Aortic Root Conservative Repair in Acute Type A Aortic Dissection In-

volving Aortic Root: Fate of Aortic Root & Aortic Valve Function

Joon Bum Kim, Su Kyung Hwang, Sung Ho Jung, Suk Jung Choo, Cheol Hyun Chung, Jae Won Lee

Department of Thoracic and Cardiovascular Surgery, Asan Medical Center,

University of Ulsan, College of Medicine, Seoul, Korea

Background

• “Conservative versus more aggressive ap-proaches” in the surgical management of aortic root in acute type A aortic dissection has been debated

• Changes in aortic valve function and aortic root geometry after conservative aortic root repair in acute type A aortic dissection have been poorly understood.

Study Aims

• To evaluate the aortic root geometry and aortic valve function long after surgery for acute type A aortic dissection involving the aortic root.

• And thereby…To elucidate the best patient and patho-anatomic substrate amenable to a conservative versus a more aggressive approach to the aortic root and thus refine our surgical decision-making process

Methods• Between January 1999 and December 2010,

289 patients underwent aortic replacement for Acute type A aortic dissection

• Aortic root involvement: n=214

• Exclusion: - Prosthetic aortic valve in-situ (n=1)

- Concomitant root or aortic valve replacement (n=17)

• Final enrollment: n=196

Methods

• Conservative root surgery:- Preservation of aortic sinus and valve- Sinotubular / commissural resuspension- Sinotubular junction reduction

• Total arch replacement: n=41 (20.9%)Hemiarch replacement: n=155 (79.1%)

• Concomitant CABG in 13 (6.6%)

Baseline CharacteristicsTotal number of patients 196Demographic & baseline risks

Age, year 56.9 ± 11.4 Female gender, n (%) 100 (51.0)

Marfan or Loeys-Dietz syndrome, n (%) 6 (3.1)Type of aortic dissection, n (%) DeBakey type I 152 (77.6) DeBakey type II 17 (8.7)

Debakey subtype III-D (retro-A) 27 (13.8)Intramural hematoma, n (%) 9 (4.6)Aortic regurgitation grade, n (%)

None 71 (36.2)1+ 62 (31.6)2+ 25 (12.8)3+ 19 (9.7)4+ 19 (9.7)

Operative Results• 30-day mortality: n=10 (5.1%)• Late death: n=28 (14.4%)

Echocardiography & CT Follow-Up• 6-month survival: n=177 (90.3%)• Echo follow-up (n=115, 65.0%): 44.9 ± 32.7 months• CT follow-up (n=138, 78.0%): 41.8 ± 31.3 months

Changes in AR grade (P < 0.001)

Echocardiography & CT Follow-Up• Root diameter at last follow-up: 38.9 ± 6.5mm• Root diameter > 45mm: 9.7% (19/138)

Freedom from AR (2+) or root dilatation (>45mm)

Risk Factor Analysis

• Cox-regression analysis to determine the risk factor for composite of AR (>2+) and the aortic root dilatation (>45mm):Maximal root diameter at initial preoperative pre-sentation was the only significant predictor(Hazard ratio 1.10, 95% confidence interval 1.02-1.19, P = 0.014)

Initial Root Diameter & Freedom from AR or Root Dilatation

Receiver operating curve method:Greatest accuracy at 47.5mm (75% sensitivity, 58.7% specificity)

Freedom from AR or root dilatation ac-cording to the cut-off value of 47mm

Conclusions

• Conservative aortic root repair in acute type A aortic dissection showed acceptable long-term clinical outcomes.

• However, more aggressive approaches should be considered in patients who have aortic root dilatation (>47mm) because these patients have a greater propensity to develop root aneurysm late after surgery.