SEARCH · PubMed Health

Results for “MM”

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 325 records · Page 18Linked to original sources

PubMed2003

Physical aspects of dynamic stereotactic radiosurgery with very small photon beams (1.5 and 3 mm in diameter).

Stereotactic radiosurgery is often used for treating functional disorders. For some of these disorders, the size of the target can be on the order of a millimeter and the radiation dose required for treatment on the order of 80 Gy. The very small radiation field and high prescribed dose present a difficult challenge in beam calibration, dose distribution calculation, and dose delivery. In this work the dose distribution for dynamic stereotactic radiosurgery, carried out with 1.5 and 3 mm circular fields, was studied. A 10 MV beam from a Clinac-18 linac (Varian, Palo Alto, CA) was used as the radiation source. The BEAM/EGS4 Monte Carlo code was used to model the treatment head of the machine along with the small-field collimators. The models were validated with the EGSnrc code, first through a calculation of percent depth doses (PDD) and dose profiles in a water phantom for the two small stationary circular beams and then through a comparison of the calculated with measured PDD and profile data. The three-dimensional (3-D) dose distributions for the dynamic rotation with the two small radiosurgical fields were calculated in a spherical water phantom using a modified version of the fast XVMC Monte Carlo code and the validated models of the machine. The dose distributions in a horizontal plane at the isocenter of the linac were measured with low-speed radiographic film. The maximum sizes of the Monte Carlo-calculated 50% isodose surfaces in this horizontal plane were 2.3 mm for the 1.5 mm diameter beam and 3.8 mm for the 3 mm diameter beam. The maximum discrepancies between the 50% isodose surface on the film and the 50% Monte Carlo-calculated isodose surfaces were 0.3 mm for both the 1.5 and 3 mm beams. In addition, the displacement of the delivered dose distributions with respect to the laser-defined isocenter of the machine was studied. The results showed that dynamic radiosurgery with very small beams has a potential for clinical use.

Dose-Response Relationship, Radiation↗

PubMed1985

Early detection of myocardial infarction in conscious dogs by analysis of plasma MM creatine kinase isoforms.

To determine whether myocardial infarction could be detected early after onset by analysis of subforms of the MM isoenzyme (isoforms) of creatine kinase (MM CK) in plasma, we subjected eight conscious dogs to coronary occlusion and quantified isoforms in serial plasma samples by chromatofocusing. The fractions of MMA (isoelectric point [pI] = 7.91), MMB (pI = 7.74), and MMC (pI = 7.51) in plasma samples before coronary occlusion averaged 11.4 +/- 4.8% (SD), 22.3 +/- 5.5%, and 66.3 +/- 9.6% of total MM CK activity. The fraction of MMA, the isoform of MM CK found in myocardium, increased significantly in plasma 1 hr after coronary occlusion, reached a maximum of 49.7 +/- 8.0% in 4.1 +/- 1.3 hr, and returned to baseline in 12.0 +/- 2.3 hr. The fraction of plasma MM CK activity attributable to MMC, an isoform formed slowly in plasma from MMA via MMB as an intermediate, decreased significantly within 1 hr, reached a minimum of 14.0 +/- 4.1% in 4.8 +/- 1.1 hr, and returned to baseline in 13.0 +/- 2.9 hr after coronary occlusion. Total CK activity did not increase significantly until later, i.e., 5 hr after occlusion, and peaked at 1371 +/- 530 IU/liter in 10.9 +/- 1.9 hr. Within the first 4 hr after coronary occlusion, MMA consistently comprised more than 20% of plasma MM CK activity despite insignificant increase of total CK. Changes in isoform proportions were consistent and independent of peak total CK activity and of cumulative CK release over a 10-fold range. Thus initial CK release indicative of infarction is detectable within 1 hr after the onset of ischemia by quantification of plasma MM CK isoforms.

Animals↗

PubMed1992

Tourniquet at 50 mm Hg followed by intravenous lidocaine diminishes hand pain associated with propofol injection.

We evaluated the efficacy of intravenous lidocaine, with and without a tourniquet, to decrease the intensity of pain during intravenous propofol injection in 82 patients undergoing general anesthesia. Patients in group A (n = 20) received propofol (2 mg/kg IV); patients in group B (n = 22) received 2% lidocaine (100 mg IV) followed 1 min later by propofol (2 mg/kg). Patients in group C (n = 21, saline placebo) and D (n = 19, 2% lidocaine) had an arm tourniquet inflated to 50 mm Hg applied for 1 min after gravity drainage of venous blood. The intensity of pain along the forearm was marked on a 0-100-mm visual analogue scale. Pain intensity was less in group B (21 +/- 19 mm) than in group A (75 +/- 28 mm; P less than 0.05). Pain intensity was significantly less in group D (1 +/- 2 mm) compared with group B (21 +/- 19 mm; P less than 0.001). We conclude that intravenous lidocaine before propofol injection attenuates the painful response; whereas, lidocaine administered after a tourniquet inflated to 50 mm Hg for 1 min virtually abolishes the pain associated with intravenous propofol.

Adult↗

PubMed1998

Functional evaluation of the bileaflet mechanical valve in the aortic position using dobutamine-stress echocardiography: is a 23-mm prosthetic valve adequately large enough?

The issue of valve prosthesis-patient mismatch in small annular patients is still controversial. The hemodynamic function of bileaflet mechanical valves in the aortic position was examined using dobutamine-stress echocardiography. Forty-four patients were enrolled in the study and divided into 5 groups, according to prosthesis size, from 21 mm to 29 mm. The aortic peak pressure gradient (APG) increased significantly in all groups with dobutamine-stress and exceeded 50 mmHg in 83% of the 21-mm group, in 64% of the 23-mm group, and in 33% of the 25-mm group. The APG even exceeded 80 mmHg in 22% and 18% of the 21-mm and 23-mm groups, respectively. In these cases, the potential of 'valve prosthesis-patient mismatch' was considered. From the relationship between the APG and the prosthesis valve area index (VAI), 'critical VAIs' were found where patients were likely to enter the 'mismatch' status; that is, 1.22 and 1.77 cm2/m2, respectively, for the 5 and 10 microg/kg per min stages of dobutamine stress. This critical VAI range is useful in predicting the 'mismatch' patients preoperatively. Alternative procedures or prostheses should then be selected for them.

Adult↗

PubMed1978

Variation in measurement of coronary lesions on 35 and 70 mm angiograms.

Inter- and intraobserver variability in the measurement of coronary artery stenosis using 35 mm cine and 70 mm spot film angiography was examined. Three experienced observers measured 52 lesions on two occasions. The 35 mm cine was evaluated visually, and a single 70 mm frame demonstrating the stenosis was assessed both visually and with a calibrated magnifying device (jeweler's eyepiece). Higher correlation coefficients within and between observers were obtained using the cine method compared to the 70 mm visual and eyepiece techniques. Observer variability was decreased further by using an average of several readings from the 35 mm cine to assess the degree of stenosis. The data suggest that neither higher resolution film (70 mm) nor calibrated magnifying devices diminish observer variability in the measurement of coronary artery lesions.

Angina Pectoris↗

PubMed2003

CT-guided transthoracic needle aspiration biopsy of small (< or = 20 mm) solitary pulmonary nodules.

OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy and to analyze the factors influencing the diagnostic accuracy and incidences of pneumothorax and chest tube insertion rates for percutaneous CT-guided needle biopsy of small (< or = 20 mm) solitary pulmonary nodules. SUBJECTS AND METHODS: One hundred sixty-two patients with 162 small solitary pulmonary nodules underwent CT-guided transthoracic needle aspiration biopsy. The overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were calculated. Factors influencing the diagnostic accuracy and pneumothorax rate were statistically evaluated. Influencing factors, diagnostic accuracies, pneumothorax rates, and chest tube insertion rates were statistically compared. RESULTS: Overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were 77.2%, 28.4%, and 2.5%, respectively. Diagnostic accuracy was significantly affected by length of needle path and lesion size (p < 0.05). The pneumothorax rate was significantly affected by the percentage of predicted forced expiratory volume in 1 sec, the number of punctures, and the needle path length (p < 0.05). The chest tube insertion rate was significantly affected by the number of punctures (p < 0.05). For diagnostic accuracy, needle path lengths of 40 mm or less and lesion sizes greater than 10 mm were significantly more accurate than other factors (p < 0.05). For pneumothorax rates, a percentage of predicted forced expiratory volume in 1 sec of greater than 70%, a single puncture, and a needle path length of 40 mm or less were significantly lower than other factors (p < 0.05). CONCLUSION: CT-guided transthoracic needle aspiration biopsy is a useful diagnostic tool for small solitary pulmonary nodules smaller than 20 mm in diameter. The diagnostic accuracy is significantly improved for large (> 10 mm) lesion size and short (< or = 40 mm) needle path length.

Adult↗

PubMed1998

Comparison of Angiographic and Clinical Outcome After Cutting Balloon and Conventional Balloon Angioplasty in Vessels Smaller than 3 mm in Diameter: A Randomized Trial.

OBJECTIVES: The purpose of the study was to evaluate and compare the immediate and six month follow-up angiographic and clinical outcome of cutting balloon angioplasty and conventional balloon angioplasty in small vessels (less than 3 mm in diameter). METHODS AND RESULTS: Between August 1995 and August 1996 a total of 71 eligible symptomatic patients with angiographically proven significant lesions in their coronary arteries smaller than 3 mm and requiring revascularization, were randomized to receive treatment by either cutting balloon angioplasty (CB) or conventional balloon angioplasty (BA). ÒStand-aloneÓ CB was performed on 51 lesions in 36 patients and BA on 47 lesions in 35 patients. Basic angiographic and clinical characteristics were similar in both groups. The overall procedural success rates for CB and BA groups were 92% and 97%, respectively. The immediate post-procedural minimal luminal diameter, residual stenosis and acute gain were similar in the CB and BA cohorts (1.93 +/- 0.36 mm, 24 +/- 12%, 1.18 +/- 0.45 mm vs. 2.01 +/- 0.34 mm, 22 +/- 9%, 1.26 +/- 0.35 mm, respectively). Total dissection rate and C-F dissections were fewer in the CB group (37%, 6% vs. 51%, 19%, respectively, p < 0.05). Six month follow-up angiographic restenosis rate was lower in the CB group (27% vs. 47%, p < 0.05). We also detected a significant difference of total number of all events at nine month clinical follow up (28% vs. 51%, p < 0.05). CONCLUSION: CB angioplasty can be performed with a comparable success rate to conventional BA in small vessels. Fewer bail-out procedures are needed as CB causes fewer and less severe dissections. There is also a significant reduction in six month restenosis rate. We suggest that CB might be a better option for revascularizing vessels smaller than 3 mm in diameter which are inherently more prone to immediate complications and late restenosis with BA.

Journal Article↗

PubMed2000

[Differential diagnosis of focal areas of ground-glass attenuation in the peripheral lung 20 mm or less in diameter: high-resolution CT-pathologic correlation].

BACKGROUND: The detection and differential diagnosis of focal areas of ground-glass attenuation (FGGA) is becoming important for early diagnosis of lung cancer. PURPOSE: The purpose of this study is to clarify the correlation between FGGA (20 mm or less in diameter) on high-resolution CT (HRCT) and histopathology of surgically resected lesions. MATERIALS AND METHODS: Ninety surgically resected peripheral lung lesions 20 mm or less in diameter with a greater than 50% area of GGA on HRCT from 58 patients (34 men and 24 women; mean age, 60.5 years) were studied. Sixty-nine lesions were adenocarcinomas (type A; 31, type B; 5, type C; 32, type D; 1, according to Noguchi et al.), 11 were atypical adenomatous hyperplasias, and 10 were inflammatory lesions. HRCT findings were retrospectively evaluated with regard to maximum diameter, marginal character, internal dense attenuation domain, and linear density radiating into surrounding lung parenchyma. Statistical analysis was performed with Mann-Whitney's t-test, Pearson's correlation coefficient, and chi 2-test between each group of lesions. RESULTS: The maximum diameters on HRCT were significantly larger in adenocarcinomas (mean, 12.7 +/- 5.5 mm) than in atypical adenomatous hyperplasias (4.6 +/- 1.9 mm, p < 0.01) and in inflammatory lesions (5.9 +/- 2.7 mm, p < 0.01). Among adenocarcinomas, the diameters of type C tumors (mean, 15.7 +/- 5.0 mm) were larger than those of type A tumors (9.0 +/- 3.1 mm, p < 0.01). Linear density radiating into surrounding lung parenchyma was not found in inflammatory lesions, atypical adenomatous hyperplasias or type A tumors. Dense attenuation domains were found more frequently in type C tumors (94%) than in type A or type B tumors. Linear density and dense attenuation domain were both correlated with size of lesion (p < 0.05, p < 0.01, respectively). CONCLUSIONS: HRCT is useful in the diagnosis of early pulmonary adenocarcinomas presenting as small FGGA.

Adenocarcinoma↗

PubMed1975

[Proceedings: 70 mm photofluorography: a valuable aid in coronary angiographic studies].

With the development of new intensifiers using cesium iodide as the input phosphor and having a spatial frequency of up to 4 lines/mm, it has become possible to obtain high contrast serial photographs using a 70 mm camera. In 48 patients undergoing coronary arteriography, 35 mm cine and 70 mm spotfilms were obtained at exposures as follows: 3 msec, 75-95 kV at 200 mA for the 35 mm cine (50 frames/sec) and 6-10 msec, 75-95 kV at 300 mA (4 FRAMES/SEc) for the 70 mm images. Image quality and diagnostic information of the two media were compared. 70 mm films were of excellent quality. The vessel edges showed up sharp, the pictures were high in contrast, and small arteries in particular could be well defined. 70 mm photofluorography offers many advantages which are discussed.

Cardiomegaly↗

PubMed1991

Astigmatism after small incision cataract surgery. A prospective, randomized, multicenter comparison of 4- and 6.5-mm incisions.

Four surgeons evaluated induced astigmatism and postoperative wound stability in a randomized prospective study of 130 patients undergoing cataract extraction. After phacoemulsification through a scleral pocket, patients received either a 6.5-mm diameter silicone optic posterior chamber intraocular lens (PC IOL) folded for insertion through a 4-mm small incision or a 6.0-mm diameter polymethylmethacrylate (PMMA) optic PC IOL placed through an approximately 6.5-mm conventional incision. Vector analysis calculations of prism diopters (D) of mean postoperative-induced keratometric astigmatism for the small incision versus conventional incision groups were, at day 1, 1.54 D versus 3.07 D (P less than 0.0001); at weeks 1 to 2, 1.00 D versus 2.43 D (P less than 0.0001); at 1 month, 0.98 D versus 1.44 D (P = 0.004); and at 3 months, 0.82 D versus 1.03 D (P = 0.089). Subgroup analysis of the suturing technique for the 6.5-mm incision showed that the technique of wound closure, as well as the wound size, influenced the induced astigmatism. For all four surgeons using three methods of suturing the 6.5-mm wound, however, the variability in the amount of induced cylinder was least with the 4.0-mm wound closed with a horizontal mattress suture. Complications in the two groups were comparable.

Aged↗

PubMed1986

Phosphorylation of tyrosine hydroxylase on at least three sites in rat pheochromocytoma PC12 cells treated with 56 mM K+: determination of the sites on tyrosine hydroxylase phosphorylated by cyclic AMP-dependent and calcium/calmodulin-dependent protein kinases.

Incubation of rat pheochromocytoma PC12 cells with the calcium ionophore, A23187 (10(-5) M), 56 mM K+, or dibutyryl cAMP (2 mM) is associated with increased activity and enhanced phosphorylation of tyrosine hydroxylase in the cells. Both the activation and the increased phosphorylation of tyrosine hydroxylase produced by A23187 and 56 mM K+ are dependent on the presence of extracellular calcium, whereas similar effects produced by dibutyryl cAMP are independent of calcium. The effects of 56 mM K+ plus dibutyryl cAMP or A23187 plus dibutyryl cAMP on the activation and phosphorylation of tyrosine hydroxylase are additive. In contrast, the effects of 56 mM K+ plus A23187 on either the activation or the phosphorylation of the enzyme are not additive. Following stimulation of intact PC12 cells with 32Pi, in order to label ATP stores, and tryptic digestion of the phosphorylated enzyme, separation of the tryptic phosphopeptides by high pressure liquid chromatography yields four distinct 32P-peptide peaks. Incubation of the cells in the presence of either 56 mM K+ or A23187 is associated with increased 32Pi incorporation into three peptides whereas, in the presence of dibutyryl cAMP, increased 32Pi incorporation is observed in only one of these peptides. When tyrosine hydroxylase purified from rat pheochromocytoma tumor is incubated in vitro with [gamma-32P]ATP and either cAMP-dependent or calcium/calmodulin-dependent protein kinase under appropriate conditions, increased phosphorylation of tyrosine hydroxylase is observed. However, even though in vitro phosphorylation by cAMP-dependent protein kinase is associated with activation of tyrosine hydroxylase, in vitro phosphorylation by calcium/calmodulin-dependent protein kinase does not lead to activation of the enzyme. Tryptic digestion of tyrosine hydroxylase phosphorylated by calcium/calmodulin-dependent protein kinase yields three distinct 32P-peptide peaks, which are identical to those phosphorylated by treatment of intact PC12 cells with either high K+ or A23187. In contrast, cAMP-dependent protein kinase phosphorylates only one peptide, which is identical to that phosphorylated by treatment of the intact cells with dibutyryl cAMP. These results indicate that tyrosine hydroxylase is activated and phosphorylated at multiple sites in PC12 cells exposed to 56 mM K+ or A23187. The results suggests that the in situ phosphorylation of these sites is catalyzed by calcium/calmodulin-dependent protein kinase; however, phosphorylation by this protein kinase is not sufficient to activate the enzyme.

Adrenal Gland Neoplasms↗

PubMed1986

Killer-helper effect of L cells in the generation of anti-MM cytotoxic T lymphocytes: replacement by beta-interferon and mechanisms of action.

Cytotoxic T lymphocytes (CTL) for MM tumor cells were generated only when L-MM tumor hybrid (L-FM3A#2)-primed spleen cells were stimulated in vitro with a mixture of mitomycin C-treated parental FM3A/R tumor cells and L cells, but not when they were stimulated with FM3A/R or L cells alone. Killer-helper activity of L cells was replaced by a beta-interferon (IFN) preparation (L-cell IFN). Anti-(alpha + beta)-IFN antibodies completely inhibited the killer-helper activity of L-cell IFN. Several lines of evidence suggested that the killer-helper effect of L-cell IFN resulted from an action at an early step in the generation of anti-MM CTL, as follows. The killer-helper effect of L-cell IFN diminished as the addition was delayed during culture for 5 days. The presence of L-cell IFN during the first 24 hr was enough to generate a maximal CTL response. Anti-(alpha + beta)-IFN antibodies showed no inhibitory activity on the generation of anti-MM CTL when they were added to the culture on day 2 or 4. It was also demonstrated that the killer-helper effect of L-cell IFN resulted from an effect on primed spleen cells, but not from an effect on stimulator cells. Furthermore, it was observed that IFN acted on nylon wool-adherent cells in the generation of anti-MM CTL. Plastic-adherent cells preincubated with L-cell IFN also enhanced the generation of anti-MM CTL when they were added to a culture where primed spleen cells were stimulated with FM3A/R tumor cells. These results suggest that activation of macrophages by L-cell IFN at the initiation step is essential for the generation of anti-MM CTL.

Animals↗

PubMed1993

Regressing thin cutaneous malignant melanomas (< or = 1.0 mm) are associated with angiogenesis.

In previous studies, we have shown that angiogenesis is often first noted in cutaneous malignant melanomas (CMMs) under 1.0 mm in thickness. Because angiogenesis may signal a more aggressive tumor phenotype, it is important to establish the circumstances associated with onset of angiogenesis. In the present study, we have quantified tumor vascularity in a series of CMMs under 1.0 mm in thickness and either associated with or lacking histologic regression. Microvessels were identified with the lectin Ulex europaeus agglutinin I and the vessels in five fields counted within an ocular grid (area 7.84 x 10(-2) mm2) at 400 x magnification. CMMs (mean 0.48 mm) with regression had greater microvessel counts (27.2 +/- 5.1) compared with CMMs (mean 0.61 mm) without regression (mean 20.1 +/- 7.9) (P < 0.01). However, of particular interest, CMMs in the radial growth phase only and associated with regression (mean 0.40 mm) had strikingly greater vascularity (mean 28.7 +/- 6.9) versus radial growth phase CMMs (mean 0.44 mm) lacking regression (mean 16.4 +/- 6.6) (P = 0.0013). CMMs in the vertical growth phase (mean 0.81 mm) without regression had slightly less vascularity (mean 24.4 +/- 7.3) compared with vertical growth phase CMMs with regression (mean microvessels 27.2 +/- 5.1) (P = 0.1878) but significantly greater microvessels versus radial growth phase CMMs without regression (P = 0.0213). These results suggest that the onset of angiogenesis in thin CMMs is related to at least two phenomena: 1) inflammatory regression and 2) development of the vertical growth phase.

Humans↗

PubMed1993

Ultrasound-guided biopsies of neuroendocrine metastases. Comparison of 0.9 and 1.2 mm biopsy-gun needle biopsies.

Twenty-five patients with known neuroendocrine tumour disease were biopsied with 1.2 mm and 0.9 mm biopsy-gun needles to evaluate the respective diagnostic accuracy of the 2 needle sizes. The influence of treatment-related fibrosis on the histopathological diagnosis was also evaluated. The overall diagnostic accuracy with the 0.9 mm needle was 69% as compared to 92% with the 1.2 mm needle. This difference, however, seems more related to needle guiding difficulties with the 0.9 mm needle than to insufficient tissue yield. When the tumour was hit with both the 0.9 and the 1.2 mm needle the tissue yield was inferior with the 0.9 mm needle in only one of 16 cases. The increased amount of fibrous tissue due to interferon treatment did not seem to negatively influence the diagnostic accuracy.

Adult↗

PubMed1998

Nerve regeneration over a 20-mm gap through a nerve conduit containing blood vessels in rats: the influence of interstump distance on nerve regeneration.

BACKGROUND: The present study was conducted in rats to investigate whether a tube with additional intrachamber vascularization could permit axons to extend over a distance greater than 10 mm, which appears to be the maximum axon regeneration distance for rat sciatic nerve axons through a normal empty tube. METHODS: A sural vessel-containing tube (VCT) was designed and interposed between transected sciatic nerve stumps in the thigh, leaving a 20-mm interneural gap. RESULTS: Twelve weeks after tubulation, six out of nine rats showed successful nerve regeneration and re-innervation of the soleus muscle using the VCT. At 24 weeks, intrachamber nerve regeneration and re-innervation of the soleus and pedal adductor muscles were electrophysiologically and histologically confirmed in all rats. However, no neural tissue was observed within any ligated sural vessel-containing tube (LVCT) or empty unmodified tube (ET) with a 20-mm interneural gap. When nerves regenerated in the VCT with a 20-mm gap were compared with those regenerated in a VCT with a 10-mm gap 12 and 24 weeks after surgery, the results produced by the VCT with a 20-mm gap were inferior to those after use of the VCT with a 10-mm gap, except for motor nerve conduction velocity at 24 weeks. CONCLUSIONS: The value recovered to almost identical levels (about 50-60% normal) in both groups.

Animals↗

PubMed1998

Results of large (8-9 mm) bilateral lateral rectus muscle recessions for exotropia.

PURPOSE: Commonly recommended maximum lateral rectus muscle recession for exotropia ranges from as little as 7 mm to as much as 11 mm. Published studies on recessions of 8 mm or more are scarce. Many ophthalmic surgeons still avoid recessions larger than 7 mm because of the fear of creating abduction deficits and surgical overcorrections. Therefore, we sought to determine the incidence of clinically detectable abduction deficits and their correlation with early surgical overcorrection in exotropic patients who had undergone large 8 to 9 mm lateral rectus muscle recessions. SUBJECTS AND METHODS: A retrospective chart review identified 30 patients with exotropia ranging from 35delta to 65delta who were treated with 8 to 9 mm recessions of both lateral rectus muscles. Patients with concurrent oblique muscle surgery were included. Mean followup time was 15 months (range 3-30 mos). RESULTS: Twenty-four patients (80%) required only one operation. The remaining 6 patients (20%) required a second operation, four for overcorrection and two for undercorrection. Nine patients (30%) had mild but persistent abduction deficits postoperatively. However, abduction deficits were not predictive of poor outcome (p=0.959). Other variables that did not significantly affect outcome included age (p=0.894), systemic anomalies (p=0.127), size of preoperative exotropia (p=0.987) and amount of rectus muscle recession (p=0.480). However, concurrent oblique muscle surgery was associated with a higher risk of a poor result. CONCLUSIONS: 8-9 mm lateral rectus recessions are not associated with a poor outcome, except in association with concurrent oblique muscle surgery.

Adolescent↗

PubMed1998

Treatment of in-stent restenosis with high speed rotational atherectomy and IVUS guidance in small <3.0 mm vessels.

The management of in-stent restenosis remains a subject for debate because no one revascularization option is considered the most appropriate. Since a high restenosis rate still occurs after repeat balloon angioplasty, new techniques are attempted in order to reduce this rate. A combination of high speed rotational atherectomy (HSRA) and adjunctive balloon angioplasty is likely to achieve good results. In small (<3.0 mm diameter) vessels, the risk of interaction between the burr and the stent increases. We thus used intravascular ultrasound (IVUS) guidance in the treatment of in-stent restenosis with HSRA in small <3.0 mm small diameter vessels. Nine patients with in-stent restenosis in small vessels were referred for repeat angioplasty. Initial IVUS examination was used to assess the minimal stent struts diameter and to guide the burr size selection. A combination of HSRA and additional balloon angioplasty was performed under IVUS and angiographic guidance. Mean angiographic reference diameter was 2.25 +/- 0.35 mm and mean stent struts diameter was 2.38 +/- 0.20 mm. Burr size was selected approximately 0.5 mm smaller than stent struts diameter and ranged from 1.75 to 2.5 mm, with a 0.88 +/- 0.12 mean burr/artery ratio (range 0.71, 1.08). In two patients, a second larger burr was used. In 4/9 patients, the burr size chosen under IVUS guidance was close to angiographic MLD at stent implantation and thus larger than what would be used without IVUS guidance. Additional balloon angioplasty was decided in all cases, using a 1.1 +/- 0.15 balloon/artery ratio. No complication occurred. Mean relative gain in minimal lumen diameter (MLD) was 94 +/- 90% after HSRA and 54 +/- 34% after balloon angioplasty (total relative gain 180 +/- 100%). IVUS guidance allowed safe management of in-stent restenosis in small vessels using combination of HSRA and balloon angioplasty. Long-term follow-up and comparison with other techniques are necessary to assess whether this technique should be used routinely.

Adult↗

PubMed1997

Safety and efficacy of angiography-guided stent placement in small native coronary arteries of < 3.0 mm in diameter.

BACKGROUND AND HYPOTHESIS: Increased operator experience, greater insight in stent deployment techniques, and improved poststent medication regimen have significantly reduced the risk of thrombotic stent closure following stent placement in large coronary arteries (> or = 3.0 mm in diameter). Whether equally favorable results are afforded by stent placement in small vessels (< 3.0 mm), however, remains unclear. Accordingly, the aim of this study was the specific examination of the risk of stent placement in small native coronary vessels, using stent deployment technique consisting of supplementary dilatations with larger balloons or high-pressure inflations, and aggressive aspirin-ticlopidine and short-term oral anticoagulation poststent therapy. METHODS: Forty-seven balloon-expandable stents (20 Gianturco-Roubin, 21 NIR, 6 Palmaz-Schatz) were successfully implanted without intravascular guidance in 45 native coronary arteries (mean reference diameter of 2.5 mm) in 44 consecutive patients (31 men, 13 men), the majority of whom (87%) were stented for the treatment of failed or suboptimal balloon angioplasty outcome. RESULTS: Successful stent placement reduced the lesion diameter stenosis from 91 +/- 9% to 3 +/- 7% (p = 0.0001). There were no early stent thrombosis or major cardiovascular events prior to hospital discharge. During a 12-month follow-up period, most patients remained symptomatically improved and no myocardial infarction, stroke, or death was observed. Five-month angiographic reassessment revealed an in-stent restenosis rate of 41%, which was higher in vessels < or = 2.5 mm in size (47 vs. 33% for vessels > 2.5 mm, p = 0.2747). CONCLUSIONS: In selected patients with small native coronary vessels < 3.0 mm in diameter, angiography-guided optimal stent placement is associated with a low risk of stent thrombosis and bleeding complications. However, the in-stent restenosis rate is high with the stents used in this study.

Angioplasty, Balloon, Coronary↗