Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery. Technical note

Reconstruction of the carotid artery by using a radial artery graft is a useful option that can produce reliable long-term patency for the surgical treatment of giant and/or large aneurysms of the cavernous and paraclinoid internal carotid artery (ICA). During the past 10 years, 43 patients with intracavernous and paraclinoid giant aneurysms of the ICA have been treated by reconstruction of the ICA with radial artery grafts after ligation of the cervical ICA. The long-term patency of the grafted radial artery was evaluated over more than a 5-year period (mean 7.2 years) in 20 of these patients by using magnetic resonance angiography or conventional angiography. There was no late occlusion of the graft in any of these cases. Stenotic graft changes were observed in two cases.     

Linear response of collateral cerebral perfusion pressure during carotid clamping

Phenylephrine is frequently used to increase systemic arterial pressure during carotid endarterectomy. However, little is known of its effect on collateral cerebral perfusion pressure, particularly in patients with high collateral cerebral vascular resistance who are at increased risk of cerebral ischemia during carotid clamping. We tested the hypothesis that this subset of patients can have collateral perfusion pressure, and hence collateral cerebral blood flow, increased in a predictable way by elevating systemic arterial pressure. We measured mean systemic arterial pressure (Pa), jugular venous pressure (Pv), and mean carotid back pressure (Pc), and calculated collateral cerebral perfusion pressure (P = Pc - Pv) and the ratio of collateral to ipsilateral hemisphere cerebral vascular resistance (Rc/Rh) in 18 patients with low P. Initial measurements were Pa = 84 +/- 8.8 (mm Hg, mean +/- SD), Pv = 7.8 +/- 3.9, Pc = 26 +/- 5.1, P = 18 +/- 4.5 and Rc/Rh = 3.4 +/- 1.15. During phenylephrine infusion, Pa = 108 +/- 11, Pc = 32 +/- 6.5, and P = 24 +/- 7.2, increases of 29, 23, and 33%, respectively (P less than 0.05). Unchanged were Pv = 8.2 +/- 4.1 (5%) and Rc/Rh = 3.5 +/- 1.30 (3%) (P greater than 0.8). The latter two findings indicate that cerebral perfusion pressure and mean systemic arterial pressure are linearly related according to the fluid mechanics equation governing these parameters: Pa = P(Rc/Rh + 1) + Pv. These results support the use of phenylephrine to increase collateral blood flow during carotid endarterectomy in patients with low cerebral perfusion pressure.     

Saphenous vein graft bypass of the cavernous internal carotid artery

Saphenous vein graft reconstruction was performed from the petrous to the supraclinoid internal carotid artery (ICA) to replace the cavernous ICA in six patients during direct intracavernous operations. Four of these patients had intracavernous neoplasms with invasion of the ICA and two had intracavernous ICA aneurysms that could not be clipped or occluded with intraluminal balloons. All but one patient had evidence of poor collateral flow reserve in a balloon occlusion test of the ICA. The superficial temporal artery was not present in four patients, was minuscule in one, and was damaged during the initial dissection in another, making it unsuitable for superficial temporal-to-middle cerebral artery branch anastomosis. Blood flow within the graft could not be established intraoperatively in one patient (who had excellent collateral circulation) due to the small size of the vein (3 mm). In all others, the grafts were patent on follow-up arteriography and transcranial Doppler studies. Three patients who had severe reduction of cerebral blood flow during test occlusion of the ICA exhibited temporary hemispheric neurological deficits postoperatively; the deficits were related to the duration of temporary ICA occlusion. All three recovered completely without evidence of infarction on computerized tomography (CT). One patient who clinically could not tolerate the balloon occlusion test of the ICA also had temporary neurological deficits with good recovery but showed evidence of border-zone infarction on CT scans. The present role of saphenous vein graft bypass of the cavernous ICA is discussed.     

Early and mid-term results of all arterial graft coronary artery bypass grafting using bilateral internal thoracic and radial arterial conduits

From March 1996 to May 2000, 41 patients [age 39-78 (mean 63.5 +/- 8.8) years, 90.2% male] underwent all arterial multiple coronary artery bypass grafting (CABG) using bilateral internal thoracic (BiITA) and radial (RA) arterial conduits. The reason for using RA was that the right gastroepiploic artery (RGEA) was small or occluded on preoperative angiography, a history of upper abdominal surgery or disease, or the right coronary arterial lesion was proximal and mild. The BiITA were used as in situ grafts and the proximal anastomosis of RA was to the ascending aorta in all cases. All patients underwent conventional elective CABG with median sternotomy using cardiopulmonary bypass. The mean number of anastomoses was 3.3 +/- 0.5 branches and complete revascularization rate was 80.5%. Postoperative follow-up averaged 20 months and the longest was 50 months. There was no early death, and overall graft patency 2-3 weeks after surgery was 96.2% (LITA 94.0%, RITA 97.6%, RA 97.6%). Four-year actuarial survival rate was 96.4 +/- 3.5% (1 patient: 9 months, no cardiac death), and cardiac event-free rate after surgery was 89.7 +/- 4.9% [4 patients: percutaneous transluminal coronary angioplasty (PTCA)]. However, once patients were discharged from hospital, cardiac event-free rate was 100%. These excellent results suggest that all arterial graft CABG was satisfactory, and RA can be used as a third suitable arterial bypass conduit, if RGEA cannot be used or is unsuitable for use.     

High-flow bypass with radial artery graft followed by internal carotid artery ligation for large or giant aneurysms of cavernous or cervical portion: clinical results and cognitive performance

Neurosurgical Review - High-flow bypass followed by ligation of the internal carotid artery (ICA) is an effective treatment, but the impact of abrupt occlusion of the ICA is unpredictable,...     

Right internal mammary artery and radial artery composite in situ pedicle graft in coronary artery bypass grafting

Background. The use of two internal mammary artery grafts in coronary artery bypass grafting has been associated with decreased risks of death, reoperation, and angioplasty. However, bilateral internal mammary artery takedown is associated with higher incidence of sternal wound infection, particularly in people with diabetes and in elderly and obese patients. This study was conducted to explore the feasibility of using right internal mammary artery (RIMA) and radial artery (RA) as a composite graft while preserving the distal two thirds of the RIMA to leave the sternal blood supply intact.

Methods. Eighteen patients underwent coronary artery bypass grafting using proximal RIMA and RA composite graft as one of the bypass conduits. The distal two thirds of the RIMA was left intact to preserve sternal blood supply. The graft-free flows of the RIMA and RA composite graft and of the left internal mammary artery graft and the length of the composite graft had been measured. The graft patency and the flow in the distal part of the unharvested RIMA was evaluated postoperatively 2 weeks after the procedure. In 6 of these patients the graft patency was evaluated by selective angiography.

Results. There was no hospital mortality or incidence of perioperative myocardial infarction. None of the patients needed intraaortic balloon pump support postoperatively. There was no sternal wound infection. The vessels grafted were distal right coronary artery (n = 7), posterior descending artery (n = 8), obtuse marginal branches (n = 3), and posterolateral ventricular branch (n = 1); 1 patient received the composite graft as a sequential graft to the posterior descending artery and posterolateral left ventricular branches. The mean graft-free flow of the RIMA and RA composite graft was 98.06 ± 16.93 mL/min compared to left internal mammary artery flows of 55.80 ± 8.99 mL/min. All 16 patients who had a good echo window showed patent grafts when evaluated by two-dimensional echocardiography and color Doppler echocardiography. All of the 6 patients in whom the angiogram was repeated postoperatively showed patent RIMA and RA grafts.

Conclusions. Myocardial revascularization using proximal RIMA and RA in situ pedicle graft was safe in patients with diabetes and in obese and chronic obstructive pulmonary disease patients. This graft was useful to revascularize posterior descending artery, posterolateral ventricular branches of right coronary artery, and obtuse marginal branches where a left internal mammary artery and RA composite graft cannot be used because of technical reasons. Its usage was not associated with sternal wound infection.     

The left internal thoracic artery and radial artery composite graft in off-pump coronary artery bypass grafting.

Arterial multivessel bypass grafting without extra corporeal circulation and manipulation of the ascending aorta should be a good surgical option for the treatment of coronary artery disease. An internal thoracic artery (ITA)-radial artery (RA) composite graft was used for this purpose. Between July 2000 and October 2001, we employed the LITA-RA composite graft for off-pump coronary artery bypass in 15 cases. Mean patient age was 71.3 +/- 5.8 years old. Left main trunk disease was present in six patients and triple-vessel disease in four patients. Preoperative concomitant disease was renal dysfunction in three cases, cerebrovascular disease in four and diabetes mellitus in five cases. Two patients had a so-called bad aorta. Twelve elective operations and three urgent operations were carried out for unstable angina. Two to four (mean 2.6 +/- 0.7) anastomoses were performed per patient. Complete revascularization was achieved in 12 out of 15 patients. Mean operating time was 335 +/- 53 min. Mean intraoperative blood loss was 595 +/- 375 ml and nine patients underwent the operation without blood transfusion. There was no PMI, no brain disorder, and no death. Postoperative coronary angiography in all patients documented a good patency rate (LITA 15/15, RA 21/21, right gastroepiploic artery (RGEA) 2/2, and saphenous vein graft (SVG) 0/2). LITA-RA composite grafting in off-pump coronary artery bypass enables arterial multivessel revascularization using an aortic no touch technique. This can be done with minimum postoperative complications and without risk of cerebral infarction even in patients at high risk for extracorporeal circulation (ECC).     

Combined carotid endarterectomy and coronary artery bypass graft

Atherosclerosis is a generalized disease which afflicts a considerable number of patients in both the carotid and coronary arteries. Although the risk of stroke or death use to combined carotid endarterectomy (CEA) and coronary artery bypass graft (CABG) is thought to be higher than that of each individual operation, the combined procedure is generally preferred over staged operations to treat such patients. We performed the combined procedure safely with the aid of intraoperative portable digital subtraction angiography (DSA). This report describes our experience with the operative strategy of simultaneous CEA and CABG. Ninety CEA and 404 CABG were carried out between January 1989 and December 1997. A total of six patients received the combined procedure with the aid of intraoperative DSA; they were studied retrospectively. Postoperative mortality and morbidity after the combined procedure was 0%. In the combined procedure, neurological complications are difficult to detect after CEA because the patient must be maintained under general anesthesia and extracorporeal circulation during the subsequent CABG. However, intraoperative DSA can confirm patency of the internal carotid artery and absence of flap formation after CEA, and the CABG can be performed safely. Intraoperative portable DSA between CEA and CABG is helpful in preventing perioperative stroke in the combined procedure.     

Role of radial artery graft in coronary artery bypass grafting

The use of the radial artery (RA) as a coronary artery bypass graft has assumed a revival and thus a multitude of issues have arisen surrounding the routine and widespread use of this conduit in myocardial revascularization. There has been no uniformity regarding harvest techniques, assessment of the adequacy of hand collateral circulation, antispasm protocols, selection of target vessels, and the site of proximal anastomosis. It is widely believed and practiced that the RA should be harvested as a pedicle graft and preferably be used to bypass critically stenosed (>70% stenosis) coronary arteries. It is used either as a free graft with proximal anastomosis to the ascending aorta or as a composite arterial graft along with the left or right internal thoracic artery. The patency of RA grafts depends on the severity of the target coronary artery stenosis and target artery location rather than its use as an aortocoronary conduit or composite graft. In this article, we reviewed the current knowledge regarding the use of RA grafts as a coronary bypass conduit in an attempt to suggest a few acceptable strategies concerning the above issues in a given clinical scenario.     

Off-pump coronary artery bypass grafting using in-situ right internal thoracic artery extended with radial artery as I-composite graft

OBJECTIVE: The purpose of this study is to assess the feasibility of utilizing the proximal right internal thoracic artery (RITA) extended with the radial artery (RA) as I-composite graft (RITA-RA graft) in off-pump coronary artery bypass grafting (OPCAB), which preserves the left internal thoracic artery to the left anterior descending artery as an isolated graft and the ascending aorta no-touch technique. METHODS: Between January 2002 and August 2006, 37 patients (aged 67.4+/-7.5 years, 86.5% male) underwent OPCAB using RITA-RA graft. All grafts were harvested in a skeletonized fashion. RITA transected at the middle portion was extended with entirely dissected RA. RITA-RA graft was anastomosed to 1 or 2 lateral artery in a parallel sequential pattern. RESULTS: The total number of distal anastomoses of RITA-RA graft was 48. The early graft patency rate was 97.9%. Five cases (13.5%) needed intra-aortic balloon pumping support during operation. Only 1 patient (2.7%) required ventilator support longer than 24 hours. The percentage of patients requiring homologous blood transfusion was 13.5%. There was no cerebrovascular accident or mediastinitis in the postoperative course. All patients were discharged from hospital. CONCLUSIONS: OPCAB using RITA-RA graft is feasible and safe. It provides satisfactory early clinical and angiographic outcomes.     

有创血压波形监测下体外循环搏动灌注效果初步评价

目的 探索桡动脉有创血压波形作为搏动灌注质控指标的可能性,并在此监测下评价搏动灌注的有效性.方法 选取2008年3月至12月需在体外循环下手术治疗的患者80例,随机分为搏动灌注组(P组)45例和非搏动灌注组(NP组)35例.主动脉阻断期间P组在桡动脉波形监测下建立搏动灌注,NP组采用常规平流灌注.将P组形成显著双峰波或单峰波(脉压差＞30 mm Hg,1 mm Hg=0.133 kPa)的病例与NP组比较,检测手术前后肌酐、尿素氮、血尿酸、乳酸脱氢酶、谷草转氨酶、超敏C反应蛋白,术中乳酸、尿量,手术后尿隐血率、心跳自复率、凝血酶原时间等指标.结果 P组有35例形成显著的双峰波形或单峰波.与NP组比较:术中乳酸较低(P＜0.01),单位时间尿量较多(P＜0.01),术后乳酸脱氢酶上升幅度(P＜0.05)、超敏C反应蛋白(P＜0.05)和凝血酶原时间(P＜0.01)较低.P组术后血尿酸下降,而NP组上升(P＜0.01);尿隐血、手术前后谷草转氨酶差率、心跳自复率两组差异无统计学意义.结论 通过设备优化和搏动参数的调控,能建立有效的搏动灌注和能最传递;桡动脉有创血压波形监测是方便有效的搏动灌注指标;在桡动脉波形监测下的搏动灌注各项监测指标明显优于平流灌注.     

Combined STA/MCA arterial bypass and gradual internal carotid artery occlusion for treatment of intracavernous and giant carotid artery aneurysms

Summary Intracavernous aneurysms are a clinical diagnostic and technical problem,. The risk of a direct surgical clipping, whenever possible, is high. Carotid ligation remains the classical surgical treatment for inaccessible aneurysms. Internal carotid artery (ICA) ligation is more effective than common carotid artery (CCA) ligation but carries a higher risk of cerebral ischaemia. The performance of ipsilateral extra-intracranial arterial bypass (EIAB) helps to maintain blood flow in the cerebral hemisphere. It also may decrease the collateral flow formation through the circle of Willis with turbulence in the aneurysmal sac, thus enhancing thrombosis.A series of five cases is reported. The results are satisfactory except in one patient who died in the immediate postoperative period for malignant hemispheric edema, in spite of the patent bypass.The EIAB can reduce but not eliminate the risk of ischaemic complications related to ICA ligation.     

Prevention of radial artery graft vasospasm after coronary bypass

Background. Pharmacologic prophylaxis for prevention of notorious radial artery (RA) spasm is critical because of the increasingly routine use of the RA conduit during coronary bypass. Therefore, we investigated the vasodilatory effect of calcium antagonist in combination with nitroglycerin (NTG) RA segments.

Methods. We evaluated the vasodilatory effect of nifedipine alone, verapamil alone, diltiazem alone, NTG alone, and calcium antagonist in combination with in endothelin-1 (ET-1)-, angiotensin II (AII)-, 5-hydroxytryptamine (5-HT)-, and norepinephrine (NE)-precontracted human RA rings mounted in organ baths.

Results. Nifedipine (10⁻⁵ M) alone, diltiazem (10⁻⁵ M) alone, verapamil (10⁻⁵ M) alone, and NTG (10⁻⁵ M) alone showed maximum vasodilatory effect in either 10⁻⁷ M ET-1-, 10⁻⁷ M AII-, 10⁻⁵ M NE-, or 10⁻⁴ M 5-HT-precontracted RA segments. The 10⁻⁵ M NTG alone-induced vasodilation (88.5% ± 7.7%) in ET-1-precontracted segments was the highest vasodilation (ANOVA, p = 0.0008) among NTG alone-induced vasodilatory effects in RA. The relaxing effect of any of the calcium antagonists alone varied from 32.7% ± 13.2% to 76.5% ± 20.5% in RA precontracted with different vasoconstrictors. Nearly 200% vasodilation was observed with calcium antagonist in combination with NTG in AII-precontracted vessels. Nonetheless, the vasodilatory effect of calcium antagonist in combination with NTG in RA segments precontracted with different vasoconstrictors other than AII was nearly 100%.

Conclusions. A calcium antagonist in combination with NTG is more potent than calcium antagonist alone or NTG alone in prevention of human RA vasospasm after coronary bypass.     

Comparison of brachial and radial arterial pressure monitoring in patients undergoing coronary artery bypass surgery

The pressure in either the radial (n = 88) or proximal brachial artery (n = 82) was compared with aortic pressure before and after cardiopulmonary bypass (CPB) in patients receiving coronary artery bypass grafts. Radial artery pressures were measured via 20-G 5-cm long catheters, brachial artery pressures via 20-G 12.7-cm catheters, and aortic pressures were measured via a luer port in the aortic perfusion cannula. Transducers were connected via 122-cm long tubing. For the various systems, mean natural frequencies were 16.1 to 17.7 Hz and damping coefficients were 0.16 to 0.27. Before CPB the brachial systolic, diastolic, and mean pressures were 108.2 +/- 5.2%, 100.9 +/- 2.8%, and 99.6 +/- 2.3% of aortic; respective radial pressures were 113.9 +/- 9.6%, 99.5 +/- 2.8%, and 98.4 +/- 2.8% of aortic. Immediately after CPB the brachial pressures were 99.5 +/- 7.5%, 98.9 +/- 3.5%, and 97.4 +/- 2.9% of aortic, whereas respective radial pressures were 92.1 +/- 14.6%, 94.7 +/- 5.6%, and 90.8 +/- 7.4%. All brachial and radial as a per cent of aortic pressure medians were significantly different, and except for prebypass diastolic and mean, the variance for brachial pressures was significantly less than that for pressures in the radial artery. The prebypass brachial correlation (r) with aortic for systolic, diastolic, and mean were 0.90, 0.98, and 0.98; respective radial correlations with aortic were 0.78, 0.97, and 0.95. Postbypass brachial systolic, diastolic, and mean correlations were 0.91, 0.97, and 0.98; radial were 0.50, 0.93, and 0.83. Brachial artery pressures were more accurate and reliable than radial artery pressures.     

Internal mammary artery bypass graft for impaired coronary perfusion after neonatal arterial switch operation.

Myocardial ischaemia caused by perfusion impairment of translocated coronary arteries is the major cause of perioperative mortality after neonatal arterial switch operation for transposition of the great arteries. We report the successful use of the right internal mammary artery as a bypass graft to a dominant right coronary artery to treat insufficient perfusion of this artery in a newborn. Eight months later, coronary angiography showed a full blood supply of the right coronary artery across the internal mammary anastomosis. After a follow-up period of more than 30 months, somatic development, electrocardiogram and echocardiographically determined contractility of both ventricles are practically normal indicating regular function of the bypass graft.