Morphologic analysis of common atrioventricular valves in patients with right atrial isomerism

Atrioventricular septal defect in Fontan circulation: Right ventricular dominance, not valve surgery, adversely affects survival

OBJECTIVE

The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation.

METHODS

We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021.

RESULTS

Of 174 patients with AVSD, 60% (105/174) had right ventricular (RV) dominance and 40% (69/174) had left ventricular (LV) dominance. The cumulative incidence of moderate or greater AVV regurgitation at 25 years after Fontan operation in patients with LV dominance was 56% (95% CI, 35%-72%), compared with 54% (95% CI, 40%-67%) in patients with RV dominance (P = .6). Nonetheless, transplantation-free survival at 25 years in patients with LV dominance was 94% (95% CI, 86%-100%), compared with 67% (95% CI, 52%-87%) in patients with RV dominance (hazard ratio, 5.9; 95% CI, 1.4-25.4; P < .01). Of note, transplantation-free survival was not different in patients who underwent AVV surgery before or at Fontan completion compared with those who did not (15 years: 81% [95% CI, 62%-100%] vs 88% [95% CI, 81%-95%]; P = .3).

CONCLUSIONS

In patients with AVSD and Fontan circulation the rate of moderate or greater common AVV regurgitation is similar in those with LV and RV dominance. RV dominance, rather than previous AVV surgery, is a risk factor for death or transplantation.

Concurrent right atrial isomerism, complete atrioventricular septal defect, and single ventricle in an L-transposition of great arteries patient complicated by brain abscess

We present a case of an 11-year-old Indonesian female who was referred to our facility after surgical excision of brain abscess. The patient has been previously diagnosed with right atrial isomerism, complete atrioventricular septal defect, and L-Transposition of great arteries. Multiple staged surgeries are required for the management of this condition.

Clinical standard for valve area after common atrioventricular valve plasty for a single ventricle

OBJECTIVES

To determine a clinical standard for post-repair common atrioventricular valve orifice area based on mid- to long-term valve function in patients with a functional single ventricle.

METHODS

The medical records of 19 single-ventricle patients who underwent common atrioventricular valve plasty from July 1988 to January 2013 were retrospectively reviewed. Bivalvation valvuloplasty was performed in 7 patients with relatively hypoplastic leaflets. The relationship between the orifice area of the repaired common atrioventricular valve measured intraoperatively and valve function and ventricular volume in the early postoperative period (median, 9.5 months) and at mid- to long-term follow-up (median, 4 years) were analysed.

RESULTS

Post-repair valve area was significantly positively correlated with valve regurgitation severity in the early postoperative period (P = 0.001, r = 0.69) and at mid- to long-term follow-up (P = 0.02, r = 0.57). Patients who did not undergo bivalvation had favourable valve function at mid- to long-term follow-up and in the early postoperative period when the post-repair valve area was 96-136% of the normal mitral valve area. Bivalvation patients had significantly more valve regurgitation in the early postoperative period than patients without bivalvation, despite equivalent repaired valve area (P = 0.02).

CONCLUSIONS

The post-repair orifice area of the common atrioventricular valve is significantly related to postoperative valve function. The clinical standard of post-repair valve orifice area might be 96-136% of the normal mitral valve area in patients undergoing repair without bivalvation. Patients undergoing bivalvation require greater reduction to obtain favourable mid- to long-term valve function.

Right atrial isomerism in children older than 3 years

Background

There is a high mortality in infants with right atrial isomerism (RAI). However, less is known about outcome in older children with RAI. This study sought to evaluate those patients with RAI who survived older than 3 years of age without surgical intervention.

Results

A total of 33 consecutive patients (20 males) were enrolled in the study, mean age 6 years (range 3–32). None of the patients had surgical intervention for the RAI before age 3. Cardiac abnormalities include altered cardiac position (39 %), atrioventricular valve anomaly (87 %), single or functional single ventricle (55 %), pulmonary/subpulmonary obstruction (97 %), abnormal origin of the aorta (100 %), bilateral superior vena cava (67 %), and anomalous pulmonary venous drainage (66 %). Surgical intervention was performed after 3 years of age in 20 patients (61 %). None of them planned or had biventricular repair performed. 10 patients underwent the total cavopulmonary connection procedure, including four (40 %) who had atrioventricular valve (AVV) repair at the same time [all with common atrioventricular valve (CAVV)]. One patient died the day after the operation. A total of 69 % of patients with a CAVV had moderate or severe regurgitation, while 27 % with a single atrioventricular valve had moderate or severe regurgitation.

Conclusion

Patients with RAI who have survived to early childhood without surgical intervention have complex cardiac abnormalities. Survival after single stage total cavopulmonary connection is good but AVV repair is common.

Improving outcomes of the surgical management of right atrial isomerism

BACKGROUND

Patients with right atrial isomerism (RAI) have several cardiac malformations historically resulting in significant morbidity and mortality. We sought to assess whether current surgical strategies have improved the outcomes of patients with RAI.

METHODS

A retrospective review of our database from 1997 to 2010 identified 60 consecutive patients with RAI who underwent initial palliation at Mt. Fuji Shizuoka Children's Hospital. All of the patients had a functional single ventricle. Of the 60 patients, 33 patients (51.7%) had obstructed total anomalous pulmonary venous drainage (TAPVD), 23 patients (40.3%) had significant (more than moderate) atrioventricular valvular regurgitation (AVVR), 7 patients (12.3%) had hiatus hernia, and 4 patients (6.7%) had major aortopulmonary collateral arteries. Pulmonary outflow atresia was present in 39 of the patients (65%), and 46 patients had systemic-to-pulmonary artery shunts. Of the 33 patients with TAPVD, 18 underwent repair of the condition at initial palliation, 9 others at the time of a Glenn operation, 2 more through a Fontan operation, and 4 at the interstage between palliative surgeries. Eight of the 23 patients with significant AVVR underwent atrioventricular valve repair at initial palliation, 8 others at the time of Glenn operation, 4 others at the time of Fontan operation, and 3 during the interstage between operations. An initial neonatal surgical procedure was performed in 30 patients (50%). The mean follow-up period for patients in the study was 53.1 months.

RESULTS

Operative mortality after initial palliation was 15.4% (4 of 26 patients) before 2003 and 17.6% (6 of 34 patients) after 2004 (p=NS). Five-year survival was 53.8% before 2003 and 81.7% after 2004 (p=0.035, log-rank test). A multivariate analysis identified persistent AVVR of more than moderate degree (p=0.04) as a factor associated with late mortality.

CONCLUSIONS

The outcomes of surgery for RAI are improving. Neonatal palliative surgery for RAI carries a high operative risk of early mortality, and persistent significant AVVR remains a risk factor for late mortality.

Appropriate additional pulmonary blood flow at the bidirectional Glenn procedure is useful for completion of total cavopulmonary connection

BACKGROUND

The role and effect of additional pulmonary blood flow at the time of bidirectional Glenn procedure (BDG) is controversial. We assessed our experiences to clarify the effects of controlled additional pulmonary blood flow on outcomes after BDG.

METHODS

Thirty-eight patients who underwent BDG (2.1 +/- 2.1 years of age) were enrolled in this study. In group A (n = 29) additional pulmonary blood flow was controlled by the banding of the pulmonary trunk, or the previously created Blalock-Taussig shunt, to keep the central venous pressure equal to or less than 16 mm Hg at BDG. In group B (n = 9), BDG was the only source of pulmonary blood flow.

RESULTS

One operative death occurred in group B. In group A, 24 patients underwent total cavopulmonary connection (TCPC) 14 +/- 6 months after BDG, and the remaining 5 patients are waiting for TCPC in good condition. In group B, 6 patients underwent TCPC 8 +/- 7 months after BDG. One patient is awaiting TCPC and the remaining patient is considered unsuitable for TCPC. Cardiac catheterization performed in 32 patients showed significant decrease of pulmonary artery (Nakata) index from 307 +/- 73 to 215 +/- 45 mm2/m2 after BDG in group B (p < 0.05). On the other hand, the Nakata index stayed in higher range from 316 +/- 115 to 287 +/- 74 mm2/m2 in group A, and there was a significant correlation between the Nakata index and the percentage of its difference (Y = 40.823 - 0.144 X; n = 26, R = 0.740, p < 0.0001).

CONCLUSIONS

Appropriate additional pulmonary blood flow is useful for the completion of TCPC by means of suppressing the decrease in the size of the pulmonary artery, especially in patients with underdeveloped pulmonary arteries.

Clinical Implications of Major Aortopulmonary Collateral Arteries in Patients With Right Isomerism

BACKGROUND

The presence of major aortopulmonary collateral arteries (MAPCA) in patients with right isomerism may alter the prognosis, which is still unclear.

METHODS

From 1994 to 2003, 138 out of 155 patients (89%) with right isomerism had pulmonary stenosis or pulmonary atresia and constituted the study population.

RESULTS

Two groups of patients were identified, one with MAPCA and the other without. The MAPCA originating from descending thoracic aorta or aortic arch was noted in 9 patients (6.5%), with a median number of MAPCA being 3 (range, 2 to 4). Patients with MAPCA commonly had congestive heart failure (8/9, 89%) and frequent lower airway infection (6/9, 67%). In comparison with patients with MAPCA and without, the intrapericardial pulmonary artery was more frequently absent (2 of 9 vs 1 of 129, p < 0.001), and the pulmonary arterial size was smaller (McGoon ratio <1.5, 8 of 9 vs 57 of 129, p = 0.009) in the MAPCA group. The mean pulmonary arterial pressure measured was often higher than the suggested limit for Fontan circulation. Major aortopulmonary collateral arteries were addressed at a median of 6 months old (2 to 19 months old) in 5 patients. Although surgical mortality was not different for first-stage palliation and Glenn shunt in both groups, total cavopulmonary connection could only be performed in one patient with MAPCA with poor results. However, the 5-year survival of patients with and without MAPCA was not statistically different (74.1% vs 55.2%, p = 0.19).

CONCLUSIONS

The presence of MAPCA was uncommon but still noted in patients with right isomerism. It may cause heart failure and a less favorable pulmonary vasculature for a complete Fontan-type operation.

Contemporary management of right atrial isomerism: effect of evolving therapeutic strategies

OBJECTIVES

Infants with right atrial isomerism have poor outcomes because of a complex combination of cardiac anomalies. Aggressive management of total anomalous pulmonary venous drainage might have a positive effect on the prognosis.

METHODS

Outcomes of all children with right atrial isomerism from 1994 to the present were reviewed. Management of total anomalous pulmonary venous drainage evolved from no repair or conventional surgical technique to primary sutureless repair on initial palliation. Cox survival models were used to identify variables associated with reduced survival.

RESULTS

There were 55 children enrolled in the study. The median age at the initial visit was 2 days. Fifty-one patients had total anomalous pulmonary venous drainage (obstructive in 22 patients). Withdrawal of treatment occurred in 11 (20%) of 55 patients during an interval of institutional bias toward no treatment. Thirteen (24%) of 55 patients had palliations without total anomalous pulmonary venous drainage repair, and 3 (23%) of 13 survived. Thirty-one (56%) of 55 patients had operations that included total anomalous pulmonary venous drainage repair, of whom 13 (42%) of 31 underwent primary sutureless repair for total anomalous pulmonary venous drainage. Sixteen (52%) of 31 survived, and their current status 1 to 10 years (median, 5.8 years) after repair is post-Fontan (7/16 [44%]), postbidirectional Glenn (6/16 [38%]), and others (3 [20%]). In patients who underwent total anomalous pulmonary venous drainage repair (n = 31), 2 risk factors of decreased survival were identified: drainage site obstruction and infracardiac or mixed-type total anomalous pulmonary venous drainage. After adjustment, sutureless repair appeared to be associated with improved survival (hazard ratio, 0.43), but this beneficial effect did not reach significance (P = .19).

CONCLUSIONS

Mortality continues to be high; however, aggressive total anomalous pulmonary venous drainage repair for right atrial isomerism has resulted in improved survival. The role of primary sutureless repair for total anomalous pulmonary venous drainage remains to be defined.

New indicator for the Fontan operation: diameters of the pulmonary veins in patients with univentricular heart

BACKGROUND

Operative survival after the Fontan procedure is good; however, there are some patients with disappointing results, especially those with atrial isomerism.

OBJECTIVES

We tested whether the diameter of the pulmonary veins, which is reported as a useful indicator of pulmonary blood flow, predicts operative results after the Fontan operation.

PATIENTS AND METHODS

We evaluated 30 consecutive patients undergoing either the bidirectional Glenn anastomosis (BDG) or the Fontan operation. Age at operation ranged from 3 to 81 months (mean 30). Diagnosis was right or left isomeric heart in 15 patients, double-outlet right ventricle in 4 and various other malformations in 11. BDG was performed in 16 patients and the Fontan operation in 14 patients. The diameters of the pulmonary veins were measured proximal to the entrance into the atrium in the late phase of a pulmonary arteriogram. The pulmonary vein (PV) index (in mm2/m2) was calculated from the sum of the cross-sectional areas of these veins divided by the body surface area.

RESULTS

Of the patients undergoing BDG (+/- ancillary procedures), 12 had successful results and 4 had unsuccessful results. The PV index for hemodynamically successful patients was 361 +/- 153 and 275 +/- 60 mm2/m2 (mean +/- SD) for unsuccessful patients (p = 0.30). Of the patients who underwent the Fontan operation, 13 had successful and 1 had unsuccessful results. The PV index for successful patients was > 285 mm2/m2 and 137 mm2/m2 for the nonsuccessful patients. The new pulmonary vascular resistance (PVR) calculated by using the PV index (mean pressure difference between the pulmonary artery and the atrium/PV index) for BDG patients with successful or unsuccessful results was 2.0 +/- 0.5 or 3.5 +/- 0.2 mmHg/mm2 per m2, respectively (p < 0.01). The new PVR for Fontan patients with successful results was < 2.0 mmHg/mm2 per m2, while that for the patient with an unsuccessful result was 4.4. The new PVR completely separated patients into successful and unsuccessful groups, while conventionally calculated PVR did not (p = 0.63).

CONCLUSIONS

PV index appears to be a useful morphological indicator of pulmonary blood flow and "new" PVR may improve the decision-making strategy for patients presenting with univentricular heart, especially those associated with isomeric heart.