J Thorac Cardiovasc Surg 1994;108:796-797
© 1994 Mosby, Inc.
Clinical trial of the Hedley Brown retractor for internal mammary artery dissection
Andrew Chatzis, MD,
Nicholas Phillips, MB, BChir,
Michael Henley, MB, BS,
Alun Rees, FRCS
Thoracic and Cardiac Surgical Unit
Harefield Hospital
Harefield, Middlesex, United Kingdom
To the Editor:
The excellent properties of the internal mammary artery (IMA) have made it the first choice as a conduit in coronary artery operations.
1 Adequate exposure is essential for accurate and safe harvesting of the IMA, and various devices have been proposed to provide it. Evidence has also surfaced that IMA dissection, especially bilateral, predisposes to a higher rate of sternal wound infection, and certain factors have been found to be involved. 2 We, however, were intrigued by the potential impact of the stretching and possible subsequent damage to the sternum or the ribs, and we questioned this in a controlled study in which most of the known factors were excluded. We used the retractor proposed by Hedley Brown and Dougenis, 3 mainly because of its simplicity and low cost.
In the study we enrolled patients undergoing first-time coronary artery bypass grafting and having the left IMA dissected for this purpose. Those with diabetes, chronic obstructive airway disease, or preoperative steroids therapy were excluded. Also, patients who needed reexploration, had a myocardial infarction or cardiac arrest, required prolonged mechanical ventilation, or stayed in the intensive care unit for more than 24 hours after the operation were withdrawn from the study. Over a 6-month period from December 1991 to May 1992, 39 patients, 33 male and 6 female, age range 38 to 76 years (mean 59 years), qualified to enter the trial. The Sellors rib retractor with Harefield Hospital pattern blades (GU Manufacturing Co. Ltd, London, United Kingdom) was used as the standard sternal retractor. In 26 cases the improved Hedley Brown retractor adapter (Thackray Surgery, Leeds, United Kingdom) was used for IMA dissection, whereas in the remaining 13 the Sellors's retractor was used alone for this purpose. The two groups were well matched for age, sex, and body mass index. Prophylactic antibiotics were administered according to a standard protocol. The IMA was dissected on a pedicle. Bone wax and diathermy to the sternum were used judiciously. The patients were reviewed daily for the first 10 days and at 6 weeks and 3 months thereafter. A wound was considered infected when it had significant purulent discharge.
Although exposure was better with the Hedley Brown retractor, its use did not expedite the procedure significantly. Nevertheless, it did not cause increased complications either (Table I). Sternal wound infection occurred in a total of eight patients from the two groups and in all cases was superficial. There were six early (6.8 ± 3.0 days) and two late infections (occurring 35 and 40 days after the operation). Cultures revealed Staphylococcus aureusin three patients and Streptococcus faecalisin two; in three patients no organism was isolated. All wounds healed in 5 to 10 days and in four patients antibiotics were necessary for 5 to 7 days. The main determinant of postoperative sternal wound infection was cardiopulmonary bypass time (p < 0.05) (Table II).
We conclude that in this small group of low-risk patients the Hedley Brown retractor blade provided improved exposure without causing increased untoward effects. Also the incidence of sternal fracture or dislocation of the ribs did not affect the sternal wound infection rate, the latter being found to correlate significantly only with cardiopulmonary bypass time.
References
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Oakies JE, Page US, Bigelow JC, Krause AH, Salomon NW. The left internal mammary artery: the graft of choice. Circulation 1984;102(Suppl):I213-21.
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Grossi EA, Esposito R, Harris LJ, et al. Sternal wound infections and the use of internal mammary artery grafts. J THORAC CARDIOVASC SURG 1991;102:342-7.[Abstract]
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Hedley Brown A, Dougenis D. Dissection of the two internal mammary arteries with maximal exposure and minimal adverse sequelae by means of an inexpensive, simple, atraumatic retractor. J THORAC CARDIOVASC SURG 1991;102:753-6.[Abstract]
