Tissue factor levels and the fibrinolytic system in thin and thick intraluminal thrombus and underlying walls of abdominal aortic aneurysms.

BACKGROUND: The hemostatic system cooperates with proteolytic degradation in processes allowing abdominal aortic aneurysm (AAA) formation. In previous studies, it has been suggested that aneurysm rupture depends on intraluminal thrombus (ILT) thickness, which varies across each individual aneurysm. We hypothesized that hemostatic components differentially accumulate in AAA tissue in relation to ILT thickness. Thick (A1) and thin (B1) segments of ILTs and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1) from one aneurysm sac were taken from 35 patients undergoing elective repair. METHODS: Factor levels were measured using enzyme-linked immunosorbent assay of protein extract. RESULTS: Tissue factor (TF) activities were significantly higher in thinner segments of AAA (B1 vs A1, P = .003; B vs A, P < .001; B vs A1, P < .001; B vs B1, P = .001). Significantly higher tissue plasminogen activator was found in thick thrombus-covered wall segments (A) than in B, A1, and B1 (P = .015, P < .001, and P < .001, respectively). Plasminogen concentrations were highest in ILT. Concentrations of α2-antiplasmin in thin ILT adjacent walls (B) were higher compared with wall (A) adjacent to thick ILT (P = .021) and thick ILT (A1; P < .001). Significant correlations between levels of different factors were mostly found in thick ILT (A1). However, no correlations were found at B sites, except for a correlation between plasmin and TF activities (r = 0.55; P = .004). CONCLUSIONS: These results suggest that higher TF activities are present in thinner AAA regions. These parameters and local fibrinolysis may be part of the processes leading to destruction of the aneurysm wall.

Homocysteine-Enhanced Proteolytic and Fibrinolytic Processes in Thin Intraluminal Thrombus and Adjacent Wall of Abdominal Aortic Aneurysm: Study In Vitro.

Homocysteine (Hcy) may affect the pathogenesis of abdominal aortic aneurysms (AAAs) through enhancement of proteolysis and an impaired coagulation/fibrinolysis system. Intensified haemostatic capacity may promote local proteolytic degradation of the aortic wall. This study aimed to examine the effects of Hcy on haemostatic and proteolytic processes in samples of thick and thin fragments of the ILT and underlying walls. Subjects and Methods. Thirty-six patients who underwent AAA surgery were enrolled. Aneurysm tissue sections were incubated with DL-Hcy (100 and 500 µmol/L) in a series of experiments and analyzed for concentration/activity of proteolytic and haemostatic markers by enzyme-linked immunosorbent assay. Results. Incubation of wall underlying thin ILT segments (B) with DL-Hcy resulted in an increase of active MMP-2 levels compared to control tissue (9.54 ± 5.88 versus 7.44 ± 4.48, p=0.011). DL-Hcy also induced t-PA and plasminogen concentration increases in thin thrombus sections (B1) compared to control tissue (respectively: 1.39 ± 1.65 versus 0.84 ± 0.74, p=0.024; 11.64 ± 5.05 versus 10.34 ± 5.52, p=0.018). In contrast, wall adjacent to thick thrombus segments (A) showed decreases in MMP-2 and TF activities compared to control (respectively, 5.89 ± 3.39 versus 7.26 ± 5.49, p=0.046; 67.13 ± 72.59 versus 114.46 ± 106.29, p=0.007). In thick ILT sections (A1), DL-Hcy decreased MMP-2 activity and t-PA and plasminogen concentrations compared to control tissue (respectively, 2.53 ± 2.02 versus 3.28 ± 2.65, p=0.006; 0.67 ± 0.57 versus 0.96 ± 0.91, p=0.021; 9.25 ± 4.59 versus 12.63 ± 9.56, p=0.017). In addition, analysis revealed positive correlations at all sites between activities/concentrations of MMP-2, TF, and PAI-1 measured in control tissues and after incubation with DL-Hcy. Conclusions. These data indicate the potential for excess Hcy to enhance damage of arterial wall in thinner AAA segments as a result of the increased activity of MMP-2 and fibrinolytic factors.

N-terminal pro-B-type Natriuretic Peptides' Prognostic Utility Is Overestimated in Meta-analyses Using Study-specific Optimal Diagnostic Thresholds.

BACKGROUND: N-terminal fragment B-type natriuretic peptide (NT-proBNP) prognostic utility is commonly determined post hoc by identifying a single optimal discrimination threshold tailored to the individual study population. The authors aimed to determine how using these study-specific post hoc thresholds impacts meta-analysis results. METHODS: The authors conducted a systematic review of studies reporting the ability of preoperative NT-proBNP measurements to predict the composite outcome of all-cause mortality and nonfatal myocardial infarction at 30 days after noncardiac surgery. Individual patient-level data NT-proBNP thresholds were determined using two different methodologies. First, a single combined NT-proBNP threshold was determined for the entire cohort of patients, and a meta-analysis conducted using this single threshold. Second, study-specific thresholds were determined for each individual study, with meta-analysis being conducted using these study-specific thresholds. RESULTS: The authors obtained individual patient data from 14 studies (n = 2,196). Using a single NT-proBNP cohort threshold, the odds ratio (OR) associated with an increased NT-proBNP measurement was 3.43 (95% CI, 2.08 to 5.64). Using individual study-specific thresholds, the OR associated with an increased NT-proBNP measurement was 6.45 (95% CI, 3.98 to 10.46). In smaller studies (<100 patients) a single cohort threshold was associated with an OR of 5.4 (95% CI, 2.27 to 12.84) as compared with an OR of 14.38 (95% CI, 6.08 to 34.01) for study-specific thresholds. CONCLUSIONS: Post hoc identification of study-specific prognostic biomarker thresholds artificially maximizes biomarker predictive power, resulting in an amplification or overestimation during meta-analysis of these results. This effect is accentuated in small studies.

Electrophysiological, hemodynamic, and metabolic response to open procedure or endovascular repair of infrarenal aortic aneurysms.

BACKGROUND: The occurrence of cardiovascular diseases in the group of patients undergoing vascular surgery because of abdominal aorta aneurysm is very high. Endovascular procedures are regarded as hemodynamically safer for the patients. The aim of this study was to compare the changes in electrophysiological, hemodynamic, and metabolic parameters depending on the type of operation, using invasive hemodynamic monitoring and Holter electrocardiography recording. METHODS: A prospective, observational, nonrandomized study was conducted to compare dynamic changes of electrophysiological parameters (dominant rhythm, arrhythmia, corrected QT interval (QTc), invasive blood pressure, electrolytes, and acid-base balance in defined points during perioperative time in 2 groups: vascular prosthesis implantation group (91 patients) and stent-graft implantation group (83 patients). RESULTS: The study group comprised 174 consecutive adult Caucasian patients (mean age 64.4 ± 8.9 years in stent-graft group and 70.0 ± 7.5 years in vascular prosthesis implantation group). Although patients in the stent-graft implantation group were younger, they were diagnosed with lower limbs vascular atherosclerosis, type 2 diabetes mellitus, and a lower left ventricle ejection fraction more often than patients in the open procedure group. During the open procedure, higher blood pressure amplitudes (P = 0.00009), higher decrease in pH (P = 0.049), increase in the arterial lactate level (P = 0.00002), prolonged QTc values (P = 0.001), more frequent ventricular extrasystoles (P = 0.005), and cardiovascular deaths were observed, when compared with those observed during the endovascular aneurysm repair. CONCLUSIONS: When compared with the chosen techniques, the one for infrarenal abdominal aneurysm was found to be associated with significant differences in electrophysiological, hemodynamic, and metabolic parameters.

The prognostic value of pre-operative and post-operative B-type natriuretic peptides in patients undergoing noncardiac surgery: B-type natriuretic peptide and N-terminal fragment of pro-B-type natriuretic peptide: a systematic review and individual patient data meta-analysis.

OBJECTIVES: The objective of this study was to determine whether measuring post-operative B-type natriuretic peptides (NPs) (i.e., B-type natriuretic peptide [BNP] and N-terminal fragment of proBNP [NT-proBNP]) enhances risk stratification in adult patients undergoing noncardiac surgery, in whom a pre-operative NP has been measured. BACKGROUND: Pre-operative NP concentrations are powerful independent predictors of perioperative cardiovascular complications, but recent studies have reported that elevated post-operative NP concentrations are independently associated with these complications. It is not clear whether there is value in measuring post-operative NP when a pre-operative measurement has been done. METHODS: We conducted a systematic review and individual patient data meta-analysis to determine whether the addition of post-operative NP levels enhanced the prediction of the composite of death and nonfatal myocardial infarction at 30 and ≥180 days after surgery. RESULTS: Eighteen eligible studies provided individual patient data (n = 2,179). Adding post-operative NP to a risk prediction model containing pre-operative NP improved model fit and risk classification at both 30 days (corrected quasi-likelihood under the independence model criterion: 1,280 to 1,204; net reclassification index: 20%; p < 0.001) and ≥180 days (corrected quasi-likelihood under the independence model criterion: 1,320 to 1,300; net reclassification index: 11%; p = 0.003). Elevated post-operative NP was the strongest independent predictor of the primary outcome at 30 days (odds ratio: 3.7; 95% confidence interval: 2.2 to 6.2; p < 0.001) and ≥180 days (odds ratio: 2.2; 95% confidence interval: 1.9 to 2.7; p < 0.001) after surgery. CONCLUSIONS: Additional post-operative NP measurement enhanced risk stratification for the composite outcomes of death or nonfatal myocardial infarction at 30 days and ≥180 days after noncardiac surgery compared with a pre-operative NP measurement alone.

Postoperative B-type natriuretic peptide for prediction of major cardiac events in patients undergoing noncardiac surgery: systematic review and individual patient meta-analysis.

BACKGROUND: It is unclear whether postoperative B-type natriuretic peptides (i.e., BNP and N-terminal proBNP) can predict cardiovascular complications in noncardiac surgery. METHODS: The authors undertook a systematic review and individual patient data meta-analysis to determine whether postoperative BNPs predict postoperative cardiovascular complications at 30 and 180 days or more. RESULTS: The authors identified 18 eligible studies (n = 2,051). For the primary outcome of 30-day mortality or nonfatal myocardial infarction, BNP of 245 pg/ml had an area under the curve of 0.71 (95% CI, 0.64-0.78), and N-terminal proBNP of 718 pg/ml had an area under the curve of 0.80 (95% CI, 0.77-0.84). These thresholds independently predicted 30-day mortality or nonfatal myocardial infarction (adjusted odds ratio [AOR] 4.5; 95% CI, 2.74-7.4; P < 0.001), mortality (AOR, 4.2; 95% CI, 2.29-7.69; P < 0.001), cardiac mortality (AOR, 9.4; 95% CI, 0.32-254.34; P < 0.001), and cardiac failure (AOR, 18.5; 95% CI, 4.55-75.29; P < 0.001). For greater than or equal to 180-day outcomes, natriuretic peptides independently predicted mortality or nonfatal myocardial infarction (AOR, 3.3; 95% CI, 2.58-4.3; P < 0.001), mortality (AOR, 2.2; 95% CI, 1.67-86; P < 0.001), cardiac mortality (AOR, 2.1; 95% CI, 0.05-1,385.17; P < 0.001), and cardiac failure (AOR, 3.5; 95% CI, 1.0-9.34; P = 0.022). Patients with BNP values of 0-250, greater than 250-400, and greater than 400 pg/ml suffered the primary outcome at a rate of 6.6, 15.7, and 29.5%, respectively. Patients with N-terminal proBNP values of 0-300, greater than 300-900, and greater than 900 pg/ml suffered the primary outcome at a rate of 1.8, 8.7, and 27%, respectively. CONCLUSIONS: Increased postoperative BNPs are independently associated with adverse cardiac events after noncardiac surgery.

[Latent chronic kidney disease in the material of the Department of Vascular Surgery, Pomeranian Medical University in Szczecin. An important clinical problem]. / Utajona przewlekla choroba nerek w materiale Kliniki Chirurgii Naczyniowej Pomorskiego Uniwersytetu Medycznego w Szczecinie. Istotny problem kliniczny.

INTRODUCTION: The percentage of patients with diagnosed chronic renal failure is many times smaller than the percentage of the latent disease. The rate of cardiovascular complications in latent kidney disease is significantly higher. The aim of this work was to determine the percentage of patients with renal failure among patients with peripheral atherosclerosis treated at our Department and to study rate (GFR) below the influence of reduced glomerular filtration rate (GFR) below 60 mL/min/1.73 m2 on the risk of early complications after vascular surgery. MATERIAL AND METHODS: A retrospective analysis of 1096 patients was done. 652 patients were operated, 321 underwent endovascular procedures, including angiography, antiglobulin test (PTA), and fibrinolysis, and 123 were conservatively treated. There were no significant differences between these groups as regards biochemical parameters prior to treatment. RESULTS: Approximately 2% of patients presented with chronic renal failure at admission. However, GFR in more than 30% (370) of them was lower than 60 mL/min/1.73 m2. The incidence of myocardial infarction and pneumonia was more than three-fold greater in patients with reduced GFR (1.89 vs. 0.55, p = 0.042; 4.59 vs. 1.38, p = 0.0017, respectively). The incidence of gastrointestinal bleeding increased more than 18 times (3.78 vs. 0.28, p = 0.00002) and the incidence of stroke increased six times (2.43 vs. 0.41, p = 0.0032) in these patients. CONCLUSIONS: Latent renal failure is present in more than one-third of patients treated for peripheral atherosclerosis. GFR below 60 mL/min/1.73 m2 is associated with a higher risk of cardiovascular complications and postoperative gastrointestinal bleeding. Glomerular filtration rate should be routinely calculated at admission to hospital.

[Early death in vascular surgery: an ongoing prognostic problem]. / Wczesny zgon w chirurgii naczyniowej. Aktualny problem prognostyczny.

INTRODUCTION: Prediction of complications in surgery is commonly done. There are conflicting reports concerning the usefulness of risk scales (P-POSSUM, APACHE, SAPS, ASA, Goldman, etc.) in vascular surgery. We decided to take a fresh look at preoperative risk factors of early death in the context of the usefulness of some parameters which have not been included in existing risk calculators. MATERIAL AND METHODS: The study group consisted of 1270 patients treated at the Department of Vascular Surgery, General Surgery, and Angiology, Pomeranian Medical University in Szczecin, during one year. METHOD This was a prospective non-randomized study. All data recorded at admission and data from P-POSSUM, ASA, Goldman, and ECOG-Zubroda-WHO scales were analyzed. Statistics were done with discriminant, multivariate, and logistic tests. RESULTS: There were 42 early deaths in the group. The following independent risk factors were involved in early death: ASA > 2 (OR = 18.31), persistent atrial fibrillation (OR = 5.75), leukocytosis (OR = 13.31), glomerular filtration rate (GFR) < 30 mL/min/1.73 m2 (OR = 5.78), systemic inflammatory response syndrome (SIRS) (OR = 11.36), emergency admission (OR = 38.62), critical limb ischemia (OR = 4.87), acute limb ischemia (OR = 8,98), abdominal aortic aneurysm (OR = 4.4), and ruptured aortic aneurysm (OR = 10.59). Logistic regression exposed the influence of five factors: ASA III, ASA IV, persistent atrial fibrillation, leukocytosis, GFR < 30 mL/kg/1.73 m2, and ruptured aortic aneurysm. The P-POSSUM calculator was found to be an accurate predictor of early death although the predicted death rate was insignificantly higher than the observed rate. CONCLUSION: Risk scales of early death currently used in vascular surgery need to be "refreshed". Creation of the Polish National Vascular Surgery Register seems to be unavoidable.

Crossed bypass femoro-femoralis in patient with external iliac artery occlusion in the course of septic hemorrhage after renal graft explantatation.

Blood vessel complications are one of most important problems in patients after renal transplantation. They influence graft chances and they are also often direct life threat, requiring fast diagnosis and immediate surgical treatment. Described case concern septic hemorrhage in vessel junction region after transplant nephrectomy, reoperated 5 times because of this complication. We discuss occurrence and severity of septic hemorrhages, usual coexisting complications, ways of surgical treatment, course of infections leading to hemorrhage and similar cases reported. As the most frequent surgical techniques we found bypass axillo-femoralis, femoro-femoralis suprapubic and through formanen obturatorius and this kind of treatment as the most effective.

[Permanent local nerve injuries after carotid endarterectomy]. / Trwale miejscowe uszkodzenia nerwów po udroznieniu tetnicy szyjnej wewnetrznej.

UNLABELLED: Functional assessment of nerves, especially motor rami of cranial nerves, in patients at postoperative period after carotid endarterectomy (CEA), is particularly important in case of necessity of contralateral carotid artery surgery. Bilateral damage to recurrent laryngeal or hypoglossal nerve is a potentially life-threatening complication. Sensory disturbances due to intraoperative injuries of cervical plexus branches may cause residual discomfort in numerous patients. The aim of this study was the assessment and comparison of frequency of persistent (for more than 12 months postoperatively) manifestations of cranial and cervical nerves injuries in patients after CEA performed either in the standard or eversion technique. A prospective study evaluating cranial and cervical nerves dysfunction after carotid endarterectomies in 144 out of 193 patients operated on from January 1999 until June 2001 was undertaken at the Department of General and Vascular Surgery, Pomeranian Medical University in Szczecin, Poland. CEA was performed in the standard way (i.e. by primary closure) in 92 patients, while 52 others were operated on by eversion technique. Neurological examination with careful functional assessment of cranial nerves: V, VII, IX, X, XII and cervical plexus, was performed according to a standard protocol within two follow-up periods: 3 to 6 and 12 to 18 months after discharge from the hospital. RESULTS: Dysfunction of recurrent laryngeal nerve and hypoglossal nerve were registered 12 to 18 months after CEA with similar incidence of 1.4%. There was no sign of residual damage to other cranial nerves. Sensory disturbances in the area supplied by cervical plexus, mainly transverse cervical and greater auricular nerve, were diagnosed in 26% of patients. There were no statistically significant differences in local neurological complication rates between patients operated on according to standard and eversion procedures. CONCLUSIONS: 1. Permanent damage of cranial nerves refers to small group of patients after carotid endarterectomy and concern predominantly recurrent laryngeal nerve and hypoglossal nerve. 2. Majority of local neurological complications are injuries to cervical plexus branches. 3. Eversion carotid endarterectomy is not related to higher incidence of local neurological deficits compared to standard procedure.