Bilateral Mammary Artery Research Articles

Effects of GABAergic Drugs on the Recovery of Reflex Potentials after Spinal Cord Ischemia in Cats

Effects of GABAergic drugs on the recovery of reflex potentials after spinal cord ischemia were examined in anesthethized spinal cats. Monosynaptic reflex (MSR) and polysynaptic reflex (PSR) potentials, elicited by electrical stimulation of the tibial nerve in spinal cats, were recorded from the lumbo-sacral ventral root. The spinal reflex potentials were immediately depressed by occlusion of the thoracic aorta and the bilateral mammary arteries for 10 min. The potentials recovered gradually to the control level within 90 min after reperfusion. Pretreatment with bicuculline (0.3 mg/kg, i.v.), a GABA antagonist, or semicarbazide (200 mg/kg, i.v.), an inhibitor of GABA synthesis, accelerated the recovery of PSR potentials after the removal of the arterial occlusion. In contrast, pretreatment with aminooxyacetic acid (10 mg/kg, i.v.), an inhibitor of GABA degradation, retarded the recovery of PSR potentials, and this effect was overcome by the addition of the opioid antagonist naloxone (10 mg/kg, i.v.). These results suggest that the GABAergic system retards the recovery of PSR potentials after a brief spinal cord ischemia, which can be antagonized by naloxone.

An Audit of Early Mortality and Morbidity in Patients Undergoing Single and Bilateral Mammary Artery Surgery

An Audit of Early Mortality and Morbidity in Patients Undergoing Single and Bilateral Mammary Artery Surgery

Bilateral mammary artery grafting: Avoidance of complications with extended use

This study was undertaken to more clearly define the operative risks and appropriate strategies for the selection of patients who might be candidates for bilateral internal mammary artery grafting. A review of the 674 patients who underwent this procedure was performed over a 10-year period from January 1982 through 1991. These patients represented 5% of the 12,824 patients who underwent bypass grafting during this period. The mean patient age was 54 ± 9.4 years, and 92% of the patient were male. Diabetes was present in 17.5%, with 24% of this group insulin dependent. The ejection fraction was less than 0.50 in 26.7% and 14% had had previous bypass procedures. Hospital mortality was 1.9% (n = 13). Hospital morbidity included wound infection in 3.6%, reoperation for bleeding in 2.1%, and stroke in 1.6%. Postoperative intraaortic balloon pump support was necessary in 2.8%. Univariate and multivariate analysis revealed that advanced age, an emergent operative status, and the number of diseased vessels (especially left main obstruction) were predictors of hospital death. Except for wound infection (9.3% versus 2.5%) and length of hospital stay (10.8 ± 11.8 days versus 8.8 ± 7.6 days), the complications in diabetics were similar to those in patients without diabetes, respectively. At 5 years, freedom from death, death or infarctions, and death, myocardial infarction, or coronary reoperation was 90%, 70%, and 62%, respectively. The only significant multivariate correlates of long-term survival were diabetes and reoperative surgery.

Internal mammary artery revascularization in the patient on long-term renal dialysis

Twenty-six patients on long-term renal dialysis underwent coronary artery bypass grafting. The patients were divided into two groups: group 1, (16 patients) saphenous vein bypass grafts, and group 2, (10 patients) internal mammary artery in combination with saphenous vein bypass grafts. Both groups were similar in terms of cardiac hemodynamics and previous number of myocardial infarctions, though more group 1 patients were in New York Heart Association class III or IV. Patients in group 1 received 2.9 bypass grafts per patient; patients in group 2 received 4.0 bypass grafts per patient (4 with bilateral mammary arteries). No wound healing problems occurred in either group. Blood replacement was similar for both groups (group 1, 5.5 units/patient; group 2, 5.3 units/patient). More platelets were given to group 1 patients (16.2 units/patient) than group 2 patients (3.1 units/patient). We conclude that use of the internal mammary artery in patients on long-term renal dialysis does not alter wound healing or increase blood loss in this subset of patients.

Bilateral mammary artery surgery or percutaneous transluminal coronary angioplasty for multivessel coronary artery disease? An analysis of effects and Costs

Seventy-two patients with stable or unstable angina treated since 1983 by multivessel-PTCA(MVP) were retrospectively compared with 44 similar patients that were suitable for MVP, but who had undergone bilateral mammary artery (BIMA) surgery (and additional vein grafts in 60.5% of the patients) since 1986. Both groups were comparable (P = not significant [NS]) for gender, age, most risk factors, objective ischaemia and left ventricular function; however, in the BIMA group there were more previous infarctions (P = 0.02), hypertension (P = 0.03), three-vessel disease (P = 0.0001), and less severe angina (P = 0.007). In the BIMA group, a mean of 3.1 (range 2-5) vessels were treated and in the MVP group 2.0 (range 2-3) vessels (P = 0.0001). Both groups were almost completely revascularized (NS). In 39.5% of the BIMA group, no veins were used and in 20.9% the BIMAs were used as sequential grafts. In-hospital mortality was comparable: 2.3% for BIMA and 1.4% for MVP, so were periprocedural infarctions (13.6% vs 8.3%), rethoracotomies (9.1% vs 0%), emergency procedures (0% vs 5.7%), low cardiac output (2.3% vs 5.6%) and other complications (18.2% vs 9.2%). The mean stay (days) on the ICU/CCU for BIMA was 2.3 and for MVP 1.6 (P = 0.005) and the mean hospital stay for BIMA 12.3 and for MVP 6.6 (P = 0.0001). The maximum and mean follow-up (months) of 43 BIMA and 71 MVP hospital survivors was 35 vs 72 and 9.5 vs 22.3 (P = 0.0001) with a late mortality of 0% and 4.2% (NS). MVP patients, including 12 with re-procedures, had more recurrent angina (17.7% vs 4.7%, P less than 0.05) and more often used anti-anginal medications (62.0% vs 18.6%, P less than 0.0001). Late complications (excluding re-procedures) were comparable for MVP and BIMA (20% vs 9.3%, 4.4% vs 0%, 9.2% vs 14%). MVP patients had more re-hospitalizations (34 vs 5, P less than 0.0001), re-catheterizations (33% vs 2.3%, P less than 0.0001) and cardiac re-procedures (16 vs 0, P = 0.0006) than BIMA patients. Recurrent-angina-free survival at 1 year was 96% after BIMA and 64% after MVP (P less than 0.01). Event-free survival at 1 year was 86% after BIMA and 58% after MVP (P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Multivessel Coronary Revascularization Without Saphenous Vein: Long-term Results of Bilateral Internal Mammary Artery Grafting

When the saphenous vein is absent or inadequate, options for multivessel coronary revascularization include bilateral mammary artery grafting and the use of conduits of unproven durability (arm vein, homologous umbilical vein, prosthetic graft). To evaluate the long-term effectiveness of bilateral mammary artery grafting, we reviewed the cases of 76 consecutive patients with multivessel disease (33 with two-vessel disease, 43 with three-vessel disease) who underwent revascularization with bilateral mammary artery grafts only during the period from 1971 to 1980. No hospital deaths occurred. Thirty-three free and 119 in situ grafts were used. Late follow-up was complete, ranging from 12 to 132 months (mean interval, 67 months) and revealed improvement by at least one New York Heart Association functional class in 59 of 71 survivors. Postoperative arteriograms (mean interval, 26 months) of 55 grafts in 28 patients showed that 49 grafts were patent (89%). Five late deaths (2 noncardiac) occurred. Actuarial survival was 97.2% to seven years and 90.2% at nine years after operation. Bilateral mammary artery grafting yielded excellent graft patency, relief of symptoms, and long-term survival. When saphenous vein is unsuitable for grafting, bilateral mammary artery grafts should be utilized before other conduits are considered.

Clinical Evaluation of Mammary Artery Ligation as Treatment Coronary Heart Disease

1. The effect of bilateral mammary artery ligation on coronary disease was discussed and the simplicity and the largesy benifical results were emphasized. 2. The ECG cnanges of 26 cases of coronary insufficiency and myocardial infarction placed under this surgical procedure was studied and a slight improvement was seen. 3. Those cases showing strong sclerotic changes in the mammary arteries during the operation did not show any improvements.

Experiences with Myocardial Revascularization By Division of the Internal Mammary Arteries

A critical although purely preliminary attempt has been made to assess the value of bilateral ligation and division of the internal mammary arteries as a means of increasing blood supply to the myocardium. The concept for this approach is that of Fieschi. Battezzati, Tagliaferro and DeMarchi have been responsible for reintroducing and amplifying this original concept. By and large the studies reported in this discussion confirm the findings of these Italian investigators. At the moment, however, considerable reservation as to the ultimate place of this surgical procedure is warranted. Whether it will eventually remain as a surgical entity on its own merits or will be used as an adjunct to other surgical techniques cannot be decided until much more investigative work, both experimental and clinical, has been carried out. That there is a naturally developing extracardiac communication between the coronary arterial and pericardiophrenic arterial vasculature has again been confirmed. As yet there is no experimental proof that ligation of the internal mammary arteries bilaterally at the level of the second interspace actually increases blood flow to the heart although the supposition that it does is entertained. There is the decided suggestion that in dogs ligation of the internal mammary arteries provides a measure of myocardial protection to the subsequent production of acute coronary occlusion by ligation of the anterior descending coronary artery at its origin. Ligation of the internal mammary arteries at the second interspace is followed by an increase in mean arterial end pressure above the point of ligature in dogs. Ninety-two patients suffering from arteriosclerotic and hypertensive cardiovascular disease with organic coronary insufficiency and angina pectoris have been subjected to bilateral mammary artery ligation (BIMAL). The angina pectoris in three of these patients was secondary to advanced aortic valve disease. Fifty of these patients have been carefully followed for one to five months. By conservative clinical evaluation 34 (68 per cent) of these patients have either lost their symptoms of pain (18—36 per cent) or have been immeasurably relieved of their discomfort (17—32 per cent). The remainder were unimproved. Objective evidence of clinical improvement lags well behind the observed clinical improvement. In 13 (26 per cent) the electrocardiographic tracings taken one month or more after surgery show obvious improvement and the same may be said in nine (18 per cent) of the ballistocardiographic studies obtained. As this evidence of improvement occurred on only one occasion in the same patient, objective signs for the better have occurred in 22 (42 per cent) patients. We are indebted to and acknowledge the very considerable help rendered by Dr. Isaac Starr, Hartzell Research Professor of Therapeutics, University of Pennsylvania Medical School, who supervised and read all ballistocardiograms. A simple technique for the performance of Division of the Internal Mammary Arteries has been detailed.