Pedro Silva-Vaz

Prof. Dr. Pedro Silva-Vaz

Consultant in General Surgery
+1
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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PSPedro Silva-Vaz
Pedro Silva-Vaz
Ana Margarida AbrantesAna Margarida Abrantes
Ana Margarida Abrantes
MCMiguel Castelo-Branco
Miguel Castelo-Branco
AGAntónio Gouveia
António Gouveia
Maria Filomena BotelhoMaria Filomena Botelho
Maria Filomena Botelho
José Guilherme TralhãoJosé Guilherme Tralhão
José Guilherme Tralhão
Acute pancreatitis (AP) is a severe inflammation of the pancreas presented with sudden onset and severe abdominal pain with a high morbidity and mortality rate, if accompanied by severe local and systemic complications. Numerous studies have been published about the pathogenesis of AP; however, the precise mechanism behind this pathology remains unclear. Extensive research conducted over the last decades has demonstrated that the first 24 h after symptom onset are critical for the identification of patients who are at risk of developing complications or death. The identification of these subgroups of patients is crucial in order to start an aggressive approach to prevent mortality. In this sense and to avoid unnecessary overtreatment, thereby reducing the financial implications, the proper identification of mild disease is also important and necessary. A large number of multifactorial scoring systems and biochemical markers are described to predict the severity. Despite recent progress in understanding the pathophysiology of AP, more research is needed to enable a faster and more accurate prediction of severe AP. This review provides an overview of the available multifactorial scoring systems and biochemical markers for predicting severe AP with a special focus on their advantages and limitations.

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PSPedro Silva-Vaz
Pedro Silva-Vaz
Ana Margarida AbrantesAna Margarida Abrantes
Ana Margarida Abrantes
Sara NunesSara Nunes
Sara Nunes
MCMiguel Castelo-Branco
Miguel Castelo-Branco
AGAntónio Gouveia
António Gouveia
José Guilherme TralhãoJosé Guilherme Tralhão
José Guilherme Tralhão
Acute pancreatitis (AP) is an inflammatory disorder of the pancreas that, when classified as severe, is associated with high morbidity and mortality. Promptly identifying the severity of AP is of extreme importance for improving clinical outcomes. The aim of this study was to compare the prognostic value of serological biomarkers, ratios, and multifactorial scores in patients with acute biliary pancreatitis and to identify the best predictors. In this observational and prospective study, the biomarkers, ratios and multifactorial scores were evaluated on admission and at 48 h of the symptom onset. On admission, regarding the AP severity, the white blood count (WBC) and neutrophil–lymphocyte ratio (NLR), and regarding the mortality, the WBC and the modified Marshall score (MMS) showed the best predictive values. At 48 h, regarding the AP severity, the hepcidin, NLR, systemic inflammatory response index (SIRI) and MMS and regarding the mortality, the NLR, hepcidin and the bedside index for severity in AP (BISAP) score, showed the best predictive values. The present study enabled the identification, for the first time, of SIRI as a new prognostic tool for AP severity, and validated hepcidin and the NLR as better prognostic markers than C-reactive protein (CRP) at 48 h of symptom onset.

24 May 2022 in The Lancet Global Health
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CSCatherine A Shaw
Catherine A Shaw
RPRiinu Pius
Riinu Pius
TDThomas M Drake
Thomas M Drake
LNLisa Norman
Lisa Norman
AAAdesoji O Ademuyiwa
Adesoji O Ademuyiwa
JLJean Wilguens Lartigue
Jean Wilguens Lartigue
Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. National Institute for Health and Care Research.

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PSPedro Silva-Vaz
Pedro Silva-Vaz
Ana Margarida AbrantesAna Margarida Abrantes
Ana Margarida Abrantes
MCMiguel Castelo-Branco
Miguel Castelo-Branco
AGAntónio Gouveia
António Gouveia
Maria Filomena BotelhoMaria Filomena Botelho
Maria Filomena Botelho
José Guilherme TralhãoJosé Guilherme Tralhão
José Guilherme Tralhão
Acute pancreatitis (AP) is a severe disease associated with high morbidity and mortality. Clinical studies can provide some data concerning the etiology, pathophysiology, and outcomes of this disease. However, the study of early events and new targeted therapies cannot be performed on humans due to ethical reasons. Experimental murine models can be used in the understanding of the pancreatic inflammation, because they are able to closely mimic the main features of human AP, namely their histologic glandular changes and distant organ failure. These models continue to be important research tools for the reproduction of the etiological, environmental, and genetic factors associated with the pathogenesis of this inflammatory pathology and the exploration of novel therapeutic options. This review provides an overview of several murine models of AP. Furthermore, special focus is made on the most frequently carried out models, the protocols used, and their advantages and limitations. Finally, examples are provided of the use of these models to improve knowledge of the mechanisms involved in the pathogenesis, identify new biomarkers of severity, and develop new targeted therapies.

21 June 2021 in Antioxidants
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PSPedro Silva-Vaz
Pedro Silva-Vaz
Ivana JarakIvana Jarak
Ivana Jarak
LRLuís Rato
Luís Rato
Pedro F. OliveiraPedro F. Oliveira
Pedro F. Oliveira
Sara NunesSara Nunes
Sara Nunes
Ana Margarida AbrantesAna Margarida Abrantes
Ana Margarida Abrantes
Acute pancreatitis (AP) is an inflammatory process of the pancreas with variable involvement of the pancreatic and peripancreatic tissues and remote organ systems. The main goal of this study was to evaluate the inflammatory biomarkers, oxidative stress (OS), and plasma metabolome of patients with different degrees of biliary AP severity to improve its prognosis. Twenty-nine patients with biliary AP and 11 healthy controls were enrolled in this study. We analyzed several inflammatory biomarkers, multifactorial scores, reactive oxygen species (ROS), antioxidants defenses, and the plasma metabolome of biliary AP and healthy controls. Hepcidin (1.00), CRP (0.94), and SIRI (0.87) were the most accurate serological biomarkers of AP severity. OS played a pivotal role in the initial phase of AP, with significant changes in ROS and antioxidant defenses relating to AP severity. Phenylalanine (p < 0.05), threonine (p < 0.05), and lipids (p < 0.01) showed significant changes in AP severity. The role of hepcidin and SIRI were confirmed as new prognostic biomarkers of biliary AP. OS appears to have a role in the onset and progression of the AP process. Overall, this study identified several metabolites that may predict the onset and progression of biliary AP severity, constituting the first metabonomic study in the field of biliary AP.

1 December 2012 in Revista da Sociedade Brasileira de Medicina Tropical
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PSPedro Silva-Vaz
Pedro Silva-Vaz
EPEduardo Pereira
Eduardo Pereira
SUSergiu Usurelu
Sergiu Usurelu
AMAna Monteiro
Ana Monteiro
ACA Teresa Caldeira
A Teresa Caldeira
ALArnandina Loureiro
Arnandina Loureiro
Echinococcosis/hydatidosis is common in societies where agriculture and livestock are frequent, and represents a public health problem. The therapeutic management depends on the cyst's characteristics, the patient, and surgical contraindications. Endoscopic retrograde cholangiopancreatography is a valuable tool in the diagnosis and treatment of complicated hepatic hydatid disease. Ultrasonography is a useful diagnostic, therapeutic and follow-up tool. The authors report a case of a 56 years old patient who was diagnosed with a hepatic hydatid cyst in the IVa/VIII segments, describe the therapeutic options and 50 months of disease-free follow-up.