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Selected commercially designated temporary clips (Acland, Biemer, Kleinert-Kutz, Variangle, and Yasargil) were applied for 1 hour to rat common carotid arteries. Scanning electron and light microscopic studies revealed varying degrees of endothelial damage. The authors believe that further improvements are needed in the design of temporary clips.
The attachment of a thin silastic sheet combined with the use of Sugita's fenestrated aneurysm clip was developed for the emergency repair of vascular perforation during surgery. The sheet is flexible and tailored in the operating room, corresponds to the vascular curve, and is semitransparent, allowing observation of the area of perforation. The device can be applied under severe bleeding conditions without temporary clipping. It may be useful as an emergency tool for vascular repair in the operating room.
BACKGROUND: Invasive cell carcinoma of the bladder often develops after complete transurethral excision of superficial transitional cell carcinoma. It has been postulated that primary tumors release angiogenesis-blocking proteins which suppress distant metastases. We have identified an endogenous protein which might be responsible for tumor dormancy. METHODS: A transitional cell carcinoma cell line was developed (UMUC-3i) which inhibits the growth of a tumor implant at a distant site in SCID mice. Conditioned media of UMUC-3i cultured cells was first pooled and then fractioned, and the capacity of individual components to block endothelial cell growth was tested. The protein fraction responsible for blocking endothelial cell growth was identified by N-terminal amino acid sequencing as well as by mass-spectrometry. The effects of the purified protein in preventing endothelial cell proliferation and tube formation in an in vitro angiogenesis assay was investigated. RESULTS: The plasma protein beta(2)-glycoprotein-I (beta(2)gpI) was isolated and identified from conditioned medium of UMUC-3i cultured cells. Based on the in vitro angiogenesis assay, beta(2)gpI strongly inhibited endothelial cell growth and tube formation, whereby the inhibitory activity corresponded to the clipped version of beta(2)gpI (cbeta(2)gpI). Clipping was induced by adding plasmin at a molar ratio 1:15 (plasmin:substrate). Further analysis indicated that cbeta(2)gpI effects were mediated by annexin II surface receptors expressed on endothelial cells. CONCLUSIONS: cbeta2gpI may be involved in blocking angiogenic processes and bladder cancer progression. In this case, cbeta2gpI may be a promising tool in bladder cancer therapy.
We investigated the antihypertensive effect of sesamin, a lignan from sesame oil, using two-kidney, one-clip (2K,1C) renal hypertensive rats. After clipping the left renal artery, animals were assigned to either a normal diet group (control group) or a sesamin-containing (1% (w/w)) diet group (sesamin group). The sham-operated rats (sham group) were fed a normal diet and tap water. The systolic blood pressure of the control group increased progressively in comparison with the sham group. This 2K,1C-induced hypertension was markedly reduced by feeding the sesamin-containing diet. The systolic blood pressure after 4 weeks was 123.60 +/- 4.01 mmHg in the sham group, 187.43 +/- 5.69 mmHg in the control group and 145.57 +/- 6.78 mmHg in the sesamin group, respectively. There were significant increases in left ventricle plus septum weight-body weight ratio in the control group compared with the sham group. This rise was also significantly reduced in the sesamin group. When the thoracic aorta was histochemically evaluated, the wall thickness and wall-to-lumen ratio in the control group were significantly increased, compared with the sham group, indicating that vascular hypertrophy had occurred in the control group. The sesamin diet tended to ameliorate this vascular hypertrophy, although its effect was not statistically significant. These findings suggest that sesamin is useful as prophylactic treatment to combat the development of renal hypertension and cardiac hypertrophy.
Hypotensive effects of SA446, an angiotensin converting enzyme (ACE) inhibitor, and effects on the renin-angiotensin system were evaluated in conscious normotensive and 2-kidney, 1-clip renal hypertensive dogs. SA446 (1 mg/kg, p.o.) remarkably inhibited the pressor response to angiotensin (Ang) I between 1 and 6 hr after the administration in normotensive dogs. SA446 significantly decreased blood pressure at 10 mg/kg, p.o., in normotensive dogs. During repeated administration of SA446 (100 mg/kg/day, p.o.) for 13 weeks, the blood pressure was lowered, and the pressor response to Ang I and plasma ACE activity were strongly inhibited. ACE activities in the aorta and kidney were also inhibited. Plasma renin activity and plasma Ang I concentration increased by repeated SA446 application, while plasma aldosterone concentration decreased. The hypotensive effect of SA446 (5 mg/kg, p.o.) was more potent in 2-kidney, 1-clip renal hypertensive dogs than in normotensive dogs. SA446 had longer inhibitory effects on the pressor response to Ang I and more potent hypotensive effects than captopril. The hypotension caused by SA446 appears to be associated mainly with an inhibition of ACE in plasma and also in the vascular wall.
For most surgeons, the gastro-clip gastroplasty is an unfamiliar operation. It was performed during the mid 1980s as an alternative to more complex bariatric operations. However, the device had problems. Because of its rigid nature, it occasionally eroded into the stomach and chest. Many of these devices required removal. However, patients may occasionally present with delayed complications. We present a patient with a Gastro-clip gastroplasty, who presented years after the procedure with a functional gastric outlet obstruction.
Constriction of one renal artery in the presence of the opposite kidney can produce persistent hypertension which is often associated with increase in plasma renin activity, decrease in serum potassium and increase in water intake. In the present study the clipped kidney was removed in 15 hypertensive rabbits 12 to 54 weeks after the constriction. Blood pressure showed a prompt and transient fall which was followed by a slight rebound and subsequently a gradual decline. However, it still remained above the normal 5 weeks after removal. Removal of the clipped kidney resulted in return to normal of increased plasma renin activity, decreased serum potassium and increased water intake at the end of the postoperative first week.
Aneurysm rest occurs in 1 to 10% of operated patients and of these, 21.8% are due to slipped clips. D'Angelo and coworker (1998) found 1 to 10% of residual aneurysms. They suggest that if the residual aneurysm has less than 2 mm, angiographic control must be performed after 3-5 years of the surgical procedure; if between 2 and 4 mm, the angiographic control must be done in the first 6 months after surgery and then, anually. If it has more than 4mm a direct surgical approach is advised. We present the cases of two female patients submitted to microsurgical treatment of intracranial aneurysm, without any intra-operative abnormal event. The angiographic study further made showed displacement of the clip from its original position and aneurysm again. A review of the literature is also presented.
Blood flow in the terminal aorta or superior mesenteric artery was recorded in conscious one-clip, two-kidney renovascular hypertensive rats and normal control rats with a chronically implanted electromagnetic flow probe. An indwelling catheter for direct measurement of arterial pressure was inserted into the terminal aorta in rats with a flow probe around the superior mesenteric artery. In the hindquarter area supplied by the terminal aorta, the elevation of vascular resistance in hypertensive rats in relation to normal rats was close to the average over the whole body. However, it was about 40% more intense than the average in the superior mesenteric area. Quantitatively, the hindquarter and superior mesenteric beds in hypertensive rats contributed about a quarter and a third of the decrease in total vascular conductance, respectively. Plots of superior mesenteric flow per body weight against arterial pressure at rest for 51 measurements in 9 hypertensive rats revealed an inverse relation between these two variables. These findings indicate that elevation of vascular resistance in the superior mesenteric area and probably the splanchnic area in general play an important role in one-clip, two-kidney renovascular hypertension.
A 50-year-old female developed subarachnoid hemorrhage due to rupture of a giant aneurysm in the left middle cerebral artery (MCA). One month later, direct surgery was performed on the aneurysm. The superficial temporal artery was anastomosed to the cortical artery of the parietal MCA segment. The MCA was exposed and trapped for 40 minutes during barbiturate infusion, with electroencephalographic and somatosensory evoked potential monitoring. During MCA trapping, the aneurysm was collapsed by dome puncture and obliterated by neck clipping. After surgery, she had only mild amnestic aphasia and an infarct in the medial temporal lobe demonstrated by computed tomography. However, cerebral angiography disclosed complete occlusion of the MCA by the displaced aneurysm clip, and perfusion of the distal MCA segments through the anastomosis. The initial bypass procedure prevented a disastrous outcome in this patient and is recommended for direct surgery on MCA aneurysms.
Late recurrence of subarachnoid hemorrhage (SAH) due to regrowth of aneurysm after neck clipping surgery occurred in four patients. Two patients underwent surgical treatment, and two patients received endovascular treatment. Endovascular treatment was successful in one case, but emergent surgery was necessary for the other case because of possible pseudoaneurysm formation. Postoperative course of all patients was excellent. Late recurrence of SAH can occur even after complete clipping, and further treatment should be considered.
A 67-year-old man died of subarachnoid hemorrhage (SAH) resulting from dissection of the distal part of the anterior cerebral artery (ACA). A saccular aneurysm in the anterior communicating artery had ruptured and was successfully clipped on Day 0. The patient recovered consciousness after surgery but his condition deteriorated due to another SAH on Day 1. A second surgical procedure disclosed bleeding from a laceration in the opposite wall of the ACA distal to the clipped aneurysm. Histological examination of the autopsy specimens revealed damage to the internal elastic lamina and inflammatory infiltration of leukocytes. The fatal dissection may have resulted from atherosclerosis, hemodynamic stress caused by hypertension, or trauma due to surgical manipulation.
OBJECTIVE: The purpose of this article is to describe a simple method for editing movie clips for PowerPoint presentations. CONCLUSION: We describe a simple method for editing movie clips using Adobe Photoshop, a common software utility used by many radiologists for preparing digital images.
OBJECTIVE: Our objective was to report the occurrence and determine the frequency of metallic fragments in the breast after placement of surgical clips that are used to delineate the margins of the biopsy cavity. CONCLUSION: Metallic fragments are commonly present in patients who have surgical clips placed during breast biopsy for both benign and malignant disease. Awareness of this phenomenon may prevent the misidentification of these fragments as microcalcifications and thus avert unnecessary concern or biopsy.
In this study, differences between dynamic-range reduction by peak clipping and single-channel compression for phoneme perception through conventional hearing aids have been investigated. The results from 16 hearing-impaired listeners show that compression limiting yields significantly better phoneme identification scores than does peak clipping if a strong reduction of the dynamic range has to be effected. In addition, some qualitative differences in confusion patterns could be established: the perception of low-frequency information appears to be relatively important in compression limiting; the perception of plosiveness is less important.
Three-dimensional computer simulations of a patient under consideration for heating by the BSD Sigma 60 phased array applicator showed marked specific absorption rate (SAR) enhancement in the region where there was a concentration of metallic surgical clips. Subsequent tests in tissue-equivalent phantom material confirmed that metallic objects much shorter than the wavelength in tissue of the radiative electromagnetic field can cause significant changes in the power deposition near the implanted metal. The placement of extensive numbers of surgical clips may therefore hinder the ability to subsequently utilize radiative electromagnetic heating modalities.
The decision to fit an induction loop system in many buildings is often dictated by cost, in particular that of the amplifier. In order to accommodate the peaks of speech the amplifier must be 4 times as powerful as that required for average speech. This often makes a profound difference to the cost and tips the balance against a loop being installed. Experience with two loops fitted for an audience of hard of hearing people where the peaks were clipped without any apparent loss of discrimination initiated this study. The findings showed that although high fidelity is to be preferred, peak clipping in loop systems can be tolerated without serious loss of intelligibility.
Chronic hypertension was induced in rats by application of a clip for 17 or 20 weeks to the unilateral renal artery and leaving the contrarenal vessel intact (two-kidney one clip hypertension, 2K-1C hypertension). Some of the rats received antihypertensive treatment with phenoxybenzamine (POB). 3H-proline was injected into all rats in the 17th experimental week to observe the in vivo incorporation rates of 3H-proline into vascular non-collagenous protein and vascular collagen. Plasma renin activity (PRA) of decapitated rats was assayed in the terminal stage of the experiment. Significant differences were noted between 2K-1C hypertensive rats and sham-operated normotensive rats, the former rats having significantly higher incorporation rates of 3H-proline into non-collagenous protein (p less than 0.001) and collagen of testicular (p less than 0.05) or mesenteric artery (p less than 0.01). The 3H-proline incorporated into each fraction of vascular protein was reduced by antihypertensive treatment with POB either in sham-operated rats (p less than 0.05) or 2K-1C rats (p less than 0.001), except for the aorta and heart. Positive correlations were noted between blood pressure and incorporated 3H-proline into non-collagenous protein of testicular arteries (r = 0.78, p less than 0.001) and mesenteric arteries (r = 0.90, p less than 0.001), in all animals. Similar positive correlations were also noted between blood pressure and tritiated collagen, to lesser extents, in testicular arteries (r = 0.67, p less than 0.001) and mesenteric arteries (r = 0.73, P less than 0.001). A rapid turnover of 3H-proline incorporated into non-collagenous protein was characteristically observed in the testicular arteries, mesenteric arteries and aorta of 2K-1C hypertensive rats 3 weeks after the proline injection. Though magnitude was low, the turnover of 3H-proline was also noted in each collagen fraction of the equivalent vessels of the same hypertensive rats. PRA of 2K-1C hypertensive rats was similar to that of sham-operated normotensive rats at the 20th week. Levels of PRA of the former or the latter rats treated with POB were 2.4-fold (p less than 0.001) or 2.5-fold (p less than 0.001) higher than those of non-medicated corresponding controls. These results indicate that (1) increased synthesis of vascular non-collagenous protein as well as collagen, especially of small arteries, plays a major role for the pathogenesis of chronic hypertension in 2K-1C rats, and (2) renin does not contribute to elevation of the blood pressure in the maintenance phase of this type of experimental hypertension.