Gustavo Maturana B

Operación de Fontan: resultados inmediatos y a mediano plazo con anastomosis cavopulmonar total

Background: During the last five years, 65 patients with univentricular heart have been treated surgically in our institution, according to a protocol of staged operations that have been previously reported. Aim: To evaluate the early and mid-term outcome of those patients that have completed their staging protocol by means of a Fontan procedure. Patients and Methods: Between April 1996 and June 2001, 23 patients (age 16 to 223 months) underwent a Fontan procedure, 15 with an intracardiac lateral tunnel technique and 8 with an extracardiac conduit. A retrospective review of their clinical, surgical, echocardiographic, angiographic and hemodynamic data was performed, trying to identify risk factors for both mortality and functional capacity (FC). Follow up was complete in all survivors. Results: Three patients died early after surgery (13.04%). Excessive pulmonary blood flow was a risk factor for early death (p= 0.03). One patient died at 14 months. Follow up was 29.9 months (1-63). For those who survived the operation, five years survival was 93.3%. The majority of patients are in FC I or II, with no related risk factors. Conclusions: Our current results are comparable with those of larger series. Patients reach good FC and mid-term survival, irrespective of type of single ventricle or the surgical strategy (Rev Med Chile 2002; 130: 1217-26).

Resultados alejados de la cirugía reconstructora de la insuficiencia mitral

Background: Surgical repair is the procedure of choice for mitral insufficiency since it preserves better left ventricular structure and function. Aim: To assess the long term clinical and echocardiographic results of mitral valve reconstructive surgery. Material and methods: A review of clinical and echocardiographic data of 68 patients (34 male, age range 17 to 82 years), subjected to surgical mitral valve repair between December 1991 and March 1998. Preoperative functional capacity of these patients was 2.96 ± 0.7. Surgical repair was assessed using transesophagic echocardiography in all subjects. Results: The etiology of mitral insufficiency was degenerative in 43 patients, rheumatic in 10, infectious in 6, ischemic in 5 and miscellaneous in 4. The most frequent pathological findings were dilatation of the mitral ring in 42% of patients, chordae tendinae rupture in 32% and enlargement in 24%. A mitral anuloplasty was done in 90% of patients, a cuadrilateral resection of posterior leaflet in 52% and chordae tendinae transference in 12%. An additional surgical procedure was done in 34% of subjects. Three patients died during hospitalization (4.4%). During the follow up of 36.5 ± 22.3 months, five patients died and one required a mitral valve replacement. The actuarial survival probability was 95.3 ± 2.6% at one year and 83.5 ± 6.5% at five years. The reoperation free survival was 100% at one year and 97.4 ± 2.5% at five years. At the end of follow up the functional capacity improved to 1.25 ± 0.4. Echocardiography showed absence of mitral insufficiency in 48.4% of patients, minimal, mild and moderate insufficiency in 35.5, 14.5 and 1.6% of patients respectively. Conclusions: Surgical valve reconstruction in mitral insufficiency has satisfactory long term results and should be the procedure of choice for eligible patients.

Cirugía paliativa mediante operación de Norwood en distintas formas de corazón univentricular: resultados quirúrgicos inmediatos

: Norwood procedure is used as the first stage in thepalliative treatment of the hypoplastic heart syndrome and can be used, with some technicalmodifications, in other forms of univentricular heart with aortic stenosis or hypoplasia. Thesepatients have a high mortality (50%), derived from the procedure itself and from their abnor-mal physiological status.

Experiencia de 36 años con marcapasos implantables: Un análisis histórico

Background: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. Aim: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. Material and methods: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificacion de Chile (Chilean Civil and Identification Registry). Results: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74% from 1988 to 1998. Complication rate was 42% in the 1963-1976 study period, it decreased to 10.6% in the 1977-1987 study period, and to 5.6% by 1988-1998. Only two patients died during surgery in the study period (0.08%). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52% at ten years, 33% at 15 years, and 21% at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. Conclusions: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures (Rev Med Chile 2002; 130: 132-42)

Cirugía de la insuficiencia mitral isquémica

Background. Ischemic mitral regurgitation (IMR) is a severe condition which may be best treated by surgery, nowithstanding a relatively high mortality rate. Objectives. To evaluate the results of mitral valve replacement or repair in patients with IMR. Patients and methods. Retrospective review of the clinical records in 29 patients with IMR who were surgically treated from 1990 to 1999. They represent 8% of surgical procedures on the mitral valve. Results. Mean age was 67 ± 9 years. Surgery was performed urgently in 19 patients (66,5%). NYHA functional class was 3.4 ± 0.8. The mechanism of IMR was annular dilatation and spreading of papillary muscles in 18 patients, papillary muscle rupture in 9 and fibrosis in 2. Mitral valve replacement was performed in 14 patients and mitral valve repair in 15. Twenty four patients (83%) had concomitant myocardial revascularization. Overall surgical mortality was 24%; 26% for mitral replacement and 13% for mitral valve repair (p=0.215). On follow up of 26±33 months, one year survival was 76±0.8% and 5 years survival was 59±12%. Excluding in hospital mortality, survival was 100% at one year and 78±14% at 5 years. Functional class improved in all survivors, to 1.4±0.5. Late echocardiographic evaluation of patients with mitral valve repair showed absence of mitral regurgitation in 58%, 1+ MR in 17% and 2+ MR in 25%. Conclusion. In spite of a high perioperative mortality, surgery for IMR is a valuable procedure for patients with an otherwise highly lethal disease (Rev Med Chile 2002; 130: 9-16)

Reoperaciones coronarias: análisis retrospectivo de 16 años de experiencia

Background: Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency. Aim: To assess the early and long term results of coronary reoperations in our institution and to identify prognostic factors. Patients and methods: 214 patients subjected to coronary reoperations between 1983 and 1999 were retrospectively studied. Results: Mean age was 64.2 years (range 42-79 years), 202 (94.4%) were male and 12 (5.6%) female. The mean interval between the operations was 125.7 months (range 6-252 months). 10 (4,6%) were emergency surgeries. Overall operative mortality was 5.6% (11 deaths) and in 5 patients (3.4%) a perioperative myocardial infarction was noted. Univariate analysis identified moderate or severe left ventricular failure (p=0.048) as predictor of increased operative mortality, meanwhile age over 75 years (p=0.02) and moderate or severe left ventricular failure (p=0.01) were identified as predictors of increased in hospital mortality in the multivariate analysis. Follow up of in hospital survivors (mean interval 65 months, range 4 to 190 months) documented a 5 years survival rate of 82.9%, a 10 years survival rate of 73.1% and a 15 years survival rate of 53.4%. Moderate or severe left ventricular failure (p <0.0001) and emergency surgeries (p=0.007) were identified as factors influencing the late survival in the stepwise logistical regression analysis. Multivariate analysis identified left ventricular failure (p=0.01) and peripheral vascular disease (p=0.01) as predictors of decreased late survival. Conclusions: Coronary reoperation has a low mortality in patients with a normal ventricular function and also has an excellent overall and disease free survival in the first 10 years of follow up. Left ventricular function is an independent risk factor increasing in hospital and late mortality (Rev Med Chile 2001; 129: 1131-41)

Canulación de arteria axilar para circulación extracorpórea

Background: When the ascending aorta and the femoral artery cannot be used for extracorporeal circulation, an emerging alternative is the use of axillary artery. Aim: To report the experience using the axillary artery for extracorporeal circulation. Patients and methods: Between November 1998 and May 2002, 22 patients (14 male) were operated with extracorporeal circulation, cannulating the axillary artery. Briefly, an incision is made below the middle third of the clavicle and a cut is made on major pectoris muscle. Minor pectoris muscle is retracted and axillary artery is exposed. It is cannulated directly or with the aid of a prosthesis. Results: Right axillary artery was used in 21 patients and in 20 it was cannulated with the aid of a prosthesis. Mean flow was 4.5 + 0.6 l/min. The most common indications were aortic dissection or aneurysms. The most common procedures done, were ascending aorta replacement in 8 cases and replacement of ascending aorta and aortic arch in 5. Thirty five percent of operations were emergencies and 32% were reoperations. In 15 patients (68%), a circulatory arrest was done. Of these, retrograde brain perfusion was used in 9, antegrade brain perfusion through the same axillary artery was used in 2 and mixed perfusion was used in 2. One patient had a complication related to the axillary cannulation. None had cerebrovascular accidents or thromboembolic complications. Two patients died in the postoperative period. Patients were followed up to 42 months after the procedure and no secondary complications of the cannulation were detected. Conclusions: When the ascending aorta and the femoral artery cannot be used, axillary artery is a good alternative for extracorporeal circulation (Rev Med Chile 2003; 131: 390-6).