Browsing by Author "Valdes, Francisco"
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- ItemAntegrade Hypogastric Revascularization During Endovascular Aortoiliac Aneurysm Repair: An Alternative to Bilateral Embolization(ELSEVIER SCIENCE INC, 2010) Mertens, Renato A.; Bergoeing, Michel P.; Marine, Leopoldo A.; Valdes, Francisco; Kramer, Albrecht H.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 ante-grade 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.
- ItemDesign for the First Narrowband Filter for the Dark Energy Camera: Optimizing the LAGER Survey for z ∼ 7 Galaxies(2019) Zheng, Zhen-Ya; Rhoads, James E.; Wang, Jun-Xian; Malhotra, Sangeeta; Walker, Alistair; Mooney, Thomas; Jiang, Chunyan; Hu, Weida; Hibon, Pascale; Jiang, Linhua; Infante, Leopoldo; Barrientos, L. Felipe; Galaz, Gaspar; Valdes, Francisco; Wester, William; Yang, Huan; Coughlin, Alicia; Harish, Santosh; Kang, Wenyong; Khostovan, Ali Ahmad; Kong, Xu; Perez, Lucia A.; Pharo, John; Wold, Isak; Zheng, XianZhongWe present the design for the first narrowband filter, NB964, for the Dark Energy Camera (DECam), which is operated on the 4-m Blanco Telescope at the Cerro Tololo Inter-American Observatory. The NB964 filter profile is essentially defined by maximizing the power of searching for Lyman-alpha emitting galaxies (LAEs) in the epoch of reionization, with the consideration of the night sky background in the near-infrared and the DECam quantum efficiency. The NB964 filter was manufactured by Materion in 2015. It has a central wavelength of 964.2 nm and a full width at half maximum (FWHM) of 9.2 nm. An NB964 survey named Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) has been ongoing since December 2015. Here, we report results of lab tests, on-site tests, and observations with the NB964 filter. The excellent performances of this filter ensure that the LAGER project is able to detect LAEs at z similar to 7 with a high efficiency.
- ItemDevelopment and validation of an improved classification and risk stratification system for carotid body tumors: A multinational collaborative cohort study(2021) Mehanna, Hisham; Mistry, Pankaj; Golusinski, Pawel; Maio, Pasquale Di; Nankivell, Paul; Snider, Francesco; Ferrante, Angela M. R.; Montalto, Nausica; Nicolai, Piero; Marcantoni, Alessandra; Grandi, Cesare; Zavatta, Marco; Grego, Franco; Malec, Kataryna; Hosal, Sefik; Suslu, Nilda; Kuscu, Oguz; Torrealba, Ignacio; Valdes, Francisco; Sharma, Neil; Ayuk, John; Monksfield, Peter; Irving, Richard; Dunn, Janet A.; Kay, Mark; Borsetto, DanieleBackground This study aims to develop and validate a new classification system that better predicts combined risk of neurological and neurovascular complications following CBT surgery, crucial for treatment decision-making. Methods Multinational retrospective cohort study with 199 consecutive cases. A cohort of 132 CBT cases was used to develop the new classification. To undertake external validation, assessment was made between the actual complication rate and predicted risk by the model on an independent cohort (n = 67). Results Univariate analyses showed statistically significant associations between developing a complication and the following factors: craniocaudal dimension, volume, Shamblin classification, and Mehanna types. In the multivariate prognostic model, only Mehanna type remained as a significant risk predictor. The risk of developing complications increases with increasing Mehanna type. Conclusions We have developed and then validated a new classification and risk stratification system for CBTs, which demonstrated better prognostic power for the risk of developing neurovascular complications after surgery.
- ItemEndovascular repair of abdominal aortic aneurysm.: Results in 80 consecutive patients(2006) Valdes, Francisco; Mertens, Renato; Kramer, Albrecht; Bergoeing, Michel; Marine, Leopoldo; Canessa, Roberto; Huete, Alvaro; Vergara, Jeanette; Valdebenito, Magaly; Rivera, DixianaBackground: Endovascular repair of abdominal aortic aneurysms (AAA) avoids laparotomy, shortens hospital stay and reduces morbidity and mortality related to surgical repair allowing full patient recovery in less time. Aim: To report short and long term results of endovascular repair of AAA in 80 consecutive patients treated at our institution. Patients and Methods: Between September 1997 and February 2005, three women and 77 men with a mean age 73.6 +/- 7.7 years with AAA 5.8 +/- 1.0 cm in diameter, were treated. The surgical risk of 38% of patients was grade III according to the American Society Anesthesiologists classification. Each procedure was performed in the operating room, under local or regional anesthesia, with the aid of digital substraction angiography. The endograft was deployed through the femoral artery (83,7016 bifurcated 16.3% tubular graft). A femoro-femoral bypass was required in 11.3% of cases. Follow-tip included a spiral CT scan at 1, 6 and 12 months postoperatively, and then annually). Results. Endovascular repair was successfully completed in 79/80 patients (98.7% technical success). The procedures lasted 147 +/- 71 min. Length of stay in the observation unit was 20.6 +/- 73.5 h. Blood transfusion was required in 10%. Sixty two percent of the patients were discharged before 72 h. One patient died 8 days after surgery due to a myocardial infarction (1.3%. During follow-up (3-90 months), 1 patient developed late AAA enlargement due to a type I endoleak, requiring a new endograft. No AAA rupture was observed. Survival at 4 years was 84.2% (SE = 9.2). Endovascular re-intervention free survival was 82.7% (SE = 9.5). Conclusion: Endovascular surgery allows affective exclusion of AAA avoiding progressive enlargement and/or rupture and is a good alternative to open repair Close and frequent postoperative follow up is mandatory.
- ItemExtra anatomical revascularization and endovascular stent-grafting for thoracoabdominal aneurysm repair. Report of four cases(2007) Mertens, Renato; Valdes, Francisco; Kramer, Albrecht; Marine, Leopoldo; Bergoeing, Michel; Sagues, Rodrigo; Huete, Alvaro; Vergara, Jeannette; Valdebenito, MagalySurgical treatment of thoracoabdominal aneurysms is a big technical challenge with a high rate of complications and mortality. It requires a large exposure and transient interruption of vital organ perfusion during its repair. Endovascular repair is a less invasive alternative available over the last decade. We report four male patients aged 44 to 76 years, with thoracic aortic aneurysms and involvement of visceral aorta, treated with a two stage procedure. During the first stage, a retrograde revascularization of the superior mesenteric and renal arteries from the infrarenal aorta was done, associated in two cases to a concomitant repair of an infrarenal aortic aneurysm. In the second stage, an endovascular graft was placed through the femoral artery, from the segment proximal to the aneurysm to the infrarenal aorta, above the origin of the visceral artery reconstructions, excluding the aneurysm from circulation. In one patient, both stages were concomitant and in three the second stage was delayed. One patient presented a postoperative bleeding that required reintervention without adverse consequences. No patient died, presented paraplegia or deterioration of renal function. After follow up of 6 to 20 months, there is no evidence of aneurysm growth or complications derived from the procedure.
- ItemExtrinsic venous compression secondary to spine osteophytes(2023) Gonzalez-Urquijo, Mauricio; Torrealba, Jose; Francisco Vargas, Jose; Mertens, Renato; Marine, Leopoldo; Valdes, FranciscoObjective This study aims to report two cases of symptomatic extrinsic compression of the inferior vena cava and left iliac vein caused by vertebral osteophytes. Methods We present two case reports of extrinsic venous compression by vertebral osteophytes. Both cases were endovascularly treated, with a successful outcome. A review of the literature of this unusual condition is also presented. Results The first patient is an 80-year-old woman who presented to the vascular surgery clinic with bilateral lower extremity edema and pain. A computed-tomography angiography (CTA) revealed extrinsic compression of the inferior vena cava from enlarged osteophytes. Venography and intravascular ultrasound were performed, confirming the diagnosis. A self-expanding venous stent was successfully deployed in the inferior vena cava relieving the extrinsic compression. The edema resolved the following day and was discharged without complications. The second patient is a 61-year-old male that presented to the emergency department with a left iliofemoral deep venous thrombosis. CTA showed left iliac vein compression by a lumbar osteophyte. Percutaneous thrombectomy was successfully achieved and an expanding stent was deployed covering the entire lesion. One month after the procedure the patient died from COVID-19-associated respiratory failure. Conclusion Osteophytes must be considered when dealing with extrinsic venous compression, especially in elderly people.
- ItemIsolated Abdominal Aortic Dissection With and Without Abdominal Aortic Aneurysm(2024) Gonzalez-Urquijo, Mauricio; Marine, Leopoldo; Valdes, Francisco; Vargas, Jose Francisco; Bergoeing, Michel; Mertens, RenatoObjective The aim of this study was to report the clinical presentation and treatment outcomes of patients treated for IAAD with and without abdominal aortic aneurysm (AAA) in a single academic institution in South America.Materials and Methods A retrospective review of all patients with IAAD with or without concomitant AAA between January 2002 and December 2023 from a single academic hospital was performed.Results Eighteen patients with IAAD were diagnosed of whom 13 (72.2%) were males. Median age was 63 years (range: 43-88 years). Sixteen (88.8%) patients presented with symptoms, and in two (11.1%) asymptomatic patients IAAD was an incidental finding. Ten (55.5%) patients had concomitant abdominal aortic aneurysm (AAA), with a median size of the aneurysm of 49.5 mm (range: 44-66 mm). No statistical differences in baseline characteristics were seen between patients with concomitant IAAD and AAA and patients with only IAAD. Seven (38.8%) patients presented chronic dissection, and 11 (61.1%) patients had acute dissection. Five (27.7%) patients were treated conservatively with blood pressure, pain control, and antiplatelets; endovascular surgery was performed in eight (44.4%) patients and open surgery in five (27.7%) patients. The complication rate was 22.2% (n = 4), and the mortality rate was 0%. Median follow-up was 36 months (range: 6-240 months). Complete remodeling was seen in all patients except two patients who underwent conservative treatment. Of those, one had partial remodeling, and the other no changed.Conclusion Isolated aortic dissection of the abdominal aorta is an uncommon condition, with acceptable different treatment strategies, from conservative to invasive treatments. Sometimes IAAD can concur with AAA, and when so, invasive treatment might be considered. More studies describing the natural history of AAA and its association with IAAD are warranted, as well as further research reporting long-term outcomes on aortic remodeling after different treatment modalities.
- ItemManagement of Spontaneous Isolated Celiac Artery Dissection(2024) Gonzalez-Urquijo, Mauricio; Vargas, Jose Francisco; Marine, Leopoldo; Mertens, Nicolas; Valdes, Francisco; Bergoeing, Michel; Mertens, RenatoBackground: Spontaneous isolated celiac artery dissection (SICAD) is uncommon, with very few series reported in the literature. The present study aims to describe the clinical characteristics and treatment outcomes of patients with SICAD treated at a single Chilean institution over 20 years. Methods: A retrospective review of all patients from a single academic hospital with SICAD diagnosed between January 2003 and March 2023 was performed. Conservative treatment included antiplatelets, anticoagulation, or both. The normal size of a celiac artery in our population was 7.9 +/- 0.79 mm in females and 8.3 +/- 1.08 mm in males. We defined a celiac artery with a diameter equal to or more than 12.5 mm as an aneurysmal celiac artery. Results: The cohort included 27 patients; 77.8% (n = 21) were males. The median age was 51.0 years (range: 38-84 years). Fourteen (51.8%) patients presented with aneurysmal dilatation. Fourteen (51.8%) patients were treated with antiplatelets, 6 (22.2%) patients with anticoagulation, and 7 (25.9%) with anticoagulation and antiplatelets. One patient was treated with endovascular therapy due to a pseudoaneurysm of the celiac artery detected 10 days after conservative treatment with antiplatelets. The median length of hospital stay was 5 days (range: 214 days). Complete remodeling was seen in 6 (22.2%) patients, partial remodeling in 10 (37.0%) patients, and no change was seen in 8 (26.9%) patients. Three (11.5%) patients were lost to follow-up. There were no significant differences between treatments and remodeling outcomes (P = 0.729). The median celiac artery diameter of patients with aneurysmal dilatation was 13.5 mm (range: 12.5-20.5 mm). Systemic arterial hypertension was found more commonly in patients who presented with aneurysmal dilatation than in patients without (87.5% vs. 12.5%, respectively, P = 0.016). Mean follow-up was 41.5 months and median follow-up was 16 months (range: 6-204 months). Conclusions: Most patients with SICAD can be treated conservatively with excellent outcomes. Hypertension was more commonly found in patients with SICAD and aneurysmal dilatation.
- ItemNew Spectroscopic Confirmations of Lyα Emitters at Z ∼ 7 from the LAGER Survey(2022) Harish, Santosh; Wold, Isak G. B.; Malhotra, Sangeeta; Rhoads, James E.; Hu, Weida; Wang, Junxian; Zheng, Zhen-ya; Barrientos, L. Felipe; Gonzalez-Lopez, Jorge; Perez, Lucia A.; Khostovan, Ali Ahmad; Infante, Leopoldo; Jiang, Chunyan; Moya-Sierralta, Cristobal; Pharo, John; Valdes, Francisco; Yang, HuanWe report spectroscopic confirmations of 15 Ly alpha galaxies at z similar to 7, implying a spectroscopic confirmation rate of similar to 80% on candidates selected from the Ly alpha Galaxies in the Epoch of Reionization (LAGER), which is the largest (24 deg(2)) survey aimed at finding Ly alpha emitters (LAEs) at z similar to 7 and uses deep narrowband imaging from the Dark Energy Camera at CTIO. LAEs at high redshifts are sensitive probes of cosmic reionization, and narrowband imaging is a robust and effective method for selecting a large number of LAEs. In this work, we present results from the spectroscopic follow-up of LAE candidates in two LAGER fields, COSMOS and WIDE-12, using observations from Keck/LRIS. We report the successful detection of Ly alpha emission in 15 candidates. Three of these in COSMOS have matching confirmations from a previous spectroscopic follow-up and are part of the overdense region, LAGER-z7OD1. Two other candidates that were not detected with LRIS have prior spectroscopic confirmations from Magellan. Including these, we obtain a spectroscopic confirmation success rate of similar to 80% for LAGER LAE candidates. Thorough checks were performed to reject the possibility of these detections being foreground emission resulting with a probability of, at most, one contaminant. We do not detect any other UV nebular lines in our LRIS spectra, apart from Ly alpha. We estimate a 2 sigma upper limit for the ratio of N v/Ly alpha, f (NV)/f (Ly alpha ) less than or similar to 0.27. Including confirmations from this work, a total of 33 LAE sources from LAGER are now spectroscopically confirmed. LAGER has more than doubled the sample of spectroscopically confirmed LAE sources at z similar to 7.
- ItemPelvic intravenous leiomyomatosis with intracardiac extension. Report of two cases(SOC MEDICA SANTIAGO, 2012) Mertens, Renato; Valdes, Francisco; Munoz, Cecilia; Irarrazaval, Manuel; Branes, Jorge; Riquelme, Carlos; Marine, Leopoldo; Bergoeing, Michel; Kraemer, AlbrechtIntravenous leiomyomatosis with extension into the heart is an infrequent entity described in 1907. Its clinical presentation is non-specific, although cardiac symptoms predominate. Diagnosis is based on clinical findings and appropriate imaging. We report two females, aged 35 and 51 years. One of them presented with a pelvic mass and dyspnea, the other patient had severe cardiac failure on admission. Computed axial tomography scan allowed an accurate preoperative diagnosis on both patients. Successful one stage resection of the tumor was performed under cardiopulmonary bypass. Both patients are asymptomatic on follow up at 6 months and 25 years. (Rev Med Chile 2012; 140: 906-909).
- ItemPulmonary Aneurysmal Arteriovenous Malformation Treated With a Vascular Plug(2024) Gonzalez-Urquijo, Mauricio; Marchesini, Michelle; Marine, Leopoldo; Vargas, Jose Francisco; Bergoeing, Michel; Mertens, Renato; Valdes, FranciscoPurpose To report a case of an asymptomatic patient with a pulmonary aneurysmal arterio-venous malformation successfully treated with a vascular plug.Case report An active 30-year-old male patient, residing at 3000 ft above sea level was referred due to an incidental finding on a CT scan of a 37 mm vascular mass localized in the lower lobe of the right lung, which corresponded to a pulmonary arteriovenous malformation with a single feeding artery. The patient was treated with an Amplatzer vascular plug, which effectively excluded the afferent vessel. An angio CT at 19 months follow-up revealed a hypodense residual mass of 9.0 mm in diameter with no arterial filling or venous drainage. The patient is fully active and remains asymptomatic at 24 months follow-up.Conclusion An unusual case of a pulmonary aneurysmal arteriovenous malformation successfully treated with a vascular plug is presented, highlighting the efficiency of this procedure.
- ItemThe One-hundred-deg2 DECam Imaging in Narrowbands (ODIN): Survey Design and Science Goals(2024) Lee, Kyoung-Soo; Gawiser, Eric; Park, Changbom; Yang, Yujin; Valdes, Francisco; Lang, Dustin; Ramakrishnan, Vandana; Moon, Byeongha; Firestone, Nicole; Appleby, Stephen; Artale, Maria Celeste; Andrews, Moira; Bauer, Franz; Benda, Barbara; Broussard, Adam; Chiang, Yi-Kuan; Ciardullo, Robin; Dey, Arjun; Farooq, Rameen; Gronwall, Caryl; Guaita, Lucia; Huang, Yun; Hwang, Ho Seong; Im, Sang Hyeok; Jeong, Woong-Seob; Karthikeyan, Shreya; Kim, Hwihyun; Kim, Seongjae; Kumar, Ankit; Nagaraj, Gautam R.; Nantais, Julie; Padilla, Nelson; Park, Jaehong; Pope, Alexandra; Popescu, Roxana; Schlegel, David; Seo, Eunsuk; Singh, Akriti; Song, Hyunmi; Troncoso, Paulina; Vivas, A. Katherina; Zabludoff, Ann; Zenteno, AlfredoWe describe the survey design and science goals for One-hundred-deg(2) DECam Imaging in Narrowbands (ODIN), a NOIRLab survey using the Dark Energy Camera (DECam) to obtain deep (AB similar to 25.7) narrowband images over an unprecedented area of sky. The three custom-built narrowband filters, N419, N501, and N673, have central wavelengths of 419, 501, and 673 nm and respective FWHM of 7.5, 7.6, and 10.0 nm, corresponding to Ly alpha at z = 2.4, 3.1, and 4.5 and cosmic times of 2.8, 2.1, and 1.4 Gyr, respectively. When combined with even deeper, public broadband data from the Hyper Suprime-Cam, DECam, and in the future, the Legacy Survey of Space and Time, the ODIN narrowband images will enable the selection of over 100,000 Ly alpha-emitting (LAE) galaxies at these epochs. ODIN-selected LAEs will identify protoclusters as galaxy overdensities, and the deep narrowband images enable detection of highly extended Ly alpha blobs (LABs). Primary science goals include measuring the clustering strength and dark matter halo connection of LAEs, LABs, and protoclusters, and their respective relationship to filaments in the cosmic web. The three epochs allow for the redshift evolution of these properties to be determined during the period known as Cosmic Noon, where star formation was at its peak. The narrowband filter wavelengths are designed to enable interloper rejection and further scientific studies by revealing [O II] and [O III] at z = 0.34, Ly alpha and He II 1640 at z = 3.1, and Lyman continuum plus Ly alpha at z = 4.5. Ancillary science includes similar studies of the lower-redshift emission-line galaxy samples and investigations of nearby star-forming galaxies resolved into numerous [O III] and [S II] emitting regions.
- ItemTrue Idiopathic Brachial Artery Aneurysm Treated With a Saphenous Vein Graft(2022) Gonzalez-Urquijo, Mauricio; Marine, Leopoldo; Vargas, Jose Francisco; Valdes, Francisco; Mertens, Renato; Bergoeing, Michel; Torrealba, JosePurpose: The objective of this study is to report a case of a 65-year-old woman who presented with pallor and pain of her left arm secondary to a true arterial brachial aneurysm, which was successfully treated with saphenous vein bypass and embolization of the aneurysm sac. A review of the literature is also presented. Case report: A 65-year-old woman presented with an acute onset of pallor and pain of her left forearm, and hand. On physical examination, there was a pulsatile mass at the forearm. A doppler ultrasound showed a fusiform aneurysmal dilatation of the brachial artery of 23 mm of diameter. A dynamic contrast-enhanced MRI angiogram confirmed a fusiform dilation of the distal brachial artery. The patient was scheduled for open repair. A fusiform 20 x 60 mm aneurysm of the distal brachial artery extending to the cubital fossa was found and a brachial artery to radial and ulnar arteries bypass with interposed reverse right saphenous vein was created. Embolization of the aneurysm sac was performed using Gelita-spon (R) (Gelita Medical, Eberbach, Germany). A final angiogram showed an adequate perfusion through the bypass to the hand, and no contrast in the aneurysmal sac. Postoperative course was uneventful with discharge on the fourth postoperative day. Conclusion: Revascularization with autologous saphenous vein graft and exclusion of the aneurysm with local embolization is a good treatment alternative in a patient with symptomatic brachial aneurysm with distal embolization.
- ItemVentana Fenestrated Stent-Graft System for Endovascular Repair of Juxtarenal Aortic Aneurysms(ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS, 2012) Mertens, Renato; Bergoeing, Michel; Marine, Leopoldo; Valdes, Francisco; Kraemer, Albrecht; Vergara, JeanettePurpose: To describe the initial use of an off-the-shelf fenestrated stent-graft system for endovascular repair of juxtarenal abdominal aortic aneurysms.