Friedrich W. Winkelbauer

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%) subclavian 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.

Covered self-expanding transhepatic biliary stents: Clinical pilot study

PurposeWe report our preliminary results with a new type of self-expanding covered stent for treatment of malignant biliary obstruction.MethodsWallstents, fully covered with high elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 69 mm, were placed transhepatically under fluoroscopic guidance in five patients. The length of the biliary obstruction varied between 30–50 mm. At 1 and 3 months (82–98 days) clinical assessment, serum bilirubin measurement, and ultrasound examination of the biliary tree were performed.ResultsInitial uncomplicated deployment of the stents and internal drainage was possible in all patients. Distal stent migration resulted in early biliary reobstruction in one patient. At 3-month follow-up, partial reobstruction, most probably due to sludge formation, was found in another patient.ConclusionOur initial results indicate that the covered, self-expanding Wallstent endoprosthesis can be reliably and safely deployed transhepatically for malignant biliary obstruction.

Endovascular AAA treatment: Expensive prestige or economic alternative?

OBJECTIVES To compare the costs of endovascular aneurysm treatment versus open surgery during the perioperative period. METHODS Retrospective analysis of a consecutive series of 44 patients undergoing infrarenal abdominal aneurysm repair from February 1995 to March 1996 at a university teaching hospital. RESULTS No endovascular procedure was converted to open repair. Operative time was shorter for endovascular treatment (207.6 min vs. 229.1 min, n.s.), as well as postoperative intensive care unit stay (ICU, 22.7 h vs. 55.0 h, p = 0.017) and the postoperative recovery period (5.6 days vs. 13.3 days, p < 0.001). Open surgery generated significantly more costs (25,374.07 ECU vs. 22,268.78 ECU, p < 0.001), despite evaluation and a more expensive endovascular procedure (10,699.48 ECU vs. 4032.01 ECU, p < 0.001). During the study, costs for open surgery exceeded the cost for endovascular treatment by 13.95%. CONCLUSIONS Endovascular aneurysm treatment is cost effective and less expensive than open surgery. The main reason for cost saving is faster patient recovery after surgery, associated with a shorter LOS in the patients treated with endovascular procedure.

Radiographic detection of intrabronchial malpositions of nasogastric tubes and subsequent complications in intensive care unit patients.

Objective: The aim of our study was to illustrate the radiographic spectrum of the intrabronchial malposition of nasogastric tubes and subsequent complications, and to discuss the role of radiography in the detection of such malpositions. Design: Retrospective clinical investigation. Setting: Tertiary care university teaching hospital. Patients and methods: We reviewed chest radiographs of 14 intensive care patients with nasogastric tubes malpositioned in the tracheobronchial tree. The site and anatomic location of the malposition were recorded. Complications due to tube malpositioning were monitored on follow-up radiographs and on computed tomographic examinations, which were available in 4 patients. Results: Nine of 14 nasogastric tubes were inserted in the right and 5 in the left tracheobronchial tree. Tube tips were malpositioned in the lower lobe bronchi (50 %), the intermediate bronchus (36 %), and the main bronchi (14 %). There was perforation of the bronchial system with subsequent pneumothorax in 4 patients. In 4 other patients, pneumonia developed at the former site of the malpositioned tube tip. Radiographic detection of nasogastric tube malpositioning was prompt in 9 patients and delayed in 5 patients. Conclusions: Whereas clinical signs of nasogastric tube malpositioning in intensive care patients may be absent or misleading, chest radiography can accurately detect nasogastric tube malpositions in the tracheobronchial tree, may prevent complications, and avoid the use of further costly or invasive diagnostic techniques.

Spiral CT angiography in the assessment of abdominal aortic aneurysms after stent grafting : Value of maximum intensity projections

PURPOSE Our goal was to evaluate the value of maximum intensity projections (MIPs) rendered from spiral CT in the assessment of abdominal aortic aneurysms after stent graft implantation. METHOD Spiral CT of the aorta was performed in 28 patients 1 week after implantation of covered aortic stent grafts. MIPs were evaluated in a blinded fashion. Transaxial scans and intravenous angiographs were considered the reference standard. RESULTS Stent deformity was evident on the MIPs in 5 cases and stent angulation was seen in 24 cases. The excluded aneurysmal sac was visualized in 14 (50%) cases. MIPs depicted the patent inferior mesenteric artery in 20 of 23 cases (87%). Renal artery occlusion (n = 3), leaks (n = 8), and parietal thrombi, (n = 3) were detected on the MIPs in all cases. CONCLUSION MIPs are a valuable tool in the assessment of aortic stent grafts.

Spiral computed tomographic angiography of the renal arteries: A prospective comparison with intravenous and intraarterial digital subtraction angiography

PurposeTo assess the accuracy of computed tomographic angiography (CTA) in the evaluation of the renal arteries in comparison with intravenous (IVDSA) and intraarterial digital subtraction angiography (IADSA).MethodsIn 18 patients, 35 CTAs and DSAs (27 IADSA, 8 IVDSA) of the renal arteries were performed. CTA was done with 2–3 mm collination, 2–4 mm/sec table speed, after intravenous injection of 80 ml of contrast medium at 4 ml/sec with a scanning delay time of 14–21 sec. No previous circulation time curve was performed. CTA data were reconstructed with maximum intensity projection (MIP) and shaded surface display (SSD). The presence of stenosis was assessed on a three-point rating scale (grade 1–3). The quality of the examinations; visualization of the ostium, the main artery, and its branches; vessel sharpness, linearity, and intraluminal contrast filling were evaluated. We compared CTA with DSA.ResultsCTA had 96% sensitivity, 77% specificity, and 89% accuracy in the detection of stenoses >50%. Due to technical errors two stenoses were erroneously diagnosed as positive but there were no false negative diagnoses. The quality of CTA was good in 56% and moderate in 34% of cases. Visualization of the ostium and main artery was graded as 1.74 (out of 2) points and of the renal branches as 1.02 (out of 2) points. The quality of CTA images was worse than that of IADSA in 52%, equal in 41%, and better in 7% of cases. CTA was equal to IVDSA in 25% and better in 75% of the cases.ConclusionCTA is an accurate noninvasive method for the evaluation of renal arteries. Examination quality is essential for the diagnosis. CTA is limited in its ability to visualize the branches of the renal artery and accessory arteries. CTA seems to be superior to IVDSA.

Malignant insulinoma: Permanent hepatic artery embolization of liver metastases—Preliminary results

PurposeTo evaluate permanent hepatic artery embolization of liver metastases of malignant insulinoma as a therapeutic procedure.MethodsThree 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.ResultsIn 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.ConclusionHepatic 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.

Successful Exclusion of a Large Femoropopliteal Aneurysm with a Covered Nitinol Stent

A 70-year-old woman presented with a large femoropopliteal aneurysm. A covered nitinol stent was implanted successfully and complete exclusion of the aneurysm was achieved. At follow-up 5 months later the stent was still patent and the patient was free of symptoms. However, moderate stenosis was seen at the proximal end of the stent.

Perkutane und intraoperative diagnostische Angioskopie

ZusammenfassungDie intravaskuläre Endoskopie ist ein neues Verfahren zur dreidimensionalen Darstellung des Gefäßsystems. Vorgestellt wird die Technik anhand von 25 Untersuchungen bei 19 Patienten sowohl intraoperativ wie auch perkutan. 6 pathologische Befunde konnten intraoperativ an 5 Patienten gefunden werden, wobei sich die Befunde gleichermaßen auf Verlauf des Bypass und die Anastomose verteiten. Ein Sofortverschluß konnte in keinem Fall beobachtet werden. Nach transluminaler perkutaner Intervention wurden Intimaveränderungen beobachtet, welche röntgenologisch nicht zur Darstellung kamen. Die Wertung der Befunde muß zu diesem Zeitpunkt vorsichtig erfolgen, da die Erfahrung mit der Deutung der angioskopischen Bilder noch sehr begrenzt ist. Die bislang erhaltenen Ergebnisse lassen jedoch neue Perspektiven sowohl in der Gefäßchirurgie als auch in den perkutanen Katheterverfahren erwarten.SummaryIntravascular endoscopy is a new possibility for three-dimensional vascular imaging. This new technique is introduced by 25 investigations performed on 19 patients either intraoperatively or percutaneously. 6 pathologic findings were seen intraoperatively in 5 patients at the anastomosis or within the bypass. No immediate bypass occlusions were seen. In percutaneous application intimal lesions (dissection, intimal rupture) were seen, which were not visualized by angiography. Interpretation of angioscopic images is difficult at that time, because there is only little experience with angioscopy available until now. New perspectives in vascular surgery and percutaneous angioplasty will be expected by further angioscopic investigations.

Massive Blutung aus der A. maxillaris 11 Tage nach einer Mittelgesichtsfraktur — ein Fallbericht

ZusammenfassungGrundlagen: Der vorliegende Fallbericht soll auf das Risiko von Spätblutungen nach Mittelgesichtsfrakturen hinweisen, die mitunter lebensbedrohliche Ausmaße aufweisen können.Methodik: 11 Tage nach der operativen Versorgung eines 50jährigen Patienten wegen einer im Rahmen eines Autounfalls erlittenen frontobasalen, nasoethmoidalen und zentralen Mittelgesichtstrümmerfraktur kam es zum spontanen Auftreten einer massiven Blutung in den Nasenrachenraum links. Nach notfallmäßiger Stillung der Blutung durch Tamponade wurde die angiographisch festgestellte Blutungsquelle der A. sphenopalatina durch superselektive Embolisation verschlossen.Ergebnisse: Das blutende Gefäße konnte superselektiv verschlossen werden, die übrigen Äste der A. maxillaris blieben offen. Nach der Embolisation kam es zum sofortigen Sistieren der Blutung.Schlußfolgerungen: Bei Trümmerfrakturen des Gesichtsschädels sollte, insbesondere wenn in der Computertomographie Frakturen oder Fragmente im Verlauf der A. maxillaris interna nachweisbar sind, an mögliche Gefäßverletzungen gedacht werden. Im Falle der Entwicklung eines Pseudoaneurysmas können Gefäßverletzungen zunächst klinisch stumm verlaufen und erst bei Ruptur desselben zu erheblichen Blutungen führen. Diese Blutungen lassen sich durch Tamponade nicht dauerhaft stillen, es ist die Transkatheter-Embolisation des zuführenden Gefäßes die Therapie der Wahl.SummaryBackground: The case report presented points to the risk of delayed, possibly life-threatening bleeding following midfacial fractures.Methods: A male patient, 50 years old, who was injured by a car accident, suffered from frontobasal, nasoethmoidal and central midfacial fractures. 11 days after reduction of these fractures severe bleeding from the left nasal cavity occurred and could be managed only incompletely by nasal packing. Angiography demonstrated bleeding from the left sphenopalatine artery. Therefore this vessel was occluded by superselective transcatheter embolization.Results: Superselective embolization of the sphenopalatine artery spared the remaining maxillary artery branches. After the procedure no more bleeding occurred.Conclusions: In patients suffering from extensive midfacial fractures the internal maxillary artery and its branches are at special risk to injury due to their close anatomical relationship to bony structures. Therefore the region of the pterygopalatine fossa should be carefully evaluated concerning fractures in the CT scans. In case of development of a pseudoaneurysm, these injuries may be silent at first until the pseudoaneurysm ruptures leading to massive, possibly life-threatening bleeding. Nasal packing is essential for initial treatment, afterwards superselective embolisation of the feeding vessel is the treatment of choice.