Lee Errett

Use of "BioGlue" in aortic surgical repair.

A new bioadhesive (BioGlue, Cryolife Inc, Kennesaw, GA) was recently introduced for surgical use in thoracic aortic surgical repair. We describe our early experience and our suggested method of repair.

A Comparison of Patient-controlled Sedation Using Either Remifentanil or Remifentanil-propofol for Shock Wave Lithotripsy

Patient-controlled sedation (PCS) has been used for extracorporeal shock wave lithotripsy (SWL) because it allows for rapid individualized titration of anesthetics. Because of its sedating effects, the addition of propofol to remifentanil may improve patient tolerance of SWL with PCS. One hundred twenty patients were randomly assigned to receive remifentanil 10 &mgr;g or remifentanil 10 &mgr;g plus propofol 5 mg for PCS with zero-lockout interval. Nine patients in the Remifentanil group and three patients in the Remifentanil-Propofol group required additional sedatives to complete their SWL (P = 0.128). Compared with the Remifentanil group, the Remifentanil-Propofol group required less remifentanil, had a decreased incidence of postoperative nausea and vomiting, and had a better overall satisfaction level. However, they had an increased incidence of transient apnea and oxygen desaturation. The incidence of apnea was 15% in the Remifentanil group and 52% in the Remifentanil-Propofol group (P < 0.001). All patients were able to move themselves to the stretcher at the end of SWL, and median time to home discharge was <70 min in both groups. Both remifentanil and remifentanil-propofol were useful for PCS during SWL.

Should Radial Arteries Be Used Routinely for Coronary Artery Bypass Grafting

Case Presentation : Mr P is a 57-year-old construction worker who has had Canadian Cardiovascular Society class III angina for the past 3 months. He has multiple cardiovascular risk factors including smoking, hypertension, dyslipidemia, and diabetes. He is obese and has had a previous laparotomy for a perforated bowel. Coronary angiography revealed triple vessel disease involving the left anterior descending artery (LAD), the first obtuse marginal branch, and the right coronary artery (RCA), and an akinetic inferior wall with an estimated ejection fraction of 40%. The patient was referred for consideration of coronary artery bypass graft (CABG) surgery. Is Mr P a candidate for CABG and, if so, which vascular conduits should be used? CABG is the standard surgical procedure for the treatment of advanced coronary artery disease. Since the first successful results reported by Favaloro,1 CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life.2 Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Five to 7 years after surgery, patients are at increased risk of suffering from ischemic complications coincident with graft failure.2 Furthermore, as patients undergoing CABG surgery become older with more preoperative risk factors, and treated patients are living longer and therefore requiring reoperation, the optimal selection of vascular grafts for bypass is essential. Conventional CABG surgery utilizes a combination of arterial and venous grafts. Saphenous vein (SV) grafts, the first vascular conduits used in CABG, are still widely utilized, primarily to bypass vessels other than the LAD. Despite being readily accessible, of adequate length to access every vessel on the heart, and the correct diameter to facilitate coronary and aortic anastomoses, SV grafts are limited by poor long-term patency. Because of a combination …

Can local application of Tranexamic acid reduce post-coronary bypass surgery blood loss? A randomized controlled trial

BackgroundDiffuse microvascular bleeding remains a common problem after cardiac procedures.Systemic use of antifibrinolytic reduces the postoperative blood loss.The purpose of this study was to examine the effectiveness of local application of tranexamic acid to reduce blood loss after coronary artery bypass grafting (CABG).MethodsThirty eight patients scheduled for primary isolated coronary artery bypass grafting were included in this double blind, prospective, randomized, placebo controlled study.Tranexamic acid (TA) group (19 patients) received 1 gram of TA diluted in 100 ml normal saline. Placebo group (19 patients) received 100 ml of normal saline only. The solution was purred in the pericardial and mediastinal cavities.ResultsBoth groups were comparable in their baseline demographic and surgical characteristics. During the first 24 hours post-operatively, cumulative blood loss was significantly less in TA group (median of 626 ml) compared to Placebo group (median of 1040 ml) (P = 0.04). There was no significant difference in the post-op Packed RBCs transfusion between both groups (median of one unit in each) (P = 0.82). Significant less platelets transfusion required in TA group (median zero unit) than in placebo group (median 2 units) (P = 0.03). Apart from re-exploration for excessive surgical bleeding in one patient in TA group, no difference was found in morbidity or mortality between both groups.ConclusionTopical application of tranexamic acid in patients undergoing primary coronary artery bypass grafting led to a significant reduction in postoperative blood loss without adding extra risk to the patient.

Off-Pump Coronary Artery Bypass Surgery Fundamentals for the Clinical Cardiologist

Case Report: Mrs. G is a 65-year-old retired banker who has had Canadian Cardiovascular Society class III angina for the past 2 months and symptomatic intermittent claudication for the past year. Her past medical history is unremarkable except for the presence of multiple vascular risk factors (smoking, hypertension, dyslipidemia, and diabetes). Coronary angiography revealed triple vessel disease involving the left anterior descending, second obtuse marginal, and right coronary arteries, as well as the akinetic anterior and inferior walls, with an estimated ejection fraction of 30%. Carotid duplex revealed 40% stenosis of the right internal carotid artery and 60% stenosis of the left internal carotid artery. A chest x-ray showed a possible calcified ascending aorta. The patient was referred for consideration of coronary artery bypass graft (CABG) surgery. Is Mrs. G a candidate for off-pump CABG? What are the indications, precautions, and considerations that facilitate decision-making about off-pump CABG surgery? Conventional CABG surgery uses cardiopulmonary bypass (CPB) to allow cardiac surgeons to operate on a motionless heart that has been arrested by means of cardioplegia. CABG with CPB (on-pump CABG) quickly became the gold standard surgical procedure for myocardial revascularization, as it allowed surgeons to bypass multiple coronary arteries with greater control and precision. However, recently there has been increasing interest in the development and use of technologies that allow surgeons to perform CABG surgery without CPB (known as off-pump CABG or OPCAB). CPB is not a benign intervention. It is associated with a number of adverse consequences that are primarily related to a systemic inflammatory response elicited by the activation of cellular and humoral mediators as circulating blood comes into contact with the extracorporeal circuit of the CPB machine. The biochemical, cellular, and molecular aspects of this pump-induced inflammatory response are believed to contribute to postoperative myocardial, renal, and neurological …

Complete mapping of the tricuspid valve apparatus using three-dimensional sonomicrometry

OBJECTIVE Many surgeons consider the tricuspid valve to be a second-class structure. Our objective was to determine the normal anatomy and dynamic characteristics of the tricuspid valve apparatus in vivo and to discern whether this would aid the design of a tricuspid valve annuloplasty ring model. METHODS Sixteen sonomicrometry crystals were placed around the tricuspid annulus, at the bases and tips of the papillary muscles, the free edges of the leaflets, and the right ventricular apex during cardiopulmonary bypass in 5 anesthetized York Hampshire pigs. Animals were studied after weaning of cardiopulmonary bypass on 10 cardiac cycles of normal hemodynamics. RESULTS Sonomicrometry array localizations demonstrate the multiplanar shape of the tricuspid annulus. The tricuspid annulus reaches its maximum area (97.9 ± 25.4 mm(2)) at the end of diastole and its minimum area (77.3 ± 22.5 mm(2)) at the end of systole, and increases again in early diastole. Papillary muscles shorten by 0.8 to 1.5 mm (11.2%) in systole, and chordae tendineae straighten by 0.8 to 1.7 mm (11.4%) in systole. CONCLUSIONS The shape of the tricuspid annulus is a multiplanar 3-dimensional one with its highest point at the anteroseptal commissure and its lowest point at the posteroseptal commissure, and the anteroposterior commissure is in a middle plane in between. The tricuspid annulus area reaches its maximum during diastole and its minimum during systole. The papillary muscles contract by the same amount of chordal straightening. The optimal tricuspid annuloplasty ring may be a multiplanar 3-dimensional one that mimics the normal tricuspid annulus.

Sternal plating for primary and secondary sternal closure; can it improve sternal stability?

BackgroundSternal instability with mediastinitis is a very serious complication after median sternotomy. Biomechanical studies have suggested superiority of rigid plate fixation over wire cerclage for sternal fixation. This study tests the hypothesis that sternal closure stability can be improved by adding plate fixation in a human cadaver model.MethodsMidline sternotomy was performed in 18 human cadavers. Four sternal closure techniques were tested: (1) approximation with six interrupted steel wires; (2) approximation with six interrupted cables; (3) closure 1 (wires) or 2 (cables) reinforced with a transverse sternal plate at the sixth rib; (4) Closure using 4 sternal plates alone. Intrathoracic pressure was increased in all techniques while sternal separation was measured by three pairs of sonomicrometry crystals fixed at the upper, middle and lower parts of the sternum until 2.0 mm separation was detected. Differences in displacement pressures were analyzed using repeated measures ANOVA and Regression Coefficients.ResultsIntrathoracic pressure required to cause 2.0 mm separation increased significantly from 183.3 ± 123.9 to 301.4 ± 204.5 in wires/cables alone vs. wires/cables plus one plate respectively, and to 355.0 ± 210.4 in the 4 plates group (p < 0.05). Regression Coefficients (95% CI) were 120 (47–194) and 142 (66–219) respectively for the plate groups.ConclusionTransverse sternal plating with 1 or 4 plates significantly improves sternal stability closure in human cadaver model. Adding a single sternal plate to primary closure improves the strength of sternal closure with traditional wiring potentially reducing the risk of sternal dehiscence and could be considered in high risk patients.

Sternal plate fixation for sternal wound reconstruction: initial experience (Retrospective study)

BackgroundMedian sternotomy infection and bony nonunion are two commonly described complications which occur in 0.4 - 5.1% of cardiac procedures. Although relatively infrequent, these complications can lead to significant morbidity and mortality. The aim of this retrospective study is to evaluate the initial experience of a transverse plate fixation system following wound complications associated with sternal dehiscence with or without infection following cardiac surgery.MethodsA retrospective chart review of 40 consecutive patients who required sternal wound reconstruction post sternotomy was performed. Soft tissue debridement with removal of all compromised tissue was performed. Sternal debridement was carried using ronguers to healthy bleeding bone. All patients underwent sternal fixation using three rib plates combined with a single manubrial plate (Titanium Sternal Fixation System®, Synthes). Incisions were closed in a layered fashion with the pectoral muscles being advanced to the midline. Data were expressed as mean ± SD, Median (range) or number (%). Statistical analyses were made by using Excel 2003 for Windows (Microsoft, Redmond, WA, USA).ResultsThere were 40 consecutive patients, 31 males and 9 females. Twenty two patients (55%) were diagnosed with sternal dehiscence alone and 18 patients (45%) with associated wound discharge. Thirty eight patients went on to heal their wounds. Two patients developed recurrent wound infection and required VAC therapy. Both were immunocompromised. Median post-op ICU stay was one day with the median hospital stay of 18 days after plating.ConclusionSternal plating appears to be an effective option for the treatment of sternal wound dehiscence associated with sternal instability. Long-term follow-up and further larger studies are needed to address the indications, benefits and complications of sternal plating.

Effect of aortic cannula characteristics and blood velocity on transcranial doppler-detected microemboli during cardiopulmonary bypass

OBJECTIVES Cerebral microemboli are responsible to a large extent for the neuropsychiatric deficits after cardiac surgery. Differences in cannula size during cardiopulmonary bypass (CPB) will result in different velocities of blood exiting the aortic cannula. This study determined whether the number of transcranial Doppler (TCD)-detected emboli in the middle cerebral artery (MCA) during CPB correlated with blood speed or the direction of flow as determined by the shape of the aortic cannula. DESIGN Patients were studied prospectively for evidence of TCD-detected emboli. If patients met the inclusion criteria, the choice of cannula was determined by surgical preference. SETTING All studies were conducted at a single tertiary care academic cardiac surgery hospital by a single observer. PARTICIPANTS Thirty-two patients undergoing first-time elective aortocoronary bypass surgery who were free of neurologic dysfunction or peripheral vascular disease and weighed 60 to 85 kg were studied. Patients who had other concurrent cardiac operations or who were in cardiogenic shock were excluded. INTERVENTIONS Three aortic cannula types for elective aortocoronary bypass surgery were used: 24F curved (n = 19), 24F straight (n = 6), and 22F straight (n = 7), with internal diameters (IDs) of 7.2, 6.6, and 5.9 mm, respectively. TCD-detected emboli were identified in the MCA. MEASUREMENTS AND MAIN RESULTS The rate of TCD-detected emboli (0.02 to 11.4 emboli per minute) was not related to the velocity of blood (46 to 77 cm/s) and was not affected by the choice of either a straight or curved aortic cannula. CONCLUSIONS The choice of a straight or curved aortic cannula or of a 24F versus 22F cannula may not be important with respect to the number of cerebral microemboli.

Preoperative Carbohydrate Loading in Patients Undergoing Coronary Artery Bypass or Spinal Surgery

BACKGROUND: Surgical stress creates a state of insulin resistance which may contribute to the development of hyperglycemia and, subsequently, postoperative complications. Consumption of an oral carbohydrate supplement before surgery may improve insulin sensitivity and reduce hyperglycemia. In this trial, we investigated the effects of carbohydrate supplementation on insulin resistance in coronary artery bypass graft and spinal decompression and fusion surgical patients. METHODS: Twenty-six patients undergoing coronary artery bypass graft and 12 undergoing spine surgery were randomized to receive 800 mL of an oral carbohydrate supplement the evening before and 400 mL 2 hours before surgery (CHO) or to fasting per standard hospital protocol (FAST). Baseline and postoperative measurements of insulin sensitivity were assessed using the short insulin tolerance test and homeostasis model assessment (HOMA). Interleukin-6, C-reactive protein, and free fatty acid levels were determined at baseline, postoperatively, and 24, 48, and 72 hours after surgery. Adiponectin was measured at baseline. Subjective feelings of well-being were measured immediately before surgery, and intra- and postoperative outcomes were documented. RESULTS: Postoperative insulin sensitivity did not differ significantly between the FAST and CHO groups whether measured by the short insulin tolerance test (rate of disappearance of blood glucose: 0.29%/min vs 0.38%/min; 99% confidence interval [CI] for difference, −0.17 to 0.32, P = 0.41) or HOMA (insulin resistance at values >1: 2.3 vs 3.3; 99% CI for difference, −0.8 to 2.8, P = 0.14). Circulating blood glucose levels after surgery in the CHO group, 6.2 mmol/L, tended to be lower than the FAST group, 6.9 mmol/L (99% CI for difference, −1.7 to 0.25, P = 0.05) and postoperative &bgr;-cell function, measured by HOMA-&bgr; (impaired &bgr;-cell function at values <100%), tended to be higher in the CHO group, 87%, vs 47.5% in the FAST group (99% CI for difference, −9.4 to 88.4), but these differences were not significant. Adiponectin levels were not different between groups at baseline, and levels of free fatty acid, interleukin-6 and C-reactive protein were not affected by treatment. CONCLUSIONS: Preoperative carbohydrate loading did not improve postoperative insulin sensitivity. However, the observed postoperative blood glucose levels and &bgr;-cell function as well as secondary outcomes warrant further study to reevaluate traditional fasting practices in surgical patients.