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RESULTS OF USING ENDOVASCULAR TECHNOLOGIES FOR REMOVAL OF CRITICAL LOWER LIMB ISCHEMIA IN PATIENTS OF REGIONAL VASCULAR CENTRES LOCATED AT MULTIDISCIPLINARY HOSPITALS

Aims. The aim of the study was to evaluate the outcomes of health care in the setting of a regional vascular centre of a multidisciplinary hospital in patients with critical lower limb ischemia based on the data of preoperative arterial hypertension of the leg circulatory bed. Materials and methods. General data on the organisational effectiveness of regional vascular centres in the second largest Russian city, Saint Petersburg, were analysed. The work of a large multidisciplinary medical organisation of the city, City Multidisciplinary Hospital No. 2, was studied in detail, whose regional vascular centre examined and treated 295 men and 88 women with pathology of the lower limb arteries in 2013–2015. The patients underwent the following surgeries: open vascular reconstruction – 282, endovascular revascularisation – 47, and hybrid surgical interventions were performed in 15 patients. In 55 cases, lower limb revascularisation was refused due to lack of opportunities for vascular bed reconstruction or because of irreversible changes in the tissues of the lower limbs.


INTRODUCTION.
Circulatory pathologies have the highest incidence in Russian adults [1]. Finding ways to improve healthcare for cardiovascular patients is a key research area of today's medicine. One such way is to create new and improve the existing regional vascular centers [2]. Atherosclerotic changes in lower-limb arteries cause most of the critical ischemia cases [3]. Atherosclerosis is usually associated with multifocal and multilevel damage to the vascular bed [4]. In this regard, introducing methods for visualizing the lumen of lower-limb arteries has a special role to play in vascular surgery. Direct angiography (AG), magnetic resonance imaging, and computed tomography run in vascular mode are considered the golden standard for such diagnosis [5]. Preoperative AG helps not only find the extent, to which the lower-limb arterial bed has been affected, or plan the surgery, but also monitor the intraoperative and postoperative outcomes [6]. These technologies are important for endovascular or hybrid surgery of general vascular pathologies, in particular, those complicated by critical lower-limb ischemia [3]. However, research data on the use of angiography in such cases remains ambiguous.
The goal hereof was to evaluate the healthcare provided to critical lower-limb ischemia patients at regional vascular centers of multiprofile inpatient hospitals; the analysis drew into consideration the preoperative AG of the arterial bed in lower limbs.

MATERIALS AND METHODS.
The research team studied medical statistics provided by the St. Petersburg Regional Vascular Center that examined and treated patients with cardiovascular surgical pathologies. To that end, the team analyzed the official databases of the St. Petersburg Health Information and Analysis Center collected over 2011-2016 and further analyzed the healthcare provided to patients examined and treated for critical lower-limb ischemia at one of the city's multiprofile inpatient hospitals, namely the City Multiprofile Hospital No. 2 (CMH2), which hosts the Regional Vascular Center and examined and treated 295 men and 88 women over 2013-2015. Twenty cases were related to bilateral lower-limb ischemia. Patients had to be hospitalized for a total of 403 times. Preoperative treatment used specific methods to visualize the vascular bed: direct angiography, computed tomography or magnetic resonance imaging in the vascular mode.
Emphasis was made on the preoperative assessment of lower-limb arteries in patients that had earlier undergone reconstructive surgeries of such arteries. Patients underwent open, endovascular, or hybrid surgery depending on the degree and length of occlusion. Comprehensive conservative treatment was provided where the lower-limb tissues could not be revascularized.
Microsoft Excel was used for statistical data processing.
The study protocol followed guidelines for experimental investigation with human subjects in accordance with the Declaration of Helsinki and was approved by the ethics committee. Written informed consent was obtained from each patient (or an official representative) before the study.
RESULTS. According to healthcare statistics, every year nearly a thousand people are killed Since 2002, St. Petersburg has had measures in place to establish regional vascular centers to provide specialized healthcare for patients with circulatory system diseases. These measures helped establish a state-of-the-art healthcare system for patients with cardiovascular pathologies, which did improve the urgent medical care available to AMI and CVA patients. In particular, the incidence of The fatality rates stalled at 10.4% to 12.0%. Since 2012, the city has had primary vascular units in place. By 2015, they had attained 319 beds and had provided specialized healthcare to 22,696 patients over four years with 1,550 fatal cases (6.8%). In 2016, St. Petersburg opened more Regional Vascular Centers at the Almazov National Medical Research Center, as well as at the primary vascular unit of CMH2. The eight regional centers with their 1,294 beds provided specialized care to 35,367 patients with a hospital fatality rate of 8.1% or 2,888 cases. Six primary vascular units treated 4,988 patients.
Apparently, the Regional Vascular Centers and primary vascular units rose in size from 907 to 1,493 beds over the studied period, while the total yearly patient counts rose from 21,171 to 40,355 cases, i.e. doubled; at the same time, the fatality rate dropped from 10 to 6.8%.
Since 2012, CMH2 has also had five primary vascular units and an X-ray surgery diagnosis and treatment unit, transformed in 2016 into a Regional Vascular Center. Over 5 years, the Regional Vascular Center of CMH2 treated 21,814 patients. The fatality rate ranged from 3.5% to 4.7%, i.e. was way below the city's average, see Table 1; this was what motivated the research team to specifically focus on this hospital and its records. Today's surgery tends to actively use the endovascular approach to treat critical lower-limb ischemia. This requires specialized X-ray enabled or hybrid operating theaters. As a rule, an inpatient hospital only has one or two X-ray enabled theaters, and peripheral artery diseases are not a priority there.
Despite some difficulties, MHT2's success in the treatment of critical lower-limb ischemia proves the diagnosis and treatment process could well be optimized if approached appropriately.  Table 2. Fifty-nine patients were found to lack substrate for revascularization, for which reason 14 of them underwent lumbar sympathectomy, 30 were treated conservatively. Primary amputation of the lower limb was performed in 15 patients: 11 transfemoral disarticulations and 4 transtibial ones. Table 2 Surgical interventions to treat critical ischemia of the lower limbs, No fatalities were observed.
The data suggests St. Petersburg's Regional Vascular Center Program is a success. It means there is well-grounded hope the positive trends in cardiovascular care will be solidified. It is therefore strongly advisable to keep and further improve this approach to healthcare.

CONCLUSIONS.
Preoperative angiography of lower-limb arteries can adequately and reliably assess the degree to which the vascular bed has been affected so as to properly choose a specific arterial revascularization method. This is especially important in critical lower-limb ischemia patients with pronounced comorbidities. Endovascular and hybrid surgery addressing the obliterative lower-limb artery diseases dramatically reduces the incidence of intra-and postoperative complications in multifocal atherosclerosis patients; combining them with less traumatic open surgery (semi-closed loop endarterectomy) opens up new opportunities in the treatment of critical LL ischemia.

FINANCIAL SUPPORT AND SPONSORSHIP
Nil.