Method for visualizing mesh implants for hernia repair

Abstract

FIELD: medicine.SUBSTANCE: method for visualizing mesh implants for hernia defect repair is proposed, according to which a 5 nm thick aluminum oxide substrate is applied to the implant, followed by a 22 nm thick nanofilm of layer-by-layer titanium oxide and vanadium oxide at a temperature of 85 degrees Celsius using atomic layer deposition technology.EFFECT: improved visualization of implants during X-ray examination in the early and late postoperative period for the timely recording of complications associated with shrinkage, wrinkling or migration of the endoprosthetic mesh.1 cl, 2 dwg

Description

[0001] This invention relates to medicine, specifically surgery, and discloses a method for visualizing mesh implants for hernia repair. The method involves applying a 5-nm-thick aluminum oxide substrate to the implant, followed by a 22-nm-thick titanium / vanadium oxide nanofilm using atomic layer deposition technology. The titanium / vanadium oxide nanofilm significantly improves the visualization of the mesh implant, resulting in a positive implant shadow during fluoroscopy and radiographic examination in the early and late postoperative periods. The aluminum oxide substrate promotes improved adhesion of the titanium / vanadium oxide nanofilm to the mesh, increases film strength, and prevents mesh degradation from exposure to an oxidizing environment.The invention can be used to study the occurrence of late postoperative complications, such as mesh shrinkage or migration, which are considered serious complications in hernia surgeries using mesh implants.

[0002] Analogues

[0003] About 20 million hernia repair surgeries are performed worldwide annually, accounting for 10-15% of all surgical interventions. According to statistics, about 1 million mesh implantations are performed worldwide annually: in Russia, abdominal wall repair for hernial defects is performed in about 180 thousand patients, in Germany - in 280 thousand, in the USA - in more than 500 thousand (Fedorov V.D. et al., 2000; Adamyan A.A., 2003; Zhebrovsky V.V. et al., 2004; Egiev V.N., 2006; Schumpelick V. et al., 1999; Klinge U., 2002; Peiper C. et al., 2006). There are a large number of hernia surgery techniques, most of which involve repair using the patient’s own tissues. However, with these plastic methods, the recurrence rate ranges from 10-15% to 40% (Cornell RB et al., 1994) (Anthony T. et al., 2000; Berger D. et al., 2002; Macintyre I.M., 2003).

[0004] In this regard, synthetic implants are increasingly being used for postoperative hernia repair. Unlike traditional repair methods, this technique avoids tissue tension and significantly reduces the incidence of both early and late postoperative complications and recurrences (Belokonev V.I. et al., 2003; Soloviev N.A. et al., 2004; Surkov N.A., 2007; Burger JWA et al., 2004).

[0005] Criticism of analogs

[0006] The use of implants (mesh endoprosthesis) was first proposed by F. Usher in 1958 (Usher FC, e.a., 1958). Although he revolutionized this field, the use of mesh implants has led and continues to lead to various complications, including serious postoperative complications such as mesh migration, shrinkage, and wrinkling, which have recently emerged with the use of synthetic materials (Poppas DP e.a., 2016); these complications had not previously developed with these surgeries. Migration of the synthetic implant into the abdominal cavity, adhesive intestinal obstruction resulting from adhesion of the intestine and mesh, fistula formation due to pressure ulcers of the intestinal wall and endoprosthesis, and seroformation in the area where the mesh has migrated are among the severe postoperative complications associated with hernia mesh implantation (Borovsky O.O., 2013; Mamedov R.A. 2013; Mishina et al., 2015). In these cases, the effectiveness of the implant is reduced to zero, as hernia recurrence is inevitable.The current diversity of endoprosthesis types is explained by the fact that none of the mesh implants proposed to date meets the requirements of an "ideal mesh." Furthermore, no existing mesh is radiopaque, making it difficult to diagnose complications such as shrinkage, migration, or wrinkling of the mesh endoprosthesis.

[0007] Therefore, the search for a plastic material that would meet the requirements of an ideal hernioprosthesis remains relevant. That is, one that would not only have high strength and maximum histocompatibility (Borovsky O.O., 2013; Mishina E.S., 2015), but also exhibit radiopaque properties to prevent complications such as implant shrinkage, migration, or wrinkling of the endoprosthetic mesh in the early and late postoperative periods. All conventional polymer textile-based meshes for abdominal hernia repair are invisible to conventional imaging methods, including magnetic resonance imaging (https: / / ichgcp.net / ru / clinical-trials-registry / NCT02177214).

[0008] Prototype

[0009] The DynaMesh®-IPOM endoprosthetic mesh, or visible IPOM mesh (DynaMesh®, FEG Textiltechnik GmbH (Aachen, Germany) is the manufacturer of the visible DynaMesh®-IPOM mesh), is used as a prototype for the proposed method. It is developed using a unique technique that contains a small amount of iron particles woven into the standard mesh structure, allowing for visualization on MRI. IPOM mesh with iron particles is used in hernia surgery for intraperitoneal implant placement.

[0010] Prototype Criticism:

[0011] • Magnetic field non-uniformity. Iron particles woven into the mesh structure may affect the uniformity of the magnetic field, which may reduce image quality.

[0012] • Need to consider patient-related factors. The exact limit for grid indication remains unclear because patient-related factors need to be considered.

[0013] • Risk of mesh shrinkage. Most implanted meshes are known to shrink, and iron particles in the mesh can contribute to this shrinkage. This can lead to recurrence due to mesh displacement or shrinkage.

[0014] • This mesh is only visible in MRI examination, X-ray examination of this implant is not possible.

[0015] The purpose of the proposed method

[0016] The purpose of the proposed method is to ensure that implants are visible during radiographic examination in the early and late postoperative period for the timely recording of complications associated with shrinkage, wrinkling or migration of the endoprosthesis mesh.

[0017] The stated goal is achieved as follows: by pre-coating the implant, which is a hernia mesh prosthesis, with a 5 nm thick aluminum oxide substrate, followed by a 22 nm thick titanium / vanadium oxide nanofilm at a temperature of 85 degrees Celsius using atomic layer deposition (ALD). ALD involves exposing one precursor to the vapor of the preceding precursor, which forms a monolayer on the substrate surface. After removing excess of the preceding precursor from the vapor phase using a purge gas (e.g., argon, Ar), the reagent gas reacts with the adsorbed layer of the preceding precursor, forming a layer of the target film-forming material. In other words, the precursors are applied sequentially and in sequence, and the reaction occurs directly on the substrate surface.

[0018] The essence of the proposed method

[0019] The essence of the proposed method is illustrated in Fig. 1, which shows a photograph of a coated mesh: the standard Flexilen mesh endoprosthesis used by us, manufactured by Lintex LLC, St. Petersburg. Fig. 2 shows the mesh shadow on an X-ray.

[0020] According to the proposed method, the target film is built up layer by layer on a substrate, which makes it possible to control the thickness of the resulting nanofilm of titanium / vanadium oxides on the standard Flexilen endoprosthesis mesh, manufactured by St. Petersburg-based Lintex LLC.

[0021] A 22 nm thick film deposited layer by layer: one layer of titanium oxide, then a layer of vanadium oxide, and so on, layer by layer. To achieve the desired film thickness, only the number of cycles used in the process is monitored.

[0022] The application of nanofilms to the surfaces of endoprostheses used based on our proposed ASO technology is carried out at significantly lower temperatures (85°C and even at a temperature of 80°C), which allows us to preserve the physical characteristics of the mesh filaments.

[0023] Comparative analysis of the features of the prototype and the method proposed as an invention

[0024] - The proposed method utilizes ASO technology to apply a nanofilm of controlled thickness (with an accuracy of 1 angstrom), achieving a uniform and clean coating. The ASO technology employed in the proposed method enables nanofilm application at low temperatures and, if necessary, the use of high temperatures to apply the film to refractory materials. This makes it possible to apply the coating to heat-sensitive materials such as mesh endoprostheses used in hernia repair.

[0025] - The prototype uses DynaMesh®-IPOM meshes, developed using a unique technique that contains a certain amount of iron particles woven into the regular mesh structure, allowing for visualization on MRI (the description does not specify the exact amount of iron particles. Furthermore, iron particles have low biocompatibility, which may cause the mesh to become coated with coarse connective tissue, leading to complications).

[0026] - According to the proposed method, high biocompatibility and antibacterial activity of nanofilms made of titanium and vanadium oxides are known, Russian Federation Patent No. 2756124 C1, published on September 28, 2021, Bulletin No. 28).

[0027] - According to the prototype, iron particles woven into the mesh structure can affect the uniformity of the magnetic field, which can reduce the quality of images.

[0028] - According to the proposed method, a uniform shadow of the coated mesh is obtained on radiographs.

[0029] - The prototype contains a risk of mesh shrinkage. Most implanted meshes are known to shrink, and iron particles in the mesh can contribute to this shrinkage. This can lead to recurrence due to mesh displacement or shrinkage.

[0030] - The proposed method provides a nanofilm with improved biocompatibility and antibacterial properties, which reduces complications associated with the implant.

[0031] Examples of specific implementation of the method

[0032] The study of radiopaque properties using the proposed method was carried out by obtaining a series of radiographs (images) of the grid using a digital X-ray machine, Duograph MTL, manufactured by Medical Technologies Ltd., Russia; the dose used was 1 m3v.

[0033] Information taken into account

[0034] 1. https: / / ichgcp.net / ru / clinical-trials-registry / NCT02177214

Claims

A method for visualizing mesh implants for hernia repair, characterized in that a 5 nm thick aluminum oxide substrate is applied to the implant, followed by a 22 nm thick nanofilm of layered titanium oxide and vanadium oxide at a temperature of 85 degrees Celsius using atomic layer deposition technology.

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