nitinol and Neoplasms

Biliary partially covered self-expandable metal stents (PC-SEMS) offer prolonged relief of symptoms of biliary obstruction but may induce complications including pancreatitis, cholecystitis and migration.. To assess efficacy and safety of the ComVi partially covered self-expandable metal stents as primary palliative treatment of distal malignant biliary obstruction.. Seventy patients (mean age 69.2 years) with distal malignant biliary strictures were prospectively included and underwent endoscopic retrograde cholangio-pancreatography and partially covered self-expandable metal stents placement. Follow-up was done for 12 months. self-expandable metal stents patency, survival and complication-rate after partially covered self-expandable metal stents placement were evaluated.. Overall median survival time was 190 days (30-856). Forty-four patients (62.8%) died after median 175.5 days (30-614) without signs of stent dysfunction; 37 patients (52.8%) were alive after 6 months without signs of self-expandable metal stents occlusion. Survival rapidly dropped between 8 and 12 months after treatment. Survival was not influenced by sex (P = 0.1) or type of neoplasia (P = 0.178). Median survival was longer (254 days [44-836]) in patients who underwent chemotherapy (P < 0.0001). Partially covered self-expandable metal stents occlusion had 24 (35.7%) patients 154 days (35-485) after treatment. Median survival after re-treatment was 66 days (13-597). Cholecystitis occurred in one patient (1.7%).. The ComVi partially covered self-expandable metal stents is effective for palliation of biliary obstruction secondary to distal malignant biliary strictures. Self-expandable metal stents patency during follow-up is satisfactory without significant complications.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bilirubin; Cholangiopancreatography, Endoscopic Retrograde; Cholestasis; Female; Follow-Up Studies; Humans; Logistic Models; Male; Middle Aged; Multivariate Analysis; Neoplasms; Palliative Care; Proportional Hazards Models; Stents

To solve the problems of small one-time ablation range and easy charring of the tissue around the electrode associated with the tumor radiofrequency ablation needle, based on the multiphysical field coupling analysis software COMSOL, the effects of needle material, the number of sub needles and the bending angle of sub needles on the ablation effect of radiofrequency ablation electrode needle were studied. The results show that compared with titanium alloy and stainless steel, nickel titanium alloy has better radiofrequency energy transmission efficiency and it is the best material for electrode needle. The number of sub needles has a great influence on the average necrosis depth and the maximum necrosis diameter. Under the same conditions, the more the number of sub needles, the larger the volume of coagulation necrosis area. The bending angle of the needle has a great effect on the maximum diameter of the coagulated necrotic area, but has little effect on the average necrotic depth. Under the same other conditions, the coagulation necrosis area formed by ablation increased with the increase of the bending angle of the sub needle. For the three needles with bending angles of 60 °, 90 ° and 120 ° analyzed in this paper, the one with bending angle of 120 ° can obtain the largest coagulation necrosis area. In general, the design of nickel titanium alloy with 120 ° bending 8-pin is the optimal. The average depth of radiofrequency ablation necrosis area is 32.40 mm, and the maximum necrosis diameter is 52.65 mm. The above optimized design parameters can provide guidance for the structure and material design of tumor radiofrequency ablation needle.. 为解决肿瘤射频消融针一次性消融范围小以及电极周围组织易发生烧焦炭化的问题，本文基于多物理场耦合分析软件COMSOL，研究针体材料、子针个数和子针弯曲角度对射频消融电极针消融效果的影响规律。研究结果表明，相较于钛合金和不锈钢，镍钛合金具有更好的射频能量传导效率，是电极针的最佳制作材料；子针个数对平均坏死深度和最大坏死直径均有较大影响，相同条件下，子针个数越多，凝固坏死区域体积越大；子针的弯曲角度对凝固坏死区域的最大直径影响较大，对平均坏死深度的影响较小。在其它条件均相同的情况下，消融形成的凝固坏死区域随子针弯曲角度的增加而增大。对于本文分析的60 °、90 °和120 °三种子针弯曲角度而言，120 °的弯曲角度可获得最大的凝固坏死区域。综合而言，镍钛合金120 °弯曲8子针的设计最优，射频消融坏死区域的平均深度为32.40 mm，最大坏死直径为52.65 mm。上述优化设计参数可为肿瘤射频消融针的结构与材料设计提供指导。.

Topics: Alloys; Catheter Ablation; Humans; Necrosis; Needles; Neoplasms; Temperature

Topics: Alloys; Humans; Immunotherapy, Adoptive; Neoplasms; T-Lymphocytes

To retrospectively evaluate the technical and clinical outcomes of superior vena cava (SVC) stent placement through upper-limb venous access in malignant SVC syndrome (SVCS) and compare the efficacy of different nitinol stent types.. Between 2006 and 2018, 156 patients (132 male; mean age, 62 y; age range, 33-81 y) underwent SVC stent placement for malignant obstructions through upper-limb venous access with 1 of 3 types of nitinol stent: 1 venous-dedicated (Sinus-XL stent) and 2 non-venous-dedicated (E-Luminexx Vascular Stent and Protégé GPS). Cases of common femoral vein access or non-nitinol stents were excluded from further analysis. The mean duration of follow-up was 8 mo.. Technical success was achieved in 99.3% of cases. One patient died during the procedure as a result of cardiac tamponade. Balloon predilation was performed in 10 patients and postdilation in 126. Mean procedural time was 34.4 min (range, 18-80 min). Overall survival rates were 92.3%, 57.3%, and 26.8%, and overall primary patency rates were 94.5%, 84.8% and 79.6%, at 1, 6, and 12 mo, respectively. There were no statistically significant differences in primary patency rates between venous- and non-venous-dedicated stents or among different Stanford SVCS grading groups (P > .05).. SVC stent placement through an upper-limb approach is a safe, fast, and effective technique. There is no evident benefit of venous-dedicated vs non-venous-dedicated stents in the treatment of malignant SVCS.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Catheterization, Peripheral; Female; Humans; Male; Middle Aged; Neoplasms; Prosthesis Design; Registries; Retrospective Studies; Stents; Superior Vena Cava Syndrome; Time Factors; Treatment Outcome; Upper Extremity; Vascular Patency; Vena Cava, Superior

Central airway obstruction (CAO) is defined as obstruction of the airway lumen in the trachea or mainstem bronchi, most commonly due to primary or metastatic malignancy; and is classified as extraluminal, endoluminal, or mixed. The majority of malignant CAO are advanced stage and require a multimodality palliative approach, including stent placement. We describe a retrospective review of a novel self-expandable metallic stent, the Bonastent; a fully covered, nitinol-braided airway stent which conforms to airway tortuosity without loss of diameter in the management of CAO.. We performed a retrospective chart review of patients with CAO who underwent Bonastent placement at a single center between February 2017 and March 2018. Ease of stent placement, short-term complications (within 24 h of stent placement) and long-term complications (within 3 mo of stent placement) were recorded.. Eleven patients were identified, reviewed and included in the study. Thirteen stents in 11 patients were placed for predominantly malignant CAO. One patient had a short-term complication of stent migration. Four patients had long-term complications; of which 3 patients had in-stent mucus impaction requiring bronchoscopy. In our study, the stent-related complication rates were comparable to the reported literature.. In our experience, Bonastent is an easy to use option which adds to the armamentarium of the self-expandable metallic stent to treat malignant CAO.

Topics: Adult; Aged; Aged, 80 and over; Airway Obstruction; Alloys; Bronchi; Bronchoscopy; Cohort Studies; Feasibility Studies; Female; Humans; Male; Middle Aged; Mucus; Neoplasms; Palliative Care; Postoperative Complications; Prosthesis Failure; Retrospective Studies; Self Expandable Metallic Stents; Trachea

Chemothermal brachytherapy seeds have been developed using a combination of polymeric dual drug chemotherapy and alternating magnetic field induced hyperthermia. The synergistic effect of chemotherapy and hyperthermia brachytherapy has been investigated in a way that has never been performed before, with an in-depth analysis of the cancer cell inhibition property of the new system. A comprehensive in vivo study on athymic mice model with SCC7 tumor has been conducted to determine optimal arrays and specifications of the chemothermal seeds. Dual drug chemotherapy has been achieved via surface deposition of polydopamine that carries bortezomib, and also via loading an acidic pH soluble hydrogel that contains 5-Fluorouracil inside the chemothermal seed; this increases the drug loading capacity of the chemothermal seed, and creates dual drug synergism. An external alternating magnetic field has been utilized to induce hyperthermia conditions, using the inherent ferromagnetic property of the nitinol alloy used as the seed casing. The materials used in this study were fully characterized using FESEM, H

Topics: Alloys; Animals; Antineoplastic Agents; Bortezomib; Brachytherapy; Combined Modality Therapy; Drug Carriers; Drug Liberation; Drug Synergism; Fluorouracil; Humans; Hydrogels; Hydrogen-Ion Concentration; Hyperthermia, Induced; Indoles; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Pilot Projects; Polymers; Xenograft Model Antitumor Assays

We sought to test the hypothesis that placement of a new nitinol duodenal self-expandable metallic stent (SEMS) for palliation of malignant gastroduodenal obstruction is effective and safe in allowing patients to tolerate an oral diet.. In a prospective multicenter study, SEMSs (Duodenal WallFlex, Boston Scientific) were placed to alleviate gastroduodenal obstruction in inoperable patients without the ability to tolerate solid food. The primary study end point was improvement in oral intake monitored according to the 4-point Gastric Outlet Obstruction Scoring System (GOOSS) up to 24 weeks after stent placement.. Forty-three patients received SEMSs, which were successfully deployed on the first attempt in 41 cases (95%) and the second attempt in two (5%). Within 1 day and 7 days after SEMS placement, 52% and 75% of patients, respectively, benefited from a GOOSS increase > or =1. Resumption of solid food intake (GOOSS 2-3) was attained by 56% of patients within 7 days and 80% by 28 days. Of the patients attaining GOOSS 2-3, 48% remained on solid food until death or last follow-up. Device-related adverse events included stent occlusion/malfunction in 9% of patients and perforation in 5% of patients.. Duodenal WallFlex stent placement promptly improves oral intake in a majority of inoperable patients with malignant gastroduodenal obstruction. In approximately half the patients achieving GOOSS 2-3, the capacity for solid food intake endures until death or last follow-up.

Topics: Alloys; Diet; Duodenum; Female; Gastric Outlet Obstruction; Humans; Male; Middle Aged; Neoplasms; Palliative Care; Prospective Studies; Risk Factors; Stents; Treatment Outcome

The purpose of this study was to evaluate the usefulness of self-expanding nitinol stents for palliative treatment of malignant colorectal obstruction caused by unresectable extrinsic tumor, colorectal metastasis, or peritoneal seeding.. One covered stent and 10 uncovered stents were deployed in eight patients with colorectal obstruction due to extrinsic tumor under fluoroscopic guidance. The sites of obstruction were located in the rectum (n = 5), in the rectosigmoid colon (n = 2), and from the transverse colon to the descending colon (n = 1). Clinical usefulness and complications were analyzed.. Stents were placed successfully in all patients. Minor modifications of the delivery system were required in the tortuous rectosigmoid and lower rectum strictures. Symptoms of obstruction were initially resolved in all but one patient. In that patient, the presence of other points of obstruction was suspected. Bowel obstruction recurred in two patients: one obstruction was due to migration of a covered stent 4 days after the procedure, and the other obstruction was due to peritoneal seeding 33 days after the procedure. Both required colostomy or ileostomy. All patients died 12-111 days after stent placement (mean, 56 days). In five patients (63%), colonic obstruction was palliated by placing a stent until the patients' death between 39 and 111 days after stent placement (mean, 62 days). Six complications occurred in four patients and included stent migration (n = 1), anal bleeding (n = 2), anal pain that required analgesia (n = 1), and fever (n = 2). CONCLUSION; This self-expandable nitinol stent adequately palliated 63% of patients with colonic obstruction due to extrinsic tumor in this small series. Patient selection is very important to the success of this treatment.

Topics: Alloys; Colonic Diseases; Colorectal Neoplasms; Female; Humans; Intestinal Obstruction; Male; Middle Aged; Neoplasms; Palliative Care; Patient Selection; Peritoneal Neoplasms; Rectal Diseases; Stents