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PubMedDate not supplied

Use of the spiral coil membrane oxygenator during open heart surgery in infants and children.

The spiral coil membrane oxygenator was used without an arterial line filter during short term total cardiopulmonary bypass in 50 infants and children. The compact oxygenator proved to be efficient and reliable, was easy to operate in a simple perfusion circuit, has a high flow rate to priming volume ratio and eliminated gaseous emboli. During perfusion, platelet counts and fibrinogen concentrations descreased 51 and 31% respectively. Coagulation studies in eight infants less than 15 kilograms perfused with the membrane oxygenator system did not differ from those in 7 infants perfused by a bubble oxygenator system.

Adolescent↗
PubMed1998

Beneficial effects of leukocyte depletion of transfused blood on postoperative complications in patients undergoing cardiac surgery: a randomized clinical trial.

BACKGROUND: Leukocytes in transfused blood are associated with several posttransfusion immunomodulatory effects. Although leukocytes play an important role in reperfusion injury, the contribution of leukocytes in transfused blood products has not been investigated. To estimate the role and the timing of leukocyte filtration of red cells in cardiac surgery, we performed a randomized study. METHODS AND RESULTS: Patients scheduled for cardiac surgery were randomly allocated to receive either packed cells without buffy coat (PC, n = 306), fresh-filtered units (FF, n = 305), or stored-filtered units (SF, n = 303) when transfusion was indicated. We evaluated the periods of hospitalization and stay at the intensive care unit, and the occurrences of postoperative complications up to 60 days after surgery. The average hospital stay was 10.7 days, of which 3.2 days were in the intensive care unit, without significant differences between the groups. In the PC trial arm, 23.0% of the patients had infections versus 16.9% and 17.9% of the patients in the leukocyte-depleted trial arms (P=.13). Within 60 days, 45 patients had died, 24 patients in the PC trial arm (7.8%), versus 11 (3.6%) and 10 (3.3%) patients in the FF and SF trial arms, respectively (P=.015). CONCLUSIONS: In cardiac surgery patients, especially when more than three blood transfusions are required, leukocyte depletion by filtration results in a significant reduction of the postoperative mortality that can only partially be explained by the higher incidence of postoperative infections in the PC group.

Aged↗
PubMed2003

Blood cardioplegia filtration.

The introduction of blood cardioplegia has been proven to limit ischaemia and reperfusion injury in cardiac surgery. But the presence of activated neutrophils in the capillary bed may cause further damage. Leukocyte filters have been shown to be very effective in reducing the leukocytes in blood cardioplegia to less than 10%. Leukocyte depletion of blood cardioplegia provides an excellent approach to minimizing myocardial injury, predominantly in high-risk cardiac surgery.

Animals↗
PubMed1982

Nanophthalmos: a perspective on identification and therapy.

Nanophthalmos is a rare and blinding disease. Diagnostic features include a small eye, small cornea, shallow anterior chamber, narrow angle, high lens/eye volume ratio, and uveal effusion. Intraocular surgery has a high rate of disastrous complications and blindness. The 32 eyes (16 patients) presented are in three categories based on angle closure and intraocular pressure levels. Treatment methods included medication, laser iridotomy and gonioplasty, peripheral iridectomy, filtration surgery, and cataract extraction. Glaucoma medication was effective, although miotics sometimes increased pupillary block. Laser iridotomy was successful in 83% of six eyes; laser gonioplasty in 91.6% of 12 eyes. Peripheral iridectomy succeeded in two of seven eyes, and filtering operations provided tension control in two of five eyes. Thirteen of 15 eyes undergoing filtration surgery suffered severe postoperative visual loss. Cataract extraction improved vision in only three of six eyes. The authors' experience confirms that surgery in nanophthalmic eyes has an extremely high complication rate with disastrous results. Medication and laser therapy are the procedures of choice for angle-closure glaucoma in nanophthalmos.

Adult↗
PubMed1984

[Filtering of the illumination of the operating field in microsurgery of the eye].

A filter (GG 475, 2 mm thickness) is presented with which the strain to which the patient's retina is subjected through the light used in surgery with operation microscopes can be reduced and which hardly impedes the surgeon's work at all. The effect of the filter on the sensitivity to damage of the retina and on the spectral sensitivity to brightness of the surgeon is demonstrated.

Filtration↗
PubMed1991

Prophylactic and early therapeutic use of the Greenfield filter in hip and knee joint arthroplasty.

The orthopaedic literature does not provide clear guidelines for the protection of the extremely high-risk thromboembolic patient undergoing hip and knee total joint or related reconstructive surgery. Nor is there agreement of how to protect the immediate postoperative patient with thromboembolic complications. The authors, believing that routine anticoagulation measures are ill-advised in these two circumstances, elected instead to place a Greenfield vena cava filter for prevention of life-threatening thromboembolism. Using prospective selection criteria, 47 patients could be followed over a 24-76-month period. There were no clinical embolic episodes in either group and no late complications of the filter placement. The few complications in this series were related to insertion, only one of which lead to minor long-term disability. The caval patency rate was 96%. The authors have concluded that such prophylactic use of the Greenfield vena cava filter is justified since it contributes to safer and more reliable total hip and total knee surgery with only minor morbidity.

Aged↗
PubMed2003

[Application of synthetic aperture magnetometry for epilepsy surgery].

Recently developed synthetic aperture magnetometry (SAM) is a new MEG signal analysis introducing a high performance spatial filtering technique. SAM is not an inverse solution like dipole analysis, but rather an adaptive beamformer for estimating source activity at each selected voxel inside of the brain. SAM can estimate source changes as a function of time, or power changes subjected to statistical analysis from the non-averaged raw MEG data. Thus this method enables to display the regional currentodensitogram of the arbitrary selected brain tissue as if depth electrodes were inserted (SAM virtual sensor), and to detect the origin of epileptic discharges and their spread. By applying statistical discrimination, SAM can also demonstrate the spatial distribution of event-related changes of brain rhythm (SAM statistical method), in other words activated cerebral cortex during task performance. We will present the usefulness of noninvasive SAM methods in epilepsy surgery detecting the epileptogenic zone by SAM virtual sensor method as well as eloquent brain by SAM statistical method.

Cerebral Cortex↗
PubMed2004

Changes in transforming growth factor-beta1 in gingival crevicular fluid following periodontal surgery.

OBJECTIVES: Growth factors play a major part in wound healing, including in the periodontium. However, the presence of growth factors in gingival crevicular fluid (GCF) in humans during periodontal wound healing has not yet been determined. Our hypothesis is that such factors are present in GCF and that changes in their levels might be of value as a prognostic marker of wound-healing activity and therapeutic progress following periodontal surgery. The aim of this study was therefore to measure transforming growth factor-beta1 (TGF-beta1) in GCF collected from sites that have undergone guided tissue regeneration (GTR) and conventional flap (CF) surgery and to compare these with GCF collected from unaffected healthy sites. MATERIALS AND METHODS: GCF samples were collected, using filter paper strips, at baseline (pre-surgical) and then at intervals up to 26 weeks from 16 patients undergoing GTR and from 11 patients undergoing CF surgery. After elution and acid treatment, TGF-beta1 levels were measured by ELISA. RESULTS: Treatment of periodontal defect sites significantly reduced the mean probing pocket depth (PPD) and improved the mean lifetime cumulative attachment loss (LCAL). Average GCF volumes also significantly increased at all sites at 2 weeks post-surgery and thereafter declined to baseline levels, except at the GTR test sites that were still elevated at 7 weeks. TGF-beta1 could be detected in almost all GCF samples, and 2 weeks after surgery, the average levels increased two-fold at the surgically treated but not at the control sites, which remained unchanged. CONCLUSION: TGF-beta1 is readily detectable in GCF and increases transiently following periodontal surgery. This suggests that changes in the levels of this growth factor in GCF might be useful for monitoring the progress of periodontal repair and regeneration.

Adult↗
PubMed1998

An unusual cause of low back pain? A case report.

STUDY DESIGN: Case report. OBJECTIVE: To highlight the evaluation of a patient with low back pain after an incidental radiographic finding clouded routine management. SUMMARY OF BACKGROUND DATA: Greenfield filters have been used for 20 years with good results. Complications have been seen and documented, but the natural history of filter placement in young patients is not fully appreciated. A prong from a Greenfield filter embedded within a vertebral body has been reported once as an incidental finding in a patient undergoing prophylactic monitoring for recurrence of tumor. METHODS: A 31-year-old woman had a pulmonary embolus after surgery for a benign adnexal mass. A bleeding complication occurred after systemic anticoagulation, and a vena caval filter was placed to limit the possibility of further emboli. The patient was referred to the orthopedic clinic 5 years later with low back pain and an unusual finding on computer tomographic scan: One prong of the filter was embedded within a vertebral body. RESULTS: A bone scan was obtained to evaluate the status of bone activity around the prong. Bone reaction was not evident. Conservative management of her low back pain was instituted, and after 2 years, the patient remains asymptomatic. CONCLUSION: The overall use of vena caval filters has produced favorable results, although numerous complications have been reported. All long-term sequelae have not been completely identified.

Adult↗
PubMed1995

Comparative efficacy and complications of vena caval filters.

PURPOSE: A variety of vena caval filters (VCFs) are available for usage. The choice of filter type depends on physician preference and certain patient variables. An evaluation of the different VCFs used in our institution was done to compare their efficacy and complication rates. METHODS: The medical records of all patients who underwent insertion of a VCF from January 1987 to June 1993 at the University of Iowa Hospitals & Clinics and the affiliated Veterans Administration Medical Center were reviewed. One hundred ninety-nine VCFs were placed in 196 patients (123 males, 73 females), with a mean age of 61 years (range 13 to 87 years). Thirty-five (18%) VCFs (30 stainless steel Greenfield filters [SGFs] and five titanium Greenfield filters with modified hook [TGF-MHs]) were inserted in the operating room via an open technique. The remaining 164 VCFs (82%) were inserted in the radiology suite by a percutaneous technique (38 SGF, 23 TGF-MH, 51 Vena Tech filters [VTFs], 48 Bird's nest filters [BNFs] and 4 Simon Nitinol filters). Thromboembolic risk factors in these 196 patients included malignancy (99), trauma (21), recent surgery (27), cerebrovascular accident with paralysis (6), and miscellaneous conditions (43). Indications for VCF placement included a contraindication to anticoagulation (92), complication of anticoagulation (44), failure of anticoagulation (26), prophylaxis (31), adjunct to pulmonary embolectomy (1), noncompliance (1), hemodynamically unstable patient (1), and prior VCF complication (3). Mean follow-up of the patients was 12 months (range 0 to 87 months). Because there were only four Simon Nitinol filters inserted during the study period, they were excluded from further analysis. RESULTS: A comparative analysis revealed that there was a significantly higher incidence of symptomatic IVC thrombosis with the use of the BNF (n = 7) (14.6%) versus the SGF (n = 0) (0%), TGF-MH (n = 1) (3.6%), or VTF (n = 2) (4%) (p < 0.05 by chi-squared testing). The VCF-related mortality rate was also higher with the BNF (n = 5) (10.9%) versus the SGF (n = 1) (1.5%), TGF-MH (n = 1) (3.6%), or VTF (n = 0) (0%) (p < 0.05 by chi-squared testing). However there was no significant difference in the occurrence of clinically apparent recurrent pulmonary embolism during follow-up between the four different filter types (2 [4.2%] BNF, 3 [4.4%] SGF, 1 [3.6%] TGF-MH, and 1 [2%] VTF). CONCLUSION: These data indicate that the use of the BNF was associated with increased morbidity and mortality rates compared with the use of the SGF, TGF-MH, and VTF filters.

Adolescent↗
PubMed1995

The repair response following Nd:YAG laser sclerostomy ab interno in rabbits.

This study was undertaken to examine ultrastructurally the course of tissue regeneration after thermally-induced laser sclerostomy and compare it with the post-operative clinical events in a rabbit model. Applying a continuous wave neodymium:YAG (Nd:YAG) laser, two sclerostomies were created ab interno on one eye in each of ten pigmented rabbits using a 200-microns-diameter quartz optical fiber; the unoperated fellow-eyes served as controls. Intraocular pressure (IOP) was measured daily before and after surgery. Animals were observed post-operatively for up to 16 days. Well-defined filtering blebs and a low complication rate demonstrated the success of the procedure. IOP was significantly lowered during the entire course of the observation period but after the fifth day, the conjunctival blebs had disappeared. The morphology of the changes in the sclerostomy fistulas were analysed at 2-day intervals by light and electron microscopy. Immediately after surgery, the canal was ensheathed by an approximately 100-microns-thick layer of coagulated collagenous tissue in which two zones could be distinguished according to the intensity of damage. Within 5 days, the inner and outer canal openings were invaded by macrophages and fibroblasts originating from the iris root and episclera, respectively. The former cells were engaged in the phagocytosis of disintegrated collagen adjacent to the lumen. More distally located fibrils which had incurred less severe damage, had retained their fibrillar structure but had lost banding periodicity. After thermal stress had faded, they appeared to undergo a process of repolymerisation. By day 10, the lumen had become occluded by a loose meshwork of phagocytes, fibroblasts and proliferating capillaries. These new vessels and the loose nature of the canal-occluding framework and of the surrounding regenerating collagenous tissue could have further permitted percolation and transport of aqueous humor, since IOP remained low, despite the disappearance of filtering blebs. Although the time course of repair is more rapid in rabbits than in humans, the data gleaned nonetheless yield valid information respecting the sequence of events following thermally-induced scleral fistula.

Animals↗
PubMed2005

[Deep vein thrombosis caused by pelvic lymphocyst following radical prostatectomy: a case report].

A 66-year-old man was admitted with distal edema of his right leg. He had undergone radical prostatectomy and pelvic lymphadenectomy for prostatic cancer 23 days previously. Abdominal computed tomography (CT) showed a lymphocyst (4.5 x 3.0 cm) along the right pelvic wall compressing the right external iliac vein. CT with contrast medium showed thrombus formation (about 9 cm) in the distal portion of the right external iliac vein and femoral vein. An inferior vena cava filter was placed to prevent pulmonary embolism, and anticoagulation with warfarin was started. One week later, CT showed shrinkage of the lymphocyst and thrombus in the vein, as well as a large thrombus trapped in the filter. Follow-up CT taken 2 months later revealed marked reduction of the lymphocyst and absence of thrombus in both the vein and filter. A lymphocyst, also known as a lymphocele, is a complication of radical pelvic surgery. Most lymphocysts are asymptomatic and regress spontaneously, but may lead to deep vein thrombosis and pulmonary embolism, usually a few weeks after surgery. Careful observation is needed even after discharge from hospital.

Aged↗
PubMedDate not supplied

Clinical experience with Günther temporary inferior vena cava filters.

This retrospective study was performed to evaluate the safety and effectiveness of Günther temporary inferior vena cava (IVC) filters. Fifteen Günther temporary filters were placed in 13 patients because of deep vein thrombosis (DVT) with pulmonary embolism (PE) despite DVT prophylaxis (9/13) or temporary contraindications for anticoagulants as well as recent or pending surgery (4/13). No clinical manifestation of PE was observed during the filtration or during the removal. Günther temporary IVC filters are easy and safe to use, and are effective in clot trapping, protecting patients at high risk for PE in whom anticoagulation treatment failed or is contraindicated.

Adult↗
PubMed1999

Bacterial filters in anesthesia: results of 9 years of surveillance.

In 9 years of surveillance of postoperative lower respiratory infections, the infection rate in patients following regional anesthesia was 0.2% and 0.1% in patients following general anesthesia. No bacterial filters in the breathing circuit were used. Infected patients had risk factors such as type of surgery, American Society of Anesthesiologists class > or =2, old age, chronic obstructive pulmonary disease, or smoking habits. Infections were not clustered. This suggests that, in our setting, patient factors are most important in the development of postoperative lower respiratory infections and that the role of bacterial filters as a preventive measure is negligible.

Adult↗
PubMedDate not supplied

Surgical management of a dysfunctional filtering bleb.

This case report presents a patient who developed a large overhanging bleb following antimetabolite trabeculectomy surgery 6 years prior. Complaints included decreasing vision and foreign body sensation for several months. Successful excisional surgery with placement of compression sutures was performed. Visual acuity and intraocular pressure were maintained with the resolution of symptoms.

Antimetabolites↗
PubMed1987

Neutrophil mobility during anaesthesia in children. A trial of ascorbate premedication.

In 20 healthy children undergoing elective surgery, mobility of neutrophils, both unstimulated and stimulated by endotoxin, was studied using a millipore filter system with microscopic determination of leading front migration. Paired samples were incubated with 10(-2) mol l-1 calcium ascorbate and ten children also received 10 mg kg-1 ascorbic acid before premedication. Stimulation of mobility was reduced after the opioid premedication (P less than 0.05) in the ascorbate group only, but not significantly during anaesthesia and surgery. A few individuals showed persisting abnormally low values. No effect of ascorbate in vivo or in vitro was demonstrated. There were no infections.

Adolescent↗
PubMed2005

P-wave signal-averaged electrocardiogram for predicting atrial arrhythmia after cardiac surgery.

BACKGROUND: Atrial arrhythmias (AF) are usually benign, but occur frequently after cardiac surgery. P-wave signal-averaged electrocardiogram has been used to characterize atrial conduction delay as a marker of risk of AF during sinus rhythm. METHODS: Ninety-five patients undergoing either primary isolated coronary artery bypass grafting or aortic valve replacement were enrolled. The duration and the root mean square voltage for the last 20 ms of filtered (40 to 300 Hz) P-wave of the spatial magnitude were recorded before surgery. Any episode of postoperative atrial fibrillation, atrial flutter, or paroxysmal atrial fibrillation lasting longer than 1 hour was considered as AF. RESULTS: Twenty-eight patients (29%) exhibited AF 3.0 +/- 2.3 days after surgery. The P-wave duration recorded with P-wave signal-averaged electrocardiogram was significantly prolonged in patients with AF (135 +/- 14 ms versus 127 +/- 9 ms; p = 0.002). Patients with AF more often had dilated left atrium (p = 0.003), left ventricular hypertrophy (p = 0.03), and advanced age (p = 0.02). Logistic regression analysis identified the following three variables as predictive of AF: P-wave duration of 135 ms or greater (p = 0.02; odds ratio, 3.5), patients 70 years of age and older (p = 0.03; odds ratio, 3.2), and left atrial dimension of 35 mm or greater (p = 0.03; odds ratio, 3.2). If a patient had two or more of these three risk factors, the occurrence of AF was predicted with a sensitivity of 75%, specificity of 76%, positive predictive accuracy of 57%, and negative predictive accuracy of 88%. CONCLUSIONS: The prolonged P-wave duration recorded with P-wave signal-averaged electrocardiogram, together with advanced age and left atrial enlargement, is a potent and independent predictor of AF after cardiac surgery. Patients with these risk factors may benefit from prophylactic antiarrhythmic treatment.

Aged↗
PubMed1992

Beam modifying devices in the treatment of early breast cancer: 3-D stepped compensating technique.

A 3-D compensating technique utilizing stepped brass filters to ensure an adequate dose distribution in the breast after conservative surgery is described. No compensation for lung inhomogeneity is applied. These compensators are part of a procedure which also involves the use of a rotatable half-beam block (HBB) and of an individualized immobilization cast. Results of patient dosimetry show a good agreement with dose prescription in the target volume (measured dose/prescribed dose = 100.9% +/- 1.8% at the reference point). Phantom dosimetry is discussed.

Breast Neoplasms↗