Tracheal Reconstruction in Children With Unilateral Lung Agenesis or Severe Hypoplasia

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1 Tracheal Reconstruction in Children With Unilateral Lung Agenesis or Severe Hypoplasia Carl Lewis Backer, MD, Angela M. Kelle, BS, Constantine Mavroudis, MD, Cynthia K. Rigsby, MD, Sunjay Kaushal, MD, and Lauren D. Holinger, MD Divisions of Cardiovascular-Thoracic Surgery, Medical Imaging, and Otolaryngology, Children s Memorial Hospital, Chicago, Illinois Background. Infants with congenital tracheal stenosis may also have unilateral lung agenesis or severe lung hypoplasia. The purpose of this review is to evaluate our results with these patients and compare their presentations and outcomes to those of tracheal stenosis patients with two lungs. Methods. Our database was queried for patients undergoing tracheal stenosis repair since Patients were divided into two groups based on pulmonary anatomy of single lung (SL unilateral lung agenesis or severe hypoplasia) or two lungs (BL bilateral lungs) and analyzed to compare presentation and outcomes. Results. From 1982 to 2008, 71 patients had tracheal stenosis repair. Bilateral lungs were present in 60 patients; 9 patients had an absent (4) or severely hypoplastic (5) right lung, and 2 patients had an absent left lung (SL 11). Age at repair was similar between groups; median age 0.42 years in the SL group (mean years) versus 0.37 years in the BL group (mean years, p not significant [ns]). In the SL group 8 of 11 (73%) were intubated preoperatively versus 15 of 60 (25%) in the BL group (p 0.004). In the SL group 4 of 11 (36%) patients had pulmonary artery sling versus 20 of 60 (33%) of BL patients (p ns). In the SL group 2 of 11 (18%) versus 14 of 60 (23%) in the BL group had intracardiac anomalies requiring simultaneous repair (p ns). Procedures included pericardial tracheoplasty (2 vs 26), tracheal autograft (4 vs 16), slide tracheoplasty (3 vs 8), and tracheal resection (2 vs 10). Overall mortality (operative and late) was 2 of 11 (18%) SL versus 10 of 60 (17%) BL (p ns). Median postoperative length of stay was 43 days SL (mean ) versus 30 days BL (mean ) (p ns). The incidence of postoperative tracheostomy (SL group) was 0 of 3 for slide tracheoplasty and 5 of 8 for the other techniques (p 0.12). Conclusions. Despite the increased severity of pathology and increased critical presentation of tracheal stenosis patients with unilateral lung agenesis or severe hypoplasia, outcome measures of mortality and length of stay were similar to patients with two lungs. The incidence of associated pulmonary artery sling (1 of 3) and intracardiac anomalies (1 of 4) was similar. Unilateral lung agenesis or severe hypoplasia should not preclude operative repair of tracheal stenosis. Slide tracheoplasty is our current procedure of choice for these infants. (Ann Thorac Surg 2009;88:624 31) 2009 by The Society of Thoracic Surgeons Agenesis of the lung is a very rare occurrence and is defined as total absence of the pulmonary parenchyma, its vascular supporting structure, and bronchi beyond the bifurcation [1, 2]. Even more rare is to have unilateral lung agenesis or severe lung hypoplasia with congenital tracheal stenosis. The reported mortality of this combination of lesions ranges from 33% to 65% [3, 4]. The purpose of this analysis was to evaluate our results with these selected patients with both tracheal stenosis and agenesis or severe hypoplasia of a lung. We then compared the presentation of these patients, their associated pathology, and their outcomes with various surgical techniques to those of congenital tracheal stenosis patients with two complete lungs [5]. Accepted for publication April 24, Presented at the Forty-fifth Annual Meeting of the Society of Thoracic Surgeons, San Francisco, CA, Jan 26 28, Address correspondence to Dr Backer, Cardiovascular-Thoracic Surgery, Children s Memorial Hospital, 2300 Children s Plaza, mc 22, Chicago, IL 60614; cbacker@childrensmemorial.org. Material and Methods This study was approved by the Institutional Review Board (IRB) of Children s Memorial Hospital as a retrospective chart analysis; requirement for consent was waived. Patients with tracheal stenosis were divided into two groups based on their pulmonary anatomy of one lung (SL unilateral lung agenesis or severe hypoplasia) or two lungs (BL bilateral lungs). The two groups were then analyzed for differences in presentation and outcomes. Factors analyzed included preoperative intubation, associated pulmonary artery sling, associated intracardiac anomalies requiring repair, type of tracheal repair (which included pericardial tracheoplasty, tracheal autograft, slide tracheoplasty, and tracheal resection), postoperative length of stay, early and late mortality, and results of long-term follow-up. Statistical analysis was with either the Fisher exact test or the Wilcoxon rank sum as appropriate using commercially available software. Our statistician is Robert Stewart, MD, MPH by The Society of Thoracic Surgeons /09/$36.00 Published by Elsevier Inc doi: /j.athoracsur

2 Ann Thorac Surg BACKER ET AL 2009;88: TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 625 Fig 1. Tracheal stenosis with absent right lung. The heart is rotated into the right chest. This appears as dextrocardia on the chest X-ray. The left lung is being retracted to the side. The trachea is behind the midportion of the aortic arch. The red area at the apex of the right hemithorax is occupied by thymus and the herniated apex of the left lung. (Ao aorta; LA left atrium; LPA left pulmonary artery; LV left ventricle.) Seventy-one patients underwent repair of tracheal stenosis secondary to complete congenital tracheal rings at Children s Memorial Hospital between 1982 and The SL group had 11 patients; 9 of these patients had absence of the right lung (4) or severe hypoplasia of the right lung (5) (Fig 1). The left lung was absent in 2 patients (Fig 2). The clinical characteristics of these patients are summarized in Table 1. Chest X-ray, axial computed tomographic (CT) image, and threedimensional (3D) CT reconstruction of a 13-day-old, 2.2 kg girl with agenesis of the right lung are shown in Figures 3, 4, and 5. There were 8 females and 3 males with SL anatomy. The age of repair in the SL group was a median age of 0.42 years with a mean age of year. The median age in the BL group was 0.37 years with a mean of years (p not significant [ns]). Echocardiography evaluation was performed in all patients to rule out associated intracardiac anomalies. Recently operated patients were evaluated with preoperative CT scan and 3D reconstruction. The clinical presentation and associated lesions, including incidence of preoperative intubation, associated pulmonary sling, and significant intracardiac anomalies, is shown in Table 2. The type of tracheal repair of the SL versus BL patients is shown in Table 3. Preoperative rigid bronchoscopy was performed on all patients in the operating room immediately prior to repair. All procedures were performed with cardiopulmonary bypass. Our current procedure of choice for both the tracheal stenosis patients with SL and BL is the slide tracheoplasty technique [6, 7]. Illustrations of this procedure for a patient with an absent right lung are shown in Figures 6 to 9. Postoperative tracheostomy was required in 5 of 8 patients in the SL group who had a nonslide tracheoplasty repair and in none of the 3 SL patients having a slide tracheoplasty (p 0.12). In the postoperative period all patients received a fiberoptic or rigid bronchoscopy prior to extubation. All patients receive a rigid bronchoscopy prior to discharge from the intensive care unit. Some patients who had difficulty with granulation tissue required multiple and occasional emergent bronchoscopies for clearing of the airway. If patients are not symptomatic from a respiratory standpoint further routine bronchoscopic evaluation was not performed. We did not perform standard postoperative imaging other than standard postoperative chest radiographs. All patients with a pulmonary artery sling were evaluated with nuclear medicine scan to assess the flow to the right and left lungs. All patients with an intracardiac lesion had sequential follow-up echocardiograms. We do not have consistent postoperative pulmonary function studies at this time in these patients. For the patients with a pulmonary artery sling (origin of the left pulmonary artery from the right pulmonary artery) and SL anatomy, the translocation technique initially described by Jonas and colleagues [8] was used Results Fig 2. Tracheal stenosis with absent left lung. The heart is rotated into the left chest. The trachea is easier to access as the aorta is off to the left side. The red area at the apex of the left hemithorax is occupied by thymus and the herniated apex of the right lung. (Ao aorta; RA right atrium; RPA right pulmonary artery; RV right ventricle.)

3 Table 1. Clinical Characteristics of SL Group Patient Surgery Date Out-of-State Referral Age Weight Gender Repair Absent Lung Assoc. Lesions Complications years F Pericardial tracheoplasty Left Occipital encephalocele V-P shunt Temporary tracheostomy (4 mos) * 13 days 2.5 kg M Pericardial tracheoplasty cartilage graft left bronchus Right Left bronchial stenosis Pulmonary hypertension ECMO expired postop d # * 2 months 4.2 kg F Autograft pericardium * 1 year 10 kg F Autograft pericardium Right Right PA sling (reimplantation) PDA PA sling (translocation) Innominate arteriopexy years F End-to-end anastomosis Right PA sling (translocation) * 6 months M Autograft Left PDA pericardium Down syndrome * 4 months 6 kg M Autograft aortic translocation Right VSD LSVC CS Tracheostomy Tracheostomy * 7 weeks 4 kg F End-to-End anastomosis Right Tracheostomy * 6 weeks 3.2 kg F Slide tracheoplasty Right PA sling (translocation) PDA LSVC CS Bronchogenic cyst days 2.2 kg F Slide tracheoplasty Right PDA months 4.5 kg F Slide tracheoplasty Right VSD ASD LPA stenosis S/P diaphragmatic hernia repair Pacemaker Tracheostomy Expired-tracheal-carotid 4 mos postop ASD atrial septal defect; CS coronary sinus; ECMO extracorporeal membrane oxygenation; LPA left pulmonary artery; LSVC left subclavian venous connection; PA pulmonary artery; PDA patent ductus arteriosus; SL single lung; S/P status post; V-P, ventriculoperitoneal; VSD ventricular septal defect. 626 BACKER ET AL Ann Thorac Surg TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 2009;88:624 31

4 Ann Thorac Surg BACKER ET AL 2009;88: TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 627 Fig 3. Chest X-ray in a 13-day-old, 2.2 kg child with complete tracheal rings and absent right lung. Note herniation of the left lung anteriorly into the right chest. The patient has been intubated for respiratory distress. for 3 of the 4 patients. The left pulmonary artery to the main pulmonary artery reimplantation technique was used for 1 patient with SL physiology and for all of the BL patients [9]. The early and late mortality in the SL group was 2 deaths (1 early, 1 late) out of 11 patients (18%). This compared to 10 deaths (6 early, 4 late) in the bilateral lung group out of 60 patients (24%) (p ns). The median postoperative length of stay mean was 43 days in the SL group, with a mean of days. The median length of stay in the BL group was 30 days, with a mean of days (p ns). Fig 5. Three-dimensional reconstruction computed tomographic scan of the same patient. The length of tracheal stenosis is 4 cm. There was only 1 cm of normal trachea immediately below the vocal chords. The child had a successful slide tracheoplasty. There was no right bronchial stump or right pulmonary artery. The internal lumen of the stenotic trachea was 2.5 mm. After slide tracheoplasty the internal tracheal lumen was 4 mm. The first death in the SL group was a 13-day-old, 2.5- kg child with right lung agenesis and left bronchial stenosis. This patient underwent pericardial patch tracheoplasty and augmentation of the left main stem bronchus with a free cartilage graft. The patient had persistent pulmonary hypertension with desaturation and hypotension at the time of weaning from cardiopulmonary bypass. This was in 1990 (pre nitric oxide). The child was placed on extracorporeal circulation. The child developed a significant intracranial hemorrhage and was withdrawn from support one week after the operation. The second death in the SL group was a 4-month-old, 6.0 kg boy with absence of the right lung, distal tracheal stenosis, and a large ventricular septal defect. He underwent repair of tracheal stenosis with a tracheal autograft, intracardiac closure of the ventricular septal defect with a GORE-TEX (W. L. Gore Associates, Flagstaff, AZ) patch (through left atrium and mitral valve), and was the only patient who had translocation of the trachea anterior to Table 2. Presentation and Associated Lesions SL (n 11) BL (n 60) p Fig 4. Axial image of a computed tomographic scan in the same patient. Note the clear rotation of the heart to fill essentially all of the right chest. Also note the left lung is herniated anteriorly across the midline to the chest wall on the right side. Intubation preoperatively 8 (73%) 15 (25%) Associated pulmonary 4 (36%) 20 (33%) ns artery sling Intracardiac anomalies requiring repair 2 (18%) 14 (23%) ns BL bilateral lung; ns not significant; SL single lung.

5 628 BACKER ET AL Ann Thorac Surg TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 2009;88: Table 3. Type of Repair (SL vs BL) Type of repair SL BL Pericardial tracheoplasty 2 26 Tracheal autograft 4 16 Slide tracheoplasty 3 8 Tracheal resection 2 10 Total BL bilateral lung; SL single lung. the aortic arch to facilitate the tracheoplasty. He developed third degree atrioventricular heart block and had insertion of an epicardial pacemaker through a right thoracotomy six weeks after the original procedure. Tracheostomy was performed when he could not be weaned from the ventilator. At 4 months after the procedure the child had an acute massive tracheal hemorrhage and was taken to the operating room for emergent sternotomy but could not be resuscitated. The autopsy demonstrated that the left carotid artery, which was traversing posterior to the tracheal reconstruction (aorta translocated posterior to trachea at repair), had eroded into the trachea and there was a carotid to tracheal fistula. Comment In our overall series of 71 patients with tracheal stenosis secondary to complete tracheal rings, 15% had unilateral Fig 7. Slide tracheoplasty; absent right lung. The ends of the trachea are beveled as shown in the small inset. The anastomosis is performed with running 6.0 polydioxanone suture. The suture line is started superiorly (parachute technique) and finished inferiorly just above the carina. lung agenesis or severe lung hypoplasia. The purpose of this review was to compare the group of patients with tracheal stenosis and one lung with those who had Fig 6. Slide tracheoplasty; absent right lung. The patient has been placed on cardiopulmonary bypass with mild hypothermia to 32 C. The trachea is transected in the midportion of the tracheal stenosis. This site is determined by either external examination or by internal bronchoscopic findings. The inferior portion of the trachea is incised anteriorly and the superior portion of the trachea is incised posteriorly. Fig 8. Completed slide tracheoplasty. The everting running suture line helps to avoid the figure 8 configuration problem after the completed repair.

6 Ann Thorac Surg BACKER ET AL 2009;88: TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 629 Fig 9. Completed slide tracheoplasty and the relationship of the repair to the great vessels in a patient with an absent right lung. (Ao aorta; LA left atrium; LPA left pulmonary artery; LV left ventricle.) tracheal stenosis and two lungs. We attempted to identify any trends with associated pathology and to evaluate and compare the outcomes of these two groups. One of the earliest reports of unilateral lung agenesis was from Maltz and Nadas published in 1968 [2]. They reported 8 new cases and reviewed the literature and at that time could find 164 total cases. A summary of recent papers on tracheal stenosis patients with the incidence of unilateral lung agenesis or severe hypoplasia along with the mortality of these patients is shown in Table 4 [3, 4, 10 13]. The mortality rate in patients with tracheal stenosis and a single lung appears to range from 33% to 65%. The mortality rate in our tracheal stenosis SL patients was 18%. A variety of tracheal reconstruction procedures have been used in our tracheal stenosis patients and in these other series. The association of significant intracardiac anomalies and pulmonary artery sling appear to be the same in one lung and two lung patients. In our series pulmonary artery sling occurred in 1 out of every 3 patients in both groups, and significant intracardiac anomalies in 1 out of every 4 patients in both groups. In our patients with only one lung we used the pulmonary artery translocation technique originally described by Jonas [8] for repair of associated pulmonary artery sling. This is in contrast to our bilateral lung patients where we have relied upon the reimplantation technique [9]. In our one lung patients with pulmonary artery sling, all had absence or severe hypoplasia of the right lung. Because of this the right pulmonary artery was either absent or diminutive in these patients. Hence, the translocation technique where the left pulmonary artery is mobilized anterior to the trachea after tracheal division for tracheal repair is a very straightforward maneuver. Because the right pulmonary artery is either small or absent it does not pull on the left pulmonary artery and cause kinking of the left pulmonary artery, as has been described in patients with two lungs having the translocation technique performed [14]. The technique of tracheal repair in our tracheal stenosis patients (both BL and SL) has evolved over time. For the first 2 patients in the SL group we used the pericardial tracheoplasty [15], for the next 4 SL patients we used the tracheal autograft technique [16]. Most recently we have used the end-to-end anastomosis in two SL patients and slide tracheoplasty in the most recent 3 SL patients [5, 17]. Our current procedure of choice for SL and BL patients is the slide tracheoplasty technique. This technique has also been reported by others as being the procedure of choice for most patients with congenital tracheal stenosis [12, 18]. Our results with this technique would substantiate that this should be the procedure of choice for patients with unilateral lung agenesis or severe hypoplasia. Kocyildirim and colleagues [12] from Great Ormond Street recently described 15 patients treated with slide tracheoplasty technique (2 SL) with only 2 early postoperative deaths. Manning and colleagues [18] from Cincinnati recently reported 40 patients undergoing slide tracheoplasty with only 4 deaths, none related to the tracheoplasty. Antón-Pacheco and colleagues from Madrid, Spain [10] reported 13 cases of long segment congenital tracheal stenosis, 2 of whom had right lung agenesis (15%). They recommended slide tracheoplasty as the procedure of choice. Our patients with SL anatomy had a higher incidence of critical presentation than patients with two lungs. Although the median age at presentation (4 to 5 months) was the same (SL vs BL), 73% of the SL patients required preoperative intubation versus only 25% of the BL group. Seven of the 11 SL patients with one lung physiology were out-of-state referrals. Seven of the 11 SL patients were 4 months of age or less at the time of presentation. Table 4. Summary of Recent Papers on Tracheal Stenosis Patients With the Incidence of Unilateral Lung Agenesis or Severe Hypoplasia Along With the Mortality of These Patients Author [Reference] Year Tracheal Stenosis Patients Single Lung Mortality (SL) Weber and colleagues [3] (20%) 40% Antón-Pacheco and (15%) 50% colleagues [10] Tsugawa and colleagues (10%) 33% [11] Kocyildirim and (15%) ns colleagues [12] Airway Reconstruction (15%) ns Team [13] Chou and colleagues [4] 2007 ns 14 64% ns not significant; SL single lung.

7 630 BACKER ET AL Ann Thorac Surg TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 2009;88: There does not seem to be a high incidence of chromosomal abnormalities in this group; we had only 1 patient with Down syndrome in the SL group. The length of stay of these patients was long in both the SL and BL groups, but not dissimilar. The use of the slide tracheoplasty technique compared with the other techniques appeared to result in a lower incidence of postoperative tracheostomy in the SL group. Other centers have reported the use of saline expanders to stabilize the mediastinum in selected patients with lung agenesis [13, 18]. We have not found that necessary in any of our patients. The combination of tracheal stenosis from complete congenital tracheal rings and unilateral lung agenesis or severe hypoplasia occurred in 15% of our 71 patients with tracheal stenosis undergoing surgical repair. The single lung group had a more critical presentation with 73% of the patients intubated preoperatively versus 20% of the patients with bilateral lungs. Severe hypoplasia or agenesis of the right lung was more common (82%) than severe hypoplasia or agenesis of the left lung. There was a similar incidence of pulmonary artery sling (1 in 3 patients) and significant intracardiac anomalies requiring simultaneous repair (1 of 4 patients) comparing SL and BL anatomy. The mortality and length of stay of the single lung patients were similar to the patients with two lungs. Unilateral lung agenesis or severe hypoplasia should not preclude operative repair of tracheal stenosis. Slide tracheoplasty is our procedure of choice for patients with tracheal stenosis and unilateral lung agenesis or severe hypoplasia. The authors wish to express their appreciation to Rachid F. Idriss for providing the illustrations depicting tracheal stenosis with absent right lung (Fig 1) and tracheal stenosis with absent left lung (Fig 2) in addition to the drawings for the slide tracheoplasty technique (Figs 6, 7, 8, and 9). References 1. Booth JB, Berry CL. Unilateral pulmonary agenesis. Arch Dis Child 1967;42: Maltz DL, Nadas AS. Agenesis of the lung. Presentation of eight new cases and review of the literature. Pediatrics 1968;42: Weber TR, Connors RH, Tracy TF Jr. Congenital tracheal stenosis with unilateral pulmonary agenesis. Ann Surg 1991; 213: Chou A-K, Huang S-C, Chen S-J, et al. Unilateral lung agenesis detrimental roles of surrounding vessels. Pediatr Pulmonol 2007;42: Backer CL, Mavroudis C, Gerber M, Holinger LD. Tracheal surgery in children: an 18-year review of four techniques. Eur J Cardiothorac Surg 2001;19: Tsang V, Murday A, Gillbe C, Goldstraw P. Slide tracheoplasty for congenital funnel-shaped tracheal stenosis. Ann Thorac Surg 1989;48: Grillo HC. Slide tracheoplasty for long-segment congenital tracheal stenosis. Ann Thorac Surg 1994;58: Jonas RA, Spevak PJ, McGill T, Castaneda AR. Pulmonary artery sling: primary repair by tracheal resection in infancy. J Thorac Cardiovasc Surg 1989;97: Backer CL, Mavroudis C, Dunham ME, Holinger LD. Pulmonary artery sling: results with median sternotomy, cardiopulmonary bypass, and reimplantation. Ann Thorac Surg 1999;67: Antón-Pacheco JL, Cano I, García A, Martínez A, Cuadros J, Berchi FJ. Patterns of management of congenital tracheal stenosis. J Pediatr Surg 2003;38: Tsugawa C, Nishijima E, Muraji T, et al. Tracheoplasty for long segment congenital tracheal stenosis: analysis of 29 patients over two decades. J Pediatr Surg 2003;38: Kocyildirim E, Kanani M, Roebuck D, et al. Long-segment tracheal stenosis: slide tracheoplasty and a multidisciplinary approach improve outcomes and reduce costs. J Thorac Cardiovasc Surg 2004;128: The Airway Reconstruction Team. Recent challenges in the management of congenital tracheal stenosis: an individualized approach. J Pediatr Surg 2005;40: van Son JA, Hambsch J, Haas GS, Schneider P, Mohr FW. Pulmonary artery sling: reimplantation versus antetracheal translocation. Ann Thorac Surg 1999;68: Idriss FS, DeLeon SY, Ilbawi MN, Gerson CR, Tucker GF, Holinger L. Tracheoplasty with pericardial patch for extensive tracheal stenosis in infants and children. J Thorac Cardiovasc Surg 1984;88: Backer CL, Mavroudis C, Dunham ME, Holinger LD. Repair of congenital tracheal stenosis with a free tracheal autograft. J Thorac Cardiovasc Surg 1998;115: Dayan SH, Dunham ME, Backer CL, Mavroudis C, Holinger LD. Slide tracheoplasty in the management of congenital tracheal stenosis. Ann Otol Rhinol Laryngol 1997;106: Manning PB, Rutter MJ, Border WL. Slide tracheoplasty in infants and children: risk factors for prolonged postoperative ventilatory support. Ann Thorac Surg 2008;85: DISCUSSION DR DAVID MORALES (Houston, TX): I was wondering, in any of these patients with a small right lung, have a small right bronchus, have you done any slides into the right bronchus or carried any of the slides into the bronchi themselves? DR BACKER: I have not carried the slide tracheoplasty into one bronchus or the other. That has, however, been successfully reported. One of our patients did have a bronchial stenosis. This was in 1990 and I put a cartilage graft into the left bronchus. One point that I would make is that frequently, for whatever reason, the CT [computed tomographic] and MRI [magnetic resonance imaging] imaging tends to overestimate the degree of bronchial stenosis. I ve had several patients where we thought we were going to run into a bronchial stenosis and then when I probed the bronchus it was actually adequate in size. I have had some phone calls from surgeons asking me about cases they re about to do expressing concern that they have a potential bronchial stenosis and I have reassured them that frequently that is an over-read by the imaging. DR JOSEPH FORBESS (Dallas, TX): Very nice presentation. Again, a further extension of this massive experience you have. You may recall a couple years ago Dr. Guleserian, my partner, presented a case at the CHSS [Congenital Heart Surgeons Society] of a child with a single lung, who had a PA [pulmonary artery] sling and complete tracheal rings. That child had to go on ECMO [extracorporeal membrane oxygenation] for pulmonary hypertension postoperatively. Like the median of your patient

8 Ann Thorac Surg BACKER ET AL 2009;88: TRACHEAL RECONSTRUCTION WITH UNILATERAL LUNG AGENESIS 631 group, that patient was several months old and recovered nicely as far as the pulmonary artery pressures. When you are faced with one of these patients and they re young and they re relatively small, what sort of preparations do you make as with regard to postoperative pulmonary hypertension? If they have a VSD [ventricular septal defect], would you leave a fenestrated VSD? Are you thinking about leaving a PFO [patent foramen ovale]? How many patients have required ECMO support? DR BACKER: There was only one case that we had to put on ECMO. That was prior to nitric oxide. In the nitric oxide era, it seems like pulmonary hypertension has not been an issue. Several of the infants did have PFOs and we left them open. DR FORBESS: Yes, I mean we had significant RV [right ventricular] failure. And the other question I had is that if they ve got a sling and they have no right lung, the thing I noticed is that the pulmonary artery was a straight shot, the geometry was just fine. And I was wondering, that was my N of 1, you ve got more numbers, do you have to reimplant the LPA [left pulmonary artery]? It seemed like it was a straight shot and it lined up nicely with the main PA. Is that a common finding? DR BACKER: Thanks for bringing that up, Joe. Four patients in our series of 11 patients with one lung and tracheal stenosis had a pulmonary artery sling. Obviously they had an absent right lung because you can t have a pulmonary artery sling with an absent left lung. In 3 of those patients I did the translocation technique that Richard Jonas originally described, where when you do the tracheal repair you translocate the left pulmonary artery anterior to the trachea. Because there is either no right pulmonary artery or a very diminutive right pulmonary artery, the left pulmonary artery does not kink from the traction from the right pulmonary artery. That occurred in the movie that Victor Hraska showed us yesterday. With these patients you don t see that problem. So in 3 of the 4 we performed the translocation technique. One patient did have a modest right pulmonary artery, even though the lung was very hypoplastic, and I did reimplant that left pulmonary artery to place it in a proper configuration. This is a very good point. In the majority of these patients the translocation technique will work just fine and you will not have to do an anastomosis with the left pulmonary artery. DR GORDON COHEN (Seattle, WA): Nice presentation. Just a quick question. Do these kids with the single lungs develop normally? Do they get scoliosis? And if so, do you do anything to try and deal with the space problem from the absent lung on the one side? Do you put a breast implant in the chest or anything like that that you can expand over time? DR BACKER: That s a good question, Gordon. One of the things that we tried to look at, but we didn t have enough data to really put into the manuscript, was the total lung volume. In the 2 patients that we have CT images where Dr. Rigsby could figure out the lung volume, the total lung volume was about 75% of predicted normal. So it seems like these patients have more than just 50% of normal lung volume. So as far as that lung capacity is concerned it s probably better from a prognostic standpoint than we originally thought. To my knowledge, none of these patients has required an operation for scoliosis. We have not used saline tissue expanders, although when I was reviewing some of the literature to write this up the Toronto group reported one patient where they put a tissue expander in to stabilize the mediastinum. Peter Manning, who has a large series of slide tracheoplasties, had one patient where he also put in a tissue expander. But we have not found that necessary in any of our patients. It seems like the trachea is lined up before the operation and it stays lined up after the operation.