Use of an aortic connector system for vein grafting

OBJECTIVE: The aortic connector system was used to minimize cerebrovascular complications when performing the proximal anastomosis of vein grafts during coronary artery bypass grafting (CABG). The goal of this study was to investigate the intermediate outcomes of patients undergoing CABG with the aortic connector system. METHODS: The aortic connector was used on nine patients undergoing CABG between November 2002 and July 2003. Intermediate outcomes of the patients were examined, and the results of coronary angiography, which were performed before patient discharge and at least 6 months after discharge, were evaluated. RESULTS: There were no operative deaths or cerebrovascular accidents. One patient died 9 months after discharge, one patient had angina, and the remaining seven patients were asymptomatic. When evaluating the results of angiography performed before patient discharge, two of the 21 distal vein graft anastomoses were occluded (patency rate, 90.5%), but there was no stenosis or occlusion at the proximal anastomoses sites that were performed using the aortic connector. When evaluating the results of the second angiography performed after patient discharge, four of the eight proximal anastomoses were patent, one was completely occluded, two had 90% stenosis and one had 75% stenosis. Further, four of the 18 distal anastomoses were occluded (patency rate, 77.8%). There was no significant difference in graft flow or device size when comparing patients with patent vein grafts and those with stenotic or occluded vein grafts. CONCLUSION: Intermediate outcomes of vein grafting using the aortic connector were suboptimal. Long-term outcome data are forthcoming.     

Changes in bone turnover markers during 14-day 6° head-down bed rest

Osteoporosis caused by exposure to microgravity represents a serious clinical concern, but the mechanisms have yet to be fully elucidated. The present research aimed to elucidate the effects of microgravity environments on bone turnover, with a specific focus on changes in bone resorption markers such as type I collagen cross-linked N-telopeptides (NTx) and deoxypyridinoline (Dpyr), for which scant data are available regarding detailed time course. Methods using 6° head-down bed rest were utilized to simulate a microgravity environment. Eleven adult male volunteers underwent 6° head-down bed rest for 14 days; measurements were made of serum and urine Ca concentrations, in addition to osteocalcin (OC), bone alkaline phosphatase (ALP), NTx, and Dpyr as bone turnover markers. By the end of bed rest, concentrations of bone ALP had significantly increased, but OC displayed a tendency toward decrease. Concentrations of Dpyr significantly increased from day 6, remaining elevated until the end of bed rest. Concentrations of NTx significantly increased on day 13 and at the end of bed rest. Serum and urinary concentrations of Ca increased significantly at the end of bed rest. Bone ALP represents a relatively early marker of osteoblast differentiation at the matrix maturation phase and OC is a late marker in osteoblast differentiation at the calcification phase. The present results therefore suggest an absolute increase in bone resorption and normal or reduced bone formation, together causing prominent uncoupling and rapid bone loss after simulated microgravity. Moreover, the present results suggest that bone resorption is enhanced at an early stage of exposure to microgravity environments.     

One and a half ventricle repair for Ebstein’s anomaly

The surgical strategy for patients having Ebstein’s anomaly and hypoplastic right ventricle is controversial. An 11-year-old boy patient having such condition, with estimated end-diastolic volume index of the atrialized and functional right ventricle being 70% of normally expected values, underwent biventricular repair. Immediately after the surgery, however, he developed right heart failure with the central venous pressure of 11 mmHg. He consequently underwent additional bidirectional cavopulmonary anastomosis, thereby converting the biventricular repair into one and a half ventricle repair. He recovered uneventfully and is doing well 2 years after the surgery.     

Effect of body fat percentage on estimated propofol concentrations at awakening from anesthesia using target controlled infusion

BACKGROUND: Target controlled infusion (TCI) for propofol allows anesthesiologists to target constant blood concentrations of propofol. However, the pharmacokinetic parameters in TCI system do not take account of the patient's age, make up and gender. We evaluated the relationship between body fat percentage and the estimated effect site propofol concentrations at awakening. METHODS: Anesthesia was induced in 37 patients with fentanyl and propofol by TCI. Patients's percentage of fat was evaluated by measuring the thickness of the three parts of the skin fat with Skyndex (Caldwell Justiss, USA). After surgery and discontinuation of anesthesia, the estimated effect site propofol concentrations (EPEC) were determined when the patient could respond to verbal command. RESULTS: The EPECs at awakening were 1.5 +/- 0.2 micrograms.ml-1 in male and 1.5 +/- 0.3 micrograms.ml-1 in female. In male, the percentage of fat and body mass index (BMI) correlated significantly with EPEC (r = 0.79 and 0.49 respectively). In female, the percentage of fat and BMI did not correlate with EPEC. The estimated fentanyl effect site concentrations at awakening did not correlate with the EPEC. CONCLUSIONS: Male patients who have high percentage of fat have a tendency to delayed of awakening from propofol anesthesia. In female, however, no correlation was seen between percentage of fat and awakening time from propofol anesthesia. Measuring the percentage of fat might bring a new insight into pharmacokinetics of propofol.     

Combination of Obesity with Hyperglycemia is a Risk Factor for the Presence of Vertebral Fractures in Type 2 Diabetic Men

Although patients with type 2 diabetes show no bone mineral density (BMD) reduction, fracture risks are known to increase. It is unclear why the patients have an increased risk of fracture despite sufficient BMD. We investigated the relationships of body mass index (BMI), HbA_1c, and urinary C-peptide (uC-peptide) versus BMD, bone metabolic markers, serum adiponectin, and prevalent vertebral fracture (VF). A total of 163 Japanese type 2 diabetic men were consecutively recruited, and radiographic and biochemical data were collected. BMI was positively correlated with BMD at the whole body, lumbar spine, and femoral neck (P < 0.05) and negatively correlated with osteocalcin and urinary N-terminal cross-linked telopeptide of type-I collagen (uNTX) (P < 0.01). HbA_1c was negatively correlated with osteocalcin (P < 0.01) but not BMD at any site. Subjects were classified into four groups based on BMI and HbA_1c (group LL BMI < 24 and HbA_1c < 9, group LH BMI < 24 and HbA_1c ≧ 9, group HL BMI ≧ 24 and HbA_1c < 9, group HH BMI ≧ 24 and HbA_1c ≧ 9). Serum adiponectin, osteocalcin, and uNTX were lower and the incidence of VF was higher despite sufficient BMD in the HH group. Multivariate logistic regression analysis adjusted for age, duration of diabetes, uC-peptide, and estimated glomerular filtration rate showed that the HH group was associated with the presence of a VF and multiple VFs (odds ratio [OR] = 3.056, 95% confidence interval [CI] 1.031–9.056, P = 0.0439, and OR = 5.415, 95% CI 1.126–26.040, P = 0.0350, respectively). Combination of obesity with hyperglycemia was a risk factor for VF despite sufficient BMD in diabetic men.     

Determination of in vivo glenohumeral translation using fluoroscopy and shape-matching techniques

The purpose of this study was to investigate glenohumeral translation in-vivo during active shoulder abduction in the scapular plane. Three-dimensional (3D) models of 9 shoulders were created from CT scans. Fluoroscopic views aligned to the plane of the scapula were recorded during active arm abduction with neutral rotation. 3D motions were determined using model-based 3D-to-two-dimensional (2D) registration. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 1.7 mm superior with arm abduction, from an inferior location to the glenoid center. The humeral head was centered within 1 mm from the glenoid center above 80 degrees abduction. Variability in glenohumeral translation between shoulders decreased significantly from initial to final arm abduction. Our findings agree with some authors' observations of inferior-to-central translation of the humerus and behavior as a congruent ball and socket. We believe this information will help improve the understanding of shoulder function.     

Near-infrared spectroscopy for noninvasive evaluation of chest wall ischemia immediately after left internal thoracic artery harvesting

OBJECTIVE: The conclusions remain controversial about whether the sternal blood flow is preserved or diminished after internal thoracic artery (ITA) harvesting for coronary artery bypass grafting (CABG), especially in diabetic patients. We investigated the blood supply of the chest wall noninvasively using near-infrared spectroscopy (NIRS) immediately after CABG. METHODS: The study group comprised 30 patients who underwent CABG using a skeletonized left ITA through median sternotomy. As a control group, three nondiabetic patients undergoing valve surgery through median sternotomy were also included. On arrival of the patient in the intensive care unit immediately after surgery, two reflectance sensors were placed on the bilateral parasternal regions at the fourth intercostal space to record regional oxygen saturation (rSO(2)) and hemoglobin index (HbI) continuously approximately for 17 h. RESULTS: The differences in right and left values (R-L rSO(2) and R-L HbI) were significantly greater in the diabetic patients than in the nondiabetic patients (3.74% +/- 2.47% vs. 1.98% +/- 1.67 %, p = 0.036; and 0.28 +/- 0.19 vs. 0.13 +/- 0.13, p = 0.020). The R-L HbI was significantly greater in the on-pump patients than in the off-pump patients, although there was no significant difference in R-L rSO(2). Both R-L rSO(2) and R-L HbI were similar among the control, nondiabetic, and off-pump patients. CONCLUSION: The technique of NIRS enables noninvasive, continuous monitoring of chest wall perfusion immediately after ITA harvesting. Our study using NIRS showed a decrease in blood flow and oxygen metabolism of the hemisternum after LITA harvest in diabetic CABG patients.     

Comparison of the effects of aortic valve replacement using 19-mm Carpentier-Edwards Perimount bioprosthesis and 19-mm Medtronic Mosaic bioprosthesis.

OBJECTIVE: Short (< or =3 months)- and middle (> or =4 months)-term results of aortic valve replacement (AVR) using 19-mm Carpentier-Edwards Perimount (CEP) bioprosthetic valves and 19-mm Medtronic Mosaic (MM) bioprosthetic valves in patients with small aortic annulus were compared. PATIENTS AND METHODS: At our facility, AVR was performed using bioprostheses in 110 patients from April 1999 to March 2006. Of these patients, 40 were treated using 19-mm CEP (Group C), and 9 using 19-mm MM (Group M). Evaluation by inquiry, physical examination, and echocardiography was performed before, a short term after, and a middle term after surgery, and the effects of AVR were compared. RESULTS: The New York Heart Association (NYHA) functional class grade showed improvements in both groups. The aortic valve peak pressure gradient was 29.8 +/- 10.1 mmHg in Group C and 53.8 +/- 17.3 mmHg in Group M, being higher in Group M, a middle term after surgery. However, the left ventricular mass index (LVMI) showed improvements in both groups compared with the values before surgery, and the left ventricular ejection fraction (LVEF) was maintained. During the middle term after surgery, the frequency of cardiac events showed no significant difference between the two groups. CONCLUSIONS: In the patients treated with 19-mm MM, the aortic valve peak pressure gradient was higher than in those treated with 19-mm CEP, but acceptable improvements in the LVMI, maintenance of the LVEF, and avoidance of cardiac events were observed in both groups.     

Oral styletted intubation under video control in a patient with a large mobile glottic tumour and a difficult airway

PURPOSE: With fibreoptic intubation, advancement of the endotracheal tube (ETT) through the glottis is blind. Thus, in patients with a laryngeal tumour, there is a potential for damage to the tumour. Previously, we proposed the use of a fibreoptic bronchoscope (FOB)-video camera system to permit visualization of tube passage. We used this technique successfully in a patient with a known difficult airway and a large glottic tumour. CLINICAL FEATURES: A 61-yr-old man with a known history of difficult laryngoscopic intubation underwent laryngeal microsurgery for recurrence of a glottic tumour. As preoperative indirect laryngoscopy revealed a large, mobile, and pedunculated glottic lesion obstructing the glottic opening, we planned a conventional awake fibreoptic intubation. Endoscopy showed that the tumour partially obstructed the glottis and the space between the tumour and the glottic opening was very narrow. To avoid damage to the tumour, we changed to an alternative fibreoptic intubation technique. The FOB attached to a video camera was passed nasally and a jaw thrust manoeuver was applied, providing an excellent view of the larynx. An anesthesiologist inserted the ETT with a curved stylet orally, and carefully advanced the tube tip into the space between the tumour and the glottic opening under video control. Absence of damage to the tumour and passage of the tube between the cords were confirmed visually. CONCLUSION: This alternative intubation technique, providing a view of the tube passage into the glottis, was a reasonable method to avoid potential damage to the glottic tumour by blind tube passage during conventional fibreoptic intubation.     

Complicated anesthetic management for esophageal atresia repair in a baby with total anomalous pulmonary venous connection diagnosed after esophageal surgery

A male newborn infant born at 38 weeks of gestation and weighing 2,660 g, was diagnosed as esophageal atresia. Although there was mild cyanosis at birth, his initial ultrasonographic examination performed by neonatologist showed normal anatomy of the heart. He underwent a surgical repair of esophageal atresia under general anesthesia. Anesthesia was induced with fentanyl and pancuronium, and maintained with sevoflurane and 60% oxygen. Frequent desaturation occurred during the procedure, requiring manual hyperventilation with 100% oxygen. Since blood pressure during the operation was unstable, volume loading with albumin was attempted. Further echocardiography was performed by pediatric cardiologist after going back to NICU. This revealed total anomalous pulmonary venous connection (TAPVC). He underwent cardiac surgery for repair of TAPVC on the next day. Although TAPVC was not preoperatively diagnosed regardless of results of echocardiogram, cyanosis and unstable blood pressure should be considered as signs of potential cardiac disease. Fluid restriction, higher hemoglobin, lower inspired oxygen and slightly higher carbon dioxide rather than albumin administration and hyperventilation should have been attempted during the esophageal repair.