Next-Generation Sequencing of microRNAs in Small Abdominal Aortic Aneurysms: MiR-24 as a Biomarker.

BACKGROUND: Small abdominal aortic aneurysms (AAAs) are asymptomatic but can potentially lead to rupture if left undetected. To date, there is a lack of simple nonradiologic routine tests available for diagnosing AAAs. MicroRNAs (miRNAs) have been proven to be good-quality biomarkers in several diseases, including AAA. METHODS: An attempt to identify a panel of circulating miRNAs with differential expression in AAAs via next-generation sequencing (NGS) was performed in serum samples: small AAAs (n = 3), large AAAs (n = 3), and controls (n = 3). For miR-24, validation with real-time polymerase chain reaction (PCR) was undertaken in a larger group (n = 80). RESULTS: In the NGS study, 23 miRNAs were identified as differentially expressed (with statistical significance) in small AAAs in comparison with controls. Among them, miR-24 showed the largest upregulation with 23-fold change (log2FC 4.5, P = 0.024). For large AAAs compared with controls, and small AAAs compared with large AAAs, a panel of 33 and 131 miRNAs showed statistically significant differential expression, respectively. Based on the results of the NGS stage, a literature search was performed, and information regarding AAA pathogenesis, coronary artery disease, and peripheral arterial disease was documented where applicable: miR-24, miR-103, miR-193a, miR-486, miR-582, and miR-3663. Of these 6 miRNAs, miR-24 was chosen for further validation with real-time PCR. Additionally, in the NGS study analysis, 17 miRNAs were common between the small-large AAAs, small AAAs-controls, and large AAAs-controls comparisons: miR-7846, miR-3195, miR-486-2, miR-3194, miR-5589, miR-1538, miR-3178, miR-4771-1, miR-5695, miR-6504, miR-1908, miR-6823, miR-3159, miR-23a, miR-7853, miR-496, and miR-193a. Interestingly, in the validation stage with real-time PCR, miR-24 was found downregulated in small and large AAAs compared with controls (fold-changes: 0.27, P = 0.015 and 0.15, P = 0.005, respectively). No correlation was found between average Ct values, aneurysm diameter, and patients' age. CONCLUSIONS: Our findings further highlight the importance of miR-24 as a potential biomarker as well as a therapeutic target for abdominal aneurysmal disease. Future research and validation of a panel of miRNAs for AAA would aid in diagnosis and discrimination between diseases with overlapping pathogeneses.

Customizing foam sclerotherapy of the great saphenous vein: A proposed algorithm to enhance technical efficacy.

OBJECTIVES: The catheter-directed foam sclerotherapy (FS) and the suggested perivenous tumescent application for great saphenous vein (GSV) diameter reduction are suggested to improve technical and clinical results; yet, their use is reported rather indiscriminately. Our aim is to introduce an algorithm categorising the use of technical modalities accompanying ultrasound-guided FS of the GSV and present the technical efficacy of FS through a 5 F × 11  cm sheath placed at the knee level. METHODS: Representative cases of GSV insufficiency were chosen to describe our methodology. RESULTS: Sole sheath-directed FS can achieve complete GSV occlusion proximally at a level comparable to the catheter-directed technique. We apply perivenous 4°C cold tumescent to GSV >6 mm even in the standing position to ensure diameter reduction of the proximal GSV as close to the saphenofemoral junction. We use long catheters only to overcome large varicosities above the knee level that could otherwise compromise the adequate foam infusion from the sheath tip. When GSV insufficiency extends along the entire limb and severe skin lesions preclude the antegrade distal catheterisation, the sheath-directed FS in the thigh can be concomitantly combined with retrograde FS from catheterisation just below the knee. CONCLUSIONS: A topology-oriented methodology with sheath-directed FS is technically feasible and avoids indiscriminate use of more complex modalities.

Circulating miRNAs as Biomarkers for Diagnosis, Surveillance, and Postoperative Follow-Up of Abdominal Aortic Aneurysms.

BACKGROUND: To provide a summary of the current state of research in English medical literature on circulating miRNAs as biomarkers for abdominal aortic aneurysm (AAA). Additionally, for the most commonly mentioned circulating miRNAs in the literature, to attempt a documentation of the biological mechanisms underlying their role in AAA development. METHODS: A literature search was undertaken in the MEDLINE database. Only reports that involved peripheral blood samples (whole blood, plasma, and serum) were included. The following terms were used in combination: microrna, mirna, AAA, human, circulating, plasma, serum, endovascular, and endovascular aneurysm repair (EVAR). RESULTS: A total of 25 reports, published from 2012 to 2022 were included with a total of 1,259 patients with AAA, predominantly men (N = 1,040, 90%). Six of these reports recruited healthy donors who underwent ultrasound screening for AAA as control samples. The majority of studies were undertaken in plasma samples and the most preferred microRNA profiling method was real - time quantitative polymerase chain reaction (qRT-PCR). The following 9 miRNAs (out of a total of 76) were studied in more than 2 references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29, and miR-133. CONCLUSIONS: The 9 miRNAs described in this study, are implicated in known pathogenetic mechanisms of AAA, such as atherosclerosis, vascular smooth muscle cell (VSMCs) phenotype switch and apoptosis, vascular inflammation, extracellular matrix (ECM) degradation, and lipid metabolism. Identifying disease-specific miRNAs, in combination with other clinical parameters, as indicators of AAA, is crucial for early diagnosis as well as follow-up of AAAs. For future research on miRNAs as AAA biomarkers, strict case and control group definitions, sample acquisition protocols, and miRNA expression profiling techniques are warranted.

Foam sclerotherapy of great saphenous vein: The need for further improvement and ill-defined issues.

Foam sclerotherapy is considered an acceptable method to treat great saphenous vein (GSV) insufficiency, promoting occlusion of its trunk and eradicating reflux. Yet, certain technical points have not been standardized while issues regarding the ultrasonographic appearance of successful or acceptable GSV obliteration or the end-points of the method are not clearly defined. This article comments on the aforementioned using examples based on personal experience.

A Misdiagnosed Case of Endoleak Type-III Caused by Inadvertent Bilateral Limb Insertion in the Same Limb Gate of the Ovation Endograft.

We describe an infrequent case of endoleak Type-III due to an unrecognized, inadvertent bilateral limb deployment into the same limb gate of the Ovation aortic endograft, accompanied by thrombosis and acute ischemia. The following computed tomography angiography revealed the open limb gate with the characteristic of radio-opaque polymer in the sealing rings. Intraoperative angiographies via the brachial route identified the open limb gate and facilitated the successful use of an occluding plug to manage the Type-III endoleak.

Superficialization Methods of Arteriovenous Fistula in Obese Patients: A Review of the Literature.

BACKGROUND: The creation of an arteriovenous fistula in obese patients with end-stage-renal-disease, might not lead to a successful hemodialysis session, partly due to excess adipose tissue overlapping the enlarged vein. This review summarizes the available evidence on superficialization methods in studies dealing with obese patients. METHODS: An English-language literature search was undertaken in the MEDLINE/SCOPUS databases looking for publications that described procedures of salvaging autologous arteriovenous access in upper extremities of obese patients. Perioperative outcomes including technical and clinical success, mean vein depth reduction, wound complications and patency rates were compared within all identified techniques. RESULTS: We identified 12 prospective and 8 retrospective studies. A total of 1149 patients with a mean age 57.2 (range: 49-68) years and a mean BMI 35.8 (range: 28.2-40.8) kg/m2 underwent mainly radial-cephalic and brachial-cephalic arteriovenous fistula superficialization procedures [transposition, 54%; elevation, 11.1%; lipectomy, 26.1%; liposuction, 2.4%; implantation of a venous window needle guide device, 6.4%]. Technical success was similar between all methods (≥96%). However, successful cannulation was lower after liposuction and elevation (81.5% and 78.1% respectively). Transposition achieved lower mean vein depth reduction and clinical success when compared with lipectomy (4.9 mm vs. 8.8 mm and 90% vs. 92.7% respectively). Transposition and liposuction had the lowest and highest complication rate respectively (1.6% vs. 40.8%). Primary and secondary patency rates were lower with liposuction (51.8% and 76.6% respectively), while lipectomy and elevation achieved the highest primary patency rates (68.3% and 71.6% respectively) at 12 months. CONCLUSIONS: In obese patients, all superficialisation techniques report high technical success rates. Although limited by the design of individual published studies and lack of a standard for reporting outcomes, these results lead to satisfactory postoperative and early outcomes. In aggregate, lipectomy and transposition are more clinically effective and more durable procedures.

A Clampless Technique to Facilitate Successful End-to-End Anastomosis in Small Vessels With Spasm.

End-to-end anastomosis in small arteries can be challenging, especially when the stumps are in spasm after traumatic transection. We describe a novel technique to facilitate such anastomoses under local anesthesia, presenting a 24-year old patient who suffered complete traumatic transection of the left ulnar artery. After having found and prepared the proximal and distal stumps, a soft polyurethane feeding tube (La-med Healthcare, India) and a vein cannula were inserted in the proximal and distal stump, respectively, without using vascular clamps. The manipulation of the catheters offered excellent visualization and widening of the anastomotic line, enabling simultaneous infusion of heparinized saline or vasodilating agents. The anastomosis was completed with no stenosis and pulpable pulses were restored immediately postoperatively. At 1-month follow-up, the Allen test was normal with a normal regular flow of the ulnar artery at duplex ultrasound. The described technique ensures efficient sealing avoiding clamping, casts the small lumens, provides optimal visualization of the anastomotic aspects and prevents stenosis. We believe it should have a place in the surgeon's armamentarium.

Irreversible Limb Ischemia Due to Embolizing Aneurysm of the Superficial Femoral Artery.

BACKGROUND: Degenerative superficial femoral artery aneurysms are rare and can lead to catastrophic complications; among these, rupture is the most usual, whereas peripheral embolization is less common. METHOD: We report a patient with a large superficial femoral artery aneurysm presenting with irreversible limb ischemia, due to multiple distal embolization as demonstrated with urgent computed tomography angiography. Due to local and systemic consequences primary limb amputation was performed. Unfortunately, the patient died from cardiac arrest on the 2nd postoperative day. CONCLUSION: Delayed diagnosis of true superficial femoral artery aneurysms can result in life-threatening consequences. Peripheral embolization is an uncommon event, but can lead to irreversible ischemia and limb loss.

Five-Year Management of Vascular Injuries of the Extremities in the "Real-World" Setting in Northeastern Greece: The Role of Iatrogenic Traumas.

BACKGROUND: Vascular trauma comprises a diagnostic and surgical challenge. Aim of this study was to present the vascular traumas treated in our Tertiary Hospital during the last 5 years. METHODS: We retrospectively reviewed the surgical records of our vascular department and documented the site and type of vascular injuries of the extremities along with the concurrence of musculoskeletal injuries. The type and outcome of surgical interventions were also recorded. RESULTS: Fifty-eight cases of vascular trauma were recorded (39 in the upper and 19 in the lower extremities). Overall, iatrogenic traumas accounted for 41.3% of cases. The arterial injuries of the upper limb were blunt and penetrating in 27% and 67%, respectively. The most affected artery in the upper limb was the radial artery (37.8%), followed by the ulnar artery (27%) and the brachial artery (24.3%). Orthopedic injuries were recorded in 19% of patients. Management involved simple revascularization, bypass operations, patch arterioplasty and endovascular management in 48.7%, 33.3%, 5.1%, and 5.1%, respectively. The most affected site in the lower extremity was the common femoral artery (36.8%) followed by the popliteal artery (21%). Bone fractures were reported in 5 cases (26.3%). The surgical management involved bypass, simple revascularization, patch arterioplasty in 42.1%, 26.3%, and 21%, respectively. Endovascular management was performed in 10.5%. CONCLUSIONS: A considerable percentage of iatrogenic vascular injuries was recorded, affecting both the upper and lower limbs. Despite the trend toward centralization of vascular services, a basic service of vascular surgery should be available in most sites to ensure that patients with vascular injuries receive fast and appropriate care.

Lessons Learned from Open Surgical Conversion after Failed Previous EVAR.

BACKGROUND: Delayed open conversion (OpC) after endovascular aortic aneurysm repair (EVAR) is becoming increasingly common worldwide. We reviewed our experience to characterize the perioperative spectrum of OpC repairs. MATERIALS AND METHODS: A retrospective analysis of a prospectively maintained institutional database to identify patients who underwent late OpC after failed EVAR was performed. Patient and aneurysm baseline characteristics, mechanism of failure, perioperative details, including type of repair/complications/survival, and late outcomes were examined. RESULTS: From January 2003 to January 2020, 38 male patients (mean age, 75 ± 7 years; range, 60-90) required late OpC. Interval time from initial EVAR to OpC was 63.6 ± 33.8 months (range, 17-120). Mean diameter of the aneurysms was 82.2 ± 22.1 mm before OpC compared with 62.9 ± 13 mm before endograft implantation. Mechanisms of failure were type Ia, Ib, II, and III endoleaks in 14 (36.8%), 9 (23.7%), 4 (10.5%), and 1 (2.6%) patient(s), respectively; infection in 3 (7.9%), leg ischemia in 2 (5.3%), and multiple causes in 5 (13.2%) patients. We observed 4 (10.5%) asymptomatic, 16 (42.1%) symptomatic, and 18 (47.3%) ruptured aneurysms. Four patients (10.5%) had stable contained ruptures, whereas the remaining 13 (34.2%) and 1 additional patient (2.6%) with aortoenteric fistula presented with hemorrhagic shock (class ≥II). Total endograft explantation, endograft preservation, or proximal/distal partial graft removal was performed in 16 (42.1%), 10 (26.3%), and 2 (5.2%)/9 (23.7%) of patients, respectively. Technical success was 100%, excluding an early postaortic clamping death. Overall, 30-day mortality was 21.1% (8 of 38) and significantly higher in patients with hemorrhagic shock or hemodynamic instability at presentation (P = 0.04 and P = 0.009, respectively) and in patients who had endografts with hooks/barbs or experiencing higher postoperative complication rate (P = 0.02 and P = 0.006, respectively). By definition, procedure success was 81.1%. Mean follow-up was 37.6 ± 39.8 months. By the end of the study, we recorded 11 deaths (2 were aneurysm related). CONCLUSIONS: Despite high technical success, OpC has a significant mortality in patients presenting with hemorrhagic shock and had active fixation endografts or experiencing high complication rate. Many other confounding factors may play a role.

The "Pull, Cast, and Fix" Technique for Bypass in the Midpopliteal (P2) Arterial Segment in Chronic Femoropopliteal Occlusions.

Femoropopliteal bypass operations can be difficult when the occlusive disease involves the superficial femoral artery and the popliteal arterial segment above the knee joint (supragenicular artery, P1). In case of lack of suitable vein graft or when the surgeon wishes to spare to infrapopliteal segment, the choice of the midpopliteal artery as anastomotic site becomes challenging because of its location. Moreover, totally endovascular recanalization procedures in such cases can be complex and demanding, whereas other reported hybrid revascularization techniques require advanced technical skills and raise significantly the cost. Therefore, we present our suggestion of a "pull, cast, and fix" technique to encounter these challenges and facilitate a successful bypass with a synthetic graft in the upper midpopliteal (P2) segment, combing a secure endarterectomy and anastomosis even under marginal visualization by means of securing the lumen with a soft feeding tube after the artery has been pulled via a Satinsky vascular clamp. Accordingly, the procedure is accomplished with placement of a flexible self-expandable stent in the midpopliteal artery through the synthetic graft.

Introducing a "no-touch" maneuver to manage challenging anastomoses in arteriovenous fistulae.

Native arteriovenous fistula or interposition of a synthetic graft for vascular access is crucial for dialysis patients. Optimal surgical technique, microsurgery instrumentation and preventive hemostasis are considered beneficial for a successful surgical outcome. We describe a simple and novel maneuver using soft-feeding tubes to facilitate the manipulation of veins and perform successful anastomoses without using microsurgery instrumentation or vascular clamps during operations for vascular access.

An update on the ovation abdominal stent graft for the treatment of abdominal aortic aneurysms: current evidence and future perspectives.

Introduction: The Ovation stent-graft has presented satisfactory mid-term results in the management of abdominal aortic aneurysms (AAA). Its unique design with uncoupling of fixation and sealing and the lowest profile in the market has expanded the treatment in AAA with challenging neck anatomies and, especially, in the females presenting mostly with narrow iliac access vessels. Morever, a new design modification, the Ovation Alto was recently introduced in the Market, while certain off-label uses of the Ovation in treating either juxtarenal- or short-necked AAA have been proposed. Areas covered: Aim of this article was to present the current articles with the long-term results of the Ovation endograft and discuss the new developments and modifications in its use. Expert commentary: the Ovation stent-graft exhibits very satisfactory clinical long-term results in AAA treated within the instructions-for-use, expands significantly the treatment of AAA in females and overcomes reliably challenging anatomical issues of the infrarenal neck that would render these cases ineligible for treatment with any other endograft. Εxperience with the specific, unique technical features of Ovation as well as careful selection of patients and meticulous preoperative study of the AAA anatomy are key-elements to the successful performance of this endograft.

Tips to Ensure Optimal Ring Apposition of the Ovation Stent Graft in Challenging Necks of Abdominal Aortic Aneurysms.

The Ovation stent graft has been recently introduced for endovascular repair of abdominal aortic aneurysms. Its sealing mechanism is based on a pair of polymer-filled inflatable rings. Based on our experience, we describe useful tips to optimize the use of Ovation in thrombosed or severely angulated necks.

A Complex Case of Synchronous Thoracic and Abdominal Endoleak Repair with Custom-Made Relay NBS Thoracic Stent Graft and Abdominal Open Reconstruction.

A 71-year old man with previous thoracic aneurysm endovascular repair and endovascular abdominal aneurysm repair presented with simultaneous type III endoleak from the thoracic components and type Ia endoleak from migration of the abdominal endograft, leading to enlargement of both aneurysms. A custom-made reverse tapered Relay NBS thoracic endograft was used to bridge the thoracic stent grafts. While a low-flow type III endoleak persisted in the immediate postoperative phase, because of incomplete apposition of the new stent graft, further deployment of its nitinol skeleton resulted in resolution of the endoleak at 1-week follow-up. The abdominal aneurysm enlargement was corrected via excision of the central segment of the abdominal endograft, preservation of the distal main body and limbs, and interposition of a short Dacron tube graft.

A Rare Case of Tibioperoneal Arterial Trunk Entrapment Caused by a Fibular Osteochondroma.

BACKGROUND: Osteochondromas or exostoses are the most common benign tumors of the bones, which appear during the growth period. The involvement of lower extremities is common, particularly in metaphyseal structures of the femur and humerus and around the knee joint. However, the incidence of the development of the tumor at the proximal fibula is rare. The most common signs and symptoms of the disease are pain, pulsatile mass, limb swelling, neurologic sequelae, bursa formation with subsequent bursitis, and impairment of the developmental growth. Vascular complications are rare, yet osteochondromas can cause catastrophic arterial complications threatening the life of the patient if they occur and can include vessel perforation and thrombosis, arterial thromboembolic events, and pseudoaneurysm formation. METHODS: We report a case of a 24-year-old male patient presenting with tibioperoneal arterial trunk entrapment caused by a massive osteochondroma derived from the proximal fibula. A combined vascular-orthopedic approach was initiated with the excision of the tumor, in which the neurovascular structures (tibial nerve, popliteal artery and vein, anterior tibial artery, and tibioperoneal trunk) were carefully recognized and protected. RESULTS: The postoperative course of the patient was uneventful. CONCLUSIONS: High clinical suspicion of a vascular complication should be raised by physicians when investigating a young patient with a suspected osseous tumor in the popliteal fossa and symptomatology of concurrent peripheral arterial disease. Prompt surgical management is crucial for the salvage of the affected limb in cases of arterial involvement. Furthermore, quick surgical exposure of the mass and regular postoperative follow-up check minimizes the risk of irreparable impairments and tumor recurrence.

A clinical update on the mid-term clinical performance of the Ovation endograft.

INTRODUCTION: The Ovation stent-graft uncouples the steps of fixation and sealing via a pair of polymer-filled inflatable rings. Apart from the well-documented early results, newer data emerged for mid-term results of Ovation and are presented in this review. AREAS COVERED: Aim of this article was to report all current studies with the mid-term results of the particular endograft, the incidence of complications and failure, and discuss their management. EXPERT COMMENTARY: The Ovation stent-graft exhibits very satisfactory clinical mid-term results in abdominal aortic aneurysms treated within the instructions-for-use. It can also have a very promising role in challenging neck anatomies with conical shape and presence of thrombus or calcification. However, this should be not considered a panacea and long-term results are needed to validate this intriguing aspect.