RU2332943C1 - Method for creating model for evaluation of trachea and thyroid body vitality after period of anoxia and reperfusion - Google Patents

Abstract

FIELD: medicine; surgery.

SUBSTANCE: thyrotracheal complex with feeding vessels is selected, then blood supply of thyrotracheal complex is stopped with further establishment of flow and estimation of changes in the organ. The thyrotracheal complex with nearby vessels is selected, resection of part of the left carotid artery is performed cephalad higher from origin of thyroid artery, caudad - on the level of the 8^th trachea semiring, prosthetic appliance of defect of the left carotid artery using vascular implant is mode followed by subsequent blood supply, the right carotid artery is clamped cephalad higher from origin of thyroid artery, caudad - on the level of the 8^th trachea semiring, trachea is transected cephalad on the level of cricotracheal membrane, caudad between the 8^th and 9^th cartilaginous semirings, lateralisation of the right vocal fold is performed, the cricotracheal and tracheotracheal inosculations are overlapped, the right carotid artery is pressed out, the vascular implant is resected from the left side, inosculation is overlapped between the resected part of the left carotid artery and central end of the remaining left carotid artery.

EFFECT: adequate estimation of trachea and thyroid body vitality after the period of anoxia and reperfusion with minimal chance of traumatising an animal.

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Description

The invention relates to the field of experimental studies in surgery, in particular to a method for creating a model for assessing the viability of the trachea and thyroid gland after a period of anoxia and reperfusion on a model of large laboratory animals.

Replacing extended sections of the trachea when it is affected is currently a difficult task in surgery. The use of synthetic, semi-synthetic and biological prostheses leads to a high incidence of postoperative complications and mortality, and therefore their use in the clinic cannot be recommended. The use of the trachea with preserved sources of blood supply and blood flow seems to be promising, however, according to the literature, experimental data are not enough to introduce this method into clinical practice. In order to solve the basic issues of transplantation, in particular, related to the resistance of the organ structures to anoxia and reperfusion, a model is proposed to assess the possibility of transplantation of the thyrotracheal complex after a period of anoxia and reperfusion.

In experimental surgery, when studying the viability of a thyrotracheal transplant after a period of anoxia and reperfusion, a method for creating a model of Genden et al. Is known. (Genden EM, Gannon PJ, Smith S, Keck N, Deftereos M, Urken ML. Microvascular transfer of long tracheal autograft segments in the canine model. Laryngoscope. 2002 Mar; 112 (3): 439-44) when a trachea is highlighted with feeding vessels and excised with the preservation of one thyroid artery, a section of the internal jugular vein and paratracheal tissue, recurrent laryngeal nerves are isolated and preserved from the paratracheal tissue, after which the trachea section is removed from the body of the experimental animal and placed in a chilled Ringer's solution for the required period in accordance with task of the experiment. At the end of the period of ischemia, the transplant is implanted to the recipient by applying two tracheotracheal anastomoses, implanting one thyroid artery into the carotid artery, and applying a venous anastomosis.

However, the known method does not allow to adequately assess the anoxic and reperfusion injuries of the thyrotracheal transplant, since:

1. only one of the two sources of blood supply to the trachea is preserved;

2. there may be a violation of the anastomotic vasculature of the wall of the studied tracheal site in the process of isolation of the return laryngeal nerves;

3. thyrotracheal transplant is removed from the body of the experimental animal and, during the period of anoxia, is maintained under conditions different from the organism’s conditions, which contradicts the purpose of the experiment - determination of the organ’s resistance to thermal anoxia;

4. Removing the trachea from the body increases the risk of infection of the operating area.

The objective of the invention is to create a more adequate model for the study of anoxic and reperfusion injuries of a thyrotracheal transplant, reducing the injury rate due to the absence of venous anastomoses.

This goal is achieved by the fact that in the method of creating a model for the study of anoxic and reperfusion injuries of the thyrotracheal complex, the thyrotracheal complex with adjacent vessels is isolated, the left carotid artery is excised cranially above the thyroid artery, caudally at the level of the tracheal half ring, and the left carotid artery prosthesis is prosthetized. vascular prosthesis followed by the start of blood flow, squeeze the right carotid artery cranially above the discharge of the thyroid artery, caudally to level 8 half-rings of the trachea, cross the trachea cranially at the level of the cavernous tracheal membrane, caudally between 8 and 9 cartilaginous half-rings, perform lateralization of the right vocal fold, apply the cavernous and tracheotracheal anastomoses, squeeze the right carotid artery, excise the left vascular prosthesis and apply the left and left vascular prosthesis. arteries and the central end of the remaining left carotid artery.

The proposed method and features that distinguish it from those known in the medical and patent literature are not found, which allows us to conclude that its criterion of "novelty" is met.

In practice, the method is as follows: they create access by means of a complete median cervicotomy, rectus muscles of the neck are pulled outward, an unpaired thyroid vein, carotid arteries are secreted, the trachea-thyroid gland-vessels complex is separated from the adjacent anatomical structures, they preserve paratracheal tissue, squeeze and cross the left common carotid artery at the level of 8 half of the trachea and at the level of the middle third of the thyroid cartilage cranial to the departure of the thyroid artery, replace the defect of the left carotid artery and a vascular prosthesis with the start of blood flow through it, the cranial end of the excised portion of the left carotid artery is ligated, the caudal end is temporarily squeezed, the right common carotid artery is squeezed at the 8th half of the trachea and above the discharge of the right thyroid artery, the trachea is crossed at the level of the cricotracheal membrane and between 8 and 9 half rings, compress the thyroid veins. It is the cessation of the blood supply to the thyroid gland and the trachea section by turning off the sections of the carotid arteries above and below the thyroid artery from the bloodstream that allows you to start the specified period of anoxia, prosthetics of one of the carotid arteries allows you to avoid complications associated with cerebral ischemia. Careful isolation of the trachea with adjacent vessels and the thyroid gland is necessary to preserve the paratracheal tissue, in which the anastomotic network of the trachea is localized. In this case, the probability of damage to the recurrent laryngeal nerves is high, therefore, in order to prevent respiratory failure due to paresis of the vocal folds, the lateralization of the right vocal fold is performed by the ligature method. Pinching the thyroid veins avoids retrograde blood flow in the tracheal wall.

A predetermined period of anoxia is carried out, at the end of which the integrity of the respiratory tube is restored by the application of finger tracheal and tracheotracheal anastomoses, reperfusion is performed by squeezing and starting the blood flow of the right carotid artery, thyroid veins. Then the left carotid artery is squeezed above and below the vascular prosthesis, the prosthesis is excised, the cranial stump of the left carotid artery is ligated, the caudal stump of the left carotid artery is compared and sutured to the caudal end of its previously dissected area, blood flow is injected into the left carotid artery, and through it into the left thyroid artery, draining and suturing the surgical wound in layers. The consequences of reperfusion syndrome after a given period of anoxia are evaluated one week after the operation. To do this, euthanasia of a laboratory animal is performed in accordance with applicable regulations and international requirements for the protection of animals. A thyrotracheal complex is collected with subsequent macroscopic evaluation and microscopic examination of the tissue of the wall of the trachea and thyroid gland.

The proposed method is implemented in the presented example.

Experiment.

The object is a purebred dog, male, ≈1.5 years old, weighing 24 kg.

Premedication - atropine sulfate 0.7 mg intramuscularly, rometar 40 mg intramuscularly, relanium 5 mg intramuscularly.

Fixation of the animal on the operating table in the supine position, catheterization of the peripheral vein.

Introductory anesthesia - ketamine 25 mg intravenously.

Orotracheal intubation, mechanical ventilation.

Preparation of the operation area - shaving, treatment with iodonate.

Basic anesthesia is ketamine, fentanyl, droperidol.

Operation protocol

December 15, 2005. A longitudinal section along the midline of the neck. The neck muscles of the neck were isolated and retracted. On the front wall of the trachea, between the medial edges of the sternum-hyoid muscles, an unpaired thyroid vein is determined, along the way it receives muscle branches throughout. After electrocoagulation and ligation, the muscle branches are crossed. The above muscles are diluted laterally. Common carotid arteries were distinguished without disturbing contact with the tracheal wall. In a blunt way and using electrocoagulation, the trachea with adjacent common carotid arteries is separated from the esophagus. The complex trachea-thyroid glands-vessels is separated along the entire length from the adjacent anatomical structures.

After clamping, the left common carotid artery was crossed at the level of the 8th half of the tracheal ring and at the level of the middle third of the thyroid cartilage of the larynx (above the discharge of the thyroid artery). The resulting defect of the left carotid artery is replaced by vascular prosthesis No. 6, blood flow is started - the pulsation of the vessel is satisfactory. The cranial end of the stump of the excised carotid artery is stitched and bandaged, the caudal is temporarily clamped by a vascular clamp.

The right common carotid artery is interrupted at the level of the 8th half of the trachea and at the level of the middle third of the thyroid cartilage of the larynx (above the discharge of the thyroid artery).

The trachea is dissected cranially - at the level of the cernic tracheal membrane, caudally - between 8 and 9 half rings of the trachea.

The period of anoxia has begun.

In order to prevent postoperative paresis of the vocal folds, their lateralization according to Lichtenberg was performed (the technique was adapted to the experimental conditions).

The graft anoxia period is 6 hours.

At the end of the anoxia period, clamps were removed from the right carotid artery, the pulsation was satisfactory. The period of reperfusion has begun. Two tracheal anastomoses were performed as follows: the membranous part was sutured with a continuous vikrilovy seam, the cartilaginous part - with separate interrupted vikrilovy sutures. Anastomosis tightness is checked under the liquid level - there is no air leakage. A vascular prosthesis is excised. The cranial end of the left common carotid artery is stitched and bandaged. An anastomosis of the caudal stump with an excised segment of the left common carotid artery was performed. The start of blood flow is satisfactory ripple. When viewed through the surgical wound, hyperemia of the peritracheal tissue is noted. One of the branches of the unpaired thyroid vein was crossed in the area of the tracheal autograft, blood flow was noted.

The surgical wound is sutured in layers, leaving drainage in the retrotracheal space.

Observation In the postoperative period, antibacterial, analgesic therapy was performed. 12/18/05, the drainage is removed.

Since December 19, 2005, stridor breathing has been noted.

Graft reperfusion - 7 days (12/15/05 - 12/22/05).

December 22, 2005. Under anesthesia, spontaneous sutures were removed and the postoperative wound was removed. During the audit, tracheal anastomoses and vascular anastomoses are well-to-do. The pulsation of the carotid and thyroid arteries is well defined. On the site of trachea undergoing ischemia, peritracheal fiber is infiltrated, edematous, bleeding. The adjacent vessels and thyroid glands are involved in the infiltrate. The trachea was crossed at the level of the thoracic region and the larynx at the level of the lower third of the thyroid cartilage. Euthanasia of an animal by intravenous administration of arduan 4 mg against the background of total intravenous anesthesia.

Macroscopic evaluation of the drug: the rigidity of the cartilage half rings at the graft level is reduced, there is a narrowing of the lumen of the trachea. Mucous dull. On the membranous part, the growth of granulation tissue. The material for histological examination was taken - the native trachea (control) - 1.1, the trachea of the ischemic area (experience) - 2.1, the thyroid gland - 2.2.

During histological examination: 1.1 - the epithelium is preserved, cilia are partially absent, moderate inflammation, cartilage is not changed; 2.1 - foci of single-row epithelium, pronounced leukocyte infiltration of the entire tracheal wall, in the outer layer - the organization of fibrin, the formation of scar-granulation tissue with inflammatory infiltration, the cartilage is not changed; 2.2 - edema of the stroma of the gland, plethora of blood vessels, around the gland - the organization of fibrin with leukocyte infiltration. In the preserved epithelium - swelling of the follicles. In the vessels - swelling of the endothelium, in places - desquamation into the lumen.

Analysis of the result: after a 6-hour period of anoxia followed by reperfusion, dystrophic and inflammatory changes are noted in the thyrotracheal autograft, which is confirmed by histological examination. The absence of carotid and thyroid vessels thrombosis indicates that the indicated changes occurred due to anoxic damage in accordance with the indicated conditions, and not secondary thrombosis of the graft-feeding vascular pedicle in the postoperative period. The locality of changes in the intervention zone with a satisfactory condition of the native trachea excludes infection as the dominant cause of the revealed changes. The satisfactory condition of the cartilage in both the experimental and control sections of the trachea may indicate the relative resistance of the cartilage to ischemia, which is apparently due to the low level of metabolic processes in it.

Thus, the proposed method allows you to create a more adequate model for the study of such damaging factors as anoxia and reperfusion on thyrotracheal transplant, which will solve the questions about the sequence of organ removal in conditions of multi-organ sampling and the possibility of using the organ complex from a cadaveric donor.

The implementation of the method is illustrated by drawings.

Figure 1. A thyrotracheal complex with adjacent vessels was isolated.

Figure 2. A section of the left carotid artery was excised and prosthetized, a portion of the right carotid artery was pinched.

Figure 3. The trachea is crossed at the level of the cricoid tracheal membrane and between 8 and 9 cartilaginous half rings.

Figure 4. Reperfusion of the thyrotracheal complex by starting blood flow to the right carotid artery, laryngotracheal and tracheotracheal anastomoses were applied, a vascular prosthesis was excised, an anastomosis was placed between the excised portion of the left carotid artery and the central end of the remaining left carotid artery.

Figure 5. Macroscopic evaluation of thyrotracheal complexes after three and six hour periods of anoxia followed by reperfusion.

Claims (1)

A method of creating a model for assessing the viability of the trachea and thyroid gland after a period of anoxia and reperfusion, including the isolation of the thyrotracheal complex with feeding vessels, the cessation of blood supply to the site of the thyrotracheal complex, followed by restoration of blood flow and the assessment of changes in the organ, characterized in that the thyrotracheal complex with adjacent vessels is isolated excise a section of the left carotid artery cranially above the discharge of the thyroid artery, caudally - at the level of 8 half rings t Achaeans, prosthetically repair the defect of the left carotid artery with a vascular prosthesis, followed by blood flow, pinch the right carotid artery cranially above the discharge of the thyroid artery, caudally at the level of the 8th half of the trachea, cross the trachea cranially at the level of the cavernous tracheal membrane, caudally between the 8th and 9th cartilaginous half-rings, perform of the vocal fold, impose finger tracheal and tracheotracheal anastomoses, squeeze the right carotid artery, excise the vascular prosthesis on the left, impose an anastomosis dy excised portion of the left carotid artery and the central end of the remainder of the left carotid artery.

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