OBJECTIVE—Because late vein graft failure is caused by intimal hyperplasia (IH) and accelerated atherosclerosis, and these processes are thought to be inflammation driven, influx of monocytes is one ...of the first phenomena seen in IH, we would like to provide direct evidence for a role of the MCP-1 pathway in the development of vein graft disease.
METHODS AND RESULTS—MCP-1 expression is demonstrated in various stages of vein graft disease in a murine model in which venous interpositions are placed in the carotid arteries of hypercholesterolemic ApoE3Leiden mice and in cultured human saphenous vein (HSV) segments in which IH occurs. The functional involvement of MCP-1 in vein graft remodeling is demonstrated by blocking the MCP-1 receptor CCR-2 using 7ND-MCP-1. 7ND-MCP1 gene transfer resulted in 51% reduction in IH in the mouse model, when compared with controls. In HSV cultures neointima formation was inhibited by 53%. In addition, we demonstrate a direct inhibitory effect of 7ND-MCP-1 on the proliferation of smooth muscle cell (SMC) in HSV cultures and in SMC cell cultures.
CONCLUSION—These data, for the first time, prove that MCP-1 has a pivotal role in vein graft thickening due to intimal hyperplasia and accelerated atherosclerosis.
OBJECTIVE—The immune system is thought to play a crucial role in regulating collateral circulation (arteriogenesis), a vital compensatory mechanism in patients with arterial obstructive disease. ...Here, we studied the role of lymphocytes in a murine model of hindlimb ischemia.
METHODS AND RESULTS—Lymphocytes, detected with markers for NK1.1, CD3, and CD4, invaded the collateral vessel wall. Arteriogenesis was impaired in C57BL/6 mice depleted for Natural Killer (NK)-cells by anti-NK1.1 antibodies and in NK-cell–deficient transgenic mice. Arteriogenesis was, however, unaffected in Jα281-knockout mice that lack NK1.1 Natural Killer T (NKT)-cells, indicating that NK-cells, rather than NKT-cells, are involved in arteriogenesis. Furthermore, arteriogenesis was impaired in C57BL/6 mice depleted for CD4 T-lymphocytes by anti-CD4 antibodies, and in major histocompatibility complex (MHC)-class-II–deficient mice that more selectively lack mature peripheral CD4 T-lymphocytes. This impairment was even more profound in anti-NK1.1-treated MHC-class-II–deficient mice that lack both NK- and CD4 T-lymphocytes. Finally, collateral growth was severely reduced in BALB/c as compared with C57BL/6 mice, 2 strains with different bias in immune responsiveness.
CONCLUSIONS—These data show that both NK-cells and CD4 T-cells modulate arteriogenesis. Promoting lymphocyte activation may represent a promising method to treat ischemic disease.
The autogenous saphenous vein is considered the best bypass graft material for arterial bypasses below the inguinal ligament. However, a synthetic graft or prosthesis is considered an acceptable ...alternative, especially when the distal anastomosis is situated above the knee. Some studies even suggest that patency rates for vein and synthetic grafts are comparable, whereas others indicate that a vein graft is superior to a prosthetic graft, even above the knee.
To test the hypothesis that both vein grafts and synthetic prostheses are equally beneficial in the above-knee position, we performed a systematic review of available studies comparing the patency of saphenous vein and polytetrafluoroethylene (PTFE) as bypass material. English and German medical literature from 1966 to 2002 was searched using Medline, and 25 articles meeting our inclusion and exclusion criteria were selected.
The patency of venous bypasses was superior to that of PTFE bypasses at all time intervals studied. After 2 years, the primary patency rate of venous bypasses was 81% as compared to 67% for PTFE bypasses, and after 5 years it was 69 and 49%, respectively. After 5 years, the secondary patency of PTFE bypasses reached 60%. When only randomized trials were considered, venous bypasses were again superior to PTFE bypasses at all intervals studied. After 2 years, the primary patency rate of venous and PTFE bypasses was 80 and 69%, respectively, and after 5 years it was 74 and 39%, respectively.
Since both randomized and retrospective studies comparing venous with PTFE bypasses showed that vein grafts were ‘better’ than PTFE prostheses, the null hypothesis that there is no difference between the two types of graft material was rejected (p=0.008).
We conclude from this systematic review that if a saphenous vein is available, a venous bypass should be chosen at all times, even if patients have an anticipated short life expectancy (<2 years). If the saphenous vein is absent or not suitable for bypass grafting, PTFE is a good alternative as bypass material.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Objective To compare postoperative complications in patients undergoing major surgery who received non-filtered or filtered red blood cell transfusions. Design Prospective, randomised, ...double blinded trial. Setting 19 hospitals throughout the Netherlands (three university; 10 clinical; six general). Participants 1051 evaluable patients: 79 patients with ruptured aneurysm, 412 patients undergoing elective surgery for aneurysm, and 560 undergoing gastrointestinal surgery. Interventions The non-filtered products had the buffy coat removed and were plasma reduced. The filtered products had the buffy coat removed, were plasma reduced, and filtered before storage to remove leucocytes. Main outcome measures Mortality and duration of stay in intensive care. Secondary end points were occurrence of multi-organ failure, infections, and length of hospital stay. Results No significant differences were found in mortality (odds ratio for filtered v non-filtered 0.80, 95% confidence interval 0.53 to 1.21) and in mean stay in intensive care (- 0.4 day, - 1.6 to 0.6 day). In the filtered group the mean length of hospital stay was 2.4 days shorter (- 4.8 to 0.0 day; P = 0.050) and the incidence of multi-organ failure was 30% lower (odds ratio 0.70, 0.49 to 1.00; P = 0.050). There were no differences in rates of infection (0.98, 0.73 to 1.32). Conclusion The use of filtered transfusions in some types of major surgery may reduce the length of hospital stay and the incidence of postoperative multi-organ failure.
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BFBNIB, CMK, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Venous bypass grafts may fail because of development of intimal hyperplasia and accelerated atherosclerosis. Inflammation plays a major role in these processes. Complement is an important part of the ...immune system and participates in the regulation of inflammation. The exact role of complement in the process of accelerated atherosclerosis of vein grafts has not yet been explored, however.
To assess the role of complement in the development of vein graft atherosclerosis, a mouse model, in which a venous interposition was placed in the common carotid artery, was used. In this model, vein graft thickening appeared within 4 weeks. The expression of complement components was studied with the use of immunohistochemistry on sections of the thickened vein graft. C1q, C3, C9, and the regulatory proteins CD59 and complement receptor-related gene y could be detected in the lesions 4 weeks after surgery. Quantitative mRNA analysis for C1q, C3, CD59, and complement receptor-related gene y revealed expression of these molecules in the thickened vein graft, whereas C9 did not show local mRNA expression. Furthermore, interference with C3 activation with complement receptor-related gene y-Ig was associated with reduced vein graft thickening, reduced C3 and C9 deposition, and reduced inflammation as assessed by analysis of influx of inflammatory cells, such as leukocytes, T cells, and monocytes. In addition, changes in apoptosis and proliferation were observed. When C3 was inhibited by cobra venom factor, a similar reduction in vein graft thickening was observed.
The complement cascade is involved in vein graft thickening and may be a target for therapy in vein graft failure disease.
Purpose
Both “high tie” (HT) and “low tie” (LT) are well-known strategies in rectal surgery. The aim of this study was to compare colonic perfusion after HT to colonic perfusion after LT.
Methods
...Patients undergoing rectal resection for malignancy were included. Colonic perfusion was measured with laser Doppler flowmetry, immediately after laparotomy on the antimesenterial side of the colon segment that was to become the afferent loop (measurement A). This measurement was repeated after rectal resection (measurement B). The blood flow ratios (B/A) were compared between the HT group and the LT group.
Results
Blood flow was measured in 33 patients, 16 undergoing HT and 17 undergoing LT. Colonic blood flow slightly decreased in the HT group whereas the flow increased in the LT group. The blood flow ratio was significantly higher in the LT group (1.48 vs. 0.91;
p
= 0.04), independent of the blood pressure.
Conclusion
This study shows the blood flow ratio to be higher in the LT group. This suggests that anastomoses may benefit from better perfusion when LT is performed.
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EMUNI, NUK, SBMB, SBNM, UL, UPUK
The role of thrombus within an aneurysm in relation to the risk of rupture is controversial. In literature, reports describing reduction and increase of rupture risk can be found. In the era of ...endovascular treatment of abdominal aortic aneurysms, a possible reduction of risk of rupture by the presence of thrombus within the aneurysmal sac can be important in relation to the location of an endoleak to the aneurysmal wall and in relation to the effect of the thrombosis of the endoleak, either spontaneously or by intervention.
In nine patients who underwent operation for an infrarenal aortic aneurysm by open procedure at the level of the thickest thrombus lining, the pressure within the aneurysmal thrombus (just inside the aneurysmal wall) was measured and compared with the systemic pressure.
Pressure within systemic circulation and aneurysmal thrombus correlated well for the mean pressure (r = 0.90; P <.001) and for pulse pressure (r = 0.74; P <.01) Also, there was agreement between the levels of the mean pressure. Conduction of mean and pulse pressure to the aneurysmal wall was not related to the thickness of the thrombus at the level of the pressure measurement (r = 0.18 and r = 0.08, respectively).
We conclude that thrombus within the aneurysm does not reduce both the mean and the pulse pressure near the aneurysmal wall and thus will not reduce the risk of rupture of the aneurysm.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
The erosion of the early mortality advantage of elective endovascular aneurysm repair (EVAR) compared with open repair of abdominal aortic aneurysm remains without a satisfactory ...explanation.
Methods
An individual‐patient data meta‐analysis of four multicentre randomized trials of EVAR versus open repair was conducted to a prespecified analysis plan, reporting on mortality, aneurysm‐related mortality and reintervention.
Results
The analysis included 2783 patients, with 14 245 person‐years of follow‐up (median 5·5 years). Early (0–6 months after randomization) mortality was lower in the EVAR groups (46 of 1393 versus 73 of 1390 deaths; pooled hazard ratio 0·61, 95 per cent c.i. 0·42 to 0·89; P = 0·010), primarily because 30‐day operative mortality was lower in the EVAR groups (16 deaths versus 40 for open repair; pooled odds ratio 0·40, 95 per cent c.i. 0·22 to 0·74). Later (within 3 years) the survival curves converged, remaining converged to 8 years. Beyond 3 years, aneurysm‐related mortality was significantly higher in the EVAR groups (19 deaths versus 3 for open repair; pooled hazard ratio 5·16, 1·49 to 17·89; P = 0·010). Patients with moderate renal dysfunction or previous coronary artery disease had no early survival advantage under EVAR. Those with peripheral artery disease had lower mortality under open repair (39 deaths versus 62 for EVAR; P = 0·022) in the period from 6 months to 4 years after randomization.
Conclusion
The early survival advantage in the EVAR group, and its subsequent erosion, were confirmed. Over 5 years, patients of marginal fitness had no early survival advantage from EVAR compared with open repair. Aneurysm‐related mortality and patients with low ankle : brachial pressure index contributed to the erosion of the early survival advantage for the EVAR group. Trial registration numbers: EVAR‐1, ISRCTN55703451; DREAM (Dutch Randomized Endovascular Aneurysm Management), NCT00421330; ACE (Anévrysme de l'aorte abdominale, Chirurgie versus Endoprothèse), NCT00224718; OVER (Open Versus Endovascular Repair Trial for Abdominal Aortic Aneurysms), NCT00094575.
Survival comparable
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Benign esophageal ruptures and anastomotic leaks are life-threatening conditions that are often treated surgically. Recently, placement of partially and fully covered metal or plastic stents has ...emerged as a minimally invasive treatment option. We aimed to determine the clinical effectiveness of covered stent placement for the treatment of esophageal ruptures and anastomotic leaks with special emphasis on different stent designs.
Consecutive patients who underwent placement of a fully covered self-expandable metal stent (FSEMS), a partially covered SEMS (PSEMS) or a self-expanding plastic stent (SEPS) for a benign esophageal rupture or anastomotic leak after upper gastrointestinal surgery in the period 2007-2010 were included. Data on patient demographics, type of lesion, stent placement and removal, clinical success and complications were collected
A total of 52 patients received 83 esophageal stents (61 PSEMS, 15 FSEMS, 7 SEPS) for an anastomotic leak (n=32), iatrogenic rupture (n=13), Boerhaave's syndrome (n=4) or other cause (n=3). Endoscopic stent removal was successful in all but eight patients treated with a PSEMS due to tissue ingrowth. Clinical success was achieved in 34 (76%, intention-to-treat: 65%) patients (PSEMS: 73%, FSEMS: 83%, SEPS: 83%) after a median of 1 (range 1-5) stent and a median stenting time of 39 (range 7-120) days. In total, 33 complications in 24 (46%) patients occurred (tissue in- or overgrowth (n=8), stent migration (n=10), ruptured stent cover (all Ultraflex; n=6), food obstruction (n=3), severe pain (n=2), esophageal rupture (n=2), hemorrhage (n=2)). One (2%) patient died of a stent-related cause.
Covered stents placed for a period of 5-6 weeks may well be an alternative to surgery for treating benign esophageal ruptures or anastomotic leaks. As efficacy between PSEMS, FSEMS and SEPS is not different, stent choice should depend on expected risks of stent migration (SEPS and FSEMS) and tissue in- or overgrowth (PSEMS).
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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