Konno-Rastan Combined with Manougiaun Root Enlargement for Small Aortic Root with Coronary Anomaly in a Young Woman.

Aortic root enlargement (ARE) is an established procedure to deal with small aortic annulus. It becomes very important to place adequate size prosthesis to prevent patient-prosthesis mismatch (PPM). Aortic root enlargement procedures procedures are technically demanding operations, particularly in obese patients. The presence of coronary artery anomalies adds more complexity to the procedure. We present an interesting case of a 22-year-old obese female with symptomatic severe aortic valve stenosis and anomalous coronary arteries. We successfully performed aortic valve replacement using the combined Konno aortoventriculoplasty and Manouguian posterior aortic root enlargement. Combined aortic root enlargement techniques techniques should be considered in the presence of major coronary anomalies. Copyright:

INTRODUCTION

Prosthesis-patient mismatch (PPM) is a complication observed after aortic valve replacement (AVR) and was first determined by Rahimtoola in 1978.[1] PPM can be associated with adverse outcomes that can result in cardiac-related morbidity and mortality.[2]

According to current recommendations for aortic prosthesis implantation, the effective orifice area (EOA) should be >0.85 cm2/m2 to prevent PPM.[3] Aortic root enlargement (ARE) is a technique that allows the insertion of an appropriate-sized aortic prosthesis in a patient with a small aortic annulus (EOA < 0.85 cm2/m2); therefore, it decreases the risk of PPM. Obese patients with small aortic annulus do not perform well postoperatively if they continue to have PPM.[4] We share an interesting case of obese patient with anomalous coronaries and small aortic annulus.

CASE PRESENTATION

A 22-year-old female with symptomatic severe aortic valve stenosis was referred for surgery. She was morbidly obese (body mass index (BMI): 42.53 kg/m2) and did not tolerate exercise. The patient was single and had no children. She wanted a biological prosthesis as she wanted to get married and have children.

Echocardiography revealed a severe aortic stenosis with a valve area of 0.8 cm2, peak velocity of 4.4 m/s, mean gradient of 48 mmHg, moderate aortic regurgitation, and normal left ventricular (LV) size and function (60%). The sinus of Valsalva was measured 25 mm, aortic annulus diameter was 19 mm, and mid ascending aorta was 28 mm, with normal right ventricular (RV) pressure (tricuspid regurgitation velocity 2.3 m/s). On preoperative computed tomography (CT) scan, an anomalous origin of the circumflex coronary artery was found which was coming off proximal RCA in a retro-aortic fashion [Figure 1].

Figure 1

Preoperative and postoperative computed tomography scan findings of anomalous coronary artery and the surrounding structures

Procedural details

After induction of general endotracheal anesthesia and placement of adequate monitoring lines, we proceeded with median sternotomy, and cardiopulmonary bypass was initiated using the high ascending aortic and bicaval cannulation at normothermia. We do not use bicaval cannulation routinely in standard AVR; however, in this case, we anticipated difficulty and possible need for extensive root enlargement, so we preemptively used bicaval canulation. A LV vent was placed. Intraoperatively, we noticed the presence of a large second left anterior descending (LAD) coronary artery that comes off the right coronary artery and crosses the RV outflow tract; hence, we decided not to proceed with the Ross procedure and perform an AVR using the ARE technique.

After cross-clamping, cardioplegia was administered directly through the coronary ostia to achieve satisfactory diastolic arrest. Intraoperative assessment showed that the aortic valve was the trileaflet with thickened, rolled-in leaflets and thickened subaortic membrane very adherent to the leaflets in the LV outflow tract. The aortic annulus was measured to be 19 mm, and coronary anomalies were also verified. Due to her large BMI, it was thought that a minimum size of 25 or 27 mm bioprosthesis will serve the best. We felt if we used both Konno and Manouguian principles, this will provide an adequate size annulus to place a large bioprosthesis.

A transverse right ventriculotomy was then performed parallel to that anomalous coronary artery (second LAD). A Konno incision was then made, splitting the aortic annulus and cutting into the interventricular septum for about 1.5 cm.

The aortic valve leaflets were excised. We also removed the subaortic membrane from the LV outflow tract. After sizing with 25 mm bioprosthesis, the aortic root was still found to be small, and we have decided to further enlarge the root. Using a coronary probe placed through the right coronary artery, we identified the course of the right coronary artery and the anomalous circumflex, which was passing in a retro-aortic fashion.

We then performed a posterior aortotomy which was extended along the commissure between the non- and the left coronary cusps into the anterior mitral valve leaflet for about 1 cm following the Manouguian technique.

There were two factors that made use decide to further enlarge the root: (a) we calculated the EOA, and based on her body surface area (2.1), we needed at least a 1.7 EOA for prosthesis which is why we have selected the 27 mm prosthesis (EOA = 1.8) and (b) this is a patient that will definitely need another procedure in the future, and it could be either surgery or transcatheter procedure or even both.

We decided to go with the 27 mm valve to allow the chance of a transcatheter valve implantation if needed and to buy more time before repeat operation, which we think will be inevitable in her case. A bovine pericardial patch was then used to augment the aortic root posteriorly. We then used a diamond-shaped bovine pericardial patch to reconstruct the interventricular septum and augment the aortic root anteriorly. A second hemostatic layer was then performed using a running 4-0 Prolene suture supplemented with one Teflon felt pledget to avoid any residual interventricular septal defects. A 27-mm St. Jude Epic aortic bioprosthesis was then seated using multiple interrupted pledgeted 2-0 Ethibond sutures with the pledgets on the outside of both the pericardial patches. The valve was seated, and the pericardial patches were then used to close the aortotomy, thus augmenting the ascending aorta. A third bovine pericardial patch was then used to reconstruct the RV outflow tract, and it was sewn to the Konno patch using a running 4-0 Prolene suture [Figure 2]. The heart was then de-aired, and the aortic cross-clamp was removed.

Figure 2

Intraoperative findings and different stages of surgical repair

The patient slowly regained her normal sinus rhythm. Of note, we measured the gradient across the LV outflow tract with a needle in the ascending aorta and then a second needle in the left ventricle, and it was 8 mmHg at a heart rate of 100 beats/min. Aortic pressure was 107/43 mmHg, and the LV pressure was 115/4 mmHg. Bypass time was 217 min, and the cross-clamp time was 164 min.

The patient made uneventful recovery, and on echocardiogram, it was noticed that there was a suspicion of periprosthetic regurgitation. This was not observed on intraoperative transesophageal echocardiogram (TEE). A cardiac CT confirmed the periprosthetic regurgitation to be of moderate degree. To address this leak, a percutaneous interventional approach was considered initially, but due to her complex anatomy, large body habitus, and the risk of failure, a reoperation was found to be a better approach. Furthermore, it was only a few days after the surgery, and it was easy to get into the chest. Intraoperative TEE showed that the leak is an isolated jet between the left main coronary artery ostium and toward the right pulmonary artery. We identified the leak and we were able to repair it with multiple interrupted pledgeted 2/0 Ethibond sutures. The prosthesis, otherwise, was functioning well, and ventricular function was well preserved.

She was then discharged home on the 4th postoperative day. The last mean gradient by follow-up transthoracic echocardiogram was 9 mmHg. At the time of this reporting this case, it has been 9 months since her surgery and so far she is doing well clinically.

DISCUSSION

PPM should always be avoided as it has been associated with perioperative mortality, reduced long-term survival, consistent symptoms, and slow regression of LV mass.[5] A meta-analysis has reported that severe PPM is associated with reduced long-term survival.[6]

Valve thrombosis is a fatal emergency during pregnancy. Younger females expecting pregnancy should have bioprosthesis to reduce the risk of cardiac and obstetric complications of thromboembolic phenomena.[7]

In one study, it is found that obesity is associated with long-term mortality in patients undergoing small aortic prosthesis replacement; the authors concluded that diabetes mellitus, systemic hypertension, and chronic lung disease were independent predictors of late mortality in this group.[4] ARE techniques can effectively increase the EOA and improve the long-term outcome, and quality of life in patients undergoes AVR with obesity and relatively small aortic annulus, especially in younger patients.[4]

CONCLUSION

A cardiac surgeon should be well skilled with the root enlargement procedures which may be helpful at the time of AVR for young obese women with small aortic root. Combined ARE techniques should be considered in the presence of major coronary anomalies.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.