Six novel minimally invasive therapies for benign prostatic hyperplasia / 浙江大学学报·医学版

Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms in men. When drug treatment is ineffective or conventional surgery is not suitable, novel minimally invasive therapies can be considered. These include prostatic urethral lift, prostatic artery embolisation, water vapor thermal therapy, Aquablation-image guided robotic waterjet ablation, temporary implantable nitinol device and prostatic stents. These novel therapies can be performed in outpatient setting under local anesthesia, with shorter operative and recovery times, and better protection of ejaculatory function and erectile function. General conditions of the patient and advantages and disadvantages of the each of these therapies should be fully considered to make individualized plans.

Comparative study on the mechanical properties of lower limb arterial stents under various deformation modes / 生物医学工程学杂志

Lower extremity movement is a complex and large range of limb movement. Arterial stents implanted in lower extremity are prone to complex mechanical deformation, so the stent is required to have high comprehensive mechanical properties. In order to evaluate the mechanical property of different stents, in this paper, finite element method was used to simulate and compare the mechanical properties of six nitinol stents (Absolute Pro, Complete SE, Lifestent, Protégé EverFlex, Pulsar-35 and New) under different deformation modes, such as radial compression, axial compression/tension, bending and torsion, and the radial support performance of the stents was verified by experiments. The results showed that the comprehensive performance of New stent was better than other stents. Among which the radial support performance was higher than Absolute Pro and Pulsar-35 stent, the axial support performance was better than Complete SE, Lifestent and Protégé EverFlex stent, the flexibility was superior to Protégé Everflex stent, and the torsion performance was better than Complete SE, Lifestent and Protégé Everflex stent. The TTR2 type radial support force tester was used to test the radial support performance of 6 types, and the finite element analysis results were verified. The mechanical properties of the stent are closely related to the structural size. The result provides a reference for choosing a suitable stent according to the needs of the diseased location in clinical applications.

Nitinol memory alloy two foot fixator with autologous cancellous bone grafting for old scaphoid fracture and nonunion / 中国修复重建外科杂志

Objective: To summarize the effectiveness of nitinol memory alloy two foot fixator with autologous cancellous bone grafting in treating old scaphoid fracture and nonunion. Methods: Between January 2013 and January 2017, 11 patients of old scaphoid fracture and nonunion were treated with nitinol memory alloy two foot fixator and autologous cancellous bone grafting. All patients were male with an average age of 26.1 years (range, 18-42 years). The fractures were caused by sport in 3 cases, falling in 7 cases, and a crashing object in 1 case. The interval between injury and operation was 6-18 months (mean, 8.9 months). Postoperative outcome measures included operation time, fracture healing time, grip strength, range of motion (ROM) of flexion, extension, ulnar deviation, and radial deviation, Mayo score, visual analogue scale (VAS) score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Results: The operation time was 35-63 minutes (mean, 48 minutes). All incisions had primary healing with no infection and loosening or breakage of internal fixator. All patients were followed up 12-30 months (mean, 20.7 months). X-ray films showed that fracture healing was achieved in all patients with an average time of 15 weeks (range, 12-25 weeks). All internal fixators were removed after 10-12 months of operation (mean, 11.2 months). At last follow-up, the grip strength, ROMs of flexion, ulnar deviation, and radial deviation were superior to those before operation ( P<0.05), no significant difference was found in ROM of extension between pre- and post-operation ( t=0.229, P=0.824). There were significant differences in above indexes between affected and normal sides ( P<0.05). At last follow-up, the Mayo, VAS, DASH scores were also significantly superior to those before operation ( P<0.05). Conclusion: For the old scaphoid fracture and nonunion, Ni-Ti arched shape-memory alloy fixator and autologous cancellous bone grafting can obtain good effectiveness, which is an effective treatment.

Clinical application of nitinol memory alloy two foot fixator combined with Kirschner wire in treatment of trans-scaphoid perilunate dislocation / 中国修复重建外科杂志

Objective: To evaluate the effectiveness of nitinol memory alloy two foot fixator combined with Kirschner wire in the treatment of trans-scaphoid perilunate dislocation. Methods: Between September 2011 and October 2018, 17 patients with trans-scaphoid perilunate dislocation were treated with nitinol memory alloy two foot fixator and Kirschner wire. There were 12 males and 5 females, with an average age of 32.6 years (range, 23-52 years). The disease duration was 8 hours to 9 days, with an average of 6.5 days. The causes of injury included 6 cases of falling injury, 4 cases of traffic accident injury, 3 cases of stress injury of wrist caused by sports, 2 cases of violent injury of wrist caused by machine impact, 1 case of military training injury, and 1 case of other injury. One case was complicated with nerve injury. According to Herbert's classification, all the fractures were type B4. At 1 week before operation, 3 months, 6 months after operation and last follow-up, the wrist function was evaluated according to the Krimmer scale score. Results: All the 17 patients were followed up 10.5-48 months, with an average of 18.6 months. There was no loosening or infection of the internal fixator, no necrosis of the scaphoid and lunate. The periosteal dislocations of the patients were well reduced and the scaphoid fractures all healed. The healing time was 4-18 months, with an average of 11.3 months. The Krimmer wrist scores were 37.5±4.4, 61.3±7.2, 83.3±9.3, 87.3±8.2 at 1 week before operation, 3 months, 6 months after operation and last follow-up, respectively. The Krimmer wrist score at each time point after operation was significantly improved when compared with that before operation ( P0.05). At last follow-up, the Krimmer wrist function was excellent in 13 cases, good in 2 cases, fair in 1 case, poor in 1 case, and the excellent and good rate was 88.23%. Conclusion: Nitinol memory alloy two foot fixator combined with Kirschner wire in the treatment of trans-scaphoid periosteal dislocation has definite effectiveness, simple operation, and good recovery of wrist function after operation.

Comparison of the formation ability of two types of machine-made nickel-titanium instruments in simulated curved root canals / 口腔疾病防治

Objective@#To compare ProTaper Universal (PU) and M3-L instruments in preparing curved root canals and to provide a reference for clinical applications.@*Methods@#Twenty resin-simulated curved single root canals were randomly divided into two groups. Root canal preparation was performed with a PU nickel-titanium file or an M3-L nickel-titanium file. Root canal preparation time, root canal length before and after preparation and root canal deviation were recorded.@*Results@#In the M3-L group, the displacement measured at the 4th to 7th sites was less than that in the PU group (P < 0.05), but there was no significant difference between the other two groups (P > 0.05); The length of the root canal before and after root canal preparation in the M3-L group was （14.90 ± 1.92）mm and （14.57 ± 1.13）mm, respectively, and the difference between the two groups was not statistically significant (t=3.18, P=0.058). The root canal length before and after root canal preparation in the PU group was（14.53 ± 1.53）mm and （14.28 ± 1.39）mm, respectively. The difference between the two groups was not statistically significant（t=2.12,P=0.124）; The average preparation time of the M3-L group [（110.15 ± 10.43）s] was less than that in the PU group [（330.48 ± 12.62）s] (P < 0.05).@*Conclusion @#The M3-L nickel-titanium file has better central positioning ability and is less time-consuming than the PU nickel-titanium file in root canal bending preparation.

Evaluation of the alignment efficiency of nickel-titanium and copper-nickel-titanium archwires in patients undergoing orthodontic treatment over a 12-week period: A single-center, randomized controlled clinical trial / 대한치과교정학회지

OBJECTIVE: The aim of this trial was to compare the alignment efficiency and intermaxillary arch dimension changes of nickel-titanium (NiTi) or copper-nickel-titanium (CuNiTi) round archwires with increasing diameters applied sequentially to the mandibular arch. METHODS: The initial alignment phase of fixed orthodontic treatment with NiTi or CuNiTi round archwires was studied in a randomly allocated sample of 66 patients. The NiTi group comprised 26 women, 10 men, and the CuNiTi (27℃) group comprised 20 women, 10 men. The eligibility criteria were as follows: anterior mandibular crowding of minimum 6 mm according to Little's Irregularity Index (LII), treatment requiring no extraction of premolars, 12 to 18 years of age, permanent dentition, skeletal and dental Class I malocclusion. The main outcome measure was the alignment of the mandibular anterior dentition; the secondary outcome measure was the change in mandibular dental arch dimensions during 12 weeks. Simple randomization (allocation ratio 1:1) was used in this single-blind study. LII and mandibular arch dimensions were measured on three-dimensional digital dental models at 2-week intervals. RESULTS: No statistically significant difference was observed between NiTi and CuNiTi according to LII (p > 0.05). Intercanine and intermolar arch perimeters increased in the CuNiTi group (p < 0.001). Inter-first premolar width showed a statistically significant interaction in week × diameter × application (p < 0.05). CONCLUSIONS: The effects of NiTi and CuNiTi round archwires were similar in terms of their alignment efficiency. However, the intercanine and intermolar arch perimeters, and the inter-first premolar width changes differed between groups.

Analysis of cutting capacity, preparation time, and apical deviation after instrumentation of artificial curved canals with the waveone ® and reciproc ® reciprocating systems / Análise da capacidade de corte, tempo de prepare e desvio apical após a instrumentação de canais curvos artificiais com sistemas reciprocantes Waveone ® e Reciproc ®

ABSTRACT Objective To analyze cutting capacity, preparation time, and occurrence of apical deviation, after instrumentation of curved canals with reciprocating Primary WaveOne ® and R25 Reciproc ® systems. Methods Twenty simulated canals with 35° bends were randomly assigned to the Primary WaveOne ® or R25 Reciproc ® . The preparations were made by a single operator. The cutting capacity was assessed by the difference in weight (on an analytical balance) of the canals before and after preparation. The time needed for the preparation was analyzed. The canals were filled with India ink and photographed on a platform before and after the preparation to analyze the apical deviation to a 1 mm length. The images were superimposed in Photoshop ® and the measurement was performed with the ruler tool. Statistical analysis was performed using Student's t-test. The level of significance was set at 5%. Results The WaveOne ® Primary system was more effective (in terms of cutting capacity) but had a longer preparation time than the R25 Reciproc ® instrument. Apical deviation was the only variable that did not significantly differ between the two systems. Conclusion The WaveOne ® Primary had a higher cutting capacity than the R25 Reciproc ® . Both systems maintained the original canal path. The preparation time was shorter for the R25 Reciproc ® than the WaveOne ® Primary system.

RESUMO Objetivo Analisar a capacidade de corte, o tempo de preparo e a ocorrência de desvio apical, após a instrumentação de canais curvos com os sistemas reciprocantes WaveOne ® e Reciproc ® . Métodos Vinte canais simulados, com 35° de curvatura, foram randomicamente divididos para os dois sistemas. Os instrumentos utilizados foram o WaveOne ® Primary e o R25 Reciproc ® . Cada instrumento foi utilizado em um canal. Os preparos foram feitos por um único operador. Para análise da capacidade de corte, os canais foram pesados em balança analítica antes e após o preparo. A diferença na pesagem foi utilizada para aferição. O tempo para execução do preparo foi cronometrado e os valores obtidos foram analisados. Já para análise do desvio a 1 mm do comprimento de trabalho, antes e após o preparo, os canais foram preenchidos com tinta nanquim e fotografados em uma plataforma. As imagens foram sobrepostas no Photoshop ® e, com a ferramenta régua, foi realizada a medição. Resultados Para análise estatística foi utilizado o teste T de Student, com nível de significância de 5%. Na análise da capacidade de corte, o sistema WaveOne ® Primary foi mais eficaz que o instrumento R25 Reciproc ® , embora o seu tempo de preparo tenha sido maior. Apenas no critério, desvio apical, não se verificou diferença significativa entre os dois sistemas. Conclusão O WaveOne ® Primary apresentou uma maior capacidade de corte que o R25 Reciproc ® . Ambos os sistemas respeitaram a trajetória original do canal. O tempo de preparo do R25 Reciproc ® foi menor que o WaveOne ® Primary.

Arcos pré-contornados de Nitinol e sua correlação com a morfologia da arcada dentária inferior: estudo longitudinal / Pre-contoured Niti archwires and its correlation with the morphology of the lower dental arch: a longitudinal study

O presente estudo tem como objetivo analisar as dimensões dos arcos pré-contornados de Nitinol e sua correlação com a morfologia da arcada dentária inferior. Foram utilizados trinta e dois modelos em gesso de indivíduos com má oclusão Classe II, divisão 1, cuja morfologia da arcada inferior foi comparada à forma de arcos pré-contornados de NiTi de três marcas. Foram obtidas imagens digitais dos modelos e dos arcos, e com o auxílio do programa Cef X (CDT Software, versão 2.3.20), foi mensurada a distância transversal entre o arco analisado e as pontas de cúspide dos dentes 34, 35, 44, 45. Observou-se que todos os arcos pré-contornados avaliados apresentam uma tendência a expandir a morfologia da arcada dentária normal. Porém, os arcos da marca TP Orthodontics apresentam uma morfologia mais próxima à forma da arcada em oclusão normal, quando comparados aos arcos das marcas 3M Uniteck e G&H Wire (p>0,05). Visto que todos os arcos pré-contornados avaliados possuem a tendência de expandir a morfologia normal da arcada dentária, é prudente individualizar os arcos utilizados para cada paciente, com o objetivo de alcançar resultados mais estáveis.(AU)

The present study aims to analyze the dimensions of pre-contoured Nitinolarches and its correlation with the morphology of the lower dental arch. Thirty-two plaster casts of individuals with Class II malocclusion were used in this study to compare the morphology of lower dental arch with the shape of NiTi pre-contoured archwire. Digital images were obtained from plaster casts and from the archwires, and after the superposition of the images, the computer software Cef X (CDT Software, version 2.3.20) was used to measure the lateral distance between the archwire analyzed and the cusp tips of teeth 34, 35, 44, 45. It was observed that all pre-contoured archwires evaluated have tendency to expand the morphology of lower dental arch. However, the TP Orthodontics archwires presented a more similar shape to the morfology of lower dental arch, when compared to the 3M Uniteck and G&H Wire archwires (p>0.05). Since all pre-contoured archwires studied have a tendency to expand the normal morphology of the dental arches, it is prudent to individualize the arches used for each patient in order to achieve more stable results.(AU)

Development of gastroduodenal self-expandable metallic stents: 30 years of trial and error

In 1991, the author (H.Y.S.) reported the first case of self-expandable metallic stent (SEMS) placement in a patient with recurrent cancer after gastrojejunostomy. Since then SEMS placement has developed into a well-established method for the palliative treatment of malignant gastroduodenal obstruction. This year marks the 30th year the author has been implicated in the development of gastrointestinal SEMSs. Thus far, the author has developed successively a total of six generations of gastroduodenal SEMSs through trial and error over the years. In the present article, the author reviews his personal experience in developing gastroduodenal stents.

The challenges: Stent materials from the perspective of the manufacturer

The article presents an overview of the basic data influencing the choice of materials for the manufacture of self-expanding metallic stents to be implanted into gastrointestinal tract, particularly esophageal stents. The data are evaluated primarily in terms of the manufacturer of stents. The text emphasizes not only the importance of the materials themselves, but also the biological environment in which the stent is used. Brief history of materials used in gastrointestinal stents mentions stainless steel, cobalt-chromium and nickel titanium alloys and polymers (polyester and polydioxanone). The text describes the properties of metal materials (composition, corrosion, mechanical properties) with particular focus on nickel-titanium alloy—nitinol. It lists advantages and disadvantages of nitinol. At the end of the review the authors briefly present their opinion on future materials of gastrointestinal stents and their covering.

Desarrollo e implementación de un nuevo diseño de stent de nitinol para el manejo de estenosis y fístulas benignas del tracto digestivo / Development and Implementation of a New Nitinol Stent Design for Managing Benign Stenoses and Fistulas of the Digestive Tract

Antecedentes: las estenosis benignas, la ruptura del tracto digestivo y las fístulas digestivas son condiciones que ponen en riesgo la vida y que por lo general son tratadas quirúrgicamente. Ahora, ha surgido la colocación de stents metálicos parcial o totalmente cubiertos como una opción de manejo con mínima invasión. Se pretende determinar la efectividad clínica de un nuevo diseño de stent de nitinol totalmente cubierto para el tratamiento de las perforaciones digestivas y las fístulas anastomóticas, con especial énfasis en la evaluación de la hiperplasia reactiva. Métodos: en el período 2012-2013 se colocó un stent de nitinol autoexpandible totalmente cubierto en 15 pacientes con perforaciones benignas de esófago, fístulas anastomóticas, estenosis después de cirugía gastrointestinal alta o baja. Se utilizó un stent de mayor diámetro en su centro (20 mm) y en su porción proximal (28 mm). Se recolectaron datos demográficos, tipo de lesión, ubicación del stent y remoción, éxito clínico y complicaciones. Resultados: a un total de 15 pacientes se les puso 15 nuevos stents por fístulas anastomóticas (n = 8), estenosis esofágica (n = 2), estenosis en anastomosis colorrectal (n = 2), estenosis de anastomosis gastroyeyunal (n = 1), ruptura iatrogénica de esófago (n = 1), y estenosis pilórica (n = 1). La remoción endoscópica del stent fue exitosa en todos los pacientes, y una fue particularmente difícil por hiperplasia reactiva. El éxito clínico se logró en 9 pacientes (73%), con una media de permanencia del stent de 10 semanas (rango 7 a 12 semanas). En total, ocurrieron 7 complicaciones en 15 pacientes (47%): hiperplasia reactiva (n = 1), migración (n = 3), dolor severo (n = 2), ulceración esofágica (n = 1), y solo 1 paciente requirió cirugía después del fallo del stent. Ningún paciente falleció como consecuencia de la colocación del mismo. Conclusiones: un stent totalmente cubierto, con nuevo diseño, dejado por 10 semanas, puede ser una alternativa ...

Background: Benign stenoses, digestive tract ruptures and fistulas are conditions that endanger life and are often treated surgically. Recently, the placement of partially or fully covered metal stents has emerged as a minimally invasive treatment option. This article looks at a new design for stents to determine its clinical effectiveness. The new stent is a completely covered nitinol stent for treatment of gastrointestinal perforations and anastomotic leaks. This article places special emphasis on evaluating reactive hyperplasia. Methods: Fifteen had the new completely covered self-expanding nitinol stent placed for treatment of benign esophageal perforations, anastomotic leaks, and stenoses following upper or lower gastrointestinal surgery during 2012 and 2013. The stents are 20 mm in diameter in the middle and 28 mm in diameter at the proximal end. Information about patient demographics, type of lesion, lesion locations, stent removal, clinical success and complications was collected. Results: A total of 15 stents were placed in 15 patients to treat anastomotic leaks (n = 8), esophageal stenoses (n = 2), colorectal stenoses (n = 2), a gastrojejunostomy stenosis (n = 1), an esophageal iatrogenic rupture (n = 1), and a pyloric stenosis (n = 1). Endoscopic removal of the stent was successful in all patients. Although it was particularly difficult in one case because of reactive hyperplasia. Clinical success was achieved in nine patients (73%). Average duration of time between stent placement and removal was 10 weeks with a range of 7 to 12 weeks. In total, seven complications occurred in 15 patients (47%): reactive hyperplasia (n = 1), migration (n = 3) severe pain (n = 2) esophageal ulceration (n = 1) only one patient required surgery after stent failure. No patients died as the result of stenting. Conclusions: A redesigned completely covered stent kept in place for 10 weeks may be an alternative to surgery for treating gastrointestinal ...

Radicular Pain due to Subsidence of the Nitinol Shape Memory Loop for Stabilization after Lumbar Decompressive Laminectomy

A number of dynamic stabilization systems have been used to overcome the problems associated with spinal fusion with rigid fixation recently and the demand for an ideal dynamic stabilization system is greater for younger patients with multisegment disc degeneration. Nitinol, a shape memory alloy of nickel and titanium, is flexible at low temperatures and regains its original shape when heated, and the Nitinol shape memory loop (SML) implant has been used as a posterior tension band mostly in decompressive laminectomy cases because the Nitinol implant has various characteristics such as high elasticity and a tensile force, flexibility, and biological compatibility. The reported short-term outcomes of the application of SMLs as posterior column supporters in cervical and lumbar decompressive laminectomies seem to be positive, and complications are minimal except for the rare occurrence of pullout and fracture of the SML. However, there was no report of neurological complications related to neural compression in spite of the use of the loop of SML in the epidural space. The authors report a case of delayed development of radiating pain caused by subsidence of the SML resulting epidural compression.

Biomechanical comparison for two types of nitinol stent-grafts / 医用生物力学

Objective To study biomechanical properties of two types of cylindrical nitinol stent-grafts under working condition of self-expanding, full deployment and bending, and analyze effects of structural change on biomechanical indexes of the grafts by numerical simulation methods. MethodsFirstly, the finite element models of two annular stent-grafts (i.e. stent-graft Ⅰ, stent graft Ⅱ, and a connecting rod was added to each stent unit of stent-graft Ⅱ for reinforcement) and target vessels were built. The stent-graft was transported to target vessel by delivery sheath, which was then removed to self-expand the stent-graft, and the contact between the vessel and the stent-graft was established. Secondly, the arterial pressure of 6.65-19.95 kPa (50-150 mmHg) was applied to inner surface of the stent-graft when the stent graft was fully deployed. Thirdly, the angular displacement was applied to both ends of the stent-graft to bend and deform the stent-graft. Finally, the maximum Von Mises stress (VMS) of the deformed vessel, the maximum principal strain (MPS), the maximum VMS and structural changes of the stent-graft were analyzed. ResultsFor both the stent-graft Ⅰ and Ⅱ, when they were self-expanding, the maximum VMS on the vessel was 0.349 MPa and 0.371 MPa, respectively; when they were fully deployed, the mean strain was 0.086% and 0.053%, the alternating strain was 0.049% and 0.027%, the maximum VMS on the membrane was 2.098 MPa and 2.430 MPa, respectively; when they were bent, the MPS was 0.069% and 0.101%, respectively, with more serious deformation on stent-graft Ⅰ. ConclusionsThe strain and stress of two stent-grafts under each working condition were less than their own material yielding limit. Stent-graft Ⅱ showed larger radial force in self-expanding, smaller strain under arterial pressure and better flexibility in bending deformation due to its connecting rod between each stent unit. These research results would provide an analysis method for structure design and material selection of the stent-graft, as well as a more intuitive and accurate technique guidance for intervention operation of the stent-graft in clinic.

Tratamiento endovascular de lesiones de arteria femoral superficial, TASC II B-C mediante stents de nitinol autoexpandibles extra largos (> 120 mm). Evaluación de la permeabilidad a los 6, 12, 24 y 36 meses post implante. / Tratamento endovascular de lesões da artéria femoral superficial, TASC II B-C com o uso de stents de nitinol auto-expansíveis extra longos (> 120mm). Avaliação da permeabilidade após 6, 12, 24 e 36 meses pós implante. / Endovascular treatment of TASC II B-C lesions of the superficial femoral artery with ultra long self expandable nitinol stents (> 120 mm). Assessment of patency at 6, 12, 24 and 36 months post-stenting

Objetivos: evaluación de la permeabilidad de los stents de Nitinol autoexpandibles extra largos(> 120 mm de longitud) en lesiones de arteria femoral superficial TASC II B-C, a los 6, 12, 24 y 36 meses post implante.Pacientes y Métodos: Entre junio de 2007 y diciembre de 2008, fueron tratados 7 miembros inferiores en 6 pacientes con lesiones de arteria femoral superficial tipo TASC II B-C mediante stents extra largos auto expandibles. Utilizamos stents autoexpandibles de Nitinol de 120-140 mm largo (Large SMART CONTROL) (Cordis). Utilizamos la vía percutánea ipsilateral anterógrada y, en aquellos pacientes que presentaron enfermedad de la cámara femoral, realizamos tratamiento hibrido: endarterectomía femoral, angioplastia con balón y colocación de stent. Se realizó elseguimiento mediante Ecodoppler y Rx de miembro inferior a los 6, 12, 24 y 36 meses post implante. Resultados: Se intervino a 5 pacientes del sexo femenino (84%) con un promedio de edad de 74 años +/- 5; 1 paciente de sexo masculino (16%) cuya edad fue de 60 años. 3 procedimientos fueron por vía percutánea ipsilateral anterógrada. Se realizaron 4 procedimientos híbridos (endarterectomía cámara femoral, angioplastia con balón y colocación de stent). La permeabilidad inicial fue del 100%, permeabilidad a los 6 meses: 100% de los casos, permeabilidad a los 12 meses: 86% de los casos, permeabilidad a los 24 meses: 86% de los casos con detección de Reestenosisen una paciente del 60%, siendo asintomática, permeabilidad a los 36 meses: 72 % de los casos. No se observaron fracturas de stent durante el estudio. Conclusiones: El stent largo de (> 120 mm longitud) es un buen instrumento para el tratamientode lesiones tipo TASC II B-C, comparables con la cirugía convencional, los cirujanos vascularesdeben conocer y aplicar todas las técnicas disponibles (cirugía, bioingeniería, endovascular, etc.) al tratar enfermedad arterial periférica encontrando la mejor opción para cada paciente...

Objetivo: avaliaçãó da permeabilidade dos stents de Nitinol auto expansíveis extra longos (> 120 mm de longitude) em lesões da artéria femoral superficial TASC II B-C, após 6, 12, 24 e 36 mesespós implante. Pacientes e Métodos: Entre junho de 2007 e dezembro de 2008, foram tratados 7 membrosinferiores em 6 pacientes com lesões da artéria femoral superficial tipo TASC II B-C com o uso de stents extra longos auto expansíveis. Utilizamos stents auto expansíveis de Nitinol de 120-140mm de comprimento (Large SMART CONTROL) (Cordis). Utilizamos a via percutânea ipsilateral anterógrada e, nos pacientes que apresentaram problemas na câmara femoral, realizamos um tratamento híbrido: endarterectomia femoral, angioplastia com balão e colocação de stent. Oseguimento foi realizado com a utilização de Ecodoppler e Rx de membro inferior após 6, 12, 24 e 36 meses pós implante. Resultados: Dos pacientes tratados, 5 eram do sexo feminino (84%) com uma média de idade de 74 anos +/- 5; 1 paciente do sexo masculino (16%) de 60 anos de idade. Com relação aos procedimentos, 3 foram por via percutãnea ipsilateral anterógrada. Foram realizados 4 procedimentos híbridos (endarterectomia câmara femoral, angioplastia com balão e colocação de stent). A permeabilidade inicial foi de 100%, após 6 meses, também de 100%, após 12 meses a permeabilidadefoi de 86% e 24 meses depois, de 86% com detecção de Reestenosis em uma paciente em 60%, sendo assintomática,apresentando uma permeabilidade após 36 meses de 72%. Não foram observadas fraturas de stent durante o estudo realizado. Conclusões: O stent longo de (> 120 mm de comp.) é um bom instrumento para o tratamentode lesões tipo TASC II B-C, comparáveis com a cirurgia convencional, os cirurgiões vasculares devem conhecer e aplicar todas as técnicas disponíveis (cirurgia, bioengenharia, endovascular, etc.) no tratamento da doença arterial periférica, encontrando a melhor opção para cada paciente...

Objetives: Evaluation of self-expanding large nitinol (> 120mm) stents patency in the treatments of TASC II B-C of SFA lesions at 6, 12 , 24 and 36 months after implantation. Patients and Methods: Between June 2007 to December 2008, we have treated 7 legs in 6 patients with TASC II B-C of Superficial Femoral Artery lesions with large nitinol stent, SMART (Cordis). The procedures was with percutaneous ipsilateral antegrade approach and when the patients had femoral common disease had made hybrid approach (open femoral endarterectomy+ balloon angioplasty & stent placement). We used nitinol stents of 120-140 mm large (Large SMART CONTROL) ( Cordis). The follow-up of patency was studied with Dupplex Scan and RX of the legs at 6, 12, 24 and 36 months after the initial treatment.Results: 5 ( five) Female patients (84%) mean age 74 years +/- 5; 1 (one) Male patient (16%) mean age 60 years. 3 procedures was with percutaneous ipsilateral antegrade approach. 4 was hybrid approach ( open femoral endarterectomy + balloon angioplasty & stent placement). Initial patency was of 100%, Restenosis in one case (14%) of 60% asintomatyc patient at 24 months and distal to stent placement; Ocluded one case (14%) at 12 month (man with reestenosiscarotid stent to). Don´t observed stent fracture in this study. Conclusions: Large Nitinol stents (> 120 mm length) are a good instrument to the treatment of superficial artery lesion with a comparable patency with surgery approach in lesions TASC II B-C. Vascular Surgeons needs to learn and use all of the technics (conventional surgery, Bio Ingeneering, Endovascular) to treat periphereal arterial disease and found the best options for each patients...

Posterior Cervical Fixation with a Nitinol Shape Memory Loop for Primary Surgical Stabilization of Atlantoaxial Instability: A Preliminary Report

OBJECTIVE: To evaluate a new posterior atlantoaxial fixation technique using a nitinol shape memory loop as a simple method that avoids the risk of vertebral artery or nerve injury. METHODS: We retrospectively evaluated 14 patients with atlantoaxial instability who had undergone posterior C1-2 fusion using a nitinol shape memory loop. The success of fusion was determined clinically and radiologically. We reviewed patients' neurologic outcomes, neck disability index (NDI), solid bone fusion on cervical spine films, changes in posterior atlantodental interval (PADI), and surgical complications. RESULTS: Solid bone fusion was documented radiologically in all cases, and PADI increased after surgery (p<0.05). All patients remained neurologically intact and showed improvement in NDI score (p<0.05). There were no surgical complications such as neural tissue or vertebral artery injury or instrument failure in the follow-up period. CONCLUSION: Posterior C1-2 fixation with a nitinol shape memory loop is a simple, less technically demanding method compared to the conventional technique and may avoid the instrument-related complications of posterior C1-2 screw and rod fixation. We introduce this technique as one of the treatment options for atlantoaxial instability.

Fatigue and fracture behavior of Nitinol cardiovascular stents / 医用生物力学

Objective To carry out analysis on the fatigue lifetime prediction of nitinol cardiovascular stents. Method By using the finite element method of fatigure fracture, the three dimensional nitinol cardiovascular stents were established to analyze the structure of cardiovascular stents under a physiological pulsating cyclic loading. Results Great normal stress, low fatigue life and serious fatigue damage were found to be located near the stents’knots, and stents with nitrided surface or shot peened surface were likely to have a longer fatigue life. During miniature fatigue testing, early fatigue cracks or fractures were always formed at locations near stents’knots. Conclusions The simulating results under the physiological loading are matched with related experimental results, which provide a theoretical basis for the reliability and design of the cardiovascular stents.

Effect of Zoledronic Acid on Early Osseointegration of Porous Implant in Rabbit / 대한정형외과연구학회지

PURPOSE: The purpose of this study was to determine whether intravenous injection of the zoledronic acid could promote osseointegration of the porous implant inserted into the rabbit medullary cavity. MATERIALS AND METHODS: A rabbit intramedullary osseointegration model was used. A specially designed porous nitinol implant (Bio-Smart, Sungnam, Gyeonggi-do, Korea) was inserted in the right distal femur of twenty six rabbits. They were randomized into the control or the experimental groups. In the control group, an intravenous injection of normal saline 2 ml/kg (Daihan Pharm, Seoul, Korea) was given at the end of the operation. In the experimental group, an intravenous injection of zoledronic acid 0.1 mg/kg (AclastaG(R) 2 ml/kg, Norvatis, Stein, Switzerland) was given at the end of the operation. Six weeks later, all animals were sacrificed and undecalcified histologic sections were prepared. Then, histomorphometric measurement of bone affinity index (%) and bone ingrowth area rate (%) was carried out. RESULTS: Six rabbits were excluded due to death and wound infection. Nine rabbits in the control group and eleven rabbits in the experimental group were included for the analysis. The bone affinity indices were 19.9+/-7.9% in the control group, and 28.4+/-7.2% in the experimental group. Although there was no statistical significance (p=0.056), the bone affinity index of the experimental group was higher than that of the control group. The bone ingrowth area rates were 8.7+/-3.7% in the control group, and 12.1+/-4.1% in the experimental group (p=0.046), indicating zoledronic acid had an positive effect on the promotion of bone ingrowth into the porous implant. CONCLUSION: In our rabbit intramedullary osseointegration model, intravenous injection of the zoledronic acid promoted early osseointegration of the porous implant. Zoledronic acid might be useful to promote the early osseointegration of the joint replacement implants.

An Experiment of Using Nitinol Alloy Momemorial Stent to Treat the Stenosis of the Rabbi / 听力学及言语疾病杂志

Objective To compare the effects of nitinol alloy memorial stent with silastic tube in treating the stenosis of the rabbit.Methods 16 rabbits with external ear canal(EEC) stenosis were randomly divided into two groups.One group was implanted with skin on the EEC wound while the other not.By self-comparison method nitinol alloy memorial stem was implanted in a rabbit's one ear and the silastic tube in the other.After days 5,15,30,and 60 later,the diameters of the external ear canal (with two materials planted) were measured respectively in the skin-planting group.In the naked group scar tissues were harvested and tested separately according to the planting material.HE coloration were used to study fibroblast hyperplasty while RT-PCR were applied to detecting the TGFβ1mRNA expression.The two brackets were compared according to their effect to scar hyperplasty.Results The EEC diameters using nitinol alloy memorial stem were found more spacious than using silastic tube.HE coloration showed the fibroblast hyperplasia was more mitigatory by using the nitinol alloy memorial stent.RT-PCR also found the TGFβ1mRNA expression was low by using same material.Conclusion The nitinol alloy memorial stent shows obvious superiority over silastic tube in external ear canal stenosis therapy.

Biocompatibility evaluation of domestically-manufactured NiTi-alloys after thermal oxidation of surface / 第二军医大学学报

Obiective: To compare the tissue biocompatibility of domestically manufactured NiTi alloy before and after thermal surface oxidation under 3 different temperatures. Methods: Domestically manufactured NiTi alloy was oxidized in air (group A) and subjected to 30 min heat treatment at 400°C (group B),500°C, (group C),and 600°C (group D) to form different protective oxide surface layers in presence of argon (607.95 kPa). Wire samples from A, B, C and D groups were subcutaneously implanted in guinea pigs. Guinea pigs received 317L stainless steel transplantation(group E) and sham-operation group (F) were taken as control. The order of inflammatory cell infiltration and tissue hyperplasia around implanted materials were observed 1, 2, 4, and 8 weeks after implantation. Results: The peak time of inflammatory cell infiltration and fibrous hyperplasia were at the first and fourth week after implantation. The inflammatory cell infiltration and fibrous hyperplasia were both slight and all met the GB/T 16886. 6-1997 in vivo implantation standard. The order of inflammatory cell infiltration and thickness of capsule walls from low to high was F

Liga com memória de forma: estudo preliminar do grampo de judet de nitinol e sua possível aplicação em tórax instável / Shape memory alloy: a preliminary study of nitinol judet staples for future application in flail chest

Este artigo sucintamente descreve a evolução da liga metálica “inteligente”, com memória de forma na área de Saúde. A confecção de grampos de Judet em nitinol ocorreu no Laboratório de Transformação Mecânica da UFRGS (LdTM) e a simples verificação das qualidades superelásticas e de memória de forma foram contempladas no LdTM e no HCPA pela equipe envolvida no projeto. A título de ilustração, demonstramos com um caso clínico a aplicabilidade do grampo de Judet no cenário de instabilidade da parede torácica, a qual, além de prejudicar a mecânica respiratória, apresenta uma alta taxa de mortalidade. Os resultados preliminares evidenciaram a transformação provocada pelo calor, ocasionando o fechamento das garras dos grampos de Judet, que se manteve firme e sem alteração da consistência com o tempo, permitindo antever sua aplicabilidade num modelo experimental. Grampos de Judet em Nitinol são apresentados teoricamente como vantajosos em relação aos já existentes em aço inoxidável 316L, especialmente pela facilidade de manuseio e possível simplificação do procedimento cirúrgico. Detalhes no acabamento permitem a biocompatibilidade e o engenheiro projetista de materiais deve compatibilizar as ligas de níquel e titânio (NiTi) utilizadas nos grampos. O nitinol possui amplo emprego no cenário médico-odontológico e há normas técnicas bem definidas. A epidemiologia do trauma e a gravidade das lesões associadas à instabilidade da parede torácica evidenciam a oportunidade de estudos nessa direção. Concluímos sobre a necessidade de prosseguir para uma avaliação experimental, agregando a mensuração de parâmetros viscosos e viscoelásticos da mecânica respiratória, especialmente em seu componente de parede torácica (cw).

The aim of this article is to briefly describe the incorporation of nitinol (NiTi) – an intelligent nickel-titanium alloy presenting shape memory – for use in medical applications. Nitinol Judet staples were developed at the Mechanical Processing Laboratory (LdTM) at Universidade Federal do Rio Grande do Sul. Simple confirmation assays of superelasticity and shape memory were performed at the LdTM and Hospital de Clínicas de Porto Alegre by the project team. A clinical case was used to demonstrate the applicability of nitinol Judet staples in the treatment of flail chest, a condition characterized by respiratory mechanics associated with fairly high mortality. The initial observation revealed a transformation resulting from heat exposure causing the closure of staple prongs. With time, the consistency of the Judet staples remained unchanged, indicating the feasibility of an experimental model employing these staples. The advantages of NiTi-made Judet staples in relation to 316L stainless steel staples are outlined, with emphasis on the ease of use and possible simplification of the surgical procedure. Finishing details ensure biocompatibility, with a focus on specific adaptations in the NiTi alloy employed to manufacture the staples; nevertheless, nitinol is widely employed in medicine and dentistry, with well-defined standards. The epidemiology of trauma and the severity of lesions associated with flail chest provide an opportunity for the proposed studies. The experimental assessment of nitinol Judet staples must now address viscosity and viscoelastic parameters of respiratory mechanics, especially concerning the chest wall.