Postoperative Trichosporon asahii spondylodiscitis after open lumbar discectomy: a case report

Microbial spectrum, patient-specific factors, and diagnostics in implant-related postoperative spondylodiscitis

Aims

Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date.

Methods

Patients treated for IPOS from January 2006 to December 2020 were included. Patient demographics, parameters upon admission and discharge, radiological imaging, and microbiological results were retrieved from medical records. CT and MRI were analyzed for epidural, paravertebral, and intervertebral abscess formation, vertebral destruction, and endplate involvement. Pathogens were identified by CT-guided or intraoperative biopsy, intraoperative tissue sampling, or implant sonication.

Results

A total of 32 cases of IPOS with a mean patient age of 68.7 years (37.6 to 84.1) were included. Diabetes, age > 60 years, and history of infection were identified as risk factors. Patient presentation upon admission included a mean body temperature of 36.7°C (36.1 to 38.0), back pain at rest (mean visual analogue scale (VAS) mean 5/10) and when mobile (mean VAS 6/10), as well as elevated levels of CRP (mean 76.8 mg/l (0.4 to 202.9)) and white blood cell count (mean 9.2 units/nl (2.6 to 32.8)). Pathogens were identified by CT-guided or conventional biopsy, intraoperative tissue sampling, or sonication, and Gram-positive cocci presented as the most common among them. Antibiotic therapy was established in all cases with pathogen-specific treatment in 23 (71.9%) subjects. Overall 27 (84.4%) patients received treatment by debridement, decompression, and fusion of the affected segment.

Conclusion

Cases of IPOS are rare and share similarities with spontaneous spondylodiscitis. While procedures such as CT-guided biopsy and sonication are valuable tools in the diagnosis of IPOS, MRI and intraoperative tissue sampling remain the gold standard. Research on known principles of PJI such as implant retention versus implant exchange need to be expanded to the field of spine surgery.

Orthopedic infections due to Trichosporon species: Case series and literature review

Reports of orthopedic fungal infections caused by Trichosporon species are extremely scarce, thus we aimed to describe a case series and review the cases published in the literature. Patients were retrospectively included if a previous culture of bone, joint, or soft tissues had resulted positive for Trichosporon species along with a clinical diagnosis of an orthopedic infection. Eight patients were included with diverse orthopedic conditions, most of them cases of osteomyelitis. The main isolated species was Trichosporon asahii. All patients were treated with antifungals, mainly voriconazole, and surgical management, resulting in high rates of clinical improvement and low associated mortality.

Trichosporon asahii septic thrombophlebitis following lower extremity amputation in an immunocompetent host

A 59-year-old man with a history of peripheral vascular disease status post femoral popliteal bypass presented with critical limb ischaemia of the left leg. An arterial Doppler ultrasound showed an occluded graft requiring an above knee amputation. Five days after surgery, the patient developed fever, leucocytosis, significant stump swelling and pain, and serosanguinous discharge from his wound. Wound swab cultures from the stump grew Trichosporon asahii A venous Doppler ultrasound revealed extensive thrombosis of the left lower extremity. Biopsy of the left thigh muscle showed necrotic thrombus with fungal hyphae in the clotted blood vessel. The left femoral vein was subsequently resected, and the excised venous tissue also grew T. asahii The patient was successfully treated with voriconazole based on antifungal susceptibilities. This case describes an invasive fungal infection in the absence of typical immunosuppressive conditions commonly associated with Trichosporon spp. It also illustrates the role of a combination of antimicrobial and surgical management in achieving cure.

Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen

Objectives: This review aimed to better depict the clinical features and address the issue of therapeutic management of Trichosporon deep-seated infections.

Methods: We comprehensively reviewed the cases of invasive Trichosporon infection reported in the literature from 1994 (date of taxonomic modification) to 2015. Data from antifungal susceptibility testing (AST) studies were also analyzed.

Results: Two hundred and three cases were retained and split into four groups: homeopathy (n = 79), other immunodeficiency conditions (n = 41), miscellaneous (n = 58) and newborns (n = 25). Trichosporon asahii was the main causative species (46.7%) and may exhibit cross-resistance to different antifungal classes. The unfavorable outcome rate was at 44.3%. By multivariate analysis, breakthrough infection (OR 2.45) was associated with unfavorable outcome, whilst the use of an azole-based therapy improved the prognosis (OR 0.16). Voriconazole-based treatment was associated with favorable outcome in hematological patients (73.6 vs. 41.8%; p = 0.016). Compiled data from AST demonstrated that (i) T. asahii exhibits the highest MICs to amphotericin B and (ii) voriconazole has the best in vitro efficacy against clinical isolates of Trichosporon spp.

Conclusions:Trichosporon infection is not only restricted to hematological patients. Analysis of compiled data from AST and clinical outcome support the use of voriconazole as first line therapy.

Postoperative spondilodiscitis

INTRODUCTION

Postoperative spondylodiscitis is a primary infection of the nucleus pulposus with secondary involvement of the cartilaginous endplate and vertebral bone. Although uncommon, postoperative spondylodiscitis causes major morbidity and may be associated with serious long-term sequelae. Several risk factors had been identified, including immunosuppression, obesity, alcohol, smoking, diabetes and malnutrition.

MATERIALS AND METHODS

A review of the literature was done to analyse the diagnosis, treatment and prevention of postoperative spondylodiscitis.

RESULTS

We found that the principles of conservative treatment are to establish an accurate microbiological diagnosis, treat with appropriate antibiotics, immobilise the spine, and closely monitor for spinal instability and neurological deterioration. The purpose of surgical treatment is to obtain multiple cultures of bone and soft tissue, perform a thorough debridement of infected tissue, decompress neural structures, and reconstruct the unstable spinal column with bone graft with or without concomitant instrumentation.

CONCLUSIONS

Appropriate management requires aggressive medical treatment and, at times, surgical intervention. If recognised early and treated appropriately, a full recovery can often be expected. Therefore, clinicians should be aware of the clinical presentation of such infections to improve patient outcome. A review of the literature was done to advance our understanding of the diagnosis, treatment, prevention and outcome of these infections.

Fungal postoperative spondylodiscitis due to Scedosporium prolificans

BACKGROUND CONTEXT

Postoperative fungal spondylodiscitis is a rare infectious disease.

PURPOSE

We report the first case of postoperative spondylodiscitis because of Scedosporium prolificans and review postoperative vertebral infection caused by fungi.

STUDY DESIGN/SETTING

Medline search.

METHODS

Case report and literature review.

RESULTS

On reviewing the cases of postoperative fungal spondylodiscitis reported so far in the literature, we found eight were caused by mold, and five by yeast. Clinically, the disease presents similar to postoperative vertebral osteomyelitis caused by bacteria, and a high clinical index of suspicion may be required to perform appropriate cultures to establish a diagnosis. Our review revealed a significant number of cases that were cured after surgical debridement and/or antifungal therapy.

CONCLUSIONS

On the basis of this limited assessment, it appears that the clinical course and prognosis of postoperative fungal spondylodiscitis is similar to that reported for postoperative pyogenic spondylodiscitis.