Solitary iliac branch endoprosthesis placement for iliac artery aneurysms.

BACKGROUND: Isolated iliac artery aneurysms (IAAs), accounting for 2% to 7% of all abdominal aneurysms, are often treated with the use of iliac branched endografts. Although outside the manufacturer's instructions for use, iliac branched devices can be used solely, without the adjunctive placement of an endovascular aneurysm repair device, for the treatment of an isolated IAA. In the present study, we have described the outcomes of the use of the Gore iliac branched endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, Ariz), without the support of an infrarenal endovascular aneurysm repair device, for the exclusion of an isolated IAA. The present study was an international multicenter retrospective cohort analysis. METHODS: All the patients who had undergone treatment with a solitary IBE for IAA exclusion from January 11, 2013 to December 31, 2018 were retrospectively reviewed. The primary outcome was technical success. The secondary outcomes included mortality, intraoperative and postoperative complications, and reintervention. RESULTS: A total of 18 European and American centers participated, with a total of 51 patients in whom 54 IAAs were excluded. The technical success rate was 94.1%, with an assisted technical success rate of 96.1%. No 30-day mortality occurred, with 98.1% patency of the internal and external iliac artery found at 24 months of follow-up. At 24 months of follow-up, 81.5% of the patients were free of complications and 90% were free of a secondary intervention. CONCLUSIONS: Treatment with a solitary IBE is a safe and, at midterm, an effective treatment strategy for selected patients with a solitary IAA.

TWEAK favors phosphate-induced calcification of vascular smooth muscle cells through canonical and non-canonical activation of NFκB.

Vascular calcification (VC) is associated with increased cardiovascular mortality in aging, chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM) and atherosclerosis. TNF-like weak inducer of apoptosis (TWEAK) recently emerged as a new biomarker for the diagnosis and prognosis of cardiovascular diseases. TWEAK binding to its functional receptor Fn14 was reported to promote several steps of atherosclerotic plaque progression. However, no information is currently available on the role of TWEAK/Fn14 on the development of medial calcification, which is highly prevalent in aging, CKD and T2DM. This study explored the involvement of TWEAK in human vascular smooth muscle cells (h-VSMCs) calcification in vitro. We report that TWEAK binding to Fn14 promotes inorganic phosphate-induced h-VSMCs calcification, favors h-VSMCs osteogenic transition, decreasing acta2 and myh11 and increasing bmp2 mRNA and tissue non-specific alkaline phosphatase (TNAP), and increases MMP9 activity. Blockade of the canonical NFκB pathway reduced by 80% TWEAK pro-calcific properties and decreased osteogenic transition, TNAP and MMP9 activity. Blockade of non-canonical NFκB signaling by a siRNA targeting RelB reduced by 20% TWEAK pro-calcific effects and decreased TWEAK-induced loss of h-VSMCs contractile phenotype and MMP9 activity, without modulating bmp2 mRNA or TNAP activity. Inhibition of ERK1/2 activation by a MAPK kinase inhibitor did not influence TWEAK pro-calcific properties. Our results suggest that TWEAK/Fn14 directly favors inorganic phosphate-induced h-VSMCs calcification by activation of both canonical and non-canonical NFκB pathways. Given the availability of neutralizing anti-TWEAK strategies, our study sheds light on the TWEAK/Fn14 axis as a novel therapeutic target in the prevention of VC.

Interactions of the growth-related, type IIc renal sodium/phosphate cotransporter with PDZ proteins.

Despite similar molecular structures, the growth-related sodium/phosphate cotransporter NaPiIIc is regulated differently than the main NaPiIIa phosphate transporter. Using two-hybrid systems and immunoprecipitation, we identified several proteins that interact with NaPiIIc that might account for this differential regulation. NaPiIIc interacted with the PDZ domain-containing sodium-hydrogen exchange-regulating factor (NHERF) 1 and NHERF3 through novel binding motifs in its C terminus. NaPiIIc from brush-border membranes coprecipitated with both NHERF1 and NHERF3, with more NHERF3 co-precipitated in rats fed a low-phosphorus diet. NaPiIIc colocalizes with both NHERF1 and NHERF3 in brush-border membranes of rats fed either a low- or high-phosphorus diet. When mouse NaPiIIc was transfected into opossum kidney cells, it was localized mainly in apical microvilli and the trans-Golgi. Both confocal and total internal reflection microscopy show that NaPiIIc colocalizes with NHERF1 and NHERF3 in the apical microvilli, and this was not altered by truncation of the last three amino acids of NaPiIIc. Interactions of NaPiIIc with NHERF1 and NHERF3 were modulated by the membrane-associated 17 kDa protein (MAP17) similarly to NaPiIIa, but only the MAP17-NaPiIIc-NHERF3 complexes were internalized to the trans-Golgi. Our study shows that NaPiIIc interacts with a limited number of PDZ domain proteins, and the mechanisms and consequences of such interactions differ from those of NaPiIIa.

Which distal anastomosis should be used in PTFE femoro-tibial bypass?

AIM: The PTFE prosthesis represents an alternative to the autologous saphenous vein in femoro-tibial revascularization for limb salvage in the absence of venous material in the patient. The aim of our study is to confirm the validity of PTFE revascularization and determine the best distal anastomosis in terms of patency using 3 different techniques. We carried out a retrospective analysis, evaluating patients who underwent PTFE femoro-tibial revascularization for critical ischemia. METHODS: Between January 1998 and June 2002 we performed 46 femoro-tibial revascularizations at the Vascular Surgery Division of the Poliambulanza Hospital in Brescia using a PTFE prosthesis, from a total of 192 infrainguinal revascularizations (24%). All patients presented a critical ischemia, with trophic lesions or gangrene in 76% of the cases (35/46) and who were previously treated unsuccessfully with medical therapy. Seventeen cases (36%) were a redo bypass due to previously failed revascularization. In all cases the saphenous vein was not available due to past peripheral or coronary revascularization (45%), saphenectomy (20%) or inadequate diameter (35%). The distal anastomoses were performed on the peroneal artery in 29 cases, on the anterior tibial artery in 14 cases and on the posterior tibial artery in 3 cases. The distal anastomosis was performed by interposing a segment of vein between the prosthesis and the tibial artery in 12 cases; in 22 cases the interposition was performed using a vein patch, and in the remaining 12 cases a PTFE prosthesis provided with a premanufactured expanded anastomosis (Distaflo(c)) was used. RESULTS: Average follow-up was 22.5 months (range: 3-48 months). The primary and secondary patency rate at 48 months, calculated with the Life table method, was 35% and 47%, respectively. Limb salvage in the same time period was 56%. Depending on the anastomosis performed (Distaflo(c), vein patch, distal vein) we obtained a secondary patency rate of 31%, 62%, and 44% respectively after 48 months with a significant difference between distal vein patch and the other two anastomoses (p<0.001). CONCLUSIONS: The PTFE bypass on the tibial artery performed for limb salvage in the absence of a saphenous vein represents a valid alternative to other types of prostheses with a patency percentage that is acceptable in the medium term. Within our study population, anastomosis by vein patch interposition gave better results than other types of tibial anastomosis.

Surgical treatment of popliteal artery aneurysm. A 20 year experience.

OBJECTIVES: A retrospective study to evaluate the treatment, long term follow-up and factors affecting revascularization results particularly in regard to clinical presentation and prosthetic materials used after 20 years of experience. MATERIALS AND METHODS: Between 1974 and September 1995 there were 67 popliteal aneurysms in 58 patients. Three patients underwent a primary amputation because of irreversible ischaemia and 3 patients a surgical sympathectomy. Operative repair was performed in 61 cases: as an emergency in 9 (14.7%) limbs and as an elective procedure in 52 (85.3%) limbs. Graft replacement was performed employing polytetrafluoroethylene (PTFE) grafts in 34 (55.7%) cases 13 of which with Ringed PTFE, autogenous saphenous vein in 10 (16.4%) cases and Dacron in 17 (27.9%). RESULTS: The cumulative primary patency (CP) and limb salvage rate (LS) at 10 years were 75.1% and 83.3% respectively. We divided the patients into two groups: asymptomatic (Group I) and symptomatic with limb threatening ischemia (Group II). At 10 years the CP in Group I and II were 78.2% vs 67.2% respectively (p < 0.05 at 18 months) and the LS 87.4% vs 74.6% (p < 0.05). There was no statistical difference in terms of CP and LS rate between saphenous vein and PTFE. The use of PTFE grafts avoided harvesting of the long saphenous vein; this resulted in a significantly reduced operation time (135 +/- 18.6 vs 195 +/- 22.4 minutes, p < 0.001) and length of stay (7.4 vs 8.8 days, p < 0.02). CONCLUSIONS: We conclude that elective repair is indicated in all patients with popliteal aneurysm > or = 2 cm to avoid a critical ischemia with poorer results in terms of CP and LS. In the last 3 years our technique of choice is the exclusion of the aneurysm with a short PTFE bypass with good long-term of CP and LS rates.

Radiation myelopathy in over-irradiated patients: MR imaging findings.

The objective of this work is to report the MRI findings in patients with radiation myelopathy due to accidental local over-irradiation syndrome. Eight patients (seven males and one female) were suffering from over-irradiation syndrome as a result of treatments from a malfunctioning linear electron accelerator. The mean accidental estimated dose was 136 Gy delivered to the "open-neck" (seven cases) and to the thoracic wall (one case), during a mean of 5.4 sessions (range 1-9 sessions). Paresthesia and weakness in the upper extremities were the earliest symptoms (87.5 %), with evolution to paralysis in all patients. No patient is alive (mean survival time 64 days). In all cases MRI was negative for neurologic lesions in the acute phase ( < 90 days from irradiation; Radiation Therapy Oncology Group scoring system). Late signs of radiation myelitis manifested as high-intensity signals on T2-weighted images in three patients, and as Gd-DTPA enhancement of T1-weighted images in one case. Autopsies performed on four patients who died in acute phase showed morphologic alterations in white matter: edema in 75 %, and necrosis and glial reaction as well as obliterative vasculitis in all cases. In cases of over-irradiation, MRI may be normal in acute phase even if the patients have severe neurologic deficit, as positive MRI findings appear only in delayed radiation myelitis.

Accidental overirradiation syndrome.

Between the 10th and 20th December 1990, there was a malfunction in the operation of the Electron Linear Accelerator (ELA) at the Hospital Clínico Universitario in Zaragoza (Spain), which led to irradiation with the highest beam energy. This situation shows the existence of a latent period between the irradiation and the appearance of the symptoms, even in situations involving much higher than normal doses in cases of localized irradiation.

In situ saphenous vein bypass for limb salvage.

A total of 130 infrapopliteal in situ saphenous vein bypasses were performed in 128 patients between January 1980 and June 1991. The indication for surgery was critical ischaemia with impending limb loss in 121 patients; seven suffered from severe claudication. The distal anastomosis was to the popliteal artery below the knee in 60 cases (46.2%) and in 70 (53.8%) to the tibioperoneal arteries. The results, in terms of secondary patency and limb salvage rates, of the first 68 procedures (1980-1985) and subsequent 62 (1986-June 1991) were compared. In the first period, a secondary patency rate of 42.6% and a limb salvage rate of 67.0% were obtained, compared with 71.3 and 80.8% respectively in the second. These differences are significant for patency (P < 0.005) and limb salvage (P < 0.01). These results show that the in situ technique can give acceptable results but a learning period with a high percentage of early failures is to be expected.