Brian Goodacre

Magnetic resonance imaging of the upper airway. Effects of propofol anesthesia and nasal continuous positive airway pressure in humans.

Background Anesthetic agents inhibit the respiratory activity of upper airway muscles more than the diaphragm, creating a potential for narrowing or complete closure of the pharyngeal airway during anesthesia. Because the underlying mechanisms leading to airway obstruction in sleep apnea and during anesthesia are similar, it was hypothesized that anesthesia-induced pharyngeal narrowing could be counteracted by applying nasal continuous positive airway pressure (CPAP). Methods Anesthesia was induced in ten healthy volunteers (aged 25-34 yr) by intravenous administration of propofol in 50-mg increments every 30-s to a maximum of 300 mg. Magnetic resonance images of the upper airway (slice thickness of 5 mm or less) were obtained in the awake state, during propofol anesthesia, and during administration of propofol plus 10 cm nasal CPAP. Results Minimum anteroposterior diameter of the pharynx at the level of the soft palate decreased from 6.6+/-2.2 mm (SD) in the awake state to 2.7+/-1.5 mm (P < 0.05) during propofol anesthesia and increased to 8.43+/-2.5 mm (P < 0.05) after nasal CPAP application. Anteroposterior diameter of the pharynx at the level of the dorsum of the tongue increased from 7.9+/-3.5 mm during propofol anesthesia to 12.9+/-3.6 mm (P < 0.05) after nasal CPAP. Pharyngeal volume (from the tip of the epiglottis to the tip of the soft palate, assuming this space to be a truncated cone) significantly increased from 2,437+/-1,008 mm3 during propofol anesthesia to 5,847+/-2,827 mm3 (P < 0.05) after nasal CPAP application. Conclusions In contrast to the traditional view that relaxation of the tongue causes airway obstruction, this study suggests that airway closure occurs at the level of the soft palate. Application of nasal CPAP can counteract an anesthesia-induced pharyngeal narrowing by functioning as a pneumatic splint. This is supported by the observed reduction in anteroposterior diameter at the level of the soft palate during propofol anesthesia and the subsequent increase in this measurement during nasal CPAP application.

Guglielmi detachable coil erosion into the common bile duct after embolization of iatrogenic hepatic artery pseudoaneurysm.

Intermittent hemobilia with a hepatic artery pseudoaneurysm can be seen after open or laparoscopic cholecystectomy. Transcatheter treatment of this complication is widely accepted. Although some authors suggest packing the pseudoaneurysm with coils as the treatment of choice, occluding the parent artery is the standard treatment. The authors present an unusual complication of Guglielmi detachable coil erosion into the common bile duct in a patient who presented with pancreatitis 2 years after undergoing packing of the hepatic artery pseudoaneurysm with coils. The probable causes of this rare outcome and alternative treatment options are discussed.

Anchoring a migrating inferior vena cava stent with use of a T-fastener.

An attempt to treat symptomatic stenosis of the inferior vena cava in a patient with metastatic liver disease was complicated by migration of a Wallstent into the right atrium. Effective palliation was achieved by insertion of a second stent, which was anchored by transhepatic insertion of a T-fastener into the intracaval stent. This anchoring maneuver was performed safely under sonographic and fluoroscopic guidance.

Successful Conservative Management of Nephrocolic Fistula

We present a case of an inflammatory nephrocolic fistula treated successfully with conservative management.

Agenesis of the right lobe of the liver.

A 70-year-old man had hepatobiliary scintigraphy, which showed agenesis of the right lobe of the liver and hypertrophy of the left lobe. There was no scintigraphic evidence of emptying of the radiotracer into the small bowel. Agenesis of the right lobe of the liver is an extremely rare congenital an

Interventional Radiology Strategies in the Treatment of Pseudomyxoma Peritonei

PurposeTo describe percutaneous maneuvers to treat the unusual entity symptomatic pseudomyxoma peritonei (PMP).MethodsFour patients with PMP were treated by interventional radiology techniques that included large catheters (20–30 Fr) alone (n = 3), multiple catheters (n = 4), and dextran sulfate as a catalytic agent through smaller catheters (n = 1). The causes of the PMP were tumors in the ovary (2 patients), appendix (1 patient), and colon (1 patient). Each patient previously had undergone at least two operations to remove the PMP, and all patients had symptomatic recurrence. An in vitro analysis of catalytic agents also was performed.ResultsAll four patients improved symptomatically. Follow-up CT scans demonstrated marked reduction of PMP material in all cases. One patient underwent another interventional radiology session 5 months after the first; the other three patients had no recurrence of symptoms. One patient had reversible hypotension 2 hr after the procedure. The amount of material removed varied from 3 to 6 L.ConclusionThese interventional radiology techniques were effective and safe for PMP and suggest options for this difficult medical and surgical problem.

Transosseous Access for Decompression of an Obstructed Pelvic Kidney

Abstract We report a case of an obstructed pelvic kidney which was decompressed using a transosseous access route. The patient presented with obstructive uropathy and fever, necessitating decompression. Initial access was gained to the kidney by traversing the ilium, allowing subsequent retrograde placement of a double-J ureteric catheter.

Removal of a Trapped Endoscopic Catheter from the Gallbladder via Percutaneous Transhepatic Cholecystostomy: Technical Innovation

BackgroundPercutaneous cholecystostomy is used for a variety of clinical problems.MethodsPercutaneous cholecystostomy was utilized in a novel setting to resolve a problematic endoscopic situation.ObservationsPercutaneous cholecystostomy permitted successful removal of a broken and trapped endoscopic biliary catheter, in addition to helping treat cholecystitis.ConclusionAnother valuable use of percutaneous cholecystostomy is demonstrated, as well as emphasizing the importance of the interplay between endoscopists and interventional radiologists.

Large bore transhepatic tract dilatation in pigs: Results and implications for human procedures

SummaryLarge bore transhepatic tracts were created in six anesthetised pigs. A peripheral tract (entering the gall-bladder bed) and a central tract were created in each pig. After balloon dilatation to 30 F and passage of a 30 F inner diameter sheath, bleeding was monitored with the sheath in place and after sheath removal. Blood loss was quantified and tracts were examined microscopically. Peripheral tracts were shorter than central tracts (mean 1.9 versus 3.6 cm). Bleeding occurred more frequently and to a greater degree from central tracts. Injury to small arteries and veins was identified microscopically in two tracts that bled heavily. Although significant bleeding, or lack thereof after dilatation of large transhepatic tracts, was variable, recommendations for large tract dilatation include: selection of a peripheral tract route, use of a working sheath with an outside diameter not exceeding that of the inflated balloon, particular care to avoid loss of access and not removing sheaths prematurely.