Wound infection in cardiothoracic surgery

Assessment of human long saphenous vein function with minimally invasive harvesting with the Mayo stripper

BACKGROUND

The use of the Mayo Stripper to harvest the long saphenous vein has been shown to improve morbidity from leg wound incisions. It has not been universally accepted because of a perceived increase in injury to the venous conduit.

OBJECTIVE

To compare the function of undistended autologous long saphenous vein harvested by a Mayo stripper with the traditional 'open' technique in the same patient (n = 12) appearance.

METHODS

Vascular reactivity was assessed in isolated organ baths. Contractile function was measured in response to increasing concentrations (10(-9)-10(-5) mol) of 5-hydroxytryptamine and noradrenaline. This was calculated as a percentage of the maximum contractile response to 90 mM KCl measured in millinewtons (mN) (control 41.4 +/- 12.1, (n = 11), open technique 35.8 +/- 11.1, (n = 11), Mayo stripper 33.7 +/- 15.9, (n = 11)). The endothelial dependent and independent function was assessed with acetylcholine and sodium nitroprusside, respectively.

RESULTS

There was no significant difference in response to both constrictors and dilators between vein taken with the Mayo stripper compared with the traditional open technique (n = 6 for each observation; P > 0.05 by ANOVA). Histological examination by light microscopy of the vessel segments removed with the Mayo stripper was unable to show any significant damage to the vessel wall. Both functional and morphological studies were conducted by 'blinded' observers. One-year follow-up with magnetic resonance angiography (MRA) and stress thallium tomography demonstrated a patency rate with lower and upper estimates of 80 and 94%.

CONCLUSIONS

We have shown that harvesting the long saphenous vein with a Mayo stripper does not compromise vascular reactivity of the long saphenous vein or long-term patency.

Frequency, manifestations, and correlates of impaired healing of saphenous vein harvest incisions

OBJECTIVE

To describe the frequency, manifestations, and correlates of impaired healing of saphenous vein (SV) harvest incisions in hospitalized patients who had undergone coronary artery bypass grafting (CABG).

DESIGN

Prospective, descriptive, correlational.

SETTING

West Coast university-affiliated medical center.

PATIENTS

Thirty-two English-speaking adults who had undergone CABG.

OUTCOME MEASURES

Impaired wound healing of SV-harvest incisions.

RESULTS

The overall incidence of impaired healing was 43.8%. The most frequent manifestations of impaired wound healing at discharge were prolonged erythema (8/32), prolonged drainage (8/32), and both prolonged erythema and drainage (2/32). Correlates of impaired healing of SV-harvest incisions were body mass index (product-moment correlation = 0.39, p = 0.026) and preoperative use of diuretics (point biserial correlation = 0.42, p = 0.016).

CONCLUSIONS

Impaired healing of SV-harvest incisions in this sample occurred more frequently than previously indicated in the literature. Although severe wound infections were infrequent, a high degree of impaired healing occurred (43.8% of patients who had undergone CABG). Future studies need to explore the long-term effects of impaired healing and test interventions to mitigate impaired healing in this population.

Randomized, prospective comparison of first- and second-generation cephalosporins as infection prophylaxis for cardiac surgery

Surgical wound infections after cardiovascular surgery may be life threatening and are resource intensive. Second-generation cephalosporins are purported to have a broader antimicrobial spectrum than first-generation cephalosporins and, therefore, may be more efficacious for infection prophylaxis. We have conducted a randomized prospective study of 702 patients undergoing open heart surgery to test the hypothesis that the second-generation cephalosporin, cefuroxime, will be more efficacious for infection prophylaxis than the first-generation cephalosporin, cefazolin. Patients were randomized to receive cefazolin 1 g intravenously every 8 hours for 48 hours begun 1 hour preoperatively plus 1 g after 4 hours of surgery (8 doses, n = 425) or cefuroxime 1.5 g 1 hour prior to surgery plus 1.5 g every 12 hours for 3 additional doses (4 doses, n = 277). Infection was defined as a draining wound with or without a positive culture. There was no difference in the wound infection rate between the groups (p = 0.68). Chest wound infections occurred in 2.1% of patients treated with cefazolin and 2.9% of patients treated with cefuroxime (p = 0.79). The rate of true mediastinitis requiring exploration and drainage was 0.7% in both groups (p = 0.084). Leg infections occurred in 6.6% of cefazolin-treated patients and 5.6% of cefuroxime-treated patients (p = 0.83). The second-generation cephalosporin, cefuroxime, did not reduce the incidence of wound infection when compared with the first-generation cephalosporin, cefazolin. Since institutional antibiotic acquisition and administration costs vary, careful analysis of these factors will allow determination of the most cost-effective infection prophylaxis regimen in cardiac surgery.

Infection following coronary artery surgery. Comparison of two antibiotic prophylaxis regimens

A prospective randomized study was conducted in 200 patients undergoing coronary artery bypass surgery. All patients received intravenous (IV) cephalothin prophylaxis for 48 hours beginning with anesthetic induction. Group A (99 eligible patients) received cephalexin 500 mg po, qid for three extra days. Group B (94 eligible patients) received no oral therapy. The overall infection rate was 9.3 percent (18 patients). Six patients had multiple sites of involvement. There was no difference between group A (9.0 percent, nine patients) vs B (9.5 percent, nine patients) (p greater than 0.5). The median sternotomy infection rate, superficial or deep, was 2.6% (five patients). The surgical wound infection rate was 4.7 percent (nine patients). The overall infection rate compares favorably with that of high risk groups for clean surgical procedures defined in SENIC study. There was no advantage to prolonged oral cephalexin prophylaxis following coronary artery bypass (CAB) surgery.

Families in which two or more cot deaths have occurred

A survey of twelve families with 2 or more cot deaths showed that in two families the deaths were completely unexplained; in three the babies had a probably familial developmental disorder; in two the care of the infants was seriously at fault and could have contributed to death; and in five filicide was probable. 3 of the mothers in the last group were psychologically ill. Detailed pathological and psychosocial investigations are needed in dealing with these deaths and in planning the care of future children.

Single-dose antimicrobial prophylaxis in open heart surgery

A single one-gram pre-operative dose of ceftriaxone was compared with seven one-gram doses of cefazolin administered peri-operatively with the aim of preventing infections associated with coronary artery bypass graft surgery. Ninety-four evaluable cases were analyzed; 49 patients received ceftriaxone and 45 received cefazolin. There was no significant difference in the number of infectious complications between the two groups. Ceftriaxone had a terminal half-life of approximately 15.7 hours. There was no toxicity associated with either antibiotic. Because of the reduced number of doses, single-dose prophylaxis may result in considerable savings. Single-dose prophylaxis with ceftriaxone was found to be an effective modality for prevention of infection in open heart surgery.