[Steno-obstructions of haemodialytic FAV: new aspects of endovascular treatments]. / Trattamento endovascolare delle complicanze steno-ostruttive delle fistole artero-venose emodialitiche: nuovi aspetti di intervento con radiologia interventistica.

Angioplasty is the usual method for the treatment of stenosis of arteriovenous fistulas for hemodialysis, along with fibrinolysis and thrombus aspiration. We evaluated the efficacy and safety of interventional radiology procedures in the treatment of stenosis or occlusion of arteriovenous fistulas. One hundred thirteen patients suffering from malfunction of arteriovenous fistulas underwent interventional radiological procedures (140 treatments). In all patients color-Doppler was performed beforehand. Stenosis at the site of the fistula was found in all patients and was treated with percutaneous transluminal angioplasty (PTA); stenosis at the anastomosis site was found in 63 cases and was treated by angioplasty with a microcatheter. In 40 patients suffering from recent thrombotic occlusion, locoregional thrombolysis and PTA were necessary. Technical and clinical success was achieved in 107 patients (94.6%); in 1 of 6 unsuccessful treatments the procedure had to be interrupted due to the rupture of a vein. Follow-up exams demonstrated primary patency in 92.5%, 71.9% and 49.5% of patients at 6 months, 1 year and 2 years, respectively. In 19 patients (17.7%) hemodynamically significant restenosis was observed, which was treated with multiple PTAs (27 treatments, only 1 of which with a negative outcome), resulting in a 94.2% success rate; only 1 patient had to undergo a fourth PTA. The overall patency rate was 95%, 87.2%, 62.3% at 6 months, 1 year and 2 years, respectively. In our experience immediate success and excellent patency rates were observed, which persisted in the medium and long term. PTA, with thrombolysis and thromboaspiration, is the treatment of choice in cases of malfunctioning arteriovenous fistulas. PTA should always be attempted before making a new surgical access in order to preserve the vascular tree.

[Use of venae comitantes in the creation of arteriovenous fistulas: retrospective evaluation of our experience]. / L'utilizzo della vena comitans nel confezionamento delle fistole artero-venose: valutazione retrospettiva della nostra esperienza.

In order to estimate the outcome of arteriovenous fistula (AVF) for hemodialysis, we reviewed our experience in the construction of AVFs using the venae comitantes in patients without an adequate superficial venous vascular territory. The study included 34 patients affected by end-stage renal disease in whom an AVF was created using the deep venous system. In 26 of them we performed an anastomosis between the brachial artery and its vena comitans. Immediate success, defined by the presence of a thrill at the end of the anastomosis, was obtained in 84%, while primary failure of the AVF (immediate postoperative failure) occurred in 3 patients (12%). Early failure, defined as failure within 6 weeks of AVF placement, occurred in 4% of patients. Of the 22 patients with a functioning AVF, 8 (36%) subsequently requested a second operation to bring the fistula to the surface. Some of these involved the placement of synthetic grafts for better accessibility. The primary patency of the AVFs was equal to 64%, while the patency after a second intervention was 91%. Among the 26 AVFs created with venae comitantes, total patency at 50 weeks was 62%. Our experience with the placement of prosthetic grafts draining into the venae comitantes has not provided encouraging results. We believe that for adequate exploitation of venae comitantes it is important to use native veins that have to meet specific anatomical and functional requirements. The creation of an AVF with a native vein, taking advantage of the deep venous system, is feasible under the right circumstances.

[Central venous stenting in patients on hemodialysis: review of our case series and long-term follow-up]. / Stenting venoso centrale in pazienti emodializzati: revisione della nostra casistica e follow-up a distanza.

Aims of the study was validate the venous stenting technique as the treatment of choice in patients affected by stenosis or occlusion of the central venous area. To evaluate the long-term patency of placed stents in our series and to detect factors predisposing to restenosis. Twenty-three hemodialyzed patients were treated by PTA or placement of a metallic self-expandable stent in the central venous area because of occlusion or severe stenosis caused by repeated central venous access puncture for Port-A-Cath or pacemaker placement. All patients were examined every 3 months after treatment by clinical examination and color-Doppler ultrasound. Stents were placed with success in all cases but one, where it was impossible to get past the occlusion. Restenosis was observed in 12 cases at 4 to 12 months (average 8 months). Intrastent restenoses were treated with success by PTA alone and stent placement in 4 cases. A new restenosis was observed in 4 retreated patients in whom the stent was short or angled. In the other patients restenosis was attributable to disregard of anticoagulant therapy. In conclusions, the availability of new devices and dedicated stents is still necessary. There is a limited relationship between patency and wrong stent placement. Patients undergoing stenting should be controlled by clinical examination and color-Doppler ultrasound in hospitals where skilled interventional radiologists are available.

[Treatment of post kidney transplantation erythrocytosis (PTE) with ACE inhibitors]. / Trattamento dell'eritrocitosi post-trapianto (PTE) renale con gli ACE-inibitori.

BACKGROUND: Post kidney transplantation erythrocytosis is a frequent complication in male subjects. in our experience, it occurs in approximately 20% of transplant patients recciving cyclosporine inununosuppression therapy. METHODS: Twenty-two patients with post kidney transplantation erythrocytosis were treated using ACE-inhibitors (lisinopril) at a dose of 2-5-5 mg/day for a mean period of 15 months. Owing to tbe onset of collateral effects, 27% of these patients requested the conversion of ACE into angiotensin II receptor antagonists (AII). Twenty out of 22 patients were male (90%). RESULTS: Treatment resulted in a 15% reduction of hematocrit values compared to basal levels, which remained stable over time. No collateral effects were recorded, either for the kidneys or in terms of hypotension. CONCLUSIONS: ACE-inhibitors (lisinopril) or alternatively the use of angiotensin II receptor antagonists, like Iosartan at low doses, is an effective and safe treatment for patients developing post-transplantation erythrocytosis (PTE).

[Treatment of post kidney transplantation erythrocytosis (PTE) with ACE inhibitors]. / Trattamento dell'eritrocitosi post-trapianto (PTE) renale con gli ACE-inibitori.

BACKGROUND: Post kidney transplantation erythrocytosis is a frequent complication in male subjects. In our experience, it occurs in approximately 20% of transplant patients receiving cyclosporine immunosuppression therapy. METHODS: Twenty-two patients with post kidney transplantation erythrocytosis were treated using ACE-inhibitors (lisinopril) at a dose of 2-5-5 mg/day for a mean period of 15 months. Owing to the onset of collateral effects, 27% of these patients requested the conversion of ACE into angiotensin II receptor antagonists (AII). Twenty out of 22 patients were male (90%). RESULTS: Treatment resulted in a 15% reduction of hematocrit values compared to basal levels, which remained stable over time. No collateral effects were recorded, either for the kidneys or in terms of hypotension. CONCLUSIONS: ACE-inhibitors (lisinopril) or alternatively the use of angiotensin II receptor antagonists, like Losartan, at low doses, is an effective and safe treatment for patients developing post-transplantation erythrocytosis (PTE).

Efficacy of nonwoven fabric bioreactor immobilized with porcine hepatocytes for ex vivo xenogeneic perfusion treatment of liver failure in dogs.

We have developed a new bioartificial liver bioreactor filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF). In this study, we investigated the efficacy of our hybrid bioartificial liver system incorporating the NWF bioreactors and an immunoglobulin adsorbent column for perfusion treatment in a canine liver failure model. Xenogeneic perfusion treatment for operative canine liver failure models were performed for 3 h, and survival time, intracranial pressure, and blood and cerebrospinal fluid data were documented. Treatment was carried out without obstruction by immunological rejection when immunoglobulin adsorbent columns were used with the NWF bioreactors in combination. Dogs treated with this system exhibited a restricted increase of intracranial pressure and significant compensatory effects on blood and cerebrospinal amino acid imbalances as shown by a significant improvement of Fischer's ratio. On the other hand, relatively low capacity for ammonia elimination was shown as compared with homologous direct hemoperfusion.

[Warm ischemia in kidney from non-heart beating donor . Instrumental evaluation]. / L'ischemia calda nel rene di donatore a cuore non-battente. Valutazione strumentale.

A dramatic shortage of kidneys available for transplantation, due do the widespread reduction in consent, has urged us to explore alternative sources of kidney harvesting, in the attempt to reduce the current gap between the small number of donations and the large number of patients on waiting-list. We set our attention on non-heart-beating donors (NHBD). In the "first step" of our research, we tested an experimental technique, by using commercial pigs' kidneys, that has been useful to determinate the maximum warm ischemic time that a kidney of NHBD could tolerate. Parameters of this research were the resistance of the kidney in perfusion machine and the renal scintigraphy. Our results permitted to establish that the maximum warm ischemic time that a kidney of NHBD could tolerate, is 50 minutes (p > 0.001). This experimental technique could be employed to remove every doubt about the effective condition of NHBD kidney before the transplant, in the outlook, by using those kidneys, to reduce the organ shortage.