Editor's Choice - Metformin Prescription is Associated with a Reduction in the Combined Incidence of Surgical Repair and Rupture Related Mortality in Patients with Abdominal Aortic Aneurysm.

OBJECTIVES: Currently there is no drug therapy for abdominal aortic aneurysm (AAA) and most previous investigations have focused on imaging rather than clinical outcomes. The aim of this study was to assess whether AAA related clinical events were lower in patients prescribed metformin. METHODS: This was a prospective cohort observational study performed in three cities in Australia, which was designed to study risk factors for clinical events not simply to focus on metformin. Patients with an asymptomatic unrepaired AAA of any diameter ≥30 mm were recruited from hospital outpatient clinics and surveillance programs run at four centres. The main outcome was the requirement for AAA repair or AAA related mortality (AAA events). The association between metformin prescription and AAA events was assessed using Kaplan-Meier analysis and Cox proportional hazard analysis. RESULTS: Patients (1,080) with a mean (SD) initial AAA diameter of 46.1 (11.3) mm were followed for a mean (SD) of 2.5 (3.1) years until an AAA event (n = 454), death (n = 176), loss to follow up (n = 128), or completion of current follow up (n = 322). Patients with diabetes who were prescribed metformin (adjusted HR 0.63, 95% CI 0.44-0.93), but not patients with diabetes who were not prescribed metformin (adjusted HR 1.15, 95% CI 0.83-1.59), had a lower incidence of AAA events compared with those without diabetes. Findings were similar in sensitivity analyses restricted to patients with an initial AAA diameter ≤50 mm and patients with a minimum follow up of six months before an AAA event. CONCLUSIONS: These findings suggest that clinically important AAA events may be reduced in patients with diabetes who are prescribed metformin, but not those with diabetes receiving other treatments. A randomised controlled trial is needed to definitively test whether metformin reduces AAA related clinical events in patients with small AAAs who do not have diabetes.

Acquired Carotid-Jugular Fistula Secondary to a Pseudoaneurysm Following Carotid Endarterectomy.

Acquired arteriovenous fistulas involving the carotid artery are most frequently the result of trauma and iatrogenic causes such as central venous catheterisation. Occasionally, they may develop spontaneously due to erosion of an aneurysm into an adjacent vein. We report a rare case of an acquired carotid-jugular fistula secondary to a pseudoaneurysm that occurred four months following carotid endarterectomy.

Association of Oral Anticoagulation Prescription with Clinical Events in Patients with an Asymptomatic Unrepaired Abdominal Aortic Aneurysm.

BACKGROUND: Most abdominal aortic aneurysms (AAA) have large volumes of intraluminal thrombus which has been implicated in promoting the risk of major adverse events. The aim of this study was to examine the association of therapeutic anticoagulation with AAA-related events and major adverse cardiovascular events (MACE) in patients with an unrepaired AAA. METHODS: Patients with an asymptomatic unrepaired AAA were recruited from four sites in Australia. The primary outcome was the combined incidence of AAA repair or AAA rupture-related mortality (AAA-related events). The main secondary outcome was MACE (the combined incidence of myocardial infarction, stroke, or cardiovascular death). The associations of anticoagulation with these outcomes were assessed using Cox proportional hazard analyses (reporting hazard ratio, HR, and 95% confidence intervals, CI) to adjust for other risk factors. RESULTS: A total of 1161 patients were followed for a mean (standard deviation) of 4.9 (4.0) years. Of them, 536 (46.2%) patients had a least one AAA-related event and 319 (27.5%) at least one MACE. In the sample, 98 (8.4%) patients were receiving long-term therapeutic anticoagulation using warfarin (84), apixaban (7), rivaroxaban (6), or dabigatran (1). Prescription of an anticoagulant was associated with a reduced risk of an AAA-related event (adjusted HR 0.61; 95% CI 0.42, 0.90, p = 0.013), but not MACE (HR 1.16; 95% CI 0.78, 1.72, p = 0.476). CONCLUSIONS: These findings suggest that AAA-related events but not MACE may be reduced in patients prescribed an anticoagulant medication. Due to the inherent biases of observational studies, a randomized controlled trial is needed to assess whether anticoagulation reduces the risk of AAA-related events.

Selective Angioembolisation of Iatrogenic Renal Artery Pseudoaneurysms Following Minimally Invasive Urological Procedures: A Single Centre Case Series.

INTRODUCTION: The purpose of this study was to report our centre's experience using selective angioembolisation in the treatment of iatrogenic renal artery pseudoaneurysms (RAP) following minimally invasive urological procedures. METHODS: Our retrospective analysis included four consecutive patients treated with angioembolisation for iatrogenic RAP between October 2016 and October 2021. Data on demographics, minimally invasive urological intervention, clinical features, imaging findings, embolization procedure and perioperative details were collected. Rates of technical and clinical success, defined as 1. total occlusion of the extravasation site on completion digital subtraction angiography (DSA), and 2. resolution of symptoms, signs, and serum hemoglobin (Hb) derangements secondary to RAP, were analysed. Renal function, measured by serum creatinine (Cr) and estimated glomerular filtration rate (eGFR), was recorded prior to and post - angioembolisation procedure and compared. RESULTS: Mean time between urological intervention and angioembolisation was 9 days (range, 2-17 days). Rates of technical and clinical success were 100% and 100% respectively. No additional angioembolisation procedures were required, and there were no peri or post-operative complications identified during mean follow-up of 662 days (range, 30-1845 days). Mean serum Cr prior to and post angioembolisation was 83 mmol/L and 79.5 mmol/L. Mean eGFR prior to and post angioembolisation was 73.8 and 77.8 mL/min/1.73 m2. In all patients, no significant difference was observed in serum Cr and eGFR prior to and post angioembolisation. CONCLUSION: Iatrogenic renal artery pseudoaneurysms can occur following a range of minimally invasive urological procedures. This retrospective review highlights the utility of angioembolisation as a safe and effective treatment with high clinical and technical success rates. Further studies involving larger populations are required to validate its broader application.

Cohort Study Examining the Association of Optimal Blood Pressure Control at Entry With Infrarenal Abdominal Aortic Aneurysm Growth.

Background and Aim: The benefit of controlling cardiovascular risk factors in slowing the progression of small abdominal aortic aneurysm (AAA) is controversial. This study investigated the association of optimal blood pressure control at entry with the growth of small AAA. Methods and Results: A total of 1,293 patients with initial AAA diameter <50 mm were followed by a median 5 (inter-quartile range, IQR, 3-7) ultrasound scans for a median of 3.6 years (IQR 1.8, 5.3). Optimal blood pressure control was defined as blood pressure ≤140/90 mmHg at recruitment. The association of optimal blood pressure control at entry with AAA growth was assessed using linear mixed effects models adjusted for established risk factors of AAA growth and factors which were unequally distributed among the blood pressure groups. Optimal blood pressure control at entry was not significantly associated with AAA growth. In the risk factor adjusted model the mean difference in AAA growth between blood pressure groups was 0.04 mm/year (95% CI -0.20, 0.13; p = 0.65). The results were similar in sensitivity analyses excluding outliers or focused on systolic or diastolic blood pressure alone. Conclusions: This observational study suggests that optimal blood pressure control at entry is not associated with slower AAA growth.

Concurrent Ilio-Enteric and Ilio-Vesical Fistula From Large Aorto-Iliac Aneurysm.

Iliac artery aneurysms (IAA) are associated frequently with abdominal aortic (AAA) and other degenerative large-vessel aneurysms. Concurrent fistulization of the aortoiliac tree into the gastrointestinal tract (GIT) and bladder is exceptionally rare. We herewith report a unique case of concurrent ilio-enteric and ilio-vesical fistula arising from a large aorto-iliac aneurysm.

Association of statin prescription with small abdominal aortic aneurysm progression.

BACKGROUND: Statins have been suggested to reduce expansion of abdominal aortic aneurysms (AAAs) independent of lipid-lowering effects. METHODS: We assessed the association of statin treatment and serum low-density lipoprotein (LDL) concentrations with small AAA expansion. Six hundred fifty-two patients undergoing surveillance of small AAAs were entered into the study from 5 vascular centers. In a subset, fasting lipids (n = 451) and other biomarkers (n = 216) were measured. The AAA diameter was followed by ultrasound surveillance for a median of 5 years. RESULTS: Three hundred forty-nine (54%) of the patients were prescribed statins. Adjusting for other risk factors, statin prescription was not associated with AAA growth (odds ratio [OR] 1.23, 95% CI 0.86-1.76). Above-median AAA growth was positively associated with initial diameter (OR 1.78 per 4.35-mm-larger initial aortic diameter, 95% CI 1.49-2.14) and negatively associated with diabetes (OR 0.37, 95% CI 0.22-0.62). Above-median serum LDL concentration was not associated with AAA growth. Patients receiving statins had lower serum C-reactive protein concentrations but similar matrix metalloproteinase-9 and interleukin-6 concentrations to those not prescribed these medications. CONCLUSIONS: We found no association between statin prescription or LDL concentration with AAA expansion. The results do not support the findings of smaller studies and suggest that statins may have no benefit in reducing AAA progression.

Cohort Study Examining the Association Between Blood Pressure and Cardiovascular Events in Patients With Peripheral Artery Disease.

Background Hypertension is an important risk factor for cardiovascular events in patients with peripheral artery disease; however, optimal blood pressure targets for these patients are poorly defined. This study investigated the association between systolic blood pressure ( SBP ) and cardiovascular events in a prospectively recruited patient cohort with peripheral artery disease. Methods and Results A total of 2773 patients were included and were grouped according to SBP at recruitment (≤120 mm Hg, n=604; 121-140 mm Hg, n=1065; and >140 mm Hg, n=1104). Adjusted Cox proportional hazards analyses suggested that patients with SBP ≤120 mm Hg were at greater risk of having a major cardiovascular event (myocardial infarction, stroke, or cardiovascular death) than patients with SBP of 121-140 mm Hg (adjusted hazard ratio, 1.36; 95% CI, 1.08-1.72; P=0.009). Patients with SBP >140 mm Hg had an adjusted hazard ratio of 1.23 (95% CI, 1.00-1.51; P=0.051) of major cardiovascular events compared with patients with SBP of 121-140 mm Hg. These findings were similar in sensitivity analyses only including patients receiving antihypertensive medications or focused on patients with a minimum of 3 months of follow-up. Conclusions This cohort study suggests that patients with peripheral artery disease and SBP ≤120 mm Hg are at increased risk of major cardiovascular events. The findings suggest caution in intensive SBP lowering in this patient group.

Early control of the distal internal carotid artery during endarterectomy: achievability and results.

PURPOSE: The purpose of this study was the report of the results of a consecutive series of carotid endarterectomy (CEA), performed by one surgeon and independently assessed by a neurologist, in which the achievability of selective early control of the distal internal carotid artery (ICA) was prospectively recorded. METHODS: All patients who underwent CEA by the surgical author between November 17, 1999, and November 15, 2001, were entered into a prospective study during which early selective exposure and clamping of the distal ICA were attempted (with initial avoidance of carotid bifurcation exposure and retraction), which allowed the remainder of the procedure (in patients without shunting) to be performed with ICA clamp protection and anticoagulation therapy. All the procedures were performed with local cervical block anesthesia, all the patients underwent a vein patch procedure, and, with one exception, cerebral angiography was not used. Major morbidity (stroke and myocardial infarction), mortality, and consecutiveness were independently verified by a neurologist. RESULTS: 148 consecutive CEAs were performed. In 142 cases (96%), the soft distal ICA could be initially isolated and controlled without dissection of the plaque-bearing bulb bifurcation area (group A), and in the remaining six cases, the carotid bifurcation had to be exposed and retracted to allow ICA clamping (group B). A shunt was needed in 15 cases (14 in group A, one in group B), which left 128 cases (86%) in which the procedure could be performed with the ICA clamped and the brain theoretically protected from particulate plaque embolism. There were no strokes or deaths, one patient had temporary vertebrobasilar ischemia, one patient had a myocardial infarct, one patient had a temporary accessory nerve palsy, one patient returned to the operating room for release of a cervical hematoma, and 94% spent one postoperative night in the hospital. CONCLUSION: Early selective distal ICA control is highly achievable during CEA without apparently compromising clinical results. Its use is relevant when selective methods of shunting that do not need initial control of the common and external carotid arteries (eg, local cervical block anesthesia, electroencephalography/other monitoring) are used. Further evaluation with transcranial Doppler scan monitoring is suggested to substantiate the theoretic potential of this method in the reduction or elimination of particulate plaque embolism.

Symptomatic sac enlargement and rupture due to seroma after open abdominal aortic aneurysm repair with polytetrafluoroethylene graft: Implications for endovascular repair and endotension.

OBJECTIVE: We report 5 patients in whom a symptomatic perigraft seroma developed within the aortic sac, without vascular endoleak, after open repair of an abdominal aortic aneurysm (AAA) with a polytetrafluoroethylene (PTFE) graft. We also discuss possible relationships of this phenomenon to endovascular repair of AAAs. PATIENTS AND METHODS: Over 18 years, 1156 patients underwent repair of an AAA by one of the authors (B.M.B.). Of these, 1084 underwent open repair, 256 with PTFE grafts. Five patients in the PTFE group (2.3%) returned at a mean of 4.5 years with acute abdominal or back pain and enlargement of the aortic sac. Mean diameter of the aneurysms was 5.9 cm preoperatively and 8.1 cm at readmission. There was no evidence of vascular endoleak on computed tomography scans, but 1 patient had a retroperitoneal hematoma. RESULTS: Laparotomy in 4 patients disclosed a seroma containing firm rubbery gelatinous material under tension, histologically identified as amorphous eosinophilic material containing thrombus and degenerate blood cells in all cases. Rupture of the sac was confirmed in the patient with a retroperitoneal hematoma. The sac contents were evacuated and the integrity of the underlying grafts and anastomoses was confirmed before sac reduction, with imbricating sutures, and closure was performed. One patient died at 8 months of an unrelated cause; the other 3 patients remain well at mean follow-up of 12 months. The fifth patient received conservative treatment and remains asymptomatic 3 years after acute presentation. CONCLUSIONS: These findings of sac enlargement without vascular endoleak after open AAA repair are reminiscent of sac enlargement in the absence of endoleak after endovascular AAA repair. This has been referred to as endotension. The comparatively benign outcome in 5 patients with symptomatic sac enlargement, including 2 patients with rupture, after open AAA repair provides data to support a circumspect approach to endotension, especially in patients with asymptomatic disease, which has been reported as occurring in almost half of patients who received a PTFE Excluder endograft.