新生儿心脏综合征最佳手术方案未定

旧金山——在美国胸外科协会(AATS)年会上的讨论中，专家们对新生儿左心发育不全综合征的最佳手术方案未能达成共识。

David J. Barron博士是1期右心室-肺动脉(RV-PA)管道术的支持者(Circulation 2003;108[suppl. 1]:II155-60)，J. William Gaynor博士更偏爱1期体肺(BT)分流术，而Mark E. Galantowicz博士则主张杂交1期手术。

纽约长老会摩根士丹利儿童医院的Emile A. Bacha博士则综合上述各种策略，对该病采取不同治疗方案。Bacha博士指出，或许没有标准答案，诸如外科医生经验或医院规模等因素可导致结局显著差异。通常他对于主动脉瓣狭窄患者采用体肺分流术，对于主动脉闭锁患者采取RV-PA管道术，而对于高危患者则采取杂交办法。

他们的主要观点如下：

• 1 期RV-PA 管道术：英国伯明翰儿童医院心脏外科的Barron博士称：“即便你有条件对同一手术采取3种不同方案，我们仍要寻找正确的方法。最重要的是对合适的患者采取合适的手术方案。”他认为，与典型Norwood分流术相比，RV-PA管道术的优势在于舒张压的维持。关闭分流时，Norwood分流术患者收缩压和舒张压均急剧下降，而RV-PA手术患者收缩压虽然下降，但舒张压能够维持。“这有助于更多的血流进入体循环，这也正是我们所希望的”。

Barron博士指出，虽然我们处在循证医学时代，但在先天性心脏病领域并非总能容易地找到Ⅰ级证据。一项针对549例婴儿的多中心随机对照研究显示，与接受改良BT术患者相比，PA-RV术患者1年生存率有10%的优势(N. Engl. J. Med. 2010:362:1980-92)。PV-RA管道术的缺点在于导管插管实验室干预比例高于BT分流术(41% vs. 26%)。此外，12个月无移植生存率无显著优势。

• 1期 BT分流术：费城儿童医院(CHOP)心胸外科主治医生Gaynor博士强调的是患儿的长期结局。 他指出，RV-PA术主要优势体现在手术间期早期。《新英格兰医学杂志》的研究显示，在32个月随访期间，无移植生存率未见统计学差异。

Bacha博士注意到两位专家均引用同一项研究证实自己的观点。他认为现在“或许需要开展一项新研究”。

Gaynor博士表示，在得到RV-PA术生存率和其他优势的充分、长期证据之前，他将继续支持改良BT分流术。他指出，在CHOP接受RV-PA术或改良BT分流术的1期重建患者总生存率未见显著差异 (Ann. Thorac. Surg. 2005:80:1582-90)。改良BT分流术患者在手术间期具有较高的患病率，而RV-PA管道术患者在2期重建手术后死亡或心衰移植率呈增加趋势。

• 杂交 1期手术：俄亥俄州哥伦布市全国儿童医院心胸外科主任Galantowicz博士称，支持杂交1期手术的主要考量是该方案对左心发育不全综合征的最初缓解效果。对标准风险患者而言，该方案与传统方案效果至少相当。杂交1期手术可使儿童有效康复，并可挽救出生时未确诊患儿的生命。

Galantowicz博士还指出，有证据表明杂交手术相对于改良BT分流术总体费用较低(Ann. Thorac. Surg. 2009;87:1885-92)。后者是最为昂贵的方案之一，而我们的资源有限。他强调，最重要的是，不是哪种手术更好，而是哪种手术更为适合。

Bacha博士表示，大家一致认为BT分流术与RV-PA管道术势均力敌，而杂交手术则更多地用于高危患者。

上述专家均声称无相关利益冲突。

爱思唯尔  版权所有

By: DAMIAN MCNAMARA, Cardiology News Digital Network

SAN FRANCISCO – There is no consensus among experts on the optimal surgical approach to repair neonatal hypoplastic left heart syndrome, if a series of consecutive talks at the annual meeting of the American Association for Thoracic Surgery is any indication.

Dr. David J. Barron is a proponent of the placement of a stage 1 right ventricle–pulmonary artery (RV-PA) conduit (Circulation 2003;108[suppl. 1]:II155-60); Dr. J. William Gaynor prefers a stage 1 Blalock-Taussig (BT) shunt; and Dr. Mark E. Galantowicz advocates a hybrid stage 1 procedure.

Dr. Emile A. Bacha tied all these strategies together in a differential approach to management of neonates with hypoplastic left heart syndrome. There may be no one answer; local factors such as surgeon experience or medical center volume can impart significant difference on outcomes, Dr. Bacha said. His bias, in general, is to use the BT shunt for aortic stenosis and the RV-PA conduit for aortic atresia, and to reserve the hybrid approach for high-risk patients. Dr. Bacha is director of the congenital and pediatric cardiac surgery at the Morgan Stanley Children’s Hospital of New York–Presbyterian in New York City.

The surgeons provided the following overview:

• Stage 1 RV-PA conduits. "If you have any condition where there are three different ways to do the same operation, [it indicates that] we are still looking for the right way of doing it. What is important is trying to find the right operation for the right patient," said Dr. Barron, a consultant cardiac surgeon at Birmingham (England) Children’s Hospital.

"It’s all about diastole" with the RV-PA conduit, Dr. Barron said. The maintenance of diastolic pressure is a benefit with RV-PA, compared with the classic Norwood shunt, he added. "When you turn off the shunt in the OR, you get dramatic drop with Norwood where both systolic and diastolic drop. With the RV-PA, the systolic pressure drops but the diastolic pressure is maintained. This facilitates "more of cardiac output to systemic circulation, where you want it to be."

"We’re in an era of evidence-based medicine, and it’s not always easy to find class I evidence in congenital heart disease. The strategy sounds good, but can we actually prove it is better?" Dr. Barron asked. He pointed to a multicenter comparison of 549 infants who were randomized to a modified BT or PA-RV shunt; the study revealed a 10% survival advantage for the PV-RA patients at 1 year (N. Engl. J. Med. 2010:362:1980-92).

A disadvantage of the PV-RA shunt was more catheterization lab interventions (41%, vs. 26% for the modified BT shunt). In addition, the transplantation-free survival advantage was no longer significant after 12 months, he said.

• Stage 1 BTshunts. "We really need to focus on how well these children do over the long run," said Dr. Gaynor, attending cardiothoracic surgeon at the Children’s Hospital of Philadelphia (CHOP).

"Most of the benefit of the RV-PA is in the early interstage period," Dr. Gaynor said. He pointed out that transplant-free survival was not statistically different in the New England Journal of Medicine study at a mean of 32 months’ follow-up.

Dr. Bacha noted that with both speakers using the same study to argue their points," it may be time for a new trial."

Dr. Gaynor suggested that he will remain a proponent of the modified BT shunt until sufficient, long-term evidence supports survival and other advantages with the use of the RV-PA. The RV PA may have some advantages for high-risk subgroups, but more data are needed, he said.

Likewise, an examination of stage 1 reconstruction at CHOP with either the RV-PA or a modified BT shunt showed no significant difference on overall survival, Dr. Gaynor said. (Ann. Thorac. Surg. 2005:80:1582-90). Interestingly, timing made a difference: Patients with the modified BT shunt had significantly higher morbidity during the interstage period, but those with an RV-PA conduit demonstrated a trend toward increased death or transplant for heart failure after stage 2 reconstruction.

• Hybrid stage 1 surgery. "I am in favor of hybrid stage 1 for initial palliation for hypoplastic left heart syndrome. Hybrid stage 1 has at least equivalent results to traditional approaches in standard-risk patients," said Dr. Galantowicz, chief of cardiothoracic surgery at Nationwide Children’s Hospital in Columbus, Ohio.

A hybrid stage 1 can effectively bridge a child to recovery and can salvage a child who was not diagnosed at birth, Dr. Galantowicz said.

There is some evidence that a hybrid approach is less costly overall, compared with placement of a modified BT shunt (Ann. Thorac. Surg. 2009;87:1885-92).

"The standard approach is one of the most costly and resource intensive for any of the congenital children we have," Dr. Galantowicz said. "It requires significant resource utilization, even in the modern era."

Ultimately, "it’s really not about which of these procedures is better as all or nothing. It’s which is better for which subcategory of patient," said Dr. Galantowicz.

According to Dr. Bacha, "I think we can all agree there is equipoise between the BT shunt and the RV-PA conduit, and the hybrid procedures are being increasingly employed for high-risk patients."

Dr. Barron, Dr. Gaynor, Dr. Galantowicz, and Dr. Bacha each said they had no relevant financial disclosures.