PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Clips”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1991

Plasma active and acid-activatable renin during the development of one-kidney, one-clip and two-kidney, one-clip hypertension in the rabbit.

Systolic blood pressure in the central ear artery of eight rabbits increased by 21 mmHg (1 mmHg = 133.32 Pa) over 40 days following renal artery clipping and contralateral nephrectomy (one-kidney, one-clip). Plasma active and acid-activatable (pH 2.8) renin did not change significantly. Similar data were obtained from a group of 12 rabbits following renal artery clipping alone (two-kidney, one-clip) except that blood pressure in this group increased for 26 days but then declined until 40 days. Two animals with one-kidney, one-clip hypertension and three rabbits with two-kidney, one-clip hypertension had large increases in plasma active and inactive renin levels, which followed a more exaggerated rise in blood pressure than in the previous two groups. Forty days after unilateral renal artery clipping, the unclipped kidney was removed in 10 animals with two-kidney, one-clip hypertension. A further increase in blood pressure (+29%) occurred in seven of the animals but no change in plasma active or inactive renin. Results were compared with two groups of control animals, a unilateral nephrectomy group and a laparotomy group. None of the surgical procedures used produced a consistent pattern of change in the relative amounts of active and inactive renin in plasma. No marked changes in sodium, potassium, or water balance occurred in any group of animals.

Animals↗
PubMed1976

Endothelial cell damage by temporary arterial occlusion with surgical clips. Study of the clip site by scanning and transmission electron microscopy.

The effects of temporary vascular occlusion with surgical clips on the underlying endothelial lining were studied with scanning (SEM) and transmission (TEM) electron microscopy. Twenty-five rabbits were anesthetized and both common carotid arteries exposed. A Heifetz clip was used to occlude the right carotid artery for 5, 15, and 30 minutes, and 2 hours in five animals each. The clips were removed and the vessels immediately perfused with glutaraldehyde. In five remaining animals, the right carotid arteries were occluded for 30 minutes followed by removal of the clip and resumption of blood flow for 30 minutes prior to fixation. Combined SEM and TEM examination of the endothelium of compressed segments revealed "craters" and "balloons", blebs and vacuoles, swollen mitochondria, dilated granular endoplasmic reticulum, and subendothelial edema. There were also areas of endothelial cell flattening, discontinuity, and desquamation exposing the subendothelial tissues. Following restoration of flow, platelets and fibrin were found adherent to altered endothelial cells and to exposed subendothelial tissues. Endothelial craters and balloons were also found distal and, significantly less frequently, proximal to the site of occlusion. It is suggested that antiplatelet aggregating agents may prove beneficial for the prevention of thrombus formation at the site of the clip as well as craters and balloons distal to the clip following procedures requiring temporary vascular occlusion.

Animals↗
PubMed1992

In vivo left ventricular anatomy in rats with two-kidney, one clip and one-kidney, one clip renovascular hypertension.

OBJECTIVES: To evaluate differences in left ventricular structural changes related to different hemodynamic patterns. DESIGN: One-kidney, one clip (1K1C; volume-dependent hypertension) rats were two-kidney, one clip (2K1C; high-resistance hypertension) to determine whether these two types of Goldblatt rats showed different types of left ventricular adaptation. METHODS: M-mode echocardiography was used to study 28 2K1C and 19 1K1C Wistar rats 8 weeks after surgery and 55 age-matched control animals. RESULTS: Systolic blood pressure was equally high in the two models; the 1K1C rats had a larger left ventricular chamber and normal plasma renin activity (PRA), whereas in the 2K1C rats PRA was increased and the left ventricular chamber was normal. The atrial natriuretic factor was significantly increased only in the 2K1C rats and was related to PRA. The left ventricular mass index was increased in both models, but more in the 1K1C than the 2K1C rats. CONCLUSIONS: In both models the degree of left ventricular hypertrophy was associated with the interacting effects of the hemodynamic component superimposed on the primary hemodynamic pattern (i.e. blood pressure as an expression of pressure overload in the primarily volume-dependent 1K1C rats and the left ventricular chamber size as an expression of volume overload in the high-resistance 2K1C rats). The interaction between pressure and volume increased the left ventricular wall thickness in both models, with additional chamber enlargement in the 1K1C rats. In these rats, the increase in left ventricular mass was more pronounced due to the greater volume load on the heart.

Adaptation, Physiological↗
PubMed1992

How secure are laparoscopically placed clips? An in vitro and in vivo study.

We tested the security of laparoscopic, hemostatic clips in vitro and in vivo. In vitro, the force needed to transversely dislodge clips that were applied to silicone (Silastic) tubing ranged from a mean +/- SEM of 1.81 +/- 0.07 N (Endo Clip) to 2.68 +/- 0.04 N (Ligaclip). The force needed to axially dislodge clips that were applied to silicone tubing ranged from 4.08 +/- 0.20 N (Endo Clip) to 4.78 +/- 0.18 N (Ligaclip). In vivo, on mesenteric vessels in anesthetized pigs, 34 of 100 clips that were applied laparoscopically with the Endo Clip were moved or dislodged compared with 11 of 100 of those applied with the Ligaclip. We conclude that laparoscopically placed vascular clips applied with the Ligaclip are more secure than those applied with the Endo Clip. The laparoscopic surgeon should be aware of the relative ease with which clips may be dislodged.

Animals↗
PubMed1991

Neurosurgical vascular complications associated with aneurysm clips evaluated by postmortem angiography.

Neurosurgical vascular complications were evaluated by postmortem angiography in a consecutive prospective series of 63 patients in Helsinki who suffered a fatal outcome following neurosurgery for ruptured intracranial aneurysm. Operative vascular complications were revealed in 28 (44%) of the cases. Massive intraoperative bleeding resulting from rupture of the aneurysm or adjacent major artery during dissection or clip application complicated the operation in 16 (25%) patients. Clip-induced obstruction of cerebral arteries was detected by angiography in seven cases (11%). In six of the patients an adjacent cerebral vessel was accidentally clipped. In one case a kinking of the clip had caused obstruction of the right anterior cerebellar artery with resulting frontal infarct. A combination of rupture of the internal carotid artery and accidental ligation of the left posterior cerebellar artery occurring simultaneously during the clipping of a ruptured basilar aneurysm was detected in one patient (2%). Other types of complication were revealed in four cases (6%): detachment of clip with re-bleeding; clipping of an uninvolved aneurysm instead of the ruptured one; displacement of the clip beneath the ruptured aneurysm. Operations on ruptured basilar artery aneurysm were significantly (P less than 0.01) more prone to complications. The results indicate that operative vascular complications play a significant role in the mortality of aneurysm patients. Post-mortem angiographic technique with contrast medium that vulcanizes at room temperature is particularly suitable for demonstration of the haemodynamic significance of clip-induced cerebrovascular accidental occlusions, and is the only method at autopsy to reveal an occlusion caused by a kinking of a properly placed aneurysm clip.

Adult↗
PubMed1991

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↗
PubMed1991

Renal atrial peptide receptors and natriuresis in two-kidney, one clip hypertension.

It has been suggested that the impaired natriuretic response of the clipped kidney in two-kidney, one clip hypertensive rats is related to downregulation of renal atrial natriuretic peptide receptors. To test this hypothesis, blood volume expansion and atrial peptide binding studies were performed in this model. Infusion of 1% and then 1.5% body weight donor blood (n = 6) caused a progressive increase in plasma immunoreactive atrial natriuretic peptide (107 +/- 26 to 168 +/- 31 to 427 +/- 154 pg/ml, p less than 0.001); the sodium excretion of the nonclipped kidney rose from 230 to 2,200 to 4,000 neq/min (p less than 0.01) but that of the clipped kidney did not rise significantly. There was a highly significant correlation between log cyclic guanosine monophosphate and log sodium excretion by the nonclipped (r2 = 0.749) but not the clipped (r2 = 0.046) kidney. Between clipped and nonclipped kidneys, the association constant (5.26 +/- 0.89 versus 5.17 +/- 0.64 x 10(9)/mol) and apparent binding site density (575 +/- 92 versus 500 +/- 74 fmol/mg protein) for atrial peptide binding in isolated glomeruli did not differ. Assay of atrial peptide-induced cyclic guanosine monophosphate release by isolated glomeruli showed that clipped and nonclipped kidneys were equally responsive. Binding affinity and receptor density did not differ in homogenates prepared from inner medullas of clipped and nonclipped kidneys. These results show that the blunted natriuretic response in clipped kidneys was not associated with any relative decrease in number or function of glomerular or papillary atrial natriuretic peptide receptors.

Animals↗
PubMed1992

[An evaluation of temporary clipping during aneurysmal surgery: a retrospective study].

A temporary clipping of a parent artery has been found convenient in facilitating an aneurysmal dissection. This is because it controls the bleeding from an unexpected rupture and keeps the sac collapsed during the operation. Such a temporary arterial occlusion, however, involves the risk of a focal ischemia that may lead to permanent postoperative neurological deficits. Therefore, to evaluate the influence of a temporary clipping on the outcome of an operation, a retrospective study of 302 patients who underwent an operation for a ruptured supratentorial aneurysm between 1981 and 1990 has been conducted. This study has revealed the information that follows: 1) Overall outcomes In patients given no temporary clipping, their postoperative activity in daily living (ADL) grade was good in 70.7%, i.e. ADL 1 or 2, whereas only 46.4% of the patients given a temporary clipping achieved a similar ADL. 2) Influence of the preoperative Hunt and Kosnik neurological classification on the outcome Irrespective of whether a temporary clip had been used, patients with a Hunt and Kosnik grade of 1 or 2 made a good recovery, whereas patients with a grade of 4 or 5 did not. The application of a temporary clip in grade 3 patients led to a poor result, whereas in grade 3 patients given no temporary clipping the results were good. This would seem to indicate that Hunt and Kosnik grade 3 rating is a critical factor in consideration whether a temporary clip should be used or not. 3) Influence of the operative timing on the outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1979

Laparoscopic sterilization with the spring clip: instrumentation development and current clinical experience.

Since the original spring clip sterilization studies were reported, a number of clinically important modifications to the spring clip and applicator have been developed. The spring-loaded clip, manufactured by Richard Wolf Medical Instruments Corporation of Chicago, Illinois, and Rocket of London, Inc., London, England, and New York, New York can be applied with either a one- or two-incision applicator and the clips and applicators currently available incorporate improvements to the original prototypes in design, manufacture, and quality control. The two-incision applicator is associated with significantly fewer misapplications and the high pregnancy rates reported with the original clip and applicator have not occurred with the current designs. Comparative studies between the clip and band have revealed less operative bleeding and pain associated with the clip. The method is appropriate to all women requesting sterilization but especially to those in the younger age group who may subsequently request reversal because of divorce and remarriage.

Female↗
PubMed1977

Vas occlusion by tantalum clips and its comparison with conventional vasectomy in man: reliability, reversibility, and complications.

Occlusion of the vas deferens has been carried out by applying tantalum clips in 60 men. Another 50 men were vasectomized conventionally and served as controls. Vasography showed that two clips were required on each vas to bring about perfect and firm occlusion. The incidence of postoperative infection and other complications was much lower in the clip-occluded cases. Under a long-term follow-up, 10% of the conventionally vasectomized men were dissatisfied with the operation as compared with 2% of the clip-occluded group. Both groups became azoospermic within 3 months and the failure rate was zero. Removal of the clips not only was difficult but left the vas compressed and leaking. The method cannot, therefore, be considered reversible by itself. However, recanalization could easily be achieved by end-to-end anastomosis after excision of the small clipped segment or by side-to-side anastomosis without any excision. This, damage to the neuromuscular apparatus of the vas may be minimized. Male sterilization by clip occlusion has the advantages of minimal surgical intervention, shorter operative time, safety from postoperative infection, and easier recanalization if desired.

Evaluation Studies as Topic↗
PubMed1978

Structural changes in the human vas deferens after tantalum clip occlusion and conventional vasectomy.

In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other. After 2 weeks, the occluded segments were recovered for histopathologic examination of serial sections. Obstructing the seminal tract did not, as such, produce any significant change in the vas: the distal and proximal segments appeared to be essentially similar and normal. At the actual site of occlusion, however, tantalum clips produced marked flattening of the tube, complete loss of lining epithelium, distortion of the muscular lamellae, and areas of hemorrhage. The lumen was converted into a narrow slit. Under the ligatures, the damage was largely confined to denudation of the mucosal epithelium. The mucosa of the intersegment left unexcised between two clips showed hyalinization, invasion by macrophages, and degeneration of the epithelium. The changes under the clips suggest that, although clip occlusion may offer several advantages, sterility cannot be reversed merely by removing the clips. The mechanisms of these changes, different in the case of clips and ligatures, are discussed and some possible long-term consequences are considered.

Epididymis↗
PubMed1978

Interrelationship of aneurysm clips and vascular tissue.

Various straight-jawed aneurysm clips were tested for occluding capabilities on a vascular tissue model. Occluding pressures varied markedly among the clip styles and were altered by changes in the lumen and tissue composition of the model. Mechanical characteristics are highly variable between clip styles, but fall within a narrow range for clips of a similar style. The complex interplay of the unique aspects of clip design and force generated by the spring in conjunction with tissue characteristics and precise clip placement upon the tissue are major variables in the apparent ability of a particular clip to occlude the neck of an aneurysm.

Animals↗
PubMedDate not supplied

A comparison of the clip and ring techniques for laparoscopic sterilization of postabortion and postpartum patients.

The spring-loaded clip and the tubal ring techniques of laparoscopic female sterilization are compared for ease of performance, safety and effectiveness at the Kandang Kerbau Hospital in Singapore. The two techniques were randomly assigned to 299 postpartum patients and 300 postabortion patients. The assigned procedure could not be performed for two of the ring cases and three of the clip cases. Bleeding and equipment problems made laparotomy necessary in two clip cases and equipment problems caused a change in technique in the other clip case. Hydrosalpinx and adhesions were responsible for a change to laparotomy in the two ring cases. Surgical difficulties, chiefly the result of equipment problems, were significantly higher for both postpartum and postabortion clip procedures. Complications and complaints reported immediately after surgery and at the 7- to 21-day follow-up visit were low for all four groups. For both postabortion and postpartum patients, six- and 12-month data show that pregnancy rates are significantly higher for patients sterilized with the clip than with tubal rings.

Abortion, Induced↗
PubMed1992

CLIP-170 links endocytic vesicles to microtubules.

Binding of endocytic carrier vesicles to microtubules depends on the microtubule-binding protein CLIP-170 in vitro. In vivo, CLIP-170 colocalizes with a subset of transferrin receptor-positive endocytic structures and, more extensively, with endosomal tubules induced by brefeldin A. The structure of CLIP-170 has been analyzed by cloning its cDNA. The predicted non-helical C- and N-terminal domains of the homodimeric protein are connected by a long coiled-coil domain. We have identified a novel motif present in a tandem repeat in the N-terminal domain of CLIP-170 that is involved in binding to microtubules. This motif is also found in the Drosophila Glued and yeast BIK1 proteins. These features, together with its very elongated structure, suggest that CLIP-170 belongs to a novel class of proteins, cytoplasmic linker proteins (CLIPs), mediating interactions of organelles with microtubules.

Amino Acid Sequence↗
PubMed1991

Imaging properties of polydioxanone and titanium ligating clips following para-aortic lymphadenectomy for testicular cancer.

Stainless steel ligating clips produce serious artefacts on CT scans. Polydioxanone (PDS) and titanium ligating clips were used in 15 patients during para-aortic lymphadenectomy for residual metastatic testicular teratoma following chemotherapy, and follow-up CT images were compared with those following the use of stainless steel ligating clips. PDS ligating clips did not produce any artefacts and were progressively absorbed. Titanium ligating clips produced artefacts similar to but less intense than those of stainless steel. PDS ligating clips should be used when follow-up CT scanning is important.

Constriction↗
PubMed1992

Increased vascular formation of angiotensin II in one-kidney, one clip hypertension.

To assess the role of the vascular angiotensin II-generating system in one-kidney, one clip hypertension, we determined the angiotensin converting enzyme activity in plasma and vascular tissues and examined the pressor response to angiotensin II, angiotensin I, and tetradecapeptide renin substrate in isolated mesenteric arteries from one-kidney, one clip hypertensive rats 7 and 30 days after clipping the renal artery and in mesenteric arteries from age-matched normotensive rats. Angiotensin converting enzyme activity, determined in aortic and mesenteric tissues, was significantly augmented in the hypertensive (30 days after clipping) group, whereas plasma activity was normal. The vasoconstrictor responses elicited by angiotensin I and tetradecapeptide in arteries from hypertensive rats were found to be significantly potentiated 30 days after clipping, whereas the angiotensin II responses were basically unchanged. Saralasin completely blocked the vasoconstrictor responses, whereas captopril blocked only the responses to angiotensin I without affecting the responses elicited by angiotensin II and tetradecapeptide. Enalapril, an angiotensin converting enzyme inhibitor given intravenously to unanesthetized rats, significantly lowered the blood pressure of hypertensive rats. The pressor responses elicited by angiotensin II, angiotensin I, and tetradecapeptide were completely inhibited by saralasin, whereas enalapril blocked only the responses of angiotensin I but not those elicited by angiotensin II and tetradecapeptide. These results indicate that local formation of angiotensin II is increased in arteries of one-kidney, one clip hypertensive rats. The data obtained with tetradecapeptide renin substrate suggest an important role for nonrenin proteases in vascular angiotensin II formation.

Angiotensin I↗
PubMed1992

Angiotensin and angiotensin converting enzyme tissue levels in two-kidney, one clip hypertensive rats.

Renal tissue angiotensin I (Ang I) and II (Ang II) content and angiotensin converting enzyme activity were assessed in both kidneys during initial (7 days) and maintenance (25 days) phases of two-kidney, one clip hypertension in rats. At 7 and 25 days, systolic arterial pressure was 146 +/- 2 and 170 +/- 7 mm Hg, respectively. After 7 days, Ang I content of clipped kidneys was 64% and 70% higher (p < 0.001) than in nonclipped and sham-operated kidneys, respectively, when compared with levels in kidneys from sham-operated rats. In kidneys harvested 25 days after clipping one renal artery, Ang I and Ang II contents in clipped kidneys were increased 102% and 24% (p < 0.01), respectively. Ang II content was also 32% higher in nonclipped kidneys. Angiotensin converting enzyme activity in nonclipped kidneys was greater (p < 0.05) than that in either clipped (46% higher) or sham-operated kidneys (57% higher). Plasma Ang I and Ang II levels were elevated at 7 days but were not different at 25 days in clipped rats. These results demonstrate a dissociation between intrarenal and circulating levels of Ang I and Ang II and suggest that qualitatively different mechanisms may be responsible for the elevated intrarenal Ang II levels during the initial and maintenance phases of renal hypertension.

Angiotensin I↗