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

Estudo comparativo da termoablação da veia safena magna na coxa, com e sem tumescência

Contexto

O tratamento com laser endovenoso das veias safenas oferece ao paciente um procedimento com baixos índices de complicações, proporcionando retorno precoce à atividade ocupacional.

Objetivo

Comparar a formação de hematoma, a presença de parestesia no trajeto da veia safena magna (VSM) e a sua taxa de obliteração em 30 dias após a termoablação ao nível da coxa, utilizando ou não a tumescência e dois tipos de fibras.

Métodos

Estudo prospectivo em que foram analisados três grupos de pacientes submetidos a termoablação da VSM em coxa, utilizando comprimento de onda 1470 nm. No grupo 1, utilizou-se fibra convencional e tumescência; no grupo 2, fibra convencional sem tumescência; e no grupo 3, fibra dupla radial sem tumescência. Foram comparados, no período de 30 dias, a taxa de obliteração ao eco-Doppler, a ocorrência de parestesias e hematomas.

Resultados

Ao se comparar 90 VSMs de coxa submetidas a termoablação, obteve-se taxas de obliterações similares entre os grupos, sem diferença estatística. Nos grupos sem tumescência, ocorreu maior número de parestesias no trajeto da VSM na coxa no sétimo dia do que no grupo com tumescência, mas somente com significância estatística na comparação com o grupo da fibra convencional. Ocorreram hematomas em todos os grupos, sendo mais frequentes no grupo 1 (73,33%).

Conclusões

A realização da tumescência mostrou-se útil na prevenção de lesões neurológicas menores, mas não influenciou a ocorrência de hematomas e a taxa de oclusão da VSM na coxa em até 30 dias de sua termoablação.

Comparing cold and warm tumescent anesthesia for pain perception during and after the endovenous laser ablation procedure with 1470 nm diode laser

Objective:

The aim of this study was to compare the pain perception and side effects during and after endovenous laser ablation with a 1470 nm diode laser using cold or room temperature tumescence anesthesia.

Methods:

One hundred and one patients were randomly assigned in two groups. Group A received room temperature (+24℃) and Group B received cold (+4℃) tumescence fluid, which was used for local anesthesia in the track of great saphenous vein. A visual analog score was recorded immediately after the procedure. Patients were asked to register pain scores and the amount of pain medication consumed during the week.

Results:

There was no significant difference concerning gender, age, Clinical Etiological Anatomical Pathological Classification, body mass index, or diameter of the treated vein. In Group A, the mean linear endovenous energy density was 59.5 J/cm and in Group B, it was 60.4 J/cm. The average visual analog score after the endovenous laser ablation procedure in Group A was 5 and in Group B was 2. Third day after the procedure, the average visual analog score in Group A was 3 and in Group B was 1. Patients in Group B needed significantly less analgesics compared with patients in Group A ( p<0.05). The most frequent side effects in both groups were ecchymosis, induration, and minor paraesthesia, all of which were more common in Group A ( p < 0.001).

Conclusions:

To date, most published endovenous laser ablation series describe the use of room temperature tumescence fluid infiltration of the perivenous stroma for tumescent analgesia and protection against thermal injury to the nearby structures. We describe an alternative technique using cold tumescence fluid infiltration, which is equally effective as, but safer than, room temperature tumescence fluid infiltration, and which yields better visual analog scores.

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.