Use of Allogeneic Fibroblasts in the Combined Treatment of Patients with Trophic Ulcers of Venous Etiology

The dissertation is devoted to increasing the effectiveness of the combined treatment of patients with trophic ulcers of venous etiology, which are the most common complication of chronic venous insufficiency of the lower limbs. The work combines experimental and clinical approaches: in the experiment, the influence of in vitro cultured allogeneic dermal fibroblasts combined with collagen on the course of the wound process is studied, while in the clinical part a method of application and the effectiveness of the dermal equivalent (DE) in the local therapy of trophic ulcers in patients with varicose and post-thrombotic disease are developed and evaluated. The immediate and long-term results of treatment in the main and control groups are compared, and the combination of local cell therapy with a pathogenetically oriented surgical intervention aimed at correcting venous hemodynamics is substantiated.

Relevance of the Problem

Trophic ulcers (TU) are a severe and the most common complication of chronic venous insufficiency (CVI). The treatment of patients with TU of the lower limbs of venous etiology represents a complex medical, social, and economic problem. The prevalence of "venous" TU among the working-age adult population of the Russian Federation is approximately 2%. Among elderly individuals (over 65 years of age) the occurrence of this pathology increases to 4–5%. In 0.3% of cases, TU of venous etiology remain unhealed for a long time and recur repeatedly (Vedensky A.N., 1986; Vasyutkov V.Ya. and Protsenko N.V., 1993; Savelyev V.S. et al., 2001; Stoyko Yu.M. et al., 2002). Despite the achievements of modern medicine, and of phlebology in particular, the incidence of TU has remained constant over the last 20 years; however, in recent decades there has been a clear tendency toward the rejuvenation of this patient population (Savelyev V.S. et al., 2001; Ruckley C.V., 1997).

The development of TU against the background of decompensated CVI considerably reduces the patients' quality of life. The long-term torpid course of trophic ulcers and their frequent recurrences lead to loss of working capacity and disability of the patients (Vedensky A.N., 1986; Vasyutkov V.Ya. and Protsenko N.V., 1993; Franks P.J., 1994; Bosanquet K., 1996). It is rather difficult to estimate the economic expenditures on the treatment of patients with venous TU in our country at the present stage; however, on the basis of data from foreign countries one can judge how great these expenses are. In Great Britain the material costs associated with the treatment of patients with TU amount to 600–900 million dollars per year, and in the USA — more than 1 billion dollars annually (Lees T.A., 1992; Phillips T., 1994; Janiet G., 1997).

The data presented indicate that the problem of the treatment of TU is still far from being finally resolved, despite the large number of various methods that have been proposed. This is fostered by the absence of standards and unified approaches to the examination and treatment of patients with decompensated CVI (Savelyev V.S., 1998; Yablokov E.G. et al., 1999; Stoyko Yu.M. et al., 2002; Bergan J., 2002).

For the selection of an effective complex of diagnostic and therapeutic measures, a profound insight into and further study of the pathogenetic basis of the origin and progression of venous TU are necessary. The specific features of the course of the destructive process arising from pronounced disturbances of microcirculation and tissue metabolism under conditions of phlebohypertension require a special, individual, and differentiated approach to the choice of local therapy for venous TU. The low effectiveness of the existing means of local treatment of TU necessitates prolonged therapy, which frequently fails to bring about healing of the trophic defect and thereby delays the surgical intervention aimed at correcting the pathologically altered venous hemodynamics (Vasyutkov V.Ya. and Protsenko N.V., 1993; Yablokov E.G. et al., 1999; Savelyev V.S. et al., 2001; Hjerppe A. et al., 2004; Negus D., 1995).

The modern development of ideas about wound and TU healing is based on the study of the cellular and molecular-genetic basis of tissue repair. The scientific achievements of recent years have made it possible to introduce into clinical practice biological preparations obtained with the use of new technologies for healing skin wounds (Paramonov B.A., 2000; Glyantsev S.P., 2004; Brem H. et al., 2000; Boyce S., 2001; Falanga V., 2005).

One of these promising directions is the use for the treatment of wounds of cells cultured in vitro — fibroblasts and keratinocytes (Gallico G., 1990; Leigh I., 1991; Phillips T., 1992), of compositions containing these cells — the dermal equivalent (DE) and the skin equivalent (Bell E., 1981; Phillips T. et al., 1992; Sabolinski M. et al., 1996; Hjerppe A. et al., 2004), as well as of growth factors (Steed D. et al., 1995; Smiell J. et al., 1999; Cross S. et al., 1999; Robson M., 2000). In practical terms, the method of using cultures of allogeneic fibroblasts for the treatment of burn wounds has found wide application (Sarkisov D.S. et al., 1995; Kolokoltseva T.D. et al., 1998; Paramonov B.A. et al., 2000).

The use of cultured allogeneic fibroblasts in the treatment of TU has been introduced into clinical practice only in recent years, and only the first, in their majority positive, results have been obtained (Khrupkin V.I. et al., 1991; Lapin A.Yu. et al., 2004; Sedov V.M. et al., 2006; Falanga V. et al., 1999; Biem H. et al., 2000; Mooney E.K. et al., 2002; Hjerppe A. et al., 2004; Tomic-Canic M. et al., 2004). However, in such a broad and promising field as cell therapy, many aspects have not been fully investigated, including the influence of DE on the healing processes of venous TU. The study of this issue constitutes the subject of the dissertation research and determines the relevance of the work.

Aim of the Work

To improve the results and shorten the duration of the combined treatment of patients with venous TU by using, in the local therapy of trophic defects, a DE containing allogeneic dermal fibroblasts.

Research Objectives

1. To study, in an experiment, the influence of in vitro cultured dermal fibroblasts and collagen on wound healing.

2. To develop an algorithm and a method for the use of DE in the treatment of venous TU.

3. To study the clinical effectiveness of DE in healing venous TU in patients.

4. To substantiate the optimal approach to local therapy and surgical treatment in patients with varicose disease (VD) and post-thrombotic disease (PTD) complicated by TU.

5. To evaluate the immediate and long-term results of the use of the dermal equivalent in the treatment of venous TU.

Scientific Novelty of the Study

1. A new modified method for studying the influence of allogeneic dermal fibroblasts and collagen gel on the course of the wound process in the experiment has been proposed.

2. A method for the use of DE in the treatment of venous TU of the lower limbs has been developed.

3. The influence of DE on wound healing in the experiment and on venous TU in the clinical study has been investigated.

4. The shortening of the healing time of venous TU when DE is used in local therapy has been demonstrated.

Practical Significance of the Work

An effective method of local therapy of venous TU has been developed and introduced into clinical practice. The use of DE in the treatment of venous TU makes it possible to shorten the healing time of trophic defects and to reduce the duration of preoperative preparation of patients with VD complicated by TU.

Main Statements Defended

1. Allogeneic cultured fibroblasts in combination with type 1 collagen stimulate the course of reparative processes and accelerate the epithelialization of experimental skin wounds.

2. DE activates the course of the wound process in experimental skin wounds and in venous TU owing to the preservation of the functional activity of allogeneic fibroblasts.

3. The effectiveness of DE in local therapy in patients with venous TU is confirmed by an increase in the rate and a shortening of the time of epithelialization and exceeds the effectiveness of conventional medications and other methods of conservative treatment of TU.

4. A combined approach, including conservative therapy with the use of DE and pathogenetically substantiated surgical intervention, ensures a stable positive effect of treatment in patients with TU arising against the background of CVI in VD and PTD.

Approbation of the Work

The main results of the dissertation research were reported at the V Conference of the Association of Phlebologists of Russia (Moscow, 2004) and at a meeting of the Section of Cardiovascular Surgery and Angiology of the N.I. Pirogov Society (Saint Petersburg, 2005).

Implementation of the Results

The results of the work have been introduced into the practice of the Clinic of Hospital Surgery No. 2 of the "SPbSMU named after Academician I.P. Pavlov of the Russian Federal Agency for Health Care" (Saint Petersburg, Lev Tolstoy Street, 6/8) and of the Department of Vascular Surgery of the Federal State Unitary Enterprise RosNIIITO named after R.R. Vreden (Saint Petersburg, Akademika Baikova Street, 8). The materials of the dissertation are used in the educational process at the Department of Hospital Surgery No. 2 of the "SPbSMU named after Academician I.P. Pavlov of the Russian Federal Agency for Health Care" during surgical classes with sixth-year students (Saint Petersburg, Lev Tolstoy Street, 6/8).

Publications and Inventive Activity

The results of the scientific research on the topic of the dissertation are presented in 7 published works and are also included in the practical guide for senior students, interns, clinical residents, postgraduate students, and physicians of various specialties entitled "Trophic Ulcers of the Lower Limbs."

Structure and Volume of the Dissertation

The dissertation is set out on 148 pages of typewritten text and consists of an introduction, four chapters, a conclusion, conclusions, practical recommendations, and a list of references comprising 288 works: 152 Russian and 136 foreign authors. The materials of the dissertation contain 28 tables and 16 figures.