Venous thrombosis associated with the placement of peripherally inserted central catheters.

PURPOSE: Peripherally inserted central catheters (PICCs) have become an essential component of the management of an increasing number of patients, including patients who may require hemodialysis. Reported symptomatic venous thrombosis rates associated with PICC lines are based on clinical signs and symptoms and range from 1% to 4%. The purpose of this study is to evaluate the true rate of thrombosis of upper extremity veins after the placement of PICCs and the potential impact on future access in hemodialysis patients. MATERIALS AND METHODS: A retrospective analysis was performed. Patients who had (i) normal findings during initial venography, (ii) PICC placement, and (iii) who underwent subsequent repeated venography were included. Age, sex, vein cannulated, catheter size, location, and incidence of thrombosis were analyzed. RESULTS: Three hundred fifty-four PICCs were placed in 119 patients. Of the 144 extremities, 137 had normal findings during initial venography. Of the 137 extremities, 32 developed thrombosis of the cannulated vein (or central veins) after initial PICC placement (23.3%). When all extremities with multiple PICC lines placed were considered, 52 developed thrombosis, for an overall thrombosis rate of 38%. The incidence of thrombosis by site was cephalic 57%, basilic 14%, and brachial 10%. No significant differences were noted in the rates of thrombosis by age, sex, or catheter size. CONCLUSIONS: There is a relatively high rate of venous thrombosis associated with PICCs, particularly cephalic thrombus. Because of the high rate of thrombosis associated with these catheters, an alternative mode of access should be considered in current or potential hemodialysis patients. All patients with a history of PICC line placement requiring dialysis access should undergo upper extremity venography prior to the placement of permanent access.

Creation of radiopaque thrombi for in vivo experiments.

PURPOSE: A number of percutaneous thrombectomy devices are undergoing investigation for treatment of patients with venous thromboembolism. Use of radiopaque thrombus to monitor thrombus delivery and assess thrombectomy has been previously reported. The purpose of this project was to quantitatively test the effect of mixing different ratios of blood and contrast material to facilitate maximum thrombus formation and radiopacity. MATERIALS AND METHODS: The following ratios of blood and contrast material were mixed: 2 mL blood to 8 mL contrast material (ratio = 0.25), 4 mL blood to 6 mL contrast material (ratio = 0.67), 6 mL blood to 4 mL contrast material (ratio = 1.5), and 8 mL blood to 2 mL contrast material (ratio = 4). Contrast material was added at day 0, 3, or 6. Each sample received one of two ionic contrast agents to opacify the clots. At day 14, thrombus mass and opacity were determined. RESULTS: Three combinations of blood and contrast material produced maximum thrombus and radiopacity. These were sodium iothalamate 30% with a ratio of 4 with contrast material added on day 0 and sodium iothalamate 60% with a ratio of 1.5 with contrast material added on day 3 or 6. CONCLUSIONS: When forming radiopaque thrombi, significant differences can result from the ratio of blood to contrast material used. Contrast material type can also affect radiopacity and mass formed. The use of optimal ratios of blood to contrast material should maximize device evaluation with minimal wasting of valuable resources such as test subjects, physician time, and equipment.

Gastroenteritis due to Salmonella sp: clinical and radiologic signs mimicking surgical peritonitis.

Salmonella infections most often are self-limited illnesses confined to the gastrointestinal system. They can, however, produce clinical and radiographic findings consistent with peritonitis. Careful attention to evaluation and treatment is required to avoid unnecessary surgery for what may initially appear to be a surgical condition.

Weights and hematology of wild black bears during hibernation.

We compared weights and hematological profiles of adult (greater than 3-yr-old) female black bears (Ursus americanus) during hibernation (after 8 January). We handled 28 bears one to four times (total of 47) over 4 yr of varying mast and berry production. Mean weight of lactating bears was greater (P less than 0.0001) than that of non-lactating females. White blood cells (P less than 0.05) and mean corpuscular volume (P = 0.005) also differed between lactating and non-lactating bears. Hemoglobin (P = 0.006) and mean corpuscular hemoglobin concentration (P = 0.02) varied among years; values were lowest during 1975, following decreased precipitation and the occurrence of a second year of mast and berry crop shortages in a three-year period. Significant (P less than 0.05) interaction between reproductive status (lactating versus non-lactating) and study year for hemoglobin, red blood cells, and packed cell volume, and increased mean corpuscular volume, suggested a greater nutritional challenge for lactating females compared to non-lactating females during the 1975 denning season. Our data suggest that hematological characteristics of denning bears may be more sensitive than weights as indicators of annual changes in nutritional status; however, other influential factors, in addition to mast and berry crop production, remain to be examined.

Extracapsular cataract extraction: prognosis and complications with and without posterior-chamber lens implantations.

Four-hundred-and-sixteen eyes that underwent cataract extraction over six years were analyzed. Extracapsular cataract extraction with posterior-chamber intraocular lens implantation (PCIOL) was performed in 186 eyes and extracapsular cataract extraction (ECCE) alone was performed in 230 eyes. The complications and visual acuity were compared in the two groups. The PCIOL group showed a low incidence of postoperative complications. In addition, there were no cases of corneal edema; retinal detachment occurred in 1.33%; cystoid macular edema occurred in 2.67%; and visual acuity recovered to 20/40 or better in 96.67% of eyes. The incidence of complications in the ECCE group was slightly higher.

Prealbumin. A major constituent of vitreous amyloid.

Vitreous amyloid may be the presenting clinical manifestation of types 1 and 2 familial amyloidotic polyneuropathy or complicate the course of these syndromes. Recent studies have shown that the major subunit protein composing amyloid fibrils in these conditions is a variant or abnormal prealbumin molecule and that affected individuals have low levels of this protein in their blood. The authors studied material obtained at vitrectomy from two cases of vitreous amyloid. One of these was nonfamilial and the other familial. Two-dimensional gels of solubilized protein from pelleted and washed vitreous amyloid in both cases were found to consist of material with the molecular weight and isofocusing coordinates of prealbumin monomer. Reactivity of fibrils with a monospecific antiserum to prealbumin was confirmed by colloidal gold immunoelectron microscopy. Non-familial as well as familial vitreous amyloid may in fact be systemic forms of amyloidosis due to deposition of prealbumin which can be characterized by biochemical or immunohistologic studies of material obtained at vitrectomy.

Retinal toxicity secondary to intraocular gentamicin injection.

The authors present five cases of severe retinal ischemia associated with gentamicin injection. In three of the cases massive doses of gentamicin were erroneously injected into the eye; in two of the cases the authors presume that gentamicin toxicity occurred. The sequence of clinical findings was similar in all five cases. The prominent findings included early superficial and intraretinal hemorrhages, opaque and edematous retina, cotton-wool infarcts, arteriolar narrowing, and venous beading. Fluorescein angiography revealed severe retinal vascular nonperfusion. Chronic findings included rubeosis irides, neovascular glaucoma, retinal pigmentary degeneration, and optic atrophy. Of the documented cases of massive intraocular gentamicin injection, two patients had no light perception (NLP) vision and one had bare light perception. Of the two cases of presumed gentamicin toxicity, one had 20/400 vision and one had count fingers vision. Strict precautions are necessary to prevent the catastrophic events resulting from inadvertent gentamicin injection; such precautions should include precise labeling of all injectable solutions on the surgical field, waiting to draw up injectable antibiotics until the time they are needed, and drawing up injectable antibiotics under direct physician observation. All intravitreal injections should be performed slowly, in the anterior vitreous, with the needle bevel up.

The incidence of retinal detachment following extracapsular cataract extraction. A ten-year study.

A long-term prospective study was conducted to evaluate the incidence of specific complications following extracapsular cataract extraction. Eight hundred forty-two consecutive extracapsular cataract extractions were performed over a ten-year period with a minimum follow-up time of one year. The mean follow up period for this series was 32.2 months. The incidence of retinal detachment in the entire population was 1.4%. In those eyes with a cataract as the only ocular abnormality and with no surgical complications, the frequency was 1.0%. The incidence in eyes following uncomplicated procedures, with no other ocular pathology and with an intact posterior capsule was 0.8%. The incidence of opacification of the posterior capsule requiring capsulotomy was 16.7%. The mean time interval for a secondary capsulotomy was 24.3 months. A positive correlation between this time interval and patient age was established.

Pars plana vitrectomy in ocular trauma.

Visual improvement was achieved in 62% of 100 consecutive patients with ocular trauma treated by pars plana vitrectomy. Anterior segment injuries had a better prognosis than posterior segment injuries, and retinal detachment was a poor prognostic sign. Patients undergoing vitrectomy during the two weeks after injury had a better visual prognosis than those who had delayed vitrectomy. Pars plana vitrectomy has increased the recovery rate in traumatized eyes which previously were deemed inoperable and frequently were enucleated. Most such eyes have intraocular fibrocellular proliferations, resulting in traction retinal detachments, cyclitic membranes, and phthisis, as documented in clinicopathological and experimentally produced specimens of penetrating ocular trauma. Vitrectomy can interrupt this sequence, if performed one to 14 days after injury, by removing the vitreous scaffold onto which proliferation occurs, together with the elements of hemorrhage, damaged lens, vitreous, and foreign material which may incite proliferation. We believe four to ten days after injury to be the optimal time for vitrectomy to avoid the hazards of immediate intervention, while removing damaged tissue before serious sequenlae occur.

Ocular findings in thoracic-pelvic-phalangeal dystrophy.

Two unrelated patients with thoracic-pelvic-phalangeal dystrophy syndrome had retinal degeneration. A pathologic study of both eyes from one of the patients showed severe degeneration of the peripheral retina, with predominantly cone-type cells remaining.

Adenocarcinoma of the retinal pigment epithelium.

A 57-year-old woman complaining of decreased vision for six months had a mass expanding the choroid inferonasally in the right eye. Clinical examination, ultrasonography, and fluorescein angiography were consistent with a malignant melanoma. The eye was enucleated and pathologic studies showed an adenocarcinoma of the retinal pigment epithelium (RPE). Malignant tumors of the RPE may simulate exactly choroidal melanomas clinically, but apparently have a much better prognosis, in that very few cases have been documented to produce metastatic disease. The vast majority of cases studied histopathologically, in which a diagnosis of adenocarcinoma of the RPE has been made, are low-grade malignant neoplasms with the absence of invasion beyond the choroid or lamina cribrosa at the time of enucleation.

Contraction of a perifoveal epiretinal membrane simulating a macular hole.

Four patients observed for a three- to four-year period had a hole in an epiretinal membrane overlying the macula that mimicked a macular hole. In two patients the clinical appearance remained essentially constant. In one, the epiretinal membrane contracted further, reducing the apparent macular hole to a slit and causing the typical appearance of a macular pucker. In the fourth patient, the epiretinal membrane peeled spontaneously causing the apparent hole to disappear. None of the patients had static perimetric findings that suggested a true macular hole. All of the patients had normal or nearly normal visual acuity when first seen. This was maintained except in the patient who suffered further membrane contraction. Fluorescein angiography demonstrated a slight fluorescence in the base of the hole in three of the four patients; however, it was not as pronounced as one sees in true macular holes. Lamellar macular holes characteristically show no fluorescence in the area of the hole.

Retinal tears 180 degrees and greater. Management with vitrectomy and intravitreal gas.

A new technique for the treatment of giant retinal dialysis of 180 degrees or more has been devised. After the lens and vitreous have been removed via the pars plana, the patient is rotated into a prone position on a special operating table. The retina is unfolded by filling the eye completely with gas and is held in place by gas. The patient is then brought back into the normal supine position, and a scleral encircling procedure is added. The initial success rate of reattachment is 12 out of 14 cases. Afterward, many eyes develop massive periretinal proliferation. After six months or more of follow-up, the retina remained attached in six of 14 cases.