Functional lymphatic anatomy for sentinel node biopsy in breast cancer: echoes from the past and the periareolar blue method.

OBJECTIVE: To simplify and improve the technique of axillary sentinel node biopsy, based on a concept of functional lymphatic anatomy of the breast. SUMMARY BACKGROUND DATA: Because of their common origin, the mammary gland and its skin envelope share the same lymph drainage pathways. The breast is essentially a single unit and has a specialized lymphatic system with preferential drainage, through select channels, to designated (sentinel) lymph nodes in the lower axilla. METHODS: These hypotheses were studied by comparing axillary lymph node targeting after intraparenchymal peritumoral radiocolloid (detected by a gamma probe) with the visible staining after an intradermal blue dye injection, either over the primary tumor site (90 procedures) or in the periareolar area (130 procedures). The radioactive content, blue coloring, and histopathology of the individual lymph nodes harvested during each procedure were analyzed. RESULTS: Radiolabeled axillary nodes were identified in 210 procedures, and these were colored blue in 200 cases (94%). The targeting concordance between peritumoral radiocolloid and intradermal blue dye was unrelated to the breast tumor location or the site of dye injection. Radioactive sentinel nodes were not stained blue in 10 procedures (5%), but this mismatching could be explained by technical problems in all cases. In two cases (1%), the (pathologic) sentinel node was blue but had no detectable radiocolloid uptake. CONCLUSIONS: The lessons learned from this study provide a functional concept of the breast lymphatic system and its role in metastasis. Anatomical and clinical investigations from the past strongly support these views, as do recent sentinel node studies. Periareolar blue dye injection appears ideally suited to identify the principal (axillary) metastasis route in early breast cancer. Awareness of the targeting mechanism and inherent technical restrictions remain crucial to the ultimate success of sentinel node biopsy and may prevent disaster.

Does impedance cardiography reliably estimate left ventricular ejection fraction?

OBJECTIVE: The objective of our study was to evaluate impedance cardiography (IMP) as a noninvasive method to determine the left ventricular ejection fraction (LVEF). METHODS. A total of 24 patients, 8 men and 16 women, aged 45.0 +/- 12.9 years, participated in the study. They used cardiotoxic chemotherapeutic drugs or suffered from cardiac failure. LVEF was measured by means of IMP (LVEFimp) and radionuclide ventriculography (LVEFnuc). LVEFimp was calculated in three ways. Capan and colleagues [13] proposed a formula in which LVEF (LVEFCap) can be calculated from the systolic time intervals, namely, left ventricular ejection time and preejection time. Judy and colleagues [14] described a systolic (S) and a diastolic (D) part in the first derivative curve of the impedance signal. The ratio S/D might equal the LVEF (LVEFJud). A new LVEF calculation was introduced (LVEFimp) in this study based on the first derivative of the impedance signal, the thoracic impedance, and heart rate. RESULTS: Mean LVEFCap was 59.9 +/- 8.4%, which did not differ from LVEFnuc (59.9 +/- 7.1%). However the correlation between both methods was not significant (r = 0.29). Mean LVEFJud was 63.9 +/- 17.4%, which was not significantly different from LVEFnuc, with a fair correlation (r = 0.55). Mean LVEFimp was 59.2 +/- 9.4%, with a better correlation with radionuclide ventriculography (r = 0.75). CONCLUSIONS: The results of this study indicate that the equations that have been used until now can be improved. The new equation provides reliable LVEF values in this group of patients.