Mammary Artery Research Articles

Giant left main pseudoaneurysm obstructing the left anterior descending coronary artery demonstrated by transesophageal echocardiography and coronary angiography

Left main pseudoaneurysm is a rare angiographic finding in young adults. We describe a 23-year-old male who presented with an acute anterior wall myocardial infarction. Coronary angiography and transesophageal echocardiography reveal a huge aneurysm of the distal left main obstructing the left anterior descending artery (LAD), which was defined by history as a pseudoaneurysm. The pseudoaneurysm was successfully resected and mammary artery was used to repair the distal left main and to bypass the LAD.

A randomized study of the systemic effects of warm heart surgery

The technique of warm heart surgery is defined as continuous warm blood cardioplegia and normothermic cardiopulmonary bypass. Although the systemic effects of traditional myocardial protection are well known, the effects of warm heart surgery are not. In a prospective trial, 204 patients undergoing coronary artery bypass grafting were randomized to the warm heart surgery technique (normothermic group) or traditional intermittent cold blood cardioplegia and cardiopulmonary bypass (hypothermic group). The groups had similar heparin sodium requirements, activated clotting times, urine output, hematocrit, and blood product utilization. There were no differences in hemodynamics immediately after cardiopulmonary bypass. The normothermic patients had a higher incidence of spontaneous defibrillation at cross-clamp removal (84%) than the hypothermic patients (33%) ( p < 0.01). An increase in the flow rate of low K + cardioplegia was necessary to eradicate electrical activity during aortic occlusion more often in the normothermic patients (20%) than in the hypothermic patients (3%) ( p < 0.01). When low K + cardioplegia was ineffective, high K + cardioplegia was necessary to eradicate electrical activity in 31% of the normothermic patients compared with 10% of the hypothermic patients ( p < 0.05). The total cardioplegia volume delivered to the normothermic group (4.7 ± 1.9 L) was higher than that delivered to the hypothermic group (2.6 ± 0.8 L) ( p < 0.01). Although urine output was similar in both groups, the serum K + levels were higher in the normothermic group (5.7 ± 0.8 mmol/L) than in the hypothermic group (5.3 ± 0.8 mmol/L) ( p < 0.001). Low systemic vascular resistance during normothermic cardiopulmonary bypass resulted in the infusion of significantly higher volumes of crystalloid solutions (3,650 ± 800 mL) and more phenylephrine hydrochloride (1.3 ± 2.2 mg) than during hypothermic cardiopulmonary bypass (3,100 ± 700 mL and 0.4 ± 0.6 mg, respectively) ( p < 0.01). Warm heart surgery should be used with caution in patients with renal failure or severe cerebrovascular disease. Serum K + levels and fluid overload must be carefully monitored during long operations. The high incidence of low systemic vascular resistance and resulting phenylephrine infusion during normothermic cardiopulmonary bypass raises concerns about possible mammary artery or coronary artery spasm and the risk of stroke.

Intra-arterial chemotherapy for breast cancer: where to now?

Attention is once again being focussed on the administration of chemotherapeutic agents given by the intraaterial route. The subject was first explored in the 1950s by Helman and colleagues in South Africa.’ A few other sporadic reports were published in the 1960s but although this approach was maintained for the treatment of head and neck cancers, it was only in the late 1970s and 1980s with introduction of new materials that interest in this approach for treatment of breast cancer was rekindled. Dr de Dycker’s article in this issue of The Breast reports the use of intra-arterial chemotherapy in patients with inflammatory breast cancer. 45 patients were given mitoxantrone by the intraarterial route as primary therapy and this was followed by surgery when the tumour was operable. After two courses (8 weeks of treatment) 91% of patients were suitable to undergo mastectomy. Response rate was highest in postmenopausal patients; with response to treatment being an important prognostic factor, those patients responding to the first course of treatment having the longest time to relapse and the longest overall survival. Response rates achieved by de Dycker are comparable to those obtained with high dose conventional chemotherapy but the advantage of the intra-arterial route is that side effects are much lower and responses are seen more quickly. Dr de Dycker used a super-selective angiographic approach with alternative cannulation of the internal mammary and lateral thoracic arteries with infusion of drugs over 72 h. Others’” have used implantable catheters with positioning of the outflow tip to allow infusion into the subclavian artery. These are implanted surgically and have been used in the management of both locally advanced as well as recurrent chest wall cancer. The catheter’s position can be checked by injecting a blue dye which produces staining in the area which will receive high doses of chemotherapy. This allows one to confirm that the blood flow to the tumour is intact and that the treatment is therefore likely to be effective. The side effects of this less selective approach are greater even

Crafting Postop Care for

e all knew Mr. Luke, but it began with Rosemary Luquire: Mr. Luke reminded me of Santa Claus-large and jovial. When we first met, 25 days after his internal mammary coronary artery bypass grafting (CABG) at age 69, he and his family were enjoying afried-food feastfried chicken, fried fish, french fries, onion rings-plus mashed potatoes with gravy. I was a little surprised at the folly, considering the gaping sternal wound beneath his chin-tucked napkin. Ihad come to his room to schedule preop teaching for an omentopexy that would use his omentum to close the hole in his

Vascular biology of coronary bypass grafts.

Clinical studies on the natural history of coronary bypass grafts strongly suggest that biologic properties of the vessels used importantly affect their function and patency. The endothelium is a source of substances regulating vascular tone, platelet function, and vascular growth; it produces nitric acid from L-arginine, which is a potent vasodilator and inhibitor of platelet function and has antiproliferative properties. Nitric oxide and prostacyclin, which have a similar profile of action, are released in greater amounts in arterial than venous coronary bypass vessels. Vascular smooth muscle cells are primary regulators of local blood flow and contribute to proliferative responses. The right gastroepiploic artery exhibits more pronounced contractions than the mammary artery but has a similar sensitivity to vasoconstrictors. Proliferative responses in coronary bypass vessels appear to be induced by changes in transmural pressure (particularly in veins), endothelial damage, and in turn, local release of platelet-derived growth factors, low-density lipoproteins, and intrinsic characteristics of the blood vessels. Thus, biologic properties of the endothelium and vascular smooth muscle significantly contribute to the function and patency of coronary bypass grafts. While the mammary artery has near-ideal characteristics, the right gastroepiploic artery exhibits marked contractile responses and the saphenous vein has unsatisfactory antithrombotic properties and more pronounced proliferative responses.

Direct Myocardial Revascularization without Extracorporeal Circulation: Experience in 700 Patients

Between May 1978 and March 1990, 700 patients were operated on with direct coronary surgery without extracorporeal circulation (ECC): 529 (76 percent) were male and 171 (24 percent) were female. The average age was 64 years (range, 35 to 86 years), 454 (65 percent) had unstable angina, 163 (23 percent) had stable angina, 51 (7 percent) had postmyocardial infarction angina, and 32 (5 percent) had acute myocardial infarction at the moment of the operation. In this series of patients, all branches of the coronary arteries were bypassed; the mammary artery was used in 40 percent of the cases, the average bypass per patient was 2.2 (range, 1 to 5), and 26 percent had associated disease of high risk to undergo ECC. The morbidity was 4 percent and the mortality for this series of patients was 1 percent; the probability of survival at seven years was 90 percent. This experience shows us that this surgery is an alternative in the treatment of coronary disease, especially for aged patients with associated disease, in some cases of acute transmural infarction, and also for patients who need coronary angioplasty. Also, it can improve the relation cost/benefit in coronary surgery.

Ten-year survival of patients with mild angina or myocardial infarction without angina: A comparison of medical and surgical treatment

Ten-year survival percentages were calculated for groups of 407 initially medically treated patients and for 390 patients who had early coronary bypass surgery; all had either mild angina pectoris or myocardial infarction without subsequent angina pectoris. Uncensored actuarial survival was 77% for medical patients and 83% for the surgical group. For 179 patients who had internal thoracic (mammary) artery grafting as part of their procedures, survival was 91% in contrast to 76% for those who had vein grafts only. A sharp drop of the survival curve for the vein graft group after the seventh year was not shown for those who had internal thoracic artery grafts. Survival was 71% for 280 patients treated medically only.

Tissue-type plasminogen activator relaxes humam coronary and mammary arteries: A new endothelium-derived relaxing factor?

Tissue-type plasminogen activator relaxes humam coronary and mammary arteries: A new endothelium-derived relaxing factor?

Endothelin-1 potentiates contractions to norepinephrine and serotonin in human mammary and coronary arteries

Endothelin-1 potentiates contractions to norepinephrine and serotonin in human mammary and coronary arteries

Favorable results of coronary artery bypass grafting in patients older than 75 years

There is controversy whether the short-term and long-term results of coronary artery bypass grafting in elderly patients justify performing the procedure. Between January 1977 and December 1986, 4580 patients underwent coronary artery bypass grafting, of whom 222 (4.9%) were 75 years old or older (mean 77 years). There were 143 men and 79 women and 139 (63%) were in New York Heart Association class IV. One hundred forty-six patients (66%) had had at least one preoperative myocardial infarction. Myocardial revascularization was performed under emergency conditions in 17 patients (18%). The mammary artery was used in 43%, 96% of the patients received two or more grafts. The mean number of bypass grafts was 3.1 per patient. The overall hospital mortality rate was 10.8% (24/222), 3.6% for elective procedures, 14.9% in urgent cases, and 35% in emergencies. In contrast, the overall early mortality rate was 3.1% in 4358 patients less than 75 years old. Complications occurred in 83 patients (37%). Of the patients discharged from the hospital, 198 were followed up for a mean of 48 months (1 to 130). Actuarial probability of survival was 75% at 48 months. Postoperatively 70% were in New York Heart Association class I or II and only 21% were rehospitalized for cardiac problems. During the follow-up period 77% of the patients were free from angina, and of those experiencing angina the mean time from operation to the first episode was 75 months. Although elderly patients have a somewhat increased operative mortality rate, particularly if operated on urgently or emergently, long-term survival and freedom from angina are excellent and justify continued performance of coronary bypass grafting in selected patients over 75 years of age.

The intima of human coronary arteries

Intimal thickness relative to that of the media (r) was measured in coronary and internal mammary arteries from 300 human subjects. Whereas this ratio remained low (<0.17) in the mammary arteries, coronary arteries showed progressive intimal thickening (r = 4.10 by 60 years). The intimal surfaces of 70 pairs of arteries were compared by light, transmission, and scanning electron microscopy. The mammary arteries had a continuous endothelial lining, but the coronary arteries showed incomplete coverage of the thickened intima. In affected vessels the endothelial cells showed loss of attachment to adjacent cells and to the underlying tissue. It was concluded that the progressive intimal thickening of the human coronary artery, which develops early in life and is associated with defects in the internal elastic lamina, is also associated with endothelial cell separation and detachment, with the formation of denuded areas on the intimal surface.

Preclinical pharmacologic properties of dilevalol, an antihypertensive agent possessing selective beta 2 agonist-mediated vasodilation and beta antagonism

Dilevalol is a vasodilator with selective partial β 2 agonism and nonselective β-antagonist activity. In contrast to its potent β 2-agonist activity, dilevalol is essentially devoid of β 1-agonist action, and is therefore distinct from pindolol and celiprolol. Dilevalol inhibits β 1- and β 2-adrenergic receptors nonselectively in dogs, rats and in isolated tissues, including human myocardium, and its β-antagonist potency is similar to that of propranolol. In contrast to its β-antagonist activity, it exerts minimal if any α-adrenergic blockade. Dilevalol is 300- to 1,000-fold more potent at β- than at α 1-adrenergic receptors, including those on human myocardium and mammary arteries. At antihypertensive and vasodilator doses in rats and dogs, dilevalol does not inhibit α 2-adrenergic receptors. Oral doses of 2.5 to 50 mg/kg of dilevalol reduce blood pressure in spontaneously hypertensive rats. Heart rate is not significantly affected. Tolerance does not develop to the antihypertensive response. In contrast, β blockers such as propranolol do not reduce blood pressure in this model. Antihypertensive activity is also observed in dogs with renal hypertension. The hemodynamic profile of dilevalol is consistent with its vasodilator properties. In spontaneously hypertensive rats, antihypertensive doses of dilevalol reduce peripheral resistance without affecting cardiac output. Dilevalol also improves the compliance and distensibility of the large arteries. The vasodilator and antihypertensive responses to dilevalol are mediated by a partial agonist action at vascular β 2 receptors, because they are inhibited by the nonselective β blocker propranolol as well as the β 2-selective antagonist ICI 118,551.

Arterial Cannulation and Myocardial Protection in Severe Diffuse Aortic Calcification

A patient with diffuse and severe aortic calcification is described. The patient had a double vessel coronary disease and it was impossible to cannulate the ascending aorta or the femoral arteries for the cardiopulmonary bypass. Arterial cannulation was performed in the innominate artery and both mammary arteries were used during a short period of ventricular fibrillation.

内胸動脈‐冠動脈吻合法の検討 結節縫合と連続縫合の比較

内胸動脈‐冠動脈吻合法の検討 結節縫合と連続縫合の比較

Recovery of integrative central nervous function after one hour global cerebro-circulatory arrest in normothermic cat

Functional and metabolic recovery of a female cat is described which survived for 1 year following 1 hour global cerebro-circulatory arrest at normothermia. Ischemia was produced by intrathoracal occlusion of the innominate, the left subclavian and both mammary arteries. Following ischemia the animal was kept under intensive care for 46 h. EEG and evoked potentials began to recover after 3 h following ischemia, and spontaneous respiration returned promptly on the 2nd day when the animal was weaned from the respirator. The neurological deficit score declined from a maximum of 395 immediately after ischemia to 158 during the first week and to 40 within 4 weeks. At this time the animal was slightly ataxic but she was able to walk and to feed and clean herself. One year after ischemia EEG and evoked potentials were normal. Morphological studies and the autoradiographic evaluation of protein biosynthesis revealed an almost normal pattern in cortical structures but there was almost complete atrophy of dorsal hippocampus and striatum leading to enlargement of the ventricular system. These observations demonstrate that despite these lesions the central nervous system is able to recover integrative neurological function after cerebro-circulatory arrest in normothermia of as long as 1 h.

EFFECTS OF ADRENALINE, OXYTOCIN AND 2-Br-α-ERGOCRYPTINE ON MAMMARY BLOOD FLOW IN THE LACTATING EWE

The mammary blood flow (MBF) and heart rate (HR) responses to standing, lying, suckling, adrenaline (A), oxytocin and 2-Br-α-ergocryptine were studied in four lactating ewes. Posture had a variable effect on MBF. In three of the four ewes there was an increase (P &lt; 0.05) and in one ewe a decrease (P &lt; 0.05) in MBF as a result of lying. Heart rate recorded while the ewes were lying was significantly lower (P &lt; 0.01) than while standing. Suckling resulted in an average decrease in MBF of 39% (P &lt; 0.01) compared to standing values. Continuous infusion of A at a rate of 300 ng kg−1 min−1 for 2.5 h resulted in a progressive increase in HR (P &lt; 0.05) for 2 h of the infusion. During the A infusion MBF decreased transiently for 10–15 min and then increased thereafter (P &lt; 0.05) throughout the A infusion in three of the ewes. In the fourth ewe, MBF increased to a peak during hour 2 of A infusion and thereafter declined. Exogenous oxytocin administered at doses [Formula: see text] had a stimulatory effect on MBF. Suckling and handmilking induced decreases in blood flow of 39 ± 6% and 54 ± 13%, respectively, after injection of 1 mU kg−1 oxytocin. Treatment of ewes with 2-Br-α-erogcryptine (a prolactin-release inhibitor) did not influence mean MBF while standing or lying but attenuated the negative effects of suckling and hand milking on MBF. Mammary blood flow in the lactating ewe is, therefore, sensitive to posture, suckling and hand milking but the response to the latter two activities could not be attributed to oxytocin on the basis of the present results. Key words: Mammary artery, suckling, milk, hormonal effect

Nonprogression of coronary artery atherosclerosis in homozygous familial hypercholesterolemia after 31 months of repetitive plasma exchange

The effects of plasma exchange performed every two weeks for 31 months in combination with diet and drug therapy were studied in a patient with receptor-defective homozygous familial hypercholesterolemia. Coronary angiography performed three years prior to commencing plasma exchange was compared to angiography 31 months after starting the program. Comparison of the angiograms taken six years apart showed no progression of coronary atheroma in the main left coronary artery in which a 30% narrowing was originally seen. An internal mammary artery-coronary artery bypass remained widely patent and showed no development of atherosclerosis. Plasma cholesterol levels were reduced 46% by plasma exchange, diet and drug compared to diet and drug alone. Achilles tendon xanthoma diminished significantly. It appears that plasma exchange combined with diet and drug therapy, while not producing regression of existing atheromatous lesions, does retard or prevent further progression.

Ascending aorta to bifemoral bypass—a ventral aorta

In the decade since April 1975 we accumulated a series of 18 patients with arterial conduits from the ascending aorta to the femoral arteries, 10 men aged 53 to 75 years (mean, 60 years) and eight women aged 33 to 56 years (mean, 50 years). In the first two patients, the conduit was placed subcutaneously; in the remaining 16 patients, it was placed behind the rectus muscle and in front of the posterior rectus fascia, thus following the ventral anastomotic axis of the internal mammary and inferior epigastric arteries. The conduit is not visible, palpable, or compressible in this position. This approach was usually chosen because of multiple failures of standard intra-abdominal and axillofemoral vascular reconstructions. Five patients had concurrent intramediastinal procedures, mostly coronary bypass or innominate artery repair. The early operations were performed with Dacron grafts with a bifurcation constructed just below the umbilicus. In the last nine patients, we have used an 8 or 10 mm polytetrafluoroethylene (PTFE) prosthesis and connected it to a 6 or 8 mm PTFE crossfemoral bypass. No operative deaths occurred. The 5-year patency rate by life-table analysis is 70%. This operation is an alternative to axillofemoral bypass in patients with an inoperable abdominal aortic aneurysm.

Measures of De Novo Synthesis of Milk Components from Propionate in Lactating Goats

Possible direct contributions of propionate to de novo synthesis of milk components by the mammary gland of lactating goats fed a concentrate-roughage diet have been studied in vivo by primed constant infusion of [1-carbon-14] propionate into the right mammary artery. Specific radioactivities of milk galactose, fatty acids, and protein were higher in the infused than in the uninfused half of the mammary gland, suggesting de novo synthesis of these compounds in the udder. Specific radioactivities of milk glucose in both udder halves were identical, ruling out any possibility of mammary gland-derived glucose from propionate of blood plasma under the experimental conditions. Of milk galactose, .8% was derived from propionate of blood plasma, and of milk glucose, 98% was derived from glucose of blood plasma. After intraruminal infusion of unlabeled propionic acid at 11 g/h, concentration of propionate in blood plasma was doubled, its contribution to milk galactose was increased to 1.5%, and proportions of milk odd-numbered fatty acids were increased. Propionate was incorporated largely into milk odd- numbered fatty acids (9:0, 11:0, 13:0, 15:0, 17:0). We conclude that small amounts of propionate can be incorporated into principal components of milk in the mammary gland of lactating goats.

Cerebral Protein Synthesis and Ischemia

Publisher Summary This chapter describes the cerebral protein synthesis rates (CPSR) in detail for normal rat and gerbil brains. The in vitro results are used as a supplement to correct the end-point measurements of specific activities in the absence of knowledge about their time course during the 45 minutes of incorporation. This approach is applied to the study of regional cerebral protein synthesis in two models of cerebral ischemia. Functional and morphological investigations have revealed that irreversible neuronal damage may develop after as little as five minutes' ischemia in selectively vulnerable areas, whereas recovery from ischemia seems to be possible in other regions of the brain after ischemia as long as one hour. There are two series of experiments: a short-lasting ischemia induced by bilateral carotid occlusion in gerbils, and a prolonged ischemia induced by intrathoracal clamping of the innominate, subclavian and mammary arteries in monkeys, are presented.