Vitreoretinal Surgery Research Articles

Postoperative Pain in Vitreoretinal Surgery with Combined Regional-General Anesthesia versus General Anesthesia: A Systematic Review and Meta-Analysis

Postoperative Pain in Vitreoretinal Surgery with Combined Regional-General Anesthesia versus General Anesthesia: A Systematic Review and Meta-Analysis

The Role of Eye Movements in the Process of Silicone Oil Emulsification After Vitreoretinal Surgery

Emulsification is a feared and common complication of the use of silicone oil (SO) as tamponade fluid after vitrectomy as it potentially associated with significant risks to ocular health, including elevated intraocular pressure (IOP), glaucoma, corneal and retinal changes. The aim of this study was to investigate the role and interplay of physical factors on the formation of SO emulsion. Experiments were performed in a model of the vitreous chamber with a realistic shape, filled with SO and an aqueous solution containing different concentrations of albumin, an endogenous protein known to modify the interfacial properties between SO and aqueous solutions. The model was subjected to harmonic and saccadic rotations and kept at body temperature. Results indicated that no emulsions were detected in the absence of albumin in the aqueous solution, while the presence of the protein facilitated emulsion formation, acting as a surfactant. Mechanical energy from eye movements was also found to be a key mechanism to produce emulsification, with higher mechanical energy provided to the system leading to smaller droplet sizes. The emulsions formed were stable over extended times. This study highlights the complex interplay of factors influencing SO emulsification in the vitreous chamber. A better understanding of the mechanisms underlying SO emulsification is crucial for developing strategies to mitigate SO emulsion and the related complications.

Human Amniotic Membrane: A Seal for Complex Retinal Detachments.

To evaluate the efficacy of human amniotic membrane (hAM) transplantation for complex retinal detachments (RD). A retrospective analysis of consecutive patients who underwent vitreoretinal surgery with hAM transplantation for complex RD was conducted. The indications included high myopic macular hole (MH)-associated RD (n=5), traumatic large macular tears (n=4), combined RD with MH due to cicatricial retinopathy of prematurity (n=2) and severe retinitis (n=1), and morning glory syndrome (n=1). Surgical procedures, anatomical and functional results, and complications were noted. Thirteen eyes of 13 patients with a median age of 7 years (range, 0-65 years) were included. The follow-up was 15 months (range, 6-30 months). All eyes achieved MH sealing. Sealing occurred after a single surgery in 75% of eyes, while 25% required a second surgery due to hAM contraction/dislocation. The retina was attached and silicone oil could be removed in 92% of eyes during follow-up. The mean logarithm of the minimum angle of resolution visual acuity increased from 2.08±0.49 to 1.78±0.70 (p=0.07). Optical coherence tomography showed good integration of the hAM grafts with the retina, albeit without discernible retinal layer differentiation in any case. Amniotic membrane grafting appears to be promising for anatomical sealing of MHs and posterior retinal tears in complex RDs such as those associated with degenerative myopia, severe trauma, tractional membranes, and retinal shortening, where conventional surgical techniques are likely to fail. Further research is needed to clarify the regenerative potential and functional capacity of hAM grafts in severe retinal pathologies.

Punctate inner choroiditis and choroidal neovascular membrane formation following vitreoretinal surgery: A case report.

To report a case of punctate inner choroiditis (PIC) and subsequent choroidal neovascular membrane (CNVM) development in a young, high myope following vitreoretinal surgery for rhegmatogenous retinal detachment. A 44-year-old male with high myopia underwent pars plana vitrectomy for subtotal retinal detachment in the left eye, followed by cataract extraction and silicone oil removal. Three years postoperatively, he presented with blurred vision, and fundus examination revealed PIC lesions at the posterior pole. Spectral-domain optical coherence tomography (SD-OCT) showed characteristic features of PIC, including hyperreflective nodule-like elevations, disrupted ellipsoid and interdigitation zones, retinal pigment epithelium (RPE) elevations and increased choroidal hyper transmission signals. Initially, no treatment was initiated, and the patient was monitored. Three years later, the patient experienced further vision loss, and fundus examination showed progression of PIC lesions and new CNVM formation in the left eye. The patient was treated with systemic corticosteroids and an intravitreal anti-VEGF injection (Razumab® 0.5 mg/0.05 ml). Three weeks after the intervention, SD-OCT showed regression of the CNVM, and the patient's visual symptoms improved. This case underscores the importance of long-term follow-up and timely intervention in managing PIC, especially in high myopes post-retinal surgery. Early identification and treatment with systemic corticosteroids and anti-VEGF therapy are crucial to preserving visual function and preventing severe complications like CNVM.

Intravitreal methotrexate as an adjuvant in vitrectomy in cases of retinal detachment with proliferative vitreoretinopathy.

To compare the rate of re-detachment in patients with rhegmatogenous retinal detachment and Grade-C PVR following vitreoretinal surgery, with and without serial intravitreal injections of methotrexate. It was a randomized control trial. Patients aged more than 18 years undergoing pars plana vitrectomy for rhegmatogenous retinal detachment with PVR grade C or more were included in the study. Patients treated with intravitreal injection of methotrexate were grouped as cases and those not injected served as controls. The cases received 3 intravitreal injections of methotrexate at monthly intervals. Patients were evaluated on Day 1, 1st month, 2nd month, 3rd month and 6th month in terms of BCVA, rate of re-attachment and grade of PVR. The case group had 23 patients and the control group had 20 patients. 2 patients in the case group were lost to follow-up after the first follow-up, so they were excluded. So 21 patients in case group and 20 patients in control group were followed up. Six months after surgery, 15 'cases' had completely attached retina whereas 6 patients had partial detachment with macula on. There was no patient amongst the cases with macula-off retinal re-detachment. Out of 20 patients in the control group, 9 had a complete retinal attachment, 4 had partial detachment with macula-on and 7 had partial detachment with macula-off. There was statistically significant difference in macula off retinal detachment rates (p-value- 0.003). Serial intravitreal methotrexate injections reduce the incidence of re-detachment in patients undergoing PPV for RRD with PVR-C. Further investigation into this promising therapeutic approach is warranted. What is known Methotrexate is an anti-inflammatory agent which is safe for intravitreal use There are case series retrospective and prospective studies suggesting potential benefit of intravitreal methotrexate in preventing re-detachment due to PVR What is new First randomized control trialstudying the efficacy of intravitreal methotrexate in preventing re-detachmentdue to PVR Our study showed statisticallysignificant difference in macula off retinal detachment between the 2 groups at6 months of follow up.

Intraretinal hyperreflective line: potential biomarker in various retinal disorders.

The intraretinal hyperreflective line (IHL) is a novel posterior segment finding demonstrable using careful optical coherence tomography (OCT) examination. It likely indicates a reaction against photoreceptor, Muller cell, and/or retinal pigment epithelial damage. This study analyzed the spectral-domain OCT characteristics of IHLs to disclose their presence in various retinal conditions. A retrospective review of the charted and imaging records of participants with IHL was conducted at Dokuz Eylul University Department of Ophthalmology between January 2019 and August 2023. The inclusion criterion was the detection of an IHL on good-quality B-scan spectral-domain OCT. An IHL was defined as a vertical line extending from the ellipsoid zone band (or lower) through the outer nuclear layer to the internal limiting membrane in the central fovea. Associated retinal conditions were recorded as potential causative factors for the presence of IHL. IHL was observed on spectral-domain OCT in 40 eyes of 38 participants with several retinal diseases assessment. Fourteen eyes (35%) underwent vitreoretinal surgery pre-IHL detection (12 were operated for full-thickness macular hole [FTMH], one for epiretinal membrane [ERM], and one for rhegmatogenous retinal detachment). In six eyes (15%) a microhole coexisted. Four eyes (10%) had a concurrent lamellar macular hole. The IHL preceded the occurrence of FTMH in three eyes (7.5%), and diabetic macular edema and type 2 idiopathic macular telangiectasia (MacTel-2) were present in three eyes (7.5%) each. The remaining conditions included vitreomacular traction (VMT), nonarteritic anterior ischemic optic neuropathy with central retinal artery occlusion, commotio retinae, exudative age-related macular degeneration, ERM, non-infectious idiopathic posterior uveitis, and Coats' disease, each affecting one eye (2.5%). Of the two participants with bilateral involvement, one was diagnosed with MacTel-2 and the other had IHL with VMT in the right eye that was detected post-vitreoretinal surgery for FTMH in the left eye. Although IHLs are mostly identified in eyes with vitreomacular surface diseases, clinicians may encounter IHLs in other types of retinal pathology. Further large-scale, multicenter, long-term studies on the presence of IHLs in OCT imaging are required to provide more substantial insight on this biomarker.

A novel drip-irrigative technique for enhanced epiretinal perfluorocarbon liquid clearance during vitreoretinal surgery

PurposeTo present a novel intraoperative application technique of basic salt solution (BSS) perfusate to address residual epiretinal perfluorocarbon liquid (PFCL) droplets.MethodsFollowing standard liquid-gas exchange and aspiration of visible PFCL using a flute needle, the adjuvant drip-irrigative method is employed. A 2mL needle containing BSS is introduced and maneuvered circumferentially around the posterior pole while injecting BSS intermittently to obviate droplet presence. Subsequently, droplets lying flat to the surface drain via the flute needle, and the process if repeated until no droplets are visible.ResultsAmong 112 consecutive patients diagnosed with rhegmatogenous retinal detachment (RDD) with at least 3 months follow-up, 109 patients (109 eyes, [97%]) experienced no PFCL-related complications follow pars plana vitrectomy. Among three patients with PFCL-related complications, two (2 eyes) presented with residual droplets on the retinal surface during silicone oil retrieval, and one (1 eyes) had PFCL migration to the anterior chamber. No patients experienced sub-retinal/ sub-foveal PFCL or iatrogenic injury.ConclusionThis adjuvant drip-irrigative technique offers enhanced droplet visibility, reduced risk of iatrogenic retinal damage, and ease of application. Findings reported suggest the potential of this approach as a standard practice when using PFCL to mitigate complications.

Evaluating the Efficacy of Pre-Emptive Peribulbar Blocks with Different Local Anesthetics or Paracetamol Using the Adequacy of Anesthesia Guidance for Vitreoretinal Surgeries: A Preliminary Report.

Precisely selected patients require vitreoretinal surgeries (VRS) performed under general anesthesia (GA) when intravenous rescue opioid analgesics (IROA) are administered intraoperatively, despite a risk of adverse events, to achieve hemodynamic stability and proper antinociception and avoid the possibility of intolerable postoperative pain perception (IPPP). Adequacy of anesthesia guidance (AoA) optimizes the titration of IROA. Preventive analgesia (PA) techniques and intravenous or preoperative peribulbar block (PBB) using different local anesthetics (LAs) are performed prior to GA to optimize IROA. The aim was to analyze the utility of PBBs compared with intravenous paracetamol added to AoA-guided GA on the incidence of IPPP and hemodynamic stability in patients undergoing VRS. A total of 185 patients undergoing vitreoretinal surgery (VRS) were randomly assigned to one of several anesthesia protocols: general anesthesia (GA) with analgesia optimized through AoA-guided intraoperative remifentanil opioid analgesia (IROA) combined with a preemptive single dose of 1 g of paracetamol (P group), or PBB using one of the following options: 7 mL of an equal mixture of 2% lidocaine and 0.5% bupivacaine (BL group), 7 mL of 0.5% bupivacaine (BPV group), or 7 mL of 0.75% ropivacaine (RPV group). According to the PA used, the primary outcome measure was postoperative pain perception assessed using the numeric pain rating scale (NPRS), whereas the secondary outcome measures were as follows: demand for IROA and values of hemodynamic parameters reflecting quality or analgesia and hemodynamic stability. A total of 175 patients were finally analyzed. No studied PA technique proved superior in terms of rate of incidence of IPPP, when IROA under AoA was administered (p = 0.22). PBB using ropivacaine resulted in an intraoperative reduction in the number of patients requiring IROA (p = 0.002; p < 0.05) with no influence on the dose of IROA (p = 0.97), compared to paracetamol, and little influence on hemodynamic stability of no clinical relevance in patients undergoing VRS under AoA-guided GA. PA using paracetamol or PBBs, regardless of LAs used, in patients undergoing VRS proved no advantage in terms of rate of incidence of IPPP and hemodynamic stability when AoA guidance for IROA administration during GA was utilized. Therefore, PA using them seems no longer justified due to the potential, although rare, side effects.

Injectable Intravitreal Fluocinolone Acetonide Implant for Chronic Postoperative CME in the Presence of Silicone Oil Tamponade

Purpose: This report describes the use of the injectable intravitreal fluocinolone acetonide 0.18mg implant (FAI) for chronic postoperative cystoid macular edema (CME) in an eye with a silicone oil-filled vitreous cavity. Methods: A retrospective chart review was performed including surgical, clinical, and imaging data. Results: The patient had multiple complicated vitreoretinal surgical procedures including long-term silicone oil tamponade. The eye developed chronic CME, which responded to intravitreal steroid therapies and subsequently received FAI for longer-term control. The eye had no complications related to FAI. Conclusion: FAI is a long-acting steroid that may be beneficial in controlling chronic CME. It can be considered for use in eyes with silicone oil tamponade, but further studies are required to better understand the pharmacokinetics and utility of the FAI when injected into silicone oil-filled vitreous cavities.

The Role of Adjunctive Triamcinolone Acetonide in Post-traumatic Vitreoretinal Surgery: Current Insights and Future Perspectives

The Role of Adjunctive Triamcinolone Acetonide in Post-traumatic Vitreoretinal Surgery: Current Insights and Future Perspectives

Vitreoretinal Surgery in Pediatric Patients with Vitreoretinal Pathology Secondary to Uveitis

In pediatric uveitis, as with all forms of uveitis, the primary treatment modality involves achieving systemic and local immunosuppression through pharmacotherapy. However, due to the challenge of articulating symptoms by patients in the younger age group, resulting in delayed presentation to clinicians, or the tendency for uveitis to manifest more quietly in this age group, pediatric uveitis cases can be diagnosed late, unfortunately presenting with secondary complications at the time of diagnosis. In these patients, after appropriate immunosuppression is achieved, vitreoretinal surgery may be necessary to address vitreoretinal complications. Additionally, in cases where etiology cannot be determined by non-invasive methods, or when there is inadequate response or no response to treatment, rapid progression of inflammation threatening the optic nerve and macula, or suspicion of malignancy, diagnostic vitreous sampling or chorioretinal biopsy via vitreoretinal surgery may be pursued. The aim of this review is to evaluate the role and significance of vitreoretinal surgery in pediatric uveitic eyes.

Preoperative Evaluation, Informed Consent and Postoperative Care in Pediatric Vitreoretinal Surgery

In childhood, vitreoretinal surgery may be required due to trauma and some congenital or developmental disorders. Pediatric vitreoretinal surgery differs from that of adults in terms of etiology, anatomical and surgical characteristics, response to treatment and follow-up. This process has many challenges that require patient follow-up over many years as the child develops. Pre-operative preparation according to the age of the patient and the nature of the pathology will make it easier for the surgeon to manage all the processes. The consent of the child must be obtained in accordance with the child's cognitive abilities, in addition to the informed consent of the family. Despite surgical and technological advances in pediatric vitrectomy, anatomical and functional outcomes are worse than in adults. This article discusses pediatric vitreoretinal surgery in terms of preoperative preparation, informed consent and follow-up.

Vitreoretinal Surgery in Retinopathy of Prematurity

In this article, vitreoretinal surgical procedures applied for retinopathy of prematurity (ROP) are discussed in comparison with indications such as traction retinal detachments (tRDs), secondary to other ischemic neovascular proliferative retinopathies such as proliferative diabetic retinopathy (PDR). Thus, by comparing the clinical features of ROP, the rationale of vitreoretinal surgical procedures applied, and the currently accepted pathogenetic hypotheses with the clinical features and vitreoretinal surgery procedures of other ischemic neovascular proliferative retinopathies as PDR, a determination of why the accepted pathogenetic hypotheses of ROP are wrong and what is the correct pathogenesis has been made.

Vitreoretinal Surgery in Pediatric Patients with the Disease of Vitreoretinal Interface

Comparing the ocular anatomy of children and adults, there are certain dimensions and structural differences. A safer surgical method is made possible by an understanding of the major distinctions between the eyes of children and adults,and specific evaluations are required. The primary distinctions are in the locations of sclerotomies, the requirement for posterior hyaloid separation and total vitrectomy, endo-tamponade, and the surgical technique according to the vitreoretinal disease. We tried to summarize the main differences in pediatric patients with the disease of the vitreoretinal interface compared to adult vitreoretinal surgery and some critical points for this surgery.

Equipment and Instruments in Pediatric Vitreoretinal Surgery

In this section, special considerations regarding vitreoretinal instrumentation when planning pediatric retinal surgery are evaluated. Instrumentation was designed considering the distinct anatomical and physiological differences in the pediatric population. Instrumentation used in the pediatric population, including eyelid speculum, scleral buckling elements, visualization systems, 25 and 27G short vitrectomy packs, and sutures, is discussed, which may include differences. In addition to instrument design, modifications and techniques used in surgical steps that differ from adults were also evaluated. With awareness of these differences, complications can be prevented and optimum treatment effectiveness may be achieved with the surgeon's operational management.

Enhance the viscosity of polydimethylsiloxane by controlling the volume ratio of monomer and chain terminator

The production of polydimethylsiloxane (PDMS) as a vitreous substitute in Indonesia has been carried out. In our previous study, a good quality of low viscosity PDMS was well provided using a low-grade octamethylcyclotetrasiloxane (D4) monomer. We also reported that a new type of PDMS with medium viscosity had been produced. In vitreoretinal surgery, medium-viscosity PDMS has advantages over the other types of PDMS due to its injectability and lower propensity to emulsify. However, to produce a high-quality medium viscosity PDMS and fulfill stringent requirements, the conditions affecting the synthesis results need to be explored. Here, we reported the effect of changing one of the PDMS synthesis parameters, namely, the volume ratio composition of low-grade D4 monomer and chain terminator of hexamethyldisiloxane (MM) in producing medium viscosity PDMS. PDMS with low viscosity was successfully synthesized with a ratio of D4:MM = 26:10. However, only by changing the ratio of D4:MM from 26:10 to 46:10, the resulting PDMS increased in viscosity from low- to medium-viscosity PDMS of 1.81 Pa s. Quality improvement was also indicated by high surface tension and higher yield values. The medium viscosity PDMS had a refractive index and functional group values similar to the PDMS produced in previous studies.

Establishing Vitreoretinal Surgery Capacity in Sierra Leone: Challenges and Opportunities to Address Retinal Health Disparities in Resource-limited Settings.

A range of challenges exists regarding vitreoretinal (VR) surgical services in resource-limited settings, including Sierra Leone. As a result, retinal pathologies may contribute to vision loss and blindness. In the wake of the 2013 to 2016 outbreak of Ebola virus disease in West Africa, gaps in ophthalmic care were underscored as survivors were experiencing a constellation of sequelae, including uveitis and VR disease. Given the unmet needs in addressing VR disease, systems for retinal surgical care were required. To further understand long-term ocular complications in Ebola survivors and molecular and immunologic factors associated with this, research infrastructure was developed for retinal evaluation and surgery. The 5 "S'" framework was implemented and considered staff, space, stuff, systems, and social support. The ongoing development of retinal health infrastructure has helped to address challenges related to program implementation, development of surgical capacity, and alignment with local stakeholders and collaborator objectives. VR surgical services have been established in Sierra Leone through multidisciplinary partnerships and collaboration and serve patients in-country, as well as others in West Africa who have traveled for care. Continued engagement across stakeholders can aim to address challenges and promote effective care delivery.

Synthesis, Properties, and Biocompatibility of 4-Carboxyphenyboronic Acid-Modified Gelatin-Methacryloyl: A Hydrogel for Retinal Surgeries.

The current surgical adjunctive for vitreoretinal surgeries fails to provide an adequate 3D structure for cellular regeneration. A one-pot synthesis of gelatin-methacryloyl (GelMA) followed by modification with 4-carboxyphenylboronic acid (4-CPBA) was performed to fabricate 4-CPBA-modified GelMA (4CPBA@GelMA), a gelatin-based hydrogel. 4CPBA@GelMA was photo-cross-linked by 405 nm violet light and examined using nuclear magnetic resonance (NMR), Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), and rheometry. In vitro biocompatibility was examined by Müller cell proliferation assays exposed to 4CPBA@GelMA and violet light. In vivo retinal biocompatibility was evaluated by electroretinography of rat eyes that were exposed to intravitreally injected and photo-cross-linked 4CPBA@GelMA at days 3, 7, 14, and 28 post-injection. Following electroretinography, histology and immunohistochemistry were performed on the retinas. The NMR results indicated amidation of GelMA by 4-CPBA, and FTIR confirmed the presence of the CPBA ring in 4CPBA@GelMA samples. SEM revealed that 4CPBA@GelMA had significantly larger pores than GelMA (56.9 ± 9.5 vs 35.1 ± 2.8 μm; P < 0.001). Rheological findings showed that, unlike GelMA and gelatin, 4CPBA@GelMA has Newtonian fluid properties at room temperature. Exposure to 4CPBA@GelMA did not significantly affect Müller cell viability in a proliferation assay; moreover, electroretinography findings indicated normal waveforms and implicit times, and histology and immunohistochemistry examinations revealed no significant changes. In this study, we established the high retinal compatibility of 4CPBA@GelMA. The low viscosity of 4CPBA@GelMA is ideal for injection via small-gauge needles, and the larger pore size and three-dimensional network both potentiate cellular migration and growth. These features made 4CPBA@GelMA a candidate for vitreoretinal surgical adjunctive that might promote retinal regeneration.

A Pilot Survey of Patient Perspectives on an Artificial Intelligence-Generated Presenter in a Patient Information Video about Face-Down Positioning after Vitreoretinal Surgery

Introduction: Video education is a commonly used patient education tool. However, the impact of integrating artificial intelligence (AI) into video education remains unexplored. This study aimed to examine the acceptability of an AI-generated presenter in a patient information video about face-down positioning after vitreoretinal surgery. Method: We prospectively enrolled participants who were planned for vitreoretinal surgery in which postoperative face-down positioning was recommended at the Royal Adelaide Hospital between December 2022 and September 2023. Participants were preoperatively provided with an educational video presented by an AI-generated presenter, incorporated into a surveyredcap. A pre- and post-video questionnaire was administered electronically. Results: There were 15 participants included in the study. In the pre-video questionnaire, most participants rated their awareness of special equipment for positioning as “not aware” (33%) and “slightly aware” (33%). The median pre-video six-item Spielberger State-Trait Anxiety Inventory Score was 12 (interquartile range 12–15). In the post-video questionnaire, most participants rated the video’s quality as “excellent” (73%) and would recommend it to others (73%). The majority of participants strongly agreed that they understood the AI presenter (60%), felt at ease with the presenter (60%), and trusted the presenter (60%). Four participants (22%) disagreed with the statement: “I was aware the presenter was computer generated.” Conclusions: Video-based education may provide information that patients find useful, particularly for physical maneuvers such as face-down positioning. The use of an AI-generated presenter was well-received by the majority of patients. Further research regarding the use of AI to develop educational video content is warranted.

Incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device

Abstract Purpose: To report the incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device (GDD). Methods: Of the total 1303 patients who underwent patch-free GDD (703 non-valved GDD and 600 valved GDD) for refractory glaucoma during January 2020–October 2023, we identified five cases of postoperative complications following GDD that required tube or shunt removal. Results: Median (IQR) age of our study cohorts was 54.5 (8–66) years. The incidence of tube exposure and tube explantation was 0.003% and 0.004%, respectively. The median time interval for tube or plate explantation from the time of GDD surgery was 11.5 (2–16) months. The diagnoses of refractory glaucoma for which GDD was performed were secondary glaucoma following multiple vitreoretinal (VR) surgery (60%), primary open-angle glaucoma (20%), and aphakic glaucoma (20%). Of these, two patients (40%) presented with recurrent tube exposures, two patients (40%) with tube exposure and early endophthalmitis, and one patient (20%) with persistent hypotony. Four patients (80%) had undergone non-valved Aurolab aqueous drainage implant and one underwent (20%) Ahmed glaucoma implant. Three patients (60%) had diabetes mellitus with a history of multiple VR surgical intervention. GDD explantation was done in three patients (60%), and the remaining two patients (40%) required only tube amputation. One patient presented with orbital cellulitis, and there was no culture growth seen in any of our study cohorts. Conclusion: Tube and plate exposures pose a significant risk for potential infections and warrant prompt explantation of GDD to avoid endophthalmitis. Previous history of multiple VR surgeries, diabetes mellitus, and non-valved implants were the common risk associations noted for tube exposures in our retrospective study.