Refractory portal hypertension complications successfully managed by parallel transjugular intrahepatic portosystemic shunt (TIPS): a case report.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is an established intervention to treat complicated portal hypertension refractory to medical or endoscopic management. TIPS dysfunction results in the recurrence of portal hypertension symptoms. In cases of TIPS dysfunction or persistent portal hypertension despite a patent primary TIPS, the creation of parallel TIPS may be the only intervention to effectively reduce portal pressure. Since the introduction of dedicated TIPS stents (Viatorr®) the incidence of TIPS dysfunction has reduced profoundly. Nevertheless, the creation of a parallel TIPS can still be necessary in the current dedicated TIPS stent era. CASE PRESENTATION: We report one such patient who experienced ongoing portal hypertension induced upper gastro-intestinal haemorrhage despite multiple TIPS revisions and a patent primary TIPS. CONCLUSION: Following creation of a parallel TIPS, the patient remains in clinical remission with no further bleeding.

Evaluation of a radiographer-led peripherally inserted central catheter insertion service.

INTRODUCTION: To evaluate a radiographer-led peripherally inserted central catheter (PICC) insertion service within an interventional radiology suite using ultrasound and fluoroscopic guidance. METHODS: Data from 366 consecutive PICC insertions by five trained angiography-specialized radiographers were prospectively collected over a 12-month period. For each PICC insertion, patient demographics, including past medical history of cystic fibrosis (CF), number of punctures, vein used, final tip position, contrast administration and screening time were recorded. Institutional review board approval was obtained. RESULTS: The overall PICC insertion success rate was 100%. Fifty-five (15%) had a known medical history of CF. Three hundred and thirty-one (90%) PICC insertions required a single puncture and 32 (9%) required two punctures. The remaining three insertions required three punctures. The basilic vein was most commonly used (69%) followed by the brachial vein (29%), and the cephalic vein was used only in 2%. Administration of contrast medium was necessary during 27 (7%) PICC insertions. Mean screening time was 10.7 s. CONCLUSION: Our specifically trained, radiographer-led PICC insertion service proved to be successful. Both straightforward and complex insertions, for example in CF patients could be adequately and efficiently performed.

Percutaneous insertion of peritoneal dialysis catheters using ultrasound and fluoroscopic guidance: A single centre experience and review of literature.

Various methods of peritoneal dialysis (PD) catheter insertion are available. The purpose of this study was to evaluate a percutaneous insertion technique using ultrasound (US) and fluoroscopy performed under conscious sedation and as day case procedure. Data of 87 percutaneous inserted dialysis catheters were prospectively collected, including patients' age, gender, body mass index, history of previous abdominal surgery and cause of end stage renal failure. Length of hospital stay, early complications and time to first use were also recorded. Institutional review board approval was obtained. A 100% technical success rate was observed. Early complications included bleeding (n = 3), catheter dysfunction (n = 6), exit site infection (n = 1) and exit site leakage (n = 1). All cases of catheter dysfunction and one case of bleeding required surgical revision. Median time of follow-up was 18 months (range 3-35), and median time from insertion to first use was days 14 (1-47). Of the 82 patients who started dialysis, 20 (23%) ceased PD at some stage during follow-up. Most frequently encountered reasons include deteriorating patient cognitive or functional status (n = 5), successful transplant kidney (n = 4) and pleuro-peritoneal fistula (n = 4). Sixty-two (71%) PD catheter insertions were performed as day case. The remaining insertions were performed on patients already admitted to the hospital. Percutaneous insertion of dialysis catheter using US and fluoroscopy is not only safe but can be performed as day case procedure in most patients, even with a medical history of abdominal surgery and/or obesity.

Endovascular closure of ascending aortic pseudoaneurysm with a type II Amplatzer vascular plug.

A 71-year-old man initially presented with an asymptomatic, incidentally detected ascending aortic pseudoaneurysm 25 years following aortic root repair with mechanical aortic valve replacement. This pseudoaneurysm was previously treated with coil embolization but due to coil impaction it reopened 8 years later. Endovascular closure of the pseudoaneurysm was achieved with the off-label use of a type II Amplatzer vascular plug.

Semiautomatic sizing software in emergency endovascular aneurysm repair for ruptured abdominal aortic aneurysms.

PURPOSE: In emergency endovascular repair (EVAR) of ruptured aneurysms of the aorta (rAAA), anatomical suitability must be determined. Semiautomatic three-dimensional assessment of the aortoiliac arteries has the potential to standardise measurements. This study assesses the fitness for purpose of such a semiautomatic approach for rAAA and determined interobserver agreement on suitability. MATERIALS AND METHODS: Interobserver study with six trained observers (4 vascular surgeons, 2 radiologists) blindly assessing preoperative computed tomography angiography scans of 50 consecutive patients with rAAA. A central lumen line (CLL) was generated, and perpendicular diameters, length along the CLL, and EVAR suitability were determined using dedicated sizing software (3mensio; 3mensio Vascular; Bilthoven, The Netherlands). Success of generating a CLL, time of assessment, and interobserver agreement was determined. RESULTS: In the majority of the patients (median 76 %, range 64-78 %), a CLL was semiautomatically generated. The median duration of CLL generation and performance measurements was 7.5 min (interquartile range 5.5-10.6). Agreement on suitability was moderate for the entire group (Fleiss' κ = 0.55, confidence interval 0.48-0.62) and ranged from moderate to good (Cohen's κ = 0.40-0.72) between observer pairs. CONCLUSION: Assessing EVAR suitability of rAAA patients using dedicated sizing software is possible in the majority of patients. The measurements can be performed in a reasonable amount of time, and the agreement of suitability for EVAR in patients with rAAA is moderate. Improvements and additional research are necessary to replace the current axial measurement.

Hyperbaric oxygen does not improve cerebral function when started 2 or 4 hours after cerebral arterial gas embolism in swine.

OBJECTIVE: Hyperbaric oxygenation is the accepted treatment for cerebral arterial gas embolism. Although earlier start of hyperbaric oxygenation is associated with better outcome, it is unknown how much delay can be tolerated before start of hyperbaric oxygenation. This study investigates the effect of hyperbaric oxygenation on cerebral function in swine when initiated 2 or 4 hours after cerebral arterial gas embolism. DESIGN: Prospective interventional animal study. SETTING: Surgical laboratory and hyperbaric chamber. SUBJECTS: Twenty-two Landrace pigs. INTERVENTIONS: Under general anesthesia, probes to measure intracranial pressure, brain oxygen tension (PbtO2), and brain microdialysis, and electrodes for electroencephalography were placed. The electroencephalogram (quantified using temporal brain symmetry index) was suppressed during 1 hour by repeated injection of air boluses through a catheter placed in the right ascending pharyngeal artery. Hyperbaric oxygenation was administered using U.S. Navy Treatment Table 6 after 2- or 4-hour delay. Control animals were maintained on an inspiratory oxygen fraction of 0.4. MEASUREMENTS AND MAIN RESULTS: Intracranial pressure increased to a mean maximum of 19 mm Hg (SD, 4.5 mm Hg) due to the embolization procedure. Hyperbaric oxygenation significantly increased PbtO2 in both groups treated with hyperbaric oxygenation (mean maximum PbtO2, 390 torr; SD, 177 torr). There were no significant differences between groups with regard to temporal brain symmetry index (control vs 2-hr delay, p = 0.078; control vs 4-hr delay, p = 0.150), intracranial pressure, and microdialysis values. CONCLUSIONS: We did not observe an effect of hyperbaric oxygenation on cerebral function after a delay of 2 or 4 hours. The injury caused in our model could be too severe for a single session of hyperbaric oxygenation to be effective. Our study should not change current hyperbaric oxygenation strategies for cerebral arterial gas embolism, but further research is necessary to elucidate our results. Whether less severe injury benefits from hyperbaric oxygenation should be investigated in models using smaller amounts of air and clinical outcome measures.

Permanent cortical blindness after bronchial artery embolization.

A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

Observer training for computer-aided detection of pulmonary nodules in chest radiography.

OBJECTIVES: To assess whether short-term feedback helps readers to increase their performance using computer-aided detection (CAD) for nodule detection in chest radiography. METHODS: The 140 CXRs (56 with a solitary CT-proven nodules and 84 negative controls) were divided into four subsets of 35; each were read in a different order by six readers. Lesion presence, location and diagnostic confidence were scored without and with CAD (IQQA-Chest, EDDA Technology) as second reader. Readers received individual feedback after each subset. Sensitivity, specificity and area under the receiver-operating characteristics curve (AUC) were calculated for readings with and without CAD with respect to change over time and impact of CAD. RESULTS: CAD stand-alone sensitivity was 59 % with 1.9 false-positives per image. Mean AUC slightly increased over time with and without CAD (0.78 vs. 0.84 with and 0.76 vs. 0.82 without CAD) but differences did not reach significance. The sensitivity increased (65 % vs. 70 % and 66 % vs. 70 %) and specificity decreased over time (79 % vs. 74 % and 80 % vs. 77 %) but no significant impact of CAD was found. CONCLUSION: Short-term feedback does not increase the ability of readers to differentiate true- from false-positive candidate lesions and to use CAD more effectively. KEY POINTS: • Computer-aided detection (CAD) is increasingly used as an adjunct for many radiological techniques. • Short-term feedback does not improve reader performance with CAD in chest radiography. • Differentiation between true- and false-positive CAD for low conspicious possible lesions proves difficult. • CAD can potentially increase reader performance for nodule detection in chest radiography.

Gray-scale reversal for the detection of pulmonary nodules on a PACS workstation.

OBJECTIVE: The purpose of this article is to evaluate the impact of gray-scale reversal on the detection of small pulmonary nodules in two-view chest radiography. MATERIALS AND METHODS: One hundred twenty-eight patients (mean age, 62 years) who underwent CT and chest radiography within 6 weeks were retrospectively selected for this study. Seventy-three percent of patients showed variable degrees of radiographic findings of a "dirty lung." A total of 129 solid pulmonary nodules were present in 74 patients (nodule diameter range, 5-30 mm; mean diameter, 13 mm). The remaining 54 patients served as negative control subjects. Six readers with varying experience levels evaluated the images without and with the availability of gray-scale reversal in two separate reading sessions. Figure of merit (FOM), sensitivity per lesion, mean number of false-positive marks per image, and accuracy were calculated. RESULTS: Five of the six readers showed a slight increase in sensitivity with the use of gray-scale reversal, but on average, the difference was not significant (48% vs 50%; p > 0.05). The mean number of false-positive marks per image also nonsignificantly increased from 0.20 to 0.23. The increases in both sensitivity and the mean number of false-positive marks per image translated into nonsignificant decreases in average FOM (0.79 vs 0.77) and accuracy (72% vs 71%). Data analysis of subgroups of nodules or different reader groups, depending on level of experience, did not reveal significant differences. CONCLUSION: Using PACS display of digital chest radiographs, gray-scale reversal does not help the radiologists in detecting pulmonary nodules.

Computer-aided detection of small pulmonary nodules in chest radiographs: an observer study.

RATIONALE AND OBJECTIVES: To evaluate the impact of computer-aided detection (CAD, IQQA-Chest; EDDA Technology, Princeton Junction, NJ) used as second reader on the detection of small pulmonary nodules in chest radiography (CXR). MATERIALS AND METHODS: A total of 113 patients (mean age 62 years) with CT and CXR within 6 weeks were selected. Fifty-nine patients showed 101 pulmonary nodules (diameter 5-15mm); the remaining 54 patients served as negative controls. Six readers of varying experience individually evaluated the CXR without and with CAD as second reader in two separate reading sessions. The sensitivity per lesion, figure of merit (FOM), and mean false positive per image (mFP) were calculated. Institutional review board approval was waived. RESULTS: With CAD, the sensitivity increased for inexperienced readers (39% vs. 45%, P < .05) and remained unchanged for experienced readers (50% vs. 51%). The mFP nonsignificantly increased for both inexperienced and experienced readers (0.27 vs. 0.34 and 0.16 vs. 0.21). The mean FOM did not significantly differ for readings without and with CAD irrespective of reader experience (0.71 vs. 0.71 and 0.84 vs. 0.87). All readers together dismissed 33% of true-positive CAD candidates. False-positive candidates by CAD provoked 40% of all false-positive marks made by the readers. CONCLUSION: CAD improves the sensitivity of inexperienced readers for the detection of small nodules at the expense of loss of specificity. Overall performance by means of FOM was therefore not affected. To use CAD more beneficial, readers need to improve their ability to differentiate true from false-positive CAD candidates.