Utilization of Multiple I-125 Radioactive Seeds in the Same Breast is Safe and Feasible: A Multi-institutional Experience.

OBJECTIVE: Radioactive seed localization has been shown to be a reliable and safe alternative to wire localization in breast surgery, but little is known about the use of multiple localization seeds. This study evaluated the utilization of multiple seeds in the same breast. METHODS: All patients who underwent localization of breast lesions using multiple I-125 seeds at three Mayo Clinic sites between January 2003 and June 2014 were included. RESULTS: A total of 461 operations were performed during an 11.5-year study period. The indications for multiple seed placement in the same breast included multiple lesions (n = 258), bracketing (n = 110), multiple lesions and bracketing (n = 67), and a second inserted for more precise localization (n = 26). Among patients with bracketing seeds, the mean distance between seeds was 45 (range 8-110) mm. Removal of the targeted lesion was successful in all cases; 96% of bracketed lesions were removed as a single specimen, and a 98% retrieval rate within the first specimen was obtained. In total 108 of 382 (28%) patients had close or positive margin resulting in a second procedure and 60 of 177 (34%) patients with bracketing procedures underwent reexcision of positive margins or culminated in a mastectomy. Routine intraoperative frozen section analysis was associated with a lower reoperation rate compared with a selective approach to intraoperative margin assessment. CONCLUSIONS: The use of multiple radioactive seeds for localizing multiple lesions in the same breast or bracketing lesions is feasible and safe. Because of the extent of disease, a substantial percentage of these patients require margin reexcision or conversion to mastectomy.

MR imaging evaluation of pericardial constriction.

Abnormal thickening or rigidity of the pericardium may compromise normal cardiac function. This condition is known as pericardial constriction, or constrictive pericarditis. Several imaging modalities are used to evaluate the pericardium, including MR, computed tomography, and echocardiography, which can all play a complementary role aiding diagnosis. This article focuses on MR imaging and its role in the detection and evaluation of pericardial constriction. MR imaging has many advantages compared with other modalities including precise delineation of the pericardial thickness, evaluation of ventricular function, detection of wall motion abnormalities, and provision of information about common (and potentially harmful) sequelae of pericardial constriction.

Comparison of treatment modalities for hemorrhagic shock.

Allogeneic blood resuscitation is the treatment of choice for hemorrhagic shock. When blood is unavailable, plasma expanders, including crystalloids, colloids, and blood substitutes, may be used. Another treatment modality is vasopressin, a vasoconstrictor administered to redistribute blood flow, increase venous return, and maintain adequate cardiac output. While much information exists on systemic function and oxygenation characteristics following treatment with these resuscitants, data on their effects on the microcirculation and correlation of real-time microvascular changes with changes in systemic function and oxygenation in the same animal are lacking. In this study, real-time microvascular changes during hemorrhagic shock treatment were correlated with systemic function and oxygenation changes in a canine hemorrhagic shock model (50-55% total blood loss with a MAP of 45-50 mmHg as a clinical criterion). Following splenectomy and hemorrhage, the dogs were assigned to five resuscitation groups: autologous/shed blood, hemoglobin-based oxygen carrier/Oxyglobin, crystalloid/saline, colloid/Hespan (6% hetastarch), and vasopressin. Systemic function and oxygenation changes were continuously monitored and periodically measured (during various phases of the study) using standard operating room protocols. Computer-assisted intravital video-microscopy was used to objectively analyze and quantify real-time microvascular changes (diameter, red-cell velocity) in the conjunctival microcirculation. Measurements were made during pre-hemorrhagic (baseline), post-hemorrhagic (pre-resuscitation), and post-resuscitation phases of the study. Pre-hemorrhagic microvascular variables were similar in all dogs (venular diameter = 42+/-4 microm, red-cell velocity = 0.55+/-0.5 mm/sec). All dogs showed significant (P < 0.05) post-hemorrhagic microvascular changes: approximately 20% decrease in venular diameter and approximately 30% increase in red-cell velocity, indicative of sympathetic effects arising from substantial blood loss. Microvascular changes correlated with post-hemorrhagic systemic function and oxygenation changes. All resuscitation modalities except vasopressin restored microvascular and systemic function changes close to pre-hemorrhagic values. However, only autologous blood restored oxygenation changes to pre-hemorrhagic levels. Vasopressin treatment resulted in further decreases in venular diameter (approximately 50%) as well as red-cell velocity (approximately 70%) without improving cardiac output. Our results suggested that volume replenishment - not oxygen-carrying capability - played an important role in pre-hospital/en route treatment for hemorrhagic shock. Vasopressin treatment resulted in inadvertent detrimental outcome without the intended benefit.