**6.1 Arrhythmias**

*Advances in Complex Valvular Disease*

bypass time.

**5.2 Follow-up results**

groups [81, 82].

the postoperative period [30, 76–78].

**6. Follow-up protocol and complications**

without fenestration had initial mortality rates ranging from 8 to 10.5% [73–75], while subjects who had total cavopulmonary connection with fenestration had

In one large single institutional study examining the results of 500 consecutive Fontan surgery patients [77], early failure was associated with high (≥19 mm Hg) mean PA pressure, young age at surgery, heterotaxy syndrome, a right-sided tricuspid valve as systemic atrioventricular valve, distorted pulmonary arteries, an atriopulmonary connection, no Fontan fenestration, and longer cardiopulmonary

These investigators also observed that a significant improvement in morbidity and mortality from early (first quartile—early failures: 27.1%) to the more recent time (last quartile—early failures: 7.5%) occurred [77]. This progress appears to be related to increasing surgical and intensive care experience as well as to more

Long-term follow-up results were also poor with older types of Fontan [9, 10]. The late mortality rates varied from 1 to 11%, and when early and late mortality rates were combined, they varied between 11 and 25%. The need for reoperations was present in 1–11% of patients. Factors adversely influencing late mortality and reoperation rates are earlier calendar year of operation, age of patient at the time of surgery, type of prior palliative procedures, hypoplasia, distortion or obstruction of PAs, subaortic obstruction, significant mitral valve insufficiency, elevated PA pressure or resistance, decreased left ventricular function, increased left ventricular

Following the introduction of staged cavopulmonary anastomosis (both lateral tunnel and extra-cardiac conduit diversion of IVC blood to the PA), the long-term outcomes have improved. In one study in which results of follow-up for 10.2 ± 0.6 years of 196 patients were examined, the estimated Kaplan-Meier survival was 93 and 91% at 5 and 10 years, respectively [79]. An equally impressive finding was freedom from supraventricular arrhythmias in 96 and 91% of patients at 5 and 10 years following surgery. In a different study, the actuarial survival 15 years following surgery was 85% [80]. But, late re-interventions were necessary in 12.7% of patients. When lateral tunnel and extra-cardiac conduit types of Fontan were compared, the outcomes were found to be similar for both

Using fenestration during Fontan appears to improve early mortality and morbidity, particularly demonstrated in high-risk patents [83]. A more recent analysis in a smaller group of patients did not demonstrate significant advantage of fenestrated Fontan over the non-fenestrated [84]. However, the general consensus is that using fenestration during Fontan decreases mortality and morbidity during

Periodic follow-up following Fontan is generally recommended. These patients are evaluated at 1, 6, and 12 months after Stage IIIB (device closure of fenestration) and yearly thereafter. During the follow-up, platelet-inhibiting doses of aspirin 2–5 mg/kg/day in children or clopidogrel 75 mg/day in adults to prevent thrombus formation and angiotensin-converting enzyme inhibitors for afterload reduction are generally prescribed. Electrocardiograms and echocardiograms are generally

slightly lower (4.5–7.5%) initial mortality rates [76–78].

recently introduced Fontan modifications.

muscle mass, asplenia syndrome, and others [9, 10].

**140**

Arrhythmias were more frequently seen in patients with old Fontan (atriopulmonary connection) than with staged TCPC. The observed arrhythmias were typically atrial arrhythmias, namely, atrial flutter/fibrillation and supraventricular tachycardia. Initially, anti-arrhythmic medications are used to control the rhythm disturbance. This should be followed by hemodynamic and angiographic assessment to identify obstructive lesions in the Fontan pathways. The obstructive lesions should be treated with balloon angioplasty, stent, or surgery, as applicable. Continued rhythm abnormality calls for radiofrequency ablation. Although the success rate of radiofrequency ablation is high in 80% range [86], rates of recurrence range from 30 to 40%. In subjects who have resistant arrhythmias, reducing the atrial mass, switch to TCPC with concomitant Maize procedure is advisable [87]. A few patients develop atrioventricular block or sick sinus syndrome which may require pacemaker implantation. Fortunately, ventricular arrhythmias are less frequent.
