Contemporary management of aortic branch compromise resulting from acute aortic dissection.

PURPOSE: In an earlier report, we documented the incidence and impact of aortic branch compromise complicating acute aortic dissection (AD) over a 21-year interval (1965-1986). In the current study, management of peripheral vascular complications (PVCs) of AD over the past decade was reviewed. METHODS: Medical records of patients treated for AD over the interval January 1, 1990, to December 31, 1999, were reviewed. Patients with branch compromise confirmed with radiography or operation and patients with spinal cord ischemia that was based on results of a physical examination defined the study group. Comparisons between subgroups with and without PVC over a 30-year interval were analyzed with the chi(2) test. RESULTS: A total of 187 patients (101 proximal and 86 distal) were treated for AD over the study interval. A total of 53 (28%) of these patients had clinical evidence of organ or limb malperfusion (7 cerebral, 3 upper extremity, 5 spinal cord, 11 mesenteric, 12 renal, and 24 lower extremity [sites inclusive]), and one of three (17 patients) of these underwent specific peripheral vascular intervention. The remaining 65% (36) of the PVC group had complete or partial malperfusion resolution after central aortic therapy (medical or surgical) alone. Open techniques for treating PVC included aortic fenestration (9), femorofemoral grafting (2), and aortofemoral grafting (1). All had favorable outcomes with no mortality. Endovascular procedures in five patients included abdominal aortic fenestration (3) or stenting of the renal (2), mesenteric (2), and iliac (1) arteries with clinical success in three patients and two deaths. The in-hospital mortality rate for the entire group of 187 patients was 18% (15% for proximal aortic operation, 8% in medically treated patients). The presence of aortic branch compromise was not a statistically significant predictor of the patient mortality rate (23% with and 16% without; P =.26). Overall mortality rate in the current study (18% vs 37%; P =.000006) and the mortality rate with PVC (23% vs 51%; P =.001), in particular with mesenteric ischemia (36% vs 87%; P =.026), decreased significantly when compared with prior experience. CONCLUSIONS: The overall mortality rate from AD during the past decade has decreased significantly. Similar trends were noted in patients with PVCs, a previously identified high-risk subgroup. Increased awareness and prompt, specific management of PVCs, in particular when visceral ischemia is present, have contributed to improved outcomes in patients with AD.

Infrared spectroscopic studies on the phosphatidylserine bilayer interacting with calcium ion: effect of cholesterol.

Fourier transform infrared (IR) spectroscopic studies of phosphatidylserine/cholesterol/Ca2+ complexes are reported using the synthetic phosphatidylserines (PS) 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS), 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), and 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS). IR spectra reveal that cholesterol does not significantly alter the binding nature of Ca2+ to PS molecules; Ca2+ binds to the phosphate ester group of PS in the presence of cholesterol up to 50 mol% as in the case of pure PS bilayers. However, the IR data indicate that the presence of cholesterol induces disorder of the acyl chain packing, increases the degree of immobilization of the interfacial and polar regions, and increases the degree of dehydration of the PS/Ca2+ complexes.