RESUMO
Background: Esophageal self-expandable metal stents (SEMS) are an important endoscopic tool. These stents have now been adapted successfully to manage post-bariatric surgery complications such as anastomotic leaks and strictures. In centers of expertise, this has become the primary standard-of-care treatment given its minimally invasive nature, and that it results in early oral feeding, decreased hospitalization, and overall favorable outcomes. Self-expandable metal stents (SEMS) fractures are a rare complication of unknown etiology. We aimed to investigate possible causes of SEMS fractures and highlight a unique endoscopic approach utilized to manage a fractured and impaled SEMS. Methods: This is a retrospective study of consecutive patients who underwent esophageal SEMS placement between 2015-2021 at a tertiary referral center to identify fractured SEMS. Patient demographics, stent characteristics, and possible etiologies of fractured SEMS were identified. A comprehensive literature review was also conducted to evaluate all prior cases of fractured SEMS and to hypothesize fracture theories. Results: There were seven fractured esophageal SEMS, of which six were used to manage post-bariatric surgery complications. Five SEMS were deployed with their distal ends in the gastric antrum and proximal ends in the distal esophagus. All stents fractured within 9 weeks of deployment. Most stents (5/7) were at least 10 cm in length with fractures commonly occurring in the distal third of the stents (6/7). The wires of a fractured SEMS were embedded within the esophagogastric junction in one case, prompting the use of an overtube that was synchronously advanced while steadily extracting the stent. Discussion: We suggest the following four etiologies of SEMS fractures: anatomical, physiological, mechanical, and chemical. Stent curvature at the stomach incisura can lead to strain- and stress-related fatigue due to mechanical bending with exacerbation from respiratory movements. Physiologic factors (gastric body contractions) can result in repetitive squeezing of the stent, adding to metal fatigue. Intrinsic properties (long length and low axial force) may be contributing factors. Lastly, the stomach acidic environment may cause nitinol-induced chemical weakness. Despite the aforementioned theories, SEMS fracture etiology remains unclear. Until more data become available, it may be advisable to remove these stents within 6 weeks.
RESUMO
Venous thromboembolic disease is a major problem among critically ill patients, with significant associated morbidity and mortality. Many critically ill patients have contraindications to systemic anticoagulation, and inferior vena cava (IVC) filters are an important alternative in preventing pulmonary emboli (PE) in this population. The Angel Catheter (Mermaid, Stenlose, Denmark) is a novel percutaneous and removable IVC filter attached to the end of a triple lumen central venous catheter which has been demonstrated to reduce PE in surgical and trauma patients. This case series describes 18 critically ill medical patients who had an Angel catheter placed either for diagnosed PE or due to high risk for PE; over half had at least submassive PE at the time of Angel catheter placement. None of the patients had a recurrence of PE during Angel catheter use, 29.4% had clot found in the filter via cavogram upon removal, and only one had a minor complication which had no clinical consequence. In 2 patients, the placement of the Angel Catheter resulted in the prevention of PE during catheter-directed thrombolysis of extensive deep vein thrombosis. This case series demonstrates that in a population of critically ill, elderly, and obese medical patients the bedside placement of the Angel IVC filter is feasible, safe, and may be effective for preventing PE.
