Cultures of Proximal and Distal Segments of Silicone Tubes After Dacryocystorhinostomy

Periocular Infection With Nocardia nova Following Dacryocystorhinostomy With Silicone Stent Intubation

Nocardia species are aerobic, rod-shaped, Gram-positive bacteria that are ubiquitous throughout the environment. Nocardia nova has been reported as the second most prevalent Nocardia species. However, reports of ocular and periocular infection caused by this organism are rare. The authors present a case of a 58-year-old woman with a medical history of acquired nasolacrimal duct obstruction of the left eye who underwent a revision dacryocystorhinostomy with silicone stent intubation and developed a surgical site infection that was culture-positive for N. nova . Treatment consisted of removal of the silicone stent and a prolonged course of oral antibiotics, resulting in the patient's full recovery. This is the second reported case of postoperative periocular N. nova infection after dacryocystorhinostomy and silicone stent intubation.

The Endoscopic Endonasal Dacryocystorhinostomy (eDCR) in the Immunocompromised Patient

We present the clinical case of a 51-year-old male patient, affected by common variable immunodeficiency (CVID). In his history recurrent orbital cellulitis, exacerbation of chronic right dacryocystitis, lacrimal sac empyema with periodic episodes of dacryocutaneous fistolization. The coexistence of these particular immunological defects and the lack of literature about similar cases required an accurate evaluation of each step of the diagnostic and therapeutic approach. We performed an endoscopic endonasal dacryocystorhinostomy with "cold" instruments. No surgical complications were observed in the immediate postsurgical period. We balanced the necessity of a follow-up based on frequent office evaluation and the current pandemic emergency, in order to not expose the patient to an additional infectious risk. The discussion will focus on several aspects: the adequacy of radiological, the "cold" surgical technique, the choice of avoiding endocanalicular prostheses. We will discuss also about the use of oral and topical therapy, avoiding probable post-surgical infectious complications.

Microbial Metagenomics of the Extubated Lacrimal Stents Following Dacryocystorhinostomy: The Lacriome Paper 4

PURPOSE

To study the metagenome of the microbes present on the extubated lacrimal stents following a dacryocystorhinostomy.

METHODS

A prospective study was performed on 10 consecutive extubated lacrimal stents obtained for the metagenomic analysis from the patients following an endoscopic dacryocystorhinostomy. The stents were extubated at 4 weeks postoperatively under endoscopic guidance and immediately transported on ice to the laboratory. Following DNA extraction and library preparation, a whole shotgun metagenome sequencing was performed on the Illumina platform. The downstream processing and bioinformatics of the samples were performed using multiple software packaged in SqueezeMeta pipeline or MG-RAST pipeline.

RESULTS

The taxonomic hit distribution across the stent samples showed that bacteria were the most common isolates (mean, 69.70%), followed by viruses (mean, 0.02%) and archaea (0.003%). The 3 major phyla identified were Firmicutes, Actinobacteria, and Proteobacteria. The prevalent organisms include Pseudomonas aeruginosa, Staphylococcus aureus, Corynebacterium accolens, Dolosigranulum pigrum, Citrobacter koserii, Staphylococcus epidermidis, E. coli, and Hemophilus influenza . The functional subsystem profiling demonstrated microbial genes associated with metabolism, cellular, and information processing. The functional subsystem categories were metabolism involving carbohydrates, amino acids, DNA and RNA, cell wall or cell capsule biogenesis, membrane transport, virulence, and defense mechanisms.

CONCLUSIONS

The present study is the first whole metagenome sequencing of the microbes isolated from the extubated lacrimal stents. The stents harbor diverse microbial communities with distinct ecosystem dynamics. Further studies on microbes-host interactions in the early postoperative period would provide valuable insights.

The Microbiological Profile of Bicanalicular Silicone Tubes Placed During External Dacryocystorhinostomy

Objectives:

To identify microbiological growth on bicanalicular silicone tubes (BST) placed during dacryocystorhinostomy (DCR) surgery and to analyze the association between culture results and surgical outcomes and BST removal time.

Materials and Methods:

A total of 80 lacrimal drainage systems of 68 patients who had external DCR with bicanalicular silicone intubation were included the study. Twenty-five tubes (31.3%) were removed up to 8 weeks, 28 tubes (35.0%) were removed between 9 and 11 weeks, and the remaining 27 tubes (33.7%) were removed 12 weeks or more after surgery. The tubes were transferred to Stuart medium and sent for microbiologic examination. The disc diffusion method was used to determine antibiotic resistance.

Results:

Culture positivity was observed for 96.2% of the tubes. Among a total of 109 isolates, 63 were gram-positive bacteria (57.8%), 37 were gram-negative bacteria (34%), and 9 were fungi (8.2%). The most commonly isolated gram-positive and gram-negative bacteria were Staphylococcus aureus (66.6%) and Enterobacter spp. (29.7%), respectively. Penicillin, clindamycin, erythromycin, and tetracycline resistances were higher among gram-positive pathogens. Cephalothin, amoxicillin-clavulanic acid, and ampicillin resistances were higher among gram-negative pathogens. There was no significant difference in terms of the microbiological profile between the three groups of removed tubes. Haemophilus influenzae was isolated at a significantly higher rate in patients with surgical failure (p=0.04).

Conclusion:

Although a variety of agents were isolated from removed BST, gram-positive organisms were more frequent than gramnegatives and fungi. S. aureus and Enterobacter were the most common gram-positive and gram-negative isolates. Later BST removal was associated with the isolation of significantly more bacterial strains per tube. There was no correlation between multiple infections and surgical failure. H. influenzae was more common in failed DCR cases.

Impact of Post-Surgical Therapies on Endoscopic and External Dacryocystorhinostomy: Systematic Review and Meta-Analysis

Background

Epiphora is a common ophthalmologic sign that is most commonly caused by distal acquired lacrimal obstruction. Recent data have demonstrated that external dacryocystorhinostomy (EXT-DCR) and endoscopic endonasal dacryocystorhinostomy (END-DCR) can be considered the treatments of choice. However, different post-surgical medical therapies are available and are currently used to improve surgical outcomes, although no direct comparison has been performed.

Objective

To analyse the influence of post-surgical medical treatments on END-DCR and EXT-DCR outcomes.

Methods

A structured search was conducted using the U.S. National Library of Medicine (PubMed), EMBASE, SCOPUS, and Cochrane databases with a final search performed in May 2020. The research identified papers published later than 2000 with at least 50 single clinician procedures performed in EXT-DCR and END-DCR. Articles that studied acute infections, revision cases, mixed cohort studies of acquired and congenital obstruction, and tumour were excluded. The influence of systemic antibiotic/steroids, local application of mitomycin C, nasal/ocular antibiotic, nasal/ocular steroids and nasal decongestants was analysed.

Results

In total, 11,445 papers were selected, 2,741 of which were reviewed after screening, and 18 included after full text review (0.6% of the initial articles reviewed) which involved 3,590 procedures. Considering the low number of publications on EXT-DCR, statistical analysis of post-surgical therapy was not feasible. In END-DCR, the analyses were performed only for nasal steroids (p = 0.58), oral antibiotics (p = 0.45) and nasal decongestant (p = 0.27), which demonstrated no meaningful influence. Given the variable association between adjunctive medical therapies, pharmacologic molecular heterogeneity and modality/concentration of application, these results should be considered critically. Additionally, no differences were seen for application of silicone stenting, whereas, no statistical analysis was performed for mitomycin C.

Conclusions

Given the high success rate of EXT-DCR and END-DCR and the heterogeneity of literature data, the effective influence of post-surgical medical therapy is difficult to identify. Future large prospective randomized studies could help in detecting the optimal adjunctive therapy for these surgeries.