New concepts for a compression anastomosis: Superelastic clips and rings

Gastrointestinal anastomosis is a crucial step in many operative procedures, and responsible for a major portion of early and late post‐operative complications. In order to improve on the results of current tools to perform an anastomosis, such as sutures and staplers, new concepts are being developed. One of these concepts is compression anastomosis. Compression anastomosis has been tried in the past but did not become popular mostly because of technical reasons. Recently, trials to accomplish compression anastomosis using Nitinol devices were conducted.

Two devices were made and tested in the past three years: A side‐to‐side device and an end‐to‐end device. The common principle in both devices is the compression of two bowel loops through the constant pressure of a Nitinol device, thus producing a dual process of necrosis and healing until the lumens of both bowels fuse, and the device falls into the lumen and is excreted. Both devices have been tested in animals and humans, with encouraging results. In animals, the anastomoses were shown to demonstrate minimal inflammation and no foreign body reaction, with perfect healing of the mucosa. The side‐to‐side device was tested in over 500 human patients, and the end‐to‐end device is currently used in a large, multi‐centric human trial.     

Circular ‘superelastic’ compression anastomosis: From the animal lab to clinical practice

The recent development of a compression device using shape memory Nitinol technogy to create an end‐to‐end anastomosis has renewed the interest in sutureless anastomotic techniques. A phase II, prospective open label clinical trial was started in May 2007 to evaluate the feasibility and safety of this new anastomotic device. Fourty patients who need left colectomy or high anterior resection for either diverticular disease or adenocarcinoma will be recruited in two academic hospitals (Uppsala,Sweden and Leuven, Belgium). Clinical leakage is the primary endpoint. Only preliminary results are available to date as the recruitment is ongoing. The median age of the first ten patients is 57.5 years (44–72). No anastomotic leakage occurred. The median hospital stay was 4.0 days. Only three patients noticed the passage of the ring through the anal canal.

By three weeks no ring was sustained in the gastrointestinal tract as was objectified by plain X‐ray. First clinical use of this new anastomotic device seems promising. Final results for the total phase II trial are awaited. A prospective randomized trial to compare the efficacy of the EndoCar 28 with conventional stapling should be the next step.     

New aspects of technical testing of intravascular stents

Maximum magnetic resonance artifacts from stents are often determined by the presence of ferromagnetic compounds in the delivery system. We propose a mathematic model describing artifacts caused by nitinol stents. A method for evaluation of critical radial rigidity of the stents was developed. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Supplement 2, pp. 112–116, April, 2007     

Tratamiento de la fístula anal mediante clip con el dispositivo OTSC®: resultados a corto plazo

Introduction

The treatment of anal fistula with the OTSC^® (over-the-scope-clip) proctology device involves the placement of an elastic alloy clip called Nitinol on the internal fistula opening to achieve fistula healing. The aim of this study was to analyze preliminary results of this technique in a case series.

Management of comminuted patellar fracture with non-absorbable suture cerclage and Nitinol patellar concentrator

PurposeTo evaluate the effectiveness and safety of a fixation technique for comminuted patellar fracture using non-absorbable suture cerclage and nickel-titanium patellar concentrator (Ni-Ti PC).MethodsTwenty-nine consecutive patients with displaced comminuted patellar fractures accepted internal fixation procedure using Ni-Ti PC augmented with different types of non-absorbable suture cerclage. During follow-up, the clinical grading scales of Böstman, including range of movement, pain, work, atrophy, assistance in walking, effusion, giving way, and stair-climbing, were used to evaluate the clinical results. Complications including implant loosening, fragment displacement, bone nonunion, infection, breakage of the implants, painful hardware, and post-traumatic osteoarthritis were also assessed.ResultsPatients were followed up for a mean period of 27 months. The bone union radiographically occurred approximately 2.5 months without implant loosening and fragment displacement. According to Böstman method, satisfactory results were obtained, and the mean score at final follow-up was 28 (range 20–30) points. Twenty-two patients with excellent results had mean score of 29.8 ± 0.5 (range 28–30) and seven patients with good results had mean score of 22.7 ± 3.14 (range 20–27). No postoperative complications, such as infection, dislocation, breakage of the implants, painful hardware, and post-traumatic osteoarthritis, were observed.ConclusionNi-Ti PC fixation with non-absorbable suture cerclage is a feasible approach for comminuted patellar fractures. Firm fixation with this technique resulted in satisfactory outcomes without obvious complications.     

Endovascular Stent-Grafting for Infected Iliac Artery Pseudoaneurysms

We report two cases of acutely infected pseudoaneurysms of the iliac arteries, successfully treated with endovascular stent-grafting. Two patients underwent stent-graft treatment for erosive rupture of the iliac artery caused by surrounding infection. The first case is that of a 61-year-old man who had undergone Miles operation for an advanced rectal cancer. Postoperatively, he developed intrapelvic abscess formation, from which methicillin-resistant Staphylococcus aureus was cultured, followed by rupture of the right external iliac artery. The second case is that of a 60-year-old man who had a pseudoaneurysm of the left common iliac artery, which was contiguous with a left psoas muscle abscess, from which Streptococcus agalactiae was cultured. Both patients were successfully treated with only a stent-graft and antibiotic therapy, and remained symptom-free 12 months and 10 months later. Although endovascular stent-grafting should not be considered standard therapy for infected aneurysms, our cases suggest that it can result in repair of infected aneurysms even in the uncontrolled active stage.     

应用记忆镍钛合金支架治疗气道狭窄

目的用记忆镍钛合金支架治疗气道狭窄疗效观察方法，选择气管癌或其他疾病致气道狭窄病人４２例，用纤维支气管镜导引、在Ｘ线监视下，置入记忆镍钛合金支架。结果：显效，气管管腔直径≥１．７ｃｍ或主支气管管腔直径≥１．３ｃｍ者３２例。有效，气管管腔直径≥１．２ｃｍ或主支气管管腔直径≥０．８ｃｍ者１０例，总有效１００％。结论：应用纤维支气管镜置入记忆镍钛合金支架治疗气道狭窄是一种简单、安全、有效的新方法。     

Treatment of Benign Tracheal Stenosis Utilizing Self-Expanding Nitinol Stents

We assessed the results of self-expanding metallic stent insertion into benign proximal tracheal stenosis in patients not appropriate or unfit for surgical repair. Proximal benign tracheal stenoses had occurred in 11 patients (7 men, 4 women, mean age 68.8 years) after long-time intubation (n = 6), tracheostomy (n = 4), or chondropathia (n = 1). Fourteen self-expanding nitinol stents were placed in the patients under general anesthesia with endoscopical and fluoroscopical guidance. Stent insertion was successful in all cases and led to immediate relief of the morphological and functional airway obstruction. No immediate complications were noted. During the mean follow-up period of 67.5 weeks we observed one recurrent dyspnea 3 months after implantation and granuloma formation at the stent insertion site in another patient. Both complications were successfully treated with additional stent insertion in one case and laser resection of granulomas in the other. Self-expanding nitinol stents should be considered for the treatment of benign proximal tracheal obstruction in selected patients for whom surgical repair is contraindicated.     

Novel self-expandable,stent-based transcatheter pulmonic valve: A preclinical animal study

Background

Because transcatheter implantation of pulmonary valve is indicated for limited-size dysfunctional right ventricular outflow tract only as a balloon-expandable stent, we investigated the feasibility of a large-diameter self-expandable valved stent and the durability of the valve after > 6 months.

Methods

We made a nitinol-wire-based, self-expandable valved stent with leaflets made from porcine pericardium. The porcine pericardium was treated with α-galactosidase, glutaraldehyde, and glycine after decellularization. After cutting the inguinal or cervical area, we implanted a valved stent in 12 sheep through the femoral or jugular vein by using an 18-Fr delivery catheter, controlling the catheter handles and hook block under fluoroscopic and echocardiographic guidance.

Results

The mean body weight of sheep was 43.9 kg. We successfully implanted valved stents (diameter: 24 mm in 7 sheep, 26 mm in 5 sheep) in good position in 8 sheep, in the main pulmonary artery (PA) in 2 sheep, and in the right ventricular outlet tract (RVOT) in 2 sheep. We sacrificed 8 sheep (6 sheep in good position, 1 sheep in the main PA, and 1 sheep in the RVOT) after > 6 months. Five of the 6 sheep implanted in good position showed well-preserved valve morphology at the time of sacrifice. Histologic findings after routine sacrifice showed well-maintained collagen wave structure and no visible calcification in all explanted valve leaflets.

Conclusions

Transcatheter implantation of a nitinol-wire-based, self-expandable valved stent in the pulmonic valve was feasible, and stents implanted in good position showed well-preserved valve leaflets with functional competence in the mid-term results.     

壳聚糖/肝素共价包被先天性心脏病介入封堵材料生物相容性的体外实验研究

目的体外评价壳聚糖/肝素(Chi/Hep)共价包被先天性心脏病介入封堵材料的生物相容性。方法在南京医科大学第一附属医院心血管内科于2005年11月至2006年10月,通过体外实验检测Chi/Hep共价包被镍钛合金片的血液相容性和细胞相容性。实验分成血液对照组、未包被组、基础包被组、Chi/Hep包被组,其中按肝素质量浓度又分为低(0.1mg.mL-1)、中(1mg.mL-1)、高(10mg.mL-1)3个剂量组。Chi/Hep共价交联于试验用镍钛金属表面,(1)血液相容性实验:通过血液溶血试验,动态人全血接触试验评价其红细胞毒性及抗栓性能,扫描电子显微镜观察镍钛金属表面血小板粘附、聚集。(2)细胞相容性:利用纤维连接蛋白、Ki67免疫荧光标记人脐静脉内皮细胞(HUVECs)观察其细胞毒性。结果(1)血液相容性实验:实验各组红细胞、白细胞、血小板计数均在正常范围内,且组间比较差异无显著性意义,各实验组溶血率均小于5%。Chi/Hep包被组部分凝血活酶活化时间(APTT)、凝血酶原时间(PT)、凝血酶时间(TT)均明显延长,血液对照组、未包被组及基础包被组两两比较差异无显著性意义,不同质量浓度肝素包被之间差异亦无显著性意义(APTT、PT方差均齐LSD、SNK法检验,TT方差不齐Dunnetts法检验P<0.05)。扫描电镜结果显示,Chi/Hep包被组金属表面少量血小板粘附。(2)细胞相容性实验:经过与HUVECs72h孵育,金属片边缘细胞生长、移行良好,无细胞变形;Fn免疫荧光标记HUVECs,发现不同包被镍钛金属片表面的HUVECs粘附顺序如下:基础包被组>未包被组>Chi/Hep组;Ki67免疫荧光标记HUVECs,随机双盲法计数细胞发现不同包被镍钛金属片表面的HUVECs增殖顺序如下:基础包被组=未包被组>Chi/Hep组(P<0.01)。结论体外观察Chi/Hep共价包被镍钛金属有良好抗血栓作用,但抑制内皮细胞粘附、增殖。