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Results for “Collateral Circulation”

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PubMed2002

Shunt between the ventricular chamber and coronary arteries preserves left ventricular function in acute myocardial infarction.

It is controversial whether newly created channels made by transmyocardial laser revascularization are functionally significant, so the present study evaluated the shunt flow from the left ventricular (LV) cavity to the ischemic myocardium in 51 patients with acute myocardial infarction (AMI) caused by complete occlusion of the proximal left anterior descending coronary artery. All patients underwent left heart catheterization within 24 h of onset and all underwent successful coronary reperfusion using primary coronary angioplasty with no angiographic restenosis on follow-up coronary angiography (CAG). The presence of the LV shunt flow was evaluated by selective left CAG after successful reperfusion. The LV global ejection fraction (EF) and regional function (centerline method) were analyzed by ventriculography in both the acute and chronic phases. The patients were divided into the 3 groups (Group A, no LV shunt without collaterals, n=20; Group B, no LV shunt with collaterals, n=24; Group C, LV shunt with collaterals, n=7). There was no difference in the grade of collateral circulation between Groups B and C. The improvements in LVEF and regional function from the acute phase to the chronic phase were significantly greater in Group C than in Groups A and B. Not only collateral circulation but also LV shunt contributes to the functional recovery of infarct myocardium in patients with AMI.

Adult↗

PubMed2006

Near infrared spectroscopy monitoring during pediatric aortic coarctation repair.

BACKGROUND: Near infrared spectroscopy (NIRS) measures regional tissue oxygenation continuously and noninvasively and may allow assessment of changes in regional perfusion in real time. METHODS: We used NIRS monitoring to track real-time changes in regional oxygenation (rSO2) above and below the aortic cross-clamp in patients undergoing aortic coarctation repair and routinely stored these data in an operative electronic data base. This allowed us to analyze the changes in rSO2 during aortic coarctation repair for three pediatric age groups (neonates, infants <1 year, and children >1 year). Two site [cerebral (rSO2-C) and somatic thoracodorsal (rSO2-S)] rSO2 monitoring was performed in patients undergoing aortic coarctation repair. Data for rSO2 were analyzed across sites and age groups before, during and after cross-clamp. RESULTS: Twenty-six patients were available for analysis (11 neonates, 5 infants and 10 children). The regional oxygenation below the cross clamp (rSO2-S) declined significantly in all three age groups, but the decrease in neonates and infants <1 year of age was significantly greater than in the older children. CONCLUSIONS: Monitoring rSO2-S provides real-time trend information of regional oxygenation below the aortic cross-clamp. The decline in rSO2-S during aortic cross-clamp was rapid and large in most neonates and young infants <1 year which suggests impairment of regional perfusion presumably because of a lack of adequate collateral circulation to the monitored regional tissue. In contrast, the rSO2-S changed only to a minor degree in most infants and children >1 year, possibly because they had time to develop a more adequate collateral circulation around incomplete aortic obstruction.

Adolescent↗

PubMed2000

Model of complete separation of the hepatic veins from the systemic venous system.

BACKGROUND: In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors. METHODS: Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit. RESULTS: Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg. CONCLUSIONS: The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as the inferior vena cava pressure stays at the levels observed in Fontan circulation.

Angiography↗

PubMed1985

[What key zones should be monitored as a function of the assessment of the initial lesion? Collateral pathways?].

Key zones to be kept under surveillance are defined as a function of initial lesion features of operated or unoperated arteriopathy of lower limbs. Knowledge of these key zones resides in the anatomical knowledge of the supply network and of the physiopathology involved and its coming into play. Collateral circulations of infrarenal aortic obstructions are studied in detail, and then those that develop after femoral and tibial artery occlusions. Valid prediction of the ischemic risk can only be made after obtaining precise data on the re-entry effectiveness through this collateral circulation, allowing a prognosis to be established and a reasoned choice of therapy to be made.

Aorta, Abdominal↗

PubMed1995

Adaptation mechanisms during myocardial ischemia in chronic unstable angina pectoris.

Unstable angina with a clinical duration of < 2 months is characterized angiographically by a high incidence of complex lesions. Some patients have ischemic rest pain syndromes of longer duration. Thus, we retrospectively analyzed, in blinded fashion, the clinical and angiographic findings in 52 patients with unstable angina of < 2 months' duration (group A), and compared the results with those of 32 patients with unstable angina of > 6 months' duration (group B). Group B had a greater number of diseased vessels and better collateral circulation, but had fewer eccentric lesions. There were no differences in age, left ventricular function, or history of prior myocardial infarction. Thus, chronic unstable angina is associated with more extensive coronary disease than unstable angina of shorter duration. The role of different anatomic substrata and collateral circulation is discussed.

Adaptation, Physiological↗

PubMed1980

[Reversal of fixed neurological deficits after extra-intracranial arterial anastomosis].

Four patients with fixed neurological deficits due to occlusion of the middle cerebral or the internal carotid arteries, and with collateral circulation to their territory diagnosed by angiography, recovered after extra-intracranial arterial anastomosis. Functional recovery was seen since the first hours after bypass in three cases and the first few days in the other. Angiographic demonstration of collateral circulation to the territory of an occluded cerebral artery seems to be useful in the selection of patients with fixed neurological deficits for extra-intracranial arterial anastomosis, mainly when other methods are not available.

Adult↗

PubMed1995

Immediate 201Tl reinjection: an alternative approach in myocardial perfusion scintigraphy? A comparison with contrast angiographic findings.

Thallium-201 (201Tl) stress-redistribution/reinjection imaging provides a reliable diagnostic approach in patients evaluated for myocardial ischaemia. Immediate reinjection of 201Tl after completing the stress images followed by imaging 1 h later shortens the investigation time to 2.5 h and may provide a novel approach. In this study, we validated the immediate reinjection approach in the assessment of myocardial perfusion and viability using contrast angiographic findings as the reference standard. We studied 114 patients with documented cardiac catheterization data using quantitative planar 201Tl stress/immediate reinjection imaging. The 201Tl findings were compared with contrast angiographic data, coronary arteriographic findings and electrocardiographic data. Myocardial regions were considered to be viable if they (1) showed normal or hypokinetic wall motion, (2) were supplied by patent coronary arteries or by occluded arteries with adequate collateral circulation, or (3) were not related to electrocardiographic infarct site. Myocardial regions were considered to be non-viable if they (1) showed akinetic or dyskinetic wall motion, (2) were supplied by occluded vessels with inadequate collateral circulation, or (3) were related to electrocardiographic infarct site. Of 280 regions with normal or hypokinetic wall motion, 47 (17%) regions showed persistent 201Tl defects compared with 21 of 26 (81%) regions with akinetic/dyskinetic wall motion (P < 0.0001). Of 318 regions supplied by patent vessels, 65 (20%) regions showed persistent 201Tl defects compared with 14 of 22 (64%) regions subtended by occluded vessels (P < 0.0001). When the 201Tl findings were compared with electrocardiographic infarct site, 37 of 259 (14%) remote regions showed persistent defects compared with 42 of 83 (51%) infarct-related regions (P < 0.0001). We conclude that persistent defects on 201Tl immediate reinjection images are significantly more often associated with severe left ventricular wall motion abnormalities, coronary artery occlusion and infarct-related regions. In particular, agreement between the wall motion approach and scintigraphic findings was excellent, with 21 of 26 akinetic or dyskinetic segments showing persistent defects and 233 of 280 normal or hypokinetic segments measured as viable by the reinjection technique, resulting in a sensitivity of 81%, a specificity of 83% and an overall accuracy of 83%. These findings show the potential of immediate 201Tl reinjection imaging for assessing myocardial perfusion and viability.

Adult↗

PubMed1977

[Occlusion of the basilar artery (author's transl)].

Occlusion of the basilar artery was demonstrated arteriographically in two cases. The symptomatology is described. Due to effective collateral circulation the patients survived and recovered from severe neurological deficits. One of the patients, clincally in a state resembling akinetic mutism for several weeks, not only survived but regained speech. To our knowledge this has not been reported in the literature previously. Our cases as well as similar ones of others showed, that for development of effective intrcranial collaterals the time, during which occlusion occurs, is clearly of importance. Development of collateral circulation also depends on the anatomy of the circle of Willis and a sufficient extracranial circulation.

Adult↗

PubMed1991

[Medical therapy in patients with left main coronary artery stenosis].

To elucidate the long-term prognosis of medically-treated patients with left main coronary artery (LMCA) lesions, 119 consecutive patients with LMCA lesions undergoing coronary angiography were analyzed retrospectively. Among these, 3 patients died soon after angiography and were excluded from this study. Among the remaining 116 patients, 22 were treated medically (Group M) for the following reasons: profound left ventricular (LV) dysfunction (3 patients), effective pharmacological treatment (10), and patients' refusal of surgical therapy (9). Among 94 patients who underwent coronary artery bypass graft (CABG), 83 patients survived (Group S). During the follow-up period, cardiac events occurred in 5 patients in Group M; cardiac deaths in 3, non-fatal myocardial infarction (MI) in one and late application of CABG in one. Two-year cardiac event-free rate after diagnosis was 77%, which remained unchanged thereafter. The cumulative survival rate was 83%. The incidence of cardiac events in Group M was higher than that in Group S (p < 0.01). However, cardiac event rates were similar between these 2 groups for patients with good collateral circulations to the left coronary arteries, no preceding MI and LV end-diastolic pressure less than 15 mmHg. We concluded that the Japanese patients with severe LMCA lesions who respond favorably to pharmacological intervention have unexpectedly good prognoses, however, obstructed collateral circulation to the left coronary system, the presence of preceding MI and high LV end-diastolic pressure were all high-risk factors for medically-treated patients.

Adult↗

PubMed1989

Renal revascularization in anuric patients: determinants of outcome.

We describe three patients who recently had surgical revascularization for prolonged anuria due to renal artery occlusion. A review of the literature revealed 31 similar patients with sufficient data to allow comparison. There was no correlation between the interval of anuria and the surgical outcome regarding survival, renal function, and blood pressure. On renal angiography, 16 patients had nephrogram as evidence of collateral circulation. Seven patients had no renal perfusion. There was no significant difference in renal function, blood pressure, or survival after renal reperfusion in patients with or without nephrogram. In patients who received vascular grafts, the postoperative serum creatinine level and blood pressure were significantly lower than those of patients who had thromboendarterectomy (P less than .05). In contradistinction to commonly held concepts, these findings are independent of collateral circulation.

Anuria↗

PubMed2004

Laser Doppler flowmetry assessment of microcirculation in upper extremities before and in long-term period after harvesting of radial artery.

Radial artery (RA) is rather commonly used as a graft for autoarterial myocardial revascularization. Consequences of RA harvesting for the development of ischemic disturbances in distal hand segments are poorly understood. The paper presents assessment of hand microcirculation (HMC) before and in late postoperative period after RA harvesting with modern precise diagnostic method - laser Doppler flowmetry (LDF). LDF assessment of HMC was carried out in 80 patients with ischemic heart disease (160 hands) to evaluate the possibility of RA harvesting for coronary artery bypass surgery. HMC classification was developed on the base of these measurements: type 1 -normocirculatory HMC: 6.7-17 ml/min/100 g (58%); type 2 - vasospastic HMC: < or = 6.7 ml/min/100 g (20%); type 3 - hyperemic HMC: > or = 17 ml/min/100 g (22%). In 34% of cases preoperative examination revealed microcirculatory asymmetry between right and left hands. Based on preoperative examination results in 22.9% of cases the decision was made to refuse from RA excision because of positive collateral circulation test developed in our Institute (positive decision about Patent award according to appeal No2000122582/14 (023905) from 28.08.2000). In 14 patients (14 upper extremities) HMC was measured before and 1-1.5 years after RA harvesting. After RA excision baseline HMC in operated hand reduced significantly while maximal HMC reserve remained at the level close to preoperative one. Postoperative HNMC alterations evidence of adequate preoperative assessment of hand collateral circulation potential. In case of blood flow asymmetry RA must be taken from the hand with higher blood supply and adequate collateral microcirculation.

Arteriovenous Shunt, Surgical↗

PubMed2003

Transanal laser Doppler flowmetry to assess microcirculation in the upper rectum during abdominal aortic aneurysmectomy.

PURPOSE: Fatal ischemic colitis can develop after abdominal aortic aneurysmectomy. We investigated the effectiveness of transanal laser Doppler flowmetry (LDF) for assessing microcirculation in the rectal mucosa during aneurysm repair. METHODS: The subjects were 17 patients who underwent abdominal aortic aneurysmectomy. A Doppler laser and Doppler probe were mounted on a rectoscope, which was inserted into the anus, and rectal flux values were obtained by a flowmeter. RESULTS: The mean flux value during aortic clamping was 146 +/- 35.6 perfusion units (PU) in patients with sufficient collateral circulation to the upper rectum and 58.3 +/- 19.4 PU in patients with insufficient collateral circulation ( P << 0.01). The LDF values and inferior mesenteric artery stump pressure measurements were well correlated ( r = 0.86). CONCLUSION: Transanal rectal LDF is useful for continuously assessing microcirculation in the rectal mucosa during abdominal aneurysmectomy, and the data obtained with this method may reflect whether a collateral pathway to the upper rectum exists.

Adult↗

PubMedDate not supplied

Middle cerebral artery occlusion: correlation of computed tomography and angiography with clinical outcome.

The clinical outcome of 40 cases with middle cerebral artery (MCA) occlusion was examined in relation to the site of occlusion and the findings on computed tomography (CT). Patients were treated conservatively without surgery. A few had decompressive craniotomy when necessary. Outcome in 7 (18%) was good, in 6 (15%) moderate, and in 15 (38%) severe; 12 (30%) died by the follow-up at 3 months. In cases with occlusion at the origin of the MCA, hypodensity on CT scan was usually localized to the basal ganglia, presumably because of collateral circulation through the anterior cerebral arteries; the outcome in these patients was not always favorable. Cases with occlusion of the trunk or branch vessels always showed marked CT hypodensity, and clinical outcome was poor. To assess quantitatively the extent of collateral circulation, the conduction time of contrast medium from the intracranial siphon (IC) to the insular portion of the MCA (M2) through the anterior cerebral arteries was calculated on serial carotid angiograms obtained within 24 hours after stroke onset. An IC-M2 time of 5 seconds was a critical indicator of whether extensive CT hypodensity would develop (the rule of 5 seconds). Furthermore, this method predicted the appearance and extent of infarction before CT revealed hypodensity. The significance of acute reconstructive surgery is also discussed.

Aged↗

PubMed1991

Are CT infarcts a separate risk factor in patients with transient cerebral ischaemic episodes?

CT cerebral infarcts have been reported in a number of studies of patients with transient ischaemic episodes. The hypothesis that these asignomatic infarcts, i.e. without associated clinical neurological deficit reflect the ability of the brain to limit the extent of neuronal damage through its collateral circulation was tested in 50 patients undergoing both CT scanning and cerebral angiography. Out of 50 patients there were 15 patients with a total of 17 infarcts on CT scan. Fourteen of 50 patients had evidence of diminished collateral reserve capacity on cerebral angiography. Ten of these 14 patients (71%) had CT evidence of infarction, in contrast to an incidence of five out of 36 patients (14%) without evidence of diminished collateral reserve. These results indicate that CT infarcts and collateral cerebral circulation must be evaluated as prognostic factors in patients with T.I.A.s.

Cerebral Angiography↗

PubMed1976

Venacavography, corticosteroids and surgery in the management of idiopathic retroperitoneal fibrosis.

Four patients with idiopathic retroperitoneal fibrosis were found to have characteristic obstruction and anterior displacement of the lumbar vena cava. Varying degrees of venous collateral circulation were present, depending on the degree of vena caval compression. All 4 patients underwent ureterolysis to relieve the hydronephrosis and to confirm diagnosis by biopsy. Two patients were treated with corticosteroids postoperatively. Followup venacavography demonstrated improved filling and decrease in the collateral circulation in these 2 patients. Of the remaining 2 untreated patients 1 was lost to followup and the other revealed no change. Diagnosis of idiopathic retroperitoneal fibrosis can be made if characteristic changes are present on inferior venacavography and may provide an objective measure for following the basic disease process during medical treatment.

Adult↗

PubMed1975

Late complications of surgery for coarctation of the aorta.

The problem of the patient who has had one operation for coarctation of the aorta and who then requires another because of a late complication at or near the coarctation site is a demanding one. The safety of aortic cross-clamping at the second operation depends on the adequacy or otherwise of the collateral circulation, and this in turn depends on the presence or absence of residual or recurrent aortic obstruction. Three illustrative cases are described in which there was complete, incomplete, and no aortic obstruction respectively at the time of reoperation, two of the cases presenting the additional complication of local aneurysm formation. The various aspects of management of such individuals are discussed, and the relevant literature has been reviewed in an attempt to provide a systematic approach to these difficult patients. The methods for assessing collateral circulation are both clinical and radiological with trial clamping of the aorta and pressure measurement as the most reliable ultimate test. A pressure of 50 mmHg in the distal aorta is accepted as indicating an adequate peripheral circulation, but it is recommended that the trial clamping should always include both the left subclavian artery and any particularly large local collaterals. The use of a perfusion technique to sustain the distal tissues is also recommended, although local bypass shunts have a place when their use is dictated in the interests of safety for the patient.

Adolescent↗

PubMed1991

[Blood flow evaluations on normal spinal cord of rabbit and the effect of aortic ligation by radioactive microsphere technique].

The microsphere technique was used to determine precise distribution of the spinal cord blood flow (SCBF) in rabbit and measurement of the SCBF was also carried out after the ligation of the thoracic aorta to examine the mechanism of collateral circulation. The results showed higher values of the SCBF in the cervical (42.3 +/- 17.1ml/100g/min) and lumbar spinal cord (42.2 +/- 25.5ml/100g/min), compared with the thoracic cord (36.6 +/- 15.5ml/100g/min). The segmental analysis of SCBF distribution revealed relatively higher in the lower cervical, lower thoracic and lumbar segments but showed lower values in the upper thoracic segments. The SCBF was also detectable only in 2-4 thoracic segments below the ligation level of the thoracic aorta, which suggests that sufficient pathway of collateral circulation is not plausible in the thoracic cord of rabbit.

Animals↗

PubMed2001

ST elevation in the anterior precordial leads during right ventricular infarction: lessons learned during primary coronary angioplasty--a case report.

ST elevation in the anterior leads may be due to isolated right ventricular infarction associated with occlusion of a nondominant or codominant right coronary artery. The authors report a case of isolated right ventricular infarction from a dominant right coronary artery's proximal occlusion in the presence of collateral circulation provided by the left coronary artery. Extensive damage occurred owing to compromise of the collateral circulation during primary coronary angioplasty. This is an unusual angiographic pattern for isolated right ventricular infarction. The potential consequences of percutaneous interventions to collateral vessels is discussed.

Adult↗