Exploiting the Transformation Temperature to Reform an Infolded Nitinol Self-Expanding Peripheral Stent

Purpose: Nickel-titanium (nitinol) alloys possess a special set of properties that allow for a wide range of applications. Specifically, the transformation temperature for self-expanding nitinol peripheral stents allows for easy crimping at or below room temperature and reformation at body temperature becoming superelastic. Case Report: We report the case of an elderly man with iliac stenting 1 month prior, who presented several weeks after recovering from coronavirus disease 2019 with recurrent anterior-wall ST-elevation myocardial infarction. This was complicated by deformation and infolding of the previously implanted nitinol self-expanding stent in his right common iliac artery (CIA). Understanding nitinol’s specific properties, we proceeded with rapid injections of iced saline to cool the nitinol stent to its transformation temperature while nudging the distal end of the stent with a partially inflated balloon. This maneuver softened the nitinol stent, allowing us to “unfold” and reappose it against the wall of the right CIA, resulting in successful restoration of the original shape of the nitinol self-expanding stent. Conclusion: This represents the first reported case describing treatment of an infolded nitinol self-expanding peripheral stent by exploiting the transformation temperature of nitinol using iced cold saline to successfully restore the stent’s original shape and structure.

Analysis of Interwoven Nitinol Stenting for the Treatment of Critical Limb Ischemia: Outcomes From an Average 3-Year Follow-up Period

We assessed the clinical outcomes of patients with critical limb-threatening ischemia (CLTI) who underwent interwoven nitinol stent (Supera) implantation for significant stenoses of the femoropopliteal segment. In this retrospective cohort study, 116 consecutive patients with CLTI who were treated with Supera stents between September 2015 and March 2020 were included in this analysis. Primary endpoint analysis was completed for amputation-free survival, target lesion revascularization (TLR), and mortality. After a mean follow-up time of 3.4 years, 21 (18%) patients had undergone amputations, 3 (2.6%) died, and, overall, the amputation-free survival rate was 81%. TLR occurred in 21 (18%) patients, resulting in the freedom from target lesion revascularization of 82%. The average Wagner score for all patients was 2.8 ± 1.1. A subgroup analysis of 57 patients revealed a median ulcer size of 3.0 cm2 [1.65, 9.0], with complete healing for 45 patients by 20 months. The Wagner score of this subgroup decreased by an average of 3.4 ± .9 points. Supera stents can be used together with other endovascular therapies and are a safe and effective treatment modality for CLTI.

Buccal ureteroplasty in a patient with an extended stricture of the proximal ureter of a solitary kidney

Buccal ureteroplasty is considered a rare operation in urology and the indications for its implementation are still not clearly defined. We have described a clinical case of successful replacement of a part of the proximal ureter with a buccal graft in a patient with a single kidney, which was drained for a long time with a nitinol stent, which was subsequently incrustated, which led to the installation of a permanent nephrostomy drainage. The patient had no postoperative complications, the patency of the urinary tract was fully restored.