Simulation case rehearsals for carotid artery stenting.

A case series of 5 patients is presented assessing the utility of simulation case rehearsals of individual patients for carotid artery stenting on an endovascular simulator. Simulated and operative device dimensions were similar. Results of subjective surveys indicated that face and content validity were excellent. The simulations predicted difficulty with vessel cannulation, however had difficulty predicting post-stent changes in bifurcation angulation. Our experience suggests that it may be feasible to use patient-specific CTA-derived data in the creation of a realistic case rehearsal simulation. The overall utility of this concept, including cost-benefit analysis, has yet to be determined.

Physical exam and occult post-traumatic vascular lesions: implications for the evaluation and management of arterial injuries in modern warfare in the endovascular era.

Based on complexity of extremity wounds sustained in recent combat, arteriography had been used routinely in evaluations for delayed or occult arterial injuries. This report aims to quantitatively analyze the sensitivity and specificity of physical exam (PE) in predicting the presence of these injuries. United States service members sustaining extremity trauma in the Global War on Terrorism were evacuated to our medical center and evaluated by a senior vascular surgeon. Those with an abnormal PE, at risk based on wounding patterns, or previously treated for vascular injury underwent arteriography. Data from each patient were prospectively entered into a Vascular Injury registry. Comprehensive information about the injuries, interventions, arteriogram results, and any periprocedural complications were analyzed. Twenty-five endovascular or open surgical interventions were performed in forty-six of 99 patients that had lesions on arteriography. Seventy-three patients had a normal PE, of which 36 had lesions that prompted 6 subsequent interventions. Twenty-two of 26 patients with an abnormal PE had lesions that prompted 19 interventions. For PE, sensitivity was 38%, specificity was 90%, and positive predictive value (PPV) and negative predictive value (NPV) were 85% and 51%, respectively. In proximity injuries, PPV improved to 100%, but was only 15% sensitive with a NPV of 60%. In conclusion normal PE did not reliably predict post-traumatic arterial lesions in these military extremity injuries. These lesions are amenable to endovascular therapies, and should be considered in cases of complex trauma involving high amounts of energy, penetrating mechanisms, or wounding patterns in proximity to named vessels.

Case of adolescent with Paget-Schroetter syndrome and underlying thrombophilia due to an elevated lipoprotein (A).

Upper extremity deep vein thrombosis (UEDVT) is a rare disorder in children and is most often associated with a central venous catheter (CVC), cancer, or an underlying thrombophilia. In adults, repetitive or strenuous upper extremity activity has been linked to mechanical compression of the thoracic outlet resulting in subclavian vein thrombosis, also known as Paget-Schroetter Syndrome (PSS). We present the case of a 14 year old female who was found to have an UEDVT consistent with PSS. On subsequent thrombophila screening, she was noted to have a significantly elevated lipoprotein (a) level of 83 (normal: <30 mg/dL). She underwent 3 months of anticoagulation therapy prior to her first rib resection and in follow-up was noted to have complete patency of her subclavian vein. This case illustrates the necessity for thrombophilia screening in the pediatric patient with UEDVT despite evidence of anatomic abnormality or mechanical venous compression.

Percutaneous arterial closure in peripheral vascular disease: a prospective randomized evaluation of the Perclose device.

BACKGROUND: Patients with peripheral vascular disease have been excluded from initial studies of percutaneous suture-mediated closure devices (SMCD) despite representing a significant proportion of those requiring endovascular intervention. We sought to determine whether these devices could be safely used in patients with peripheral vascular disease. METHODS: Patients were stratified into two groups and five subgroups on the basis of indication for arteriography, and they were prospectively randomized at the end of the procedure to receive either the SMCD or manual compression. Ankle-brachial index was determined and duplex ultrasound scanning of the accessed femoral artery was performed, before and after the procedure. Ultrasound data included peak systolic velocity, minimum intraluminal vessel diameter, and presence or absence of calcified plaque. Time to hemostasis, ambulation, and discharge were recorded, and major or minor complications were noted. RESULTS: Of 102 patients included in the study, 52 patients were randomized to receive the SMCD. There was no difference in ankle-brachial index, minimum intraluminal vessel diameter, or peak systolic velocity in the accessed vessel after closure with SMCD or manual compression. Time to hemostasis, ambulation, and discharge was significantly less in the SMCD group (P =.001). Presence of calcified plaque was not associated with complications (P =.146). In the SMCD group, hemostasis was achieved with 49 of 52 devices (94.2%). There were six complications (5.9%), two of which were major and required operative intervention. All complications were hemorrhagic and not occlusive. There was no difference in overall complication rate between SMCD (7.7%) and manual compression (4.0%) groups (P =.678). No infection was noted in any of the 102 patients. CONCLUSIONS: Suture-mediated percutaneous arterial closure can be safely performed in patients with peripheral vascular disease, even in the presence of calcified plaque. This closure technique enables shorter time to hemostasis, ambulation, and hospital discharge. There are observed differences in minor, but not major, complication rates for MC versus percutaneous arterial closure in patients with peripheral vascular disease, but these differences did not achieve statistical significance in this small series.

Varicose veins possess greater quantities of MMP-1 than normal veins and demonstrate regional variation in MMP-1 and MMP-13.

BACKGROUND: Studies have reported that structural proteins such as elastin and collagen are decreased in varicose veins compared to normal controls. We hypothesized that the changes observed in varicose vein wall composition may be related to alterations in extracellular matrix remodeling proteins, such as the matrix metalloproteases and serine proteases. In addition we hypothesized that there may be regional variation in the expression of these enzymes within the leg. PATIENTS AND MATERIALS: One-centimeter segments of the proximal and distal greater saphenous vein (GSV) were obtained from patients undergoing ligation and stripping for venous insufficiency (vv) (n = 15) or GSV harvest in conjunction with coronary artery bypass grafting (CABG) (n = 7). All vv patients had incompetence of the GSV by color flow duplex. Vein specimens were examined for MMP-1, 3, and 13, tryptase, and GAPDH mRNA using semiquantitative RT-PCR analysis. Quantification of MMP-1 and 13 (active/latent forms) and tryptase was performed using Western blot analysis. Western blots were analyzed using scanning densitometry and standardized to normal controls and values expressed as the median densitometric index (D.I.). Nonparametric statistical methods (Wilcoxan signed rank test and Mann-Whitney U test) were used for analysis. RESULTS: We were able to amplify MMP-1, MMP-13, and tryptase mRNA from both proximal and distal segments of all greater saphenous veins studied. MMP-3 mRNA, however, was not found in either segment of any of the veins examined. A semiquantitative analysis of RT-PCR products comparing the ratio of MMP-1, MMP-13, or tryptase mRNA to GAPDH mRNA showed no difference between cases and controls nor proximal vs distal vein segments. Western blot analysis revealed larger quantities of MMP-1 in varicose veins than in nondiseased veins from CABG patients (48.0 +/- 36.7 D.I. vs 12.5 +/- 6.8 D.I., P = 0.036). Investigation into the regional variation of proteases revealed lower amounts of MMP-1 in distal than in proximal vein segments (37.9 +/- 35.0 D.I. vs 44.1 +/- 41.6 D.I., P = 0.01). Similarly, we found significantly less MMP-13 in distal segments of varicose veins than in proximal segments (152.8 +/- 130.0 D.I. vs 206.7 +/- 173.3 D.I., P = 0.006). CONCLUSIONS: This study found that MMP-1 protein is increased in varicose veins when compared to controls despite no differences in mRNA expression. In addition we found that there is regional variation of MMP-1 and MMP-13 in diseased varicose veins. Lower leg veins have significantly reduced amounts of these proteolytic enzymes when compared to veins of the upper thigh. These data suggest that posttranscriptional regulatory controls could be responsible for the observed differences.

The nutcracker syndrome: its role in the pelvic venous disorders.

BACKGROUND: Symptoms of pelvic venous congestion (chronic pelvic pain, dyspareunia, dysuria, and dysmenorrhea) have been attributed to massive gonadal reflux. However, obstruction of the gonadal outflow may produce similar symptoms. Mesoaortic compression of the left renal vein (nutcracker syndrome) produces both obstruction and reflux, resulting in symptoms of pelvic congestion. We describe the diagnosis and management of nine patients studied in our institutions. MATERIALS AND METHODS: From a group of 51 female patients with pelvic congestion symptoms studied at our institutions, there were nine patients with symptoms of pelvic congestion, microscopic hematuria, and left-sided flank pain. The diagnosis of the nutcracker syndrome was suspected based on clinical examination, Doppler scan, duplex ultrasound scan, computed tomography scan, and magnetic resonance imaging. The diagnosis was confirmed by retrograde cine-video-angiography with renocaval gradient determination and catheterization of both internal iliac venous systems. All patients had a renocaval pressure gradient >4 mm Hg (normal, 0-1 mm Hg). Renal compression was relieved by external stent (ES) in two patients, internal stent (IS) in one patient, and gonadocaval bypass (GCB) in three. GCB was preceded by coil embolization of internal iliac vein tributaries connecting with lower-extremity varicose veins in three patients. Three patients deferred surgery and are under observation. Mean follow-up time was 36 months (range, 12-72 months). RESULTS: Hematuria disappeared postoperatively in all patients. ES and IS normalized the renocaval gradient and resulted in significant alleviation of symptoms (90% improvement on a scale of 0-10 where 0 = no improvement and 10 = greatest improvement). Two patients with GCB had a residual gradient of 3 mm Hg. The third patient normalized the gradient. In this group, improvement of symptoms was 60%. Patients awaiting surgery are being treated conservatively (elastic stockings, hormones, and pelvic compression). They have shown only moderate improvement. CONCLUSION: The nutcracker syndrome should be considered in women with symptoms of pelvic venous congestion and hematuria. The diagnosis is suspected by compression of the left renal vein on magnetic resonance imaging or computed tomography scan and confirmed by retrograde cine-video-angiography with determination of the renocaval gradient. Internal and external renal stenting as well as gonadocaval bypass are effective methods of treatment of the nutcracker syndrome. IS and ES were accompanied by better results than GCB. Surgical and radiologic interventional methods should be guided by the clinical, radiologic, and hemodynamic findings.

Controlled ischemia for complex venous surgery: the technique of choice.

Surgery under controlled ischemia has been extensively practiced by cardiac, plastic, orthopedic, vascular, and general surgeons. During the past 20 years, we have routinely used this technique to operate on a clean, bloodless field in complex cases of congenital vascular malformations. Based on our favorable experience, we have extended the use of the pneumatic tourniquet to complex cases of primary varicose veins. The use of the tourniquet has dramatically decreased the blood loss and operating time in complex venous surgery without complications secondary to its use. This technique represents a welcome alternative to the bloody, tedious, and time-consuming traditional varicose vein surgery of the past. Complex venous surgery for extensive varicose veins of the extremities can be safely and expeditiously performed under controlled ischemia. It should be the technique of choice.

Bilateral spontaneous dissection of the internal carotid arteries--a case report.

A 41-year-old African American man presented with an acute stroke secondary to bilateral spontaneous internal carotid artery dissections following exercise. Spontaneous bilateral carotid artery dissection is an unusual and uncommon occurrence that can be successfully diagnosed by color-flow duplex ultrasonography and magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) imaging. A review of the literature and the authors' experience supports initial medical management of these patients. Surgery should be considered for those patients who exhibit progressive neurologic symptoms during medical management or when significant carotid artery complications, aneurysms, or flow-limiting stenoses persist.

Repair of bilateral iliac artery aneurysms associated with a congenital pelvic kidney.

The association of iliac artery aneurysms with a congenital pelvic kidney is extremely rare. Although multiple techniques are well described for renal preservation with renal ectopia in the setting of aortic reconstruction, few reports exist describing techniques for renal preservation in the setting of bilateral iliac artery aneurysms. A case is presented of a middle-aged man with a 6-cm right common iliac artery aneurysm and a 3-cm left common iliac artery aneurysm and a right pelvic kidney. A double-proximal-clamp technique and temporary shunting to the pelvic kidney were used during the aneurysm repair. The technical aspects of this procedure are presented as well as a brief discussion of the various options for renal preservation with renal ectopia when repairing complex aneurysmal disease.

The fate of a patent carotid artery contralateral to an occlusion.

The finding of carotid stenosis contralateral to a carotid occlusion is becoming more frequent. While the neurologic outcomes in this patient population have been described, the rate of disease progression measured by duplex examination and the eventual need for carotid endarterectomy has not been described. In this study, a computerized database of carotid duplex examinations was reviewed and clinical data were obtained from clinic records. From 9124 studies 117 patients were identified. Thirty patients had previous carotid surgery on the patent side and were excluded. Of 87 patients 33 required carotid endarterectomy on the patent side. The rate of disease progression and/or the performance of a carotid endarterectomy by life-table analysis was 85.9% over 8 years. There were 10 neurologic events during the follow-up period. Patients with carotid stenosis and contralateral occlusion are at significant risk for disease progression. Follow-up should be more frequent and of longer duration in this patient population. A significant number of patients with carotid artery occlusion will require a carotid endarterectomy of the patent contralateral carotid.

Hemostatic efficacy of fibrin sealant (human) on expanded poly-tetrafluoroethylene carotid patch angioplasty: a randomized clinical trial.

PURPOSE: The efficacy of solvent-detergent-treated fibrin sealant (human [FSH]) for controlling anastomotic bleeding from expanded polytetrafluoroethylene (ePTFE) patch angioplasty during carotid endarterectomy was evaluated, and FSH was compared with thrombin-soaked gelatin sponge (Gelfoam; TSG). METHODS: The study was of a randomized, open-label, single-site, single-treatment, parallel design that took place in a referral center with hospitalized patients. Forty-seven adult patients (33 men, 14 women) underwent elective carotid endarterectomy. Patients were randomized to receive either FSH (N = 24) or TSG (N = 23). FSH was obtained as an investigational new drug. FSH was applied as a liquid by means of a dual-syringe technique. Heparin anticoagulation, patch thickness, and suture type were standardized. Two different needle sizes were used (CV-6, PT-13: N = 21 [FSH: N = 10, TSG: N = 11]; CV-6, PT-9: N = 26 [FSH: N = 14, TSG: N = 13]). The FSH or TSG was applied to the ePTFE patch, and then blood flow was restored through the carotid artery. Degree of anticoagulation was assessed by anti-factor Xa activity. The time from restoration of carotid blood flow until achieving hemostasis was recorded. The blood loss from patch suture hole bleeding was measured. Completion intraoperative duplex ultrasound scanning was performed in all cases. Heparin was reversed with protamine sulfate. The primary end point was successful hemostasis within 15 minutes of restoration of carotid blood flow. The secondary end points were the amount of blood loss caused by suture line bleeding and the time to achieve hemostasis. RESULTS: There was no difference in the number of patients with complete hemostasis at 15 minutes (TSG, 13 of 23; FSH, 12 of 24; P =.77). The measured blood loss was 99.0 +/- 119.9 (SD) mL for TSG, and 105.0 +/- 107.9 mL for FSH (P =.86). The time to hemostasis was the same for both groups (TSG, 16.5 +/- 16.5 minutes; FSH, 16.6 +/- 14.2 minutes; P =.97). Within both treatment groups, the use of larger needles (PT-13) was associated with greater blood loss (FSH, 169.7 +/- 124.2 mL; TSG, 172.7 +/- 151.5 mL) than was the use of smaller needles (PT-9; FSH, 58.8 +/- 66.3 mL; TSG, 34.1 +/- 25.6 mL; P =.036, P =.001, respectively). There were no postoperative strokes or bleeding complications in either group. No abnormalities were shown in either group by means of completion carotid duplex ultrasound scanning. CONCLUSION: FSH was equivalent, but not superior to, TSG in achieving hemostasis during carotid endarterectomy performed with ePTFE patch angioplasty. Adhesion properties of FSH to ePTFE are possibly different than those to native tissue and warrant additional investigation.

Histopathologic evaluation of an expanded polytetrafluoroethylene-nitinol stent endoprosthesis in canine iliofemoral arteries.

PURPOSE: The authors assess a new ePTFE-nitinol stent for its long-term patency, healing, and properties of endothelialization. MATERIALS AND METHODS: Adult greyhounds (n = 18) underwent bilateral iliofemoral placement of an endoprosthesis (Hemobahn) consisting of a nitinol stent lined with an ultrathin expanded polytetrafluoroethylene (ePTFE) material. Histologic and quantitative morphometric analyses were performed on devices explanted at 2 weeks and 1, 3, 6, and 12 months. The source of endothelialization was examined in four additional devices modified by sealing either the proximal and distal ends or the entire graft with poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), a nonporous laminate to prevent potential transgraft endothelial cell migration. RESULTS: Device patency assessed with both intravascular ultrasound and histologic study showed minimal arterial stenosis, irrespective of implant duration. The neointima at less than 3 months consisted of fibrin and inflammatory infiltrate; at later time points, it was composed of mostly smooth muscle cells. Flow surfaces were more than 75% endothelialized by 3 months, which was nearly complete by 6 months. Modified endoprostheses entirely enveloped with FEP resulted in endothelialization of only the proximal and distal ends; the middle regions showed nonocclusive thrombi. Conversely, devices wrapped proximally and distally showed nearly complete endothelialization. CONCLUSIONS: This ePTFE-nitinol endoprosthesis demonstrated long-term patency at up to 1 year after implantation and showed early and nearly complete endothelialization by 6 months. The design promoted rapid endothelialization of flow surfaces, particularly in the midregion of the device possibly by transgraft migration.

The incidence of heparin-induced antibodies in patients undergoing vascular surgery: a prospective study.

PURPOSE: This study prospectively assessed the incidence of heparin-induced antibodies in patients undergoing peripheral vascular surgery and determined whether the incidence is influenced by previous heparin exposure. METHODS: Fifty-four hospitalized patients (36 men and 18 women) undergoing peripheral vascular surgery and receiving intraoperative heparin anticoagulation were studied. Unfractionated porcine heparin was given for intraoperative anticoagulation and was not continued postoperatively. Carotid endarterectomy was performed in 36 patients, aortic reconstruction in 11 patients, and infrainguinal bypass in 7 patients. Plasma was tested before and after (14 +/- 7.5 [SD] days) surgery for IgG antibodies to the complex of heparin/platelet factor 4, using a standardized, validated enzyme-linked immunosorbent assay (ELISA). Results are expressed as an optical density ratio (ODR) of patient plasma to normal plasma, with the threshold for a positive result of > or = 1.8. Platelet counts and clinical outcomes were also assessed. RESULTS: The mean patient age was 67.2 +/- 9.7 years. A prior exposure to heparin was documented in 41% of patients. The mean intraoperative heparin dose was 9089 +/- 3607 units. Only 1 patient converted from a negative antibody status to a positive status (1.9%, 95% CI = 0.10%-11.18%). The change in the ELISA ODR after surgery was not significantly different for patients with (+0.042 +/- 0.272) and without (-0.022 +/- 0.299, P = 0.57) prior heparin exposure. Postoperatively, the platelet counts dropped from 227,620 +/- 78,308 microL, to 185,706 +/- 80,842 microL (P < .001). The decrease in platelet count was the same in patients with prior heparin exposure (-23.0 +/- 18.0%) and without (-18.0 +/- 14.0%, P = .46). One thrombotic complication occurred, a femorotibial bypass graft occlusion in a patient who tested negative for antibodies. CONCLUSION: Heparin-induced antibodies occur infrequently after peripheral vascular surgery. The commonly observed, mild degree of postoperative thrombocytopenia does not appear to be caused by heparin-induced antibodies. These results indicate that a standard dose of heparin for intraoperative anticoagulation during vascular surgery is not associated with a significant risk of heparin-induced thrombocytopenia and thrombosis.

Determination of 60% or greater carotid stenosis: a prospective comparison of magnetic resonance angiography and duplex ultrasound with conventional angiography.

The morbidity and cost of conventional angiography (CA) have focused recent efforts in cerebrovascular imaging upon the exclusive use of noninvasive techniques. Our purpose was to prospectively evaluate carotid magnetic resonance angiography (MRA) and to compare its accuracy with color-flow duplex (CFD). Fifty patients were prospectively evaluated with CA and MRA after clinical and CFD findings indicated the need for carotid angiography. CFD measurements of peak systolic velocity (PSV) and end-diastolic velocity (EDV) were made. MRA results were categorized as 0%-39%, 40%-59%, 60%-79%, or 80%-99% stenosis or occluded. Determination of percent carotid stenosis by CA was made as in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Using receiver operating characteristic (ROC) curves, the probability of correctly predicting a > or =60% stenosis using various CFD thresholds and MRA was assessed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in determining > or =60% stenosis were estimated. For MRA the sensitivity was 85% (95% Confidence Interval [CI] = 69%-94%), specificity 70% (CI = 56%-81 %), PPV 68% (CI = 53%-80%), and NPV 86% (CI = 72%-94%). For CFD the sensitivity was 89% (CI = 74%-96%), specificity 93% (CI = 82%-98%), PPV 89% (CI = 74%-96%), and NPV 93% (CI = 82%-98%). When MRA and CFD results were concordant (n = 64), the sensitivity was 100% (CI = 89%-100%), specificity 95% (CI = 81%-99%), PPV 94% (CI = 77%-99%), and the NPV was 100% (CI = 92%-100%). The area under the ROC curve for CFD was 95%, compared to 83% for MRA (p = 0.0005). We conclude that the low specificity of MRA precludes its use as the definitive imaging modality for carotid stenosis. The 93% specificity of CFD alone warrants its consideration as a definitive carotid imaging study. By ROC curve analysis, CFD offers superior accuracy to MRA. Our data support noninvasive preoperative carotid imaging for detecting a threshold stenosis of > or =60% whether CFD is used alone, or in combination with the selective use of MRA.

Primary stenting of atherosclerotic renal artery ostial stenosis.

Percutaneous transluminal angioplasty for atherosclerotic ostial lesions of the renal arteries has resulted in high restenosis rates. Recent reports of angioplasty with intravascular stenting show improved results over angioplasty alone. The purpose of this study is to review the results of primary stenting of ostial renal artery stenosis at our institution. Twenty one patients (11 men, 10 women, age 63 +/- 11 years), with atherosclerotic renal artery ostial stenosis in association with hypertension or renal insufficiency underwent renal angioplasty with primary stenting during a 2-year period. Medical records were reviewed for indications, technical success, complications, restenosis, response of hypertension and response of renal insufficiency. A technical success was defined as a normal postprocedure arteriogram with no residual stenosis and no residual gradient. Restenosis was defined as > or =60% diameter reduction identified by arteriography, or duplex scan demonstrating a renal artery to aortic ratio of > or =3.5. Thirty-three stents were placed in 25 arteries with four patients having bilateral procedures. All patients were hypertensive. Nine patients (43%) had chronic renal insufficiency (creatinine > or =1.5 mg/dl). One patient was on hemodialysis. The immediate technical success rate was 95%. Six complications occurred in four patients (two pseudoaneurysms, two dissections requiring additional stents, renal failure, and atheroembolization). Mean arterial blood pressure improved from 117 +/- 13.4 to 103 +/- 12.8 mmHg (p = 0.002) after stenting. Serum creatinine levels decreased from 1.48 +/- 0.57 to 1.31 +/- 0.41 (p = 0.07). Eight patients developed restenosis. The mean follow up was 13 +/- 7 months. Life table analysis showed a cumulative restenosis rate of 65 +/- 18% at 24 months. We advise caution in the application of renal stenting for the treatment of ostial lesions, particularly in patients for whom standard surgical revascularization options are available.

Long-term follow-up of a superficial femoral vein injury: a case report from the Vietnam Vascular Registry.

We report a 29-year follow-up of a high-velocity superficial femoral vein injury sustained during the Vietnam War that was treated by emergent ligation. After years of suffering recurrent ulceration from chronic venous insufficiency, this patient underwent axillary vein valve transfer with improvement in his venous hypertension. Long-term follow-up of patients with deep venous injuries is necessary to avoid complications from chronic venous insufficiency.