Pectoralis major-rectus abdominis bipedicled muscle flap in the treatment of poststernotomy mediastinitis

Efficacy of Computed Tomography-Guided Catheter Drainage as the Initial Intervention and of Omentopexy as the Staged Surgery for a Prosthetic Graft Infection of Very Late Onset

On the basis of computed tomography (CT) examination, a prosthetic graft infection of very late onset was suspected in a 72-year-old man who had undergone replacement of an bifurcated prosthetic graft 6 years earlier because of an abdominal aortic aneurysm and bilateral common iliac artery aneurysms. Emergency CT-guided needle aspiration was performed, and analysis of directly aspirated fluid confirmed the rapid diagnosis. Instead of conventional emergency surgery, CT-guided catheter drainage was the initial treatment and led to the gradual improvement of symptoms and laboratory data. Elective staged surgery was performed later to examine the cavity around the prosthetic graft. The cavity was then filled with in-situ omentum. Thus, CT-guided catheter drainage as the initial treatment and following omentopexy as the staged surgery avoided the need for highly invasive conventional surgery.

Endoscope-Assisted Pectoralis Major-Rectus Abdominis Bipedicle Muscle Flap for the Treatment of Poststernotomy Mediastinitis

INTRODUCTION

Various management strategies have been reported for sternal wound care; however, they exhibit limited effectiveness or are associated with severe complications. Furthermore, it is difficult for the standard pectoralis major (PM) muscle advance flap to reach the lower third of the sternum. This article examines using the PM-rectus abdominis (RA) bipedicle muscle flap to treat lower-third deep sternal wound infection.

METHODS

The outcomes of patients who received a PM-RA bipedicle muscle flap harvest at our institution between 1996 and 2014 were reviewed. The method involves performing a subfascial and subperiosteal dissection of the PM to elevate the muscle flap. Blunt dissection may be performed carefully under an endoscope. Endoscope visualization enables us to identify the critical structures lateral to the PM muscle. In addition, the connective tissue to the RA muscle was preserved. Continuity was carefully preserved from the pectoral-thoracoepigastric fascia to the anterior rectus sheath. The flap could then be transposed to fill the lower-third sternal tissue defect with ease.

RESULTS

A total of 12 patients, with a mean age of 71 years (45-89 years), were treated using an endoscope-assisted PM-RA bipedicle muscle flap harvest. Wound microbiology of the 12 patients revealed that 3 patients had methicillin-resistant Staphylococcus aureus, 4 had S. aureus, 1 had coagulase-negative Staphylococcus, 1 had Escherichia coli, 1 had Pseudomonas aeruginosa, 1 had Mycobacterium tuberculosis, and 1 had a mixed growth of organisms. One instance of recurrent sternal infection was identified among the patients. Moreover, 1 patient died from heart failure 5 weeks after surgery, but the coverage of the sternal wound was successful. Accidental injury to the surrounding neurovascular structure of the patients was avoided, and only 10 to 15 minutes was required to divide the PM muscle.

CONCLUSIONS

Performing this harvest method under endoscopic assistance has several advantages, such as preventing excess traction of the skin edge to diminish the skin slough. This method could be an effective alternative for harvesting the PM-RA bipedicle muscle flap to reconstruct the lower-third sternal wound.

Pectoralis Muscle Flap Repair Reduces Paradoxical Motion of the Chest Wall in Complex Sternal Wound Dehiscence

BACKGROUND

The aim of the study was to test the hypothesis that in patients with chronic complex sternum dehiscence, the use of muscle flap repair minimizes the occurrence of paradoxical motion of the chest wall (CWPM) when compared to sternal rewiring, eventually leading to better respiratory function and clinical outcomes during follow-up.

METHODS

In a propensity score matching analysis, out of 94 patients who underwent sternal reconstruction, 20 patients were selected: 10 patients underwent sternal reconstruction with bilateral pectoralis muscle flaps (group 1) and 10 underwent sternal rewiring (group 2). Eligibility criteria included the presence of hemisternum diastases associated with multiple (≥3) bone fractures and radiologic evidence of synchronous chest wall motion (CWSM). We compared radiologically assessed (volumetric computed tomography) ventilatory mechanic indices such as single lung and global vital capacity (VC), diaphragm excursion, synchronous and paradoxical chest wall motion.

RESULTS

Follow-up was 100% complete (mean 85±24 months). CWPM was inversely correlated with single lung VC (Spearman R=-0.72, p=0.0003), global VC (R=-0.51, p=0.02) and diaphragm excursion (R=-0.80, p=0.0003), whereas it proved directly correlated with dyspnea grade (Spearman R=0.51, p=0.02) and pain (R=0.59, p=0.005). Mean CWPM and single lung VC were both better in group 1, whereas there was no difference in CWSM, diaphragm excursion and global VC.

CONCLUSION

Our study suggests that in patients with complex chronic sternal dehiscence, pectoralis muscle flap reconstruction guarantees lower CWPM and greater single-lung VC when compared with sternal rewiring and it is associated with better clinical outcomes with less pain and dyspnea.

Effect of negative pressure wound therapy followed by tissue flaps for deep sternal wound infection after cardiovascular surgery: propensity score matching analysis

OBJECTIVES

Deep sternal wound infection (DSWI) after cardiovascular surgery via median sternotomy remains a severe complication associated with a drastic decrease in the quality of life. We assessed the risk factors for in-hospital death caused by DSWI and the available treatments for DSWI.

METHODS

Between January 1991 and August 2015, we retrospectively reviewed 73 patients (51 males and 22 females, mean age 67.5 ± 10.3 years) who developed DSWI after cardiovascular surgery via median sternotomy. Pathogenic bacteria mainly comprised methicillin-resistant Staphylococcus aureus (MRSA) (49.3%). Fifteen patients (20.5%) died in hospital with DSWI. Treatment of DSWI consisted of open daily irrigation (up to 2006) or negative pressure wound therapy (NPWT) (2007 onwards), followed by primary closure or reconstruction of tissue flaps. We assessed the risk factors for in-hospital mortality from DSWI by comparing data from the 15 patients who died and the 58 survivors using propensity score matching analysis of the treatments used for DSWI.

RESULTS

Univariate analysis identified age, use of intra-aortic balloon pumping, prolonged mechanical ventilation, tracheotomy, prolonged intensive care unit stay, postoperative low output syndrome, postoperative myocardial infarction, postoperative renal failure, postoperative use of haemodialysis, postoperative pneumonia, postoperative cerebral disorder, MRSA infection, NPWT and tissue flaps as being associated with in-hospital mortality (P < 0.05). Multivariate analysis identified NPWT (odds ratio, 0.062; 95% confidence interval, 0.004-0.897; P = 0.041) and tissue flaps (odds ratio, 0.022; 95% confidence interval, 0.000-0.960; P = 0.048) as independently associated with reduced in-hospital mortality after DSWI. On comparing 22 patients receiving NPWT with 22 not on NPWT using propensity score matching, patients on NPWT had significantly lower in-hospital mortality than those without NPWT (NPWT vs non-NPWT, 5 vs 36%, P = 0.021). In DSWI infected by MRSA, NPWT significantly reduced the in-hospital mortality caused by DSWI (NPWT vs non-NPWT, 0 vs 52%, P = 0.003).

CONCLUSIONS

NPWT and tissue flaps may be favourable factors associated with reduced in-hospital mortality attributable to DSWI. NPWT as a bridge therapy to tissue flaps may play a major role in treating DSWI and improve the prognosis for patients with MRSA-infected DSWI.

Single-stage repair of the anterior chest wall following sternal destruction complicated by mediastinitis

PURPOSE

Although various techniques have been described, the ideal reconstructive procedure for treating massive sternal fragmentation and necrosis is still a matter of debate. Sometimes, reconstruction is so challenging that repetitive operations are required, particularly when complicated by mediastinitis and sternal osteomyelitis.

METHODS

Five patients (three males, two females, median age 66) with severe osteomyelitis and sternal destruction after receiving myocardial revascularization underwent partial or radical sternal resection, omental flap transposition, titanium mesh implantation and rectus abdominis muscle flap transposition. The final procedure involved single-stage closure.

RESULTS

One patient died 9 days after the final procedure due to pneumonia and septicemia. The other patients received antibiotics for at least 6 weeks postoperatively. The mean hospital stay was 36 days. Optimal wound healing was observed, with acceptable cosmetic disorders.

CONCLUSIONS

Although lateral sternal support is the first-line surgical treatment for sternal dehiscence, performing primary closure of complicated defects is often impossible. Aggressive treatment modalities are required in such cases for anterior chest wall defects. This technique provides the ability to perform rigid and stable sternal closure in complicated cases.

Evaluation of risk factors for hospital mortality and current treatment for poststernotomy mediastinitis

PURPOSE

Poststernotomy mediastinitis (PSM) following cardiovascular surgery remains an intractable complication associated with considerable mortality. It is therefore necessary to assess the risk factors associated with hospital mortality and evaluate the surgical treatment options for PSM.

METHODS

We identified 59 (2.2%) patients who developed PSM after cardiovascular surgery between January 1991 and January 2010. PSM was defined as deep sternal wound infection requiring surgical treatment. In all, 31 patients were infected with methicillin-resistant Staphylococcus aureus (MRSA); and 14 patients died in hospital from PSM. A total of 51 patients were treated by simple closure or tissue flap reconstruction after débridement (traditional treatment), and 8 underwent closure or reconstruction after negative-pressure wound therapy (NPWT). The risk factors for in-hospital mortality due to PSM were analyzed by comparing the characteristics of survivors and nonsurvivors. The available surgical treatments for mediastinitis were also assessed.

RESULTS

Univariate analysis identified age, sex, pulmonary disease, MRSA infection, prolonged mechanical ventilation and prolonged intensive care unit stay as risk factors for in-hospital mortality (P < 0.05). Multiple logistic regression analysis identified MRSA infection (odds ratio 20.263, 95% confidence interval 1.580-259.814; P = 0.0208) as an independent risk factor for hospital mortality. NPWT was associated with significantly less surgical failure than traditional treatment (P = 0.0204). There were no deaths as a result of PSM in patients who underwent NPWT irrespective of the presence of MRSA infection.

CONCLUSION

MRSA infection was an independent risk factor for PSM-related in-hospital mortality. NPWT may improve the prognosis for patients with MRSA mediastinitis.