Atrioventricular Groove Rupture After Mitral Valve Replacement in A Patient With Atrial Fibrillation Secondary to Rheumatic Cardiopatia: Case Report

ABSTRACT


INTRODUCTION
Atrioventricular sulcus lesion (AVGD) is a catastrophic complication of mitral valve surgery that occurs in less than 2% of the population, with 90% mortality. (1) Depending on the start time of the rupture, it can be classified as early rupture (which takes place in the operating room), late rupture (which occurs in hours or days) and late rupture (which occurs days or years after MVR and presents as a pseudoaneurysm. (2) Breaks are classified into three types according to the location of the tear site. Type I rupture is located in the atrioventricular groove, type II rupture is at the base of the posterior papillary muscle, and type III rupture occurs midway between type I and II sites. Type I is the most common type and can be seen in the highly calcified mitral valve ring, the pathological finding is the separation of the fibrous skeleton ring from the heart with blood extravasations to the myocardium and ultimately frank perforation and rupture. The result of type I rupture is worse than type II. This high mortality is due to the anatomical location of the rupture that requires a specific surgical approach and a close trajectory of the left circumflex coronary artery, which can be sutured and lead to myocardial infarction. (3) Successful management of a type I atrioventricular groove rupture in a protocolized patient for left auriculotomy and mitral valve implantation is described, using extracorporeal circulation and correcting the defect with 48-hour packaging and a mixed pericardial patch, with appropriate postoperative results in coronary intensive care unit.

PRESENTATION OF THE CASE
We present the case of a 56-year-old patient with a history of inactive rheumatic heart disease with double mitral injury; Atrial fibrillation in management with acenocumarina and amiodarone, with a register of cardioembolic cerebral vascular event in the right middle cerebral artery, with motor sequelae of the left hemibody, RANKIN 3. Hypothyroidism in treatment with levothyroxine. Assessed by clinical cardiology service for rheumatic heart disease, with progressive dyspnea in increase of functional class NYHA IV. Left atrium echocardiogram was performed with measurements of 78x49 mm, right atrium: 64x36 mms, inferior vena cava: 21mm -collapse of 50%. VD: 39x18x32. FEVI 88 %, FAC 52 %, TAPSE 24 mms. severe dysfunction type filling pattern. Mitral valve: thickened. AVM 0.86 cm without failure. golf club sign, thickened valves with nonassertable aperture limitation with aortic insufficiency, concluding severe diastolic dysfunction by large atrial dilation. Moderate to severe mitral stenosis AMV 0.86 GRAD MED 7 severe biauricular dilation. Transesophageal echocardiogram was performed showing double mitral lesion, thickened leaflets, calcified with dome opening and hockey stick image (Figure 1), with moderate insufficiency, severe AV stenosis 0.8cm by THP, GP 33 mmHg, mean 12 mmHg in addition to thrombi of heterogeneous appearance that occupy almost completely left atrium .

Figure 1.
As part of the pre-surgical process, catheterization was performed without angiographic lesions in coronary arteries. It was protocolized for mechanical mitral valve implantation and left atrial thrombus exceresis. Left auriculotomy was performed, showing severe thickening of mitral subvalvular apparatus with giant thrombus in the left atrium occupying 80% with posterior exceresis. Mechanical mitral valve implant 27 mm Medtronic was placed, with pump time 67 minutes and aortic impingement of 56 minutes, at the point of release to complete AV block, temporary epicardial pacemaker was placed, DCP output at the first attempt, with hemostasis review documenting active bleeding in a layer from the posterior atrioventricular sulcus, hemostatic sealant type BIOGLUE was placed, warranting packing of the atrioventricular sulcus with a compress in a hammock as well as 7 gauze, managing to contain the bleeding, placing two permeable mediastinal probes. Patient admitted for severity criteria in coronary intensive care unit taking one week in the same. During his stay in the unit, he was supported by double vasopressors, inotropics and transfusions of hemocomponents due to mixed shock criteria. After the first surgery, unpacking was performed (Figure 2) at 48 hours, of 1 compress and 7 gauze, with 100cc bleeding, in the revision of the posterior atrioventricular groove, was observed without bleeding, noting infiltration of the groove with non-bleeding hematoma (Figure 3), allowed apex contractility and left ventricular lateral face, preserved right ventricular contractility. Secondary to reintervention was maintained with mechanical ventilation for 2 more days with subsequent successful weaning, removal of mediastinal probes and pericardial pacemaker, as well as vasopressor support achieving mean blood pressure (GPA) perfusoria, adjusts anticoagulant management and is discharged to floor Cardiology.

DISCUSSION OF THE CASE
Our case report shows an infrequent transoperative complication, addressing in an integral way the general context of our patient, since it had important comorbids for the development of the same, an arrhythmia as a basic pathology, which translated the formation of a coagulum of uncommon characteristics. In our scenario, advanced age stands out, providing tissues with greater friability and calcifications in rings, complicating the procedure itself. Age is a risk factor for AV groove rupture due to the higher incidence of annular calcification and friable tissues. Preservation of the posterior leaflet and basal cords may help prevent AV rupture, but this is not always possible. (3) Elderly patients have a more friable myocardium and more severe mitral annular calcification in mitral stenosis. Once broken, treatment is difficult and results in high mortality and morbidity for the patient. (4) Decalcification of the mitral ring is an essential component of rupture in patients with calcified mitral valve disease, extensive decalcification is at risk of interrupting the AV groove, leading to potentially irreparable heart injury. (5) Therefore, the rupture of the left ventricle after mitral valve (MVR) replacement should be immediately diagnosed and repaired without hesitation. (3) Spontaneous rupture has been associated with elevated left atrial pressure and overdistenion, elevated tension in the atrioventricular groove at the time of ejection and use of inotropic agents. (6) There are numerous complications described and known after MVR, such as thromboembolism, structural valve degeneration and endocarditis, paravalvular leakage, conduction irregularities in the pathway and bleeding. (5) Different techniques were included as part of the treatment of the lesion, observing a mixed approach with internal, external repairs and sealant applications during the procedure, which showed an adequate therapeutic effectiveness with translation in the hemodynamic state of the patient. (7) The most recommended procedure is internal repair, which consists of implanting a patch inside the cardiac cavity with subsequent implantation of a prosthesis in a second time. The mechanism of injury has changed dramatically over time, elderly patients present a disproportionate degree of friable tissue, have a decreased tolerance to prolonged surgical periods.
(1) Several repair techniques have been described with different success rates; However, the rarity of the complication prevents consensus on the safest technique. (8) Large amounts of hemostatic agents have been successfully used, such as a combination of fibrin sheets, fibrin glue and gelatin glue, resorcin and formalin. Application of BioGlue type adhesive under an intracardiac patch has also been described. (9) The most commonly used approaches for mitral valve surgery are the right atrial septum approach or the atrial atrial sulcus approach, which can achieve satisfactory exposure in most cases (10) ; However, in special cases, such as patients with a small left atrium, pericardial adhesions, or deep thorax, it may be difficult to obtain satisfactory exposure with the conventional approach. (11) Beyond standard internal and external repair techniques, supplementation has been tried as a way to achieve adequate hemostasis, achieving variable success. (12) Although there are different techniques as part of the treatment of the injury, in our patient with mitral valve injury, mediastinal packing was decided as the technique of choice to contain acute bleeding for 48 hours in which our patient merits double vasopressor therapy for a state of secondary obstructive shock due to cardiac tamponade as a consequence placement of compresses and mediastinal gauze, after 48 hours in which it was decided to remove packaging, a hematoma was observed in the posterior interventricular groove without residual bleeding so it was decided to repair stereotomy by remitting the shock state, This technique showed an adequate therapeutic effectiveness with translation into hemodynamics of the patient reducing short-term mortality.