Turki B. Albacker

High-Dose Insulin Therapy Attenuates Systemic Inflammatory Response in Coronary Artery Bypass Grafting Patients

BACKGROUND Cardiac surgery with cardiopulmonary bypass (CPB) induces an acute phase reaction that is implicated in the pathogenesis of several postoperative complications. Studies have shown that proinflammatory cytokines are increased by acute hyperglycemia. Recent evidence suggests that insulin has antiinflammatory properties. Therefore, we hypothesized that high-dose insulin therapy would attenuate the systemic inflammatory response to cardiopulmonary bypass and surgery in coronary artery bypass patients while maintaining normoglycemia. METHODS A total of 52 patients who presented for elective coronary artery bypass were randomized to receive intraoperative intravenous insulin infusion, titrated to maintain blood glucose concentrations less than 180 mg/dL (group I, n = 25), or receive intraoperative fixed high dose of intravenous insulin infusion (5 mU/kg/min) with dextrose 20% infused separately to maintain a blood glucose level between 70 and 110 mg/dL (group II, n = 27). Blood samples were collected at different time points to determine tumor necrosis factor alpha (TNFalpha), interleukin 6 and 8 (IL6 and IL8), and complement factor 3 and 4 (C3 and C4). RESULTS Patients in both groups had similar preoperative characteristics. Patients in the high-dose insulin group had higher blood insulin concentrations and tighter blood glucose control. There were lower levels of IL6 (150 pg/dL vs 245 pg/dL, p = 0.03), IL-8 (49 pg/dL vs 74 pg/dL, p = 0.05), and TNFalpha (2.2 pg/dL vs 3.0 pg/dL, p = 0.04) in group II in the early postoperative period. CONCLUSIONS High-dose insulin therapy blunts the early postoperative surge in inflammatory response to CPB as reflected by decreased levels of IL6, IL8, and TNFalpha.

Cardioprotective Effects of Glucose and Insulin Administration While Maintaining Normoglycemia (GIN Therapy) in Patients Undergoing Coronary Artery Bypass Grafting

CONTEXT Coronary artery bypass grafting (CABG) is complicated by ischemia-reperfusion injury jeopardizing myocyte survival. OBJECTIVE The aim of the study was to investigate whether glucose and insulin administration, while maintaining normoglycemia (GIN therapy) using a hyperinsulinemic-normoglycemic clamp technique, is cardioprotective in patients undergoing CABG. DESIGN AND SETTING We conducted a randomized controlled trial at a tertiary care university teaching hospital. PATIENTS We studied 99 patients undergoing elective CABG. INTERVENTION Patients were randomly assigned to receive either GIN from the beginning of surgery until 24 h after CABG (GIN, n = 49) or standard metabolic care (control, n = 50). MAIN OUTCOME MEASURES We measured plasma concentrations of cardiac troponin I and free fatty acids, cardiac function as assessed by transesophageal echocardiography, glycogen content, glycogen synthase activity, and the expression of AMP-activated protein kinase (AMPK) and protein kinase B (AKT) in cardiomyocytes. RESULTS Patients receiving GIN therapy showed an attenuated release of cardiac troponin I (P < 0.05) and improved myocardial function (P < 0.05). Systemic free fatty acid concentrations were suppressed (P < 0.05), whereas intracellular glycogen content and glycogen synthase activity were not altered. The AMPK activity remained unchanged during ischemia in the GIN group, whereas it increased in the control group (P < 0.05). Enhanced AKT phosphorylation before ischemia was observed (P < 0.05) in the presence of GIN. However, there was no evidence for AKT-dependent AMPK inhibition. CONCLUSIONS GIN therapy protects the myocardium and inhibits ischemia-induced AMPK activation.

The effect of using microplegia on perioperative morbidity and mortality in elderly patients undergoing cardiac surgery

Old age is a significant risk factor for perioperative morbidity and mortality following cardiac surgery and optimal myocardial protection strategy should be sought in this group of patients. We, therefore, reviewed the data on 295 consecutive patients older than 75 years who underwent any cardiac surgical procedure. Microplegia was used in 144 patients compared to 151 patients who had the standard 4:1 blood cardioplegia. Logistic regression analysis was used for propensity matching to balance the differences between the two groups. The microplegia group included more females and sicker patients as indicated by higher Parsonnet scores. There were differences in the pump time, aortic cross-clamp time, procedure type and surgeons between the two groups. These differences were balanced using the propensity matching. In-hospital mortality, acute renal injury and confusion were higher in the microplegia group (17%, 34%, 35%, respectively) compared to the standard 4:1 cardioplegia group (9%, 23%, 24%, respectively) (P=0.04, 0.04, 0.04, respectively). These differences were not statistically significant after propensity matching. These results demonstrate that the use of microplegia is safe in patients older than 75 years who are undergoing cardiac surgery and results in similar in-hospital morbidity and mortality to the standard 4:1 blood cardioplegia.

Transapical Endovascular Ascending Repair for Inoperable Acute Type A Dissection

Acute aortic dissection remains a surgical emergency. The conventional approach involves graft replacement of the ascending aorta under circulatory arrest with variable extension into the root or arch depending on morphology at presentation. A significant proportion of patients are deemed too high-

Hybrid Thoracoabdominal Aneurysm Repair With Antegrade Visceral Debranching From the Ascending Aorta: Concomitant Cardiac Surgery and Stent-Grafting

Patients with thoracoabdominal aneurysm that require concomitant cardiac surgery present a complex surgical challenge. A staged hybrid technique including combined cardiac surgery and visceral revascularization from the ascending aorta, followed by endovascular aneurysmal exclusion is reported in four patients. No perioperative death and no neurological complications were observed. The surgical technique is described.

Successful Management of a Posterior Saccular Coronary Artery Aneurysm at the Left Main Coronary Artery Bifurcation

Abstract  Left main coronary artery aneurysm is a rare condition that presents as a potential surgical challenge due to its location. We present a case of successful repair of a posterior saccular aneurysm of the left main coronary artery by aneurysm exclusion, afferent and efferent ligation with coronary artery bypass grafting. (J Card Surg 2011;26:37‐39)

Assessment of Image Quality of Repeated Limited Transthoracic Echocardiography After Cardiac Surgery

OBJECTIVES The use of limited transthoracic echocardiography (TTE) has been restricted in patients after cardiac surgery due to reported poor image quality. The authors hypothesized that the hemodynamic state could be evaluated in a high proportion of patients at repeated intervals after cardiac surgery. DESIGN Prospective observational study. SETTING Tertiary university hospital. PARTICIPANTS The study comprised 51 patients aged 18 years or older presenting for cardiac surgery. INTERVENTIONS Patients underwent TTE before surgery and at 3 time points after cardiac surgery. Images were assessed offline using an image quality scoring system by 2 expert observers. Hemodynamic state was assessed using the iHeartScan protocol, and the primary endpoint was the proportion of limited TTE studies in which the hemodynamic state was interpretable at each of the 3 postoperative time points. MEASUREMENTS AND MAIN RESULTS Hemodynamic state interpretability varied over time and was highest before surgery (90%) and lowest on the first postoperative day (49%) (p<0.01). This variation in interpretability over time was reflected in all 3 transthoracic windows, ranging from 43% to 80% before surgery and from 2% to 35% on the first postoperative day (p<0.01). Image quality scores were highest with the apical window, ranging from 53% to 77% across time points, and lowest with the subcostal window, ranging from 4% to 70% across time points (p< 0.01). CONCLUSIONS Hemodynamic state can be determined with TTE in a high proportion of cardiac surgery patients after extubation and removal of surgical drains.

Total arch replacement after a failed repair for Takayasu's ascending aortitis.

The constellation of Takayasus disease most commonly includes aortitis with resultant coarctations and aneurysm formation. Surgical repair of these lesions can be compromised by the chronic inflammation of Takayasus arteritis. We present a case of a 22-year-old female with Takayasus disease who had undergone an ascending and aortic hemiarch replacement then subsequently developed anastomotic dehiscence and re-expansion of the previous aneurysmal sac. Complete aneurysm resection and replacement of the ascending aorta and aortic arch was performed on repeated surgery.

Bartonella Infective Endocarditis of a Prosthetic Aortic Valve with a Subvalvular Abscess

Abstract  A patient with a prosthetic aortic valve, and culture negative endocarditis caused by Bartonella henselae presented with nonspecific constitutional symptoms, skin rash, and then later developed acute renal failure. The patient underwent redo sternotomy, aortic root, and ascending aorta replacement with a homograft, which resolved his symptoms and the renal failure. (J Card Surg 2011;26:483‐485)

Traumatic dehiscence of Medtronic Freestyle stentless bioprosthesis.

We report a case of deceleration injury causing traumatic dehiscence of a Medtronic Freestyle aortic bioprosthesis (Medtronic Inc, Minneapolis, MN) in a 70-year-old patient 5 years after a total root reconstruction. The patient presented with progressive exertional dyspnea 6 months after a significant impact during a hockey game. Intraoperatively, there was a posterior dehiscence of the proximal suture line and almost complete tear of the left coronary leaflet. At reoperation, the patient underwent reconstruction of the aortic root and Bentall procedure with a size 23 mechanical aortic valved conduit.