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Melina R Kibbe

Publications and source records attributed to Melina R Kibbe.

At least 19 recordsLinked to original sources

Decreased incidence of left common iliac vein compression in patients with abdominal aortic aneurysms.

OBJECTIVE: Compression of the left common iliac vein (LCIV) by the right common iliac artery is an anatomic variant that may increase the risk for LCIV thrombosis. The incidence of LCIV compression in patients with abdominal aortic aneurysms (AAA) is unknown, however. The aim of this descriptive anatomic study was to determine (1) the incidence of LCIV compression in patients with and without AAA and (2) if endovascular AAA repair acutely alters the incidence of LCIV compression and, hence, the risk of LCIV thrombosis. METHOD: A retrospective analysis of medical records and helical computed tomography (CT) scans was conducted in 100 AAA patients and 100 non-AAA patients (n = 200). Medical records were reviewed for symptoms and risk factors for deep vein thrombosis, and data were reported according to the Joint Society Reporting Standards for acute lower-extremity venous thrombosis. The minor diameters of the aorta, inferior vena cava, and common iliac arteries and veins were measured. For AAA patients, measurements were obtained from preoperative and 30-day postoperative CT scans. RESULTS: The mean age of the study cohort was 38 years (range, 17 to 85 years) for non-AAA subjects and 73 years (range, 51 to 89 years) for AAA subjects. The mean acute lower-extremity venous thrombosis risk factor score was low for both patient groups (non-AAA, 0.82 +/- 0.12; AAA, 2.63 +/- 0.14). Mean compression of the LCIV was 37.8% (range, 0% to 74.8%) for non-AAA patients but only 27.3% (range, 0% to 74.2%; P < .0006) for AAA patients. Of non-AAA patients with venous compression, the right common iliac artery was the compressing structure in 87% of cases. However, of AAA patients with venous compression, the left common iliac artery was the compressing structure in 76% of cases. There was no statistically significant change in the degree of compression of the LCIV before and after endovascular repair (27.3% vs 25.1%, respectively) nor was there a change in the structure that compressed the LCIV. CONCLUSION: Patients with AAA were found to have more tortuous iliac arteries that led to less anatomic compression of the LCIV compared with nonaneurysmal patients. Furthermore, the left common iliac artery was found to compress the LCIV in most of the AAA patients, and the right iliac artery was found to compress the LCIV in most non-AAA patients. Endovascular AAA repair did not acutely alter these anatomic findings. Patients with AAA may therefore be at lower risk of developing LCIV thrombosis owing to the nature of their anatomy.

Adolescent↗

Duplex ultrasound remains a reliable test even after carotid stenting.

Transluminal arterial stenting reduces vessel compliance and may alter accurate interpretation of flow velocities. We reviewed duplex ultrasonography (DUS) following carotid stenting to identify criteria indicative of severe recurrent stenosis. This is a single-center retrospective review of 158 carotid stenoses treated with carotid angioplasty and stenting (CAS) from April 2001 to December 2004. DUS was obtained preoperatively, postoperatively, and at 3-month intervals thereafter. Peak systolic velocity (PSV) and end diastolic velocity (EDV) were analyzed. Mean follow-up was 12 months (range 1-40). Mean age was 71 +/- 9 years (range 51-91; 74% men, 26% women). Three patients (1.9%) developed restenosis and one (0.6%) developed an asymptomatic occlusion during follow-up. Average preoperative PSV was 373 +/- 123 cm/sec (mean +/- SD) and EDV was 148 +/- 63 cm/sec. Immediate postoperative PSV and EDV decreased by an average of 70% (average 118 +/- 45 cm/sec) and 72% (average 32 +/- 15 cm/sec), respectively. In patients free from restenosis or occlusion, these reductions (range 65-80%) were maintained throughout follow-up and remained within 1-25% of immediate postoperative values. In patients suffering restenosis or occlusion, follow-up PSV and EDV increased 34% and 28%, respectively, compared to preoperative values. PSV and EDV increased by an average of 287% and 500%, respectively, compared to immediate postoperative values. Using criteria of PSV >170 cm/sec and a 50% increase of PSV over immediate postoperative values, restenosis or occlusion was detected with 100% sensitivity and specificity in our patients. Additionally, EDV >120 cm/sec and a 50% increase in EDV over immediate postoperative values detected restenosis and occlusion with 100% sensitivity and specificity. Presumed restenosis and occlusion detected by DUS were confirmed in all cases with angiography. Restenosis or occlusion after CAS at our institution can reliably be detected by carotid duplex using cut-off values of 170 cm/sec PSV, 120 cm/sec EDV, and >50% increase over immediate postoperative values. While these criteria are applied to patients undergoing CAS at our institution, they serve only as suggested guidelines for patient populations at other centers and must be customized to each Intersocietal Commission for the Accreditation of Vascular Laboratories-accredited vascular laboratory.

Aged↗

Carotid artery stenting in octogenarians: is it too risky?

Recent clinical trials have shown that the safety of carotid angioplasty and stenting (CAS) is equivalent to that of carotid endarterectomy (CEA) in high-risk patients. Despite this, the beneficial outcome in octogenarians has come under scrutiny in light of the interim results of the Carotid Artery Revascularization versus Stent Trial (CREST). We report on a single-center experience of patients > or =80 years of age compared to younger cohorts treated with CAS. CAS procedures, performed exclusively by vascular surgeons, from April 2001 to December 2004 were retrospectively reviewed. Mechanical cerebral protection with either a distal balloon occlusion system or a distal filter device was used in 140 cases and in all patients > or =80 years of age. Patients were divided into age categories: <60, 60-69, 70-79, and > or =80 years old. Data analysis included patient demographics, perioperative death, myocardial infarction, stroke, and other major complications. Statistics were derived using the SPSS program. A total of 158 procedures were performed on 151 patients. There were no statistical differences among the four groups with respect to mean stenosis or the presence of preoperative symptoms. Rates of stroke were 1 of 16 (6.25%) <60 years old, 0 of 54 (0%) age 60-69, 2 of 59 (3.4%) age 70-79, and 1 of 29 (3.4%) > or =80 years old. Preoperative symptoms were present in 6 of 29 (21%) patients > or =80 years old. Myocardial infarction and mortality rates were 0% for all groups. There were no statistical differences in stroke, death, or nonneurological complication rates among the four groups. Vascular surgeons facile at CAS should expect 30-day results comparable to CEA in all age groups. Octogenarians, whether symptomatic or asymptomatic, should not be denied this form of treatment.

Age Factors↗

Endovascular repair of thoracic aortic pathology with custom-made devices.

BACKGROUND: Open repair of thoracic aortic aneurysms (TAAs) is fraught with high morbidity and mortality rates. The availability of endoprostheses for treating thoracic aortic pathology has not kept pace with those for treating abdominal aneurysms. Technical feasibility, durability, and safety of custom-made stent-grafts for the treatment of TAAs and dissections are evaluated. METHODS: From July 2002 to October 2004 there were 15 patients with TAAs, intramural hematoma, or dissections treated with custom-made endografts. Grafts were deployed after brief adenosine-induced cardiac arrest. Computed tomography scans were obtained 1 month postoperatively and every 6 months thereafter. The mean follow-up period was 15 months (range, 3-31 mo). RESULTS: The mean age of patients was 67 +/- 11 years (range, 47-81 y; 67% men, 33% women). Indications for repair included TAA (10), chronic type B dissection (3), penetrating ulcer (1), and acute dissection (1). Planned concomitant procedures included subclavian-carotid transposition (2) and aortosplenic bypass (2) to achieve adequate proximal or distal landing seal zones, respectively. The mean length of hospital stay was 8 days (range, 1-49 d). Immediate complications included 2 access-related events, 1 cerebellar infarction treated expectantly, and 1 death from a large hemispheric stroke. There were no cases of postoperative paralysis and on follow-up imaging no cases of endoleak, endograft migration, or stent fractures were found. No late deaths occurred caused by stent-graft repair or aneurysm-related causes. CONCLUSIONS: Endoluminal exclusion of thoracic aortic aneurysms and dissections can be achieved successfully using custom-made stent-grafts. The use of specially designed devices appears to be technically feasible and durable, with acceptable morbidity and mortality rates.

Aged↗

Aneurysms of the carotid artery.

Carotid artery aneurysms are an uncommon but important problem. The available data suggests that, untreated, these aneurysms lead to neurologic symptoms from embolization. Pseudoaneurysms of the carotid artery result from injury or may be the long-term sequelae of a spontaneous carotid dissection. While open surgery has been the primary mode of treatment, these aneurysms are being treated more commonly with endovascular approaches. This trend is partly the result of the increasing experience with the endovascular treatment of carotid artery stenosis. The endovascular approach offers advantages in other situations where open access to the distal extent of the aneurysm is difficult or neck radiation leads to concerns about wound healing. This article outlines the etiology, new diagnostic modalities, and treatment of aneurysms of the carotid artery.

Aneurysm↗

Carotid stenting done exclusively by vascular surgeons: first 175 cases.

BACKGROUND: Percutaneous CAS may well replace CEA as standard of care. CAS has been performed largely by interventional cardiologists; however, with recent Food and Drug Administration approval, vascular surgeons are now hurriedly attempting to obtain the requisite endovascular skills. Reported are our 30-day and midterm outcomes of CAS. METHODS: Retrospective review of 175 cervical carotid stenoses treated with elective CAS from April 2001 to February 2005. All procedures were performed under local anesthesia via percutaneous femoral access in an operating room angiosuite. Mechanical cerebral protection was used in 90% of cases. Data analysis includes demographics, procedural records, and duplex exams over a mean follow-up of 21 months. RESULTS: Mean age is 70 years (74% men and 26% women). Preprocedural neurologic symptoms were present in 32%. Intraoperative complications included 2 seizures (1.1%) and 4 asystolic arrests (2.3%), all managed medically without sequelae. Over the 30-day follow-up there were no deaths, no myocardial infarctions (MIs), 2 major strokes (1.1%), 2 minor strokes (1.1%), 3 transient ischemic attacks (TIAs) (1.7%), and 1 major access-site complication (0.6%). At late follow-up, 3 cases (1.7%) of restenosis occurred; all were treated with repeat angioplasty and remain patent. One (0.6%) asymptomatic occlusion was detected at 6-month follow-up. There have been no late carotid-related complications or deaths. CONCLUSIONS: Vascular surgeons possessing advanced catheter-based skills can safely perform CAS and achieve perioperative results comparable to CEA. Such skills are crucial to those surgeons intent on the future management of carotid occlusive disease.

Aged↗

Mesenteric ischemia.

Mesenteric ischemia is a morbid, potentially life-threatening disease that is associated with a relatively high mortality, often due to its late diagnosis. Currently, the incidence of mesenteric ischemia in the United States is low; however, the incidence is predicted to increase because of the aging population. Therefore, whether the presentation is acute or chronic in nature, the challenge for the physician remains early diagnosis through a high index of suspicion based on vague and often atypical presentations. Surgical intervention remains the mainstay of therapy. Despite ongoing investigations of the different treatment options, including single vs multivessel bypass, antegrade vs retrograde graft placement, autogenous vs prosthetic conduits, and endovascular vs open surgical repair, many questions remain unanswered. This review summarizes the clinical presentation, diagnosis, and treatment options, including both open and endovascular approaches, for acute and chronic mesenteric ischemia.

Acute Disease↗

Iliac vein compression in an asymptomatic patient population.

OBJECTIVE: May-Thurner syndrome is a well-recognized anatomic variant that is associated with the development of symptomatic acute venous thrombosis of the left iliac vein. However, the natural frequency of compression of the left iliac vein and its clinical significance in asymptomatic disease has not been established. Therefore the purpose of this descriptive anatomic study was to determine the incidence of left common iliac vein compression in an asymptomatic population. METHODS: A retrospective analysis of medical records and helical abdominal computed tomography scans was conducted in 50 consecutive patients evaluated in the emergency department because of abdominal pain. Medical records were reviewed for symptoms and risk factors for deep venous thrombosis, and data were collected and reported according to the Joint Society Reporting Standards for acute lower extremity venous thrombosis. All computed tomography was performed with intravenous contrast medium, and 2-mm to 5-mm axial images were obtained. The minor diameter of the common iliac arteries and veins was measured. The technique of transverse image measurement was validated with multiplanar reconstructions and orthogonal diameter measurements in a subset of subjects. Statistical analysis was performed with the Student t test or Spearman rank correlation. RESULTS: Mean age of subjects without symptoms was 40 years (range, 19-85 years), and 60% (n = 30) were female patients. The mean acute lower extremity venous thrombosis risk factor score was 1.16 +/- 0.23 (range, 0-6; maximum possible score, 28). It was surprising that 24% (n = 12) of patients had greater than 50% compression and 66% (n = 33) had greater than 25% compression. Mean compression of the left common iliac vein was 35.5% (range, -5.6%-74.8%). The structure most often compressing the left common iliac vein against the vertebral body was the right common iliac artery (84%). There was no strong correlation between patient age or common iliac artery size and compression of the left common iliac vein. However, women had greater mean compression of the left common iliac vein (women, 41.2% +/- 3.1%; men, 27.0% +/- 3.0%; P =.003). CONCLUSION: Hemodynamically significant left common iliac vein compression is a frequent anatomic variant in asymptomatic individuals. Therefore compression of the left iliac vein may represent a normal anatomic pattern that has thus far been thought of as a pathologic condition.

Adult↗

Early results with use of gracilis muscle flap coverage of infected groin wounds after vascular surgery.

INTRODUCTION: Management of a nonhealing femoral wound after vascular surgery can pose a challenging problem, particularly when there is prosthetic material involved. We prefer to use pedicled gracilis muscle flaps (PGMFs) to cover problematic groin wounds when more conventional management is not possible. METHODS: We describe the technique for using PGMFs to provide groin coverage, report a summary of our short-term and long-term results, and describe why we prefer this reconstructive technique. RESULTS: Twenty PGMFs were placed in 18 patients to treat nonhealing and infected groin wounds. Exposed prosthetic vascular reconstructions were covered with the PGMF in 14 wounds, and in situ autogenous vascular reconstructions were covered in four. Seven wound infections were polymicrobial, 10 had a single gram-positive organism, and one had a single gram-negative organism. Pseudomonas cultured out in four wounds, and Candida in one wound. Two patients had a virulent combination of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus. Complete healing was initially achieved in all wounds, and no patient died within 30 days of surgery. Two PGMFs failed, at 2 weeks and 2 months, respectively, one from tension on the flap pedicle and one from acute inflow occlusion. Underlying prosthetic reconstruction was salvaged in 12 of 14 wounds; the remaining wounds with autogenous reconstructions or exposed femoral vessels all closed successfully. At a mean follow-up of 40 +/- 10 months there were no recurrent groin infections. Seven patients died, at 2.5, 3, 8, 12, 14, 22, and 28 months, respectively. CONCLUSION: PGMF transposition is an effective option to cover infected or exposed femoral vessels or salvage prosthetic graft material in the groin. In appropriately selected patients, when complete graft removal and extra-anatomic bypass is not an acceptable option, gracilis muscle flap coverage is a viable alternative. The technique is relatively simple, and morbidity from PGMF harvest is minimal.

Adult↗

Percutaneous repair of abdominal aortic aneurysm.

OBJECTIVE: Percutaneous treatment of an abdominal aortic aneurysm (AAA) is feasible, but is associated with a unique set of risks. A comparison of Excluder endograft deployment with femoral artery cutdown (FAC) versus percutaneous femoral access (PFA) for treatment of infrarenal AAA was undertaken. METHODS: A single-institution, controlled, retrospective review was carried out in patients who underwent either bilateral FAC or bilateral PFA for endovascular repair of infrarenal AAA with the Gore bifurcated Excluder endograft between March 1999 and November 2003. To November 2000, 35 patients underwent bilateral FAC; since then, 47 patients have undergone bilateral PFA. All have been followed up for at least 30 days. RESULTS: Mean AAA size was 5.7 cm in the FAC group and 6.0 cm in the PFA group. During hospitalization there were six access-related complications in the FAC group; three required early surgical intervention. In the PFA group nine perioperative access-related complications occurred, all consisting of either hemorrhage or arterial occlusion; seven required additional intervention, and were recognized and ameliorated while the patient was still in the operating room. At 30-day follow-up there were no additional access-related complications in the PFA group. There were eight other access-related complications in eight additional patients who underwent FAC. In patients undergoing bilateral PFA total operative time was shorter (PFA 139 minutes vs FAC 169 minutes; P =.002), total in-room anesthesia time was less (PFA 201 minutes vs FAC 225 minutes; P <.008), and use of general anesthesia was reduced (P <.001). No significant differences were observed between groups with respect to estimated blood loss (PFA 459 mL vs FAC 389 mL; P =.851). CONCLUSION: Complete percutaneous treatment of AAA may have some advantages over open femoral artery access, but it is not free from risk. Percutaneous treatment of AAA can be completed successfully in most patients, but should be performed at an institution where conversion to an open procedure can be completed expeditiously if necessary.

Aged↗

Adenovirus-mediated nitric oxide synthase gene transfer.

The varied biological effects of nitric oxide (NO) have led to intense research into its diverse physiologic and pathophysiologic roles in multiple disease processes. It has been implicated in the development of altered vasomotor tone, intimal hyperplasia, atherosclerosis, impotence, host defense, and wound healing. Using the modern technologies of recombinant DNA and gene transfer using adenoviral vectors, the effects of NO derived from various NO synthase (NOS) enzymes can be studied in a variety of tissues and the therapeutic applications of NOS is possible. Such uses of NOS gene transfer have been investigated extensively in the vasculature where NO is critical to regulating vascular homeostasis. NOS gene therapy has the theoretical advantage of allowing NO delivery to be localized, thereby limiting potential adverse effects of NO. The benefits of adenoviral vectors in gene transfer include relatively high transduction efficiencies, both replicating and nonreplicating cells may be infected, and the high titers of adenovirus that can be produced. The methods described in this chapter include the cloning of the iNOS cDNA into a recombinant adenoviral vector, large-scale production of that vector AdiNOS preparation, and the use of the vector to transduce tissue in vitro and in vivo.

Adenoviridae↗

Percutaneous drainage and explanation of an infected aortic endoluminal stent graft.

Endoluminal repair of abdominal aortic aneurysms (AAAs) has undergone explosive growth in the last decade. Although immediate benefits are attractive to both the patient and the treating physician, concerns regarding long-term success have dampened sustained enthusiasm for this technique. A rare but catastrophic complication is stent graft infection. This case report describes an early infection of an endoluminal aortic stent graft treated initially with percutaneous drainage and ultimately with staged extraanatomic bypass and graft explantation.

Aged↗

The Gore Excluder US multi-center trial: analysis of adverse events at 2 years.

Although open surgical repair of abdominal aortic aneurysms remains the standard of care, endovascular repair is becoming an attractive alternative as more long-term outcome data become available to show its safety and efficacy. The authors review data on the 2-year outcome of the pivotal US multicenter, prospective Gore Excluder Trial. Patients treated with the Excluder endograft (W.L. Gore, Flaggstaff, AZ) had less blood loss (310 +/- 19 v 1,590 +/- 124 mL; P <.0001), required fewer homologous transfusions (6% v 32%; P <.0001), and had faster inpatient recovery (2.0 +/- 0.1 v 9.8 +/- 1.4 days; P <.0001) compared with those treated with open repair. Early major adverse events were reduced significantly in the patients treated with the endograft (14% v 57% in control; P <.0001), and this persisted at 2 years. There was no difference in overall survival rate (P =.13). There were no deployment failures, early conversions, or aneurysm ruptures. At the 2-year time-point, trunk migration occurred in 1%, limb migration in 1%, limb narrowing in 1%, endoleak in 20%, and aneurysm growth in 14%. There was a 7% annual reintervention rate in the endograft group in the first 2 years. The Excluder endograft is a safe and effective treatment compared with open surgical repair for infrarenal abdominal aortic aneurysms with appropriate anatomy.

Aged↗

Regulation of tissue factor expression in smooth muscle cells with nitric oxide.

OBJECTIVE: This study was undertaken to determine the effect of nitric oxide (NO) on tissue factor (TF) expression in vascular smooth muscle cells. STUDY DESIGN: Rat aortic smooth muscle cells (RASMCs) were exposed to NO delivered exogenously with the NO donor S-nitroso-N-acetylpenicillamine (SNAP) or produced endogenously after infection with an adenoviral vector carrying human inducible NO synthase (AdiNOS). Functional TF activity was assessed with chromogenic TF assay. TF antigen was determined with immunohistochemistry. Northern blot analysis was used to determine steady- state TF messenger RNA (mRNA). Electrophoretic mobility gel shift assay was performed to determine the nuclear binding activity of nuclear factor kappa-B (NFkappaB). NFkappaB activity was inhibited by either prior transduction of RASMCs with mutant IkappaB or treatment with pyrrolidine dithiocarbamate. RESULTS: RASMCs exposed to SNAP or infected with AdiNOS exhibited increased functional TF activity and antigen. Regardless of the source of NO, a time-dependent and concentration-dependent increase in TF activity was observed. Steady-state TF mRNA levels were also increased by NO delivered via either method. NFkappaB nuclear binding activity was also increased by NO. Inhibition of NFkappaB activity by either pyrrolidine dithiocarbamate treatment or mutant IkappaB transduction abrogated NO-induced enhancement of TF mRNA and functional activity. CONCLUSION: In RASMC, NO exposure results in upregulation of TF functional activity, antigen, and mRNA. This effect appears to be mediated by an NFkappaB-dependent pathway.

Adenoviridae↗