Christophe Acar

Revival of the radial artery for coronary artery bypass grafting

Eighteen years after its first introduction for coronary artery revascularization, the radial artery (RA) was reinvestigated because of unexpected good long-term results in the early series. Since July 1989, 104 patients underwent myocardial revascularization using 122 RA grafts (18 patients received two grafts). The left internal mammary artery (IMA) was concomitantly used as a pedicled graft in 100 cases and the right IMA in 19 cases; a free IMA graft was used in 29 cases and a saphenous vein graft in 24 cases. A mean of 2.8 grafts per patient were performed. Nine patients underwent associated procedures: carotid endarterectomy (3), aortic valve replacement (3), Bigelow procedure (1), and mitral valve repair (2). The target artery receiving the RA was the circumflex (n = 59), diagonal (n = 29), right coronary (n = 27), and left anterior descending (n = 7). One patient died (0.96%) and 2 had perioperative myocardial infarct. Sternal wound infection was noted in 3 cases of double IMA implantation. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition aspirin (100 mg/day) was given at discharge. Early angiographic controls (less than 2 weeks) were obtained in the first 50 consecutive patients and revealed 56 of 56 patent RA grafts, 48 of 48 patent left IMA grafts, 11 of 11 patent right IMA grafts, 14 of 18 patent free IMA grafts, and 8 of 9 patent vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

The radial artery for coronary artery bypass grafting: Clinical and angiographic results at five years☆☆☆★

OBJECTIVE The aim of this study was to assess the long-term results of use of the radial artery as a conduit for coronary artery bypass grafting. METHODS After revival of the technique in 1989, the radial artery was used as a conduit in 910 patients undergoing coronary artery bypass grafting. A complete follow-up was obtained for the first 102 consecutive patients from 4 to 7 years after the operation (mean 5.27 +/- 1.30 years). Fifty-nine percent of the patients were receiving calcium-channel inhibitors. An electrocardiographic stress test was obtained for 51 patients, with no contraindications found. Routine follow-up angiography was performed in 50 cases, including those of all patients with symptoms. Thus 64 radial artery and 48 left internal thoracic artery grafts were followed up from 4 to 7 years after the operation (mean 5.6 +/- 1.40 years). RESULTS The actuarial survival was 91.6% at 5 years, and the actuarial rate of freedom from angina was 88.7% at 5 years. Four patients underwent percutaneous transluminal angioplasty during the period of follow-up, and there were no reoperations for revision of the bypass. The electrocardiographic stress test showed negative results in 73% of cases, electrocardiographic changes alone in 21%, and clinically positive results in 6%. Angiography showed that the patency rate of the radial artery grafts was 83%. The patency rate of the left internal thoracic artery grafts (n = 47) was 91%. The difference in patency could be related to the implantation sites of the grafts, mainly the circumflex artery (51%) for the radial artery grafts and almost exclusively the left anterior descending artery (94%) for the left internal thoracic artery. CONCLUSION The use of the radial artery for coronary bypass grafting provides excellent clinical and angiographic results at 5 years. Routine use of the radial artery in combination with the left internal thoracic artery can be recommended.

Homograft replacement of the mitral valve: graft selection, technique of implantation, and results in forty-three patients

UNLABELLED Because of experience gained in reconstructive mitral valve surgery, we have reevaluated the implantation of cryopreserved homografts in the mitral position. Forty-three patients, aged 11 to 69 years (mean 34 years), underwent mitral valve replacement with cryopreserved mitral homografts. The indications for the procedure were acute endocarditis (n = 14), rheumatic stenosis (n = 26), systemic lupus endocarditis (n = 2), and marasmic endocarditis (n = 1). All homografts were obtained from hearts explanted in the course of transplantation and were cryopreserved at -160 degrees C in 10% dimethyl sulfoxide solution without antibiotics. Appropriate sizing was based on morphologic study of the homografts and preoperative echocardiographic assessment of the recipient valve. In 82 homografts analyzed, the height of the anterior leaflet was 25 +/- 3 mm and the distance from the anulus to the apex of the anterior papillary muscle was 21 +/- 3 mm. The morphologic features of the papillary muscles were classified according to four types of increasing complexity. Nine valves with complex (type IV) papillary muscle abnormalities were discarded. Echocardiographic measurements of the valve were matched with those of the homograft identification cards and a slightly larger homograft was selected (measurements + 3 mm). Partial homograft replacement was done in case of a localized lesion (abscess or calcification) (n = 21). Total homograft replacement was undertaken in the presence of diffuse lesions (n = 22). Two hospital deaths occurred as a result of poor cardiac output. One patient required reoperation on the tenth postoperative day after a dehiscence on the valvular suture line. After a mean follow-up of 14 months, there has been one late death caused by a bronchial neoplasm and one reoperation for residual stenosis (partial replacement). The remaining patients were in either New York Heart Association class I (n = 25) or II (n = 13). Thirty-three patients were in sinus rhythm. Follow-up echocardiography has revealed no mitral regurgitation (n = 20), minimal mitral regurgitation (n = 13), and mild mitral regurgitation (n = 5). Surface valve area has been calculated at 2.5 +/- 0.4 cm2 in partial homograft reconstruction and 2.7 +/- 0.3 cm2 in total homograft replacement, with a transvalvular gradient of 3 +/- 4 mm Hg. CONCLUSION In a selected group of patients, the use of mitral homografts significantly extended the present limitations of reparative surgery of the mitral valve.

Noninvasive Measurement of Medium-Sized Artery Intima-Media Thickness in Humans: In vitro Validation

Recent research in ultrasound technology has led to the development of a high-resolution echo-tracking device. The present study was performed to evaluate the accuracy in the measurement of human radial artery intima-media thickness with this new device. We determined the correlation between histological and ultrasonic measurements of intima-media thickness in 15 radial artery segments obtained from the distal end of the wrist-elbow harvest for coronary bypass grafting in patients with coronary heart disease. For arterial intima-media thickness, a positive correlation was observed between ultrasonic and histological measurements (r = 0.618; p < 0.014), and the difference between ultrasound and histology measurements was 41 +/- 66 microns, with the higher measurements found by the ultrasonic device. In a subgroup of 11 patients, we determined the correlation between in vivo ultrasonic measurements of radial artery intima-media thickness at the preoperative stage and in vitro ultrasonic measurements of intima-media thickness obtained postoperatively in the same arterial segments. Internal diameter was larger in vivo than in vitro, and intima-media thickness was smaller in vivo than in vitro. The cross-sectional area of the arterial wall was calculated from internal diameter and intima-media thickness. In vitro wall cross-sectional area was correlated with in vivo wall cross-sectional area (r = 0.929; p < 0.0001). Repeatability of in vivo intima-media thickness measurements was investigated in 10 subjects through the calculation of the repeatability coefficient as defined by the British Standards Institution.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term (5- to 20-year) patency of the radial artery for coronary bypass grafting

OBJECTIVE The aim of this study was to assess the angiographic results of the radial artery as a coronary bypass conduit at long term (>5 years). METHODS Radial artery grafts were controlled in 202 patients at 10.1 years by conventional angiography (n = 79) and computed tomography (n = 123). Clinical or paraclinical evidence of ischemia was noted in 81 patients, whereas 121 patients were asymptomatic. Some 520 conduits were controlled: radial artery (n = 230), left internal thoracic artery (n = 190), right internal thoracic artery (n = 30), and veins (n = 70). Radial arteries were anastomosed to the right coronary (24%), marginal (58%), diagonal (16%), and left anterior descending (<1%) arteries, whereas left internal thoracic arteries were primarily anastomosed to the left anterior descending artery (95%). The mean number of antithrombotic and anti-anginal medications was 1.2 and 1.9 per patient, respectively. RESULTS The ejection fraction was slightly decreased compared with its preoperative value (54% +/- 11% vs 57% +/- 9%; P = .009). Nine reoperations were required at 10.5 years for valve replacement (n = 8) and isolated bypass (n = 1). Percutaneous intervention was performed in 48 patients (24%) at 7.6 years on a graft (28%) or a native coronary artery (72%). The 10-year patency of radial artery grafts was 83%, which was lower than the patency of left internal thoracic arteries (95%, P < .001) and similar to the patency of right internal thoracic arteries (87%, P = .66) and veins (81%, P = .50). No medication seemed to influence radial artery graft patency (aspirin: P = .26; calcium blockers: P = .36). All graft patency was lower when clinical or paraclinical evidence of ischemia was present than in asymptomatic cases (83% vs 90% P = .02). The patency of left anterior descending grafts was higher than that of non-left anterior descending grafts (96% vs 82% P < .001). CONCLUSION The radial artery-to-coronary bypass conduit provided a low coronary reoperation rate with an excellent patency (83%) up to 20 years postoperatively.

Mitral valve replacement using a cryopreserved mitral homograft

Mitral valve replacement, using a cryopreserved mitral homograft, was performed in a 49-year-old patient with calcified mitral stenosis. Postoperative course was uneventful. Transesophageal echocardiography performed 6 months later showed normal function of the mitral homograft.

An aortic ring: From physiologic reconstruction of the root to a standardized approach for aortic valve repair

OBJECTIVE We suggest standardizing aortic valve repair using a physiologic approach by associating root remodeling with resuspension of the cusp effective height and external subvalvular aortic ring annuloplasty. METHODS A total of 187 patients underwent remodeling associated with subvalvular aortic ring annuloplasty (14 centers, 24 surgeons). Three strategies for cusp repair were evaluated: group 1, gross visual estimation (74 patients); group 2, alignment of cusp free edges (62 patients); and group 3, 2-step approach, alignment of the cusp free edges and effective height resuspension (51 patients). The composite outcome was defined as recurrence of aortic insufficiency of grade 2 or greater and/or reoperation. RESULTS The operative mortality rate was 3.2% (n = 6). Treatment of a cusp lesion was most frequently performed in group 3 (70.6% vs 20.3% in group 1 and 30.6% in group 2, P < .001). Nine patients required reoperation during a follow-up period of 24 months (range, 12-45), 6 patients in group 1 and 3 patients in group 2. At 1 year, no patients in group 3 presented with composite outcome events compared with 28.1% in group 1 and 15% in group 2 (P < .001). Residual aortic insufficiency and tricuspid anatomy were independent risk factors for the composite outcome in groups 1 and 2. The annulus diameter, the presence of Marfan syndrome, and cusp repair had no effect on aortic insufficiency recurrence or reoperation. CONCLUSIONS A standardized and physiologic approach to aortic valve repair, considering both the aorta (root remodeling) and the valve (resuspension of the cusp effective height and subvalvular ring annuloplasty) improved the preliminary results and might affect their long-term durability. The ongoing Conservative Aortic Valve Surgery for Aortic Insufficiency and Aneurysm of the Aortic Root (CAVIAAR) trial will compare this strategy to mechanical valve replacement.

Reappraisal of a 20-year experience with the radial artery as a conduit for coronary bypass grafting.

OBJECTIVE This study aimed at evaluating the clinical and angiographic results of the radial artery (RA) used as a coronary bypass graft over 20 years. METHODS Clinical follow-up was obtained in 563 patients at 9.2 years. Angiographic follow-up was obtained in 351 patients with opacification of 1427 conduits, including 629 RA at 7.0 years. RESULTS At 9.2 years, freedom from overall and cardiovascular death was 80.3% and 92.7%, respectively. Symptoms were: acute myocardial infarction: 2.1% (n=12); angina: 17.4% (n=98), and congestive heart failure 10.6% (n=60). Percutaneous revascularization was required in 13.5% (n=76) of cases on: native coronary (n=77), RA conduit (n=21), and other graft (n=7). Reoperation was needed in 2.3% (n=13) of cases for valve replacement (n=10) and redo coronary artery bypass grafting (CABG) (n=3). At 7.0 years, RA patency was 82.8% (521/629) and was lower than that of left internal mammary artery (IMA), 95.5% (491/514) (p<0.001); similar to right IMA, 87.9% (51/58, p=0.32); free IMA, 80.0% (44/55, p=0.60); and vein, 81.9% (140/171, p=0.77). RA patency was lower in the case of myocardial ischemia: 74.0% (174/235) versus 88.1% (347/394) in asymptomatics (p<0.001). RA patency was higher for diagonal (93.1% (95/102)) compared to circumflex (82.5% (274/332, p<0.01)) and right coronary (77.6% (146/188, p<0.001)). Calcium channel blockers had no impact on RA patency. Separating four groups at successive follow-up intervals, RA patency was: 86.2%, 81.9%, 81.4%, and 81.6% at 1.0, 5.4, 8.3, and 13.1 years, respectively. CONCLUSION CABG with the RA offered long-lasting clinical benefit. Beyond the first postoperative year during which some attrition was observed, RA patency was remarkably stable for up to 20 years.

An aortic ring to standardise aortic valve repair: preliminary results of a prospective multicentric cohort of 144 patients

OBJECTIVES Multiplicity of aortic valve repair or sparing techniques results in a lack of standardisation, limiting widespread adoption of such procedures. To treat dilated diameters at the aortic annular base and sinotubular junction while maintaining root dynamics, we propose a standardised and physiological repair approach to the surgical management of aortic root aneurysms, consisting of root remodelling, cusp re-suspension and subvalvular aortic ring annuloplasty. METHODS From May 2003 to September 2009, 144 unselected patients with aortic root aneurysms underwent remodelling with external subvalvular ring annuloplasty in 13 centres (21 surgeons). Preoperative aortic insufficiency (AI) > or =grade 2 was present in 63.9% (92), Marfan syndrome in 12.5% (18) and bicuspid valve in 22.9% (33). Cusp repair was performed in 40.3% (58) patients. RESULTS Valve repair was successful in all but two cases. Repair of cusp prolapse was necessary in 58 patients, significantly more frequent in bicuspid (24/33, 72.7%) than in tricuspid (34/111, 30.6%) valves (p<0.05). Operative mortality was 2.8% (four). Subvalvular ring implantation produced a significant annular base reduction from 27.6+/-2.5 mm to 20.5+/-2.6 mm (p<0.01) without significant mean trans-valvular gradient (7.2+/-1.7 mmHg). During follow-up (median 2.2 years (0.75-4.4, maximum 6.25 years)), five patients died while eight required a re-operation. Six were operated on during our early experience. Strategy for cusp re-suspension evolved over three operative periods, with a significant increase in the rate of cusp repair. From May 2003 to December 2006: eye balling evaluation (15/67 (22.4%)); from January 2007 to August 2008: alignment of cusp free edges (17/38 (44.7%)); and from September 2008 to September 2009: a two-step standardised repair consisting of alignment of cusp free edges and effective height re-suspension (26/39 (66.7%) p<0.05). Freedom from AI> or =grade 2 was 91.3% (115) at the end of follow-up. CONCLUSIONS Implantation of an external aortic ring provides a reproducible technique for aortic valve repair with satisfactory preliminary results. The ongoing CAVIAAR trial (Conservative Aortic Valve surgery for aortic Insufficiency and Aneurysm of the Aortic Root) will compare this standardised repair technique using an expansible aortic ring to mechanical valve replacement.

A lesional classification to standardize surgical management of aortic insufficiency towards valve repair

OBJECTIVE Aortic valve repair is an alternative to valve replacement for treatment of chronic aortic insufficiency (AI). In order to standardize surgical management, we suggest a classification based on echocardiographic and operative analysis of valvular lesions. METHODS Classification was based on the retrospective analysis of chronic AI mechanisms of 781 adults operated on electively between 1997 and 2003. RESULTS AI was isolated (406 patients (52%)), associated with supra-coronary aneurysm (97 cases (12.4%)), or with aortic root aneurysm (278 patients (35.6%)). Etiologies of valvular or aortic lesions were respectively rheumatic, dystrophic and atheromatous in 17%, 73.6% and 9.4% of cases. Lesional classification is based on the analysis of chronic AI mechanisms defining type I with central jet (354 cases, 45.3%) and type II with eccentric jet (54.7%). Type Ia is defined as isolated dilation of sino-tubular junction (47 supra-coronary aneurysms), and type Ib as dilation of both sino-tubular junction and aortic annular base (233 root aneurysms, 74 isolated AI). The type II associates dilation of sino-tubular junction and annular base to a valvular lesion: IIa cusp prolapse (95 aneurysms, 200 isolated AI); IIb cusp retraction (132 rheumatic AI), IIc cusp tear (endocarditis, traumatic). CONCLUSION A lesional classification aims to standardize the surgical management of aortic valve repair: type Ia, by supra-coronary graft; type Ib, by subvalvular aortic annuloplasty associated with the aortic root replacement with a remodelling technique (root aneurysm) or double sub- and supravalvular annuloplasty (isolated AI). For chronic AI type II, aortic annuloplasty associated a remodelling technique or double sub- and supravalvular annuloplasty is combined with the treatment of the cusp lesion (cusp resuspension, cusp reconstruction with autologous pericardium).