Transfusion criteria in free flap surgery.

Objective: The ideal hematocrit for patients undergoing free flap reconstruction is unknown. It is standard practice to keep hematocrit levels above 30 percent, although there is evidence that blood transfusions are associated with both infectious and noninfectious complications. We propose that lowering the trigger for postoperative transfusions from 30 percent to 25 percent will not increase flap-related complications and may reduce unnecessary blood transfusions.

Modified ileocolic free flap: viable choice for reconstruction of total laryngopharyngectomy with total glossectomy.

Background: Reconstruction following total laryngopharyngectomy and total glossectomy is quite challenging. Many free flaps are not options for reconstruction of this particular defect because of the large area that requires reconstruction and the size discrepancies of the oral and esophageal stomas. We propose a modified ileocolic free flap for reconstruction of these defects.

Molality as a unit of measure for expressing 1H MRS brain metabolite concentrations in vivo.

Absolute concentrations of cerebral metabolite in in vivo 1H magnetic resonance spectroscopy studies (1H-MRS) are widely reported in molar units as moles per liter of tissue, or in molal units as moles per kilogram of tissue. Such measurements require external referencing or assumptions as to local water content. To reduce the scan time, avoid assumptions that may be invalid under specific pathologies, and provide a universally accessible referencing procedure, we suggest that metabolite concentrations from 1H-MRS measurements in vivo be reported in molal units as moles per kilogram of tissue water.