Naringenin inhibits neointimal hyperplasia following arterial reconstruction with interpositional vein graft.

Vessels respond to injury by a healing process that includes the development of neointima. Stenosis secondary to neointima formation is the main cause of failure following arterial reconstructions. Vessel wall homeostasis is regulated by proinflammatory cytokines that affect smooth muscle cell proliferation, growth, migration, and death. We assessed the hypothesis that naringenin, a flavinoid possessing anti-inflammatory, antioxidant, and antiproliferative activities, reduces neointimal hyperplasia (NIH) following vascular injury.Arterial injury was created by interposition grafting of autologous right superficial epigastric vein graft into the right femoral artery (FA) in 48 male Sprague-Dawley rats. Following injury, the rats were divided into 4 groups (n = 12). Two groups were treated with naringenin (100 mg/kg intraperitoneal q daily) for 2 and 4 weeks each while 2 control groups received normal saline for the same durations. For Sham group (n = 10), the FA and vein were isolated without any additional procedure. Rats were killed at the end of treatment regimen in all groups, and FAs were harvested. Thickness of intima was measured in histologic sections, and levels of platelet derived growth factor (PDGF)-BB, TNFalpha, and Ki67 labeling index (Ki67 LI) were quantified in immunohistochemical analyses to assess the amount of NIH and mechanisms underlying its formation.Although there was no significant difference between the groups at 2 weeks, neointima thickness was lower in the naringenin treated group at 4 weeks (23.7 +/- 2.3 vs. 35.6 +/- 2.6 microm in control group; P < 0.001). The levels of PDGF-BB, and TNFalpha were lower in naringenin treated groups at both 2 weeks (PDGF-BB [0.21% +/- 0.03% versus 0.39% +/- 0.05% in control group, P < 0.001), TNFalpha (21.2% +/- 0.8% vs. 36.1% +/- 1.9% in control group, P < 0.001]) and 4 weeks (PDGF-BB [0.25% +/- 0.03% vs. 0.57% +/- 0.09% in control group, P < 0.001], TNFalpha [25.5% +/- 1.8% vs. 45.0% +/- 2.9% in control group, P < 0.001]). Ki67 LI was lower in naringenin treated groups at 2 weeks (13.9% +/- 2.8% vs. 18.7% +/- 3.7% in control group, P < 0.05), and at 4 weeks (17.5% +/- 2.6% vs. 31.1% +/- 4.7% in control group, P < 0.001), indicating a lower level of cellular proliferation.Naringenin reduces NIH following arterial reconstruction. This may be mediated by a decrease in PDGF-BB and TNFalpha levels and the resulting down-regulation of smooth muscle cells' migration and proliferation.

Risk analysis of deep sternal wound infections and their impact on long-term survival: a propensity analysis.

The objectives of this study are to determine risk factors associated with deep sternal wound infections (DSWIs) following cardiac surgery, and to describe their impact on long-term survival. Data was obtained from a departmental database. Analysis included 7,978 consecutive patients who underwent cardiac surgery between 1997 and 2003. To identify risk factors for DSWI, regression analysis was performed. The probability scores obtained from logistic regression were used for propensity analysis of 2 groups. Kaplan-Meier analysis with log-rank test and Cox proportional hazard models were then used in survival analysis. DSWI developed in 123 of 7,978 patients (1.5%). Preoperative predictors of DSWI were body mass index >30 kg/m(2) (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1 to 2.4; P < 0.05), diabetes mellitus (OR, 2.4; 95% CI, 1.6 to 3.4; P < 0.001), urgent operation (OR, 1.7; 95% CI, 1.2 to 2.6; P < 0.05), smoking history within past year (OR, 2.7; 95% CI, 1.5 to 4.9; P < 0.001), smoking history within past 2 weeks (OR, 2.6; 95% CI, 1.5 to 4.5; P < 0.001), and a history of stroke (OR, 1.9; 95% CI, 1.1 to 3.1; P < 0.005). In addition, total length of hospital stay (OR, 1.01; 95% CI, 1.01 to 1.02; P < 0.05) and sepsis and/or endocarditis following surgery (OR, 5.1; 95% CI, 2.9 to 9.0; P < 0.001) were also predictive of DSWI. Patients with DSWI had a prolonged total length of hospital stay (40.3 days versus 16.1 days; P < 0.001), and higher 30-day mortality (1.6% versus 7.3% in DSWI group, P < 0.05). There were no differences between groups in 4-year and 8-year survival rates, with 77.2% and 61.8%, respectively, in patients with DSWI compared with 78.0% and 67.5% in patients without DSWI (P = 0.16). After adjustments for preoperative, intraoperative, and postoperative factors, the adjusted hazard ratio of long-term mortality for patients with DSWI was 0.9 (95% CI, 0.6 to 1.2, P = 0.39). Though DSWIs are associated with increased early mortality, patients undergoing cardiac surgery complicated by DSWI do not experience worse long-term survival.

Neuraminidase produces a decrease of adherence of slime-forming Staphylococcus aureus to gelatin-impregnated polyester fiber graft fabric: an experimental study.

Because slime-forming microorganisms are the major causative agents of graft infections, we aimed to investigate bacterial adherence in slime-forming and nonslime-forming Staphylococcus aureus and to determine the role of neuraminidase (NANase) on adherence to gelatin-impregnated polyester fiber graft fabric. An in vitro model was developed to quantitatively measure bacterial adherence to the surface of the graft. The grafts were divided into two groups - those colonized with slime-forming S. aureus and those colonized with nonslime-forming S. aureus. The grafts were put into sterile tubes and human plasma was instilled and incubated at 37 degrees C to perform fibrin deposition on the grafts. After 48 h of incubation, grafts were drained and inoculated with slime-forming or nonslime-forming S. aureus in triptic soy broth in the presence or absence of NANase. Following 36 h of incubation at 36 degrees C, grafts were vortexed and cultured to perform a colony count. Bacterial counts were expressed as total colony-forming units per square centimeter of graft. Slime-forming S. aureus had greater affinity with the graft compared with nonslime-forming S. aureus (P < 0.05). The adherence of slime-forming S. aureus was impaired by NANase treatment (P < 0.001) but NANase treatment of nonslime-forming S. aureus did not change the adherence to the graft (P > 0.05). These results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming S. aureus can be decreased by NANase treatment. This may have implications for the development of neuraminidase-embedded vascular grafts to diminish biomaterial-related infections.

Catheter entrapment during balloon angioplasty in patient with in-stent restenosis: an unusual complication and its surgical management.

Entrapment of coronary angioplasty hardware is one of the rare complications of percutaneous coronary artery interventions. We reported herein a case of 58-year-old man with an entrapped balloon catheter and guidewire within the right coronary artery during the application of a conventional balloon angioplasty for in-stent restenosis. Surgical removal of the entrapped balloon catheter and guidewire was performed successfully with a coronary artery bypass grafting to the affected vessel. The application of the balloon angioplasty for in-stent restenosis requires every caution against such type of complications.

Linezolid alone and in combination with rifampicin prevents experimental vascular graft infection due to methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.

BACKGROUND: In this report we describe the in vivo antibacterial activity of linezolid in an experimental graft infection model in rats and compare it with teicoplanin. The objective of this study was also to determine the effects of the interaction of linezolid when it was combined with rifampicin and test this effect against strains of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. MATERIALS AND METHODS: Graft infections were established in the subcutaneous tissue of 130 Wistar rats by implantation of Dacron grafts followed by a topical inoculation with 2 x 10(7) CFU of clinical isolates of MRSA and MRSE. The study included a control group and six groups for each of the staphylococcal strains: an inoculated group that did not receive any antibiotic prophylaxis, two inoculated groups that received intraperitoneal prophylaxis with teicoplanin or linezolid alone, an inoculated group that received rifampicin-soaked grafts, and two inoculated groups that received a combination prophylaxis consisting of intraperitoneal teicoplanin or linezolid and rifampicin-soaked grafts. RESULTS: There was a reduction in the quantitative bacterial graft cultures in all prophylaxis groups when compared with inoculated control groups. There was not a statistically significant difference between linezolid and teicoplanin prophylaxis groups. The best results were obtained by a combination of rifampicin-soaked grafts with linezolid or teicoplanin. CONCLUSIONS: We found no evidence to suggest that linezolid differs from teicoplanin regarding effectiveness in the prevention of prosthetic vascular graft infection. Linezolid plus rifampicin and teicoplanin plus rifampicin are demonstrated to be valuable prophylactic regimens.

Preservation of pleural integrity in patients undergoing coronary artery bypass grafting: effect on postoperative bleeding and respiratory function.

OBJECTIVE: The purpose of this study was to evaluate the influence of preserved integrity of pleura on postoperative bleeding and respiratory function in patients undergoing coronary artery bypass grafting (CABG). METHODS AND RESULTS: Seventy-two CABG patients who received pedunculated IMA graft without opening the pleura (group of intact pleura, group IP) between July 2002 and September 2004 were matched to 72 CABG patients who received pedunculated IMA graft with opened pleura (group of opened pleura, group OP). To match the patients with IP and unique patients with OP, logistic regression was used to develop a propensity score. The C statistic for this model was 0.79. Patients with IP were matched to unique patients with OP with an identical 5-digit propensity score. If this could not be done, we proceeded to a 4-, 3-, 2-, or 1-digit match. Patients characteristics were well matched. There were no differences in preoperative and peroperative variables between the groups. The incidence of postoperative pleural effusion and thoracentesis were significantly lower in group IP than group OP (pleural effusion in 15.2 versus 30.5%; p = 0.029, thoracentesis in 5.5 versus 18.5%; p = 0.036). Other pulmonary complications such as prolonged ventilation, reintubation, pneumothorax, atelectasis, diaphragmatic paralysis were similar in both groups. Patients with IP had significantly lower blood loss (520 versus 870 ml; p < 0.001) and whole blood unit transfusion (26.3 versus 41.6%, p = 0.036). Also, intensive care unit and hospital stay were similar in both groups. CONCLUSIONS: Meticulous internal mammary artery harvesting and preservation of the pleural integrity significantly reduces postoperative bleeding and pleural effusion.

Ascorbic acid (vitamin C) and iloprost attenuate the lung injury caused by ischemia/reperfusion of the lower extremities of rats.

The objectives of this study were to compare the protective effects of ascorbic acid and iloprost on lung injury caused by ischemia reperfusion (I/R) of the lower extremities of rats. Wistar albino rats (n = 34) were divided into five groups. In the I/R group (n = 6), the aorta was cross-clamped for 3 hr, followed by 1 hr of reperfusion. In the vitamin C group (n = 8), animals were pretreated with 100 mg/kg ascorbic acid via the left jugular vein before aortic cross-clamping. In the iloprost group (n = 8), animals were pretreated with 20 ng/(kg x min) iloprost by constant intravenous infusion via the left jugular venous cannula. In the sham group (n = 6), the abdomen was left open at the same period and a juguler venous line was established. In the control group (n = 6), lungs were removed and blood samples taken immediately after sternotomy. No treatment was given in this group. After both lungs were removed, biochemical parameters were measured and histopathological evaluation was made. Although the arterial blood pO2 and HCO3 levels were statistically significantly high in both the vitamin C and iloprost groups compared to the I/R group, plasma malondialdehyde (MDA) levels were significantly low. Meanwhile, the MDA levels in the lung tissue were significantly low in the vitamin C group compared to the I/R group. The MDA level in the lung tissue in the iloprost group was also low compared to the I/R group, but it was not statistically significant. The lungs of the I/R group displayed intense interstitial leukocytic infiltration in histopathological examination compared to the other groups. Pretreatment of animals with iloprost and vitamin C significantly decreased the pulmonary injury characterized by decreased plasma leukocyte sequestration. The results suggest that both vitamin C and iloprost are useful agents for attenuating the lung injury caused by increased oxidative stress and neutrophil accumulation after a period of I/R of the lower extremities.

The prophylactic efficacy of rifampicin-soaked graft in combination with systemic vancomycin in the prevention of prosthetic vascular graft infection: an experimental study.

OBJECTIVE: To investigate the prophylactic efficacy of systemic, topical, or combined antibiotic usage in the prevention of late prosthetic vascular graft infection caused by methicillin-resistant Staphylococcus epidermidis (MRSE) and the differential adherence of S. epidermidis to Dacron and ePTFE grafts in a rat model. MATERIALS AND METHODS: Graft infections were established in the back subcutaneous tissue of 120 adult male Wistar rats by implantation of 1-cm(2) Dacron/ePTFE prosthesis followed by topical inoculation with 2 x 10(7) CFU of clinical isolate of MRSE. Each of the series included one group with no graft contamination and no antibiotic prophylaxis (uncontaminated control), one contaminated group that did not receive any antibiotic prophylaxis (untreated control), one contaminated group in which perioperative intraperitoneal prophylaxis with vancomycin (10 mg/kg) was administered, two contaminated groups that received rifampicin-soaked (5 mg/1 ml) or vancomycin-soaked (1 mg/1 ml) grafts, and one contaminated group that received a combination of rifampicin-soaked (5 mg/1 ml) graft with perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg). The grafts were removed sterilely 7 days after implantation and evaluated by using sonication and quantitative blood agar culture. RESULTS: MRSE had significantly greater adherence to Dacron than ePTFE grafts in the untreated contaminated groups (P < 0.001). Rifampicin had better efficacy than vancomycin in topical application, but the difference was not statistically significant (P > 0.05). Intraperitoneal vancomycin showed a significantly higher efficacy than topical vancomycin or rifampicin (P < 0.001). The best results were provided by a combination of intraperitoneal vancomycin in rifampicin-soaked graft groups (P < 0.001). CONCLUSIONS: The combination of rifampicin and intraperitoneal vancomycin seems to be the best choice for the prophylaxis of late prosthetic vascular graft infections caused by MRSE.

[The effect of glutamate and aspartate on myocardial protection at cardiopulmonary bypass]. / Kardiyopulmoner Baypasta Glutamat ve Aspartatin Miyokardiyal Koruma Uzerine Etkisi.

OBJECTIVE: To determine whether glutamat and aspartat enriched cold crystalloid cardioplegia which was given in antegrade way has any effect on the myocardial protection during cardiopulmonary bypass. METHODS: Thirty-four patients who were electively undergone open heart surgery at Osmangazi University Faculty of Medicine, thoracic and cardiovascular surgery department, between March 2001 and May 2001 were included in this study. The patients were divided in two groups, each consisting of 17 patients. In group 1 coronary artery bypass surgery (CABG) was performed in 11 patients, mitral valve replacement (MVR) in 3 patients, aortic valve replacement (AVR) in 1 patient and AVR and MVR in 2 patients. While in group 2 CABG was performed in 13 patients and MVR was done in 4 patients. Group 1 patients received antegrade glutamat and aspartat (15 mmol/L) enriched cold crystalloid cardioplegia and group 2 patients were given cold crystalloid cardioplegia by antegrade route. Age, gender, diabetes mellitus, hypertension, preoperative myocardial infarction, smoking, ejection fraction, aortic cross-clamp time, need to defibrillation, inotropic support, and intraaortic balloon pump were recorded. The levels of cardiac troponin I (cTI) and creatine kinase myocardial band fraction (CK-MB) were measured in arterial blood samples at five different times. Statistical analysis was performed using Student's t-test and Chi-square test. RESULTS: There were no statistically significant differences in cTI and CK-MB values in blood samples taken at 5 different times pre and postoperatively between group 1 and group 2. CONCLUSION: It is concluded that glutamat and aspartat enriched cold crystalloid cardioplegia does not have any effect on myocardial protection.

[Experiments on minimally invasive open heart surgery using right anterolateral minithoracotomy]. / Açik Kalp Cerrahisinde Minimal Invazif Sag Anterolateral Minitorakotomi Deneyimlerimiz.

OBJECTIVE: Minimal invasive cardiac surgical techniques recently have been applied in the management of various cardiac lesions. The aim of the study was to evaluate right anterolateral minithoracotomy as an alternative procedure with a better cosmetic and clinical outcomes. METHODS: Fifteen male and 64 female patients underwent open heart surgery during cardiopulmonary bypass through a right anterolateral minithoracotomy at the fourth intercostal space. The average age was 41+/-6 years. Fifty-two (65.8%) patients underwent mitral valve replacement, 5 (6.3%) patients underwent mitral valve replacement + tricuspid annuloplasty, 5 (6.3%) patients underwent tricuspid valve replacement, 7 (8.9%) patients underwent closure of the atrial septal defect (ASD), 3 (3.8%) patients underwent closure of the ventricular septal defect (VSD), 1 (1.2%) patient underwent closure of the ASD+VSD and 5(6.3%) patients underwent mitral re-replacement. RESULTS: The postoperative average ventilation time was 6+/-2 h in 38 (48.1%) patients and 11+/-3 h in 41 (51.9%) patients. The postoperative average mediastinal drainage was 350+/-110 ml during first 24 hours, and postoperative stay in intensive care was 1.8+/-0.8 days. CONCLUSION: As a result, the right anterolateral minithoracotomy incision is a safe and effective alternative to the median sternotomy for open heart surgical procedures. Most of minimal surgical accesses can be achieved with better cosmetic results and faster recovery.