Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms

OBJECTIVES

This study aims to evaluate intra-peritoneal (ip) microdialysis after endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) in patients developing intra-abdominal hypertension (IAH), requiring abdominal decompression.

DESIGN

Prospective study.

MATERIAL AND METHODS

A total of 16 patients with rAAA treated with an emergency EVAR were followed up hourly for intra-abdominal pressure (IAP), urine production and ip lactate, pyruvate, glycerol and glucose by microdialysis, analysed only at the end of the study. Abdominal decompression was performed on clinical criteria, and decompressed (D) and non-decompressed (ND) patients were compared.

RESULTS

The ip lactate/pyruvate (l/p) ratio was higher in the D group than in the ND group during the first five postoperative hours (mean 20 vs. 12), p = 0.005 and at 1 h prior to decompression compared to the fifth hour in the ND group (24 vs. 13), p = 0.016. Glycerol levels were higher in the D group during the first postoperative hours (mean 274.6 vs. 121.7 μM), p = 0.022. The IAP was higher only at 1 h prior to decompression in the D group compared to the ND group at the fifth hour (mean 19 vs. 14 mmHg).

CONCLUSIONS

Ip l/p ratio and glycerol levels are elevated immediately postoperatively in patients developing IAH leading to organ failure and subsequent abdominal decompression.

Adverse events during treatment of critical limb ischemia with autologous peripheral blood mononuclear cell implant

AIM

Trials have reported clinical improvement and reduced need for amputation in critical limb ischemia (CLI) patients receiving therapeutic angiogenesis with stem cells. Our objective was to test peripheral stem cell therapy efficacy and safety to gain experiences for further work.

METHODS

We included nine CLI patients (mean age 76.7 ±9.7). Stem cells were mobilized to the peripheral blood by administration of G-CSF (Filgrastim) for 4 days, and were collected on day five, when 30 mL of a stem cell suspension was injected into 40 points of the limb. The clinical efficacy was evaluated by assessing pain relief, wound healing and changes in ankle-brachial pressure index (ABI). Local metabolic and inflammatory changes were measured with microdialysis, growth factors and cytokine level determination. Patients were followed for 24 weeks.

RESULTS

Four patients experienced some degree of improvement with pain relief and/or improved wound healing and ABI increase. One patient was lost to follow up due to chronic psychiatric illness; one was amputated after two weeks. Two patients had a myocardial infarction (MI), one died. One patient died from a massive mesenteric thrombosis after two weeks and one died from heart failure at week 11. Improved patients showed variable effects in cytokine-, growth factor- and local metabolic response.

CONCLUSION

Even with some improvement in four patients, severe complications in four out of nine patients, and two in relation to the bone marrow stimulation, made us terminate the study prematurely. We conclude that with the increased risk and the reduced potential of the treatment, peripheral blood stem cell treatment in the older age group is less appropriate. Metabolic and inflammatory response may be of value to gain insight into mechanisms and possibly to evaluate effects of therapeutic angiogenesis.

High MAPK p38 activity and low level of IL-10 in intermittent claudication as opposed to stable angina

AIM

The aim of the present pilot study was to relate the activity of MAPK p38 with the levels of pro- and anti-inflammatory cytokines in a small cohort of patients with either stable angina (N=5) or intermittent claudication (N=5) compared to healthy controls (N=10).

METHODS

The activity of MAPK p38 was determined in peripheral blood mononuclear cells, isolated from whole blood by western blot using phospho-specific anti-MAPK p38 antibodies. Cytokine levels of 11 pro- and anti-inflammatory cytokines were determined from the serum using flow cytometry.

RESULTS

We found a significant elevation of the MAPK p38 activity in the intermittent claudication group (P=0.0027) compared with the healthy control group whereas the stable angina group showed similar MAPK p38 activity as the healthy control group. The IL-10 level in serum found in the stable angina group was significantly higher compared with both the healthy control group (P=0.0116) and the intermittent claudication group (P=0.0317).

CONCLUSION

Our results imply that there is a casual relationship between increased levels of the anti-inflammatory cytokines IL-10 and IL-4 and the activity of the MAPK p38. Possibly has IL-10 a protective role that down-regulates the activity of MAPK p38 and thereby further inflammatory processes in stable angina patients.

Results of the randomized, placebo-controlled clopidogrel and acetylsalicylic acid in bypass surgery for peripheral arterial disease (CASPAR) trial

OBJECTIVE

Dual antiplatelet therapy with clopidogrel plus acetylsalicylic acid (ASA) is superior to ASA alone in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention. We sought to determine whether clopidogrel plus ASA conferred benefit on limb outcomes over ASA alone in patients undergoing below-knee bypass grafting.

METHODS

Patients undergoing unilateral, below-knee bypass graft for atherosclerotic peripheral arterial disease (PAD) were enrolled 2 to 4 days after surgery and were randomly assigned to clopidogrel 75 mg/day plus ASA 75 to 100 mg/day or placebo plus ASA 75 to 100 mg/day for 6 to 24 months. The primary efficacy endpoint was a composite of index-graft occlusion or revascularization, above-ankle amputation of the affected limb, or death. The primary safety endpoint was severe bleeding (Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries [GUSTO] classification).

RESULTS

In the overall population, the primary endpoint occurred in 149 of 425 patients in the clopidogrel group vs 151 of 426 patients in the placebo (plus ASA) group (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.78-1.23). In a prespecified subgroup analysis, the primary endpoint was significantly reduced by clopidogrel in prosthetic graft patients (HR, 0.65; 95% CI, 0.45-0.95; P = .025) but not in venous graft patients (HR, 1.25; 95% CI, 0.94-1.67, not significant [NS]). A significant statistical interaction between treatment effect and graft type was observed (P(interaction) = .008). Although total bleeds were more frequent with clopidogrel, there was no significant difference between the rates of severe bleeding in the clopidogrel and placebo (plus ASA) groups (2.1% vs 1.2%).

CONCLUSION

The combination of clopidogrel plus ASA did not improve limb or systemic outcomes in the overall population of PAD patients requiring below-knee bypass grafting. Subgroup analysis suggests that clopidogrel plus ASA confers benefit in patients receiving prosthetic grafts without significantly increasing major bleeding risk.

Normal values and differences between intraperitoneal and subcutaneous microdialysis in patients after non‐complicated gastrointestinal surgery

OBJECTIVE

Visceral ischemia is an early event in the development of shock and organ failure. Microdialysis has been presented as a promising method for detection of visceral hypoxia and ischemia. The aim of this study was to investigate differences in the metabolic response measured by microdialysis between intraperitoneal and subcutaneous locations and to estimate normal values of lactate/pyruvate ratio, glucose and glycerol.

MATERIAL AND METHODS

Intraperitoneal and subcutaneous metabolic responses were compared regarding lacate/pyruvate ratio, glucose and glycerol, during 45 postoperative hours in 33 patients undergoing various non-complicated elective major gastrointestinal surgery.

RESULTS

Intraperitoneal lactate/pyruvate ratio started around 15 and decreased over time, while subcutaneous levels were stable around 9. Glucose levels were higher intraperitoneally and increased rapidly during the first 9 h to 8.6 mM, while the subcutaneous levels increased during 21 h to 7.5 mM. Intraperitoneal glycerol levels were stable around 100 microM, while subcutaneous values started around 230 microM and then increased.

CONCLUSIONS

In a non-complicated postoperative course the lactate/pyruvate ratio and glucose levels are higher intraperitoneally, suggesting a higher postoperative intraperitoneal metabolism. Glycerol levels are higher and increase subcutaneously, suggesting increased postoperative energy demand, particularly in the visceral organs, as being responsible for the lipolysis seen in the subcutaneous tissue.

Incidence of deep vein thrombosis in bedridden non-surgical patients

In order to detect deep vein thrombosis (DVT), 101 patients with acute medical or infectious disorders were examined with the 125I-fibrinogen uptake test. All patients were bedridden on admission and were scanned daily from the second to the eighth day. Thirteen patients developed a positive fibrinogen uptake test. Thus, if a positive test is interpreted as DVT, the incidence of DVT was 13% in our bedridden patients. Of the patients admitted because of heart disease or pneumonia 20% had DVT, but only 4% of those admitted with other diagnoses. Other clinical "risk factors" studied, could not identify patients who developed DVT.

Low prevalence of abdominal aortic aneurysm in hypertensive patients. A population-based study

The prevalence of abdominal aortic aneurysms (AAA) was estimated by ultrasonography in hypertensives in the age group 50-70 years in geographically defined population. Only one case of AAA was found among 245 patients. This rather unexpected result implies a probability of less than 5% that the true prevalence of AAA is as high as 2% in hypertensives. Our population-based study indicates a lower prevalence than earlier studies based on necropsies and is an example of research cooperation between primary health care and specialized hospital care.

Endovascular Repair of the Ruptured Abdominal Aortic Aneurysm

The present knowledge on endovascular repair of ruptured abdominal aortic aneurysms (rAAA) prevents firm conclusions when to use this method in comparison to open repair. This review article briefly summarizes results from case series, and discusses how to achieve reliable information despite the absence of randomized controlled trials. At present a careful conclusion might be that dedicated centers with an adequate organization and reasonably high volume of abdominal aortic aneurysm (AAA) should use detailed registry protocols to achieve experience and data to create an as reliable basis as possible for future recommendations.

Systemic white blood and endothelial cell response after revascularization of critical limb ischemia is only influenced in case of ischemic ulcers

AIM

The aim of this study was to study the inflammatory response to open revascularization of an ischemic leg in terms of activation of white blood cells (WBC), platelets and endothelial cells.

DESIGN

prospective study.

METHODS

Venous samples from 21 patients suffering critical limb ischemia (CLI) were drawn before, and 4 weeks after (20 patients) revascularization. Total WBC, differentiated WBC, and platelets were counted. Expression of CD11b/CD18 on granulocytes and monocytes and CD41 on platelets was measured by flow cytometry. Soluble endothelial markers (sICAM-1, sVCAM-1, sE-selectin and sP-selectin) were analysed with ELISA.

RESULTS

WBC and granulocyte count decreased in the subgroup of patients with ulcer and gangrene but no change in activation of WBC was recorded. The endothelial marker sICAM-1 decreased while VCAM-1 increased following surgery, most evident in the subgroup with ulcers and gangrene.

CONCLUSIONS

This study shows that revascularization of CLI does not significantly influence the inflammatory response in patients with rest pain only, but a limited response of down regulation was found in the ulcer/gangrene patients probably as an effect of healing ulcers.

Arteriogenic gene therapy in patients with unreconstructable critical limb ischemia: a randomized, placebo-controlled clinical trial of adenovirus 5-delivered fibroblast growth factor-4

The objectives of this study were to assess the safety and potential clinical efficacy of adenovirus-delivered fibroblast growth factor-4 (Ad5FGF-4) by intramuscular injection into patients with critical limb ischemia (CLI). This study was a double-blind, randomized, placebo-controlled study with escalating dose groups of 2.87 x 10(8) to 2.87 x 10(10) viral particles. Thirteen patients with CLI were randomized to receive active drug (n = 10) or placebo (n = 3). Safety evaluations and efficacy parameters (ankle-brachial index, digital subtraction angiograms, magnetic resonance imaging, and scintigraphy) were performed at baseline and for 12 weeks after treatment. Injections of Ad5FGF-4 were generally well tolerated and considered safe. Transfection efficacy at these concentrations may have been limited or local. The small sample size did not allow any firm conclusions regarding clinical efficacy but a trend toward more and slightly larger blood vessels was observed in the angiograms. It is concluded that intramuscular injection of Ad5FGF-4 into CLI patients seemed safe, but transfection efficacy was limited at the assessed doses. Conclusions regarding clinical efficacy are impossible to draw from this small patient cohort.

Experiences of Intentional Carotid Stenting in Endovascular Repair of Aortic Arch Aneurysms—Two Case Reports

Endovascular repair of thoracic aneurysms has emerged as an attractive alternative especially in patients at high risk. However, the left common carotid artery limits the use of stent-grafts in aneurysms located in the aortic arch or close to the left subclavian artery. We report two cases with aneurysms in the distal arch and proximal descending aorta, where we have used a carotid stent in juxtaposition to an aortic stent-graft, to gain a longer proximal neck in the aortic arch in an attempt not to rely only on a by-pass graft feeding the left carotid artery.