Spectrum of congenital anomalies of the inferior vena cava: cross-sectional imaging findings.

Congenital anomalies of the inferior vena cava (IVC) and its tributaries have become more commonly recognized in asymptomatic patients. The embryogenesis of the IVC is a complex process involving the formation of several anastomoses between three paired embryonic veins. The result is numerous variations in the basic venous plan of the abdomen and pelvis. A left IVC typically ends at the left renal vein, which crosses anterior to the aorta to form a normal right-sided prerenal IVC. In double IVC, the left IVC typically ends at the left renal vein, which crosses anterior to the aorta to join the right IVC. In azygos continuation of the IVC, the prerenal IVC passes posterior to the diaphragmatic crura to enter the thorax as the azygos vein. In circumaortic left renal vein, one left renal vein crosses anterior to the aorta and another crosses posterior to the aorta. In retroaortic left renal vein, the left renal vein passes posterior to the aorta. In circumcaval ureter, the proximal ureter courses posterior to the IVC. Other anomalies include absence of the infrarenal IVC or the entire IVC. These anomalies can have significant clinical implications. Awareness of these anomalies is necessary to avoid diagnostic pitfalls.

Solitary spinal cord sarcoidosis without other manifestations of systemic sarcoidosis.

We report a biopsy-proven case of sarcoidosis limited to the spinal cord and responsive to treatment with oral corticosteroids. Involvement of the spinal cord by systemic sarcoidosis is uncommon and is associated with several unusual pathological and radiological characteristics that may contribute to its misdiagnosis and subsequent mismanagement. The importance of these unusual characteristics is greatly amplified in solitary spinal cord sarcoidosis because there are no systemic findings to suggest a sarcoid etiology.

Lifestyle and low-back pain. The influence of smoking and obesity.

The authors examined associations between back pain prevalence and lifestyle factors (smoking and obesity) using national survey data. Back pain prevalence rose with increasing levels of smoking, with a relative risk of 1.47 for persons reporting 50 or more pack-years of smoking. This association was strongest in persons under the age of 45 years, however, for whom the corresponding relative risk was 2.33. There were similar trends toward greater prevalence with increasing body mass index, but prevalence rose substantially only in the most obese 20% of subjects (1.7 times higher than the lowest 20%). In a logistic regression, smoking and obesity contributed independent risk, even after controlling for age, education, exercise level, and employment status. Programs for back pain prevention may wish to test interventions for these lifestyle-related factors.

Prognostic variability among chronic pain patients: implications for study design, interpretation, and reporting.

Chronic pain patients share many characteristics, but there is important prognostic variability among them. By selecting for certain characteristics, different recruitment methods and entry criteria for clinical or research programs may influence the likelihood of success regardless of treatment efficacy. This was demonstrated when subjects (n = 55) were recruited through lay publicity for a clinical trial of therapy for chronic back pain. In comparison to routine pain clinic patients (n=61), subjects in the clinical trial were better educated, were more often employed, had more favorable personality profiles, and were less likely to have had surgery or narcotic use (all p less than 0.004). Pain relief was significantly better for clinical trial subjects, apparently due to baseline prognostic differences rather than uniquely efficacious therapy. We conclude that chronic pain patients vary in prognostically important ways; that recruitment methods and criteria strongly influence these characteristics; and that greater attention to these details is needed when interpreting and reporting clinical research.