Dermot J. Moore

Histologic characteristics of carotid artery plaque

Carotid plaque characteristics associated with the production of symptoms were identified with quantification of carotid plaque constituents in high-grade stenotic asymptomatic (n = 8) and symptomatic (n = 44) plaques. Asymptomatic plaques contained significantly more fibrous/collagen material (88%) than symptomatic plaques (66%) (p less than 0.05). Hemorrhage constituted 2% and 1% of asymptomatic and symptomatic plaques, respectively. The predominant nonfibrous material was a pink amorphous material mixed with cholesterol, which composed 7% of asymptomatic and 27% of symptomatic plaques (p less than 0.05). No relationship was found between plaque composition and the number of ipsilateral ischemic neurologic events, nor was there evidence of a healing process. B-mode ultrasound scanning had a sensitivity of 94% in identifying plaque with greater than 80% fibrous content. We believe that plaque composition may be a useful discriminating factor in selecting asymptomatic patients for carotid endarterectomy.

Prospective randomized multicenter comparison of in situ and reversed vein infrapopliteal bypasses

We have performed a prospective, randomized, multicenter study to compare in situ and reversed vein grafts for long limb salvage bypasses from the proximal thigh to an infrapopliteal artery. Three hundred eighty-four patients required an infrapopliteal bypass for critical lower extremity ischemia. Of these, 259 were excluded because a short vein bypass was performed or because the vein was considered inadequate. The remaining 125 patients had a randomized vein bypass, 63 reversed, 62 in situ. The two groups were similar with regard to risk factors, indications, graft dimensions, and outflow. Secondary patency at 30 months was similar for both techniques: reversed 67% +/- 9% (+/- SE); in situ 69% +/- 8%. For veins less than or equal to 3.0 mm in minimum distended diameter 24-month patency rates were 61% +/- 22% for 12 in situ veins and 37% +/- 29% for 10 reversed veins (p greater than 0.05). Angiographic evaluation of failing grafts revealed lesions similar in type and frequency in both types of grafts. These included focal (in situ, n = 4; reversed, n = 7) and diffuse vein hyperplasia (in situ, n = 2; reversed, n = 1), and inflow and outflow stenoses (in situ, n = 4; reversed, n = 3). The incidence of wound complications and the mortality rate were similar for the two groups. These data show no significant difference in overall patency rates for the two types of vein grafts at 2 1/2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Duplex ultrasound in aneurysm surveillance following endovascular aneurysm repair: a comparison with computed tomography aortography

OBJECTIVES Cumulative radiation dose, cost, and increased demand for computed tomography aortography (CTA) suggest that duplex ultrasonography (DU) may be an alternative to CTA-based surveillance. We compared CTA with DU during endovascular aneurysm repair (EVAR) follow-up. METHODS Patients undergoing EVAR had clinical and radiological follow-up data entered in a prospectively maintained database. For the purpose of this study, the gold standard test for endoleak detection was CTA, and an endoleak detected on DU alone was assumed to be a false positive result. DU interpretation was performed independently of CTA and vice versa. RESULTS One hundred thirty-two patients underwent EVAR, of whom 117 attended for follow-up ranging from six months to nine years (mean, 32 months). Adequate aneurysm sac visualisation on DU was not possible in 1.7% of patients, predominantly due to obesity. Twenty-eight endoleaks were detected in 28 patients during follow-up. Of these, 24 were initially identified on DU (four false negative DU examinations), and eight had at least one negative CTA with a positive DU prior to diagnosis. Twenty-three endoleaks were type II in nature and three of these patients had increased sac size. There was one type I and four type III endoleaks. Two of these (both type III) had an increased sac size. Of 12 patients with increased aneurysm size of 5 mm or more at follow-up, five had an endoleak visible on DU, yet negative CTA and a further five had endoleak visualisation on both DU and CTA. Of six endoleaks which underwent re-intervention, all were initially picked up on DU. One of these endoleaks was never demonstrated on CTA and a further two had at least one negative CTA prior to endoleak confirmation. Positive predictive value for DU was 45% and negative predictive value 94%. Specificity of DU for endoleak detection was 67% when compared with CTA, because of the large number of false positive DU results. Sensitivity for DU was 86%, with all clinically significant endoleaks demonstrated on CTA also detected on DU. CONCLUSION Despite its low positive predictive value, we found DU to be a sensitive test for the detection of clinically significant endoleaks. Given concerns about cumulative radiation exposure and cost, and the surprisingly low sensitivity of CTA for endoleak detection in this series, selective CTA based on DU surveillance may be a more appropriate long-term strategy.

Popliteal aneurysms: a 10-year experience

BACKGROUND Popliteal aneurysms account for 70% of peripheral arterial aneurysms and, if untreated, pose a serious threat to the affected limb. Debate continues about the best form of treatment especially for asymptomatic lesions. METHOD We reviewed the computer records and charts of patients seen at this department with a diagnosis of popliteal aneurysm over the last 10 years. Patients who had not been seen within the last year were followed-up through their G.P. RESULTS Twenty-four patients (M 23/F 1) presented with 40 popliteal aneurysms. The mean age was 63.5 +/- 9 years. Symptoms were present in 23 of the affected limbs while 17 were asymptomatic. Thirty were treated surgically and 10 followed with regular ultrasound. The mean diameter of the repaired aneurysms was 3.3 +/- 1 cm. Aneurysms < 2 cm were more likely to be asymptomatic. No limbs were lost in patients undergoing elective repair of popliteal aneurysms. The secondary patency and limb salvage rates at 3 years were 84% and 96% respectively. Conservative management of asymptomatic lesions < 2 cm was not complicated by the development of symptoms. CONCLUSIONS Elective repair of popliteal aneurysms by exclusion and bypass is a safe, effective and durable technique. Small asymptomatic lesions can be safely managed with close follow-up.

The use of infrared laser therapy in the treatment of venous ulceration

Management of intractable venous ulceration remains an unrewarding task which is increasingly delegated to the realm of the vascular surgeon. The purpose of this pilot study was to assess the ulcer-healing effects of the newest form of biostimulation—the low power laser. Twelve patients with chronic venous ulcers unresponsive to conservative measures were treated with infrared laser irradiation for twelve weeks. Two ulcers healed completely and there was a 27% (p<0.01) reduction in size of the remaining ulcers. Treatment resulted in a 44% (p<0.01) increase in ulcer floor area occupied by healthy granulation tissue. The most dramatic effect of laser treatment was the reduction in ulcer pain, from 7.5 to 3.5 (linear analogue scale) (p<0.001). Laser irradiation had no effect on TcPO2, number of skin capillaries or pericapillary fibrin deposition in the lipodermatosclerotic area around the ulcer. The results of this pilot study are encouraging and a carefully controlled randomized study is indicated to compare low power laser irradiation to conventional treatment in the management of venous ulcers.

Lipoprotein [Lp(a)] and peripheral vascular disease

Lipoprotein(a) [Lp(a)], which combines structural elements of the lipid and fibrinolytic systems, is a major independent risk factor for the development of coronary heart disease. Eighty‐four consecutive patients with peripheral vascular disease (of whom 42 had concomitant ischaemic heart disease) and 43 healthy controls were enrolled in a case‐control study. We found that the mean Lp(a) concentration in male patients with peripheral vascular disease (PVD) was almost threefold higher than that of controls, while in female patients the Lp(a) concentration was more than twice that of controls. This marked difference was borne out in patients with and without concomitant ischaemic heart disease (IHD). A multivariate logistic regression analysis indicated that Lp(a) is independently associated with PVD when adjusted for age and sex (odds ratio per 100 mg l−1 increase in Lp(a) = 1.35; P < 0.01). A similar association is observed for patients with concomitant IHD (odds ratio per 100 mg l−1 increase in Lp(a) = 1.65; P < 0.01).

Haemorrhagic carotid plaque does not contain haemorrhage.

The presence of haemorrhage in carotid bifurcation atheromatous plaques is widely believed to be associated with the production of ischaemic neurological events. This study set out to characterise plaque composition in symptomatic (SYM) and asymptomatic (ASYM) patients and to identify, if possible, the origin of intra-plaque haemorrhage. Fifty-nine plaques (50 SYM and 9 ASYM) were serially sectioned and examined for haemorrhage, haemosiderin, fibrin, cholesterol and collagen. Immunoperoxidase and electron microscopy studies were carried out on sections from five plaques in order to identify blood breakdown products. Intra-plaque haemorrhage was identified in 40 (68%) plaques and was similar in SYM and ASYM plaques. In only one did it constitute more than 15% of plaque content, and in the remainder it consisted of small collections of erythrocytes constituting greater than 1% of plaque content in only 21 (35%) plaques. The predominant non-fibrous component was a pink amorphous material mixed with cholesterol. Apart from traces of platelet breakdown products there was no evidence of haemorrhage in this pink material. Plaque roof rupture or ulceration was seen in 39 (66%) and in almost all cases overlay the amorphous/cholesterol material. Blood vessels were identified in 51 87%) plaques but were in close proximity to haemorrhage in only nine (15%).

Suprarenal mycotic aneurysm exclusion using a stent with a partial autologous covering.

Purpose: To report a combined endovascular and open technique to manage a suprarenal mycotic aortic aneurysm using a stent-graft partially covered with a section of autologous artery. Methods and Results: A 50-year-old was hospitalized for staphylococcal septicemia and severe back pain. A previously diagnosed 3-cm abdominal aortic aneurysm was found to have expanded 2 cm in 3 weeks. Aortography documented some periaortic thickening and 2 mycotic aneurysms, one posterior at the level of the superior mesenteric artery and the second at the aortic bifurcation. After intensive antibiotic therapy, an endovascular approach to exclude the suprarenal mycotic aneurysm was undertaken in tandem with surgical excision of the infrarenal aneurysm. The harvested right common iliac artery was used to partially cover a Palmaz stent, which was deployed under direct vision just above the renal artery ostia so that the covered portion of the stent excluded the aneurysm. A right axillofemoral bypass with a femorofemoral bypass completed the revascularization. Postoperatively, the patient developed renal failure, ischemic colitis necessitating a left hemicolectomy, and paraplegia. Although the patient is paralyzed, the aneurysm remains excluded with patent visceral vessels at 12 months following surgery. No organisms were grown from excised aortic tissue, and no signs of recurrent infection have been seen. Conclusions: Stent-graft repair may be able to lessen the invasiveness and reduce the morbidity associated with treatment of mycotic aortic aneurysms.

Endovascular Management of Rare Sciatic Artery Aneurysm

Purpose: To present a rare case of complete persistent sciatic artery aneurysm successfully treated by coil embolization and to suggest a new classification for this anomaly that encompasses both clinical and pathological factors. Methods and Results: A 77-year-old female presented with sudden onset of sharp, throbbing left thigh and foot pain. A nontender 10.0- × 7.0-cm pulsatile mass was found over the inferolateral aspect of the left buttock on examination in the right lateral decubitus position. Angiography demonstrated a 6.9-cm sciatic artery aneurysm with the distal sciatic artery completely thrombosed. Before planned bypass grafting, the aneurysm and distal segment of the internal iliac artery were successfully embolized with coils through a left percutaneous approach. The patients symptoms resolved with no deterioration in limb perfusion, and further revascularization was unnecessary. Postembolization imaging showed complete occlusion of the aneurysm, which has continued for 19 months. Conclusions: The application of endovascular techniques and surgical revascularization procedures provides numerous management options for the treatment of an aneurysmal persistent sciatic artery. This case demonstrates that clinical evaluation between staged procedures may obviate the need for further intervention.

The profunda femoris: A durable outflow vessel in aortofemoral surgery

Aorta-common femoral artery bypass is the standard operation for relief of aortoiliac occlusive disease. When extensive superficial femoral artery disease coexists, the profunda femoris, even in its distal portion, may be used as the outflow vessel. To test this assumption we compared cumulative patency, limb salvage, and the need for distal bypass of 134 aorta-profunda femoris and 151 aorta-common femoral artery bypasses performed consecutively for aortoiliac occlusive disease over a 12-year period. We also analyzed results of proximal (n = 103) and distal (n = 31) aortoprofunda bypasses. Angiographic and noninvasive studies showed greater disease in limbs undergoing aorta-profunda femoris bypass. However, no difference was observed in cumulative patency (91% +/- 6% vs 96% +/- 3%) or limb salvage (90% +/- 6% vs 94% +/- 3%) at 5 years. Seventeen distal bypasses in the group undergoing profunda femoris bypass and 20 distal bypasses in the group undergoing common femoral artery bypass were required to maintain limb salvage. Proximal and distal aorta-profunda femoris bypasses showed no difference in cumulative patency (91% +/- 9% vs 95% +/- 6%) or limb salvage (94% in each group) at 3 years. Standard aorta-common femoral artery and aorta-profunda femoris bypass provide cumulative patency and limb salvage exceeding 90% at 5 years; concomitant or subsequent distal bypass was required in 12% or limbs undergoing aorta-profunda femoris bypasses. Both proximal and distal profunda femoris arteries provide a durable outflow tract when aortoiliac and femoropopliteal occlusive disease are combined.