Right pulmonary agenesis converts an incomplete vascular ring into a near-complete vascular ring.

A unique combination of pulmonary agenesis and anatomic left aortic arch with aberrant right subclavian artery was identified in two patients. Because of the right pulmonary agenesis, there is rotation of mediastinal contents, especially the aortic arch, into the right chest, converting an incomplete vascular ring to a near-complete vascular ring. The anterior portion of the ring is formed by the ascending aorta and aortic arch, whereas the posterior portion is formed by the aberrant right subclavian artery. Subclavian artery reimplantation and aortopexy effectively relieve the anterior and posterior tracheoesophageal compressive forces.

Hemodynamic and electrocardiographic effects of early pulmonary valve replacement in pediatric patients after transannular complete repair of tetralogy of Fallot.

In adults, pulmonary value replacement (PVR) shows improvement in right ventricular (RV) volume and function and reduces QRS duration. In addition, RV volume correlates with QRS duration and QRS change. This has not been shown in pediatric patients. The purpose of this study was to evaluate serial magnetic resonance imaging (MRI) and electrocardiogram measurements before and after early PVR in a pediatric population with repaired Tetralogy of Fallot and whether QRS duration and QRS change correlated with RV volume. A retrospective review of MRIs and electrocardiograms was conducted on 10 patients. Median age at repair was 2.1 +/- 0.7 years, and median age at PVR was 11.5 +/- 2.0 years. There were significant decreases in RV end diastolic volume (EDV)/body surface area (BSA) (p < 0.0004), end systolic volume (ESV)/BSA (p = 0.02), RVEDV/left ventricular (LV) EDV (p < 0.001), RV ejection fraction (p < 0.04), RV stroke volume (SV)/BSA (p < 0.0002), and (RVSV - LVSV)/BSA (p = 0.0007). No significant change in QRS duration occurred (p = 0.08). QRS duration (pre-r = 0.44, p = 0.20; post-r = 0.34, p = 0.33) and QRS change (r = -0.08, p = 0.83) did not correlate with RVEDV. We propose early consideration of PVR in pediatric patients. PVR improves RV volumes and function and may provide beneficial electromechanical effects by slowing the progression of QRS duration.

Pulmonary atresia with intact ventricular septum, right-sided aortic arch and ventriculocoronary connection--prenatal echocardiographic diagnosis.

The authors describe the prenatal echocardiographic diagnosis of a rare case of pulmonary atresia with intact ventricular septum, right-sided aortic arch, and ventriculocoronary connection in a fetus at 21 weeks gestation. The diagnosis was confirmed at autopsy.

Traumatic brain injuries in Alaska, 1996-1998.

Traumatic brain injuries often lead to severe disability or death. These injuries most often affect younger, more active people and are likely to have enduring physical, emotional, and financial costs. In order to determine the incidence, etiology and severity of traumatic brain injuries in Alaska, the Alaska Department of Health and Social Services has conducted a three-year study of the demographic and epidemiologic characteristics of traumatic brain injuries in Alaska. From 1996 through 1998, 1,932 hospitalized cases or out-of-hospital deaths occurred in the state among Alaska residents, for an average incidence rate of 105.2 per 100,000 population. To analyze the incidence of these injuries, the Traumatic Brain Injury Surveillance Project analyzed the location, demographics, and etiology.

A proposed scheduling model to improve use of computed tomography facilities.

A nonpreemptive queuing system based upon operations management theory is used to evaluate expected steady state wait periods for traditional and distributed CT scheduling models. Both models are constructed using two classes of patient service--emergent and nonemergent. The former model uses only one point of service per scanner while the latter employs multiple points of service in order to accomplish all of the functions necessary to complete a CT scan. Sample data are drawn from a tertiary care hospital-based system using a traditional service model. Comparison of a traditional and distributed service system, each with emergent and nonemergent service classes, shows that breaking as many activities as possible out of the scanner should provide substantial improvements in cost efficiency and service for patients having CT scans. Nonemergent patients may experience as much as an 89% reduction in steady-state wait times while emergent patients may experience as much as a 59% reduction in wait times. The cost efficiencies recognized either through increased scanner utilization or reduced scanner needs, even with only modest improvements, should more than offset any additional personnel needed to implement a distributed model. Proper implementation of a distributed scheduling model for CT scanning can provide substantial cost efficiencies and improvements in service for both nonemergent and emergent CT scans.

Primary pediatric cardiac tumors: a 17 year experience.

We reviewed 22 cases of primary pediatric cardiac tumors followed at our institution from January 1981 through November 1997, analyzing them by subtype, age and manner of presentation, location, associated findings, interventions, and clinical course. Rhabdomyomas were the most common (11), followed by intrapericardial teratomas (2), myxomas (1), fibromas (1), hemangiomas (1), mesotheliomas (1), and rhabdomyosarcomas (1), with 4 undetermined tumors. The majority (77%) of tumors were diagnosed before the age of one year, including six prenatally. The most common presentations were murmurs (5), arrhythmias (5), and abnormal screening fetal ultrasound examinations (4). Tumors were located most frequently in the right ventricle (13) and left ventricle (7), with multiple tumors being present in 10 cases. Eight patients (36%) had associated arrhythmias or conduction abnormalities, and of the 11 patients with rhabdomyomas, tuberous sclerosis was diagnosed in 8. Eight patients underwent cardiac catheterization, including two for electrophysiologic study with radiofrequency ablation, and seven patients had complete or partial tumor resection. The follow-up period ranged from 2 months to 15 years, and there were 3 tumor-related deaths. Therefore, despite the benign histology of most primary pediatric cardiac tumors, there may be significant associated morbidity and occasional mortality. As echocardiographic techniques such as fetal ultrasonography have continued to improve, however, these cardiac tumors have increasingly been detected early before significant symptoms develop.

Preexcitation secondary to fasciculoventricular pathways in children: a report of three cases.

INTRODUCTION: Fasciculoventricular connections are the rarest form of accessory pathways leading to preexcitation. Electrophysiologic characteristics of these pathways include ventricular preexcitation with normal PR and AH intervals and short HV intervals during sinus rhythm. In addition, atrial overdrive pacing prolongs the PR interval without affecting the HV interval or the degree of preexcitation. METHODS AND RESULTS: From March 1994 through February 1997, 3 of 59 pediatric patients referred for electrophysiologic study for preexcitation on surface ECGs were found to have fasciculoventricular pathways. Two patients had no inducible supraventricular tachycardia. One patient had successful ablation of both a left lateral pathway and a concealed anterolateral pathway that had facilitated antidromic and orthodromic supraventricular tachycardias, respectively. CONCLUSION: Children often manifest minimal preexcitation via accessory AV pathways due to rapid AV conduction and/or left lateral pathway location. Fasciculoventricular pathways may masquerade as Wolff-Parkinson-White syndrome. Separation of the two diagnoses depends on the demonstration of specific electrophysiologic criteria.

Malignant and normal T cells show random use of T-cell receptor alpha chain variable regions in patients with cutaneous T-cell lymphoma.

Cutaneous T-cell lymphoma (CTCL) is a malignancy of mature T lymphocytes, most of which express alpha/beta type T-cell receptors (TCRs). The cause of CTCL is unknown, but hypotheses postulating chronic stimulation of TCRs by superantigen or by a leukemogenic virus have been proposed. Either mechanism might produce bias in the TCR variable (V) region types used by the malignant cells. To determine if TCR alpha use is restricted in CTCL, we used reverse transcription and the polymerase chain reaction to determine V alpha and V beta usage by malignant cells purified from the peripheral blood of leukemic patients with CTCL. Usage of alpha chain V region segments appeared totally random; malignant lymphocytes isolated from each of six patients used different V alpha regions. As has been previously reported, no bias was found in beta chain V region usage either. In addition to productive (in frame) TCR V region mRNAs in malignant cells from each patient, we detected non-productive (out of frame) beta chain transcripts in these cells in two of six patients, and non-productive alpha chain transcripts in five of six. Residual normal peripheral blood lymphocytes from these patients showed a random, polyclonal or oligoclonal pattern of V region usage. We conclude that there is no bias in V region usage in CTCL, making it unlikely that interactions between superantigen or virus and the TCR V regions play a role in the pathogenesis of CTCL.

Percutaneous transjugular portosystemic shunt.

OBJECTIVE: --To determine the effectiveness of the Palmaz balloon expandable stent for the creation of a transjugular intrahepatic portosystemic shunt. The device is designed to achieve portal decompression in patients with variceal hemorrhage secondary to portal hypertension. DESIGN: --Transjugular intrahepatic portosystemic shunting was performed in eight patients during a 9-month period. Mean follow-up was 5 months. PATIENTS: --All patients had cirrhosis with portal hypertension and varices. Bleeding occurred in seven patients from esophageal varices and in one patient from hemorrhoids. MAIN OUTCOME MEASURES: --Shunt patency and recurrent variceal hemorrhage. RESULTS: --Shunts created from a transjugular approach between a hepatic and a portal vein (diameters of 8 to 12 mm) lowered the average portosystemic pressure gradient from 36 to 11 mm Hg. Mean postoperative hospital stay was 7.7 days. Complete variceal decompression after transjugular intrahepatic portosystemic shunt placement was identified endoscopically in all eight patients. The patient treated for hemorrhoids rebled and was treated successfully by transfemoral balloon expansion of the shunt diameter from 8 to 12 mm. All shunts were patent at 1 to 9 months (mean, 5 months) of follow-up. CONCLUSION: --Initial results suggest that transjugular intrahepatic portosystemic shunt is a safe and effective method of portal decompression for the treatment of variceal hemorrhage.

Percutaneous placement of a balloon-expandable intraluminal graft for life-threatening subclavian arterial hemorrhage.

A balloon-expandable intraluminal graft was percutaneously deployed in the left subclavian artery of a 43-year-old woman. This graft was made of a stainless steel, 30-mm Palmaz balloon-expandable iliac stent completely covered with a thin coat of silicone. The procedure was successful in managing and preventing life-threatening hemorrhage as a large-bore catheter was removed from the subclavian artery via its subcutaneous tunnel. Surgical repair of the high brachial-axillary sheath insertion site was required after percutaneous deployment of the graft. However, the grafting procedure succeeded in obviating a thoracotomy. At follow-up of 6 months, despite diminution in brachial pulse volume recordings, the patient is asymptomatic at rest. She experiences mild fatigue with extremes of upper extremity exercise and declines angiographic follow-up and further intervention.

Compact contrast material bolus with a new 5-F angiographic catheter.

The conventional pigtail catheter was compared with the 5-F Tennis Racquet catheter for abdominal aortography with digital subtraction angiography. Resulting aortograms were judged on the basis of the quality of aortic opacification and renal artery visualization. The authors concluded that the Tennis Racquet catheter produces a more compact contrast material bolus, and its use is associated with acquisition of superior abdominal aortograms.

Medical student perceptions of diagnostic radiology. Influence of a senior radiology elective.

To assess the impact of a four-week elective on medical student perceptions of diagnostic radiology, we gave questionnaires to 96 senior students on the first and last days of the rotation. Eighty-five anonymous entrance responses and 73 exit responses were obtained during a 13-month interval. Compared with other clinical specialties, the students viewed radiology as third, behind surgery and medicine, in terms of required breadth of knowledge, skill, training, and "glamour." Radiology was also perceived to have the lightest workload with the exception of psychiatry. Responses did not significantly change after completion of the elective. Perceived advantages and disadvantages of radiology were studied in detail in a subset of students. Exit responses indicated that the elective promoted favorable perceptions of radiology but did not change the relative rankings of the various specialties. It appears that at our institution basic attitudes concerning radiology are formed prior to the senior radiology elective and are affected only moderately during the elective.

Hickman nodule: a mimic of metastatic disease.

A characteristic small subcutaneous soft-tissue mass can be seen on the computed tomographic scans of patients after removal of Hickman catheters. The mass is indistinguishable from subcutaneous metastatic deposits seen with a variety of malignant tumors. This potentially confusing finding can be differentiated from true metastatic disease by the characteristic location of the subcutaneous nodule in the second or third anterior intercostal space, along the midclavicular line, and by the absence of other subcutaneous masses.

Neuroimaging of scuba diving injuries to the CNS.

Diving accidents related to barotrauma constitute a unique subset of ischemic insults to the CNS. Victims may demonstrate components of arterial gas embolism, which has a propensity for cerebral involvement, and/or decompression sickness, with primarily spinal cord involvement. Fourteen patients with diving-related barotrauma were studied with MR imaging of the brain and spinal cord and with CT of the brain. In four patients with presumed cerebral gas embolism, cranial MR was abnormal in three patients while CT was abnormal in only one. Twelve patients had decompression sickness and spinal cord symptoms. MR documented spinal cord abnormalities in three patients. However, scans obtained early in our study were frequently limited by technical constraints. MR of the brain is more sensitive than conventional CT scanning techniques in detecting and characterizing foci of cerebral ischemia caused by embolic barotrauma to the CNS. Although spinal MR may be less successful in the localization of spinal cord lesions related to decompression sickness, these lesions were previously undetectable by other neuroimaging methods.

Aortobronchopulmonary fistula complicating aortic aneurysm: diagnosis in four cases.

Aortobronchopulmonary fistula, a fistulous connection between the aorta and lung, is uniformly fatal in untreated cases. However, with early recognition and surgery, the survival rate exceeds 80%. We have had four patients with aortobronchopulmonary fistula, all of which resulted from thoracic aortic aneurysms (two after grafting of thoracic aortic aneurysms, one mycotic, one atherosclerotic). All four patients presented with hemoptysis. All four had a chest radiograph, which in two showed the aneurysm and in three showed airspace disease adjacent to the aorta. The aneurysm was shown by CT in one of two patients and by aortography in two of three patients. Neither CT nor aortography showed the fistula. Aortobronchopulmonary fistula was proved by surgery in two of the patients and by autopsy in the other two. A high index of suspicion is necessary to make the diagnosis of aortobronchopulmonary fistula. The diagnosis should be considered in patients who have minor or major hemoptysis, with either coexisting thoracic aortic aneurysms or history of thoracic aneurysm repair.

Relationship between sex drive and sexual frustration and purpose in life.

Forty-eight college students (18 males, M age = 24.3, 30 females, M age = 23.5) participated in a study that investigated the relationship between one's sense of purpose in life and sexual attitudes and behavior. The test instruments included the Purpose in Life Test (PIL), a Sex Drive and Interest Scale, and a Sexual Frustration and Maladjustment Scale. Correlations were computed between the students' PIL scores and scores on each of the sex scales. The results indicated no relationship between PIL scores and the scores on the sex drive scale, whereas significant negative correlations were found between PIL scores and the sexual frustration scores for males and for the combined group of males and females. The scores on the PIL and the sexual frustration scale were not related to the students' sex. These results support Frankl's theory that sexual frustration may be a manifestation of a more general existential frustration.