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

eNOS transfection of adipose-derived stem cells yields bioactive nitric oxide production and improved results in vascular tissue engineering.

This study evaluates the durability of a novel tissue engineered blood vessel (TEBV) created by seeding a natural vascular tissue scaffold (decellularized human saphenous vein allograft) with autologous adipose-derived stem cells (ASC) differentiated into endothelial-like cells. Previous work with this model revealed the graft to be thrombogenic, likely due to inadequate endothelial differentiation as evidenced by minimal production of nitric oxide (NO). To evaluate the importance of NO expression by the seeded cells, we created TEBV using autologous ASC transfected with the endothelial nitric oxide synthase (eNOS) gene to produce NO. We found that transfected ASC produced NO at levels similar to endothelial cell (EC) controls in vitro which was capable of causing vasorelaxation of aortic specimens ex vivo. TEBV (n = 5) created with NO-producing ASC and implanted as interposition grafts within the aorta of rabbits remained patent for two months and demonstrated a non-thrombogenic surface compared to unseeded controls (n = 5). Despite the xenograft nature of the scaffold, the TEBV structure remained well preserved in seeded grafts. In sum, this study demonstrates that upregulation of NO expression within adult stem cells differentiated towards an endothelial-like lineage imparts a non-thrombogenic phenotype and highlights the importance of NO production by cells to be used as endothelial cell substitutes in vascular tissue engineering applications

Acute occlusion of aortic endovascular aneurysm repair stent graft with bilateral limb ischemia

Endovascular aneurysm repair has dramatically changed the management of abdominal aortic aneurysms as an alternative to open repair. However, complications can occur, including stent graft migration, kinking, and occlusion, leading to compromise of the excluded aneurysm walls and acute limb ischemia. In the present report, we have described a case of migration and kinking of an abdominal aortic stent graft in the main body that led to occlusion of the abdominal aorta and bilateral acute limb ischemia. The patient required emergent explantation of the stent graft and open repair of the abdominal aneurysm with a rifampin-soaked Dacron graft, which achieved a favorable outcome

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

Penumbra Aspiration Thrombectomy of the Superior Mesenteric Artery for Mesenteric Ischemia

Acute mesenteric ischemia from thromboembolic occlusion is a life-threatening emergency associated with a high mortality rate. Prompt diagnosis and intervention are vital to preserve viable bowel and prevent mortality. In the past decade, a shift has occurred toward minimally invasive alternatives such as endovascular therapies. We present a case of acute mesenteric ischemia from superior mesenteric artery thrombosis treated promptly with the Penumbra suction thrombectomy device (Penumbra Inc)

Giant abdominal aortic aneurysms

Giant abdominal aortic aneurysms (AAAs) are defined as AAAs \u3e10 to 13 cm in the maximum transverse diameter. We have described a case of a patient who had presented for open repair of an 18-cm AAA and a review of reported cases of giant AAAs \u3e10 cm in the maximum transverse diameter. Forty cases were compiled. The average maximum AAA diameter was 14.5 ± 4.1 cm. The AAA was ruptured on presentation in 12 patients (30%). Of the 40 cases, 34 (85%) were repaired with open surgery. The reported mortality was 15%. Despite the case complexity, five endovascular repairs were attempted

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

Serum High Mobility Group Box-1 Levels Associated With Cardiovascular Events After Lower Extremity Revascularization: A Prospective Study of a Diabetic Population

Background: Peripheral arterial disease (PAD) is one of the most disabling cardiovascular complications of type 2 diabetes mellitus and is indeed associated with a high risk of cardiovascular and limb adverse events. High mobility group box-1 (HMGB-1) is a nuclear protein involved in the inflammatory response that acts as a pro-inflammatory cytokine when released into the extracellular space. HMBG-1 is associated with PAD in diabetic patients. The aim of this study was to evaluate the association between serum HMGB-1 levels and major adverse cardiovascular events (MACE) and major adverse limb events (MALE) after lower-extremity endovascular revascularization (LER) in a group of diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: We conducted a prospective observational study of 201 diabetic patients with PAD and CLTI requiring LER. Baseline serum HMGB-1 levels were determined before endovascular procedure. Data on cardiovascular and limb outcomes were collected in a 12-month follow-up. Results: During the follow-up period, 81 cases of MACE and 93 cases of MALE occurred. Patients who subsequently developed MACE and MALE had higher serum HMGB-1 levels. Specifically, 7.5 ng/mL vs 4.9 ng/mL (p \u3c 0.01) for MACE and 7.2 ng/mL vs 4.8 ng/mL (p \u3c 0.01) for MALE. After adjusting for traditional cardiovascular risk factors, the association between serum HMGB-1 levels and cardiovascular outcomes remained significant in multivariable analysis. In our receiver operating characteristic (ROC) curve analysis, serum HMGB-1 levels were a good predictor of MACE incidence (area under the curve [AUC] = 0.78) and MALE incidence (AUC = 0.75). Conclusions: This study demonstrates that serum HMGB-1 levels are associated with the incidence of MACE and MALE after LER in diabetic populations with PAD and CLTI

The Role of Klotho and FGF23 in Cardiovascular Outcomes of Diabetic Patients With Chronic Limb Threatening Ischemia: A Prospective Study

Cardiovascular complications after lower extremity revascularization (LER) are common in diabetic patients with peripheral arterial disease (PAD) and chronic limb threatening ischemia (CLTI). The Klotho-fibroblast growth factor 23 (FGF23) axis is associated with endothelial injury and cardiovascular risk. We aimed to analyze the relationship between Klotho and FGF23 serum levels and the incidence of major adverse cardiovascular events (MACE) and major adverse limb events (MALE) after LER in diabetic patients with PAD and CLTI. Baseline levels of Klotho and FGF23, and their association with subsequent incidence of MACE and MALE were analyzed in a prospective, non-randomized study in a population of diabetic patients with PAD and CLTI requiring LER. A total of 220 patients were followed for 12 months after LER. Sixty-three MACE and 122 MALE were recorded during follow-up period. Baseline lower Klotho serum levels (295.3 ± 151.3 pg/mL vs. 446.4 ± 171.7 pg/mL, p \u3c 0.01), whereas increased serum levels FGF23 (75.0 ± 11.8 pg/mL vs. 53.2 ± 15.4 pg/mL, p \u3c 0.01) were significantly associated with the development of MACE. Receiver operating characteristic (ROC) analysis confirmed the predictive power of Klotho and FGF23 baseline levels. Furthermore, decreased Klotho levels were associated with the occurrence of MALE after LER (329.1 ± 136.8 pg/mL vs 495.4 ± 183.9 pg/mL, p \u3c 0.01). We found that Klotho and FGF23 baseline levels are a potential biomarker for increased cardiovascular risk after LER in diabetic patients with PAD and CLTI