Francisco Valdés

One-year outcomes from an international study of the Ovation Abdominal Stent Graft System for endovascular aneurysm repair.

OBJECTIVE This study evaluated 1-year safety and effectiveness outcomes of the United States regulatory trial for the Ovation Abdominal Stent Graft System (TriVascular Inc, Santa Rosa, Calif) for endovascular repair of abdominal aortic aneurysms (AAAs). METHODS This prospective, multicenter, single-arm trial was conducted at 36 sites in the United States, Germany, and Chile to evaluate the safety and effectiveness of the Ovation stent graft. From November 2009 to May 2011, 161 patients (88% males; mean age, 73 ± 8 years) with AAAs (mean diameter, 54 ± 9 mm) were treated with the Ovation stent graft. The main body is a modular two-docking limb device with a 14F outer diameter delivery system, active suprarenal fixation, and polymer-filled proximal rings that accommodate the aortic neck for seal. Main inclusion criteria included proximal aortic neck length ≥ 7 mm, inner neck diameter between 16 and 30 mm, distal iliac landing zones length ≥ 10 mm, and diameter between 8 and 20 mm. Patients were treated under a common protocol, including clinical and imaging follow-up at discharge, 30 days, 6 months, and annually through 5 years. A Clinical Events Committee adjudicated adverse events, an independent imaging core laboratory analyzed imaging, and a Data Safety and Monitoring Board provided study oversight. Complete 1-year follow-up data were available for this report. RESULTS The Ovation stent graft was implanted successfully in 161 patients (100%), including 69 (42.9%) by percutaneous access. General anesthesia was used in 106 patients (65.8%). Technical success was 100%, and mean procedure time was 110 minutes. Median procedural blood loss was 150 mL, and median hospital stay was 1 day. The 30-day major adverse event rate was 2.5%. At 1 year, AAA-related and all-cause mortality were 0.6% and 2.5%, respectively. Major adverse event and serious adverse event rates through 1 year were 6.2% and 38.5%, respectively. The 1-year treatment success rate was 99.3%. The imaging core laboratory reported no stent graft migration or type I, III, or IV endoleaks. At 1 year, type II endoleaks were identified in 34% of patients, and AAA enlargement was identified in one patient (0.7%). No AAA rupture or conversion to open surgery was reported. AAA-related secondary procedures were performed in 10 patients (6.2%) for 12 findings, including endoleak (six), aortic main body stenosis (three), and iliac limb stenosis or occlusion (three). CONCLUSIONS The 1-year results of the Ovation Abdominal Stent Graft System demonstrate excellent safety and effectiveness in treatment of patients with AAAs, particularly in patients with challenging anatomic characteristics, including short aortic necks and narrow iliac arteries. Longer-term follow-up is needed.

Percutaneous Transluminal Angioplasty in Patients with Takayasu Arteritis: Five-year Experience

PURPOSE The authors report their 5-year experience with percutaneous transluminal angioplasty (PTA) for treatment of stenoses related to Takayasu arteritis. PATIENTS AND METHODS Twenty patients were treated; 12 patients had renovascular hypertension at presentation, three patients had abdominal aortic coarctation syndrome, and five patients had aortoiliac occlusive disease. RESULTS The initial success rate for patients with renovascular hypertension was 83%, with a 5-year patency of 33.3%. In patients with abdominal aortic coarctation, initial success rate was 100% but 5-year patency was 33.3%. In patients with aortoiliac occlusive disease, the initial success rate was 100%, with a 5-year patency of 60%. CONCLUSION Despite the high initial success rate for PTA in these patients, the disease recurs in a substantial number of the, due to the fact that this technique does not treat the disease itself but only its consequences.

A rapid procedure for purifying a restriction endonuclease from thermus thermophilus (Tth I)

Restriction enzymes have proved to be a powerful tool for mapping genomes [l] and developing molecular cloning and DNA sequencing techniques [2]. A few restriction enzymes have been isolated from thermophilic bacteria [3], showing a high thermostability and resistance to protein denaturing agents. These properties could be useful to study DNA structure at higher temperatures. Looking for a stable enzyme with a new recognition sequence, we have isolated Tth I, an enzyme from the extreme thermophile Thermus thermophilus HB8 [4]. This thermostable enzyme turned out to be an isoschizomer of Taq I, which recognizes the sequence 5’-TCGA-3’ [5]. Thermus thermophilus is a very convenient source for purifying this enzyme since this bacterium does not produce the pigmented ‘slime’ described in Thermus aquaticus [6], which interferes with the purification of Taq I [5,7] and other enzymes [8,9]. Furthermore, Tth I was readily released by osmotic shock, which allowed us to develop a simplified, rapid two-step procedure to obtain an enzyme preparation free of contaminating nucleases. We report here the purification method and some of the properties of Tth I.

Arterial Thoracic Outlet Syndrome: A 32-year Experience

BACKGROUND Clinical manifestations of thoracic outlet syndrome (TOS) differ depending on the compromised anatomic structure. Arterial TOS is the least common (1-5% of all cases of TOS), yet the most threatening, due to the risk of limb loss. METHODS We conducted a retrospective review of consecutive patients treated for arterial TOS between January 1979 and June 2012. Medical records and diagnostic images were reviewed, and follow-up was obtained. RESULTS Nineteen procedures were performed in 18 patients for symptomatic arterial TOS. The average age was 34 years (range 16-69 years), and 12 patients were female (63.2%). Surgical indications were upper limb critical ischemia in 8 (acute in 5 cases and acute-on-chronic in 3 cases) and claudication in 11. Imaging studies revealed a subclavian aneurysm in 7 patients, stenosis in 4 patients, and 2 patients with subclavian artery occlusion. The 6 remaining cases had symptoms caused by arterial compression in dynamic studies without arterial wall damage at rest. All limbs underwent surgery with outlet decompression; in addition, 13 underwent arterial reconstruction, and 7 were treated for distal embolic complications. There were no deaths, amputations, or early reoperations; 1 patient was readmitted 2 weeks after surgery for chylothorax, which resolved with conservative measures. During a mean follow-up of 155.8±103.1 months, 1 patient underwent successful reintervention at 4 months for bypass occlusion. CONCLUSIONS Arterial TOS is an infrequent but relevant manifestation of TOS. An accurate and early diagnosis allows for timely surgery and adequate results, as shown in this group of patients.

Antegrade Hypogastric Revascularization During Endovascular Aortoiliac Aneurysm Repair: An Alternative to Bilateral Embolization

Anatomy has been the major challenge to overcome to increase safe and durable applicability of endografting for the treatment of abdominal aortic aneurysm. Bilateral iliac aneurysm preventing an appropriate distal landing zone for the endograft is a common condition and can be managed by (a) increasing the diameter of the endograft, with limitations in available sizes, (b) bilateral hypogastric embolization, accepting an increased morbidity, (c) the use of a branched device, increasing the cost and currently with limited availability, (d) combined surgical hypogastric revascularization by the retroperitoneal approach, or (e) retrograde revascularization from the ipsilateral external iliac artery using an endograft. We describe the use of widely available devices to obtain stable antegrade revascularization of one hypogastric artery during aortic endografting. We report the case of a 68-year-old man, at high risk for an open procedure, who presented with bilateral iliac aneurysm and minor aortic ectasia; no iliac landing zone was available. A regular bifurcated graft was deployed and extended into one of the external iliac arteries, preceded by ipsilateral hypogastric embolization. Through an upper extremity approach, an endograft was deployed from the remaining bifurcated graft branch into the other hypogastric artery, followed by ipsilateral external iliac occlusion. Finally a femorofemoral crossover bypass was performed. The patient recovered event free, and patency of the endograft and absence of endoleak were demonstrated on computed tomography. Minor unilateral buttock claudication resolved in 6 weeks and sexual function was preserved. This technique is a reasonable alternative to consider in the endovascular treatment of patients with bilateral iliac aneurysm, allowing preservation of pelvic perfusion, limiting cost, and using available devices.

Endovascular Treatment of Symptomatic Pulmonary Sequestration

Pulmonary sequestration is a rare congenital malformation whose origin is bronchial and arterial simultaneously and its vascularization comes from an anomalous systemic artery. Its clinical presentation includes recurrent pneumopathy in the same anatomic location of the lung and difficult to resolve or recurrent lung abscess. It is usually treated with antibiotherapy and eventual surgical resection. A 23-year-old woman with history of recurrent respiratory infections and three episodes of hemoptysis was admitted at the hospital. Computed tomography and magnetic resonance imaging confirmed diagnosis of pulmonary sequestration. The angiographic study showed the presence of three inflow arteries arising from the thoracic aorta (T10) and supplying the abnormal lung parenchyma at the base of the left hemithorax. The patient underwent endovascular treatment consisting of exclusion of the inflow vessels with Amplatzer occlusive devices and coils. Subsequent computed tomography angiogram confirmed complete infarction of the sequestration. At 7 months, the patient presented with a new episode of bronchial infection. Repeated angiography showed persistence of intermediate small nutrient branches that were treated with coil embolization. The patient is symptom-free at 41 months after this secondary procedure. Endovascular treatment of pulmonary sequestration, with selective embolization of the inflow arteries, is a very attractive minimally invasive therapeutic option, as compared with conventional surgery, and potentially less prone to associated complications.

Endovascular Treatment of Cystic Adventitial Disease of the Popliteal Artery

Cystic adventitial disease of the popliteal artery is an uncommon cause of intermittent claudication in young patients. Several treatment options are available, oriented to either drainage of the cyst and/or arterial reconstruction. Endovascular techniques have been used in exceptional cases to treat this condition, mostly balloon angioplasty and only 2 cases of stenting, with mixed to poor results. We report the case of a 36-year-old female patient with claudication who was treated with primary stenting with long-term symptomatic relief and arterial patency.

Four-Limb Acute Ischemia Induced by Ergotamine in an AIDS Patient Treated With Protease Inhibitors

A 32-year-old man infected with HIV presented to the emergency department of our hospital reporting pain, coldness, paresthesias, and cyanosis in both feet and hands. The symptoms had started 3 days before, with lower extremities claudication at 200 m, which progressed to rest pain the day of admission; it was worse on the right foot. He was on chronic antiretroviral therapy with 300 mg QID tenofovir (Viread), 300 mg BID abacavir (Ziagen), and two 200/50 mg BID lopinavir/ritonavir (Kaletra). His CD4 cell count was 245 cells/mm and his HIV viral load was 45 copies/mL. When directly interviewed, the patient remembered that he had taken a single dose of ergotamine (1 mg) for migraine 24 hours before the onset of symptoms. He denied any recent drug intake. On examination, his 4 extremities were cold, cyanotic, and pulseless (Figure 1A). Only femoral pulses were weakly palpable. Plethysmography revealed bilateral multilevel ischemia, with severe proximal disease …

Uso de endoprótesis en el tratamiento de lesiones no oclusivas del territorio iliaco

OBJETIVO: La cirugia endovascular se ha establecido como una opcion eficaz en el tratamiento de la enfermedad oclusiva ateroesclerotica de las arterias iliacas. Sin embargo, el uso de estos procedimientos para tratar otro tipo de lesiones aun no ha sido bien estudiado. Nuestro objetivo es analizar indicaciones y resultados del uso de endoprotesis en lesiones iliacas no oclusivas. MATERIAL Y METODOS: Revisamos retrospectivamente los registros de 14 pacientes consecutivos, todos hombres, 61,6 anos de edad en promedio (rango: 25-80) tratados por via endovascular entre 2001 y 2006 por lesiones iliacas no oclusivas. El estudio pre y postoperatorio incluyo tomografia computada. El procedimiento se efectuo en quirofano, utilizando un angiografo digital. Se uso acceso femoral insertando endoprotesis tubulares. RESULTADOS: En 11 pacientes se asocio embolizacion de arteria hipogastrica ipsilateral. Las patologias tratadas fueron: ocho aneurismas ateroescleroticos, 3 disecciones, 2 lesiones traumaticas y un pseudoaneurisma anastomotico. La co-morbilidad mas frecuente fue la hipertension en 43% de los casos. No hubo mortalidad operatoria. Un paciente presento un pseudoaneurisma femoral tratado con compresion. Un paciente tratado por fistula arteriovenosa traumatica a nivel iliaco resuelve su insuficiencia cardiaca, con persistencia asintomatica de minimo flujo. La estadia postoperatoria fue de 3 dias (mediana). No se presentaron otras endofugas iniciales o tardias. Durante un seguimiento promedio de 20,5 meses (rango 1 a 49), un paciente fallece por cancer y ninguno ha requerido procedimientos complementarios. CONCLUSION: El tratamiento endovascular de lesiones iliacas mediante endoprotesis es seguro y permite un resultado durable en el manejo de un amplio espectro de patologias.

Trombolisis mecánica y fármaco-mecánica en el tratamiento de trombosis venosa profunda sin respuesta clínica con tratamiento médico convencional

BACKGROUND Conventional treatment of deep vein thrombosis (DVT) is anticoagulation, bed rest and limb elevation. Proximal DVT patients with persisting edema, pain and cyanosis of extremities despite of conventional therapy may develop ischemia. Direct treatment of thrombosis becomes necessary. AIM To report our experience with mechanical trombolysis of proximal lower extremity DVT. MATERIAL AND METHODS Retrospective review of medical records of proximal DVT patients treated with thrombolysis between March 2012 and August 2015. Thirteen patients, 14 limbs, median age 34 years (22-85), 8 women, were admitted with pain and swelling of recent onset; one patient with venous gangrene. All patients initially received heparin in therapeutic doses without clinical improvement. RESULTS In all 13 cases, mechanical thrombolysis was performed using AngioJet®, and associated with single dose thrombolytic agent in 9. Additional angioplasty for residual stenosis was performed in 12 (7 stents) and IVCF were implanted in 8. All patients were subsequently anticoagulated. Early outcomes with disappearance of pain and decrease of edema, with no mortality or bleeding complications. The patient with foot gangrene required amputation. CONCLUSIONS Mechanical thrombolysis with a single dose of a thrombolytic agent is safe and effective in patients with proximal DVT with an unfavorable evolution.Background: Conventional treatment of deep vein thrombosis (DVT) is anticoagulation, bed rest and limb elevation. Proximal DVT patients with persisting edema, pain and cyanosis of extremities despite of conventional therapy may develop ischemia. Direct treatment of thrombosis becomes necessary. Aim: To report our experience with mechanical trombolysis of proximal lower extremity DVT. Material and Methods: Retrospective review of medical records of proximal DVT patients treated with thrombolysis between March 2012 and August 2015. Thirteen patients, 14 limbs, median 34 years (22-85), 8 women, were admitted with pain and swelling of recent onset; one patient with venous gangrene. All patients initially received heparin in therapeutic doses without clinical improvement. Results: In all 13 cases, mechanical thrombolysis was performed using AngioJet®, and associated with single dose thrombolytic agent in 9. Additional angioplasty for residual stenosis was performed in 12 (7 stents) and IVCF were implanted in 8. All patients were subsequently anticoagulated. Early outcomes with disappearance of pain and decrease of edema, with no mortality or bleeding complications. The patient with foot gangrene required amputation. Conclusions: Mechanical Thombolysis with a single dose of a thrombolytic agent is safe and effective in patients with proximal DVT with an unfavorable evolution.