The hemodynamics and diagnosis of venous disease.

The venous system is, in many respects, more complex than the arterial system and a thorough understanding of venous anatomy, pathophysiology, and available diagnostic tests is required in the management of acute and chronic venous disorders. The venous system develops through several stages, which may be associated with a number of development anomalies. A thorough knowledge of lower extremity venous anatomy, anatomic variants, and the recently updated nomenclature is required of all venous practitioners. Effective venous return from the lower extremities requires the interaction of the heart, a pressure gradient, the peripheral muscle pumps of the leg, and competent venous valves. In the absence of pathology, this system functions to reduce venous pressure from approximately 100 mm Hg to a mean of 22 mm Hg within a few steps. The severe manifestations of chronic venous insufficiency result from ambulatory venous hypertension, or a failure to reduce venous pressure with exercise. Although the precise mechanism remains unclear, venous hypertension is thought to induce the associated skin changes through a number of inflammatory mechanisms. Several diagnostic tests are available for the evaluation of acute and chronic venous disease. Although venous duplex ultrasonography has become the standard for detection of acute deep venous thrombosis, adjuvant modalities such as contrast, computed tomographic, and magnetic resonance venography have an increasing role. Duplex ultrasonography is also the most useful test for detecting and localizing chronic venous obstruction and valvular incompetence. However, it provides relatively little quantitative hemodynamic information and is often combined with measurements of hemodynamic severity determined by a number of plethysmographic methods. Finally, critical assessment of venous treatment modalities requires an understanding of the objective clinical outcome and quality of life instruments available.

Vibrometry: a novel noninvasive application of ultrasonographic physics to estimate wall stress in native aneurysms.

Our objective was to test vibrometry as a means to measure changes in aneurysm sac pressure in an in vitro aneurysm model. Explanted porcine abdominal aortas and nitrile rubber tubes were used to model an aneurysm sac. An ultrasound beam was used to vibrate the surface of the aneurysm model. The motion generated on the surface was detected either by reflected laser light or by a second ultrasound probe. This was recorded at different aneurysm pressures. The phase of the propagating wave was measured to assess changes in velocity and to see if there was a correlation with aneurysm pressure. The cumulative phase shift detected by laser or Doppler correlated well with increasing hydrostatic pressure in both the rubber and the porcine aorta model. The square of the mean pressure correlated well with the cumulative phase shift when dynamic pressure was generated by a pump. However, the pulse pressure was poorly correlated with the cumulative phase shift. Noninvasive measurement of changes in aortic aneurysm sac tension is feasible in an in vitro setting using the concept of vibrometry. This could potentially be used to noninvasively detect wall stress in native aneurysms and endotension after endovascular aneurysm repair (EVAR) and to predict the risk of rupture.

Aortic neck dilation after endovascular abdominal aortic aneurysm repair: should oversizing be blamed?

Long-term durability after endovascular abdominal aortic aneurysm repair (EVAR) is dependent upon the maintenance of an effective seal between the endograft and the proximal landing zone. Continuous neck dilation might lead to the loss of such a seal. This study aims at evaluating the incidence, risk factors, and clinical consequences of post-EVAR aneurysm neck dilation in patients treated with two types of endografts: AneuRx and Ancure. We reviewed data concerning all consecutive patients submitted to primary EVAR using the AneuRx and Ancure devices. Preoperative neck anatomic characteristics (diameter, calcification, and thrombus load) were evaluated, and device oversize percentage was calculated. Postoperative same-level neck diameter was measured on all postoperative computed tomographic (CT) scans. Probabilities of neck dilation (> or = 10% and > or = 15%) relative to preoperative diameter and first postoperative diameter were estimated with the Kaplan-Meier method and compared between patients using both types of endograft. The impact of anatomic characteristics on neck dilation incidence was evaluated using Cox proportional hazards models. Mean neck dilation was compared between patients with and without device migration and proximal type I endoleak. Both groups had similar probabilities of dilating > 10% relative to preoperative diameter and to first postoperative diameter. Proximal necks in AneuRx-treated patients had higher probabilities of dilating > or = 15% relative to preoperative diameter than Ancure-treated patients (45.5% vs. 18.7% at 1.5 years, p = 0.025), but the probability of such dilation relative to the first postoperative diameter was not different between the two groups (12.4% vs. 9.1% at 1.5 years, p = 0.832). None of the preoperative neck characteristics was associated with neck dilation risk. Device oversize percentage was correlated with the percentage of neck dilation at first postoperative CT scan relative to preoperative diameter in both the AneuRx (correlation coefficient = 0.469, p < 0.0001) and the Ancure (correlation coefficient = 0.464, p < 0.011) groups, but it was not correlated with the percentage of neck dilation at 1 or 1.5 years relative to first postoperative CT scan in either group. Patients with and without caudad device migration (> or = 5 mm) had similar percentages of neck dilation at 1.5 years relative to preoperative diameter, but migrators had higher mean percentages of dilation at 1.5 years relative to first postoperative neck diameter (11.4% vs. 5.6, p = 0.012). Two phenomena may be differentiated: an immediate postimplant dilation, strongly correlated with the percentage of oversize and more likely to reach values > or = 15% with an AneuRx device than with an Ancure graft, and a subsequent dilation, relative to the first postoperatively measured diameter, equally probable with either type of device, not correlated with the percentage of oversizing but associated with caudad device migration. Our study does not support any adverse role for the degree of oversize.

Noninvasive measurement of aortic aneurysm sac tension with vibrometry.

OBJECTIVE: Currently, the risk of aneurysm sac rupture after endovascular abdominal aortic aneurysm repair (EVAR) is estimated by using a group of anatomic variables. Available techniques for pressure monitoring include either direct measurement using catheter-based techniques or indirect measurement requiring implantation of a pressure sensor during aneurysm repair. None of these methods is without limitations. Radiation pressure, such as that generated by a modulated ultrasound (US) beam, can induce surface vibration at a distance. The velocity of the resulting surface waves depends on the tensile stress of the vibrated surface. By measuring the change in wave velocity, it is possible to detect the change in tensile stress and calculate the pressure through the vibrated surface. We tested this concept in an in vitro aneurysm model. METHODS: Rubber tubes and explanted porcine abdominal aortas were used to model an aneurysm sac. The surface of the model was vibrated with an amplitude-modulated US beam. The resulting motion was detected either by reflected laser light or by Doppler US. The phase of the propagating wave was measured to assess changes in velocity with different pressures. RESULTS: Increasing hydrostatic pressure in the rubber model correlated well with the cumulative phase shift (R(2) = 0.96-0.99; P < .0001). By using a pump to generate dynamic pressure (between 110 and 200 mm Hg), the cumulative phase shift correlated well with the square of the mean pressure (R(2) = 0.92; P < .0001); however, the correlation with pulse pressure was poor (24-36 mm Hg; r = 0.38; P < .02). In the porcine in vitro aortic sac model, the cumulative phase shift detected with both laser (r = 0.94-0.99; P < .0001) and Doppler (r = 0.96-0.99; P < .0001) correlated well with the aneurysm pressure. CONCLUSIONS: Application of vibrometry for noninvasive measurement of aortic aneurysm sac tension is feasible in an in vitro setting. The concept of vibrometry may be used to detect endotension noninvasively after EVAR. Vibrometry may also be used to estimate wall stress in native aneurysms, and it may predict the risk of aneurysm rupture. CLINICAL RELEVANCE: Vibrometry may offer a technique for completely noninvasive monitoring of aneurysm sac pressure after EVAR. Vibrometry is based on the following principles: radiation pressure, such as that generated by modulated US, can induce surface vibration at a distance; by measuring the change in wave velocity of vibration, it is possible to detect changes in tensile stress and calculate the pressure through the vibrated surface. We tested this concept in an in vitro model and found that application of vibrometry for noninvasive measurement of aortic aneurysm sac tension is feasible. Vibrometry may also be used to estimate wall stress in native aneurysms.

Endovenous laser therapy and radiofrequency ablation of the great saphenous vein: analysis of early efficacy and complications.

BACKGROUND: Endovenous laser therapy (EVLT) and radiofrequency ablation (RFA) are new, minimally invasive percutaneous endovenous techniques for ablation of the incompetent great saphenous vein (GSV). We have performed both procedures at the Mayo Clinic during two different consecutive periods. At the time of this report, no single-institution report has compared RFA with EVLT in the management of saphenous reflux. To evaluate early results, we reviewed saphenous closure rates and complications of both procedures. METHODS: Between June 1, 2001, and June 25, 2004, endovenous GSV ablation was performed on 130 limbs in 92 patients. RFA was the procedure of choice in 53 limbs over the first 24-month period of the study. This technique was subsequently replaced by EVLT, which was performed on the successive 77 limbs. The institutional review board approved the retrospective chart review of patients who underwent saphenous ablation. According to the CEAP classification, 124 limbs were C2-C4, and six were C5-C6. Concomitant procedures included avulsion phlebectomy in 126 limbs, subfascial endoscopic perforator surgery in 10, and small saphenous vein ablation in 4 (EVLT in 1, ligation in 1, stripping in 2). Routine postoperative duplex scanning was initiated at our institution only after recent publications reported thrombotic complications following RFA. This was obtained in 65 limbs (50%) (54/77 [70%] of the EVLT group and 11/53 [20.8%] of the RFA group) between 1 and 23 days (median, 7 days). RESULTS: Occlusion of the GSV was confirmed in 93.9% of limbs studied (94.4% in the EVLT [51/54] and 90.9% in the RFA group [10/11]). The distance between the GSV thrombus and the common femoral vein (CFV) ranged from -20 mm (protrusion in the CFV) to +50 mm (median, 9.5 mm) and was similar between the two groups (median, 9.5 mm vs 10 mm). Thrombus protruded into the lumen of the CFV in three limbs (2.3%) after EVLT. All three patients were treated with anticoagulation. One received a temporary inferior vena cava filter because of a floating thrombus in the CFV. Duplex follow-up scans of these three patients performed at 12, 14, and 95 days, respectively, showed that the thrombus previously identified at duplex scan was no longer protruding into the CFV. No cases of pulmonary embolism occurred. The distance between GSV thrombus and the saphenofemoral junction after EVLT was shorter in older patients (P = .006, r(2) = 0.13). The overall complication rate was 15.4% (20.8% in the EVLT and 7.6% in the RFA group, P =.049) and included superficial thrombophlebitis in 4, excessive pain in 6 (3 in the RFA group), hematoma in 1, edema in 3 (1 in the RFA group), and cellulitis in 2. Except for two of the three patients with thrombus extension into the CFV, none of these adverse effects required hospitalization. CONCLUSION: GSV occlusion was achieved in >90% of cases after both EVLT and RFA at 1 month. We observed three cases of thrombus protrusion into the CFV after EVLT and recommend early duplex scanning in all patients after endovenous saphenous ablations. DVT prophylaxis may be considered in patients >50 years old. Long-term follow-up and comparison with standard GSV stripping are required to confirm the durability of these endovenous procedures.

High-risk carotid endarterectomy.

"High-risk" carotid endarterectomy (CEA): fact or fiction? To answer this question we reviewed the available evidence starting from controlled randomized trials, through retrospective population- and large institution-based studies to case-series. CEA can be performed in most "high-risk" patients with low mortality and morbidity. A broad concept of high-risk CEA, based merely on exclusion from previous controlled randomized CEA trials, cannot be justified. The vast majority of evidence suggests that age (> or =80 years) per se should not be considered a high-risk criterion for CEA. However, it appears that there are certain individual risk factors, which may influence outcome adversely. It appears that CEA in the setting of contralateral carotid occlusion may be associated with very slightly increased risk of adverse perioperative events. Local risk factors, namely carotid reoperation and CEA following prior cervical radiation therapy, are associated with slightly increased stroke, death and probably cranial nerve injury rates. If these risk factors are frequent in a particular series the overall outcome of CEA will be worse. In the absence of level-one evidence on the long-term efficacy of carotid artery stenting (CAS) in stroke prophylaxis, selection for CAS should be restricted to well-defined high-risk categories, such as severe medical comorbidities or local-anatomic risk factors.

Aneurysm sac thrombus load predicts type II endoleaks after endovascular aneurysm repair.

Type II endoleaks are associated with the absence of aneurysm shrinkage after endovascular abdominal aortic aneurysm repair (EVAR). This study aims at determining the predictability of this complication, whose potential risk factors have been the subject of conflicting reports. Preoperative computed tomography (CT) scans of 178 patients who underwent EVAR for true infrarenal abdominal aortic aneurysms between January 20, and April 17, 2003, with a minimum follow-up of 30 days, were reviewed. The following information was retrieved: maximum aneurysm diameter, aneurysm thrombus load (maximum thickness, percentage of sac circumference wall coverage, percentage of maximum sac area occupancy); number, diameter, and nature (lumbar, inferior mesenteric, accessory renal, middle sacral) of patent aortic side-branch arteries; thrombus thickness at each aortic branch ostium, and aneurysm diameter at that level. Postoperative CT and duplex scans supplemented with angiography in selected cases were reviewed for the presence of a type II endoleak observable beyond the 30th postoperative day. Logistic regression was used to assess the association of each variable with this outcome. There were 38 (21.3%) patients with type II endoleaks after the 30th postoperative day. The median follow-up was 12 months (range 1-65 months). By univariate analysis, the following variables significantly decreased the risk of a type II endoleak: thrombus maximum thickness [odds ratio (OR) 0.77 for a 5 mm increase, p = 0.009], mean thrombus thickness at aortic side-branches ostia (OR 0.65 for a 1 mm increase, p = 0.0006), thrombus-occupied percentage of maximum aneurysm area (OR 0.72 for a 10% increase, p < 0.0001), percentage of thrombus-lined aneurysm wall (OR 0.53 for a 25% increase, p < 0.0001). The presence of a patent inferior mesenteric artery (OR 6.84, p < 0.01) and the number of patent aortic side-branches (OR 1.37 for each additional vessel, p = 0.002) significantly increased the risk of detecting a late type II endoleak. Aneurysm and aortic side-branch diameters did not have any impact. In a multiple logistic regression model (whole model p < 0.0001), the thrombus-occupied percentage of maximum aneurysm area (OR 0.74 for a 10% increase, p < 0.0005) and the number of patent aortic side-branches (OR 1.31 for each additional vessel, p = 0.009) remained independent predictors of type II endoleaks. The simple measure of the proportion of maximum aneurysm area occupied by thrombus may be a useful way to identify patients at high risk of a persistent type II endoleak. Patients with low preoperative sac thrombus load should be followed with a high degree of suspicion for this complication.

Surgical management of renal fibromuscular dysplasia: challenges in the endovascular era.

Percutaneous transluminal renal angioplasty (PTRA) is the primary treatment for renal fibromuscular dysplasia (RFMD). Surgical revascularization is limited to patients who fail or are unsuitable for PTRA. All patients who were operated on with RFMD since the indications for renal PTRA were expanded in our institution were retrospectively reviewed. Outcome included patency, hypertension, and renal function. Twenty-six patients had reconstruction of 32 renal arteries between 1998 and 2004. The mean age was 47.1 +/- 14 years; the majority (81%) were female. Six patients had bilateral disease and three had a solitary kidney. Operations were done for hypertension in 25 patients, renal artery aneurysm in 8, and chronic dissection in 1, alone or in combination. Six patients had a failed PTRA and 20 were unsuitable for it. Aortorenal bypass was done most often (n = 28) and saphenous vein was the preferred conduit (n = 25). The distal anastomosis was to the main renal artery in 13 patients and to the branch arteries in 19. Ex vivo repair was needed in five patients. Five intraoperative revisions were done because of abnormalities on duplex scan. One patient died unexpectedly 42 days after operation from myocardial infarction. Extrarenal complications occurred in five patients. Median follow-up was 2.4 (range, 42 days to 6.3) years and was available in all but one patient (96%). Two bypasses occluded at 3 and 376 days, which resulted in loss of the kidneys. One graft stenosis was treated successfully with PTRA at 239 days. All failures occurred in men. One-year cumulative primary patency was 89 +/- 8% and was not adversely affected by prior PTRA or complex repair. Hypertension at 1 year was cured in 27% of the patients and improved in 60%. No patient developed acute or chronic renal failure. Surgical reconstruction for RFMD has excellent short-term patency. Failed PTRA or complex reconstructions did not adversely affect outcome.

AneuRx device migration: incidence, risk factors, and consequences.

Success after endovascular abdominal aortic aneurysm repair (EVAR) is dependent on device positional stability. The quest for such stability has motivated different endograft designs, and the risk factors entailed remain the subject of debate. This study aims at defining the incidence, risk factors, and clinical implications of device migration after EVAR with the AneuRx endograft. In this study we included all consecutive 109 patients submitted to primary AneuRx placement for infrarenal aortic or aortoiliac aneurysms. Preoperative computed tomography (CT) scans were reviewed for the following anatomic characteristics: neck length, diameter, angulation, calcification, and thrombus load; and sac diameter and thrombus load. Percentage of device oversizing relative to the proximal neck diameter was determined. All postoperative CT scans were reviewed, and the distance between the lowest renal artery and the craniad end of the device was measured. A >/=5-mm increase in such distance was considered indicative of device migration. Migration cumulative incidence was estimated by the Kaplan-Meier method, and its association with any of the preoperative anatomical characteristics was tested using Cox proportional hazards models. Median follow-up time was 9 (range, 1-31) months. Migration occurred in nine patients, corresponding to a 15.6% estimated probability of migration at 30 months (SE = 5.1%). Migration was associated with the risk of proximal type I endoleak (hazard ratio = 3.39, 95% confidence interval = 1.46-7.87; p = 0.007). This type of endoleak occurred in three of the migration-affected patients (33.3%); all of them were resolved by additional cuff placement at the proximal landing zone. No other migration-related reinterventions were performed. The only significant associations between anatomic factors and device migration probability were the protective effects of longer necks (odds ratio [OR] = 0.71 for each additional 5 mm, p = 0.045) and longer overlapped portions of neck and device (OR = 0.56 for each additional 5 mm, p = 0.003). There was a trend toward higher probability of migration among reverse-tapered necks (OR = 1.75, p = 0.109). Percentage of device oversizing correlated with early neck dilation (between preoperative and first postoperative diameters, correlation coefficient = 0.4, p < 0.0001), but not with late neck dilatation (between first postoperative and 1.5-year scan diameters, correlation coefficient = 0.29, p = 0.112). There was a trend toward higher mean percentage of late dilation among migrators (11.4%, standard error of the mean [SEM] 2.6) than nonmigrators (5.7%, SEM = 1) (p = 0.08), but both groups had similar mean percentages of early dilation (3%, SEM = 1.6%, vs. 5.5%, SEM = 0.6%; p = 0.365). This result indicates that device migration is not a rare event after AneuRx implantation. This phenomenon is associated with proximal type I endoleaks. Deployment of the endograft immediately below the renal arteries might help to prevent migration, since use of greater lengths of overlapped device relative to the proximal neck has a protective effect. Migration seems to be independent of the degree of device oversizing.

Extension of saphenous thrombus into the femoral vein: a potential complication of new endovenous ablation techniques.

Endovenous techniques such as radiofrequency ablation (RFA) and endovenous laser therapy (ELT) have emerged as percutaneous minimally invasive procedures for ablation of incompetent great saphenous veins in patients with varicosity and venous insufficiency. Early reports showed safety and efficacy of both techniques, with excellent technical success rates and few major complications, such as deep vein thrombosis or pulmonary embolism. During our initial experience with ELT in 56 limbs of 41 patients, 39 underwent postoperative duplex scanning. We encountered three cases (7.7%) with thrombus extension into the common femoral vein. All three patients were anticoagulated, and a temporary inferior vena cava filter was placed in one. All remained asymptomatic. The thrombus resolved by 1 month in all three patients. Review of the literature revealed that the incidence of thrombus extension into the common femoral vein or deep vein thrombosis in published clinical series is 0.3% after ELT and 2.1% after RFA. This possibility warrants routine postoperative duplex scanning, more alertness during these procedures, and patient education on this possible complication.

Proximal type I endoleak after endovascular abdominal aortic aneurysm repair: predictive factors.

Proximal type I endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) are associated with a high risk of rupture. Risk factors for developing this complication are not fully elucidated. We aimed to define preoperative predictors for proximal type I endoleak and describe its clinical outcome. From a consecutive series of 257 patients who underwent EVAR, we selected 202 who had available pre- and postoperative CT scan studies. Proximal neck diameter, length, angulation, calcification, thrombus load (thickness, percentage of neck circumference coverage, percentage of neck area occupancy), and maximum aneurysm diameter were evaluated on preoperative CT scans. All postoperative CT and duplex ultrasound scans, supplemented with angiograms in selected cases, were reviewed for the presence or absence of endoleak. Device overlap and oversizing (relative to the proximal neck) were also determined. Type I proximal endoleak rates were estimated using the Kaplan-Meier method. The associations between the variables listed above and proximal type I endoleak were evaluated by use of Cox proportional hazards models. Proximal type I endoleak occurred in eight patients, corresponding to a 3-year incidence rate of 4% (SE = 1.5%). The median follow-up was 340 days (range, 22-1954). Univariate analyses found significant associations between proximal type I endoleak and the following variables: percentage of calcified neck circumference (hazards ratio = 2.19 for a 25% increase, p = 0.019), aneurysm maximum diameter (hazards ratio = 1.98 for a 1-cm increase, p = 0.006) and proximal neck and device overlap (hazards ratio = 0.53 for a 5-mm increase, p = 0.007). The mean overlap among cases with and without type I proximal endoleak was 15.6 mm and 29.3 mm, respectively. When these variables were included in a multivariate model, all remained statistically significant. No significant association could be documented for neck thrombus-related variables. Thirty-nine (19.3%) patients had a beta neck angle inferior to 120 degrees . There was a trend toward a higher incidence of proximal type I endoleaks in these patients (p = 0.057). Device oversize relative to proximal neck diameter did not affect the probability of this type of endoleak. One patient survived an emergency open repair of a ruptured aneurysm after significant expansion. Six patients underwent endovascular reinterventions (4 additional proximal cuff placements, 2 proximal angioplasties). The mean interval for reintervention was 389 days. Distal migration (>or=5 mm) was identified in four cases (50%). Proximal type I endoleak is a rare complication after EVAR, but it is associated with a high number of reinterventions and potentially serious consequences. Patients with short and heavily calcified aneurysmal necks and large aneurysms are at increased risk of proximal type I endoleaks.

Endovascular abdominal aortic aneurysm repair: does gender matter?

Substantial differences across genders have been documented for the natural history and clinical course of cardiovascular diseases. This study's objective is to compare preoperative characteristics, intraoperative events, and postoperative outcomes in men and women undergoing endovascular abdominal aortic aneurysm repair (EVAR). We hypothesized that despite gender anatomic specificities, EVAR may achieve similar results across genders. We included 241 consecutive patients who underwent elective EVAR at our institution from December 1996 through May 2003. Demographic variables and comorbidities were collected by chart review, and intraoperative events were from surgical notes. Baseline anatomic characteristics were evaluated on the last preoperative computed tomography (CT) scan. Radiologic outcomes were evaluated on all postoperative CT scans, and clinical follow-up information was abstracted from charts. Women constituted 12% (n = 29) of our cohort and were older than men (79.9 vs. 74.9 years, p = 0.0003). When compared to men, they had aneurysms with similar diameter (54.1 vs. 55.5 mm, p = 0.491) but narrower (23.1 vs 25.5 mm, p < 0.0001) and shorter (18.9 vs. 30.4 mm, p < 0.0001) proximal necks. Female iliac arteries were narrower (9.6 vs. 11.4 mm, p < 0.0001), with higher calcification scores (2.5 vs. 2.3, p = 0.047) but lower tortuosity indexes (1.2 vs. 1.3, p = 0.0001). Additional access maneuvers were more frequent in women: iliac access angioplasty (31% vs. 10.9%, = p = 0.007), uni-iliac conversion (13.8% vs. 1.4%, p = 0.005), and iliac "chimney" conduit (12.1% vs. 1.2%, p = 0.0001). There was a trend toward longer fluoroscopy time in women (34.6 vs. 26.9 min, p = 0.056). The following postoperative outcomes at 24 months were similar in women and men: freedom from endoleak (63.4% vs. 72.7%, p = 0.74), reintervention rate (28% vs. 24.5%, p = 0.878), aneurysm shrinkage (24.3% vs. 68.7%, p = 0.199), aneurysm expansion (0% vs. 3%, p = 0.213), and survival (92.9% vs. 84.3%, p = 0.341). There was a trend toward higher rates of neck dilation relative to preoperative diameter in women (48.5% vs. 16% at 12 months, p = 0.059) and toward lower limb patency rates in men (100% vs. 92.8%, p = 0.098). In sum, women have shorter proximal necks and smaller and more calcified iliac arteries, which increases the necessity of access-related additional maneuvers. Despite being older and having a less favorable anatomy, women can expect similar technical and clinical outcomes after EVAR.

Chlamydia pneumoniae in coronary bypass grafts of redo patients. The concept of the 'adventitial baseline infection'.

The pathogenic role of Chlamydia pneumoniae in late coronary bypass graft failure has not yet been extensively investigated. We examined failed and new arterial/venous bypass grafts using immunohistochemistry, polymerase chain reaction (PCR), and serology. Thirty-four long-term failed grafts and 28 new grafts were examined in 21 patients undergoing redo coronary artery bypass grafting (CABG). Immunohistochemically, 28 (82%) failed grafts were positive in the intimal-medial compartment, and 33 grafts (97%) were positive for C. pneumoniae in the adventitia. Thirteen (46%) and 27 (96%) new grafts showed infection in the intima-media and in the adventitia, respectively (p < 0.05). Immunohistochemically, the overall presence of C. pneumoniae in all vessels examined was 66% in the intima-media and 97% in the adventitia (p < 0.05). C. pneumoniae was detected by PCR in 19 (31%) of all the vessels examined. C. pneumoniae seems to be frequently present in grafts of patients considered for redo CABG in Hungary. The adventitia of both failed, and new grafts particularly often contained C. pneumoniae. The results suggest that there exists an adventitial baseline infection from which infection of the inner wall layers develops, depending on local microenvironmental conditions. This is the first study to evaluate chlamydial infection in arterial/venous coronary grafts by immunohistochemistry, PCR, and serology.

New discoveries in anatomy and new terminology of leg veins: clinical implications.

Advances in diagnosis and in endovascular and surgical treatments of both acute and chronic venous diseases have focused attention on several, previously clinically less important, details of venous anatomy. The time has come to standardize venous nomenclature so that general practitioners and specialists in the United States and abroad speak the same language. There is a need to adopt a universal terminology for the saphenous veins, to avoid the myriad of eponyms of perforators and, most importantly, to omit once and for all, the term "superficial" femoral vein when talking about a deep vein of the thigh. New anatomic names, such as the saphenous fascia and saphenous subcompartment, have to gain better recognition. To achieve the desired consensus on venous nomenclature, an international meeting was held in Rome, Italy, in 2001, under the auspices of the International Union of Phlebology. In this review on venous anatomy, we describe the most important previously published clinical recommendations from this conference, and suggest modifications based on their clinical experience using the new terminology.

Carotid endarterectomy in SAPPHIRE-eligible high-risk patients: implications for selecting patients for carotid angioplasty and stenting.

OBJECTIVES: Carotid angioplasty and stenting (CAS) has been proposed as an alternative to carotid endarterectomy (CEA) in patients excluded from the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study and in those considered at high risk for CEA. In light of recently released CAS data in patients at high risk, we reviewed our experience with CEA. METHODS: The records for consecutive patients who underwent CEA between 1998 and 2002 were retrospectively reviewed, and risk was stratified according to inclusion and exclusion criteria from a "high-risk" or CAS-CEA trial, The Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial. RESULTS: Of 776 CEAs performed, 323 (42%) were considered high risk, on the basis of criteria including positive stress test (n = 109, 14%), age older than 80 years (n = 85, 11%), contralateral carotid occlusion (n = 66, 9%), pulmonary dysfunction (n = 56, 7%), high cervical lesion (n = 36, 5%), and repeat carotid operation (n = 27, 3%). Other high-risk criteria included recent myocardial infarction (MI), cardiac surgery, or class III or IV cardiac status; left ventricular ejection fraction less than 30%; contralateral laryngeal palsy; and previous neck irradiation (each <1.5%). Clinical presentation was similar in the high-risk and low-risk groups: asymptomatic (73% versus 73%), transient ischemic attack (23% vs 22%), and previous stroke (4% vs 5%). The overall postoperative stroke rate was 1.4% (symptomatic, 2.9%; asymptomatic, 0.9%). Comparison of high-risk and low-risk CEAs demonstrated no statistical difference in the stroke rate. Factors associated with significantly increased stroke risk included cervical radiation therapy, class III or IV angina, symptomatic presentation, and age 60 years or younger. Overall mortality was 0.3% (symptomatic, 0.5%; asymptomatic, 0.2%), not significantly different between the high-risk (0.6%) and low-risk groups (0.0%). Non-Q-wave MI was more frequent in the high-risk group (3.1 vs 0.9%; P <.05). A composite cluster of adverse clinical events (death, stroke, MI) was more frequent in the symptomatic high-risk group (9.3% vs 1.6%; P <.005), but not in the asymptomatic cohort. There was a trend for more major cranial nerve injuries in patients with local risk factors, such as high carotid bifurcation, repeat operation, and cervical radiation therapy (4.6% vs 1.7%; P <.13). In 121 patients excluded on the basis of synchronous or immediate subsequent operations, who also would have been excluded from SAPPHIRE, the overall rates for stroke (1.65%; P =.69), death (1.65%; P =.09), and MI (0.83%; P =.71) were not significantly different from those in the study population. CONCLUSIONS: CEA can be performed in patients at high risk, with stroke and death rates well within accepted standards. These data question the use of CAS as an alternative to CEA, even in patients at high risk.

Prolonged survival of a patient with multiple endocrine neoplasia type 2b and stage IV medullary thyroid carcinoma.

OBJECTIVE: To present a case of multiple endocrine neoplasia type 2B (MEN2B) with a prolonged course. METHODS: We describe the clinical, laboratory, and radiologic findings in a patient with MEN2B and review the various interventions during a period of approximately 3 decades. RESULTS: In 1962, a 19-year-old man with a marfanoid body habitus presented with multiple thyroid nodules and neurofibromas of the tongue. Total thyroidectomy demonstrated multicentric medullary thyroid carcinoma with cervical lymph node metastatic involvement. At the time of the first description of the MEN2B syndrome, the patient was enrolled in a surveillance program. An increase in urinary metanephrines resulted in bilateral adrenalectomy for multinodular pheochromocytoma in 1972. Increased serum calcitonin levels and the appearance of cervical lymphadenopathy led to modified radical neck dissection 12 years after the initial diagnosis of medullary thyroid carcinoma. In 1975, angiography revealed extensive hepatic lesions metastatic from the medullary thyroid carcinoma; this finding was confirmed by open liver biopsy in 1988. The patient lived 16 years after the initial diagnosis of liver metastatic disease and died 29 years after the initial examination. CONCLUSION: The 3-decade course of this patient not only represents a classic case of MEN2B but also allows us to present the history of this disease from its discovery to the current era of genetic testing and exemplifies the possibility of long-term survival in a patient with liver metastatic involvement from medullary thyroid carcinoma.

Spontaneous dissection of the infrarenal abdominal aorta.

Spontaneous infrarenal abdominal aortic dissection is rare. We observed enlargement of a spontaneous infrarenal aortoiliac dissection in a 55-year-old hypertensive man. Open surgical repair with a bifurcated polyester graft was successful. A review of the English literature found 41 previously published cases. Mean age was 58 years, 74% of the patients were male, and 62% had hypertension. None had Marfan or Ehlers-Danlos syndrome. More than three fourths of the patients had symptoms, 6 patients (14%) presented with aortic rupture. Dissection was limited to the infrarenal aorta in 50% and extended into the iliac or femoral arteries in 50%. Three patients died before treatment, no death occurred after endovascular repair of after elective open aortic grafting. Mortality following rupture was 67%. Abdominal aortic dissection did not reoccur but 1 patient died at 14 month because of rupture of a thoracic aneurysm. Spontaneous infrarenal abdominal aortic dissections are rare, but usually symptomatic and 14% rupture. Rupture carries high mortality. Elective open repair is recommended, but endovascular repair is a new treatment option for suitable patients.

Epidural cooling for the prevention of ischemic injury to the spinal cord during aortic occlusion in a rabbit model: determination of the optimal temperature.

PURPOSE: This experiment was designed for the determination of the optimal epidural cooling temperature for the allowance of spinal cord protection with minimal side effects during an aortic occlusion-induced spinal cord ischemia model in rabbits. METHODS: Spinal cord ischemia was induced in rabbits with infrarenal aortic occlusion for 40 minutes. Spinal cord cooling was effected with epidural infusion of normal saline solution at the following different temperatures: group 1, 17 degrees C (n = 6); group 2, 24 degrees C (n = 6); group 3, 32 degrees C (n = 6); and group 4, 39 degrees C (n = 3). Sham-operated rabbits without aortic occlusion were used as controls with epidural infusion at healthy body temperature (39 degrees C; n = 3). Motor function was assessed at 48 hours with Tarlov's criteria, and the animals were killed. The spinal cord was sectioned into multiple segments, and semiquantitative histologic scoring (0 to 5) was used to grade ischemic injury. RESULTS: Cooling solution and spinal cord temperatures showed linear correlation (r = 0.95). All the rabbits in groups 1 (except one with mild weakness), 2, and 3 were neurologically intact, and all in group 4 had paraplegia develop (P < .001). One rabbit in group 1 died from increased intracranial pressure (ICP). Mean blood pressure, ICP, and body temperature were similar among the groups. Histology correlated with the clinical findings. In groups 1 and 2, minimal histologic changes were noted. Low-grade ischemic changes were present in group 3 in the low-lumbar and mid-lumbar segments. Severe ischemic injury occurred at the same segments in group 4 (P < .05). CONCLUSION: These study results suggest that in rabbits satisfactory spinal cord protection during aortic occlusion can be achieved at moderate regional hypothermia (24 degrees C). Large volume infusion for the achievement of profound hypothermia may cause deleterious effects of increased ICP and is not warranted.

The predictive value of laboratory findings in patients with primary hyperparathyroidism.

BACKGROUND: Despite extensive preoperative imaging and intraoperative "gadgetry" to facilitate localization of abnormal parathyroid glands, the onus of identification and resection remains with the surgeon in the operating room. We pondered the relative usefulness of routine laboratory studies to the surgeon as predictive guides to the intraoperative findings in patients with primary hyperparathyroidism (HPT). STUDY DESIGN: Pre- and postoperative laboratory data were analyzed in 166 consecutive patients (1998 to 1999) undergoing successful cervical exploration for sporadic primary HPT and were correlated with the pathologic findings. Patients with secondary HPT, multiple endocrine neoplasia, familial HPT, and parathyroid carcinoma were not included in this study. RESULTS: One hundred eighteen women and 48 men (mean age = 63 years) with parathyroid adenoma (n = 155) and sporadic hyperplasia (n = 11) were evaluated. Mean parathormone (PTH) levels varied little with the pathology: adenoma = 9.6 pmol/L and hyperplasia = 10.2 pmol/L (p > 0.05). In patients with parathyroid adenoma, analysis of preoperative measures showed a positive correlation (r = 0.48, p < 0.0001) with PTH and gland weight. The correlation appeared to be the strongest in the tails of the distribution; in 22 of 23 (96%) cases with PTH levels lower than 6 pmol/L, the offending lesion or lesions were less than 400 mg; in all six cases with PTH levels higher than 18.0 pmol/L, the abnormal gland or glands weighed more than 800 mg. PTH levels between 6 and 18 pmol/L revealed mean adenoma weight of 757 mg (median = 420 mg; range = 50 to 5,500 mg). CONCLUSIONS: Extreme values of PTH in patients with single-gland parathyroid disease alert the surgeon to the likelihood of small or large parathyroid adenomas. Laboratory studies do not differentiate adenoma from hyperplasia, nor do they pinpoint the size of abnormal glands with moderate-range PTH values.