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Clip with enclosed spring for aneurysm surgery. Technical note.

A clip for aneurysm surgery has been designed with several unique features. The coil spring is fully hidden and protected within two hub sections so that it cannot be handled or become entrapped in tissue. The clip is milled from a piece of solid stock of nonmagnetic stainless steel to the desired size and shape by a computer milling process, thus avoiding the stresses and structural weaknesses caused by the bending, curling, and milling needed to prepare clips made from wire or sheet metal. The only means of opening the clip is by applying pressure to the solid milled surfaces, thus the spring cannot be weakened or bent by squeezing it or by trauma applied to the clip. The clip may be grasped in either a clip applier that holds the clip in one fixed position or in an applier that allows the clip to be rotated through an arc of 180 degrees.

Aneurysm↗

Aneurysm clips: evaluation of magnetic field interactions and translational attraction by use of "long-bore" and "short-bore" 3.0-T MR imaging systems.

BACKGROUND AND PURPOSE: The use of 3.0-T MR systems is increasing worldwide. We evaluated magnetic field interactions and translational attraction for 32 aneurysm clips in association with exposure to "long-bore" and "short-bore" 3.0-T MR imaging systems. METHODS: Thirty-two different aneurysm clips were evaluated in this investigation. Each aneurysm clip was qualitatively evaluated for magnetic field interactions and quantitatively assessed for translational attraction by using the deflection angle test. The deflection angle tests were performed at the points of the highest spatial gradients for long-bore and short-bore 3.0-T MR imaging systems. RESULTS: Seventeen of the 32 aneurysm clips showed positive magnetic field interactions. Deflection angles for the aneurysm clips were significantly (P <.001) higher on the short-bore (range, 0-18 degrees) compared with those recorded on the long-bore (range, 0-16 degrees) 3.0-T MR imaging system. Aneurysm clips made from commercially pure titanium and titanium alloy displayed no translational attraction (n = 15), whereas those made from stainless steel alloy, Phynox, and Elgiloy displayed positive deflection angles (n = 17). CONCLUSION: The 32 different aneurysm clips passed (angle <45 degrees) the deflection angle test by using the long- and short-bore 3.0-T MR imaging systems, indicating that they are safe for patients and other persons in these MR environments (ie, immediate area of MR imaging systems). However, only clips made from the titanium and titanium alloy are entirely safe for patients undergoing MR imaging procedures because of the total lack of magnetic field interactions. The remaining clips require characterization of magnetic field-induced torque. Because of possible differences in the points of the highest spatial gradients for different 3.0-T MR imaging systems, the results are specific to the imaging units and bore designs used in this investigation.

Contraindications↗

Efficacy of endoscopic clipping for actively bleeding peptic ulcer: comparison with polidocanol injection therapy.

BACKGROUND/AIMS: The use of hemostatic clips is conceptually attractive for achieving definitive hemostasis in peptic ulcer bleeding. There are only a few clinical trials comparing clipping with other endoscopic hemostatic methods. The aim of this study is to assess the efficacy and safety of endoscopic clipping with that of injection of polidocanol for hemostasis from actively (spurting or oozing) bleeding peptic ulcer. METHODOLOGY: 61 patients with active (spurting or oozing) bleeding gastroduodenal ulcers were randomly assigned to one of two endoscopic treatments: injection therapy with polidocanol 1% (injected in 0.5-1.0 mL increments at three to five sites around the bleeding vessel to a total of 5 mL) (n=30), or endoscopic clipping using a clipping device and clips (n=31). All patients from the polidocanol group and 22 (68.8%) patients from the clipping group received pretreatment with epinephrine. Hemostatic rates, rebleeding rates, amounts of blood transfusion, and durations of hospital stay were analyzed. RESULTS: The initial hemostatic rate was 96.8% in the clipping group, and 96.7% in the polidocanol group, respectively. Mean transfusion requirements, mean number of hospital days and percentage needing surgery were comparable in both groups. Recurrent bleeding rates were higher, although not statistically significant in the polidocanol group than in the clipping group (13.3% vs. 6.5%, respectively). CONCLUSIONS: Our data suggest that injection therapy with polidocanol and endoscopic hemoclips seems to be equivalent for actively (spurting and oozing) bleeding peptic ulcer.

Adult↗

Laparoscopic clips. Evaluation of absorbable and titanium with regard to hemostasis and tissue reactivity.

Advanced laparoscopic techniques require laparoscopic means of providing hemostasis. We tested the hemostatic ability of laparoscopic surgical clips and their tissue reactivity as assessed by adhesion formation in an animal model. Twenty-six New Zealand white rabbits were randomized at laparotomy to one of three treatment groups: titanium surgical clips, absorbable surgical clips (both applied with a laparoscopic clip applicator) and chromic sutures of equal mass. Either the right fallopian tube was transected, with clips or sutures applied proximally and distally to control bleeding, or the clips or sutures were applied 5 mm apart and the tube transected. A clip or suture of the same material was placed on the midportion of the left fallopian tube. Necropsy was performed at 42 days, and each clip/suture site was scored for adhesions. All the materials were easily applied and effective in achieving hemostasis. The adhesion scores tended to be lower with the absorbable clips; however, there were no statistically significant differences between the groups. Laparoscopic clips are effective in providing hemostasis, are easily applied and cause no more adhesion formation than do conventional suture materials.

Animals↗

Surgical clips: a cause of late recurrent gallstones.

The formation of gallstones around surgical clips after cholecystectomy is a rare complication, with only seven reported cases in the English literature since its initial description in 1979. Three other cases report clip migration into the common bile duct and obstruction. We report a recent experience with "clip cholelithiasis." A 78-year-old female, 16 years following cholecystectomy, presented with a several-month history of colicky abdominal pain worsened by meals, and a 1 week history of jaundice, anorexia, nausea, and vomiting. An abdominal ultrasound demonstrated dilatation of the biliary tree without visible choledocholithiasis. Endoscopic retrograde cholangiopancreatography demonstrated a 1.5-cm radiolucent stone in the common bile duct containing a central surgical clip. She was successfully treated with endoscopic sphincterotomy and stone retrieval. The first report of clip cholelithiasis occurred in 1979. Six additional cases have been reported as well as three cases of clip migration without stone formation into the common bile duct. The incidence of clip cholelithiasis may increase in frequency with the increased use of metallic clips during laparoscopic cholecystectomy. The occurrence of cholelithiasis around inert metals is rare and may be prevented using absorbable clips; however, stone formation is also reported around absorbable materials.

Absorption↗

[Is tubal sterilization with the Tupla-clip a reversible method?].

Between 1976 and 1981 402 tubal sterilizations were performed with Tupla-clip most of them by laparoscopic application. 11 tubes were removed between 15 and 47 months following the sterilization with the Tupla-clip. The local changes both macroscopically and microscopically to the tupla-clip were evaluated. The possibility of tubal patency following removal of the clips was tested by carbon dioxide pertubation. The tubal-occlusion with the tupla-clip is definitive since all tubes had a fibrous tissue strand where the clip had been applied which still carried blood vessels. No tube was patent with the carbon dioxide pertubation. The intra-operative testing of correct application of the clip and the documentation of this correct application is again mentioned. This is especially important in view of the recent judgements of the federal supreme court regarding liability in failed tubal sterilizations. The excellent chance of reversal by tubal anastomosis and the 100% success rate of this method of sterilization within the 6 years under observation will increase the acceptance of the tupla-clip as a method for tubal sterilizations.

Female↗

Randomized clinical trial of continuous sutures or non-penetrating clips for radiocephalic arteriovenous fistula.

BACKGROUND: Despite several modifications to the original design, patency rates of radiocephalic arteriovenous fistulas have changed little since the first report in 1966. The use of non-penetrating clips for vascular anastomosis on the outcome of such fistulas was studied. METHODS: Between January 2000 and August 2003, 107 primary radiocephalic fistulas were constructed in 98 patients. The vascular anastomoses were performed at random with either sutures (n = 56) or clips (n = 51). RESULTS: Although there were trends for better primary and primary assisted patency of clipped fistulas, the differences were not statistically significant. The 6-month primary patency rate was 61 per cent with sutures and 69 per cent with clips (P = 0.393). The mean(s.d.) primary patency was 315(306) and 285(285) days for clipped and sutured fistulas respectively. With regard to secondary patency, clipped fistulas were better (P = 0.009). The mean(s.d.) secondary patency was 435(376) and 344(316) days for clipped and sutured fistulas, respectively. There were no significant differences in flow characteristics, number of revisions or other morbidity. CONCLUSION: This randomized clinical trial provided further evidence that the use of vascular clips may improve the patency rate of radiocephalic arteriovenous fistulas for haemodialysis.

Adolescent↗

The emergence of catalytic and structural diversity within the beta-clip fold.

The beta-clip fold includes a diverse group of protein domains that are unified by the presence of two characteristic waist-like constrictions, which bound a central extended region. Members of this fold include enzymes like deoxyuridine triphosphatase and the SET methylase, carbohydrate-binding domains like the fish antifreeze proteins/Sialate synthase C-terminal domains, and functionally enigmatic accessory subunits of urease and molybdopterin biosynthesis protein MoeA. In this study, we reconstruct the evolutionary history of this fold using sensitive sequence and structure comparisons methods. Using sequence profile searches, we identified novel versions of the beta-clip fold in the bacterial flagellar chaperone FlgA and the related pilus protein CpaB, the StrU-like dehydrogenases, and the UxaA/GarD-like hexuronate dehydratases (SAF superfamily). We present evidence that these versions of the beta-clip domain, like the related type III anti-freeze proteins and C-terminal domains of sialic acid synthases, are involved in interactions with carbohydrates. We propose that the FlgA and CpaB-like proteins mediate the assembly of bacterial flagella and Flp pili by means of their interactions with the carbohydrate moieties of peptidoglycan. The N-terminal beta-clip domain of the hexuronate dehydratases appears to have evolved a novel metal-binding site, while their C-terminal domain is likely to adopt a metal-binding TIM barrel-like fold. Using structural comparisons, we show that the beta-clip fold can be further classified into two major groups, one that includes the SAF, SET, dUTPase superfamilies, and the other that includes the phage lambda head decoration protein, the beta subunit of urease and the C-terminal domain of the molybdenum cofactor biosynthesis protein MoeA. Structural comparisons also suggest the beta-clip fold was assembled through the duplication of a three-stranded unit. Though the three-stranded units are likely to have had a common origin, we present evidence that complete beta-clip domains were assembled through such duplications, independently on multiple occasions. There is also evidence for circular permutation of the basic three-stranded unit on different occasions in the evolution of the beta-clip unit. We also describe how assembly of this fold from a basic three-stranded unit has been utilized to accommodate a variety of activities in its different versions.

Amino Acid Sequence↗

Magnetic resonance imaging of the metal clip in a breast: safety and its availability as a negative marker.

PURPOSE: This study assesses magnetic resonance (MR) safety of the stainless-steel clip inserted after stereotactic-guided directional vacuum-assisted biopsy (DVAB) of the breast, and evaluates its imaging value. METHODS: We used a sausage as a substitute breast and inserted the clip into it. The MR images of the substitute were scanned using a breast coil, and it was then dissected. After the substitute experimentation, MR scanning of the breast was performed using a dynamic contrast enhanced technique, in which a clip was placed after DVAB for suspicion of ductal carcinoma was seen as grouped amorphous calcifications on mammography. RESULTS: On every magnetic resonance image of the substitute, the clip was seen as a spotty signal void, with no surrounding artifact. There was no movement and no evidence of increased clip temperature on dissected of the substitute, confirming the safety of breast MR with a clip in place. There was no patient complaint of feeling heat or pain during the MRI examination and there were only biopsy scars on the surgically excised breast specimen material. On the breast MR images, a spreading region of the tumor adjoining the position of the signal void was identified as an early enhancing lesion. CONCLUSIONS: The safety and reliability of breast MR examination using a mammotome clip was demonstrated by both the mock examination and the breast examination. It is possible to localize of tumor spread regions based on the marker position using the clip as a negative signal marker.

Breast Neoplasms↗

[Endoscopic pretherapeutic clipping for gastrointestinal tumors. A method for exact definition of the target volume].

BACKGROUND: In many cases it is not possible to exactly define the extension of carcinoma of the gastrointestinal tract with the help of computertomography scans made for 3-D-radiation treatment planning. Consequently, the planning of external beam radiotherapy is made more difficult for the gross tumor volume as well as, in some cases, also for the clinical target volume. PATIENTS AND METHODS: Eleven patients with macroscopic tumors (rectal cancer n = 5, cardiac cancer n = 6) were included. Just before 3-D planning, the oral and aboral border of the tumor was marked endoscopically with hemoclips. Subsequently, CT scans for radiotherapy planning were made and the clinical target volume was defined. Five to 6 weeks thereafter, new CT scans were done to define the gross tumor volume for boost planning. Two investigators independently assessed the influence of the hemoclips on the different planning volumes, and whether the number of clips was sufficient to define the gross tumor volume. RESULTS: In all patients, the implantation of the clips was done without complications. Start of radiotherapy was not delayed. With the help of the clips it was possible to exactly define the position and the extension of the primary tumor. The clinical target volume was modified according to the position of the clips in 5/11 patients; the gross tumor volume was modified in 7/11 patients. The use of the clips made the documentation and verification of the treatment portals by the simulator easier. Moreover, the clips helped the surgeon to define the primary tumor region following marked regression after neoadjuvant therapy in 3 patients. CONCLUSIONS: Endoscopic clipping of gastrointestinal tumors helps to define the tumor volumes more precisely in radiation therapy. The clips are easily recognized on the portal films and, thus, contribute to quality control.

Endoscopy, Gastrointestinal↗

Endoscopic thoracic sympathetic block by clipping for palmar and axillary hyperhidrosis in children and adolescents.

Endoscopic thoracic sympathectomy or sympathicotomy is a safe and effective method of treating primary hyperhidrosis (PH), but postoperative compensatory sweating may be a problem. There are few reports of sympathetic blockade by clipping for PH. We present our experience of endoscopic thoracic sympathetic block (ETSB) by clipping in treating palmar (PAH) and axillary hyperhidrosis (AH) in children and adolescents. Between May 1997 and June 1998, a total of 78 patients with PAH or AH underwent ETSB by clipping using an 8-mm, 0 degrees thoracoscope. There were 33 males and 45 females with a mean age of 14.1 years (range 9-16 y). All patients were placed in a semi-sitting position under single-lumen intubation anesthesia; 52 patients with PAH underwent T2 sympathetic block by clipping at the 2nd and 3rd rib beds, and T3 and T4 sympathetic block was performed at the 3rd, 4th and 5th rib beds in 26 patients with AH. A total of 156 sympathetic blocks by clipping were achieved. The operation was usually accomplished within 20 min (range 16-30 min). Most patients were discharged within 4 h after the operation. There were neither surgical complications nor mortality. The mean postoperative follow-up period was 32.7 months (range 26-40). Improvement of PAH or AH could be obtained in all cases; 70 patients (85.4%) developed compensatory sweating of the trunk and lower limbs. One patient with PAH underwent a reverse operation with improvement of the sweating 14 days after removal of the endo-clips. ETSB by clipping is thus a safe and effective method for treating PH in children and adolescents; compensatory sweating may be improved after a reverse operation with removal of the endo-clip.

Adolescent↗

Vascular closure system type of nonpenetrating arcuate-legged titanium clips for graft-artery and graft-graft anastomoses: review of our clinical experience.

PURPOSE: To assess the durability of Vascular Closure System (VCS) clips for graft-artery and graft-graft anastomoses. METHODS: The subjects were 100 consecutive patients, who had undergone vascular procedures in which VCS clip application was attempted for anastomoses. The operative indications were arteriosclerosis obliterans in 69 patients, aortic aneurysm in 26, and other disorders in 5. Large clips were used for both graft-artery and graft-graft anastomoses, and medium-sized clips were used for the smaller caliber femoral or popliteal arteries. RESULTS: Vascular Closure System clips could not be applied to anastomose the graft to the artery in 13 patients because the arterial wall was too thick or stiff. Anastomosis was accomplished without any problems in 80 patients, although suture-line bleeding occurred in 7 patients. This was ameliorated by an additional clip in four patients, but interrupted sutures were needed to seal the anastomosis in the other three patients. The 1-, 3-, and 5-year cumulative primary patency rates were 98.7%, 97.4%, and 87.7%, respectively. There were two graft failures and two anastomotic aneurysms. CONCLUSION: Vascular Closure System clips were useful to coapt a prosthetic graft to an artery unless the arterial wall was thicker than 2 mm or calcified. Thus, VCS clips could be durable enough for graft-artery anastomoses in the iliac or popliteal region.

Adult↗

The MHC class II-associated invariant chain-derived peptide clip binds to the peptide-binding groove of class II molecules.

Major Histocompatibility Complex (MHC) class II proteins bind to peptides derived from processed foreign antigens, and display them on the cell surface of antigen presenting cells for recognition by CD4+ regulatory T lymphocytes. Prior to their binding to antigenic peptides in endosomal compartments, class II molecules are associated with a nested set of peptides CLIP derived from amino acids 80 to 107 of the invariant chain (Ii). Currently the interaction between the CLIP peptide and class II molecules is not clear. Using an FITC-labeled CLIP peptide and soluble empty class II molecules synthesized in insect cells, we have investigated the direct binding of the CLIP peptide to class II molecules, and the influence of localized polymorphic residues in the peptide-binding groove on the binding. We found that the human class II HLA-DR1 molecule contains a single-binding site for the CLIP peptide as well as the antigenic peptide MP19-31, as analysed by Scatchard analysis. Further studies also showed that occupancy of the peptide-binding groove by antigenic peptides inhibited the binding of CLIP to DR1 molecules and vice versa. Most importantly, the polymorphic residues beta 85 and 86, which define the major peptide-binding pocket, strikingly influence the CLIP-DR1 interaction, as assayed by the SDS-stability of class II-peptide complexes and the affinity of class II-peptide interactions. These data indicate that the peptide-binding pocket and thus the peptide-binding groove of the class II molecule are directly involved in the association with the CLIP peptide.

Antigens, Differentiation, B-Lymphocyte↗

Surgical clips in planning the electron boost in breast cancer: a qualitative and quantitative evaluation.

PURPOSE: To evaluate, qualitatively and quantitatively, the role of surgical clips in planning the tumor bed electron boost in patients undergoing breast conserving surgery and radiotherapy. METHODS AND MATERIALS: In 50 patients, the excision cavity boundaries were marked by clips at surgery. The electron boost field was first planned using clinical information, aiming to achieve a margin of 2 cm, and its accuracy evaluated by screening the surgical clips and, if necessary, adjusting the field to encompass all clips with 2 cm margins. Orthogonal radiographs were take with solder wire delineating the clinical and screened fields and the scar. Hypothetical clinical and radiological fields, with 1 and 3 cm margins, were reconstructed on the radiographs. RESULTS: The clinical field was inadequate in 34 patients (68%). The precision of each clinical setup was quantified by two indices. The Normal Tissue Index defined the percentage of the clinical field comprised of tissue, beyond the tumor bed, not at high risk of local recurrence, and gave an estimate of potential spring of normal tissue: median 14.6% (range 0-83.0), 17 out of 50 > 25%; median 13% (range 0-70.7), 12 out of 50 > 25%; median 9.7% (range 0-59.8), 10 out of 50 > 25%, for 1, 2, and 3 cm margins, respectively. The Geographical Miss Index defined the percentage of the radiologically defined field, at high risk of local recurrence, not predicted by the clinical field, and gave an estimate of the extent of geographical miss: median 32.9% (range 0-83.5), 28 out of 50 > 25%; median 26.1% (range 0-69.8%), 26 out of 50 > 25%; median 18.6% (range 0-60.3), 20 out of 50 > 25%, for 1, 2, and 3 cm margins, respectively. The median distance from the scar midpoint to the furthest clip was 3.8 (range 1.2-8.1) cm. The median maximal clip depth was 3.1 (range 1.4-5.2) cm. CONCLUSION: (a) Electron boost field planning by clinical landmarks alone was inaccurate in 68% of cases. (b) Quantitative measures, based on margins of 1, 2, and 3 cm, revealed that in 20-34% of patients more than one-quarter of the clinical field covered tissue at low risk of local recurrence, and in 40-56% of patients less than three-quarters of the final radiological field was predicted clinically. (c) The relative positions of the scar and clips may be widely disparate. (d) Clip depth measurements reveal a significant risk of underdosing at depth.

Breast Neoplasms↗

In vitro changes in clips and bars used to retain implant overdentures.

Although implant-retained overdentures are a less expensive alternative to fixed implant-supported prostheses in certain situations, problems with retentive clips fracturing and needing frequent replacement have been reported. This study compared baseline and posttest retention of metal and plastic clip-retained overdenture analogs and monitored surface changes in bars and clips throughout the testing process. A laboratory model was made with two implant analogs processed into an acrylic resin platform to which three bars were fitted. Two overdenture analogs were made and retained on the model with metal or plastic clips. Each bar-clip assembly was subjected to 5500 insertion and removal cycles to simulate 3 years of in vivo insertion and removal. Although the differences in retention between metal and plastic clips and between clips before and after testing were statistically significant, it is questionable whether they are clinically significant. Neither clip fracture nor loss occurred during this study, which suggests that it may be functional or parafunctional loading and not repeated insertion and removal of an implant overdenture that may cause the stated problems.

Acrylic Resins↗

The effect of simulated function on the retention of bar-clip retained removable prostheses.

Patients wearing bar-clip retained removable prostheses may have loss of retention because of changes within the bar-clip assembly. This in vitro study recorded and compared the retention of one- and two-clip retained simulated mandibular complete denture prostheses before and after simulated function. Cast metal Hader bars and clip holders were used to make 10 one-clip and 10 two-clip specimen pairs. Tensile removal values before and after simulated function were recorded and compared by repeated-measures analysis of variance and Student tau tests (significance level 0.05). The results revealed that the use of two clips instead of one significantly increased retention of the simulated prosthesis. It was also found that there was a significant loss of retention after the specimens were placed on the bars and then removed once for both the one- and two-clip groups. Simulated function did not cause a significant change in retention for either group.

Analysis of Variance↗

Magnetic characteristics of Yaşargil aneurysm clips.

BACKGROUND: Metallic bioimplants are subject to great scrutiny in order to ensure that they are totally harmless to patients. Aneurysm clips are no exception to this rule. Considering the number of aneurysm clips used and their potential for injury, they should be evaluated very meticulously. Determining the magnetic characteristics of these clips is an important part of the evaluation process. In this study, a new method for evaluating magnetism is described and the importance of that information is briefly discussed. METHODS: Twenty Yaşargil aneurysm clips were analyzed using a vibrating sample magnetometer under 1.5 Tesla. This device is highly sensitive, and is capable of measuring the magnetism of small objects. RESULTS: Our measurements showed magnetism of the aneurysm clips ranged from 0.0334-0.1369 electromagnetic units (emu). CONCLUSIONS: Magnetometer measurements and real life tests under magnetic resonance imaging (MRI) have shown that these clips have a very low magnetism and are safe to use in 1.5 Tesla MRI scanners. This study also proves that the vibrating sample magnetometer is a useful device for analyzing the magnetism of aneurysm clips, and their emu values can be used as another industry standard in the production line to increase the safety of these clips.

Aneurysm↗

The importance of surgical clips for adequate tangential beam planning in breast conserving surgery and irradiation.

PURPOSE: To evaluate the role of surgical clips in the planning of tangential beams in patients undergoing breast conserving surgery and adjuvant radiotherapy. METHODS AND MATERIALS: Between September 1996 and April 1998, 25 consecutive female patients with ductal carcinoma in situ, Stage I and II cancer of the breast, underwent lumpectomy with the excision cavity marked by the surgical clips. Subsequently, tangential fields were planned using clinical and radiologic information obtained during simulation without the clips position being visible. RESULTS: When measured from the center of the deepest clip to the posterior field border of the tangential fields in 6/25 patients (24%) the distance was less than 2 cm, with the closest being only 0.5 cm. Respective measurements for the distal end of the clip and the posterior border were: 9/25 patients (36%); less than 2 cm, with the closest distance of 0.3 cm. There was a positive correlation between the distance from the scar to the palpable breast border and the distance between the deepest clip and the posterior border of the tangential beams. CONCLUSION: The lumpectomy scar is often a poor indicator of the excision cavity as demarcated by surgical clips. Without the clips, part of the cavity may be underdosed by the tangential radiation beams. This is more likely for the cavities located close to the lateral or medial border of the breast tissue.

Breast Neoplasms↗