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PubMed1980

Filtering valve implant surgery for eyes wtih neovascular glaucoma.

We performed filtration surgery with a unidirectional, pressure-sensitive valve implant in 40 eyes with neovascular glaucoma. The device consisted of an open Supramid tube (outside diameter 0.58 mm, inside diameter 0.38 mm) sealed to a Silastic tube with a slit valve. The Supramid tube was inserted at the corneoscleral limbus 1 to 4 mm into the anterior chamber and the Silastic portion was located under a lamellar scleral flap. Twenty-seven of 40 eyes (68%) had a postoperative IOP less than or equal to 24 mm Hg with a mean follow-up of 13.8 months. Ten of these 27 eyes required postoperative medical therapy to achieve this level of IOP control. The glaucoma valve implant failed to return IOP to normal in 13 of the 40 eyes (32%), 11 of these as a consequence of scarring of the external bleb.

Adult↗
PubMed1997

Depletion of activated neutrophils by a filter during cardiac valve surgery.

PURPOSE: To determine whether inclusion of a neutrophil-specific filter into the extracorporeal circuit during open heart valve surgery alters postoperative outcomes. METHODS: Convenience sampling of 24 patients undergoing elective open heart valve surgery between July 1993 and June 1994. Patients were randomized to a neutrophil-specific filter (n = 11) or to a standard blood filter (n = 13) during cardiopulmonary bypass. RESULTS: Neutrophil-specific filter diminished (P < 0.02) the expression of CD18, a neutrophil surface adhesion molecule, at I (84.5 +/- 4.2 vs 94.8 +/- 3.8%), 4 (80.0 +/- 4.2 vs 95.1 +/- 3.9%) and 24 hr (75.2 +/- 4.2 vs 98.2 +/- 3.9%) post-operatively compared with standard filter. Total white blood cell count, neutrophil count, and pro-inflammatory cytokines (IL-6, IL-8) were similar between groups at all times. Measured outcomes including: PaO2 cardiac index, ejection fraction, haemodynamic variables, use of inotropes, spirometry (FEV1, FVC), and hospitalization duration were similar between groups. CONCLUSIONS: Inclusion of the neutrophil filter during open heart valve surgery selectively depletes activated neutrophils. There were no other detectable differences between the two groups and the use of a neutrophil-specific filter in routine clinical practice for patients undergoing open heart valve surgery is not supported.

Adult↗
PubMed2002

[Impact of cataract surgery on intraocular pressure after filtering operation due to primary open angle glaucoma and secondary glaucoma in pseudoexfoliation syndrome].

PURPOSE: To analyse the impact of cataract surgery after filtering operation on the intraocular pressure (IOP) due to primary open angle glaucoma (pOAG) versus secondary open angle glaucoma in pseudoexfoliation syndrome (PEX). The regulation of IOP was evaluated on the basis of criteria of advanced glaucoma intervention study (AGIS). PATIENTS AND METHODS: Retrospectively 95 eyes of 95 patients (53 x pOAG, 36 x clear cornea approach [group 1] and 17 x corneoscleral tunnel [group 2]; 42 x PEX, 30 x clear cornea approach [group 3] and 12 x corneoscleral tunnel [group 4]) were included. The IOP and antiglaucomatous eye drops were analysed before filtering operation, before cataract surgery and on average 33 months after cataract surgery. RESULTS: In all groups there was a significant reduction of IOP after filtering operation by 8.7 mm Hg on average and no significant difference of IOP before and after cataract surgery. At no time there was a significant difference in IOP between the four subgroups. According to criteria of the AGIS study 34 % of group 1, 29 % of group 2, 36 % of group 3 and 17 % of group 4 had an IOP lower than 14 mm Hg before cataract surgery. After cataract surgery only 31 % of group 1, 18 % of group 2, 13 % of group 3 and 8 % of group 4 met this criterion. CONCLUSION: On first glance sequential cataract surgery after filtering operation seems to have no clinically relevant impact on the IOP, neither with regard to the type of glaucoma nor in respect of the approach for cataract surgery. However, if IOP is evaluated based on the criteria of the AGIS, primary open angle glaucoma with clear cornea approach appears to yield superior results in contrast to secondary open angle glaucoma in pseudoexfoliation syndrome with corneoscleral tunnel concerning the regulation of intraocular pressure.

Aged↗
PubMed2002

The rationale for fat filtration during cardiac surgery.

Improved filter technology may enable the removal of specific substances such as lipids from the blood. Lipids form a heterogeneous group of compounds, but during surgery, the main interest is focussed on triglycerides, glycerol and free fatty acids. Fat emboli have been demonstrated in the brain after cardiac surgery and are associated with ischaemic brain injury. Fat emboli have also been demonstrated in lung and kidney tissue. Lung tissue and leucocytes are especially vulnerable to the effects of free fatty acids. The surgical wound suction blood during cardiac surgery contains a considerable quantity of microemboli. Therefore, as a first step to determining the place of fat filtration during cardiac surgery, the use of a fat removal filter for surgical wound suction blood is advocated.

Cardiac Surgical Procedures↗
PubMed1995

Depletion of neutrophils by filter during aortocoronary bypass surgery transiently improves postoperative cardiorespiratory status.

STUDY OBJECTIVE: To determine whether inclusion of a leukocyte specific filter into the extracorporeal circuit during aortocoronary bypass surgery alters postoperative cardiopulmonary function. DESIGN: Randomized, double-blinded control trial. SETTING: Tertiary care hospital. PATIENTS: Convenience sampling of patients undergoing elective aortocoronary bypass between October 1992 and June 1993. INTERVENTIONS: A total of 32 patients were randomized to a leukocyte specific filter (n = 16) or to a standard blood filter (n = 16) during the surgical procedure. MEASUREMENTS AND RESULTS: White blood cell count in the standard filter group (12.2 +/- 3.6 10(9)/L) was higher (p = 0.047) than in the leukocyte filter group (9.9 +/- 2.6 10(9)/L) at 4 h postoperatively but counts were similar (p = 0.063) at 24 h (10.8 +/- 2.7 vs 8.9 +/- 2.6 10(9)/L, respectively). Leukocyte activation assessed by chemiluminescence was similar between groups at all measurement periods. We noted transient improvements (p < 0.05) in intrapulmonary shunt (19 +/- 50% vs 24 +/- 9%) and mean blood pressure (85 +/- 8 vs 76 +/- 9 mm Hg, respectively) in the leukocyte filter group compared with the standard filter group, respectively. Otherwise there were no differences noted between groups. CONCLUSIONS: Inclusion of a leukocyte filter during cardiopulmonary bypass caused transient cardiorespiratory improvement that was lost within 24 h and did not offer any significant clinical benefits.

Aged↗
PubMed2004

Does the site of filtration influence the medium to long term intraocular pressure control following microtrabeculectomy in low risk eyes?

AIMS: To evaluate the influence of varying surgical site on the medium to long term intraocular pressure (IOP) control in patients undergoing unenhanced small flap trabeculectomy (microtrabeculectomy) in eyes at low risk of failure. METHODS: A retrospective non-concurrent analysis was performed on two cohorts of patients who underwent unenhanced microtrabeculectomy at different sites by a single surgeon (SAV). The first cohort of eyes was part of a trial to study the astigmatic effect of microtrabeculectomy (results published elsewhere) and all had flaps centred at the 12 o'clock meridian (superior flaps). The second cohort consisted of eyes with flaps created on either side of the 12 o'clock-that is, superonasal in left eyes and superotemporal in right eyes. All case notes were reviewed for the preoperative and presenting IOPs, the number and duration of antiglaucoma medication use preoperatively and, postoperatively, any intraoperative, early, or late postoperative complications. All IOPs measured at 6 months and then yearly intervals were recorded. The baseline characteristics and IOPs at each follow up were compared between the eyes with the superonasal and superotemporal flaps of the non-12 o'clock group against those with superior flaps in the 12 o'clock group up to a maximum of 72 months. Survival was assessed by the site of microtrabeculectomy, with failure considered as any IOP above 22 and 15 mm Hg with or without medications. RESULTS: All patients had a minimum follow up of 12 months and 12/17 patients in the 12 o'clock group and 17/28 in the non-12 o'clock group completed the full follow up of 72 months. The IOPs at all points in time were lower in the left eyes with superonasal flaps compared to both the superior and the superotemporal groups. This difference was statistically significant between the three groups to the end of 4 years (p = 0.001) and remains clinically significant thereafter with the mean last recorded IOPs of 15.9, 12.4 (p = 0.03), and 14.3 mm Hg in the superior, superonasal and superotemporal groups respectively, with a smaller mean number of drops in the non-12 o'clock group. Kaplan-Meier curves showed a significantly better outcome for the cutoff IOP of 15 mm Hg in the superonasal group (p = 0.003) compared with both the other groups. CONCLUSION: Eyes with superonasal flaps achieve and maintain lower IOPs when compared with both the superior and superotemporal flaps. The results suggest that, when a low target IOP is desired, the site of surgery in an unenhanced filtering procedure should be superonasally sited.

Aged↗
PubMed1997

Antiglaucomatous trabecular surgery.

In contrast to conventional filtering procedures, microtrabecular surgery is intended to selectively combat the diseased structure in the pathogenesis of chronic open-angle glaucoma, thereby reducing potential risks during and after transscleral drainage operations. This overview considers new techniques in trabecular surgery, with special emphasis on the description of each novel technique, its instrumentation, its presumed mechanism of action, and its clinical results. Trabecular aspiration is evaluated as a method of clearing extracellular debris from intertrabecular spaces in pseudoexfoliation glaucoma or goniocurretage, and laser trabecular ablation for the treatment of absolute glaucomas is discussed. Although preliminary results are promising, most of these procedures are still experimental and under careful clinical evaluation, leaving plenty of room for refinements and further developments.

Animals↗
PubMed1987

Ab interno and ab externo filtering operations by laser contact surgery.

A new method to create filtering tracts ab interno or ab externo which may eventually prove useful in eyes with poorly controlled glaucoma is described. Fiberoptics of 200 microns diameter, with either cleaved or 500 microns ball lens tips, were coupled to the output of an argon gas laser emitting a number of radiation lines in the ultraviolet (333 to 363 nm) wavelengths. This system was used to perforate the corneoscleral limbal tissue of enucleated bovine eyes with a small number of laser applications to create a filtering fistula. Corneoscleral limbal perforation with a 200 microns cleaved fiber required 0.6 to 1.1 J total energy, delivered with a laser power of 0.5 W, or greater, for 0.1 second. With a 500 microns ball lens fiber tip a tract of nearly 0.5 mm diameter was created, requiring 5.1 to 10.4 J total energy, delivered with a laser power of 2.0 W, or greater, for at least 0.1 second. The energy required for perforation from the external surface to the anterior chamber was the same as the energy required for ab interno perforation.

Animals↗
PubMed2002

Postoperative subconjunctival mitomycin-C injection after non-penetrating glaucoma surgery.

PURPOSE: To evaluate subconjunctival mitomycin C (MMC) injection efficacy and safety in patients with failing glaucoma non-penetrating filtering blebs. METHODS: Twenty-eight eyes were consecutively recruited for this study. Only one eye for each patient was randomly selected. All the recruited patients had glaucoma and uncontrolled intraocular pressure after a non-penetrating filtering glaucoma surgery and/or a pathological aspect of the filtering bleb (i.e., vascularized and/or encysted). One or more MMC injections were performed under the conjunctiva closed to the bleb to improve filtration. Local effects and complications of subconjunctival MMC injections were analyzed. RESULTS: Out of the 28 patients, 21 (75%) had MMC also applied intraoperatively. The mean postoperative IOP before MMC injections was 17 +/- 6.6 mmHg. The final IOP after MMC injections was 13.9 +/- 2.9 mmHg after a mean follow-up of 6 months. A total of 67 subconjunctival MMC injections were performed with a mean of 2.9 (ranging from 1 to 5) injections per patient. The only complication found to be possibly related to MMC injections was two cases of corneal Dellen. CONCLUSION: From these preliminary results, subconjunctival MMC injections in selected cases appear to be not only safe but also effective in promoting further the postoperative IOP drop.

Administration, Topical↗
PubMed2003

Neurological and neuropsychological examination and outcome after use of an intra-aortic filter device during cardiac surgery.

Cerebral embolization of particles after cardiac surgery is frequently associated with neurological deficits. Aortic crossclamp manipulation seems to be the most significant cause of emboli release during cardiac surgery. The goal of this study was to demonstrate whether the use of an intra-aortic filter device has an effect on the magnet resonance imaging (MRI) and functional neurological outcome. Twenty-four patients undergoing cardiosurgical procedures using cardiopulmonary bypass (CPB) were selected: coronary artery bypass graft (CABG) surgery (n = 17), aortic valve replacement (AVR) surgery (n = 4) or combined procedures (n = 3). Patients were evaluated by diffusion weighted MRI of the brain, neurological examination and neuropsychological assessment regarding alertness as well as divided and selective attention before and five to seven days after surgery. The patients were divided into two groups. In group I, 12 patients received a filter through a modified 24 F arterial cannula immediately before the aortic crossclamp was released. Filters remained in the aorta until CPB was discontinued. Intraoperatively, bilateral middle cerebral artery transcranial Doppler (TCD) was monitored at baseline, at the beginning of CPB, at a timepoint when the aorta was crossclamped, when the filter was inserted and while the crossclamp was switched to partial clamping until the CPB was discontinued. TCD was used for detection of microembolic signals (MES). The captured material in the filter was examined histologically. Twelve patients served as controls without aortic filtration (group II). The MRI of the brain did not show any diffusion alterations in either group before or after surgery. No patient developed a focal neurological deficit or stroke. Intraoperative quantitative MES detection revealed a four to tenfold increase in patients of group I compared with group II (5-6 versus 0.5-1 MES/min) during the filter dwell time. There was no consistent pattern regarding the neurobehavioural sequelae. Filters showed arteriosclerotic debris in 75% of the patients. The use of the intra-aortic filter device did not show a positive effect on neurological, neuroradiographical and neuropsychological outcomes. The increase of the MES rate in group I patients may be due to microbubbles generated as microcavitations by the filter or the aortic filter cannula. The intra-aortic filter was able to capture atheromatous material in 75% of the patients.

Aorta, Thoracic↗
PubMed2002

The regained referral ground and clinical practice of vena cava filter placement in vascular surgery.

Interventional radiologist rather than vascular surgeons have become the predominant clinicians placing inferior vena cava (IVC) filters since the percutaneous device was introduced more than a decade ago. We conducted a retrospective analysis of 592 patients treated at a single institution between 1987 and 2000 to determine the indications, referral pattern, and clinical outcome of IVC filter placement between the radiologist and surgeon groups. Before 1989 all filters were placed by surgeons in the operating room. The adoption of the percutaneous delivery method by radiologists in 1989 led to a dramatic increase in its practice volume accounting for 99 per cent of all filters placed from 1991 to 1993 (P < 0.001). The development of an endovascular program by the vascular surgeons in 1994 led to a steady increase in its IVC filter practice annually (P < 0.05) and accounted for 42 per cent of all filter placements in 2000. A distinct referral pattern also emerged as 74 per cent of all filter placements by surgeons were referred by surgical services. The proportion of filter placement for strict indications remained constant over time between the two groups (P = 0.86). The complications and survival rates were not significantly different between the two groups (P = 0.24). Percutaneous devices have dramatically increased the clinical volume of IVC filter placement by interventional radiologists. Vascular surgeons with endovascular interest are well suited to perform the procedure and can regain referral ground of IVC filter placement.

Humans↗
PubMedDate not supplied

Upper eyelid extension of a filtering bleb following glaucoma shunt surgery.

The authors describe a case of a filtering bleb that extended into the eyelid of a 71-year-old man following glaucoma surgery with a shunt implant. The patient presented with a left upper eyelid mass and had ocular surface and mechanical sequelae. Computed tomography scan demonstrated a fistula between the original filtering tract and the eyelid, creating an inadvertent filtering bleb. Cytology revealed fluid consistent with aqueous humor. Intraocular pressure remained normal and symptoms improved with conservative management. The patient deferred any surgical revision. Glaucoma tube shunts may lead to ocular and rare orbital complications from inadvertent bleb extension, as seen in this case.

Aged↗