- Research article
- Open Access
- Open Peer Review
Reduction in deep sternal wound infection with use of a peristernal cable-tie closure system: a retrospective case series
© Stelly et al. 2015
- Received: 12 October 2015
- Accepted: 8 November 2015
- Published: 14 November 2015
Deep sternal wound infections are a rare but serious complication after median sternotomy. We evaluated the incidence of deep sternal wound infection associated with two techniques for sternal closure.
In this retrospective case series, we recorded the method of sternal closure in consecutive patients undergoing a variety of cardiothoracic surgical procedures. Sternal closure in the historical control group was performed using trans-sternal, stainless-steel wire sutures; subsequent patients were closed using wire sutures in conjunction with a novel, peristernal cable-tie closure system to reinforce the corpus sterni. Perioperative care was standardized between groups. Demographics, risk factors, and postoperative outcomes were analyzed.
Between July 2010 and July 2014, 609 consecutive adult patients underwent sternal closure following open median sternotomy at a single hospital in Mobile, Alabama. Sternal closure was accomplished with wire sutures in the first 309 patients and with cable-tie reinforcement in the subsequent 300 patients. Baseline characteristics were comparable between groups, except that the cable-tie group exhibited greater preoperative comorbidity. Mean body mass index was comparable between groups (30.2 ± 6.6 kg/m2 wire suture versus 30.5 ± 7.7 cable-tie, p = 0.568). Deep sternal wound infection occurred in 2.6 % (8/309) patients in the wire-suture group, whereas no deep sternal wound infections were observed in the cable tie group (p = 0.008).
The peristernal cable-tie system was a simple and reliable method for sternal closure after open median sternotomy, and was associated with a reduced risk of deep sternal wound infection, even in an obese and comorbid population.
- Surgical equipment
Despite the increasing use of minimally invasive approaches, the majority of cardiac operations are still performed by way of a median sternotomy . In our practice, this is the most common operative approach for adult cardiac procedures because it is easily and expeditiously performed and provides excellent exposure.
Although post-sternotomy complications are rare, the occurrence of a deep sternal wound infection (DSWI) can be catastrophic, with reported mortality rates between 19 and 29 % . Despite modern prophylactic measures, the reported incidence of DSWI persists at between 0.8 and 6.0 % [3–8].
DSWI is associated with multiple risk factors, including obesity, pulmonary disease, diabetes mellitus, renal failure, advanced age, malnutrition, osteoporosis, and bilateral internal thoracic arterial harvest [3, 6, 9–15]. Postoperative complications, such as the low cardiac output syndrome, respiratory failure, and re-exploration for postoperative hemorrhage, have also been shown to contribute to higher incidence of DSWI [16–19]. Effective strategies for reducing the risk of DSWI include appropriately timed and dosed administration of intravenous antibiotic medications, optimal aseptic/antiseptic skin preparation, avoidance of shaving, and intranasal administration of mupricion [10, 20–22]. Intensive perioperative glucose control has also been proposed to decrease DSWI in patients undergoing coronary artery bypass (CABG) procedures, although the precise targets and appropriate subpopulations remain a matter of debate .
Another potential risk factor for DSWI is sternal wound instability, which has been reported to compromise wound integrity and predispose patients to infection [23–25]. However, the relationship between this instability, DSWI, and emerging methods for sternal closure after median sternotomy remains to be explored.
Our practice has historically relied on the placement of a series of parasternal stainless steel wire sutures to coapt the sternum at multiple points from the manubrium sterni to the most caudal portion of the corpus sterni. In 2012, we adopted the use of a novel, polyether ether ketone (PEEK) based, parasternal cable-tie closure system to replace the wire-suture closure at the corpus sterni. This portion of the sternum has been shown to be more fragile and more subject to potentially disruptive forces during patient recovery than the more cephalad portions of the sternum . We hypothesized that the presence of the wide cable ties would help to stabilize the corpus sterni during healing, reducing the risk of DSWI. The present retrospective chart review was designed to determine whether the change in our technique affected the incidence of DSWI in our practice.
The protocol for this retrospective chart review was approved by the institutional review board at Springhill Medical Center (Mobile, Alabama). Individual informed consent was waived.
Patients and data collection
Hospital and office charts were reviewed for all consecutive adult patients who underwent sternal closure after primary or repeat median sternotomy for cardiothoracic procedures at Springhill Medical Center during the study period. Data regarding demographics, risk factors, intraoperative variables, sternal closure method, and postoperative outcomes were recorded.
Patient preparation and perioperative antibiotic medications
All patients received a shower with 2 % chlorhexidine gluconate (CareFusion Corporation, San Diego, CA), along with 2 % mupirocin ointment to both nostrils, on the evening prior to and the morning of the operation. Removal of excess hair from sternum, groin, and bilateral hind limbs (circumferential) was performed with clippers in the operating room. Chlorhexidine gluconate (2 % in 70 % isopropyl alcohol; ChloraPrep, CareFusion Corporation) was applied topically as a skin disinfectant. Bio drapes (Medline Industries, Inc., Mundelein, IL) and disposable paper drapes were then applied sequentially.
All patients received perioperative antibiotic medications according to the following protocol: All patients received intravenous cefazolin timed to be completed 30 minutes prior to skin incision (2.0 g for less than 80 kg body weight, 3.0 g for 60 to 109 kg, and 3.5 g for 110 to 124 kg, 4.0 g for greater than 124 kg.) An additional 1.0 gram was given just prior to initiation of cardiopulmonary bypass, and one half the loading dose was given every 3 hours thereafter while on bypass. Off-pump cases or bypass cases lasting less than 3 hours did not receive additional antibiotic. In the case of penicillin allergy, patients with preoperative hospital stays of greater than 3 days or patients undergoing valve procedures received a weight-based intravenous vancomycin protocol (1.0 g for less than 80 kg body weight, 1.25 g for 80 to 99 kg, 1.5 g for 100 or more kg) with gentamycin (4.0 mg/kg) single dose, timed to be completed 30 min prior to skin incision. If surgery was delayed for more than 2 hours, an additional single dose of levofloxacin (500 mg) was administered. Patients were re-dosed with one half the original Vancomycin dose at cessation of bypass. Mupirocin was administered to the nares of all patients before leaving the operating room.
Postoperative follow-up and diagnosis of DSWI
Postoperative care was according to each patient’s primary indication for surgery. After discharge all patients returned for follow-up at 2 weeks, 2 months, and quarterly thereafter. DSWI was diagnosed according to US Centers for Disease Control and Prevention criteria . Any patient exhibiting symptoms of DSWI underwent computed tomography imaging of the chest and plastic surgery consultation. The wounds were managed by formal sternal debridement and placement of a negative pressure therapy device (V.A.C, KCI, Inc, San Antonio, TX), with subsequent muscle flap closure once the septic process was controlled.
Body mass index was calculated from height to weight data. Patient data were analyzed using SAS software, version 9.2.2. Data are expressed as mean ± standard deviation, n/N (%), or median (minimum-maximum) unless otherwise noted. Significance testing was performed by an independent biostatistician, using a Two-Sample T-test for comparisons between groups (continuous data), either a Chi-square test or a Fisher’s exact test for homogeneity between groups (categorical data), or Wilcoxon Rank-Sum test when median (range) was presented. Alpha was defined as 0.05 for all tests. The primary outcome for this study was the incidence of DSWI in the two groups, and the null hypothesis was that no difference would be observed.
Between July 2010 and July 2014, sternal incisions were performed on 611 patients at Springhill Medical Center in Mobile, Alabama. Two patients who died intraoperatively were not closed and were therefore excluded from the analysis. A total of 309 patients were closed with the wire suture technique and served as the historical control group, and 300 were closed with the cable-tie system. One of the authors (TCS) performed 71.8 % (222/309) of the wire suture procedures and 92.7 % (278/300) of the cable-tie procedures; the others were performed by a single other partner in his practice. No patients were lost to follow-up. Follow-up evaluation ranged from 21 days to 4 years 5 months, with a median follow-up of 26.6 months.
Summary of baseline and preoperative characteristics for 609 patients undergoing standard median sternotomya
Total population (N = 609)
Standard wire suture (N = 309)
Cable-tie closure (N = 300)
64.8 ± 11.4
64.3 ± 10.8
65.3 ± 11.9
30.4 ± 7.2
30.2 ± 6.6
30.5 ± 7.7
Intraoperative variables for 609 patients undergoing standard median sternotomya
Total population (N = 609)
Standard wire suture (N = 309)
Cable-tie closure (N = 300)
CPB time, min
Operative time, min
Deep sternal wound infections
The incidence of DSWI in the historical control group was 2.6 % (8 of 309 patients). No DSWI was observed in the experimental group (p = 0.008).
Secondary outcomes and adverse events
Secondary outcomes and adverse events in 609 patients after sternal closure with standard wire suture or cable-tie systema
Total population (N = 609)
Standard wire suture (N = 309)
Cable-tie closure (N = 300)
Return to operating room
Re-exploration for bleeding
Postoperative blood loss, first 18 hours, L
Superficial sternal wound infection
Ventilation time, days
Length of ICU stay, days
Length of hospital stay, days
Devices that provide rigid or otherwise secure osseous and soft-tissue coaptation and fixation have been shown to promote earlier union and primary healing . These are especially important in the caudal half of the corpus sterni, where physiologic forces have been shown to distract disproportionately. Using human cadavers, McGregor and colleagues observed that intrapleural pressure can exceed 300 mmHg during a cough , meaning that a force of 150 N (150 kg-m/s2) could routinely be experienced across the sternum during normal physiologic conditions. Divided evenly across the standard 6 twisted stainless steel monofilament wire suture closure, this force exceeds the 20 to 22 N associated with wire fatigue, fracture, loosening, or cutting into sternal bone. They also observed that the caudal end of the corpus sterni was most vulnerable, as it was thinner than the manubrium sterni and lacked clavicular support.
The ideal material for sternal closure and fixation would be simple, inexpensive, reproducible, durable, would provide adequate support to the caudal portion of the corpus sterni, and would allow for rapid reentry in the event of emergent re-exploration. While many techniques for sternal fixation have been tried, each has had its limitations, and stainless steel monofilament wire suture remains the current standard of care. For example, rigid-plate fixation has been demonstrated to be structurally superior to wire suture closure, but adds operative time and costs and is problematic during emergent re-entry [26, 27]. Wider configurations of various suture materials have also been tried, based on the hypothesis that a larger suture surface area would allow more favorable distribution of distracting forces and better stabilization compared to wires. Polyethylene terephthalate ribbon, jacketed steel wires, and steel bands have been tried but have not been widely adopted, possibly because of the complexity of application [16, 19, 28, 29]. Nylon bands are associated with an increased incidence of DSWI [30, 31].
The PEEK-based cable ties used in the present study are wider than monofilament wire suture (4.2 mm versus 0.7 mm) and may provide additional support by providing a larger surface area for osseous contact. We found the ties to be simple to deploy and their cost was relatively inexpensive at less than $100 per tie.
In a retrospective, non-inferiority study of sternal closure in 680 patients, the reported incidence of DSWI was 6 % in the total population, and was comparable in both the cable-tie and standard-of-care groups (n = 95 and 498, respectively) [32, 33]. While the results showed that the cable tie system adequately stabilized the sternum, the study was not designed or adequately powered to determine superiority. Our study, while not a prospective, randomized trial, does include more balanced distribution of patient groups and was designed to reduce the potentially confounding selection bias that limited the previous studies.
It is of interest to note that our results found lower incidence of DSWI in the cable-tie group, even though both groups had similar BMI scores that were high compared to the national average. Obesity is known to increase the risk of postoperative wound infections, although the exact mechanisms are not well understood and may include hypovascularity of adipose tissue, decreased oxygen tension, compromised collagenization, compromised immunity, oxidative stress, and adiponectin deficiency [34–38]. The cable-tie group was also generally a more comorbid population, which might have been expected to predispose them to DSWI.
This study was limited by its retrospective design and the potential for a time effect since the control group was operated on first. Follow-up times were relatively short for some patients in the cable tie group, but it should be noted that DSWI typically manifests within 2 weeks postoperatively and this is well within the minimum follow-up time reported. Additionally, since wire sutures and cable ties were used together, we are unable to draw conclusions about the efficacy and safety of the cable ties as a standalone method for sternal fixation.
We conclude that the cable-tie closure system, when used in conjunction with wire sutures, is a simple and reliable method for coapting the corpus sterni after median sternotomy. Our results also suggest that use of the cable ties for this purpose may reduce the risk of DSWI compared to wire sutures alone.
An educational grant from DePuy Synthes CMF (West Chester, PA) funded the costs of data collection, statistical analysis, and manuscript preparation. The authors thank Amy Hendrix RN and Melissa Vandenberg, PA-C for assistance with data collection; Mark Jaros PhD (Summit Analytical, Denver, CO) for biostatistical analysis; and Jeanne McAdara-Berkowitz PhD (Biolexica, Longmont, CO) for editorial assistance.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- McGregor WE, Trumble DR, Magovern JA. Mechanical analysis of midline sternotomy wound closure. J Thorac Cardiovasc Surg. 1999;117:1144–50.View ArticlePubMedGoogle Scholar
- Loop FD, Lytle BW, Cosgrove DM, Mahfood S, McHenry MC, Goormastic M, et al. J. Maxwell Chamberlain memorial paper. Sternal wound complications after isolated coronary artery bypass grafting: early and late mortality, morbidity, and cost of care. Ann Thorac Surg. 1990;49:179–86. discussion 186.View ArticlePubMedGoogle Scholar
- Eklund AM, Lyytikainen O, Klemets P, Huotari K, Anttila VJ, Werkkala KA, et al. Mediastinitis after more than 10,000 cardiac surgical procedures. Ann Thorac Surg. 2006;82:1784–9.View ArticlePubMedGoogle Scholar
- Gardlund B, Bitkover CY, Vaage J. Postoperative mediastinitis in cardiac surgery - microbiology and pathogenesis. Eur J Cardiothorac Surg. 2002;21:825–30.View ArticlePubMedGoogle Scholar
- Lu JC, Grayson AD, Jha P, Srinivasan AK, Fabri BM. Risk factors for sternal wound infection and mid-term survival following coronary artery bypass surgery. Eur J Cardiothorac Surg. 2003;23:943–9.View ArticlePubMedGoogle Scholar
- Milano CA, Kesler K, Archibald N, Sexton DJ, Jones RH. Mediastinitis after coronary artery bypass graft surgery. Risk factors and long-term survival. Circulation. 1995;92:2245–51.View ArticlePubMedGoogle Scholar
- Raudat CW, Pagel J, Woodhall D, Wojtanowski M, Van Bergen R. Early intervention and aggressive management of infected median sternotomy incision: a review of 2242 open-heart procedures. Am Surg. 1997;63:238–41. discussion 241.PubMedGoogle Scholar
- Tang AT, Ohri SK, Haw MP. Novel application of vacuum assisted closure technique to the treatment of sternotomy wound infection. Eur J Cardiothorac Surg. 2000;17:482–4.View ArticlePubMedGoogle Scholar
- Borger MA, Rao V, Weisel RD, Ivanov J, Cohen G, Scully HE, et al. Deep sternal wound infection: risk factors and outcomes. Ann Thorac Surg. 1998;65:1050–6.View ArticlePubMedGoogle Scholar
- Bratzler DW, Houck PM. Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project. Clin Infect Dis. 2004;38:1706–15.View ArticlePubMedGoogle Scholar
- Braxton JH, Marrin CA, McGrath PD, Morton JR, Norotsky M, Charlesworth DC, et al. 10-year follow-up of patients with and without mediastinitis. Semin Thorac Cardiovasc Surg. 2004;16:70–6.View ArticlePubMedGoogle Scholar
- Guvener M, Pasaoglu I, Demircin M, Oc M. Perioperative hyperglycemia is a strong correlate of postoperative infection in type II diabetic patients after coronary artery bypass grafting. Endocr J. 2002;49:531–7.View ArticlePubMedGoogle Scholar
- Lipshutz AK, Gropper MA. Perioperative glycemic control: an evidence-based review. Anesthesiology. 2009;110:408–21.PubMedGoogle Scholar
- Ottino G, De Paulis R, Pansini S, Rocca G, Tallone MV, Comoglio C, et al. Major sternal wound infection after open-heart surgery: a multivariate analysis of risk factors in 2,579 consecutive operative procedures. Ann Thorac Surg. 1987;44:173–9.View ArticlePubMedGoogle Scholar
- Toumpoulis IK, Theakos N, Dunning J. Does bilateral internal thoracic artery harvest increase the risk of mediastinitis? Interact Cardiovasc Thorac Surg. 2007;6:787–91.View ArticlePubMedGoogle Scholar
- Johnston RHJ, Garcia-Rinaldi R, Vaughan GD, Bricker D. Mersilene ribbon closure of the median sternotomy: an improvement over wire closure. Ann Thorac Surg. 1985;39:88–9.View ArticlePubMedGoogle Scholar
- Kalush SL, Bonchek LI. Peristernal closure of median sternotomy using stainless steel bands. Ann Thorac Surg. 1976;21:172–3.View ArticlePubMedGoogle Scholar
- Sirivella S, Zikria EA, Ford WB, Samadani SR, Miller WH, Sullivan ME. Improved technique for closure of median sternotomy incision. Mersilene tapes versus standard wire closure. J Thorac Cardiovasc Surg. 1987;94:591–5.PubMedGoogle Scholar
- Soroff HS, Hartman AR, Pak E, Sasvary DH, Pollak SB. Improved sternal closure using steel bands: early experience with three-year follow-up. Ann Thorac Surg. 1996;61:1172–6.View ArticlePubMedGoogle Scholar
- Kluytmans JA, Mouton JW, VandenBergh MF, Manders MJ, Maat AP, Wagenvoort JH, et al. Reduction of surgical-site infections in cardiothoracic surgery by elimination of nasal carriage of Staphylococcus aureus. Infect Control Hosp Epidemiol. 1996;17:780–5.View ArticlePubMedGoogle Scholar
- Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for Prevention of Surgical Site Infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control. 1999;27:97–132. quiz 133.View ArticlePubMedGoogle Scholar
- Nicholson MR, Huesman LA. Controlling the usage of intranasal mupirocin does impact the rate of Staphylococcus aureus deep sternal wound infections in cardiac surgery patients. Am J Infect Control. 2006;34:44–8.View ArticlePubMedGoogle Scholar
- Bitkover CY, Gardlund B. Mediastinitis after cardiovascular operations: a case–control study of risk factors. Ann Thorac Surg. 1998;65:36–40.View ArticlePubMedGoogle Scholar
- Serry C, Bleck PC, Javid H, Hunter JA, Goldin MD, DeLaria GA, et al. Sternal wound complications. Management and results. J Thorac Cardiovasc Surg. 1980;80:861–7.PubMedGoogle Scholar
- Stoney WS, Alford WCJ, Burrus GR, Frist RA, Thomas CSJ. Median sternotomy dehiscence. Ann Thorac Surg. 1978;26:421–6.View ArticlePubMedGoogle Scholar
- Sargent LA, Seyfer AE, Hollinger J, Hinson RM, Graeber GM. The healing sternum: a comparison of osseous healing with wire versus rigid fixation. Ann Thorac Surg. 1991;52:490–4.View ArticlePubMedGoogle Scholar
- Raman J, Lehmann S, Zehr K, De Guzman BJ, Aklog L, Garrett HE, et al. Sternal closure with rigid plate fixation versus wire closure: a randomized controlled multicenter trial. Ann Thorac Surg. 2012;94:1854–61.View ArticlePubMedGoogle Scholar
- Casha AR, Yang L, Kay PH, Saleh M, Cooper GJ. A biomechanical study of median sternotomy closure techniques. Eur J Cardiothorac Surg. 1999;15:365–9.View ArticlePubMedGoogle Scholar
- McGregor WE, Payne M, Trumble DR, Farkas KM, Magovern JA. Improvement of sternal closure stability with reinforced steel wires. Ann Thorac Surg. 2003;76:1631–4.View ArticlePubMedGoogle Scholar
- LeVeen HL, Piccone VA. Nylon-band chest closure. Arch Surg. 1968;96:36–9.View ArticlePubMedGoogle Scholar
- Sanfelippo PM, Danielson GK. Nylon bands for closure of median sternotomy incisions: an unacceptable method. Ann Thorac Surg. 1972;13:404–6.View ArticlePubMedGoogle Scholar
- Grapow MT, Melly LF, Eckstein FS, Reuthebuch OT. A new cable-tie based sternal closure system: description of the device, technique of implantation and first clinical evaluation. J Cardiothorac Surg. 2012;7:59.PubMed CentralView ArticlePubMedGoogle Scholar
- Melly L, Gahl B, Meinke R, Rueter F, Matt P, Reuthebuch O, et al. A new cable-tie-based sternal closure device: infectious considerations. Interact Cardiovasc Thorac Surg. 2013;17(2):219–23.PubMed CentralView ArticlePubMedGoogle Scholar
- Conolly WB, Hunt TK, Sonne M, Dunphy JE. Influence of distant trauma on local wound infection. Surg Gynecol Obstet. 1969;128:713–8.PubMedGoogle Scholar
- Kawai K, Kageyama A, Tsumano T, Nishimoto S, Fukuda K, Yokoyama S, et al. Effects of adiponectin on growth and differentiation of human keratinocytes--implication of impaired wound healing in diabetes. Biochem Biophys Res Commun. 2008;374:269–73.View ArticlePubMedGoogle Scholar
- Pierpont YN, Dinh TP, Salas RE, Johnson EL, Wright TG, Robson MC, et al. Obesity and surgical wound healing: a current review. ISRN Obes. 2014;2014:638936.PubMed CentralPubMedGoogle Scholar
- Shibata R, Ouchi N, Kihara S, Sato K, Funahashi T, Walsh K. Adiponectin stimulates angiogenesis in response to tissue ischemia through stimulation of amp-activated protein kinase signaling. J Biol Chem. 2004;279:28670–4.View ArticlePubMedGoogle Scholar
- Shipman AR, Millington GW. Obesity and the skin. Br J Dermatol. 2011;165:743–50.View ArticlePubMedGoogle Scholar