Asian Cardiovasc Thorac Ann 2006;14:57-59
© 2006 Asia Publishing EXchange Ltd
Above-Knee Vein Harvest for Coronary Revascularization Increases ASEPSIS Score
Enoch Akowuah, MD,
Vivek Shrivastava, MRCS,
Alan Ponniah, MBChB,
Binal Jamnadas, MBCHB,
Gary Chilton, RGN,
Graham Cooper, FRCS
Department of Cardiothoracic Surgery, Northern General Hospital, Sheffield, United Kingdom
For reprint information contact: Enoch Akowuah, MD Tel: 44 117 942 5628 Fax: 44 175 276 3830 Email: akowuah{at}yahoo.com, Department of Cardiothoracic Surgery, Derriford Hospital, Plymouth PL6 8DH, England, United Kingdom.
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ABSTRACT
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The long saphenous vein may be harvested from the thigh or the lower leg, depending on the operating surgeon’s preference. This prospective study compared the incidence of altered wound healing between these two sites in 175 patients undergoing routine coronary artery bypass grafting over a 3-month period. The patients were divided into 3 groups. In group A, the vein harvest site was restricted to above the upper border of the patella. Group B included harvest sites that started at the ankle but extended above the level of the upper border of the patella. In group C, the vein harvest site was restricted to below the upper border of the patella. The wounds were assessed daily using the ASEPSIS scoring system. In group A, significantly more patients (24%) had an ASEPSIS score > 10, compared to group B (3%) and group C (2%). The mean ASEPSIS score was significantly lower in group C than groups A or B, 1.5 ± 2.4 vs. 6.5 ± 3.2 or 3.7 ± 1.7, respectively. The ASEPSIS score is reduced when vein harvest is restricted to below the level of the knee.
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INTRODUCTION
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Despite an increasing trend towards the use of arterial conduits, the long saphenous vein (LSV) remains the most widely used conduit in coronary artery bypass grafting (CABG). With over 32,000 CABG procedures performed in the United Kingdom each year, leg wound infection has a great impact on morbidity and adds to the cost of the procedure.1 The LSV may be dissected free starting from either the ankle or the thigh, depending on the preference of the operating surgeon. LSV dissected from the thigh may be of a larger caliber; however, it involves working closer to the perineum and requires more tissue dissection as the vein is less superficial. Alternatively, dissecting the LSV from the ankle involves less tissue dissection and may pose a smaller risk of infection. We carried out a prospective observational study comparing leg wound infection rates between these two sites of vein harvest in our unit, using the ASEPSIS scoring system (Additional treatment, the presence of Serous discharge, Erythema, Purulent exudate, and Separation of deep tissues, the Isolation of bacteria, and the duration of inpatient Stay).2,3
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PATIENTS AND METHODS
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The 201 consecutive patients scheduled for routine CABG over a 3-month period from June to August 2002 in our institution were entered into this study. On admission, a wound data leaflet was attached to their case notes. Demographic data and intraoperative variables were recorded prospectively. Twenty-one patients underwent total arterial revascularization and were excluded from the analysis. Four patients were excluded because they had preexisting inflammatory conditions and/or were on immunosuppressive medication. One patient died on the first postoperative day, and was also excluded. The remaining 175 patients were divided into 3 groups for analysis. Group A had LSV harvest sites restricted to above the upper border of the patella. Group B included patients in whom the vein harvest started at the ankle and extended to above the level of the patella. Group C included patients in whom the LSV harvest site was limited to below the upper border of the patella.
All leg wounds were assessed daily during the postoperative period using the ASEPSIS score, by one of two investigators (VS or EA), to reduce observer bias. Wounds were scored for the first 5 postoperative days or until the day of discharge, whichever occurred first. The ASEPSIS scoring system requires daily assessment of the wound for the first 5 postoperative days, checking for the presence of serous exudate, erythema, purulent exudate, and separation of deep tissues. A score ranging from 0–10 was allocated to each of these wound characteristics, according to the proportion of the wound involved. Additional points were scored for surgical debridement, prolonged hospital stay, isolation of bacteria, and antibiotic treatment. The final ASEPSIS score was generated by adding the daily wound characteristic scores to the additional points. The wounds were then categorized: 0–10 satisfactory wound healing, 11–20 altered wound healing, 21–30 mild infection, 31–40 moderate infection, and > 40 severe infection.2–4
Data are expressed as mean ± standard deviation unless stated otherwise Continuous data were compared using one-way ANOVA with a Student-Newman-Keuls post-test. Categorical data were compared using the chi-squared or Fisher’s exact test where appropriate. Statistical significance was set at p < 0.05.
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RESULTS
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The demographic data are listed in Table 1
. The 3 groups were similar with regard to preoperative demographics. Fourteen patients (8%) had an ASEPSIS score greater than 10 (Table 2). Of these, 11 had a score of 11–20, 2 had a score of 21–30, and 1 had a score of 31–40 points. No patient had a score > 40. Comparison of ASEPSIS scores between the sites of LSV harvest revealed that significantly more (24%) patients who had the LSV harvested from above the level of the knee (group A) had an ASEPSIS score > 10 (Table 2). Patients in group A had a significantly higher mean ASEPSIS score than those in whom the incision was limited to below the knee (6.5 ± 3.23 vs. 1.7 ± 3.66, p = 0.04). Patients in group A were more likely to have a suction drain used to drain the leg wound (p = 0.0001) and a longer leg surgery time (p = 0.001) compared to groups B and C. There were no differences between the groups with regards to the experience of the surgeon harvesting the LSV, aortic crossclamp time, duration of cardiopulmonary bypass, or total duration of the operation (Table 2).
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DISCUSSION
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Previously reported rates of LSV infection vary from 2.9% to 32%.5–7 This depends on the definition of wound infection, duration of postoperative follow-up, and patient demographics. Most available published data are retrospective and do not use an objective score for wound infection, and therefore, may underestimate the incidence of altered wound healing. The ASEPSIS score enabled us to objectively assess the leg wounds in this study and also to reduce interobserver bias.
In this prospective cohort study, patients in whom the saphenous vein was harvested from the thigh had a significantly higher ASEPSIS score than those in whom the incision was limited to below the level of the knee. This finding may be due to the close proximity of the wound to the groin, the greater dissection required for harvesting the vein, and the longer time to close a wound at this site. In contrast, minimally invasive LSV harvest techniques, which involve minimal tissue dissection, have been shown to reduce leg wound infection and postoperative pain.8,9 Patients in group A were more likely to have a suction drain used at the wound site, and this may have contributed to the higher ASEPSIS score in this group.
Interestingly, the seniority of the surgeon harvesting the LSV vein did not appear to have an affect on the ASEPSIS score. The majority of LSV grafts (78%) were harvested by the more skilled Cardiac Surgical Assistant. Possibly, the incidence of altered wound healing in this study might have been higher if a greater proportion of grafts were harvested by a less skilled trainee.
The major limitation of this study is the fact that patients were not randomized into the groups. However, the groups were evenly matched in terms of demographic characteristics, in particular, body mass index. Another limitation was the use of drains in the wound. Significantly more patients in group A required a suction drain than in the other two groups. Whilst there is a theoretical possibility that drains may increase the risk of infection, our experience was that suction drainage actually decreased the ASEPSIS score due to a decrease in the presence of serous exudates.
This study concentrated on wound infection in hospital, but it is well recognized that late infections occurring after hospital discharge may also be a significant cause of morbidity after CABG.5 Nevertheless, this study suggests that LSV harvest should be limited to sites below the knee as much as possible.
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REFERENCES
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- Kollef MH, Vlasnik J, Sharpless L, Pasque C, Murphy D, Fraser V. The impact of nosocomial infections on patient outcomes following cardiac surgery. Chest 1997;112:666–75.[Medline]
- Wilson AP, Weavill C, Burridge J, Kelsey MC. The use of the wound scoring method ‘ASEPSIS’ in postoperative wound surveillance. J Hosp Infect 1990;16:297–309.[Medline]
- Wilson AP, Treasure T, Sturridge MF, Gruneberg RN. A scoring method (ASEPSIS) for postoperative wound infections for use in clinical trials of antibiotic prophylaxis. Lancet 1986;1(8476):311–3.[Medline]
- Wilson AP, Webster A, Gruneberg RN, Treasure T, Sturridge MF. Repeatability of ASEPSIS wound scoring method. Lancet 1986;1(8491):1208–9.[Medline]
- Garland R, Frizelle FA, Dobbs BR, Singh H. A retrospective audit of long-term lower limb complications following leg vein harvesting for coronary artery bypass grafting. Eur J Cardiothorac Surg 2003;23:950–5.[Abstract/Free Full Text]
- Paletta CE, Huang DB, Fiore AC, Swartz MT, Rilloraza FL, Gardner JE. Major leg wound complications after saphenous vein harvest for coronary revascularization. Ann Thorac Surg 2000;70:492–7.[Abstract/Free Full Text]
- Mullen J, Bentley MJ, Mong K, Karmy-Jones R, Lemermeyer G, Gelfand ET, et al. Reduction of leg wound infections following coronary artery bypass surgery. Can J Cardiol 1999;15:65–8.[Medline]
- Black EA, Campbell RK, Channon KM, Ratnatunga C, Pillai R. Minimally invasive vein harvesting significantly reduces pain and wound morbidity. Eur J Cardiothorac Surg 2002;22:381–6.[Abstract/Free Full Text]
- Schurr UP, Lachat ML, Reuthebuch O, Kadner A, Mader M, Seiffert B, et al. Endoscopic saphenous vein harvesting for CABG—a randomized prospective trial. Thorac Cardiovasc Surg 2002;50:160–3.[Medline]
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Endoscopic vs open saphenous vein harvest for coronary artery bypass grafting: a prospective randomized trial.
Eur. J. Cardiothorac. Surg.,
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34(2):
384 - 389.
[Abstract]
[Full Text]
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ABSTRACT
INTRODUCTION
