Oxygen supply by photosynthesis to an implantable islet cell device.

Transplantation of islet cells is an effective treatment for type 1 diabetes with critically labile metabolic control. However, during islet isolation, blood supply is disrupted, and the transport of nutrients/metabolites to and from the islet cells occurs entirely by diffusion. Adequate oxygen supply is essential for function/survival of islet cells and is the limiting factor for graft integrity. Recently, we developed an immunoisolated chamber system for transplantation of human islets without immunosuppression. This system depended on daily oxygen supply. To provide independence from this external source, we incorporated a novel approach based on photosynthetically-generated oxygen. The chamber system was packed sandwich-like with a slab of immobilized photosynthetically active microorganisms (Synechococcus lividus) on top of a flat light source (LEDs, red light at 660 nm, intensity of 8 µE/m(2)/s). Islet cells immobilized in an alginate slab (500-1,000 islet equivalents/cm(2)) were mounted on the photosynthetic slab separated by a gas permeable silicone rubber-Teflon membrane, and the complete module was sealed with a microporous polytetrafluorethylene (Teflon) membrane (pore size: 0.4 µm) to protect the contents from the host immune cells. Upon illumination, oxygen produced by photosynthesis diffused via the silicone Teflon membrane into the islet compartment. Oxygen production from implanted encapsulated microorganisms was stable for 1 month. After implantation of the device into diabetic rats, normoglycemia was achieved for 1 week. Upon retrieval of the device, blood glucose levels returned to the diabetic state. Our results demonstrate that an implanted photosynthetic bioreactor can supply oxygen to transplanted islets and thus maintain islet viability/functionality.

A revised intracarotid etomidate memory (Wada) procedure.

OBJECTIVES: To evaluate unilateral memory function by the means of a modified Montreal etomidate speech and memory procedure (e-SAM) in epilepsy patients who were candidates for standard anterior temporal lobectomy involving resection of mesial temporal lobe structures. MATERIALS AND METHODS: After the first three patients experienced significant side effects with the e-SAM procedure, we modified the procedure to a single bolus injection. The neuropsychological data of all 21 patients who underwent unilateral memory testing by means of intracarotid injection of etomidate were analyzed. RESULTS: There was a significant difference in memory scores when injections were on the side ipsilateral to the epileptogenic focus compared with when the injections were on the contralateral side (P < 0.01), supposedly reflecting unilateral hippocampal memory function and dysfunction. In addition, the procedural modification resulted in eradication of all major side effects in the ensuing 18 patients. CONCLUSIONS: The technical modification of the Montreal procedure from continuous to bolus injection effectively enabled the demonstration of the relative weakness of the memory function of the epileptogenic hemisphere. The revised etomidate procedure provided the clinical information on unilateral hippocampal memory function necessary for surgical decision.

Endovascular treatment of isolated dissecting aneurysm of the posterior inferior cerebellar artery.

BACKGROUND AND PURPOSE: Isolated dissecting aneurysms of the posterior inferior cerebellar artery (PICA) carry a high risk of rebleeding with an associated increased mortality rate. Although rare, they present a therapeutic challenge. Surgical treatment carries a significant risk of neurologic complications, predominantly lower cranial nerve deficits because of the close relationship of the aneurysm with the brain stem and cranial nerves. The purpose of this article is to show that endovascular treatment of dissecting aneurysms of the PICA can be effective and can allow the patient to avoid the complications associated with surgery. METHODS: Six patients (age range, 28-70 years) with dissecting aneurysms of the PICA were treated at our center by endovascular occlusion with Guglielmi detachable coils or glue and followed for up to 30 months. Inclusion of patients in the study was based on careful angiographic assessment of the vascular anatomy and collateral supply of the posterior fossa. When on the basis of the anatomy, potential lack of sufficient collaterals was suggested, a test occlusion was performed to determine the feasibility of an endovascular approach. Four additional cases, which have been described in the literature, were included in the analysis of results. RESULTS: In all patients, the aneurysm was successfully occluded with no apparent procedure-related complications. Follow-up studies showed stable and complete occlusion of the aneurysm in all patients with no long-term neurologic deficits. CONCLUSIONS: Endovascular treatment by aneurysm and parent artery occlusion is a relatively safe and reliable alternative to surgery for isolated dissecting aneurysms of the PICA.

Acute stroke after coronary angiography associated with protruding mobile thoracic aortic atheromas.

We describe two patients who developed acute embolic stroke immediately after coronary catheterization for unstable angina. Transesophageal echocardiography (TEE) and spiral CT of the chest revealed protruding floating atheromas within the aortic arch. These cases of stroke immediately after coronary catheterization suggest that protruding floating atheromas of the thoracic aorta place patients at risk for stroke. TEE or CT might predict a risk of stroke in such patients.

Treatment of spontaneous carotid-cavernous fistula in Ehlers-Danlos syndrome by transvenous occlusion with Guglielmi detachable coils. Case report and review of the literature.

The authors report on a young woman with Ehlers-Danlos syndrome (EDS) Type IV in whom a spontaneous direct carotid-cavernous fistula (CCF) was treated by transvenous occlusion with regular and fiber-coated Guglielmi detachable coils. To the authors' knowledge, this is the first time this approach has been used in a patient with EDS. The different treatment options are discussed, and the literature on endovascular treatment of direct CCFs in EDS is reviewed.

Spinal dural arteriovenous fistulae--a diagnostic challenge.

BACKGROUND: Spinal dural arteriovenous fistulae comprise the majority of spinal vascular malformations. The most common clinical presentation is that of progressive myeloradiculopathy, probably related to venous hypertension, which may lead to permanent disability and even death. OBJECTIVE: To report our clinical experience with spinal dural arteriovenous fistulae. METHODS: Nine patients with spinal dural AVF were managed at our center during a one year period (1998-1999). The patients, eight men and one woman ranging in age from 46 to 75 years, presented with initially fluctuating and eventually permanent and progressive paraparesis, sensory disturbances and sphincter dysfunction. The neurological signs generally began symmetrically and progressed from the distal to proximal limb regions. The duration of symptoms before diagnosis ranged from 6 to 36 months during which the patients underwent an extensive but fruitless work-up and even unnecessary operations due to misdiagnosis. All patients finally underwent magnetic resonance imaging and spinal angiography, which demonstrated the pathological vascular fistula. Interruption of the AVF was achieved by embolization or by surgical resection. RESULTS: Following treatment, six patients experienced improvement of gait and sphincter control, and the severe neurological deficits stabilized in the other three patients with long duration of illness. There was no further deterioration in any of the treated patients. CONCLUSIONS: The history, neurological findings and radiological changes on MRI scan should alert clinicians to the possibility of spinal dural AVF, leading to diagnostic spinal angiography. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality.

[Endoscopic drainage of pancreatic pseudocyst: endoscopic cysto-enterostomy].

Pancreatic pseudocysts occur in 20% of cases of chronic pancreatitis. Spontaneous resolution is seen in about 9% of the cases, but most cysts persist and frequently cause complications, such as compression of adjacent organs or infection. Endoscopic cysto-enterostomy has recently been reported as a new nonsurgical invasive approach. We present a 40-year-old alcoholic man with a large pancreatic pseudocyst compressing the distal choledochus and pancreatic duct, who was treated successfully by endoscopic cysto-duodenostomy.

[Extensive postpartum, bilateral ovarian vein thrombosis].

A 29-year-old woman with extensive pelvic thrombophelebitis complicating postpartum, ovarian vein thrombosis is described. The phlebitic process involved both ovaries, extending upwards to the inferior vena cava above the level of the renal veins and downwards to the ileo-femoral system, obstructing the venous drainage of the lower limbs. Extensive postpartum thrombophlebitis is now rarely encountered, since its early clinical diagnosis using CT and US techniques allows early treatment, obviates this complication. Postpartum bedside alertness, aided by modern imaging techniques, may prevent serious, life-threatening complications.

[Pulmonary sequestration detected by ultrasound].

Pulmonary sequestration is part of the spectrum of bronchopulmonary foregut anomaly. It is a rare type of congenital malformation in which a mass of pulmonary tissue is separate from the normal lung and receives its arterial supply directly from the systemic circulation. Angiographic demonstration of a systemic artery leading to the sequestrated lung has usually been used to diagnose this condition. In the past 10 years cases of this rare anomaly have been detected and diagnosed by ultrasonography in the pre- and postnatal period. We describe a very rare case of intraabdominal, extralobar pulmonary sequestration detected in the antenatal period. Ultrasonography showed a hyperechoic subdiaphragmatic mass above the left kidney, near the aorta. In the mass were 2 echo-free vascular structures. 2 arterial branches originating from the abdominal aorta which traversed the subdiaphragmatic mass. The near-diaphragmatic location of many pulmonary sequestrations provides an excellent acoustic window for sonographic detection. MRI can help in the diagnosis when ultrasonographic findings are equivocal. Ultrasound and MRI will soon replace aortic angiography in the diagnosis of this condition in the pre- and postnatal period, pulmonary sequestration should be included in the differential diagnosis of upper abdominal masses identified by ultrasonography.

Transarterial treatment with Onyx of intracranial dural arteriovenous fistula with cortical drainage in 17 patients.

BACKGROUND AND PURPOSE: Intracranial DAVFs with cortical venous drainage have a high tendency to bleed. Complete closure of these lesions is essential to prevent clinically deleterious events. We describe our experience using Onyx in an arterial approach for treatment of DAVFs in 17 patients. MATERIALS AND METHODS: Between 2006 and 2010, we used Onyx for performing transarterial embolization in 17 patients with intracranial DAVFs and cortical venous drainage. Clinical assessment was performed before and after every treatment at discharge and at follow-up. Fourteen patients underwent follow-up MR imaging and MRA, 8 of them also underwent follow-up diagnostic angiography. RESULTS: Fifteen patients (88%) underwent 1 procedure. Complete obliteration by embolization with Onyx was achieved in 16 patients (94% acute obliteration). The mean amount of Onyx injected was 2.3 mL (range, 0.4-4.8 mL). The sole technical complication was an embolus to a branch of the MCA, which was resolved by intra-arterial tPA injection. A clinical complication of transient trochlear nerve palsy in the same patient due to mass effect of Onyx resolved spontaneously within 3 months. CONCLUSIONS: Intra-arterial embolization of cranial DAVFs with cortical venous drainage by using Onyx results in a high rate of complete obliteration (94%) with low morbidity (6%). Follow-up DSA in 8 patients revealed no evidence of reopening.

Brain arteriovenous malformation treatment using a combination of Onyx and a new detachable tip microcatheter, SONIC: short-term results.

BACKGROUND AND PURPOSE: Endovascular embolization with Onyx is one of the tools used in the treatment of intracerebral AVMs. The recent introduction of a new microcatheter with detachable tip has led us to adopt a new treatment approach by using endovascular embolization with Onyx as the main treatment for brain AVM with curative intent. The purpose of the present study is to evaluate our initial results by using this new treatment strategy with special emphasis on the safety and feasibility of the technique. MATERIALS AND METHODS: Forty-three consecutive patients were treated by embolization for brain AVM over a 14-month period, mostly by using Onyx and a microcatheter with detachable tip. Twenty-six of these patients (60%) harbored Spetzler-Martin AVMs of grades 4-5. RESULTS: Endovascular treatments were completed in 29 out of 43 patients; the median number of procedures per patient was 2 (range, 1-4). Complete obliteration by using embolization exclusively was achieved in 16 patients, resulting in a 55% cure rate in patients who concluded treatments (16/29) and 37% in the cohort (16/43). The amount of Onyx injected by using microcatheters with detachable tips was significantly larger than that injected with the nondetachable microcatheters (mean volume, 2.5 +/- 2.2 versus 1.7 +/- 1.3 mL, respectively, P < .05, t test). Seven clinical complications were observed in a total of 76 embolization sessions (9.2%). CONCLUSIONS: Endovascular embolization of brain AVM by using Onyx and SONIC results in a relatively high complete obliteration. The use of the microcatheter with detachable tip adds several advantages, mainly in that higher volumes of Onyx can be safely injected.

Osteomyelitis of the ribs in the antibiotic era.

A total of 106 cases of rib osteomyelitis were reviewed, including 2 cases described in detail. Mycobacterial and bacterial infections accounted for 47 cases each. Fungal rib osteomyelitis occurred in 11 cases and 1 case was caused by Entamoeba histolytica. Most cases occurred in children and young adults. The mean duration of symptoms before diagnosis was 16, 26 and 32 weeks for bacterial, mycobacterial and fungal rib osteomyelitis, respectively. Common clinical signs were fever (73%), soft tissue mass (64%) and chest pain (60%). Route of infection was defined in 85 cases: 62% from contiguous spread and 38% via haematogenous route of infection. Eighty-nine percent had a favourable outcome after antimicrobial therapy with or without surgery. In conclusion, rib osteomyelitis is a rare infection of various aetiologies. The majority of cases occur in children and young adults and its diagnosis is usually delayed for several weeks.