Does bilateral internal thoracic artery harvest increase the risk of mediastinitis?

Date First Published:
November 28, 2007
Last Updated:
April 16, 2008
Report by:
Ioannis K. Toumpoulis, Nikolaos Theakos, and Joel Dunning, Specialist Registrars in Cardiothoracic Surgery (Department of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Evangelismos General Hospital, Athens, Greece)
Search checked by:
Joel Dunning RCS, Department of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Evangelismos General Hospital, Athens, Greece
Three-Part Question:
In [patients who undergo coronary artery bypass grafting] does [bilateral internal thoracic artery grafting] increase the risk of [mediastinitis]?
Clinical Scenario:
You are seeing a 60-year-old man who has been referred for multivessel coronary artery bypass grafting (CABG). He is an insulin-treated diabetic with a body mass index of 27 and no previous myocardial infarction. His father also died of a heart attack when he was 65 years old. You tell him that the grafts with the best long-term patency are the internal thoracic arteries. You would like to perform CABG using bilateral internal thoracic arteries (BITA) and a vein graft. You inform the patient that this configuration of the procedure carries higher risk for mediastinitis, which is associated with about 20% in-hospital mortality and higher long-term mortality [Toumpoulis]. He is not that keen on the idea and asks if there are any other configurations that could have the same long-term results without the risks of mediastinitis. You wonder whether BITA would be performed in diabetics with low risk of mediastinitis
Search Strategy:
Medline 1995 – July 2007 using the OVID interface.
Search Details:
[Coronary artery bypass OR CABG OR aortocoronary bypass OR off-pump bypass OR on-pump bypass.mp] AND [Internal thoracic OR internal mammary.mp] AND [double OR bilateral] AND [Mediastinitis OR deep sternal OR sternal infection OR chest infection OR surgical site infection.mp].
Outcome:
One hundred and forty papers were found in Medline. Twenty-four were deemed to be relevant. The papers are documented in the table
Relevant Paper(s):
Study Title Patient Group Study type (level of evidence) Outcomes Key results Study Weaknesses
Risk factors for deep sternal wound infection after sternotomy: a prospective, multicenter study. The Parisian Mediastinitis group. 1996, France CABG (n=960). BITA (n=126) Deep sternal wound infection 3.3% deep sternal wound infection. BITA was an independent predictor (OR 4.78, 95% CIs 1.36–16.7, P=0.01) No randomized, not double-blind. No evaluation of pedicled and skeletonized BITA
Superficial and deep sternal wound complications: incidence, risk factors and mortality. Ridderstolpe L, Gill H, Granfeldt H et al. 2001, Sweden Cardiac surgery (n=3008). CABG (n=2108). BITA (n=87) Deep sternal infection/mediastinitis BITA was an independent predictor for deep sternal infection/mediastinitis (OR 4.23, 95% CIs 1.71–10.51, P=0.002) Retrospective study. No propensity matching. Not only CABG patients analyzed
Sternal wound complications – incidence, microbiology and risk factors. Stahle E, Tammelin A, Bergstrom R et al. 1997, Sweden CABG patients (n=9989) Mediastinitis 1.7% mediastinitis after CABG. BITA was an independent predictor (OR 3.3, 95% CIs 1.1–7.7) Retrospective study. No evaluation of pedicled and skeletonized BITA
Does bilateral internal thoracic artery grafting increase long-term survival of diabetic patients. Toumpoulis IK, Anagnostopoulos CE, Balaram S et al. 2006 USA Diabetics. Comparison of propensity matched BITA (n=490) with SITA (n=490) Deep sternal wound infection 3.3% vs. 1.2% deep sternal wound infection in BITA vs. SITA (P=0.05) Retrospective study. No evaluation of pedicled and skeletonized BITA
Off-pump coronary artery bypass grafting with skeletonized bilateral internal thoracic arteries in insulin-dependent diabetics. Kai M, Hanyu M, Soga Y et al. 2007 Japan Insulin-dependent diabetics. Off-pump CABG with skeletonized BITA (n=162) vs on-pump CABG with pedicled BITA (n=23) Deep sternal infection 0.6% vs. 13.0% deep sternal infection in off-pump vs. on-pump (P=0.01) Small sample size. Retrospective study. No propensity matching
Skeletonization of bilateral internal thoracic artery grafts lowers the risk of sternal infection in patients with diabetes. Peterson MD, Borger MA, Rao V et al. 2003 Canada Diabetics. Skeletonized BITA (n=79) vs. nonskeletonized BITA (n=36). Deep sternal wound infection 1.3% vs. 11.1% deep sternal wound infection in skeletonized BITA vs. non-skeletonized BITA (P=0.03) Small sample size. Retrospective study. No propensity matching
Mediastinitis after coronary artery bypass graft surgery: influence of the mammary grafting for diabetic patients. Tavolacci MP, Merle V, Josset V et al. 2003 France CABG in diabetics (n=256). BITA (n=79) Mediastinitis 1.7% vs. 10.1% mediastinitis in SITA vs. BITA (P<0.001). BITA was independent predictor for mediastinitis (OR 5.97, 95% CIs 1.63–21.93, P=0.004) Small sample size. Retrospective study. No propensity matching
Bilateral versus unilateral internal mammary revascularization in patients with diabetes. Endo M, Tomizawa Y, Nishida H. 2003 Japan Non-diabetics: SITA (n=411) vs. skeletonized BITA (n=253).
Diabetics: SITA (n=277) vs. skeletonized BITA (n=190)		 Deep sternal wound infection 0.2% vs. 0.4% deep sternal wound infection in non-diabetics with SITA vs. BITA (P=0.99). 1.1% vs. 0.5% deep sternal wound infection in diabetics with SITA vs. BITA (P=0.65) Small sample size. Retrospective study. No propensity matching
Influence of bilateral skeletonized harvesting on occurrence of deep sternal wound infection in 1,000 consecutive patients undergoing bilateral internal thoracic artery grafting. Pevni D, Mohr R, Lev-Run O et al. 2003 Israel Skeletonized BITA (n=1000). Diabetics (n=304) Deep sternal wound infection 2.2% deep sternal wound infection. Diabetes was not an independent predictor Retrospective study. No control group
Bilateral versus single internal thoracic artery grafting in oral-treated diabetic subsets: comparative seven-year outcome analysis. Lev-Ran O, Braunstein R, Nesher N et al. 2004 Israel Diabetics (oral-treated). BITA (n=228) vs. SITA (n=57) Deep sternal wound infection 1.8% vs. 1.8% deep sternal wound infection in BITA vs. SITA (P=0.999) Small sample size. Retrospective study. No propensity matching
Bilateral internal thoracic artery grafting in diabetic patients: short-term and long-term results of a 515-patient series. Lev-Ran O, Mohr R, Pevni D et al. 2004 Israel Diabetics with skeletonized BITA (n=515). Oral-treated (n=468) and insulin-treated (n=47). In situ BITA was compared to T-grafting Deep sternal infections 1.9% vs. 4.3% deep sternal infection in oral-treated vs. insulin-treated. 1.9% vs. 2.3% deep sternal infection in patients with in situ skeletonized BITA vs. T-graft skeletonized BITA (P=0.999) Small sample size. Retrospective study. No propensity matching
Skeletonized internal thoracic artery harvest reduces pain and dysesthesia and improves sternal perfusion after coronary artery bypass surgery: a randomized, double-blind, within-patient comparison. Boodhwani M, Lam BK, Nathan HJ et al. 2006 Canada BITA (n=48) randomized to receive 1 skeletonized and 1 nonskeletonized
Randomized, double blind, within patient comparison study		 Postanastomotic flow, sternal perfusion No significant different postanastomotic flows (p=0.16). Increased sternal perfusion with skeletonized BITA (p=0.03) Small sample size. No comparison between groups with only skeletonized BITA vs only pedicled BITA. No evaluation of deep sternal wound infection
Influence of diabetes and bilateral internal thoracic artery grafts on long-term outcome for multivessel coronary artery bypass grafting. Stevens LM, Carrier M, Perrault LP et al. 2005 Canada Non-diabetics: SITA (n=2079) vs. BITA (1594). Diabetics: SITA (n=419) vs. BITA (n=214) Deep sternal wound infection 1.2% vs. 1.2% deep sternal wound infection in non-diabetics with SITA vs. BITA. 2.2% vs. 1.4% deep sternal wound infection in diabetics with SITA vs. BITA Retrospective study. No propensity matching
Incidence of sternal infection in diabetic patients undergoing bilateral internal thoracic artery grafting. Momin AU, Deshpande R, Potts J et al. 2005 UK Insulin-dependent diabetics. SITA (n=166) vs. BITA (n=95) Deep sternal wound infection, sternal dehiscence 1.2% vs. 3.2% deep sternal infection in SITA vs. BITA (P=0.27). 1.2% vs. 3.2% sternal dehiscence in SITA vs. BITA (P=0.27) Small sample size. Retrospective study
Routine use of bilateral skeletonized internal thoracic artery grafts in middle-aged diabetic patients. Bical OM, Khoury W, Fromes Y et al. 2004 France Patients <70 years. Diabetics BITA (n=164) vs. non-diabetics BITA (n=548) Deep sternal wound infection 1.1% vs. 1.2% deep sternal wound infection in BITA diabetics vs. non-diabetics (P=NS) Small sample size. Retrospective study. No propensity matching
Multivariate analysis of risk factors for deep and superficial sternal infection after coronary artery bypass grafting at a tertiary care medical center. Crabtree TD, Codd JE, Fraser VJ et al. 2004 USA CABG patients (n=4004). Deep sternal wound infection (n=73) Superficial and deep sternal wound infection 1.8% deep and 2.2% superficial sternal wound infection respectively. BITA was an independent predictor for superficial sternal wound infection (OR 7.55, 95% CIs 3.18–17.94, P<0.001) Retrospective study. No evaluation of pedicled and skeletonized BITA
Bilateral pedicled internal thoracic artery grafting. Ura M, Sakata R, Nakayama Y et al. 2002 Japan Pedicled BITA (n=558). Diabetics (n=143) Mediastinitis 1.3% mediastinitis rate. 2.1% mediastinitis in diabetics. Diabetes was not an independent predictor for mediastinitis Small sample size. Retrospective study. No control group
The effect of bilateral internal thoracic artery harvesting on superficial and deep sternal infection: the role of skeletonization. De PR, de NS, Scaffa R, Nardella S et al. 2005 Italy SITA (n=450) vs. pedicled BITA (n=300) vs. skeletonized BITA (n=150) Deep sternal infection 1.1% vs. 3.3% vs. 4.7% deep sternal infection in SITA vs. skeletonized BITA vs. pedicled BITA (P=0.01) Retrospective study. No propensity matching
The impact of deep sternal wound infection on long-term survival after coronary artery bypass grafting. Toumpoulis IK, Anagnostopoulos CE, DeRose JJ Jr et al. 2005 USA CABG patients (n=3760). BITA (n=2076). Deep sternal wound infection (n=40) Deep sternal wound infection 1.4% vs. 0.7% deep sternal wound infection in BITA vs. non-BITA. BITA was an independent predictor for deep sternal wound infection (OR 2.6, 95% CIs 1.3–5.3, P=0.01) Retrospective study. No evaluation of pedicled and skeletonized BITA
Outcomes in single versus bilateral internal thoracic artery grafting in coronary artery bypass surgery. Walkes JC, Earle N, Reardon MJ et al. 2002 USA SITA (n=911) vs. BITA (n=158) Mediastinitis 2.0% vs. 4.4% mediastinitis in SITA vs. BITA (P=0.06) Small sample size. Retrospective study. No propensity matching
Author Commentary:
Mediastinitis (or deep sternal wound infection) is an infrequent, yet potentially devastating complication after CABG, which is associated with increased cost of care, prolonged hospitalization, and increased morbidity and mortality. The reported incidence of mediastinitis range from 1.3% to 4.7% in patients with BITA grafting [2–6] and indeed BITA has been shown to be an independent predictor for mediastinitis with an odds ratio ranging from 2.6 to 4.8 [7–11]. Furthermore, in diabetic patients undergoing CABG the use of BITA has been associated with higher percentages of mediastinitis which can be as high as >10% [12–14].

There is a subgroup of patients in whom skeletonized BITA was used with lower rates of mediastinitis. Skeletonized use of BITA has been associated with mediastinitis ranging from 0.4% to 2.6% in the whole context of CABG [15–17] and from 0.5% to 3.3% in diabetic patients [4, 15, 16, 18, 19]. The beneficial effect of BITA skeletonization with respect to reduced rates of mediastinitis can be attributed to the statistically significant increased sternal perfusion with skeletonized BITA compared to pedicled BITA. This was shown clearly in a randomized, double-blind within-patient comparison study, in which patients were randomized to receive one skeletonized and one pedicled internal thoracic artery graft [20].
Bottom Line:
In general, the use of pedicled BITA grafts carries increased risk for mediastinitis after CABG and this is even higher among diabetic patients, thus rendering many surgeons reluctant in using BITA grafting in this subgroup of patients. However, the use of skeletonized BITA grafts can reduce this risk and both non-diabetics and diabetics can be operated on without increased risk of mediastinitis. The current available evidence shows that skeletonized BITA grafting can be safely applied in almost every patient. All cardiac surgeons should be trained efficiently in using skeletonized BITA.
References:
  1. The Parisian Mediastinitis group.. Risk factors for deep sternal wound infection after sternotomy: a prospective, multicenter study.
  2. Ridderstolpe L, Gill H, Granfeldt H et al.. Superficial and deep sternal wound complications: incidence, risk factors and mortality.
  3. Stahle E, Tammelin A, Bergstrom R et al.. Sternal wound complications – incidence, microbiology and risk factors.
  4. Toumpoulis IK, Anagnostopoulos CE, Balaram S et al.. Does bilateral internal thoracic artery grafting increase long-term survival of diabetic patients.
  5. Kai M, Hanyu M, Soga Y et al.. Off-pump coronary artery bypass grafting with skeletonized bilateral internal thoracic arteries in insulin-dependent diabetics.
  6. Peterson MD, Borger MA, Rao V et al.. Skeletonization of bilateral internal thoracic artery grafts lowers the risk of sternal infection in patients with diabetes.
  7. Tavolacci MP, Merle V, Josset V et al.. Mediastinitis after coronary artery bypass graft surgery: influence of the mammary grafting for diabetic patients.
  8. Endo M, Tomizawa Y, Nishida H.. Bilateral versus unilateral internal mammary revascularization in patients with diabetes.
  9. Pevni D, Mohr R, Lev-Run O et al.. Influence of bilateral skeletonized harvesting on occurrence of deep sternal wound infection in 1,000 consecutive patients undergoing bilateral internal thoracic artery grafting.
  10. Lev-Ran O, Braunstein R, Nesher N et al.. Bilateral versus single internal thoracic artery grafting in oral-treated diabetic subsets: comparative seven-year outcome analysis.
  11. Lev-Ran O, Mohr R, Pevni D et al.. Bilateral internal thoracic artery grafting in diabetic patients: short-term and long-term results of a 515-patient series.
  12. Boodhwani M, Lam BK, Nathan HJ et al.. Skeletonized internal thoracic artery harvest reduces pain and dysesthesia and improves sternal perfusion after coronary artery bypass surgery: a randomized, double-blind, within-patient comparison.
  13. Stevens LM, Carrier M, Perrault LP et al.. Influence of diabetes and bilateral internal thoracic artery grafts on long-term outcome for multivessel coronary artery bypass grafting.
  14. Momin AU, Deshpande R, Potts J et al.. Incidence of sternal infection in diabetic patients undergoing bilateral internal thoracic artery grafting.
  15. Bical OM, Khoury W, Fromes Y et al.. Routine use of bilateral skeletonized internal thoracic artery grafts in middle-aged diabetic patients.
  16. Crabtree TD, Codd JE, Fraser VJ et al.. Multivariate analysis of risk factors for deep and superficial sternal infection after coronary artery bypass grafting at a tertiary care medical center.
  17. Ura M, Sakata R, Nakayama Y et al.. Bilateral pedicled internal thoracic artery grafting.
  18. De PR, de NS, Scaffa R, Nardella S et al.. The effect of bilateral internal thoracic artery harvesting on superficial and deep sternal infection: the role of skeletonization.
  19. Toumpoulis IK, Anagnostopoulos CE, DeRose JJ Jr et al.. The impact of deep sternal wound infection on long-term survival after coronary artery bypass grafting.
  20. Walkes JC, Earle N, Reardon MJ et al.. Outcomes in single versus bilateral internal thoracic artery grafting in coronary artery bypass surgery.