Procedure

Postpneumonectomy syndrome

^a Division of Thoracic Surgery, Hôpital Maisonneuve-Rosemont (University of Montreal), 5415 boulevard de l'Assomption, Montréal, Que H1T 2M4, Canada
^b Department of Anesthesia, Hôpital Laval, Centre universitaire de cardiologie et de pneumologie (Laval University), Ste-Foy, Que, Canada
^c Division of Thoracic Surgery, Hôpital Laval, Centre universitaire de cardiologie et de pneumologie (Laval University), Ste-Foy, Que, Canada

^* Corresponding author: Tel.: +1-514-252 3822 ext. 7703; fax: +1-514-252 3894. george.rakovich{at}umontreal.ca

	Summary

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Postpneumonectomy syndrome is a rare postoperative complication whereby mediastinal shifting toward the pneumonectomy space results in bronchial compression between the pulmonary artery, aorta, and vertebral column. This syndrome is more common after right pneumonectomy; other risk factors include young age and female sex. Imaging studies consistently reveal massive mediastinal shifting and document airway compromise. Bronchoscopy and flow-volume loops are helpful in confirming the diagnosis. Other causes of dyspnea, including cancer recurrence, should be excluded. Definitive treatment involves surgical repositioning of the mediastinum in the midline, as well as insertion of a saline-filled silicone prosthesis into the pneumonectomy space in order to prevent recurrence.

Key Words: Airway obstruction • Complications • Pneumonectomy

	Introduction

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Postpneumonectomy syndrome refers to bronchial compression occurring as a result of massive mediastinal shift following pneumonectomy [1, 2, 3]. Incidence is approximately one in 640 cases [4]. This syndrome is much more common after right pneumonectomy: the mediastinum undergoes counterclockwise rotation as it shifts toward the pneumonectomy space [2, 3, 5, 6, 7]. This results in stretching, distortion, and compression of the left main bronchus between the pulmonary artery anteriorly and the aorta and vertebral column posteriorly (Schematic 1). The syndrome has also been described after left pneumonectomy, both in patients with and without an aberrant right aortic arch [6, 8, 9, 10]. Variations of postpneumonectomy syndrome include compression of the pulmonary artery and compression of the esophagus, also as a result of mediastinal shifting; these have been reported anecdotally [1, 11, 12, 13].

View larger version (29K): [in this window] [in a new window]   Schematic 1 Mechanism of bronchial compression in postpneumonectomy syndrome: following right pneumonectomy (A), massive mediastinal shifting toward the pneumonectomy space causes compression of the left main bronchus between the pulmonary artery anteriorly (PA), and the vertebral column and descending aorta (Ao) posteriorly. Alternatively, after left pneumonectomy, mediastinal shifting toward the left results in compression of the right main bronchus across the vertebral column (B). [Modified with permission from: Chest Surgery Clinics, Vol. 9, Mehran RJ, Deslauriers J. Late complications: postpneumonectomy syndrome, Pages 655–73, Copyright Elsevier (1999) (6).]

Patients typically present with exertional dyspnea, stridor, and recurrent pulmonary infection [6, 14, 15] within one year of pneumonectomy [16]. The onset is usually gradual, but acute obstruction may ensue in children [5, 6, 11, 14].

Chest X-ray and cross-sectional imaging reveal massive mediastinal shift [2, 4] (Photo 1). Flow volume loops, bronchoscopy, and computed tomography are important in demonstrating the bronchial obstruction [2, 12] (Video 1).

View larger version (151K): [in this window] [in a new window]   Photo 1 Chest X-ray of a 45-year-old female patient who underwent a right pneumonectomy for stage 2b adenocarcinoma and who presented with postpneumonectomy syndrome 6 months after the operation. Massive mediastinal shift toward the pneumonectomy space as well as stretching of the left main bronchus across the vertebral column are evident.

Click on image to view video Video 1 Computed tomography of the chest obtained in the same patient demonstrates massive mediastinal shifting toward the pneumonectomy space and consequent compression of the left main bronchus between the pulmonary artery anteriorly, and the vertebral column and descending aorta posteriorly.

Airway stenting has been used in the treatment of inoperable patients and as a bridge to surgery in cases of acute obstruction [9, 11, 14, 17]. However, removable silicone-covered stents are particularly prone to migration in this setting and fatal cases of airway obstruction have been reported [14]. Definitive treatment involves surgical repositioning of the mediastinum in the midline. The mediastinum is then maintained in position by a saline-filled silicone prosthesis which is inserted into the pneumonectomy space [2, 6, 14, 16, 18].

	Surgical technique

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The following illustrates surgical correction of postpneumonectomy syndrome in the patient whose case was described in Photo 1 and Video 1.

Step 1: thoracotomy (Video 2)
The original posterolateral thoracotomy incision is reopened in standard fashion. It is prudent to enter the thoracic cavity one interspace above the original incision, to facilitate the dissection and to obtain easier access to the residual intrathoracic cavity that will be small in size and located at the higher part of the chest following upward migration of the dome of the diaphragm.

Click on image to view video Video 2 Surgical correction of postpneumonectomy syndrome, step 1: the postpneumonectomy space is accessed through a posterolateral thoracotomy, while intraoperative bronchoscopy shows bronchial compression.

Intraoperative bronchoscopy at this point shows compression of the left main bronchus.

Step 2: mediastinal repositioning (Video 3)
Once the pleural cavity has been accessed, the mediastinum is completely freed from the chest wall using sharp and blunt dissection, with the objective of returning the mediastinum to the midline. In up to one-third of cases, adhesions may be absent and the mediastinum completely falls away from the chest wall as the pleura is opened [2, 14, 16].

Click on image to view video Video 3 Surgical correction of postpneumonectomy syndrome, step 2: the mediastinum is dissected from the chest wall and repositioned in the midline.

Click on image to view video Video 4 Surgical correction of postpneumonectomy syndrome, step 3: a saline-filled breast implant of appropriate size is selected and inserted into the pneumonectomy space.

Step 4: prosthesis inflation (Video 5)
Generally, it is necessary to fill the prosthesis to a volume of 1 l [2, 4, 11, 14]. However, filling volumes vary dramatically from case to case [2, 4, 11, 14]. It has also been very difficult to estimate the required volume from preoperative imaging. Thus, the decision rests on intraoperative assessment of mediastinal position as well as on intraoperative bronchoscopy, which confirms that the bronchial obstruction has been lifted [2, 11, 16].

Click on image to view video Video 5 Surgical correction of postpneumonectomy syndrome, step 4: the breast prosthesis is filled with saline until intraoperative bronchoscopy confirms that the bronchial obstruction has been lifted.

A subcutaneous port may be connected to the prosthesis for subsequent adjustment of filling volume, as dictated by the patient's symptoms and postoperative imaging [2, 14]. The thoracotomy is then closed in standard fashion.

	Results

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Immediate anatomic correction is achieved in 85% of patients [2] (Photo 2, Video 6).

View larger version (138K): [in this window] [in a new window]   Photo 2 Chest X-ray obtained after mediastinal repositioning and insertion of a saline-filled silicone prosthesis into the pneumonectomy space to correct postpneumonectomy syndrome: the trachea is perfectly midline, confirming adequate correction. (Contrast with the preoperative chest X-ray shown in Photo 2.)

Click on image to view video Video 6 Computed tomography obtained after mediastinal repositioning and insertion of a saline-filled silicone prosthesis into the pneumonectomy space. Adequate mediastinal repositioning and relief of bronchial compression are evident. (Contrast with the preoperative examination shown in Video 1.)

	Discussion

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Important points relating to the prosthesis:

• Using an unduly large prosthesis or overfilling may result in decreased venous return and circulatory collapse [2, 11, 16].
  
• Depending on anatomic circumstances, it is possible to insert more than one prosthesis, if necessary [12, 19].
  
• Potential problems include malpositioning, migration, herniation across the midline, and deflation over time. Occasionally, such problems may warrant reoperation in the symptomatic patient [2, 3, 14].
  
• Standard antibiotic prophylaxis seems warranted, although infection is rare [14].
  

Failure is often due to the presence of tracheobronchomalacia [4, 6, 7] (Video 7). This problem is not necessarily related to the duration of compression. It is difficult to anticipate, has been difficult to correct, and may have a poor prognosis [4, 6, 7]. Management consists of supportive care along with airway stenting as needed. Aggressive surgery (such as membranous tracheoplasty, segmental airway resection, aortic resection and reconstruction, as well as vertebral resection) is rarely needed [6, 7].

Click on image to view video Video 7 Bronchoscopy is performed in a patient having undergone successful mediastinal repositioning for postpneumonectomy syndrome. Although her symptoms were improved, she complained of persistent stridor. Tracheobronchomalacia is observed as the membranous wall collapses during expiration. TRA, trachea; LB, left main bronchus.

	References

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1. Rodefeld MD, Wile FD, Whyte RI, Pitlick PT, Black MD. Pulmonary vascular compromise in a child with postpneumonectomy syndrome. J Thorac Cardiovasc Surg 2000;119:851–853.[Free Full Text]
2. Macaré van Maurik AF, Stubenitsky BM, van Swieten HA, Duurkens VA, Laban E, Kon M. Use of tissue expanders in adult postpneumonectomy syndrome. J Thorac Cardiovasc Surg 2007;134:608–612.[Abstract/Free Full Text]
3. Podevin G, Larroquet M, Camby C, Audry G, Plattner V, Heloury Y. Postpneumonectomy syndrome in children: advantages and long-term follow-up of expandable prosthesis. J Pediatr Surg 2001;36:1425–1427.[CrossRef][Medline]
4. Jansen JP, Brutel de la Rivière A, Alting MP, Westermann CJ, Bergstein PG, Duurkens VA. Postpneumonectomy syndrome in adulthood. Surgical correction using an expandable prosthesis. Chest 1992;101:1167–1170.[CrossRef][Medline]
5. Ozcelik C, Onat S, Askar I, Topal E. Surgical correction of postpneumonectomy syndrome by intrapleural expandable prosthesis in a child. Interact CardioVasc Thorac Surg 2004;3:390–392.[Abstract/Free Full Text]
6. Mehran RJ, Deslauriers J. Late complications: postpneumonectomy syndrome. Chest Surg Clin N Am 1999;9:655–673.[Medline]
7. Grillo HC, Shepard JA, Mathisen DJ, Kanarek DJ. Postpneumonectomy syndrome: diagnosis, management, and results. Ann Thorac Surg 1992;54:638–650.[Abstract]
8. Kelly RF, Hunter DW, Maddaus MA. Postpneumonectomy syndrome after left pneumonectomy. Ann Thorac Surg 2001;71:701–703.[Abstract/Free Full Text]
9. Cordova FC, Travaline JM, O'Brien GM, Ball DS, Lippmann M. Treatment of left pneumonectomy syndrome with an expandable endobronchial prosthesis. Chest 1996;109:567–570.[CrossRef][Medline]
10. Uyama T, Monden Y, Sakiyama S, Fukumoto T, Sumitomo M, Harada K. Management of postpneumonectomy syndrome by intrapleural injection of sulfur hexafluoride. Case report. Scand J Thorac Cardiovasc Surg 1993;27:179–181.[Medline]
11. Bédard ELR, Uy K, Keshavjee S. Postpneumonectomy syndrome: a spectrum of clinical presentations. Ann Thorac Surg 2007;83:1185–1188.[Abstract/Free Full Text]
12. Reed MF, Lewis JD. Thoracoscopic mediastinal repositioning for postpneumonectomy syndrome. J Thorac Cardiovasc Surg 2007;133:264–265.[Free Full Text]
13. Yüksel M, Yildizeli B, Evman S, Kodalli N. Postpneumonectomy esophageal compression: an unusual complication. Eur J Cardiothorac Surg 2005;28:180–181.[Abstract/Free Full Text]
14. Régnard JF, Pouliquen E, Magdeleinat P, Sohier L, Gourden P, Gharbi N, Bourcereau J, Levasseur P. Postpneumonectomy syndrome in adults: description and therapeutic propositions apropos of 8 cases. Rev Mal Respir 1999;16:1113–1119.[Medline]
15. Chae EJ, Seo JB, Kim SY, Do KH, Heo JN, Lee JS, Song KS, Song JW, Lim TH. Radiographic and CT findings of thoracic complications after pneumonectomy. Radiographics 2006;26:1449–1468.[Abstract/Free Full Text]
16. Valji AM, Maziak DE, Shamji FM, Matzinger FR. Postpneumonectomy syndrome: recognition and management. Chest 1998;114:1766–1769.[CrossRef][Medline]
17. Moser NJ, Woodring JH, Wolf KM, Reed JC. Management of postpneumonectomy syndrome with a bronchoscopically placed endobronchial stent. South Med J 1994;87:1156–1159.[CrossRef][Medline]
18. Audry G, Balquet P, Vazquez MP, Dejerine ES, Baculard A, Boule M, Grimfeld A, Gruner M. Expandable prosthesis in right postpneumonectomy syndrome in childhood and adolescence. Ann Thorac Surg 1993;56:323–327.[Abstract]
19. Birdi I, Baghai M, Wells FC. Surgical correction of postpneumonectomy stridor by saline breast implantation. Ann Thorac Surg 2001;71:1704–1706.[Abstract/Free Full Text]