Early Impairment of Paracrine and Phenotypic Features in Resident Cardiac Mesenchymal Stromal Cells after Thoracic Radiotherapy.

Radiotherapy-induced cardiac toxicity and consequent diseases still represent potential severe late complications for many cancer survivors who undergo therapeutic thoracic irradiation. We aimed to assess the phenotypic and paracrine features of resident cardiac mesenchymal stromal cells (CMSCs) at early follow-up after the end of thoracic irradiation of the heart as an early sign and/or mechanism of cardiac toxicity anticipating late organ dysfunction. Resident CMSCs were isolated from a rat model of fractionated thoracic irradiation with accurate and clinically relevant heart dosimetry that developed delayed dose-dependent cardiac dysfunction after 1 year. Cells were isolated 6 and 12 weeks after the end of radiotherapy and fully characterized at the transcriptional, paracrine, and functional levels. CMSCs displayed several altered features in a dose- and time-dependent trend, with the most impaired characteristics observed in those exposed in situ to the highest radiation dose with time. In particular, altered features included impaired cell migration and 3D growth and a and significant association of transcriptomic data with GO terms related to altered cytokine and growth factor signaling. Indeed, the altered paracrine profile of CMSCs derived from the group at the highest dose at the 12-week follow-up gave significantly reduced angiogenic support to endothelial cells and polarized macrophages toward a pro-inflammatory profile. Data collected in a clinically relevant rat model of heart irradiation simulating thoracic radiotherapy suggest that early paracrine and transcriptional alterations of the cardiac stroma may represent a dose- and time-dependent biological substrate for the delayed cardiac dysfunction phenotype observed in vivo.

Study protocol of a prospective single-arm multicenter clinical study to assess the safety and performance of the aXess hemodialysis graft: The pivotal study.

BACKGROUND: Arteriovenous grafts (AVGs) are used for patients deemed unsuitable for the creation of an autogenous arteriovenous fistula (AVF) or unable to await maturation of the AVF before starting hemodialysis. However, AVGs are prone to infection and thrombosis resulting in low long-term patency rates. The novel aXess Hemodialysis Graft consists of porous polymeric biomaterial allowing the infiltration by cells and the growth of neotissue, while the graft itself is gradually absorbed, ultimately resulting in a fully functional natural blood vessel. The Pivotal Study will examine the long-term effectiveness and safety of the aXess Hemodialysis Graft. METHODS: The Pivotal Study is a prospective, single-arm, multicenter study that will be conducted in 110 subjects with end-stage renal disease who are not deemed suitable for the creation of an autogenous vascular access. The primary efficacy endpoint will be the primary patency rate at 6 months. The primary safety endpoint will be the freedom from device-related serious adverse events at 6 months. The secondary endpoints will include the procedural success rate, time to first cannulation, patency rates, the rate of access-related interventions to maintain patency, the freedom from device-related serious adverse events and the rate of access site infections. Patients will be followed for 60 months. An exploratory Health Economic and Outcomes Research sub-study will determine potential additional benefits of the aXess graft to patients, health care institutions, and reimbursement programs. DISCUSSION: The Pivotal study will examine the long-term performance and safety of the aXess Hemodialysis Graft and compare the outcome measures with historical data obtained with other graft types and autogenous AVFs. Potential advantages may include superior long-term patency rates and lower infection rates versus currently available AVGs and a shorter time to first cannulation compared to an autologous AVF. As such, the aXess Hemodialysis Graft may fulfill an unmet clinical need in the field of hemodialysis access.

Urethral Stricture Induction Followed by Buccal Mucosa Graft Urethroplasty in a Rat Model.

Urethral reconstruction is an important area of expertise for urologists. The buccal mucosa is considered the best option when urethral grafting is necessary, although in some cases, it is inappropriate or needs to be optimized to repair a given stricture. Therefore, developing innovative procedures and evaluating their putative success in experimental models is crucial to fit the clinical need. With this goal, this study describes a protocol in which urethral stricture was induced by electrocautery in Wistar rats. Urethral reconstruction was performed 1 week later with a buccal mucosa graft, harvested from the lower lip, and placed in a ventral onlay fashion. A retrograde urethrogram showed a significant improvement in urethral diameter after urethroplasty compared to the respective value after stricture induction. Additionally, the graft placement was assessed by blood perfusion analysis using laser Doppler. As expected, a dark blue area corresponded to the non-vascularized buccal mucosa graft. This procedure can successfully simulate the normal pathophysiological process of urethral injury and tissue modulation, as well as urethral reconstruction using a buccal mucosa graft in a reproducible manner, and serve as the basis for future research based on tissue engineering or urethral grafts.

The evolution of management of type B aortic dissection in a series of 100 consecutive cases in a tertiary center.

INTRODUCTION AND OBJECTIVES: Management of aortic dissection is rapidly evolving. The present study aims to assess paradigm shifts in type B aortic dissection (TBAD) treatment modalities and their outcomes according to clinical presentation and type of treatment. We also aim to assess the impact of endovascular technology in TBAD management in order to define organizational strategies to provide an integrated cardiovascular approach. METHODS: We performed a retrospective review with descriptive analysis of the last 100 consecutive patients with TBAD admitted to the Vascular Surgery Department of Centro Hospitalar Universitário Lisboa Norte over a 16-year period. Results were stratified according to treatment modality and stage of the disease. The study was further divided into two time periods, 2003-2010 and 2011-2019, respectively before and after the introduction of a dedicated endovascular program for aortic dissections. RESULTS: A total of 100 patients (83% male; mean age 60 years) were included, of whom 59 were admitted in the acute stage (50.8% with complicated dissections). The other 41 patients were admitted for chronic dissections, most of them for surgical treatment of aneurysmal degeneration. Temporal analysis demonstrated an increase in the number of patients operated for aortic dissection, mainly due to an increase in chronic patients (33.3% in 2003-2010 vs. 64.4% in 2011-2019) and a clear shift toward endovascular treatment from 2015 onward. Overall in-hospital mortality was 14% and was significantly higher in the chronic phase (acute 5.1% vs. chronic 26.8%; OR 5.30, 95% CI 1.71-16.39; p=0.003) and in patients with aneurysmal degeneration, regardless of the temporal phase. Only one death was recorded in the endovascular group. CONCLUSION: Management of TABD carried an overall mortality of 14% during a 16-year period, but the appropriate use of endovascular technology has substantially reduced in-hospital mortality.

Investigation of Different Methods of Intraoperative Graft Perfusion Assessment during Kidney Transplantation for the Prediction of Delayed Graft Function: A Prospective Pilot Trial.

Delayed graft function (DGF) after renal transplantation is a relevant clinical problem affecting long-term organ function. The early detection of patients at risk is crucial for postoperative monitoring and treatment algorithms. In this prospective cohort study, allograft perfusion was evaluated intraoperatively in 26 kidney recipients by visual and formal perfusion assessment, duplex sonography, and quantitative microperfusion assessment using O2C spectrometry and ICG fluorescence angiography. The O2C tissue spectrometry device provides a quantitative method of microperfusion assessment that can be employed during kidney transplantation as an easy-to-use and highly sensitive alternative to ICG fluorescence angiography. Intraoperative microvascular flow and velocity in the allograft cortex after reperfusion predicted DGF with a sensitivity of 100% and a specificity of 82%. Threshold values of 57 A.U. for microvascular flow and 13 A.U. for microvascular velocity were identified by an ROC analysis. This study, therefore, confirmed that impairment of microperfusion of the allograft cortex directly after reperfusion was a key indicator for the occurrence of DGF after kidney transplantation. Our results support the combined use of intraoperative duplex sonography, for macrovascular quality control, and quantitative microperfusion assessment, such as O2C spectrometry, for individual risk stratification to guide subsequent postoperative management.

Molecular Changes In Cardiac Tissue As A New Marker To Predict Cardiac Dysfunction Induced By Radiotherapy.

The contribution of radiotherapy, per se, to late cardiotoxicity remains controversial. To clarify its impact on the development of early cardiac dysfunction, we developed an experimental model in which the hearts of rats were exposed, in a fractionated plan, to clinically relevant doses of ionizing radiation for oncological patients that undergo thoracic radiotherapy. Rat hearts were exposed to daily doses of 0.04, 0.3, and 1.2 Gy for 23 days, achieving cumulative doses of 0.92, 6.9, and 27.6 Gy, respectively. We demonstrate that myocardial deformation, assessed by global longitudinal strain, was impaired (a relative percentage reduction of >15% from baseline) in a dose-dependent manner at 18 months. Moreover, by scanning electron microscopy, the microvascular density in the cardiac apex was significantly decreased exclusively at 27.6 Gy dosage. Before GLS impairment detection, several tools (qRT-PCR, mass spectrometry, and western blot) were used to assess molecular changes in the cardiac tissue. The number/expression of several genes, proteins, and KEGG pathways, related to inflammation, fibrosis, and cardiac muscle contraction, were differently expressed in the cardiac tissue according to the cumulative dose. Subclinical cardiac dysfunction occurs in a dose-dependent manner as detected by molecular changes in cardiac tissue, a predictor of the severity of global longitudinal strain impairment. Moreover, there was no dose threshold below which no myocardial deformation impairment was detected. Our findings i) contribute to developing new markers and exploring non-invasive magnetic resonance imaging to assess cardiac tissue changes as an early predictor of cardiac dysfunction; ii) should raise red flags, since there is no dose threshold below which no myocardial deformation impairment was detected and should be considered in radiation-based imaging and -guided therapeutic cardiac procedures; and iii) highlights the need for personalized clinical approaches.

A catastrophic seronegative anti-phospholipid syndrome: case and literature review.

BACKGROUND: Antiphospholipid Syndrome (APS) is a multisystemic autoimmune disease characterized by arterial and venous thrombosis and / or obstetric morbidity in the presence of at least one circulating anti-phospholipid antibody. The spectrum of vascular events varies from deep venous thrombosis to catastrophic APS, a rare form characterized by acute multiorgan thrombosis and high mortality. CASE REPORT: We present the case of a 32-week pregnant woman arriving in the hospital emergency room with bilateral acute lower limb ischemia. In the obstetric evaluation, fetal death was declared. Computerized Tomography angiography showed pulmonary embolism of both pulmonary arteries, areas of splenic and right renal infarction and multiple arterial and venous thrombosis. The patient underwent urgent caesarean section and axillary-bifemoral bypass. No events registered. In the postoperative period, in an intensive care unit, treatment with rituximab and plasmapheresis were added to anticoagulant therapy. The laboratorial investigation was negative for thrombophilia and autoimmune diseases. CONCLUSION: Catastrophic APS develops quickly, with multiorgan involvement and high mortality rate. The presented case poses a multidisciplinary challenge, with the surgical approach of extra-anatomical revascularization being less invasive and guaranteeing immediate perfusion of the lower limbs. Although the serological tests were negative for anti-phospholipid antibodies, this case hardly fits into another diagnosis. Therefore, it was treated as a catastrophic APS, having shown a favorable evolution.

Clinical outcomes of aortic arch hybrid repair in a real-world single-center experience.

OBJECTIVE: Aortic arch aneurysmal disease remains a therapeutic challenge. For patients unsuitable for standard open surgery, hybrid repair with debranching of the supra-aortic arteries followed by thoracic endovascular grafting has been shown to be an effective solution. The aim of this study was to report the clinical outcomes of a single-institution experience using hybrid aortic arch repair. METHODS: The cases of all consecutive patients submitted to hybrid aortic arch repair between January 2010 and June 2018 were prospectively collected and retrospectively analyzed. The outcomes of the study were 30-day mortality, perioperative complications, 2-year survival, endoleak, and reintervention rates. RESULTS: A total of 35 patients with a median age of 71 years (interquartile range, 62-77 years) were submitted to hybrid aortic arch repair, with a median follow-up of 26.9 months (interquartile range, 2.4-63.6 months). Ten procedures (28.6%) were performed urgently for contained rupture. The most common etiology was degenerative (n = 14 [40.0%]). The proximal landing zones according to the Ishimaru classification were zone 2 in 20 patients (57.1%), zone 1 in 12 patients (34.3%), and zone 0 in 3 patients (8.6%). Early endoleaks were observed in six patients (17.1%), equally distributed between type I and type II. Late endoleaks were identified in 4 of 24 patients (16.7%; type I, n = 2 [8.3%]; type II, n = 1 [4.2%]; and type III, n = 1 [4.2%]). Thirty-day mortality rate was 14.3% (n = 5) with an early death rate of 8.7% (2/23) in elective cases and 30.0% (3/10) in urgent cases (odds ratio [OR], 4.93; confidence interval [CI], 0.68-35.67; P = .128). Except in one patient, 30-day mortality was associated with landing zone 0 or zone 1 (26.7% vs 5.0%; OR, 6.91; CI, 0.68-69.86; P = .141). Three patients (8.6%) suffered a postoperative stroke, and no episodes of spinal cord ischemia were observed. Two-year survival rate was 67.8% (CI, 49.4%-80.8%). Survival rates were significantly lower with increasing age (hazard ratio [HR], 1.10; CI, 1.03-1.18; P = .004), urgent procedure (HR, 4.80; CI, 1.56-14.80; P = .003), zone 0 or zone 1 (HR, 6.34; CI, 1.73-23.18; P = .001), presence of arrhythmia (HR, 3.76; CI, 1.22-11.62; P = .013), and cerebrovascular disease (HR, 4.12; CI, 1.38-12.35; P = .006). A multivariate analysis identified age (HR, 1.11; P = .047) and zone 0 or zone 1 (HR, 4.93; P = .033) as the only predictors for overall mortality. CONCLUSIONS: Hybrid aortic arch repair seems to be an alternative for higher risk patients not suitable for open repair, but selection of patients is crucial and may benefit from further refinement. In this study, worse outcomes were seen in older patients and those who required more proximal landing zones.

Clinical aspects and present challenges of the seat belt aorta.

OBJECTIVE: Seat belt aorta is rare and difficult to manage. The lack of data and follow-up increases the complexity of treating such patients. We aimed to create a decision algorithm by reviewing our current experience and analyzing the presentation and management of our patients. METHODS: We performed a descriptive case series based on retrospective analysis of all consecutive patients admitted with the diagnosis of seat belt aorta from 2008 to 2018. Seat belt aorta was defined as any blunt abdominal aortic lesion resulting from a seat belt compression mechanism after a car accident. RESULTS: Nine consecutive patients were admitted with the diagnosis of seat belt aorta, all of whom developed lesions in the infrarenal aorta. Eight patients were assessed in the acute phase and one patient presented with late-onset symptoms. Associated injuries were present in all acute patients, and seat belt sign and small bowel injury were present in 88%. One patient presented with a small intimal tear and was treated conservatively. All other patients diagnosed with large intimal flaps (seven patients) and pseudoaneurysm (one patient) underwent open repair in five cases and endovascular repair in three cases. In-hospital mortality for the acute cases was 38%, with no mortality seen during follow-up. Two patients submitted to endovascular repair required reinterventions. CONCLUSIONS: Seat belt aorta is a deadly condition, frequently associated with blunt thoracoabdominal trauma with concomitant injuries; the presence of a seat belt sign or lower limb ischemia must lead to a high diagnostic suspicion. Management must take into account the other concomitant injuries. Follow-up is crucial as most patients are young; they may develop complications and subsequently require further intervention.

Ex-vivo Surgical Repair of a Renal Artery Aneurysm with Kidney Autotransplantation.

Renal artery aneurysms are rare. They are most commonly degenerative, congenital or due to medial fibroplasia. Proximal aneurysms can be repaired by endovascular and in-situ surgical techniques. However, aneurysms of the distal renal artery and its branches require ex-vivo surgical repair, also known as auto-transplantation: the kidney is removed, dissected and reconstructed in cold ischemia, and put back in place. A 69-year-old woman, with hypertension, presented with bilateral renal artery aneurysms with a diameter of 3.4 cm on the right kidney and 1 cm on the left kidney. The right renal artery aneurysm, which was due to medial fibroplasia, was successfully repaired using the ex-vivo surgical technique. Patency was confirmed by postoperative computed tomography angiography.

Concomitant pulmonary embolism and aortic dissection: approach to anticoagulation. / Tromboembolismo pulmonar e disseção da aorta concomitantes: abordagem à anticoagulação.

The authors describe a case of a patient admitted with a pre-syncopal episode and precordial discomfort, and whose cardiac ultrasound performed in the Emergency Room was suggestive of Pulmonary Embolism. The patient was submitted to fibrinolytic therapy after cardiac arrest. The computerized tomography done after this episode not only confirmed the presence of pulmonary embolism but had also shown a Stanford Type B Aortic Dissection. The option was to maintain the therapeutic anticoagulation, having the patient evolved favourably.

Echocardiographic Assessment of Cardiac Anatomy and Function in Adult Rats.

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional imaging to study the cardiac anatomy of the left ventricle and M-mode echo to assess its dimensions. However, this could limit a comprehensive study. Herein, we describe a protocol that allows an assessment of the heart chamber size, left ventricular function (systolic and diastolic) and valvular function. A conventional medical ultrasound machine was used in this protocol and different echo views were obtained through left parasternal, apical and suprasternal windows. In the left parasternal window, the long and short axis were acquired to analyze left chamber dimensions, right ventricle and pulmonary artery dimensions, and mitral, pulmonary and aortic valve function. The apical window allows the measurement of heart chamber dimensions and evaluation of systolic and diastolic parameters. It also allows Doppler assessment with detection and quantification of heart valve disturbances (regurgitation or stenosis). Different segments and walls of the left ventricle are visualized throughout all views. Finally, the ascending aorta, aortic arch, and descending aorta can be imaged through the suprasternal window. A combination of ultrasound imaging, Doppler flow and tissue Doppler assessment have been obtained to study cardiac morphology and function. This represents an important contribution to improve the assessment of cardiac function in adult rats with impact for research using these animal models.

Hybrid Surgery in Lower Limb Revascularization: A Real-World Experience from a Single Center.

BACKGROUND: Through the association of endovascular and open procedures, hybrid surgery for lower limb revascularization allows the treatment of multilevel occlusive disease with a lower risk when compared to extensive open interventions. The aim of this study is to evaluate the immediate and midterm clinical outcomes of hybrid techniques for lower limb revascularization in a cohort of patients with multilevel arterial disease. METHODS: Data from elective procedures between 2012 and 2017 were retrospectively collected regarding hybrid lower limb revascularization procedures. The outcomes of the study were categorical clinical improvement, patency rates, major amputation rates, and mortality. RESULTS: A total of 81 patients, 89 limbs, with a median age of 69 years (interquartile range [IQR] 61-73) were submitted to hybrid lower limb revascularization, with a median follow-up of 10.7 months (IQR 2.5-25.1). Treatment indications were chronic limb-threatening ischemia in 80.9% of the cases (rest pain in 18.0% and tissue loss in 62.9%). One-year primary, primary-assisted, and secondary patency rates were 78.28% (95% confidence interval [CI] 65.20-86.92), 85.12% (95% CI 72.96-92.09), and 90.19% (95% CI 79.13-95.54), respectively. Overall categorical clinical improvement was observed in 56.2%. Major amputation and mortality rates were 14.6% and 16.0%, respectively. Multilevel Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) C or D and stage IV Leriche-Fontaine classification were strongly associated with decreased categorical clinical improvement (adjusted odds ratio [aOR] 0.08, P < 0.0001 and aOR 0.25, P = 0.013, respectively). Multilevel TASC C or D was also related to higher amputation rates, contrary to clinical presentation (adjusted hazard ratio [aHR] 11.37, P = 0.002 and aHR 4.70, P = 0.091, respectively). Primary-assisted and secondary patency rates were associated with higher categorical clinical improvement (aOR 4.30, P = 0.036 and aOR 7.36, P = 0.021, respectively) and decreased major amputation rates (aHR 0.11, P = 0.003 and aHR 0.09, P = 0.001, respectively) but were not related to multilevel TASC and Leriche-Fontaine classifications. CONCLUSIONS: The present study reports a real-world experience with a large proportion of patients with chronic limb-threatening ischemia. Hybrid interventions for lower limb revascularization revealed to be a potential approach for patients with complex arterial disease that would beneficiate from less invasive procedures.

Assessing Therapeutic Angiogenesis in a Murine Model of Hindlimb Ischemia.

Critical limb ischemia (CLI) is a serious condition that entails a high risk of lower limb amputation. Despite revascularization being the gold-standard therapy, a considerable number of CLI patients are not suited for either surgical or endovascular revascularization. Angiogenic therapies are emerging as an option for these patients but are currently still under investigation. Before application in humans, those therapies must be tested in animal models and its mechanisms must be clearly understood. An animal model of hindlimb ischemia (HLI) has been developed by the ligation and excision of the distal external iliac and femoral arteries and veins in mice. A comprehensive panel of tests was assembled to assess the effects of ischemia and putative angiogenic therapies at functional, histologic and molecular levels. Laser Doppler was used for the flow measurement and functional assessment of perfusion. Tissue response was evaluated by the analysis of capillary density after staining with the anti-CD31 antibody on histological sections of gastrocnemius muscle and by measurement of collateral vessel density after diaphonization. Expression of angiogenic genes was quantified by RT-PCR targeting selected angiogenic factors exclusively in endothelial cells (ECs) after laser capture microdissection from mice gastrocnemius muscles. These methods were sensitive in identifying differences between ischemic and non-ischemic limbs and between treated and non-treated limbs. This protocol provides a reproducible model of CLI and a framework for testing angiogenic therapies.

Low-dose ionizing radiation induces therapeutic neovascularization in a pre-clinical model of hindlimb ischemia.

AIMS: We have previously shown that low-dose ionizing radiation (LDIR) induces angiogenesis but there is no evidence that it induces neovascularization in the setting of peripheral arterial disease. Here, we investigated the use of LDIR as an innovative and non-invasive strategy to stimulate therapeutic neovascularization using a model of experimentally induced hindlimb ischemia (HLI). METHODS AND RESULTS: After surgical induction of unilateral HLI, both hindlimbs of female C57BL/6 mice were sham-irradiated or irradiated with four daily fractions of 0.3 Gy, in consecutive days and allowed to recover. We demonstrate that LDIR, significantly improved blood perfusion in the murine ischemic limb by stimulating neovascularization, as assessed by laser Doppler flow, capillary density, and collateral vessel formation. LDIR significantly increased the circulating levels of VEGF, PlGF, and G-CSF, as well as the number of circulating endothelial progenitor cells (EPCs) mediating their incorporation to ischemic muscles. These effects were dependent upon LDIR exposition on the ischemic niche (thigh and shank regions). In irradiated ischemic muscles, these effects were independent of the recruitment of monocytes and macrophages. Importantly, LDIR induced a durable and simultaneous up-regulation of a repertoire of pro-angiogenic factors and their receptors in endothelial cells (ECs), as evident in ECs isolated from the irradiated gastrocnemius muscles by laser capture microdissection. This specific mechanism was mediated via vascular endothelial growth factor (VEGF) receptor signaling, since VEGF receptor inhibition abrogated the LDIR-mediated gene up-regulation and impeded the increase in capillary density. Finally, the vasculature in an irradiated non-ischemic bed was not affected and after 52 week of LDIR exposure no differences in the incidence of morbidity and mortality were seen. CONCLUSIONS: These findings disclose an innovative, non-invasive strategy to induce therapeutic neovascularization in a mouse model of HLI, emerging as a novel approach in the treatment of critical limb ischemia patients.

Umbilical cord tissue-derived mesenchymal stromal cells maintain immunomodulatory and angiogenic potencies after cryopreservation and subsequent thawing.

BACKGROUND AIMS: The effect of cryopreservation on mesenchymal stromal cell (MSC) therapeutic properties has become highly controversial. However, data thus far have indiscriminately involved the assessment of different types of MSCs with distinct production processes. This study assumed that MSC-based products are affected differently depending on the tissue source and manufacturing process and analyzed the effect of cryopreservation on a specific population of umbilical cord tissue-derived MSCs (UC-MSCs), UCX®. METHODS: Cell phenotype was assessed by flow cytometry through the evaluation of the expression of relevant surface markers such as CD14, CD19, CD31, CD34, CD44, CD45, CD90, CD105, CD146, CD200, CD273, CD274 and HLA-DR. Immunomodulatory activity was analyzed in vitro through the ability to inhibit activated T cells and in vivo by the ability to reverse the signs of inflammation in an adjuvant-induced arthritis (AIA) model. Angiogenic potential was evaluated in vitro using a human umbilical vein endothelial cell-based angiogenesis assay, and in vivo using a mouse model for hindlimb ischemia. RESULTS: Phenotype and immunomodulatory and angiogenic potencies of this specific UC-MSC population were not impaired by cryopreservation and subsequent thawing, both in vitro and in vivo. DISCUSSION: This study suggests that potency impairment related to cryopreservation in a given tissue source can be avoided by the production process. The results have positive implications for the development of advanced-therapy medicinal products.

Therapeutic angiogenesis induced by human umbilical cord tissue-derived mesenchymal stromal cells in a murine model of hindlimb ischemia.

BACKGROUND: Mesenchymal stem cells derived from human umbilical cord tissue, termed UCX®, have the potential to promote a full range of events leading to tissue regeneration and homeostasis. The main goal of this work was to investigate UCX® action in experimentally induced hindlimb ischemia (HLI). METHODS: UCX®, obtained by using a proprietary technology developed by ECBio (Amadora, Portugal), were delivered via intramuscular injection to C57BL/6 females after unilateral HLI induction. Perfusion recovery, capillary and collateral density increase were evaluated by laser doppler, CD31 immunohistochemistry and diaphonisation, respectively. The activation state of endothelial cells (ECs) was analysed after EC isolation by laser capture microdissection microscopy followed by RNA extraction, cDNA synthesis and quantitative RT-PCR analysis. The UCX®-conditioned medium was analysed on Gallios flow cytometer. The capacity of UCX® in promoting tubulogenesis and EC migration was assessed by matrigel tubule formation and wound-healing assay, respectively. RESULTS: We demonstrated that UCX® enhance angiogenesis in vitro via a paracrine effect. Importantly, after HLI induction, UCX® improve blood perfusion by stimulating angiogenesis and arteriogenesis. This is achieved through a new mechanism in which durable and simultaneous upregulation of transforming growth factor ß2, angiopoietin 2, fibroblast growth factor 2, and hepatocyte growth factor, in endothelial cells is induced by UCX®. CONCLUSIONS: In conclusion, our data demonstrate that UCX® improve the angiogenic potency of endothelial cells in the murine ischemic limb suggesting the potential of UCX® as a new therapeutic tool for critical limb ischemia.

[Chronic mesenteric ischemia revisited]. / Isquemia mesentérica crónica revisitada.

The authors report two clinical cases of rare and complex situations - an aortic dissection and an aortitis -, which had as a common denominator a chronic mesenteric ischemia. They discuss the indications and surgical strategies adopted.

[Conventional open surgery of a splenic artery aneurysm following failure of endovascular management]. / Tratamento cirúrgico convencional de um aneurisma da artéria esplénica após fracasso de intervenção endovascular.

The clinical case of a 73 years old man is reported, complaining for a long time of a persistent abdominal pain in the left upper quadrants, without irradiation and no identified causative factor. These symptoms affected notoriously his quality of life, becoming disabling for his social and professional activities. The investigation by means of CT-scans disclosed a spheric mass, partially calcified, having 44x41mms of maximum size, located between the pancreatic tail and the splenic hilum. A subsequent angio-CT confirmed the diagnosis of a large splenic artery aneurysm and the patient underwent the attempt of an endovascular exclusion by means of an endoprosthesis, which could not be successfully accomplished due to the multiple kinkings and coilings of the splenic artery. Several coils were then used to occlude the aneurismal sac. Contrarily to the expectations, the pain did not disappear after the procedure, becoming even worse, and an open surgical approach was then advised, in another hospital institution, which he promptly accepted. The operation consisted in the resection of the aneurysm and an associated splenectomy, due to multiple infarcts identified in the spleen, consequence of the previous endovascular management. The post operative course was uneventful and he was discharged on day 3. One and four months later he was found in excellent condition and totally pain-free, having resumed his social and professional activities. Based on this clinical case, the authors intend to put an emphasis on this constraint of the endovascular management of peripheral arterial aneurysms, namely on those causing external compression syndromes, painful or others, which can not be relieved by the endovascular exclusion of the aneurysm, as it happened with this patient, thus justifying its presentation and dissemination.