A structured blood conservation program in pediatric cardiac surgery.

OBJECTIVE: The limitation of alternative transfusion practices in infants increases the benefits of blood conservation. We analyzed the efficacy of a structured program to reduce transfusions and transfusion-associated complications in cardiac surgery PATIENTS AND METHODS: Our pediatric surgery database was reviewed retrospectively, comparing outcomes from two different time periods, after the implementation of an effective blood conservation program beginning in March 2014. A total of 214 infants (8.1±3.4 months) who underwent biventricular repair utilizing CPB (Group 1 - Blood conservation) were studied in a 12-month period (March 2014-February 2015) after the implementation of the new program, and compared with 250 infants (7.91±3.2 months) (Group 2 - Control-No blood conservation) of the previous 12-month period (March 2013-February 2014). RESULTS: The proportion of patients transfused with red blood cells was 75.2% (N=188) in control group and reduced by 16.4% in the study group (58.8% - 126 patients, p <0.01). The mean number of transfusions was 1.25 ± 0.5 units per patient in control group and decreased to 0.7 ± 0.5 units per patient after the start of the program (p = 0.035). Cerebral oximetry demonstrated better follow-up during the operative period confirming less hemodilution in Group 1. Respiratory support, inotropic need and ICU stay were significantly better in the study group. CONCLUSIONS: These findings, in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in pediatric cardiac operations. Circuit miniaturization, ultrafiltration, and reduced postoperative bleeding, presumably secondary to higher fibrinogen and other coagulation factor levels, contributed to this outcome.

Polylactic acid and polyethylene glycol prevent surgical adhesions.

OBJECTIVES: Re-mediastinoscopy could be risky because of adhesions from the previous mediastinoscopy. The aim of this study was to evaluate the efficacy of a bio-resorbable barrier on adhesion formation in a re-mediastinoscopy rat model. METHODS: Mediastinal dissection similar to mediastinoscopy was done in twenty-eight rats and a polymeric film comprising of polylactic acid and polyethylene glycol (Repel-cv®, SyntheMed Inc., NJ, USA) was placed on trachea in the study groups. Group 1 (sham, sacrificed at day 30), Group 2 (single barrier, sacrificed at day 30), Group 3 (single barrier, sacrificed at day 60), Group 4(double layer barrier, sacrificed at day 60). Mediastinal adhesions, degree of inflammation, vascular proliferation, foreign body reaction and fibroblast proliferation was compared. RESULTS: Macroscopic dissection showed significantly dense adhesions in Sham Group and Group 3 (p < 0.05). Histopathologic examination showed that there was a significant difference between groups when the foreign body reaction and fibroblast proliferation was evaluated (p0.05). CONCLUSIONS: This unique experimental study showed that adhesion barrier was effective as single layer application at day 30 and double layer application at day 60. At clinical conversion, by the application of barrier, the formation of adhesions might be decreased to provide a safe re-mediastinoscopy (Tab. 2, Fig. 4, Ref. 23).

Research using qualitative, quantitative or mixed methods and choice based on the research.

Research is fundamental to the advancement of medicine and critical to identifying the most optimal therapies unique to particular societies. This is easily observed through the dynamics associated with pharmacology, surgical technique and the medical equipment used today versus short years ago. Advancements in knowledge synthesis and reporting guidelines enhance the quality, scope and applicability of results; thus, improving health science and clinical practice and advancing health policy. While advancements are critical to the progression of optimal health care, the high cost associated with these endeavors cannot be ignored. Research fundamentally needs to be evaluated to identify the most efficient methods of evaluation. The primary objective of this paper is to look at a specific research methodology when applied to the area of clinical research, especially extracorporeal circulation and its prognosis for the future.

Impact of the intensity of microemboli on neurocognitive outcome following cardiopulmonary bypass.

BACKGROUND: This study aimed to determine whether there was any association between the intensity of intraoperative gaseous microembolic signals (GME), neuropsychological testing and clinical outcome in high-risk patients undergoing coronary artery surgery (CABG). METHODS: Over a 6-month period, GME activity was monitored in 102 Euroscore 6+ patients during cardiopulmonary bypass (CPB) with a conventional 32-micron arterial filter by non-invasive, real-time ultrasonic device. Cognitive tests; line bisection, the Stroop test, finger tapping, and the Rey Auditory Verbal Learning Test were performed at baseline, postoperative one week and postoperative one month. RESULTS: The distribution of GME activity showed that there were three groups of patients: >500 total emboli (n = 38); 250 to 500 emboli (n = 30) and <250 emboli (n = 34) at a detection level of 2% of the circuit diameter on the arterial side. Line bisection, the Stroop test and finger tapping were impaired significantly in >500 emboli patients versus control (<250 emboli) in postoperative week one, but resolved in one month. CONCLUSIONS: Correlation between intraoperative GME intensity and neurocognitive tests suggests that the level of GME might have a role in determining the psychological outcome after CABG with CPB.

Clinical efficacy of leukofiltration on cardiopulmonary bypass related inflammatory response: Fact or Foe?

OBJECTIVE: The powerful precept of preoperative risk assessment has been applied to compare the efficacy of leukofiltration techniques for high-risk cohorts with the documentation of broad indicators of systemic inflammation. METHODS: Forty high risk patients were prospectively assigned to four perfusion protocols; the first group (n=10): Polyethyleneoxide (PEO) based heparin bonded extracorporeal circuits (ECC) + Continuous Leukocyte filtration; the second group (n=10): uncoated ECC + leukofiltration; the third group (n=10): PEO based heparin bonded ECC without leukofiltration; and control (n=10). Blood samples were obtained at the following intervals: Baseline (T1), on cardiopulmonary bypass (CPB) (T2), Cross clamp (T3), off CPB (T4), Intensive care unit-24 h (ICU24) (T5), ICU48 (T6). RESULTS: Tumor Necrosis Factor-alpha levels were significantly lower in Group 1 at T3, T4 (p<0.05) vs. control. Procalcitonin levels were significantly lower in Group 1 at T5, T6 (p<0.05) vs. control. Creatinine kinase-MB levels in coronary sinus blood demonstrated well preserved myocardium in filtered+coated (Group 1) and coated groups (Group 3) (p<0.05). Matrix metallopeptidase- 9 and D-Dimer levels in filtered+coated group were significantly lower at T5 and T6 vs. control (p<0.05). CONCLUSION: Leukocyte filtration on coated surfaces alleviated systemic inflammatory response with a better clinical outcome in high risk patients.

Clinical impact and biomaterial evaluation of autologous platelet gel in cardiac surgery.

We compared the clinical efficacy of autologous platelet gel (APG) and gelatine (CONT), including biomaterial evaluation. In a prospective, randomized, controlled trial, 64 patients undergoing complex coronary artery bypass graft (CABG) surgery and/or aortic surgery, in whom the surgeon was able to identify a bleeding site for which conventional means to stop bleeding were impractical or proved unsuccessful, were enrolled. Aortic punch biopsy from each patient was harvested in explant cell (EC) culture media. Hemostasis success for the "oozing" category was 89% in APG and 60% in CONT (p< 0.05). For the "heavy bleeding" category, the success rates were 92% in APG and 45% in CONT (p<0.01). Contact of gelatine inhibited EC proliferation and APG increased cell cycling and EC quantity. Phagocytic capacity (PC) was significantly higher in the APG group (p<0.001). APG was significantly better than CONT with respect to hemostatic success rate, effects on wound healing and increased resistance to infection (PC).

Strategic leukofiltration in cardiac surgery.

Systemic inflammatory response syndrome (SIRS) with activation of molecular cascades, cell activation, accumulation of interstitial fluid, organ dysfunction and, occasionally, organ failure is still a commonly recognized consequence of cardiac surgery. SIRS leads to costly complications and several strategies intended to ameliorate the symptoms that have been studied, including leukocyte reduction, using filtration. Although, the body of work suggests that leukoreduction attenuates SIRS, discrepancies remain within the literature. The recent literature is reviewed highlighting the areas where concordance is lacking. In our study, on the basis of indirect indicators of SIRS, platelet function by thromboelastography biomaterial evaluation by light and scanning electron microscopy, we present our conclusions regarding clinical outcomes and the role of leukofiltration.

Elevated levels of s-100beta correlate with neurocognitive outcome after cardiac surgery.

AIM: S-100beta is a specific astroglial protein whose serum level increases after cerebral injury. The purpose of this study was to investigate the correlation between elevated levels of S-100beta and the neurocognitive outcome after cardiac surgery. METHODS: Fifty consecutive patients undergoing elective coronary artery bypass grafting were studied. Serum S-100beta levels were measured on induction of anaesthesia, at the 15(th) minute, at skin closure and on the 1(st) postoperative day. Neurocognitive outcome was evaluated by STAI-T and Zung tests preoperatively and by Mini-mental state examination every postoperative day until discharge. Neurocognitive tests and S-100beta levels were correlated within the scope of risk factors by Pearson correlation. RESULTS: Serum S-100beta was not detected preoperatively. Peak serum S-100beta levels were reached at skin closure in 36 of 50 patients (72%). In 24 hours, serum S-100beta disappeared in 25 patients but was still elevated in 11 (22%). A highly significant correlation was demonstrated between the duration of CPB and peak serum S-100beta levels (r=0.91). There was a weak correlation between age and peak S-100beta levels (r=0.62). Nine patients (18%) had a positive MMSE test which correlated well with persistent high serum S-100 levels (r=0.98). CONCLUSIONS: Serum S-100beta is a promising early biochemical marker for cerebral injury following cardiac surgery within a good correlation with the CPB time, age and especially with neurocognitive tests.

An alternative application of sodium nitroprusside to overcome perioperative spasm of the internal thoracic artery.

OBJECTIVE: The internal thoracic artery (ITA) is currently the preferred conduit for myocardial revascularization; however, perioperative vasospasm of the internal thoracic artery may cause morbidity. Pedicle preparation and pharmacological vasodilatory treatment vary greatly. This clinical study was performed in order to define the effectiveness of two different applications of sodium nitroprusside as vasodilating agent. METHODS: Eighty-six (86) consecutive patients whose left internal thoracic artery was mobilized only by one surgeon for elective coronary artery bypass graft operations were randomly divided into two groups. The internal thoracic artery was allowed to bleed freely, and the flow was determined (flow 1). In group I (n=42) 3mg sodium nitroprusside in 10ml of 5% dextrose solution was sprayed with pressure on the pedicle with a thin 25 gauge needle. In group II (n=44) half of the solution was sprayed in the same manner, and the other half of the solution was injected into the pedicle in the periarterial tissue along the length of the pedicle. Free flows of the internal thoracic artery were registered before cardiopulmonary bypass (flow 2) and also just prior to performing internal thoracic artery anastomosis to the left anterior descending artery (flow 3). With each measurement hemodynamic parameters and the time between measurements were recorded. RESULTS: No statistically significant differences were found between the groups in respect to sex ratio, age, body surface area, heart rate 1 and 2, mean arterial pressure 1 and 3. There was no significant difference in the initial flow among groups. Significant differences were noted in the second flow measurement (P<0.05) and in the third flow measurement (P<0.01) between two groups. For each group there was a significant increase in flow from flow 1 to flow 2 and from flow 2 to flow 3 (P<0.02). CONCLUSION: Sodium nitroprusside injection to the pedicle provides a better flow than simple spraying of the same agent.

Evaluation of heparin-coated circuits with full heparin dose strategy.

Heparin-coated cardiopulmonary circuits (HCC) in combination with a reduced systemic heparin dose has been demonstrated to reduce postoperative hemorrhage after cardiac surgery. But, it has still been equivocal whether this effect was related to the improved bio-compatibility or to the reduced exposure of the circulating heparin. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into two groups either to be operated by HCC (30 patients) or uncoated but otherwise identical circuits (NHCC). Full systemic heparinization was induced in both groups. Hemodynamic parameters, hematological and biocompatibility tests were monitored within 24 hours. Postoperative blood loss, requirements for transfusions, clinical performance were recorded. Arterial filters were examined electron microscopically. Platelet levels remained significantly higher in the HCC group starting at the tenth minute following the institution of cardiopulmonary bypass until postoperative 24 hours. Electron microscopy showed significantly more platelet adhesion and pseudopod formation in the NHCC group. The mean amount of shed pleural and mediastinal blood measured from the time of the sternal closure was significantly lower in the HCC group (316 +/- 30 cc for HCC and 550 +/- 35 cc for NHCC). Mean postoperative transfusion requirements were also lower in the HCC group (230 +/- 23 cc for HCC and 320 +/- 25 cc for NHCC). The use of HCC and full systemic heparinization did not change the inflammatory response or biocompatibility but demonstrated benefits in platelet preservation and postoperative bleeding.

Technetium-99m hexamethyl propylenamine oxime lung clearance in the estimation of pulmonary hypertension in congenital heart disease: A preliminary comparative study with cardiac catheterization and pathology.

Thirty-six patients ranging in age from 7 months to 15 years and weighing from 5300 g to 49 kg (24 undergoing corrective surgery and 12 cases with reversed shunt and no operation) underwent technetium 99m hexamethyl propylenamine oxime (Tc-99m HMPAO) lung clearance study and the results were compared with catheterization and pathology. Patients were allocated into three groups with respect to pathological grading (Heath-Edwards' classification) and the results were correlated on the basis of pathology. In group I (grades I and II), Pearson correlation coefficient was 0.86 with pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), and Tc-99m HMPAO lung clearance (t1/2). Pearson correlation coefficients were 0. 863 and 0.88 in the second (grade III) and third group (with reversed shunt and no operation). There were statistically significant differences among the groups with respect to PAP, PVR, or t1/2. The results of radionuclide study (t1/2) were very well correlated within the groups with respect to hemodynamic parameters (PAP and PVR). Tc-99m HMPAO has potential as a highly sensitive indicator for detecting early and minimal microvascular lung injuries, and it may reflect accurate lung clearance and retention enabling an estimation of the state of pulmonary hypertension.

Sequential revascularization of intramuscular left anterior descending coronary artery.

We present a new technique for avoiding possible kinking or angulation of the sequential left internal mammary artery to left anterior descending artery (LIMA-LAD) anastomoses when the LAD follows an intramuscular course. A 3- to 5-mm cusp of saphenous vein segment is interposed between the intramuscular LAD segment and internal mammary artery (IMA) at the sequential anastomotic site, to which the distal portion of the IMA was anastomosed in standard end-to-side fashion.

Eight year experience with the CarboMedics bileaflet valvular prosthesis.

Two hundred and two patients (97 female and 105 male; mean age: 45. 5+/-9 years) received CarboMedics bileaflet valves during a period of eight years. Ninety-one patients received mitral, 72 aortic and 39 aortic+mitral valve prosthesis. Tricuspid plasty and coronary artery bypass surgery were the concomitant operations in 17 and 12 patients, respectively. The mean follow-up period was 24.7 months and the ratio was 91%. Overall operative mortality was 3.96% (8 patients); 2.78% for aortic valve replacement (AVR), 3.29% for mitral valve replacement (MVR) and 7.7% for double valve replacement (DVR). The late mortality rate was 2.89% for AVR, 2.2% for MVR and 8. 3% for DVR. The main cause of mortality was low cardiac output. The overall survival rate was 91.5% in 2 years. The actuarial freedom from thromboembolism in 2 years was 97% for AVR, 95% for MVR and 84% for DVR. No mortality due to heamorrhagic events was observed. CarboMedics prosthetic heart valves may be used satisfactorily with a low incidence of valve-related morbidity and mortality.

Effects of selenium enriched reperfusion solutions on isolated guinea pig hearts.

A comparative study on isolated guinea pig hearts was carried out to determine the role of selenium enriched reperfusion solutions on postischemic reperfusion injury. The hearts of 20 control and 20 study group guinea pigs were mounted on a Langendorff perfusion apparatus and were perfused by gassed Krebs-Henseleit solution at 37 degrees C. The hearts were then arrested by discontinuing the Krebs-Henseleit perfusion. After 20 minutes of normothermic ischemia, in the study group, the hearts were reperfused by selenium enriched Krebs-Henseleit solution (10(-3) mMol/L) and in the control group only Krebs-Henseleit solution was used. Postischemic percentage recovery of mechanical cardiac functions (heart rate and contractile force) and postischemic tissue degeneration indicators. Malondialdehyde (MDA) and Adenosine deaminase (ADA) were compared between the groups. Mean percentage change of heart rate, contractile force and heart work were significantly higher (p < or = 0.0001) and tissue MDA and ADA levels were lower (p < or = 0.001) in the selenium reperfused group. Our results demonstrated that addition of selenium to reperfusion solutions significantly improved cardiac functional recovery and decreased postischemic myocardial injury.

Bland-White-Garland syndrome in an adult. Case report and review of diagnostic and predictive strategies.

In a 27-year-old man with Bland-White-Garland syndrome (anomalous origin of the left coronary artery from the pulmonary artery), comparison was made between conventional diagnostic techniques and radionuclide imaging for selection of surgical procedure and evaluating the outcome. Dynamic 99mTc imaging exactly located the left coronary artery orifice, which was not seen on angiography, thereby determining the surgical approach, and 123I study revealed that, despite absence of symptoms, the adrenergic activity of the heart was globally diminished, with limited response to revascularization.

Psychiatric complications of cardiac surgery postoperative delirium syndrome.

Psychiatric disturbances due to cardiopulmonary bypass, especially postoperative delirium syndrome, are among the immediate complications of open-heart surgery. In a series of 32 male and 18 female patients the prevalence of such disorders was investigated and search was made for possible risk factors for their occurrence. Psychiatric, neurologic and electroencephalographic evaluation was made pre- and postoperatively, in addition to haemodynamic, echocardiographic, angiographic and regional cerebral blood flow studies. Nine of the 50 patients had significantly reduced perfusion of certain cerebral lobes in single photon emission computed tomography, and in six of them the psychiatric tests indicated postoperative delirium; three of these six also had moderate electroencephalographic changes. The cerebral hypoperfusion persisted on day 15 in four patients, while psychiatric tests were negative. The study showed possible risk factors to be patient age, long aortic cross-clamp time, high-dose inotropic support and excessive transfusion of blood or blood products.

Mitral and aortic valve replacement using fresh unstented pulmonary and aortic homografts.

The use of prosthetic valves carries a high incidence of complications including thromboembolism, hemolysis, infection, impaired hemodynamic function and mechanical failure. Unstented homograft valves provide a good quality of life, particularly in terms of a reasonable freedom from these complications. This paper presents the first simultaneous replacement of the mitral and aortic valves using fresh unstented pulmonary and aortic homografts collected from the same donor. We believe that this technique will be especially useful in developing countries facing financial difficulties and problems with patient education.

The effect of propofol on systemic vascular resistance during cardiopulmonary bypass: a comparative study with thiopentone.

30 patients undergoing elective coronary artery bypass grafting surgery were allocated randomly to receive either propofol--2.5mg/kg--(N = 10, Group I) or thiopentone--4mg/kg--(N = 10, Group II) during cardiopulmonary bypass with constant pump flow and temperature. Two groups and another control group-receiving no medication-(N = 10, Group III) were compared with respect to the changes in hemodynamic parameters, especially systemic vascular resistance (SVR). After propofol, SVR decreased from 2489 +/- 302 to 1594 +/- 286 dyn sec cm-5 and remained significantly less than the control values until 16.6 +/- 4 min. after the administration of propofol. Following thiopentone administration, SVR decreased from 2653 +/- 298 to 2162 +/- 279 dyn sec cm-5 and remained so for the following 9.4 +/- 3 min. There were more significant decreases in especially cardiac index, perfusion pressure and SVR in the propofol group compared with thiopentone or control groups. Cardiopulmonary bypass has been shown to be a useful model for studying the isolated effects of anesthetic drugs on hemodynamic parameters. In our study, we tried to discuss the mechanism of the hypotensive effects of anesthetic agents, especially propofol and give an idea about the possible precautions that should be taken.