Surgical Management of Total Anomalous Pulmonary Venous Drainage

Chris Caldarone, MD

Recent reports have identified a trend towards decreasing operative mortality in surgical management of total anomalous pulmonary venous drainage. Most reports, however, cite decreasing mortality in series limited to cases without other co-existing cardiac anomalies. For purposes of this discussion, let us define simple cases as cases without co-existing cardiac anomalies and complex cases as those with co-existing cardiac anomalies. Surgical management of the complex cases is less frequently reported, perhaps more difficult, and associated with a higher mortality. Most reports also note a persistent incidence of post repair pulmonary venous stenosis . Another surgical entity which is often difficult to treat often with the relentless clinical progression to pulmonary vein stenosis.

The objective of this study was to define the results of operative management of this lesion at the Hospital for Sick Children in Toronto to assess the impact of associated cardiac anomalies and to assess the efficacy of therapy for post repair pulmonary vein stenosis.

A retrospective review identified all patients with total anomalous pulmonary veins in the Hospital for Sick Children database over a fourteen year period. Of these patients, 126 were defined as simple, having cardiac lesions limited to either no lesion, simple PDA or ASD. The complex group was composed of 44 patients having any other cardiac lesion. There was a slight preponderance of males in the series. The median age at repair was 20.5 days and the median weight was 3.5 kilograms.

The diagnostic components contributing to the designation of complex are listed here. Any of the listed lesions was sufficient to classify the patient as complex. Also note that for purposes of the multi-variable analysis, univentricular heart, isomerism, and a catch-all term, associated complex lesions, were separated into three sub-variables for purposes of the analysis. Any individual patient could have multiple diagnosis on this list.

In this chart survival is plotted for the entire group of 170 patients. The majority of attrition occurs early and five year survival is roughly 65 percent.

In order to identify important predictors of operative mortality a multi-variable analysis was performed using these variables. In the multi-variable analysis, univentricular hearts and associated complex lesions were identified as important predictors of operative mortality.

Stressing the significance of the complex designation here the group is split into simple and complex subsets. The simple group shown here in blue enjoys a five year survival of approximately 75 percent, while the complex group shown here in red has a five year survival of approximately 35 percent.

In an effort to better assess our operative management, cumulative operative mortality is plotted here on the Y axis against the 126 consecutive cases with simple cardiac anatomy. It is interesting to note, there appears to be an inflection point approximately here after approximately 50 cases corresponding to an operative date in September 1987. Prior to this juncture operative mortality is approximately 26 percent and afterwards is approximately 7.9 percent for the latter two-thirds of the series.

In contrast, for the complex cases, operative mortality remains relatively constant at approximately 52 percent. There is no evidence of recent improvement in the operative mortality for the complex cases. The complex cases were managed with variety of operative strategies depending on the constellation of lesions in any single patient. The largest common groups include patients undergoing arterial pulmonary shunting and PA banding. In this chart these two operative strategies, PA banding and arterial pulmonary shunting are charted. Despite anatomic considerations requiring nearly opposite objectives, PA banding shown here in blue to limit pulmonary blood flow and arterial pulmonary shunting shown here in red to augment pulmonary blood flow, the results are equally poor in both groups. We would speculate that in our experience the use of shunts and bands to non-dynamically regulate pulmonary blood flow may be ineffective in the face of a combination of 1) the pathological vascular changes associated with total anomalous pulmonary veins and 2) the more common but still significant alterations in pulmonary resistance in the post-op neonate.

Let's shift gears for one minute to briefly discuss the late complication of post repair pulmonary vein stenosis. This complication occurred in 13 patients or 7 percent of the series, and occurred most frequently in the infradiaphragmatic subtype. 17 reoperations were performed on these 13 patients, 3 had second operations and one had a third reoperation. Five patients underwent stenting, four of which were in the operating room. The age at these patients' initial repair was 15 days and they presented with a pulmonary vein stenosis approximately one year later.

Our results for this group could be broken into two subsets. Patients with unilateral disease enjoyed 100 percent survival. There were zero deaths out of 4 patients. Patients with bilateral disease had 6 deaths out of 9 patients. The bilateral disease presented more aggressively with an interval to stenosis of 141 days versus 828 days for the unilateral group. Although there were no deaths in the unilateral group, there was unilateral progression of disease in two of the four patients to complete or near complete occlusion of the respective pulmonary veins.

This is a plot of survival after reoperation for post repair pulmonary vein stenosis. A wide variety of operative techniques were employed to repair the pulmonary vein stenosis. One procedure which we are encouraged with was used in two of the three survivors with bilateral pulmonary disease and those are these two points here which are now actually out to about here - 1.8 years of follow-up. We call this procedure the sutureless neo-atrium for lack of a better term. The concept behind it being to create a controlled bleed into a neoatrial chamber. There is no direct suturing of the divided edges of the stenotic pulmonary veins. The hypothesis is that this will allow conformation of the tissue to local flow characteristics and hopefully minimize ongoing turbulent injury.

In this diagram the junction of the right superior and inferior pulmonary veins with the left atrium is illustrated. An incision is made across the base of the left atrium and carried out through the stenoses in the pulmonary veins out to the secondary or tertiary branches if necessary. That pericardium is then sutured to the lateral atrial wall some distance away from the divided edges of the stenotic veins. These are left to gape open and bleed freely into the neo-atrial chamber. At the end of the procedure the pericardium sutured to the lateral atrial wall. The egress of blood from the pulmonary veins is shown here in red if you can imagine passing through these open ended stenotic veins into the left atria proper.

This procedure has been used in 2 of our 3 survivors with bilateral disease. At present both of them are clinically asymptotic at 1.8 years of follow-up. By echo-cardiogram at a year and a half, one has no evidence of obstruction and one has mild 1+ obstruction with low right ventricular pressures and essentially no change since immediately postop.

Our conclusions are that in simple cases at the Hospital for Sick Children, our patients are enjoying improved survival which is similar to other reported series. However, the complex single ventricles remain problematic. Mechanical control of pulmonary blood flow is generated unsatisfactory results in our hands. We would hypothesize that this lack of dynamic control in the face of the abnormal pulmonary vasculature may limit this approach.

Peripulmonary vein stenosis may progress to occlusion on the affected side; however, this seems to be survivable with loss of single lung function. Bilateral post repair pulmonary vein stenosis carries a high mortality and is often characterized by a relentless progression to pulmonary vein obstruction and with short term results the sutureless neoatrial technique may offer some benefit.

Thank you.