Nontuberculous mycobacterial infections in left ventricular assist device patients

Detection of Gram-Ghost Bacilli and Additional Ziehl-Neelsen Stain for the Early Diagnosis of Driveline Infection: A Case Report

BACKGROUND

Driveline infections (DLI) caused by nontuberculous mycobacteria (NTM) in patients with implantable left ventricular assist devices (iLVAD) are rare but fatal, requiring early diagnosis and appropriate treatment. Herein, we present a rare case of DLI caused by Mycobacterium chelonae, which was promptly diagnosed using Gram stain and Ziehl-Neelsen stain and followed a favorable clinical course.

CASE PRESENTATION

A 51-year-old man with an iLVAD complicated by DLI was admitted to our center. He had no fever but had a slight ache and rash around the driveline exit site on admission. The wound condition gradually deteriorated with increasing purulent discharge from the driveline exit site and an elevated inflammatory response, despite daily irrigation. Gallium scintigraphy led to the diagnosis of deep DLI, followed by surgical debridement and omental flap transposition with driveline translocation. The Gram stain of the purulent discharge from the surgical site showed unstained bacilli (Gram-neutral, neither positive nor negative) along with leukocyte phagocytosis. Additionally, the Ziehl-Neelsen stain was positive. NTM was suspected after confirming the negative polymerase chain reaction for M. tuberculosis. Antibiotic therapy was switched to a specific regimen for skin and soft tissue infections caused by NTM. After identifying M. chelonae, antibiotic therapy was switched to a more specific regimen (clarithromycin and doxycycline) for M. chelonae according to the susceptibility test results. The patient was discharged after 3 months without infection recurrence.

CONCLUSIONS

Detecting Gram-ghost bacilli and using an additional Ziehl-Neelsen stain can be beneficial for the early diagnosis of repeated DLI with unknown etiology.

Risk factors, diagnostic methods and treatment of infection in adult patients undergoing left ventricular assist device implantation: A scoping review

BACKGROUND

Evidence on infection risk factors is scarce, and precise localization of the site of infection and its treatment remain clinically challenging.

OBJECTIVES

This study aimed to map the recommendations for adult patients undergoing left ventricular assist device implantation.

DESIGN

This is a scoping review, registered in the Open Science Framework under DOI10.17605/OSF.IO/Q76B3(https://osf.io/q76b3/).

METHOD

This is a scoping review limited to the period between 2015 and 2022.The results of this scoping review are discussed and presented separately in 3 articles. This second paper synthesizes research evidence on the risk factors, diagnostic methods and treatment of infection in adult patients undergoing left ventricular assist device implantation.

RESULTS

The initial searches identified 771 studies. Sixty-nine patients met the eligibility criteria and were included in the scoping review. Forty-three articles addressing the risk factors, diagnosis and treatment of infection were included to answer the questions of this review.

CONCLUSION

Obesity has been shown to be the most common risk factor for the described process of infection by left ventricular assist devices.18F-fluorodeoxyglucose positron emission tomography showed high sensitivity in detecting cardiac device infection, and labeled leukocyte or gallium citrate-67 scintigraphy showed high specificity for left ventricular assist device infections; therefore, it can help differentiate infection from inflammation, particularly in patients with equivocal fluorodeoxyglucose positron emission tomography. Also, this review brings and discusses the limitations and strengths of diagnostic tests, the knowledge regarding the risk factors for left ventricular assist device infection, the therapeutic heterogeneity, the methodological issues of the studies, and the vast opportunity for future research on left ventricular assist device.

IMPLICATIONS FOR CLINICAL PRACTICE

Ventricular assist device professionals should evaluate risk factors prior to device implantation and periodically.18F-fluorodeoxyglucose positron emission tomography should be considered as diagnostic tool in detecting superficial and deep driveline infections. Early treatment, including chronic suppressive therapy and serial surgical debridement, combined with driveline exteriorization and delayed driveline relocation may constitute a potential therapeutic strategy for deep driveline infections.

Epidemiology, management, and clinical outcomes of extrapulmonary Mycobacterium abscessus complex infections in heart transplant and ventricular assist device recipients

Nontuberculous mycobacteria are emerging pathogens, yet data on the epidemiology and management of extrapulmonary nontuberculous mycobacteria infections in orthotopic heart transplantation (OHT) and ventricular assist device (VAD) recipients are scarce. We retrospectively reviewed records of OHT and VAD recipients who underwent cardiac surgery at our hospital and developed Mycobacterium abscessus complex (MABC) infection from 2013 to 2016 during a hospital outbreak of MABC linked to heater-cooler units. We analyzed patient characteristics, medical and surgical management, and long-term outcomes. Ten OHT patients and 7 patients with VAD developed extrapulmonary M. abscessus subspecies abscessus infection. The median time from presumed inoculation during cardiac surgery to the first positive culture was 106 days in OHT and 29 days in VAD recipients. The most common sites of positive cultures were blood (n = 12), sternum/mediastinum (n = 8), and the VAD driveline exit site (n = 7). The 14 patients diagnosed when alive received combination antimicrobial therapy for a median of 21 weeks, developed 28 antibiotic-related adverse events, and underwent 27 surgeries. Only 8 (47%) patients survived longer than 12 weeks after diagnosis, including 2 patients with VAD who experienced long-term survival after an explantation of infected VADs and OHT. Despite aggressive medical and surgical management, OHT and VAD patients with MABC infection experienced substantial morbidity and mortality.

Left ventricular assist device exchange from HeartMate II to HeartMate 3 in an Asian patient-a case report and literature review

BACKGROUND

Pump exchange surgery of left ventricular assist device (LVAD) has been demonstrated in several studies; however, information for Asian patients was limited.

CASE PRESENTATION

A 63-year-old man underwent a pump upgrade from HeartMate II to HeartMate 3 for driveline damage through limited left anterior thoracotomy and lower partial sternotomy. He did not experience any hemodynamic adverse events or device malfunction during postoperative follow-ups of 12 months. We also reviewed all published cases with HeartMate II exchange to HeartMate 3.

CONCLUSIONS

The case demonstrated that it was safe and feasible to perform HMII LVAD exchange to HM3 through a limited approach for Asian patients.

A case of mediastinal abscess and infected aortic aneurysm caused by dissemination of Mycobacterium abscessus subsp. massiliense pulmonary disease

An 81-year-old man was admitted to our hospital because of fever and malaise that had persisted for 3 months. The patient had undergone two aortic valve replacements, 10 and 5 years previously, because of aortic valve regurgitation and infectious endocarditis. He also had had asymptomatic Mycobacterium abscessus complex (MABC) pulmonary disease for the two previous years. Contrast-enhanced computed tomography showed a mediastinal abscess and an ascending aortic aneurysm. Mycobacterium abscessus subsp. massiliense was cultured from his blood, suggesting the aortic aneurysm was secondary to infection of an implanted device. After enlargement over only a few days, a leakage of contrast medium to the mediastinal abscess was found on computed tomography. The patient was diagnosed with rupture of an infectious aortic aneurysm, and emergency aortic replacement and drainage of the mediastinal abscess were successful. The patient was treated with several antibiotics, including meropenem, amikacin, and clarithromycin, and his general condition improved. Cultures from both the mediastinal abscess and a pericardial patch that was placed at the time of surgery 5 years previously revealed MABC. In our case, the infected aortic aneurysm most likely resulted from MABC pulmonary disease rather than from previous intraoperative contamination. This route of infection is rare. Physicians should be aware of the possibility of dissemination and subsequent infection of implants related to MABC pulmonary disease.

Nontuberculous Mycobacterial Infections Associated With Left Ventricular Assist Devices in 3 Patients

Durable left ventricular assist devices (LVADs) provide circulatory support in patients with end-stage heart failure; however, complications include infection of the driveline exit site. Nontuberculous mycobacterial infections are rare in patients with LVADs, but they should be considered in those who have undergone device exchanges and have bacterial infections with driveline exit-site discharge but no fever or leukocytosis. We reviewed the charts of patients who had an LVAD implanted at our institution from January 2009 through December 2019, to identify those with a device-related nontuberculous mycobacterial infection. Collected data included patient demographics, premorbid conditions, infection type, previous device complications, treatment, and outcomes. We identified infections in 3 patients (mean age, 41 yr): Mycobacterium abscessus in 2 and M. chimaera in 1. All had a HeartMate II device and had undergone device exchanges for pump thrombosis or for driveline fault or infections. All presented with driveline exit-site discharge without fever or leukocytosis. The mean time between initial device implantation and diagnosis of a nontuberculous mycobacterial infection was 55 months. All 3 patients were treated with antibiotics and underwent localized surgical débridement; one underwent an additional device exchange. The M. abscessus infections disseminated, and both patients died; the patient with M. chimaera infection continued to take suppressive antibiotics. Nontuberculous mycobacterial infections are associated with high morbidity and mortality rates, warranting prompt diagnosis and treatment.

Mycobacterium abscessus Infection in Left Ventricular Assist Device (LVAD): A Case Series

The limited availability of donor organs worldwide, has provoked a surge in the need for implantable left ventricular assist devices (LVADs) mainly as a bridge to heart transplantation or destination therapy. The rate of complications from LVAD use is also increasing, impacting morbidity, mortality, and costs. LVAD infections due to nontuberculous mycobacteria (NTM) are exceedingly rare, yet very difficult to treat. Here we present three cases of Mycobacterium abscessus LVAD infections. To our knowledge, only two other cases have been documented.