ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Runar Lundblad
Jan L. Svennevig
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Risnes, I.
Right arrow Articles by Svennevig, J. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Risnes, I.
Right arrow Articles by Svennevig, J. L.
Related Collections
Right arrow Cardiac - other

Ann Thorac Surg 2001;72:1587-1591
© 2001 The Society of Thoracic Surgeons

Original article: cardiovascular

Sternal wound infections in patients undergoing open heart surgery: randomized study comparing intracutaneous and transcutaneous suture techniques

Ivar Risnes, MD*a, Michel Abdelnoor, MPH, PhDa, Svein Tore Baksaas, MD, PhDa, Runar Lundblad, MD, PhDa, Jan L. Svennevig, MD, PhDa

a Department of Thoracic and Cardiovascular Surgery, Rikshospitalet, Oslo, Norway

Accepted for publication July 10, 2001.

* Address reprint requests to Dr Risnes, Department of Thoracic and Cardiovascular Surgery, Rikshospitalet, N-0027 Oslo, Norway
e-mail: ivar.risnes{at}rikshospitalet.no


   Abstract
Top
 Abstract
Introduction
 Material and methods
 Results
 Comment
 References
 
Background. Intracutaneous suture technique has been our standard method for closing sternal wounds in cardiac surgery, mainly for cosmetic reasons. However, an increased rate of postoperative infections has been reported in cosmetic surgery with this method compared with the percutanous or transcutaneous closure technique. A comparison of these two techniques in cardiac surgery is presented.

Methods. In a randomized study, 300 patients were selected to intracutaneous suture (n = 150) or percutanous suture (n = 150). The endpoints were superficial and deep sternal wound infections within 6 weeks postoperatively.

Results. The total infection rate was lower in the percutanous group compared with the intracutaneous group (3% versus 8%) (p = 0.007). The superficial infection rate was lower in the percutaneous group (2.3% versus 6.7%) (p = 0.01), whereas there was no statistically significant difference in the deep infection rate between the groups.

Conclusions. The percutaneous suture technique reduces the incidence of superficial wound infections, but not the deep infection rate in open heart surgery. There was no difference in the cosmetic results on a visual scale, assessed by the patients.


   Introduction
Top
 Abstract
 Introduction
Material and methods
 Results
 Comment
 References
 
In cardiac surgery, sternal wound infections following median sternotomy is a serious complication, associated with prolonged hospitalization, increased hospital costs, and increased morbidity and mortality [1–4]. The severity of infections may range from minor, superficial wound infection to fulminate mediastinitis with involvement of the sternum, heart, and great vessels [1, 2]. Superficial wound infections do not penetrate the sternum, whereas deep wound infections include mediastinitis with sternal dehiscence and osteomyelitis of the sternum [5]. Staphylococcus species are responsible for the majority of sternal infections [1, 2, 4]. A multitude of patient- and procedure-related risk factors for sternal infections have been reported [6–11]. The aims of this study were to investigate the sternal wound infection rate and the cosmetic results by comparing percutaneous and intracutaneous suture techniques in patients undergoing open heart surgery, and to identify possible risk factors for wound infection.


   Material and methods
Top
 Abstract
 Introduction
 Material and methods
Results
 Comment
 References
 
Patients and procedures
Between October 1999 and July 2000, a total of 300 consecutive patients undergoing open-heart surgery at Rikshopitalet, Oslo, Norway were included in this prospective, randomized study. There were 104 women and 196 men with mean age 64.8 years (range, 16.0 to 91.5 years). Ninety-six patients underwent coronary artery bypass grafting, 71 patients had valve replacement or plasty, 66 patients had combined coronary artery bypass grafting and valve replacement, while 67 patients underwent various other procedures (Table 1). Patients over 16 years undergoing elective or emergency cardiac surgery with sternotomy and cardiopulmonary bypass (CPB) were included in the study. The only exclusion criteria were immunsuppresive or steroid medications prior to surgery. All patients with mediastinitis underwent reexploration with debridement, sternal closure ad modem Robicsek, irrigation of the closed sternum with antibiotic solution, and systemic antibiotic therapy.


View this table:
[in this window]
[in a new window]
  		Table 1. Type of Operation and Infection Rate

 
Surgical technique
Anesthesia was induced with diazepam, Fentanyl and Pancuronium and maintained with Fentanyl, Midazolam, Isoflurane, and nitrous oxide (all from ALPHARMA, Oslo, Norway). In all patients, the operative approach was through a median sternotomy, with cardiopulmonary bypass and systemic hypothermia (28°C to 32°C). Eighteen patients were operated in circulatory arrest and deep hypothermia. Crystalloid cardioplegia and topical cooling were used routinely, accomplished by ice slush. All CPB circuits were heparin coated with Baxter Duraflo II, including the Spiral Gold Oxygenator (Baxter Healthcare Inc, Irvine, CA). The initial heparin dose was 4 mg/kg to achieve activated clothing time (ACT) greater than 480 seconds. After CPB was ended, protamine sulphate 10 mg/ml (Leo, Copenhagen, Denmark) was administered to reestablish the preoperative ACT level. Mediastinal shed blood was retransfused. The amount of heparine and protamine, the ACT values, the mediastinal blood loss, and the retransfused blood volumes during the first 12 postoperative hours were recorded in all patients.

Data collection and analysis
Data were obtained by review of the patients charts, including the following preoperative risk factors: age, gender, underlying disease, New York Heart Association preoperative functional class (NYHA classification), cardiac index, chronic obstructive pulmonary disease, redo surgery, preoperative serum creatinine, endocarditis, emergency surgery, and previous myocardial infarction (Table 2). Operative risk factors included the type of operative procedure, duration of anesthesia and length of cardiopulmonary bypass, aortic cross-clamping, timing of surgery (emergency versus elective), and duration of surgery. Postoperative factors included duration of mechanical ventilation, number of blood transfusions, reexploration for bleeding, mediastinal drainage, and length of hospital stay.


View this table:
[in this window]
[in a new window]
  		Table 2. Variables Analyzed as Potential Risk Factors for Total Infection in 33 Infected Patientsa

 
Methods
The patients were randomly selected to skin closure with poliglecaprone (Monocryl 3-0), intracutaneous suture (IC), n = 150 or polyamid (Ethilone 3-0; Ethicon Inc, Somerville, NJ), percutaneous, n = 150. In both groups, the sternum was closed with steel wires and the subcutaneous layer with polyglactin (Vicryl 2-0). Poliglecaprone is a resorbable monofilament suture, polyamide is a nonresorbable monofilament suture, and polyglactin is a resorbable multifilament suture. The patients received standard antibiotic prophylactics with three doses of intravenous (IV) cephalotin 2 g x 3 for at least 24 hours and until all drains or monitor lines were removed.

Postoperative wound inspection was performed regularly 3 days and 6 weeks after the operation. Assessment of wound infection was made according to a specific classification scheme. Each wound was given a score from 0 to 7 with zero representing the optimal, physiologic postoperative wound appearance. Wound infection was defined as a score of 4 or more, that means postoperative wound conditions with pus combined with other signs and symptoms such as erythema, edema, or increased pain [12–15]. The wounds were cosmetically evaluated on a visual scale from 1 to 10 by the patients themselves after 6 weeks.

Baseline blood samples
Hemoglobin, leukocytes, C-reactive protein, and S-creatinine were determined preoperatively, and on the 1st, 2nd, and 3rd day postoperatively.

Statistical methods
We estimated the crude effect of the two techniques for wound closure on different endpoints by odd ratio, and 95% confidence interval (CI). The major endpoints were the total number of infected patients, superficial wound infections (SWI), and mediastinitis. To adjust for possible risk factors, we used the multivariate logistic model to estimate the efficacy of the two treatments when controlling for the major risk factor [16, 17].


   Results
Top
 Abstract
 Introduction
 Material and methods
 Results
Comment
 References
 
Clinical observations
The 2 groups of patients were comparable with respect to preoperative, intraoperative, and postoperative variables. Eighteen patients died within 30 days of surgery (6%), early mortality was 5.3% and 6.7%, respectively, for the IC versus the percutaneous (PC) group, respectively (p = 0.87). In all cases, signs of clinical infection developed after the 3rd postoperative day. The incidence of total infection after 6 weeks was 3.0% in the PC group versus 8.0% in the IC group, which gives an odd ratio of 0.35 (CI 95%, 0.14 to 0.82) (p = 0.007). Using our scheme, the average infection scores were 0.6 and 1.2 for the PC and IC group, respectively (p = 0.02). There was a lower risk of superficial wound infection in the PC group; 2.3% versus 6.7% in the IC group, which gives an odd ratio of 0.35 (CI 95%, 0.12 to 0.85) (p = 0.010). The incidence of mediastinitis was lower in the PC group, 0.7% compared to 1.3% in the PC group, odd ratio 0.51 (CI 95%, 0.06 to 3.7), which is not statistically significant (p = 0.43) (Table 3).


View this table:
[in this window]
[in a new window]
  		Table 3. Crude Effect of PC Versus IC on the Endpoints SWI, DWI, and Total Infection

 
Risk factors
We studied a series of potential risk factor of the three endpoints. In order to adjust for the effect on the endpoint SWI, we used a multivariate logistic model and we adjusted for the multiconfounder age, emergency surgery procedure, or respiratory time. This gives an odd ratio of 0.38, 95% CI (0.15 to 0.9), and a reduction of 62% for the risk of developing SWI in patients with PC suture as compared with IC suture (Table 4). For total infection, we adjusted for age and the adjusted odd ratio was 0.37, 95% CI (0.16 to 0.84), indicating 63% reduction of incidence SWI in PC versus IC treatment. One patient died of mediastinitis 1 month after surgical debridement.


View this table:
[in this window]
[in a new window]
  		Table 4. Adjusted Effect of PC/IC on the Endpoints of Total Infection and SWI Using the Multivariate Logistic Model

 
Baseline blood samples
There were no differences between the groups for any of the hematological parameters (Hemoglobin, leukocytes, C-reactive protein, and S-creatinine).

Microorganisms
A variety of causative organisms were found with gram-positive bacteria, Staphylococcus aureus and Staphylococcus epidermidis dominating. Gram-positive bacteria, principally S aureus made up for 33.3% of all organisms, while 4 of the cases had positive growth of S epidermidis, in 1 patient the causative organism was Candida albicans, and in 4 patients there was no growth. In 11 patients, no bacterial test was performed.

Cosmetic results
The patients were satisfied with the cosmetic result. On a cosmetic scale from 1 to 10, the IC got a score of 8.3 versus 8.0 in PC (p = 0.19). There was no difference between groups.


   Comment
Top
 Abstract
 Introduction
 Material and methods
 Results
 Comment
References
 
In this prospective study, sternal infections after heart surgery occurred in 33 of 300 patients (11%). Twenty-seven patients developed superficial wound infection (9%) and 6 deep wound infection (2%). There is little information in the literature on superficial infections in open heart surgery. The incidence of deep sternal infection after cardiac surgery in our study is in accordance with the literature, reporting rates between 0.16% and 5.0% [1–5]. Mediastinitis is considered a serious postoperative complication, associated with mortality rates between 20% and 50%. Superficial infections occur with higher frequency than deep infections in patient series, but only deep infections are associated with increased mortality [2–4].

The etiology and pathogenesis of postoperative sternal infection are complex and involve a great variety of variables [1–4, 6–8]. Our study shows that the skin closure technique may represent one important risk factor for wound infection. In our study, we consecutively included all patients being operated on, and follow-up was 100% complete. The length of the preoperative hospital stay did not influence the infection rate. Most of our patients were admitted for complex cardiovascular surgery procedures. The majority of uncomplicated coronary patients were admitted to two other non-university hospitals.

When comparing the two different skin closure techniques, the intracutaneous technique was associated with a significant higher rate of infection compared to transcutaneous closure of wound with respect to total infection and SWI. Our findings are in agreement with the results reported by Andenaes and colleagues (1995–1996), studying alternative closure techniques in patients undergoing plastic surgery [13–15]. In our department, intracutaneous suture has been the standard technique for closing sternal wounds in patients undergoing cardiac surgery. This closing technique was chosen for cosmetic reasons.

It has been postulated that serious underlying noncardiac diseases are determinants for deep and superficial sternal infections [1, 2, 6, 7]. Many preoperative, perioperative, and postoperative risk factors may be important for wound infections. Earlier studies have concluded that the use of potent antimicrobial agents in complex cardiovascular surgical procedures represent an important risk factor in patients [18–20]. Our study revealed that the presence of chronic obstructive pulmonary disease, renal insufficiency, and other organ failure were not of statistical importance, neither were left ventricular ejection fraction, preoperative hospital stay, previous myocardial infarctions, the presence of angina pectoris, dyspnoe, and endocarditis. There was no association between the NYHA functional class and the rate of infections. The duration of surgery, the cardiopulmonary bypass time, and the cross-clamp time did not correlate with the incidence of infection, nor did the use of the internal mammary artery. Several postoperative variables, including prolonged ventilation time, tracheotomy, reexploration for bleeding, the number of blood transfusions, and postoperative myocardial infarction did not influence the incidence of infection. Age, emergency surgery procedure, and respiratory time were the multiconfounders for SWI, and for total infection.

The aim of our study was to find the best method for wound closure. Our findings are in agreement with previous published data from plastic surgery [12–14]. Both closing techniques included a subcutaneous suture with polyglactin. The blood collected in the dead space is proved to increase the frequency of postoperative wound infection [5]. Subcuticular suturing is supposed to reduce the dead space [14]. Secondly, the intracutaneous stitches may tend to hinder the drainage capacity of the wound, which may favor an accumulation of perioperative blood fluid, causing a subdermal hematoma and superficial infection.

Bacterial adhesion to surgical suture represents an important factor in the development of postoperative wound infection. Low virulent bacteria, eg, Staphylococcus epidermidis, are highly adhesive to biomaterials in general [23, 24]. When infected tissue contains an implant, the bacteria are concentrated to the surrounding tissue.

The healing of an operation wound and the connective tissue depends upon rapid synthesis of new cells and collagen, and the vascular continuity must be restored. In reparative tissue, the nutritional needs of healing are greatest during the time when the local circulation is least able to satisfy them. When tissue is injured, the typical sequential vascular response to injury occurs. After the initial vasodilatation, blood in the damaged vessels is thrombosed, and the larger muscular vessels contract [20, 23, 24]. An inadequate circulation limits the healing. Obviously, the quantity of nutritional blood flow is extremely important in the process. It appears that oxygen insufficiency is the first rate-limiting deficiency, which may occur under conditions of poor nutritional blood flow [14, 20, 22, 24], and is of great importance.

In our study, poliglecaprone intracutaneous suture was applied superficially in dermis. This might promote the access of superficial bacteria into the underlying suture and tissues, where both adhesions, interfilament spread, and protection from phagocytosis might provide an easier development of infection [14, 20, 21–24]. The overall limit of oxygen present in the healing wound is very important for postoperative wound infection, as the decomposition of absorbable sutures necessarily needs oxygen additionally to the requirements for the healing process [14, 22, 23]. The relation between ischemic tissue after surgery, protection from phagocytosis, and easier survival of bacteria is of critical importance to wound healing and to the susceptibility of wound infection [14, 23–25]. By using the right wound closure technique, all these objectives can better be overcome. Therefore, in elimination of an increased risk of infection, the percutaneous technique should be favored.

In summary, our analysis indicates that the wound closure technique represent an important risk factor of postoperative total infection rate after cardiac surgery. The incidence of superficial wound infection was significantly increased with the intracutaneous technique compared with the percutaneous method. As the cosmetic result was good and judged to be equal for the two techniques, the percutaneous method should be recommended.


   References
Top
 Abstract
 Introduction
 Material and methods
 Results
 Comment
 References
 

  1. Vaska P.L. Sternal wound infections. AACN Clin Issues Crit Care Nurs 1993;4:475-483.[Medline]
  2. Blanchard A., Hurni M., Ruchat P., Stumpe F., Fischer A., Sadeghi H. Incidence of deep and superficial sternal infection after open heart surgery. A ten years retrospective study from 1981 to 1991. Eur J Cardiothorac Surg 1995;9:153-157.[Abstract]
  3. Farinas M.C., Gald P.F., Bernal J.M., Rabasa J.M., Revuelta J.M., Gonzalez-Macias J. Suppurative mediastinitis after open-heart surgery: a case-control study covering a seven-year period in Santander, Spain. Clin Infect Dis 1995;20:272-279.[Medline]
  4. Cheung E.H., Craver J.M., Jones E.L., Murphy D.A., Hatcher C.R.J., Guyton R.A. Mediastinitis after cardiac valve operations. Impact upon survival. J Thorac Cardiovasc Surg 1985;90:517-522.[Abstract]
  5. Borger M.A., Rao V., Weisel R.D., et al. Deep sternal wound infection: risk factors and outcomes. Ann Thorac Surg 1998;65:1050-1056.[Abstract/Free Full Text]
  6. Stahle E., Tammelin A., Bergstrom R., Hambreus A., Nystrom S.O., Hansson H.E. Sternal wound complications—incidence, microbiology and risk factors. Eur J Cardiothorac Surg 1997;11:1146-1153.[Abstract]
  7. Orita H., Shimanuki T., Fukasawa M., et al. A clinical study of postoperative infections following open-heart surgery: occurrence and microbiological findings in 782 cases. Surg Today 1992;22:207-212.[Medline]
  8. Zacharias A., Habib R.H. Factors predisposing to median sternotomy complications. Deep vs superficial infection. Chest 1996;110:1173-1178.[Abstract/Free Full Text]
  9. Breyer R.H., Mills S.A., Hudspeth A.S., Johnston F.R., Cordell A.R. A prospective study of sternal wound complications. Ann Thorac Surg 1984;37:412-416.[Abstract]
  10. El Oakley R.M., Wright J.E. Postoperative mediastinitis: classification and management. Ann Thorac Surg 1996;61:1030-1036.[Abstract/Free Full Text]
  11. Ivert T., Lindblom D., Sahni J., Eldh J. Management of deep sternal wound infection after cardiac surgery—Hanuman syndrome. Scand J Thorac Cardiovasc Surg 1991;25:111-117.[Medline]
  12. Bitkover C.Y., Marcusson E., Ransjo U. Spread of coagulase-negative staphylococci during cardiac operations in a modern operating room. Ann Thorac Surg 2000;69:1110-1115.[Abstract/Free Full Text]
  13. Andenaes K., Lingaas E., Amland P.F., Giercksky K.E., Abyholm F. Preoperative bacterial colonization and its influence on postoperative wound infections in plastic surgery. J Hosp Infect 1996;34:291-299.[Medline]
  14. Amland P.F., Andenaes K., Samdal F., et al. A prospective, double-blind, placebo-controlled trial of a single dose of azithromycin on postoperative wound infections in plastic surgery. Plast Reconstr Surg 1995;96:1378-1383.[Medline]
  15. Andenaes K., Amland P.F., Lingaas E., Abyholm F., Samdal F., Giercksky K.E. A prospective, randomized surveillance study of postoperative wound infections after plastic surgery: a study of incidence and surveillance methods. Plast Reconstr Surg 1995;96:948-956.[Medline]
  16. Pocock S.J. Clinical trials, a practical approach. Oslo, Norway: Department of Plastic Surgery, Rikshospitalet, 1990.
  17. Kleinbaum D.G. Epidemiologogic research, principles and quantitative methods. New York: Van Nostrand Reinhold Company, 2001.
  18. Cruse P.J., Foord R. The epidemiology of wound infection. A 10-year prospective study of 62,939 wounds. Surg Clin North Am 1980;60:27-40.[Medline]
  19. Braxton J.H., Marrin C.A., McGrath P.D., et al. Mediastinitis and long-term survival after coronary artery bypass graft surgery. Northern New England Cardiovascular Disease Study Group. Ann Thorac Surg 2000;70:2004-2007.[Abstract/Free Full Text]
  20. Chu C.C., Williams D.F. Effects of physical configuration and chemical structure of suture materials on bacterial adhesion. A possible link to wound infection. Am J Surg 1984;147:197-204.[Medline]
  21. Blomstedt B., Osterberg B., Bergstrand A. Suture material and bacterial transport. An experimental study. Acta Chir Scand 1977;143:71-73.[Medline]
  22. Alexander J.W., Kaplan J.Z., Altemeier W.A. Role of suture materials in the development of wound infection. Ann Surg 1967;165:192-199.[Medline]
  23. Heughan C., Zederfeldt B., Grislis G., Hunt T.K. Effect of dextran solutions on oxygen transport in wound tissue. An experimental study in rabbits. Acta Chir Scand 1972;138:639-643.[Medline]
  24. Johnson P., Frederiksen J.W., Sanders J.H., Lewis V., Michaelis L.L. Management of chronic sternal osteomyelitis. Ann Thorac Surg 1985;40:69-72.[Abstract]
  25. Gurevitch J., Kramer A., Locker C., et al. Technical aspects of double-skeletonized internal mammary artery grafting. Ann Thorac Surg 2000;69:841-846.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 ICVTSHome page
A. Sanni and J. Dunning
Staples or sutures for chest and leg wounds following cardiovascular surgery
Interactive CardioVascular and Thoracic Surgery, April 1, 2007; 6(2): 243 - 246.
[Abstract] [Full Text] [PDF]

Home page
 ICVTSHome page
L.-G. Dahlin, H. Granfeldt, and H. Hultkvist
A multimodal approach for reducing wound infections after sternotomy
Interactive CardioVascular and Thoracic Surgery, March 1, 2004; 3(1): 206 - 210.
[Abstract] [Full Text] [PDF]

Home page
 J Intensive Care MedHome page
R. S. Poston and B. P. Griffith
Heart Transplantation
J Intensive Care Med, January 1, 2004; 19(1): 3 - 12.
[Abstract] [PDF]

Home page
 J. Thorac. Cardiovasc. Surg.Home page
T. Bottio, G. Rizzoli, V. Vida, D. Casarotto, and G. Gerosa
Double crisscross sternal wiring and chest wound infections: A prospective randomized study
J. Thorac. Cardiovasc. Surg., November 1, 2003; 126(5): 1352 - 1356.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
T. Bottio, V. L. Vida, G. Gerosa, and D. Casarotto
Double criss-cross sternal wiring and chest wound infections
Ann. Thorac. Surg., September 1, 2003; 76(3): 975 - 976.
[Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
I. Risnes
Double criss-cross sternal wiring and chest wound infections: Reply
Ann. Thorac. Surg., September 1, 2003; 76(3): 976 - 977.
[Full Text] [PDF]

Home page
 Eur. J. Cardiothorac. Surg.Home page
I. Risnes, M. Abdelnoor, R. Lundblad, S. T. Baksaas, and J. L. Svennevig
Sternal wound closure in patients undergoing open-heart surgery: a prospective randomized study comparing intracutaneous and zipper techniques
Eur. J. Cardiothorac. Surg., August 1, 2002; 22(2): 271 - 277.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
H. Hirose and A. Takahashi
Sternal suturing technique and chest wound complication
Ann. Thorac. Surg., August 1, 2002; 74(2): 634 - 635.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Runar Lundblad
Jan L. Svennevig
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Risnes, I.
Right arrow Articles by Svennevig, J. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Risnes, I.
Right arrow Articles by Svennevig, J. L.
Related Collections
Right arrow Cardiac - other

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS