Repair of the left AV valve in atrioventricular septal defect in adults

BACKGROUND: This study examined the septal cleft and septal commissure of the left atrioventricular (AV) valve, which are two different anatomical structures. METHODS: We presented 36 cases of adult partial atrioventricular septal defect. A distinction was made between patients based on the anatomy of the anterior leaflet of the left AV valve. The left AV valve appeared to be normal or to have minimal radial openings from the free edge of the anterior leaflet of the left AV valve in 10 patients (28%). There was a septal commissure structure in 8 (22%), and a septal cleft structure in 18 (50%) patients. In the commissure type anatomy, leaflet coaptation was usually adequate and no or mild degree of left AV regurgitation existed preoperatively. Cleft type structure usually was associated with some degree of left AV regurgitation. Attempts were made to close the septal clefts and leave the septal commissures unsutured during the repair of the partial AV septal defects. RESULTS: We have not found any increase of left AV regurgitation in patients with commissures during the follow-up period. Closure of the cleft successfully eliminated regurgitation. Long-term results for septal cleft and septal commissure after repair of partial AV septal defect were excellent with survival of 100% and freedom from reoperation of 100% at mean 6.5 years. CONCLUSIONS: Septal cleft and septal commissure should be considered two different structures. Repairing procedures for left AV valve abnormalities associated with partial AV septal defect should only be done in patients who have cleft type of leaflet structure.     

Monocusp homograft VSD patch in atrioventricular canal with tetralogy of Fallot

A monocusp aortic homograft was used to compensate for deficient right atrioventricular valve tissue during repair of complete atrioventricular canal defect with tetralogy of Fallot. The homograft was used to produce a comma-shaped ventricular septal defect patch together with the septal leaflet of the right atrioventricular valve, thus committing native leaflet tissue to left atrioventricular valve reconstruction. One year postoperatively the child is in New York Heart Association class I with no tricuspid regurgitation.     

Surgical repair of the congenitally malformed mitral valve in infants and children

BACKGROUND: Mitral valve remodeling techniques were applied to 26 infants and children (mean age, 6.0 years, range, 0.4 to 15.9 years) with various forms of congenital mitral valve disease over a 7-year period. Patients with atrioventricular canal, L-transposition and single ventricle were excluded. Intraoperative transesophageal echocardiography (TEE) was utilized to assess the repair and guide the need for immediate intervention. METHODS: Twenty-one patients had mitral regurgitation: 10 with cleft anterior mitral leaflet, 7 with annular dilatation, 1 with normal leaflets with an obstructing cord, 2 with prolapsed leaflets and elongated cords, and 1 with restricted leaflet motion, normal papillary muscles, and shortened cords. Of the 5 mitral stenosis patients, 3 had supravalvular mitral ring, 1 had midvalvular mitral ring, and 1 had a parachute valve. Three of the mitral stenosis patients had additional stenotic lesions. Concurrent repair of associated lesions was performed in 21 patients (78%). RESULTS: Operative mortality was 3.8% (n = 1). There were no late deaths. Immediate rerepair in 4 patients resulted in improved function. All mitral stenosis patients improved. A total of 20 mitral regurgitation patients (95%) improved; 1 required mitral valve replacement. Mean follow-up is 31 months (range, 2 to 81 months). All patients are in New York Heart Association functional class I or II. CONCLUSIONS: Mitral valve repair can be successfully performed in infants and children with excellent short- and midterm results. Assessment using transesophageal echocardiography can guide the necessity for immediate rerepair to achieve improved function.     

Atrioventricular valve function after single patch repair of complete atrioventricular septal defect in infancy: how early should repair be attempted?

BACKGROUND: Though repair of complete atrioventricular septal defect in infancy has become routine at most centers, it is not unusual for very young infants to be managed medically because of concerns about the fragility of the atrioventricular valve tissue. METHODS: Since July 1992, seventy-two infants have undergone primary repair of complete atrioventricular septal defects at a median age of 3.9 months (40% < 3 months). A single-patch technique was used in all patients. The cleft was closed completely in 61 patients and partially (n = 10) or not at all (n = 1) in select patients at risk for valve stenosis. Left atrioventricular valve annuloplasty was performed in 18 patients. On the basis of transesophageal echocardiographic findings, 10 patients were returned to bypass for revision of the valve repair. RESULTS: There was one early death in a patient with single left papillary muscle, no early reoperations, and no new permanent arrhythmias. Only three patients had moderate left atrioventricular valve regurgitation at discharge. During a median follow-up of 24 months, there was one late death and five reoperations for left atrioventricular valve regurgitation (n = 2) and/or systemic outflow obstruction (n = 4). Follow-up left atrioventricular valve regurgitation was moderate in three patients, mild in 14, and none/trace in 54. Age had no relation to postoperative atrioventricular valve regurgitation, death, or reoperation. CONCLUSIONS: Despite concerns about fragility of valve tissue in very young patients, excellent results can be achieved with meticulous techniques. From neonates to older infants, age at repair does not influence outcome or valve function.     

The edge-to-edge technique: a simplified method to correct mitral insufficiency

OBJECTIVE: Repair of mitral regurgitation (MR) is more demanding in case of prolapse of the anterior leaflet, posterior leaflet with calcified annulus, or prolapse of both leaflets. We evaluated a repair which consists of anchoring the free edge of the prolapsing leaflet to the corresponding free edge of the facing leaflet: the 'edge-to-edge' (E-to-E) technique. The correction results in a double orifice valve when the prolapse is in the middle portion of the leaflet and in a smaller valve orifice when the prolapse is close to a commissure. METHODS: Out of 432 patients with MR submitted to valve repair between January 1991 and September 1997, 121 (mean age 56 +/- 15.8 years) underwent E-to-E correction. The most prevalent etiology was degenerative disease (82 patients, 68%). The mechanism of MR was anterior leaflet prolapse (61 patients), posterior leaflet prolapse (24 patients), prolapse of both leaflets (28 patients) and other complex mechanisms (8 patients). In 72 patients, a double orifice was created, the paracommissural repair was done in 49 patients. RESULTS: Hospital mortality was 1.6%. Overall survival was 92 +/- 3.1% at 6 years with 95 +/- 4.8% freedom from reoperation. Mortality was unrelated to the type of repair. Mitral stenosis was never observed after the correction. At the follow-up (mean 2.2 +/- 1.5 years), all patients but 15 are class I or II. Symptoms at the follow-up are not related to residual MR. CONCLUSIONS: Midterm results of this alternative repair technique are promising, considering the high prevalence of complex anatomical lesions. The technique is simple, easily reproducible and rapidly feasible also when mitral exposure is suboptimal.     

Durability of mitral valve repair for degenerative disease

BACKGROUND: Degenerative mitral valve disease is the most common cause of mitral regurgitation in the United States. Mitral valve repair is applicable in the majority of these patients and has become the procedure of choice. OBJECTIVE: This study was undertaken to identify factors influencing the durability of mitral valve repair. PATIENTS AND METHODS: Between 1985 and 1997, 1072 patients underwent primary isolated mitral valve repair for valvular regurgitation caused by degenerative disease. Repair durability was assessed by multivariable risk factor analysis of reoperation. It was supplemented by a search for valve-related risk factors for death before reoperation. Three hospital deaths occurred (0.3%); complete follow-up (4152 patient-years) was available in 1062 of 1069 hospital survivors (99.3%). RESULTS: At 10 years, freedom from reoperation was 93%. Among 30 patients who required reoperation for late mitral valve dysfunction, the repair failed in 16 (53%) as a result of progressive degenerative disease. Durability of repair was adversely affected by pathologic conditions other than posterior leaflet prolapse, use of chordal shortening, annuloplasty alone, and posterior leaflet resection without annuloplasty. Durability was greatest after quadrangular resection and annuloplasty for posterior leaflet prolapse and was enhanced by the use of intraoperative echocardiography. Death before reoperation was increased in patients having isolated anterior leaflet prolapse or valvular calcification and by use of chordal shortening or annuloplasty alone. CONCLUSIONS: Repair durability is greatest in patients with isolated posterior leaflet prolapse who have posterior leaflet resection and annuloplasty. Chordal shortening, annuloplasty alone, and leaflet resection without annuloplasty jeopardize late results.     

Artificial chordae in the treatment of anterior mitral leaflet pathology

This report describes the authors' clinical experience with expanded polytetrafluorethylene (e-PTFE) sutures to replace the anterior mitral leaflet chordae for valve repair. Between November 1986 and July 1995, 203 patients underwent operations with e-PTFE chordae insertion. Among these, 122 had artificial chordae utilized for anterior mitral leaflet repair. Four patients had the valve replaced during the same operation because of an unsatisfactory result. One patient died from respiratory insufficiency 16 days after operation. Transoesophageal echocardiography at discharge from hospital showed no evidence of regurgitation in 81 cases, and trivial regurgitation in 36. During a mean follow-up of 36.6 (range 1-106) months two other patients died from causes unrelated to the valve repair, while one patient had a transient ischaemic attack returning to sinus rhythm. Two patients were reoperated on 12 and 18 months respectively after their initial operation for progression of valvular degeneration causing natural chordae rupture. Among the remaining 113 patients, 111 are in New York Heart Association functional class I and yearly transoesophageal echocardiography has shown absent or trivial regurgitation. The utilization of e-PTFE as artificial chordae for anterior mitral leaflet pathology is a safe and reliable procedure, yielding excellent results and increasing the number of candidates for valve repair.     

A case report of mitral valve repair of broad posterior leaflet prolapse due to ruptured chordae tendinea by replacement of chordae tendineae with EPTFE sutured and Carpentier-Edwards ring techniques]

A 68-year-old woman with mitral valve regurgitation due to ruptured chordae tendineae of posterior leaflet underwent mitral valve repair by replacement of chordae tendineae with EPTFE sutures and Carpentier-Edwards ring techniques. Preoperative study showed massive mitral regurgitation and moderate tricuspid regurgitation with CTR 54% of chest X-ray. The postoperative course was not eventful. Postoperative study showed trivial mitral and trivial tricuspid regurgitation. Postoperative CTR was 45%. Mitral valve repair by these techniques could be modified and applicable to mitral valve regurgitation due to ruptured chordae tendineae of posterior leaflet. There was no complication during follow-up period of 8 months.     

Late postoperative outcome of plastic operation versus valve replacement for mitral regurgitation]

Between January 1980 and August 1991, 99 patients underwent operation for mitral valve regurgitation (MR). The ages of the patients ranged from 12 to 67 years, (49.4 +/- 11.9 years), and there were 39 males and 60 females. Pathological cause of regurgitation, which was determined by intraoperative inspection and histological findings of excised leaflets, was rheumatic in 46, degenerative in 38, infective endocarditis in 9, ischemic in 4 and unknown in 2 patients. Cardiac rhythm was atrial fibrillation in 73, normal sinus rhythm in 24 and junctional rhythm in 2 patients. Our principles for valve repair were (1) excision of responsible segment and repair for prolapsed leaflet due to torn chordae, (2) shortening of elongated chordae, (3) annuloplasty, and (4) repair of perforated leaflet. Finally, 19 patients endured plastic operation, and 80 patients underwent prosthetic valve replacement. The rate of plastic procedure was 62.5% (10/16) in degenerative MR with mural chordal lesions, 42.9% (3/7) in rheumatic MR without stenosis, 22.2% (2/9) in infective endocarditis and 100% (2/2) in MR with unknown etiology. Mitral valve repair was failed both in rheumatic MR associated with stenosis (39 patients) and in ischemic MR (4 patients). A ten-year survival rate after operation was 92.2 +/- 3.1% in patients with valve replacement and 83.6 +/- 10.0% with valve repair (N.S.), and a proportion of event-free survival in patients with valve replacement was similar to valve. Late postoperative cardiac catheterization revealed decreased left ventricular volume indices and increased left ventricular end-systolic stress/volume ratio in both groups compared to preoperative values, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-term results of mitral valve repair for myxomatous disease with and without chordal replacement with expanded polytetrafluoroethylene sutures

OBJECTIVE: This study was carried out to evaluate the long-term results of mitral valve repair for mitral regurgitation caused by myxomatous disease of the mitral valve and the late effects of chordal replacement with expanded polytetrafluoroethylene sutures in this operation. METHODS: A total of 324 patients with mitral regurgitation caused by myxomatous disease underwent mitral valve repair from 1981 to 1995; the group comprised 241 men and 83 women whose mean age was 58 +/- 14 years. Chordal replacement with expanded polytetrafluoroethylene sutures has been performed in 165 patients since 1985. Most of the patients who had chordal replacement with expanded polytetrafluoroethylene sutures had prolapse of the anterior leaflet or prolapse of both leaflets, whereas most patients who had mitral valve repair without chordal replacement had prolapse of the posterior leaflet. Patients were followed up at annual intervals and had a Doppler echocardiographic study. The follow-up was complete and extended from 6 to 156 months (mean 36 +/- 30 months). RESULTS: Two operative and 21 late deaths occurred (14 cardiac and 7 noncardiac). At 10 years the actuarial survival was 75% +/- 5%, the freedom from stroke was 94% +/- 2%, the freedom from transient ischemic attacks was 92% +/- 4%, the freedom from endocarditis was 99% +/- 1%, the freedom from mitral valve reoperation was 96% +/- 1%, and the freedom from severe mitral regurgitation was 93% +/- 3%. Chordal replacement with expanded polytetrafluoroethylene sutures had no effect on any of these end points. CONCLUSIONS: Mitral valve repair was feasible in most patients with mitral regurgitation caused by myxomatous disease and it was associated with low rates of valve-related complications. Chordal replacement with expanded polytetrafluoroethylene had no adverse effect on the late outcome and was believed to have increased the probability of mitral valve repair.     

Valve repair in infective endocarditis

From 1985 to 1995, 12 patients with native valve endocarditis underwent valve repair instead of replacement. Mean age was 41.9 years (range from 5 to 79 years). Eight patients had active and 4 patients inactive infection. The mitral valve was involved in 6 patients, the aortic valve in 1, both valves in 2, the tricuspid valve in 2, and the mitral and pulmonary valves in 1. The pathological findings were as follows: leaflet perforation in 2 patients, chordal rupture in 3, and vegetations in 10. Valve sparing procedures were carried out on the mitral valve in 8 patients, on the aortic valve in 1, on the tricuspid valve in 2, and on the pulmonary valve in 1. The following repair techniques were used: vegetectomy in 10 patients, leaflet patching in 2, posterior mitral leaflet resection in 3, mitral annuloplasty in 4, and pulmonary valve repair in 1. Uncontrolled sepsis, progressive heart failure, peripheral embolism, and echocardiographically demonstrated vegetations were the indications for surgery. There was no operative or late mortality and all infections were cured with no recurrences. One patient required valve replacement following aortic valve repair because of progressive aortic regurgitation. Postoperative Doppler echocardiography showed trivial to no regurgitation in 11 patients after valve repair. The overall outcome was favorable during the mean follow-up period of 39.3 months (range from 1 to 120 months). Reparative or reconstructive approaches for native valve endocarditis should be considered and can be successfully performed. Their advantages include (1) improved hemodynamics, (2) no recurrence, (3) no mortality, and (4) favorable long-term results.     

Mitral regurgitation: a new clinical perspective

Mitral regurgitation is a common valvular heart disease, particularly in the elderly population. The timing of surgical repair is controversial, but recent literature suggests a new clinical perspective on the management of this disease. Despite receiving medical treatment and having few initial symptoms, patients with mitral regurgitation due to flail leaflets have an excess mortality rate (6.3% per year) and high morbidity. Ten years after mitral regurgitation has been diagnosed, 90% of the patients have either died or undergone an operation. After surgical correction of mitral regurgitation, left ventricular dysfunction is a frequent complication and is the cause of excess heart failure and mortality. This complication is due to preoperative left ventricular dysfunction but is incompletely predictable with use of current methods. Conversely, considerable progress in surgery has resulted in an extremely low operative mortality rate (about 1% in patients younger than 75 years of age) and high feasibility of valve repair, even in patients with anterior leaflet prolapse. These facts have led to the new perspective that early surgical correction (before occurrence of overt symptoms or left ventricular dysfunction) should be considered when patients are diagnosed with severe mitral regurgitation.     

Accurate localization of mitral regurgitant defects using multiplane transesophageal echocardiography

BACKGROUND: Appropriate patient selection for surgical repair of the mitral valve depends on the specific location and mechanism of regurgitation, which, in turn, has necessitated a more detailed method to accurately describe mitral pathology. This study tests a strategy of using multiplane transesophageal echocardiography to systematically localize mitral regurgitant defects and compares these results with the surgical findings. METHODS: Fifty patients with mitral regurgitation underwent intraoperative transesophageal echocardiography for the evaluation of mitral pathology and potential repair. Mitral regurgitant defects were localized using a systematic strategy and a simple nomenclature that divides each mitral valve into six sections (three sections per leaflet) and each prosthetic sewing ring into six sections (60 radial degrees = one section). RESULTS: Thirty-nine patients with native mitral valves were studied, for a total of 234 sections evaluated. Eighty-seven of these sections contained regurgitant defects by transesophageal echocardiography (mean number of regurgitant defects per valve, 2.2; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 96% (224/234; p < 0.0001) of the sections. Eleven patients with prosthetic mitral valves were studied, for a total of 66 sections evaluated. Twenty-three of these sections contained paravalvular leaks by transesophageal echocardiography (mean number of leaks per prosthesis, 2.1; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 88% (58/66; p < 0.001) of the sections. CONCLUSIONS: This transesophageal echocardiographic strategy provides a systematic method to accurately localize mitral regurgitant lesions and has the potential to improve the preoperative assessment of patients with significant mitral regurgitation.     

Long-term outcome of mitral valve repair of dystrophic mitral regurgitation

Between January 1984 and December 1994, 130 patients underwent mitral valvuloplasty for pure dystrophic mitral regurgitation. There were 94 men and 36 women with a mean age of 61 +/- 9 years: 52 patients were in atrial fibrillation; 91% of patients were in NYHA Classes III or IV. At preoperative echocardiography, the regurgitation was assessed as Grade III or IV and classified using the Carpentier classification according to type I (dilatation of the annulus) or II (mitral valve prolapse); 95% of patients had isolated prolapse of the posterior leaflet, 3% had isolated prolapse of the anterior leaflet and 2% had prolapse of the two leaflets. After valvuloplasty, a prosthetic ring was implanted in 124 patients (95%). The early mortality was 3%; 5.3% of patients had early complications. All patients underwent control transthoracic echocardiography in the first postoperative week. They were reviewed with a second transthoracic echocardiography after a mean follow-up of 5 +/- 0.3 years and a cumulative follow-up of 657 years-patients. At the immediate postoperative echocardiography, 24 minimal residual regurgitations were observed; at long-term, 20 new mitral regurgitations developed, all mild without any clinical symptoms and 98% of patients were in the NYHA Classes I or II. At 10 years, the actuarial survival was 73 +/- 16%; absence of thromboembolic complications 95 +/- 3%, absence of reoperation 95 +/- 5%. This study confirms the efficacy of mitral valvuloplasty and the postoperative stability of repaired valvular lesions. These results suggest that the operative indications should be considered at an earlier stage.     

Analysis of the T cell receptor repertoire in rheumatoid arthritis

BACKGROUND AND AIMS OF THE STUDY: Valve repair, where suitable, is the preferred option in patients who require mitral surgery. A number of studies have shown excellent long-term results, but most were undertaken in tertiary referral centers with a high throughput of patients. METHODS: We present our experience in 60 patients, aged 60 +/- 14 years, undergoing repair between 1984 and 1993. Most patients (83%) were in New York Heart Association (NYHA) class II or III at the time of surgery; 27% had concomitant ischemic heart disease. Almost all (98%) had posterior leaflet repair and 18% had anterior leaflet repair. Eight surgeons each performed a mean of 7.5 operations during this period. RESULTS: The 30-day mortality rate was 3.3%. There were seven late deaths. Five patients underwent reoperation for mitral regurgitation (two early, three late). At six years, 60% of patients were alive, or free of stroke or reoperation. Late follow up was obtained in 45 of 47 surviving patients: 95% were in NYHA class I or II; one-third were on anticoagulants for atrial fibrillation; 90% had mild (or less) mitral regurgitation on echocardiography. CONCLUSIONS: These data show that most patients have a very good outcome from valve repair surgery and encourage the trend towards operating earlier in the course of the disease. Adverse outcomes occurred mainly in patients who were highly symptomatic at the time of surgery. The high proportion of patients on postoperative anticoagulants underscores the importance of operating before atrial fibrillation becomes permanent.     

Mitral valve repair vs replacement. Current recommendations and long-term results

Techniques now exist to correct abnormalities of all components of the mitral valvular apparatus except extensive loss of pliable leaflet area. Thus, paradoxically, myxomatous valves with redundant leaflets represent the ideal candidates for mitral valve repair. Repair for mitral insufficiency can be performed for some rheumatic valves, but patient selection is critical. Loss of leaflet area, leaflet thickening, and extensive calcification of the leaflets or commissures are contraindications to repair. The abnormalities of the subvalvular apparatus are less important because a complete set of new chordae can be reconstructed using PTFE suture material. Some cases of endocarditis are ideal for repair using localized débridement and pericardial patch repair with or without PTFE chordal replacement. True ischemic mitral regurgitation of the Carpentier type I category is still something of a surgical enigma. Because it is a restrictive leaflet motion problem, annuloplasty alone is not always effective, and the outcome of any given repair attempt is less predictable. Repairs in patients with small annuli and multiple leaflet defects requiring complex series of maneuvers have a low probability of success. Furthermore, such patients with small left ventricular cavities are more prone to experience SAM. Several factors contributing to which therapy is chosen for mitral valve disease are summarized in Table 1. Patient selection, accurate evaluation of the cause or causes of mitral regurgitation, and well-executed application of the appropriate techniques for repair are all critical factors in the early and late success of mitral valve repair.     

Successful repair of tricuspid regurgitation due to blunt trauma

A 19-year-old man developed paralysis of the left arm as a result of left brachial plexus injury by a traffic accident. He underwent operation for the brachial plexus paralysis, and then severe heart failure developed postoperatively. Echocardiography revealed severe tricuspid valve regurgitation. Tricuspid valve plasty was performed 14 months after the traffic accident. The anterior leaflet of the tricuspid valve was torn and the chordae attached there were torn as well. The torn anterior leaflet was sutured directly, and the prolapsed portion of this leaflet was collected by transfer of the elongated chordae. Annuloplasty (DeVega technique) was then added. Postoperative echocardiography revealed trivial regurgitation of the tricuspid valve. Only 9 cases of successful repair of traumatic tricuspid regurgitation have been reported in Japan.     

Artificial chordae for mitral valve reconstruction in children

BACKGROUND: Congenital mitral regurgitation continues to present a challenge for cardiac surgeons because of the diversity of the anatomy of the congenitally malformed mitral valve. We undertook aggressive repair of the mitral valve with artificial chordae for reconstruction of the prolapsed anterior leaflet in some children. The short-term results are reported herein. METHODS: Three patients with isolated congenital mitral regurgitation underwent mitral valve repair with use of expanded polytetrafluoroethylene sutures as artificial chordae. RESULTS: There have been no late deaths and no valve-related complications. Serial follow-up echocardiographic examinations have not revealed any increase in the severity of mitral regurgitation with continuing patient growth up to 39 months after the operation. CONCLUSIONS: When combined with other conservative methods of mitral valve repair, chordal replacement with expanded polytetrafluoroethylene sutures in children undergoing mitral valve reconstruction produces good short-term results. We believe that it delays and possibly prevents the need for a mechanical prosthesis with its associated complications in this young patient population.     

Mitral valve repair after excision of a fibrolipoma

A 2-year-old patient with severe mitral regurgitation associated with a mass originating from the anterior leaflet of the mitral valve is reported. Excision of the tumor and mitral valve repair was performed. Four years later the child remains asymptomatic with no recurrence of the tumor or regurgitation.     

Repair of mitral valve prolapse by resection and sliding plasty

There have been many techniques applied to the repair of mitral valve prolapse, and the method used in a particular case is usually selected according to the position and extent of the lesion. To simplify and standardize the technique of mitral valve repair, we have adopted the resection, sliding plasty and ring annuloplasty methods since December 1992. Of 10 consecutive surgical cases, 2 involved prolapse of the anterior leaflet, 1 the posteromedial commissural, and 7 the posterior leaflet. One patient with posterior leaflet prolapse required valve replacement due to dehiscence of the plastied site on the 3rd postoperative day, and one died because of sepsis. However, the remaining patients were doing well without mitral regurgitation at a mean of 20 months (range: 8-32) after the operation. The advantages of these techniques include easy adjustment of the height of the leaflet and a good chance of long-term durability, since the affected lesion is resected.