Ann Thorac Surg 2001;71:2002
© 2001 The Society of Thoracic Surgeons
Invited commentary
Ralph E. Delius, MDa
a Division of Cardiovascular Surgery, Children’s Hospital of Michigan, 3901 Beaubien Blvd, Detroit, MI 48201-2196, USA
e-mail: rdelius{at}dmc.org
The one and a half ventricle repair is an intuitively attractive concept in which a hypoplastic or hypofunctional right ventricle is incorporated into the pulmonary circulation. The shortcomings of the Fontan procedure have been well documented, and the idea of imparting some degree of kinetic energy to pulmonary blood flow is enticing, providing the anatomic substrate allows this approach. The report by Chowdhury and colleagues further expands the number of patients in the medical literature that have undergone this approach. Given the heterogeneity and relative rarity of patients that are candidates for this approach, a prospective evaluation of this concept is unlikely. Continued expansion of knowledge in this area will therefore likely continue to depend on retrospective reports such as the one by Chowdhury and colleagues.
Previous reports have largely concentrated on establishing the anatomic criteria for this operation. Right ventricular size is a continuum, ranging from ventricles that are clearly unsuitable for use to those that are nearly normal. Within this range are a bandwidth of ventricles that are capable of dealing with venous return from the inferior vena cava, but not the entire systemic venous return. Establishing where in this spectrum the right ventricle is satisfactory for the one and a half ventricle repair is probably the predominant concern when considering this approach for a given patient, so the emphasis in previous reports is understandable and appropriate. What has not been well documented, however, is the physiological criteria for this operation, particularly in regards to pulmonary vascular resistance. It seems conceivable that the physiologic criteria for a one and a half ventricle repair may be less stringent than those required for a single ventricle approach. Although the number of patients is small, the report by Chowdhury and colleagues suggests that this hypothesis may not be true. One half of the deaths in this report are attributed to elevated pulmonary vascular resistance, and the physiological criteria they recommend are similar to those for Fontan candidates.
As noted earlier, this report expands the number of patients in the medical literature which have successfully undergone this procedure. Like all previously published reports, this study confirms that the operation can be performed with reasonable morbidity and mortality. An improvement in short and intermediate term survival has not been demonstrated in this or any other report, which is not surprising given the excellent short term survival recently reported in patients undergoing modern variations of the Fontan procedure. In fact, the theoretical benefits of a one and a half ventricle approach are probably going to manifest in terms of diminished arrythmias and, most notably, improved exercise performance. Long term survival may conceivably be improved as well. However, these are all suppositions at this point. The medical literature is rife with examples of therapies that seemed likely to be beneficial, but were in fact either pointless or even harmful. The most compelling need for information in this subset of patients is determining whether there is, in fact, any benefit to the one and a half ventricle repair.
Related Article
-
One and a half ventricle repair with pulsatile bidirectional Glenn: results and guidelines for patient selection
- Ujjwal Kumar Chowdhury, Balram Airan, Rajesh Sharma, Anil Bhan, Shyam Sunder Kothari, Anita Saxena, and Panangipalli Venugopal
Ann. Thorac. Surg. 2001 71: 1995-2002.
[Abstract]
[Full Text]
[PDF]
