Luís Loureiro
Grupo México
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Featured researches published by Luís Loureiro.
Hemodialysis International | 2017
António Norton de Matos; Clemente Neves Sousa; Paulo Almeida; Paulo Teles; Luís Loureiro; Gabriela Teixeira; Duarte Rego; Sérgio Teixeira
Dysfunction problems with vascular access are a concern to patients and dialysis units. The vascular surgeon should analyse such dysfunction and perform a careful assessment of the vascular network in order to find new fistula layouts. We introduce and discuss the case of creation of a radio‐cephalic fistula with outflow into the forearm basilic vein through rotation of the forearm basilic vein toward the cephalic vein in the forearm of an 88‐year‐old hemodialysis male patient. This technique enables extending fistula patency and improves cost efficiency.
Annals of Vascular Surgery | 2017
António Norton de Matos; Clemente Neves Sousa; Paulo Almeida; José Queirós; Duarte Rego; Gabriela Teixeira; Luís Loureiro; Sérgio Teixeira
The exhaustion of superficial venous patrimony or reduced diameter of superficial veins usually prevents patients from having an arteriovenous fistula created. In such cases, using deep vessels can be a more viable option as opposed to an arteriovenous graft. We describe a new approach for the brachio-brachial arteriovenous fistula creation technique. It consists of 3 small incisions, thus causing minimal surgical damage. We have found it to be better tolerated by the patients and well received by dialysis nurses. This procedure also allows improved access for cannulation and more available puncture sites.
Archive | 2012
Carolina Vaz; Arlindo Matos; Maria do Sameiro C. Pereira; Clara Nogueira; Tiago Loureiro; Luís Loureiro; Diogo Silveira; Rui de Almeida
During the past decade, Endovenous Laser Ablation (EVLA) has been introduced as a minimally invasive alternative to high ligation and open surgical stripping of the incompetent Great Saphenous Vein (GSV) or Short Saphenous Vein (SSV). There is great variability in EVLA protocols and at the present time there is data from more than 60 publications with more than 15000 EVLA treatments reporting good clinical results but also undesired side effects. Post-operative pain in the operated area is rated from slight to moderate by most patients (81, 5%),post-operative induration of the truncal vein can be expected in 78, 1% of patients and perivenous ecchymosis and hematoma are observed in an average of 52% of patients. Further complications such as persistent dysesthesia after nerve lesions (0, 8%) and burns on the skin (0, 2%) are reported in a minority of cases. Great care must be taken to ensure adequate tumescent anesthesia and light dosimetry in order to avoid post-operative paresthesia.
Hemodialysis International | 2018
António Norton de Matos; Clemente Neves Sousa; Paulo Almeida; Paulo Teles; Duarte Rego; Gabriela Teixeira; Luís Loureiro; Sérgio Teixeira
Dysfunction of arteriovenous access for hemodialysis is a challenge for the vascular surgeon. Some patients have complex vascular access with problems that are difficult to solve. Careful analysis of the vascular network with ultrasound and dissection of the veins during surgery can help to identify the best option for each access. We introduce and discuss the case of creation of a radio‐cephalic fistula with outflow into the brachial vein in 64‐year‐old hemodialysis male patient. This technique enables extending fistula patency, arterializing the brachial vein, and improves cost efficiency.
Journal of Vascular Access | 2017
Gabriela Teixeira; Paulo Almeida; Clemente Neves Sousa; Paulo Teles; Paulo De Sousa; Luís Loureiro; Sérgio Teixeira; Duarte Rego; Rui M. S. Almeida; António Norton de Matos
Purpose The aim of this study is to validate the current applicability of arteriovenous access banding in high flow access (HFA) and/or haemodialysis access-induced distal ischaemia (HAIDI). Methods This retrospective study was conducted at the GEV (Grupo de Estudos Vasculares) vascular access centre. The clinical records of consecutive patients undergoing banding for HAIDI and HFA symptoms, between June 2011 and January 2015, were reviewed until April 2015. All vascular access patients’ consultation records and surgical notes were reviewed. We analysed and compared patients’ age, gender, comorbidities, symptoms and intraoperative ultrasound control. We defined technical failure as recurrence of symptoms, requiring new banding. Excessive banding, access thrombosis, rupture and false aneurysm development were registered as complications. Primary clinical success was defined as improvement of symptoms or effective flow reduction after banding, with no need for reintervention. If one reintervention was necessary, we have defined it as secondary clinical success. Results Overall, 119 patients underwent banding: 64 (54%) with HAIDI and 55 (46%) with HFA. The HAIDI group was significantly older (65 ± 13 years compared with 56 ± 22 years, p = 0.001) and had significantly greater number of patients with diabetes (56% vs 24%, p = 0.004). Primary success was achieved in 85 patients (71.4%) and the secondary success rate was 84.9%. Older age (p = 0.016) and intraoperative ultrasound control (p = 0.012) were significantly associated with primary success. Conclusions Our results do not corroborate the high incidence of thrombosis previously reported as associated with AV access banding and suggest that ultrasound control is crucial for preventing technical failure. The procedure was effective on both compared groups.
Therapeutic Apheresis and Dialysis | 2018
António Norton de Matos; Clemente Neves Sousa; Paulo Almeida; Paulo Teles; Duarte Rego; Gabriela Teixeira; Luís Loureiro; Sérgio Teixeira; Inês Antunes
Vascular access dysfunction is a serious problem in dialysis units. Some patients have complex dysfunctions that are difficult to resolve. In this article, we report the case a of two patients with radiocephalic arteriovenous fistulae (RC‐AVF) who had stenosis/occlusion of the forearm median vein and where we used the basilic vein of the forearm as a solution. We reviewed the use of this surgical solution in RC‐AVF. Two male patients on hemodialysis exhibited stenosis/occlusion of the forearm median vein. The forearm basilic vein was isolated and rotated toward the forearm median vein in order to solve RC‐AVF problems. One patient had fistula thrombosis 5 months after the procedure, while for the other patient, the fistula continues to work without problems. Literature describes only a few cases using the forearm basilic vein or the brachial vein for fistula recovery. This procedure increased the patency of fistulas. This approach has been proven to be a good solution for solving outflow problems using the superficial or deep veins, increasing fistula patency and avoiding the need to place a central venous catheter and all the related complications.
Blood Purification | 2018
Ana Castro; Carla Moreira; Paulo Almeida; Norton de Matos; Luís Loureiro; Gabriela Teixeira; Duarte Rego; Sérgio Teixeira; Joaquim Pinheiro; Telmo Carvalho; Isabel Fonseca; José Queirós
Background: The definition of significant stenosis (SS) remains controversial. Methods: We retrospectively reviewed 1,040 consultations. SS was defined in the presence of clinical and echo-Doppler (DDU) criteria: Qa <500 mL/min or Qa decrease >25%; RI >0.7 in the feeding artery or absolute minimal luminal stenosis diameter <2.0 mm. Stenosis without any additional criteria were considered borderline stenosis (BS). Results: Two hundred twenty-one arteriovenous fistulas (AVFs) were included: 58.8% had SS, 18.6% had BS, and 22.6% had no dysfunctional access (ND). SS had a significantly higher thrombotic events than BS and ND (13.1 vs. 4.4%, p = 0.018). The annual thrombosis rate was 0.007, 0.037, and 0.004 in the ND, SS, and BS, respectively. AVF cumulative survival at 5 years was significantly lower in SS (89.5%) compared to BS (100%) and ND (97.4%; p = 0.03). BS had an HR for AVF failure of 1.1, p = 0.955, while the SS presented an HR of 5.9, p = 0.09. Conclusion: AVF clinical monitoring with additional DDU criteria appear to be appropriate for therapeutic referral.
Nephrology Dialysis Transplantation | 2017
Ana Laura Pimentel; Paulo Almeida; Norton de Matos; Luís Loureiro; Gabriela Teixeira; Duarte Rego; Sérgio Teixeira; Joaquim Pinheiro; Isabel Fonseca; Telmo Carvalho; José Queirós
Background: Juxta-anastomotic stenosis (JAS) is a common complication of radiocephalic arteriovenous fistulas. There is diverging data as to the best therapeutic approach being angioplasty or surgery. Pre-operative color Doppler ultrasound (CDU) is accurately used for initial assessment of the vascular access and follow-up monitoring. The aim of this study was to evaluate immediate and long-term results of endovascular versus open surgical intervention of juxta-anastomotic venous stenosis of forearm radiocephalic fistulas and to test if CDU assessment can be used to ameliorate preoperative strategy and long-term outcomes. Methods: This retrospective cohort study included 63 patients with JAS radiocephalic fistulas referred to vascular access consultation. CDU was used to assess preoperative morphological, functional and hemodynamic stenosis characteristics and according to specific criteria, allocate patients to endovascular or surgical treatment. Results: Surgical revision was proposed in 68.2% of patients (N=43), namely the creation of a new proximal fistula (N=41), while angiographic evaluation was proposed in 31.7% of the cases (N=20). Mean follow-up time was 720±524 days with a maximum follow-up of 4.6 years. In the surgical group, primary patency was 92% and 84% at 6 and 12 months respectively, while in the endovascular group, it was 76% and 47% (p=0.013). There was no significant difference in the assisted primary patency between the interventional groups at 12 months: 94% in the endovascular vs. 93% in the surgical group (p=0.542). Conclusion: Pre-operative CDU assessment of JAS and specific allocation criteria with an access-centered approach choosing the best option in each fistula allowed the correct diagnosis of the lesion, improved the global results of the treatment and optimized the financial resources by reserving PTA for selected cases where surgery could be more difficult with higher risk of access loss.
Brazilian Journal of Cardiovascular Surgery | 2016
Rui Machado; Luís Loureiro; João Gonçalves; Pedro Oliveira; Rui M. S. Almeida
Objective The endovascular repair of aortic abdominal aneurysms exposes the patients and surgical team to ionizing radiation with risk of direct tissue damage and induction of gene mutation. This study aims to describe our standard of radiation exposure in endovascular aortic aneurysm repair and the factors that influence it. Methods Retrospective analysis of a prospective database of patients with abdominal infra-renal aortic aneurysms submitted to endovascular repair. This study evaluated the radiation doses (dose area product (DAP)), fluoroscopy durations and their relationships to the patients, aneurysms, and stent-graft characteristics. Results This study included 127 patients with a mean age of 73 years. The mean DAP was 4.8 mGy.m2, and the fluoroscopy time was 21.8 minutes. Aortic bilateral iliac aneurysms, higher body mass index, aneurysms with diameters larger than 60 mm, necks with diameters larger than 28 mm, common iliac arteries with diameters larger than 20 mm, and neck angulations superior to 50 degrees were associated with an increased radiation dose. The number of anatomic risk factors present was associated with increased radiation exposure and fluoroscopy time, regardless of the anatomical risk factors. Conclusion The radiation exposure during endovascular aortic aneurysm repair is significant (mean DAP 4.8 mGy.m2) with potential hazards to the surgical team and the patients. The anatomical characteristics of the aneurysm, patient characteristics, and the procedures technical difficulty were all related to increased radiation exposure during endovascular aortic aneurysm repair procedures. Approximately 40% of radiation exposure can be explained by body mass index, neck angulation, aneurysm diameter, neck diameter, and aneurysm type.
Brazilian Journal of Cardiovascular Surgery | 2016
Rui Machado; Gabriela Teixeira; Pedro Oliveira; Luís Loureiro; Carlos Pereira; Rui M. S. Almeida
INTRODUCTION: Abdominal aortic aneurysm has a lower incidence in the female population, but a higher complication rate. It was been hypothesized that some anatomical differences of abdominal aortic aneurysm in women could be responsible for that. We proposed to analyze our data to understand the differences in the clinical and anatomical characteristics and the outcomes of patients undergoing endovascular aneurysm repair, according to gender. METHODS: A retrospective analysis of patients undergoing endovascular aneurysm repair between 2001-2013 was performed. Patients were divided according gender and evaluated regarding age, atherosclerotic risk factors, aneurysm anatomic features, endograft type, anesthesic risk classification, length of stay, reinterventions and mortality. Two statistical studies were performed, first comparing women and men (Group A) and a second one comparing women and men, adjusted by age (Group B). RESULTS: Of the 171 patients, only 5.8% (n=10) were females. Women were older (P<0.05) and the number of women with no atherosclerotic risk factor was significantly higher. The comparison adjusted by age revealed women with statistically less smoking history, less cerebrovascular disease and ischemic heart disease. Women had a trend to more complex anatomy, with more iliac intern artery aneurysms, larger aneurysm diameter and neck angulations statistically more elevated. No other variables were statistically different between age groups, neither reintervention nor mortality rates. CONCLUSION: Our study showed a clear difference in the clinical characteristics of women. The female population was statistically older, and when compared with men adjusted by age, had less atherosclerotic risk factors and less target organ disease. Women showed a more complex anatomy but with the same outcomes.