Automated end-to-side anastomosis to the middle cerebral artery: a feasibility study

The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model.

Automated, compliant, high-flow common carotid to middle cerebral artery bypass

The authors describe the use of the Cardica C-Port xA Distal Anastomosis System to perform an automated, high-flow extracranial-intracranial bypass. The C-Port system has been developed and tested in coronary artery bypass surgery for rapid distal coronary artery anastomoses. Air-powered, it performs an automated end-to-side anastomosis within seconds by nearly simultaneously making an arteriotomy and inserting 13 microclips into the graft and recipient vessel. Intracranial use of the device was first simulated in a cadaver prepared for microsurgical anatomical dissection. The authors used this system in a 43-year-old man who sustained a subarachnoid hemorrhage after being assaulted and was found to have a traumatic pseudoaneurysm of the proximal intracranial internal carotid artery. The aneurysm appeared to be enlarging on serial imaging studies and it was anticipated that a bypass would probably be needed to treat the lesion. An end-to-side bypass was performed with the C-Port system using a saphenous vein conduit extending from the common carotid artery to the middle cerebral artery. The bypass was demonstrated to be patent on intraoperative and postoperative arteriography. The patient had a temporary hyperperfusion syndrome and subsequently made a good neurological recovery. The C-Port system facilitates the performance of a high-flow extracranial-intracranial bypass with short periods of temporary arterial occlusion. Because of the size and configuration of the device, its use is not feasible in all anatomical situations that require a high-flow bypass; however it is a useful addition to the armamentarium of the neurovascular surgeon.

A rare anomaly of the anterior communicating artery complex hidden by a large broad-neck aneurysm and disclosed by three-dimensional rotational angiography

Double fenestration of the anterior communicating artery (ACoA) complex associated with an aneurysm is a very rare finding and is usually caused by ACoA duplication and the presence of a median artery of the corpus callosum (MACC). We present a patient in whom double fenestration was not associated with ACoA duplication or even with MACC, representing therefore, a previously unreported anatomic variation. A 43 year old woman experienced sudden headache and the CT scans showed subarachnoid haemorrhage (SAH). On admission, her clinical condition was consistent with Hunt and Hess grade II. Conventional digital subtraction angiography (DSA) was performed and revealed multiple intracranial aneurysms arising from both middle cerebral arteries (MCA) and from the ACoA. Three-dimensional rotational angiography (3D-RA) disclosed a double fenestration of the ACoA complex which was missed by DSA. The patient underwent a classic pterional approach in order to achieve occlusion of both left MCA and ACoA aneurysms by surgical clipping. The post-operative period was uneventful. A rare anatomical variation characterised by a double fenestration not associated with ACoA duplication or MACC is described. The DSA images missed the double fenestration which was disclosed by 3D-RA, indicating the importance of 3D-RA in the diagnosis and surgical planning of intracranial aneurysms.

Different anticoagulation strategies in off-pump coronary artery bypass operations: a European survey

In order to determine anticoagulation strategies in OPCAB a questionnaire survey among 750 European cardio-thoracic surgeons was performed. Questions addressed volume of OPCAB procedures performed, intra- and perioperative heparinization and antiplatelet therapy, as well as perioperative management. A total of 325 (43.7%) questionnaires were returned and validated. Perioperative protocols for administration of antiplatelets differed among the respondent surgeons. Perioperative prophylaxis of thrombosis (low or high molecular weight heparin) is performed by 78%. Intraoperative heparin dosage range between 70 U/kg to 500 U/kg, 60% of respondents prefer a low-dose regimen (< or = 150 U/kg). Correspondingly, the lowest activated clotting time (ACT) during surgery is accepted to be 200 s by 24%, 250 s by 18% and 300 s by 26% of surgeons. Protamine is used by 91% of respondents, while 52% perform a 1:1 reversal. A cell-saver and antifibrinolytics are used by 70% and 40%, respectively. Interestingly, 56% of respondents think bleeding in OPCAB patients is not reduced when compared to on-pump CABG. In addition, 34% of respondents believe there is an increased risk of early graft occlusion following OPCAB. This survey demonstrates widely different intra- and perioperative anticoagulation strategies for OPCAB procedures among European surgeons.

R2-recanalization of spontaneous carotid artery dissection

BACKGROUND AND PURPOSE: We set out to investigate the predictors and time course for recanalization of spontaneous dissection of the cervical internal carotid artery (SICAD). METHODS: We prospectively included 249 consecutive patients (mean age, 45+/-11 years) with 268 SICAD. Ultrasound examinations were performed at presentation, during the first month, and then at 3, 6, and 12 months, and clinical follow-ups after 3, 6, and 12 months. RESULTS: Of 268 SICADs, 20 (7.5%) presented with

Outcome of acute stroke patients without visible occlusion on early arteriography

BACKGROUND: The aim of this study was to determine the clinical and radiological outcome of acute stroke patients who had no vessel occlusion on arteriography and to define predictors of clinical outcome. METHODS: We analyzed clinical and radiological data of stroke patients whose arteriography performed within 6 hours of symptom onset did not visualize any vessel occlusion. RESULTS: Twenty-eight of 283 consecutive patients (10%) who underwent arteriography with the intention to perform intraarterial thrombolysis did not show any arterial occlusion. Their median baseline National Institutes of Health Stroke Scale (NIHSS) score was 7. Time from symptom onset to arteriography ranged from 115 to 315 minutes; on average, it was 226 minutes. Presumed stroke cause was cardiac embolism in 11 patients (39%), small artery disease in 6 (21%), coronary angiography in 1 (4%), and undetermined in 10 patients (36%). After 3 months, modified Rankin Scale score (mRS) was < or =2 in 21 patients (75%), indicating a favorable outcome. Six patients (21%) had a poor outcome (mRS 3 or 4) and 1 patient (4%) had a myocardial infarction and died. Twenty-seven patients had follow-up brain imaging. It was normal in 5, showed a lacunar lesion in 8, a striatocapsular infarct in 2, a small or medium-sized anterior circulation infarct in 6, multiple small anterior circulation infarcts in 2, and multiple posterior circulation infarcts in 4. No predictors of clinical outcome were identified. CONCLUSIONS: Most acute stroke patients with normal early arteriography show infarcts on brain imaging; however, clinical outcome is usually favorable.

Percutaneous coronary revascularization in patients with formerly "refractory angina pectoris in end-stage coronary artery disease" - not "end-stage" after all

BACKGROUND: Patients with refractory angina pectoris in end-stage coronary artery disease represent a severe condition with a higher reduction of life-expectancy and quality of life as compared to patients with stable coronary artery disease. It was the purpose of this study to invasively re-evaluate highly symptomatic patients with formerly diagnosed refractory angina pectoris in end-stage coronary artery disease for feasible options of myocardial revascularization. METHODS: Thirty-four patients formerly characterized as having end stage coronary artery disease with refractory angina pectoris were retrospectively followed for coronary interventions. RESULTS: Of those 34 patients 21 (61.8%) were eventually revascularized with percutaneous interventional revascularization (PCI). Due to complex coronary morphology (angulation, chronic total occlusion) PCI demanded an above-average amount of time (66 +/- 42 minutes, range 25-206 minutes) and materials (contrast media 247 +/- 209 ml, range 50-750 ml; PCI guiding wires 2.0 +/- 1.4, range 1-6 wires). Of PCI patients 7 (33.3%) showed a new lesion as a sign of progression of atherosclerosis. Clinical success rate with a reduction to angina class II or lower was 71.4% at 30 days. Surgery was performed in a total of8 (23.5%) patients with a clinical success rate of 62.5%. Based on an intention-to-treat 2 patients of originally 8 (25%) demonstrated clinical success. Mortality during follow-up (1-18 months) was 4.8% in patients who underwent PCI, 25% in patients treated surgically and 25% in those only treated medically. CONCLUSION: The majority of patients with end-stage coronary artery disease can be treated effectively with conventional invasive treatment modalities. Therefore even though it is challenging and demanding PCI should be considered as a first choice before experimental interventions are considered.

Myocardial salvage through coronary collateral growth by granulocyte colony-stimulating factor in chronic coronary artery disease: a controlled randomized trial

BACKGROUND: The efficacy of granulocyte colony-stimulating factor (G-CSF) for coronary collateral growth promotion and thus impending myocardial salvage has not been studied so far, to our best knowledge. METHODS AND RESULTS: In 52 patients with chronic stable coronary artery disease, age 62+/-11 years, the effect on a marker of myocardial infarct size (ECG ST segment elevation) and on quantitative collateral function during a 1-minute coronary balloon occlusion was tested in a randomized, placebo-controlled, double-blind fashion. The study protocol before coronary intervention consisted of occlusive surface and intracoronary lead ECG recording as well as collateral flow index (CFI, no unit) measurement in a stenotic and a > or =1 normal coronary artery before and after a 2-week period with subcutaneous G-CSF (10 microg/kg; n=26) or placebo (n=26). The CFI was determined by simultaneous measurement of mean aortic, distal coronary occlusive, and central venous pressure. The ECG ST segment elevation >0.1 mV disappeared significantly more often in response to G-CSF (11/53 vessels; 21%) than to placebo (0/55 vessels; P=0.0005), and simultaneously, CFI changed from 0.121+/-0.087 at baseline to 0.166+/-0.086 at follow-up in the G-CSF group, and from 0.152+/-0.082 to 0.131+/-0.071 in the placebo group (P<0.0001 for interaction of treatment and time). The absolute change in CFI from baseline to follow-up amounted to +0.049+/-0.062 in the G-CSF group and to -0.010+/-0.060 in the placebo group (P<0.0001). CONCLUSIONS: Subcutaneous G-CSF is efficacious during a short-term protocol in improving signs of myocardial salvage by coronary collateral growth promotion.

Coronary artery injury due to catheter ablation in adults: presentations and outcomes

BACKGROUND: Currently, only anecdotal information exists on the presentation and outcome of coronary arterial injury after ablation procedures. METHODS AND RESULTS: Four patients who sustained coronary artery injury of a cohort of patients undergoing 4655 consecutive ablation procedures (0.09%) are described. The patients' mean age was 45+/-11 years, and 1.8+/-0.5 prior ablation attempts had been unsuccessful. Coronary injury occurred from epicardial ventricular tachycardia ablation in 2 patients (irrigated radiofrequency ablation in one and cryoablation in the other) and ablation within the middle cardiac vein with irrigated radiofrequency in 2 patients. All involved branches of the right coronary artery. Acute occlusion presenting with ST-segment elevation immediately after ablation was recognized during the procedure in 2 cases. Occlusion failed to respond to nitroglycerin or balloon dilation, and stenting was required in both cases. Acute myocardial infarction occurred 2 weeks after epicardial ablation as a result of occlusion of a right ventricular branch of the right coronary artery giving rise to the posterior descending coronary artery in 1 patient. A moderate asymptomatic stenosis was seen on angiography after epicardial cryoablation in 1 patient. All patients recovered and remained asymptomatic from the coronary injury and arrhythmias during 37+/-53 months of follow-up. CONCLUSIONS: Coronary arterial injury after ablation procedures is rare. It may present acutely or several weeks after an ablation procedure. Acute occlusion appears to require coronary stenting. Unanticipated anatomic variations can predispose to coronary injury.

Bailout revascularization of chronic femoral artery occlusions with the new outback catheter following failed conventional endovascular intervention

PURPOSE: To report the application of a true lumen re-entry device in the bailout treatment of chronic total occlusions (CTO) of the superficial femoral artery (SFA) after failed angioplasty. METHODS: Nineteen patients (12 men; mean age 81 years, range 61-97) with 20 SFA CTOs and Rutherford category 2 to 5 ischemia were prospectively evaluated. All CTOs had unsuccessful recanalization using conventional techniques and were subsequently treated with the Outback LTD catheter. Follow-up at 3, 6, and 12 months included ankle/toe pressure measurement and pulse volume recordings. Endpoints were revascularization rate, target lesion revascularization, and limb salvage. RESULTS: Revascularization was achieved in 95% of the cases. There were 2 (10%) periprocedural complications unrelated to the re-entry device, which were resolved by endovascular or surgical treatment. The target lesion revascularization rate was 10%, with the 2 events occurring at 3 and 6 months, respectively, in patients with Rutherford category 4-5 ischemia. There was one below-the-knee amputation in the patient with failed revascularization. CONCLUSION: The acute failure of endovascular treatment of SFA CTOs is most often due to an inability to re-enter the true lumen after the occlusion is crossed in a subintimal plane. Bailout revascularization with the Outback LTD catheter is highly successful and shows a low device-related complication rate. This needle- and fluoroscopic-based re-entry device increases the endovascular success rate and is therefore expanding the minimally invasive treatment options for surgically unfit patients.

Aspirin vs anticoagulation in carotid artery dissection: a study of 298 patients

BACKGROUND: No randomized study has yet compared efficacy and safety of aspirin and anticoagulants in patients with spontaneous dissection of the cervical carotid artery (sICAD). METHODS: Prospectively collected data from 298 consecutive patients with sICAD (56% men; mean age 46 +/- 10 years) treated with anticoagulants alone (n = 202) or aspirin alone (n = 96) were retrospectively analyzed. Admission diagnosis was ischemic stroke in 165, TIA in 37, retinal ischemia in 8, and local symptoms and signs (headache, neck pain, Horner syndrome, cranial nerve palsy) in 80 patients, while 8 patients were asymptomatic. Clinical follow-up was obtained after 3 months by neurologic examination (97% of patients) or structured telephone interview. Outcome measures were 1) new cerebral ischemic events, defined as ischemic stroke, TIA, or retinal ischemia, 2) symptomatic intracranial hemorrhage, and 3) major extracranial bleeding. RESULTS: During follow-up, ischemic events were rare (ischemic stroke, 0.3%; TIA, 3.4%; retinal ischemia, 1%); their frequency did not significantly differ between patients treated with anticoagulants (5.9%) and those treated with aspirin (2.1%). The same was true for hemorrhagic adverse events (anticoagulants, 2%; aspirin, 1%). New ischemic events were significantly more frequent in patients with ischemic events at onset (6.2%) than in patients with local symptoms or asymptomatic patients (1.1%). CONCLUSIONS: Within the limitations of a nonrandomized study, our data suggest that frequency of new cerebral and retinal ischemic events in patients with spontaneous dissection of the cervical carotid artery is low and probably independent of the type of antithrombotic treatment (aspirin or anticoagulants).

Activity of the glycosylating enzyme, core 2 GlcNAc (beta1,6) transferase, is higher in polymorphonuclear leukocytes from diabetic patients compared with age-matched control subjects: relevance to capillary occlusion in diabetic retinopathy

The exact mechanism for capillary occlusion in diabetic retinopathy is still unclear, but increased leukocyte-endothelial cell adhesion has been implicated. We examined the possibility that posttranslational modification of surface O-glycans by increased activity of core 2 transferase (UDP-Glc:Galbeta1-3GalNAcalphaRbeta-N-acetylglucoaminyltr ansferase) is responsible for increased adhesion of leukocytes to vascular endothelium in diabetes. The mean activity of core 2 transferase in polymorphonuclear leukocytes isolated from type 1 and type 2 diabetic patients was higher compared with age-matched control subjects (1,638 +/- 91 [n = 42] vs. 249 +/- 35 pmol x h(-1) x mg(-1) protein [n = 24], P = 0.00013; 1,459 +/- 194 [n = 58] vs. 334 +/- 86 [n = 11], P = 0.01). As a group, diabetic patients with retinopathy had significantly higher mean activity of core 2 transferase compared with individuals with no retinopathy. There was a significant association between enzyme activity and severity of retinopathy in type 1 and type 2 diabetic patients. There was a strong correlation between activity of core 2 transferase and extent of leukocyte adhesion to cultured retinal capillary endothelial cells for diabetic patients but not for age-matched control subjects. Results from transfection experiments using human myelocytic cell line (U937) demonstrated a direct relationship between increased activity of core 2 transferase and increased binding to cultured endothelial cells. There was no relationship between activity of core 2 transferase and HbA(1c) (P = 0.8314), serum advanced glycation end product levels (P = 0.4159), age of the patient (P = 0.7896), and duration of diabetes (P = 0.3307). On the basis that branched O-glycans formed by the action of core 2 transferase participate in leukocyte adhesion, the present data suggest the involvement of this enzyme in increased leukocyte-endothelial cell adhesion and the pathogenesis of capillary occlusion in diabetic retinopathy.

Effects of coronary sinus occlusion on myocardial ischaemia in humans: role of coronary collateral function

OBJECTIVE This study tested the hypotheses that intermittent coronary sinus occlusion (iCSO) reduces myocardial ischaemia, and that the amount of ischaemia reduction is related to coronary collateral function. DESIGN Prospective case-control study with intraindividual comparison of myocardial ischaemia during two 2-min coronary artery balloon occlusions with and without simultaneous iCSO by a balloon-tipped catheter. SETTING University Hospital. PATIENTS 35 patients with chronic stable coronary artery disease. INTERVENTION 2-min iCSO. MAIN OUTCOME MEASURES Myocardial ischaemia as assessed by intracoronary (i.c.) ECG ST shift at 2 min of coronary artery balloon occlusion. Collateral flow index (CFI) without iCSO, that is, the ratio between mean distal coronary occlusive (Poccl) and mean aortic pressure (Pao) both minus central venous pressure. RESULTS I.c. ECG ST segment shift (elevation in all) at the end of the procedure with iCSO versus without iCSO was 1.33±1.25 mV versus 1.85±1.45 mV, p<0.0001. Regression analysis showed that the degree of i.c. ECG ST shift reduction during iCSO was related to CFI, best fitting a Lorentzian function (r(2)=0.61). Ischaemia reduction with iCSO was greatest at a CFI of 0.05-0.20, whereas in the low and high CFI range the effect of iCSO was absent. CONCLUSIONS ICSO reduces myocardial ischaemia in patients with chronic coronary artery disease. Ischaemia reduction by iCSO depends on coronary collateral function. A minimal degree of collateral function is necessary to render iCSO effective. ICSO cannot manifest an effect when collateral function prevents ischaemia in the first place.

Clinical parameters associated with collateral development in patients with chronic total coronary occlusion

OBJECTIVE Well-developed collaterals provide survival benefit in patients with obstructive coronary artery disease (CAD). Therefore, in this study we sought to determine which clinical variables are associated with arteriogenesis. DESIGN Clinical and laboratory variables were collected before percutaneous coronary intervention. Multivariate analysis was performed to determine which variables are associated with the collateral flow index (CFI). PATIENTS Data from 295 chronic total occlusion (CTO) patients (Bern, Switzerland, Amsterdam, the Netherlands and Jena, Germany) were pooled. In earlier studies, patients had varying degrees of stenosis. Therefore, different stages of development of the collaterals were used. In our study, a unique group of patients with CTO was analysed. INTERVENTIONS Instead of angiography used earlier, we used a more accurate method to determine CFI using intracoronary pressure measurements. CFI was calculated from the occlusive pressure distal of the coronary lesion, the aortic pressure and central venous pressure. RESULTS The mean CFI was 0.39 ± 0.14. After multivariate analysis, β blockers, hypertension and angina pectoris duration were positively associated with CFI (B: correlation coefficient β=0.07, SE=0.03, p=0.02, B=0.040, SE=0.02, p=0.042 and B=0.001, SE=0.000, p=0.02). Furthermore also after multivariate analysis, high serum leucocytes, prior myocardial infarction and high diastolic blood pressure were negatively associated with CFI (B=-0.01, SE=0.005, p=0.03, B=-0.04, SE=0.02, p=0.03 and B=-0.002, SE=0.001, p=0.011). CONCLUSIONS In this unique cohort, high serum leucocytes and high diastolic blood pressure are associated with poorly developed collaterals. Interestingly, the use of β blockers is associated with well-developed collaterals, shedding new light on the potential action mode of this drug in patients with CAD.

The effect of heart rate reduction by ivabradine on collateral function in patients with chronic stable coronary artery disease

Objective To evaluate the effect of heart rate reduction by ivabradine on coronary collateral function in patients with chronic stable coronary artery disease (CAD). Methods This was a prospective randomised placebo-controlled monocentre trial in a university hospital setting. 46 patients with chronic stable CAD received placebo (n=23) or ivabradine (n=23) for the duration of 6 months. The main outcome measure was collateral flow index (CFI) as obtained during a 1 min coronary artery balloon occlusion at study inclusion (baseline) and at the 6-month follow-up examination. CFI is the ratio between simultaneously recorded mean coronary occlusive pressure divided by mean aortic pressure both subtracted by mean central venous pressure. Results During follow-up, heart rate changed by +0.2±7.8 beats/min in the placebo group, and by –8.1±11.6 beats/min in the ivabradine group (p=0.0089). In the placebo group, CFI decreased from 0.140±0.097 at baseline to 0.109±0.067 at follow-up (p=0.12); it increased from 0.107±0.077 at baseline to 0.152±0.090 at follow-up in the ivabradine group (p=0.0461). The difference in CFI between the 6-month follow-up and baseline examination amounted to −0.031±0.090 in the placebo group and to +0.040±0.094 in the ivabradine group (p=0.0113). Conclusions Heart rate reduction by ivabradine appears to have a positive effect on coronary collateral function in patients with chronic stable CAD.