Quantitative analysis of three-dimensional fibrillar collagen microstructure within the normal, aged and glaucomatous human optic nerve head.

The aim of this study was to quantify connective tissue fibre orientation and alignment in young, old and glaucomatous human optic nerve heads (ONH) to understand ONH microstructure and predisposition to glaucomatous optic neuropathy. Transverse (seven healthy, three glaucomatous) and longitudinal (14 healthy) human ONH cryosections were imaged by both second harmonic generation microscopy and small angle light scattering (SALS) in order to quantify preferred fibre orientation (PFO) and degree of fibre alignment (DOFA). DOFA was highest within the peripapillary sclera (ppsclera), with relatively low values in the lamina cribrosa (LC). Elderly ppsclera DOFA was higher than that in young ppsclera (p < 0.00007), and generally higher than in glaucoma ppsclera. In all LCs, a majority of fibres had preferential orientation horizontally across the nasal-temporal axis. In all glaucomatous LCs, PFO was significantly different from controls in a minimum of seven out of 12 LC regions (p < 0.05). Additionally, higher fibre alignment was observed in the glaucomatous inferior-temporal LC (p < 0.017). The differences between young and elderly ONH fibre alignment within regions suggest that age-related microstructural changes occur within the structure. The additional differences in fibre alignment observed within the glaucomatous LC may reflect an inherent susceptibility to glaucomatous optic neuropathy, or may be a consequence of ONH remodelling and/or collapse.

Asymptomatic hydropneumothorax after therapeutic thoracentesis for malignant pleural effusions.

OBJECTIVE: The purpose of this study was to document in a historical cohort the incidence and clinical observations of pneumothorax ex vacuo after therapeutic thoracentesis for malignant pleural effusions in patients with underlying parenchymal lung disease. MATERIALS AND METHODS: Forty pneumothoraces resulted from 512 therapeutic thoracentesis performed for malignant pleural effusions over a 3-year period. Twenty-nine patients with pneumothoraces underwent catheter placement in the pleural space for treatment. Of these, 12 pneumothoraces resolved and 17 remained unchanged. We reviewed the charts of these 17 patients to document the cause of malignant pleural effusion, presence of underlying malignant parenchymal disease, volume of fluid aspirated, and improvement in symptoms. Clinical outcome was then evaluated, including size of residual pneumothorax, duration of catheter drainage, and reaccumulation of effusion. RESULTS: No patients' lungs reexpanded despite insertion of large-bore (16- to 35-French) chest tubes. All had pneumothoraces that occupied at least 30% of the hemithorax; all were asymptomatic; all had underlying parenchymal disease and noncompliant lungs. Pleural effusion reaccumulated in all 17 after removal of the chest tube. CONCLUSION: A subgroup of patients with malignant lung parenchymal disease who undergo therapeutic thoracentesis will develop asymptomatic hydropneumothoraces due to poor lung compliance. These patients do not require further catheter drainage. Pleural effusion will reaccumulate in the residual space over a variable period of time.

Percutaneous obliteration of the cystic duct with a holmium:yttrium-aluminum-garnet laser: results of in vitro and animal experiments.

OBJECTIVE: The purpose of this study was to investigate the feasibility of using a holmium:yttrium-aluminum-garnet laser to permanently occlude the cystic duct in order to isolate the gallbladder from the biliary-enteric circulation and prevent gallstone formation. MATERIALS AND METHODS: To determine the optimal laser parameters (power and pulsing rate) for cystic duct thermocoagulation, 20 freshly excised porcine gallbladders with intact cystic ducts underwent low-energy (0.075-0.085 J/pulse) or high-energy (0.20-0.25 J/pulse) thermocoagulation. Histopathologic examination was done to determine the extent of cystic duct injury. After in vitro experiments, percutaneous transcholecystic laser thermocoagulation of the cystic duct was performed on 23 anesthetized domestic pigs (four controls). Cholangiograms immediately after laser thermocoagulation were obtained to assess cystic duct occlusion. Animals were sacrificed for histopathologic correlation immediately after laser thermocoagulation (n = 4), 72 hr later (n = 4), and 6 weeks later (n = 15). RESULTS: In the in vitro studies, all 10 cystic ducts in the high-energy group were occluded, while only four in the low-energy group were occluded. At histology, all cases in both groups showed circumferential injury to the cystic duct wall without injury to the cystic artery or vein. In the in vitro experiments, the cystic duct was successfully cannulated in 21 (91%) of 23 animals. Cholangiography after thermocoagulation showed occlusion of the cystic duct in 16 (84%) of 19 cases. Immediately after laser thermocoagulation, the cystic duct mucosa was circumferentially destroyed, whereas after 72 hr necrosis of the cystic duct wall and periductal tissues had occurred. By 6 weeks, all pigs had complete cystic duct fibrosis without injury to the common bile duct. CONCLUSION: Holmium:yttrium-aluminum-garnet laser thermocoagulation of the cystic duct can be performed easily, results in immediate cystic duct occlusion, and leads to permanent fibrous ductal obliteration by 6 weeks.

Percutaneous chemical gallbladder sclerosis after laser-induced cystic duct obliteration: results in an experimental model.

OBJECTIVE: Chemical gallbladder sclerosis has been attempted as a way to defunctionalize the gallbladder in patients who have undergone nonsurgical removal of gallstones and who are unable to undergo surgical/laparoscopic cholecystectomy. The purpose of this investigation was threefold: to study an animal model for chemical sclerosis of the gallbladder with 95% ethanol and 3% sodium tetradecyl sulfate, to attempt chemical sclerosis immediately after percutaneous cystic duct obliteration by laser thermocoagulation, and to assess histopathologic changes in the gallbladder after sclerosis. MATERIALS AND METHODS: Percutaneous cholecystostomy and laser thermocoagulation of the cystic duct was performed in 13 pigs. Eight pigs underwent immediate gallbladder sclerosis with 95% ethanol and 3% sodium tetradecyl sulfate while two pigs received 95% ethanol only. The remaining three pigs served as controls. The cholecystostomy catheter was removed immediately after the procedure. All animals were sacrificed 6 weeks after laser thermocoagulation. Multiple sections through the gallbladder, which included the adjacent liver, the cystic duct, and the common bile duct, were obtained for histologic examination. RESULTS: At autopsy, the gallbladder in all 10 animals who underwent gallbladder sclerosis was reduced in size compared with controls. In all treated animals, the gallbladder mucosa was denuded; however, in nine of 10 cases reepithelialization had occurred. Complete sclerosis without reepithelialization was achieved in one pig who received both ethanol and sodium tetradecyl sulfate. In the two animals who received ethanol only, the depth of wall necrosis around the gallbladder lumen was less than in those pigs who received both ethanol and sodium tetradecyl sulfate. No pigs showed signs of hepatic necrosis or injury to the common bile duct. CONCLUSION: Cystic duct laser thermocoagulation allows immediate gallbladder sclerotherapy without injury to the common bile duct. Sclerosis with ethanol and sodium tetradecyl sulfate results in denudation of the gallbladder mucosa. However, a single therapeutic session with immediate removal of the cholecystostomy catheter was inadequate for gallbladder ablation in this model because of reepithelialization.

Wallstent metallic biliary endoprosthesis: MR imaging characteristics.

Image quality and safety of magnetic resonance (MR) imaging were evaluated in vitro and in eight patients with the most commonly employed metallic biliary endoprosthesis. In vitro, the stent produced no tip deflection at 0.6 or 1.5 T. Trace magnetic susceptibility artifact, similar to artifact from a column of air, paralleled the stent. In patients, image degradation was minimal with conventional pulse sequences. Middle-field-strength spin-echo images revealed minimal artifacts indistinguishable from those produced by pneumobilia.

Importance of daily rounds by the radiologist after interventional procedures of the abdomen and chest.

A prospective study was performed to evaluate the clinical utility of daily rounds by the radiologist for patients with indwelling catheters in the chest and abdomen, placed during interventional radiologic procedures. The 7-week evaluation included documentation of the number of patients seen, time spent with each per day, number of problems identified, management of these problems, and consultations for new cases generated by interaction with other staff. During the 268 visits to 37 patients, 59 catheter-related problems were identified; 17 (29%) required further intervention in the radiology department, and 42 (71%) were managed at the patient's bedside. Of the patients who were followed up, 22 (59%) had some catheter-related problem identified during their hospital stay. Daily rounds by the radiologist are an essential component of patient care after catheter-related interventional procedures and should be made by those who perform and understand the procedures.

Drainage of a malignant common hepatic duct obstruction by a biliary endoprosthesis placed through a T-tube tract: technical note.

For patients with high biliary obstruction drained by a T-tube, achieving internal drainage requires special techniques. Modification of a method described by Sammon for common bile duct obstruction permits placement of a biliary endoprosthesis astride the T-tube tract. The key step is traction exerted downward on the endoprosthesis by a suture passing through a second catheter temporarily inserted into the common bile duct. A case is described in which the technique has been applied successfully.