Kronična venska insuficijencija i transkatetersko postavljanje bioprotetske bikuspidne venske valvule s četverokutnim stentom

The past 25 years have witnessed experimental efforts at catheter-based management of aortic, pulmonary and venous valve regurgitation. This chapter describes the initial designs and experimental evolution of a bioprosthetic venous valve that can be implanted by using a transcatheter technique. An evaluation of a percutaneously placed bioprosthetic, bicuspid venous valve (BBVV) consisting of a square stent and small intestinal submucosa (SIS) covering was performed in 15 sheep. Of 30 BBVVs placed into the jugular veins, 28 exhibited good valve function on immediate venograms, and 25 on venograms prior to sacrifice. Gross and histologic examinations demonstrated incorporation of remodeled and endothelialized SIS BBVVs into the vein wall. Minimally invasive placed square stent based SIS valve is a promising one-way, competent valve.Proteklih 25 godina bili smo svjedoci eksperimentalnih pokušaja u liječenju aortne i pulmonalne regurgitacije te insuficijencije venskih zalistaka pomoću katetera. U ovom članku opisuju se početne zamisli i eksperimentalni razvoj bioprotetskih venskih valvula koje se mogu ugraditi transkateterskom metodom. Procjena perkutano postavljene bioprotetske bikuspidne venske valvule (BBVV), koja se sastoji od četverokutnog stenta i pokrova submukoze tankog crijeva (SIS), učinjena je na 15 ovaca. Od 30 BBVV-a postavljenih u jugularnu venu 28 je imalo urednu funkciju na venogramima učinjenima odmah poslije zahvata, a 25 na venogramima učinjenima prije žrtvovanja životinja. Makroskopska i histološka analiza pokazale su uklapanje remodeliranogi endoteliziranog SIS-BBVV-a u vensku stjenku. Valvula koja sadrži četverokutni stent i SIS, postavljena uz minimalnu invazivnost, jednosmjerna je valvula od koje se može očekivati uspješnost

Transcatheter placement of a low-profile biodegradable pulmonary valve made of small intestinal submucosa: A long-term study in a swine model

ObjectiveWe sought to investigate a placement of a percutaneous low-profile prosthetic valve constructed of small intestinal submucosa in the pulmonary position in a swine model.MethodsTwelve female farm pigs were stented at the native pulmonary valve to induce pulmonary insufficiency. Once right ventricular dilation occurred, the small intestinal submucosa valve was implanted. The pigs were followed up with transthoracic echocardiographic Doppler scanning. One animal died of heart failure before valve replacement. Animals were euthanized at 1 day, 1 month, 3 months, 6 months, and 12 months after valve implantation.ResultsThe small intestinal submucosa pulmonary valve showed effective reversal of pulmonary regurgitation. There were no misplacements during deployment. There were no embolizations. One-year echocardiographic follow-up showed minimal regurgitation and no stenosis for a valve/vessel ratio of 0.78 or greater. Histologic examination demonstrated intensive remodeling of the small intestinal submucosal valve. Within 1 month, the surface was covered by endothelium, and fibroblasts invaded the interior. Over the following months, the small intestinal submucosal valve remodeled without apparent graft rejection.ConclusionThe small intestinal submucosa valve has the potential for graft longevity without the need for anticoagulation or immunosuppression. Histologic remodeling of the valve tissue provides a replacement capable of resembling a native valve that can be placed percutaneously with low-profile delivery systems

Slovenian experience from diagnostic angiography to interventional radiology

Background. The purpose of writing this article is to document the important events and people in the first 50 years of diagnostic angiography and interventional radiology in Slovenia. During this period not only did the name of the institutions and departments change, but also its governance

Percutaneous autologous venous valve transplantation: short-term feasibility study in an ovine model

BACKGROUND: Limited experience with bioprosthetic venous valve percutaneously inserted into femoral veins in 15 patients has been promising in short-term results only to show disappointing long-term results. Percutaneous autogenous venous valve (PAVV) transplantation was explored in an ovine model as a possible alternative treatment. METHODS: PAVV consisted of a vein segment containing a valve that was attached to a stent template. The stent templates (n = 9) were designed and hand made in our research laboratory. They consist of two stainless steel square stents 13 or 15 mm in diameter to fit the ovine jugular veins (JV), which ranges from 10 to 15 mm in diameter. A valve-containing segment of JV was harvested and attached with sutures and barbs inside the stent template (n = 9). The valve devices were then manually folded and front loaded inside the 4 cm chamber of the 13F delivery sheath and delivered into the contralateral JV by femoral vein approach. Transplanted PAVVs were studied by immediate and 3 months venograms. Animals were euthanized at 3 months, and jugular veins harvested to perform angioscopic evaluations in vitro. RESULTS: PAVV transplantation was successful in all nine animals. Good valve function with no reflux was observed on immediate and 3 months venograms in eight valves. The transplanted maximal JV diameter ranged from 10.2 mm to 15.4 mm (mean 13.1 +/- 1.5 mm). Venoscopic examination revealed intact, flexible, nonthickened valve leaflets in eight specimens. One PAVV exhibited normal function of one leaflet only; the other cusp was accidentally cut during the transplantation procedure. All transplanted autologous valves were free of thrombus and incorporated into the vein wall of the host vessel. CONCLUSION: This study demonstrated that autogenous valve transplants remained patent and competent without long-term anticoagulation for up to 3 months. The percutaneous autogenous venous valve may provide in future minimally invasive treatment for patients with chronic deep venous insufficiency, but long-term studies need to be done to document its continued patency and function

Optional vena cava filter with disengaging centering struts: retrieval in an animal model

An optional inferior vena cava (IVC) filter prototype was evaluated for safety and long-term retrievability as an initial feasibility study in an animal model. This filter has four centering struts that have the ability to disengage from the filtering cone portion, allowing the legs to slide out of endothelial growth. Retrieval of six filters in three animals was successful up to 27 weeks. There was no substantial filter tilt, migration, or IVC damage. In conclusion, this filter design may help overcome some of the shortcomings in currently approved optional IVC filters, including long-term retrieval difficulties, tilting, or migration