Contralateral stenosis and stump pressures: parameters to identify the high risk patient undergoing carotid endarterectomy under local anaesthesia.

Carotid endarterectomy (CEA) under local anaesthesia (LA) enables the assessment of the two parameters of stump pressure and contralateral stenosis as predictors of neurological complications both intra- and postoperatively. Over a 7 year period, 175 carotid endarterectomies were performed under LA and of these, stump pressure measurements and angiographic findings were recorded on 99 patients. There were no deaths, two patients (2.0%) suffered a perioperative stroke (CVA) and one (1.0%) a transient ischaemic attack (TIA). An additional eight patients "obtunded" while the internal carotid artery was clamped, with complete resolution upon revascularisation in all but one patient who recovered fully within 24 h. Patients with contralateral occlusion or > or = 80% stenosis were more likely to develop complications (6/25 vs. 5/74 p < 0.03) and stump pressures were significantly lower in patients suffering an event (34.36 +/- 23.15 vs. 55.57 +/- 27.58, p < 0.02). By combining contralateral stenosis (> or = 80%) and stump pressure (< or = 35 mmHg), a "high risk" group of 42 patients in whom eight of the 11 events occurred, were identified. Contralateral stenosis and low stump pressures can be used in combination to identify high risk patients likely to develop neurological complications during or following CEA.

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.

Increased in-vitro incubation time of endothelial cells on fibronectin-treated ePTFE increases cell retention in blood flow.

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency of small calibre vascular grafts. However, the majority of seeded cells are lost within hours following restoration of blood flow. We postulated that incubating EC in-vitro on a graft will improve adherence and resistance to the sheer stresses of pulsatile blood flow. Fibronectin-treated ePTFE (5 cm x 4 mm ID) seeded with Indium-111-labelled autologous canine EC (1.5 x 10(5) cells/cm2) were incubated for four different time periods; 90 min, 24 h, 72 h and 6 days. Incubated grafts were subjected to blood flow of 75 ml/min for 6 h, in a canine ex-vivo arteriovenous shunt circuit. EC retention during perfusion was studied by measuring gamma activity emitted by the grafts. Cell morphology of non-perfused control groups and perfused groups was compared using scanning electron microscopy (SEM). SEM of control grafts showed progressive EC spreading on the ePTFE surface for up to 72 h incubation. Gamma activity was significantly higher at 6 h perfusion in grafts incubated for 72 h (82 +/- 4%) and 24 h (63 +/- 6%) vs. 90 min (34 +/- 13%, p less than 0.05), and between grafts incubated for 72 h vs. 6 days (55 +/- 7%, p less than 0.05). Perfused grafts incubated for 72 h showed unaltered EC morphology on SEM, few cells remained on 90 min incubated grafts. We conclude that incubating EC on fibronectin-treated ePTFE for 72 h in-vitro after seeding improves cell retention during blood flow.

Long-term follow-up of patients operated on for recurrent carotid stenosis.

We reviewed our experience with 29 operations for recurrent carotid stenosis in 27 patients who underwent both their primary carotid endarterectomy and their reoperations at our institution. These 27 patients represent 4% of the 667 patients who underwent primary carotid endarterectomies at our institution and who are included in our carotid follow-up registry. Reoperation was prompted by recurrent symptoms in 19/29 (65.5%) cases. Comparison of long-term stroke prevention in those patients who did (84% at 5 years, 78.6% at 10 years) and did not (90.3% at 5 years, 83.6% at 10 years) develop recurrent stenosis requiring reoperation revealed no statistically significant difference (p = 0.48) when measured from the time of primary operation. The perioperative stroke and death rates for reoperation (3.4% and 0%) were acceptable. We conclude that with our acceptably low perioperative stroke morbidity (3.4%), surgery for recurrent carotid stenosis in symptomatic patients or in asymptomatic patients with high-grade (greater than or equal to 75%) stenosis maintains the durable stroke prevention offered by primary carotid endarterectomy.

Long-term results with the above-knee popliteal expanded polytetrafluoroethylene graft.

Since approximately 30% to 40% of autogenous vein bypass grafts to the femoropopliteal level may occlude within 5 years of implantation, additional vein will be required for subsequent revisions. We undertook a study to determine whether the preferential use of an above-knee expanded polytetrafluoroethylene bypass graft to save vein is an appropriate option. We reviewed our experience with 114 above-knee expanded polytetrafluoroethylene bypass reconstructions. Life-table analysis of primary and secondary graft patency was carried out by the method of Peto and statistically analyzed for the influence of clinical indication, runoff as determined by both preoperative and intraoperative completion arteriography, smoking, and diabetes. The 5-year primary patency rate of 57% for patients with claudication was comparable to contemporary randomized or retrospective series with below-knee autogenous vein for that indication, and it was superior to the patency rate for limb salvage. The status of the runoff vessels was an important determinant of outcome. The 59 limbs with good arteriographic runoff (2 to 3 vessels) had a markedly higher 5-year patency rate (70%) than the poor arteriographic runoff (0 to 1 vessels) group (30%). Continued cigarette smoking and diabetes mellitus also appeared to affect adversely primary graft patency in our hands. Our data support the use of preferential above-knee expanded polytetrafluoroethylene grafts in patients with good angiographic runoff. This approach does not appear to prejudice the limb against secondary revisionary procedures or the use of a new autogenous graft, if required.

Nursing interventions. The nurse's role in the care of a 730 g baby treated with prostaglandins for 62 days for a coarctation of the aorta.

As techniques for saving very low birth weight babies improve, there will be a need to maintain babies with cardiac lesions on continuous infusions of prostaglandins until they gain enough weight so that corrective surgery can be performed. An organized approach to overcome the problems of prematurity through primary nursing is essential when caring for the very low birth weight baby with congenital heart disease requiring long-term prostaglandin therapy.