Radial artery pseudoaneurysm in the intensive care unit.

Pseudoaneurysms may occur at the wrist after catheterization of the radial artery but may also occur after arteriovenous shunting for dialysis or after direct trauma to an artery. Radial artery pseudoaneurysms are being increasingly reported because of widespread use of invasive monitoring. We report a case of radial artery pseudoaneurysm at the wrist related to catheterization. The pseudoaneurysm thrombosed after 6 days of external compression. In selected cases, extended external compression is a useful therapeutic option, especially in patients who are medically unfit to undergo general anesthesia or operative treatment.

Extracranial internal carotid artery mycotic aneurysm: case report and review.

Mycotic aneurysms of the internal carotid artery (ICA) are rare and often difficult to diagnose. They can have nonspecific signs and symptoms, an unclear etiology, and can lead to severe morbidity and mortality if left untreated. We present a case of a 47-year-old woman with an apparent mycotic aneurysm of the extracranial ICA associated with Klebsiella pneumonia. We discuss the various clinical findings and radiographic imaging that lead to this unusual diagnosis and the details of our surgical treatment, which included excision of the mycotic aneurysm and reconstruction with a greater saphenous vein interposition graft. We also review the literature on mycotic aneurysms of the ICA, including the radiologic modalities available to diagnose this condition, epidemiology, pathophysiology, and treatment options.

Detection of rupture-prone atherosclerotic plaques by time-resolved laser-induced fluorescence spectroscopy.

OBJECTIVE: Plaque with dense inflammatory cells, including macrophages, thin fibrous cap and superficial necrotic/lipid core is thought to be prone-to-rupture. We report a time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) technique for detection of such markers of plaque vulnerability in human plaques. METHODS: The autofluorescence of carotid plaques (65 endarterectomy patients) induced by a pulsed laser (337 nm, 0.7 ns) was measured from 831 distinct areas. The emission was resolved spectrally (360-550 nm range) and temporally (0.3 ns resolution) using a prototype fiber-optic TR-LIFS apparatus. Lesions were evaluated microscopically and quantified as to the % of different components (fibrous cap, necrotic core, inflammatory cells, foam cells, mature and degraded collagen, elastic fibers, calcification, and smooth muscle cell of the vessel wall). RESULTS: We determined that the spectral intensities and time-dependent parameters at discrete emission wavelengths (1) allow for discrimination (sensitivity >81%, specificity >94%) of various compositional and pathological features associated with plaque vulnerability including infiltration of macrophages into intima and necrotic/lipid core under a thin fibrous cap, and (2) show a linear correlation with plaque biochemical content: elastin (P<0.008), collagen (P<0.02), inflammatory cells (P<0.003), necrosis (P<0.004). CONCLUSION: Our results demonstrate the feasibility of TR-LIFS as a method for the identification of markers of plaque vulnerability. Current findings enable future development of TR-LIFS-based clinical devices for rapid investigation of atherosclerotic plaques and detection of those at high-risk.

Endovascular exclusion of superior mesenteric artery pseudoaneurysms: an alternative to open laparotomy in high-risk patients.

Superior mesenteric artery (SMA) aneurysms are rare. However, patients are frequently symptomatic on presentation and require urgent repair. SMA aneurysms have the potential for severe complications, including thrombosis or rupture, resulting in acute mesenteric ischemia and death. In patients with adhesions secondary to prior abdominal surgery, traditional open exposure of the aneurysm neck via dissection at the base of the transverse colon mesentery may be technically difficult. Endovascular exclusion of visceral artery aneurysms using covered stent grafts presents a reasonable alternative to the morbidity associated with laparotomy. We report an interesting case of a patient with a large SMA aneurysm and multiple prior laparotomies treated percutaneously with a combined expanded polytetrafluoroethylene/nitinol self-expanding stent-graft allowing maintenance of end-organ perfusion and bowel viability.

Interposition grafts for difficult carotid artery reconstruction: a 17-year experience.

Carotid interposition grafts (CIP) for carotid artery revascularization can be a viable alternative to carotid endarterectomy (CEA) or carotid artery stenting (CAS) for complex carotid disease. This is a retrospective review of the UCLA 17-year experience with CIP for carotid reconstruction. Carotid operations performed between 1988 and 2005 revealed 41 CIP procedures in 39 patients using polytetrafluoroethylene (PTFE, n = 31) or reversed greater saphenous vein (Vein) (n = 10). Perioperative data and long-term follow-up for each conduit were statistically compared. There were no significant differences in demographics, risk factors, operative indications, complications, or 30-day perioperative deaths. There was one postoperative stroke in each group, for an overall stroke rate of 4.9% (PTFE 3.2%, Vein 10%). There was one asymptomatic occlusion and there were two high-grade restenoses in the PTFE group compared with one asymptomatic occlusion and one high-grade restenosis in the Vein group. Overall primary patency was 90% and the assisted primary patency was 97% for the PTFE group (mean follow-up 50 months), whereas primary patency was 80% (mean follow-up 30 months) in the Vein group. CIP is a safe and effective technique with excellent long-term follow-up for complex carotid reconstruction when CEA or CAS may be contraindicated.

Laguerre-based method for analysis of time-resolved fluorescence data: application to in-vivo characterization and diagnosis of atherosclerotic lesions.

We report the application of the Laguerre deconvolution technique (LDT) to the analysis of in-vivo time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data and the diagnosis of atherosclerotic plaques. TR-LIFS measurements were obtained in vivo from normal and atherosclerotic aortas (eight rabbits, 73 areas), and subsequently analyzed using LDT. Spectral and time-resolved features were used to develop four classification algorithms: linear discriminant analysis (LDA), stepwise LDA (SLDA), principal component analysis (PCA), and artificial neural network (ANN). Accurate deconvolution of TR-LIFS in-vivo measurements from normal and atherosclerotic arteries was provided by LDT. The derived Laguerre expansion coefficients reflected changes in the arterial biochemical composition, and provided a means to discriminate lesions rich in macrophages with high sensitivity (>85%) and specificity (>95%). Classification algorithms (SLDA and PCA) using a selected number of features with maximum discriminating power provided the best performance. This study demonstrates the potential of the LDT for in-vivo tissue diagnosis, and specifically for the detection of macrophages infiltration in atherosclerotic lesions, a key marker of plaque vulnerability.

The influence of the ipsilateral superficial femoral artery on iliac angioplasty.

Our objective was to evaluate the impact of the ipsilateral superficial femoral artery (SFA) on percutaneous transluminal angioplasty (PTA) of the iliac arteries. From 1993 to 2005, 183 iliac lesions (179 stenoses, 4 occlusions; 37 common, 35 external, and 111 both iliac arteries) in 127 patients with disabling claudication [94 (52%)], rest pain [43 (23%)], and ulcer/gangrene [46 (25%)] were treated by PTA. TransAtlantic Inter-Society Consensus (TASC) iliac lesion types were A in 48 limbs (26%), B in 92 (50%), C in 38 (21%), and D in 5 (3%). Stents were placed selectively for primary angioplasty failure [residual stenosis (>30%) or pressure gradient (>5 mm Hg)]. Seventy-seven limbs (42%) had patent SFAs (66 intact/<50% stenosis and 11 previously bypassed, pSFA group), 28 (15%) had stenotic SFAs (50-99%, sSFA group), 51 (28%) had occluded SFAs (oSFA group), and 27 (15%) had concomitant SFA angioplasty (aSFA group). The Society for Vascular Surgery and the International Society for Cardiovascular Surgery reporting standards were followed to define outcomes. There were no perioperative deaths. Total complication rate was 1.1% (2/183, groin hematomas). The mean follow-up was 20 months (range 1-115). One hundred twenty-five limbs (68%) had PTA alone for iliac lesions, and 58 (32%) had iliac stenting (a total of 91 stents). TASC iliac lesion types and the status of the ipsilateral profunda femoris artery were not significantly different among the four groups. Seventeen limbs (9%) had subsequent infrainguinal bypass: three in the pSFA, seven in the oSFA, four in the sSFA, and three in the aSFA groups (p = 0.19). The primary patency rate was significantly decreased in the sSFA group (29% at 3 years, Kaplan-Meier log-rank, p < 0.0001) compared with the other three groups; however, there were no significant differences among the pSFA, oSFA, and aSFA groups (67%, 67%, and 86% at 3 years, respectively; p = 0.92). The continued clinical improvement rates were significantly decreased in the sSFA group (36% at 3 years, p = 0.0043) compared with the other three groups; however, there was no significant difference between the pSFA, oSFA, and aSFA groups (81%, 84%, and 75% at 3 years, respectively; p = 0.088). The assisted primary and secondary patency and limb salvage rates were not significantly different among the four groups (p > 0.40). Stratified analysis in patients with TASC type B/type C, critical limb ischemia, or claudicants revealed similar results. The primary patency and continued clinical improvement were significantly decreased in patients with stenotic SFAs, suggesting that concomitant SFA angioplasty might improve iliac patency after iliac PTA for patients with stenotic SFAs. The presence of an occluded SFA did not adversely affect the outcomes of iliac PTA. During iliac PTA, a stenotic SFA should be considered for revascularization via endovascular means but an occluded SFA can be observed.

Bilateral lower extremity gangrene requiring amputation associated with heparin-induced thrombocytopenia--a case report.

Heparin use, both prophylactically and therapeutically, is prevalent among hospitalized patients. Patients on heparin may develop a thrombocytopenia that is self-limited. Fewer patients develop a heparin-induced thrombocytopenia that can cause severe bleeding and thrombosis owing to intravascular platelet aggregation. The authors present a case report of heparin-induced thrombocytopenia in a patient who underwent aortic arch and aortic valve replacement that resulted in bilateral above-knee amputations. The patient developed limb ischemia related to heparin-associated thrombosis, but had a delay in antibody seroconversion. Early and accurate diagnosis of heparin-induced thrombocytopenia requires a high clinical suspicion and may be present despite the absence of serum antibodies.

In vivo detection of macrophages in a rabbit atherosclerotic model by time-resolved laser-induced fluorescence spectroscopy.

Accumulation of numerous macrophages in the fibrous cap is a key identifying feature of plaque inflammation and vulnerability. This study investigates the use of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) as a potential tool for detection of macrophage foam cells in the intima of atherosclerotic plaques. Experiments were conducted in vivo on 14 New Zealand rabbits (6 control, 8 hypercholesterolemic) following aortotomy to expose the intimal luminal surface of the aorta. Tissue autofluorescence was induced with a nitrogen pulse laser (337 nm, 1 ns). Lesions were histologically classified by the percent of collagen or macrophage foam cells as well as thickness of the intima. Using parameters derived from the time-resolved fluorescence emission of plaques, we determined that intima rich in macrophage foam cells can be distinguished from intima rich in collagen with high sensitivity (>85%) and specificity (>95%). This study demonstrates, for the first time, that a time-resolved fluorescence-based technique can differentiate and demark macrophage content versus collagen content in vivo. Our results suggest that TR-LIFS technique can be used in clinical applications for identification of inflammatory cells important in plaque formation and rupture.

Laparoscopic aortic reinforcement and endovascular graft placement in swine: a new external wrap.

OBJECTIVE: To evaluate the feasibility, safety, and histological response of laparoscopic external aortic wrap implantation in conjunction with an endovascular stent/stent-graft placement in the infrarenal aorta in a porcine model. METHODS: Seven swine underwent laparoscopic retroperitoneal placement of a custom-made Dacron fabric wrap placed around the infrarenal aorta to create a landing zone for an endovascularly placed aortic stent/stent-graft. RESULTS: Technical success was achieved in all animals without any major complications. Follow-up ranged from 1 to 4 weeks. At necropsy, the external wraps were well incorporated into the adventitia, and the stents/stent-grafts were well incorporated into the intima. Small patches of medial necrosis of the aortic wall were observed in one animal in the stent model and in two animals in the stent-graft model. There was no transmural necrosis observed. CONCLUSIONS This adjunct technique, an external wrap around the infrarenal aorta combined with endovascular grafting, is feasible and deserves further studies into how it may be used to facilitate endovascular repair of aortic aneurysms. CLINICAL RELEVANCE: We hypothesize that our new device could provide capability of altering the proximal neck morphology of abdominal aortic aneurysm and reinforcement to the aortic wall. This, in turn, could improve eligibility for endovascular aneurysm repair and prevent or treat type I endoleak and graft migration. Future investigations will involve evaluation of the long-term effect of the external aortic wrap on the integrity of the aortic wall in an animal model and testing the clinical usefulness of this new technique.

Cost analysis of carotid endarterectomy: is age a factor?

Carotid endarterectomy (CEA) has been demonstrated to be safe and effective in elderly patients. Our aim was to analyze and compare outcome and cost of CEA in both elderly and younger patient groups. A total of 125 consecutive patients who underwent CEA were examined retrospectively and grouped according to age (<80 years old, n = 95; and >or=80 years old, n = 30). The actual total costs and itemized costs were analyzed, and diagnosis-related group (DRG) code payor mix were identified. Patient demographics and risk factors were similar except for a greater incidence of coronary artery disease (CAD) in the >or=80 group than in these <80 (43.3% vs. 21.1%, p < 0.05). Patients had similar minor complication rates; however, the >or=80 group had higher perioperative major complications (16.7% vs. 1.1%, p < 0.01). There were no deaths and there was one perioperative stroke, which occurred in the <80 group. Mean length of stay (LOS), intensive care unit (ICU) LOS, and ICU admissions were greater in the >or=80 group. Cost figures were normalized to a base value of 10 US dollars to maintain proprietary data. Actual total costs of CEA were 131.50 US dollars for the >or=80 group and $100 for the <80 group (p < 0.001). Significant cost differences were found in ICU room costs, and costs for clinical laboratory, radiology imaging, other specialty consults, operating room, and ancillary services in the >or=80 group compared with the <80 group. These results show that the cost of CEA in the elderly is significantly greater than that for younger patients. This difference can be attributed to a greater number of major complications in the more elderly group, who require increased ICU stay, and thus require more clinical laboratory, radiology imaging, and specialty consult service resources. Consideration should be given for a DRG modifier code to increase hospital reimbursement for increased associated costs in elderly patients undergoing CEA.

The safety of carotid endarterectomy in patients with preoperative renal dysfunction.

Recent published data suggest that performing carotid endarterectomy (CEA) in patients with renal dysfunction is associated with a prohibitively high perioperative stroke and death rate. On the basis of our experience, we hypothesized that CEA is a safe procedure in patients with renal insufficiency. A retrospective review of one surgeon's CEA experience from 1988 to 1998 was performed. A total of 398 procedures performed on 370 patients were reviewed for patient demographics and adverse events in the 30-day perioperative period. Risk factors, indications for procedure, and degree of stenosis, as well as intraoperative use of shunts, patch angioplasty, drains, completion angiography, and EEG monitoring were compared. Patients were categorized by preoperative creatinine (Cr) levels as normal (Cr 1.5). All data were subjected to statistical analysis. Our results showed that CEA can be performed safely in patients with renal dysfunction with no increase in perioperative stroke or death rate. Performing CEA in patients with renal insufficiency does require preoperative cardiac evaluation and close cardiac monitoring, as there appears to be an increased rate of myocardial infarction in our series.

Infrapopliteal-lower extremity revascularization with prosthetic conduit: a 20-year experience.

The use of prosthetic conduits for lower extremity revascularization in the infrapopliteal location remains controversial. The objective of this report is to describe the immediate and long-term results in a series collected over two decades. Of the approximately 1,500 lower extremity revascularizations performed between 1978 and 1998, 81 infrapopliteal bypass cases using polytetrafluoroethylene (PTFE) as conduit in 77 patients were identified. Autogenous conduit was unavailable (86%) due to prior surgery: coronary artery bypass graft (25%), femoro-popliteal bypass (60%), or femoro-distal bypass (23%). All cases were done for critical ischemia using PTFE (6 mm, 95%; ring reinforced, 54%) under general (75%) or regional (25%) anesthesia. The distal anastomosis was to the anterior tibial artery (43%), posterior tibial artery (28%), tibioperoneal trunk (16%), or peroneal artery (12%), and vein patch was used in 25% of cases. Postoperative features included acute graft thrombosis in 11 cases (14%), all done under general anesthesia, perioperative death in 3 (4%), and a mean in-hospital stay of 17 days. Long-term follow-up has ranged from 1 to 144 months (mean, 22 months). At 36 months, primary patency was 20%, secondary patency 42%, and limb salvage 55% calculated by the Kaplan-Meier method. Univariate analyses revealed regional anesthesia was associated with prolonged primary patency (35% vs 15%, p=0.026) while the use of ring-reinforced PTFE conduit was associated with prolonged limb salvage (65% vs 40%, p=0.042). All other variables including gender, smoking, diabetes mellitus, renal failure, decade of operation, use of vein patch or postoperative warfarin were not significantly associated with either prolonged patency or limb salvage. Despite poor primary patency, distal prosthetic bypass can lead to long-term limb salvage. These data suggest distal anastomotic vein patches and postoperative anticoagulation may not be beneficial adjuncts. However, the use of regional anesthesia may decrease the incidence of perioperative thrombosis and the use of ring reinforced conduit may prolong limb salvage.