Paradoxical embolism, stroke and sclerotherapy

Sclerotherapy has been associated with 13 published cases of stroke since 1994. Four earlier reports implicated liquid sclerosants while nine recent cases have followed foam sclerotherapy. This adverse event represents a very rare complication of a very popular procedure. Ten of the 13 reported patients recovered completely with no long-term sequelae. A right-to-left shunt and in particular a patent foramen ovale (PFO) was the most consistent risk factor. Paradoxical gas emboli were observed in the brain-supplying or the intra-cranial arteries of five patients with an immediate onset of stroke after foam sclerotherapy. Paradoxical clot embolism was suspected in three patients with a delayed onset of stroke and concurrent venous thrombosis. In the remaining five cases, which included two cases with an immediate onset after liquid sclerotherapy, no specific cause was identified. Patients with a past history of cryptogenic stroke or a long life history of recurrent classic migraine attacks (with aura) have a higher risk of neurological adverse events and may benefit from preoperative screening and percutaneous closure of PFO.

Principles and Technique of Foam Sclerotherapy and Its Specific Use in the Treatment of Venous Leg Ulcers

Invention of foam sclerotherapy has significantly changed the current phlebological practice. Compared with liquid sclerosants, obliterating foam is more efficient, especially for the closure of larger veins. This review discusses clinical aspects of foam sclerotherapy with a focus on its use for the treatment of venous leg ulceration, including the rationale for its use in the treatment of these chronic wounds, physicochemical mechanisms responsible for stability and disintegration of sclerosant foam, pathomechanism of neurologic adverse events seen after foam sclerotherapy, and techniques that can increase efficacy of this procedure and lower frequency of adverse events.