RESUMEN

OBJECTIVE: Placement of vena caval filters under fluoroscopic surveillance incurs significant expense and potential risks associated with the transportation of critically ill patients. Intravascular ultrasound (IVUS) allows direct intraluminal visualization of the vena cava and the renal veins. The purpose of this study is to evaluate the accuracy of vena caval filter placement under IVUS in an animal model. METHODS: Fifteen Simon-Nitinol venal cava filters (C.R. Bard, Inc., Covington, GA) were placed under IVUS guidance into four anesthetized sheep. Twelve were placed transfemorally, and three were placed transjugularly. Accuracy of placement was confirmed with fluoroscopy by measurement between the filter tip and the targeted side branch. RESULTS: The vena caval filters placed femorally averaged 0.33+/-0.42 cm distance from the target vein side branch. Jugular approach filter placement was less accurate. Although two out of three filters placed from the jugular vein were correctly positioned, the distance from the target vein side branch was much greater averaging 2.5+/-1.04 cm. CONCLUSION: Femoral placement of vena caval filters under IVUS is extremely accurate. The transjugular route, however, was technically challenging and standard fluoroscopic vena caval filter placement appears to be more appropriate. Our success with the femoral approach merits further clinical investigation in the use of IVUS for critically ill patients that would benefit from bedside vena caval filter placement.

Asunto(s)

Ultrasonografía Intervencional , Filtros de Vena Cava , Animales , Estudios de Factibilidad , Modelos Animales , Ovinos

RESUMEN

OBJECTIVE: The results of percutaneous transluminal angioplasty, atherectomy, and laser angioplasty for the treatment of long-segment (>10 cm) superficial femoral artery (SFA) occlusive disease have proved disappointing. Remote superficial femoral artery endarterectomy (RSFAE) is a minimally invasive procedure, performed through a single limited groin incision that may offer patency rates comparable with those of above-knee femoropopliteal (AKFP) bypass graft. In this retrospective multicenter study the medium-term results of RSFAE are examined. METHODS: Sixty patients were included in this study. Indications for the procedure were claudication in 52 patients and limb salvage in eight patients. RSFAE was performed with the MollRing Cutter device through a femoral arteriotomy. The distal "flap" of atheroma was anchored by balloon/stent angioplasty through the femoral arteriotomy. All patients underwent a follow-up examination with serial color flow ultrasound scanning. RESULTS: Ten patients with heavily calcified SFAs failed as "intentions to treat"; these patients underwent AKFP bypass grafting. The mean length of the endarterectomized SFAs was 22.3 cm (range, 8-37 cm). The primary cumulative patency rate by means of life-table analysis was 61.4% +/- 9% (SE), (mean, 12.9 months; range, 3-36 months). During follow-up, percutaneous transluminal angioplasty was necessary in 14 patients, for a primary-assisted patency rate of 82.6% +/- 8%. The locations of the restenoses after RSFAE were evenly distributed along the endarterectomized SFAs. There were no deaths and one wound complication (hematoma), and the mean hospital length of stay was 1.4 days +/- 0.8 days. CONCLUSIONS: RSFAE is a safe and moderately durable procedure. If long-term patency rates are similar to those of AKFP bypass graft, RSFAE may prove to be a minimally invasive adjunct for the treatment of SFA occlusive disease that will lower operative morbidity, reduce hospital LOS, and shorten recuperation.

Asunto(s)

Arteriosclerosis/cirugía , Endarterectomía/métodos , Arteria Femoral/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo

RESUMEN

In cholinergic nerve terminals, Na(+)- and Cl(-)-dependent, hemicholinium-3-sensitive, high-affinity choline uptake is thought to be the rate-limiting step in acetylcholine synthesis. The high-affinity choline transporter cDNA responsible for the activity was recently cloned. Here we report production of a highly specific antibody to the high-affinity choline transporter and distribution of the protein in the CNS of the rat. The antibody stained almost all known cholinergic neurons and their terminal fields. High-affinity choline transporter-immunoreactive cell bodies were demonstrated in the olfactory tubercle, basal forebrain complex, striatum, mesopontine complex, medial habenula, cranial nerve motor nuclei, and ventral horn and intermediate zone of the spinal cord. Noticeably, high densities of high-affinity choline transporter-positive axonal fibers and puncta were encountered in many brain regions such as cerebral cortex, hippocampus, amygdala, striatum, several thalamic nuclei, and brainstem. Transection of the hypoglossal nerve resulted in a loss of high-affinity choline transporter immunoreactivity in neurons within the ipsilateral hypoglossal motor nucleus, which paralleled a loss of immunoreactivity to choline acetyltransferase. The antibody also stained brain sections from human and mouse, suggesting cross-reactivity. These results confirm that the high-affinity choline transporter is uniquely expressed in cholinergic neurons and is efficiently transported to axon terminals. The antibody will be useful to investigate possible changes in cholinergic cell bodies and axon terminals in human and rodents under various pathological conditions.

Asunto(s)

Acetilcolina/biosíntesis , Transporte Axonal/fisiología , Proteínas Portadoras/metabolismo , Sistema Nervioso Central/metabolismo , Fibras Colinérgicas/metabolismo , Proteínas de Transporte de Membrana , Terminales Presinápticos/metabolismo , Animales , Especificidad de Anticuerpos/fisiología , Axotomía , Sistema Nervioso Central/citología , Colina O-Acetiltransferasa/metabolismo , Reacciones Cruzadas/fisiología , Nervio Hipogloso/metabolismo , Immunoblotting , Ratones , Ratones Endogámicos C57BL , Neuronas Motoras/metabolismo , Conejos , Ratas , Ratas Wistar , Proteínas Recombinantes de Fusión/metabolismo

RESUMEN

The CD40 ligand molecule is unique, consisting of a receptor-binding domain anchored by an isoleucine zipper moiety. Exact determination of the multimeric state and its tendency to form molten globules has not been elucidated. Corroborating evidence of a trimerized molecule in aqueous solution was obtained from size-exclusion chromatography, laser light scattering, and analytical ultracentrifugation. A reversible acid-denatured molten globule state was observed from circular dichroism and fluorescence spectroscopy data. The molten globule state was characterized by a loss of tertiary structure with associated retention of secondary structure near pH 3. Once returned to pH 7, the acid-denatured state refolded over the course of 7 days resulting in approximately 90% recovery of the native structure. The molten globule state was characterized by a broadening of structural features in the second-derivative spectra of Fourier transform infrared spectroscopy. A component band at 1650 cm(-1) was shown to be alpha-helix and originate from amide carbonyl vibrations of the isoleucine zipper. Differential scanning calorimetry measurements characterized the pH-sensitive molten globule state at pH 3.3 as one lacking a well-defined unfolding transition with an accompanying baseline shift at 58 degrees C (a consequence of increased heat capacity). The tendency to form molten globules during acid denaturation stress permits an opportunity to study the process of partial protein unfolding with implications concerning stability. Although reversible molten globules can be formed, it is important to recognize the unusual nature since the molten globule state is formed exclusively within the beta-sheet receptor-binding region.

Asunto(s)

Ligando de CD40/química , Animales , Células CHO , Rastreo Diferencial de Calorimetría , Cromatografía , Dicroismo Circular , Cricetinae , Dimerización , Análisis de Fourier , Concentración de Iones de Hidrógeno , Luz , Modelos Moleculares , Conformación Proteica , Pliegue de Proteína , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Dispersión de Radiación , Espectrometría de Fluorescencia , Temperatura , Ultracentrifugación

RESUMEN

PURPOSE: To describe an endovascular method of performing femoropopliteal in situ saphenous vein (SV) bypass and popliteal artery aneurysm (PAA) embolization. METHODS: Twenty-two patients underwent PAA operations. Twelve patients had conventional SV bypasses with PAA proximal and distal ligation, whereas 10 underwent PAA embolization and an endovascular in situ SV bypass (EISB). The endovascular procedure was performed using an angioscopically guided side branch coil occlusion system. The PAAs were coil embolized under fluoroscopic surveillance. RESULTS: No deaths or wound complications occurred in the EISB group. The mean hospital length of stay (LOS) was 2.1 days. Seven EISB procedures were performed through 2 incisions, whereas 3 operations required an additional incision. One graft occluded at 3 months. All PAAs remained occluded by color-flow ultrasonography at follow-up ranging from 4 to 23 months (mean 13.6); cumulative primary patency was 89%. In the conventional bypass group, no deaths occurred, but 3 (25%) patients had wound complications. The mean LOS was 6.2 days, and 1 graft occluded, giving an 86% cumulative primary patency at 42 months. CONCLUSIONS: This minimally invasive technique obviates an extensive incision to harvest the SV and ligate the PAA proximally and distally. If long-term endovascular bypass graft patency and PAA occlusion rates prove to be similar to open operative results, the benefits of reduced wound complications, decreased hospital LOS, and increased health care savings support further investigation of this endovascular approach for the treatment of PAA.

Asunto(s)

Aneurisma/cirugía , Embolización Terapéutica/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Arteria Poplítea , Adulto , Anciano , Anciano de 80 o más Años , Anastomosis Quirúrgica , Implantación de Prótesis Vascular/métodos , Arteria Femoral/cirugía , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Arteria Poplítea/cirugía , Vena Safena/trasplante , Resultado del Tratamiento , Ultrasonografía , Grado de Desobstrucción Vascular

RESUMEN

Improved survival of patients with renal failure has led to the need for complex angioaccess procedures. The use of cryopreserved femoral vein for angioaccess when prosthetic arteriovenous grafts (AVG) could not be placed, owing to infection or the loss of conventional angioaccess sites from multiple AVG failures, was prospectively evaluated. Forty-eight cryopreserved femoral vein AVGs were placed in 44 patients. Thirty-eight (82%) of the cryopreserved femoral vein AVGs were placed for infection, whereas the other 10 (18%) were placed for multiple graft failures with compromised venous outflow. Even with implantation of the cryoveins into infected patients, there were no cryopreserved femoral vein AVG infections. The 1-year primary graft patency rate was 49% and the secondary graft patency rate was 75%. During the same time interval, 68 prosthetic brachial artery-to-axillary vein AVGs were placed. The 1-year primary and secondary patency rates for the prosthetic AVGs were 65 and 78%, respectively. In this study the overall patency rate of the cryopreserved femoral vein AVGs was similar to that for the PTFE AVGs (p = 0.519). In conclusion, the cryopreserved femoral vein proved useful in difficult angioaccess cases. The lack of infection after cryovein implantation around an infected area shows promise for salvaging an angioaccess site that would otherwise have been abandoned.

Asunto(s)

Derivación Arteriovenosa Quirúrgica , Criopreservación , Vena Femoral/trasplante , Diálisis Renal , Adulto , Anciano , Prótesis Vascular , Femenino , Humanos , Tablas de Vida , Masculino , Persona de Mediana Edad , Politetrafluoroetileno , Periodo Posoperatorio , Estudios Prospectivos , Resultado del Tratamiento , Grado de Desobstrucción Vascular

RESUMEN

Effects of heavy water (D2O) on various organisms have been extensively studied and a majority of D2O actions were generally ascribed to the viscosity (1.23 times of H2O) and a larger inter-molecule force of D2O that may eventually alternate molecular structure of various enzymes and ion channels. It is reported that chronic application of D2O induces toxic effects and the 35% substitution of whole body water with D2O induced fatal effects in the mouse. Mitosis of a fertile egg of sea urchin was completely inhibited by 75% D2O but the paused segmentation was recovered after rinse of D2O. In addition, we also observed that neuronal development of the Lymnaea stagnalis was reversibly inhibited by D2O (M. Sakakibara, unpublished data). However, mechanism of the toxicity of D2O and the effects of D2O on cellular events have not been fully understood. The spontaneous oscillation in cytosolic free Ca2+ concentration is one of the typical physiological events in living secretory cells. We previously demonstrated that the Ca2+ oscillations are regulated by voltage-sensitive Ca2+ channels (VSCC), Ca2+ ATPases, and Ca(2+)-induced Ca2+ release from intracellular stores. To analyze the site(s) of action of D2O in the living cellular systems, the present study examined effects of D2O on the Ca2+ mobilization and resting membrane potentials in AtT20 mouse pituitary cells.

Asunto(s)

Canales de Calcio/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Calcio/metabolismo , Óxido de Deuterio/farmacología , Gravitación , Animales , Canales de Calcio/metabolismo , Línea Celular , Células Cultivadas , Relación Dosis-Respuesta a Droga , Potenciales de la Membrana , Ratones , Hipófisis/citología , Potasio/metabolismo , Viscosidad

Asunto(s)

Angioscopía , Pierna/irrigación sanguínea , Vena Safena/trasplante , Procedimientos Quirúrgicos Vasculares , Humanos , Grado de Desobstrucción Vascular

RESUMEN

PURPOSE: The purpose of this study was to compare the transabdominal approach with the retroperitoneal approach for elective aortic reconstruction in the patient who is at high risk. METHODS: From January 1992 through January 1997, 148 patients underwent aortic operations: 92 of the patients were classified as American Society of Anesthesia (ASA) class IV. Forty-four operations on the patients of ASA class IV were performed with the transabdominal approach (25 for abdominal aortic aneurysms and 19 for aortoiliac occlusive disease), and 48 operations were performed with the retroperitoneal approach (27 for abdominal aortic aneurysms and 21 for aortoiliac occlusive disease). There were no significant differences between the groups for comorbid risk factors or perioperative care. RESULTS: Among the patients of ASA class IV, eight (8.7%) died after operation (retroperitoneal, 3 [6.26%]; transabdominal, 5 [11.3%]; P =.5). There was no difference between groups in the number of pulmonary complications (retroperitoneal, 23 [47.9%]; transabdominal, 19 [43.2%]; P =.7) or in the development of incisional hernias (retroperitoneal, 6 [12.5%]; transabdominal, 5 [11.3%]; P =.5). The retroperitoneal approach was associated with a significant reduction in cardiac complications (retroperitoneal, 6 [12.5%]; transabdominal, 10 [22.7%]; P =.004) and in gastrointestinal complications (retroperitoneal, 5 [8.3%]; transabdominal, 15 [34.1%]). Operative time was significantly longer in the retroperitoneal group (retroperitoneal, 3.35 hours; transabdominal, 2.98 hours; P =.006), as was blood loss (retroperitoneal, 803 mL; transabdominal, 647 mL; P =.012). The patients in the retroperitoneal group required less intravenous narcotics (retroperitoneal, 36.6 +/- 21 mg; transabdominal, 49.5 +/- 28.5 mg; P =.004) and less epidural analgesics (retroperitoneal, 39.5 +/- 6.4 mg; transabdominal, 56.6 +/- 9.5 mg; P =.004). Hospital length of stay (retroperitoneal, 7.2 +/- 1.6 days; transabdominal, 12.8 +/- 2.3 days; P =.024) and hospital charges (retroperitoneal, $35,587 +/- $980; transabdominal, $54,832 +/- $1105; P =.04) were significantly lower in the retroperitoneal group. The survival rates at the 40-month follow-up period were similar between the groups (retroperitoneal, 81.3%; transabdominal, 78.7%; P =.53). CONCLUSION: In this subset of patients who were at high risk for aortic reconstruction, the postoperative complications were common. However, the number of complications was significantly lower in the retroperitoneal group. Aortic reconstruction in patients of ASA class IV appears to be more safely and economically performed with the retroperitoneal approach.

Asunto(s)

Abdomen/cirugía , Enfermedades de la Aorta/cirugía , Espacio Retroperitoneal/cirugía , Anciano , Analgesia Epidural , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/uso terapéutico , Aneurisma de la Aorta Abdominal/clasificación , Aneurisma de la Aorta Abdominal/cirugía , Enfermedades de la Aorta/clasificación , Arteriopatías Oclusivas/clasificación , Arteriopatías Oclusivas/cirugía , Pérdida de Sangre Quirúrgica , Procedimientos Quirúrgicos Electivos , Estudios de Seguimiento , Enfermedades Gastrointestinales/etiología , Cardiopatías/etiología , Hernia/etiología , Precios de Hospital , Hospitalización , Humanos , Arteria Ilíaca/cirugía , Inyecciones Intravenosas , Tiempo de Internación , Enfermedades Pulmonares/etiología , Complicaciones Posoperatorias , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Factores de Tiempo

RESUMEN

Since the report of a successful femoropopliteal in situ saphenous vein bypass in 1962, surgeons have attempted to make this bypass a less invasive operation and simplify the two principal technical components of the operation: (1) rendering the saphenous vein valves incompetent and (2) occluding the venous side branches. To accomplish this bypass, however, a long incision that is the length of the leg over the course of the saphenous vein is often necessary, which can be fraught with hazard, especially in patients with diabetes in whom wound complications can be devastating. An angioscopically assisted technique that allows the surgeon to perform valvulotomy and occlude venous side branches from within the saphenous vein--a minimally invasive in situ vein bypass--has been developed. This article discusses preclinical, fluoroscopic clinical, and angioscopic clinical studies of minimally invasive in situ bypass.

Asunto(s)

Arteriopatías Oclusivas/cirugía , Arteria Femoral/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Arteria Poplítea/cirugía , Vena Safena/trasplante , Procedimientos Quirúrgicos Vasculares/métodos , Animales , Fluoroscopía , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Procedimientos Quirúrgicos Vasculares/instrumentación

RESUMEN

For certain patients who experience intense vertigo arising from unilateral vestibular lesions, the primary therapy is a vestibular nerve section, an intracranial surgical procedure. One alternative to this treatment is therapeutic ablation of vestibular function on the unaffected side using an ototoxic agent. We prepared a biodegradable sustained-release gel delivery system using sodium hyaluronate that can be administered into the middle ear using only a local anesthetic. The gel contains gentamycin sulfate, the ototoxic agent of choice for treatment of unilateral vestibulopathy, and it exhibits diffusion-controlled release of the drug over a period of hours. The released gentamycin could then diffuse into the inner ear through the round membrane. This represents an important advance over previous formulations, which used only gentamycin sulfate solutions, in that it should allow more careful control of the dose, it should reduce loss of the drug from the middle ear site, and it should maintain intimate contact with the round membrane. By carefully controlling the dose, it should be possible to inhibit vestibular function while minimizing hearing loss. Herein we describe the in vitro release kinetics of gentamycin sulfate from sodium hyaluronate gels and find that the system obeys Fickian behavior.

Asunto(s)

Sistemas de Liberación de Medicamentos , Gentamicinas/química , Ácido Hialurónico , Preparaciones de Acción Retardada , Geles , Gentamicinas/administración & dosificación

RESUMEN

The primary structures of the C and D subunits of sarcosine oxidase from Corynebacterium sp. U-96 were determined by sequencing the peptide fragments derived from their enzymatic digestions. The C and D subunits were shown to be composed of 199 and 92 residues, respectively. Each amino acid sequence showed a high homology with the sequence of the corresponding subunit from Corynebacterium sp. P-1. However, there were some differences between these two species, that is, four N-terminal residues were truncated in the C subunit, but six C-terminal residues were truncated in the D subunit. The D subunit contained three cysteine residues, but no disulfide bonds are in the subunit. Overall sequences of both subunit showed no homology with any other protein in the data base.

Asunto(s)

Corynebacterium/enzimología , Oxidorreductasas N-Desmetilantes/química , Secuencia de Aminoácidos , Cromatografía en Gel , Disulfuros/química , Electroforesis en Gel de Poliacrilamida , Datos de Secuencia Molecular , Oxidorreductasas N-Desmetilantes/aislamiento & purificación , Sarcosina-Oxidasa , Homología de Secuencia de Aminoácido

RESUMEN

BACKGROUND: Both transposed basilic vein (BV) and polytetrafluorethylene (PTFE) upper arm arteriovenous fistulas (AVF) are common angioaccess operations. To evaluate the patency and complication rates after AVF, a concurrent series of patients was reviewed. METHODS: Ninety-eight patients underwent brachial artery to axillary vein AVF: 30 BV and 68 PTFE. The PTFE grafts were performed in the standard fashion, whereas the basilic veins were translocated subcutaneously to the brachial artery. RESULTS: Risk factors were similar between the two groups. Basilic vein AVF had better patency at 24 months (70% BV versus 46% PTFE, P = 0.023). The dialysis access complications were higher in the BV group (20%) versus PTFE (5%), but the PTFE group had a higher infection rate (10%) than BV (0%). CONCLUSIONS: The primary and secondary patency rates were superior in the BV AVFs. The BV AVF preserves the venous outflow tract after AVF thrombosis for a future PTFE AVF operation.

Asunto(s)

Derivación Arteriovenosa Quirúrgica/métodos , Derivación Arteriovenosa Quirúrgica/efectos adversos , Vena Axilar , Arteria Braquial , Femenino , Antebrazo/irrigación sanguínea , Mano/irrigación sanguínea , Humanos , Masculino , Persona de Mediana Edad , Politetrafluoroetileno , Factores de Riesgo , Factores de Tiempo , Grado de Desobstrucción Vascular , Venas/cirugía

RESUMEN

2,2,2-Trifluoroethanol (TFE)-induced nonnative alpha-helical structure in peptides and proteins has been extensively studied with circular dichroism (CD) spectroscopy. However, to date, complementary information from infrared (IR) spectroscopy has not been reported. Using both IR and CD spectroscopy, we demonstrate here that the TFE-induced nonnative alpha-helical structure in two beta-sheet-predominant proteins, beta-lactoglobulin and alpha-chymotrypsin, is unstable in comparison with those found in the alpha-helix-predominant proteins myoglobin and cytochrome c under identical conditions. IR spectra showed that, immediately after dissolution of the beta-sheet proteins in 50% (v/v) TFE, a strong amide I band component appears at 1654 cm-1 in H2O and at 1650 cm-1 in D2O, which is ascribed to alpha-helical structure. However, the intensities of the alpha-helical bands decrease as a function of time, concomitant with the appearance of two new band components near 1620 and 1695 cm-1 in H2O and 1612 and 1684 cm-1 in D2O, a typical IR spectral pattern for an intermolecular beta-sheet aggregate. Clear gels begin to develop within 30 min. No similar spectral changes were observed for the alpha-helical proteins. CD spectra suggested initially that the TFE-induced alpha-helix was retained in the gelled state. However, further analysis of the spectra, and Gaussian function modeling with basic spectra, indicated that the apparent alpha-helix signal was actually due to a combination of signals from intermolecular beta-sheet and residual alpha-helix. These results indicate that the TFE-induced nonnative alpha-helix structure in predominantly beta-sheet proteins is unstable and readily converts to an intermolecular beta-sheet aggregate.

Asunto(s)

Estructura Secundaria de Proteína/efectos de los fármacos , Trifluoroetanol/farmacología , Animales , Bovinos , Quimotripsina/química , Quimotripsina/efectos de los fármacos , Dicroismo Circular , Grupo Citocromo c/química , Grupo Citocromo c/efectos de los fármacos , Lactoglobulinas/química , Lactoglobulinas/efectos de los fármacos , Mioglobina/química , Mioglobina/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier

RESUMEN

PURPOSE: To report the success of a minimally invasive treatment for phlegmasia cerulea dolens without gangrene caused by compression from an internal iliac artery aneurysm. METHODS AND RESULTS: An 81-year-old male with a 1-month history of paralysis owing to a hemorrhagic stroke presented with massive edema and skin mottling of the right lower extremity. Imaging confirmed right iliofemoral deep vein thrombosis caused by compression from a 4-cm internal iliac artery aneurysm. With thrombolysis ruled out, a minimally invasive treatment plan was undertaken, featuring percutaneous coil embolization of the aneurysm and surgical venous thrombectomy with proximal arteriovenous fistula creation and iliac vein stent placement. Failure of the coils to embolize the iliac aneurysm prompted the use of an endovascular graft to exclude the aneurysm. The patient's symptoms subsided, and he has a patent right iliofemoral venous system and internal iliac artery at his latest (16-month) follow-up. CONCLUSIONS: This case demonstrates that minimally invasive endovascular and open techniques can be combined to achieve an optimum outcome in patients at high risk for standard surgical approaches.

Asunto(s)

Aneurisma/complicaciones , Vena Femoral , Arteria Ilíaca , Vena Ilíaca , Tromboflebitis/etiología , Tromboflebitis/cirugía , Anciano , Anciano de 80 o más Años , Derivación Arteriovenosa Quirúrgica , Implantación de Prótesis Vascular , Embolización Terapéutica , Humanos , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos , Presión , Stents

RESUMEN

PURPOSE: To report a minimally invasive approach to popliteal artery aneurysm (PAA) treatment. METHODS AND RESULTS: A 48-year-old male with a 3-cm PAA was treated electively with an endovascular in situ saphenous vein bypass and transluminal antegrade coil embolization of the PAA prior to completion of the proximal anastomosis. Two short incisions at the anastomosis sites resulted in no wound complications, and the patient was discharged after 2 days. After 14 months of follow-up, the patient is asymptomatic with continued patency of the in situ bypass and occlusion of the PAA. CONCLUSIONS: This endovascular approach for minimally invasive femoropopliteal in situ saphenous vein bypass grafting appears feasible for treatment of PAAs. This method may reduce the rate of wound complications attending classic open in situ bypass grafts.

Asunto(s)

Aneurisma/terapia , Derivación Arteriovenosa Quirúrgica/métodos , Embolización Terapéutica , Arteria Poplítea , Anastomosis Quirúrgica , Aneurisma/diagnóstico por imagen , Vena Femoral/cirugía , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos , Arteria Poplítea/diagnóstico por imagen , Radiografía , Vena Safena/trasplante

RESUMEN

The decision to use prosthetic or autogenous vein as the initial conduit for first-time vascular bypass of the lower extremity depends in part on the likelihood of subsequent need for autogenous conduit for another leg or heart bypass. The true frequency of these later events is not known. To answer this question, we analyzed a database of infrainguinal and coronary artery bypasses (CABG) performed at one institution between January 1980 and July 1995, to determine how many patients required subsequent infrainguinal bypass or CABG after their initial leg bypass. Five hundred and seventy-two infrainguinal bypasses were performed on 440 patients (mean age 63.9); average follow-up was 5.6 years. The clinical philosophy favored autogenous vein for first bypass, which was used in 84% of first operations performed during the study period while prosthetic material was used in 16%. For patients in which vein was used for the first operation, and who went on to have a second operation, the use of prosthetic conduit rose from 16% of operations to 27% (p < 0.05). The rate of subsequent CABG after leg bypass was very low, 2% at 5 years, 3% at 10 years. The cumulative probability of requiring a subsequent infrainguinal bypass was 27% at 5 years, 32% at 10 years. Of these, 46% were ipsilateral and 54% were contralateral. Considering only subsequent tibial bypasses (where vein might be considered obligatory), the cumulative 5-year rate of subsequent leg bypass was only 13%. Another bypass was most likely to occur within the first 3 years, rarely thereafter. In summary, after primary infrainguinal bypass, additional procedures using vein may arise in 1/4 to 1/3 of patients, mostly in the first 3 years. However, only 13% will definitely need vein for tibial bypass in 5 years, and subsequent CABG is uncommon.

Asunto(s)

Extremidades/cirugía , Procedimientos Quirúrgicos Vasculares , Venas/trasplante , Anciano , Implantación de Prótesis Vascular , Puente de Arteria Coronaria , Estudios de Seguimiento , Humanos , Tablas de Vida , Persona de Mediana Edad , Probabilidad , Reoperación , Estudios Retrospectivos , Trasplante Autólogo

RESUMEN

Abnormal venous valvular function may produce venous reflux and venous insufficiency. While valvular agenesis is a known, but rare cause of venous insufficiency. While valvular agenesis is a known, but rare cause of venous insufficiency, little work has been done on the relative number of greater saphenous vein (GSV) valves in patients with venous insufficiency. This study investigates whether the GSV in patients with symptomatic venous insufficiency has fewer valves than the GSV of patients without venous insufficiency. The number of GSV valves in patients (n = 51) with symptomatic venous insufficiency undergoing saphenectomy (VI) were compared with the number of GSV valves in patients (n = 26) without venous insufficiency undergoing in situ GSV bypass under angioscopic surveillance who served as a control group. The two groups differed, as expected, in age and sex distribution. The VI group had a mean of 25.7 +/- 11.0 centimeters of GSV between valves, while the control group had 19.0 +/- 9.7 centimeters of GSV between valves (F = 6.99; p = 0.01). The mean number of valves in the saphenous veins of the two groups also differed significantly: VI = 2.3 +/- 0.83 versus control (CTRL) = 4.8 +/- 2.01 (F = 61.86; p < 0.0001). That properly functioning valve leaflets help maintain physiologic antegrade venous flow is indisputable. This study, however, suggests that the relative lack of valves may be related to the development of venous insufficiency. This report documents that patients with symptomatic reflux in the GSV have significantly fewer valves than patients with apparently normal functioning saphenous veins.

Asunto(s)

Vena Safena/patología , Insuficiencia Venosa/patología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Insuficiencia Venosa/etiología

RESUMEN

A case of an aortocaval fistula documented by contrast-enhancement computed tomography is reported. In the presence of a large abdominal aortic aneurysm, the computed tomography (CT) triad findings of: (1) vena caval effacement, (2) loss of the fat plane between the aorta and vena cava, and (3) rapid flow of contrast from the aorta into a dilated inferior vena cava is characteristic of an aortocaval fistula.

Asunto(s)

Enfermedades de la Aorta/diagnóstico por imagen , Fístula Arteriovenosa/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Venas Cavas/diagnóstico por imagen , Anciano , Humanos , Masculino

RESUMEN

The secondary structure and thermal denaturation (in H2O vs D2O) of recombinant human factor XIII in aqueous solutions were investigated using infrared and circular dichroism (CD) spectroscopies. The infrared amide I spectrum of the protein in H2O solution at 25 degrees C exhibited an absorbance maximum near 1642 cm-1, indicating the presence of a predominantly beta-sheet structure. Quantitative analysis revealed that the native protein contains 13-16% alpha-helix, 41-49% beta-sheet, 29% beta-turn, and 10-14% extended strand structures. The presence of a strong low-wavenumber beta-sheet band at 1641 cm-1 and a weak high-wavenumber beta-sheet band at 1689 cm-1 indicated that the beta-sheet structure of the protein is predominantly antiparallel. Quantitative analysis of the CD spectrum using the SELCON method indicated a secondary structural content of 10% alpha-helix, 40-50% beta-sheet, 20-35% beta-turns, and 20-35% unordered elements, which matches that determined by X-ray crystallography. The apparent discrepancy with the contents of unordered element determined by infrared spectroscopy is reconciled by considering that CD spectroscopy and X-ray crystallography assign extended loops and strands to unordered elements, whereas infrared spectroscopy recognizes these as distinct structured elements. During heating above 60 degrees C, a pair of new infrared bands appeared at 1626 and 1693 cm-1 for the protein in H2O and 1619 and 1683 cm-1 in D2O, indicating a formation of intermolecular beta-sheet aggregates. The intensities of the new bands increased as a function of temperature, concomitant with an intensity decrease in bands for the native protein structural elements. As expected, there was an increase in thermal stability in D2O relative to that in H2O, which was manifested as an increase of about 5 degrees C in the temperature for initial loss of infrared bands assigned to native structural elements and for appearance of bands due to intermolecular beta-sheet. In addition, the midpoint of the thermally induced transitions in infrared spectra were about 2.5 degrees C higher in D2O than in H2O. Based on the infrared analysis, the thermally denatured state of the protein in both H2O and D2O contains predominantly intermolecular beta-sheet. The broad, poorly resolved absorbance that spans the region between the intermolecular beta-sheet bands was assigned to an ensemble of heterogeneous structural elements (including unordered), none of which is populated to a high enough degree to result in a distinct infrared band. Results from CD spectroscopy support these conclusions about the structure of the denatured, aggregated protein.

Asunto(s)

Factor VIII/química , Estructura Secundaria de Proteína , Dicroismo Circular , Óxido de Deuterio , Calor , Humanos , Desnaturalización Proteica , Proteínas Recombinantes/química , Soluciones , Espectrofotometría Infrarroja , Agua