Preliminary report on a new concept stent prototype designed for venous implant

Venous obstruction at iliocaval level in both forms, primary and secondary, is a significant cause of severe chronic venous insufficiency. A new therapeutic approach to this pathology emerged with the introduction of stenting procedures that proved effective, leading to good long-term results. However, at present, the majority of implanted stents have been designed for arterial implant and this can pose a limit in particular districts. The purpose of this preliminary acute study was to verify the deliverability and safety of a new stent specially designed for venous-vessel implant. We assess the safety and deliverability of two braided, self-expanding, nickel–titanium stents (Jotec GmbH, Hechingen, Germany) specially designed for endovascular implant in veins. The two stents, despite being based on the same concept, have a different design: stent A presents a proximal tapering shape specially designed to reduce migration, while stent B does not. Both of them are enlarged at their distal extremity and present variable radial force the length of the stent itself, the said force becoming very high in the intermediate segment. Stents were implanted in the internal jugular vein of a sheep, showing optimal deliverability. The completion venography showed the migration of stent B into the right atrium. Stent A maintained its location, confirmed by intravascular ultrasound examination. No scaffolding effect was detected and an adequate adherence and adaptability to the vein wall was obtained. In conclusions, the stent A design matches the characteristics required by vein implants. Stability is achieved even where difficult anatomical conditions apply, such as in the jugular vein. Deployment is easy and precise in a given landing zone. Radial resistive force is very high, as required in specific vein districts, but is also associated with good flexibility. Following this preliminary acute report, further studies are required.

Quantitation of reflux and outflow obstruction in patients with CVD and correlation with clinical severity

AIM

Chronic venous disease (CVD) is the result of venous reflux, obstruction or a combination of both. So far, attempts to correlate venous hemodynamic measurements with symptoms and signs of CVD have produced poor to moderate results, probably because of lack of methods to quantitate obstruction and combine measurements of reflux and obstruction. Our hypothesis is that the combination of quantitative measurements of (a) overall reflux (superficial and deep) and (b) overall outflow resistance i.e. including the collateral circulation would provide a hemodynamic index that should be related to the severity of the disease.

METHODS

Twenty-five limbs with chronic venous disease and 1 limb from a healthy volunteer (VCSS 0-13) were studied. The clinical CEAP classification was C0 in one limb, C1 in 2 limbs, C2 in 10 limbs, C3 in 3 limbs, C4 in 1 limb, C5 in 6 limbs and C6 in 3 limbs. Air-plethysmography was used to measure reflux (VFI in mL/s) when the subject changed position from horizontal to standing. Subsequently, with the subject horizontal and the foot elevated 15 cm, simultaneous recordings of pressure and volume were made on release of a proximal thigh cuff inflated to 70 mmHg. Pressure change was recorded with a needle in the foot and volume change with air-plethysmography. Flow (Q in mL/min) was calculated at intervals of 0.1 seconds from tangents on the volume outflow curve. Outflow resistance (R) was calculated at 0.1 second intervals by dividing pressure by the corresponding flow (R=P/Q). R increased markedly at pressures lower than 25 mmHg due to decrease in vein cross-sectional area, so resistance at 25 mmHg (R25) was used in this study.

RESULTS

In a multivariable linear regression analysis with VCSS as the dependent variable, both VFI and R25 were independent predictors (P<0.001). Using the constant (0.595) and regression coefficients, the regression equation provided a Hemodynamic Index (HI) or estimated VCSS=0.595 + (VFI x 0.41) + (R25 x 98). Thus, HI could be calculated for every patient by substituting VFI and R25 in the equation. HI or calculated VCSS was linearly related to the observed VCSS (r=0.86).

CONCLUSION

The results indicate that the combination of quantitative measurements of reflux and outflow resistance provide a hemodynamic index which is linearly related to the VCSS. These findings need to be confirmed in larger series.

The hypothesis of patho-physiological correlation between chronic cerebrospinal venous insufficiency and multiple sclerosis: rationale of treatment

BACKGROUND

The possible role of the venous system in the pathogenesis of chronic neurodegenerative diseases has been hypothesized for decades. Quite recently, the description of a venous condition defined as chronic cerebrospinal venous insufficiency (CCSVI) and its strong association with multiple sclerosis (MS) has brought back the attention of the scientific community to the hypothesis of an aetiological or concomitant role of an altered venous function in the occurrence of this pathology. CCSVI is identified by sonographic criteria, thus the indication for its possible treatment is based on ultrasound findings.

METHOD

We retrospectively examined 167 consecutive patients affected by clinically defined MS and CCSVI, identified by ultrasound assessment by the presence of at least two sonographic criteria. Ultrasonographic diagnosis of CCSVI was then integrated by venography and intravascular ultrasound examination (in 43 patients). Patients were all submitted to endovascular procedure (venoplasty).

RESULTS

In 37% of cases there was no correspondence between the preoperative ultrasound assessment and the venographic findings. In the event of incongruity between venography and sonography, the intravascular ultrasound examination investigation, when performed, confirmed ultrasound findings in 42% of cases and venography results in 58%. At one month in 12% of cases ultrasound assessment showed the persistence of altered flux. In 67% of cases patients reported subjective amelioration, regarding non-specific symptoms.

CONCLUSION

The pathophysiology of CCSVI is yet to be defined. The superior cava venous system is highly complex in terms of anatomy and possible anomalies, as well as its haemodynamic mechanisms. Further studies are required to define the parameters of diagnosis and treatment of CCSVI.

Invasive treatment of deep venous disease. A UIP consensus

Deep venous disease includes primary and/or secondary pathological changes in the deep venous system. These may consist of valve insufficiency, complete or incomplete vein obliteration and/or functional impairment.

Effects of eccentric compression by a crossed-tape technique after endovenous laser ablation of the great saphenous vein: a randomized study

OBJECTIVES

To evaluate the effect of eccentric compression applied by a new crossed-tape technique on procedure-related pain occurrence after endovenous laser ablation (ELA) of the great saphenous vein (GSV).

METHODS

From April 2005 to June 2006, 200 consecutive ELA procedures were randomized to receive (group A: 100) or not (group B: 100) an eccentric compression applied in the medial aspect of the thigh. Patients were scheduled for a seven-day examination to assess the level of pain experienced. Pain intensity was measured using a visual analogue scale giving a numerical grade from 0 (no pain) to 10 (worst pain ever).

RESULTS

The intensity of postoperative pain was significantly reduced (P < 0.001) in the eccentric compression group as compared with the non-compression one.

CONCLUSIONS

This technique of eccentric compression greatly reduces the intensity of postoperative pain after ELA of the GSV.

Venous valvular reconstruction in post-thrombotic syndrome. A new technique

Patients affected by post-thrombotic syndrome at clinical stage C6 CEAP present invalidating symptomatology often not controllable with conservative therapies. Deep vein valves reconstruction enables the patient to achieve clinical benefit. Femoral transposition and venous segment transplantation are not feasible in all situations, due to anatomical and technical limitations. These reasons have led different authors to develop techniques of valvular reconstruction. We have applied a new valvular reconstruction technique in the case of 7 patients on whom it was not possible to perform a conventional operation. Outcome evaluation needs a long term follow-up but good preliminary results suggest continuing with this technique.

Outpatient surgery of varices of the lower limbs: experience of 2,568 cases at four universities

Outpatient surgery of varices of the lower limbs is currently considered a viable alternative to traditional surgery with hospitalization. This paper reports the experience of 4 university groups (Padua, Modena, Verona, Milan), where outpatient treatment has been used since 1987. From June 1987 to June 1992, 2,568 lower limb varices were treated in this way. Different techniques of anaesthesia were used (local infiltration, combined local and general, general, subarachnoid). In all cases, crossectomy was combined with short or long saphenous stripping. There were no intra- or perioperative deaths, and only limited morbidity. Postoperative hospitalization was required in only 2 cases: for hemorrhaging of the inguinal wound in one case, and headache 2 days after spinal anaesthesia in the other. In 2 separate samples of 100 patients, 88 and 89 indicated satisfaction with the surgical treatment. In conclusion, outpatient surgery of varices can be based on the same techniques as in-patients treatment. The risks of surgery and anaesthesia in specialised centres are very limited, with scope for a variety of anaesthetic techniques according to facilities available. Patients satisfaction is high.

[Program for the development and storing of images]

This procedure has been carried out on the bases of the most updated computer science technologies. This program aims at making use of the computer both as a storing and date processor instrument and as an examination aid with a visual result. Promed Phlebology makes it possible to carry out the test starting straight from the patients medical filing card. The storing system has been simplified at most, all the obliged steps being eliminated. The user will be able to choose the file according to his own needs, as well as avoid the intermediate steps by creating practical and synthetic files. This procedure allows enclosing of data to patient related images (photographs, instrumental text, X-rays, intraoperatory images, etc.), directly drawn by any video source (camera or still video camera). With this way, it is possible to use data storing to practical and statistical goals and to look quickly through the file.

Double-blind, double-dummy, randomized, multi-centre clinical assessment of the efficacy, tolerability and dose-effect relationship of sulodexide in chronic venous insufficiency

A multi-centre study was carried out in 476 patients with chronic venous insufficiency to compare the efficacy, tolerability and dose-effect relationship of sulodexide given orally as either capsules or as a new, enteric-coated tablet formulation. Three comparable groups of patients each with chronic venous insufficiency of thrombotic or varicose aetiology received during 60 consecutive days either sulodexide 250 LRU (= 25 mg) capsules twice daily, 50 mg sulodexide enteric-coated tablets twice daily or 100 mg sulodexide enteric-coated tablets once daily, according to a double-blind, double-dummy, randomized design. Doppler and echoduplex examinations, supine and standing peripheral venous pressure, specific symptoms and signs, peripheral haemodynamics and safety haematology and haematochemistry were monitored monthly. The results showed that peripheral venous pressure improved to a clinically relevant and statistically significant extent in all groups and symptoms and signs were rapidly and significantly relieved. These effects were dose-related, as in both cases the recovery was faster and greater with the 100 mg per day dose however administered. Both the thrombotic and varicose aetiologic sub-groups benefited from treatment to approximately the same extent. Mild to moderate gastro-intestinal adverse experiences occurred in 48 patients evenly split between groups but spontaneously disappeared within 72 hours, none leading to treatment withdrawal. No clinically relevant modifications of peripheral haemodynamics or of safety haematology and haematochemistry was observed. The haemocoagulation parameters failed to exhibit appreciable variations. While the known clinical usefulness of sulodexide 250 LRU (= 25 mg) capsules twice daily was confirmed in this trial, the enteric-coated tablets, 50 mg twice daily or 100 mg once daily, were shown to have greater efficacy and similar tolerability to the standard formulation and dose.