Loomba Rohit S, Danduran Michael E, Dixon Jennifer E, Rao Rohit P
Department of Cardiology, Children's Hospital of Wisconsin, 9000 Wisconsin Avenue, Milwaukee, WI, 53226, USA,
Pediatr Cardiol. 2014 Mar;35(3):514-20. doi: 10.1007/s00246-013-0817-y. Epub 2013 Oct 23.
Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients with fenestrations have better exercise times, higher absolute regional oxygen venous saturations, and smaller arteriovenous differences than Fontan patients without fenestrations. For this study, 50 consecutive Fontan patients and 51 consecutive patients with normal cardiovascular anatomy were recruited. Placement of NIRS probes was performed to obtain regional oxygen saturations from the brain and the kidney. Readings were obtained at 1-min intervals during rest, exercise, and recovery. A standard Bruce protocol was used with a 5-min recovery period. Absolute regional tissue oxygenation values (rSO2) and arterial-venous oxygen saturation differences (AVDO2) calculated as arterial oxygen saturation (SPO2)--rSO2 for normal versus Fontan patients and for fenestrated versus unfenestrated Fontan patients were compared using independent t tests. When normal and Fontan patients were compared, the Fontan patients had a significantly shorter duration of exercise (9.3 vs 13.2 min; p < 0.001). No statistically significant difference in rSO2 change or AVDO2 was evident at the time of peak exercise, at 2 min into the recovery, or at 5 min into the recovery. A small oxygen debt also was paid back to the brain in the Fontan patients after exercise, as evidenced by a narrower AVDO2 than at baseline. The comparison of Fontan patients with and without fenestration showed no statistically significant difference in exercise time, rSO2 change, or AVDO2. The Fontan patients were noted to have shorter exercise times than the normal patients and also appeared to have an alteration in postexertional regional blood flow. However, when the various Fontan subtypes were compared by presence or absence of a fenestration, no significant differences were noted with regard to change in regional oxygen saturation or arteriovenous oxygen saturation. Thus, for patients with Fontan physiology, closure of the fenestration does not seem to have an impact on the dynamics of regional oxygen extraction during exercise or recovery.
Fontan 开窗关闭术是一个备受争议的话题。关于开窗关闭术风险和益处的数据有限，但仍在不断增加。先前的研究表明，Fontan 患者的运动能力低于心血管解剖结构正常的患者。在 Fontan 患者的不同亚组中也发现了差异，例如 Fontan 是否开窗。本研究旨在使用近红外光谱（NIRS）比较 Fontan 循环患者在递增运动期间局部氧饱和度的变化趋势，以进一步明确有开窗和无开窗患者之间的差异。研究假设是，有开窗的 Fontan 患者比无开窗的 Fontan 患者有更好的运动时间、更高的局部绝对氧静脉饱和度和更小的动静脉差异。在本研究中，连续招募了 50 例 Fontan 患者和 51 例心血管解剖结构正常的患者。放置 NIRS 探头以获取大脑和肾脏的局部氧饱和度。在休息、运动和恢复期间每隔 1 分钟读取一次数据。采用标准 Bruce 方案，恢复期为 5 分钟。使用独立 t 检验比较正常患者与 Fontan 患者以及有开窗与无开窗的 Fontan 患者的局部组织氧合绝对值（rSO2）和动静脉氧饱和度差异（AVDO2），计算方法为动脉血氧饱和度（SPO2）减去 rSO2。比较正常患者与 Fontan 患者时，Fontan 患者的运动持续时间明显较短（9.3 分钟对 13.2 分钟；p < 0.001）。在运动峰值时、恢复 2 分钟时或恢复 5 分钟时，rSO2 变化或 AVDO2 均无统计学显著差异。运动后，Fontan 患者的大脑也偿还了少量氧债，表现为 AVDO2 比基线时更窄。比较有开窗和无开窗的 Fontan 患者，在运动时间、rSO2 变化或 AVDO2 方面均无统计学显著差异。Fontan 患者的运动时间比正常患者短，并且运动后局部血流似乎也有改变。然而，当按是否有开窗比较不同的 Fontan 亚型时，在局部氧饱和度变化或动静脉氧饱和度方面未发现显著差异。因此，对于具有 Fontan 生理特征的患者，开窗关闭术似乎对运动或恢复期间局部氧摄取动态没有影响。
