Richard J. DeMasi

Endoleak after aortic stent graft repair: Diagnosis by color duplex ultrasound scan versus computed tomography scan

PURPOSE The purpose of this study was to compare the accuracy of a color duplex ultrasound scan (CDU) to a computerized axial tomography scan (CT) in the diagnosis of endoleaks after stent graft repair of abdominal aortic aneurysms. METHODS The Endovascular Aneurysm Clinical Trial Core Laboratory records were reviewed from 117 concurrent CDU and CT studies that were performed in 79 patients who were implanted with the Endovascular Technologies stent graft device between December 1995 and January 1997. All of the studies were interpreted by the Core Laboratory as having the presence or the absence of an endoleak or as being indeterminate because of technical factors. Of the 117 videotaped CDU studies available for reexamination, 100 were reassessed for technical adequacy on the basis of the following criteria: a satisfactory imaging of the aneurysm sac and of the stent graft with gray scale, and both color and spectral Doppler scan evaluation for endoleak outside the endograft and within the aneurysm sac. RESULTS Of the 117 studies, 103 CDUs (88%) and 114 CTs (97%) were recorded as having the presence or the absence of an endoleak and 14 CDUs (12%) and 3 CTs (3%) were indeterminate. For the studies that were recorded to have the presence or the absence of an endoleak, the sensitivity, the specificity, the positive and the negative predictive values, and the accuracy of CDUs as compared with CTs were 97%, 74%, 66%, 98%, and 82%, respectively. Of the 100 CDU videotaped studies available for review, the following results were seen: (1) 93 CDUs had satisfactory B-mode images, (2) 76 had satisfactory color Doppler scan images to evaluate for endoleaks, (3) 55 had color Doppler scan assessment of the entire abdominal aortic aneurysm sac for endoleak, and (4) 27 had spectral Doppler scan waveform confirmation of suspected endoleaks. Only 19 CDU studies (19%) with all 4 criteria for complete assessment of endoleak were performed. CONCLUSION Although most of the CDU studies were technically suboptimal, the CDUs reliably identified endoleaks with an excellent sensitivity and a negative predictive value as compared with CT scans.

Blunt Injury of the Abdominal Aorta: A Review

Injury to the abdominal aorta after blunt trauma occurs much less frequently than injury to the thoracic aorta. Although presentations vary, common themes continue to emerge with each patient. Within a 6-month period, our trauma unit diagnosed and treated two cases of blunt abdominal aortic trauma. Both patients were restrained passengers in motor vehicle crashes with resultant abdominal aortic injuries and demonstrated some of the most common associated injuries. Our two cases bring the number found in the literature to 62 and demonstrate the need for rapid recognition and treatment of this potentially lethal injury. This article is a comprehensive review of the management of abdominal aortic injury from blunt trauma.

Comparison of abdominal aortic aneurysm diameter measurements obtained with ultrasound and computed tomography: is there a difference?

OBJECTIVES Accurate diameter measurements of abdominal aortic aneurysm (AAA) with both computed tomography (CT) and ultrasound (US) are essential for screening, planning surgical intervention, and follow-up after endovascular repair. Often there is a discrepancy between measurements obtained with CT and US, and neither limit of agreement (LOA) nor correlation between the two imaging methods has been clearly established. The purpose of this study was to assess the paired differences in AAA diameter measurements obtained with CT and US in a large national endograft trial. METHODS CT and US measurements were obtained from an independent core laboratory established to assess imaging data in a national endograft trial (Ancure; Guidant, Menlo Park, Calif). The study included only baseline examinations in which both CT and US measurements were available. Axial CT images and transverse US images were assessed for maximal AAA diameter and recorded as CT(max) and US(max), respectively. Correlations and LOA were performed between all image diameters, and differences in their means were assessed with paired t test. RESULTS A total of 334 concurrent measurements were available at baseline after endovascular repair. CT(max) was greater than US(max) in 95% (n = 312), and mean CT(max) (5.69 +/- 0.89 cm) was significantly larger (P <.001) than mean US(max) (4.74 +/- 0.91 cm). The correlation coefficient between CT(max) and US(max) was 0.705, but the difference between the two was less than 1.0 cm in only 51%. There was less discrepancy between CT(max) and US(max) for small AAA (0.7 cm, 15.3%) compared with medium (0.9 cm, 17.9%) and large (1.46 cm, 20.3%) AAA; however, the difference was not statistically significant. LOA between CT(max) and US(max) (-0.45-2.36 cm) exceeded the limits of clinical acceptability (-0.5-0.5 cm). Poor LOA was also found in each subgroup based on AAA size. CONCLUSIONS Maximal AAA diameter measured with CT is significantly and consistently larger than maximal AAA diameter measured with US. The clinical significance of this difference and its cause remains a subject for further investigation.

Subfascial perforator vein ablation: comparison of open versus endoscopic techniques.

Purpose: To compare the outcomes and complications of open (OSPS) versus endoscopic subfascial perforator surgery (SEPS) for treatment of chronic venous insufficiency. Methods: Data were retrospectively collected on 25 patients who underwent 27 SEPSs from February 1996 to August 1997 and from 22 patients who underwent 29 OSPSs between March 1978 and May 1993. Outcomes were evaluated for postoperative complications, ulcer healing, recurrence, and venous dysfunction scores on the last follow-up for the SEPS group and at 1-year follow-up for the OSPS group. Results: The 2 groups were similar in age, sex, history of previous venous surgery, healed or active ulcers, etiology, deep venous incompetency, pathophysiology, and venous refill times. Eighteen (90%) of 20 active ulcers in the SEPS group healed with recurrences in 5 (28%) limbs at 7.5 ± 5.4-month follow-up. All 19 ulcers in the OSPS group healed, with recurrences in 13 (68%) limbs at 35 ± 35-month follow-up. Clinical venous dysfunction scores showed significant improvement following SEPS (10.0 ± 3.6 to 5.4 ± 4.1, p < 0.001) and OSPS (10.0 ± 3.2 to 6.7 ± 3.6, p < 0.001) with no significant difference between groups. Both groups also had significant improvement in anatomical and disability scores. There was no postoperative mortality in either group. The OSPS group had significantly more wound complications (45%) than the SEPS group (7%) (p < 0.005). The hospital stay and readmission rate for wound problems were also higher in the OSPS group. Conclusions: The early outcome showed equal improvement in clinical venous dysfunction scores in the 2 groups, but with significantly fewer complications in the SEPS group. Although the long-term durability of the endoscopic approach has not been determined, the short-term results would favor SEPS for treatment of severe venous insufficiency when perforator incompetence is a significant component.

Carotid angioplasty and stenting in anatomically high-risk patients: Safe and durable except for radiation-induced stenosis

OBJECTIVE Carotid angioplasty and stenting (CAS) is used in patients considered high-risk for carotid endarterectomy (CEA). Patients qualify as high-risk because of medical comorbid conditions or for anatomic considerations (previous CEA, radical neck dissection, radiation). We compared the technical feasibility and durability of CAS in medically high-risk patients (MED) vs anatomically high-risk patients (ANAT). METHODS A retrospective review was performed of all consecutive patients undergoing CAS by a single vascular surgery group. All patients were high risk and evaluated with duplex ultrasound imaging and angiography. Primary end points were technical success, 30-day stroke, myocardial infarction (MI), death, and in-stent restenosis. Standard statistical analysis included Kaplan-Meier life tables. RESULTS From January 2003 to December 2007, 230 CAS (98 ANAT, 132 MED) procedures were attempted. The ANAT cohort comprised 84 patients with a single anatomic risk factor: 71 with a previous ipsilateral CEA, 6 high lesions, 6 history of neck radiation, and 1 with a tracheostomy. Ten patients had two or three anatomic risk factors: nine with radical neck dissection and radiation and one with neck radiation and ipsilateral CEA. The mean age was 71.1 years for ANAT vs 73.9 years for MED (P = .021). Technical success rates were 98% in ANAT and 98.5% in MED (P = .76). Thirty-day stroke rate was 1.0% in ANAT and 5.3% in MED (P = .14); the mortality rate was 2.0% in ANAT and 0.8% in MED (P = .79). The 2-year survival free from stroke was MED, 93.6% and ANAT, 98.9% (P = .118); and from restenosis was MED, 91.9%; and ANAT, 91.0% (P = .98). Two-year overall survival was significantly better in ANAT (84.6%) vs MED (70.1%; P = .026). Four of the seven restenoses in the ANAT group occurred in patients with previous neck radiation. The restenosis rate for radiation-induced (RAD) stenosis treated with CAS was significantly higher at 22.2% (4 of 18) compared with 3.8% (3 of 78) in ANAT group patients without a history of radiation (non-RAD; P = .028). The 2-year restenosis-free survival was 72.7% in the RAD group vs 95.9% in the non-RAD group (P = .017). CONCLUSION CAS is as technically feasible, safe, and durable in anatomically high-risk patients as in medically high-risk patients, with similar rates of periprocedural stroke and death and late restenosis. However, patients with radiation-induced stenosis appear to be at an increased risk for restenosis.

Utility of Basilic Vein Transposition for Dialysis Access

Autologous arteriovenous access is the key to long-term success with hemodialysis and is strongly supported by the National Kidney Foundations Dialysis Outcomes Quality Initiative guidelines. Basilic vein transposition (BVT) fulfills the need for a durable conduit with high patency and maturation rates. This retrospective review examines a single groups experience with this procedure. All patients undergoing BVT for hemodialysis with available follow-up data were reviewed. Telephone interviews were used to supplement clinical data where needed. Functional assisted patency was used as the end point for this procedure, and if the access was never used for dialysis, then the patency was considered zero. Secondary interventions performed while the access remained patent and in use were not considered detrimental to the patency reported. One hundred seventy BVTs in 162 patients were performed between November 1992 and October 2001. There were 87 women (53.7%) and 112 black patients (69.1%); hypertension was present in 138 patients (85.2%) and diabetes in 89 patients (54.9%). Each year, an increasing incidence of BVT was performed in our dialysis population. The BVT was performed as the first access in that extremity in 73 of the procedures (42.9%). Functional patency (primary assisted) was achieved in 40.0% at 2 years and 15.2% at 5 years. The mean assisted patency was 14.6 months. To maintain BVT patency, 40 percutaneous secondary interventions (69.0%) and 18 surgical revisions (31.0%) occurred in 32 patients (19.0%). Ligation for swelling was necessary in 4 patients (2.5%), and steal syndrome occurred in 3 patients (1.9%). BVT is a useful autologous procedure for hemodialysis and the preferred access alternative in patients without an adequate cephalic vein. Although patencies remain poor relative to other conventional arterial vascular procedures, BVT is our most durable hemodialysis access procedure and is often the only available autologous conduit for hemodialysis.

A comparison of surgery for neurogenic thoracic outlet syndrome between laborers and nonlaborers

OBJECTIVE To determine factors of outcome following surgical intervention for neurologic thoracic outlet syndrome (NTOS). METHODS In a retrospective study of patients surgically treated for NTOS, outcome was evaluated by postoperative symptoms and the ability of patients to return to work. RESULTS Good, fair, and poor results were obtained in 26 (48%), 21 (39%), and 7 (13%) patients, respectively. The best predictor of a good outcome was occupation. Nonlaborers were more likely to have good outcome (21 of 32, 66%) when compared with laborers (5 of 22, 23%; P = 0.0025). Only 6 of 20 (30%) laborers were able to return to their original occupation compared with 17 of 26 (65%) nonlaborers (P = 0.036). CONCLUSIONS Laborers with NTOS are less likely to have a good result from surgical intervention, are unlikely to return to their original occupation, and may require retraining for a non-labor-intensive occupation if they cannot return to their original work.

The Current Status of Prosthetic-Vein Composite Grafts for Lower Extremity Revascularization

When infrageniculate lower extremity vascular reconstructions are required in the face of inadequate or insufficient autogenous vein, prosthetic-vein composite grafts remain a viable alternative. Graft patency and limb salvage for composite grafts are intermediate between those of completely autogenous and prosthetic bypasses alone. The sequential technique may offer superior patency in patients with the appropriate anatomy. The addition of adjunctive techniques such as a distal arteriovenous fistula and/or anticoagulation may further improve results. An algorithm illustrating the proper role of composite grafts for distal lower extremity reconstructions is shown in Figure 6. Any significant interval of patency is important in this group of patients in whom limb salvage can often be achieved by healing ischemic lesions and in whom overall life expectancy is limited.

Are we undertreating carotid stenoses diagnosed by ultrasound alone

Clinical management of carotid disease is primarily based on results of national trials (ACAS and NASCET) that used the distal internal carotid artery diameter as a reference. However, commonly accepted ultrasound (US) criteria for carotid stenosis were derived from the correlation of velocity measurements with angiographic bulb diameter reductions (BDR). This study was undertaken to compare the degree of carotid stenosis determined by conventional velocity criteria to the degree of stenosis measured by B-mode (gray scale) diameter at both the carotid bulb and at the distal internal carotid artery, and, second, to evaluate US imaging to derive distal diameter reductions (DDR) noninvasively. During a 3-month period patients referred for carotid US were prospectively analyzed for standard velocity criteria and plaque morphology. Minimum carotid diameter was measured by longitudinal and transverse B-mode measurements and compared to carotid bulb diameter and internal carotid diameter distal to all disease. B-mode diameter reductions were compared to the degree of stenosis determined by velocity criteria and to patient symptoms and the decision for carotid endarterectomy. In total, 131 carotid arteries in 74 patients were evaluated. Based on the University of Washington velocity criteria, lesions were classified as grade I (n= 61, 46%), IIA (n= 58, 44%), IIB (n= 7, 5%), or III (n= 5, 4%). BDR measured by B-mode predicted the grade of disease based on velocity criteria (p<0.001) with an overall accuracy of 95%. With use of the B-mode for DDR (NASCET style), 18 patients exceeded the 60% threshold for surgical intervention. Of these, only 3 patients were symptomatic and were operated on. An additional 3 operated-on patients had an asymptomatic grade III stenosis, our usual threshold for intervention. Twelve additional patients were appropriate for surgical intervention by B-mode but were not treated based on conventional velocity criteria alone. Bulb diameter reduction by B-mode imaging correlates strongly with diameter reduction determined by velocity criteria, and independently predicts the grade of carotid disease. With this in mind, the accuracy of B-mode imaging may be extended to the measurement of carotid stenosis based on DDR. By B-mode criteria, many patients appropriate for intervention were not offered treatment based on conventional velocity criteria. Modern B-mode imaging provides a noninvasive method to obtain “arteriographic equivalent” measurements and should be added as a routine to carotid ultrasound interrogation.

A Technique to Improve the Confidence of Color Duplex Ultrasound assessment of Aortic Endografts: The use of Contrast Agents

Introduction Color duplex ultrasound (CDU) is routinely used in the evaluation of aortic endografts in many centers. CDU compliments computed tomography (CT) and selective angiography in the identification of persistent endoleaks in these grafts. Because of the complexity of these procedures and the subtle nature of endoleaks, CDU can be time-consuming and challenging. Contrast agents can improve the ease of imaging by rapidly detecting low flow endoleaks. The application of ultrasound contrast agents has been studied in other specialties, such as cardiac echocardiography. This article describes our technique and early experience using contrast-enhanced CDU in aortic endograft assessment. Methods Nineteen patients being seen for a routine CDU examination after endovascular aortic aneurysm repair were evaluated according to published protocol. An initial CDU examination was completed, thoroughly assessing for the presence of graft patency, limb dysfunction, and endoleak. After patient consent, a focused ultrasound was performed using a Food and Drug Administration–approved contrast agent (Optison). The residual aneurysm sac was closely inspected after a 0.3-ml intravenous injection. A maximum of three injections were given in 10-min intervals, with careful evaluation in transverse and sagittal views of the residual aortic sac. Contrast was used to confirm endoleaks noted on the baseline study and help clarify subtle perigraft flow, especially on suboptimal examinations. Results Of the 19 patients given the contrast agent, none had side effects, and all tolerated contrast well. In 9 of 19 examinations, contrast-enhanced CDU confirmed the baseline results positive for perigraft endoleak. Six of nine studies had improved ease of identification of endoleak with contrast. Six of 19 studies were negative for endoleak before and after contrast. Three of 19 studies were indeterminate for endoleak by CDU only secondary to bowel gas and body habitus. The contrast agent was given and was negative for endoleak in these three cases. One study was initially negative for endoleak by CDU, and contrast revealed a small lumber artery leaking into the aneurysm sac. The contrast was easily identified within the endograft and leak sites in all patients. Conclusions CDU is a valuable modality in the postoperative evaluation of endovascular aortic aneurysm repairs. These examinations can be challenging and subject to limitations including bowel gas and body habitus, even when performed by experienced technologists. Color artifacts within the residual aneurysm sac can be difficult to differentiate from true endoleak. Contrast-enhanced CDU can improve the technologists confidence in the detection of endoleaks.