The cleft sternum: a possible role for pliable prosthetic reconstruction.

BACKGROUND: Faced with our intraoperative inability to primarily close a very wide isolated cleft sternum of a pediatric patient without causing cardiovascular decompensation, we describe our use of a synthetic material for partial approximation allowing muscular coverage. METHOD: We report an infant who was born with an isolated large complete sternal cleft where a trial of primary surgical repair had to be abandoned because of cardiovascular compromise. A similar difficulty was encountered in approximating the origins of both pectoralis major muscle flaps at the midline. Thus, a pliable synthetic patch was helpful in partially obliterating the widened sternal defect allowing successful muscular coverage. RESULT: Closure of a wide congenital sternal cleft using a synthetic material that partially obliterated an otherwise widely separated cleft sternum which was neither amenable for primary repair, nor by bilateral pectoralis major advancement alone, was possible. CONCLUSION: Strong prosthetic pliable material may offer a simple and useful procedure allowing obliteration of the widely separated cleft sternum not amenable for primary repair.

Rupture of sinus of Valsalva aneurysm with aorto-biventricular fistulas and right-ventricular outflow tract obstruction: a unique association.

Sinus of Valsalva aneurysms are a rare entity. Rupture of such aneurysms is a major cause of aortocardiac fistulas usually occurring between the right sinus of Valsalva and right cardiac chambers. We report an exceptional case of a ruptured congenital sinus of Valsalva aneurysm with fistulas involving both the right- and left-ventricular outflow tracts and causing RVOT obstruction. We also demonstrate the utility of computed tomography angiography and transesophageal echocardiography in diagnosing these fistulas.

Femoral vein cannulation performed by residents: a comparison between ultrasound-guided and landmark technique in infants and children undergoing cardiac surgery.

BACKGROUND: Percutaneous cannulation of the femoral vein, in the pediatric age group, can be technically challenging, especially when performed by residents in training. We examined whether the use of real-time ultrasound guidance is superior to a landmark technique for femoral vein catheterization in children undergoing heart surgery. METHODS: Patients were prospectively randomized into 2 groups. In group LM, the femoral vein was cannulated using the traditional method of palpation of arterial pulse. In group US, cannulation was guided by real-time scanning with an ultrasound probe. The time to complete cannulation (primary outcome), success rate, number of needle passes, number of successful cannulations on first needle pass, and incidence of complications were compared between the 2 groups. RESULTS: Forty-eight pediatric patients were studied. The time to complete cannulation was significantly shorter (155 [46-690] vs 370 [45-1620] seconds; P = 0.02) in group US versus group LM. The success rate was similar in both groups (95.8%). The number of needle passes was smaller (1 [1-8] vs 3 [1-21]; P = 0.001) and the number of successful cannulations on first needle pass higher (18 vs 6; P = 0.001) in group US compared with group LM. The incidence of femoral artery puncture was comparable between the 2 groups. CONCLUSIONS: Ultrasound-guided cannulation of the femoral vein, in pediatric patients, when performed by senior anesthesia residents, is superior to the landmark technique in terms of speed and number of needle passes, with remarkable improvement in first attempt success.

Role of glucagon-like peptide-1 analogues on insulin receptor regulation in diabetic rat hearts.

This study focused on the regulation and affinity modulation of the insulin receptor of coronary endothelium and cardiomyocytes in nondiabetic and STZ-induced type 1 diabetic rats. Male rats were divided into the following 9 groups: nondiabetic (N), nondiabetic treated with exendin-4 (NE), nondiabetic treated with dipeptidyl peptidase IV (DPP-IV) inhibitor (NDp), diabetic (D), diabetic treated with insulin (DI), diabetic treated with exendin-4 (DE), diabetic co-treated with insulin and exendin-4 (DIE), diabetic treated with DPP-IV inhibitor (DDp), and diabetic co-treated with insulin and DPP-IV inhibitor (DIDp). After the rats were treated for 1 month, a first-order Bessel function was employed to estimate the insulin binding affinity (with time constant tau = 1/k-n) to its receptors on the coronary endothelium and cardiomyocytes using CHAPS-untreated and CHAPS-treated heart perfusion, respectively. The results showed that diabetes (D) decreased the tau value on the coronary endothelium and increased it on cardiomyocytes compared with the nondiabetic group (N). Treatment with insulin and (or) exendin-4, a glucagon-like peptide-1 (GLP-1) analogue, increased tau on the coronary endothelium only. On the coronary endothelium, tau values of DI and DIDp were normalized. Western blots of the insulin receptor showed upregulation in D, downregulation in DI, and normalization in DE and DDp. Immunohistochemistry and RT-PCR findings indicated atrial natriuretic factor (ANF) in all diabetic ventricles, thus ascertaining hypertrophy. Therefore, negative myocardial effects related to the insulin receptor were diminished in diabetic rats treated with DPP-IV inhibitor and, more efficiently, by exendin-4.

Coronary artery bypass surgery in octogenarians: outcomes in a tertiary referral university hospital in a developing country.

BACKGROUND: The number of people older than 80 years is increasing worldwide and many of these patients are being referred for coronary artery bypass surgery (CABG). Several recent reports from the USA and Europe have shown that CABG can be performed in octogenarians with an acceptable risk. However, data from developing countries regarding this subject is lacking. The objective of this study was to analyze the clinical characteristics and in-hospital events of octogenarian patients undergoing CABG at a tertiary referral university hospital in a developing country. METHODS: The study included 28 consecutive octogenarian patients who underwent CABG at the American University of Beirut, between January 1998 and December 2000. The medical records of these patients were reviewed for demographic information, clinical and catheterization findings, operative characteristics, and in-hospital events (death, myocardial infarction, and stroke). RESULTS: The mean age of the study group was 82 +/- 2 years and 75% were males. Seventy-eight percent of the patients had an acute myocardial infarction or unstable angina prior to CABG. All of the patients were in NYHA class I or II and none of the operations were done on an emergent basis. The mean ejection fraction was 48 +/- 7%. Eighty-six percent of patients had multivessel disease and four patients had aortic valve replacement (AVR) concomitantly with the CABG. The in-hospital mortality was 0%. Three patients (11%) had a post-operative myocardial infarction, and one patient (4%) had a stroke. The mean post-operative stay was 9 +/- 7 days with only three patients (11%) staying for more than 14 days. The multivariate predictors of in-hospital cardiovascular events were concomitant AVR (P=0.01), and an ejection fraction <40% (P=0.03). CONCLUSION: In carefully selected octogenarian patients who are clinically stable in NYHA class I or II, and where the operation is not done on an emergent basis, CABG can be performed with an acceptable risk and a low in-hospital mortality.

Parental consanguinity and congenital heart malformations in a developing country.

The association between isolated congenital heart defects and consanguinity was examined in 759 Lebanese patients with different types of congenital heart malformations. The subjects were patients of the Children's Cardiac Registry Center (CCRC) at the American University of Beirut Medical Center. The proportion of first-cousin marriages among cardiac subjects was compared to that of the National Collaborative Perinatal Neonatal Network (NCPNN), after adjusting for the subjects' geographic distribution, and to the highest proportion reported by NCPNN. In general, the proportion of overall parental consanguinity and first-cousin matings among CCRC subjects (34.7 and 20.2%, respectively) were significantly higher than the highest proportion of first-cousin marriages reported by NCPNN (Bekaa subjects; 13.2%) (P < 0.0001). Comparison with the NCPNN-adjusted first-cousin mating proportion revealed a significantly increased rate of consanguinity in all categories of cardiac malformations except great vessel and coronary artery lesions (P < 0.05). The following lesions were significantly associated with increased parental consanguinity: aortic anomalies (aortic insufficiency, aortic stenosis, bicuspid aortic valve), atrial septal defect, double-outlet right ventricle, pulmonary atresia, patent ductus arteriosus, pulmonic stenosis, tetralogy of Fallot, and ventricular septal defect (P < 0.05). Higher maternal education was the only variable that was negatively correlated with parental consanguinity (P = 0.037). Our study emphasizes the role of homozygous recessive genes in the causation of different types of isolated congenital heart malformations, known to follow a multifactorial pattern of inheritance. There is an urgent need for educating the public on the deleterious effects of inbreeding, especially in developing countries with high overall consanguinity rates and limited financial resources.

Effect of continuous positive airway pressure on the rapid shallow breathing index in patients following cardiac surgery.

OBJECTIVES: To compare the rapid shallow breathing index (RSBI) under different ventilatory support settings prior to extubation trials. DESIGN: Prospective study. SETTING: Cardiac surgery unit at a university hospital. PATIENTS: A total of 33 coronary artery bypass grafting patients ready for extubation. INTERVENTIONS: Enrolled patients received a continuous positive airway pressure (CPAP) trial of 5 cm H(2)O and fraction of inspired oxygen (FIO(2)) of 40% (condition 1), a CPAP trial of 5 cmH(2)O and FIO(2) of 21% (condition 2), and a 1-min spontaneously breathing room air trial without ventilatory support (condition 3). These trials were applied in random order. MEASUREMENTS AND MAIN RESULTS: Average values of respiratory frequency and tidal volume were measured under the three experimental conditions in all patients immediately prior to extubation. The RSBIs were determined for each patient under each condition; the average RSBIs under conditions 1, 2, and 3 were compared for significance. The average RSBIs (+/- SD) were significantly smaller under condition 1 (34 +/- 13) and condition 2 (36 +/- 14) compared to condition 3 (71 +/- 24). There was no significant difference in RSBI between conditions 1 and 2. CONCLUSIONS: The administration of 5 cm H(2)O of CPAP can influence the determination of the RSBI. In contrast, changes in FIO(2) have no effect on RSBI determination. We speculate that using the RSBI during CPAP may mislead the clinician into premature discontinuation of mechanical ventilation. Consequently, different threshold values for the RSBI should be derived for different ventilatory support levels.