Faculty Bibliography

This study attempted to evaluate the efficacy of chronic extra-aortic counterpulsation with a latissimus dorsi neuro vascular flap. Five dogs had a preliminary procedure consisting of the creation of a latissimus dorsi flap and a thoracotomy in which the flap was wrapped around the descending aorta just distal to the left subclavian artery. An epicardial lead was placed on the left ventricle and a nerve stimulating lead placed around the thoraco-dorsal nerve. Three weeks later, both leads were connected to a cardiomyostimulator programmed to function in a counterpulsation mode with a 1:2 assist frequency. Hemodynamic measurements were made at 6 and 8 and 10 and 12 weeks and the dogs were sacrificed. Three dogs had all sets of hemodynamic measurements made. Two of the three dogs demonstrated diastolic augmentation at 6 and 8 and 10 and 12 weeks average 20 to 25 mmHg. The third dog failed to demonstrate any change. All dogs were sacrificed at 12 weeks and specimens were submitted for histologic evaluation. The muscle flap was preserved in all animals. The aorta subjacent to the flap showed, (1) normal intima with no evidence of disruption or thrombus in all animals, (2) in the animals in whom counterpulsation was observed, there appeared to be thinning of the media in the aorta subjacent to the muscle flap, and (3) no evidence of distal emboli. This study demonstrated that chronic counterpulsation can be obtained with a latissimus dorsi flap. The actual hemodynamic benefits are not determined from this study. The medial thinning in the aortic wall may limit the long-term benefit of this procedure.

The aim of this study was to evaluate the hemodynamic effects of extraaortic counterpulsation with a latissimus dorsi (LD) neurovascular flap in a canine heart failure model. Five dogs (8-18 kg) had a left LD neurovascular muscle flap raised. The muscle was brought into the chest through the second interspace and wrapped around the aorta. Parameters studied were heart rate (HR), systolic pressure (SP), diastolic pressure (DP) pulmonary artery pressure (PAP), mixed venous oxygen saturation (MVO2), and cardiac output (CO). Baseline measurements were obtained with the muscle nonstimulated and stimulated by a prototype burst stimulation. The only parameter that changed significantly with muscle stimulation was DP (55.8 +/- 3.8 mmHg to 72.4 +/- 4.8 mmHg, p less than 0.05). Propranolol (3-4 mg/kg) and verapamil (2-3 mg) were given intravenously to induce heart failure. Mean blood pressure decreased from 64.12 +/- 5.03 mmHg to 43.3 +/- 9.28 mmHg (p less than 0.05). Repeat measurements were obtained. With stimulation of the muscle flap there was an increase in DP from 36.8 +/- 9.2 mmHg to 55.4 +/- 19.3 mmHg (p less than 0.05). Although CO increased from 8% to 18% in all animals (1.42 +/- 0.33 L/mm to 1.58 +/- 0.34 L/mm) this did not reach statistical significance. This data indicates that both DP and CO can be improved by this method of cardiac assist in a heart failure model.

Changes in atrial adenosine triphosphate (ATP) and the presence of postoperative arrhythmias were studied in 14 patients during routine coronary artery bypass grafting to 1) attempt to evaluate atrial preservation, and 2) determine if a relationship exists between changes in ATP and the development of postoperative arrhythmias. Atrial biopsies were obtained at the time of cannulation (preischemic sample) and after the removal of the aortic crossclamp (postischemic sample). Methods of myocardial protection included systemic hypothermia (28 degrees C), periodic reinfusion of crystalloid cardioplegia into the aortic root and completed vein grafts, and iced slush in the pericardial well. Atrial temperature was monitored. Preischemic ATP was 0.412 +/- 0.32 mu mol/gm, and the postischemic value was 0.220 +/- 0.13 mu mol/gm (p less than .02). Atrial temperature routinely decreased to 13-18 degrees C after cardioplegic infusion but rose to 24 degrees C between infusions. There was no correlation between postoperative supraventricular arrhythmias (4 patients) and changes in ATP. In conclusion, routine coronary artery bypass grafting with standard methods of cardiac preservation does not appear to satisfactorily preserve atrial tissue. The clinical correlation and significance of this remains to be elucidated.

Nursing documentation in the medical record is an important source of information for the medical record coder. Coded data are necessary for quality assurance, risk management, research and statistical purposes, as well as for proper DRG assignment for reimbursement. Facts gleaned from nursing documentation, supported by physician documentation and laboratory data, can often result in increased reimbursement for the hospital.

Crossover femoral-popliteal or femoral-tibial bypass has been employed as an alternative extra-anatomic bypass in 3 patients who had occlusion of an iliac artery with subsequent occlusion of the ipsilateral femoral artery with patency of either a popliteal or tibial artery and a patency of the contralateral common femoral artery. Each patient had a contraindication to a more conventional type of procedure. All procedures were performed with reinforced PTFE grafts. All grafts have remained patent for 6 months to 3 years. This operation should be considered as an alternative extra-anatomic reconstructive procedure in patients with the appropriate anatomy and who are not candidates for more standard types of vascular reconstruction.

The presence of a bruit after carotid endarterectomy may indicate a persistent or recurrent lesion. The authors noninvasively evaluated, by Duplex scanning, 18 asymptomatic postoperative patients who underwent a total of 23 carotid endarterectomies and who developed a postoperative bruit to determine the significance of the bruit. Eleven men and seven women were studied from 6 weeks to 2 years postsurgery. Ages ranged from 49 to 75 years (63.6 +/- 8.0 years). Indications for endarterectomy were: transient ischemic attacks (including amaurosis fugax), 17 vessels; completed stroke with significant functional recovery and residual carotid disease, 3 vessels; and asymptomatic bruit with hemodynamically significant carotid stenosis, 3 vessels. Each patient had a Duplex scan performed to noninvasively evaluate the carotid artery. All scans were independently reviewed by two observers. Real-time B images were interpreted as normal in 14 vessels, mild thickening in eight vessels, and moderate thickening in only one vessel. Doppler recordings demonstrated a spectral range of 15-40 cm/sec (26 +/- 8 cm/sec). Ratio of velocity in the internal carotid artery to common carotid artery (VIC/VCC) ranged from 0.389 to 1.281 (0.779 +/- 0.250). This study demonstrates that the presence of a postoperative carotid bruit does not necessarily signify the presence of residual carotid disease or a hemodynamically significant lesion.

Papaverine hydrochloride was added to a standard asanguinous cardioplegic solution to study its effect on cardioplegic distribution by evaluating coronary resistance, myocardial temperature, and postoperative enzyme changes. Seventeen patients were randomized into a control group (8 patients) and a papaverine group (9 patients). All patients received 300 cc of a standard asanguinous cardioplegic solution into the aortic root after systemic cooling to 28 degrees C and measurement of septal temperature (To). The duration of infusion (t1), root pressure (p1), and septal temperature (T1) were recorded. All patients received a subsequent infusion of 200 cc of cardioplegia to which had been added either 10 cc normal saline (control group) or 1 mg papaverine hydrochloride in 10 cc normal saline (papaverine group). Time of infusion, root pressure, and septal temperature (t2, p2, T2) were recorded. Coronary resistance was calculated. Postoperative CPK and CPK-MB were recorded and compared. Mean high CPK in the papaverine group was 163 units and 182 units in the control group. There was no statistically significant difference in any parameter between groups. This study, in contradistinction to experience with animal research models, failed to demonstrate any significant value in adding papaverine hydrochloride to standard cardioplegic solutions.

Seven patients who underwent femoral-femoral by pass between June 1980 and September 1982 underwent pre-operative angiography and pre and post-operative non-invasive evaluation to determine: (1) the hemodynamic effects created by the crossover graft, and (2) if angiographic findings would be predicative of post-operative results. The mean ankle/arm (a/a) index in the donor extremity changed from 0.82 +/- 0.20 to 0.70 +/- 0.27 (NS). The a/a index in the recipient extremity increased from 0.39 +/- 0.30 to 0.74 +/- (p less than 0.02). One patient developed a "steal" syndrome. There was no correlation between angiographic findings and post-operative changes. This study demonstrated a significant increase in recipient extremity ankle pressure and a clinically insignificant decrease in donor limb pressure.