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Peripheral pulmonary artery stenosis (PPAS) is a relatively rare form of congenital heart disease often associated with Williams syndrome, Alagille syndrome, and elastin arteriopathy. This disease is characterized by stenoses at nearly all lobar and segmental ostia and results in systemic-level right ventricular pressures. The current study summarizes our experience with the surgical treatment of PPAS.
Methods
This was a retrospective review of 145 patients who underwent surgical repair of PPAS. This included 43 patients with Williams syndrome, 39 with Alagille syndrome, and 21 with elastin arteriopathy. Other diagnoses include tetralogy of Fallot with PPAS (n = 21), truncus arteriosus (n = 5), transposition (n = 3), double-outlet right ventricle (n = 2), arterial tortuosity syndrome (n = 3), and other (n = 8).
Results
The median preoperative right ventricle to aortic peak systolic pressure ratio was 1.01 (range, 0.50-1.60) which was reduced to 0.30 (range, 0.17-0.60) postoperatively. The median number of ostial repairs was 17 (range, 6-34) and median duration of cardiopulmonary bypass was 398 minutes (range, 92-844). There were 3 in-hospital deaths (2.1%). The median duration of follow-up was 26 months (range, 1-220) with 4 late deaths (2.9%). Eighty-two patients have subsequently undergone catheterization and 74 had a pressure ratio <0.50.
Conclusions
The surgical treatment of PPAS resulted in a 70% reduction in right ventricular pressures. At 3 years, freedom from death was 94% and 90% of those evaluated maintained low pressures. These results suggest that the surgical treatment of PPAS is highly effective in most patients.
One hundred forty-five patients underwent surgical repair of peripheral pulmonary artery stenosis. Median RV/Ao pressure ratio decreased from 1.01 preoperatively to 0.30 postoperatively.
Surgical treatment was used in 145 patients with peripheral pulmonary artery stenosis. Right ventricular pressures were reduced by 70% after surgery. Median follow-up has been 26 months. At follow-up catheterization, right ventricular pressure ratios were <0.50 in 74 of 82 (90%) patients. These results suggest that the surgical treatment of PPAS is highly effective for most patients.
See Commentary on page 1503.
Peripheral pulmonary artery stenosis (PPAS) is a relatively rare form of congenital heart disease that is often associated with Williams syndrome, Alagille syndrome, and elastin arteriopathy.
This disease is characterized by stenoses of nearly all lobar, segmental, and even subsegmental ostia. The physiologic result of these widespread ostial stenoses is an elevation of right ventricular (RV) pressures to approximate systemic-level pressures. The adverse effects of RV hypertension include RV hypertrophy, an increase in myocardial oxygen consumption, and eventually the development of RV failure.
In 2013, our group reported on the surgical treatment of PPAS in patients with Williams and Alagille syndromes.
This 2013 report was the first in the literature advocating an entirely surgical approach to the disease. The report summarized an experience with 16 patients who had undergone surgical repair over the decade from 2002 to 2012. The surgical technique used during that time frame included incisions in the branch PAs to the level of the basilar segments with homograft patch augmentation as well as homograft patch augmentation of lobar and some segmental ostial stenoses. The data demonstrated a 55% reduction in RV to aortic (RV/Ao) peak systolic pressure ratios with a relatively low (6%) mortality and no late mortality or need for reoperation. On the basis of these data, we concluded the surgical treatment of PPAS was highly successful and hypothesized the reduction in RV pressures would confer a long-term survival benefit.
Over the subsequent decade (2012-2022) since our original report, we have garnered a considerably larger experience with the surgical treatment of PPAS and have continued to evolve our surgical techniques.
The purpose of this report is to summarize our experience with the surgical treatment of PPAS over 2 decades and describe the evolution in surgical technique that has occurred over the second decade.
Methods
This was a retrospective review of 145 consecutive patients who underwent surgical repair of PPAS at our institution from 2002 through the end of 2021. The study was approved by the institutional review board at Stanford University (protocol ID 48389 approved on October 16, 2018, and protocol ID 42875 approved on August 24, 2018). The need for written consent was waived by the institutional review board.
Excluded from this analysis were patients with the diagnosis of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs). A summary of patients with PA/VSD/MAPCAs who subsequently underwent unifocalization revision was previously reported.
Also excluded were patients who underwent pulmonary artery stent placement primarily for treatment of branch pulmonary artery stenosis at outside institutions and subsequently were referred to Stanford for a complex PA reconstruction in the setting of a failed pulmonary artery stent.
Impact of phrenic nerve palsy and the need for diaphragm plication following surgery for pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals.
The procedures are performed through a median sternotomy and the thymus is completely removed for optimal exposure. The pleural spaces are widely opened and the phrenic nerves marked bilaterally.
The branch pulmonary arteries are completely dissected free from adjacent structures to a point well beyond the origin of the segmental branches (Figure 1, A).
Figure 1A, Artist's depiction of peripheral pulmonary artery (PA) stenosis (PPAS). The branch pulmonary arteries are diminutive and there are ostial stenoses at the lobar and segmental levels. B, Original published drawings showing the surgical technique used for the first decade of our experience with the surgical treatment of PPAS. Reproduced with permission from Monge and colleagues.
C, Artist's depiction of the surgical approach to PPAS. The main PA has been divided as well as the right and left branch PAs. An incision is then made along the inferior and medial aspect of the artery. D, Artist's depiction of the surgical reconstruction of PPAS. Most ostial stenoses have been treated using the “V-plasty” technique. The incision in the branch PAs has been augmented with a long homograft patch. E, Artist's depiction of the completed repair of PPAS. The branch PAs have been sewn together and the main PA anastomosed to the reconstituted branch pulmonary arteries. MPA, Main pulmonary artery.
During cooling, the main pulmonary artery is divided and the proximal end oversewn. The branch pulmonary arteries are divided and the right pulmonary artery is passed under the aorta. Division of the main pulmonary artery and branch pulmonary arteries is an important difference compared with our original technique (Figure 1, B).
A longitudinal incision is made along the inferior and medial surface of the branch pulmonary arteries. This incision is carried onto the origin of the medial basilar branch of the lower lobe. Stay sutures are placed to apply upward traction to bring the lower lobe vessels into better view (Figure 1, C). Neuroclips are used to occlude the lobar and segmental branches.
Each of the segmental branches can be visualized and probed for their relative degree of stenosis. Typical visual findings include a thickened, white fibrous ring encircling the ostia.
Probing the ostia yields resistance at the ostial level followed by a sudden release as the probe passes into the nondiseased distal vessel. In patients with systemic or suprasystemic RV pressures, one can expect that nearly every ostium will be affected.
Our current method of treating most diseased ostia is to perform a side-to-side ostioplasty. An incision is made through the carina and continued onto the distal, nondiseased vessels. This creates a deep V-shaped pattern (hence the nickname, “V-plasty”). The side-to-side anastomosis is performed with 8-0 Prolene. The V-plasty technique is the second important alteration in the surgical approach to PPAS compared with the original series.
The ostioplasty technique is applicable to nearly all basilar and middle lobe (or lingular) segmental branches because they emanate at an acute angle. The right upper lobe and its 3 segments are the vessels where an ostioplasty might not be applicable due to the broader angle of takeoff. In this situation, a homograft patch may be used to augment the main right upper lobe vessel and 1 of the 3 segmental branches while performing osteoplasties on the other 2 segmental branches. The original incision along the inferior and medial aspect of the branch pulmonary artery is patch-augmented with pulmonary homograft (Figure 1, D). This axial patch is oversized by at least 20% because it will not have any growth potential.
When both pulmonary arteries have been reconstructed, the right pulmonary artery is passed behind the aorta and the 2 branch pulmonary arteries sutured together (there are circumstances in which a LeCompte maneuver might be preferable including a narrow aortopulmonary window when the aortic arch is reconstructed). The main pulmonary artery is sewn to the reconstructed branch pulmonary arteries (Figure 1, E). This reconstruction is performed with the heart beating and without the need for aortic crossclamp (see Figure E1 for an example of a preoperative and postoperative angiogram). Concomitant procedures requiring aortic crossclamp are performed after the pulmonary artery reconstruction.
The patients are rewarmed and cardiopulmonary bypass discontinued. We avoid the use of inotropic agents because these might exacerbate gradients within the RV caused by hypertrophied muscle bundles. Nitric oxide at 20 parts per million is used in the immediate postoperative period. We initially place pressure monitoring catheters in the left atrium, RV, and main pulmonary artery to have exact measurements of these pressures in context with the systemic pressure. The postoperative pulmonary artery to aortic peak systolic pressures and pressure ratios are recorded in the operative record and reported in this article as the postoperative values.
Results are reported as the median and range for all descriptive data, and mean and standard deviation when indicated. A comparison of the preoperative and postoperative hemodynamic data was performed using the Student t test. In this report, operative mortality is defined in accordance with the Society of Thoracic Surgeons database as all deaths occurring during the hospitalization in which the operation was performed and all deaths occurring after discharge from the hospital but before the end of the 30th postoperative day. Kaplan–Meier curves were constructed for survival and freedom from subsequent reintervention on the branch pulmonary arteries. 95% Confidence intervals are shown in the shaded areas.
Results
The 145 patients with PPAS included 43 with Williams syndrome, 39 with Alagille syndrome, and 21 with elastin arteriopathy. Forty-two patients had other underlying diagnoses, which included tetralogy of Fallot with PPAS (n = 21), truncus arteriosus (n = 5), transposition of the great arteries (n = 3), double-outlet right ventricle (n = 2), arterial tortuosity syndrome (n = 3), hypoplastic left heart syndrome (n = 2), and 1 each with Noonan syndrome, chromosome 19 microdeletion, pulmonary artery calcinosis, scimitar syndrome, congenital rubella, and Leiden deficiency.
The mean age at PPAS surgery was 36 ± 15 months (range, 3-226 months; interquartile range [IQR], 24-90 months). The primary indication for surgical intervention was the finding at cardiac catheterization of an RV/Ao peak systolic pressure ratio of >0.60. Ninety of the 145 patients had a history of exercise intolerance. Twenty-one patients had symptoms related to left-sided obstruction including 7 with a history of cardiac arrest. Seventy-three patients had undergone previous cardiac surgical procedures, with 12 having undergone more than 1 previous sternotomy. A summary of these previous procedures is shown in Table 1.
Table 1List of previous procedures
Procedure
n
Supravalvar aortic stenosis
22
Supravalvar aortic stenosis and CAOS
3
Tetralogy of Fallot repair
21
Main pulmonary artery patch
14
Hilum-to-hilum patch
15
Aortic arch repair
14
Atrial septal defect
6
Truncus arteriosus
5
Arterial switch
3
Ventricular septal defect repair
3
Pulmonary valvotomy
3
RVOTO muscle resection
3
Double-outlet right ventricle
2
Norwood procedure
2
Systemic-to-pulmonary artery shunt
2
Conduit
1
Tricuspid valve repair
1
TAPVR repair
1
CAOS, Coronary artery ostial stenosis; RVOTO, right ventricular outflow tract obstruction; TAPVR, total anomalous pulmonary venous return.
The 145 patients underwent a total of 150 surgical repairs of PPAS. This includes 140 patients who underwent a single PPAS repair, 4 patients who underwent a staged approach by repairing 1 lung followed by subsequent repair of the other, and 1 patient who underwent a rerepair after an initial repair.
The mean preoperative RV/Ao pressure ratio was 1.01 ± 0.20 (median, 1.01; range, 0.60-1.60; IQR, 0.88-1.14). This was reduced to a mean postoperative value of 0.30 ± 0.08 (median, 0.30; range, 0.17-0.60; IQR, 0.25-0.35). A comparison of the mean preoperative to postoperative values is shown graphically in Figure 2, A. A more detailed depiction of the postoperative pressure ratios is shown in the histogram in Figure 2, B. There were no differences in either the preoperative or postoperative pressure ratio values in comparisons of patients with Williams syndrome, Alagille syndrome, and those without these syndromes. Specifically, the mean preoperative values were 1.04 ± 0.09, 1.06 ± 0.11, and 0.96 ± 0.08, and the mean postoperative values were 0.31 ± 0.05, 0.28 ± 0.06, and 0.35 ± 0.09, respectively. Six patients had a postoperative pulmonary artery to aortic peak systolic pressure ratio >0.5 including 1 with Williams syndrome, 4 with Alagille syndrome, and 1 without either of these syndromes.
Figure 2A, Bar graph comparing the preoperative (pre-op), postoperative (post-op), and late right ventricle (RV) to aortic (RV/Ao) peak systolic pressure ratios. The height (top) of the bar represents the mean value with the box demonstrating the interquartile values and the whiskers demonstrating the standard deviations. The mean pre-op RV/Ao pressure ratio was 1.01 ± 0.20 (median, 1.01; range, 0.60-1.60; interquartile range [IQR], 1.14-0.88). This was reduced to a mean post-op value of 0.30 ± 0.08 (median, 0.30; range, 0.17-0.60; IQR, 0.25-0.35). The mean RV/Ao peak systolic pressure ratio at subsequent catheterization was 0.35 ± 0.08 (median, 0.35; range, 0.22-0.62; IQR, 0.30-0.40). B, Histogram showing a detailed breakdown of the post-op RV/Ao peak systolic pressure ratios. The median value was 0.30. There were 6 patients with a post-op pressure ratio >0.50. LV, Left ventricle; W/A, non-Williams or Alagille.
The mean number of lobar, segmental, and subsegmental ostial stenosis repairs performed was 17 ± 8 (median, 17; range, 6-34; IQR, 12-22). The mean duration of cardiopulmonary bypass was 398 ± 62 minutes (median, 398; range, 92-844; IQR, 345-487 minutes). Fifty-four of the 145 patients required a period of aortic crossclamping with a mean of 36 ± 12 minutes (median, 36 minutes; range, 17-204 minutes; IQR, 28-45 minutes). A summary of the concomitant procedures is presented in Table 2.
The mean length of hospital stay was 12 ± 7 days (median, 11 days; range, 4-118 days; IQR, 8-18 days). There were 3 in-hospital deaths (2.1%); 1 with Williams syndrome and 2 with Alagille syndrome. The proximate causes of death for these 3 patients were sudden cardiac arrest in 1, multisystem organ failure in 1, and sepsis in 1. Nine patients received extracorporeal membrane oxygenation (ECMO) postoperatively (8 for lung support and 1 for cardiac support). One patient had been receiving ECMO preoperatively for cardiac support after a cardiac arrest and required ECMO postoperatively for lung support. Two of the 3 in-hospital deaths occurred in patients who required ECMO postoperatively. The 7 ECMO survivors had a median hospital length of stay of 62 days.
Mean duration of follow-up was 26 ± 15 months (median, 27 months; range, 1-220 months; IQR, 17-32 months). There have been 4 deaths (2.9%) since discharge from the hospital. These deaths occurred at 2, 9, 15, and 17 months postoperatively. The proximate causes of late death were sudden cardiac arrest (n = 1), respiratory decompensation (n = 2), and advanced liver disease (n = 1). The Kaplan–Meier survival curve is shown in Figure 3, which estimates a 3-year survival of 93% (Video Abstract).
Figure 3Kaplan–Meier survival curve showing a predicted 3-year survival of 93%. Confidence intervals (95%) are shown in the shaded area.
Eighty-two of the 138 (59%) survivors have subsequently undergone a cardiac catheterization after surgical repair of PPAS (see flow diagram in Figure 4). The mean RV/Ao peak systolic pressure ratio was 0.35 ± 0.08 (median, 0.35; range, 0.22-0.62; IQR, 0.30-0.40), which was lower than the preoperative value (P < .05) and unchanged compared with the immediate postoperative value. These data are summarized on the far right side of Figure 2, A.
Figure 4Flow diagram showing the follow-up evaluation of the 138 survivors. Eighty-two patients (59%) underwent a postoperative (post op) cardiac catheterization (cath), of which 63 were diagnostic studies whereas 19 had balloon angioplasty performed.
On the basis of the catheterization information, 1 patient underwent surgical rerepair of the peripheral pulmonary arteries and 19 patients underwent balloon angioplasty. The Kaplan–Meier curves showing freedom from surgical reintervention and freedom from any reintervention are shown in Figure 5.
Figure 5Kaplan–Meier curves showing freedom from surgical reintervention on the branch pulmonary arteries in blue and freedom from any reintervention in red. Confidence intervals (95%) are shown in the shaded area.
For the 6 patients who had an RV/Ao peak systolic pressure ratio >0.50 in the immediate postoperative period, 4 patients have subsequently undergone a cardiac catheterization whereas 2 have not been re-studied. Three of the 4 patients continued to have an elevated pressure ratio whereas 1 patient with Alagille syndrome showed resolution of the elevated pressures. The 3 patients with ongoing elevated RV/Ao pressure ratios all underwent balloon angioplasty (see left side of flow diagram in Figure 6).
Figure 6Flow diagram showing an analysis of the 6 patients who had an immediate postoperative (post-op) right ventricle (RV):left ventricle (LV) pressure ratio >0.50 and an analysis of the 132 patients who had a postoperative pressure ratio <0.50. Cath, Catheterization.
For the 132 surgical survivors who had an intraoperative RV/Ao peak systolic pressure ratio <0.50, 78 patients have undergone a follow-up cardiac catheterization whereas 54 patients have not been re-studied. In the cohort of patients who were re-studied, 73 (94%) continued to have pressure ratios <0.50 whereas 5 (6%) had pressure ratios that increased to values >0.50 (including 2 with Williams syndrome, 2 with Alagille syndrome, and 1 with neither of these syndromes). All 5 of the patients with elevated pressure ratios underwent reintervention (4 balloon angioplasty and 1 surgical). For the 73 patients who had pressure ratios <0.50, 12 (16%) underwent balloon angioplasty (see right side of flow diagram in Figure 6). The efficacy of these reintervention procedures is summarized in the Appendix E1.
There were 4 patients who underwent staged management of their PPAS. One patient was the third patient in the entire series and underwent sequential thoracotomies for repair. Two patients had Alagille syndrome with advanced liver failure and underwent a staged approach in deference to the multisystem organ impact of this syndrome. Finally, 1 patient underwent a staged approach for treatment of acquired discontinuity of the branch pulmonary arteries with loss of flow to the left lung that occurred at an outside institution. This patient underwent repair of PPAS in the right lung and rehabilitation of the left pulmonary artery.
Two patients in this series had hypoplastic left heart syndrome. Both underwent a Norwood procedure at outside institutions and were subsequently discovered to have PPAS when evaluated for their bidirectional Glenn procedure. The 2 patients underwent bilateral PPAS repair at our institution and have subsequently undergone bidirectional Glenn and Fontan procedures. These are the only 2 patients in our series with functional single ventricle.
Discussion
The current study was performed to review our experience with the surgical repair of PPAS over the span of 2 decades. This series includes 145 patients, with 16 from the first decade and 129 from the second decade. The data show that surgical repair resulted in a 70% reduction in RV/Ao peak systolic pressure ratios. Surgical mortality was 2.1% and late mortality was 2.9%. Follow-up cardiac catheterizations have been performed in 59% of the survivors with 90% maintaining pressure ratios <0.50. These results suggest that the surgical treatment of PPAS is effective in reducing RV pressures and can be achieved with a relatively low mortality and with sustainable effects (Figure 7).
Figure 7Depiction of the surgical results of peripheral pulmonary artery stenosis (PPAS) repair. Most patients had Williams syndrome, Alagille syndrome, elastin arteriopathy, or a conotruncal abnormality. Surgical treatment resulted in a mean reduction of 70% in right ventricular (RV) pressure ratios.
This 2013 report included 7 patients with Williams syndrome, 6 with Alagille syndrome, and 3 with no identifiable syndrome who underwent patch augmentation of the branch pulmonary arteries and patch augmentation of ostial stenoses that were deemed most important from a hemodynamic standpoint. The median reduction in RV pressure ratios was 55% and the median number of ostial interventions was 7. Over the subsequent decade we have applied the surgical approach for PPAS to a much broader array of underlying diagnoses. Although Williams syndrome and Alagille syndrome still comprise 57% of the cohort, 43% of the patients did not have either of these syndromes.
The median reduction in RV pressure ratios for the 145 patients was 70% and the median number of ostial interventions was 17. We believe the combination of increased experience plus modifications in surgical technique account for the improved hemodynamic results.
The evolution of surgical techniques occurred in 2 areas and have greatly facilitated performing these reconstructive procedures. The first paradigm shift was the recognition that division of the right and left branch pulmonary arteries greatly facilitated the pulmonary artery reconstruction.
Although the intentional creation of branch pulmonary discontinuity might seem counterintuitive, this maneuver allows one to pull up the hilum and bring the lower lobe vessels into much clearer view. Because the orientation of the main incision of the branch pulmonary artery is along the inferior and medial aspect of the vessel, the discontinuity provides a direct view of the suture lines for the surgeon.
A second important modification of our technique was the introduction of the side-to-side ostioplasty technique (Video 1). This technique is highly reproducible, is more time-efficient than patch augmentation, and can be applied to much smaller-sized ostium including segmental and subsegmental ostium. The number of ostial interventions has increased considerably over the years from a median of 7 to 17. Corresponding with this increase in the number of ostial interventions, the postoperative RV pressure ratios have decreased from a median of 0.40 to 0.30, or a 25% decrement. We believe the V-plasty technique will also maintain better growth potential over the long-term because it is a tissue-to-tissue anastomosis.
Although most patients with PPAS have Williams (n = 43) or Alagille syndromes (n = 39), there are also a significant number of patients with elastin arteriopathy (n = 21) and conotruncal abnormalities (n = 31). Collectively, these 4 groups would account for 92.4% of the patients in this series. Despite this heterogeneity in diagnoses, there was no significant difference in the preoperative RV/Ao pressure ratios, postoperative RV/Ao pressure ratios, prevalence of pressure ratios >0.50, or prevalence of reintervention among these groups. It is our observation that most patients have a very similar disease pattern characterized by discrete ostial stenoses at nearly every lobar and segmental ostium. The surgical approach to this disease is relatively uniform and independent of the underlying syndrome. We would qualify this statement by saying that patients with Alagille syndrome tend to have a more aggressive form of disease but does not translate into statistically different results.
For the 138 survivors, 82 have subsequently undergone cardiac catheterization whereas 56 patients have not been re-studied. Twenty-six of the 56 patients who have not been re-studied have been followed for a year or less since their surgical repair. In contrast, 30 patients who have not been re-studied have been followed for more than a year (range, 13-134 months).
Many of the patients who have been followed for an extensive time without catheterization had echocardiograms providing reassuring information that the RV pressures are remaining low. It is our recommendation that patients should undergo a cardiac catheterization at 1 year after surgical repair of PPAS to evaluate the reconstructed pulmonary vascular bed. It should be recognized that the preponderance of patients in this series are referrals from outside institutions where the practices of following patients might vary considerably. Clinical indications for re-study would include: (1) elevated RV/Ao pressure ratios immediately after surgery, (2) rising RV pressures during follow-up, and (3) evidence of left-sided obstruction or reobstruction.
In contrast to patients with PPAS, patients who undergo unifocalization for PA/VSD/MAPCAs have a much higher prevalence of requiring surgical reoperation. In a study of 257 patients who underwent unifocalization at our institution, 48 patients (20%) subsequently underwent unifocalization revision.
To date, there has been only 1 patient who has undergone PPAS repair and subsequently had surgical revision and thus there is a 30-fold difference in the prevalence of surgical reinterventions compared with unifocalization procedures.
There are undoubtedly many factors that account for this disparity—one of the most obvious being that the repair of PA/VSD/MAPCAs requires placement of a conduit from the RV to the reconstructed pulmonary arteries. This conduit has a limited functional longevity in young patients, and obligatorily commits patients to a reoperation for conduit replacement. One-third of unifocalization revisions performed were in patients with low PA pressures but in whom the revision was performed as a concomitant procedure during conduit replacement. It is likely that some of the disparity between unifocalization procedures and PPAS repairs is attributable to the more extensive use of patch material in the former operation.
It is intuitively appealing to think that interventional catheterization techniques might be suitable for treatment of PPAS. Unfortunately, the results of catheterizations interventions have been extremely disappointing.
Attempts at balloon angioplasty have proven to be quite hazardous because the thick, fibrous ring of tissue at the ostia is resistant to dilation whereas the thin-walled distal vessel is easily perforated or ruptured. The role of balloon angioplasty after surgical repair has yet to be fully elucidated (see the Appendix E1). In our series, 19 patients underwent balloon angioplasty postrepair, 7 of whom had RV/Ao pressure ratios >0.50 and 12 who had pressure ratios <0.50. Most of the angioplasties were directed at 1, 2, or 3 segmental stenoses and in most instances showed some angiographic improvement. None of the patients who underwent postoperative angioplasty have been re-studied at this time.
There is one other program that has reported a large series of patients who have undergone surgical repair of PPAS.
This program has adopted the same surgical techniques as developed at Stanford and has achieved very similar outcome results. Specifically, the operative mortality was 2.2% and the decrease in RV/Ao pressure ratios was identical at 70%. The one notable difference between the series from Saudi Arabia and Stanford is the fact that more than one-third of the patients at the former center had the diagnosis of arterial tortuosity syndrome compared with just 1.5% in our series at Stanford. This 20-fold difference in the prevalence of arterial tortuosity syndrome suggests that there might be regional differences in the epidemiology of PPAS.
Conclusions
This report describes our 2-decade experience with the surgical treatment of PPAS and the evolution of the surgical techniques. The data demonstrate that RV pressure ratios are reduced by an average of 70% and are achieved with a relatively low early and late mortality. The follow-up data now show that the results of PPAS are durable as evidenced by a low prevalence of hemodynamically significant re-stenoses. These results suggest that the surgical treatment of PPAS is highly effective for most patients.
Conflict of Interest Statement
The authors reported no conflicts of interest.
The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.
There were 20 patients who underwent a reintervention after PPAS repair. This included 1 patient who had surgical rerepair and 19 patients who had balloon angioplasty performed in the cardiac catheterization laboratory. Eight of the 19 balloon angioplasties were performed at our institution whereas 11 were performed at outside institutions.
The single patient who had surgical rerepair was a patient with elastin arteriopathy who underwent repair of supravalvar aortic stenosis, coronary artery ostial stenosis, and PPAS 10 years ago. The preoperative RV/Ao peak systolic pressure ratio was 0.95 preoperatively and decreased to 0.28 postoperatively with a total of 12 ostial interventions performed. This patient subsequently underwent aortic arch repair for treatment of progressive arch gradients. Nine years after initial treatment, the patient had a cardiac catheterization showing an RV/Ao peak systolic pressure ratio of 0.58. During reoperation, a total of 18 ostial reinterventions were performed with the postoperative RV/Ao pressure ratio decreased to 0.41.
For the 19 patients who underwent postoperative balloon angioplasty, 7 had RV/Ao peak systolic pressure ratios >0.50. Four of these patients had Alagille syndrome, 2 had Williams syndrome, and 1 had neither of these syndromes. The number of segments that underwent balloon angioplasty was 2, 3, 3, 4, 4, 4, and 6. Comments provided by the interventional radiologist graded the angiographic improvement as marginal in 1, mild in 3, and moderate in 3. The hemodynamic change in pulmonary artery pressures was no or minimal change (n = 4) and >10 mm Hg in 3.
Twelve patients underwent postoperative balloon angioplasty in the setting of RV/Ao peak systolic pressure ratios <0.50. Two of these patients had Alagille syndrome, 5 had Williams syndrome, and 5 had neither of these syndromes. The number of segments that underwent balloon angioplasty was 2, 2, 3, 4, 4, 5, 6, and 7, and then 3 patients with balloon of the left pulmonary artery and 1 patient with balloon of the right and left pulmonary artery.
Comments provided by the interventional radiologist graded the angiographic improvement as marginal in 2, mild in 3, moderate in 4, and a good result in 3. The hemodynamic change in pulmonary artery pressures was no or minimal change (n = 4) and >10 mm Hg in 8.
Follow-up for the 20 patients who underwent reintervention has a mean duration of 8 ± 7 months (range, 1-52 months; IQR, 4-14 months). There are no patients who have been reevaluated after their reintervention and therefore no patients have undergone a second reintervention.
Figure E1A preoperative (A and B) angiogram and a postoperative (C and D) angiogram in the same patient after peripheral pulmonary artery stenosis repair.
Impact of phrenic nerve palsy and the need for diaphragm plication following surgery for pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals.
The manuscript from Felmly and colleagues1 is to be commended for a comprehensive 2-decade surgical experience of outstanding results in patients with peripheral pulmonary artery stenosis (PPAS). In 71% of the cases presented by the authors, the pathologic condition was associated with a genetic syndrome, with the remaining 29% of cases mainly associated with anatomical diagnoses. In 2013, the authors reported on their experience,2 advocating for an entirely surgical approach to the treatment of PPAS.
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