Venous ligation of dural arteriovenous fistulae.

This study evaluated the clinical outcomes following venous ligation for the treatment of dural arteriovenous fistulas (DAVF) with leptomeningeal or cortical venous drainage. The authors conducted a single-centre, retrospective study of 15 patients with DAVF treated consecutively between 1990 and 2000. There were eight female patients of mean age 60 years (range 36-71). Eight patients presented with haemorrhage, two with mass affect, two with headaches, one with seizures and two patients were asymptomatic. Four fistulas were located in the petrosal region, three at the torcula, three in the transverse sigmoid region, three in the parasagittal region and two at the foramen magnum. Leptomeningeal or cortical veins drained all DAVF. Eight patients underwent preoperative embolization of the arterial feeders. Venous ligation resulted in obliteration of all fistula confirmed by direct visualization of the thrombosed veins and/or radiographic follow up. Mean follow up period was 37 months with a range of 1-112 months. All symptomatic patients improved and there was no surgical morbidity. These results indicated that venous ligation to obliterate DAVF with leptomeningeal or cortical drainage is safe and effective. With appropriate neuroradiological diagnosis and preoperative neuroendovascular intervention, this technique resulted in obliteration of DAVF in 15 patients without significant morbidity.

Percutaneous transthoracic needle biopsy of the lung: review of 612 lesions.

PURPOSE: The results and complications of 651 pulmonary fine-needle aspiration biopsies (FNABs) were reviewed. The number of needle passes and needle size were correlated to pneumothorax and chest tube placement rates. MATERIALS AND METHODS: FNAB of the lung was performed on 651 occasions in 612 patients with 18- to 22-gauge Franseen needles. Diagnostic rates were calculated. The number of needle passes performed and needle size used were evaluated for their association with pneumothorax and subsequent chest tube placement. RESULTS: Diagnostic accuracy was 94% with sensitivity for malignancy of 95%. Positive and negative predictive values were 99.5% and 90%, respectively. Pneumothorax occurred in 26.9% of patients with 9.2% requiring chest tube placement. Increasing numbers of needle passes and larger needle sizes did not increase the rates of pneumothorax or chest tube placement. CONCLUSIONS: FNAB of the lung has excellent diagnostic rates and remains the procedure of choice for diagnosing pulmonary lesions. This large study contradicts perceptions that pneumothorax and chest tube placement rates decrease with thinner needles and fewer passes.

Comparative rumen morphology of sympatric sika deer (Cervus nippon) and red deer (C. elaphus scoticus) in the Ahimanawa and Kaweka Ranges, central North Island, New Zealand.

Eighteen sika deer (Cervus nippon) and 14 red deer (C. elaphus scoticus) were sampled from two areas where these closely related species are sympatric. Total body weight, carcass weight, age class, sex, and internal parameters (e.g. liver weight, kidney weight, rumen volume) were recorded. Samples of rumen wall mucosa taken from the dorsal rumen wall, atrium ruminis, caudoventral blindsac, and ventral rumen wall were used to compare rumen morphology between the two species (and also any area, sex, and age effects). Sika deer had significantly lower papilla densities in three of the four rumen wall sites and significantly smaller papillae than red deer in two of the four sites. Surface enlargement factors (SEFs) were calculated to provide comparisons of the effective absorptive surface within the rumens of the two species. The mean SEF for sika deer (4.76) was significantly less that for red deer (6.77), which suggests a greater degree of adaptation to digesting fibrous forage. In the central North Island, New Zealand, where the habitat has been considerably modified by introduced herbivores over the last century and food resources are depleted, such an adaptation would confer a competitive advantage on sika deer over red deer. It is postulated that this diet-related difference largely accounts for the ongoing replacement of red deer by sika deer where these two species are sympatric.

Treatment of dural sinus thrombosis by urokinase infusion.

PURPOSE: To gain a preliminary understanding of the role of thrombolytic therapy for the thrombosed dural sinus, we retrospectively reviewed our initial experience. METHODS: Seven patients, ages 25 to 71, who presented with symptomatic dural sinus thrombosis and who failed a trial of medical therapy were treated with direct infusion of urokinase into the thrombosed sinus. Patients received urokinase doses ranging from 20,000 to 150,000 U/h with a mean infusion time of 163 hours (range 88 to 244 hours). RESULTS: Patency of the affected dural sinus was achieved with antegrade flow in all patients. Six patients either improved neurologically over their prethrombolysis state or were healthy after thrombolysis; one of them required angioplasty. The other patient improved after surgical repair of a residual dural arteriovenous fistula. The only complications were an infected femoral access site which resolved after treatment with antibiotics and hematuria which cleared after discontinuation of anticoagulation. CONCLUSIONS: Thrombolysis of the thrombosed dural sinus shows promise as a safe and efficacious treatment. The results of this study should provide the impetus for further research.

The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect.

Endovascular obliteration of intracranial aneurysms with preservation of the parent artery (endosaccular occlusion) has been advocated for patients who fail or are excluded from surgical clipping and cannot undergo Hunterian ligation therapy. To clarify the effect that endosaccular occlusion has on the presenting neurological signs, 26 patients with aneurysms and symptoms related to mass effect who underwent this therapy were followed for a mean of 60 months. Only patients with objective neurological deficits who had not suffered a hemorrhage were included in this series. Response to therapy was classified into one of three groups: "resolved," if the patient had complete resolution of presenting signs; "improved," if significant and sustained improvement was recorded in the neurological examinations, and "unchanged," if no change was observed. Thirteen patients (50%) were classified as resolved, 11 (42.3%) as improved, and two (7.7%) as unchanged. A comparison of patients classified as resolved with those who were improved revealed that the former group had less wall calcification (30% vs. 60%) and a shorter duration of symptoms. Patients with neurological sign resolution (62%) were more likely to have totally occluded aneurysms on late follow-up arteriograms than those who had improvement (28%) or were unchanged (0%). This study suggests that endosaccular embolization therapy can improve or alleviate presenting neurological signs unrelated to hemorrhage or distal embolization in the majority of cases.

Endovascular platinum coil embolization of incompletely surgically clipped cerebral aneurysms.

The natural history of incompletely clipped intracranial aneurysms is largely unknown. The authors present two cases of residual aneurysm filling after surgical clipping which were successfully managed by intravascular placement of platinum coils. Management of residual aneurysms and possible future role of transcatheter therapy are discussed.

Treatment of giant intradural (perimedullary) arteriovenous fistulas.

Ten patients with giant intradural spinal arteriovenous fistulas (perimedullary Types II and III) were treated with embolization alone (three patients) or in combination with surgery (seven patients). Their ages at the time of treatment ranged from 2 to 40 years, with a mean of 19.5 years. The indications for treatment included progressive myelopathy in five patients, spinal subarachnoid hemorrhage in four, and acute paraplegia in one. Associated conditions included Rendu-Osler-Weber syndrome in two patients, and Cobb's syndrome in two patients. In one patient, the cause of the fistula may have been related to epidural anesthesia traumatizing a low tethered cord. Angiographically, the fistulas were subclassified in three groups: a single-hole fistula supplied by a single feeding medullary artery (three patients); a single-hole fistula supplied by multiple medullary arteries (three patients); and multiple separate fistulas supplied by multiple medullary arteries (four patients). Eight patients were classified as perimedullary Type III and two as perimedullary Type II. Embolic agents were delivered from transarterial routes in 14 procedures and transvenous routes in 2 procedures. A total of 16 embolizations and 8 operations were performed in 10 patients. Seven patients were cured of their fistula (as demonstrated by angiography), two patients had 5% residual filling and are scheduled for future therapy. One refused a follow-up angiographic examination. Complications related to embolization included rupture of the anterior spinal artery by a detachable balloon, resulting in transient worsening of paraplegia with recovery to baseline. Transient worsening of symptoms after surgery was common, but all patients returned to baseline or better. Dramatic improvement was observed in four patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Transarterial embolization of vertebral hemangioma.

PURPOSE: The authors retrospectively reviewed their 4-year clinical experience to determine the role of transarterial embolization in the treatment of symptomatic vertebral hemangioma. PATIENTS AND METHODS: Eight patients (age range, 12-56 years) underwent a total of 10 embolization procedures; one patient underwent three procedures. The lesions were located between T-5 and L-5, and all patients presented with pain and symptoms referable to the lower extremities. RESULTS: Embolization was technically successful in all patients, and no complications were encountered. Six of eight patients underwent surgery within 48 hours of embolization; four of the six showed significant clinical improvement immediately after surgery and on follow-up (average, 34 months). Two patients did not improve postoperatively. Two patients initially underwent embolization as the sole therapy. The first refused surgery and did not improve clinically; the second underwent two embolization procedures without clinical improvement and eventually underwent a third followed by surgery, which resulted in clinical improvement. All patients were hemodynamically stable during surgery, and blood loss was not problematic in any patient. CONCLUSIONS: Overall, surgery was an effective treatment for symptomatic vertebral hemangioma and the authors conclude that transarterial embolization of vertebral hemangioma is a safe and efficacious adjunctive procedure to such surgery. However, embolization was not as promising as a sole therapeutic modality in this small group of patients.

Endovascular treatment of vertebral artery dissections and pseudoaneurysms.

Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography. In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second). Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.

Microcatheter retrieval device for intravascular foreign body removal.

A microcatheter foreign body retrieval device is described and its first two clinical applications are presented. The device functions identically to larger loop snare retrievers. It permits access to small vessels and was successful in its first clinical applications.

Determination of mimosine and 3-hydroxy-4(1h)-pyridone in Leucaena, avian excreta and serum using reversed-phase ion-pair high-performance liquid chromatography.

The estimation of mimosine and 3-hydroxy-4(1H)-pyridone in Leucaena leucocephala, Leucaena seeds, chick excreta and chick serum using reversed-phase ion-pair high-performance liquid chromatography was investigated. Isocratic elution of both compounds was achieved in 11 min using sodium octyl sulphate as the pairing agent in a pH 2.25 buffer. Good recoveries of both mimosine and 3-hydroxy-4(1H)-pyridone in all but serum samples were obtained.