Repair of complete atrioventricular canal in early childhood

From November 1977 to January 1981, 10 consecutive patients underwent intracardiac repair of the complete atrioventricular canal at our institution. Ages ranged from 14 months to 4.5 years (mean age 20 months). Four patients were predominantly of type A, while 6 were predominantly of type C according to Rastelli's classification. Three patients had associated cardiac anomalies (2 tetralogy of Fallot and one parachute mitral valve). Standard repair and correction of the associated anomalies were performed under cold cardioplegic cardiac arrest and deep hypothermia with low-flow perfusion or circulatory arrest. Two patients died early postoperatively in severe renal failure and one died 6.5 months postoperatively in cardiac failure due to progressive mitral valve incompetence. One patient, with parachute mitral valve, was reoperated and the mitral valve was replaced because of persistent mitral insufficiency. The patients were followed up for a period of 4 to 35 months (mean 14 months) with a total of 112 patient months. The result of the operation was very good and all patients with retarded growth curve preoperatively showed a marked acceleration of their growth curve after operation. The operative results in this group of patients are independent of age and weight at the time of operation but appear to be influenced by associated cardiac anomalies and by the quality and quantity of atrioventricular valve tissue available for reconstruction.     

63例心房室管畸形的外科治疗

目的:总结心房室管畸形外科治疗的经验。方法:我院自2005年5月至2009年12月手术治疗心房室管畸形患者63例。其中部分性房室管畸形56例,完全性房室管畸形7例。部分性房室管畸形瓣裂修补采用间断褥式缝合并连续缝合加固;原发孔型房间隔缺损24例采用Kirklin的方法修补将冠状静脉窦开口隔入左心房,32例采用McGoon法冠状静脉窦开口保留在右心房。完全性房室管畸形7例。按Rastalli分型属A型4例,C型3例,分别采用自体心包加涤纶片的双片法(4例)或自体心包单片法(3例)修复。合并畸形均予以同期处理。结果:无早期死亡病例。术后发生低心排出量综合征(低心排)8例;Ⅲ°房室传导阻滞1例,7d后恢复窦性心律。术后随访46例,随访时间2个月～4年,心功能均为Ⅰ～Ⅱ级。结论:部分性房室管畸形手术治疗的关键,是完善修复二尖瓣关闭不全和避免房室传导阻滞。完全性房室管畸形除注重房室瓣修补完善外,强调将二尖瓣和三尖瓣环纠正至正常解剖位置,以恢复室间隔的面积和增宽左心室流出道。     

Surgical treatment of complete atrioventricular canal. Value of the "composite double patch" technic

Between January 1, 1982 and January 1, 1988, 49 complete corrections of complete atrioventricular canal were performed in children aged from 4 months to 8 years. 41 were infants less than 2 years' old and 31 were less than one year old. In the last 35 patients the "composite double patch" technique was used, consisting of closure of the interventricular septal defect with a dacron patch, followed by closure of the ostium primum with a pericardial patch. The mitral cleft was left intact in the last 6 operations. The overall mortality rate was 35 p. 100 (17 patients). It was 23 p. 100 in infants under 1 year and 17 p. 100 in infants aged from 6 to 12 months at the time of surgery (p less than 0.01). Seven of the 35 children in whom the "composite double patch" technique was used died (20 p. 100). Only one early death was recorded among the last 15 children operated upon. Two reoperations were performed: one within one month of the first operation, the other 4 months later for residual mitral regurgitation with haemolysis. 32 children were followed up for periods of 2 months to 6 years, 10 of them for more than 3 years. Two late deaths occurred during the follow-up. Grade 2 or 3/4 residual regurgitation was found in 14 patients who have regular clinical and echocardiographic examinations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical and medical results of complete atrioventricular canal: a ten year review

The files of 121 patients who presented to Children's Hospital of Michigan over the last 10 years with complete atrioventricular (AV) canal were reviewed to evaluate long-term management and overall outcome. Of 121 patients, 70 underwent corrective surgery, 21 (30%) of whom died perioperatively. The surgical mortality rate was 13% when patients with hypoplastic left or right ventricle (n = 6), double-orifice mitral valve or extreme deficiency of mitral tissue (n = 5), and pulmonary vascular obstructive disease (n = 5) were excluded. Of the 49 patients who survived operation, 36 are in New York Heart Association class I, 1 patient requires a pacemaker and 3 died late. In 34 of the 51 patients (28%) who did not undergo operation, pulmonary vascular obstructive disease developed; it occurred within 12 months in 10 patients (8%). Eight other patients who did not undergo operation died before planned surgery (age 1 to 9 months). Although surgical prognosis in good candidates is acceptable, the overall prognosis for children with complete AV canal is guarded because of the risk of early death or early pulmonary vascular obstructive disease and frequently unfavorable anatomy.     

Echocardiographic classification of complete atrioventricular canal defects

M-mode echocardiographic records of 26 patients with surgically proven complete atrioventricular canal defect were reviewed. Fragmentation of the interventricular septum and anterior displacement of the mitral annulus into the left ventricular outflow tract were noted in all patients. In 25 of 26 a common atrioventricular valve leaflet echo could be identified in the left ventricular outflow tract at the area of the crest of the interventricular septum. Recordings of echographic scans performed in the area of the left ventricle demonstrated separate “mitral” and “tricuspid” contributions to atrioventricular valve echoes in all 13 patients with type A defect, and a single common atrioventricular valve leaflet in 10 of 11 patients with type C complete atrioventricular canal. Two patients with type B defect had findings intermediate between these two patterns. M-mode echocardiography presumptively diagnosed complete atrioventricular canal in all 26 patients and diagnosis was definitive in 25 of 26. In addition, echocardiographic atrioventricular valve patterns permitted anatomic classification in the large majority of cases.     

Echocardiographic differentiation of partial and complete atrioventricular canal

Retrospective examination of echocardiograms was performed in 34 patients with persistent atrioventricular (A-V) canal who had undergone cardiac catheterization. Characteristic findings in 16 patients with partial A-V canal were lack of continuity of mitral and tricuspid valves, paradoxical interventricular septal motion, definite E and A waves of the mitral valve anterior leaflet (MVAL) echoes and late systolic anterior motion of the mitral valve. Eighteen patients with persistent A-V canal had an interventricular communication and were classified as having the complete form. They characteristically had continuous mitral and tricuspid valves, normal interventricular septal motion, disorganized MVAL echoes, and normal systolic mitral valve motion. Combining these findings allowed differentiation of 31 of the 34 patients (91%) as having partial or complete A-V canal. Determining the presence of a VSD from loss of interventricular septal echoes was unsatisfactory. The severity of mitral insufficiency could not be estimated from echocardiograms of our patients with partial A-V canal.     

Pulmonary vascular disease in complete atrioventricular canal defect.

The incidence and time of occurrence of pulmonary vascular disease were studied in 67 children with the complete form of atrioventricular (A-V) canal defect. Advanced pulmonary vascular disease begins to develop during the first year of life, with intimal fibrosis (grade 3 cahnges) noted between age 6 months to 1 year. Vascular dilatation with plexiform lesions (grade 4 changes) can be found by age 1 year. These changes can be found in some patients in spite of hemodynamic findings usually considered to indicate lesser degrees of vascular disease. After age 2 years advanced pulmonary vascular disease is commonly found and may persist after surgical correction of the defects. A similar rapid progression of pulmonary vascular disease was noted in 40 children who had a large ventricular septal defect without A-V canal in whom systemic pressure was transmitted directly to the pulmonary vascular bed. Thirty-six of the 67 children had trisomy-21. No difference was noted in the speed of progression of pulmonary vascular disease between these children and those without trisomy 21. Palliative or corrective surgery should be performed in these patients by age 1 year to prevent development of advanced pulmonary vascular disease.     

Echocardiographic estimation of ventricular hypoplasia in complete atrioventricular canal.

Echocardiograms from 10 patients with complete atrioventricular canal (CAVC) were compared with autopsy specimens to determine the capabilities of echocardiography in identifying patients with ventricular hypoplasia. On the basis of echographic ventricular size, patients could be divided into three groups: 1) "balanced" CAVC patients had both increased right and left ventricular end-diastolic dimensions (RVED and LVED) and an increased RVED/LVED ratio; 2) "dominant left ventricular" CAVC patients had an increased LVED and small or normal RVED and a diminished RVED/LVED ratio; 3) "dominant right ventricular" CAVC patients had an increased RVED, but small LVED, and increased RVED/LVED. There was complete agreement between echographic ventricular dominance and pathologic findings. This study demonstrates that echocardiography may be valuable in assessing ventricular dominance in the presence of CAVC.     

Surgical correction of atrioventricular canal without heart catheterization

In our department, 35 patients with atrioventricular canal underwent elective surgery between June 1983 and May 1989. The diagnosis was based on clinical and echocardiographic assessment without cardiac catheterization. Nineteen patients (age 2-12 years; mean 6.6 years) had a partial atrioventricular canal and 16 (age 5-8 months; mean 7 months) presented a complete atrioventricular canal. The echocardiographic diagnosis was confirmed at surgery in all but one patient (2.8%). The latter was diagnosed as having a complete canal but at surgery a transitional canal with a restrictive ventricular septal defect was found. We based our patient selection on the natural history which excluded cases with early heart failure and pulmonary hypertension. We also relied on an accurate morphological study using two-dimensional echocardiography which excluded cases with associated cardiac malformations. Our recent experience (1986-1989) showed that 50% of the patients with complete canal and 60% of patients with partial canal underwent surgery without cardiac catheterization.     

The electrocardiogram in tetralogy of Fallot with complete atrioventricular canal

The electrocardiograms in nine cases of tetralogy of Fallot with complete atrioventricular canal were reviewed. Only six patients had the typical pattern of right ventricular hypertrophy and superiorly displaced loop in the frontal plane. Of the remaining three patients, two had only right ventricular hypertrophy and one had a normal electrocardiogram. The necessity of two-dimensional echocardiography or an accurate catheterization technique designed to reveal the combined lesions, even when unsuspected, is emphasized.     

Primary repair of d-transposition with complete atrioventricular canal defect

A 4-month-old boy underwent successful single-stage anatomic repair of d-transposition of the great arteries with complete balanced atrioventricular canal defect, using the arterial switch procedure and two-patch repair of the atrioventricular canal defect. He had associated persistent left superior vena cava draining to the coronary sinus, and a patent ductus arteriosus.     

Repair of complete atrioventricular canal before one year of age

We report a series of 22 children with complete atrioventricular canal (CAVC) operated upon before the age of one year. The youngest patient was 1 month old and weighed 3 kg. The patients' mean age was 7 months and their mean weight was 5.4 kg. 15 patients had trisomy 21, and in one patient the CAVC was associated with tetralogy of Fallot. The remaining 21 patients had congestive heart failure resistant to medical treatment, with clinical evidence of pulmonary arterial hypertension (PAHT). At the time of surgery, 2 patients had been under artificial respiration for one month. All patients were explored by echocardiography and cardiac catheterization. The mean pulmonary pressure/aortic pressure ratio was 0.92; the mean pulmonary flow rate/systemic flow rate ratio (Qp/Qs) was 2.9/1 and the mean pulmonary resistance/systemic resistance ratio (Rp/Rs) was 0.22. All children were operated upon under deep hypothermia with circulatory arrest (mean 54 min); the patient with tetralogy of Fallot had an additional period of extracorporeal circulation. Fourteen patients had Rastelli's type A CAVC and 8 had type C CAVC. All were operated upon by the classical Rastelli technique, using a single autologous pericardial patch; in none of the patients was the septal "slit" or "commissure" entirely closed. Three patients died within 48 hours of the operation: the first one died of sudden low cardiac output 18 hours after surgery, the second one of persistent PAHT and the third one of malignant hyperthermia. The patient under artificial respiration before surgery could not be disconnected and died on the 30th post-operative day.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical treatment of partial atrioventricular canal in a 69 year-old woman with secondary pulmonary hypertension

We present a case of a 69 year-old female with partial atrioventricular canal treated with surgical complete correction of defect.     

Play safe: band the late presenting complete atrioventricular canal

Primary repair of complete atrioventricular canal in patients who present beyond one year of age carries a high mortality. Between January 1995 and February 2000, 16 patients aged 8 to 24 months (mean, 14.5 months) received pulmonary artery banding at presentation and underwent total correction at 24 to 96 months old (mean, 41.9 months). There was one hospital death (mortality, 6.25%). During a mean follow-up of 10.2 months (range, 6 to 28 months), there was no late death, 13 of the 15 survivors (87%) were in New York Heart Association functional class I, and 2 (13%) were in class III. In patients with complete atrioventricular canal who present late with severe reactive pulmonary hypertension, banding followed by complete repair reduces the risk associated with primary repair.     

Surgical treatment of complete atrioventricular canals, regular and irregular forms, in 75 patients

The cases of 75 consecutive patients operated for complete atrioventricular canal between 1/1/1978 and 1/1/1985 at Marie-Lannelongue Hospital were reviewed. The age ranged from 1.5 months to 16 years. Forty-nine per cent of patients were operated in the first year of life in the period 1982-1984. Seventy-eight per cent of patients were operated before one year of age. Certain anatomical characteristics enable regular and irregular forms of the condition to be distinguished. Regular forms are characterised by the association of a defect of the inter atrio-ventricular septum, of a common atrioventricular orifice and of ventricles of equal volume without other associated malformations. Irregular forms include the parachute mitral valve, the double mitral orifice, deficient mitral valvular tissue, ventricular hypoplasia, subaortic stenosis, abnormal right ventricular muscular bands, associated cardiac malformations and pulmonary obstructive vascular disease. Surgery comprises repair of the ventricular septal defect and the ostium primum with two separate patches, respecting the anterior and posterior valves and partial or complete closure of the cleft valve. The hospital mortality rate was 33 p. cent. It was 16 p. cent in regular forms and 58 p. cent in irregular forms (p less than 0.01). The hospital mortality of patients operated before 1 year of age with the regular form of the malformation was 22 p. cent. Six children were reoperated secondarily with 2 deaths. Four pacemakers were implanted for complete atrioventricular block. The secondary mortality was 10 p. cent. Thirty-nine patients were followed up for an average of 28 months (range 3 months to 5.5 years).(ABSTRACT TRUNCATED AT 250 WORDS)     

Short-term hemodynamic effects of hydralazine in infants with complete atrioventricular canal defects

We evaluated the acute hemodynamic responses to hydralazine during cardiac catheterization in eight infants (ages 1.0 to 5.5 months) with congestive heart failure due to complete atrioventricular canal defect. Hydralazine administered intravenously (0.5 to 1.0 mg/kg body weight) increased heart rate and systemic blood flow and decreased mean right atrial pressure, systemic and pulmonic arterial pressures, systemic arteriolar resistance, and the ratio of pulmonary to systemic blood flow (p less than .05). The percentage of pulmonary flow contributed by shunted blood (percent left-to-right shunt; measured by indicator dilution) was decreased by hydralazine in six (mean = 85% before to 64% after hydralazine; p less than .01), but remained unchanged (79%) in two infants. The two infants with no change in percent left-to-right shunt had higher pulmonary arteriolar resistances (Rp) before hydralazine (mean = 12.8 vs 3.2 U/m2) and had greater declines in Rp (mean change = -5.1 vs + 0.3 U/m2) in response to hydralazine. Thus, if Rp does not fall, hydralazine reduces the percentage of left-to-right shunt over the short term and therefore might be useful for managing congestive heart failure in these infants. However, because the response varies, an evaluation of the short-term hemodynamic effects of hydralazine may be warranted in an attempt to select those infants who might respond favorably to long-term hydralazine therapy.