Endovascular management of acute extensive iliofemoral deep venous thrombosis caused by May-Thurner syndrome.

PURPOSE: The authors report their experience on the treatment of acute extensive iliofemoral deep venous thrombosis (DVT) due to May-Thurner syndrome using endovascular techniques. MATERIALS AND METHODS: During a 1-year period, 10 symptomatic women (age range, 22-52 years; mean, 35.5 years) were referred for treatment. After ascending venography, an infusion catheter system was placed and urokinase was infused locally into the thrombus burden. After near complete clot dissolution (> or = 95%) or lytic stagnation, the residual left common iliac vein narrowing was treated by means of angioplasty and/or placement of Wallstent endoprosthesis. All patients continued to receive oral warfarin. Patients were followed-up by means of clinic visits, and stent patency was assessed by means of duplex Doppler sonography performed at 1, 3, 6, and 12 months, and then yearly thereafter. RESULTS: The total dose of urokinase used and the duration of infusion were 5.87 +/- 2.57 million units (range, 3.18-10.7) and 51.95 +/- 21.57 hours (range, 26.5-89), respectively. After completion of thrombolytic therapy, the iliac vein narrowing was successfully treated by deployment of a Wallstent endoprosthesis in all 10 patients because of failure of angioplasty. No major bleeding complications occurred. Initial clinical success was 100%, with complete resolution of symptoms in all patients. One patient, who was hypercoagulable and was receiving chemotherapy for metastatic adenocarcinoma, had recurrent symptomatic acute DVT 1 month after therapy. She underwent successful repeated lysis. The remaining nine patients were asymptomatic, with a mean follow-up of 15.2 months (range, 6-36 months). One asymptomatic patient, at 36-month follow-up ultrasound, had iliac vein occlusion and well-developed venous collaterals. Serial ultrasonography in all 10 patients showed no evidence of valvular insufficiency in the femoral and popliteal veins. CONCLUSION: Catheter-directed thrombolytic therapy for the treatment of acute extensive iliofemoral DVT due to May-Thurner syndrome is an effective method for restoring venous patency and provides relief of the acute symptoms. The underlying left common iliac vein lesion invariably needs to undergo stent placement.

Kinetics of release of heparin from alginate hydrogel.

PURPOSE: Injected sodium alginate may be a useful perivascular drug delivery vehicle. This study was performed to determine the release rates of heparin from sodium alginate hydrogels cross-linked with varying amounts of calcium gluconate. MATERIALS AND METHODS: Six hydrogels, composed of 0.16 mEq sodium alginate and 4,000 units unfractionated heparin, were cross-linked with calcium gluconate to yield ion equivalence (IE) ratios (calcium:alginate) of 0.2, 0.4, 0.58, 0.8, 1.0, or 1.2. Two milliliters of normal saline was placed on top of each gel and allowed to remain in contact for up to 10 days. At set time intervals, the amount of heparin in the eluent was determined with use of high-performance liquid chromatography. RESULTS: Gels with 0.2 and 0.4 IE were partially liquid at 24 hours; the other gels solidified within 10 minutes. The 0.58 IE gel was slowest to solidify but immobilized the most heparin and released heparin slowest over 10 days. At 10 days, between 5.5% and 9.8% of the heparin immobilized was retained in the gel. CONCLUSION: This hydrogel shows promise as a vehicle for in vivo perivascular heparin delivery. The 0.58:1 IE ratio hydrogel has slowest release rate and the greatest immobilization despite its longer cross-linking time.

Effect of zinc upon cell attachment and proliferation on periodontally-diseased root surfaces.

The purpose of this study was to determine the effect of zinc ions on fibroblast attachment to periodontally-diseased root surfaces in vitro. Extracted periodontally-diseased teeth were treated with 0.5% ZnCl2 by iontophoresis at 0.5 mA for 2 to 6 minutes. Control groups were untreated diseased and untreated healthy teeth. Sections of the root underlying the pocket were cut from the diseased teeth. The specimens were incubated for 18 hours with L929 mouse fibroblasts, then transferred and incubated in cell-free medium for 48 hours. Cell attachment was evaluated by cell counts and scanning electron microscopy (SEM). Root surfaces were sampled with an acid-etch technique and zinc was measured with an atomic absorption spectrophotometer. Two samples from each group were examined for cell attachment with SEM. Data were analyzed using the appropriate statistical methods. The results showed that diseased, untreated root surfaces had significantly fewer cells attached; however, zinc iontophoresis did not significantly improve cell attachment to the diseased root surfaces. Zinc analysis showed that diseased, untreated root surfaces had a higher zinc content than healthy ones. SEM examination showed striking differences in cell attachment to healthy versus diseased root surfaces. The data indicated that zinc iontophoresis did not significantly enhance cell attachment to root surfaces of diseased teeth.