Options for managing infected ascending aortic grafts

Mediastinal transposition of the greater omentum for treatment of infected prostheses of the ascending aorta and aortic arch

OBJECTIVES

The aim of this study was to evaluate the outcomes of transposition of the omentum into the mediastinum to support the replacement of infected aortic grafts or to cover infected aortic grafts that are not amenable for surgical replacement.

METHODS

All patients with thoracic aortic graft infections who underwent mediastinal transposition of the omentum at our institution between 2005 and 2023 were included in this study. Mediastinal transposition of the omentum was performed either after replacement of the infected graft ('curative concept') or solely as bailout procedure by wrapping the infected graft ('palliative concept'). The diagnosis, including computed tomography scans during follow-up, was made according to the criteria of the Management of Aortic Graft Infection Collaboration.

RESULTS

The patient cohort consisted of 31 patients. Both in-hospital and 1-year mortality were 0% (n = 0) for the curative concept (n = 9) compared to 23% (n = 5) and 41% (n = 9) for the palliative concept (n = 22), respectively. There was no graft infection-associated death or recurrence of infection after 3 years in the curative group. Survival was 52% at 3 years in the palliative group, with freedom of infection in 59% of the patients (n = 13).

CONCLUSIONS

Transposition of the omentum and wrapping of the infected aortic prosthetic graft is a useful bailout strategy for patients who are ineligible for replacement of an infected aortic graft. However, mortality stays high. For radical treatment of aortic graft infections, it may prove an effective supportive therapy and represents an important tool in the armamentarium of cardiac surgeons.

The presence of skin bacteria in the sternal wound and contamination of implantation materials during cardiac surgery

BACKGROUND

Sternal wound infections (SWI) and aortic graft infections (AGI) are serious complications after cardiac surgery. Staphylococcus aureus and coagulase-negative staphylococci are the most common causes of SWI, while AGI are less studied. AGI may occur from contamination during surgery or postoperative haematogenous spread. Skin commensals, such as Cutibacterium acnes, are present in the surgical wound; however, their ability to cause infection is debated.

AIM

The aim of this study was to investigate the presence of skin bacteria in the sternal wound and to evaluate their possible ability to contaminate surgical materials.

METHODS

We included 50 patients that underwent coronary artery bypass graft surgery and/or valve replacement surgery at our centre from 2020 to 2021. Cultures were collected from skin and subcutaneous tissue at two time points during surgery, and from pieces of vascular graft and felt that were pressed against subcutaneous tissue. The most common bacterial isolates were tested for antibiotic susceptibility with disk diffusion and gradient tests.

FINDINGS

Cultures from skin had bacterial growth in 48% of patients at surgery start and in 78% after two hours, and cultures from subcutaneous tissue were positive in 72% and 76% of patients, respectively. The most common isolates were C. acnes and S. epidermidis. Cultures from surgical materials were positive in 80-88%. No difference in susceptibility was found for S. epidermidis isolates at surgery start compared to after two hours.

CONCLUSIONS

The results suggest that skin bacteria are present in the wound and may contaminate surgical graft material during cardiac surgery.

Three-dimensional printing in integrated multi-modality imaging approach for management of prosthetic valves infective endocarditis

After heart failure, infectious endocarditis is the second leading cause of death in patients with prosthetic valves. Aortic pseudoaneurysms are a serious complication of infective endocarditis in mechanical or bioprosthetic aortic prostheses. Diagnostic and management challenges are posed by aortic pseudoaneurysms. In these cases, a multi-modality imaging approach with a heart team is recommended. We described two cases of aortic pseudoaneurysms that developed as a result of infective endocarditis. The first case involved a TAVI patient who developed infective endocarditis as a result of diabetic foot complications. Because traditional echocardiography and computed tomography failed to show the anatomy of the lesion, we used 3D printing to show the anatomy, extension of the pseudoaneurysm, and proximity to the right coronary artery. The second case involved a patient who underwent Bentall's surgery with an aortic root and mechanical aortic valve and later developed infective endocarditis complicated by pseudoaneurysms. In this case, 3D printing was used for preoperative surgical planning.

Enhanced strategy against mediastinitis with thoracic vascular graft infection: A combination of hydro-debridement with pulsed lavage and negative pressure wound therapies

BACKGROUND

We investigated the effects of hydrodebridement with pulsed lavage (HDPL) and negative pressure (NP) wound therapies, instead of excising the prosthetic graft, in patients with postoperative thoracic vascular graft infection (TVGI).

METHODS

Between 2020 and 2021, five TVGI patients aged 49.6 ± 19.4 years old underwent a combined therapy of HDPL and NP. The patients underwent a two-step procedure (first step: re-sternotomy and HDPL; second step: NP) every 3 or 4 days. After negative tissue culture, the patients underwent omentum flap wrapping and skin closure.

RESULTS

No hospital death was observed. The time to skin closure was 10.8 ± 3.4 days. The time to the day in which bacteria were not cultured was 3.5 ± 2.4 days. No recurrent infections occurred for 241 ± 186 postoperative days.

CONCLUSION

Our strategy for TVGI patients may contribute to (1) sufficient infection control, (2) physical rehabilitation, and (3) less invasiveness for high-risk patients.

Thoracic Aortic Graft Salvage after Sternal Wound Infection with Antibiotic Beads and Flap Coverage

Infections involving thoracic aortic grafts are difficult to treat and have devastating consequences. The traditional approaches to surgical management include aggressive debridement with graft explantation and replacement. Despite treatment, the reported morbidity and mortality rates are high. The purpose of this study was to present our experience with an innovative approach to aortic graft salvage in the setting of sternal wound infection using antibiotic impregnated polymethylmethacrylate beads followed by definitive wound closure with flap coverage. A retrospective review identified patients with surgical wounds after aortic graft or cardiac valve placement over a 7-year period at a single institution. Patients were treated using an algorithm consisting of repeated surgical debridement and placement of antibiotic beads followed by flap coverage after suppression of the infection. A total of 20 patients were treated for surgical wounds, including 19 sternal and one thoracotomy wound. Culture positive surgical site infections were documented in 16 patients. One patient required a bead exchange before definitive closure. There were no in-hospital mortalities. All but two patients achieved successful infection suppression and wound closure with flap coverage. The use of antibiotic beads with serial debridement and flap closure may offer a valid option for aortic graft salvage in the setting of infected sternal wounds in the appropriate patient population. The proposed algorithm showed that patients may be successfully treated, and their infection suppressed without the need for graft removal. Mortality rates were lower from those previously reported in the literature.

Stent infection and pseudoaneurysm formation after carotid artery stent treated by excision and in situ reconstruction with polytetrafluoroethylene graft: A case report

Background:

Stent infection after carotid artery stenting (CAS) can be a life-threatening postoperative complication, but there is a paucity of data due to its exceedingly low frequency. We report a case of stent infection with pseudoaneurysm formation after CAS that was treated through replacing the infected stent and pseudoaneurysm with a polytetrafluoroethylene (PTFE) synthetic vessel graft.

Case Description:

An 86-year-old man was treated for the right internal carotid artery with CAS in local hospital. One month after stenting, he suffered aspiration pneumonia and septicemia. Three months after stenting, swelling and tenderness of the right side of his neck appeared. His general condition deteriorated due to septicemia and he was unable to ingest anything by mouth as a result of decreasing levels of consciousness. He was transferred to our hospital. Computed tomography and digital subtraction angiography showed the presence of a pseudoaneurysm around the stent. The neck mass enlarged daily and surgical intervention was required to prevent closure of the airway. Stent and pseudoaneurysm resection and in situ reconstruction with a PTFE synthetic vessel graft were performed. The patient returned to his local hospital 36 days after surgery and had a modified Rankin Score of 5.

Conclusion:

Although the risk of reinfection is high due to the nature of artificial material, stent/pseudoaneurysm resection and in situ reconstruction with a PTFE synthetic vessel graft might be one of the best options for patients suffering stent infection after CAS. To the best of our knowledge, this is the first report of treatment using this material.

Role of Multimodal Imaging in Patients With Suspected Infections After the Bentall Procedure

Purpose: This study aimed to assess the diagnostic performances of multimodal imaging [i.e., white blood cell single-photon emission computed tomography/CT (^99mTc-HMPAO-WBC SPECT/CT) and 18-fluoride-fluorodeoxyglucose positron emission tomography/CT ([¹⁸F]FDG PET/CT)] in patients with suspected infection after the Bentall procedure, proposing new specific diagnostic criteria for the diagnosis.

Methods: Between January 2009 and December 2019, we selected within a cardiovascular infections registry, 76 surgically treated patients (27 women and 49 men, median 66 years, and range 29–83 years). All the patients underwent molecular imaging for a suspected infection after the replacement of the aortic valve and ascending aorta according to the Bentall procedure. We analyzed 98 scans including 49 ^99mTc-WBC and 49 [¹⁸F]FDG PET/CT. A total of 22 patients with very early/early suspected infection (<3 months after surgery) were imaged with both the techniques. Positive imaging was classified according to the anatomical site of increased uptake: to the aortic valve (AV), to both the AV and AV tube graft (AVTG) or to the TG, to surrounding tissue, and/or to extracardiac sites (embolic events or other sites of concomitant infection). Standard clinical workup included in all the patients having echocardiography/CT, blood culture, and the Duke criteria. Pretest probability and positive/negative likelihood ratio were calculated. Sensitivity and specificity of ^99mTc labeled hexamethylpropylene amine oxime-WBC SPECT/CT (^99mTc-HMPAO-WBC SPECT/CT) and [¹⁸F]FDG PET/CT imaging were calculated by using microbiology (n = 35) or clinical follow-up (n = 41) as final diagnosis. ^99mTc-HMPAO-WBC scintigraphy and [¹⁸F]FDG PET/CT findings were compared with 95% CIs by using the McNemar test to those of echocardiography/CT, blood culture, and the Duke criteria.

Results: Sensitivity, specificity, and accuracy of ^99mTc-HMPAO-WBC were 86, 92, and 88%, respectively, with a slightly higher sensitivity for tube graft infection (TGI) as compared to isolated AV and combined AVTG. Overall, sensitivity, specificity, and accuracy of [¹⁸F]FDG PET/CT were 97, 73, and 90%, respectively. In 22 patients with suspected very early and early postsurgical infections, the two imaging modalities were concordant in 17 cases [10 true positive (TP) and 7 true negative (TN)]. [¹⁸F]FDG PET/CT presented a higher sensitivity than ^99mTc-HMPAO-WBC scan. ^99mTc-HMPAO-WBC scan correctly classified as negative three false-positive (FP) PET/CT findings.

Conclusion: Our findings supported the use of ^99mTc-HMPAO-WBC SPECT/CT and [¹⁸F]FDG PET/CT in patients with suspicion infection after the Bentall procedure early in the course of the disease onset to confirm the diagnosis and provide a comprehensive assessment of disease burden through the proposed criteria.

The impact of vascularized tissue flap coverage on aortic graft infection with and without infected graft excision

OBJECTIVES

Aortic graft infection (AGI) is a serious condition associated with a high mortality rate. However, optimal surgical options have not been identified. Therefore, we retrospectively reviewed AGI cases, including those in the thoracic and abdominal regions, with or without fistula formation, to investigate the various options for better outcomes.

METHODS

We reviewed 50 patients who underwent surgical interventions for AGI out of 97 patients with arterial infective disease. The mean patient age was 67 ± 17 years. Fourteen patients (28%) had a fistula with the gastrointestinal tract or lung. A combination of graft excision and vascularized tissue flap coverage was performed in 25 cases (50%). Tissue flap alone, graft excision alone and cleansing alone were performed in 9 (18%), 10 (20%), and 6 cases (12%), respectively.

RESULTS

Total in-hospital mortality rate was 32% (n = 16). In-hospital mortalities in patients with and without fistulas were 43% (6/14) and 28% (10/36), respectively (P = 0.33). Subgroup analysis among patients without fistula demonstrated that the in-hospital mortality rate of the patients with vascularized tissue flap (3/21, 14%) was significantly lower than that of the patients without vascularized tissue flap (7/14, 50%, P = 0.026). Overall 1- and 5-year survival rates were 66% and 46%, respectively. In multivariable analysis, an independent factor associated with in-hospital mortality was vascularized tissue flap (odds ratio 0.20, P = 0.024).

CONCLUSIONS

Vascularized tissue flaps could provide better outcomes for AGI. Graft preservation with vascularized tissue flaps could be a useful option for AGI without fistula.

Infections of the aorta

Infection of the aorta continues to be a clinical challenge with high morbidity and mortality. The incidence varies between 0.6 and 2.6%. There has been a steady increase in graft infections, especially endograft infections, due to increased procedures (0.2 to 5%). Staphylococcus species remains the most common organism; however, gram-negative and rare causative agents are also reported. The clinical presentation can be very diverse and a high degree of suspicion is necessary to diagnose them. Sometimes, they may present as an emergency with rupture or fistulation. Diagnosis is based on a triad of clinical features, microbial cultures and imaging. Culture-specific antibiotics are mandatory during the entire course, but seldom cure alone. Surgical management remains the standard of care and involves an integrated approach involving debridement, reconstruction and use of adjuncts. Various aortic substitutes have been described with advantages and limitations. Pericardial tube grafts have emerged as a good option. Endo-vascular options are practiced mostly as a bridge to definitive surgery. A small role for conservative management is described. Aortic fistulation to the gut and airway carries a very high mortality. There are no large series in the literature to define guideline-directed treatment and most often it is a customized solution. The 30-day mortality remains close to 30%. Outcomes depend on multiple factors including patient's age, the timing of presentation, diagnosis, causative organism, host status and the treatment strategy adopted.

[Multi-component multi-stage treatment of a patient with infection of thoracic aorta prosthesis, deep sternal wound infection and soft tissue deficit of the chest]

We report a comorbid patient after redo Frozen Elephant Trunk procedure followed by recurrent infection of thoracic aortic prosthesis, deep sternal wound infection and extensive soft tissue defect. Closure with skin-muscle thoracodorsal flap and graft-sparing technique with omentoplasty is an alternative to total graft replacement for thoracic aortic graft infection in comorbid patients with concomitant extensive defect of the chest wall or recurrent infection in early postoperative period.

Native and prosthetic graft infections of the thoracic aorta: surgical management

 

OBJECTIVES

Infection of the native aorta or after previous open or endovascular repair of the thoracic aorta is associated with high risks for morbidity and mortality. We analysed the outcome after surgical management of a native mycotic aneurysm or of prosthetic graft infection of the descending aorta.

METHODS

From June 2000 to May 2019, a total of 39 patients underwent surgery in our centre for infection of the native descending aorta (n = 19 [49%], group A) or a prosthetic descending aorta [n = 20 (51%), group B]. In the 20 patients in group B, a total of 8 patients had prior open aortic repair with a prosthesis and 12 patients had a previous endovascular graft repair.

RESULTS

The cohort patients had a mean age of 57 ± 14; 62% were men (n = 24). The most common symptoms at the time of presentation included fever, thoracic or abdominal pain and active bleeding. Emergency surgery was performed in 11 patients (28%); 3 patients had emergency endovascular stent grafts implanted during thoracic endovascular aortic repair for aortic rupture before further open repair. The 30-day mortality was 42% in group A and 35% in group B. The 90-day mortality was 47% in group A and 45% in group B. Pathogens could be identified in approximately half of the patients (46%). The most commonly identified pathogens were Staphylococcus aureus in 6 patients (15%) and Staphylococcus epidermidis in 4 patients (10%). Survival of the entire group (including patients with both native and prosthetic graft infections) was 44 ± 8%, 39 ± 8% and 39 ± 8% at 1, 2 and 3 years after surgery. The percentage of patients who survived the initial perioperative period was 81 ± 9%, 71 ± 9% and 71 ± 10% at 1, 2 and 3 years after surgery.

CONCLUSIONS

Patients with infection of the descending aorta, either native or prosthetic, are associated with both high morbidity and mortality. However, patients who survive the initial perioperative period have an acceptable long-term prognosis. In emergency situations, thoracic endovascular aortic repair may help to stabilize patients and serve as bridge to open repair.

Systematic approach to diagnosis and management of infected prosthetic grafts in the proximal aorta

Objectives

Management of infected prosthetic aortic grafts in the ascending and or root is complex and multifaceted. We report our diagnostic pathway, management and outcomes, identifying successful strategies.

Methods

This was a retrospective, single center, observational study. Consecutive patients who underwent management of infected aortic grafts in the ascending and/or root at our institution between October 1998 and December 2019 were included. The main outcome measures were: discharge from hospital alive with at least 1 year survival, operative mortality and success of primary treatment strategy.

Results

Twenty‐six patients presented with infection of proximal aortic grafts and were managed through a number of strategies with an overall hospital‐survival of 81% and 1 year survival of 69%. Twenty of them ultimately underwent redo surgery with 25% operative mortality (within 24 h of surgery). Five patients underwent washout and irrigation of which two were successfully treated and cured with adjunctive antibiotics and two went on to have staged explant and definitive surgery. Interval between surgery and infection was 42.5 ± 35.8 months. All patients had at least one major criterion and three minor criterions with no diagnostic uncertainty. The commonest primary strategy was 3a (definitive surgery), (13/26, 50%).

Conclusions

Adopting a systematic and flexible patient specific approach to the diagnosis and management of patients with proximal aortic graft infections results in reasonable overall 1 year survival. In the majority of patients surgery is ultimately required in an attempt to achieve a curative treatment; however this comes with high operative mortality risk.

Aortic penetration due to a fish bone: a case report

Background

Aortoesophageal fistula (AEF) caused by an esophageal foreign body is a life-threatening crisis, with rapid progress and high mortality. The first case of AEF was reported in 1818, but the first successfully managed case was not until 1980. Although there have been some reports on this condition, in most cases, the aorta was invaded and corroded due to its adjacent relationship with the esophagus and subsequent mediastinitis. To date, few reports have described an aortic wall directly penetrated by a sharp foreign body, likely because this type of injury is extremely rare and most patients cannot receive timely treatment. Here, we present a rare case of a fish bone that directly pierced the aorta via the esophagus.

Case presentation

A 31-year-old female experienced poststernum swallowing pain after eating a meal of fish. Gastroscope showed a fishbone-like foreign body had penetrated the esophagus wall. Computed tomography revealed that the foreign body had directly pierced the aorta to form an AEF. Surgery was successfully performed to repair the aorta and esophagus. The postoperation and follow-up was uneventful.

Conclusions

For the treatment of foreign bodies in the esophagus, we should be alert of the possibility of AEFs. The effective management of AEFs requires early diagnosis and intervention, as well as long-term treatment and follow-up, which still has a long way to go.

Successful treatment of thoracic aortic graft infection by omental flap following vacuum-assisted closure therapy

BACKGROUND

Postoperative thoracic aortic graft infection (TAGI) is a serious and potentially fatal complication. The classical approach is to replace the infected graft. However, this approach has a high mortality rate. Alternatively, treatment of TAGI without graft replacement can be performed METHOD: Herein, we present a 72-year-old case with mediastinitis and graft infection after type A aortic dissection operation and successful treatment using omental flap coverage following vacuum-assisted wound closure therapy without graft replacement.

CONCLUSION

The patient had an uneventful postoperative course and remains infection-free to date.

Successful treatment of left ventricular patch infection by latissimus dorsi muscle flap covering without patch removal

Removal of the infected prosthesis is considered an essential procedure in the treatment of prosthetic graft infection following cardiovascular surgery. Here, we present a case of left ventricular patch infection following repair of left ventricular rupture that was successfully treated by coverage with a latissimus dorsi muscle flap without patch removal. A 61-year-old man underwent double-patch repair for left ventricular-free wall rupture following posterior myocardial infarction. He underwent drainage and omental transposition with re-sternotomy for postoperative mediastinitis by Candida albicans, followed by pericardial fenestration via left thoracotomy for infectious pericarditis; however, left ventricular patch infection was detected. Considering the high invasiveness of a reoperation for patch removal, we preserved and covered the patch using a left pedicled latissimus dorsi muscle flap via left thoracotomy. The postoperative course was uneventful, and the patient was asymptomatic with no signs of recurrence at 30 months.

Incidence and Surgical Outcomes of Patients With Native and Prosthetic Aortic Valve Endocarditis

BACKGROUND

The aim of this study was to retrospectively evaluate the incidence and surgical outcomes of patients with native infective endocarditis (IE) and prosthetic aortic valve endocarditis (PVE) over the past decade at a single institution.

METHODS

Between January 2005 and December 2015, 289 patients (mean age, 63.3 ± 14.2 years) suffering from native IE (n = 186) and PVE (n = 103) of the aortic valve underwent surgical procedures. Perioperative data were acquired retrospectively for statistical analysis.

RESULTS

During the study period the mean incidence of endocarditis increased from 22.0 ± 4.2 (2005-2009) to 29.8 ± 10.1 (2010-2015) cases per year. In-hospital mortality was significantly increased in PVE (22.3%) versus IE (9.1%) patients (P < .001). In elective cases in-hospital mortality between the 2 groups was comparable (2.2% vs 4.6%; P = .288). Multivariate analysis identified urgent surgery (odds ratio [OR], 6.461; 95% CI, 1.941-21.509; P = .002), mitral regurgitation II (OR, 4.230; 95% CI, 1.249-14.331; P = .021), previous homograft operation (OR, 66.096; 95% CI, 2.369-1844.272; P = .0.14), and left ventricular ejection fraction < 40% (OR, 8.267; 95% CI, 1.931-35.388; P = .004) as independent risk factors for in-hospital mortality, whereas pathogen identification by preoperative blood cultures (OR, .228; 95% CI, 0.063-0.817; P = .023) was found to be independently protective.

CONCLUSIONS

Surgery for native IE and PVE of the aortic valve may be performed with satisfactorily results at experienced cardiac surgical centers. In comparison PVE patients suffer from a more than twice as high in-hospital mortality, more postoperative complications, and inferior long-term survival. However preoperative identification of causative pathogens in IE and PVE allows for improved in-hospital survival.

Current AATS guidelines on surgical treatment of infective endocarditis

The 2016 American Association for Thoracic Surgery (AATS) guidelines for surgical treatment of infective endocarditis (IE) are question based and address questions of specific relevance to cardiac surgeons. Clinical scenarios in IE are often complex, requiring prompt diagnosis, early institution of antibiotics, and decision-making related to complications, including risk of embolism and timing of surgery when indicated. The importance of an early, multispecialty team approach to patients with IE is emphasized. Management issues are divided into groups of questions related to indications for and timing of surgery, pre-surgical work-up, preoperative antibiotic treatment, surgical risk assessment, intraoperative management, surgical management, surveillance, and follow up. Standard indications for surgery are severe heart failure, severe valve dysfunction, prosthetic valve infection, invasion beyond the valve leaflets, recurrent systemic embolization, large mobile vegetations, or persistent sepsis despite adequate antibiotic therapy for more than 5-7 days. The guidelines emphasize that once an indication for surgery is established, the operation should be performed as soon as possible. Timing of surgery in patients with strokes and neurologic deficits require close collaboration with neurological services. In surgery infected and necrotic tissue and foreign material is radically debrided and removed. Valve repair is performed whenever possible, particularly for the mitral and tricuspid valves. When simple valve replacement is required, choice of valve-mechanical or tissue prosthesis-should be based on normal criteria for valve replacement. For patients with invasive disease and destruction, reconstruction should depend on the involved valve, severity of destruction, and available options for cardiac reconstruction. For the aortic valve, use of allograft is still favored.

Massive prosthetic aortic abscess: an overarching plight 7 years post-Bentall's procedure

Infections of proximal aortic vascular grafts are a catastrophic complication of aortic surgery. Despite aggressive antimicrobial and surgical intervention, mortality and reinfection rates remain significant. Here, we describe a man aged 71 years with a medical history of bioprosthetic aortic valve with aortic arch replacement (modified Bentall's procedure), who developed a large periprosthetic abscess due to Staphylococcus aureus 7 years after his initial surgery. The patient's preference was to avoid redo surgery, however despite high-dose intravenous flucloxacillin and oral rifampicin therapy, there was rapid progression of the abscess, necessitating urgent surgery. Notwithstanding the burden of infection, the patient underwent successful surgical excision and graft re-implantation and remains independent and well, almost 2 years postoperatively.

The "3M" Approach to Cardiovascular Infections: Multimodality, Multitracers, and Multidisciplinary

Cardiovascular infections are associated with high morbidity and mortality. Early diagnosis is crucial for adequate patient management, as early treatment improves the prognosis. The diagnosis cannot be made on the basis of a single symptom, sign, or diagnostic test. Rather, the diagnosis requires a multidisciplinary discussion in addition to the integration of clinical signs, microbiology data, and imaging data. The application of multimodality imaging, including molecular imaging techniques, has improved the sensitivity to detect infections involving heart valves and vessels and implanted cardiovascular devices while also allowing for early detection of septic emboli and metastatic infections before these become clinically apparent. In this review, we describe data supporting the use of a Multimodality, Multitracer, and Multidisciplinary approach (the 3M approach) to cardiovascular infections. In particular, the role of white blood cell SPECT/CT and [¹⁸F]FDG PET/CT in most prevalent and clinically relevant cardiovascular infections will be discussed. In addition, the needs of advanced hybrid equipment, dedicated imaging acquisition protocols, specific expertise for image reading, and interpretation in this field are discussed, emphasizing the need for a specific reference framework within a Cardiovascular Multidisciplinary Team Approach to select the best test or combination of tests for each specific clinical situation.

Endocarditis in patients with ascending aortic prosthetic graft: a case series from a national multicentre registry

OBJECTIVES

Endocarditis in patients with ascending aortic prosthetic graft (AAPG) is a life-threatening complication. The purpose of this study was to examine the clinical presentation and prognosis of patients with AAPG endocarditis included in a large prospective infectious endocarditis multicentre study.

METHODS

From January 2008 to April 2015, 3200 consecutive patients with infectious endocarditis according to the modified Duke criteria, were prospectively included in the 'Spanish Collaboration on Endocarditis Registry (GAMES)' registry. Twenty-seven definite episodes of endocarditis (0.8%) occurred in patients with AAPG.

RESULTS

During the study period, 27 cases of endocarditis were detected in patients with AAPG. The median age of patients was 61 years [interquartile range (IQR) 51-68 years] and 23 (85.2%) patients were male. The median time from AAPG surgery to the episode of AAPG infection was 24 months (IQR 6-108 months). The most frequently isolated micro-organisms were coagulase-negative staphylococci and S. aureus (11 patients, 40.7%). Four patients (14.8%) underwent medical treatment, whereas surgery was performed in 21 (77.7%). Two patients (7.4%) died before surgery could be performed. The median hospital stay prior to surgery was 7 days (IQR 4-21 days). Surgery consisted of replacing previous grafts with a composite aortic graft (10 cases) or aortic homograft (2 patients), and removal of a large vegetation attached to the valve of a composite tube (1 case). Nine patients had an infected aortic valve prosthesis without evidence of involvement of the AAPG. Isolated redo-aortic valve replacement was performed in 8 (88.9%) of these patients. Reinfection occurring during 1 year of follow-up was not detected in any patient. Two patients (7.4%) died while awaiting surgery and 6 did so after surgery (22.2%). A New York Heart Association (NYHA) Class IV was associated with mortality in patients undergoing surgery (P < 0.019).

CONCLUSIONS

Most cases of endocarditis in patients with AAPG occur late after initial surgery. Mortality rate of patients with AAPG endocarditis who undergo surgery is acceptable. NYHA Class IV before surgery is associated with an increased postoperative mortality.

Management of early graft infections in the ascending aorta and aortic arch: a comparison between graft replacement and graft preservation techniques

OBJECTIVES

Treatment of infected thoracic aortic grafts is associated with considerable morbidity and mortality. The replacement of an infected graft is an effective strategy, yet a complex surgical endeavour, especially if the aortic root or aortic arch is involved. In situ graft-sparing surgical therapy with continuous mediastinal irrigation after surgical debridement might offer an alternative in the management of early graft infections in the thoracic aorta.

METHODS

Between 1996 and August 2015, 25 patients were treated in our institution for early graft infection after thoracic aortic surgery via sternotomy. In 11 patients, the infected prosthesis was replaced by a cryopreserved homograft or a biological valved pericardial xenograft. In 14 patients, an attempt to salvage the graft was made by resternotomy, aggressive debridement and subsequent continuous mediastinal antibiotic irrigation over a course of 2 weeks, accompanied by systemic antibiotic therapy.

RESULTS

In-hospital mortality was comparable (replacement group: 2/11 = 18%, graft-sparing group: 2/14 = 14%, P = ns). The time interval from the initial surgery was significantly shorter in the graft-sparing group (replacement group: 165 days [range 95-300 days] and graft-sparing group: 24 days [range 15-93 days], P = 0.004]. Two patients (14%), who were treated with the graft-sparing approach >100 days after the initial surgery, were retreated for infection, and 1 due to an intra-aortic infection of an aortic arch hybrid stent graft was not amenable to external irrigation (median follow-up: 1.5 years [range 1.1-2.1 years]). One patient in the replacement group (9%) was reoperated on due to homograft degeneration (median follow-up: 6.0 years [3.0-8.9 years]).

CONCLUSIONS

In situ graft-sparing surgical therapy is safe and effective if diagnosis and treatment of aortic graft infection is initiated promptly and aggressively (ideally <1 month post-surgery). Our method produces good midterm results (3 years). For aortic graft infections that become clinically apparent >3-6 months after surgery, replacement of grafts with biological conduits (homografts or pericardial xenografts) most likely remains the best treatment option.

Resistance to infection of long-term cryopreserved human aortic valve allografts

OBJECTIVE

To analyze the in vitro antimicrobial activity of 3 antibiotic regimens (group A, gentamicin-piperacillin-vancomycin-metronidazole-amphotericin B; group B, gentamicin-piperacillin-flucloxacillin-metronidazole-amphotericin B; and group C, meropenem-vancomycin-tobramycin-colistin-amphotericin B) used in the processing of cryopreserved human ascending aortic tissue and aortic valves against Staphylococcus epidermidis and Staphylococcus aureus. The results were additionally compared with the infection resistance of cryopreserved ascending aortic tissue against Escherichia coli and Pseudomonas aeruginosa.

MATERIALS

Each of 10 cryopreserved human allografts (CHAs) was divided into 25 pieces (separating aortic wall and valve). Eighteen segments were microbiologically tested, and 7 pieces underwent scanning electron microscopy. A bacterial solution (4 mL; optical density, 0.20 ± 0.02) was used for contamination. After incubation, the optical density of the solution was measured. CHAs underwent sonication to release viable adherent bacteria. The number of attached bacteria was quantified by the colony forming units per square centimeter of CHA surface.

RESULTS

Antibiotic regimen groups B and C were more efficient than group A in eradicating gram-positive organisms adherent to the aortic wall (P < .001). Group C showed enhanced resistance against E coli compared with group A or B (P < .001), whereas group B appeared to be more effective against P aeruginosa (P < .001). With reference to each antibiotic regimen, ascending aortic tissue showed significantly less bacterial contamination with staphylococcal bacteria than valve grafts (P ≤ .01).

CONCLUSIONS

CHAs possess antibacterial activity despite long-term storage over 5 years. Antibiotic combinations applied during CHA processing have a significant influence on their infection resistance. Ascending aortic tissue shows a significantly enhanced bacterial resistance against staphylococcal bacteria compared with aortic valves.

Multidisciplinary Treatment Approach for Prosthetic Vascular Graft Infection in the Thoracic Aortic Area

Prosthetic vascular graft infection in the thoracic aortic area is a rare but serious complication. Adequate management of the complication is essential to increase the chance of success of open surgery. While surgical site infection is suggested as the root cause of the complication, it is also related to decreased host tolerance, especially as found in elderly patients. The handling of prosthetic vascular graft infection has been widely discussed to date. This paper mainly provides a summary of literature reports published within the past 5 years to discuss issues related to multidisciplinary treatment approaches, including surgical site infection, timing of onset, diagnostic methods, causative pathogens, auxiliary diagnostic methods, antibiotic treatment, anti-infective structures of vascular prostheses, surgical treatment, treatment strategy against infectious aortic aneurysms, future surgical treatment, postoperative systemic therapy, and antimicrobial stewardship. A thorough understanding of these issues will enable us to prevent prosthetic vascular graft infection in the thoracic aortic area as far as possible. In the event of its occurrence, the early introduction of appropriate treatment is expected to cure the disease without worsening of the underlying pathological condition.

Successful treatment of mediastinitis in a young child by omental translocation following extracardiac Fontan graft placement

Mediastinitis after a midline sternotomy can become a serious complication, especially after implantation of prosthetic vascular grafts. We present a case of a three-year-old boy with hypoplastic left heart syndrome who developed mediastinitis following his third-stage palliation (Fontan operation). Rather than following the "traditional" surgical therapy of graft explantation, debridement, and replacement, we chose to preserve the graft and protect it by omental translocation. The relative merits of this therapeutic approach, which is rarely utilized and underappreciated in children, are outlined and discussed.

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.

Late prosthetic graft infection after frozen elephant trunk presenting by haemoptysis and positive ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography

In cardiothoracic surgery, prosthetic graft infection represents a diagnostic and therapeutic challenge. Although clinical assessment, imaging techniques and microbiological investigations are helpful, late graft infection can be difficult to identify using classical diagnostic tools. An aggressive surgical approach involving removal and replacement of all prosthetic materials is technically demanding but remains the best strategy to eradicate infection. Herein, we report a case of a late aortic graft infection, after frozen elephant trunk implantation with atypical presentation, diagnosed with (18)F-fluorodeoxyglucose-positron emission tomography and treated successfully through a radical surgical strategy. This case emphasizes the emerging diagnostic role of positron emission tomography and encourages the adoption of an aggressive surgical approach.

Successful treatment using percutaneous drainage for aortic arch prosthetic graft infection

Prosthetic graft infection in the ascending aorta or aortic arch is a life-threatening complication. Redo graft replacement is also associated with high mortality and morbidity rates. Conservative treatments without graft removal recently developed as alternatives to conventional surgical approach have been reported with successful outcomes. We report a case of successful treatment of prosthetic graft infection in the aortic arch, for which percutaneous catheter drainage was initially performed prior to open surgery, followed by graft coverage with an omental flap. <Learning objective: Redo graft replacement for the prosthetic graft infection in the ascending aorta or aortic arch is associated with high mortality and morbidity rates. Conservative treatments without graft removal have recently been developed as alternatives to surgical approaches. Less invasive percutaneous drainage and irrigation would be a useful alternative second-line treatment before radical open repairs for the treatment of aortic graft infection.>.

Successful surgical in situ treatment of prosthetic graft infection by staged procedure after Bentall operation and total aortic arch replacement

We report a case of a 29-year-old Marfan patient who developed prosthetic graft infection 10 months after Bentall operation and successive replacement of the remaining ascending aorta and the entire aortic arch for acute aortic dissection. Instead of an aggressive high-risk aortic redo procedure with removal and replacement of the infected prosthetic graft we elected a staged graft-sparing surgical approach. After 18 months of close follow-up the patient is in good condition and free from infectious sequela. This case and our review of the literature suggest that open extensive disinfection followed by tissue flap coverage is highly effective in controlling thoracic aortic prosthetic graft infection and may be considered as first-line treatment in such high-risk aortic arch redo patients.

Management of vascular graft and endoprosthetic infection of the thoracic and thoraco-abdominal aorta

Infection of a vascular prosthesis or endovascular stent-graft is probably the most serious complication that may occur after implantation and dramatically affects the patient's outcome. Surgical treatment is almost always required but even after surgery, morbidity can be significant. Several approaches have been described with some advantages and/or some limitations. Complete resection of the infected foreign material with debridement of the surrounding tissue gives most probably the better results. Orthotopic reconstruction is the best option for all thoracic and thoraco-abdominal pathologies and the use of coated prostheses, homografts or self-made vascular tubes from xenopericardial tissue has to be discussed from case to case. In some exceptional situations, endovascular stent-graft can be performed as bridging to a more complete treatment if general condition of the patient has to be stabilized.

Successful management of an aortoesophageal fistula caused by a fish bone--case report and review of literature

We report a case of aortoesophageal fistula (AEF) caused by a fish bone that had a successful outcome. Aortoesophageal fistula is a rare complication of foreign body ingestion from which few patients survive. Over one hundred cases of AEF secondary to foreign body ingestion have been documented but only seven, including our case, have survived over 12 months. Treatment involved stabilising the patient with a Sengstaken-Blakemore tube and insertion of a thoracic aortic endovascular stent-graft. Unfortunately the stent became infected and definitive open surgical repair involved removing the stent, replacing the aorta with a homograft and coverage with a left trapezius flap while under deep hypothermic arrest.