Surgical technique
DSWI is defined as infection involving fascia or deeper with at least
one of the following: evidence of infection seen at re-operation or
spontaneous dehiscence, positive culture of mediastinal fluid and/or
positive blood culture and/or chest pain with sternal instability and
temperature higher than 38 degrees Celsius[7]. All patients with
DSWI are well prepared preoperatively, including early wound exploration
and drainage, antibiotic therapy, nutritional support and
cardiopulmonary function.
All patients are anesthetized with tracheal intubation. The infected
tissue is resected in full layer along the edge of the incision and all
sternal wires are removed. Use a rongeur to remove the infected sternum
until healthy solid bone with briskly bleeding margins is found. If the
bone is obviously necrotic, the entire sternum is resected. Explore the
posterior sternum space to thoroughly remove infected tissue and foreign
materials, such as residual pacemaker wires. If infection involves
extracardiac conduit and patch, they must also be removed.Mediastinal
secretions and infected tissue are sent for culture. The wound is
irrigated with hydrogen peroxide and normal saline.
According to the size of the wound defect decide whether unilateral or
bilateral pectoralis major flap. If an unilateral pectoralis major flap
is used, the right pectoralis major is usually chosen because muscles
are more developed on this side. Dissect the overlying skin off the
pectoralis major muscle from medial to the anterior axillary line.Cut
off the muscle at the junction of medial 2/3 and the lateral 1/3 by
using electrotome.Dissect the medial muscle from lateral to medial until
the perforating vessels are visible. Flip muscles to fill the
mediastinum as a turnover flap. The turnover muscle flap is fixed with
double-stranded no.7 silk sutures by methods of relieving tension. The
drainage tube is placed in the mediastinum. skin is closed with
interrupted silk sutures.Postoperatively,chest wall is pressurized with
elastic bandage. The drainage tube is left in place for 4-7 days based
on the amount of drained fluid. Postoperative antibiotic therapy was
performed for 2-3 weeks according to culture results.
Table 1 Preoperative characteristics of patients