Varicose veins of the lower extremities are common and frequently occurring diseases in vascular surgery. Due to abnormalities in the structure or function of veins and valves, venous reflux is poor and venous hypertension persists, leading to varicose veins of the lower extremities and a series of symptoms and signs, mostly manifested as varicose veins of the lower extremities, accompanied by heaviness, fatigue, distending pain, edema, skin nutritional changes and ulcers. At present, the incidence of great saphenous veins is increasing year by year. According to reports, the incidence of great saphenous veins in China is about 10%, which is slightly higher in the United States. About 15% of men and 25% of women over the age of 50 suffer from varicose veins of the lower extremities. In recent years, with the continuous emergence of new technologies, various minimally invasive treatments have been achieved in the treatment of varicose veins of the lower extremities, mainly including electrocoagulation therapy, radiofrequency therapy, microwave therapy and laser endovenous closure (EVLT). The surgical treatment of varicose veins is developing in a more effective and minimally invasive direction. For these minimally invasive surgeries, the first step is always to find a suitable approach. For example, the common approach options for laser endocavity closure and sclerosing agents include direct vision puncture, ultrasound-guided puncture, and puncture under the guidance of a vein locator. In cases where the veins are not obvious, direct vision puncture and injection are difficult to accurately locate the veins, which often leads to puncture failure, extravascular injection of sclerosants, and related complications, the vein finding device uses the hemoglobin in the blood to absorb infrared light, accurately locate and guide the puncture, facilitate the placement of optical fibers and the injection of foam sclerosing agents into the cavity during EVLT, improve the success rate of puncture, and dynamically observe the filling and distribution of foam in the venous cavity to determine whether the varicose veins are closed.
1.Application of vein locator in minimally invasive intracavitary surgery for varicose veins
The minimally invasive treatment of intracavitary thermal injury for varicose veins of the lower extremities mainly includes electrocoagulation therapy, radiofrequency therapy, microwave therapy and laser intracavitary closure (EVLT). Taking laser intracavitary closure as an example, it has been developed in China for more than ten years. It can enter the great saphenous vein and its small branches through a thin optical fiber, and the optical fiber is transmitted into the blood vessel cavity to burn and destroy the blood vessel wall to close the blood vessel. Lasers that can be efficiently absorbed by water molecules are used to achieve better vascular occlusion effects with lower energy output, reduce vascular perforation, reduce thermal damage effects and carbonization of blood vessel walls, nerve damage, and reduce postoperative complications such as bruises, edema, and skin burns, thereby reducing intraoperative and postoperative pain.
Locating the ankle and superficial veins and puncturing and inserting optical fibers during surgery is the first step of EVLT, and is also the first step of all other minimally invasive intracavitary surgeries. It plays a very important role in the overall surgical process, not only affecting the length of the operation time, but also affecting the probability of postoperative complications. Therefore, if the superficial veins can be accurately located, it is extremely important for EVLT. The vein locator based on infrared spectroscopy detection to locate the veins under the skin can accurately determine the superficial veins during surgery (Figure 1), improve the success rate of puncture, avoid repeated punctures, speed up the surgical process, shorten the surgical time, reduce the incidence of postoperative complications, and improve the quality of medical care.
2. Application of vein locator in foam sclerotherapy injection
In addition to laser closure, sclerotherapy for varicose veins has a long history. Foam sclerotherapy is being used by many vascular surgeons for patients with varicose veins of the lower limbs due to its advantages of less trauma, less pain, low cost, fewer complications, no scars left, and convenient repeated treatment, providing another new choice for patients. The recently emerged polidocanol (polyethylene glycol monolauryl ether) rapidly induces vasospasm, and polidocanol has both concentration-dependent and volume-dependent damage to vascular endothelial cells, which further enhances the sclerosing effect.
Common complications of foam sclerosant treatment of varicose veins include redness, swelling, pain, pigmentation, and nodules. The key to preventing complications is to control the dose and concentration of the sclerosant, and accurate intracavitary injection during surgery is the key.
The injection of foam sclerosant can be used with a vein locator to locate the vein. When the vein locator is placed 18 cm above the skin, the hemoglobin in the vein can absorb the infrared light emitted by the locator, revealing the course of the vein, assisting the operator to accurately puncture the vein, accurately inject the foam sclerosant, and avoid the sclerosant from leaking out of the cavity and causing complications.
After the sclerosant is successfully injected, the filling and distribution of the sclerosant in the cavity can be judged by irradiation with the vein locator, and the closure of the blood vessels can be observed.
3. Advantages and Prospects
Precision medicine is the goal pursued by modern medicine. With the development of various minimally invasive procedures, minimally invasive, effective and safe procedures have received more and more attention in clinical practice. The vein scanner machine can accurately show the course of venous vessels, greatly improve the accuracy of vein positioning in clinical practice, ensure the success rate of puncture in minimally invasive surgery of varicose veins in the lower limbs and the injection of sclerosant into the venous lumen, improve surgical efficiency, reduce the occurrence of postoperative complications, reduce the possibility of medical disputes, and improve medical quality.
The vein locator has good practicality in the minimally invasive treatment of varicose veins and is an indispensable medical tool in the process of venous puncture and injection.