Intestinal mucormycosis as a differential diagnosis of small bowel ischemia.

Intestinal mucormycosis is a rare manifestation of the Mucor fungus, associated with high mortality and typically found in immunocompromised patients, though it has also been described in immunocompetent individuals. The mode of acquisition is digestive. It usually presents as abdominal pain, with ischemia and intestinal perforation, and the diagnosis is often histopathological after surgical resection. We present the case of a 54-year-old female patient with recurrent acute myeloid leukemia undergoing treatment with daunorubicin-cytarabine and experiencing febrile neutropenia. She developed patchy and progressive intestinal ischemia that evolved into intestinal necrosis, which was treated with antifungal medications and surgery. Examination of the surgical specimen revealed aseptate wide hyphae with branching at right angles, suggestive of Mucor fungus. This is a rare but highly mortal pathology in which clinical, radiological, and surgical suspicion is essential for early diagnosis and treatment, thus improving the patient's prognosis.

Ibero-American Consensus for the Management of Peritoneal Sarcomatosis: Updated Review and Clinical Recommendations.

Peritoneal sarcomatosis is a rare malignant disease with a poor prognosis, secondary to peritoneal dissemination of abdominopelvic soft tissue sarcomas. Its rarity, together with the characteristic histological heterogeneity and the historically poor response to systemic treatments, has prevented the establishment of widely accepted treatment criteria with curative intent. In this sense, radical cytoreductive surgery (CRS) with peritonectomy procedures and hyperthermic intraperitoneal chemotherapy (HIPEC), widely used in peritoneal carcinomatosis with excellent results, have not had the same evolutionary development in patients with peritoneal sarcomatosis. A multidisciplinary working group of experts in sarcomas and peritoneal oncological surgery established a series of recommendations based on current scientific evidence for the management of peritoneal sarcomatosis, taking into account the different histological subgroups of abdominopelvic sarcomas that can cause it depending on their origin: retroperitoneal sarcomas, uterine sarcomas, and visceral/peritoneal sarcomas of GIST (gastrointestinal stromal tumor) and non-GIST origin. This article shows the results of sarcoma experts' voting on the recommendations presented during the I Ibero-American Consensus on the Management of Peritoneal Sarcomatosis, which took place during the recent celebration of the III Hispanic-Portuguese Meeting for Updates on the Treatment of Sarcomas.

Robotic pelvic exenteration in males: systematization of the technique.

Male pelvic exenteration is a challenging procedure with high morbidity. In very selected cases, the robotic approach could make dissection easier and decrease morbidity due to the better vision provided and higher range of movements. In this paper, we describe port placement, instruments, minilaparotomy location, and the stepwise sequence of these procedures. We address 3 different situations: total pelvic exenteration with abdominoperineal resection, colostomy and urostomy; pelvic exenteration with colorectal/anal anastomosis and urostomy; and pelvic exenteration with abdominoperineal resection, colostomy and urinary tract reconstruction.

Sclerosing angiomatoid nodular transformation, a rare splenic tumor with increasing incidence.

SANT (sclerosing angiomatoid nodular transformation) tumor is a rare splenic tumor of unknown etiology and vascular lineage, first described in 2004. Most cases are asymptomatic, although cases of anemia or abdominal pain in association with growth have been described. Spontaneous ruptures have not been described. Radiologically it presents a radial pattern with centripetal filling in dynamic MRI, being a characteristic feature, but not pathognomonic. It may present hypermetabolism in PET-CT. Its incidence is increasing since its description as an independent clinical and histopathological entity, especially in the oncological patients follow-up. Due to its radiological resemblance to metastatic lesions and its growth despite being a vascular lesion, splenectomy is indicated following the principles of oncologic surgery until a definitive diagnosis is made. It presents a benign behavior, requiring neither treatment nor specific subsequent surveillance. Two diagnosed cases of SANT are presented, as well as a review of the clinical, radiological and histopathological characteristics of this little-known splenic lesion.

Prioritization, patient selection, and multimodal perioperative management of colorectal cancer facing health-care system saturation.

OBJECTIVE: The aim is to analyze the usefulness of pre-operative COVID-19 screening to detect asymptomatic patients, the capability of our patient selection algorithm to detect patients with more advanced tumors and the results of colorectal cancer surgery managed with a multimodal approach. We propose the use of a preoperative patient selection algorithm to prioritize the surgical treatment of patients with worse oncological prognosis and lower perioperative risk in situations of health system saturation. MATERIAL AND METHODS: Prospective descriptive study including 71 patients operated on for colorectal cancer during COVID-19's high incidence period. A division was made into two periods of time that were later compared with the aim of assessing whether the scale used identified those patients with lower surgical risk and higher oncological priority for their priority scheduling. RESULTS: Post-operative severe acute respiratory syndrome coronavirus 2 infection occurred in one patient (1.4%). Pre-operative polymerase chain reaction detected one asymptomatic patient (3%). Tumor stage was ≥ IIIA in 39% and node positive in 39% of patients in the first period, while 26% and 21% in the second period, respectively (p = 0.320; p = 0.179), without increasing the surgical stay or complications. Median hospital stay was 5 days. Grades III and IV morbidity were 4.4% and 1.4%. CONCLUSION: The use of an algorithm and Patient Selection Scale can detect patients with more advanced tumors to be operated before. Multimodal management/ERAS have a role in achieving short stay and low morbidity.

OBJETIVO: El retraso terapéutico derivado de la saturación del Sistema sanitario conlleva un peor pronóstico oncológico y un aumento de complicaciones en el cáncer colorrectal. Proponemos el usode un algoritmo de selección de pacientes de forma preoperatoria para priorizar el tratamiento quirúrgico de los pacientes con peor pronóstico oncológico y menor riesgo perioperatorio. MATERIAL Y MÉTODOS: Realizamos un estudio descriptivo prospectivo de 71 pacientes intervenidos por cáncer colorrectal durante el periodo de máxima incidencia por COVID. Se realizó una división en dos periodos de tiempo que fueron comparados posteriormente con el objetivo de valorar si la escala utilizada conseguía identificar aquellos pacientes con menor riesgo quirúrgico y mayor prioridad oncológica para su programación prioritaria. RESULTADOS: Utilizando la escala de priorización de pacientes (PSS) observamos que el estadio tumoral fue mayor de IIIA en un 39% de los pacientes con un 39% de ganglios positivos en un primer periodo, frente a un 26% y 21% en un segundo periodo (p = 0.320; p = 0.179) de tiempo, sin aumentar la estancia operatoria ni las complicaciones. Se realizaron dos métodos de cribado de COVID-19 en dos periodos de tiempo, detectando un 3% de pacientes asintomáticos de forma preoperatoria con PCR, y documentando un 1.4% de infección por COVID postoperatoria. CONCLUSIONES: Ante la saturación del sistema sanitario, la utilización de protocolos y algoritmos para selección de pacientes con cáncer colorrectal puede ayudar a dar preferencia quirúrgica a aquellos casos que no deben ser demorados.

Exceptionally high but still growing predatory reef fish biomass after 23 years of protection in a Marine Protected Area.

Marine Protected Areas (MPAs) help replenish fish assemblages, though different trophic levels may show diverse recovery patterns. Long-term protection is required to achieve total recovery but poaching events may prevent the achievement of full carrying capacity. Here, we have analysed the effect of long-term protection on the entire reef fish community and the different trophic levels in the Cabo de Palos-Islas Hormigas MPA (SE Spain; SW Mediterranean Sea) in order to assess their recovery patterns after 23 years of protection. We compared the values for carrying capacity obtained with the maximum values achieved at regional scale, and we assessed the effect of a reduction in the surveillance over a few years, during which poaching events increased, on the recovery patterns. We found that, overall, biomass of fishes increased with time while density diminished. In particular, piscivorous and macro-invertivore fish increased while the other trophic groups remained constant or declined, suggesting top-down processes. For the entire study period, those trophic groups were approaching carrying capacity; however, when accounting only for the period in which enforcement was high and constant, they grew exponentially, indicating that full carrying capacity may have not been achieved yet. When compared to other Mediterranean MPAs, the Cabo de Palos-Islas Hormigas MPA showed values for biomass that were disproportionately higher, suggesting that local factors, such as habitat structure and associated oceanographic processes, may be responsible for the dynamics found. Our results help to understand the potential trajectories of fish assemblages over a consolidated MPA and highlight empirically how the reduction of surveillance in a period may change the recovery patterns.

Preoperative hepatic artery embolization before distal pancreatectomy plus celiac axis resection does not improve surgical results: A Spanish multicentre study.

BACKGROUND: Distal pancreatectomy with celiac axis resection (DP-CAR) is a surgical procedure with high morbidity and mortality performed in patients with locally advanced pancreatic cancer. Preoperative embolization of hepatic artery (PHAE) has been postulated as a technical option to increase resection rate. OBJECTIVE: comparison of morbidity and mortality at 90 days, operative time, hospital stay and survival between patients that performed DP-CAR with and without PHAE. METHODS: Observational retrospective multicentre study. INCLUSION CRITERIA: patient operated in Spanish centers with DP-CAR for pancreatic cancer from April 2004 until 23 June 2018. Preoperative (PHAE, neodjuvant treatment), intraoperative (operative time and blood loss) and postoperative data (morbidity, hospital stay, R0 and survival) were studied. Complications were measured with Clavien classification at 90 days. Specific pancreatic complications were measured using ISGPS classifications. Data were analyzed using R version 3.1.3 (http://www.r-project.org). Level of significance was set at 0.05. RESULTS: 41 patients were studied. 26 patients were not embolized (NO-PHAE group) and 15 patients received PHAE. Preoperative BMI and percentage of neoadjuvant chemotherapy were the only preoperative variables different between both groups. The operative time in the PHAE group was shorter (343 min) than in the non-PHAE group (411 min) (p < 0.06). Major morbidity (Clavien > IIIa) and mortality at 90 days were higher in the PHAE group than in the non-PHAE group (60% vs 23% and 26.6% vs 11.6% respectively) (p < 0.004). No statistical difference in overall survival was observed between both groups (p = 0.14). CONCLUSION: In our study PHAE is not related with less postoperative morbidity. Even more, major morbidity (Clavien III-IV) and mortality was higher in PHAE group.

The impact of SARS-CoV-2 infection on the surgical management of colorectal cancer: lessons learned from a multicenter study in Spain.

OBJECTIVE: the aim of the study was to analyze the management of colorectal cancer (CRC) patients diagnosed with CRC or undergoing elective surgery during the period of the SARS-CoV-2 pandemic. MATERIAL AND METHODS: a multicenter ambispective analysis was performed in nine centers in Spain during a four-month period. Data were collected from every patient, including changes in treatments, referrals or delays in surgeries, changes in surgical approaches, postoperative outcomes and perioperative SARS-CoV-2 status. The hospital's response to the outbreak and available resources were categorized, and outcomes were divided into periods based on the timeline of the pandemic. RESULTS: a total of 301 patients were included by the study centers and 259 (86 %) underwent surgery. Five hospitals went into phase III during the peak of incidence period, one remained in phase II and three in phase I. More than 60 % of patients suffered some form of change: 48 % referrals, 39 % delays, 4 % of rectal cancer patients had a prolonged interval to surgery and 5 % underwent neoadjuvant treatment. At the time of study closure, 3 % did not undergo surgery. More than 85 % of the patients were tested preoperatively for SARS-CoV-2. A total of nine patients (3 %) developed postoperative pneumonia; three of them had confirmed SARS-CoV-2. The observed surgical complications and mortality rates were similar as expected in a usual situation. CONCLUSIONS: the present multicenter study shows different patterns of response to the SARS-CoV-2 pandemic and collateral effects in managing CRC patients. Knowing these patterns could be useful for planning future changes in surgical departments in preparation for new outbreaks.

The role of mucin cell-free DNA detection as a new marker for the study of acellular pseudomyxoma peritonei of appendicular origin by liquid biopsy.

BACKGROUND: Acellular pseudomyxoma peritonei (aPMP) is a rare peritoneal malignancy characterized by the accumulation of large amounts of mucin (lacking tumor cells) in the peritoneum. Many cases account for several kilograms of mucin to be screened by the pathologist. This is a comprehensive study of three patients with aPMP, whose tumors showed KRAS mutation, allowing for the tracking of this marker by liquid biopsy. METHODS: Pre and post-surgery plasma, and mucin removed during cytoreductive surgery were collected from the patients. KRAS mutations were analyzed using droplet digital polymerase chain reaction (ddPCR). Mucin was injected in mice. KRAS and cytokine levels were measured in plasma of the mice using ddPCR and a magnetic bead-based assay. Mucin microbiome was analyzed by 16S rRNA sequencing. RESULTS: KRAS mutations were detected in mucin cell-free DNA (cfDNA) from the three patients but not in the pre or post-surgery plasma. Electron microscopy detected microparticles (diameter <0.4 µm) in mucin. Mucin from one patient grew up inside the peritoneal cavity of mice and human KRAS was identified in mucin cfDNA, but not in plasma. All mucins showed the same bacterial profile. Cytokine levels were slightly altered in mice. CONCLUSIONS: The three aPMP patients included in this study shared some common aspects: the absence of tumor cells in mucin, the presence of KRAS mutated cfDNA in mucin, and the absence of this tumor-derived mutation in the bloodstream, providing additional information to the routine pathological examinations and suggesting that mucin cfDNA could potentially play a role in aPMP recurrence and prognosis.

Liquid biopsy in peritoneal fluid and plasma as a prognostic factor in advanced colorectal and appendiceal tumors after complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Positive cytology has been identified as an independent negative prognostic factor in patients with peritoneal metastases (PM) of colorectal origin. Liquid biopsy in plasma may detect increasing levels of circulating tumor DNA (ctDNA) and could help predict systemic relapse in patients with colorectal cancer, but little is known about the role of liquid biopsy in peritoneal fluid. The aim of this study was to evaluate the prognostic value of peritoneal fluid and plasma liquid biopsy in patients undergoing complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CC-HIPEC). METHODS: A longitudinal prospective study was designed in patients with KRAS-mutated colorectal or appendiceal primary tumor, including PM of colorectal origin, pseudomyxoma peritonei and patients at high risk of developing PM (selected for second-look surgery). Eleven patients were recruited according to inclusion and exclusion criteria. ctDNA from plasma and peritoneal fluid before and after HIPEC was studied by droplet digital PCR looking for KRAS mutation. A close follow-up was scheduled (mean of 28.5 months) to monitor for systemic and peritoneal recurrences. RESULTS: All patients with positive plasma postHIPEC had systemic relapse and four patients died as a result, while those with negative plasma postHIPEC did not relapse. Patients with negative peritoneal ctDNA after CC-HIPEC did not present peritoneal relapse. Of six patients with positive peritoneal ctDNA postHIPEC, two presented peritoneal recurrence and four systemic relapses. CONCLUSIONS: Treatment with CC-HIPEC does not always neutralize ctDNA in peritoneal fluid, and its persistence after treatment may predict adverse outcome. Despite being a proof of concept, an adequate correlation between liquid biopsy in plasma and peritoneal fluid with both systemic and peritoneal relapse has been observed.

Accelerated Monte Carlo Rendering of Finite-Time Lyapunov Exponents.

Time-dependent fluid flows often contain numerous hyperbolic Lagrangian coherent structures, which act as transport barriers that guide the advection. The finite-time Lyapunov exponent is a commonly-used approximation to locate these repelling or attracting structures. Especially on large numerical simulations, the FTLE ridges can become arbitrarily sharp and very complex. Thus, the discrete sampling onto a grid for a subsequent direct volume rendering is likely to miss sharp ridges in the visualization. For this reason, an unbiased Monte Carlo-based rendering approach was recently proposed that treats the FTLE field as participating medium with single scattering. This method constructs a ground truth rendering without discretization, but it is prohibitively slow with render times in the order of days or weeks for a single image. In this paper, we accelerate the rendering process significantly, which allows us to compute video sequence of high-resolution FTLE animations in a much more reasonable time frame. For this, we follow two orthogonal approaches to improve on the rendering process: the volumetric light path integration in gradient domain and an acceleration of the transmittance estimation. We analyze the convergence and performance of the proposed method and demonstrate the approach by rendering complex FTLE fields in several 3D vector fields.

Vector Field Topology of Time-Dependent Flows in a Steady Reference Frame.

The topological analysis of unsteady vector fields remains to this day one of the largest challenges in flow visualization. We build up on recent work on vortex extraction to define a time-dependent vector field topology for 2D and 3D flows. In our work, we split the vector field into two components: a vector field in which the flow becomes steady, and the remaining ambient flow that describes the motion of topological elements (such as sinks, sources and saddles) and feature curves (vortex corelines and bifurcation lines). To this end, we expand on recent local optimization approaches by modeling spatially-varying deformations through displacement transformations from continuum mechanics. We compare and discuss the relationships with existing local and integration-based topology extraction methods, showing for instance that separatrices seeded from saddles in the optimal frame align with the integration-based streakline vector field topology. In contrast to the streakline-based approach, our method gives a complete picture of the topology for every time slice, including the steps near the temporal domain boundaries. With our work it now becomes possible to extract topological information even when only few time slices are available. We demonstrate the method in several analytical and numerically-simulated flows and discuss practical aspects, limitations and opportunities for future work.

Fourier Opacity Optimization for Scalable Exploration.

Over the past decades, scientific visualization became a fundamental aspect of modern scientific data analysis. Across all data-intensive research fields, ranging from structural biology to cosmology, data sizes increase rapidly. Dealing with the growing large-scale data is one of the top research challenges of this century. For the visual exploratory data analysis, interactivity, a view-dependent visibility optimization and frame coherence are indispensable. In this work, we extend the recent decoupled opacity optimization framework to enable a navigation without occlusion of important features through large geometric data. By expressing the accumulation of importance and optical depth in Fourier basis, the computation, evaluation and rendering of optimized transparent geometry become not only order-independent, but also operate within a fixed memory bound. We study the quality of our Fourier approximation in terms of accuracy, memory requirements and efficiency for both the opacity computation, as well as the order-independent compositing. We apply the method to different point, line and surface data sets originating from various research fields, including meteorology, health science, astrophysics and organic chemistry.

Small-sized and well-enforced Marine Protected Areas provide ecological benefits for piscivorous fish populations worldwide.

Many piscivorous fish species are depleted and/or threatened around the world. Marine Protected Areas (MPAs) are tools for conservation and fisheries management, though there is still controversy regarding the best design for increasing their ecological effectiveness. Here, on the basis of a weighted meta-analytical approach, we have assessed the effect of 32 MPAs, distributed worldwide, on the biomass and density of piscivorous fishes. We analysed the MPA features and the biological, commercial and ecological characteristics of fishes that may affect the response of species to protection. We found a positive effect on the biomass and density of piscivores inside MPAs. This effect was stronger for the biomass of medium-sized fishes (in relation to the maximum size reported for the species) and the density of large and gregarious species. The size of the no-take zone had a significant negative impact on both response variables and differed according to the level of enforcement, with smaller no-take zones having higher levels of enforcement. Thus, MPAs help to protect piscivorous fish species, with smaller, but well enforced reserves being more effective for the protection of the local populations of piscivorous fishes throughout the world.

Current use of molecular profiling for indeterminate thyroid nodules. / Utilidad del estudio molecular de nódulos tiroideos con citología indeterminada.

Even though cytology remains the gold standard to assess the nature of thyroid nodules, up to 30% of the results are indeterminate (BethesdaIII and IV). In these cases, current guidelines recommend performing diagnostic surgery, which proves malignancy in only 15-30% of cases. A more precise method is needed to avoid unnecessary surgeries, surgical complications and costs in the process of diagnosing indeterminate nodules. Complementary use of molecular profiling tests seems to help in this complex scenario. We present a review of the current literature on the usefulness of molecular profiling of thyroid nodules so as to define its indications, costs and usability for clinical practice.

The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.

Underwater visual census (UVC) is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT), designed to maximize transect length (and thus the surveyed area) with respect to diving time invested in monitoring, as compared to Conventional Strip Transects (CST). Additionally, we analyze the effect of increasing transect width and length on the precision of density estimates by comparing TRT vs. CST methods using different fixed widths of 6 and 20 m (FW3 and FW10, respectively) and the Distance Sampling (DS) method, in which perpendicular distance of each fish or group of fishes to the transect line is estimated by divers up to 20 m from the transect line. The TRT was 74% more time and cost efficient than the CST (all transect widths considered together) and, for a given time, the use of TRT and/or increasing the transect width increased the precision of density estimates. In addition, since with the DS method distances of fishes to the transect line have to be estimated, and not measured directly as in terrestrial environments, errors in estimations of perpendicular distances can seriously affect DS density estimations. To assess the occurrence of distance estimation errors and their dependence on the observer's experience, a field experiment using wooden fish models was performed. We tested the precision and accuracy of density estimators based on fixed widths and the DS method. The accuracy of the estimates was measured comparing the actual total abundance with those estimated by divers using FW3, FW10, and DS estimators. Density estimates differed by 13% (range 0.1-31%) from the actual values (average = 13.09%; median = 14.16%). Based on our results we encourage the use of the Tracked Roaming Transect with Distance Sampling (TRT+DS) method for improving density estimates of species occurring at low densities and/or highly aggregated, as well as for exploratory rapid-assessment surveys in which divers could gather spatial ecological and ecosystem information on large areas during UVC.

Complete tubular colonic duplication in an adult: a rare incidental finding and the risk of colonoscopic perforation.

Gastrointestinal duplications are unusual congenital malformations, nearly always diagnosed in childhood. Roughly 80% are cysts-like lesions and only a small percentage (4-18%) involves the colonic wall. Almost all are asymptomatic and therefore diagnosed as an incidental finding on imaging tests or when become complicated and present with perforation or bleeding. The need for an elective surgical treatment is controversial and should be indicated on an individual basis. This report is a case of an adult with a complete tubular colonic duplication found incidentally by colonoscopy that required surgical treatment due to perforation.