South American Centers Research Articles

The South American Center of the Institution of Locomotive Engineers: Circulation of British Engineers in South America, 1920–1949

British migration to Argentina was a phenomenon that occurred at the end of the nineteenth century, reaching its peak between 1850 and 1880. The circulation of British professionals, however, took place during the first half of the twentieth century as part of the migratory phenomenon framed in the context of a second phase of imperialism, the large number of British engineers, and the demand of South-American countries to develop their railways. This migratory process of professionals implied the transmission of knowledge and technology transfer, as well as a response from local engineering communities. The Institution of Locomotive Engineers and its center in Argentina are a clear example of the evolution of the forms of association characteristic of the nineteenth century, but also of the structuring, organisation, and expansion of the circulation of British engineers.

Experience in awake glioma surgery in a South American center. Correlation between intraoperative evaluation, extent of resection and functional outcomes

IntroductionGliomas are the second most frequent primary brain tumors. Surgical resection remains a crucial part of treatment, as well as maximum preservation of neurological function. For this reason awake surgery has an important role.The objectives of this article are to present our experience with awake surgery for gliomas in a South American center and to analyze how intraoperative functional findings may influence the extent of resection and neurological outcomes. Materials and methodsRetrospective single center study of a cohort of adult patients undergoing awake surgery for brain glioma, by the same neurosurgeon, between 2012 and 2022 in the city of Buenos Aires, Argentina. ResultsA total of 71 patients were included (mean age 34 years, 62% males). Seventy seven percent of tumors were low grade, with average extent of resection reaching 94% of preoperative volumetric assessment. At six months follow up, 81.7% of patients presented no motor or language deficit.Further analysis showed that having a positive mapping did not have a negative impact in the extent of resection, but was associated with short term postoperative motor and language deficits, among other variables, with later improvement. ConclusionAwake surgery for gliomas is a safe procedure, with the proper training. In this study it was observed that guiding the resection by negative mapping did not worsen the results and that positive subcortical mapping correlated with short term postoperative neurological deficits with posterior improvement within six months in most cases.

The Roles of Protocols and Protocolization in Improving Outcome From Severe Traumatic Brain Injury.

Our Phase-I parallel-cohort study suggested that managing severe traumatic brain injury (sTBI) in the absence of intracranial pressure (ICP) monitoring using an ad hoc Imaging and Clinical Examination (ICE) treatment protocol was associated with superior outcome vs nonprotocolized management but could not differentiate the influence of protocolization from that of the specific protocol. Phase II investigates whether adopting the Consensus REVised Imaging and Clinical Examination (CREVICE) protocol improved outcome directly or indirectly via protocolization. We performed a Phase-II sequential parallel-cohort study examining adoption of the CREVICE protocol from no protocol vs a previous protocol in patients with sTBI older than 13 years presenting ≤24 hours after injury. Primary outcome was prespecified 6-month recovery. The study was done mostly at public South American centers managing sTBI without ICP monitoring. Fourteen Phase-I nonprotocol centers and 5 Phase-I protocol centers adopted CREVICE. Data were analyzed using generalized estimating equation regression adjusting for demographic imbalances. A total of 501 patients (86% male, mean age 35.4 years) enrolled; 81% had 6 months of follow-up. Adopting CREVICE from no protocol was associated with significantly superior results for overall 6-month extended Glasgow Outcome Score (GOSE) (protocol effect = 0.53 [0.11, 0.95], P = .013), mortality (36% vs 21%, HR = 0.59 [0.46, 0.76], P < .001), and orientation (Galveston Orientation and Amnesia Test discharge protocol effect = 10.9 [6.0, 15.8], P < .001, 6-month protocol effect = 11.4 [4.1, 18.6], P < .005). Adopting CREVICE from ICE was associated with significant benefits to GOSE (protocol effect = 0.51 [0.04, 0.98], P = .033), 6-month mortality (25% vs 18%, HR = 0.55 [0.39, 0.77], P < .001), and orientation (Galveston Orientation and Amnesia Test 6-month protocol effect = 9.2 [3.6, 14.7], P = .004). Comparing both groups using CREVICE, those who had used ICE previously had significantly better GOSE (protocol effect = 1.15 [0.09, 2.20], P = .033). Centers managing adult sTBI without ICP monitoring should strongly consider protocolization through adopting/adapting the CREVICE protocol. Protocolization is indirectly supported at sTBI centers regardless of resource availability.

Retrospective analysis of outcomes for pediatric acute lymphoblastic leukemia in South American centers.

Acute lymphoblastic Leukemia (ALL) is the most common pediatric malignancy. While the survival rate for childhood ALL exceeds 90% in high-income countries, the estimated survival in low-and middle-income countries ranges from 22-79%, depending on the region and local resources. This study retrospectively reviewed demographic, biological, and clinical parameters of children under 18 years of age with newly diagnosed ALL presenting between 2013-2017 across five pediatric centers in 4 countries in South America. Survival analyses were estimated using the Kaplan-Meier method. Across the five centers, 752 patients were analyzed (Bolivia [N=9], Ecuador [N=221], Paraguay [N=197], Peru [N=325]) and 92.1% (n=690) patients were diagnosed with B-cell and 7.5% (n= 56) with T-cell ALL. The median age was 5.5 years old (IQR 7.29). At diagnosis, 47.8% of patients were categorized as standard and 51.9% as high risk per their institutional regimen. Advanced diagnostics availability varied between modalities. MRD was evaluated in 69.1% of patients; molecular testing was available for ETV6-RUNX, BCR-ABL1, TCF3-PBX1, and KMT2A-rearranged ALL in 75-81% of patients; however, karyotyping and evaluation for iAMP21 were only performed in 42-61% of patients. Central nervous system (CNS) involvement was evaluated at diagnosis in 57.3% (n=429) patients; of these, 93.7% (n=402) were CNS 1, 1.6% (n=7) were CNS 2, 0.7% (n=11) were CNS3, 1.9% (n=8) had cranial nerve palsy, and 2.1% (n=9) results unavailable. Chemotherapy delays >2 weeks were reported in 56.0% (n=421) patients during treatment. Delays were attributed to infection in 63.2% (n=265), drug-related toxicities in 47.3% (n=198), and resource constraints, including lack of bed availability in 23.2% (n=97) of patients. The 3-year Abandonment-sensitive EFS and OS were 61.0±1.9% and 67.2±1.8%, respectively. The 3-year EFS and OS were 71.0±1.8% and 79.6±1.7%, respectively. This work reveals opportunities to improve survival, including addressing severe infections, treatment interruptions, and modifications due to drug shortages. In 2018, healthcare professionals across South America established the Pediatric Oncology Latin America (POLA) group in collaboration with St. Jude Children's Research Hospital. POLA collaborators developed an evidence-based, consensus-derived, adapted treatment guideline, informed by preliminary results of this evaluation, to serve as the new standard of care for pediatric ALL in participating institutions.

Risk-stratified Results among Congenital Diaphragmatic Hernia Patients in Two Large Extracorporeal Membrane Oxygenation Centers in South America

IntroductionMortality related to CDH is high, but with great variability among centers. There are few studies on patients with this condition born in South America which show poor outcomes. The goal of this study is to present the outcome of CDH in several high-volume quaternary centers in South America, ascertain the factors associated with lower mortality in our population, and compare our outcomes to those of the CDH Study Group (CDHSG). MethodsThe data from two South American centers were retrospectively analyzed and compared with contemporary data from other CDHSG participating centers. Patient demographic and clinical characteristics were also evaluated and compared. ResultsBetween 2013 and 2018, the two South American centers saw 335 patients with CDH with an overall survival rate of 73.1%. Survival for the high, intermediate, and low-risk groups as determined by the Brindle score was 50%, 70%, and 87%, respectively. In our cohort the strongest predictors of mortality were ECMO use and early PaCO2. There were no significant differences in mortality between the two South American centers and the other CDHSG centers when adjusted by risk score, however, the South American centers had higher use of ECMO in the intermediate-risk group. DiscussionQuaternary South American centers had similar outcomes to CDHSG centers worldwide. The availability and coordination of centralized dedicated care allow more efficient use of scarce technical and professional resources in patients with CDH. Level of evidenceIII.

Real-world data metanalysis: procedural success and clinical outcomes after radiofrequency ablation of atrial fibrillation in South America

ABSTRACT Objective To profile patients’ characteristics, in-hospital results, and recurrence rates after radiofrequency ablation of atrial fibrillation (RAAF) in South America. Methods We comprehensively searched for single-center studies from South America with ≥10 patients receiving RAAF, published or presented from January 1, 2010, through June 29, 2020, excluding those reports aimed to specific populations such as permanent atrial fibrillation, structural cardiopathies, or re-do procedures. Results Main pooled estimates from a random-effects meta-analysis that included 3909 patients from 27 cohorts (from 5 countries): a) Patients characteristics: age 57.6 years (95% CI 55.7–59.5), male gender 71.5% (95% CI 67.0–75.6%), hypertension 54.2% (95% CI 45.4–62.8%), paroxysmal atrial fibrillation 79.8% (95% CI 71.3–94.5%), CHADS score 1.2 (95% CI 0.5–1.9), b) Acute procedural success 91.1% (95% CI 82.2–95.8%), c) In-hospital complications: stroke 0.6% (95% CI 0.3–1.2%), cardiac tamponade 2.3% (95% CI 1.4–3.7), hematoma 3.5% (95% CI 2.0–6.1), pseudoaneurysm 1.2% (95% CI 0.6–2.3), arteriovenous fistula 2.5% (95% CI 1.6–4.1). There were no cases of esophageal-atrial fistula nor death. Pooled estimate for arrhythmia recurrence (excluded 3-months blanking period) at 12 months was 19.9% (95% CI 17.0–23.1). Conclusion In-hospital results of RAAF reported for South American centers were worse than published international registries, even when included populations profile was of lower risk, as reflected in younger age and less prevalence of non-paroxysmal AF. Late recurrence rates seemed appropriate. This study provides a real-life framework for the analysis of the performance of this technology in the region.

Clinical Presentation, Treatment Outcomes, and Resistance-related Factors in South American Women with Low-risk Postmolar Gestational Trophoblastic Neoplasia.

There are few multinational studies on gestational trophoblastic neoplasia (GTN) treatment outcomes in South America. The purpose of this study was to assess the clinical presentation, treatment outcomes, and factors associated with chemoresistance in low-risk postmolar GTN treated with first-line single-agent chemotherapy in three South American centers. Multicentric, historical cohort study including women with International Federation of Gynecology and Obstetrics (FIGO)-staged low-risk postmolar GTN attending centers in Argentina, Brazil, and Colombia between 1990 and 2014. Data were obtained on patient characteristics, disease presentation, and treatment response. Logistic regression was used to assess the relationship between clinical factors and resistance to first-line single-agent treatment. A multivariate analysis of the clinical factors significant in univariate analysis was performed. A total of 163 women with low-risk GTN were included in the analysis. The overall rate of complete response to first-line chemotherapy was 80% (130/163). The rates of complete response to methotrexate or actinomycin-D as first-line treatment, and actinomycin-D as second-line treatment postmethotrexate failure were 79% (125/157), 83% (⅚), and 70% (23/33), respectively. Switching to second-line treatment due to chemoresistance occurred in 20.2% of cases (33/163). The multivariate analysis demonstrated that patients with a 5 to 6 FIGO risk score were 4.2-fold more likely to develop resistance to first-line single-agent treatment (p = 0.019). 1) At presentation, most women showed clinical characteristics favorable to a good outcome, 2) the overall rate of sustained complete remission after first-line single-agent treatment was comparable to that observed in developed countries, 3) a FIGO risk score of 5 or 6 is associated with development of resistance to first-line single-agent chemotherapy.

Evaluation of prognostic factors in patients undergoing first-line chemotherapy for advanced biliary tract cancer: a retrospective analysis from a South American cancer centre.

IntroductionBiliary tract cancers (BTCs) are rare tumours with regional differences. Prognostic factors are poorly understood. Gemcitabine + platinum (GP) is the standard first-line chemotherapy in metastatic patients. We aimed to search for prognostic factors in patients with advanced disease in a cancer centre in South America.MethodsWe conducted a retrospective analysis of patients with advanced BTC treated with chemotherapy. Variables were age (< or ≥70 years), Eastern Cooperative Oncology Group (ECOG) performance status (0/1 versus 2/3), gender, primary site (intrahepatic (IHC), extrahepatic (EHC), gallbladder (GB)), staging (locally advanced versus metastatic), metastatic sites, albumin (>3.5 g/dL versus <3.5 g/dL), biliary obstruction and first-line chemotherapy (GP, 5FU-based or single-agent). Cox regression method was used to explore factors.ResultsFrom 2010 to 2017, 104 patients were included. Median age was 62 years (32–86) and 22.1% were older than 70 years. Most patients had ECOG performance status 0/1 (63.4%), were female (51.9%) and were metastatic (82.7%). Bone metastases were found in 19.2%. Primary IHC, EHC and GB were 54.8%, 36.5% and 8.7%, respectively. GP was used by 79.8%. Median follow-up was 32.4 months. Median overall survival (mOS) was 11.4 months. In univariate analysis, male (p = 0.007), albumin < 3.5 g/dL (p = 0.001), biliary obstruction (p = 0.006), 5FU-based (p = 0.006) and single-agent (p < 0.0001) were associated with worse OS. ECOG performance status 2/3 (p = 0.058) and bone metastases (p = 0.051) were marginally related. In multivariate analysis, male (p = 0.003), bone metastases (p = 0.023), biliary obstruction (p = 0.001), 5FU-based (p = 0.016) and single-agent (p = 0.023) were independently associated with inferior OS.ConclusionIn this retrospective study, we observed that male patients, bone metastases, biliary obstruction and regimens other than GP had worse survival. Larger studies should be conducted to confirm our findings.

The history and distribution of nodulating Paraburkholderia, a potential inoculum for Fynbos forage species

AbstractLegumes in the Fynbos vegetation of the Western Cape of South Africa have emerged as candidates for domestication, particularly for their adaptation to acidic and infertile soils. However, South African rhizobia have been shown to be very diverse and unique, and a detailed understanding of them is essential to success in forage breeding programs that seek to exploit these “new” legumes. Symbionts of legumes in South Africa that belong to traditional rhizobial genera have been shown to have a unique origin for their symbiotic loci in comparison to members sampled from other regions of the world. Some of the legume tribes in the Fynbos have also been shown to associate predominantly with unique species in the Betaproteobacterial genus Paraburkholderia. The rhizobial members of this genus have two main centres of diversity, of which South Africa is one. In this centre, the legume hosts are principally from the Papilionoideae subfamily while hosts from the mimosoid clade (now in the Caesalpinioideae) are abundant in the South American centre. Not only do these rhizobia differ in terms of host, but their symbiotic loci also show separate origins. The dominance and uniqueness of the Paraburkholderia symbionts, in the context of indigenous South African legumes, makes understanding the history and factors that affect the distribution of this genus essential if successful adaptation and effective nodulation of these legumes in Agriculture are to be achieved globally.

Laparoscopic Liver Resection: A South American Experience with 2887 Cases.

Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers. From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results. Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%. This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Call to action for a South American network to fight COVID-19 in pregnancy.

A call to action for joint efforts by South American centers to tackle COVID‐19 in pregnancy.

Prognostic value of six-minute walk distance at a South American pulmonary hypertension referral center.

Six-minute walk distance (6MWD) assessment is recommended for pulmonary arterial hypertension multidimensional risk stratification. However, current 6MWD cut-off values were mainly derived from North American and European pulmonary arterial hypertension registries. Therefore, it is unknown if such cut-off values broadly apply to other geographical populations. In this study, we aimed to identify 6MWD cut-off values for Brazilian pulmonary arterial hypertension patients and to contrast our findings to current international Pulmonary Hypertension guidelines recommendations. One-hundred four consecutive pulmonary arterial hypertension patients were allocated in groups according to their 6MWD, considering 50 m as a clinically relevant 6MWD difference. Next, patients were categorized into different 6MWD ranges based on similar survival rates in each group: < 250 m, 250–400 m, and >400 m. The study outcome was all-cause mortality and transplantation according to the 6MWD range. Survival was truncated at five years. Median follow-up period was 4.35 years (0.48–5.00). Survival rates at 1, 2, 3, and 5 years were 96%, 89%, 81%, and 73%, respectively. Cox analyses adjusted for age, sex, and pulmonary arterial hypertension etiology showed that 6MWD < 250 m and >400 m were associated with higher and lower risk of all-cause mortality and transplantation. According to Harrell's c-statistic, the prognostic discrimination of the 6MWD cut-off value identified by the current study was 0.70 while international Pulmonary Hypertension guidelines 6MWD cut-offs value was 0.61. In conclusion, our findings suggest that 6MWD geographical variations should be considered when assessing risk stratification in pulmonary arterial hypertension.

Climate change threatens micro-endemic amphibians of an important South American high-altitude center of endemism

Abstract Species inhabiting broad altitudinal gradients are particularly exposed to the effects of global climate change (GCC). Those species reaching mountain tops are the most negatively affected. Here, using ecological niche models we estimated the climate change exposure of endemic amphibians of the most important extra-Andean mountain system of Argentina: the Sierras Pampeanas Centrales. Our results pinpoint that micro-endemic amphibians of this mountain system are heavily exposed to the effects of GCC, with important constraints of suitable climatic conditions for the six analyzed species. Among the most important findings, our models predict a high probability of a total disappearance of suitable climatic conditions for two of the species, currently restricted to mountain tops. This high exposure, in synergy with their very restricted ranges, and other important human induced threats (as fish invasion and emergent diseases), pose a serious threat to these endemic species, which can enter into the “extinction pathway” in a near future if no concrete conservation actions are taken. Our findings provide additional evidence of the great negative impact of GCC in high-altitude centers of endemism.

Effect of Nonmyeloablative Hematopoietic Stem Cell Transplantation vs Continued Disease-Modifying Therapy on Disease Progression in Patients With Relapsing-Remitting Multiple Sclerosis

Hematopoietic stem cell transplantation (HSCT) represents a potentially useful approach to slow or prevent progressive disability in relapsing-remitting multiple sclerosis (MS). To compare the effect of nonmyeloablative HSCT vs disease-modifying therapy (DMT) on disease progression. Between September 20, 2005, and July 7, 2016, a total of 110 patients with relapsing-remitting MS, at least 2 relapses while receiving DMT in the prior year, and an Expanded Disability Status Scale (EDSS; score range, 0-10 [10 = worst neurologic disability]) score of 2.0 to 6.0 were randomized at 4 US, European, and South American centers. Final follow-up occurred in January 2018 and database lock in February 2018. Patients were randomized to receive HSCT along with cyclophosphamide (200 mg/kg) and antithymocyte globulin (6 mg/kg) (n = 55) or DMT of higher efficacy or a different class than DMT taken during the previous year (n = 55). The primary end point was disease progression, defined as an EDSS score increase after at least 1 year of 1.0 point or more (minimal clinically important difference, 0.5) on 2 evaluations 6 months apart, with differences in time to progression estimated as hazard ratios. Among 110 randomized patients (73 [66%] women; mean age, 36 [SD, 8.6] years), 103 remained in the trial, with 98 evaluated at 1 year and 23 evaluated yearly for 5 years (median follow-up, 2 years; mean, 2.8 years). Disease progression occurred in 3 patients in the HSCT group and 34 patients in the DMT group. Median time to progression could not be calculated in the HSCT group because of too few events; it was 24 months (interquartile range, 18-48 months) in the DMT group (hazard ratio, 0.07; 95% CI, 0.02-0.24; P < .001). During the first year, mean EDSS scores decreased (improved) from 3.38 to 2.36 in the HSCT group and increased (worsened) from 3.31 to 3.98 in the DMT group (between-group mean difference, -1.7; 95% CI, -2.03 to -1.29; P < .001). There were no deaths and no patients who received HSCT developed nonhematopoietic grade 4 toxicities (such as myocardial infarction, sepsis, or other disabling or potential life-threatening events). In this preliminary study of patients with relapsing-remitting MS, nonmyeloablative HSCT, compared with DMT, resulted in prolonged time to disease progression. Further research is needed to replicate these findings and to assess long-term outcomes and safety. ClinicalTrials.gov Identifier: NCT00273364.

Long Term Outcomes after Intestinal Transplantation from a Single South-American Center, Lessons Learned

Introduction In many countries, intestinal failure patients (IF pts) had the only option of parenteral nutrition (PN) as available treatment until intestinal transplantation (ITx) evolves as part of a multidisciplinary team. We would like to report the long-term outcomes of a series of ITx performed in children and adults at a single center, 9 years after its creation. Material and Methods retrospective analysis of all consecutive ITx performed between May 2006 and Oct 2017. Diagnoses, pre ITx mean time on PN, indication for ITx, time on the waiting list (WL), type of ITx, mean total ischemia time (TIT), and warm ischemia time (WIT), time for PN discontinuation, 5-year actuarial patient survival are reported. Results 44 patients received 47 ITx. The mean time on PN for the Tx group was 1604 days*. The main indication for ITx was: lack of central venous accesses followed by PN associated liver disease, and catheter related infectious complications. The mean time on the WL was 222 days (SD: 195 days). ITx were performed in 28 children and 16 adults. Thirty-seven procedures were isolated ITx; 10 multiorgan (MTO) (4 combined, 7 multivisceral - 2 with kidney); 4 (8,5%) were re-transplants: 3 isolated, 1 multivisceral; 8 included right colon. Sixteen pts (36%) received the abdominal rectus fascia. All procedures were performed by the same team; TIT was 7:36±2:10 hs, WIT was 39.1±10.5 min. Mean length of implanted intestine: 325 ± 59.5 cm, BC ileostomy were performed in 59.5% of the cases. 18/47 Tx required early re-operations. The overall mean follow up time is 49±45.2 months; the mean time to be off PN was 68 days (* p: 0,001); the overall 5 year pt survival is 55.1%; 60.5% for Isolated ITx vs 35% for MTO (p=0,01); 60.3% for ped recipient’s vs 44.9% for adults (p=NS). Conclusions After 11 years of establishing a dedicated adult and ped IF program, we proved that ITX is a valid therapeutic alternative for pediatric and adult candidates. Long term results are comparable to a large series reported from centers of develop countries or the ITR.

Description of a Myasthenia Gravis population from a referral South-American center. (P6.451)

Description of a Myasthenia Gravis population from a referral South-American center. (P6.451)

Infectious diarrhea in autologous stem cell transplantation: high prevalence of coccidia in a South American center

BackgroundDiarrhea is frequently seen in autologous stem cell transplantation. Although toxicity related to conditioning is the most common cause, infectious pathogens can play a distinctive role particularly in certain regions and environments. MethodsThe role of enteropathogens was investigated in 47 patients submitted to autologous stem cell transplantation at a Brazilian center between May 2011 and May 2013. All patients who presented with diarrhea consented to stool sample analysis to identify the etiological agents including coccidia, Strongyloides sp., Clostridium difficile and other pathogenic bacteria. ResultsThirty-nine patients (83%) had diarrhea, among whom seven (17.5%) presented with coccidia, three (7.5%) with Candida sp., one (2.5%) with C. difficile, and one (2.5%) with Giardia lamblia. There was a tendency toward a higher incidence of diarrhea in older patients (p-value=0.09) and those who received conditioning with lomustine, etoposide, cytarabine, and melphalan (p-value=0.083). Furthermore, the number of days of neutropenia was higher in patients with diarrhea (p-value=0.06). ConclusionsThe high frequency of diarrhea caused by coccidia shows the importance of investigating and correctly identifying etiological agents and highlights the possible varieties of intestinal infections in patients who undergo autologous stem cell transplantation.

Incidental gallbladder cancer: how residual disease affects outcome in two different South American referral centers

Objective: The purpose of this study was to analyze the patterns of residual disease and influencing factors in patients undergoing re-resection for incidental gallbladder cancer. Methods: Consecutive patients with IGC undergoing re-exploration between 1990 and 2014 were identified in two centers from different South-American countries. Those patients submitted to a radical definitive resection were analyzed. Demographics and tumor-treated related variables were correlated with RD and survival. Cancer specific survival correlated with the site of RD, local (gallbladder bed) or regional (lymph nodes & bile duct). Results: Of 265 patients with incidental gallbladder cancer, re-resection was performed in 168, RD was found in 58 (34.5%).Comparison of demographic, clinical and surgical variables between both centers showed differences in T stage and disease stage (<0.0001). Site of RD was regional in 34 (20.2%).The T stage (p=0.002), positive lymph nodes (p=0.008) and stage of the gallbladder specimen (p≤0.0001) were independent predictors of RD. The presence of RD at any site reduced the disease specific survival (DSS) (19.6 month vs 62.7 month p<0.001) in comparison with non RD patients. There was no difference in DSS according the location of RD, with all anatomic sites been equally poor (p=0.27). RD at any site predicted DSS (p<0.001), independent of all other tumor related variables. Conclusion: Residual disease is the most critical prognostic factor in patients with incidental gallbladder cancer treated by radical resection. Outcome was poor in the presence of RD regardless of the anatomic location.

Un tributo a Roberto Caldeyro-Barcia, considerado el pionero de la Perinatología

Roberto Caldeyro-Barcia was born in Montevideo in 1921, and studied medicine graduating as medical physician in 1947. He was accepted as associate investigator at the Instituto de Fisiologia under Professor Hermogenes Alvarez, who was working on the effect of uterine activity on the foetal cardiac pulse during delivery. The amniotic pressure was registered by the use of a small catheter introduced inside the amniotic cavity. Thereby, Dr. Caldeyro-Barcia proposed to introduce a micro-catheter directly into the uterine muscle to obtain more specific information on the uterus contraction and its effect on foetal heart activity. It was observed that heart pulse was decreased in those cases of hypoxia. These decreases were called DIP I and II. Therefore, the theory was that during delivery hypoxia had a deleterious action on foetal oxygenation, which was registered and graduated as “Montevideo units”. Two years later Eduard H. Hon working in Yale University confirmed these findings, and it was the beginning of foetal heart beat monitoring during delivery in the whole world. Dr. Caldeyro-Barcia was presented worldwide with research awards. Moreover, he became the Director of the South-American Centre of Perinatology and President of the International Gynaeco-Obstetrics Federation. He was very fond of Mexico, a place that he visited several times, and had a close and warm relationship with Luis Castelazo-Ayala. Dr. Caldeyro-Barcia was considered an accomplished scientist, an exemplary mentor, and a leader in perinatology.

Neurological neonatal ICU: New approaches for neonates at high risk for brain injury and the South American centers experience

Neurological neonatal ICU: New approaches for neonates at high risk for brain injury and the South American centers experience