Omental pedicle graft in the management of infected ascending aortic prostheses

Management and Outcomes of Proximal Aortic Graft Infection: A Systematic Review

OBJECTIVE

Proximal aortic graft infection (PAGI) is a rare but often fatal postoperative complication. Its management often relied on surgical preferences and resource availability of each centre, until the recent unifying guidelines published by the European Society for Vascular Surgery (ESVS). This paper aimed to amalgamate the published experience in managing PAGI and their outcomes.

METHODS

PubMed, Scopus and Cochrane Library databases were searched systematically. All primary studies besides single-patient case reports were included. Data extracted included study and patient characteristics, type of index surgery, type of microorganisms involved, definitive treatment modality, and any outcome measures reported.

RESULTS

Of the 20 studies included, 157 of the 290 PAGI patients underwent complete graft explantation and replacement, 106 underwent graft-preservation interventions (debridement and/or irrigation), and 25 had antibiotics alone. Adjunctive interventions included graft coverage, vacuum-assisted closure, use of infection-resistant graft materials, and lifelong suppressive therapy. In-hospital mortality was 20.8% (n=60), with postoperative sepsis and multiorgan failure (n=24) being the most common cause. Recurrent infection occurred in 10 post-discharge patients. Post-discharge mortality rate was 11.4% (n=33), with cardiac complications and stroke being the most common cause in surgically-treated and medically-treated patients, respectively.

CONCLUSIONS

Given the risk of mortality, the management approach of PAGI highly depends on the fitness of the patient. We believe that early referral to specialised aortic centres is essential to plan for optimal management strategies and improve patient outcomes. Further studies are also required to parse out the most effective adjunctive interventions to maximise patient outcomes.

Omental Flap Coverage for Management of Thoracic Aortic Graft Infection

BACKGROUND

Since the first reported use of prosthetic aortic grafts, infection has remained a feared complication. Pedicled omentum is the preferred flap in managing thoracic aortic graft infection (TAGI); however the literature is sparse. The authors present their experience with TAGI managed with pedicled omental flaps.

METHODS

A single-institutional review from 2007 to 2018 was performed to analyze postoperative outcomes of omental flap reconstruction, performed by 2 surgeons, after a confirmed diagnosis of TAGI. The primary outcomes of overall complication rate, 30-day mortality, and in-hospital mortality were evaluated with univariate analysis.

RESULTS

Twenty patients requiring omental flap reconstruction after TAGI met inclusion criteria. The patient cohort included 14 men and 6 women with a mean age of 60.6 ± 12.9 years and a mean Charlson comorbidity index of 3.3 ± 2.1. Nine patients (45%) received omental flap reconstruction at the time of incipient TAGI surgical management by the cardiothoracic surgery team, whereas 11 patients received delayed reconstruction (mean, 6.22 days [range, 1-27]). The most common complications were graft leak (20%) and pseudoaneurysm (25%), with only 1 patient developing recurrent infection. Overall 30-day mortality was 20%. Chronic obstructive pulmonary disease and delayed omental flap reconstruction were associated with 30-day mortality (P = .04). Four of 11 patients (36.4%) who received delayed omental flap reconstruction died within 30 days, whereas 0 of 9 patients (0%) in the immediate omental coverage group died within 30 days (P = .043).

CONCLUSIONS

High mortality rates associated with TAGI exemplify the challenges associated with this disease process and patient population. Pedicled omentum is a safe adjunct with promising results to the management of TAGI while significantly reducing the risk of reinfection.

The Cardioplastic Approach to the Treatment of Infected Aortic Grafts

BACKGROUND

Aortic graft infection (AGI) is a rare complication following reconstructive aortic surgery, yet it represents a significant source of morbidity and mortality. There is no consensus regarding the optimal surgical management, due in part to the small cohorts of patient reports. Pedicled muscle or omental flap coverage of AGI has been shown to improve outcomes, making them a valuable consideration in the treatment algorithm. Thus, we aim to compile and evaluate cases of autologous vascularized tissue (AVT) in the treatment of infected aortic grafts, summarizing location specific trends, treatments, and outcomes.

METHODS

A comprehensive review of peer-reviewed literature regarding the management of AGI was performed. Data collected included patient characteristics, original procedure, pathogen, infection location, tissue utilized, technique of tissue isolation and delivery, staging, outcome, length of follow-up, and level of evidence.

RESULTS

Ninety-four cases of AGI managed with AVT transfer were identified. Infection of ascending aorta grafts accounted for 59% of cases, followed by a combination of ascending aorta and aortic arch (21%), the descending thoracic aorta (18%), and the thoracoabdominal aorta (2%). The infected graft was preserved in 81% of cases, followed by debridement and AVT coverage. The omentum was the most commonly applied flap (69%) for all divisions of the aorta followed by the pectoralis major (19%), the rectus abdominis (5%), and latissimus dorsi (4%). Mortality was limited, and the Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation overall survival was 93% (7 deaths), with a mean follow-up of 33.5 months.

CONCLUSIONS

Autologous vascularized tissue coverage has proven to be a successful approach for treatment of infected aortic grafts. Although the incidence of AGI is rare, it represents an area of scarce evidence-based literature that warrants increased attention and surgical refinement. These results, which show a remarkably low infection-related mortality rate (3%), should encourage interdisciplinary collaboration with the plastic surgeon, cardiothoracic surgeon, and infectious disease specialists with the goal of improving outcomes in the treatment of infected aortic grafts.

Contemporary outcome of the surgical management of prosthetic graft infection after a thoracic aortic replacement: is there a room to consider vacuum-assisted wound closure as an alternative?

Objective

Once a replaced prosthetic graft is infected, it is usually necessary to re-replace the thoracic aorta to achieve complete resolution of the infection. It is, however, an exceedingly invasive approach to perform such a repeat surgery on patients in a poor condition. We have managed both re-replacement of an infected prosthetic graft and conservative therapy with vacuum-assisted wound closure (VAC) without re-replacement. These two treatment modalities were retrospectively assessed.

Methods

Retrospective clinical chart review was undertaken on 21 patients with prosthetic graft infection after thoracic aortic replacement between December 1999 and December 2012. Surgical outcomes were evaluated between the two groups: re-replacement group (group R, n = 14) and no-replacement group (group NR, n = 7).

Results

In-hospital survival rates were 64.3 % in group R and 85.7 % in group NR. Mortality in group R included five patients, sepsis in two patients, and intraoperative aortic rupture, heart failure, and cerebral infarction in one. Mortality in group NR included one patient (sepsis). In terms of long-term outcome, one patient in group R and one patient in group NR died of rupture of a residual aortic aneurysm, and one patient in group NR died of renal disease during follow-up (52.8 ± 41.5 months for R and 43.2 ± 28.5 months for NR; mean ± standard deviation).

Conclusions

Re-replacement of an infected prosthetic graft after a thoracic aortic operation still carries a significant risk for mortality. VAC therapy may provide an acceptable option for such a subgroup of patients with this serious condition.

Acute aortic dissection type A discloses Corpus alienum

We report an unusual case of an aortic type A dissection with a corpus alienum which compresses the right ventricle. The patient successfully underwent an aortic root replacement in deep hypothermia with re-implantation of the coronary arteries using a modified Bentall procedure and the resection of the corpus alienum. Intraoperative finding reveals 3 greatly adhered gauze compresses, which were most likely forgotten in the operation 34 years ago.

Complete coverage of in situ aortograft by total omental pedicle flap as the most reliable treatment of aortoesophageal fistula

Aortoesophageal fistula secondary to a thoracic aortic aneurysm is usually a fatal disease with few survivors reported previously. We encountered 2 consecutive patients who were treated successfully with esophagectomy and in situ aorta reconstruction using cryopreserved homograft that was wrapped completely with omental pedicle flap. For the construction of omental flap, the right gastroepiploic artery was resected at the root and all the vessels entering the greater curvature and the transverse colon were resected at the adherent edges. Because the gastroepiploic arcade is totally preserved, large amounts of omental tissue could be obtained, with an excellent blood supply mainly from the left gastroepiploic artery. This type of omental flap is highly mobile, easily transferred to the left hemithorax, and has enough volume to cover the in situ aortic graft completely including anastomosis lines. Thus, our omental coverage appears to be the most reliable method to prevent postoperative graft infection.

Mycotic aneurysm of the descending thoracic aorta caused by Pseudomonas aeruginosa in a solid organ transplant recipient: case report and review

BACKGROUND

Pseudomonas aeruginosa is a rare cause of aortic mycotic aneurysms. Optimal treatment, including reconstructive graft material and appropriate length of antibiotic therapy, is being debated.

METHODS

We describe a 26-year-old kidney-pancreas recipient who developed an aneurysm of the descending thoracic aorta caused by P. aeruginosa.

RESULTS

After surgical debridement and cryopreserved allograft reconstruction, parenteral antibiotics were continued for 12 months, at which time the patient was converted to oral antibiotic therapy. Within 6 months, he redeveloped a thoracic aortic aneurysm, necessitating reoperation and lifelong parenteral antibiotic therapy.

CONCLUSION

Herein we review and discuss the relevant literature concerning surgical and antibiotic treatment of mycotic thoracic aneurysms.

Successful in situ treatment of an infected ascending aortic graft

Infection of an ascending aortic prosthesis is a grave complication associated with a high mortality. In most cases, extraanatomic bypass and removal of the infected vascular graft are not possible. Furthermore, the standard approach to this problem, which includes excision and replacement or debridement and repair of infected thoracic aortic grafts, carries a high early mortality. We report the successful treatment of this life-threatening complication using a conservative strategy in which the aortic prosthesis was salvaged by in situ disinfection followed by coverage with tissue flaps.

A new method for the treatment of graft infection in the thoracic aorta: in situ preservation

BACKGROUND

We have developed a new method to control graft infection by a combination of two procedures, extensive disinfection followed by tissue flap implantation, allowing preservation of the original graft.

METHOD

Soon after the diagnosis of graft infection was confirmed, the wound was re-explored, and debridement, irrigation and packing with sponges soaked with 10% iodine solution were employed. This procedure was repeated every 8 hours for the first 48 hours. For the second step, tissue flaps using omentum or muscle were implanted around the graft as well as in dead space, and the wound was closed primarily.

MATERIALS

A total of 6 patients were treated: 4 in the acute and 2 in the chronic phase of infection. The original procedures were a Bentall procedure + arch replacement (1), ascending aorta replacement + arch (3) and replacement of the descending aorta (2). In descending aorta cases, an extended thoracoplasty was concomitantly added to eliminate dead space in the pleural cavity.

RESULTS

Graft infections were controlled in all 6 patients. One hospital death unrelated to infection was encountered. Five patients were discharged, but 1 died of a stent-graft complication. The follow-up period ranged from 4 months to 10 years.

CONCLUSION

Our method of extensive disinfection followed by tissue flap coverage of the graft proved to be highly effective in controlling the serious complication of graft infection associated with surgery of the thoracic aorta.

Salvage of externally exposed ventricular assist devices

Although externally exposed ventricular assist devices are associated with extremely high mortality rates, salvage may be accomplished by early aggressive wound debridement, transposition of a well-perfused autologous tissue (such as omentum), dead space obliteration, and adequate external coverage using vascularized tissue. The temporary suppression rather than the total eradication of the infection should be the goal of these procedures.

Combined therapies for composite graft infection after Bentall's procedure

We present a patient who suffered from composite graft infection and mediastinitis. After replacement of the infected composite graft, in addition to administration of antibiotics, continuous irrigation of the mediastinum with solutions containing povidone-iodine and cefazolin sodium and transposition of the greater omentum were performed. His postoperative course was uneventful. Combined therapies including mediastinal irrigation and omental transposition should be considered after an operation for composite graft infection complicated with mediastinitis.

Results of omental flap transposition for deep sternal wound infection after cardiovascular surgery

OBJECTIVE

Our experience with omental flap transposition in the treatment of deep sternal wound infections is reviewed here with an emphasis on efficacy, risk factors for in-hospital mortality rates, and long-term results.

SUMMARY BACKGROUND DATA

Even with improvements in muscle and omental flap transposition, the timing of closure and the surgical strategy are controversial.

METHODS

Forty-four consecutive patients with deep sternal wound infections were treated using the omental flap transposition from 1985 through 1994. The strategies included debridement with delayed omental flap transposition or single-stage management, which consisted of debridement of the sternal wound and omental flap transposition. Methicillin-resistant Staphylococcus aureus was cultured from more than 50% of the wounds. A logistic regression analysis was used to identify the predictors of in-hospital death after omental flap transposition.

RESULTS

There were seven (16%) in-hospital deaths. Univariate analysis demonstrated that hemodialysis and ventilatory support at the time of omental flap transposition were significantly associated with in-hospital mortality rates (p = 0.0023 and p = 0.0075, respectively). Thirty-seven patients whose wounds healed well were discharged from the hospital. Two patients with cultures positive for methicillin-resistant Staphylococcus aureus had recurrent sternal infections. Patients without positive methicillin-resistant Staphylococcus aureus cultures had good long-term results after reconstructive surgery.

CONCLUSIONS

Transposition of an omental flap is a reliable option in the treatment of deep sternal wound infections, unless the patients require ventilatory support or hemodialysis at the time of transposition.

Reconstruction of complex chest wall defects

BACKGROUND

Reconstruction of complex chest wall defects represents a major challenge and requires close cooperation between the cardiothoracic and reconstructive surgeon to achieve an optimal outcome and reduce the incidence of complications. The principles of chest wall reconstruction include control of infection, local wound care, wide debridement of all necrotic and devitalized tissues, obliteration of all residual cavities and spaces with well-vascularized tissues, reestablishment, when necessary, of the continuity and skeletal stability of the chest wall, and immediate or early definitive coverage of all defects with well-vascularized tissues.

METHODS

This paper is based on our experience with 113 patients who underwent chest wall reconstruction for a variety of defects resulting from infection, trauma, tumor extirpation, and radionecrosis. All patients were treated with a variety of muscle flaps and/or omentum which provided obliteration of dead space and coverage. Seven patients with large anterolateral defects required additional skeletal stability with synthetic patches or mesh.

RESULTS

88.6% of patients healed without significant problems. 8.8% had major complications requiring reoperation and prolonged hospitalization while 4.4% had minor complications.

CONCLUSIONS

Based on long-term experience, we believe that currently the use of well-vascularized tissue is the method of choice for reconstruction of complex chest wall defects. This provides stable coverage, reduces hospital stay, and thus lowers overall care cost for these patients.

Management of mycotic aneurysm following repair of corrected transposition

Omental flaps have been used for the treatment of infected aortic prosthetic grafts in adults. We report the case of a 26-month-old male who developed a mycotic aneurysm 9 months following insertion of a ventricle to pulmonary artery conduit. The aneurysm was excised and the reconstructed outflow tract wrapped with omentum. The patient has not had recurrence of his aneurysm following this course of management.

Omental transfer for the treatment of mediastinitis in an infant

Mediastinitis following congenital heart surgery is relatively uncommon but is usually seen in the setting of postoperative low cardiac output. Conservative treatment utilizing debridement and irrigation is associated with significant morbidity and mortality. We report the successful application of the omental transfer technique in the treatment of mediastinitis in a 6 month old.

The use of omental pedicle flap for tracheobronchial reconstruction in infants and children

For the surgical repair of long-segment tracheal stenosis, costal cartilage graft or extensive resection with end-to-end anastomosis has often been used. Both procedures have a risk of developing anastomotic leakage, which is potentially a lethal complication, or stenosis resulting from compromised blood supply to the tissue at the anastomosis. We have used omental pedicle flap (OPF) to seal the anastomotic line and to restore the vascularity of the graft and the trachea in an attempt to avoid fatal complications. During the period between 1986 and 1990, OPF technique was used in tracheobronchial reconstruction in six patients aged 4 months to 3 years; cartilage graft for extensive tracheal stenosis (4), tracheal resection and anastomosis (1), and bronchial resection and anastomosis (1). The omentum was separated from the colon to form an OPF with the right gastroepiploic vessels preserved. The OPF was brought to the upper trachea in the mediastinum through the retrosternal space. There was no immediate postoperative death due to anastomotic leak. Endotrachial tubes were removed in all patients. Four of the six are totally free of airway problems. One patient showed persistent stridor because of remaining stenosis at the cervical trachea. The remaining one patient who underwent bronchial resection developed anastomotic stenosis probably due to the compression of the floppy left main bronchus by adjacent aorta. The OPF seems to be an important surgical adjunct in order to eliminate fatal complications in tracheobronchial reconstruction.

Fistulas between the aorta and tracheobronchial tree

Aortobronchial fistula is a rare condition that is invariably fatal if not diagnosed and surgically treated. With appropriate surgical intervention, survival rates greater than 70% can be achieved. A review of the literature and an illustrative case report are presented. A total of 63 fistulas in 62 patients have been described. The case we present is unusual in the use of serratus anterior muscle for repair of the fistula. Eighty-seven percent of the cases documented in the literature were associated with an aneurysm of the thoracic aorta. Eighty-six percent of the fistulas were between the descending aorta and left bronchopulmonary tree. More than 95% of patients experienced at least a single episode of hemoptysis, and massive hemoptysis occurred in more than half of the reported cases. A correct preoperative diagnosis was made in only 54% of cases. Plain chest radiographs definitively demonstrated an aneurysm in only 16%. The computed tomographic scan was the most rewarding test, identifying an aneurysm in 11 of 12 patients and the fistula in 50% of them. Surgical repair resulted in a 76% survival rate.

Non-heparin-binding endothelial cell growth factor from bovine omentum

The graft of omental pedicle is known to be clinically effective for wound healing and revascularization of ischemic organs. We found that bovine greater omentum contained growth factor that was capable of stimulating the proliferation of bovine aortic endothelial cells. Gel filtration of the tissue extract showed at least two activity peaks corresponding to molecular weights of 96,000 and 21,000. The major Mr 21,000 growth factor was partially purified approx 120-fold from the omental extract. The purified factor was not mitogenic to BALB/c 3T3 cells and, importantly, had no affinity for immobilized heparin. This factor is thus clearly distinct from fibroblast growth factors and related mitogens. The pI of the factor was estimated to be 5.6-6.0. This factor may be involved in the potent angiogenic activity expressed by the implanted omentum. The omental fat, which was previously shown to cause neovascularization in the assay in vivo, did not promote the growth of endothelial cells in vitro.

Use of the omentum in chest-wall reconstruction

Increased use of the omentum in chest-wall reconstruction has paralleled the refinement of anatomic knowledge and the development of safe mobilization techniques. Important anatomic points are the omental attachments to surrounding structures, the major blood supply from the left and right gastroepiploic vessels, and the collateral circulation via the gastroepiploic arch and Barkow's marginal artery. Mobilization of the omentum to the thorax involves division of its attachments to the transverse colon and separation from the greater curvature to fabricate a bipedicled flap. Most anterior chest wounds and virtually all mediastinal wounds can be covered with the omentum based on both sets of gastroepiploic vessels. The arc of transposition is increased when the omentum is based on a single pedicle, allowing coverage of virtually all chest-wall defects. The final method of increasing flap length involves division of the gastroepiploic arch and reliance on Barkow's marginal artery as collateral circulation to maintain flap viability. With regard to chest-wall reconstruction, we have included the omentum in the armamentarium of flaps used to cover mediastinal wounds. The omentum is our flap of choice for the reconstruction of most radiation injuries of the chest wall. The omentum may also be used to provide protection to visceral anastomoses, vascular conduits, and damaged structures in the chest, as well as to cover defects secondary to tumor excision or trauma. In brief, the omentum has proved to be a most dependable and versatile flap, particularly applicable to chest-wall reconstruction.