RU2728706C1 - Method for reconstructing arteriovenous fistula - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to surgery, and can be used for reconstruction of arteriovenous fistula. Preoperative ultrasonic examination is performed. Fistulas vein branches are visualized. Vein branches are ligatured through two microincisions on the skin with loops of absorbable suture material, pricking through one incision, conducting under the vein and puncturing from the opposite side through the other incision, sticking the needle into the first prick-out point, holding above the vein under the skin and puncturing through the opposite incision, forming a loop node under the skin. Additionally, an ultrasonic examination involves measuring blood flow velocities in the punctured segment of the vein distally to each of its branches V_nd and in all branches of V_nv. Method includes determining the ratio V_nv/V_nd, where V_nv is volumetric blood flow velocity along the vein branch, V_nd is blood flow velocity in the vein directly distal to the branch, n is the branch number. Only those branches are ligated, the ratio of which is V_nv/V_nd ≥ 0.2. Skin micro-incisions are 4–5 mm long from the diametrically opposite sides of the vein. Then blood pressure is measured and compression is performed with pressure equal to arithmetic average of systolic and diastolic measured arterial pressure by cuff on middle one-third of arm. Ligation is performed in the period of created compression. Needle is selected by curvature 1/2 and length by formula d = π * (L + D + 5), where d - length of needle in mm, L - distance from skin to external wall of vein branch, D - external diameter of vein branch. Suture material is used to form another hinge of two loops, wherein both loops are arranged X-shaped at a pitch equal to the length of the microincision. When tightening the assembly, the compression is stopped in the middle one-third of the shoulder and the arterial blood discharge along the vein of the arteriovenous fistula is simultaneously briefly closed.

EFFECT: method enables to effectively solve the problem of delayed aging of arteriovenous fistula without increasing the risk of developing complications, reliably completely stop blood discharge along the branches and stolen the main vein shaft and preserve haemodynamically insignificant branches by determining before ligation of volume velocity of blood flow in the punctured vein segment and in all its branches.

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Description

The invention relates to medicine, namely to surgery. This method can be used in surgical departments in which the formation and maintenance of permanent vascular access for hemodialysis in patients with stage 5 chronic kidney disease who receive programmed hemodialysis is carried out.

Vascular access is one of the most important determinants of long-term treatment outcomes for patients with stage 5 chronic kidney disease. The optimal vascular access for the vast majority of such patients is an arteriovenous fistula (AVF). After the formation of the AVF before its use ("maturation"), on average, it takes from 3 to 8 weeks. During this time, the wall of the vein under the influence of arterial blood flow thickens ("arteriolizes"), the lumen of the vein and the artery feeding it with blood is dilated. As a result, the AVF provides the blood flow rate necessary to achieve an acceptable efficiency of hemodialysis.

The time of AVF “maturation” is an important parameter, since if the fistula cannot provide an acceptable blood flow rate by the time of hemodialysis initiation, it becomes necessary to implant a central venous catheter. Central venous catheter is the least preferred type of vascular access for programmed hemodialysis in the vast majority of patients. It is known that the use of a dialysis central venous catheter is associated with a significantly increased risk of developing infections and stenosis of the central veins, as well as with a worsening long-term prognosis.

Signs of its dysfunction in the form of delayed maturation are noted in a significant number of patients after the formation of the AVF. In about half of the cases, the reason for the delayed maturation of the AVF is the presence of additional branches of the “fistular” vein proximal to the arteriovenous anastomosis.

There is a known method of reconstruction of a long-term "maturing" AVF, in which, in the presence of venous collaterals, open surgery is performed [Planken R.N., Duijm L.E., Kessels A.G., Leiner T., Kooman J.P., Van Der Sande F.M., Tordoir J.H. Accessory veins and radial-cephalic arteriovenous fistula non-maturation: a prospective analysis using contrast-enhanced magnetic resonance angiography. J Vase Access. 2007; 8 (4): 281-6.]. The method involves preoperative visualization of veins, identification of large branches of the vein of an arteriovenous fistula, making a skin incision, surgical isolation of a branch of a vein from surrounding tissues, ligation of a branch, creating a new, wider arteriovenous anastomosis, suturing a postoperative wound.

The disadvantage of this method is the need for open surgery, implying a skin incision of about 5 cm in length, the resulting discomfort (pain in the postoperative period). This circumstance requires mandatory intervention in the operating room. The formation of a new arteriovenous anastomosis inevitably leads to a decrease in the length of the punctured segment of the vein of the arteriovenous fistula. In addition, the authors consider its diameter as an indication for ligation of a branch of a vein. This does not allow to adequately assess the contribution of the vein branch to stealing of the main vein trunk of the arteriovenous fistula.

Endrych L. (Simple technique of percutaneous ligation of accessory veins for salvage of failing arteriovenous fistulae. Article in Czech. Rozhl Chir. Fall 2017; 96(7): 296-301). Способ включает дооперационное ультразвуковое обследование, визуализацию ветвей вены артериовенозной фистулы, лигирование ветвей вены через два микроразреза на коже петлей из рассасывающегося шовного материала, вкол иглы длиной 20 мм и кривизной 1/2 диаметра через один разрез, проведение под веной и выкалывание с противоположной стороны через другой разрез, вкалывание иглы в место первого выкола, проведение над веной под кожей и выкалывание через противоположный разрез, формирование узла петли под кожей.The closest known method of AVF reconstruction for programmed hemodialysis is the method proposed

Endrych L. (Simple technique of percutaneous ligation of accessory veins for salvage of failing arteriovenous fistulae. Article in Czech. Rozhl Chir. Fall 2017; 96 (7): 296-301). The method includes preoperative ultrasound examination, visualization of the branches of the vein of the arteriovenous fistula, ligation of the branches of the vein through two micro-incisions on the skin with a loop of absorbable suture material, injecting a needle 20 mm long and curvature of 1/2 diameter through one incision, conducting under the vein and puncturing from the opposite side through another incision, injecting a needle into the site of the first puncture, passing over the vein under the skin and puncturing through the opposite incision, forming a loop node under the skin.

In this case, micro-incisions of the skin are made with a length of about 2 mm from diametrically opposite sides of the vein. Micro-incisions are not sutured, but a sterile plaster is applied to them. Ultrasonic testing is carried out.

This method has a number of disadvantages that significantly affect its safety and effectiveness. First, the branch of the vein, which is not subject to constant punctures and does not have tight adhesions to the skin, has significant mobility within its anatomical sheath. This increases the risk of trauma to the branch of the vein when passing the needle. Second, the authors propose to conduct a preoperative vein examination, which is used only to visualize the largest branch of the vein. At the same time, focusing on the diameter of the branch of the vein, it is impossible to estimate how much it steals from the main trunk of the "fistular" vein. Ligation of an excessive number of large branches significantly reduces the vascular resource of this limb and complicates further reconstruction in the event of dysfunction of the vascular access. While preserving hemodynamically significant branches, the terms of "maturation" of the main vein trunk increase. In addition, the diameter of the native vein can change significantly as a result of compression by the ultrasound probe. Thirdly, ligation with one loop does not in all cases allow to radically eliminate the discharge of blood from the main trunk of the "fistular" vein into its branch. Fourthly, when the node is tightened, there is a significant likelihood of insufficient tightening and the preservation of residual blood flow along the AVF branch, which is due to a significant increase in pressure in the vein.

The objective of the proposed method is to eliminate these disadvantages, reduce the risk of injury to the branch of the vein during its ligation, identify all hemodynamically significant branches of the vein, and ensure their complete ligation, exclude the ligation of an excessive number of branches of the vein, reduce the maturation of the fistula.

To solve this problem, preoperative ultrasound examination, visualization of the branches of the vein of the arteriovenous fistula, ligation of the branches of the vein through two micro-incisions on the skin with a loop of absorbable suture material, injecting through one incision, conducting under the vein and puncturing from the opposite side through another incision, injecting the needle into place first puncture, holding it over the vein under the skin and puncturing through the opposite incision, forming a loop node under the skin. What is new is that additionally during preoperative ultrasound examination, volumetric blood flow velocities are measured in the punctured segment of the fistular vein distal to each of its branches V _nd and in all its branches V _nv .

V _nv / V _nd ,

where V _nv is the volumetric blood flow velocity along the vein branch,

V _nd - volumetric blood flow velocity in the punctured segment of the fistular vein distal to its branch,

n is the branch number.

Only those branches are ligated, the ratio of which is V _nv / V _nd ≥0.2. In this case, micro-incisions during ligation of the identified branch are performed with a length of 4-5 mm, from diametrically opposite sides of the vein, then blood pressure is measured and compression is performed with

pressure equal to the arithmetic mean of the systolic and diastolic measured blood pressure by the cuff in the middle third of the shoulder. Ligation is carried out during the period of created compression, and the needle is chosen with a curvature of 1/2 and a length according to the formula d = π * (L + D + 5), where d is the length of the needle in mm, L is the distance from the skin to the outer wall of the vein branch, D - the outer diameter of the vein branch. The suture material is carried out with the formation of another loop, while both loops are located in an X-shape with a step equal to the length of the micro-incision. When the knot is tightened, the compression in the middle third of the shoulder is stopped and at the same time the arterial blood discharge through the vein of the arteriovenous fistula is briefly blocked.

Determination of the V _nv / V _nd ratio makes it possible to determine all hemodynamically significant venous branches on the punctured segment of the vein of the arteriovenous fistula, which are subject to mandatory ligation. This allows us to solve the problem of reducing the maturation time of the fistula. It also allows avoiding excessive ligation of non-hemodynamically significant branches, allows them to be preserved for subsequent reconstructions, which significantly increases the resource of using the AVF.

Ligation of the venous branch during the period of compression created by the cuff in the middle third of the shoulder with a pressure equal to the arithmetic mean of the systolic and diastolic measured arterial pressures can significantly reduce the risk of complications due to injury to the venous branch during needle placement.

The formation of two X-shaped loops and the overlap of the arterial discharge along the vein when tightening the knot allows the venous branch to be ligated from the first time and completely stop stealing it from the main trunk of the fistular vein. This leads to a significant reduction in the maturation time of the arteriovenous fistula.

FIG. 1 shows a diagram of measuring the volumetric blood flow velocities in the punctured segment of the vein distal to each of its branches V _nd and in all branches of V _nv ; in fig. 2 shows a diagram of the formation of two X-shaped loops with a pitch equal to the length of micro-incisions on the skin.

The implementation of the proposed method is shown in specific clinical examples.

Example 1.

Patient N., 37 years old, was admitted to the surgical department of transplantology and dialysis for the formation of an arteriovenous fistula in preparation for hemodialysis. Diagnosis: chronic glomerulonephritis, stage 5 chronic kidney disease.

An arteriovenous fistula was formed on the non-dominant left arm in the lower third of the forearm. Delayed "maturation" of the AVF was noted: 4 months after formation, the vein is poorly contoured, has a diameter of 5 mm. In this case, the blood flow in the distal part of the fistula (paraanastomotic segment) is sufficient - 850 ml per minute.

Preoperative ultrasound examination revealed that the vein has three branches in the middle third of the forearm (punctured segment of the vein). Was measured volumetric blood flow (Fig. 2) in the vein of the AVF distal to each of its branches V _nd , as well as to each branch, and the ratio of the velocities was determined. So, for the first branch V _1d was 850 ml / min, V _1v = 300 ml / min, for the second branch V _2d was 510 ml / min, V _2v = 70 ml / min, for the third branch V _3d was 420 ml / min , V _3v = 50 ml / min. Thus, the ratio V _nv / V _nd for the first branch was 0.353, for the second - 0.137, for the third - 0.119. The decision was made to ligate the first branch. The outer diameter of this branch of the vein was 4 mm, the depth of occurrence was 4 mm. Under local anesthesia with a 0.5% solution of novocaine 10.0, 5 mm skin incisions were made from diametrically opposite sides of the first branch.

Measured blood pressure - 130/90 mm Hg. Using a cuff on the middle third of the shoulder, a compression was created with a pressure of 110 mm Hg. This led to tension of the vein branch, a decrease in its mobility within the anatomical case, while the main blood flow through the arteries of the forearm was preserved. For ligation, an absorbable suture material ("Monosorb") and a 40 mm long needle with a curvature of 1/2 diameter were used. The length of the needle was chosen according to the formula

d = π * (L + D + 5),

where d is the length of the needle in mm, L is the distance from the skin to the outer wall of the vein branch, D is the outer diameter of the vein branch.

During the period of the created compression, the first injection of 1 needle was made in one of the ends of the skin incision on one side (Fig. 1), the needle was held under the vein perpendicular to it and punctured at point 2 on the opposite side. Then they made a second injection of the needle at the same point 2, held the needle over the vein at an angle to it and punctured it at point 3 at the other end of the incision from the opposite side. After that, a third injection of the needle was made at point 3, the needle was passed under the vein perpendicular to it and punctured at point 4 from the opposite side. Then they made the fourth injection of the needle at the same point, held the needle over the vein at an angle to it and punctured the needle from the site of the first injection 1. Thus, two loops were formed, located in an X-shape with a step equal to the length of the micro-incision - 5 mm.

After that, the compression in the middle third of the shoulder was stopped and the arterial blood discharge through the vein of the arteriovenous fistula was briefly blocked (manual compression on the arteriovenous anastomosis zone) in order to reduce the pressure in the ligated branch of the vein. We tightened the loops and formed a knot, cut off the loose ends of the thread and sank the knot under the skin. Skin incisions were sealed with sterile material.

The application of the proposed method led to a good effect: after three weeks the vein was well contoured, its diameter was 6-7 mm, which made it possible to successfully use the AVF for hemodialysis.

In this case, the preoperative ultrasound study allowed not only to visualize the branches of the AVF vein, but also to assess their hemodynamic significance, namely, the contribution to stealing of the main vein trunk. A branch was ligated, along which an outflow of 35.3% of the blood entering the main trunk of the AVF vein was carried out. Preservation of the vein branches that do not contribute significantly to stealing the main vein trunk will allow them to be used for subsequent reconstructions in case of AVF dysfunction. Compression in the middle third of the upper arm increased the tension of the vein branch and decreased its mobility, which allowed safe ligation. Also, the safety of the procedure is greatly facilitated by the choice of the optimal needle length. Ligation with two X-shaped loops with a step equal to the length of the micro-incision and short-term overlap of arterial blood discharge along the vein of the arteriovenous fistula made it possible to radically eliminate blood discharge along the branch of the AVF vein from the first time.

Example 2.

Patient N., 47 years old, was admitted to the surgical department of transplantology and dialysis for the formation of an arteriovenous fistula in preparation for hemodialysis. Diagnosis: polycystic kidney disease, stage 5 chronic kidney disease.

An arteriovenous fistula was formed on the lower third of the forearm. Delayed “maturation” of the AVF was noted: after 3 months, the fistula was not available for puncture on hemodialysis. The diameter of the main vein trunk was 4 mm, the blood flow in the distal fistula (para-anastomotic segment) was sufficient - 800 ml per minute.

Preoperative ultrasound examination revealed that the vein has four branches in the middle third of the forearm (punctured segment of the vein). The volumetric blood flow rates were V _1d = 700 ml / min and V _1v = 140 ml / min for the first branch, V _2d = 550 ml / min and V _2v = 150 ml / min for the second branch, V _3d = 400 ml / min and V _3v = 50 ml / min for the third branch, V _4d = 340 ml / min and V _2v = 40 ml / min for the fourth branch. Thus, the ratio V _nv / V _nd for the first branch was 0.2, for the second - 0.273, for the third - 0.125, for the fourth branch - 0.118. It was decided to ligate the first and second branches. The outer diameter of this vein branches was 3 mm, the depth of occurrence was 3 mm.

According to the method described above, the ligation of the first and second branches was carried out. In this case, 4 mm skin incisions were made from diametrically opposite sides of each branch. Blood pressure at the time of surgery was 90/60 mm Hg. Art., thus, when carrying out the suture material in the middle third of the shoulder, compression was carried out with a pressure of 75 mm Hg. Art. For ligation, absorbable suture material ("Monosorb") and a 35 mm needle were used

Application of the proposed method led to the rapid maturation of the AVF, which made it possible to use it for hemodialysis after 4 weeks.

This method was used in 24 patients who showed delayed maturation of the AVF. The period after formation was from 3 to 6 months. Within 3-4 weeks, the AVF was available for puncture after reconstruction according to the described technique. There were no complications.

The method allows to significantly improve the results of AVF reconstruction by:

- identification and ligation of hemodynamically significant branches of the vein,

- preservation of hemodynamically insignificant branches for subsequent reconstructions in case of dysfunction,

- reducing the risk of damage to the branch of the vein when carrying out suture material;

- ensuring complete ligation of the vein.

The proposed method allows you to effectively solve the problem of delayed maturation of arteriovenous fistula, without increasing the risk of complications, reliably completely stop the discharge of blood through the branches and robbing the main vein trunk and preserve hemodynamically insignificant branches.

Claims (1)

A method of reconstruction of an arteriovenous fistula, including preoperative ultrasound examination, visualization of the branches of the vein of the fistula, ligation of the branches of the vein through two micro-incisions on the skin with a loop of absorbable suture material, injecting through one incision, conducting under the vein and puncturing from the opposite side through another incision, injecting the needle into place the first puncture, holding over the vein under the skin and puncturing through the opposite incision, the formation of a loop node under the skin, characterized in that, in addition, during ultrasound examination, volumetric blood flow velocities in the punctured segment of the vein distal to each of its branches V _nd and in all branches of V _nv are measured, the ratio V _nv / V _nd , where V _nv is the volumetric blood flow velocity in the vein branch, V _nd is the volumetric blood flow velocity in the vein immediately distal to the branch, n is the branch number, only those branches are ligated, the ratio of which V _nv / V _nd ≥0 , 2, and the skin micro-incisions are made 4-5 mm long with a diameter metrically opposite sides of the vein, then the blood pressure is measured and compression is performed with a pressure equal to the arithmetic mean of the systolic and diastolic measured blood pressure with a cuff in the middle third of the shoulder, ligation is carried out during the period of the created compression, and the needle is chosen with a curvature of 1/2 and a length according to the formula d = π * (L + D + 5), where d is the length of the needle in mm, L is the distance from the skin to the outer wall of the vein branch, D is the outer diameter of the vein branch, and the suture material is carried out with the formation of another loop of two loops, while both loops are located X-shaped with a step equal to the length of the micro-incision; when tightening the knot, the compression in the middle third of the shoulder is stopped and at the same time the arterial blood discharge through the vein of the arteriovenous fistula is briefly blocked.

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