St Petersburg University scientists find a "safe" zone for surgical treatment of patients with lower limb ischaemia

Over the last decade, the number of people with lower extremity peripheral artery disease has increased by about 13%, which according to the researchers, can be attributed to sedentary lifestyle; obesity; smoking; and some chronic health conditions, such as diabetes. Today, atherosclerosis of the lower limb arteries is among the most common arterial diseases. Moreover, the researchers stress that surgical treatment of atherosclerosis of the lower extremities is one of the current challenges for vascular surgery.

The research study was conducted in the Laboratory of Microangiopathic Mechanisms of Atherogenesis at St Petersburg University established within the framework of the mega-grant programme of the Government of the Russian Federation. The research findings are published in the scientific journal "Angiology and Vascular Surgery".

Atherosclerosis of the lower limbs is a build-up of plaque that could eventually obstruct blood flow in the arteries supplying the legs. If left untreated, the disease multiplies the risk of various adverse clinical outcomes affecting blood flow in the extremities, such as lower limb ischaemia, that is a severe blockage in the arteries. Critical limb ischaemia can lead to amputation, disability and even death. Hence, such a disease requires early diagnosis and timely treatment. 

In recent years, the medical researchers have gained experience in surgical intervention for peripheral arterial disease. The number of surgeries for chronic lower limb ischaemia is growing every year. However, postoperative complications, such as trophic disorders and gangrene, affect on average 40-60% of surgical patients, leading to long-term disability and a significant reduction in their quality of life. In some cases, the absence of necessary treatment can lead to amputation and death.

In circulatory disorders of the lower limbs, collateral circulation is of paramount importance. The collateral circulation is a network of specialised bypass blood vessels that provide alternative routes for blood flow when the main pathway becomes blocked or damaged. Collateral blood vessels in the leg are the internal iliac and deep femoral arteries.

Aleksei Kebriakov, Junior Research Associate in the Department of Hospital Surgery at St Petersburg University

‘If both the collateral arteries and the main arteries are affected by atherosclerotic lesions, the risks of developing postoperative complications increase dramatically. The deep femoral artery and its collaterals can play a crucial role in limb salvage; its functional assessment, however, is extremely difficult,’ said Aleksei Kebriakov, Junior Research Associate in the Department of Hospital Surgery at St Petersburg University. 

To date, there have not been determined specific indications for isolated vascular surgeries on the deep femoral arteries in patients with critical lower limb ischaemia, because it is impossible to reliably predict the effectiveness of surgical revascularisation through collateral arteries. 

St Petersburg University medical researchers have studied clinical cases of 99 patients suffering from chronic arterial insufficiency of the lower extremities and introduced the concept of "recipient zone", referring to the presence of a main pathway capable of receiving collaterals from the deep femoral artery. This enables surgeons to determine in advance, i.e. before surgery, whether or not there is a chance for successful limb revascularisation.

The research study was carried out by the team of the Department of Vascular and Endovascular Surgery of the Centre of Atherosclerosis and Lipid Metabolism Disorders at the Sokolov Northwestern District Scientific and Clinical Centre, under the supervision of Professor Aleksei Svetlikov, Doctor of Science (Medicine), and Professor Viktor Gurevich, Doctor of Science (Medicine), in conjunction with the Department of Hospital Surgery at St Petersburg University headed by Professor Piotr Yablonsky, Doctor of Science (Medicine), Vice-Rector for Medical Activities of St Petersburg University.

The St Petersburg University surgeons underline that for the success of the limb revascularisation surgery, a recipient zone should include at least one third of the superficial femoral artery, the hamstring artery, the tibioperoneal trunk or the proximal section of at least one of the main tibial arteries. The presence of a recipient zone allows for full compensation of blood flow during and after the surgery.

‘The research study is based on the retrospective results of examinations and treatment of 99 patients suffering from chronic arterial insufficiency of the lower extremities, who underwent indirect revascularisation. We determined that the identified recipient zone is a statistically significant factor positively affecting postoperative recovery, including in patients with critical ischaemia. In our opinion, the presence of a preserved recipient zone is central to producing a desired clinical effect after revascularisation surgery through the deep femoral artery, especially in patients with trophic disorders,’ said Aleksei Kebriakov. 

In this approach to treatment of patients with chronic arterial insufficiency of the lower extremities, collateral circulation and microcirculation take on a major role in the blood flow restoration and limb salvage. The surgeons also stress that for patients with related diagnoses, the postoperative period is crucial for recovery. Thus, to restore the lower limb motor function, it is necessary to stimulate the development of collaterals through rehabilitate walking exercises, with the support of the novel genetically engineered drugs.

St Petersburg University, the oldest university in Russia was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University will celebrate its 300th anniversary. 

The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Deputy Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; the creation of postage stamps dedicated to the history of the oldest university in Russia; and the branding of the aircraft of the Rossiya Airlines to name just a few. Additionally, the University has launched a website dedicated to the upcoming holiday. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of preparations for the anniversary.