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Original Research: Pulmonary Procedures |

A New Method to Detect Air Leakage in a Patient With Pneumothorax Using Saline Solution and Multidetector-Row Spiral CT ScanSaline-Filled CT Thoracography to Detect Air Leak FREE TO VIEW

Kozo Nakanishi, MD, PhD; Akihiro Shimotakahara, MD, PhD; Yuko Asato, MD, PhD; Toshihiro Ishihara
Author and Funding Information

From the Department of General Thoracic Surgery (Drs Nakanishi and Shimotakahara), Department of Pulmonary Medicine (Dr Asato), and Department of Radiology (Mr Ishihara), National Hospital Organization Saitama Hospital, Wako, Saitama, Japan.

Correspondence to: Kozo Nakanishi, MD, PhD, Department of General Thoracic Surgery, National Hospital Organization Saitama Hospital, 2-1 Suwa, Wako, Saitama, 351-0102, Japan; e-mail: konakanishi-ths@umin.ac.jp


Funding/Support: The authors have reported to CHEST that no funding was received for this study.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.


Chest. 2013;144(3):940-946. doi:10.1378/chest.12-2678
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Background:  The purpose of this study was to establish a new CT scan method to show signs of air leakage and to detect the point of the lung leak in patients with spontaneous pneumothorax by using saline solution and phonation.

Methods:  Eleven patients with spontaneous pneumothorax who had a chest tube placed and underwent an operation because of continuing air leakage were studied. After a plain chest CT scan was performed, 0.9% saline was injected into the affected pleural cavity. A CT scan was acquired again while the patient vocalized continuously. The CT images were evaluated by two thoracic surgeons. All patients underwent video-assisted thoracoscopic surgery to confirm their points of leakage and were treated for spontaneous pneumothorax.

Results:  Bubble shadows were seen in nine of 11 cases. In seven of those nine cases, multiple bubbles formed foam or wave shadows. These cases had a small pleural fistula. In the other two cases with a large fistula, air-fluid level in bulla and ground-glass attenuation areas were seen in the pulmonary parenchyma. In all 11 cases, some air-leakage signs were seen on CT scan, and a culprit lesion was presumed to exist by analyzing CT imaging findings and confirming with a surgical air-leak test.

Conclusions:  With a saline injection and vocalization, CT scan could demonstrate air-leak signs in patients with spontaneous pneumothorax. This method does not require contrast medium, special instruments, or high skill and, thus, is a novel and useful examination to detect the culprit lesion in pneumothorax.

Figures in this Article

At present, and to our knowledge, a surgical air-leak test is the only way to detect the location of air leakage in patients with pneumothorax. Although we have treated cases of pneumothorax without knowing the position of the air leak, its location is of interest to clinicians who are trying to seal the leakage surgically or bronchoscopically.

Unfortunately, video-assisted thoracoscopic surgery (VATS) has made surgical air-leak testing more difficult, especially in cases of multiple bullae or diffuse pleural adhesion. Operators sometimes spend a great deal of time to find a leak point or even fail to find it. Such failures are a factor in the higher recurrence rate after VATS than open surgery.14 This problem is unsolvable, as VATS requires the affected lung to be collapsed. It would, thus, be very useful for an operator to know the position of the air leakage preoperatively, even if it is not localized with pinpoint accuracy.

In our clinical practice, we have observed a few true round low-attenuation areas in the CT images of a young patient with pneumothorax. We interpreted these findings to be bullae at the apical lung. However, at the time of surgery a solitary bulla was found to be leaking air. Retrospectively, the round shadows may in fact have been one bulla accompanied by a number of air bubbles blown out from the bulla.

We thus realized that both positive airway pressure and pleural fluid are needed. Because the CT scan is always executed under a breath hold, air bubbles from the lung would not be expected to appear on CT images. The aim of this study was to describe air bubbles and any other signs of air leakage on CT images by recreating these same conditions at the time of CT scanning in patients with spontaneous pneumothorax.

This was a prospective clinical study conducted on patients who had undergone the placement of a chest tube for treatment of spontaneous pneumothorax and who subsequently underwent an operation because of persistent air leakage. Inclusion criteria included the need for subjects to show greater than level 2 air leakage at the time of their CT image examination, according to the grade classification scheme given in Table 1. The subjects of this study were admitted to our department at National Saitama Hospital, Saitama, Japan, between October 1, 2010, and September 30, 2012. This study was conducted in accordance with the amended Declaration of Helsinki and was approved by the Saitama Hospital’s ethics committee. Patients gave written informed consent to participate before their examination; in the case of minor children, the patient consented to study participation.

Table Graphic Jump Location
Table 1 —Classification of Air-Leak Grades
CT Imaging Study

In this study, patients underwent imaging with a multidetector-row spiral CT (MDCT) scanner (Aquilion64; Toshiba Medical Systems Corporation). Patients were imaged twice in one CT image examination. The scan parameters were set as follows: tube voltage, 135 kV; rotation time, 0.5 s; pitch factor, 0.805; collimation, 0.5 mm × 64; CT imaging auto exposure control: SD, 14.5 The first scan was a standard plain-chest MDCT imaging study in the supine position to determine the existence and location of any lesions causing spontaneous pneumothorax. After the first scan, the postural position of the patient was changed to head-down, with a pillow under the patient’s waist. A preplaced chest tube had been connected to a chest drainage system (Sumitomo Bakelite Co, Ltd), and povidone iodine was used to clean the tube’s rubber port prior to saline being injected at the port using a 50-mL syringe with a 16-gauge needle. This antiseptic was used to prevent contamination introduced by port puncture. A 500-mL volume of 0.9% saline solution was injected into the pleural cavity through the chest tube. After the injection was finished, the second MDCT scan was prepared. At the start of the second scan, the patient was ordered to make vocalizations as strongly and consistently as possible; the second scan was acquired during this vocalization. If any lesions were detected on the medial side of the lung at the first scan, an additional third scan was performed at the unaffected lateral or hemilateral position of the patient. The chest tube was managed with water seal drainage and was not clamped at any point during the study. Most of the injected saline solution drained out into a chest drain bag immediately after the patient stepped down from the CT imaging table and stood up on his or her feet.

Orthogonal images were reconstructed from the CT image volume data and were evaluated by two thoracic surgeons at our institute. They analyzed any air-leakage signs on the CT images, discussed their findings, and estimated the location of the culprit lesion of the pneumothorax before surgery. In this study, we describe all bullous lesions as “bulla,” without distinguishing between “bulla” and “bleb.”

Surgery

All surgical procedures were performed under thoracoscopy. At the beginning of the surgical procedure, an air-leak test was performed. Minimal adhesiolysis was performed if necessary. The surgeons observed the lesion and confirmed air leakage thoracoscopically. Bullectomy and/or other surgical procedures were subsequently performed according to the accepted standards of care for management of spontaneous pneumothorax.

A total of 11 patients were enrolled in the study. Their characteristics are summarized in Table 2. Radiologic findings of air leakage are summarized in Table 3. In all 11 cases, we were able to observe air leaking from the lung and confirm a culprit lesion surgically. The correlations between radiologic findings and surgical findings in each case are shown in Tables 4 and 5.

Table Graphic Jump Location
Table 2 —Patient Characteristics

PSP = primary spontaneous pneumothorax; SSP = secondary spontaneous pneumothorax.

a 

Mean ± SD (minimum-maximum value).

b 

According to Table 1.

Table Graphic Jump Location
Table 3 —Findings of Air Leakage in Saline-Filled CT Thoracography

Total number of cases: 11.

Table Graphic Jump Location
Table 4 —Relationship Between Findings of Saline-Filled CT Thoracography and Surgery in Primary Spontaneous Pneumothorax Cases

, none; +, some; ++, several; +++, many.

a 

No. of shown bubbles.

b 

“Same” means that the leak point detected at the time of surgery was consistent with the preoperative estimate.

Table Graphic Jump Location
Table 5 —Relationship Between Findings of Saline-Filled CT Thoracography and Surgery in Secondary Spontaneous Pneumothorax Cases

, none; +, some; ++, several; +++, many.

a 

No. of shown bubbles.

b 

“Same” means that the leak point detected at the surgery was consistent with the preoperative estimate.

Radiologic and Surgical Findings
Bubble Shadow:

Small, round, low-attenuation areas were seen along the lung on CT images after saline injection (Figs 13) but were not observed on plain CT images. We named this radiologic finding the “bubble” shadow. This shadow was believed to reflect an air bubble blown out from the lung. The bubble shadow finding was found in nine of the 11 cases.

Figure Jump LinkFigure 1. Foam and wave shadow on saline-filled thoracography CT scan and its surgical finding (case 1). A1, Coronal section and magnified view. A2, Supine position. Multiple round low-attenuation areas are shown in the injected saline around the apical lung. These grouped multiple round shadows have the appearance of foam. B1, Axial section, supine; surface of saline water injected into the pleural cavity was not flat but a “wave form.” B2, Magnified view of Figure B1; a bulla was seen at the visceral pleura of the apical lung near the wave-shaped shadow. C, Surgical air-leak test. Air bubbles are blown out from a small fistula of the apical bulla.Grahic Jump Location
Figure Jump LinkFigure 2. Culprit bulla and foam/wave shadows in another case (case 2). A, A bulla and a wave shadow on the surface of the injected saline can be seen on the axial section of the saline-filled CT images. B, Foam shadows are shown on a coronal view reconstructed from multidetector-row spiral CT scan volume data.Grahic Jump Location
Figure Jump LinkFigure 3. Culprit bulla and bubble shadows forming foam shadows (case 4). A, Coronal section, supine position, before saline injection. B, Coronal section, supine position, saline-filled CT scan. The view and position of Slice 0 have been adjusted to be nearest to those of A. A bulla (arrowhead) can be seen at the lateral side of the left upper lung before saline injection (A). A bulla and a few bubble shadows can be seen on the most posterior layer of the saline-filled CT images (B, Slice 0). According to the anterior layers (B, Slices 1-3), bubble shadows were increasing and spreading to the saline water surface. Judging from the appearance and location of the two bullae marked with black triangles in A and B Slice 0, they should be identical. We were able to determine that the bulla must be the culprit lesion of the air leakage.Grahic Jump Location
Air-Fluid Level in Bulla:

The air-fluid level was seen in a bulla in two cases. In these two cases, no air bubble shadows were seen; however, infiltrative shadows could be demonstrated as so-called “ground-glass attenuation” and were seen in the pulmonary parenchyma near the bulla that had an air-fluid level shadow (Figs 4B1, 4B5). Surgical findings revealed that both cases had a > 5-mm-sized pore at the bulla (Fig 5). The CT image findings showed that a bulla with an air-fluid level had a relatively large fistula. A ground-glass attenuation shadow should reflect saline solution aspirated in the lung parenchyma, and thus saline that flowed in a culprit bulla through the large pleural fistula should infiltrate into the alveoli of the lung. Therefore, it was postulated that a culprit lesion should arise in the lung lobe where infiltrative shadows are seen. Infiltrative shadow would be an indirect CT image sign of air-leakage.

Figure Jump LinkFigure 4. Air-fluid level in bulla, infiltrative shadow, “spout” shadow, and other radiologic findings in a patient with secondary pneumothorax (case 8). A, Axial view, lateral position, before saline injection. B, Axial view, lateral position, saline-filled CT scan. Three major bullae (α, β, and γ) are shown in A and B. The pleural space was aerially connected to bulla-γ1 through two defects (arrowheads) of the wall of bulla-α (A1). This indicated that there was an aerial pathway from bulla-γ to the pleural space through bulla-α. The low-density area of γ1 was connecting to the γ2 part (A1-5). An infiltrative shadow was seen in the lung parenchyma near bulla-γ, in which the air-fluid level was shown (B5). It reflects saline aspirated into the lung through bulla-γ. The air-fluid level was also shown in bulla-α on the pathway (Β1, 2). There were no findings of air leaks in or near bulla-β (B1-5). Air leaking to the pleural space should originate from the lung parenchyma near bulla-γ and may not pass through bulla-β. A hypertranslucent stripe and radial artifacts were seen along the aerial pathway (B1-4). At the pleural end of the stripe, the wall of bulla-α was obscured (Β1, 2). The shadow had the appearance of a water spout or fire (B1). Surgical findings revealed that air and saline in the bulla were entering the pleural space like a water spout.Grahic Jump Location
Figure Jump LinkFigure 5. Surgical findings of the left apical lung of case 8. Surgical view (on the left is the anterior of the patient). A, Apical view before bulla resection. Two bullae (α and β, which are radiologically shown as bulla-α and β in Fig 4) can be seen in this viewpoint. Thin-walled bulla-α had a large fistula (arrowhead) and adhered to the apical chest wall. B, Apical view after cutting a part of the wall of bulla-α (asterisks). Another large fistula (arrowhead) was exposed, and the apical lung near the bulla collapsed. Nevertheless, bulla-β was still expansive.Grahic Jump Location
Other Relevant Findings:

In eight of nine cases that showed bubble shadows, several bubble shadows were grouped near one another and resembled “foam,” mainly on the surface of the injected saline (Figs 1A, 2B, 3B). The lateral view of the foam formation was the “wave” shadow (Figs 1B, 2A). The wave shape is formed by the presence of a small amount of saline water between the bottom walls of two spherical air bubbles laying side-by-side on the surface of the saline solution. Therefore, foam shadows on the surface of injected saline are shown in the coronal plane of CT images, and the wave shadows are seen in the axial or sagittal planes. In cases showing foam and/or wave formation, surgical findings revealed that a pleural fistula was small, with a size of less than a couple of millimeters (Fig 1C). These shadows were believed to reflect air leakage through the narrow pore of the lung. The bulla blowing out air should be considered to exit in or near the shadows (Figs 1B2, 2A, 3).

A finding that we call a “spouting” shadow was demonstrated in two cases (Fig 4B1). Here, a part of the wall of the bulla is obscured on the CT image. The wall of the bulla near the air-leak point would be blurred by the massive quantity of air blown out from the large fistula. Surgical findings revealed that in these cases, there was a bulla with a large pleural fistula.

In one case, a large bulla collapsed after the patient’s posture was changed from supine to the lateral position (Fig 6). In addition, both the air-fluid level in the bulla and ground-glass attenuation areas in the pulmonary parenchyma near the lesion were seen. A collapsed bulla is believed to leak air. Because bullae without air leakage will collapse over time, a finding of a bulla collapse would be an indirect sign of air leakage.

Figure Jump LinkFigure 6. Collapsed bulla (case 9). A, An expanded bulla was seen among the middle and lower lobes in the supine position. B, The bulla was collapsed after the postural change. The lower lobe was collapsed and infiltrative shadows were seen in the lower lobe (B). The bulla should arise on the lower lobe.Grahic Jump Location

With this new method using saline and vocalization, we successfully demonstrated air leakage from the lung as air-bubble shadows or other radiologic findings on CT images for all cases. Furthermore, the findings of the CT imaging study were predictive of culprit lesions. To our knowledge, there are no similar examinations using a CT scanner except in a handful of experimental studies.611 We refer to our new method as “saline-filled CT thoracography.”

Aside from contrast thoracography with fluoroscopy10,11 and experimental scintigraphic studies with special radioisotopes,6,1214 there exist few nonsurgical methods for detecting air leakage. Unfortunately, the use of such techniques is not widespread. These methods may require an expensive specialized imaging modality, introduce potential harm from contrast media, or require a high level of skill from the examiner. On the contrary, our method uses low-cost saline water and a general-purpose standard CT scanner. The physician’s skill is never required except during radiographic image interpretation. The acquired CT images show the three-dimensional shape and location of the shadows around the lung and lesions in the lung, and radiographic interpretation is not difficult.

In addition to air bubbles, in this study we observed several other signs that were indicative of air leakage. Air-bubble shadows could directly indicate air leakage in the pleural cavity. The shadows were scattered or collected in the pleural gutter formed with the visceral pleura and the parietal pleura. The distribution of the bubble shadows and the direction of the in-lined bubble shadows are most important for estimating the region of a pleural fistula and the culprit lesion. The lifespan of an air bubble is so short that the described bubble shadows should only exist near the leak point. Thus, if there are few bubble shadows, then the bubble shadows should be arrayed along the route from the leak point to the water surface. The distribution of bubble shadows helps to locate the suspicious lesion.

In our study, five of six primary spontaneous pneumothorax cases demonstrated foam shadows around a bulla at the apical lung. In these five cases, the bulla near the foam shadow was easily identified as the culprit lesion for pneumothorax. Conversely, a case (case #6) had a bulla in the interlobar fissure. In this case, bubble shadows were shown on CT images around the bulla, among the fissure, and along the chest tube located among the fissure. Although it was preoperatively impossible to determine the lobe on which the bulla had arisen in the case, it was easy to establish via CT imaging that the bulla was blowing out air. In fact, because surgeons knew the approximate location of the bulla preoperatively, air leakage could be detected immediately at the beginning of the operation. Even if the information about the location was somewhat imprecise, it would still prove valuable for surgeons. Surgeons could use such information to narrow their focus upon areas such as the medial or apical surface of the lung and to approach the leaking point with minimal surgical invasiveness.

In this study, it was not difficult to distinguish bullae from air bubbles. However, as small, round bullae were similar to air-bubble shadows, we sometimes could not distinguish them on saline-filled CT images only. In such cases, we compared CT images before and after saline injection to distinguish the two. Therefore, conventional static CT images are still needed. Although air bubbles were not shown on the breath-holding CT scan, bullae were always shown on CT images regardless of the patients’ breath control at the time of the scans.

It should be noted that fewer bubble shadows tend to be shown on CT images in secondary spontaneous pneumothorax cases with massive air leakage from a large pleural fistula rather than in patients with primary spontaneous pneumothorax with a small fistula. In cases of no or fewer bubble shadows, the other air-leakage signs help in estimating the air-leakage location. The air-fluid level shadow in a bulla may be a sign that the bulla has a large fistula. Infiltrative shadows could indicate that the bulla arises from the lobe of the lung that has infiltrative shadows.

In this study, air leakage and their culprit lesions in only the apex but also other sites, including the lower lobe, could be detected when using a head-down scan position. However, this result should not mean that all air-leakage in all patients with pneumothorax should be detected at only a head-down position. Certainly, some patients would show no air-leak signs only at the head-down position. More positions may be necessary to search the entire lung in such cases.

We paid close attention to aseptic manipulation while performing the saline injection. No contamination was seen in this study; thus, we consider the risk of infection to have been low. It is sufficient to disinfect the outer surface of the chest tube with povidone iodine before injection of saline. The method of injecting a large volume of saline into the pleural cavity and allowing it to flow out in a short time is the same as used for pleural lavage of empyema.

Air bubbles arising from the injection of saline were not seen in any cases. We believe that this was because we slowly injected 500 mL of saline over several minutes so as not to produce air bubbles. Further research is needed to establish the clinical significance of this methodology. A limitation of this study was the lack of blinded reviewing for localization of the culprit lesions. It would have been more reliable if the radiologists were suggesting the radiologic location based on the saline-filled CT thoracography, and the surgeons blinded to the radiologic localization would have reported the surgical localization of the fistula. These two blinded reports should have been compared following completion of the study.

We expect that the results of this study should also be applicable to patients with inoperable pneumothorax. Our method is a direct nonsurgical approach to the pleural fistula. Internal physicians who perform nonsurgical treatments, such as bronchial occlusion therapy,15 likely desire a better way of localizing air leaks. Our method could lead to the development of a new nonsurgical therapy for spontaneous pneumothorax.

We have proposed a new CT scanning method for patients with pneumothorax. Radiologic findings on CT images could be used to detect air leaks. Additionally, we demonstrated that we could detect the culprit bulla causing pneumothorax. We believe that these findings can create new possibilities for a more direct approach to pleural fistula than existing surgical methods.

Author contributions: Dr Nakanishi takes full responsibility for the work represented in this manuscript.

Dr Nakanishi: contributed to the study concept and design; data collection and analysis; performing all study examinations and surgeries; and writing, reading, and approval of the final manuscript.

Dr Shimotakahara: contributed to data collection and analysis; performing examinations and surgeries; and writing, reading, revising, and approval of the final manuscript.

Dr Asato: contributed to the treatment of patients and writing, reading, revising and approval of the final manuscript.

Mr Ishihara: contributed to the manipulation of the CT scanner and reconstruction of CT images, and writing, reading, revising and approval of the final manuscript.

Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

MDCT

multidetector-row spiral CT

VATS

video-assisted thoracoscopic surgery

MacDuff A, Arnold A, Harvey J; BTS Pleural Disease Guideline Group. Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(suppl 2):ii18-ii31. [CrossRef] [PubMed]
 
Sawada S, Watanabe Y, Moriyama S. Video-assisted thoracoscopic surgery for primary spontaneous pneumothorax: evaluation of indications and long-term outcome compared with conservative treatment and open thoracotomy. Chest. 2005;127(6):2226-2230. [CrossRef] [PubMed]
 
Nakanishi K. An apical symphysial technique using a wide absorbable mesh placed on the apex for primary spontaneous pneumothorax. Surg Endosc. 2009;23(11):2515-2521. [CrossRef] [PubMed]
 
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Figures

Figure Jump LinkFigure 1. Foam and wave shadow on saline-filled thoracography CT scan and its surgical finding (case 1). A1, Coronal section and magnified view. A2, Supine position. Multiple round low-attenuation areas are shown in the injected saline around the apical lung. These grouped multiple round shadows have the appearance of foam. B1, Axial section, supine; surface of saline water injected into the pleural cavity was not flat but a “wave form.” B2, Magnified view of Figure B1; a bulla was seen at the visceral pleura of the apical lung near the wave-shaped shadow. C, Surgical air-leak test. Air bubbles are blown out from a small fistula of the apical bulla.Grahic Jump Location
Figure Jump LinkFigure 2. Culprit bulla and foam/wave shadows in another case (case 2). A, A bulla and a wave shadow on the surface of the injected saline can be seen on the axial section of the saline-filled CT images. B, Foam shadows are shown on a coronal view reconstructed from multidetector-row spiral CT scan volume data.Grahic Jump Location
Figure Jump LinkFigure 3. Culprit bulla and bubble shadows forming foam shadows (case 4). A, Coronal section, supine position, before saline injection. B, Coronal section, supine position, saline-filled CT scan. The view and position of Slice 0 have been adjusted to be nearest to those of A. A bulla (arrowhead) can be seen at the lateral side of the left upper lung before saline injection (A). A bulla and a few bubble shadows can be seen on the most posterior layer of the saline-filled CT images (B, Slice 0). According to the anterior layers (B, Slices 1-3), bubble shadows were increasing and spreading to the saline water surface. Judging from the appearance and location of the two bullae marked with black triangles in A and B Slice 0, they should be identical. We were able to determine that the bulla must be the culprit lesion of the air leakage.Grahic Jump Location
Figure Jump LinkFigure 4. Air-fluid level in bulla, infiltrative shadow, “spout” shadow, and other radiologic findings in a patient with secondary pneumothorax (case 8). A, Axial view, lateral position, before saline injection. B, Axial view, lateral position, saline-filled CT scan. Three major bullae (α, β, and γ) are shown in A and B. The pleural space was aerially connected to bulla-γ1 through two defects (arrowheads) of the wall of bulla-α (A1). This indicated that there was an aerial pathway from bulla-γ to the pleural space through bulla-α. The low-density area of γ1 was connecting to the γ2 part (A1-5). An infiltrative shadow was seen in the lung parenchyma near bulla-γ, in which the air-fluid level was shown (B5). It reflects saline aspirated into the lung through bulla-γ. The air-fluid level was also shown in bulla-α on the pathway (Β1, 2). There were no findings of air leaks in or near bulla-β (B1-5). Air leaking to the pleural space should originate from the lung parenchyma near bulla-γ and may not pass through bulla-β. A hypertranslucent stripe and radial artifacts were seen along the aerial pathway (B1-4). At the pleural end of the stripe, the wall of bulla-α was obscured (Β1, 2). The shadow had the appearance of a water spout or fire (B1). Surgical findings revealed that air and saline in the bulla were entering the pleural space like a water spout.Grahic Jump Location
Figure Jump LinkFigure 5. Surgical findings of the left apical lung of case 8. Surgical view (on the left is the anterior of the patient). A, Apical view before bulla resection. Two bullae (α and β, which are radiologically shown as bulla-α and β in Fig 4) can be seen in this viewpoint. Thin-walled bulla-α had a large fistula (arrowhead) and adhered to the apical chest wall. B, Apical view after cutting a part of the wall of bulla-α (asterisks). Another large fistula (arrowhead) was exposed, and the apical lung near the bulla collapsed. Nevertheless, bulla-β was still expansive.Grahic Jump Location
Figure Jump LinkFigure 6. Collapsed bulla (case 9). A, An expanded bulla was seen among the middle and lower lobes in the supine position. B, The bulla was collapsed after the postural change. The lower lobe was collapsed and infiltrative shadows were seen in the lower lobe (B). The bulla should arise on the lower lobe.Grahic Jump Location

Tables

Table Graphic Jump Location
Table 1 —Classification of Air-Leak Grades
Table Graphic Jump Location
Table 2 —Patient Characteristics

PSP = primary spontaneous pneumothorax; SSP = secondary spontaneous pneumothorax.

a 

Mean ± SD (minimum-maximum value).

b 

According to Table 1.

Table Graphic Jump Location
Table 3 —Findings of Air Leakage in Saline-Filled CT Thoracography

Total number of cases: 11.

Table Graphic Jump Location
Table 4 —Relationship Between Findings of Saline-Filled CT Thoracography and Surgery in Primary Spontaneous Pneumothorax Cases

, none; +, some; ++, several; +++, many.

a 

No. of shown bubbles.

b 

“Same” means that the leak point detected at the time of surgery was consistent with the preoperative estimate.

Table Graphic Jump Location
Table 5 —Relationship Between Findings of Saline-Filled CT Thoracography and Surgery in Secondary Spontaneous Pneumothorax Cases

, none; +, some; ++, several; +++, many.

a 

No. of shown bubbles.

b 

“Same” means that the leak point detected at the surgery was consistent with the preoperative estimate.

References

MacDuff A, Arnold A, Harvey J; BTS Pleural Disease Guideline Group. Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(suppl 2):ii18-ii31. [CrossRef] [PubMed]
 
Sawada S, Watanabe Y, Moriyama S. Video-assisted thoracoscopic surgery for primary spontaneous pneumothorax: evaluation of indications and long-term outcome compared with conservative treatment and open thoracotomy. Chest. 2005;127(6):2226-2230. [CrossRef] [PubMed]
 
Nakanishi K. An apical symphysial technique using a wide absorbable mesh placed on the apex for primary spontaneous pneumothorax. Surg Endosc. 2009;23(11):2515-2521. [CrossRef] [PubMed]
 
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