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QS239. Adventitial Fibroblasts in Thoracic Aortic Aneurysm and Dissection (TAAD)
362 ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS Douglas A. Wiegmann3, Thoralf M. Sundt III2; 1Mayo Medical School, Rochester, MN; 2Mayo Clinic, Rochester, MN; 3 University of Wisconsin - Madison, Madison, WI Objective: The objective of this study was to develop and implement a pre-operative briefing specific to cardiac surgery. As efforts to introduce such processes may be hampered due to poor acceptance by staff, we took a collaborative approach to its development and implementation. Methods: In order to tailor the informational content to the local practice and reinforce by-in from members of the team, the briefing format was generated through a team-oriented process using a combined questionnaire and semi-structured focus group approach involving six surgical staff subspecialties (n⫽66; Certified Surgical Technician, Certified Surgical Assistant, Registered Nurse, Surgeon, Perfusionist, and Certified Registered Nurse Anesthesiologist). This information was gathered to determine (1) staff attitude regarding preoperative briefings, (2) logistical issues related to the conduct and content of briefings and (3) potential barriers that would impede implementation of the briefing. These findings were then utilized to develop a pre-operative briefing specific to cardiac surgery. Results: A briefing format was successfully developed and has now been instituted. Analyses prior to institution of the briefing revealed positive consensus among surgical staff regarding the pre-operative briefing’s benefits, duration ( Discussion: This study demonstrates the feasibility of creating a preoperative briefing protocol with a high degree of acceptance by OR personnel. We recommend a collaborative approach to the development of an institution-specific and specialty-specific briefing too, as well as collaborative conduct of the briefing itself. Bibliography: Sexton, J.B., Helmreich, R.L., Neilands, T.B., Rowan, K., Vella, K., Boyden, J., Roberts, P.R., Thomas, E.J. (2006). The Safety Attitudes Questionnaire: psychometric properties, benchmarking data, and emerging research. BMC Health Services Research 6(44). QS239. ADVENTITIAL FIBROBLASTS IN THORACIC AORTIC ANEURYSM AND DISSECTION (TAAD). Jeong S. Yoon1, Lin Zhang1, Ying H. Shen1, Monique Criddell1, Scott A. LeMaire1, Dianna M. Milewicz2, Joseph S. Coselli1, Xing Li Wang1; 1Baylor College of Medicine, Houston, TX; 2University of Texas Health Science Center Houston, Houston, TX Thoracic aortic aneurysms and dissection (TAAD) occur when the original aortic structure is too weak, destructive forces are too powerful, and repair mechanisms are not competent. Central to the repair mechanisms, are adequately functional cellular components of the aortic wall, including endothelial cells, smooth muscle cells (SMCs), inflammatory cells, and adventitial fibroblasts. Physiologically, adventitial fibroblasts regulate the metabolism of aortic extracellular matrix (ECM) and, when required, can migrate to the medial layer and transform into SMCs, which are critical in aortic wall remodeling and repair. Therefore, we tested the hypothesis that adventitial fibroblasts in TAAD patients have reduced capacity for SMC transformation and ECM metabolism, which contributes to the pathogenesis of TAAD. Adventitial fibroblasts were collected from the adventitial layer of fresh aortic tissues excised from patients during aortic repair operations and from organ donors after the transplant organs were removed. The cells were cultured no more than 4 passages before the functional analyses. We first treated cells with TNF␣_an inflammatory cytokine_and found that MMP-3 expression was significantly higher in fibroblasts from normal aortas than in fibroblasts from TAAD aortas. We further treated the adventitial fibroblasts with TGF-1 (10 pM) for up to 12 days, during which TGF-1 levels were supplemented every 4 days to assess the capacity of SMCs for differentiation. Whereas it took 2 days for normal aortic adventitial fibroblasts to express SM ␣-actin and SM-MHC, indicating SMC transformation, it took ⬎6 days for fibroblasts of TAAD aorta to express these markers. Furthermore, TGF-1-stimulated ad-
ventitial fibroblasts from TAAD aortas expressed less Ki-67 (a synthetic phenotype for SMCs) than did TGF-1-stimulated healthy control fibroblasts, whereas SM-calponin expression was not different between the two types of fibroblasts. Our results suggest that ECM production and SMC transformation are compromised in fibroblasts from TAAD aortas. Functional restoration of adventitial fibroblasts could be a novel target for medical treatment of TAAD. QS240. THE EFFECT OF CENTRAL VENOUS DIALYSIS CATHETERS ON ARTERIOVENOUS GRAFT PATENCY. Isela Vasquez, Melissa E. Grammer, Nicole P. Bernal, Pawel T. Dyk, James R. Mark, Paul J. Garvin; Saint Louis University Hospital, Saint Louis, MO Introduction: The arteriovenous fistula remains the preferred procedure for hemodialysis vascular access, however, alternate means of vascular access are necessary in patients whose superficial veins are inadequate. Since the polytetrafluoroethylene (PTFE) graft continues to be our secondary vascular access of choice, we undertook a 58-month evaluation of our results with this conduit. Although many patients present for placement of permanent access with a dialysis catheter in place, little is known about the effect this has on the survival of the patient’s long term access. Methods: A retrospective analysis was undertaken of patients undergoing arteriovenous graft (AVG) placement between August 1, 2002 and May, 31, 2007. Actuarial graft patencies were calculated using the Kaplan-Meier method and the chi-squared test, F-test, and student t-test were used for comparative analysis of variables. Results: A total of 647 arteriovenous grafts were constructed in this interval. The average patient age was 54.5 ⫹/⫺ 14.6 years with a female to male predominance of 53.5% to 46.5%. The incidence of diabetes was 53.9% while 84.5% of patients were dialysis dependent at the time of graft insertion. The forearm was the most common site for insertion (68.8%) with the upper arm (24.4%) and thigh (6.8%) also being utilized. One-year primary actuarial patency was 41.4%, and one-year secondary actuarial patency was 64.0%. Of the 274 AVGs abandoned, 23.7% (65) were not referred to our center for intervention. Excluding these patients from analysis, one-year secondary actuarial patency was 68.1%. Reasons for AVG loss were thrombosis [52.9% (145)], infection [37.6% (103)], steal [4.0% (11)], infection and thrombosis [1.8% (5)], seroma [1.1% (3)], and other [2.6% (7)]. No statistically significant differences in one-year patency rates were observed based upon graft location, gender, diabetes mellitus, or history of prior access. Reduced one-year patency rates were seen with documented central venous occlusion (p ⬍ 0.001), and the presence of tunneled catheter at time of insertion (p ⫽ 0.035). Conclusion: Our results suggest patients who were not referred after graft loss, may have benefited from an attempt at secondary patency prior to abandonment. AVG patency remains problematic and is adversely affected by known central vein occlusion, and the presence of a tunneled catheter. As the presence or history of catheters are associated with a central venous occlusion, earlier referral for access prior to placement of central venous catheter would be beneficial to improve the long term outcome of PTFE AVG. QS241. SURGICAL THROMBECTOMY REMAINS A STANDARD OF CARE FOR TREATMENT OF THROMBOSED ARTERIOVENOUS GRAFTS. Nicole P. Bernal, Melissa E. Grammer, James R. Mark, Pawel T. Dyk, Paul J. Garvin; Saint Louis University Hospital, Saint Louis, MO Introduction: Arteriovenous grafts (AVG) for hemodialysis provide a safe alternative to central venous catheters (CVC) in hemodialysis patients in which AV fistulas are unattainable. While the familiar complication of thrombosis persists as a challenge to long term AVG patency, the combination of advances in endovascular techniques and the availability of CVCs has led to the unnecessary abandon-
ventitial fibroblasts from TAAD aortas expressed less Ki-67 (a synthetic phenotype for SMCs) than did TGF-1-stimulated healthy control fibroblasts, whereas SM-calponin expression was not different between the two types of fibroblasts. Our results suggest that ECM production and SMC transformation are compromised in fibroblasts from TAAD aortas. Functional restoration of adventitial fibroblasts could be a novel target for medical treatment of TAAD. QS240. THE EFFECT OF CENTRAL VENOUS DIALYSIS CATHETERS ON ARTERIOVENOUS GRAFT PATENCY. Isela Vasquez, Melissa E. Grammer, Nicole P. Bernal, Pawel T. Dyk, James R. Mark, Paul J. Garvin; Saint Louis University Hospital, Saint Louis, MO Introduction: The arteriovenous fistula remains the preferred procedure for hemodialysis vascular access, however, alternate means of vascular access are necessary in patients whose superficial veins are inadequate. Since the polytetrafluoroethylene (PTFE) graft continues to be our secondary vascular access of choice, we undertook a 58-month evaluation of our results with this conduit. Although many patients present for placement of permanent access with a dialysis catheter in place, little is known about the effect this has on the survival of the patient’s long term access. Methods: A retrospective analysis was undertaken of patients undergoing arteriovenous graft (AVG) placement between August 1, 2002 and May, 31, 2007. Actuarial graft patencies were calculated using the Kaplan-Meier method and the chi-squared test, F-test, and student t-test were used for comparative analysis of variables. Results: A total of 647 arteriovenous grafts were constructed in this interval. The average patient age was 54.5 ⫹/⫺ 14.6 years with a female to male predominance of 53.5% to 46.5%. The incidence of diabetes was 53.9% while 84.5% of patients were dialysis dependent at the time of graft insertion. The forearm was the most common site for insertion (68.8%) with the upper arm (24.4%) and thigh (6.8%) also being utilized. One-year primary actuarial patency was 41.4%, and one-year secondary actuarial patency was 64.0%. Of the 274 AVGs abandoned, 23.7% (65) were not referred to our center for intervention. Excluding these patients from analysis, one-year secondary actuarial patency was 68.1%. Reasons for AVG loss were thrombosis [52.9% (145)], infection [37.6% (103)], steal [4.0% (11)], infection and thrombosis [1.8% (5)], seroma [1.1% (3)], and other [2.6% (7)]. No statistically significant differences in one-year patency rates were observed based upon graft location, gender, diabetes mellitus, or history of prior access. Reduced one-year patency rates were seen with documented central venous occlusion (p ⬍ 0.001), and the presence of tunneled catheter at time of insertion (p ⫽ 0.035). Conclusion: Our results suggest patients who were not referred after graft loss, may have benefited from an attempt at secondary patency prior to abandonment. AVG patency remains problematic and is adversely affected by known central vein occlusion, and the presence of a tunneled catheter. As the presence or history of catheters are associated with a central venous occlusion, earlier referral for access prior to placement of central venous catheter would be beneficial to improve the long term outcome of PTFE AVG. QS241. SURGICAL THROMBECTOMY REMAINS A STANDARD OF CARE FOR TREATMENT OF THROMBOSED ARTERIOVENOUS GRAFTS. Nicole P. Bernal, Melissa E. Grammer, James R. Mark, Pawel T. Dyk, Paul J. Garvin; Saint Louis University Hospital, Saint Louis, MO Introduction: Arteriovenous grafts (AVG) for hemodialysis provide a safe alternative to central venous catheters (CVC) in hemodialysis patients in which AV fistulas are unattainable. While the familiar complication of thrombosis persists as a challenge to long term AVG patency, the combination of advances in endovascular techniques and the availability of CVCs has led to the unnecessary abandon-