An unusual cause of chylothorax after Norwood stage one reconstruction.

We report an unusual cause of prolonged chylothorax drainage after Norwood stage one reconstruction. This 1-month-old girl's chylous drainage was refractory to medical treatment. Echocardiography revealed thrombosis of the superior vena cava. Upon sternotomy to remove the thrombus, we were surprised to find the ePTFE (expanded polytetrafluoroethylene) tube previously used for selective cerebral perfusion compressing the innominate vein and the pericardium-based aortic arch. We performed a superior vena cava thrombectomy and shortened the ePTFE tube. Her chylothorax subsided gradually. We suggest that external compression of the venous drainage system should be considered in patients with prolonged chylothorax drainage. Once medical treatment fails, early surgical exploration may be helpful to stop the chylothorax.

Autonomic neuropathy precedes cardiovascular dysfunction in rats with diabetes.

BACKGROUND: Our team previously demonstrated arterial stiffening and cardiac hypertrophy in type 2 diabetic rats at 8 but not 4 weeks after being administered streptozotocin (STZ) and nicotinamide (NA). The present study focused on investigating the effects of type 2 diabetes on cardiac autonomic nerve function in the STZ- and NA-treated animals, using modern spectral estimation technique. DESIGN: An autoregressive process was performed to each detrended signal of heart rate and systolic blood pressure measured in the 4- and 8-week STZ-NA rats with anaesthesia. The power of low-frequency and high-frequency oscillations was automatically quantified with each spectral peak by computing the residuals. The closed-loop baroreflex gain was estimated using the square root of the ratio between heart rate and systolic blood pressure powers in the low-frequency band. RESULTS: Compared with the age-matched controls, both the 4- and 8-week STZ-NA diabetic rats had significantly decreased low-frequency oscillations of heart rate but not systolic blood pressure variability, showing a decline in baroreflex gain (0.451 +/- 0.060 and 0.484 +/- 0.056 vs. 1.196 +/- 0.064 ms mmHg(-1), P < 0.05). On the other hand, the low frequency-high frequency power ratio of the heart period was also diminished in the two diabetic groups, indicating a shift in sympatho-vagal balance of the heart control (0.472 +/- 0.109 and 0.504 +/- 0.090 vs. 1.857 +/- 0.336, P < 0.05). CONCLUSIONS: The cardiac autonomic dysfunction in the absence of any significant changes in vascular dynamics, 4 but not 8 weeks after induction of type 2 diabetes, suggests that the diabetic autonomic neuropathy may precede arterial stiffening and cardiac hypertrophy in the STZ- and NA-treated rats.

Evaluation of intraoperative cardiovascular responses to closed repair for pectus excavatum.

OBJECTIVE: Closed repair of pectus excavatum (PE), also known as the Nuss procedure, has become more popular recently, and whether this operation results in true cardiac improvement as opposed to postoperative physical rehabilitation or a psychological effect deserves examination. METHODS: Ten PE patients (8 males, 2 females) aged 4 to 54 years (average, 19.6+/-14 years) were prospectively evaluated using preoperative computed tomography (CT) scan, pulmonary function studies, electrocardiogram and transthoracic echocardiographic (TTE) evaluation of cardiac function. The same studies were repeated at 3 months post bar placement. In addition, intraoperative transesophageal echocardiogram (TEE) was done to measure the procedure-related values of the cardiac chamber and functional indices before and after turning of the pectus bar. RESULTS: Statistically significant changes in the pectus index, obtained by dividing the internal transverse distance of the thorax by the vertebral-sternal distance at the most depressed portion of the deformity, were noted after surgery, decreasing from 5.06+/-1.46 to 3.55+/-0.48 (P<0.05). Most patients with previously abnormal electrocardiograms showed a normal pattern after surgical repair (P<0.05). Five subjects in the PE group (50%) showed mitral valve prolapse in TTE and 4 of them had mitral regurgitation. However, these valve patterns could not be corrected after surgical repair of the chest wall deformity (P=0.25). The cardiac chamber and the function of the right ventricle were evaluated by intraoperative TEE and showed significantly increased values after retrosternal dissection and post-turning of the pectus bar. CONCLUSION: The data of this study supports the concept that closed repair directly contributes to hemodynamic improvement.

Evolving strategies and improving outcomes of Norwood stage one reconstruction: a decade experience of a single institution in Taiwan.

AIM: The aim of this study was to define the improvement in short-term outcome and risk factors of Norwood stage one reconstruction for hypoplastic left heart syndrome (HLHS) in Taiwan, after implementing new perioperative management strategies. METHODS: Data were retrieved from a retrospective chart review of patients with HLHS treated between July 1997 and July 2007. Since we implemented new perioperative strategies in 2004, we divided our patients into two groups, early era (1997-2003) and late era (2004-2007), and compared the outcome. RESULTS: We enrolled 48 patients. In the early era group (n=28), the diagnosis was confirmed by cardiac catheterization and controlled ventilation was used to manipulate the balance between systemic and pulmonary blood flow. The survival rate was only 17.9% (5/28). Surgery was performed at 15.2+/-10.7 days, which was significantly later than in the late era group (4.6+/-4.0 days, n=20). A lower preoperative shock and more prenatal diagnoses were recorded for the late era group. RV-PA conduit was used in 17 patients in the late era group of which 12 (70.6%) survived to be discharged from hospital. The risk factor was significant TR (tricuspid regurgitation). CONCLUSIONS: With our contemporary perioperative management and change in surgical strategy, survival after first-stage palliation has improved. We believe that our HLHS experience is valuable for low volume centers and also for Asian cohorts.

Aminoguanidine prevents the impairment of cardiac pumping mechanics in rats with streptozotocin and nicotinamide-induced type 2 diabetes.

BACKGROUND AND PURPOSE: Aminoguanidine (AG), an inhibitor of advanced glycation endproducts, has been shown to prevent arterial stiffening and cardiac hypertrophy in streptozotocin (STZ) and nicotinamide (NA)-induced type 2 diabetes in rats. Our aims were to examine whether AG produced benefits on cardiac pumping mechanics in the STZ and NA-treated animals in terms of maximal systolic elastance (E(max)) and theoretical maximum flow (Q(max)). EXPERIMENTAL APPROACH: After induction of type 2 diabetes, rats received daily injections of AG (50 mg kg(-1), i.p.) for 8 weeks and were compared with age-matched, untreated, diabetic controls. Left ventricular (LV) pressure and ascending aortic flow signals were recorded to calculate E(max) and Q(max), using the elastance-resistance model. Physically, E(max) reflects the contractility of the myocardium as an intact heart, whereas Q(max) has an inverse relationship with the LV internal resistance. KEY RESULTS: Both type 2 diabetes and AG affected E(max) and Q(max), and there was an interaction between diabetes and AG for these two variables. The E(max) and Q(max) were reduced in rats with type 2 diabetes, but showed a significant rise after administration of AG to these diabetic rats. Moreover, the increase in Q(max) corresponded to a decrease in total peripheral resistance of the systemic circulation when the STZ and NA-induced diabetic rats were treated with AG. CONCLUSIONS AND IMPLICATIONS: AG therapy prevented not only the contractile dysfunction of the heart, but also the augmentation in LV internal resistance in rats with STZ and NA-induced type 2 diabetes.

Aminoguanidine prevents fructose-induced deterioration in left ventricular-arterial coupling in Wistar rats.

BACKGROUND AND PURPOSE: Aminoguanidine (AG), an inhibitor of advanced glycation endproducts, has been identified as a prominent agent that prevents the fructose-induced arterial stiffening in male Wistar rats. Our aims were to examine whether AG produced benefits on the left ventricular (LV)-arterial coupling in fructose-fed (FF) animals in terms of the ventricular and arterial chamber properties. EXPERIMENTAL APPROACH: Rats given 10% fructose in drinking water (FF) were daily treated with AG (50 mg x kg(-1), i.p.) for 2 weeks and compared with the untreated FF group. In anaesthetised rats, LV pressure and ascending aortic flow signals were recorded to calculate LV end-systolic elastance (E(es), an indicator of myocardial contractility) and effective arterial volume elastance (E(a)). The optimal afterload (Q(load)) determined by the ratio of E(a) to E(es) was used to measure the coupling efficiency between the left ventricle and its vasculature. KEY RESULTS: There was a significant interaction between fructose and AG in their effects on E(a). Fructose loading significantly elevated E(a) and AG prevented the fructose-derived deterioration in arterial chamber elastance. Both fructose and AG affected E(es) and Q(load), and there was an interaction between fructose and AG for these two variables. Both E(es) and Q(load) exhibited a decline with fructose feeding but showed a significant rise after AG treatment in the FF rats. CONCLUSIONS AND IMPLICATIONS: AG prevented not only the contractile dysfunction of the heart caused by fructose loading, but also the fructose-induced deterioration in matching left ventricular function to the arterial system.

Single-center experience of pediatric heart transplantation in taiwan.

Heart transplantation (HTx) is a treatment for end-stage heart failure or a complex or inoperable congenital defect. The long-term survival and the adequate donor to recipient body weight (D/R BW) ratio remain to be determined. From March 1995 to May 2004, 14 children (6 months-16 years of age) underwent HTx due to underlying diseases of idiopathic dilated cardiomyopathy (n = 10; 71.4%), congenital heart disease (n = 3; 21.4%), and Kawasaki disease (n = 1; 7.1%). Donor-recipient body weight ratio ranged from 0.89 to 3.9. Big heart syndrome was present in one patient when D/R BW ratio was more than 3. Actuarial survival was 92.9% at 5 years after transplantation. Only the one patient who had Kawasaki disease died due to early primary graft failure. HTx is a feasible method with good long-term survival rates for end-stage heart failure or for complex or inoperable congenital defects. After careful pretransplant evaluation, a high D/R BW ratio (more than 3) is acceptable.

Chylothorax as a complication of innominate vein thrombosis induced by a peripherally inserted central catheter.

A 5-month-old boy with hypoplastic left heart syndrome developed chylothorax and oedema of the left upper arm more than 2 months after recovering from a Norwood stage II operation. Venography showed occlusion of the innominate vein with abundant collaterals crossing the midline to join the right internal jugular vein. The occlusion was caused by a peripherally inserted central catheter under systemic heparinisation. This case highlights the importance of a patent venous pathway, especially in patients with a cavopulmonary connection in the upper extremities.

Modified Nuss operation for pectus excavatum: design for decreasing cardiopulmonary complications.

BACKGROUND: Thoracoscopic Nuss operation of funnel chest is increasingly performed. However, it has a high rate of complications. This study developed some modifications to facilitate Nuss operations with the intention of reducing several major complications. METHODS: Patients who presented for surgical repair of pectus excavatum from July 2003 through June 2004 had a preoperative computed tomography (CT) scan, pulmonary function tests, and cardiac echo before and two months after the modified Nuss operation. The following modifications of the standard Nuss procedure were implemented: (1) One small subxyphoid incision was made to guide the plate implantation and to decrease cardiopulmonary complications. (2) Thoracic muscles were dissected off the ribs to provide muscle pockets. (3) Shorter thick stainless-steel AO bars were selected to avoid thoracic outlet syndrome and restriction. (4) The bars were fixed to adjacent ribs by 4-0 stainless steel wires into the submuscular pockets. (5) No thoracoscope routinely used. (6) No chest tubes were placed to decrease chest pain or for cosmetic purposes. RESULTS: 15 patients aged between 4 and 32 years (mean, 18.6 +/- 7.8) underwent evaluation. Preoperative CT index was 4.14 +/- 0.86. The average operating time was 95.7 +/- 27.0 min. There was no bar dislocation, prolonged pain, or neuralgia. Echocardiography showed no pericarditis and no pneumothorax occurred after placement of the intrathoracic bar. CONCLUSION: A small subxiphoid incision makes bar implantation easier and has reduced the incidence of major complications in this early experience with 15 patients.

Bacterial cholangitis in patients with biliary atresia: impact on short-term outcome.

Bacterial cholangitis (BC) is a common complication in patients with biliary atresia (BA) and is characterized by fever, acholic stools and positive blood cultures. The diagnosis is often empirical because the yield of blood cultures is low. It is difficult to differentiate BC from other febrile episodes. In order to characterize the clinical and laboratory features of BC in patients with BA, identify risk factors, and correlate cholangitis with outcome, 37 patients with BA from 1993 to 1998 who underwent a Kasai operation in our hospital were studied. The follow-up period ranged from 6 to 59 months. A total of 107 febrile episodes were documented in these patients. The diagnostic criteria for cholangitis were fever, increased jaundice, or acholic stools. The clinical features, laboratory data, results of bacterial cultures, and outcomes were analyzed retrospectively. A total of 107 febrile episodes, including 78 bouts of cholangitis and 29 non-cholangitis infections, were found in 34 patients. Patients with BC had higher postoperative bilirubin levels (P = 0.02) and less frequent use of prophylactic antibiotics (P = 0.05) than those with non-cholangitis infections. Abnormal white blood cell counts (> 12,000 or <4,000 mm3) tended to be present in patients with BC (P = 0.08). There were no statistical differences in the risk factors and laboratory data between culture-positive (n = 16) and -negative (n = 62) cholangitis cases. The occurrence of cholangitis significantly reduced survival in both patients with good (P = 0.03) and inadequate bile flow (P = 0.03). All 9 patients who had never had cholangitis survived during the follow-up period. Repeated attacks of BC further decreased survival probability. The responsive organisms were mainly enteric bacteria, including Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanni, and Salmonella typhi. The sensitivity tests justified empirical therapy with ceftriaxone. The effectiveness of prophylactic trimethoprim-sulfamethoxazole or neomycin warrants further studies. BC was a highly prevalent postoperative complication in patients with BA, especially those with inadequate bile drainage. It significantly affected early mortality. Aggressive and complete treatment with empirical ceftriaxone was appropriate.