Clearance of mucus by simulated cough.

We examined the relationship between mucus rheology, depth of mucus layer, and clearance by simulated cough. A model trachea was constructed of rigid Plexiglas of rectangular cross section (1 X 2 X 35 cm). The bottom of the trachea was lined with mucus simulants, gels prepared from locust bean gum cross-linked with sodium borate. Cough was simulated by opening a solenoid valve connecting the model trachea to a pressurized tank. An upstream flow-constrictive element was used to shape the flow profile of the simulated cough to approximate the pattern seen in a normal adult. Clearance of mucus was quantitated by observing the movement of contrasting marker particles floating in the mucus layer. The median particle displacement per cough maneuver was defined as the clearance index (CI). We found that CI for any initial depth of mucus increased with the driving pressure in the tank. For a given driving pressure, CI increased linearly with increasing mucus depth. For a given driving pressure and depth, CI decreased with increasing mucus cross-link density. For mucus samples with comparable levels of dynamic viscosity, samples with higher elasticity cleared less well. Mucus clearance was associated with transient wave formation in the lining layer.

Percutaneous angiographic embolization for hepatic arterial hemorrhage.

Eight cases of hepatic arterial bleeding are reported. Bleeding in five instances was consequent to trauma and was either persistent postoperative (three cases) or delayed with hemobilia (two cases). Bleeding in the other three cases was from rupture of a subcapsular hematoma of the liver, with spontaneous hepatic rupture of pregnancy (two cases) and metastatic melanoma (one case). Angiography demonstrated pseudoaneurysm in six cases, a hepatic artery to portal venous fistula in one case, and a subcapsular hematoma in the final case. Percutaneous angiographic embolization controlled bleeding in seven cases and was not feasible in one case with tortuosity of the celiac axis. Complications included hepatobiliary necrosis in one patient and subphrenic abscess in two patients. Percutaneous angiographic embolization can selectively occlude a branch of the hepatic artery and is effective in the control of hepatic arterial bleeding from a variety of causes.

Diagnosis and control of posttraumatic pelvic hemorrhage. Transcatheter angiographic embolization techniques.

Fourteen patients with posttraumatic pelvic hemorrhage underwent therapeutic transcatheter embolization of bleeding vessels. Six of them were victims of blunt trauma, six had penetrating trauma, and two had iatrogenic hemorrhage. Eleven patients had a celiotomy prior to angiographic embolization, and large retroperitoneal hematomas were evident in nine patients. Bleeding persisted postoperatively. It was initially controlled by embolization in all patients, but two rebled and were successfully reembolized. Two patients died because of traumatic injuries. There were no complications directly associated with the embolization procedures. Transcatheter embolization is a safe, effective method for controlling pelvic hemorrhage in patients with unstable or multiple pelvic fractures whose conditions fail to respond to more conventional forms of therapy.

The therapist's role in the management of girls with Rett syndrome.

Guidelines for providing therapy intervention for persons with Rett syndrome are presented according to the four stages of the disease. In describing various aspects of Rett syndrome the differences between Rett syndrome, cerebral palsy, and autism are discussed. The role of the therapist in maintaining functional skills is emphasized. The changing nature of the therapist's involvement in relation to the progression of the disease is briefly addressed.

Vomiting in pregnancy resulting in oesophageal perforation in a 15-year-old.

Spontaneous perforation of the oesophagus is extremely rare in children, as is perforation due to vomiting in pregnancy. We report the case of a 15-year-old in whom vomiting in early pregnancy resulted in oesophageal perforation with subcutaneous emphysema causing marked facial swelling in the absence of other signs. The more common clinical presentation of spontaneous oesophageal rupture (Boerhaave's syndrome) is discussed.

MR of intravenous leiomyomatosis of the uterus extending into the inferior vena cava.

We report the first case of the unusual entity intravenous leiomyomatosis of the uterus in which the MR findings are described. Because of this tumor's intravenous extension and growth up the inferior vena cava. MR is ideally suited for its imaging.

Traumatic laceration of the ascending aorta: angiographic assessment.

Radiographic evaluation of ascending aortic injuries is rare because they are almost always immediately fatal. We report three cases of ascending aortic laceration studied by angiography, with a review of the literature and discussion of mechanisms of injury. The type of deceleration trauma resulting in ascending aortic laceration differs from the usual driver deceleration injury in that no attenuation of force on the victim occurs at the time of impact. Traction-torsion forces on the aorta at points of fixation and increased intraluminal aortic pressure are the likely mechanisms of rupture. Adequate angiographic evaluation of these patients requires visualizing the entire aortic arch from aortic valve to diaphragm.

Femoropopliteal percutaneous transluminal angioplasty for limb salvage.

The role of balloon catheter femoropopliteal percutaneous transluminal angioplasty (FP PTA) continues to be controversial 14 years after its initial description. In high-risk patients with limb-threatening ischemia, the role of FP PTA is unknown. We reviewed the cases of 27 patients in whom high operative risk and advanced ischemia resulted in referral for PTA of the femoropopliteal segment. Technical and hemodynamic success rates were 74% and 52%, respectively. Patient follow-up was 3 to 84 months after PTA (mean 24 months). Nine patients (33%) had successful limb salvage for more than 12 months. The cumulative limb salvage rate was 47% at 2 years. Established prognostic criteria did not predict this subset of patients. Hemodynamic improvement after PTA did correlate closely with both early and late successful limb salvage. There were two periprocedural deaths. Morbidity included an acute arterial occlusion necessitating an emergency FP bypass and two minor complications. FP PTA is useful in selected high-risk patients with limb-threatening ischemia. Protocols to facilitate successful long-term limb salvage must include close liaison between the vascular surgeon and interventional radiologist, intensive periprocedural monitoring, and serial noninvasive hemodynamic assessment.

Computed tomography of Sipple syndrome.

The computed tomographic (CT) findings of pheochromocytoma, adrenal medullary hyperplasia, and medullary thyroid carcinoma in a patient with Sipple syndrome are presented. The CT finding of diffuse enlargement of one or both adrenal glands in a patient with clinical and laboratory evidence of pheochromocytoma should raise the suspicion of adrenal medullary hyperplasia and Sipple syndrome.

Transpancreatic catheterization of the right hepatic artery for chemoembolization using a new infusion system.

The right hepatic artery was catheterized for chemoembolization in a patient with liver-dominant metastatic breast carcinoma and occlusion of the celiac artery by tumor compression. This was accomplished by use of a new coaxial infusion catheter-steerable guidewire system passed through the superior mesenteric artery and posterior pancreatic arcade.

Spontaneous hepatic hemorrhage in preeclampsia: treatment with hepatic arterial embolization.

Four patients with spontaneous rupture of the liver due to preeclampsia of pregnancy underwent diagnostic angiography followed by successful transcatheter embolization of the hepatic artery with gelatin particles. All patients stopped bleeding and were discharged in good condition. Transcatheter embolization of the hepatic artery may be an attractive alternative to surgery for control of spontaneous rupture of the liver in preeclampsia.

Reliability of selective pulmonary arteriography in the diagnosis of pulmonary embolism.

To test the reliability of conventional selective pulmonary arteriography in the diagnosis of pulmonary embolism, three angiographers reviewed the arteriograms of a series of 60 patients retrospectively, independently, and without benefit of additional data. Pulmonary arteriograms had been interpreted as positive for pulmonary embolism in 25 of these patients during their hospitalizations. Angiographers A, B, and C judged the arteriograms of 24, 29, and 25 patients, respectively, as positive for pulmonary embolism. Mean interobserver agreement was 86%. Interobserver agreement was not associated significantly with the quality of the arteriogram or with selective injection of a lobar vs a pulmonary artery, but was associated strongly with the magnitude of thromboembolism. All angiographers agreed that the arteriograms were positive in 18 cases of pulmonary embolism graded as massive, lobar, or segmental, but agreed in only two of 15 cases graded as subsegmental. We conclude that conventional selective pulmonary arteriography is reliable in the detection of embolus in segmental or larger pulmonary arteries. Observer disagreement becomes considerable for embolus limited to subsegmental pulmonary arteries, indicating that emboli of this size are at the resolution limit of the technique.