Sternal wound dehiscence after internal mammary artery harvesting. Logical management. Part 2
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《血管的通路杂志》
Department of Surgery, Papworth Hospital, Papworth Everard, Cambridgeshire, CB3 8RE, UK
Abstract
Wound breakdown is a serious complication of median sternotomy. This is generally met with a further attempt at surgical apposition using sutures of monofilament surgical steel, following wound debridement. This often fails. The aim of this article is to demonstrate one surgeon's experience in his revised management of sternal wound dehiscence, following internal mammary artery (IMA) harvest, over a 7-year period. Treatment consisted of sternal and soft tissue debridement, and closed irrigation. Wound closure was performed using multiple interrupted deep tension sutures (DTS) only. We believe this article demonstrates that the use of DTS is a safe and effective method of closure, for patients suffering from sternal wound dehiscence following IMA harvest.
Key Words: IMA harvest; Sternum; Dehiscence; Closure
1. Introduction
The use of median sternotomy is established in cardiac surgery. There are numerous techniques and materials used for the primary closure of a median sternotomy wound [1]. However, standard closure is still considered to be five or more sutures of monofilament surgical steel, passed through the sternum, approximately 1.5 cm lateral to the midline incision. The wire is then crossed, pulled and twisted, and the remaining ends bent over to lie flat against the sternum.
Sternal wound dehiscence remains a rare complication of median sternotomy, and is associated with significant morbidity, mortality and cost [2]. The pre-operative risk factors for sternal wound complications following median sternotomy include: diabetes mellitus, obesity, chronic obstructive pulmonary disease and smoking [3]. The main peri-operative risk factor is length of time on bypass, with concerns raised over the safety of internal mammary artery (IMA) harvest. The major post-operative risk factors include: blood transfusion, chest re-exploration, prolonged ventilation and length of stay in intensive care unit (ICU).
Median sternotomy wound breakdown is generally met with a further attempt at surgical apposition by standard closure, following wound debridement. This often fails. The aim of this article is to demonstrate one surgeon's experience in his revised management of sternal wound dehiscence, following IMA harvest (Manifold and Large [4]) for coronary artery bypass grafting (CABG) over a 7-year period, which includes 1575 CABG cases.
In the past, we argued for delayed primary closure of broken down sternal wounds [4]. Like others, we found this method to be complicated by right ventricular rupture. As a result we moved to deep tension sutures (DTS) alone, believing this to be a safe and effective method of managing this dangerous complication.
2. Patients and methods
Data were obtained retrospectively from case notes of patients who suffered wound dehiscence, following median sternotomy and IMA harvest for CABG, at Papworth Hospital between July 1997 and July 2004.
2.1. Operative technique
The patients were prepared and draped in the usual manner and the incision performed through the sternotomy wound. All suture material and wires were removed and the chest re-entered and re-explored. The sternal bone was trimmed by 2 mm on either side of the sternotomy. All necrotic soft tissue was curetted back to bleeding healthy tissue. A bacteriological swab was sent to microbiology for culture and sensitivity. The wound was washed out with a 10% solution of aqueous Betadine and warm saline. An irrigation system was set up by placing a size 14 French gauge nasogastric tube retrosternally at the superior end of the wound, as an inlet, and a standard chest drain at the inferior end, as an outlet. One litre of normal saline was irrigated through this circuit every 12 h.
The wound was closed en masse with multiple interrupted DTS of 1/0 ethylon, surrounding the skin, subcutaneous tissue and sternum (Fig. 1). Left and right pectoral flaps (2 cm mobilisation) were advanced and opposed with a continuous suture of 1/0 PDS. The skin was closed using one interrupted 2/0 nylon mattress suture between the DTS. Therefore only a single length of absorbable suture was left in the wound.
Following re-approximation, patients were transferred to ICU, and once in a stable condition onto a general ward. Irrigation was continued for 5 days and any effluent sent for bacteriological review. This was removed after evidence that wound infection had settled. The patients were discharged as inpatients and followed up weekly in the wound clinic (Fig. 2). The DTS were removed after 12 weeks and the patients were discharged from the wound clinic.
3. Results
During this period, 15 out of 1575 patients (incidence 1%) were found to have sternal wound dehiscence. One patient was excluded from this review as she suffered a fall early after surgery, leading to a fractured neck of femur and sternal dehiscence. In this case, the overall hospital stay was dictated by the orthopaedic recovery.
There were nine males and five females with ages ranging from 48 years to 82 years (mean 67.4 years, S.D. 9.50). Three patients had a body mass index in excess of 30 (group mean 27.5, S.D. 2.95). Three patients were diabetic. Two had a history of long-term (two years) steroid use and 12 patients had a history of smoking. Eight patients underwent single IMA harvest and six had bilateral IMA harvest. One patient had a valve replacement combined with CABG and one patient had a graft redo. Two were emergency operations. In the primary operation, the mean time on bypass was 84.8 min (S.D. 35.7) and the mean ischaemic time was 46.5 min (S.D. 22.5). No patients were re-explored during their post-operative course. Three patients stayed for more than 24 h in ICU following the primary operation. The number of days before re-operation varied between 3 and 29 days (mean 17.2, S.D. 6.20). Infection (presence of bacteriological pathogens) was identified in 12 cases.
Patient outcomes following re-operation for sternal wound dehiscence are presented in Table 1. Ten patients made a complete recovery and were discharged with both sternum and wound healing. One patient required an operation for excision of a sinus tract; one patient required further debridement on two occasions for a persisting wound followed by excision of a sinus tract; two patients had superficial wound infection requiring admission for a course of antibiotics.
4. Discussion
The treatment for sternal wound dehiscence varies from simple antibiotic therapy to complete sternectomy combined with plastic reconstruction [5]. Despite newer techniques that limit surgical trauma now emerging [6,7], it has recently been proposed that flap procedures should be reserved for cases of sternal wound dehiscence with severe sternal necrosis precluding re-wiring or those refractory to initial sternal preservation techniques [8].
In those instances where the sternum can be preserved, DTS provides a simple, inexpensive and quick method of closure, has familiar handling characteristics, and allows fast access if emergency chest re-entry is needed. It also allows for prompt stabilisation of the sternum to facilitate healing and promote normal chest wall dynamics in line with other recent reports [9]. The post-operative hospital stay is comparable with competing methods [9,10], and there was no post-operative mortality, although there was some morbidity risk.
While we do not propose to draw any conclusions about the role of the IMA in sternal healing from such a small number of patients, there is evidence to suggest that there is an increased incidence of sternal wound complications following IMA harvest [3]. This effect is probably due to a reduced blood flow to the wound as a direct result of IMA harvest. This reduction in blood flow has been shown to be temporary [11]. The ischaemic bone is likely to be weaker and more susceptible to infection, encouraging sternal wire ‘pull through’.
We believe that this technique provides a logical treatment for the management of sternal wound dehiscence following IMA harvest. Possible short-term advantages of DTS closure are that there is a reduced stress on individual sutures, as the disruptive forces are distributed over a higher number of sutures and the wider sternum, thereby reducing the force on individual sutures to cut into and pull through the weakened sternum. By placing the sutures peristernally, there is also a larger area of bone cortex resisting the sutures and any fractures resulting from previous wire ‘pull through’ are compressed by the lateral support [12]. Furthermore, the sutures are exposed, allowing residual infection to track up the suture line away from the deep tissues and discouraging concealed infection.
In the longer term, a 12-week delay before removing the DTS permits support throughout return of sternal blood flow and subsequent sternal healing. After removal of the DTS, as there is no foreign body material left in place, there can be no consequent foreign body associated morbidity.
Avoidance of this troublesome complication is the ideal. However, from our experience thus far, we believe that the use of DTS is a safe and effective method of closure for patients suffering from sternal wound dehiscence, following IMA harvest.
References
Losanoff JE, Jones JW, Richman BW. Primary closure of median sternotomy: techniques and principles. Cardiovasc Surg 2002;10:102–110.
Stahle E, Tammelin A, Bergstrom R, Hambreus A, Nystrom SO, Hansson HE. Sternal wound complications – incidence, microbiology and risk factors. Eur J Cardiothorac Surg 1997;11:1146–1153.
Losanoff JE, Richman BW, Jones JW. Disruption and infection of median sternotomy: a comprehensive review. Eur J Cardiothorac Surg 2002;21:831–839.
Manifold DK, Large SR. Sternal wound dehiscence after internal mammary artery harvesting. Logical management. Eur J Cardiothorac Surg 1994;8:46–47.
El Oakley RM, Wright JE. Postoperative mediastinitis: classification and management. Ann Thorac Surg 1996;61:1030–1036.
Klesius AA, Dzemali O, Simon A, Kleine P, Abdel-Rahman U, Herzog C, WimmerGreinecker G, Moritz A. Successful treatment of deep sternal infections following open heart surgery by bilateral pectoralis major flaps. Eur J Cardiothorac Surg 2004;25:218–223.
Dimarakis I, Oswal D, Nair R. Single stage sternal reconstruction using titanium mesh for dehiscence following open-heart surgery. Interact CardioVasc and Thorac Surg 2005;4:49–51.
Douville EC, Asaph JW, Dworkin RJ, Handy JR Jr, Canepa CS, Grunkemeier GL, Wu Y. Sternal preservation: a better way to treat most sternal wound complications after cardiac surgery. Ann Thorac Surg 2004;78:1659–1664.
Merrill WH, Akhter SA, Wolf RK, Schneeberger EW, Flege JB Jr. Simplified treatment of postoperative mediastinitis. Ann Thorac Surg 2004;78:608–612.
Gustafsson RI, Sjogren J, Ingemansson R. Deep sternal wound infection: a sternal-sparing technique with vacuum-assisted closure therapy. Ann Thorac Surg 2003;76:2048–2053.
Medalion B, Katz MG, Lorberboym M, Bder O, Schachner A, Cohen AJ. Decreased sternal vascularity after internal thoracic artery harvesting resolves with time: an assessment with single photon emission computed tomography. J Thorac Cardiovasc Surg 2002;123:508–511.
Casha AR, Gauci M, Yang L, Saleh M, Kay PH, Cooper GJ. Fatigue testing median sternotomy closures. Eur J Cardiothorac Surg 2001;19:249–253.(Alex J. Doyle, Stephen R.)
Abstract
Wound breakdown is a serious complication of median sternotomy. This is generally met with a further attempt at surgical apposition using sutures of monofilament surgical steel, following wound debridement. This often fails. The aim of this article is to demonstrate one surgeon's experience in his revised management of sternal wound dehiscence, following internal mammary artery (IMA) harvest, over a 7-year period. Treatment consisted of sternal and soft tissue debridement, and closed irrigation. Wound closure was performed using multiple interrupted deep tension sutures (DTS) only. We believe this article demonstrates that the use of DTS is a safe and effective method of closure, for patients suffering from sternal wound dehiscence following IMA harvest.
Key Words: IMA harvest; Sternum; Dehiscence; Closure
1. Introduction
The use of median sternotomy is established in cardiac surgery. There are numerous techniques and materials used for the primary closure of a median sternotomy wound [1]. However, standard closure is still considered to be five or more sutures of monofilament surgical steel, passed through the sternum, approximately 1.5 cm lateral to the midline incision. The wire is then crossed, pulled and twisted, and the remaining ends bent over to lie flat against the sternum.
Sternal wound dehiscence remains a rare complication of median sternotomy, and is associated with significant morbidity, mortality and cost [2]. The pre-operative risk factors for sternal wound complications following median sternotomy include: diabetes mellitus, obesity, chronic obstructive pulmonary disease and smoking [3]. The main peri-operative risk factor is length of time on bypass, with concerns raised over the safety of internal mammary artery (IMA) harvest. The major post-operative risk factors include: blood transfusion, chest re-exploration, prolonged ventilation and length of stay in intensive care unit (ICU).
Median sternotomy wound breakdown is generally met with a further attempt at surgical apposition by standard closure, following wound debridement. This often fails. The aim of this article is to demonstrate one surgeon's experience in his revised management of sternal wound dehiscence, following IMA harvest (Manifold and Large [4]) for coronary artery bypass grafting (CABG) over a 7-year period, which includes 1575 CABG cases.
In the past, we argued for delayed primary closure of broken down sternal wounds [4]. Like others, we found this method to be complicated by right ventricular rupture. As a result we moved to deep tension sutures (DTS) alone, believing this to be a safe and effective method of managing this dangerous complication.
2. Patients and methods
Data were obtained retrospectively from case notes of patients who suffered wound dehiscence, following median sternotomy and IMA harvest for CABG, at Papworth Hospital between July 1997 and July 2004.
2.1. Operative technique
The patients were prepared and draped in the usual manner and the incision performed through the sternotomy wound. All suture material and wires were removed and the chest re-entered and re-explored. The sternal bone was trimmed by 2 mm on either side of the sternotomy. All necrotic soft tissue was curetted back to bleeding healthy tissue. A bacteriological swab was sent to microbiology for culture and sensitivity. The wound was washed out with a 10% solution of aqueous Betadine and warm saline. An irrigation system was set up by placing a size 14 French gauge nasogastric tube retrosternally at the superior end of the wound, as an inlet, and a standard chest drain at the inferior end, as an outlet. One litre of normal saline was irrigated through this circuit every 12 h.
The wound was closed en masse with multiple interrupted DTS of 1/0 ethylon, surrounding the skin, subcutaneous tissue and sternum (Fig. 1). Left and right pectoral flaps (2 cm mobilisation) were advanced and opposed with a continuous suture of 1/0 PDS. The skin was closed using one interrupted 2/0 nylon mattress suture between the DTS. Therefore only a single length of absorbable suture was left in the wound.
Following re-approximation, patients were transferred to ICU, and once in a stable condition onto a general ward. Irrigation was continued for 5 days and any effluent sent for bacteriological review. This was removed after evidence that wound infection had settled. The patients were discharged as inpatients and followed up weekly in the wound clinic (Fig. 2). The DTS were removed after 12 weeks and the patients were discharged from the wound clinic.
3. Results
During this period, 15 out of 1575 patients (incidence 1%) were found to have sternal wound dehiscence. One patient was excluded from this review as she suffered a fall early after surgery, leading to a fractured neck of femur and sternal dehiscence. In this case, the overall hospital stay was dictated by the orthopaedic recovery.
There were nine males and five females with ages ranging from 48 years to 82 years (mean 67.4 years, S.D. 9.50). Three patients had a body mass index in excess of 30 (group mean 27.5, S.D. 2.95). Three patients were diabetic. Two had a history of long-term (two years) steroid use and 12 patients had a history of smoking. Eight patients underwent single IMA harvest and six had bilateral IMA harvest. One patient had a valve replacement combined with CABG and one patient had a graft redo. Two were emergency operations. In the primary operation, the mean time on bypass was 84.8 min (S.D. 35.7) and the mean ischaemic time was 46.5 min (S.D. 22.5). No patients were re-explored during their post-operative course. Three patients stayed for more than 24 h in ICU following the primary operation. The number of days before re-operation varied between 3 and 29 days (mean 17.2, S.D. 6.20). Infection (presence of bacteriological pathogens) was identified in 12 cases.
Patient outcomes following re-operation for sternal wound dehiscence are presented in Table 1. Ten patients made a complete recovery and were discharged with both sternum and wound healing. One patient required an operation for excision of a sinus tract; one patient required further debridement on two occasions for a persisting wound followed by excision of a sinus tract; two patients had superficial wound infection requiring admission for a course of antibiotics.
4. Discussion
The treatment for sternal wound dehiscence varies from simple antibiotic therapy to complete sternectomy combined with plastic reconstruction [5]. Despite newer techniques that limit surgical trauma now emerging [6,7], it has recently been proposed that flap procedures should be reserved for cases of sternal wound dehiscence with severe sternal necrosis precluding re-wiring or those refractory to initial sternal preservation techniques [8].
In those instances where the sternum can be preserved, DTS provides a simple, inexpensive and quick method of closure, has familiar handling characteristics, and allows fast access if emergency chest re-entry is needed. It also allows for prompt stabilisation of the sternum to facilitate healing and promote normal chest wall dynamics in line with other recent reports [9]. The post-operative hospital stay is comparable with competing methods [9,10], and there was no post-operative mortality, although there was some morbidity risk.
While we do not propose to draw any conclusions about the role of the IMA in sternal healing from such a small number of patients, there is evidence to suggest that there is an increased incidence of sternal wound complications following IMA harvest [3]. This effect is probably due to a reduced blood flow to the wound as a direct result of IMA harvest. This reduction in blood flow has been shown to be temporary [11]. The ischaemic bone is likely to be weaker and more susceptible to infection, encouraging sternal wire ‘pull through’.
We believe that this technique provides a logical treatment for the management of sternal wound dehiscence following IMA harvest. Possible short-term advantages of DTS closure are that there is a reduced stress on individual sutures, as the disruptive forces are distributed over a higher number of sutures and the wider sternum, thereby reducing the force on individual sutures to cut into and pull through the weakened sternum. By placing the sutures peristernally, there is also a larger area of bone cortex resisting the sutures and any fractures resulting from previous wire ‘pull through’ are compressed by the lateral support [12]. Furthermore, the sutures are exposed, allowing residual infection to track up the suture line away from the deep tissues and discouraging concealed infection.
In the longer term, a 12-week delay before removing the DTS permits support throughout return of sternal blood flow and subsequent sternal healing. After removal of the DTS, as there is no foreign body material left in place, there can be no consequent foreign body associated morbidity.
Avoidance of this troublesome complication is the ideal. However, from our experience thus far, we believe that the use of DTS is a safe and effective method of closure for patients suffering from sternal wound dehiscence, following IMA harvest.
References
Losanoff JE, Jones JW, Richman BW. Primary closure of median sternotomy: techniques and principles. Cardiovasc Surg 2002;10:102–110.
Stahle E, Tammelin A, Bergstrom R, Hambreus A, Nystrom SO, Hansson HE. Sternal wound complications – incidence, microbiology and risk factors. Eur J Cardiothorac Surg 1997;11:1146–1153.
Losanoff JE, Richman BW, Jones JW. Disruption and infection of median sternotomy: a comprehensive review. Eur J Cardiothorac Surg 2002;21:831–839.
Manifold DK, Large SR. Sternal wound dehiscence after internal mammary artery harvesting. Logical management. Eur J Cardiothorac Surg 1994;8:46–47.
El Oakley RM, Wright JE. Postoperative mediastinitis: classification and management. Ann Thorac Surg 1996;61:1030–1036.
Klesius AA, Dzemali O, Simon A, Kleine P, Abdel-Rahman U, Herzog C, WimmerGreinecker G, Moritz A. Successful treatment of deep sternal infections following open heart surgery by bilateral pectoralis major flaps. Eur J Cardiothorac Surg 2004;25:218–223.
Dimarakis I, Oswal D, Nair R. Single stage sternal reconstruction using titanium mesh for dehiscence following open-heart surgery. Interact CardioVasc and Thorac Surg 2005;4:49–51.
Douville EC, Asaph JW, Dworkin RJ, Handy JR Jr, Canepa CS, Grunkemeier GL, Wu Y. Sternal preservation: a better way to treat most sternal wound complications after cardiac surgery. Ann Thorac Surg 2004;78:1659–1664.
Merrill WH, Akhter SA, Wolf RK, Schneeberger EW, Flege JB Jr. Simplified treatment of postoperative mediastinitis. Ann Thorac Surg 2004;78:608–612.
Gustafsson RI, Sjogren J, Ingemansson R. Deep sternal wound infection: a sternal-sparing technique with vacuum-assisted closure therapy. Ann Thorac Surg 2003;76:2048–2053.
Medalion B, Katz MG, Lorberboym M, Bder O, Schachner A, Cohen AJ. Decreased sternal vascularity after internal thoracic artery harvesting resolves with time: an assessment with single photon emission computed tomography. J Thorac Cardiovasc Surg 2002;123:508–511.
Casha AR, Gauci M, Yang L, Saleh M, Kay PH, Cooper GJ. Fatigue testing median sternotomy closures. Eur J Cardiothorac Surg 2001;19:249–253.(Alex J. Doyle, Stephen R.)