Toxic effects of indocyanine green, infracyanine green, and trypan blue on the human retinal pigmented epithelium.

BACKGROUND: Indocyanine green, infracyanine green, and trypan blue are frequently used as aids to visualize structures removed during vitreoretinal surgery. But they may have toxic effects on the retina. We therefore compared the acute and chronic toxicities of these stains on cultured human retinal pigmented epithelial (RPE) cells using clinically relevant concentrations and an identical experimental setup for each agent. METHODS: Monolayers of RPE cells were incubated with various concentrations of indocyanine green, infracyanine green (each at 0.005%, 0.05%, and 0.5%) or trypan blue (0.05%, 0.06%, 0.1%, 0.15%, and 0.5%) for 5 min (acute exposure) or 6 days (chronic exposure). Using the propidium iodide assay, acute cytotoxicity was monitored at 15-min intervals for up to 3 h. Chronic cytotoxicity was assessed by monitoring cell calcein esterase activity, cell proliferation, and cell morphology (viability) after 6 days of exposure. RESULTS: Indocyanine and infracyanine green induced acute and chronic toxicities at a concentration above 0.05%. Trypan blue evoked no acute toxicity, but it was chronically cytotoxic at all tested concentrations. CONCLUSIONS: Despite thorough rinsing after application, significant amounts of the not sufficiently water soluble indocyanine and infracyanine green are retained after surgery by the eye. Trypan blue, being more water-soluble than ICG, is probably retained to the least degree. This circumstance is fortunate given that trypan blue exhibits a chronic cytotoxicity comparable to ICG at all clinically relevant concentrations. During vitrectomy, surgeons should aim to expose retinal tissue to only low concentrations of these stains and for as short a period as possible.

The reverse target sign in liver disease: a potential ultrasound feature in cirrhotic liver nodules characterization.

In patients with suspected liver disease, ultrasound is the most commonly performed initial imaging modality. We report a patient who had previously undiagnosed liver cirrhosis with target-shaped lesions interspersed throughout the liver parenchyma on ultrasound seen as multiple uniform round shaped lesions with varying isoechoic to hyperechoic centres surrounded by a hyperechoic rim. We have termed this the "reverse" target sign as there is inversion of the typical echoic pattern that is normally seen in metastatic liver disease. We suggest this ultrasound sign may represent a method for differentiating cirrhotic liver nodules from other nodular liver lesions.

Pulmonary hypertension. Response of vasoactive peptides to a nonionic contrast medium in patients undergoing pulmonary angiography.

RATIONALE AND OBJECTIVES: The degree to which pulmonary angiography may contribute to serious complications in patients with pulmonary hypertension has not been clarified and remains a matter of debate. Accordingly, this study was designed (1) to detect the potential release of vasoactive peptides and (2) to investigate the hemodynamic response after administration of a nonionic contrast medium in patients with pulmonary hypertension undergoing pulmonary angiography. Allergy-mediating substances also were measured to monitor for possible anaphylactoid reactions. METHODS: Pulmonary digital subtraction angiography was performed in 20 patients with pulmonary hypertension (mean pulmonary arterial pressure more than 20 mm Hg). Iopromide was administered as a total of 100 mL via a 7F catheter inserted from the right femoral vein. The injected volume and duration of injection (15 to 20 mL/sec) were kept constant. Hemodynamic parameters were continuously monitored, including electrocardiogram, heart rate, phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and after administration of contrast media to assay for the concentration of the following vasoactive peptides using radioimmunoassay techniques: renin, angiotensin-I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic-guanosine monophosphate, and myoglobin, as well as allergy-mediating substances such as tryptase, eosinophil protein X, and eosinophil cationic protein. RESULTS: Administration of iopromide caused significant increases in atrial natriuretic peptide (from 61.3 +/- 11.8 to 94.0 +/- 16.7) and antidiuretic hormone (from 6.6 +/- 1.9 to 12.3 +/- 3.1), whereas renin significantly decreased (from 3.0 +/- 0.6 to 1.3 +/- 0.5). After administration of contrast media, there were no significant changes in the other measured vasoactive peptides, allergy-mediating substances, and monitored cardiovascular parameters. CONCLUSION: Administration of iopromide for pulmonary angiography in patients with pulmonary hypertension resulted in no appreciable hemodynamic alterations associated with the observed changes in atrial natriuretic peptide, antidiuretic hormone, and renin. No allergy-mediated reactions were observed in these patients.

Extended infusion of rtPA lysis of pulmonary emboli: influence of time after onset of symptoms on outcome.

PURPOSE: Evaluate efficacy and safety of short-term thrombolysis with recombinant human-tissue plasminogen activator (rtPA). METHODS: Thrombolysis with rtPA was performed in 29 patients with angiographically documented severe acute pulmonary embolism (Miller score of 20/34 or more). All patients received 100 mg rtPA through peripheral veins within the first 2 hr, followed by a continuous infusion of rtPA (0.05 mg/kg/hr) over a 4-hr period. Concomitant intravenous heparin 1000 U/hr infusion was applicated for the first 6 hr. RESULTS: Using this treatment, 83% of our patients showed clinical improvement objectified by the Miller score, by the clinical stage (Grosser), and by the pulmonary artery mean pressure (PAPm). The treatment regimen was unsuccessful if the clinical history lasted more than 3 days. Complications occurred in 10 patients (34%), and 3 patients (10%) died of acute right heart failure. CONCLUSION: The success of rtPA treatment appears to depend on the interval between onset of symptoms and start of thrombolytic therapy. Otherwise the technique leads to objectifiable improvement within 6 hr with an acceptable bleeding risk.

Effects of iopromide on vasoactive peptides and allergy-mediated substances in healthy volunteers.

RATIONALE AND OBJECTIVES: Little information is available about the direct action of angiographic contrast media on vasoactive peptides and allergy-mediated substances in humans. This study defined the acute effects of iopromide, a nonionic contrast medium (370 mg/mL iodine), on vasoactive peptides, allergy-mediated substances, and hemodynamic parameters in healthy volunteers. METHODS: Pulmonary digital subtraction angiography was performed in seven healthy volunteers with no cardiovascular or pulmonary disease. Iopromide was administered as a total volume of 100 mL through a 7-Fr catheter inserted in the right femoral vein. The injected volumes and duration of injection (15-20 mL/second) were kept constant. The following hemodynamic parameters were monitored continuously: results of electrocardiogram, heart rate, and phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and 3 to 5 minutes after injection of contrast media to determine the concentrations of the following vasoactive peptides: renin, angiotensin I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic guanosine monophosphate, and myoglobin; and to allergy-mediated substances such as tryptase, eosinophil protein X, and eosinophil cationic protein, using radioimmunoassay techniques. RESULTS: Iopromide substantially increased atrial natriuretic peptide (48.8 +/- 8.9 to 85.8 +/- 13.0) and antidiuretic hormone (3.4 +/- 0.3 to 4.6 +/- 0.5) levels, whereas renin decreased (0.9 +/- 0.1 to 0.8 +/- 0.2) slightly but not significantly. Iopromide did not induce substantial changes in the other vasoactive peptides or in allergy-mediated substances after the contrast medium was injected. Similarly, cardiovascular parameters (heart rate, pulmonary and systemic blood pressures, and results of electrocardiogram) also remained unchanged after contrast injection. CONCLUSION: Iopromide caused no appreciable hemodynamic alterations associated with the changes in atrial natriuretic peptide and antidiuretic hormone and no evidence of allergy-mediated reactions in all volunteers.

Strength, elasticity, and plasticity of expandable metal stents: in vitro studies with three types of stress.

PURPOSE: Five types of expandable metal stents (Palmaz, Strecker, Gianturco, Cragg, and Wallstent) were subjected to standardized tests to obtain objective, comparable data of their mechanical characteristics. MATERIALS AND METHODS: The stents were subjected to area loads, point loads, and circular loads; the resistance of the stents to a continually increasing deformation was measured. Elasticity and deformation characteristics of the stents were also noted. Another experiment simulated the situation of the stent in an implanted state. The stents were covered with a thin self-adhesive foil to simulate optimal wall contact by limiting the mobility of the mesh struts. RESULTS: For all types of stress, the Palmaz stent showed the highest resistance but was completely inelastic. The Strecker stent and the Wallstent showed higher resistance when coated in foil (simulating good wall contact). The Gianturco stent showed the lowest resistances but was completely elastic. A point load on a Wallstent caused concentric constriction over a longer distance. CONCLUSIONS: Palmaz stents are appropriate for insertion into highly resistant obstructions. Strecker stents and Wallstents require good wall contact to achieve adequate strength. Because of their unique deformation characteristics, Wallstents may not function well if implanted into eccentric stenoses of tough consistency. The Gianturco stent showed the lowest resistances.

Malignant ureteral obstruction: preliminary results of treatment with metallic self-expandable stents.

Self-expandable metal stents 7 mm in diameter were percutaneously implanted into 13 ureters in 10 patients with malignant ureteral obstruction not amenable to double-J stent placement. In nine ureters, one stent was placed, and in four ureters, two overlapping stents were placed. Primary reconstitution of ureteral patency was achieved in all ureters. After 1-2 weeks, four ureters showed a urothelial reaction encroaching on the lumen of the ureter, and a double-J stent was placed coaxially. One ureter was occluded by urothelial hyperplasia 4 weeks after stent placement, and a double-J stent was therefore placed. One ureter was occluded 8 months after stent placement by distal tumor overgrowth. The other ureters showed no signs of obstruction during a follow-up of 3-14 (average, 5.8) months. Peristalsis was preserved at both ends of the stent in all ureters. The use of this stent alone or in combination with a double-J stent alleviated upper urinary tract obstruction and avoided external drainage in all patients.

Cervical cancer: serial MR imaging before and after primary radiation therapy--a 2-year follow-up study.

Serial magnetic resonance imaging studies were performed in 28 patients undergoing primary radiation therapy for invasive cervical cancer. T2-weighted spin-echo pulse sequences with long repetition times (2,500 msec) and echo times (30-100 msec) were used at a field strength of 1.5 T. Eighteen tumors responded promptly to radiation therapy with a volume reduction and significant decrease of signal intensity in the early posttreatment phase (1-3 months) and with total tumor regression at 1-6 months (immediate responders). At 6 months seven tumors were visible as residual tumors with declining signal intensity; all seven of these tumors had resolved at 9 months (delayed responders). Thus, a delayed response with residual tumor at 6 months was still compatible with subsequent clinical cure. The tumors showed progression and no marked change in signal intensity (nonresponders). Primary tumors with a volume of more than 50 cm3 were more likely to have no or delayed response. An early (2-3 months) and significant decrease in the signal intensity and volume of a tumor indicates a favorable response. Large primary tumors may show a delayed response.

Percutaneous transluminal angioplasty of crural arteries.

In 91 patients suffering from peripheral arterial occlusive disease (Fontaine stage IIb-IV) 125 percutaneous transluminal angioplasties (PTA) of crural arteries were performed. Eighty-six of the dilatations were done in combination with a recanalization procedure (PTA, laser angioplasty, fibrinolysis) of a femoropopliteal obstruction in order to improve outflow. PTA was performed with 5 F balloon catheters 2.5 to 4 mm in diameter in combination with steerable guide wires. A primary technical success was achieved in 41 of 42 (97.6%) vessels with a single stenosis, in 64 of 68 (94.1%) vessels with 2 or more stenoses, and 9 of 15 (60%) vessels with total occlusions (overall primary success rate 91.2%). Complications included spasm (n = 3), thrombosis (n = 2), peripheral embolization (n = 2), and dissection (n = 1). None of the complications required surgical intervention. After PTA, accumulative patency rate of 71% at 2 years and 64.2% at 3 years was achieved. These results demonstrated that PTA of crural arteries is a safe procedure with an excellent primary success rate and satisfying long-term results. Thus we believe that even arterial occlusive disease in the clinical stage Fontaine IIb should be accepted as an indication for crural PTA. Furthermore, crural PTA should be used to improve reduced peripheral outflow after femoropopliteal PTA.

[Cystic adventitia degeneration of the popliteal artery: sonographic confirmation of the diagnosis]. / Zystische Adventitia-Degeneration der Arteria poplitea: Sonographische Sicherung der Diagnose.

Cystic adventitial disease is a rare condition resulting in arterial occlusive symptoms. The characteristic clinical and angiographic findings suggest the diagnosis cystic adventitial disease. The presented case shows, that sonography can demonstrate the adventitial cyst and the resulting stenosis and confirm the diagnosis.

Nodular focal fatty infiltration of the liver in acquired porphyria cutanea tarda.

A case is reported of acquired porphyria cutanea tarda (PCT) due to administered valproate acid in an epileptic patient. Sonography (US) and computed tomography (CT) showed multiple nodular, well-defined lesions of the liver. Biopsy confirmed the diagnosis of focal fatty infiltration and revealed additionally the signs of hepatic involvement in PCT. Focal fatty infiltration should be considered in patients with multiple liver lesions if there is a predisposing condition. PCT can be a further cause of this type of infiltration.

Diminished response to furosemide in I-123 Hippuran renal studies of renovascular hypertension caused by unilateral renal artery stenosis.

Dynamic I-123 Hippuran renal studies to measure furosemide response (FR) were performed in three groups of patients: 1) 57 patients with renovascular hypertension due to a poststenotic, ischemic kidney; 2) 23 patients with essential hypertension; and 3) 50 nonhypertensive patients with healthy kidneys (control group). FR was observed as renal parenchymal tracer washout within 10 minutes after the injection of 40 mg of furosemide. The retention index (RI) took into consideration the renal parenchymal tracer content before and 10 minutes after furosemide injection. In the control group, the FR was greater than 50% and the RI was less than 20. Patients with essential hypertension revealed no differences in the amounts of FR and RI compared with the control group. In renovascular hypertension, the FR was diminished and the RI was raised significantly. The values of FR and RI showed a good correlation to the degree of the renal artery stenosis before and after percutaneous transluminal angioplasty. It is concluded that the stimulation of diuresis with furosemide and its quantification represent an important additional step in the evaluation of dynamic I-123 Hippuran studies to detect renal ischemia.

Colobronchial and gastrocolic fistulas: rare complication of Crohn's disease.

A rare case of colobronchial and gastrocolic fistulas originating from the splenic flexure in a patient with Crohn's disease is presented. A computed tomographic (CT) examination of the chest first suggested the presence of the colobronchial fistula.

Quantitative static and dynamic renal scintigraphy with diuresis stimulation in renovascular hypertension.

The results of computer-assisted static and dynamic renal scintigraphy in 57 patients with renovascular hypertension (RVH) and 23 patients with essential hypertension (EH) are presented. The following parameters were quantified: renal size (RS), count density (CD), relative unilateral renal clearance (RRC), mean parenchymal transit time (PTT), difference of time-to-peak of activity (tmaxd) to stenosed minus non-stenosed side, effect of frusemide (FE) and renal parenchymal radionuclide retention (RI). Among 57 stenosed renal arteries we detected 54 (true-positive cases) and missed three (false-negative cases); among 23 patients with EH and no significant haemodynamic renal artery stenosis, we found 21 cases correctly negative and two patients falsely positive. These data yielded a sensitivity of 95% and a specificity of 92%. The quantification of renal radionuclide studies in renal artery stenoses minimizes false-positive results and increases their specificity. This study shows that, because of its sensitivity, quantitative renal scintigraphy reliably allows the assessment of the functional haemodynamic effects of a renovascular lesion (significant stenosis) in the diagnostic work-up and during follow-up after surgical reconstruction or percutaneous transluminal angioplasty (PTA). The evaluation of renal function is in general greatly supported by the quantitative parameters, yet particularly after medication with converting enzyme inhibitors and after intervention.

Hypertrophic osteoarthropathy caused by lung metastasis of an osteosarcoma.

A case of hypertrophic osteoarthropathy (HOA) caused by lung metastasis of an osteosarcoma in a 14-year-old boy and the remission of the HOA after intra-arterial chemotherapy is presented. The clinical, radiological and scintigraphic findings are discussed.