Aortic clamping during elective operations for infrarenal disease: The influence of clamping time on renal function

AbstractObjective: Aortic clamping proximal to the renal arteries is sometimes necessitated during infrarenal and juxtarenal aortic surgery and may be associated with an increased risk of renal ischemia and its consequences. The aim of the study was to estimate this risk and possibly identify a “safe” duration of renal ischemia. Methods: Medical records were retrospectively reviewed for 60 consecutive patients (from 1987 to 1994) with abdominal aortic aneurysm (n = 43) and occlusive disease (n = 17) confined to the infrarenal or juxtarenal aorta who underwent infrarenal aortic reconstruction with temporary suprarenal clamping. The data obtained included risk factors, preoperative and postoperative serum creatinine level, blood urea nitrogen (BUN) value, proteinuria before surgery, and suprarenal clamping times. Results: The mean age of the patients was 64.4 years (± 11.4 years), and 74% were men. Concomitant cardiac disease was present in 41% of the patients, and 9% had diabetes. The preoperative creatinine level was 1.21 mg/dL (± 0.54 mg/dL), and the BUN value was 16.6 mg/dL (± 7.8 mg/dL). During surgery, blood flow to the renal arteries was interrupted for 32.0 minutes (± 17 minutes). None of the surviving patients needed dialysis or had signs of acute renal failure after the operations, but transient azotemia (rise in creatinine level) occurred in 23% of the patients. Risk factors for this condition were high preoperative creatinine values and hypotension during surgery, but the main determinant was total renal ischemia time. Odds ratios for such transient renal dysfunction showed as much as a 10-fold risk when suprarenal aortic clamping was greater than 50 minutes as compared with 30 minutes or less. Conclusion: Postoperative renal function impairment is rare in this group of patients. If suprarenal clamp duration (renal ischemia time) is brief, patients with normal preoperative creatinine levels exhibit no increase or a marginal increase in BUN or creatinine levels after surgery. Accordingly, suprarenal aortic clamping less than 50 minutes in this patient group appears safe and well tolerated. (J Vasc Surg 2002;36:13-8.

Sphingosine-1-phosphate promotes the differentiation of adipose-derived stem cells into endothelial nitric oxide synthase (eNOS) expressing endothelial-like cells.

BACKGROUND: Adipose tissue provides a readily available source of autologous stem cells. Adipose-derived stem cells (ASCs) have been proposed as a source for endothelial cell substitutes for lining the luminal surface of tissue engineered bypass grafts. Endothelial nitric oxide synthase (eNOS) is a key protein in endothelial cell function. Currently, endothelial differentiation from ASCs is limited by poor eNOS expression. The goal of this study was to investigate the role of three molecules, sphingosine-1-phosphate (S1P), bradykinin, and prostaglandin-E1 (PGE1) in ASC endothelial differentiation. Endothelial differentiation markers (CD31, vWF and eNOS) were used to evaluate the level of ASCs differentiation capability. RESULTS: ASCs demonstrated differentiation capability toward to adipose, osteocyte and endothelial like cell phenotypes. Bradykinin, S1P and PGE were used to promote differentiation of ASCs to an endothelial phenotype. Real-time PCR showed that all three molecules induced significantly greater expression of endothelial differentiation markers CD31, vWF and eNOS than untreated cells. Among the three molecules, S1P showed the highest up-regulation on endothelial differentiation markers. Immunostaining confirmed presence of more eNOS in cells treated with S1P than the other groups. Cell growth measurements by MTT assay, cell counting and EdU DNA incorporation suggest that S1P promotes cell growth during ASCs endothelial differentiation. The S1P1 receptor was expressed in ASC-differentiated endothelial cells and S1P induced up-regulation of PI3K. CONCLUSIONS: S1P up-regulates endothelial cell markers including eNOS in ASCs differentiated to endothelial like cells. This up-regulation appears to be mediated by the up-regulation of PI3K via S1P1 receptor. ASCs treated with S1P offer promising use as endothelial cell substitutes for tissue engineered vascular grafts and vascular networks

Assessing the Operative Log Data of Traditional (5+2) vs. Integrated (0+5) Vascular Training Programs

Introduction: In 2006, the Accreditation Council for Graduate Medical Education (ACGME) approved an integrated 5 year vascular surgery residency program. Operative experience can be used as a surrogate marker for success in the evolving field of vascular surgery training. Objective: The purpose of this study is to compare the operative experience of those graduating from the traditional (5+2) vascular training program with the integrated (0+5) program. Methods: National operative case log data supplied by the ACGME was gathered and organized for vascular surgery residents graduating between 2013 and 2018. Mean case numbers were compared between integrated vascular residents and traditional vascular fellows (mean case numbers for vascular fellows included cases from their general surgery residencies). Results: The 5+2 trainees performed 36% more overall procedures than the 0+5 trainees (mean, 1650 vs 1050). The greater number of overall procedures performed by the 5+2 trainees was primarily realized by an increased number of abdomen (e.g. biliary, small/large intestine) cases. However, the 5+2 trainees performed 8% less vascular procedures (mean, 786 vs 854). The greater number of vascular procedures performed by the 0+5 trainees was primarily realized by increased numbers of endovascular (e.g. endovascular peripheral obstruction) and venous (e.g. caval filter) cases. Discussion: The integrated 0+5 graduates performed more total vascular procedures than their 5+2 counterparts. The overall total operative experience remains greater for the traditional 5+2 graduates, given their additional two years of training. Further longitudinal studies will be needed to fully assess the effect of the new integrated 0+5 training paradigm

Fate of the lower extremity in patients with VA-ECMO via femoral cannulation

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a salvage therapy in patients with severe cardiopulmonary failure. Femoral cannulation is associated with limb complications including ischemia, limb loss, arterial infections and wound infections. This study aims to evaluate these complications and management related to successful outcomes. Methods: A retrospective review was conducted in 17 patients requiring VA- ECMO support via femoral cannulation from 1/ 2010 till 4/2012. After cannulation, all patients had near infared spectroscopy (NIRS) monitoring after cannula placement and most had placement of distal arterial perfusion catheters (DPC). At decannulation, all patients had femoral cutdown with closure of arteriotomies by primary repair or patch angioplasty with bovine pericardium. Primary study endpoints included ischemia, limb loss, arterial infection; secondary endpoints were wound infection and post-discharge symptoms. Results: Seventeen patients were supported with VA-ECMO during the study period with arterial cannula size of 16-20 French. All patients had NIRS monitoring after cannula placement and 13/17 patients had DPC placement, with no subsequent ischemia. Two of 4 patients without DPC developed ischemia; one was decannulated and the other resolved spontaneously. At decannulation, open arterial repair was performed as described. In this study population, simple wound infection occurred in 3/17with Vacuum Assisted Closure (VAC) devices were placed at the timed if appropriate. There were no arterial infections and no instances of limb ischemia requiring amputation. There were no complaints of rest pain during outpatient follow-up. Conclusions: Limb complications related to femoral cannulation for VA-ECMO can lead to prolonged morbidity and limb loss. NIRS and placement of DPC, primary repair of arteriotomy or patch angioplasty, along with aggressive wound care, can dramatically decrease rates of limb ischemia, limb loss and infection

False lumen embolization as a rescue technique in the setting of acute and chronic dissecting aneurysms as adjunct to thoracic endovascular aortic repair.

Complicated type B aortic dissection (TBAD) is a life-threatening condition requiring surgical intervention. One such complication in the acute or chronic setting is aneurysmal degeneration. The dissected aortic wall is weakened, and the pressures in the false lumen are often high. In the past decade, thoracic endovascular aortic repair (TEVAR) has become the treatment of choice for TBAD. TEVAR can be complicated by lack of false lumen thrombosis, increasing the risk of death. We present three cases of TBAD with patent false lumens after TEVAR that were treated by false lumen coil embolization

External Iliac Vein Aneurysm Treated Via Balloon-Assisted Aneurysmorrhaphy with a Contemporary Review of the Literature

Isolated external iliac vein aneurysm is exceedingly rare, not well-described in the literature, and presents several potential surgical approaches. Herein, we describe the case of a 72-year-old woman who presented with incidentally found 4.3 cm x 3.4 cm x 5.6 cm right external iliac vein aneurysm after undergoing magnetic resonance imaging for orthopedic work-up. She was treated via parallel supra- and infra-inguinal incisions and novel combination of primary aneurysmorrhaphy with intraluminal balloon mandrel-assisted closure. The patient was discharged on postoperative day two, and 6-month follow-up ultrasound showed a normal caliber vessel with normal compressibility, suggesting this technique is safe and effective for appropriately selected patients

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies