The Konno Procedure for a Redo Aortic Root Abscess

<p>This video highlights the use of the Konno procedure to safely expose the root of the aorta in a patient with an aortic root abscess and a history of multiple cardiac surgeries.<br></p><p>The patient was a 28-year-old man with endocarditis, complicated by four prior cardiac surgeries. The original pathology was Shone’s syndrome with an aberrant right subclavian artery. He presented with four days of fever, weakness, and vomiting. Blood cultures grew <em>Streptococcus</em> and imaging demonstrated an aortic root abscess. Echocardiography revealed severe central prosthetic valve aortic regurgitation. The thick echocardiographic density posterior to the aortic valve annulus and root, seen in the video, represents the aortic root abscess. Computed tomography angiography revealed a 25 mm x 36 mm x 41 mm pseudoaneurysm to the right of the midascending aorta.</p><p>The authors exposed the right axillary artery and anastomosed an 8 mm conduit using 5-0 Prolene® sutures. The right atrium was drained via a right femoral vein cannulation. Heparin was administered, and cardiopulmonary bypass was initiated. Piercing towel clamps aided in upward and lateral traction of the sternum while the redo sternotomy was performed. Extensive adhesions from the patient’s prior surgeries made visualization of the anatomy extremely difficult. Dissection was carried out until the authors were close to entering the abscess.</p><p>Cooling was increased to 22 degrees Celsius. The right superior pulmonary vein was exposed, and a vent was inserted. Once the target temperature of 22 degrees Celsius was achieved, the circulation was arrested and the abscess cavity was opened. The aorta was transected and mobilized circumferentially to allow for adequate clamping. The abscess cavity was extensively debrided. The aorta was circumferentially dissected free. A cross-clamp was applied, and bypass was restarted.</p><p>The previously-placed Manougian patch was removed, allowing the posterior part of the prosthesis to be visualized but not the coronary arteries. Despite removal of the prosthesis by cutting in the plane of the sewing ring, the right coronary was not visualized. The aortic root was completely fibrotic and frozen. Finally, the left coronary ostia was partially visualized.</p><p>The inability to see the coronary arteries or blindly cannulate the ostia was solved by retrograde cardioplegia. The circulation was again arrested, and a small right atrial incision was made. A retrograde cardioplegia cannula was placed through the right atrial wall and positioned in the coronary sinus.</p><p>Del Nido cardioplegia was administered, which gave immediate cardiac arrest. The right atrium was closed with a 3-0 Prolene® suture. Having removed the valve, a right-angle instrument was used to identify the origin of the right coronary artery, allowing the aortic root to be incised anteriorly. Following this, the orifice of the left coronary artery could just be discerned anterior to the usual position as a result of the posterior enlargement of the aortic root. This allowed circumferential mobilization of the left coronary button.</p><p>It was still not possible to visualize the annulus, and there was no mobility in the completely fibrotic annulus. Therefore, the authors decided to approach the aortic annulus via a Konno incision to the left of the right coronary artery orifice. A longitudinal incision was made in the right ventricular outflow tract below the pulmonary valve, thereby exposing the conal septum, which was then incised across the annulus, finally displaying both coronary arteries and the annulus. All the foreign material was debrided, which opened both of the abscesses previously mentioned. Samples of all infected tissue were sent to the laboratory for culture. The annulus could only be fully seen and debrided after the Konno procedure.</p><p>The 22 mm aortic homograft, which had been soaked in rifampin, was then implanted. It was placed using a continuous 4-0 Prolene® suture. A medially-based L-shaped flap was used to create a sinus for the left coronary artery, which had poor mobility due to scarring from previous surgeries. The L-shaped flap was cut into the left coronary sinus of the homograft, and the left coronary artery was implanted without difficulty using a 6-0 Prolene® suture. Having closed the flap around the left coronary artery button, the vertical limb was closed using the same suture.</p><p>The position of the right coronary artery was rotated clockwise by the Konno incision, leaving a gap between the right coronary artery button and the homograft. A similar flap was cut for the right coronary artery into the right coronary sinus of the homograft. The right ventricle free wall incision was extended to ensure that there was not right ventricular outflow tract obstruction, and the conal septal incision was closed by suturing it to the homograft. The gap at the right coronary artery was bridged using the homograft innominate artery, which was anastomosed to the right coronary artery button with a 6-0 Prolene® suture. Continued closure of the septal conal incision was closed around the homograft. The video demonstrates why the septal incision must be closed first in order to correctly judge the length and orientation of the right coronary artery extension.</p><p>The extended right coronary artery button was sewn to the homograft using a 6-0 Prolene® suture. Once the right coronary artery flap was closed around the right coronary artery button, the vertical limb was left open to facilitate the later tailoring of the homograft-aorta anastomosis. Circulation was arrested, and the aortic cross-clamp was removed with the patient in the Trendelenburg position to allow the back wall of the anastomosis to be constructed. Circulation was then restarted, and the clamp was reapplied while the anastomosis was completed. The homograft was then trimmed, and the anastomosis was completed prior to closing the vertical limb of the right coronary artery flap. The proximal portion of the right ventricular conal septum was sutured over the homograft until the anterior wall of the right ventricle was reached. At this point, a patch of pericardium was used to augment the right ventricular outflow tract, ensuring that the enlargement of the left ventricular outflow tract did not cause right ventricle outflow obstruction. Full-thickness bites of the right ventricle were taken.</p><p>The cross-clamp was released, and the patient was rewarmed then weaned from cardiopulmonary bypass into normal sinus rhythm. Total cardiopulmonary bypass time was 374 minutes and the cross-clamp time was 164 minutes. The patient was in deep hypothermic circulatory arrest for 23 minutes. The patient underwent delayed closure on postoperative day two. On postoperative day four, the patient was extubated and inotropes were weaned. On postoperative day seven, the patient was discharged on ceftriaxone. An echocardiogram performed two months after discharge did not show any valvular abnormality. It showed normal biventricular function and no left ventricular outflow tract obstruction.</p><p><strong>Suggested Reading</strong></p><ol><li>Vermeulen F, Swinkels B, van Boven WJ. Konno procedure for prosthetic aortic valve endocarditis: 34-year follow-up. <a href="https://doi.org/10.1016/j.athoracsur.2011.06.070"><em>Ann Thorac Surg</em>. 2012;93(1):302-304</a>.</li><li>Erez E, Kanter KR, Tam VK, Williams WH. Konno aortoventriculoplasty in children and adolescents: from prosthetic valves to the Ross operation. <a href="https://www.ncbi.nlm.nih.gov/pubmed/12118742"><em>Ann Thorac Surg</em>. 2002;74(1):122-126</a>.</li><li>Black MD, Walley VM, Keon WJ. Fibrous skeleton endocarditis: repair using Konno procedure. <a href="https://www.ncbi.nlm.nih.gov/pubmed/8279901"><em>Ann Thorac Surg</em>. 1994;57(1):225-228</a>.</li></ol>

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