Is phrenic nerve dysfunction after cardiac surgery related to internal mammary harvesting?

BACKGROUND: Although many surgeons feel that internal mammary artery (IMA) harvesting is a risk factor for phrenic nerve dysfunction (PND) following coronary artery bypass grafting surgery (CABG), objective data confirming this are lacking. We sought to compare two groups of cardiac surgical patients to determine if an association exists between IMA harvesting and PND following CABG. METHODS: Using inpatient medical records and chest radiographs, we performed a retrospective analysis of 25 consecutive CABG patients and 25 consecutive valve procedure patients in order to compare the incidence of PND following cardiac surgery with and without IMA harvesting. RESULTS: Two patients were excluded. Thirty-one patients underwent IMA harvesting as part of their procedure, of whom 42% had PND evidenced on postextubation chest X-ray. Seventeen patients did not have IMA harvesting, and the incidence of PND in this group was 12% (p = 0.05). Both groups were similar in preoperative variables and operative techniques. CONCLUSION: This study suggests IMA harvesting is indeed a risk factor for PND following CABG.

A method for mediastinal drainage after cardiac procedures using small silastic drains.

BACKGROUND: It has been standard teaching in cardiac surgery that drainage of the mediastinum following cardiac surgical procedures is best accomplished using rigid large-bore chest tubes. Recent trends in cardiac surgery have suggested less invasive approaches to a variety of diseases. Difficult drainage problems in the field of general surgery including hepatic and pancreatic collections have been drained successfully with smaller flexible drains for many years. Additionally, many difficult to reach collections in the chest have been drained by invasive radiologists using small pigtail catheters. METHODS: We have introduced drainage of the mediastinum using 10-mm flexible, flat, fluted Blake drains. To date, we have used these drains in more than 100 cardiac operations including coronary artery bypass grafting, valve repair/replacements, combined coronary artery bypass grafting/valve operations, heart transplants, septal defects, and mediastinal tumors. RESULTS: We have demonstrated that this form of drainage is as good as using large-bore chest tubes with no significant risk of bleeding or tamponade. Additionally, use of these tubes is less painful, allows more mobility, and earlier discharge with functioning drains in place if necessary. CONCLUSIONS: Larger chest tubes are not necessarily better when it comes to draining the mediastinum. The actual area of ingress through the sideholes is considerably less than the surface area provided by the fluted Blake drain. We believe that this system can replace standard chest tubes.

Ascending aortic atheroma assessed intraoperatively by epiaortic and transesophageal echocardiography.

BACKGROUND: The presence of ascending aortic atheroma is a known risk for systemic emboli or early saphenous vein graft failure if unrecognized at the time of cardiopulmonary bypass. METHODS: This study prospectively compared intraoperative omniplane transesophageal echocardiography (TEE) and epiaortic ultrasound (EAU) images in 22 patients (6 women, 16 men, age 66 +/- 8 years) before surgical manipulation of the ascending aorta. Atheroma lesion severity was scored: 1 = normal, 2 = nonprotruding intimal thickening (> 2 mm), 3 = atheroma less than 4 mm +/- Ca++, 4 = atheroma greater than or equal to 4 mm +/- Ca++, and 5 = any size mobile or ulcerated lesion +/- Ca++. The ascending aorta between the aortic valve and innominate artery was divided into proximal, middle, and distal segments. A total of 66 segments were evaluated. RESULTS: Although the overall agreement of scores between procedures was 75.8%, significantly more lesions were identified by EAU (15) than by TEE (5) (p < 0.03). TEE failed to identify lesions in the middle and distal segments of the aorta with a score of more than 3. CONCLUSIONS: Although atheromatous lesions were identified in the ascending aorta by both ultrasound modalities, the results suggest that intraoperative EAU may have an advantage over TEE for surgeons assessing target sites for surgical procedures involving the ascending aorta.