Transjugular intrahepatic portosystemic shunt and cardiac arrhythmias.

The approach to the liver for a transjugular intrahepatic porto-systemic shunt (TIPS) is through the venous system. Because catheter and guidewire system traverses the heart, cardiac arrhythmias may be expected during the procedure. We have prospectively investigated the incidence of such dysrhythmias during TIPS implantation. Twelve consecutive patients, 4 women and 8 men aged 26 to 75 years (mean, 58 +/- 13 years), were studied. Before and on the day of TIPS implantation, a 24-hour Holter recording was performed. Transjugular intrahepatic portosystemic shunt implantation was performed under local anesthesia (lidocaine) and sedoanalgesia (midazolam and fentanyl). None of the patients had concomitant cardiac disease or electrolyte disturbances. In all patients except one, TIPS implantation was successful without any technical complications. A mean of 43 +/- 5.3 hours of Holter recording was performed before and after TIPS implantation. All recordings obtained during this control period were considered inconspicuous. The mean heart rate was significantly higher during the implantation procedure of 136 +/- 37 minutes' duration (83 +/- 20 beats per minute vs 70 +/- 19 beats per minute; p < 0.01). Nine of the 12 patients experienced episodes of nonsustained supraventricular tachycardias, and one patient had two sustained supraventricular tachycardias. Frequent episodes of nonsustained ventricular tachycardias developed in 75% of the patients. It seems clear that TIPS implantation is frequently associated with supraventricular and ventricular tachyarrhythmias even in patients with apparently good cardiac condition at the beginning of the procedure. Thus close cardiac monitoring with resuscitation equipment immediately available throughout the procedure is mandatory.

Evaluation of abdominal aortic aneurysm for stent-graft placement: comparison of gadolinium-enhanced MR angiography versus helical CT angiography and digital subtraction angiography.

PURPOSE: To determine whether magnetic resonance (MR) angiography can be used alone to evaluate abdominal aortic aneurysms (AAAs) for endovascular placement of stent grafts. MATERIALS AND METHODS: Sixty-one patients with AAAs underwent gadolinium-enhanced MR angiography of the abdominal aorta and pelvic arteries. Measurements of the size and extent of the AAAs were compared with helical computed tomographic (CT) and digital subtraction angiographic measurements; 95% confidence intervals for the differences in the means were determined. RESULTS: Because of the larger field of view, MR angiography was superior to CT angiography in assessing visceral iliac artery disease. Both modalities were equal in evaluating the proximal extent of the AAA (mean difference, -0.16 mm; 95% CI, -0.31, 0.64) and in measuring all aortic dimensions (e.g., mean difference in the proximal neck diameter, -0.74 mm; 95% CI, -0.98, -0.49). MR angiography was inferior to CT angiography in depicting accessory renal arteries (seven of 12) and in grading renal artery stenoses (sensitivity, 100% [95% CI, 0.90, 1.00]; specificity, 84% [95% CI, 0.74, 0.91]). CONCLUSION: Gadolinium-enhanced MR angiography is a fast, reliable means of providing all the information relevant to the preoperative assessment of endovascular aortic stent-graft placement.

Azygos arch cannulation by central venous catheters: radiographic detection of malposition and subsequent complications.

The aim of this study was to determine the frequency of radiographically evident central venous catheter misplacement in the azygos arch and to analyze whether the frequency of azygos arch cannulation is dependent on the anatomical site of catheter insertion. We reviewed 1,287 postprocedural examinations and 3,441 follow-up examinations. Catheters had been inserted through the left (6%) or right (15%) internal jugular veins and through the left (32%) or right (46%) subclavin veins. Radiographs were analyzed for possible catheter malposition in the azygos arch and for complications related to this malposition. Catheter malposition in the azygos arch was seen on 16/1,287 (1.2%) postprocedural radiographic examinations. Of the 16 malpositioned catheters, 11 (69%) had been inserted in the left subclavian vein, three (19%) in the left jugular vein, two (12%) in the right subclavian vein, and none (0%) in the right jugular vein. There was a statistically significant difference in the frequency of azygos arch cannulation between left- and right-sided catheters (p = 0.001). All complications consisted of venous perforations and were seen in three of 16 cases (19%). Azygos arch cannulation is a rare but hazardous central venous catheter malposition that occurs early after catheter insertion and carries a substantial risk for complication. The risk for azygos arch cannulation is substantially increased if catheters are inserted in left-sided veins. Because of the severity of subsequent complications, radiologists should be vigilant in the detection of this rare malposition.

Common bile duct obstruction due to malignancy: treatment with plastic versus metal stents.

PURPOSE: To compare the clinical efficacy and treatment costs of plastic versus metal biliary stents. MATERIALS AND METHODS: In a randomized trial, 101 patients with malignant common bile duct obstruction underwent transhepatic stent implantation and were followed up until death. Patients were stratified into risk and nonrisk groups. Forty-nine patients received 12-F plastic stents, and 52 received expandable metal stents. Plastic endoprostheses were placed in a two-step procedure; metal stent, in a single procedure. Kaplan-Meier analyses were used to compare patient survival and stent patency rates. RESULTS: The 30-day mortality rate was significantly lower for metal stents (five of 52 [10%]) than plastic stents (12 of 49 [24%]; P = .05). The obstruction rate was 19% (10 of 52; median patency, 272 days) for metal stents and 27% for plastic stents (13 of 49; median patency, 96 days; P < .01). Median time until death or obstruction was longer for metal stents (122 vs 81 days; P < .01). Placement of metal stents was associated with shorter hospital stay (10 vs 21 days; P < .01) and lower cost ($7,542 vs $12,129; P < .01). CONCLUSION: Use of self-expanding metal stents appears to show substantial benefits for patients and to be cost-effective.

[Spiral-CT [corrected] in chronic lung thromboembolism. / Spiral-CT bei chronisch-thrombembolischer Lungenerkrankung.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare result of recurrent pulmonary embolism and is treated by pulmonary thromboendarterectomy. Knowledge of the exact location of the thrombi is necessary in planning this operation. To date, pulmonary, angiography is the diagnostic imaging gold standard. Since the introduction of spiral CT excellent vascular opacification of the pulmonary arteries has become feasible, and thrombi in the pulmonary arteries can be visualized directly. Spiral CT is superior to angiography in demonstrating thrombi in the central pulmonary arteries, whereas angiography proves superior to CT in the evaluation of abnormalities within segmental arteries. The sensitivity of spiral CT in confirming the diagnosis of CTEPH is reported to be more than 90%. According to the literature and based on our own results, the decision concerning operability is possible on the basis of spiral CT images in more than 80% of patients with CTEPH. Spiral CT as a non-invasive tool may be used for CTEPH screening, for postoperative follow-up after pulmonary thrombendarterectomy and, combined with pulmonary angiography, to optimize operation planning.

Bronchial wall thickness: appropriate window settings for thin-section CT and radiologic-anatomic correlation.

PURPOSE: To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation. MATERIALS AND METHODS: Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined. RESULTS: Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001). CONCLUSION: Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.

Palliative treatment of obstructing esophageal cancer with nitinol stents: value, safety, and long-term results.

OBJECTIVE: The purpose of our study was to evaluate the effectiveness of nitinol stents for palliation of dysphagia due obstructing esophageal cancer, safety of stent placement, and long-term results. SUBJECTS AND METHODS: Self-expanding uncoated nitinol stents were inserted either radiologically (14 patients) or endoscopically (12 patients) on an outpatient basis in 26 consecutive patients with dysphagia grade 3 or 4 caused by incurable malignant obstructions in the middle or distal third of the esophagus (n = 22) or at esophagojejunal anastomoses (n = 4). No esophagotracheal fistulas were seen in any patient. In 22 patients prior treatments had failed. Following insertion, the stent lumen was dilated to the maximum diameter. Finally, esophagography or esophagoscopy was done to confirm the position of the stent and patency of the esophageal lumen. Twenty-four hours after the procedure, esophageal function was investigated by a barium swallow. Patients were encouraged to ingest solid food thereafter. Improvement in dysphagia was evaluated 1 week after stent placement and during monthly interviews. Complications were defined as major (aspiration, bleeding, stent misplacement or dislocation, perforation) or minor (reflux esophagitis, chest pain, pharyngeal discomfort). Tumor ingrowth or overgrowth was considered a treatment failure. Twenty-three patients (88%) were followed until death: three patients (12%) were followed for a mean of 14 months. RESULTS: Exact positioning of the stent and dilation to its maximum diameter were technically feasible in all patients. No stents were placed in the stomach. Patency of the esophageal lumen was successfully restored in 25 patients. In one patient a broken strut of the stent after dilation caused a partial obstruction, which was detected endoscopically. Two patients had recurrent dysphagia due to tumor ingrowth or overgrowth, one after 1 month and the other after 3 months. In these patients an additional overlapping stent was successfully placed. No procedure-related mortalities or major complications occurred. The mean dysphagia grade of 3.5 was improved to a mean grade of 0.6 after stent placement. All patients could take liquids within the first 24 hr. Fifteen patients improved to dysphagia grade 0, seven patients to grade 1, and four patients to grade 2 within 1 week after the procedure. Twenty-three patients (88%) died during the follow-up period (mean survival, 5 months) as a result of their disease. Latest evaluation of the mean dysphagia grade was 0.7. Three patients (12%) are still alive (mean survival, 14 months) with a dysphagia grade 1 in one patient and grade 0 in two. CONCLUSION: Implantation of nitinol stents proved to be an effective and safe method of palliating severe dysphagia in patients with obstructing esophageal cancer. The improvement in dysphagia was impressive and long lasting. Placement of the stents was feasible without major procedure-related complications.

Malignant insulinoma: permanent hepatic artery embolization of liver metastases--preliminary results.

PURPOSE: To evaluate permanent hepatic artery embolization of liver metastases of malignant insulinoma as a therapeutic procedure. METHODS: Three female patients had persistent severe hypoglycemia after distal pancreatectomy because of a malignant insulinoma. Computed tomography (CT) and CT-portography (CTAP) were used for tumor assessment and follow-up and demonstrated multiple hypervascular metastases 0.5-3 cm in diameter in both lobes of the liver. Unilobar sequential transcatheter embolization of the hepatic artery was performed with an interval of 1-2 months between the procedures. Permanent occlusion was achieved by using a mixture of n-butyl-2-cyanoacrylate and ethiodized oil as an embolizing agent. RESULTS: In all patients, embolization of the hepatic artery was technically feasible and complete occlusion could be obtained. In two patients, collaterals originating from the right inferior phrenic artery were embolized superselectively 3 months after bilobar embolization. CTAP at that time revealed marked decrease in tumor size of more than 50%. All patients responded to the treatment as confirmed by normalization of measurable hormone levels, glucose levels, and disappearance of symptoms. Two patients are still alive after 24 and 31 months from the time of the first embolization. Current investigations revealed normal laboratory data and no further tumor progression in the liver. The third patient died 15 months after the first embolization; she also had developed ileus due to local recurrence of the primary tumor and lymph node metastases. CONCLUSION: Hepatic arterial embolization appears to be an effective means of palliation for liver metastases of malignant insulinoma. Long-term improvement seems most likely to be the result of extensive ischemia from permanent occlusion.

Hepatic artery embolotherapy of hepatic metastases from carcinoid tumors: value of using a mixture of cyanoacrylate and ethiodized oil.

OBJECTIVE: Transcatheter embolization of the hepatic arterial supply is a well-known palliative treatment of tumor deposits in the liver. We performed a prospective study to evaluate the use of a mixture of N-butyl-2-cyanoacrylate and ethiodized oil with which a permanent vascular occlusion can be obtained, as an embolizing agent for transcatheter hepatic artery embolization for treatment of carcinoid hepatic metastases. SUBJECTS AND METHODS: Six patients had clinical symptoms from hormonal release by carcinoid hepatic metastases as well as elevated levels of 5-hydroxyindole acetic acid (5-HIAA) in the urine. Unilobar sequential transcatheter embolization of both the hepatic artery and the segmental hepatic arteries of both lobes of the liver was performed with a mixture of N-butyl-2-cyanoacrylate and ethiodized oil. CT and CT arterial portography (CTAP) were done to assess hepatic metastases and were used to monitor follow-up. Each patient had three CTAP studies; the third CTAP, performed 3 months after complete arterial devascularization, was compared with the first CTAP to evaluate tumor size. CT studies were performed routinely every 3 months thereafter and were compared with the initial CT scan to evaluate further tumor regression or progression. Tumor decrease and biochemical and symptomatic response rates were defined according to World Health Organization criteria. All complications and side effects of the treatment were documented. RESULTS: All patients showed complete symptomatic relief after embolization. The previously elevated levels of 5-HIAA in the urine returned to normal in three patients and in the other three patients were reduced by a mean of 89% of preembolization values. A decrease in tumor size by more than 50% was demonstrable in one patient; in five patients, hepatic lesions decreased in size by 25-50%. No new sites of metastatic liver disease were demonstrable in any patient during follow-up. No deaths or serious complications were directly attributable to the embolization procedure. All patients are alive after 12, 17, 18, 19, 19, and 19 months (mean, 17.3 months), respectively, with permanent relief of symptoms so far. CONCLUSION: Transcatheter embolization of both the hepatic artery and the segmental hepatic arteries with a mixture of N-butyl-2-cyanoacrylate and ethiodized oil provided excellent palliation in patients with carcinoid hepatic metastases. Complete and long-lasting relief of symptoms, a significant decrease or normalization of levels of 5-HIAA in the urine, and a reduction of metastatic tumor in the liver seem most likely to be the effect of sustained ischemia obtained with this permanent embolizing agent.

Doppler sonography of varicocele: long-term follow-up after venography and transcatheter sclerotherapy.

Sixty-eight patients with unilateral left-sided idiopathic varicocele who had not been treated previously were examined with Doppler sonography before and 1, 3, and 12 months after selective venography with balloon occlusion and transcatheter sclerotherapy of the internal spermatic vein. Varicocele and its persistence or recurrence was diagnosed by reflux only. Reflux was differentiated into stop-type and shunt-type by Doppler sonography. The resolution of varicocele was defined by absence of any reflux. The rate of resolution was greatest 3 months after sclerotherapy (49 patients, 72%). The diagnosis of persisting or recurring varicocele at this time does not seem to be justified, however, as in our study both further improvement and deterioration were observed up to 12 months after treatment. Twenty patients (29%) had a persisting or recurring varicocele 12 months after sclerotherapy. Reflux is the parameter of significance for diagnosing varicocele and its persistence or recurrence after therapy. Improvement of clinical aspects of varicocele (e.g., sperm count, sperm motility, and conception rates) depends on therapy of even subclinical varicoceles. Therefore, diagnosis and retreatment of persistent or recurrent varicoceles seems essential. The high sensitivity of Doppler sonography permits adequate assessment of the therapeutic result and evaluation of real rates of persistent or recurrent varicoceles after venography with balloon occlusion and transcatheter sclerotherapy.