Numerical simulation of endovenous laser treatment of the incompetent great saphenous vein with external air cooling.

Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein. Before the procedure, peri-saphenous subcutaneous tumescent saline solution infiltration is usually performed. However, diffusion of this tumescent fluid is rapidly observed and can potentially reduce the efficacy as a heat sink. External skin cooling with cold air was proposed as an alternative solution. The objective of this study is to compare endovenous laser treatment without and with air cooling by realistic numerical simulations. An optical-thermal damage model was formulated and implemented using finite element modeling. The general model simulated light distribution using the diffusion approximation of the transport theory, temperature rise using the bioheat equation, and laser-induced injury using the Arrhenius damage model. Parameters, used in clinical procedures, were considered: power, 15 W; pulse duration, 1 s; fiber pull back, 3-mm increments every second; cold air applied in continuous mode during ELT; and no tumescent anesthesia. Simulations were performed for vein locations at 5, 10, and 15 mm in depth, with and without air cooling. For a vein located at 15 mm in depth, no significant difference was observed with and without cooling. For a vein located at 10 mm in depth, surface temperature increase up to 45 °C is observed without cooling. For a vein located at 5 mm, without cooling, temperature increase leads to irreversible damage of dermis and epidermis. Conversely, with air cooling, surface temperature reaches a maximum of 38 °C in accordance with recordings performed on patients. ELT of the incompetent great saphenous vein with external air cooling system is a promising therapy technique. Use of cold air on the skin continuously flowing in the area of laser shot decreased significantly the heat extent and the thermal damage in the perivenous tissues and the skin.

A comparative study of the efficacy of endovenous laser treatment of the incompetent great saphenous under general anesthesia with external air cooling with and without tumescent anesthesia.

BACKGROUND: This clinical study reports our experience with endovenous laser treatment (ELT) in which external air cooling is used without classic tumescent anesthesia. METHODS: Two hundred thirty-two patients underwent ELT under general sedation. In group A (n = 192), ELT was performed with air cooling but without the concurrent use of tumescent anesthesia. In group B (n = 40), patients were treated using the traditional tumescent technique. The parameters were similar for both groups: 980-nm diode laser, power of 15 W, and pulse duration of 1 second. The laser fiber and catheter were manually withdrawn in 3-mm increments. Ultrasound was performed to reevaluate vein closure at the end of surgery and 2 and 8 weeks and 1 year after. During follow-up, complications such as burns, dyschromia, pain, and dysesthesia, as well as time used for surgery were recorded. RESULTS: A 96% closure rate was obtained in groups A and B at 2 and 8 weeks. This rate remained stable 1 year after the ELT procedure. Except for a higher percentage of ecchymoses in group B (55%) than in group A (0%) (p < 0.001), no significant differences were observed for complications. With external air cooling, ELT took 17.5 minutes to perform for the whole leg, compared with 38.5 minutes when using tumescent anesthesia (p < 0.05). CONCLUSION: ELT surgery for the great saphenous vein can be safely performed using the air cooling method and is as efficacious as ELT done with tumescent anesthesia but takes significantly less time to perform.

Aneurismas micóticos de ambos miembros inferiores secundarios a endocarditis infecciosa / No disponible

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Aneurismas poplíteos. Evolución y factores pronósticos en la trombosis del saco / Popliteal aneurysms. Their course and prognostic factors in thrombosis of the sac

Objetivos. Conocer la evolución de aneurismas poplíteos tratados quirúrgicamente y evaluar factores pronósticos en la trombosis del saco. Pacientes y métodos. Desde mayo de 1993 hasta junio del año 2005, 43 pacientes presentaron 64 aneurismas poplíteos (diámetro medio: 2,8 cm; intervalo: 1,2-8 cm); de ellos, 19 (29%) han recibido tratamiento médico (compensación tras trombosis), dos (3%) aneurismectomía más injerto terminoterminal vía posterior, 22 (34%) exclusión por ligadura más bypass poplíteo-poplíteo y, por último, 21 (32%) exclusión y bypass femoropoplíteo. Hemos realizado un estudio descriptivo transversal en los 43 aneurismas tratados mediante exclusión y bypass (67%). Mediante eco-Doppler de control se evaluó: diámetro, presencia de flujo o trombosis del aneurisma y permeabilidad del bypass. Se analizó, mediante regresión de Cox, si existía asociación estadísticamente significativa entre la trombosis postoperatoria del saco aneurismático y los siguientes factores: diámetro preoperatorio del aneurisma, edad, factores de riesgo cardiovascular, comorbilidad, tipo de tratamiento, run-off, permeabilidad del bypass y presencia de aneurisma contralateral o de aorta. Resultados. De 43 aneurismas intervenidos, se pudieron evaluar 25 (56%). Se detectó flujo Doppler intraaneurismático en cuatro casos (16%); de éstos, hubo crecimiento del saco en tres (12%), y en uno (4%) disminuyó. De los 21 casos (84%) con trombosis completa del saco, se detectó su crecimiento en dos (8%), y en los 19 restantes (76%) disminuyó. El control clínico medio fue de 65 meses (intervalo: 1-128 meses). No se detectaron roturas ni síntomas compresivos. El tipo de cirugía resultó ser el único factor estadísticamente significativo (p = 0,04). Conclusiones. La reparación quirúrgica no garantiza la trombosis del aneurisma. El bypass poplíteo-poplíteo muestra mayores garantías en la trombosis del saco aneurismático

Aims. To determine how surgically treated popliteal aneurysms progressed and to evaluate the prognostic factors for thrombosis of the aneurysmal sac. Patients and methods. Between May 1993 and June 2005, 43 patients presented with 64 popliteal aneurysms (mean diameter: 2.8 cm; interval: 1.2-8 cm), of which 19 (29%) received medical treatment (compensation following thrombosis), two (3%) underwent an aneurysmectomy plus an end-to-end graft inserted using a posterior approach, 22 (34%) were treated with exclusion by ligation plus popliteal-popliteal bypass and, lastly, 21 (32%) underwent exclusion and femoral-popliteal bypass. We conducted a cross-sectional descriptive study in the 43 aneurysms treated by means of exclusion and bypass (67%). A control Doppler ultrasound recording was used to evaluate diameter, presence of flow or thrombosis of the aneurysm and patency of the bypass. Cox regression was used to analyse whether there was a statistically significant association between post-operative thrombosis of the aneurysmal sac and the following factors: pre-operative diameter of the aneurysm, age, cardiovascular risk factors, comorbidity, type of treatment, run-off, patency of the bypass and the presence of a contralateral or aortic aneurysm. Results. Of the 43 aneurysms that were treated with surgery, we were able to evaluate 25 (56%). Intra-aneurysmal Doppler flow was detected in four cases (16%); of these, the sac was seen to have grown in three (12%) and it had diminished in one (4%). Of the 21 cases (84%) with complete thrombosis of the sac, growth was detected in two of them (8%) and it had diminished in the remaining 19 (76%). Mean clinical monitoring time was 65 months (interval: 1-128 months). No ruptures or symptoms of compression were detected. Findings showed that type of surgery is the only statistically significant factor (p = 0.04). Conclusions. Surgical repair does not guarantee thrombosis of the aneurysm. A popliteal-popliteal bypass offers a higher degree of safety in thrombosis of the aneurysmal sac

Gestión de la lista de espera de varices en un hospital de nivel B / Management of the waiting list for varicose veins operations in a level B hospital

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Derivación iliofemoral frente a femorofemoral. ¿Cuál es la mejor opción? Seguimiento a largo plazo / Ileofemoral or femorofemoral by-pass. Which is the best option? A long-term follow-up study

Objetivo. Comparar la permeabilidad primaria y el salvamento de la extremidad a los cinco años entre la derivación iliofemoral y la femorofemoral y determinar los factores que influyen en la permeabilidad de estas derivaciones. Pacientes y métodos. Desde enero de 1992 a diciembre de 2000, se intervinieron 72 pacientes con enfermedad ilíaca unilateral e isquemia crítica de la extremidad (21 iliofemorales, con una edad media de 66,3 años y 51 femorofemorales, con una edad media de 70 años). Se realizaron tablas de contingencia (c2, t de Student) para comparar los grupos entre sí, según los factores de riesgo cardiovascular, el sexo, la edad y la salida distal; test de log-rank para comparar la permeabilidad primaria y el salvamento de la extremidad entre grupos (representación gráfica por Kaplan-Meier), y se realizó un análisis multivariante por regresión de Cox para determinar los factores predictivos de oclusión a los cinco años. Resultados. La permeabilidad primaria del grupo femorofemoral fue del 63 por ciento a los cinco años; en el grupo iliofemoral fue del 76 por ciento, sin que existieran diferencias entre ellos (p = 0,831). El salvamento de la extremidad del grupo femorofemoral fue del 87 por ciento a los cinco años; la del grupo iliofemoral fue del 85 por ciento. No hubo diferencias significativas entre los grupos (p = 0,449). Por regresión de Cox, el único factor que influye en la permeabilidad de estas derivaciones a largo plazo es la salida distal. Conclusiones. A los cinco años, no hay diferencias entre los dos grupos en cuanto a permeabilidad primaria y salvamento de la extremidad. La única variable predictiva de oclusión de estas derivaciones a los cinco años es la salida distal (AU)