Answer:
Case reports of sclerotherapy appear throughout the latter half of the 19th century. All early agents were thrombogenic, until it was discovered that quinine obliterated small vessels by causing intimal damage. Thereafter sodium morrhuate (1930) and hypertonic saline (1924) were used and are still in use today. The indications for the use of sclerotherapy include telangiectasias, reticular varicosities and veins, isolated varicosities, below knee varicosities and recurrent varicosities. Sclerotherapy is the only modality effective in the ablation of telangiectatic blemishes, and is especially effective on vessels smaller than 4 mm in diameter. In general, sclerotherapy is most effective in small incompetent vessels. Agents used in sclerotherapy may cause thrombosis, fibrosis, or both. They are either detergents, which produce endothelial damage through interference with cell surface lipids; hypertonic solutions, which cause cell lysis; and chemical irritants, which directly damage endothelial cells and cause fibrin deposition in the lumen. Excessive thrombosis is undesirable and may lead to excessive perivascular inflammation and recanalization of the vessel.
With regard to more recent improvements in technique: In 1993, a publication entitled “Advanced sclerotherapy treatment of varicose veins with duplex ultrasonographic guidance” (Seminars in Dermatology. 12(2):123-8, June 1993) described the use of advanced sclerotherapy of varicose veins using duplex ultrasonographic guidance in three phases of the process. In the presclerotherapeutic stage, patency and competency of the deep venous system are evaluated, location and morphology of the highest point of reflux are determined, luminal and parietal diameters of the target vein, venous compressibility, leaflets of the incompetent valve, and the degree, extent, and velocity of reflux are assessed. In the sclerotherapeutic stage, ultrasonographic guidance is helpful when the anatomy is intricate and points of reflux would otherwise be inaccessible. In the postsclerotherapeutic stage, duplex ultrasonography is indispensable for determination of the extent of the sclerosing reaction,
measurement of luminal and parietal diameters, and to elucidate luminal content and its degree of adherence to the venous wall. The study demonstrated that duplex ultrasonography provides a sound basis for clinical decision making and thereby enhances the precision and safety of advanced sclerotherapy.