Integrative multiomics analysis of neointima proliferation in human saphenous vein: implications for bypass graft disease.

Introduction: Human saphenous veins (SV) are widely used as grafts in coronary artery bypass (CABG) surgery but often fail due to neointima proliferation (NP). NP involves complex interplay between vascular smooth muscle cells (VSMC) and fibroblasts. Little is known, however, regarding the transcriptomic and proteomic dynamics of NP. Here, we performed multi-omics analysis in an ex vivo tissue culture model of NP in human SV procured for CABG surgery. Methods and results: Histological examination demonstrated significant elastin degradation and NP (indicated by increased neointima area and neointima/media ratio) in SV subjected to tissue culture. Analysis of data from 73 patients suggest that the process of SV adaptation and NP may differ according to sex and body mass index. RNA sequencing confirmed upregulation of pro-inflammatory and proliferation-related genes during NP and identified novel processes, including increased cellular stress and DNA damage responses, which may reflect tissue trauma associated with SV harvesting. Proteomic analysis identified upregulated extracellular matrix-related and coagulation/thrombosis proteins and downregulated metabolic proteins. Spatial transcriptomics detected transdifferentiating VSMC in the intima on the day of harvesting and highlighted dynamic alterations in fibroblast and VSMC phenotype and behavior during NP. Specifically, we identified new cell subpopulations contributing to NP, including SPP1 + , LGALS3 + VSMC and MMP2 + , MMP14 + fibroblasts. Conclusion: Dynamic alterations of gene and protein expression occur during NP in human SV. Identification of the human-specific molecular and cellular mechanisms may provide novel insight into SV bypass graft disease.

Aortic Dissection as a Cause of Pulsus Bisferiens: A Case Report and Review.

We present a case of a 62-year-old woman who developed an aortic dissection after aortic valve replacement for aortic stenosis and supracoronary replacement of the ascending aorta for aneurysmal dilation. Dynamic compression of the distal aorta by the dissection flap was identified with the detection of abnormal continuous wave Doppler signals heard while performing ankle-brachial indices. Duplex ultrasound (US) and Doppler spectral waveforms confirmed dynamic compression of the distal aorta with each cardiac cycle. We review some of the characteristics of continuous wave Doppler signals, specifically discussing the distinguishing characteristics of pulsus bisferiens, and the use of duplex US in imaging the distal aorta.

The use of rigid sternal fixation for complex poststernotomy wounds and a military-unique fracture at an Army medical center.

Sternal wound complications after sternotomy carry significant morbidity and mortality rates. Sternal fractures attributable to blunt trauma may cause incapacitating pain or may be plagued by symptoms resulting from chronic nonunion. A sternal fixation system has been developed and used successfully for the management of poststernotomy complications, as well as for symptomatic fractures and fracture nonunion. This article reports the successful use of this technique for three patients at our institution. The use of rigid sternal fixation could potentially be extended to include primary sternotomy closure in patients at high risk for sternal dehiscence and nonunion. This technique may also substitute for sternal rewiring in the initial management of poststernotomy complications.

Surgical repair of a chronic traumatic sternal fracture.

Chronic sternal fracture nonunion is usually reported after median sternotomy, but rarely after blunt chest trauma. Most traumatic fractures of the sternum are managed nonoperatively if they are asymptomatic and nondisplaced. Acute surgical therapy is indicated for debilitating chest pain usually associated with fracture displacement. We report a case of debilitating chest pain associated with a chronic sternal fracture. Our surgical technique is discussed and the literature is reviewed.