MRA of the skin: mapping for advanced breast reconstructive surgery.

Autologous breast reconstruction using muscle-sparing free flaps are becoming increasingly popular, although microvascular free flap reconstruction has been utilised for autologous breast reconstructions for >20 years. This innovative microsurgical technique involves meticulous dissection of artery-vein bundle (perforators) responsible for perfusion of the subcutaneous fat and skin of the flap; however, due to unpredictable anatomical variations, preoperative imaging of the donor site to select appropriate perforators has become routine. Preoperative imaging also reduces operating time and enhances the surgeon's confidence in choosing the appropriate donor site for harvesting flaps. Although computed tomography angiography has been widely used for preoperative imaging, concerns over excessive exposure to ionising radiation and poor iodinated contrast agent enhancement of the intramuscular perforator course has made magnetic resonance angiography, the first choice imaging modality in our centre. Magnetic resonance angiography with specific post-processing of the images has established itself as a reliable method for mapping tiny perforator vessels. Multiple donor sites can be imaged in a single setting without concern for ionising radiation exposure. This provides anatomical information of more reconstruction donor site options, so that a surgeon can design a flap of tissue centralised around the best perforator, as well as a back-up perforator, and even a back-up flap option located on a different region of the body. This information is especially helpful in patients with a history of scar tissue from previous surgeries, where the primary choice perforator is found to be damaged or unsuitable intraoperatively. In addition, chest magnetic resonance angiography evaluates recipient site blood vessel suitability including vessel diameters, course, and branching patterns. In this article we provide a broad overview of various skin flaps, clinical indications, advantages and disadvantages of each of these flaps, basic imaging technique, along with advanced sequences for visualising tiny arteries in the groin and in the chest. Post-processing techniques, structure of the report and how automation of the reporting system improves workflow is described. We also describe applications of magnetic resonance angiography in postoperative imaging.

Clozapine and the development of salivary gland swelling: a case study.

BACKGROUND: Clozapine is a novel antipsychotic that is effective in 30% to 50% of treatment-resistant schizophrenia. It is known to cause sialorrhea in 23% of patients. This phenomenon is paradoxical and poorly understood since clozapine is known to have potent anticholinergic effects. We have observed the development of transient salivary gland swelling in four patients on clozapine therapy. Although not clearly related to sialorrhea, this phenomenon may share a similar pathophysiology. METHOD: A retrospective chart review was performed on the 4 of 27 patients started on clozapine treatment during a 6-month period who developed salivary gland swelling. RESULTS: Four patients, none of whom had previously complained of sialorrhea, developed salivary gland swelling after starting clozapine treatment. In all cases, the swelling resolved within days. A possible etiology may be the formation of a calculus that blocks the duct and causes swelling, which resolves when the stone passes. CONCLUSION: Clinicians should be aware that salivary gland swelling may be a possible side effect of clozapine use.

Clozapine: its impact on aggressive behavior among patients in a state psychiatric hospital.

Clozapine has shown consistent efficacy against positive symptoms of psychoses, and emerging reports indicate improvements in aggression and suicidality. This study evaluated the impact of clozapine aggression in a psychiatric hospital. Over a three year period, 137 subjects with schizophrenia or schizoaffective disorder received clozapine, of whom nearly 50% (n=69) experienced seclusion or restraint. Using a mirror-image study design, seclusion and restraint rates were computed per patient-month pre-clozapine and compared during clozapine treatment to a maximum of 12 months in either direction. The rest of the hospital not receiving clozapine served as a comparator group. Statistically significant reductions occurred in both seclusion (0.44+/-0.46 vs. 0.16+/-0.32, z=-3.91, p=0.0003) and restraint (0.34+/-0.47 vs. 0.08+/-0.23, z=-2.27, p=0.032) during clozapine treatment as compared with the pre-clozapine period. The comparator group experienced a low rate of seclusion and restraint throughout. While there are limitations to a mirror-image design, this study supports the emerging data on the benefits of clozapine for aggressive and violent patients with psychoses. Preliminary data suggests other second generation antipsychotic agents may have similar effects.

Expression of Von Willebrand factor, an endothelial cell marker, is up-regulated by angiogenesis factors: a potential method for objective assessment of tumor angiogenesis.

von Willebrand factor (vWF), a glycoprotein produced uniquely by endothelial cells and megakaryocytes, is routinely used to identify vessels in tissue sections. Vessel density in tumor specimens, as determined by immuno-histochemical staining for vWF or other endothelial cell markers, is a negative prognostic factor for many solid tumors. vWF is heterogeneously distributed throughout the vasculature, transcriptional control in response to the tissue microenvironment being responsible for local variations in endothelial cell levels of vWF. Here, we report that fibroblast growth factor-2 and vascular endothelial growth factor, potent angiogenesis inducers expressed in a variety of tumors, up-regulate expression of vWF mRNA and protein in cultured endothelial cells with a synergistic effect. Our data support the measurement of vWF mRNA in tumors to detect activated endothelium or angiogenesis. For this purpose, we developed a semi-quantitative RT-PCR for vWF mRNA. Preliminary results obtained with specimens from colon carcinoma and the corresponding normal colonic mucosa showed higher vWF mRNA levels in most tumors than in their normal counterparts. The differences in vWF mRNA levels were much larger than the differences in vessel counts between a tumor and the corresponding normal mucosa, indicating that high vWF mRNA levels in tumors may indeed be an early sign of activation of the endothelium. The rapidity, objectivity, sensitivity and specificity of this technique make it suitable for routine clinical application to identify aggressive, highly angiogenic tumors.