Midterm Outcomes Using the Physio Ring in Mitral Valve Reconstruction: Experience in 492 Patients

Transcription

1 Midterm Outcomes Using the Physio Ring in Mitral Valve Reconstruction: Experience in 492 Patients Kevin D. Accola, MD, Meredith L. Scott, MD, Paul A. Thompson, MD, George J. Palmer III, MD, Mark E. Sand, MD, and George Ebra, EdD Cardiovascular Surgeons, PA, Florida Hospital Cardiovascular Institute, Orlando, Florida Background. Mitral valve reconstruction using standardized Carpentier techniques is the treatment of choice for most patients with regurgitant lesions. Demonstrated predictability and stability make it an attractive alternative to valve replacement. The Physio Ring s inherent flexibility provides a viable alternative in the application of remodeling techniques and appears to be physiologically superior to traditional approaches. Methods. Between April 1994 and October 2000, 492 consecutive patients underwent mitral valve reconstruction using standardized Carpentier techniques with the Carpentier-Edwards Physio Ring (Edwards Lifesciences LLC, Irvine, CA). There were 267 men (54.3%) and 225 women (45.7%). Mean age was 64.2 years (range, 18 to 86). Almost one-half (44.3%) were 70 years of age or over. The mitral valve etiology was congenital in 7 patients (1.4%), myxomatous in 351 patients (71.3%), ischemic in 88 (17.9%), rheumatic in 26 (5.3%), endocarditis in 9 (1.8%), calcific in 8 (1.6%), and other abnormalities in 3 (0.6%). Results. Isolated mitral valve reconstruction was performed in 282 patients (57.3%), with coronary artery bypass grafting (CABG) in 182 (37.0%), with valve replacement in 11 (2.2%), and with CABG and valve replacement in 17 (3.5%). All patients (100.0%) had ring annuloplasty, 263 (53.5%) leaflet resection, 140 (28.5%) chordal resection, 55 (11.2%) chordal transposition, 48 (9.8%) chordal shortening, and 15 (3.0%) commissurotomy. Overall hospital mortality was 3.5% (17 of 492). Postoperative complications included respiratory insufficiency in 55 patients (11.2%), low cardiac output in 13 (2.6%), stroke in 14 (2.8%), reoperation for bleeding in 13 (2.6%), renal insufficiency in 21 (4.3%), and myocardial infarction in 5 (1.0%), and new onset of atrial fibrillation in 74 patients (15.0%). The cumulative follow-up for the series was 1,522.9 patient years and ranged from 1 to months (mean, 38.5 months). There were 11 reconstruction failures (2.3%) requiring ring explant. Actuarial survival was 81.5% 2.1% at 4 years and 67.9% 4.6% at 7 years. Freedom from reoperation at 4 years was 81.5% 2.1% and 67.9% 4.6% at 7 years. Conclusions. Mitral valve reconstruction with the Physio Ring can be accomplished with low hospital mortality and morbidity even in combined procedures. Moreover, the low incidence of reoperation and late cardiac events suggests that the Physio Ring, with its inherent flexibility, offers a definite advantage in the application of remodeling techniques in mitral valve reconstruction. (Ann Thorac Surg 2005;79: ) 2005 by The Society of Thoracic Surgeons Mitral valve reconstruction is the treatment of choice for most patients with regurgitant lesions. It is physiologically durable and represents a more beneficial long-term alternative than valve replacement in selected patients, by maintaining native valve function and avoiding anticoagulation. Since first introduced [1 5] the evolution of mitral valve reconstruction techniques have flourished. The work of Carpentier and colleagues [6 8] and Duran and colleagues [9 11] has established and demonstrated surgical techniques that are standardized, reproducible, and over time have provided excellent long-term clinical results. Mitral valve reconstruction is associated with low Accepted for publication Sept 21, Presented at the Fiftieth Annual Meeting of the Southern Thoracic Surgical Association, Bonita Springs, FL, Nov 13 15, Address reprint requests to Dr Accola, Cardiovascular Surgeons, PA, 217 Hillcrest St, Orlando, FL 32801; kaccola@aol.com. operative mortality and morbidity [12], improved left ventricular function in the immediate postoperative period [13], and enhanced long-term survival [14]. The application of reconstructive techniques in various cohorts of patients (those with rheumatic disease [15], flail leaflet [16], cardiomyopathy [17], the elderly [18], etc) have also demonstrated excellent results. Moreover, ischemic mitral insufficiency, now better understood as a left ventricular or papillary muscle dysfunction, has been shown functionally to be treated effectively with reduction annuloplasty. A physiologic annuloplasty ring offers an advantage in these patients by maintaining the fluidlike dynamic function of the annulus. These factors make reconstructive surgery the procedure of choice for the treatment of a vast majority of patients with mitral valve disease. The purpose of this retrospective study is to discern the efficacy and clinical performance of the Physio Ring as an 2005 by The Society of Thoracic Surgeons /05/$30.00 Published by Elsevier Inc doi: /j.athoracsur

2 Ann Thorac Surg ACCOLA ET AL 2005;79: MITRAL VALVE RECONSTRUCTION 1277 Table 1. Preoperative Clinical Variables and Risk Factors Characteristic No. (%) No. of patients 492 Gender Male 267 (54.3) Female 225 (45.7) Age (y) Mean Range Age groups (y) (15.4) (13.4) (26.8) (37.8) (6.5) Risk factors Systemic hypertension (diastolic pressure (59.3) mm Hg) Pulmonary hypertension 181 (36.8) Diabetes mellitus 67 (13.6) Hypercholesterolemia (cholesterol 200 mg/dl) 143 (29.1) Cerebrovascular accident 25 (5.1) Peripheral vascular disease 38 (7.7) Renal insufficiency (creatinine 2.0 mg/dl) 47 (9.6) Previous myocardial infarction 96 (19.5) History of congestive heart failure 352 (71.5) Arrhythmia 175 (35.6) Chronic obstructive pulmonary disease 87 (17.7) New York Heart Association Class I 35 (7.1) II 212 (43.1) III 171 (34.8) IV 74 (15.0) Canadian Cardiovascular Society Class 0 30 (6.1) I 51 (10.4) II 202 (41.1) III 151 (30.7) IV 58 (11.8) advanced concept in mitral valve reconstruction [19]. Moreover, it focuses on assessing the durability of valve reconstruction, patient symptomatic improvement, and patient functional outcomes. Patients and Methods Patient Population From August 1981 through October 2000, 1,058 consecutive patients underwent mitral or tricuspid valve reconstruction using the Carpentier-Edwards Classic or Physio Annuloplasty Ring. Of this cohort, 492 underwent mitral valve reconstruction with the Physio Ring (Carpentier- Edwards Physio Annuloplasty Ring; Edwards Lifesciences LLC, Irvine, CA) applying standardized Carpentier-type techniques [8] from April 1994 through October There were 267 men (54.3%) and 225 women (45.7%) between 18 and 86 years old, with a mean age of years. The preoperative cardiovascular status indicated systemic hypertension (diastolic blood pressure higher than 90 mm Hg) in 292 patients (59.3%), pulmonary hypertension in 181 patients (36.8%), diabetes mellitus (insulin and noninsulin-dependent) in 67 patients (13.6%), hypercholesterolemia (cholesterol level higher than 200 mg/dl) in 143 patients (29.1%), cerebral vascular accident in 25 patients (5.1%), and peripheral vascular disease in 38 patients (7.7%). In addition, renal insufficiency (creatinine level at least 2.0 mg/dl) was documented in 47 patients (9.6%), previous myocardial infarctions in 96 patients (19.5%), congestive heart failure in 352 patients (71.5%), arrhythmias in 175 patients (35.6%), and chronic obstructive pulmonary disease in 87 patients (17.7%). The patient s preoperative functional status was ranked according to the New York Heart Association (NYHA) classification system. Thirty-five patients (7.1%) were in class I, 212 patients (43.1%) in class II, 171 patients (34.8%) in class III, and 74 patients (15.0%) in class IV. In addition, the patient s preoperative angina status was rated according to the Canadian Cardiovascular Society classification system. Thirty patients (6.1%) were in class 0 (no angina), 51 patients (10.4%) were in class I, 202 patients (41.1%) in class II, 151 patients (30.7%) in class III, and 58 patients (11.8%) in class IV. The clinical characteristics of the patient population are summarized in Table 1. There were 30 patients (6.1%) who previously had undergone a cardiovascular operation. Preoperative diagnostic assessment was performed with cardiac catheterization including cineangiography, transesophageal echocardiography, or a combination thereof to establish the diagnosis. Definitions PREOPERATIVE VARIABLES. Pulmonary hypertension was defined as systolic pulmonary artery pressure greater than 60 mm Hg or pulmonary vascular resistance greater than 260 dynes sec cm 5. Congestive heart failure was defined as paroxysmal nocturnal dyspnea, dyspnea on exertion due to heart failure, or chest roentgenogram showing pulmonary congestion. Elective surgery was defined as an operation, which could be deferred without increased risk of compromised cardiac outcome. An urgent operation was defined as being required within 48 hours in an effort to prevent further clinical deterioration. An emergency operation was defined as those instances where the patient did not respond to aggressive clinical measures and clinical decompensation continued to occur. A salvage operation was defined as those in which the patient was undergoing cardiopulmonary resuscitation in route to the operating room, before anesthesia induction, or in cardiogenic shock. POSTOPERATIVE VARIABLES. Respiratory insufficiency was defined as patients requiring ventilatory support for greater than 48 hours. Cerebrovascular accident was defined as a

3 1278 ACCOLA ET AL Ann Thorac Surg MITRAL VALVE RECONSTRUCTION 2005;79: focal neurologic deficit that remained unresolved and persisted for greater than 24 hours. Perioperative myocardial infarction was defined as the occurrence of a new onset of Q waves, with or without increased myocardial enzyme levels. Renal insufficiency was defined as a creatinine level greater than or equal to 2.0 mg/dl. Low cardiac output referred to clinical evidence of hypotension, oliguria, and peripheral vascular constriction with normal or supranormal left ventricular filling pressure or a measured cardiac index of less than 2L min 1 m 2, necessitating the administration of catecholamines or the use of the intraaortic balloon pump, or both. Hospital mortality was defined as death occurring during the operation or the hospitalization in which the procedure was performed, or death occurring after discharge from the hospital but within 30 days of the surgical procedure, unless the cause was clearly unrelated to the operation. Operative Technique Median sternotomy was utilized for a majority of cases; however, a right thoracotomy approach was used in selected cases. Echocardiography has provided for more accurate assessment preoperatively of pathologic valve anatomy and improved intraoperative assessment of the reconstructed value. Transesophageal echocardiography was performed in all cases intraoperatively and early postreconstruction to assess valve function. Standard cannulation and myocardial preservation techniques were utilized with cardiopulmonary bypass and moderate hypothermia. Concomitant coronary revascularization, if required, was performed after initially instituting bypass and before the application of valve reconstruction techniques. Assessment of the mitral valve was accomplished utilizing Carpentier s methods of valve analysis [8]. Prosthetic ring annuloplasty was performed in all cases to reinforce the reconstruction, to enhance its durability, and for its remodeling effect. The annuloplasty reduces the area that the leaflets must cover and allows for appropriate leaflet coaptation. The Physio Ring, with its inherent flexibility, allows for the necessary changes in shape required during the cardiac cycle. Simple type I annular remodeling was performed with reduction of the annulus, which was typically downsized one to two sizes. Standardized horizontal mattress sutures were placed circumferentially to secure the annuloplasty ring. In more complex type II and III reconstructions, involving increased valve abnormality, judicious use of concomitant posterior chordal elongationresection, posterior leaflet sliding valvuloplasty, and leaflet resection techniques were incorporated in the valve reconstruction. Quadrangular resection was performed at the base of the posterior leaflet remnants to correct excessive tissue. Interrupted or figure eight 4-0 and 5-0 polypropylene sutures were utilized when performing posterior leaflet reconstruction. Anterior leaflet pathology was addressed using chordal transfer techniques or Gore-Tex suture chordal replacement (W L Gore & Assoc, Flagstaff, AZ). The mean cardiopulmonary bypass time for isolated mitral valve reconstruction was minutes (range, 38 to 234 minutes) and minutes (range, 52 to 274 minutes) for combined procedures (p 0.001). The mean aortic cross-clamping time for isolated mitral valve was minutes (range, 25 to 193 minutes) and minutes (range, 30 to 192 minutes) for combined procedures (p 0.001). Operative Data The operation was performed electively in 439 patients (89.2%), urgently in 41 patients (8.3%), emergently in 8 patients (1.6%), and as salvage in 4 patients (0.8%). The mitral valve dysfunction was pure insufficiency in 483 patients (98.2%) and mixed disease, stenosis, and insufficiency, in 9 patients (1.8%). In 201 patients (40.9%) the degree of insufficiency was 3 and in 291 patients (59.1%) it was 4. The etiology of the mitral valve disease was congenital in 7 patients (1.4%), myxomatous degeneration in 351 patients (71.3%), associated ischemic in 88 patients (17.9%), rheumatic in 26 patients (5.3%), endocarditis in 9 patients (1.8%), calcific in 8 patients (1.6%), and other abnormalities in 3 patients (0.6%). Physiopathology of the valve lesion based on Carpentier s functional classification system was the following: type I, normal leaflet motion, dilated annulus, or leaflet perforation in 128 patients (26.0%); type II, leaflet prolapse, chordal rupture, chordal elongation, papillary muscle rupture, or papillary muscle elongation in 183 patients (37.2%); and type III, restricted leaflet motion, commissure fusion, leaflet thickening, or chordal fusionthickening in 28 patients (5.7%). One hundred forty-one patients (28.7%) were classified as type I/II and 12 patients (2.4%) as type II/III. Leaflet involvement was normal in 72 patients (14.6%), anterior only in 52 patients (10.6%), anterior and posterior in 74 patients (15.0%), and posterior only in 294 patients (59.8%). Mitral valve reconstruction techniques used included: commissurotomy in 15 patients (3.0%), chordal shortening in 48 patients (9.8%), chordal transposition in 55 patients (11.2%), chordal resection in 140 patients (28.5%), and leaflet resection in 263 patients (53.5%). All patients (100.0%) in the study underwent mitral valve ring annuloplasty with the Physio Ring. Concomitant cardiac procedures performed in the series included coronary artery bypass grafting (CABG) in 182 patients (37.0%), aortic valve replacement in 11 patients (2.2%), and CABG with valve replacement in 17 patients (3.5%). Echocardiography was performed preoperatively and intraoperatively after mitral valve reconstruction. The pattern of change and the degree of mitral insufficiency prevalve and postvalve reconstruction is shown in Figure 1. Data Sources Perioperative data were obtained by review of the patient s hospital record, catheterization reports, cineangiograms, and transesophageal echocardiography. Follow-up information was obtained through comprehensive questionnaires and by telephone interview with surviving patients, family members, or the patient s personal physician. Follow-up data included activity

4 Ann Thorac Surg ACCOLA ET AL 2005;79: MITRAL VALVE RECONSTRUCTION 1279 Fig 1. Preoperative and postoperative mitral valve reconstruction echocardiography. level, current symptoms, diagnostic tests, occurrence of late cardiac events, and medications being taken. Patients were asked to describe their functional capacity and were ranked according to the NYHA classification system. A Patient Registration Form and a Patient Follow-Up Form were completed for each participant in the study. These data collection instruments provided standardized reporting of each patient s clinical status before and after the operation. A 96.7% follow-up was obtained in the present study (n 492) with 16 patients lost to follow-up. Statistical Analysis Data are presented as frequency distributions and simple percentages. Values of continuous variables are expressed as mean standard deviation. Univariate analysis of selected discrete variables was accomplished by 2, the continuity-adjusted 2 analysis, or a two-tailed Fisher s exact test with the appropriate degrees of freedom to test for the equality of proportions in the case of categorical variables. Patient survival was expressed by actuarial analysis according to the method of Cutler and Ederer [20] using time zero as the date of operation and late death as the endpoint (with variability expressed as the standard error of the mean) and by linearized occurrence rates with standard errors. Data collected were subjected to both quantitative and qualitative analysis using the biostatistical capabilities of the Patient Analysis and Tracking Systems (PATS; Axis Clinical Software, Inc, Portland, OR) and the Number Cruncher Statistical System (NCSS; Kaysville, UT). A significant difference between measurements was defined as p less than or equal to Results Hospital Morbidity Rate The incidence of postoperative morbidity revealed that 207 of 492 patients (42.1%) in the series experienced no hospital complication. The postoperative in-hospital complications documented included: reoperation for bleeding in 13 patients (2.6%), respiratory insufficiency in 55 patients (11.2%), cerebrovascular accident in 14 patients (2.8%), myocardial infarction in 5 patients (1.0%), renal insufficiency in 21 patients (4.3%), low cardiac output in 13 patients (2.6%), and new onset of atrial fibrillation in 74 patients (15.0%). Placement of the intraaortic balloon pump was required in 54 patients (11.0%), 38 (7.7%) of whom had it placed preoperatively, 14 patients (2.8%) intraoperatively, and 2 patients (0.4%) postoperatively. The need for intraaortic balloon placement preoperatively (n 38) was low cardiac output in 9 patients (1.8%), unstable angina in 1 patient (0.2%), shock in 3 patients (0.6%), prophylactic in 23 patients (4.7%), and other in 2 patients (0.4%). The indications for intraaortic balloon intraoperatively (n 14) was low cardiac output in 4 patients (0.8%), cardiopulmonary bypass wean in 9 patients (1.8%), and shock in 1 patient (0.2%). The intraaortic balloon was placed postoperatively (n 2) for low cardiac output in 1 patient (0.2%) and shock in 1 patient (0.2%). None of the patients requiring the intraaortic balloon pump experienced a major vascular complication. The average postoperative length of stay in the series was days. Hospital Mortality Rate The hospital mortality rate for isolated mitral valve reconstruction was 2.1% (6 of 282); for valve reconstruction and CABG, 4.9% (9 of 182); for valve reconstruction and aortic valve replacement, 9.1% (1 of 11); and for valve reconstruction, aortic valve replacement, and CABG, 5.9% (1 of 17). A comparison of the isolated valve reconstruction and combined procedure hospital mortality rates was found to be nonsignificant. The overall hospital mortality rate for the series was 3.5% (17 of 492). The elective mortality rate was 2.5% (11 of 439), the urgent mortality rate 9.8% (4 of 41), the emergent mortality rate 12.5% (1 of 8), and the salvage mortality rate 25.0% (1 of 4). Comparisons of the mortality rates for elective and nonelective operation was found to be statistically significant (p 0.003). The mortality rate for first operation was 3.2% (15 of 462) and 6.7% (2 of 30) for reoperation. This difference did not achieve statistical significance. Patient Follow-Up Follow-up data were collected for 475 patients (96.5%) discharged from the hospital. The follow-up ranged from 1 month to months (mean, 38.5 months). The cumulative follow-up for the series was 1,522.9 patientyears. The linearized late mortality rate was 4.40% 0.54% per patient-year (67 events). At the completion of the follow-up, 392 (83.5%) of the hospital survivors were alive. Information concerning the causes of late death and the number of patients lost to follow-up is presented in Table 2. The actuarial survival data for all patients in the series are shown in Figure 2. At 4 years, survival was % standard error of the mean (SEM), and at 7 years was 67.9% 4.6% SEM. The preoperative and postoperative NYHA classification of current survivors (n 392) and their patterns of change are shown in Figure 3. Preoperatively, 45.6% of the patients were in either

5 1280 ACCOLA ET AL Ann Thorac Surg MITRAL VALVE RECONSTRUCTION 2005;79: Table 2. Status of Hospital Survivors Status Number Percent a Alive Dead (late death) Cardiac-related Noncardiac-related Cause unknown Lost to follow-up a Percentages of hospital survivors (n 475). NYHA class III or IV; on completion of the current follow-up, 97.4% were in class I or II. These results are impressive and demonstrate an overall enhanced symptomatic and functional improvement in this cohort of patients. Echocardiography was obtained in 293 of 392 patients (74.7%) at the time of last follow-up (mean, years). None-trace-trivial or 1 mitral insufficiency was observed in 262 patients (89.4%) and 2 insufficiency in 31 patients (10.6%). Ejection fraction at last follow-up was reported in 297 of 392 patients (75.8%). The ejection fraction was greater than 0.50 in 182 patients (65.2%), 0.30 to 0.50 in 84 patients (29.3%), and less than 0.30 in 31 patients (7.3%). There were 11 valve reconstruction failures in the series occurring at various time intervals and for varying causes (Table 3). In 10 cases, the valve was replaced and in one case reconstruction was performed again using a Carpentier-Edwards Classic ring. The actuarial freedom from reoperation (Physio Ring explant) or death for the series is shown in Figure 4. The freedom from reoperation at 4 years was 81.5% 2.1% and 67.9% 4.6% at 7 years. The linearized occurrence rate and number of late cardiac events in the hospital survivors were as follows: nonfatal myocardial infarction, 0.26% 0.13% per patient-year (4 events); reoperation, 0.72% 0.22% per patient-year (11 events); and stroke, 0.33% 0.15% per patient-year (5 events). Late nonfatal myocardial infarction was diagnosed and documented by a standardized reporting method that included a review of the patient s Fig 2. Actuarial survival of patients undergoing mitral valve reconstruction with the Carpentier-Edwards Physio Ring. Fig 3. Preoperative (PRE-OP) and postoperative (POST-OP) New York Heart Association functional classification of current survivors. hospital records, physician s records, or the patient s medical history. Comment In the 1970s, mitral valve reconstruction flourished in Europe with the work of Carpentier [6 8, 19] and Duran [9 11] and their respective colleagues. Carpentier and Duran established surgical techniques that were standardized, reproducible, and demonstrated long-term clinical results. Their work clearly defined the functional anatomy of the mitral valve and furnished standardized classification terminology. Prosthetic ring annuloplasty and the application of concomitant valve reconstruction techniques is now the treatment of choice for patients presenting with mitral insufficiency. The stabilizing effect of ring annuloplasty has contributed significantly to the excellent long-term clinical results achieved in mitral reconstruction and in patients presenting with ischemic valve disease. Standardized techniques as described by Carpentier and used since the decades of the 1970s have shown their reproducibility [8] and have demonstrated excellent outcomes over time [13]. The early and long-term results of mitral valve reconstruction have yielded better outcomes than those achieved with valve replacement. Moreover, the application of reparative techniques reduces or eliminates the need for long-term anticoagulation and its attendant risks. Controversy continues to exist as to the appropriate annuloplasty ring for mitral valve reconstruction. Our choice of the Physio Ring, a flexible device, is based on a series of considerations. The dynamic relationship between the annulus and the subvalvular apparatus raises a series of questions concerning the application of rigid annuloplasty fixation. The use of a rigid ring may induce systolic anterior

6 Ann Thorac Surg ACCOLA ET AL 2005;79: MITRAL VALVE RECONSTRUCTION 1281 Table 3. Causes of Mitral Valve Reconstruction Failure Patient Valve Etiology Physiopathological Classification Implant to Explant (Months) Failure Cause 1 Myxomatous degeneration Type I 4.3 Anterior leaflet fenestration ring dislodgment Valve re-repaired with closure of anterior leaflet fenestration and 28 mm Carpentier-Edwards Classic Ring 2 Myxomatous degeneration Type II 74.3 Severe recurrent regurgitation 3 Ischemic Type I 87.7 Thickened anterior leaflet Progressive degenerative process Posterior leaflet tethering 4 Ischemic Type I/II 11.7 Chordae rupture Leaflet prolapse 5 Myxomatous degeneration Type II 35.5 Anterior leaflet prolapse Severe recurrent regurgitation 6 Myxomatous degeneration Type II 41.3 Posterior leaflet scarred and retracted downward Severe recurrent regurgitation 7 Myxomatous degeneration Type I 8.2 Chordae rupture Leaflet prolapse 8 Myxomatous degeneration Type I 11.3 Markedly thickened valve with reduced pliability Severe recurrent regurgitation 9 Myxomatous degeneration Type I 27.6 Retracted posterior leaflet Severe recurrent regurgitation 10 Ischemic Type I 12.4 Restrictive physiology Calcification of leaflets Foreshortening of the chordae tendinae 11 Rheumatic Type III 6.0 Posterior leaflet retraction Chordal shortening Fig 4. Actuarial freedom from reoperation for patients undergoing mitral valve reconstruction with the Carpentier-Edwards Physio Ring. motion and left ventricular outflow tract obstruction [21] which may, in turn, cause postoperative left ventricular dysfunction [12]. Moreover, a rigid annuloplasty ring has been noted to impair left ventricular systolic function [22] and may cause subvalvular stenosis [23]. The benefits of flexible versus rigid rings in left ventricular pump function have been previously reported [12]. It has been demonstrated that flexible rings follow the physiologic movement of the mitral annulus and interfere less with pump function. Flexible rings interfere less with valve motion, improve peak velocity, enhance left ventricular fractional shortening, and improve enddiastolic diameter and volume. The Physio Ring furnishes not only variable flexibility but allows for remodeling of the annulus. It provides for remodeling by the presence of rigid fixation between the two commissures. This allows for restoration of the physiologic shape of the mitral annulus including its posterior aspect [19]. The Physio Ring, with its inherent variable flexibility, offers a definite advancement in the application of remodeling techniques in mitral valve reconstruction. It affords the opportunity for the application of remodeling techniques by the presence of a given degree of rigidity between the commissures. This allows for restoration of the physiologic shape of the mitral annulus including its posterior aspects. Moreover, it provides substantial benefits in the remodeling process and appears to be a more physiologically appropriate choice in mitral valve reconstruction. Valve classification and reconstruction have

7 1282 ACCOLA ET AL Ann Thorac Surg MITRAL VALVE RECONSTRUCTION 2005;79: become universally standardized utilizing Carpentier s techniques. Moreover, surgeons have achieved an understanding of the fluidlike dynamic function of the mitral annulus, which has further influenced the development of reparative techniques [12]. It is now recognized that in circumstances of ischemic mitral insufficiency type I and type IIIb (tethered posterior and anterior leaflet with annular dilatation) are generally attributed to left ventricular dysfunction and dilatation of the annulus generally attributed to ischemic cardiomyopathy. In these cases, simple annular reduction annuloplasty is typically sufficient to correct the problem of mitral insufficiency. In cases where decreasing annular size is required, the benefits of a complete ring are well recognized. A more physiologic or dynamic ring as opposed to the fixed or rigid ring has been shown to achieve enhanced results and improved postoperative ventricular function in these circumstances [19]. Complex type II classification reconstruction is best supported with an appropriately sized Physio Ring using classic trigone to trigone and anterior leaflet sizing techniques. The evidence of pliable and dynamic posterior annulus benefits may serve to enhance left ventricular function as well as the longevity of the reconstructed valve [12]. The Carpentier standard rigid Ring continues to be the device of choice in patients presenting with Barlow s disease. The advantage of this device in patients with this pathology is that the anterior-posterior dimension of the anterior leaflet can be expanded, thus allowing the surgeon to open the ring to accommodate performing a complex reconstruction. In valves presenting with type III physiopathology, it is often difficult to perform reconstruction and achieve the desired long-term benefits. Often these valves have an abnormal or thickened subvalvular apparatus, which generally is progressive in nature. This finding has often influenced us to proceed with mitral valve replacement rather than reconstruction in these patients. In the present series, an overall operative mortality rate of 3.5% was observed. This compares favorably with that of other series of mitral valve reconstruction [24, 25]. Moreover the operative mortality was low; 2.1% for isolated valve reconstruction and 4.9% for mitral reconstruction and CABG. Follow-up data were obtained for 475 hospital survivors. At the completion of the current follow-up, there were 392 patients (83.5%) alive. The actuarial survival for patients discharged from the hospital at 4 years was 84.3% 2.1% and was 70.1% 4.6% at 7 years. In the present study, symptomatic improvement was 97.4% of the patients in NYHA class I or II at last follow-up. Moreover, the patients functional capacity has been improved thereby enhancing their ability to carry out their activities of daily living and their overall quality of life. Valve reconstruction failure in our experience has generally been a rare event. In the present study 11 patients (2.2%) required reoperation. An analysis of the etiology of the valve disease and the physiopathological classification revealed no causative pattern for the failures. The freedom from reoperation at 4 years was 81.5% 2.1% and 67.9% 4.6% at 7 years. Moreover, no case of atrial ventricular groove disruption or systolic anterior motion causing left ventricle outflow track obstruction was observed in the present series. These midterm results using the Physio Ring provide substantial evidence that mitral valve reconstruction can be accomplished with low hospital morbidity and mortality rates even in patients undergoing combined procedures. The low incidence of reoperation and late cardiac events suggests that the Physio Ring, with its inherent flexibility, offers a definite advantage in the application of remodeling techniques and may positively influence long-term results. These findings support the continued use of the Physio Ring in patients presenting with mitral insufficiency secondary to degenerative disease of the mitral valve as well as in the clinical setting of ischemic mitral insufficiency. The Physio Ring can play a critical role in the operative management of patients presenting with mitral valve disease. The authors thank Dr Debra D. Guest for technical assistance in the preparation of this report and Jim Ferrell, PA-C, and Wayne Mutch, PA-C, for assistance in data collection. References 1. Lillehei CW, Gott VL, Dewall RA, Varco RL. Surgical correction of pure mitral insufficiency by annuloplasty under direct vision. Lancet 1957;2: Merendino KA, Bruce RA. One hundred seventeen surgically treated cases of valvular rheumatic heart disease with a preliminary report of two cases of mitral regurgitation treated under direct vision with the aid of a pumpoxygenator. J Am Med Assoc 1957;174: McGoon DC. Repair of mitral insufficiency due to ruptured chordae tendineae. J Thorac Cardiovasc Surg 1960;39: Kay JH, Egerton WS. The repair of mitral insufficiency associated with ruptured chordae tendineae. Ann Surg 1963; 157: Reed GE, Tice DA, Clauss RH. Asymmetric exaggerated mitral annuloplasty: repair of mitral insufficiency with hemodynamic predictability. J Thorac Cardiovasc Surg 1963;49: Carpentier A, Relland J, Deloche A, et al. Conservative management of the prolapsed mitral valve. Ann Thorac Surg 1978;26: Carpentier A, Chauvand S, Fabiani JN, et al. Reconstructive surgery of mitral valve incompetence: ten year appraisal. J Thorac Cardiovasc Surg 1980;79: Carpentier A. Cardiac valve surgery the French correction. J Thorac Cardiovasc Surg 1983;863: Duran CMG, Poman JL, Cucchiara G. A flexible ring for atrioventricular heart valve reconstruction. J Cardiovasc Surg (Torino) 1978;19: Duran CG, Pomar JL, Revuelta JM, et al. Conservative operation for mitral insufficiency: critical analysis supported by postoperative hemodynamic studies of 72 patients. J Thorac Cardiovasc Surg 1980;79: Duran CG, Revuelta JM, Gaite L, et al. Stability of mitral reconstructive surgery at years for predominantly rheumatic valvular disease. Circulation 1988;78:I David TE. Effect of mitral annuloplasty ring in left ventricular function. Semin Thorac Cardiovasc Surg 1989;1:144 8.

8 Ann Thorac Surg ACCOLA ET AL 2005;79: MITRAL VALVE RECONSTRUCTION Loop RD. Long-term results of mitral valve repair. Semin Thorac Cardiovasc Surg 1989;1: Cosgrove DM. Surgery for degenerative mitral valve disease. Semin Thorac Cardiovasc Surg 1989;1: Kumar AS, Rao PN. Mitral valve reconstruction: intermediate term results in rheumatic mitral regurgitation. J Heart Valve Dis 1994;3: Ling LH, Enriquez-Sarano M, Seward JB, et al. Clinical outcome of mitral regurgitation due to flail leaflet. N Engl J Med 1996;335: Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediateterm outcome of mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998;115: Scott ML, Stowe CL, Nunnally LC, et al. Mitral valve reconstruction in the elderly population. Ann Thorac Surg 1989;48: Carpentier AF, Lessana A, Relland JYM, et al. The Physio- Ring : an advanced concept in mitral valve annuloplasty. Ann Thorac Surg 1995;60: Cutler SJ, Ederer F. Maximum utilization of the life table method in analyzing survival. J Chronic Dis 1958;8: Kreindel MS, Schivone WA, Level JM, Cosgrove D. Systolic anterior motion of the mitral valve after Carpentier ring valvuloplasty for mitral valve prolapse. Am J Cardiol 1986; 57: Spence PA, Peniston CM, David TE, et al. Toward a better understanding of the etiology of left ventricular dysfunction after mitral valve replacement: an experimental study with possible clinical implications. Ann Thorac Surg 1986;41: Van Rijk-Zwikker GL, Mast F, Shipperheyn JJ, et al. Comparison of rigid and flexible rings for annuloplasty of the porcine mitral valve. Circulation 1990;82(suppl4): IV- 58 IV Thourani VH, Weintraub WS, Guyton RA, et al. Outcomes and long-term survival for patients undergoing mitral valve repair versus replacement. Circulation 2003;108: Akins CW, Hilgenberg AD, Buckley MJ, et al. Mitral valve reconstruction versus replacement for degenerative or ischemic mitral regurgitation. Ann Thorac Surg 1994;58: DISCUSSION DR ALAA Y. AFIFI (Albany, NY): Dr Accola, I want to congratulate you on a very nice presentation. We have also transitioned from the classic to the Physio ring with very good results; certainly mortality is very low. One question I do have reflects the approach to postoperative oral anticoagulation in these patients. There are some institutions that do not anticoagulate their patients postoperatively. What has your experience been and do you recommend a three-month post-op course of oral anticoagulation or aspirin therapy postoperatively? Thank you. DR ACCOLA: I appreciate your question. We anticoagulate all of our mitral valve repairs still. We don t necessarily do it for three months but anywhere from six to eight weeks, for a couple of reasons: one, because a lot of these repairs are complex repairs with a lot of suture lines; the other reason is simply, too, because these patients, a lot of them, either had preoperative atrial fibrillation or experienced postoperative fibrillation. In our current environment where we practice, the majority of cardiologists also feel it is important to anticoagulate these patients for a temporary period of time. Notice From the American Board of Thoracic Surgery Regarding Trainees and Candidates for Certification Who Are Called to Military Service Related to the War on Terrorism The Board appreciates the concern of those who have received emergency calls to military service. They may be assured that the Board will exercise the same sympathetic consideration as was given to candidates in recognition of their special contributions to their country during the Vietnam conflict and the Persian Gulf conflict with regard to applications, examinations, and interruption of training. If you have any questions about how this might affect you, please call the Board office at (312) Timothy J. Gardner, MD Chairman The American Board of Thoracic Surgery 2005 by The Society of Thoracic Surgeons Ann Thorac Surg 2005;79: /05/$30.00 Published by Elsevier Inc