Maintaining long-term central venous access by repetitive hepatic vein cannulation

Long-term central venous access has become a critical issue in the treatment of pediatric patients. Exhaustion of access sites can lead to superior and inferior vena cava thrombosis, limiting the choices for central line placement. Under such circumstances, hepatic vein cannulation is a viable option. We present the cases of two patients who, combined, have undergone five hepatic vein catheterizations. One patient has received four consecutive central lines via a hepatic vein. This experience suggests that the hepatic vein is a reusable site of cannulation in patients with no other alternative for venous access.

Amlodipine reduces graft coronary artery disease in rat heterotopic cardiac allografts

The long-acting dihydropyridine calcium antagonist, amlodipine, suppresses atherogenesis in experimental animals. To determine the effect of amlodipine on allograft coronary artery disease in the transplanted heart, we used a working heterotopic rat heart transplant model. All rats were immunosuppressed with cyclosporine as a single agent and randomized to a control group (n = 9) and an amlodipine-treated group (n = 9). After 90 days, rats were killed, and the extent of graft coronary artery disease was assessed by digitizing morphometry. No significant differences were noted for mean arterial blood pressure or serum total cholesterol, high-density lipoprotein cholesterol, or triglycerides at the time of death. Amlodipine was associated with significantly less narrowing in the coronary arteries (mean percent narrowing for control group, 48.9% +/- 8.2%; mean percent narrowing for amlodipine group, 25.5% +/- 9.9%; P < 0.05). These findings suggest a role for calcium channel blockers in the prevention of graft coronary artery disease.

Patterns of relapse after autologous purged bone marrow transplantation for neuroblastoma: a Childrens Cancer Group pilot study

PURPOSE

The goal of this investigation was to determine if comparing sites of neuroblastoma at relapse after myeloablative chemoradiotherapy and purged autologous bone marrow transplantation (ABMT) with sites of disease at diagnosis and before ABMT could provide insight to the reasons for treatment failure.

PATIENTS AND METHODS

Ninety-nine patients with high-risk neuroblastoma underwent ABMT after induction chemotherapy, surgery +/- local radiation (RT) and then myeloablative therapy with teniposide (or etoposide), melphalan, doxorubicin, cisplatin, and total-body irradiation (TBI).

RESULTS

Forty-one of 84 assessable patients (15 toxic deaths) developed progressive disease 1 to 44 months after ABMT. The overall probability of relapse 36 months after ABMT was 49%. Tumor recurred in primary (n = 22), bone (n = 20), bone marrow (n = 18), lung (n = 3), and other sites (n = 9). Eight patients relapsed in the primary site alone, 14 in primary and distant sites, and 19 in distant sites only. Of 41 patients with progressive disease, 33 have died, with a median interval from relapse to death of 4 months. Both bone and bone marrow involvement at diagnosis correlated with specific relapse in that site (P < .05). Bone marrow tumor content at harvest greater than 0.1% also correlated with bone marrow relapse (P = .001). There was an association between incomplete resection of the primary tumor at diagnosis and relapse in that site (P = .06).

CONCLUSION

Neuroblastoma normally recurs in multiple sites after ABMT, particularly in areas of previous disease. More intensive treatment to known areas of disease (aggressive early surgery, effective myeloablative consolidation therapy) and post-ABMT therapy for minimal residual disease should be studied for their potential to decrease the frequency of relapse.

Noninvasive detection of acute rejection in a new experimental model of heart transplantation

We have shown that positron emission scintigraphy detects changes in the uptake of 18-F 2-deoxyglucose and 13-N ammonia by the acutely rejecting myocardium in a nonworking model of heterotopic heart transplantation in the rat. We developed a new working model of heterotopic heart transplantation to determine the possible relevance of these changes to clinical transplantation. Moderate aortic valvular regurgitation was produced allowing the heterotopic left ventricle to fill and eject. Rejecting allografts and nonrejecting isografts (controls) were studied 4 days after transplantation. Histologically, isografts were normal and all allografts showed mild acute rejection. Decay-corrected uptakes of 18-F 2-deoxyglucose and 13-N ammonia reflect glucose metabolism and blood flow, respectively. Values are presented as percent of injected dose per gram of tissue. Uptake of 18-F 2-deoxyglucose was higher in rejecting allografts compared with nonrejecting isografts (3.0 +/- 1.8 versus 1.1 +/- 0.4; p = 0.024). Ammonia uptake was elevated in allografts compared with isografts (2.2 +/- 0.5 versus 1.3 +/- 0.5; p = 0.023). Uptakes of 18-F 2-deoxyglucose and 13-N ammonia are higher in mildly rejecting allografts, implying increased glucose utilization and blood flow during acute rejection. These data support our earlier findings of changes in myocardial metabolism in the absence of diminishing blood flow in acutely rejecting hearts. This model may lead to a better understanding of the physiology and metabolism of acute rejection.

Molecular forms of atrial natriuretic factor in normal and failing human myocardium

BACKGROUND

Atrial natriuretic factor (ANF) is produced by myocardial tissue, and the plasma ANF concentration is known to be elevated in congestive heart failure (CHF). Data from animal models indicate that myocardial concentrations of ANF are depleted in CHF, and this has given rise to the hypothesis that CHF is characterized by depletion of stored ANF. To date, the molecular forms of ANF and their concentrations in atrial and ventricular myocardium remain poorly characterized in the normal and the failing human heart.

METHODS AND RESULTS

We measured ANF concentrations in fresh tissue from failing human hearts explanted at the time of cardiac transplantation and from organ donors whose normal hearts could not be used for transplantation. We determined total ANF and alpha, beta, and gamma ANF concentrations in the right and left atrial appendages, atrial free walls, and ventricles. In normal hearts, ANF concentration in the atrial appendages was 40-fold higher than ANF in the rest of the atrial free wall and in the ventricles. In the failing hearts, atrial appendage ANF concentrations increased 5- to 10-fold, and atrial free wall ANF concentrations increased 200-fold. Analysis of molecular forms of ANF demonstrated significant increases in the gamma and beta forms in the left atrial appendage of failing hearts. alpha, beta, and gamma ANF forms were also significantly increased in right and left atrial free wall tissue from failing hearts. In addition, failing hearts were characterized by absolute and relative increases in the precursor form gamma ANF.

CONCLUSIONS

These data from fresh tissues suggest that cardiac ANF stores are not decreased in severe CHF in humans; rather, chronic CHF is characterized by marked increases in atrial ANF tissue concentrations, particularly the beta and gamma ANF forms. These findings are consistent with intracellular accumulation of precursor ANF forms in severe chronic human CHF.

Management of splenic abscess in immunocompromised children

Splenic abscess is an infrequent complication in the immunocompromised patient. Six patients underwent splenectomy for presumed splenic abscess from 1987 to 1991. Chemotherapy altered the immune system of four patients; the human immunodeficiency virus (HIV) rendered the other two vulnerable to infection. Five presented with fever but none had leukocytosis; only one exhibited palpable splenomegaly; three had abdominal pain. Cultures documented systemic infection in all but one, an HIV-positive individual. Respiratory embarrassment was the indication for surgery in one patient. In five cases the decision for surgical intervention was made after computed tomography (CT) indicated the presence of multiple splenic lesions and systemic antibiotics failed to resolve the fevers. CT additionally showed hepatic and/or renal microabscesses in four patients. Signs and symptoms experienced preoperatively resolved with splenectomy in all six patients. No additional surgery was required for the patients with extrasplenic abscesses. Surgical pathology determined that three spleens had fungal and two had mycobacterial abscesses. The other was shown to be a spindle cell sarcoma; no abscess was present. This patient had preoperative blood cultures positive for mycobacteria, and the same organism was recovered from retroperitoneal nodes sampled at the time of splenectomy for the sarcoma. Follow-up indicates that no patients experienced surgical complications or sequelae related to their splenic pathology. Splenectomy is necessary and effective in treating splenic abscesses in immunocompromised patients and is appropriate for diagnosis as well as therapy.

Estimation of left ventricular mass and infarct size from nitrogen-13-ammonia PET images based on pathological examination of explanted human hearts

The purpose of this study was to develop a technique to quantify left ventricular mass and infarct size in chronic ischemic heart disease from PET images based on correlation with pathological examination of explanted human hearts. Fourteen hearts from patients with cardiomyopathy who had 13N-ammonia scans prior to orthoptic heart transplantation were studied. Accurate estimation of the relative infarct size was possible in patients with a well-delineated, nearly transmural infarct (r = 0.93, y = 1.1x - 0.7, n = 11). Both absolute and relative infarct mass measurements on PET images correlated well with pathological measurements. We identified a population of patients with patchy interstitial or subendocardial scarring with globally reduced perfusion, for which the infarct size could not be estimated using the criteria derived for the patients with well-delineated infarcts.

Doxorubicin cardiomyopathy is associated with a decrease in calcium release channel of the sarcoplasmic reticulum in a chronic rabbit model

Doxorubicin is a highly effective cancer chemotherapeutic agent that produces a dose-dependent cardiomyopathy that limits its clinical usefulness. Clinical and animal studies of morphological changes during the early stages of doxorubicin-induced cardiomyopathy have suggested that the sarcoplasmic reticulum, the intracellular membrane system responsible for myoplasmic calcium regulation in adult mammalian heart, may be the early target of doxorubicin. To detect changes in the calcium pump protein or the calcium release channel (ryanodine receptor) of the sarcoplasmic reticulum during chronic doxorubicin treatment, rabbits were treated with intravenous doxorubicin (1 mg/kg) twice weekly for 12 to 18 doses. Pair-fed controls received intravenous normal saline. The severity of cardiomyopathy was scored by light and electron microscopy of left ventricular papillary muscles. Developed tension was measured in isolated atrial strips. In subcellular fractions from heart, [3H]ryanodine binding was decreased in doxorubicin-treated rabbits (0.33 +/- 0.03 pmol/mg) compared with control rabbits (0.66 +/- 0.02 pmol/mg; P < 0.0001). The magnitude of the decrease in [3H]ryanodine binding correlated with both the severity of the cardiomyopathy graded by pathology score (light and electron microscopy) and the decrease in developed tension in isolated atrial strips. Bmax for [3H]ryanodine binding and the amount of immunoreactive ryanodine receptor by Western blot analysis using sequence-specific antibody were both decreased, consistent with a decrease in the amount of calcium release channel of sarcoplasmic reticulum in doxorubicin-treated rabbits. In contrast, there was no decrease in the amount or the activity of the calcium pump protein of the sarcoplasmic reticulum in doxorubicin-treated rabbits. Doxorubicin treatment did not decrease [3H]ryanodine binding or the amount of immunoreactive calcium release channel of sarcoplasmic reticulum in skeletal muscle. Since the sarcoplasmic reticulum regulates muscle contraction by the cyclic uptake and release of a large internal calcium pool, altered function of the calcium release channel could lead to the abnormalities of contraction and relaxation observed in the doxorubicin cardiomyopathy.

Management of pulmonary blastoma in children

Pulmonary blastoma is a rare neoplasm, accounting for 0.5 per cent of all primary malignant pulmonary tumors. The clinical features, radiologic findings, and management of five children with pulmonary blastoma are described. The female/male ratio was 4:1. Mean age at presentation was 34 months, with a mean duration of symptoms of 1.8 months. Fever and cough were the most common symptoms. Opacification of the right lung field with mediastinal shift to the left was the predominant roentgenologic feature. The tumor involved the right chest in all patients. Thoracotomy was performed in all patients to establish the diagnosis. Two patients underwent complete resection at the initial operation, an incomplete resection was performed in one patient. Delayed complete resection was performed in another patient. All the patients received combination chemotherapy and one patient also received radiotherapy for primary disease. Two patients with histologic and immunohistochemical evidence of striated muscle differentiation were treated as rhabdomyosarcomas. Both these patients have survived for 24 and 67 months after diagnosis. The tumor recurred in three patients. Recurrence was treated with a combination of surgery, chemotherapy, and radiotherapy. Overall disease-free survival rate was 40 per cent. Long-term follow-up and additional patients are required to provide prognostic information.

Ventricular defibrillation in canines with chronic infarction, and effects of lidocaine and procainamide

Prior studies in dogs with normal hearts have demonstrated that lidocaine increases but procainamide does not change the energy required for successful defibrillation. Because many postinfarct patients receiving implantable cardioverter defibrillator devices require adjunctive antiarrhythmic therapy, we have studied the effects of lidocaine and procainamide on the relationship between delivered voltage and defibrillation success in mongrel dogs 21 +/- 3 days following ligation of the left anterior descending and first diagonal coronary arteries. Internal defibrillation testing using a patch-patch electrode configuration was performed before and during the administration of saline controls (n = 10), lidocaine (n = 10) and procainamide (n = 10). The mean infarct size as determined by staining with tetrazolium was 13.4% +/- 8.3% of right and left ventricles, and did not differ significantly between groups. The 50% effective defibrillation (ED50) voltage increased with infusions of saline (16% +/- 15%), lidocaine (40% +/- 22%), and procainamide (13% +/- 15%) and the ED50 energy increased 41% +/- 44%, 104% +/- 62%, and 35% +/- 36%, respectively. However, the increase in ED50 voltages and energies were significantly greater in animals receiving lidocaine compared to those receiving either saline control or procainamide (P < 0.01). There were trends toward change of hemodynamic parameters in all animals following baseline defibrillation testing; stroke volume declined 21% +/- 16%; and mean pulmonary artery and aortic pressure increased by 22% +/- 25% and 11% +/- 15%, respectively. In conclusion, unlike our previous studies in dogs with normal hearts, in this model hemodynamic deterioration occurred with repeated fibrillation and defibrillation, and defibrillation voltage requirements increased in the control series. Taking into consideration the increase in defibrillation voltage requirements over the duration of the experiments, lidocaine increases and procainamide does not change ED50; thus, their effects are similar in normal and infarcted canine hearts.

Severe arteriosclerosis in the kidney of a cocaine addict

Cocaine abuse has been associated with sudden cardiac death with coronary artery thrombosis with or without underlying vessel disease. Additional vascular beds thus far implicated in cocaine-associated arteriopathy include thoracic and abdominal aorta, and pulmonary, cerebral, and placental vessels; abnormalities include vasospasm, thrombosis, and accelerated atherosclerosis. We report the case of an adult male cocaine user with severe arteriosclerosis of renal vessels, and suggest that cocaine may also affect the renal vasculature.

Congenital diaphragmatic hernia. Stabilization and repair on ECMO

Availability of extracorporeal membrane oxygenation (ECMO) support and the potential advantages of delayed repair of congenital diaphragmatic hernia (CDH) have led several centers to delay CDH repair, using ECMO support if necessary. This study reviews the combined experience of five ECMO centers with infants who underwent stabilization with ECMO and repair of CDH while still on ECMO. All infants were symptomatic at birth, with a mean arterial oxygen pressure (PaO2) of 34 mmHg on institution of bypass despite maximal ventilatory support. A total of 42 infants were repaired on ECMO, with 18 (43%) surviving. Seven infants had total absence of the diaphragm, and 28 required a prosthetic patch to close the defect. Only five infants ever achieved a best postductal PaO2 over 100 mmHg before institution of ECMO. Prematurity was a significant risk factor, with no infants younger than 37 weeks of age surviving. Significant hemorrhage on bypass was also a hallmark of a poor outcome, with 10 of the 24 nonsurvivors requiring five thoracotomies and six laparotomies to control bleeding, whereas only one survivor required a thoracotomy to control bleeding. In follow-up, nine of the 18 survivors (50%) have developed recurrent herniation and seven (43%) have significant gastroesophageal reflux. Importantly, five of the 18 survivors were in the extremely high-risk group who never achieved a PaO2 over 100 mmHg or an arterial carbon dioxide pressure (PaCO2) less than 40 mmHg before the institution of ECMO. In conclusion, preoperative stabilization with ECMO and repair on bypass may allow some high-risk infants to survive. Surviving infants will require long-term follow-up because many will require secondary operations.

Preoperative thyroid scanning in presumed thyroglossal duct cysts

The purpose of this study was to determine if preoperative thyroid scans are essential in the workup of presumed thyroglossal duct cysts. Questionnaires were sent to pediatric otolaryngologists and pediatric general surgeons with a 65% response rate. Fifty-seven percent of the physicians have encountered ectopic thyroid. In 58% of these, this was the only functioning thyroid tissue. Twenty eight percent of pediatric surgeons vs 65% of pediatric otolaryngologists routinely order scans. Two of the physicians encountering ectopic thyroid volunteered that they had successful litigation directed against them for removing the sole functioning thyroid and creating permanent hypothyroidism. There is a likelihood of encountering ectopic thyroid during the course of one's practice. A case of ectopic thyroid is presented, and management strategies are discussed.

Major surgical intervention during extracorporeal membrane oxygenation

Of 135 patients treated with extracorporeal membrane oxygenation (ECMO) between January 1987 and December 1989, 19 (14.0%) patients underwent surgical procedures while on ECMO. Thirteen (68%) patients had operations related to hemorrhage, including cannula site (6), mediastinal (1), hemoperitoneum (3), and hemothorax (3). Six of 13 patients required repetitive operations for bleeding; 4 of 6 died. Six (35%) patients had operations for congenital pathology including patent ductus (PDA) ligation (2), repair of transposition of the great vessels (2), repair of coarctation (1), and repair of congenital diaphragmatic hernia (3). One patient had multiple simultaneous procedures performed. Of these 6 patients, 4 were decannulated immediately and 2 were decannulated within 28 hours following surgery without any bleeding complications. Fifteen of 19 patients were operated on in the neonatal intensive care unit. The 4 remaining patients required transport on ECMO to the surgical suite. Thirteen of the 19 patients requiring surgical intervention on ECMO survived. In the 13 survivors, the mean time to decannulation postoperative was 45 hours, and in those that died it was 90 hours. Our experience suggests that surgical intervention while on ECMO is technically feasible with the best results achieved when rapid discontinuation of ECMO can be accomplished postoperatively. Due to this fact major surgical intervention should be postponed if possible until near the conclusion of the ECMO therapy.

Proximal and distal cannulation of the internal jugular vein for ECMO in a primate

Extracorporeal membrane oxygenation (ECMO) is lifesaving for infants with severe respiratory distress but is complicated by severe intracranial hemorrhage in 10% to 30% of patients. Intracranial venous hypertension, as a result of ligation of the internal jugular vein (IJV), has been hypothesized as a contributing factor to cerebral edema and subsequent hemorrhage. Accessory cephalad IJV cannulation may serve as a means of additional venous drainage to the pump as well as protection against intracranial venous hypertension. Proximal and distal cannulation of the IJV were studied in a primate model. The parameters monitored included sagittal sinus, right and left ventricular pressures as well as venous pressure in the ECMO circuit. The cephalad venous cannula was clamped and unclamped at 30-minute intervals. There was no significant difference in sagittal sinus or intracranial pressures during periods of cephalad cannula clamping or unclamping. Venous return was augmented when the cephalad cannula was unclamped. Cephalad cannulation has no demonstrable protective effect on intracranial, subarachnoid or venous pressures but does improve venous return to the ECMO circuit. It is concluded that cephalad venous cannulation is not necessary in all cases and should be reserved for those patients requiring additional venous drainage to support pump flow.

Growth hormone reverses impaired wound healing in protein-malnourished rats treated with corticosteroids

Corticosteroid (CS) administration amplifies the inhibitory effect of protein malnutrition (PM) on wound healing. Abdominal surgery in protein malnourished patients receiving corticosteroids (eg, advanced malignancy, transplant recipients) may be complicated by wound dehiscence or anastomotic breakdown. Although preoperative parenteral nutrition can reduce the incidence of these complications, this is not possible in patients requiring urgent surgical intervention. In a previous report we demonstrated that postoperative growth hormone (GH) administration could restore normal wound healing in PM rats. This study evaluates the effect of GH on wound healing in PM rats treated with CS. Forty-eight female Sprague-Dawley rats weighing 180 to 210 g were divided into four groups: (1) normally nourished; (2) PM only; (3) PM + CS; and (4) PM + CS + GH. PM rats (groups 2 to 4) received 5.5% protein chow every other day for 8 weeks. Control rats (group 1) received 23.4% protein chow for the same duration. Group 3 and 4 rats received prednisolone (2 mg/kg, intramuscularly) during the last 3 weeks of PM. All animals underwent precise 5-cm midline celiotomies. Postoperatively, rats in all groups were given 23.4% protein chow. Group 3 and 4 rats continued to receive CS postoperatively. Group 4 rats were given GH (0.5 mg/d, intraperitoneally) postoperatively for 5 days. Wound testing was performed on the 6th postoperative day after removal of the sutures. A balloon inserted into the peritoneal cavity through the vagina was gradually inflated. The pressure at which the wound disrupted was recorded as the wound bursting strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of cardiac findings in patients with mitral valve prolapse who die suddenly to those who have congestive heart failure from mitral regurgitation and to those with fatal noncardiac conditions

Sudden death occurs in a small but important subset of patients with mitral valve prolapse (MVP). Clinical criteria for identifying patients at risk for sudden death have been elusive. To determine if certain morphologic characteristics were present in hearts from patients with sudden cardiac death and MVP, autopsy hearts from persons with sudden death and isolated MVP who were previously asymptomatic or had a history of cardiac arrhythmias (n = 27) were compared with (1) hearts from patients with congestive heart failure (CHF) and mitral regurgitation (MR) secondary to MVP (n = 14), and (2) hearts from persons dying from non-cardiac causes in which MVP was an incidental finding (n = 19). Patients who died suddenly were younger than both patients with MR/CHF and incidental cases (37 +/- 10 vs 65 +/- 16 and 58 +/- 21 years, respectively, p less than 0.001). Mitral valve annular circumference, anterior and posterior mitral valve leaflet lengths, posterior mitral valve thickness, and presence and extent of endocardial plaque were greater in hearts from patients with sudden death than hearts from those with incidental MVP. Hearts from patients with MR/CHF weighed significantly more, had greater left and right atrial cavity sizes and left ventricular cavity diameter than hearts from both sudden death and incidental cases.

ECMO and the management of congenital diaphragmatic hernia with large diaphragmatic defects requiring a prosthetic patch

From 1977 to 1991, 136 neonates have had corrective surgery for diaphragmatic hernia at Children's Hospital of Los Angeles. A retrospective study was performed to determine how many of the 136 neonates had defects large enough to require the use of a prosthetic patch to repair the defect. Twelve were found. All 12 were symptomatic at birth for respiratory distress. Mean arterial blood gas values at birth were pH 6.95, PCO2 94.8, and PO2 47.2. The mean oxygen index (n = 10) was 61.8. Six of these patients were repaired without extracorporeal membrane oxygenation (ECMO) support while the other six received ECMO bypass perioperatively. All six of the patients who did not receive ECMO support died despite successful diaphragmatic repair. Five of six patients who received ECMO perioperatively survived (83%). These surviving infants are now between 1 month and 4 years of age. In the survivors, four of five required subsequent repair and patch enlargement for a recurrent diaphragmatic hernia. Gastroesophageal reflux, requiring a Nissen fundoplication in two infants, complicated the course of three survivors. Four survivors were discharged with supplemental oxygen therapy lasting less than 13 months. Patch disruption is predicted to occur at approximately 18 months of age in all patients, especially if little or no muscle was available at primary repair for prosthetic attachment. These children should be followed closely for feeding or respiratory symptoms. Diagnosis of patch disruption can be made by chest x-rays and confirmed by contrast studies. Patch expansion by laparotomy and careful search for additional musculature for patch attachment is recommended when reherniation occurs.

Noninvasive detection of heart transplant rejection with positron emission scintigraphy

Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.

Augmented venous access in the problematic ECMO patient: a case report

Extracorporeal membrane oxygenation (ECMO) provides an adjunct to support of neonates with respiratory distress. The rate of venous drainage is the limiting step to the amount of arterial flow that may be generated during ECMO. We present a 3-kg, 37-week gestation female with congenital diaphragmatic hernia (CDH) whose anatomic venous drainage was insufficient to allow total extracorporeal support. The internal jugular vein was of insufficient size to allow placement of a cannula large enough to support adequate bypass flow. We established minimally acceptable flow by simultaneous caudad and cephalad catheterization of the internal vein. We performed a right lower quadrant retroperitoneal dissection and cannulated the common iliac vein when systemic pressures deteriorated at 24 hours with marginal venous drainage. After triple cannulation the bypass flows were normal. The right leg developed mild cyanosis and edema immediately following cannulation, but these changes resolved over 24 hours with elevation. The common iliac vein provides a desirable route for augmentation of venous drainage in the patient with difficult standard, or cephalad, jugular venous access for extracorporeal support.

Skeletal muscle composition in dietary obesity-susceptible and dietary obesity-resistant rats

The intent of this study was to determine whether a relationship exists between susceptibility to high-fat diet (HFD)-induced obesity and skeletal muscle fiber type. Forty-four adult male Wistar rats were given ad libitum access to a HFD (60% of calories from fat) for 4 wk. Rats were then grouped into quartiles for total weight gain, and the top-quartile [obesity prone (OP)] rats were compared with the bottom-quartile [obesity resistant (OR)] rats. OP rats gained 1.5 times as much weight as OR rats. OR rats had a significantly higher proportion of type I muscle fibers in the medial head of the gastrocnemius muscle than OP rats both before (determined from a muscle biopsy) and after the HFD feeding period. A greater proportion of type I fibers may be associated with a greater capacity for fat oxidation, which would favor resistance to body fat accumulation. Preexisting differences in muscle fiber composition may play a role in determining susceptibility to dietary obesity.

Watanabe heritable hyperlipidemic rabbits. Familial hypercholesterolemia

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Persistent pulmonary hypertension complicating cystic adenomatoid malformation in neonates

Neonates with congenital diaphragmatic hernia (CDH) are known to be susceptible to stress-induced persistent pulmonary hypertension (PPHN). Congenital cystic adenomatoid malformations (CCAMs) may also present as respiratory distress in the newborn. Intubation and mechanical ventilation cause clinical deterioration because of air trapping within cystic spaces; these patients require prompt lobectomy. PPHN has not been commonly associated with CCAM. Three patients with CCAM were encountered who developed PPHN postlobectomy. Three newborns, 36 to 38 weeks' gestation, presented with respiratory distress. Two had diagnosis of thoracic tumors on fetal ultrasound (22 and 33 weeks). Chest x-ray at birth confirmed cystic intrathoracic tumors in all and they underwent immediate thoracotomy and lobectomy (1 right upper, 1 left lower, 1 left upper). The patients were stable for 4 hours to 5 days postoperatively and then developed findings consistent with PPHN by cardiac echocardiography and required extracorporeal membrane oxygen (ECMO) support. ECMO was required for 66.5 to 120 hours. Each patient was successfully weaned to conventional ventilatory support. The clinical course of these patients was similar to those with CDH who undergo immediate surgery. The stress of surgical intervention combined with hypoxia and hypercarbia stimulates a hyperactive pulmonary vasculature and the development of PPHN. ECMO provides an effective adjunct to support patients with PPHN on the basis of congenital cystic adenomatoid malformations.

Primary endodermal sinus (yolk sac) tumor of the falciform ligament

Extragonadal yolk sac tumors (YSTs) are uncommon and YSTs of the liver are exceedingly rare, with only three reported cases in the literature. A case is described of primary YST of the falciform ligament extending into the left lobe of the liver in a 14-month-old boy. This is the first reported case of primary YST arising within the falciform ligament. The patient underwent an exploratory laparotomy after presenting with hemoperitoneum. An extremely friable and necrotic tumor was found extending from the falciform ligament into the liver. The tumor was debulked and the patient received 5 months of chemotherapy employing a modified Einhorn regimen. After a partial response to chemotherapy the patient had a second-look laparotomy, at which time a left hepatic lobectomy and en bloc resection of the falciform ligament was performed in order to remove residual tumor. At the present time the patient has no signs of metastases and is alive and well 2 years after his presentation.