Runar Lundblad

Comparison of Cerebral Embolization During Off-Pump and On-Pump Coronary Artery Bypass Surgery

BACKGROUND Coronary artery bypass surgery with cardiopulmonary bypass carries a significant risk of perioperative brain injury. At least 1% to 5% will suffer a stroke, and at 3-months postoperatively approximately 30% are reported to have cognitive impairment assessed by neuropsychologic testing. In off-pump surgery cardiopulmonary bypass is not used and instrumentation on the ascending aorta is reduced. The main aim of this study was to assess if off-pump surgery reduces intraoperative cerebral embolization. METHODS This was a prospective and randomized study of two comparable groups with regard to age, sex, years of education, preoperative cognitive functioning, and surgical characteristics. Fifty-two patients (29 off-pump) were monitored by the use of transcranial Doppler ultrasound for cerebral microembolization during surgery. Preoperative and postoperative clinical, cerebral magnetic resonance imaging, and neuropsychologic examinations were also carried out. RESULTS There was a significant reduction in the number of cerebral microemboli during off-pump compared with on-pump surgery (16.3 [range 0 to 131] versus 90.0 [range 15 to 274], p < 0.0001). No significant difference with regard to the incidence of neuropsychologic performance (decline in 29% off-pump, 35% on-pump) or neuroradiologic findings at 3 months was found, and there was no association between the number of cerebral microemboli and cognitive outcome. CONCLUSIONS This study clearly demonstrates that off-pump surgery leads to a reduction in intraoperative cerebral microembolization. A significant reduction in the number of off-pump patients with cognitive decline or ischemic brain lesions on cerebral magnetic resonance imaging could not be demonstrated in this relatively small patient population.

Granulocyte colony-stimulating factor improves survival rate and reduces concentrations of bacteria, endotoxin, tumor necrosis factor, and endothelin-1 in fulminant intra-abdominal sepsis in rats.

OBJECTIVE To study the therapeutic effect of granulocyte colony-stimulating factor (G-CSF) on the mortality rate and host defense pattern in fulminant intra-abdominal sepsis. DESIGN Prospective, randomized, controlled trial. SETTING Research laboratory in a university hospital. SUBJECTS Adult male Wistar rats. INTERVENTIONS Fulminant polymicrobial intra-abdominal sepsis was induced by a 4-mm cecal perforation. Survival experiments were performed with two different doses of G-CSF (20 and 100 microg/kg/24 hrs), and therapy was started 7 days or 1 day before, or 4 hrs after sepsis induction (n = 24). To examine alterations in host response pattern, G-CSF (20 microg/kg/24 hrs) was given at sepsis induction, and rats were killed 4, 8, 12 and 24 hrs later (n = 8-16 per time period). Histologic examination of lung, liver, spleen, and kidney was performed, and blood concentrations of bacteria, endotoxin, tumor necrosis factor (TNF), endothelin-1, packed cell volume, and lactate were determined. MEASUREMENTS AND MAIN RESULTS G-CSF (20 microg/kg/24 hrs), given 4 hrs after sepsis induction, reduced the mortality rate from 96% to 42%. Increasing the dose (100 micrograms/kg/24 hrs), or giving G-CSF as prophylaxis (starting 7 days or 1 day before sepsis), gave no further protection. G-CSF attenuated the sepsis-induced enhancement of circulating bacteria, endotoxin, TNF, and endothelin-1, resulting in improved fluid balance and reduced lactate concentration. No histopathologic alterations were observed after G-CSF treatment. CONCLUSIONS G-CSF improves host defense and survival rate in experimentally induced fulminant intra-abdominal sepsis. Clearance of bacteria and endotoxin is improved, concentrations of TNF and endothelin-1 are suppressed, and microvascular flow is improved. G-CSF does not induce neutrophil-mediated tissue damage.

Pentoxifylline improves survival and reduces tumor necrosis factor, interleukin-6, and endothelin-1 in fulminant intra-abdominal sepsis in rats

The influence of pentoxifylline (PTX) on mortality and some important mediators was studied in a model of cecal perforation with fulminant intra-abdominal sepsis in rats. Cumulative mortality was registered in three groups of animals: untreated sepsis (n = 36), sepsis + PTX 20 mg/kg/24 h (n = 24), and sepsis + PTX 80 mg/kg/24 h (n = 24). PTX therapy was started at sepsis induction or after 4 h, and mortality was reduced from 89% in untreated sepsis to 60-66% in the PTX groups. Levels of sepsis mediators were studied in two groups: untreated sepsis and sepsis + PTX 40 mg/kg started 1 h after sepsis induction. In both groups 6-10 animals were sacrificed at 4 and 8 h to measure blood levels of bacteria, endotoxin, tumor necrosis factor (TNF), interleukin-6 (IL-6), endothelin-1, lactate, neutrophils, and packed cell volume. Cecal perforation gave high levels of bacteria, endotoxin, TNF, IL-6, and endothelin-1, leading to dehydration, lactacidosis, neutropenia, and death. Treatment with PTX did not modify dehydration, neutropenia, or concentrations of bacteria and endotoxin. Release of endothelin-1 was delayed, TNF burst was nearly abolished, and levels of IL-6 and lactate were substantially suppressed. In summary, PTX improves survival and reduces blood concentrations of TNF, IL-6, lactate, and endothelin-1 in fulminant intra-abdominal sepsis in rats. The primary effect of PTX in this sequence is probably reduction of TNF.

Agreement between PiCCO pulse-contour analysis, pulmonal artery thermodilution and transthoracic thermodilution during off-pump coronary artery by-pass surgery

Background:  Haemodynamic instability during off‐pump coronary artery bypass surgery (OPCAB) may appear rapidly, and continuous monitoring of the cardiac index (CI) during the procedure is advisable. With the PiCCO monitor, CI can be measured continuously and almost real time with pulse‐contour analysis and intermittently with transthoracic thermodilution. The agreement between pulmonal artery thermodilution CI (Tpa), transthoracic thermodilution CI (Tpc) and pulse‐contour CI (PCCI) during OPCAB surgery has not been evaluated sufficiently.

Endothelin-1 and neutrophil activation during heparin-coated cardiopulmonary bypass

BACKGROUND Heparin-coated circuits attenuate the systemic inflammatory response to cardiopulmonary bypass. The present study compares two different heparin coatings in terms of the release of endothelin-1 and neutrophil glycoproteins. METHODS Forty low-risk patients undergoing coronary artery bypass grafting were investigated, having cardiopulmonary bypass with a Duraflo II heparin-coated circuit (n = 10), an identical but uncoated circuit (n = 10), a Carmeda BioActive Surface heparin-coated circuit (n = 10), or an identical but uncoated circuit (n = 10). A standard systemic heparin dosage was used in all patients. Endothelin-1 and the neutrophil glycoproteins lactoferrin and myeloperoxidase were quantified throughout the operation and 3 hours postoperatively. RESULTS Enhanced plasma levels of endothelin-1, lactoferrin, and myeloperoxidase were observed during and after uncoated cardiopulmonary bypass, but this was not associated with clinical side effects. Compared with the respective uncoated controls, Duraflo II attenuated only the lactoferrin levels, whereas Carmeda BioActive Surface was associated with lower levels of both endothelin-1, lactoferrin, and myeloperoxidase. Of the two heparin coatings, Carmeda BioActive Surface proved more effective than Duraflo II in attenuating the levels of these substances. CONCLUSIONS The plasma levels of endothelin-1, lactoferrin, and myeloperoxidase increase during cardiopulmonary bypass in coronary artery bypass grafting, but this has no clinical side effects in low-risk patients. The increase is attenuated using heparin-coated extracorporeal circuits, and then more effectively by Carmeda BioActive Surface than by Duraflo II.

Surgical repair of postinfarction ventricular septal rupture: Risk factors of early and late death

OBJECTIVE The aim of the study was to identify risk factors of early and late death after surgical repair of postinfarction ventricular septal rupture. METHODS During a 25-year period, from May 1981 to August 2006, 102 patients underwent repair of postinfarction ventricular septal rupture. Data were collected on clinical, angiographic, and echocardiographic findings; operative procedures; early morbidity; and survival time. Univariable and multivariable analyses were performed to identify risk factors of 30-day mortality and total mortality. RESULTS Thirty-day mortality was 33% altogether and decreased from 45% in the first half to 21% in the second half of the period (P = .01). Follow-up was a mean of 5.2 +/- 6.2 years and a median of 2.9 years (range, 0-26.3 years). Five- and 10-year cumulative survival was 50% and 32%, respectively. Shock at surgical intervention and incomplete coronary revascularization were strong and independent risk factors of both 30-day mortality and poor long-term survival. CONCLUSIONS Early outcome after repair of ventricular septal rupture improved significantly during time, with 30-day mortality being 21% in the last decade. Five- and 10-year cumulative survival was 50% and 32%, respectively. Shock at surgical intervention and incomplete coronary revascularization were strong and independent predictors of poor early and late survival.

Repair of left ventricular aneurysm: surgical risk and long-term survival

BACKGROUND The aim of the study was to identify predictors for survival after repair of postinfarction left ventricular aneurysm. METHODS We retrospectively reviewed the records of 149 patients who had an operation for postinfarction left ventricular aneurysm between 1989 and 2001. The following variables were recorded: preoperative clinical, angiographic, and echocardiographic findings and operative procedures. Outcomes were early mortality (<30 days) and long-term survival. Risk factors were pinpointed using t test or Mann-Whitney test, contingency tables, and survival curves. Independent risk factors were identified by logistic regression and Cox regression methods. Mean follow-up was 5.8 years (range, 0 to 13.8 years). RESULTS The early mortality (<30 days) rate was 8.7% altogether, and the 5-year cumulative survival rate was 77%. Advanced age, history of ventricular arrhythmia, three-vessel disease, and linear repair technique were independent risk factors for early and total mortality. Poor left ventricular function predicted reduced long-term survival but did not increase surgical risk. Survival was not affected by gender, diabetes, type and severity of symptoms, anterior or posterior aneurysm, revascularization of the left anterior descending artery, or number of distal anastomoses. CONCLUSIONS Postinfarction left ventricular aneurysm can be repaired with acceptable surgical risk and long-term survival. Survival is reduced in cases with advanced age, history of ventricular arrhythmia, three-vessel disease, poor left ventricular function, and linear repair of the aneurysm.

Sternal wound infections in patients undergoing open heart surgery: randomized study comparing intracutaneous and transcutaneous suture techniques

BACKGROUND Intracutaneous suture technique has been our standard method for closing sternal wounds in cardiac surgery, mainly for cosmetic reasons. However, an increased rate of postoperative infections has been reported in cosmetic surgery with this method compared with the percutanous or transcutaneous closure technique. A comparison of these two techniques in cardiac surgery is presented. METHODS In a randomized study, 300 patients were selected to intracutaneous suture (n = 150) or percutanous suture (n = 150). The endpoints were superficial and deep sternal wound infections within 6 weeks postoperatively. RESULTS The total infection rate was lower in the percutanous group compared with the intracutaneous group (3% versus 8%) (p = 0.007). The superficial infection rate was lower in the percutaneous group (2.3% versus 6.7%) (p = 0.01), whereas there was no statistically significant difference in the deep infection rate between the groups. CONCLUSIONS The percutaneous suture technique reduces the incidence of superficial wound infections, but not the deep infection rate in open heart surgery. There was no difference in the cosmetic results on a visual scale, assessed by the patients.

Granulocyte colony-stimulating factor improves myelopoiesis and host defense in fulminant intra-abdominal sepsis in rats.

The therapeutic efficacy of granulocyte colony-stimulating factor (G-CSF) was studied in a model of fulminant sepsis in rats. Polymicrobial peritonitis was induced by a 4 mm cecal perforation and 10 micrograms/kg recombinant human G-CSF was given intravenously every 12 h, with the first dose at sepsis induction or 4 h post-induction. Rats were sacrificed at various intervals throughout sepsis to measure levels of neutrophil progenitors in the bone marrow and neutrophils and bacteria in blood and peritoneal fluid. Sepsis gave a sustained neutropenia and bacteremia, but did not affect numbers of blast- or GM-colonies, and only a delayed and moderate proliferation of G-clones was seen. Treatment with G-CSF at sepsis induction improved myelopoiesis by doubling the numbers of GM- and G-progenitors at 12 and 24 h post-induction. Concentrations of neutrophils increased twofold in blood and 5-fold in peritoneal fluid, while bacteria counts in the same compartments declined logarithmically. Mortality was 92% in untreated sepsis and declined to 46% when G-CSF therapy was started at sepsis induction, and to 42% following 4 h delayed therapy.

Intracoronary Shunt Prevents Ischemia in Off-Pump Coronary Artery Bypass Surgery

BACKGROUND The purpose of this study was to evaluate the role of intracoronary shunt during off-pump coronary artery bypass surgery. METHODS Fifty-six patients undergoing off-pump coronary artery bypass using the left internal mammary artery to bypass the left anterior descending coronary artery were randomly assigned to have the bypass performed with intracoronary shunt or by occlusive snaring. Ischemia during grafting was monitored by tissue Doppler. Hemodynamic status and indicators of ischemia were monitored, and on-table and postoperative angiography were performed. RESULTS In patients with retrograde filling of the left anterior descending coronary artery, ischemia did not develop, but occlusion of antegradely perfused vessels caused ischemia in 26 of 33 patients. Ischemia was reversed in 14 of 16 shunted patients, and in 3 of 17 nonshunted cases (p = 0.004). Angiography showed a trend toward improved on-table angiographic results in shunted patients. After 3 months, graft patency was 100%, but 1 patient treated without shunt required reintervention and 15 patients had new angiographic lesions, equally distributed between shunted and nonshunted patients. CONCLUSIONS Intracoronary shunt prevents ischemia during grafting of the left anterior descending coronary artery and provides satisfactory immediate- and short-term graft patency.