Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Filtering Surgery”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,531 records · Page 85Linked to original sources
PubMed1996

Recurrent choroidal detachment following combined trabeculectomy and cataract extraction.

Two patients with glaucoma who underwent uneventful trabeculectomy and extracapsular cataract extraction with posterior chamber intraocular lens implantation, experienced late and recurrent choroidal detachment. Both patients received aqueous suppressant therapy before and after surgery. Hypotony and choroidal detachment occurred 7 months and 15 months after the combined surgery. There was no shallowing of the anterior chamber or leakage from the filtering blebs, and there were no signs of inflammation. The choroidal detachment completely resolved in the two patients 4 days and 4 weeks following discontinuation of the aqueous suppressant therapy.

Aged↗
PubMedDate not supplied

In-line leukocyte filtration during bypass. Clinical results from a randomized prospective trial.

Leukocyte mediated pulmonary injury may delay recovery after cardiac surgery, and leukocyte depletion during bypass has been suggested. Two groups of patients were randomly, prospectively assigned from 50 sequential patients to undergo open heart surgery using cardiopulmonary bypass, either with (n = 25) or without (n = 25) leukocyte filters. The two groups were not significantly different regarding age, gender, race, pre-operative ejection fraction, pump time, or cross-clamp time. Post operative arterial blood gases (pO2: 173 +/- 66 vs 192 +/- 107; pCO2: 30.2 +/- 8.2 vs 30.8 +/- 8.0), pulmonary vascular resistance (PVR 105 +/- 45 vs 112 +/- 50 dyne cm-5), time on ventilator (17.8 +/- 6.4 vs 19.7 +/- 8.6 hr), and length of hospital stay (7.65 +/- 4.57 vs 8.52 +/- 5.87 days) were not different between groups (mean +/- SD, with vs without filters, respectively). Arterial oxygenation was somewhat poorer, and PVR was somewhat lower in the leukocyte filtered group. However, these trends did not produce significant decreases in total ventilator time or length of hospital stay. In-line filtration did remove leukocytes, but did not reduce circulating leukocyte count. In effect, leukocyte filtration produced an effective leukocyte concentration at the filter site. These data do not support routine incorporation of in-line leukocyte filtration during bypass.

Cardiac Surgical Procedures↗
PubMed1984

Intraoperative evoked potential monitoring of the spinal cord. A restricted filter, scalp method during Harrington instrumentation for scoliosis.

Intraoperative monitoring of somatosensory evoked potentials (EPs) can improve the margin of safety during surgery around the spine. Several methods are available. The authors report their experience in monitoring 65 patients who underwent Harrington instrumentation and spinal fusion for correction of scoliosis. They studied the effects of changes in stimulating and recording parameters, seeking ways to reduce noise and variability in the EP signal. The authors were able to improve the quality of the monitoring records significantly by closer spacing of the scalp electrodes, bipolar rather than referential recording, faster rates of stimulation, and greater low-frequency filtering. The technique seems to be safe, easily performed, reproducible, and relatively inexpensive. It has produced no false-negative results to date, and it significantly reduced the incidence of false-positive results (false alarms) as compared with previously described techniques.

Adolescent↗
PubMed2007

Factors causing early relapse after lung metastasis surgery.

Haematogenous lung metastases are usually considered a sign of widespread metastatic disease. However, in most primary cancers, the first filter for distant tumours are the lungs. In some patients, the metastatic process may stop at the lungs. In these selected patients, there are studies that have shown the benefits of metastasectomy. The objective of this paper is to analyse the morbidity and mortality of lung metastasectomy and determine the factors that predispose to early relapse. Forty-two patients operated on for lung metastases, and four were excluded as they were assessed intraoperatively to be unresectable, leaving 38 patients to be analysed. The variables analysed were: age, sex, primary tumour, disease-free interval, number of metastases, bilaterality, morbidity and mortality, relapse, reinterventions, relapse-free interval after metastasectomy and survival. The surgical technique was a posterolateral thoracotomy, and there were no perioperative deaths. Morbidity was 11% (n = 4), and surgical reintervention of the haemothorax was necessary. Survival after 1, 2 or 3 years was 87%, 61% and 25% respectively, and the percentage of relapse-free patients was 71%, 56% and 17% respectively. The main factors associated with early relapse were histological type of tumour (more relapse in sarcoma, and less in adenocarcinoma), the disease-free interval between the primary tumour and lung metastases, and the number of metastases. Surgery was required a second time in five patients who had relapsed lung metastases, but extirpation could be performed in only four patients, of whom three were relapse free after 6, 12 and 24 months respectively, and the fourth had relapsed lung metastases after 18 months. Resection of lung metastases can be performed with low morbidity and mortality. The main prognostic factors for survival are complete surgery, histological type, disease-free interval between the primary tumour and metastases, and the number of lung metastases.

Adult↗
PubMed1985

Phototoxicity. The eclipse filter.

In conjunction with ultraviolet filtration and to further minimize the risk of phototoxic retinal damage during anterior segment surgery, the operation microscope has been modified to eliminate on demand all light entering the eye by eclipsing the pupil when the red reflex is not required. Retinal light exposure may be reduced as much as 75%.

Anterior Chamber↗
PubMed2006

Control of filtering bleb structure through tissue bioengineering: An animal model.

PURPOSE: To devise a means of providing controlled resistance between the anterior chamber and the subconjunctival space after trabeculectomy by implantation of a biodegradable, porous collagen matrix. METHODS: Matrices were implanted in the right eyes of 17 rabbits after trabeculectomy, while left eyes served as surgical controls. The scleral flap was sutured loosely, and the implant provided pressure on the scleral flap to reduce overfiltration. Trabeculectomy in the control eyes was performed with tight sutures using standard methodology. Intraocular pressure (IOP) was measured before surgery and on days 3, 7, 14, 21, and 28 after surgery. Masson trichrome and alpha-smooth muscle actin stains were used for histologic study of the filtering blebs. RESULTS: The initial postoperative IOP reduction was approximately equal, at 14% to 16%, for both groups. In the implanted group, the IOP continued to decrease to 55% below baseline at day 28 as the implant gradually degraded. In the control group, IOP had returned to the preoperative level by day 21. Histologic examination with Masson trichrome and alpha-smooth muscle actin stains showed a prominent bleb in the implanted group compared with scar formation and limited bleb formation in the control group. CONCLUSIONS: Implantation of a biodegradable, porous collagen matrix in the subconjunctival space offers the potential for a new means of avoiding early scar formation and maintaining long-term IOP control by creating a loosely structured filtering bleb.

Absorbable Implants↗
PubMed1995

The morbidity of heparin therapy after development of pulmonary embolus in patients undergoing thoracolumbar or lumbar spinal fusion.

STUDY DESIGN: The postoperative course of patients who developed a pulmonary embolus after thoracolumbar or lumbar spinal fusion treated with heparin was studied to quantify the morbidity risk of anticoagulation. OBJECTIVE: To compare the morbidity risk of heparinization with that of an alternative form of therapy--inferior vena cava filter placement. SUMMARY OF BACKGROUND DATA: Therapeutic heparinization was the current treatment of choice for patients who develop thromboembolic disease after surgery. Although heparin usage was reported to be associated with a number of complications after other orthopedic and general surgical procedures, no information was available to identify complications of heparinization after lumbar or thoracolumbar spine surgery or to define the risk of such complications. METHODS: Twenty-two members of the Scoliosis Research Society were polled to determine their experiences with the anticoagulation of this subset of patients. Surgeons polled had a combined experience of 250 man-years and had performed more than 13000 thoracolumbar and lumbar spinal fusions. The MEDLINE database was used to review pertinent English language publications describing inferior vena cava filter complications, effectiveness, safety, and indications for use. RESULTS: Nine patients were located who fit the inclusion criteria of this study. Six (67%) had complications attributable to heparinization. Clinically significant complications of filter placement ranged from 0.12% to 10.1%. CONCLUSIONS: Heparinization after the development of pulmonary embolus in patients recently undergoing spinal fusion is associated with a high complication rate. The morbidity of vena cava filter placement is low and should be considered a treatment alternative in the treatment of patients who experience pulmonary embolus after surgery.

Adolescent↗
PubMed1990

Human papillomavirus DNA in CO2 laser-generated plume of smoke and its consequences to the surgeon.

Carbon dioxide laser energy is absorbed by intracellular water but not by proteins or nucleic acids. The possibility of dispersing viral DNA during laser therapy of human papillomavirus (HPV)-containing genital infections was explored using a filter hybridization technique. Samples were taken using dacron swabs from 110 patients in nine separate treatment sessions as well as from five pre-filter canisters, four fume vacuum tubes, and from the nasopharynx, eyelids, and ears of the laser surgeon before and after laser surgery. The viral RNA probes were specific for groups of HPV types 6/11, 16/18, and 31/33/35. Human papillomavirus DNA was identified in swabs from 65 of 110 (60%) of histologically unequivocal condylomata and cervical intraepithelial neoplasias. One of the five pre-filter canisters (20%) tested was HPV DNA-positive after laser treatment of 65 patients; it contained HPV DNA type 6. The four fume vacuum tubes tested in the remaining 45 patients were HPV DNA-negative, as were the nasopharynx, eyelids, and ears of the operator. Although HPV DNA may be released during laser vaporization of genital HPV infections, contamination of the operator is unlikely provided appropriate equipment for evacuating HPV DNA-positive smoke is used.

Adolescent↗
PubMed1979

Control of proximal bicarbonate reabsorption in normal and acidotic rats.

This free-flow micropuncture study examined the dependence of bicarbonate reabsorption in the rat superficial proximal convoluted tubule to changes in filtered bicarbonate load, and thereby the contribution of the proximal tubule to the whole kidney's response to such changes. The independent effects of extracellular fluid (ECF) volume expansion and of acidosis on proximal bicarbonate reabsorption were also examined. When the plasma volume contraction incurred by the micropuncture preparatory surgery was corrected by isoncotic plasma infusion ( congruent with1.3% body wt), single nephron glomerular filtration rate (SNGFR), and the filtered total CO(2) load increased by 50%. Absolute proximal reabsorption of total CO(2) (measured by microcalorimetry) increased by 30%, from 808+/-47 during volume contraction to 1,081+/-57 pmol/min.g kidney wt after plasma repletion, as fractional total CO(2) reabsorption decreased from 0.90 to 0.77. Aortic constriction in these plasma-repleted rats returned the filtered load and reabsorption of total CO(2) to the previous volume contracted levels. In other animals isohydric ECF expansion with plasma (5% body wt) or Ringer's solution (10% body wt), or both, produced no further diminution in fractional proximal total CO(2) reabsorption (0.76-0.81). Metabolic acidosis was associated with very high fractional proximal total CO(2) reabsorptive rates of 0.82 to 0.91 over a wide range of SNGFR and ECF volumes. At a single level of SNGFR, end-proximal total CO(2) concentration progressively decreased from 5.6+/-0.5 to 1.6 +/-0.2 mM as arterial pH fell from 7.4 to 7.1. Expansion of ECF volume in the acidotic rats did not inhibit the ability of the proximal tubule to lower end-proximal total CO(2) concentrations to minimal levels. In conclusion, bicarbonate reabsorption in the superficial proximal convoluted tubule is highly load-dependent (75-90%) in normal and acidotic rats. No inhibitory effect of ECF volume per se on proximal bicarbonate reabsorption, independent of altering the filtered bicarbonate load, could be discerned. Acidosis enabled the end-proximal luminal bicarbonate concentration to fall below normal values and reduced distal bicarbonate delivery.

Absorption↗
PubMed2006

Filter connected with three-way cock in remove of the vehicle in triamcinolone acetonide.

PURPOSE: To evaluate the clinical effect of 5-microm pore filter connected with three-way cock by removing the vehicle in triamcinolone acetonide(TA) suspension. METHODS: Through 5-microm pore filter connected with three-way cock, TA suspension was replaced by intraocular irrigating solution. The new suspension has been applied to 60 cases of diabetic branch retinal vein occlusion, diabetic macular edema and age-related macular degeneration patients through intravitreal injection. It was also been applied to 41 cases of diabetic retinopathy, epimacular membrane, proliferative vitreoretinopathy and idiopathic macular hole patients to assist pas plana vitrectomy (PPV). Whether TA particles can adhere to posterior hyaloid cortex, epiretinal membrane and internal limiting membrane during the surgery have been observed. During follow up, corrected visual acuity and intraocular pressure were recorded. RESULTS: Five microm pore filter connected with three-way cock can remove the vehicle in TA suspension successfully and retain TA particles. When the new suspension was applied to assist PPV, it can adhere to posterior hyaloid cortex, epiretinal membrane, internal limiting membrane and visualized them clearly. In all the 41 cases that underwent PPV surgery, visual acuity of 30 cases increased or remained stable. Intraocular hypertension happened in 4 cases. Two cases of the 41 patients had cataract formation during follow up. In the 60 cases that underwent TA intravitreal injection, 45 cases increased their visual acuity at least 2 lines. Intraocular hypertension happened in 17 cases and 4 patients had cataract formation. None of the 101 patients caught endophthalmitis or other serious complications. CONCLUSION: Filter connected with three-way cock can remove the vehicle in TA suspension effectively and this procedure can be applied to intravitreal injection or PPV. This manipulation is so simple that it deserves to be popularized for clinical use.

Administration, Topical↗
PubMedDate not supplied

[Experimental studies of using highly fluorinated alkane in the surgical treatment of retinal detachment].

Fluids which are heavier than the vitreous fluid find recently their application in retinal detachment surgery. They fall down to the bottom of the eye and exerted pressure on the retina. Experimental investigations have been carried out on the possibility of application of these highly fluorinated alkane for operation. It has been demonstrated that this compound was very well tolerated by the tissues. It did not provoke any inflammatory or toxic reaction and did not cause any opacification of the optic media. On the spot of adherence it filtered in small quantities to the internal retinal layers. It could find probably its application in ophthalmic surgery.

Alkanes↗
PubMed1994

Magnetic resonance imaging and neuropsychological changes after coronary artery bypass graft surgery: preliminary findings.

Cerebral morbidity is a problem after cardiac surgery. Although neuropsychological tests and imaging techniques have been applied to cardiac patients, the relationship between them has not been considered. In the preliminary investigation, we studied 15 patients (11 male, mean age 59 years) having coronary artery bypass graft (CABG) surgery. Before surgery, patients had magnetic resonance (MR) imaging and neuropsychological assessment with a battery of 10 tests. During surgery, cardiopulmonary bypass was maintained at 28 degrees C with a flow rate of 2.4 L/m2/min-1 and at a mean arterial pressure of 50-70 mm Hg. Bubble or membrane oxygenators with in-line filters were used. Arterial blood gases were maintained using a pH-stat protocol. Fourteen of the 15 patients showed MR abnormalities before surgery. One week after surgery, four patients had additional MR changes. Six patients had significant postoperative neuropsychological deficit in memory (verbal and nonverbal) and attention. The four patients with new MR abnormalities all had significant neuropsychological deficit. In addition to corroborating previous observations that a high proportion of patients undergoing elective CABG have MR abnormalities before surgery, these preliminary data suggest a promising concordance between structural brain changes and cerebral function after CABG.

Adult↗
PubMed2005

Needle revision of failed filtering blebs using 5-Fluorouracil and a combined ab-externo and ab-interno approach.

PURPOSE: To evaluate a surgical technique to revise a failed filtering bleb using subconjunctival 5-Fluorouracil with a combined ab-externo and ab-interno approach. PATIENTS AND METHODS: This study is a retrospective review of the outcome of 77 consecutive bleb revisions, with greater than 6-month follow-up, performed by a single glaucoma surgeon (MW). All eyes had previously functioning filtering blebs with currently inadequately controlled intraocular pressures (IOP) prior to the bleb revisions. All surgery was performed in the operating room, using a retrobulbar injection and a microscope. Visco-elastic was injected into the anterior chamber. 5-Fluorouracil (0.1 mL; 50 mg/ml) was infiltrated around the bleb. A 30-gauge needle was used to lyse subconjunctival fibrosis and episcleral scar tissue binding down the scleral flap, and elevate the scleral flap. Through an inferior paracentesis, a cyclodialysis spatula was used to confirm and enlarge the communication with the subconjunctival space. The main outcome measurements were IOP and number of glaucoma medications. A successful outcome was defined as a 20% reduction from baseline IOP and a maximum IOP of 18 mm Hg, with or without medications, and a minimal follow-up of 6 months. RESULTS: 52% of patients achieved success after one revision with an average follow-up of 29.6 +/- 14.4 months. In successful cases, the mean IOP decreased from 22.7 +/- 4.5 mm Hg to 11.3 +/- 3.5 mm Hg and medications were reduced from an average of 2.2 +/- 1.1 to 0.4 +/- 0.7. Kaplan-Meier survival analysis calculated a success of 77% at 1 year, 68% at 2 years, and 58% at 3 years. CONCLUSIONS: In failed filtering blebs, needle revision with 5-Fluorouracil and a combined ab-externo and ab-interno approach results in high success and low complication rates. The outcome of this procedure compares favorably with previously reported revision techniques.

Aged↗
PubMed2006

Different endovascular referral patterns are being learned in medical and surgical residency training programs.

Physicians in residency training will be the referring physicians of tomorrow. We sought to determine the current surgical and medical trainees' perception of vascular surgery's endovascular qualifications and capabilities. An anonymous survey was sent to all general surgery and internal medicine residents at a single academic institution. Respondents answered the question "Which specialty is the most qualified to perform (1) inferior vena cava (IVC) filter insertion; (2) angiograms, angioplasty, and stenting of the carotid arteries; (3) renal arteries; (4) aorta; and (5) lower extremity arteries?" For each question, respondents chose one response, either vascular surgery, interventional radiology, interventional cardiology, or do not know. One hundred respondents completed the survey (general surgery, n=50; internal medicine, n=50). There was a significant difference in the attitudes of surgery and medicine residents when choosing the most qualified endovascular specialist (p<0.05). Surgery residents chose vascular surgery as the most qualified specialty for each listed procedure: carotid (80%, n=40), IVC (56%, n=28), aorta (100%, n=50), extremity (86%, n=43), renal (78%, n=39). Medicine residents chose vascular surgery as the most qualified specialty less frequently: carotid (66%, n=33), IVC (6%, n=3), aorta (88%, n=44), extremity (72%, n=36), renal (16%, n=8). There was no significant difference in specialty selection based on postgraduate year. There is a large discrepancy between surgical and medical trainees' perception of vascular surgery's endovascular abilities, particularly regarding IVC placement and renal artery interventions. If our own institution mirrors the nation, each passing year a significant portion of the 21,722 graduating internal medicine residents go into practice viewing vascular surgeons as second-tier endovascular providers. A concerted campaign should be undertaken to educate medical residents regarding the skills and capabilities of vascular surgeons.

Angioplasty↗
PubMed1999

Advances in digital imaging during endoscopic surgery.

BACKGROUND AND OBJECTIVE: Digital imaging capabilities have recently been incorporated into a number of video systems. Contrast enhancement when using a rigid or semirigid endoscope improves image definition by seeking out existing transitions in detail. Only the areas of transition are accentuated, whereas areas without detail are unaffected. During flexible endoscopy, fiberoptic bundles create a classic honeycomb appearance. The use of "fiberscope" filters minimizes this appearance by expanding the image of each fiberoptic fiber. We therefore assessed whether new developments in digital video image processing have improved image quality for endoscopic surgery. MATERIALS AND METHODS: Fifty urologists reviewed a video playback of various endourologic procedures. The type of endoscope was identified, but the urologic surgeon was blinded to the level of enhancement (high or low) or fiberscope filter (A or B) used. Each video clip was scored from 1 to 5 for the following image variables: identification of structure, detail of image, and background noise or interference. All results were averaged and compared using Student's paired t-test. RESULTS: During rigid endoscopy, the high and low digital enhancement settings were both superior to no enhancement (P < 0.001), and high enhancement was better than low (P < 0.001). With semirigid endoscopic procedures, high and low digital enhancement were comparable but were superior to no enhancement (P < 0.001). Filters A and B were no better than no enhancement. There was a significant improvement noted with the use of filter A or B during flexible ureteroscopy over no enhancement (P < 0.001). In addition, filter A was better than filter B (P < 0.001). CONCLUSIONS: Digital enhancement settings during video endoscopy significantly improve images from rigid and semirigid endoscopes. The digital fiberscope filter significantly improves images obtained during flexible ureteroscopy. Digital image enhancement capabilities should be strongly considered when upgrading video systems. Digital technology must be further studied to improve clinical video imaging during endoscopic surgery.

Endoscopy↗
PubMedDate not supplied

Later potentials on signal-averaged electrocardiograms in children after right ventriculotomy.

After corrective surgery for congenital heart defects, scars may create fractionation and delay of the electrical signals in the heart muscle, providing a substrate for arrhythmias. Signal-averaged electrocardiograms (SAECGs) were obtained from 33 children after right ventriculotomy, on average 6 years after surgery, and from 38 healthy controls of the same age. The duration of the filtered QRS complex (fQRS), the duration of the low amplitude signal (< 40 microV) in the terminal QRS complex (LAS40), and the root mean square amplitude of the terminal 40 ms of the QRS complex (RMS40) were determined. The values of fQRS > or = 117 ms, RMS40 < or = 25 microV, and LAS40 > or = 35 ms, which were beyond the mean +/- 2 SD of the healthy controls, were considered abnormal. Most patients had right bundle branch block and therefore a prolonged fQRS. Late potentials were defined as present if both the RMS40 and LAS40 were abnormal. Altogether nine patients (27%) had late potentials. In the patients with late potentials the incidence of serious ventricular arrhythmias was 44% (4 of 9) and in the patients without late potentials 0% (0 of 24). In seven patients with enlargement of the right ventricle, the incidence of arrhythmias was 57% (4 of 7) when late potentials were present and 0% (0 of 7) when they were absent. In the present study late potentials were associated with a history of arrhythmias, especially when the right ventricle was enlarged. Therefore the SAECG may be useful for determining the risk of serious arrhythmia events in children operated for congenital heart defects.

Adolescent↗