RU2223055C2 - Device for building urethral anastomoses - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: device has tubular rim from biologically inert material which wall is laminated as foil rolled-up into a cylindrical roll. The foil is manufactured from titanium nickelide possessing shape memory and superelasticity properties. Initial tube diameter and blood vessel lumen diameter relation corresponds to its tight flexible fitting to enable internal sealing of connection area with no urothelium ischemia manifesting. EFFECT: high quality of anastomosis zone sealing resulting in operation consistency. 2 dwg

Description

 The invention relates to medical equipment, specifically to devices of urological surgery.

 One of the surgical methods for treating life-threatening narrowing (stenosis) of the urethral urethra is resection of the stenotic area, followed by anastomosis. To facilitate the tightening of the ends of the shortened after resection of the urethra, butt joints and suturing use tubular mandrels, which also perform the function of bougie in the operation.

 A device for anastomosis of the urethra is known, in which a silicone catheter is adapted [1]. By the greatest similarity of function and technical essence, this device is selected as a prototype of the invention.

The device has disadvantages:
1. Hydrophilic material (silicone) complicates disinfection, is the danger of additional infection and the associated need for constant irrigation of an installed device with an antiseptic.

 2. Low biocompatibility of silicone leads to a negative reaction of the mucous membrane of the urethra, the need for premature evacuation of the device and, as a result, increase the possibility of relapse of stenosis.

 3. Leakage due to inadequacy of the rigid size (diameter) of the tube, the landing of the device in the urethra does not allow to seal the anastomosis zone from the inside, to exclude leakage of urine, the formation of fistulas on the perineum.

 The technical result of the invention is to increase the sealing zone of the anastomosis, leading to an increase in the viability of the operation.

 The specified technical result is achieved by the fact that in the device for an urethral anastomosis containing a tubular mandrel of bioinert material, the mandrel wall is laminated in the form of a titanium nickelide foil rolled into a cylindrical roll with a shape memory effect and superelasticity, while the ratio of the initial tube diameter and normal clearance the urethra corresponds to a tight elastic fit of the day of internal sealing of the joint area in the absence of urothelium ischemia.

 The material of the device - titanium nickelide - has high biocompatibility, so it does not cause a negative reaction of urothelium for the entire period of operation and healing. Prolonged bougieurage allows the formation of a normal urethral lumen, and the absence of a pronounced inflammatory reaction - a gentle, uniform connective scar.

 The shape memory effect of the material is used in conjunction with the roll structure of the device wall to ensure convenient delivery to the installation site. To do this, the device (Fig. 1) is deformed to a smaller diameter in a cooled state (twist the roll), fit onto the handle (silicone tube, Fig. 2) and freely lead to the installation site, where the device, turning when heated, is freed from the handle and dilates the walls of the urethra.

 Opened to the original diameter, the tube is held in a slightly stressed state by tensioning the walls of the urethra and due to the superelasticity effect of titanium nickelide. The ratio of the initial ("cold") diameter of the tube and the normal lumen of the urethra is selected corresponding to a dense elastic fit, which provides internal sealing of the connection area in the absence of urothelium ischemia. Thus, the possibility of independent urination remains and, therefore, the need for an epicystostomy is eliminated.

 The dense and heat-resistant material titanium nickelide allows reliable sterilization of the device, which prevents infection of the urethral cavity. The sterility of the operation is also accompanied by the absence of protruding sections of the device protruding beyond the urethra, as is the case in the prototype.

Figure 1 shows a device for anastomosis of the urethra in the "cold"state;
figure 2 - device for anastomosis of the urethra on the handle, prepared for installation.

 The attainability of the technical result is confirmed by examples of specific use in the Novosibirsk State Regional Clinical Hospital.

 Example. Patient P., 32 years old. Diagnosis of the disease: post-traumatic stenosis of the membranous-prostatic urethra. Due to the impossibility of self-urination, an epicystostomy was previously imposed. Attempts were made to quickly restore patency, which did not lead to the desired results.

 05/15/01 the patient underwent resection of the urethra using a device according to the claims.

 A tubular mandrel with a length of 50 mm (Fig. 1), a diameter of 10 mm, a foil thickness of 0.005 mm, the number of layers in a roll convolution 3. The material of the device is titanium nickelide TH-10. The device during the operation works as follows. After resection of the urethra with a wide (20 mm) excision with open access, the device is prepared for installation. Cooled in chloroethyl and a disinfected device is rolled up to a smaller lumen diameter and inserted with an interference fit on a silicone tube (Fig. 2) with a diameter of 5 mm serving as a handle. Transurethrally delivered to the area of the anastomosis, carried out in the proximal section of the resected urethra and tighten its ends for suturing. The device heated to the patient’s body temperature, returning to the initial diameter and unwinding in a roll, releases the handle, which is removed by traction, dilates the walls of the urethra and self-fixes in it due to the elastic pressure and reaction of the dilated walls. Anastomosis is performed according to a standard technique and the wound is sutured.

 On the second day, the patient is allowed to urinate on his own. Primary healing. The anastomosis device was removed after two weeks.

 According to the proposed technique, with a similarly favorable outcome, the clinic performed 8 operations for stenosis of the urethral membranous section of the post-transferred gonorrhea (2 patients), trauma (5 patients) and repeated surgical interventions for hypospadias (1 patient).

Sourse of information
1. Rusakov V. I. Surgery of the urethra. Rostov-on-Don, 1998, p. 150-158 (prototype).

Claims (1)

A device for an urethral anastomosis containing a tubular mandrel of bioinert material, characterized in that the mandrel wall is laminated in the form of a titanium nickelide foil rolled into a cylindrical roll with a shape memory effect and superelasticity, while the ratio of the initial diameter of the tube to the normal urethral lumen corresponds to a dense elastic landing for internal sealing of the connection area in the absence of urothelium ischemia.

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