Esophageal Perforation after Using a Single-Use Disposable Duodenoscope

The Food and Drug Administration (FDA) has recently released a safety communication recommending transition to duodenoscopes with innovative designs that facilitate or eliminate the need for reprocessing. Thus, there has been a significant amount of development into disposable duodenoscope components and single-use duodenoscopes, with variable tactile feedback. We describe a case of esophageal perforation after using a single-use disposable duodenoscope (EXALT Model D; Boston Scientific Corporation, Marlborough, MA, USA). To our knowledge, this is the first reported case of an esophageal perforation since FDA approval of this device in December 2019. ERCP was performed with the EXALT Model D single-use duodenoscope (Boston Scientific Corporation) by an experienced gastroenterologist. During the procedure, gentle force applied through the gastroesophageal junction caused a liner perforation in the distal esophagus. An esophageal stent was placed with satisfactory wound healing and no fistula formation. There have been a few reports in the last 2 years showing promising results using this device; however, the differences in the tactile feedback, navigation, and pushability of the device may make it prone to unintended consequences.

One-Year Outcomes of Two Different Paclitaxel-Eluting Stents (Zilver PTX and Eluvia) for Trans-Atlantic Inter-Society Consensus Document (TASC) C/D Obstructive Femoropopliteal Lesions

Background: Endovascular therapy is one of the standard treatment options for patients with peripheral arterial disease. Paclitaxel-eluting stents (PES) have shown promising results in the treatment of obstructive femoropopliteal lesions. Two types of PES, namely, Zilver PTX (Cook Medical, USA) and Eluvia (Boston Scientific, USA), are available worldwide. However, no study has yet compared the outcomes of applying both PES types in the real world. Objectives: This study aimed to assess the one-year outcomes of two different types of PES for Trans-Atlantic Inter-Society Consensus Document (TASC) C/D obstructive femoropopliteal lesions following suboptimal angioplasty. Patients and Methods: This single-center, retrospective, observational study examined 37 limbs of 34 patients (30 males and four females) with the mean age of 71.9 ± 9.1 years (range, 53-90 years), who were included consecutively from February 2017 to May 2018. In all patients, either a Zilver PTX (Cook Medical) or an Eluvia (Boston Scientific) PES was used for TASC C/D obstructive femoropopliteal lesions following suboptimal angioplasty. Moreover, the patients’ one-year primary patency rate, freedom from clinically driven target lesion revascularization (TLR), and event-free survival rates were determined. Results: The mean lesion length was measured to be 24.6 ± 6.6 cm (range, 9 - 46 cm). Based on the results, 78% of the lesions (29 limbs) showed occlusion, and 46% (17 limbs) showed more than moderate calcification. According to the TASC classification, type D lesions were detected in 25 (68%) limbs, while type C lesions were detected in 12 (32%) limbs. The mean number of stents used was 2.5 ± 0.7 per limb (range, 1 - 3) to cover a mean length of 24.3 ± 7.9 cm (range, 6-35 cm). Overall, 56 Zilver PTX stents for 23 limbs and 36 Eluvia stents for 14 limbs were used. The Kaplan-Meier estimates of one-year primary patency and freedom from TLR were 78% and 88%, respectively (Zilver PTX stent, 76.3% and 81.2%, respectively; Eluvia stent, 91.7% and 100%, respectively). Major adverse events were reported in two patients (2/37, 5.4%), including acute thrombotic occlusion of the treated lesions. Conclusion: Both types of PES showed promising one-year outcomes for TASC C/D lesions regarding safety and efficacy, without any significant differences; therefore, they can be considered as an alternative therapeutic approach for surgery.

620 Onco-immunological mechanisms of focal ablation and localized IL-12 immunotherapy

BackgroundUnresectable solid malignancies are responsible for a major proportion of total cancer-related mortalities, making focal ablation an attractive alternative. Nevertheless, there are high rates of recurrence after ablation [1,2]. The addition of an immune agonist to ablation has the potential to prevent this recurrence and improve treatment outcomes. The goal of this study is to determine if localized interleukin-12 (IL-12) can prevent primary tumor recurrence after cryoablation in both minimal ablation and metastasis models.MethodsLLC (LL/2) (ATCC) and MC38 (NCI) were implanted in 6–9 week old C57BL/6 mice. All tumors were treated at volumes of 200–500 mm3. LLC tumors with treated with three cycles of freeze/thaw and then monitored for tumor recurrence and lung metastasis 22–25 days after implantation. MC38 tumors were treated with a minimal cryoablation protocol where the tumor undergoes one cycle of freezing at 100% intensity up to the tumor margin by visual inspection, followed by one cycle of active thaw until the cryo probe can be removed. Ablation was performed using the Argon-Helium Visual-ICETM Cryoablation System (Boston Scientific). Interleukin-12 (IL-12) in 1.5% (w/v) chitosan acetate (CS) dissolved in dPBS was injected intratumorally within an hour after cryoablation, or as indicated. The dose of IL-12 was 1 ug unless otherwise indicated.ResultsWe established a model of 100% recurrence using the minimal cryoablation protocol. Using this protocol, we demonstrated that a single intratumoral injection of CS/IL-12 within an hour after cryoablation prevents recurrence in 7/8 mice while only 3/8 mice remained tumor-free without CS/IL-12 (Figure 1). Studies evaluating the impact of CS/IL-12 on tumor-specific T cell responses following cryoablation are ongoing. In the spontaneously metastatic LLC model, delivering CS/IL-12 two days before treatment, either resection or cryoablation, reduced the number of metastatic lung nodules and furthermore prevented the recurrence of the primary tumor after resection (Figure 2).Abstract 620 Figure 1CS/IL-12 prevents tumor recurrence after minimal cryoAbstract 620 Figure 2CS/IL-12 before cryo or surgery prevents metastasisConclusionsDue to the high percentage of solid malignancies that are unresectable at diagnosis, focal ablation is an attractive alternative, yet has a high rate of recurrence. We demonstrated that intratumoral neoadjuvant CS/IL-12 protects not only against primary recurrence after cryoablation, but also protects against lung metastasis and recurrence after resection. Further studies are necessary to explore the immune populations responsible for this therapeutic effect.AcknowledgementsThis work is supported by Boston Scientific, the NC State University Provost’s Fellowship, the NSF Graduate Research Fellowship and startup funds provided by the College of Engineering at NC State University.ReferencesWeld KJ, Landman J. Comparison of cryoablation, radiofrequency ablation and high-intensity focused ultrasound for treating small renal tumours. BJU Int. 2005;96(9):1224–1229. doi:10.1111/j.1464–410X.2005.05848.x.Guenther E, Klein N, Zapf S, et al. Prostate cancer treatment with Irreversible Electroporation (IRE): Safety, efficacy and clinical experience in 471 treatments. PloS One. 2019;14(4):e0215093. doi:10.1371/journal.pone.0215093Ethics ApprovalThe Institutional Animal Care and Use Committee at North Carolina State University approved of all animal protocols (#19–795) in compliance with The Guide for Care and Use of Laboratory Animals (National Research Council).

High Impedance Alerts with Pulse Generator -- Lead Mismatch

Background: Cardiac Implantable Electronic Devices (CIED) include pulse generators and leads. In some implanting centres, it is common practice to combine devices with leads from different companies. Case series have reported episodic high-impedance changes in Boston Scientific CIEDs with competitor leads. We investigated the incidence of high-impedance abnormalities in matched vs. mismatched Boston Scientific CIEDs. Methods: Retrospective chart review identified all consecutive Boston Scientific Accolade pacemakers and Autogen implantable cardioverter defibrillators (ICD) implanted between January 2017 and June 2019 at a Canadian tertiary care centre. The primary outcome was the occurrence of transient, high-impedance changes which resulted in a switch to unipolar pacing / sensing in the absence of any other identifiable lead issue. Fisher exact tests (two-tailed, α = 0.05) were used to compare the incidence of outcomes in matched vs. mismatched systems. Results: 564 Boston Scientific CIEDs were identified associated with 969 individual leads. The primary outcome occurred with 22 leads (21 Medtronic and 1 Abbott), associated with occasional pacing inhibition, syncope, and/or early surgical revision. Mismatched systems were significantly associated with CIED malfunction compared to matched systems (3.4% vs. 0%, P = 0.0001). Median time from implant to unipolar safety switch was 19.3 months. Median follow-up time was 21.6 months. Conclusion: Use of mismatched leads with a Boston Scientific Accolade or Autogen device was associated with increased system malfunction and adverse clinical outcomes. Awareness of this interaction can allow for institution of appropriate programming remedies and may increase scrutiny of the use of mismatched CIED systems.

Treatment Failure After Rotational Atherectomy and Balloon Angioplasty in Recurrent Cystic Adventitial Disease of the Popliteal Artery: a Case Report

Background: Cystic adventitial disease (CAD) is a rare non-atherosclerotic condition in which fluid accumulates in the sub-adventitial layer, compressing the lumen of the arteries and veins. Historically, surgical treatment of CAD is preferred over endovascular or minimally invasive techniques owing to the considerably lower recurrence rates after surgery. Case presentation: We here report the first case in which rotational atherectomy was performed using Jetstream XC (Boston Scientific, Natick, MA) for recurrent CAD. Post-procedure angiography showed that satisfactory increase in the luminal diameter. However, the patient’s symptoms recurred 1 day after procedure, and repeat Computed tomography angiography (CTA) showed recurrent of the disease.Conclusions: Our experience showed that endovascular treatment is not satisfactory for CAD recurrence even with atherectomy.