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Biomedical subjects

John A Curci

Publications and source records attributed to John A Curci.

11 recordsLinked to original sources
PubMed2006

Management of arterial injuries caused by laser extraction of indwelling venous pacemaker and defibrillator leads.

The use of laser technology for the removal of pacemaker and defibrillator leads has decreased the lead extraction time and improved the success rate for complete lead removal when compared to traditional techniques. However, this extraction method may be associated with significant complications. This report documents two cases of iatrogenic arteriovenous fistula created by laser lead extraction. Endovascular repair of these fistulas provides an effective and less invasive alternative to open repair.

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PubMed2006

Pathophysiology of abdominal aortic aneurysms: insights from the elastase-induced model in mice with different genetic backgrounds.

Abdominal aortic aneurysms (AAAs) represent a complex degenerative disorder involving chronic aortic wall inflammation and destructive remodeling of structural connective tissue. Studies using human AAA tissues have helped identify a variety of molecular mediators and matrix-degrading proteinases, which contribute to aneurysm disease, thereby providing a sound foundation for understanding AAAs; however, these human tissue specimens represent only the "end stage" of a long and progressive disease process. Further progress in understanding the pathophysiology of AAAs is therefore dependent in part on the development and application of effective animal models that recapitulate key aspects of the disease. Based on original studies in rats, transient perfusion of the abdominal aorta with porcine pancreatic elastase has provided a reproducible and robust model of AAAs. More recent applications of this model to mice have also opened new avenues for investigation. In this review, we summarize investigations using the elastase-induced mouse model of AAAs including results in animals with targeted deletion of specific genes and more general differences in mice on different genetic backgrounds. These studies have helped us identify genes that are essential to the development of AAAs (such as MMP9, IL6, and AT1R) and to reveal other genes that may be dispensable in aneurysm formation. Investigations on mice from different genetic backgrounds are also beginning to offer a novel approach to evaluate the genetic basis for susceptibility to aneurysm development.

Animals↗
PubMed2006

Pharmacological targets in the treatment of abdominal aortic aneurysms.

The natural history of an abdominal aortic aneurysm (AAA) is of progressive aortic wall degeneration occurring over the course of many years, ultimately, culminating in loss of structural integrity and fatal aortic rupture. Although surgical exclusion of an aneurysm can effectively prevent aortic rupture in large aneurysms, small aneurysms are generally completely asymptomatic and are very unlikely to rupture. Further, AAA can be easily diagnosed with noninvasive testing; thus, small aneurysms present an excellent opportunity for disease-modifying pharmacological intervention. Research over the past two decades has defined many of the mechanisms which result in aortic matrix degeneration in both human tissue and particularly within animal models. This has resulted in the identification of several potential targets for pharmacological intervention. Drugs directed at inhibition of the inflammatory process and matrix degrading enzymes have been successful in multiple animal models, and early evidence now suggests that disease modification with some of these agents may be successful in slowing AAA growth in humans as well. The future of AAA therapy, however, may belong to agents which can induce aneurysm regression and to delivery methods which specifically target affected arterial tissue.

Anti-Inflammatory Agents↗
PubMed2005

Aortic neck attachment failure and the AneuRx graft: incidence, treatment options, and early results.

Some investigators have reported that proximal attachment failure is a long-term complication of endovascular abdominal aortic aneurysm repair (EVAR) with the AneuRx (Medtronic, Santa Rosa, CA) device. We evaluated the need for an intervention in patients with suboptimal proximal fixation as well as the feasibility and early success of a variety of treatment strategies. From October 1999 to October 2003, we performed 365 EVARs using the AneuRx graft. At a mean follow-up of 23.7 +/- 14.8 months, 20 patients (5.5%) with suboptimal outcomes (14 with a type I endoleak, one with a type III endoleak, and 5 with an inadequate seal zone <1 cm) were considered for treatment. Characteristics of each patient''s aortic neck anatomy that could be associated with proximal attachment failure were evaluated. Eighteen patients (90%) underwent successful treatment (9 AneuRx cuffs, 6 Talent cuffs, 5 aortic stents, one redo endograft, and two surgical conversions) without major perioperative complications, one patient had a persistent type I endoleak despite endovascular treatment, and one patient refused treatment, ultimately leading to aneurysm rupture. There have been no further endoleaks or graft migrations noted since the secondary intervention at a mean follow-up of 13.9 +/- 11.8 months. In our experience, proximal attachment failure associated with the AneuRx graft is relatively uncommon and usually associated with unfavorable neck anatomy. Despite this, most cases are treatable by endovascular means. Long-term follow-up is needed to assess the ultimate frequency of these combined device reconstructions.

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PubMed2005

Treatment of nonaortic aneurysms in the endograft era: aneurysms of the innominate and subclavian arteries.

Although open aneurysm repair remains the standard of care, the advent of endoluminal techniques and stent grafts has significant potential to improve treatment of aneurysms of the innominate and subclavian arteries. Regardless of the modality chosen, therapy must be individualized and treatments tailored on the basis of anatomic and etiologic considerations. Occasionally, definitive treatment of an aneurysm with endoluminal stent-graft placement is possible for focal aneurysms or pseudoaneurysms of the innominate or subclavian arteries. In other situations, endoluminal grafting may be combined with open repair to allow for the benefits of both techniques. Ultimately long-term follow-up data are necessary to determine whether the durability of the endoluminal approach warrants more widespread use.

Aneurysm↗
PubMed2004

Accelerated enlargement of experimental abdominal aortic aneurysms in a mouse model of chronic cigarette smoke exposure.

BACKGROUND: Cigarette smoking and pulmonary emphysema are strongly associated with abdominal aortic aneurysms (AAAs), but the biologic mechanisms linking these conditions are undefined. STUDY DESIGN: To determine if exposure to cigarette smoke influences formation and growth of experimental AAAs, 129/SvEv mice were acclimated to daily cigarette smoke exposure for 2 weeks followed by transient elastase perfusion of the abdominal aorta to induce aneurysmal degeneration. Smoking was continued for intervals of either 2 or 12 weeks (8 mice per group). Nonsmoking 129/SvEv controls (n = 29) underwent elastase perfusion and followup evaluation at the same time intervals. In all animals, abdominal aortic diameter (AD) was measured to determine interval increases in AD (Delta AD), with AAAs defined as a Delta AD > 100%. RESULTS: Preperfusion and immediate postperfusion ADs were not significantly different between experimental groups. Aneurysmal dilatation was present 2 weeks after elastase perfusion in both smoking mice and nonsmoking controls, with no significant difference in final AD (mean +/- SEM: smoking, 1.23 +/- 0.11 mm versus nonsmoking, 1.22 +/- 0.05 mm). There were also no differences in the overall extent of aortic dilatation (Delta AD smoking, 136 +/- 24% versus nonsmoking, 138 +/- 10%), or the incidence of AAAs (smoking, 75% versus nonsmoking, 79%). Although all animals had developed AAAs by 12 weeks after elastase perfusion, the overall extent of aortic dilatation was 50% greater in smoking mice compared with nonsmoking controls (Delta AD smoking, 204 +/- 23% versus nonsmoking, 135 +/- 17%; p < 0.05). CONCLUSIONS: Short-term exposure to cigarette smoke did not alter initial development of experimental AAAs, but chronic smoke exposure was associated with a substantial increase in the late progression of aneurysmal dilatation. This novel combination of in vivo experimental models offers a new approach to investigate mechanisms by which cigarette smoking promotes aneurysmal degeneration.

Animals↗
PubMed2004

Overt ischemic colitis after endovascular repair of aortoiliac aneurysms.

OBJECTIVE: Controversy exists as to the cause of ischemic colitis complicating endovascular aneurysm repair. Occlusion of the hypogastric arteries (HAs) during endovascular repair of aortoiliac aneurysms (AIAs) results in a significant incidence of buttock claudication, and has been suggested as a causative factor in the development of postprocedural colonic ischemia, in addition to factors such as systemic hypotension, embolization of atheromatous debris, and interruption of inferior mesenteric artery inflow. To analyze the relationship between perioperative HA occlusion and postoperative ischemic colitis, we reviewed our experience over 2 years with Food and Drug Administration-approved endovascular graft devices for treatment of AIAs. METHODS: Elective repair of AIAs with bifurcated endovascular grafts was performed in 233 patients over a 2-year period. These included 184 AneuRx grafts, 17 Ancure grafts, and 32 Excluder grafts. During the experience, 44 patients (18.9%) underwent unilateral perioperative HA occlusion (28 right, 16 left) during the course of endovascular AIA repair, and 1 patient (0.4%) underwent bilateral HA occlusion. RESULTS: In 4 patients (1.7%) signs and symptoms of ischemic colitis developed 2.0 +/- 1.4 days postoperatively. In all patients the diagnosis was confirmed at sigmoidoscopy, and initial treatment included bowel rest, hydration, and intravenous antibiotic agents. Three patients with bilateral patent HAs required colonic resection 14.7 +/- 9.7 days after the initial diagnosis, and 2 of these 3 patients died in the postoperative period. Pathologic findings confirmed the presence of atheroemboli in the colonic vasculature in all 3 patients who underwent colonic resection. The fourth patient had undergone multiple manipulations of the left HA in an unsuccessful attempt to preserve patency of this vessel during AIA repair. This patient recovered completely with nonoperative management. Perioperative unilateral HA occlusion was not associated with a significantly higher incidence of postoperative ischemic colitis. CONCLUSION: Perioperative HA occlusion during aortoiliac open or endovascular surgery may contribute to development of the rare but potentially lethal complication of ischemic colitis. However, our extensive experience suggests that embolization of atheromatous debris to the HA tissue beds during endovascular manipulations, rather than proximal HA occlusion, is the primary cause of clinically significant ischemic colitis after endovascular aneurysm repair.

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PubMed2004

Adaptive cellular immunity in aortic aneurysms: cause, consequence, or context?

Abdominal aortic aneurysms are common and life threatening. Although CD4(+) T cells are abundant in aneurysm tissue, their role in disease progression remains unclear. A new study shows that mouse aortic allografts placed in animals lacking IFN-gamma receptors develop a Th2 inflammatory response with aortic aneurysms, whereas Th1 responses promote intimal hyperplasia. It is expected that these surprising findings will stimulate further efforts to clarify whether adaptive cellular immunity in aneurysm disease is detrimental or potentially beneficial.

Animals↗
PubMed2003

Medical treatment of peripheral arterial disease.

PURPOSE OF REVIEW: The evolution of interventional treatments of peripheral arterial disease is progressing at a dizzying pace. However, optimized medical therapy of these patients may be neglected. Recent advances in our understanding of atherosclerosis and the epidemiology of vascular disease reemphasize the importance of a consistent and complete medical regimen. They have also opened new avenues for potential therapy. RECENT FINDINGS: A diagnosis of peripheral arterial disease confers an increased risk of morbidity and mortality that can be at least partially mitigated with a properly designed medical regimen. New evidence supports the importance of risk factor modification including controlling hypertension, lowering lipid levels, and the routine use of antiplatelet agents. For claudication symptoms, several newer drugs and the use of immune-modifying therapy are showing some improvement in symptoms. The use of gene therapy and other means to achieve improved collateral formation in ischemic tissues are showing some promise in the early stages of study. SUMMARY: Peripheral arterial disease is a marker of cardiovascular morbidity and mortality risk. An individualized plan should be devised to include smoking cessation, exercise, lowering serum lipids, lowering high blood pressure, and daily antiplatelet therapy. Supervised exercise programs and cilostazol remain the first-line medical therapies for claudication symptoms, and anticoagulants are added to patients who have bypasses at high risk for thrombosis. The utilities of immune-modifying, antibiotic, and angiogenic therapies remain to be proven.

Blood Pressure↗
PubMedDate not supplied

Endovascular repair of traumatic descending thoracic aortic disruptions: should endovascular therapy become the gold standard?

Acute arterial disruptions of the thoracic aorta are rare and often lethal. They are most often due to blunt trauma and occur most commonly just distal to the left subclavian artery origin in the setting of multisystem injuries. The very proximal nature of the lesion in survivors makes open surgical repair hazardous, with mortality rates reaching over 20%. Endovascular therapy is a new and attractive option for the treatment of those challenging patients. Since March 2002, 3 patients with blunt and 1 patient with a stable iatrogenic descending aortic injury were successfully treated at this institution. Spiral computed tomography followed by angiography was used for diagnosis. No preexisting aortic pathology was present. Major associated injuries included unstable thoracic spinal fractures, abdominal solid organ injuries, and hip fractures, making the subjects poor surgical candidates. The Talent Endovascular Graft was deployed via open femoral or iliac artery access under fluoroscopic guidance. All 4 patients underwent successful exclusion of their thoracic pseudoaneurysm with use of the Talent endovascular graft. One patient required partial coverage of the left subclavian artery, and a second patient had an iliac artery stent deployed after traversal of an area of stenosis with the delivery system. There were no cardiac, neurologic, pulmonary, or peripheral vascular complications. Acute aortic disruption, with its associated high surgical morbidity and mortality, is an excellent indication for endovascular therapy to improve patient outcomes. More long-term data are needed on repair durability.

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