Glenn M. LaMuraglia

Magnetic Resonance Images Lipid, Fibrous, Calcified, Hemorrhagic, and Thrombotic Components of Human Atherosclerosis In Vivo

BACKGROUND Although MRI can discriminate the lipid core from the collagenous cap of atherosclerotic lesions in vitro with T2 contrast, it has not yet produced detailed in vivo images of these human plaque components. METHODS AND RESULTS We imaged seven lesions from six patients who required surgical carotid endarterectomy and calculated T2 in vivo before surgery in various plaque regions. Using the same acquisition parameters, we repeated these measurements in vitro on the resected fragment and compared MR images with histology. T2 values calculated in vivo correlate with in vitro measurements for each plaque component; the in vitro discrimination we demonstrated previously with T2 contrast can therefore be performed similarly in vivo. CONCLUSIONS MRI is the first noninvasive imaging technique that allows the discrimination of lipid cores, fibrous caps, calcifications, normal media, and adventitia in human atheromatous plaques in vivo. This technique also characterizes intraplaque hemorrhage and acute thrombosis. This result may support further investigations that include MRI of plaque progression, stabilization, and rupture in human atherosclerosis.

Initial experience with endovascular aneurysm repair: Comparison of early results with outcome of conventional open repair

PURPOSE To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA. METHODS Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months. RESULTS Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture. CONCLUSIONS Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk.

Long-term Outcomes After Endovascular Abdominal Aortic Aneurysm Repair: The First Decade

Objective:The proper role of endovascular abdominal aortic aneurysm repair (EVAR) remains controversial, largely due to uncertain late results. We reviewed a 12-year experience with EVAR to document late outcomes. Methods:During the interval January 7, 1994 through December 31, 2005, 873 patients underwent EVAR utilizing 10 different stent graft devices. Primary outcomes examined included operative mortality, aneurysm rupture, aneurysm-related mortality, open surgical conversion, and late survival rates. The incidence of endoleak, migration, aneurysm enlargement, and graft patency was also determined. Finally, the need for reintervention and success of such secondary procedures were evaluated. Kaplan-Meier and multivariate methodology were used for analysis. Results:Mean patient age was 75.7 years (range, 49–99 years); 81.4% were male. Mean follow-up was 27 months; 39.3% of patients had 2 or more major comorbidities, and 19.5% would be categorized as unfit for open repair. On an intent-to-treat basis, device deployment was successful in 99.3%. Thirty-day mortality was 1.8%. By Kaplan-Meier analysis, freedom from AAA rupture was 97.6% at 5 years and 94% at 9 years. Significant risk factors for late AAA rupture included female gender (odds ratio OR, 6.9; P = 0.004) and device-related endoleak (OR, 16.06; P = 0.009). Aneurysm-related death was avoided in 96.1% of patients, with the need for any reintervention (OR, 5.7 P = 0.006), family history of aneurysmal disease (OR, 9.5; P = 0.075), and renal insufficiency (OR, 7.1; P = 0.003) among its most important predictors. 87 (10%) patients required reintervention, with 92% of such procedures being catheter-based and a success rate of 84%. Significant predictors of reintervention included use of first-generation devices (OR, 1.2; P < 0.01) and late onset endoleak (OR, 64; P < 0.001). Current generation stent grafts correlated with significantly improved outcomes. Cumulative freedom from conversion to open repair was 93.3% at 5 through 9 years, with the need for prior reintervention (OR, 16.7; P = 0.001) its most important predictor. Cumulative survival was 52% at 5 years. Conclusions:EVAR using contemporary devices is a safe, effective, and durable method to prevent AAA rupture and aneurysm-related death. Assuming suitable AAA anatomy, these data justify a broad application of EVAR across a wide spectrum of patients.

Outcomes following endovascular abdominal aortic aneurysm repair (EVAR): an anatomic and device-specific analysis.

OBJECTIVE We performed a device-specific comparison of long-term outcomes following endovascular abdominal aortic aneurysm repair (EVAR) to determine the effect(s) of device type on early and late clinical outcomes. In addition, the impact of performing EVAR both within and outside of specific instructions for use (IFU) for each device was examined. METHODS Between January 8, 1999 and December 31, 2005, 565 patients underwent EVAR utilizing one of three commercially available stent graft devices. Study outcomes included perioperative (< or =30 days) mortality, intraoperative technical complications and need for adjunctive procedures, aneurysm rupture, aneurysm-related mortality, conversion to open repair, reintervention, development and/or resolution of endoleak, device related adverse events (migration, thrombosis, or kinking), and a combined endpoint of any graft-related adverse event (GRAE). Study outcomes were correlated by aneurysm morphology that was within or outside of the recommended device IFU. chi2 and Kaplan Meier methods were used for analysis. RESULTS Grafts implanted included 177 Cook Zenith (CZ, 31%), 111 Gore Excluder (GE, 20%), and 277 Medtronic AneuRx (MA, 49%); 39.3% of grafts were placed outside of at least one IFU parameter. Mean follow-up was 30 +/- 21 months and was shorter for CZ (20 months CZ vs 35 and 31 months for GE and MA, respectively; P < .001). Overall actuarial 5-year freedom from aneurysm-related death, reintervention, and GRAE was similar among devices. CZ had a lower number of graft migration events (0 CZ vs 1 GE and 9 MA); however, there was no difference between devices on actuarial analysis. Combined GRAE was lowest for CZ (29% CZ, 35% GE, and 43% MA; P = .01). Graft placement outside of IFU was associated with similar 5-year freedom from aneurysm-related death, migration, and reintervention (P > .05), but a lower freedom from GRAE (74% outside IFU vs 86% within IFU; P = .021), likely related to a higher incidence of graft thrombosis (2.3% outside IFU vs 0.3% within IFU; P = .026). The differences in outcome for grafts placed within vs outside IFU were not device-specific. CONCLUSION EVAR performed with three commercially available devices provided similar clinically relevant outcomes at 5 years, although no graft migration occurred with a suprarenal fixation device. As anticipated, application outside of anatomically specific IFU variables had an incremental negative effect on late results, indicating that adherence to such IFU guidelines is appropriate clinical practice.

Clinical experience with epidural cooling for spinal cord protection during thoracic and thoracoabdominal aneurysm repair

PURPOSE This report summarizes our experience with epidural cooling (EC) to achieve regional spinal cord hypothermia and thereby decrease the risk of spinal cord ischemic injury during the course of descending thoracic aneurysm (TA) and thoracoabdominal aneurysm (TAA) repair. METHODS During the interval July 1993 to Dec. 1995, 70 patients underwent TA (n = 9, 13%) or TAA (n = 61) (type I, 24 [34%], type II, 11 [15%], type III, 26 [37%]) repair using the EC technique. The latter was accomplished by continuous infusion of normal saline (4 degrees C) into a T11-12 epidural catheter; an intrathecal catheter was placed at the L3-4 level for monitoring of cerebrospinal fluid temperature (CSFT) and pressure (CSFP). All operations (one exception, atriofemoral bypass) were performed with the clamp-and-sew technique, and 50% of patients had preservation of intercostal vessels at proximal or distal anastomoses (30%) or by separate inclusion button (20%). Neurologic outcome was compared with a published predictive model for the incidence of neurologic deficits after TAA repair and with a matched (Type IV excluded) consecutive, control group (n = 55) who underwent TAA repair in the period 1990 to 1993 before use of EC. RESULTS EC was successful in all patients, with a 1442 +/- 718 ml mean (range, 200 to 3500 ml) volume of infusate; CSFT was reduced to a mean of 24 degrees +/- 3 degrees C during aortic cross-clamping with maintenance of core temperature of 34 degrees +/- 0.8 +/- C. Mean CSFP increased from baseline values of 13 +/- 8 mm Hg to 31 +/- 6 mm Hg during cross-clamp. Seven patients (10%) died within 60 days of surgery, but all survived long enough for evaluation of neurologic deficits. The EC group and control group were well-matched with respect to mean age, incidence of acute presentations/aortic dissection/aneurysm rupture, TAA type distribution, and aortic cross-clamp times. Two lower extremity neurologic deficits (2.9%) were observed in the EC patients and 13 (23%) in the control group (p < 0.0001). Observed and predicted deficits in the EC patients were 2.9% and 20.0% (p = 0.001), and for the control group 23% and 17.8% (p = 0.48). In considering EC and control patients (n = 115), variables associated with postoperative neurologic deficit were prolonged (> 60 min) visceral aortic cross-clamp time (relative risk, 4.4; 95% CI, 1.2 to 16.5; p = 0.02) and lack of epidural cooling (relative risk, 9.8; 95% CI, 2 to 48; p = 0.005). CONCLUSION EC is a safe and effective technique to increase the ischemic tolerance of the spinal cord during TA or TAA repair. When used in conjunction with a clamp-and-sew technique and a strategy of selective intercostal reanastomosis, EC has significantly reduced the incidence of neurologic deficits after TAA repair.

Transperitoneal versus retroperitoneal approach for aortic reconstruction: A randomized prospective study*

A prospective, randomized study was conducted to compare the retroperitoneal versus transperitoneal approach for elective aortic reconstruction. One hundred thirteen patients (transperitoneal = 59, retroperitoneal = 54) were randomized between March 1987 and October 1988. In addition, to assess the changing course of patients undergoing aortic reconstruction similar data were gathered retrospectively on a group of 56 patients undergoing aortic reconstruction by the same surgeons performed via a transperitoneal approach in 1984 to 1985. Randomized patients were identical in age, male to female ratio, smoking history, incidence and severity of cardiopulmonary disease, indication for operation, and use of epidural anesthetics. Details of operation including operative and aortic cross-clamp times, crystalloid and transfusion requirements, degree of hypothermia on arrival at the intensive care unit, and perioperative fluid and blood requirements did not differ significantly for patients undergoing transperitoneal versus retroperitoneal reconstruction. Respiratory morbidity, as assessed by percent of patients requiring postoperative ventilation, deterioration in pulmonary function tests, and the incidence of respiratory complications, was identical in randomized patients. Other aspects of postoperative recovery including recovery of gastrointestinal function, the requirement for narcotics, metabolic parameters of operative stress, the incidence of major and minor complications, and the duration of hospital stay were similar for randomized patients undergoing transperitoneal and retroperitoneal reconstruction. When compared to retrospectively reviewed patients having aortic reconstruction, randomized patients undergoing transperitoneal and retroperitoneal operations had highly significant (p less than 0.001) reductions in postoperative ventilation, transfusion requirements, and length of hospital stay. Such trends were all independent of transperitoneal versus retroperitoneal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Are familial abdominal aortic aneurysms different

A 9-year prospective study of 542 consecutive patients undergoing operation by one of the authors for abdominal aortic aneurysms was undertaken to define the incidence, clinical behavior, and anatomic characteristics of familial abdominal aortic aneurysms. Eighty-two (15.1%) patients having surgery for abdominal aortic aneurysms were found to have a first-degree relative with an aneurysm, as compared to nine (1.8%) of a control group of 500 patients of similar age and sex without aneurysmal disease (p less than 0.001). Detailed analysis was next performed of the pedigree charts of patients with a positive family history of aneurysm who underwent repair of abdominal aortic aneurysms by all authors over the 9-year study period. This review identified a total study population of 86 families with 209 first-degree relatives with abdominal aortic aneurysms. Clinical and anatomic features of this familial group were compared to those of 460 patients operated on for abdominal aortic aneurysms who had no family history of abdominal aortic aneurysms. Patients with familial abdominal aortic aneurysms were more likely to be women (35% vs 14%), and men with familial abdominal aortic aneurysms tended to be about 5 years younger than the women. There was no significant difference between the patients with nonfamilial and familial abdominal aortic aneurysms in anatomic extent of aneurysmal disease, multiplicity of aneurysms, associated occlusive disease, or blood type. There was a history of aneurysm rupture in 35 of 86 (40.7%) families with familial abdominal aortic aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortocaval and iliac arteriovenous fistulas: Recognition and treatment

Despite the well characterized physiologic effects of aortocaval or iliac arteriovenous fistulas, patients with such uncommon lesions may manifest a diverse array of symptoms, and diagnosis is often delayed or overlooked. To examine clinical features that facilitate recognition and allow successful repair, a 30-year experience with 20 such fistulas was reviewed. Fourteen fistulas were caused by aneurysm erosion, four followed iatrogenic injury during lumbar disk surgery, and two developed from abdominal gunshot wounds. The interval from presumed occurrence to diagnosis ranged from 3 hours to 8 years. The diagnosis was not recognized before surgery in five (25%) patients. Back pain (70%) was the most common symptom. The presence of a typical abdominal bruit (80%) was the most reliable physical finding, but its significance was occasionally overlooked or misinterpreted. Congestive heart failure was prominent in only seven (35%) patients. Severe lower extremity edema and mottling was the primary manifestation in eight cases, often causing initial confusion with venous thrombosis. Hematuria (5 patients) and oliguric renal failure (4 patients), both fully reversible after fistula repair, also caused diagnostic uncertainty. The mean preoperative cardiac output was 12.2 L/min, falling to 5.4 L/min with fistula repair. Mean blood loss was 5960 ml, supporting use of intraoperative autotransfusion. Two operative deaths (10%) occurred, both in patients not correctly diagnosed before surgery. Despite varied modes of presentation, prompt recognition and use of appropriate operative techniques should achieve successful repair.

The reduction of the allogenic transfusion requirement in aortic surgery with a hemoglobin-based solution******

OBJECTIVE Because of allogenic red blood cell (RBC) availability and infection problems, novel alternatives, including hemoglobin-based oxygen-carrying solutions (HBOC), are being explored to minimize the perioperative requirement of RBC transfusions. This study evaluated HBOC-201, a room-temperature stable, polymerized, bovine-HBOC, as a substitute for allogenic RBC transfusion in patients undergoing elective infrarenal aortic operations. METHODS In a single blind, multicenter trial, 72 patients were prospectively randomized two-to-one to HBOC (n = 48) or allogenic RBC (n = 24) at the time of the first transfusion decision, either during or after elective infrarenal aortic reconstruction. Patients randomized to the HBOC group received 60 g of HBOC for the initial transfusion and had the option to receive three more doses (30 g each) within 96 hours. In this group, any further blood requirement was met with allogenic RBCs. Patients randomized to the allogenic RBC group received only standard RBC transfusions. The efficacy analysis was a means of assessing the ability of HBOC to eliminate the requirement for any allogenic RBC transfusions from the time of randomization through 28 days. Safety was evaluated by means of standard clinical trial methods. RESULTS The two treatment groups were comparable for all baseline characteristics. Although all patients in the allogenic RBC group required at least one allogenic RBC transfusion, 13 of 48 patients (27%; 95% CI, 15% to 42%) in the HBOC group did not require any allogenic RBC transfusions. The only significant changes documented were a 15% increase in mean arterial pressure and a three-fold peak increase in serum urea nitrogen concentration after HBOC. The complications were similar in both groups, with no allergic reactions. There were two perioperative deaths (8%) in the allogenic RBC group and three perioperative deaths (6%) in the HBOC group (P = 1.0). CONCLUSION HBOC significantly eliminated the need for any allogenic RBC transfusion in 27% of patients undergoing infrarenal aortic reconstruction, but did not reduce the median allogenic RBC requirement. HBOC transfusion was well tolerated and did not influence morbidity or mortality rates.

Common femoral artery occlusive disease: Contemporary results following surgical endarterectomy

OBJECTIVE Proliferation of endovascular techniques with perceived reduction in treatment morbidity repetitively question the precept that surgical endarterectomy is the preferred treatment for occlusive disease of the common femoral artery (CFA). This study details a contemporary experience with common femoral endarterectomy (CFE) with and without concomitantly performed endovascular therapies. METHODS Technical, hemodynamic, and clinical success of CFE performed between 2002 and 2005 were determined according to the Society of Vascular Surgery reporting standards. Primary and assisted patencies of the CFA segment, freedom from reintervention in the ipsilateral limb, and survival were assessed using Kaplan-Meier life-table analysis. Multivariate analysis was performed to evaluate factors associated with patency and survival. RESULTS CFE was performed on 65 limbs in 58 patients (mean age 71 +/- 10; male 77%; diabetes 28%; creatinine >/= 1.5 mg/dL 19%). Forty-four cases (68%) were performed for claudication, and 21 cases (32%) for critical limb ischemia. Thirty-seven cases (57%) were performed as a hybrid procedure wherein concomitant endovascular interventions were performed. Twenty iliac (TASC II A-30%; B-35%; C-20%; D-15%) and 25 femoropopliteal (TASC II A-24%; B-60%; C-12%; D-4%) lesions were treated. Technical success was achieved in 100% of the cases. Hemodynamic success was achieved in 95% of the cases with mean postoperative increase in ankle-brachial index (ABI) of 0.24 +/- 0.24. All but one patient (98.5%) had improvement in symptoms and/or ABI. Average hospital stay was 3.2 days (range 1-12 days). There were 3 (5%) major complications requiring reintervention (early failure secondary to untreated inflow lesion, hematoma, and wound infection), six (9%) minor complications which were treated conservatively (five wound infections, one lymph leak), and no perioperative mortality. With a mean follow-up period of 27 months (range 1-58 months), 1- and 5-year primary patencies were 93% and 91%, respectively. Assisted patency was 100% at both time points. There was no difference in patencies between CFE performed alone or as a hybrid procedure. Multivariate analysis showed congestive heart failure (CHF) as the only predictor of primary failure (odds ratio [OR] 18.5 [2.6-142.9]; P = .004). Freedom from reintervention in the ipsilateral limb was 82% at 1 year and 78% at 5 years, with CHF again as the only predictor of reintervention (OR 5.3 [1.4-19.6]; P =.012). Survival was 89% at 1 year and 70% at 5 years. There were no amputations. CONCLUSIONS These data suggest CFE should remain the standard of care for occlusive disease of the CFA. Its safety and efficacy establish a standard for comparison with emerging endovascular therapies.