The effect of bilateral internal thoracic artery harvesting on superficial and deep sternal infection: The role of skeletonization

Objective: To determine the relative risk of sternal dehiscence in patients undergoing bilateral internal thoracic artery harvesting and to assess whether and to what extent the technique of artery skeletonization might reduce this risk. Methods: Prospectively collected data on patients undergoing coronary artery bypass operations with at least a single internal thoracic artery were reviewed. The last 450 patients receiving bilateral internal thoracic artery grafts were compared with 450 patients who received a single internal thoracic artery during the same period. The left internal thoracic artery was always harvested in a pedicled fashion. Among patients receiving a bilateral internal thoracic artery, both arteries were harvested in a pedicled fashion in 300 cases, whereas both internal thoracic arteries were skeletonized in the remaining 150 cases. Results: Compared with a single internal thoracic artery, harvesting both internal thoracic arteries either in a skeletonized or in a pedicled fashion increased the chance of deep (1.1% vs 3.3% vs 4.7%; P =. 01) or superficial (4.8% vs 7.8% vs 12%; P =. 002) sternal infection. However, the technique of artery harvesting (odds ratio, 4.1; 95% confidence interval, 1.4-12.1); the presence of peripheral arteriopathy (odds ratio, 3.1; 95% confidence interval, 1.2-8.5), and resternotomy for bleeding (odds ratio, 8.2; 95% confidence interval, 2.0-33.6) were the only independent predictors for deep sternal infection, whereas the technique of artery harvesting (odds ratio, 3.0; 95% confidence interval, 1.6-5.4), female sex (odds ratio, 2.2; 95% confidence interval, 1.2-4.2), and diabetes (odds ratio, 1.7; 95% confidence interval, 1.0-2.9) were the only independent predictors of superficial sternal infection. In diabetic patients, there was no difference in the incidence of deep sternal infection among patients receiving a single internal thoracic artery or double skeletonized internal thoracic arteries (P =. 4). Conclusions: Bilateral internal thoracic artery harvesting carries a higher risk of sternal infection than harvesting a single internal thoracic artery. Skeletonization of both internal thoracic arteries significantly decreases this risk. A strategy of bilateral thoracic artery grafting can also be offered to patients at high risk for wound infection. Copyright © 2005 by The American Association for Thoracic Surgery

Biochemical and immunohistochemical identification of MMP-7 in human dentin

Objectives: Matrix metalloproteinases (MMPs) are dentinal endogenous enzymes claimed to have a vital role in dentin organic matrix breakdown. The aim of the study was to investigate presence, localization and distribution of MMP-7 in sound human dentin. Methods: Dentin was powdered, demineralized and dissolved in isoelectric focusing buffer. Resolved proteins were transferred to nitrocellulose membranes for western blotting (WB) analyses. For the zymographic analysis, aliquots of dentin protein were electrophoresed in 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing fluorescently labeled gelatin. Further, the concentrations of dentinal MMPs were measured using Fluorescent Microsphere Immunoassay with a human MMP-MAP multiplex kit. Pre- and post-embedding immunolabeling technique was used to investigate the localization and distribution of MMP-7 in dentin. Dentin was cryo-fractured, the fragments partially decalcified and labeled with a primary monoclonal anti-MMP-7 and a secondary antibody conjugated with gold nanoparticles. MMP-7 labelings were identified in the demineralized dentin matrix as highly electron-dense dispersed gold particles. Results: WB and zymographic analysis of extracted dentin proteins showed presence of MMP-7 (similar to 20-28 KDa). Further, MMP-7 was found in the supernatants of the incubated dentin beams using Fluorescent Microsphere Immunoassay. FEI-SEM and TEM analyses established MMP-7 as an intrinsic constituent of the human dentin organic matrix. Conclusion: This study demonstrated that MMP-7 is an endogenous component of the human dentin fibrillar network. Clinical significance: It is pivotal to understand the underlying processes behind dentin matrix remodeling and degradation in order to develop the most optimal clinical protocols and ensure the longevity of dental restorations.Peer reviewe

How to achieve an aortic root remodelling by performing an aortic root reimplantation

The aortic root remodelling procedure, introduced by Yacoub in the early 1980s, is the valve-sparing aortic root replacement procedure that better reproduces the anatomical and functional properties of the native aortic root. Long-term durability of the repair, in terms of freedom from recurrent aortic regurgitation, has been questioned and can probably be improved by appropriate patient selection. Reproducibility of the operation, however, depends on subjective evaluations and surgical skill. We report a simplification of the technique designed to possibly increase the reproducibility of the aortic root remodelling operation while retaining its functional advantages

Bentall procedures with a novel valved conduit incorporating "sinuses of Valsalva"

The Bentall operation is preferred when a diseased aortic valve is associated with a dilated or dissected ascending aorta. Composite valved grafts have been devised to facilitate and expedite this procedure. The initial clinical results of the Bentall procedure using a vascular conduit modified to incorporate "pseudosinuses of Valsalva," with the aim of simplifying coronary button anastomoses and decreasing tension upon them, is described herein. Over a period of 40 months since its introduction, the novel conduit has been used, for a Bentall procedure in 37 consecutive patients. Of this group, 31 were men and 6 were women, with a mean age of 63.8+/-9.9 years. Five were Marfan patients, 8 were patients after acute or chronic dissection, and 8 were patients who required redo procedures. In 22 patients, the modified conduit was used in association with a biological valve (4 stentless valve) and in 15, with a mechanical valve. The mean durations of CPB and X-clamp time were 117+/-32 and 88+/-22 minutes, respectively. No operative or late deaths occurred after a mean follow-up period of 20+/-12 months. This study indicates that the new vascular prosthesis appears to facilitate implantation by maintaining a more natural shape of the reconstructed aortic root

Differences in aortic cusp coaptation between the reimplantation and the remodeling techniques of aortic valve-sparing surgery: An in vitro porcine model study

We sought to evaluate the effects of the reimplantation type versus the remodeling type of aortic valve-sparing technique on the geometry of the same aortic root