Tayfun AYBEK, Anton MORİTZ, Selami DOĞAN

Aort kök anevrizmalarında yeni sinüs oluşturularak kapak koruma

Amaç: Asandan aort anevrizmalarında uygulanacak aort kapak resüspansiyon tekniğinde sinus Valsalva'lar rezeke edilir. Bu ek girişim yaprakçık hareketlerini ve uzun dönem durabilitesini olumsuz etkileyebilir. Aort kapak yaprakçıklarının açılım ve kapanma karakteristikleri David ve neosinüs yaratılan modifikasyonlarında reimplantasyon sonrası karşılaştırdık. Materyal ve Metod: Eylül 1995 - Mayıs 2002 tarihleri arasında 25 hastaya David tekniği (Grup A) ve 24 hastaya modifiye neosinüs tekniği (Grup B) ile aort kök rekonstrüksiyonu uygulandı. Her iki grupta aort kapak muhafaza edilerek aort kökünün sentetik greft ile replasmanı sonrası suspense edildi ve koroner ostiumlar reimplante edildi. Transtorasik ve transözefageal çalışmalar intraoperatif, taburcu edilmeden önce ve 1 yıl sonra yapılarak üç grup karşılaştırıldı. Üçüncü bir grup kontrol grubu olarak (Grup C) ele alındı ve aort girişimi yapılmayan 25 hasta bu gruba dahil edildi. Bulgular: Peroperatif mortalite 2 hastada (miyokard enfarktüsü ve mezentur embolisi) görüldü. İki hastada strok gelişti. Yirmialtı hasta 12 ay takip edildi ve bunların 22 tanesi fonksiyonel kapasite I, iki tanesi II ve iki tanesi III. sınıfta idi. Üç hasta postoperatif dönemde kaybedildi. Altı hastada minimal, 4 hastada hafif ve bir hastada orta derecede aort yetmezliği saptandı. Tromboembolik olay görülmedi. Ortalama transvalvuler gradiyent 3.5 ± 2.2 mmHg idi. Kapak açılım velositesi Grup A'da 61.3 ± 20.1 cm/sn, Grup B'de 46.3 ± 8 cm/sn ve Grup C'de 29.2 ± 9.8 cm/sn idi (Grup A ile B arasındaki p = 0.003, Grup A ile C arasındaki p < 0.001, Grup B ile C arasındaki p < 0.001). Kapanma velositesi Grup A'da 57.5 ± 23 cm/sn, Grup B'de 43.8 ± 7 cm/sn ve Grup C'de 23.6 ± 7 cm/sn idi (Grup A ile B arasında p = 0.012, Grup A ile C arasındaki p < 0.001, Grup B ile C arasındaki p < 0.001). Grup A'daki 7 hastada nativ aort yaprakçıkları sistolde prostetik aort duvarına çarpıyordu. Sonuç: Nativ aort kapağının prostetik greft içerisine reimplantasyonu, anormal açılım ve kapanma hızlarına neden olur. Konvansiyonel tekniğine nazaran sinus bombesi yaratılması daha fizyolojik kapak dinamiklerine neden olur. Orta dönem klinik gözlemler her iki tip yöntemde olumlu sonuçlar verse de, kapak durabilitesini devam ettirecek daha fizyolojik yaprakçık dinamiklerinin hangi teknikte olacağı konusunda uzun dönem takip sonuçlarına ihtiyaç vardır.

Valve sparing surgery using creation of a neosinus for aortic root aneurysms

Background: Aortic valve resuspension for ascending aortic aneurysm repair is associated with removal of the sinus of Valsalva. This may cause changes in leaflet motion and thus impact on long term durability. We studied the opening and closing characteristics of the aortic valve leaflets after reimplantation by the technique described by T. David and a modification to create a "neosinus" compared to an age matched control group. Methods: Between September 1995 and May 2002, 25 patients underwent aortic root reconstruction as described by Tirone David (Group A). In 24 patients the technique was modified by shaping a "neosinus" (Group B). In both groups the native valve was preserved and suspended inside a tubular prosthesis with reimplantation of the coronary arteries. Transthoracic and transesophageal studies on aortic valve dynamics were performed intraoperatively, before hospital discharge and one year after surgery in all patients and compared to a separate group of 25 matched control individuals (Group C). Results: There was two perioperative deaths due to myocardial infarction and mesenterial emboli. Two patients suffered a stroke. Twentysix patients were followed up 12 months postoperatively. Twentytwo out of 26 patients were in NYHA functional class I, 2 patients in class II and the remaining 2 in class III. Three patients died in the postoperative period. Six patients had trivial AR, 4 had mild and 1 had moderate regurgitation. There were no thromboembolic events during follow up. The mean transvalvular gradient was 3.5 ± 2.2 mmHg. Valve opening velocity was 61.3 ± 20.1 cm/s in Group A, 46.3 ± 8 cm/s in Group B, and 29.2 ± 9.8 cm/s in Group C (Group A vs. B p = 0.003, A vs. Group C p < 0.001, B vs. C p < 0.001). Closing velocity was accelerated to 57.5 ± 23 cm/s in Group A and 43.8 ± 7 cm/s in Group B compared to 23.6 ± 7 cm/s in Group C (A vs B p = 0.012, A vs C p < 0.001, B vs C p = 0.002). In 7 patients of Group A the leaflets touched the prosthetic wall during systole. Conclusions: Reimplantation of the natural aortic valve in a prosthetic graft causes abnormally high opening and closing speeds with possibly increased stress. We could prove more physiologic valve dynamics after creation of a sinus bulge compared to the conventional reimplantation technique. Midterm clinical observation however showed favourable valve competence for both types of repair. Long term follow up is necessary to prove whether more physiologic leaflet dynamics lead to improved durability.

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