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INTRODUCTION: Kidney autotransplantation (KAT) is a versatile surgical technique used to treat multiple diseases affecting the kidney. This procedure allows the reconstruction of the renal artery or vein with optimal surgical exposure reducing warm ischemia time compared to open direct repair. Although infrequently reported nowadays and despite the growing use of endovascular treatments, KAT still has a place in treating complex kidney vascular conditions. METHODS: We performed a literature review using the MEDLINE®, SCOPUS, and Web of Science databases with the combination of the terms: “kidney autotransplantation,” “renal artery,” “renal vein,” “aorta,” “aneurysm,” and “nutcracker syndrome.” All relevant English-language studies published between January 1990 and June 2022 reporting the outcomes of the KAT technique in vascular disorders were included. RESULTS: A total of 32 articles were included. Ex-vivo repair and KAT is widely described in treating renal artery aneurysms (RAA), with a reported technical success rate of 99.9%, a complication rate ranging from 6.9 to 9.4%, and a graft loss rate of up to 4.1%. The use of the laparoscopic technique for harvesting the kidney was variable throughout the series published, and heterotopic KAT was performed in most treated patients. Ex-vivo repair and KAT was successfully used after failed endovascular therapy and is a viable option in women of childbearing age with bilateral complex RAA. Concerning renal artery stenosis associated with different etiologies (fibromuscular dysplasia, Takayasu's arteritis, and neurofibromatosis type 1), significant reduction of blood pressure and the number of anti-hypertensive drugs have been reported in most patients after KAT. Results of arterial hypertension improvement associated with RAA after KAT are more variable. The use of KAT in treating nutcracker syndrome is reported with good results, even after left renal vein transposition or venous stenting failure. Other reports exist on the successful use of KAT for treating renal vein aneurysms and as an adjunct in open surgical or hybrid aortic reconstructions. CONCLUSION: Renal autotransplantation is a useful technique in the treatment of kidney vascular disorders with good overall results reported in the literature. It may be an essential adjunct in open surgical or hybrid treatments for abdominal and thoracoabdominal aortic diseases. Defining the patients who would benefit from this technique as a preferential treatment choice in different renal vessel disorders would be necessary., Angiologia e Cirurgia Vascular, Vol. 19 No. 1 (2023): March

There is increasing interest in the study of nonperturbative aspects of three-dimensional quantum field theories (QFT). They appear as holographic dual to theories of (strongly coupled) gravity. For instance, in Holographic Cosmology, the two-point function of the Energy-Momentum Tensor (EMT) of a particular class of three-dimensional QFTs can be mapped into the power spectrum of the Cosmic Microwave Background in the gravitational theory. However, the presence of divergent contact terms poses challenges in extracting a renormalised EMT two-point function on the lattice. Using a $\phi^4$ theory of adjoint scalars valued in the $\mathfrak{su}(N)$ Lie Algebra as a proof-of-concept motivated by Holographic Cosmology, we apply a novel method for filtering out such contact terms by making use of infinitely differentiable "bump" functions which enforce a smooth window that excludes contributions at zero spatial separation. The process effectively removes the local contact terms and allows us to extract the continuum limit behaviour of the renormalised EMT two-point function., Comment: Proceedings for the 39th International Symposium on Lattice Field Theory

Portuguese Journal of Cardiac Thoracic and Vascular Surgery, Vol. 30 No. 1 (2023): Jan - Mar

Peripheral arterial disease (PAD), abdominal aortic aneurysm (AAA) and chronic mesenteric ischaemia (CMI) are vascular diseases uncommonly observed in the same patient, especially when treatment is required. This case report illustrates a patient requiring mesenteric revascularization due to CMI. A long flush occlusion of the superior mesenteric artery (SMA) precluded endovascular revascularization. Therefore, we performed a retrograde bypass from the right common iliac artery (CIA) to the SMA. On the 6-month follow-up, the patient developed right limb ischemia despite the absence of intestinal angina. CT angiography revealed CIA occlusion, bypass patency through hypogastric retrograde filling and modest growth of a AAA. Due to the presence of contralateral CIA lesions and to achieve durable revascularization, we opted to perform a AAA repair with an aorto-uni-iliac endograft followed by a femorofemoral crossover bypass. This achieved AAA’s repair, lower limb revascularization, and a suitable and durable inflow to the mesenteric bypass., Portuguese Journal of Cardiac Thoracic and Vascular Surgery, Vol. 30 No. 1 (2023): Jan - Mar

INTRODUCTION: Percutaneous endovenous treatment is the first-line therapy for chronic nonmalignant iliocaval venous obstruction (ICVO) due to low morbidity and suitable medium and long-term results. Open surgical procedures are only used as a last resort therapy. However, there is a lack of updated data regarding surgical techniques and outcomes. We present two cases of surgical venous reconstructions to treat ICVO using expanded polytetrafluoroethylene (ePTFE) grafts and discuss the evidence regarding technical aspects to improve long-term patency. CASE REPORTS: The first case concerns a 69-year-old male with chronic edema and venous ulceration associated with ICVO secondary to iliocaval stent thrombosis. After an unsuccessful endovascular treatment attempt, we performed a surgical iliocaval bypass using a 10mm ringed ePTFE graft. After three months, complete ulcer healing was observed. The other patient was a 63-year-old female with disabling chronic edema of the right lower limb and venous claudication consequent to the ligation of the right common femoral vein to correct an iatrogenic vascular injury during orthopedic surgery. The patient underwent venous bypass between the deep femoral vein and the ipsilateral common iliac vein using a 12mm ringed ePTFE graft. A marked improvement in clinical symptoms was observed after treatment. A venous stent was used later to treat an anastomotic stenosis. CONCLUSION: Our experience supports open venous reconstruction as a viable option for patients with benign ICVO and debilitating symptoms not amenable to endovascular treatment. Important technical aspects such as adequate inflow vein, the choice of the prosthetic graft, long-term anticoagulation, and the creation of a distal arteriovenous fistula should be considered to improve patency., Angiologia e Cirurgia Vascular, Vol. 18 No. 4 (2022): December

INTRODUCTION: Congenital vascular malformations are entities with a broad spectrum of presentations and variable prognosis. They typically present at a young age and are historically associated with extensive resection surgeries and with high morbidity. This study aims to evaluate the results of arteriovenous malformations (AVMs) embolization as a first-line approach in lesions which are not suitable for surgical resection. METHODS: A retrospective analysis of the clinical records of patients with infiltrative arteriovenous malformations who underwent embolization at our center between 2019 and 2021 was performed. The Schobinger Classification was applied to categorize the clinical stage. Angiographic findings were reported according to the Yakes classification. The decrease in the Schöbinger grade after treatment, the need for reintervention and the associated complications were the main outcomes. A descriptive statistical analysis was performed. RESULTS: Nine patients undergoing embolization of infiltrative arteriovenous malformations were evaluated, accounting for a total of seventeen interventions. There was a preponderance of females (n=6; 66.7%) and the mean age of referral to the Vascular Surgery consultation and the first treatment was 16.8 (±12.9) and 20.9 (± 14.5) years, respectively. All patients were in stage II (n=4; 44.4%) or III (n=5; 55.6%) of Schöbinger. The angiographic pattern of the AVMs was classified according to the Yakes Classification, which guided the approach. Yakes type IIa was found most frequently (n=6; 55.6%), followed by type IV (n=2; 22.2%) and type IIb (n=1; 1.1%). Patients underwent AVM embolization via transarterial, transvenous or direct nidus puncture with sclerosing agents, liquid embolizers, microparticles and microcoils, separately or in combination. The median number of interventions per patient was 1 (1 – 5) and Yakes type IV appears to be associated with a higher rate of reintervention. Reduction of the Schöbinger stage was achieved in 7 (77.8%) patients with clinical resolution in 3 (33.3%). Tissue necrosis was the only complication reported in this series (n=2; 11,8%). CONCLUSION: The endovascular approach of arteriovenous malformations through nidus and/or afferent/ efferent embolization requires a detailed angiographic characterization but seems to be an effective strategy with a low risk of complications. The Yakes classification, can be useful both in guiding the approach and inpredicting the need for reintervention., Angiologia e Cirurgia Vascular, Vol. 18 No. 3 (2022): September

INTRODUCTION: Light induced amaurosis refers to a transient monocular or binocular vision loss triggered by bright lights. Like amaurosis fugax, light induced amaurosis is associated with carotid artery stenosis but they differ from each other in presentation and pathophysiology. It is thought to be an impairment in the regeneration of retinal visual pigments caused by the inability of carotid circulation to sustain the increased metabolic activity occurring when the retina is exposed to bright lights. With this report we aim to present a case of light induced amaurosis and its management. CASE REPORT: We describe a 74-year-old man with the isolated complaint of monocular visual loss from his left eye when exposed to bright lights. These episodes were self-limited and lasted for several minutes. His vision was reportedly good between episodes. He also complained of headache and dizziness. There were no other focal neurological deficits present. The patient had a history of peripheral artery disease, chronic heart failure, hypertension, dyslipidaemia, permanent atrial fibrillation and had a history of heavy smoking in the past. Chronic medical therapy included anticoagulation with rivaroxaban, antiplatelet therapy with acetylsalicylic acid and atorvastatin. Imaging studies (doppler ultrasonography and Computed tomography angiography) revealed a significant morphologic stenosis of the left common carotid artery, left internal carotid artery with sub occlusive disease and right internal carotid artery with 70-75% stenosis (North American Symptomatic Carotid Endarterectomy Trial - NASCET). The vertebral arteries study did not reveal significant morphologic disease. The patient was submitted to left common and internal carotid artery endarterectomy and Dacron patch angioplasty. The visual symptoms progressively improved after surgical treatment. The dizziness and headache were completely gone. CONCLUSION: Light induced amaurosis is a rare and less known symptom associated with severe carotid artery stenosis. Its timely recognition is important to not deprive patients of timely treatment., Angiologia e Cirurgia Vascular, Vol. 18 No. 3 (2022): September

Introduction: Percutaneous endovenous treatment is the first-line therapy for chronic nonmalignant iliocaval venous obstruction (ICVO) due to low morbidity and suitable medium and long-term results. Open surgical procedures are only used as a last resort therapy. However, there is a lack of updated data regarding surgical techniques and outcomes. We present two cases of surgical venous reconstructions to treat ICVO using expanded polytetrafluoroethylene (ePTFE) grafts and discuss the evidence regarding technical aspects to improve long-term patency. Case reports: The first case concerns a 69-year-old male with chronic edema and venous ulceration associated with ICVO secondary to iliocaval stent thrombosis. After an unsuccessful endovascular treatment attempt, we performed a surgical iliocaval bypass using a 10mm ringed ePTFE graft. After three months, complete ulcer healing was observed. The other patient was a 63-year-old female with disabling chronic edema of the right lower limb and venous claudication consequent to the ligation of the right common femoral vein to correct an iatrogenic vascular injury during orthopedic surgery. The patient underwent venous bypass between the deep femoral vein and the ipsilateral common iliac vein using a 12mm ringed ePTFE graft. A marked improvement in clinical symptoms was observed after treatment. A venous stent was used later to treat an anastomotic stenosis. Conclusion: Our experience supports open venous reconstruction as a viable option for patients with benign ICVO and debilitating symptoms not amenable to endovascular treatment. Important technical aspects such as adequate inflow vein, the choice of the prosthetic graft, long-term anticoagulation, and the creation of a distal arteriovenous fistula should be considered to improve patency.

For a smooth algebraic variety $X$, we study the category of finitely generated modules over the ring of function of $X$ that has a compatible action of the Lie algebra $\mathcal{V}$ of polynomials vector fields on $X$. We show that the associated representation of $\mathcal{V}$ is given by a differential operator of order depending on the rank of the module. The order of the differential operator provides a natural measure of the complexity of the representation, with the simplest case being that of $D$-modules.

INTRODUCTION: Ectopic kidneys with concomitant aortoiliac aneurysmal disease have been previously reported in the literature, however its exact prevalence is unknown. The objective of this review is to summarize current knowledge on the treatment this special group of patients. METHODS: A non-systematic literature research was performed on the treatment of aortoiliac aneurysmal disease in patients with ectopic kidneys. RESULTS: Literature on the management of patients with aorto-iliac aneurysms and concomitant ectopic kidneys is limited to case reports and very small series. Treatment modalities which include open, endovascular or hybrid techniques, should preserve the variable vasculature of the ectopic kidney. Several different surgical solutions have been proposed, highlighting the uncertainty on the optimal management strategy. However, a growing number of reports suggest safety and efficacy with adapted endovascular techniques. CONCLUSION: In parallel to the general trend in the management of abdominal aortic aneurysm, it is expected that a growing number of patients will concomitant aorto-iliac aneurysm and ectopic kidneys will be treated with endovascular techniques., Angiologia e Cirurgia Vascular, Vol. 18 No. 2 (2022): June

Introduction: Renal artery aneurysms are rare clinical entities whose treatment criteria are not fully established. Endovascular treatment has gained acceptance in the case of renal artery trunk aneurysms. However, in the case of aneurysms of the renal artery branches, such procedures are often impossible due to high morbidity, so the question remains about the best treatment modality. We present a clinical case of multiple bilateral aneurysms of the renal artery branches in a young patient adequately treated with ex-vivo reconstruction and renal autotransplantation. Case-presentation: A 35-year-old woman was diagnosed with bilateral renal artery aneurysms during an investigation of secondary arterial hypertension (AHT). The patient underwent surgical treatment with renal autotransplantation, and the right kidney was initially treated. Transperitoneal laparoscopic nephrectomy was performed. She underwent ex vivo repair of aneurysms, on the bench, with aneurysmectomy and aneurysmorrhaphy. The graft was implanted in the right iliac fossa with anastomoses to the external iliac artery and vein. After three months, an identical procedure was performed on the left. Upon inspection, a large aneurysm was observed in the renal artery bifurcation and another small aneurysm in one of the branches; both corrected with aneurysmec- tomy and aneurysmorrhaphy. Ex-vivo angiographic control ensured the preservation of graft arteries patency without evidence of residual aneurysms. The kidney was implanted in the left external iliac vessels uneventfully. A study with renal scintigraphy confirmed the adequate function of both kidneys. The patient is asymptomatic at nine months of follow-up with serum creatinine and glomerular filtration rate within normal values. Conclusion: Renal autotransplantation with ex vivo arterial repair seems to be a good solution in treating aneurysms of the renal artery, particularly in complex cases with multiple aneurysms., Angiologia e Cirurgia Vascular, Vol. 17 No. 4 (2021): December

INTRODUCTION: In situ lesser saphenous vein (LSV) graft has been advocated in cases of lower limb revascularization where target arteries are confined to the lower leg and the greater saphenous vein (GSV) is neither available nor suitable. This often occurs in diabetic or end-stage renal diseased patients, whose occlusive disease pattern typically affects the tibioperoneal vessels, sparing the femoropopliteal segment. In situ technique offers the potential advantages of decreased surgical trauma to the vein, better size-matching and improved hemodynamics. The posterior approach simplifies the surgical procedure; it achieves similar graft patency and limb salvage rates compared to standard procedures. CASE REPORT: We report a case of an 89 years-old male diabetic patient with previous attempts of endovascular revascularization of the posterior tibial and peroneal arteries; he presents with a nonhealing ulcer of the first toe of the right foot. Ultrasonographic vein mapping revealed varicose GSV in both limbs and a linear, ~3mm diameter, LSV in the right leg. The patient underwent right limb retrogeniculate popliteal to distal posterior tibial artery bypass with in situ LSV through a posterior approach. Post-operative bypass thrombosis occurred after seven days; it was resolved with surgical thrombectomy, vein angioplasty and arteriovenous shunt ligation. During follow-up at the outpatient clinic, the bypass remains patent and skin lesions healing without complications. CONCLUSION: In situ LSV is a safe and viable option conduit for popliteal to distal arteries bypasses. Vascular surgeons should be aware of the posterior approach, which simplifies and comfortably exposes the anatomic structures required for this surgery., Angiologia e Cirurgia Vascular, Vol 17 No 3 (2021): September

Introduction: The development of aneurysms in iliac arteries excluded from high-pressure direct flow from the aorta is very uncommon. We report a case of successful treatment of bilateral metachronous iliac artery aneurysms (MIA), found 10 years after an aortobifemoral bypass, with perfusion only by retrograde flow from the common femoral arteries (CFA). Case Report: A 76-year-old man came for consultation after incidental finding of bilateral MIAs, 10-years after aorto- bifemoral bypass for treatment of an aortic abdominal aneurysm (AAA). Computed tomography angiography (CTA) showed a right internal iliac artery (IIA) aneurysm of 43-mm diameter and a left common iliac artery (CIA) aneurysm of 45-mm diameter that were not present 10-years before. Exclusion of the left CIA aneurysm was achieved with a left IIA to external iliac artery (EIA) endograft using two covered stents (���banana��� technique). The right IIA aneurysm was excluded with embolization of the distal internal iliac branches and aneurysm sac with coils and occlusion of the proximal EIA with an occluder. There were no postoperative complications. A CTA two months after surgery showed total exclusion of the left CIA aneurysm and normal filling of the left IIA, as well as complete occlusion of the right IIA aneurysm. Conclusion: This case highlights that aneurysmal degeneration of iliac arteries can be generated by retrograde blood flow after treatment of AAAs with aortobifemoral grafts. An endovascular approach using the ���banana��� technique proved to be effective in treating MIAs while maintaining patency of one IIA., Angiologia e Cirurgia Vascular, Vol 17 No 3 (2021): September

Introduction: Renal artery aneurysms are rare clinical entities whose treatment criteria are not fully established. Endovascular treatment has gained acceptance in the case of renal artery trunk aneurysms. However, in the case of aneurysms of the renal artery branches, such procedures are often impossible due to high morbidity, so the question remains about the best treatment modality. We present a clinical case of multiple bilateral aneurysms of the renal artery branches in a young patient adequately treated with ex-vivo reconstruction and renal autotransplantation. Case-presentation: A 35-year-old woman was diagnosed with bilateral renal artery aneurysms during an investigation of secondary arterial hypertension (AHT). The patient underwent surgical treatment with renal autotransplantation, and the right kidney was initially treated. Transperitoneal laparoscopic nephrectomy was performed. She underwent ex vivo repair of aneurysms, on the bench, with aneurysmectomy and aneurysmorrhaphy. The graft was implanted in the right iliac fossa with anastomoses to the external iliac artery and vein. After three months, an identical procedure was performed on the left. Upon inspection, a large aneurysm was observed in the renal artery bifurcation and another small aneurysm in one of the branches; both corrected with aneurysmec- tomy and aneurysmorrhaphy. Ex-vivo angiographic control ensured the preservation of graft arteries patency without evidence of residual aneurysms. The kidney was implanted in the left external iliac vessels uneventfully. A study with renal scintigraphy confirmed the adequate function of both kidneys. The patient is asymptomatic at nine months of follow-up with serum creatinine and glomerular filtration rate within normal values. Conclusion: Renal autotransplantation with ex vivo arterial repair seems to be a good solution in treating aneurysms of the renal artery, particularly in complex cases with multiple aneurysms.