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Subpleural Honeycombing on High ResolutionComputed Tomography is Risk Factor for FatalPneumonitisHiroyuki Ito, MD, Haruhiko Nakayama, MD, Masahiro Tsuboi, MD, MD,Yoichi Kameda, MD, Tomoyuki Yokose, MD, Chikako Hasegawa, MD, and

ouzo Yamada, MD

Divisions of Thoracic Surgery, Thoracic Oncology, and Pathology, Kanagawa Cancer Center, Yokohama, Japan

Background. Postoperative interstitial pneumonitis is alife-threatening complication after lung cancer surgery.We conducted this study to identify risk factors forpostoperative interstitial pneumonitis in patients withno clinical evidence of interstitial lung disease.

Methods. We retrospectively studied patients who un-derwent lung cancer resection. The characteristics ofpatients were analyzed by reviewing their clinical andsurgical records and preoperative chest high-resolutioncomputed tomographic scans. Postoperative interstitialpneumonitis was defined as acute severe hypoxemiaaccompanied by radiographic diffuse interstitial infil-trates of the lung with no apparent cause within a fewweeks after surgery.

Results. From 2002 through 2005, 651 patients wereevaluated, operated on, and managed by the same team.Postoperative interstitial pneumonia developed in 7 pa-tients (7 of 651, 1.1%). Five of these patients had local, butnot diffuse, dorsal subpleural honeycombing occupying

three or more segments in both lower lobes on high-

gawa Cancer Center, 1-1-2 Nakao, Asahi-ku, Yokohama, Japan 241-0815;e-mail: h-ito@kcch.jp.

© 2011 by The Society of Thoracic SurgeonsPublished by Elsevier Inc

resolution computed tomography (CT honeycombing).During the same period, 46 patients had CT honeycomb-ing. The incidence of postoperative interstitial pneumo-nia was 10.9% (5 of 46) among patients with CT honey-combing and 0.3% (2 of 605) among those without CThoneycombing. Four of the 7 (57%) patients with postop-erative interstitial pneumonia died of respiratory failure.Mortality among the patients who had postoperativeinterstitial pneumonia as well as CT honeycombing was80% (4 of 5); in contrast, none of the patients without CThoneycombing died. Multivariate analyses showed thatthe presence of CT honeycombing and prolonged oper-ation time were significant risk factors.

Conclusions. Subpleural honeycombing on high-reso-lution computed tomography is a significant predictor ofpostoperative interstitial pneumonia in asymptomaticpatients who undergo resection for lung cancer.

(Ann Thorac Surg 2011;91:874–9)

© 2011 by The Society of Thoracic Surgeons

Recent improvements in patient-selection criteria, op-erative techniques, and postoperative management

have contributed to lower mortality from lung cancersurgery. In 1983 the Lung Cancer Study Group reporteda mortality rate of 3.7% [1]. In 1999 an analysis of datafrom a Japanese lung cancer registry estimated thatmortality had decreased to 0.9% [2]. Respiratory compli-cations frequently occur after lung cancer resection andabout half of all postoperative deaths are attributed tointerstitial pneumonia (IP) [3]. Of course, apparent inter-stitial lung disease (ILD), including idiopathic pulmonaryfibrosis (IPF), is an important risk factor for postoperativeIP as well as for poor outcomes in patients with lungcancer [4, 5]. The treatment strategy for patients whohave lung cancer with apparent ILD must therefore bedecided more judiciously than usual [5, 6]. On theother hand, postoperative IP sometimes occurs unex-pectedly in patients without apparent ILD who have

Accepted for publication Oct 22, 2010.

Address correspondence to Dr Ito, Division of Thoracic Surgery, Kana-

acute lung injury-acute respiratory distress syndrome(ALI/ARDS) accompanied by bilateral reticular infil-trations on chest radiography. In many such patients,ILD is not diagnosed preoperatively because theirclinical signs and symptoms are atypical of ILD; ie,focal (not diffuse) fibrotic changes on computed tomog-raphy (CT) of the chest with no apparent symptoms [7].High-resolution computed tomography (HR-CT) hasbeen shown to delineate the anatomy of the lungsmore clearly than conventional CT. Using HR-CT, itcan be easier to check focal fibrosis of the lung andexclude gravitational effect. It is difficult to estimate theincidence of serious but infrequent complications by amultiinstitutional analysis because preoperative eval-uations of CT findings as well as operative proceduresand postoperative management differ among hospitals.Intraoperative management by anesthesiologists alsohas a considerable influence on postoperative ALI [8].To exclude these potential biases, we conducted thisstudy to identify risk factors for postoperative IP inpatients with no clinical evidence of ILD before surgi-

cal resection who were treated in a single center.

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Patients and Methods

Our institutional Internal Review Board approved thisretrospective study. From January 2002 through Decem-ber 2005, a total of 651 patients underwent resection ofprimary lung cancer at Kanagawa Cancer Center. Pa-tients with apparent ILD or obstructive pneumonia be-fore operation were excluded from this study. All pa-tients were closely evaluated by a single team ofpulmonologists, radiologists, medical oncologist, andthoracic surgeons together. Surgery and postoperativemanagement were performed by the same surgical teamin all patients. After operation, patients were admitted tothe intensive care unit for only that day, transfusion wasperformed at the speed of 1.25 mL · kg�1 · hour�1, and an

xygen mask (40%) was set in until next morning. Fromhe next day of operation, patients started to walk byhemselves with support. In our routine daily check-up ofostoperative patients, Spo2 (oxygen saturation as mea-ured by pulse oximetry) and body weight were checkedt least twice a day, and chest X-ray was undertaken onostoperative days 0, 1, 4, and 7. Laboratory values werehecked on postoperative days 1, 4, and 7. Cefazolin1.0 g) was used just before operation to postoperativeay 1 twice a day. When we noted a patient with Spo2

less than 93 in room air and infiltrating shadow on chestX-ray, a chest CT was immediately undertaken. Sputumculture was examined or bronchofiberscopy performedto exclude aspiration and bacterial infection.

No patient was given a diagnosis of ILD preoperativelyand had no clinical symptoms such as breathlessness,presence of crackles, or finger clubbing except caused bylung cancer. We retrospectively studied patients inwhom IP developed postoperatively by reviewing theirclinical characteristics (age, sex, smoking history, arterialoxygen tension, % forced vital capacity, forced expiratory

Abbreviations and Acronyms

ALI � acute lung injuryARDS � acute respiratory distress syndromeCT � computed tomographyFEV1 � forced expiratory volume in 1 secondFVC � forced vital capacityHE � hematoxylin-eosin stainHR-CT� high-resolution computed tomographicHU � Hounsfield unitICU � intensive care unitILD � interstitial lung diseaseIP � interstitial pneumoniaIPF � idiopathic pulmonary fibrosisLDH � lactate dehydrogenaseLob. � lobectomyNSIP � nonspecific interstitial pneumoniaPao2 � arterial oxygen tensionPneu. � pneumonectomySub. � sublober resectionUIP � usual interstitial pneumonia

volume in 1 second %, coexisting heart disease, tumor-

nodes-metastasis stage), surgical records (operation time,blood loss, operative procedure, blood transfusion), andpreoperative HR-CT scans of the chest. Postoperative IPwas diagnosed on the basis of acute hypoxia-like ALI-ARDS, an arterial oxygen tension to fraction of inspiredoxygen ratio of less than 300 with bilateral infiltrations onchest radiography, and the involvement of both lungs.Patients who had ALI-ARDS caused by bacterial pneu-monia or aspiration were excluded. An ultrasound car-diogram was performed to rule out acute heart failure.

Both lungs were examined by HR-CT. The conditionsof HR-CT were a slice thickness of 3 mm or thinner usingthe mediastinal (level, 40 Hounsfield unit [HU]; width,400 HU) and lung (level, 600 HU; width, 1,600 HU)window settings. The HR-CT scans were double-checkedby a pulmonologist and a radiologist. We assumed thatsubpleural localized CT honeycombing may be a predic-tor of subclinical ILD. The criteria for CT honeycombingin this study were dorsal and focal (not diffuse) subpleu-ral honeycomb formation with or without fibroticchanges occupying three or more segments in both lowerlobes (CT honeycombing), without any physical symp-toms (Fig 1). Curvilinear shadows and dependent densi-ties indicating gravitational effects were excluded. Allpatients in whom apparent ILD had been previouslydiagnosed were excluded. Lung specimens from all pa-tients in whom ALI-ARDS developed during the studyperiod were histopathologically examined to confirm thepresence or absence of ILD findings.

Each variable was tested by the �2 test, Fisher exacttest, and Student t test. Logistic-regression analysis wasused for multivariate analysis, performed with Stat Viewfor Windows (version 5.0; SAS Institute Inc, Cary, NC).The p values of less than 0.05 were considered to indicatestatistical significance.

Results

Postoperative IP developed in 7 patients (7 of 651, 1.1%).Four of these patients (4 of 7, 57%) died of respiratoryfailure. Table 1 shows the clinical characteristics of thepatients with postoperative IP. All 7 patients were men,with an average age of 66.5 years (62 to 73). All were

Fig 1. Preoperative high-resolution computed tomographic films ofcomputed tomographic honeycombing in three patients. Focal, notdiffuse subpleural dorsal honeycombing with focal fibrotic changescan be seen.

smokers, and the average smoking index (cigarettes/day �

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years) was 1,008. The histologic diagnosis of lung cancerwas adenocarcinoma in 3 patients, squamous cell carci-noma in 2, a large neuroendocrine carcinoma in 1, and asmall cell carcinoma in 1. The clinical stage was stage IAin 1 patient, stage IB in 3, stage IIB in 2, and stage IIIA in1. No patient received induction therapy or had a pasthistory of thoracic irradiation. Five of the 7 patients withpostoperative IP showed abnormal findings on preoper-ative spirometry: 3 had obstructive disorders, and 2 hadrestrictive disorders. The mean operation time was 301minutes, the mean blood loss was 162 g, and no patientreceived blood transfusion. When a pneumonectomypatient showed hypoxia and unilateral infiltrations onchest X-ray, ultrasound cardiogram showed slight pul-monary hypertension caused by pneumonectomy butacute heart failure was ruled out. Bronchofiberscopy didnot show purulent discharge; the result of bacterialculture was normal flora. On average, the onset day ofpostoperative IP was 8.3 days (4 to 10) after operation.The most common initial symptoms were fever andhypoxia. The place of postoperative IP was diffuse; therewas no tendency in the location of postoperative IP. Six ofthe seven patients with postoperative IP (86%) had ele-vated serum lactate dehydrogenase levels at the time ofonset. The surgical procedures were pneumonectomy in21 patients, lobectomy in 500, and sublobar resection in130. Table 2 compares the clinical characteristics of pa-tients with or without postoperative IP; age, sex, CThoneycombing, and prolonged operation time were riskfactors for the development of postoperative IP. Multi-variate analyses showed that CT honeycombing (p �

Table 2. Comparison of Patients According to the Presenceor Absence of Postoperative Interstitial Pneumonia

Variable

Postop IP(�)

(n � 7)

Postop IP(�)

(n � 644)p

Value

Age 73 (68–76) 65 (29–86) 0.04Sex (male/female) 7/0 367/277 0.02Smoking (yes/no) 7/0 373/271 0.25%FVC 97 (69–161) 105 (81–170) 0.22FEV1% 72 (58–84) 75 (72–97) 0.29

oexisting heart disease(�/-)

2/5 183/461 �0.99

NM stage (I vs II�III) 5/2 487/157 0.68ao2 85 (72–100) 88 (55–100) 0.57T fibrosis (�/�) 5/2 41/603 �0.01rocedure (pneu�lob/sub) 7/0 514/130 0.36peration time 301 (147–410) 198 (27–555) �0.01peration time �4 hours 5/2 154/490 0.01lood transfusion (�/�) 0/7 4/640 �0.99lood loss (mL) 162 (10–390) 91 (10–1,600) 0.17

Data are presented as mean (range).

CT � computed tomography; FEV1 � forced expiratory volume in 1second; FVC � forced vital capacity; lob � lobectomy; Pao2 �arterial oxygen tension; pneu � pneumonectomy; Postop IP � post-operative interstitial pneumonia; sub � sublober resection; TNM �tumor-nodes-metastasis.

0.01) and prolonged operation time were significant in-Ta Ca

1 2 3 4 5 6 7 CT

�n

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dependent risk factors (p � 0.04) (Table 3); combinationof CT honeycombing and operation time above 4 hoursstrongly suggested the risk of postoperative IP. Whensublobar resection was excluded from analysis becauseof a less invasive procedure, age, sex, CT honeycombing,and prolonged operation were risk factors again. Theresult of multivariate analysis was the same when sub-lobar resection was excluded. Five of the 7 patients withpostoperative IP had CT honeycombing. During thestudy period, a total of 46 patients had CT honeycomb-ing. The incidence of postoperative IP was 10.9% (5 of 46)among patients with CT honeycombing and 0.3% (2 of598) among those without CT honeycombing. All 4 pa-tients who died had CT honeycombing and were given adiagnosis of usual interstitial pneumonia (UIP) on histo-pathologic examinations of surgical specimens (Fig 2).One survivor with CT honeycombing who had postoper-ative IP showed nonspecific interstitial pneumonia onhistopathologic examination. In the other 39 patientswith CT honeycombing without developing postopera-tive IP, not all were histologically examined with asample from the CT honeycombing area. We examinedpathologic specimens from a non-cancer area in 11 pa-tients. Six patients had UIP, 2 had nonspecific interstitialpneumonia, and 3 had tobacco-related emphysema.

All patients who had postoperative IP received respi-ratory support, antibiotics, and steroid therapy. Twopatients who had postoperative IP without CT honey-combing recovered successfully. Histopathologic exami-nation showed no evidence of ILD in either of thesepatients. Mortality among the patients who had postop-erative IP as well as CT honeycombing was 80% (4 of 5);in contrast, none of the patients without CT honeycomb-ing died. During the study period, three cases of bacterialpneumonia developed but all responded to treatment withantibiotics. In this period none of the patients without CThoneycombing developed IPF in postoperative observationas outpatients. In 46 patients with CT honey combing, meanpostoperative intensive care unit stay was 1.03 days. In 596patients without CT honeycombing mean postoperativeICU stay was 1.08 days. There was no statistical differencebetween the two groups (p � 0.99). During this period, 4patients with apparent ILD excluded from this study had alung cancer operation. Two lobectomies and 2 partial resec-tions were carried out. None of them developed acutepostoperative IP. Two of the patients died of respiratory

Table 3. Logistic Regression Analysis

Variable p ValueRelative

Risk95% Confidence

Interval

Operation time�4 hours

p � 0.04 6.134 1.047–35.939

CT fibrosis p � 0.01 16.967 3.004–95.820Operation time

�4 hours �CT fibrosis

p � 0.01 1607.5 124.65–20730

CT � computed tomography.

failure 23 months and 38 months later because of gradual

deterioration of ILD. The overall operative mortality ratewas 1.1%, including 2 patients who died of cerebral infarc-tion and 1 patient who died of bronchopleural arterialfistula. Two thirds of postoperative mortality was caused bypostoperative IP.

Comment

In this study we could precisely reevaluate preoperativechest HR-CT scans in the same setting. A single surgicalteam performed surgery and postoperative managementin a similar manner for all patients with lung cancer inthis series. Thus, we could exclude variables of postop-erative management as the risk of postoperative IP. Mostof the patients with postoperative IP had CT honeycomb-ing. The surgical specimens of some postoperative IPpatients in the CT honeycombing group showed UIP onhistopathologic examination, but IPF or other types ofILD were not diagnosed clinically before surgery. Typicalradiologic findings of IPF on chest CT scans includediffuse and apparent subpleural honeycomb formation,occasionally accompanied by fibrotic changes [7, 9].High-resolution computed tomography has been shownto delineate the anatomy of the lungs more clearly thanconventional CT. The anatomic abnormalities of IPF areprogressive, beginning with the microscopic inflamma-tion that precedes fibrosis. In this context, focal (notdiffuse) dorsal subpleural honeycombing with or withoutfibrotic changes occupying three or more segments ofboth lower lobes on HR-CT, may be able to predict thepresence of occult or early-stage IPF owing to the finedefinition of the lung anatomy on HR-CT [10]. To thispoint, CT honeycombing of HR-CT is a simple and usefulpredictor of the risk of postoperative IP. But not all thepatients with this HR-CT finding were pathologicallyconfirmed as UIP in this study, so further prospectivestudies will be needed to confirm it. But once postoper-ative IP develops in such patients with occult or early-

Fig 2. Histopathologic findings of the resected specimen, showingtypical usual interstitial pneumonia in a subpleural lesion (hematox-

ylin-eosin stain, �100).

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stage IPF, its mortality is extremely high, similar to that inpatients with clinically apparent IPF [11, 12].

In clinical practice, surgeons sometimes encounter post-operative patients with fever, acute hypoxia, and bilateralinfiltrations on chest radiography but it is difficult to singleout the cause. Partial atelectasis, lung edema, intrapulmo-nary oozing, and pleural fluid aspiration sometimes showradiologic characteristics similar to those of postoperativeIP but are not always fatal. In this study, preoperative CThoneycombing and prolonged operation times were inde-pendent risk factors of fatal postoperative IP; combinationof these two factors strongly suggested high risk. Themechanism of acute exacerbation is still unclear, but occultIPF might be exacerbated by long operation times. Oncefever with acute hypoxia and bilateral infiltrations develop,suggesting a potential risk of postoperative IP, the manage-ment strategy depends on whether occult IPF progresses topostoperative IP or not.

The treatment strategy for postoperative IP and acuteexacerbations of ILD is basically the same as that for ARDS(ie, ventilator support plus antibiotics with or without ste-roid therapy) but mortality remains high [13]. The use ofcorticosteroids for the treatment of ARDS remains contro-versial but early low-dose steroid therapy may improveoutcomes [14–16]. Our results suggest that patients withpostoperative IP who did not have occult IPF may respondto conventional therapy. In contrast, once postoperative IPdevelops in patients with occult UIP, mortality is high. Ourstudy showed that fatal postoperative IP rarely developedin patients with no apparent IPF before surgery. If patientswith occult IPF can be identified preoperatively carefulpostoperative management and countermeasures againstpostoperative IP could be implemented.

Surgery remains the standard treatment for primarylung cancer even in such high-risk patients [5]. However,about half of all postoperative deaths among patientswith primary lung cancer are attributed to postoperativeIP. In case of occult IPF patients who developed postop-erative IP, there will be a tiny percent of survival. Thus itis important to predict this risk preoperatively in candi-dates for lung cancer surgery. The detailed pictures ofHR-CT were very useful to know the presence of honey-combing and exclude a gravitational effect. Measures toprevent postoperative IP in patients with occult IPF areessential to improving the safety of lung cancer surgery.

Subpleural honeycombing with or without fibroticchanges on HR-CT was a significant predictor of both therisk and severity of postoperative IP in asymptomaticpatients who underwent resection for lung cancer. Ourresults and the diagnostic usefulness of HR-CT findingsshould be confirmed in larger prospective clinical trials,with the ultimate goal of preventing life-threatening

complications after lung cancer surgery.

diagnosis, yet the disease course in individual patients is

© 2011 by The Society of Thoracic SurgeonsPublished by Elsevier Inc

References

1. Ginsberg RJ, Hill LD, Eagan RT, et al. Modern thirty-dayoperative mortality for surgical resections in lung cancer.J Thorac Cardiovasc Surg 1983;86:654–8.

2. Koike T, Yamato Y, Asamura H, et al. Improvements insurgical results for lung cancer from 1989 to 1999 in Japan.J Thorac Oncol 2009;4:1364–9.

3. Watanabe S, Asamura H, Suzuki K, Tsuchiya R. Recentresults of postoperative mortality for surgical resections inlung cancer. Ann Thorac Surg 2004;78:999–1002.

4. Kudoh S, Kato H, Nishiwaki Y, et al. Interstitial lung diseasein Japanese patients with lung cancer: a cohort and nestedcase-control study. Am J Respir Crit Care Med 2008;177:1348–57.

5. Watanabe A, Higami T, Ohori S, Koyanagi T, Nakashima S,Mawatari T. Is lung cancer resection indicated in patientswith idiopathic pulmonary fibrosis? J Thorac CardiovascSurg 2008;136:1357–63.

6. Tsuboi M, Le Chevalier T. Interstitial lung disease in pa-tients with non-small-cell lung cancer treated with epider-mal growth factor receptor inhibitors. Med Oncol 2006;23:161–70.

7. American Thoracic Society. Idiopathic pulmonary fibrosis.Diagnosis and treatment. International consensus state-ment. American Thoracic Society (ATS), and the EuropeanRespiratory Society (ERS). Am J Respir Crit Care Med2000;161 (2 Pt 1:646-64.

8. Licker M, Fauconnet P, Villiger Y, Tschopp JM. Acute lunginjury and outcomes after thoracic surgery. Curr Opin An-aesthesiol 2009;22:61–7.

9. American Thoracic Society; European Respiratory Society.American Thoracic Society/European Respiratory SocietyInternational Multidisciplinary Consensus Classification ofthe Idiopathic Interstitial Pneumonias. Am J Respir Crit CareMed 2002;165:277–304.

10. Orens JB, Kazerooni EA, Martinez FJ, et al. The sensitivity ofhigh-resolution CT in detecting idiopathic pulmonary fibro-sis proved by open lung biopsy. A prospective study. Chest1995;108:109–15.

11. Chida M, Ono S, Hoshikawa Y, Kondo T. Subclinical idio-pathic pulmonary fibrosis is also a risk factor of postopera-tive acute respiratory distress syndrome following thoracicsurgery. Eur J Cardiothorac Surg 2008;34:878–81.

12. Tanita T, Chida M, Hoshikawa Y, et al. Experience with fatalinterstitial pneumonia after operation for lung cancer. J Car-diovasc Surg (Torino) 2001;42:125–9.

13. Deslauriers J, Mehran R. Handbook of perioperative care ingeneral thoracic surgery. Elsevier Mosby: Philadelphia, PA;2005:314–7.

14. Lee HS, Lee JM, Kim MS, Kim HY, Hwangbo B, Zo JI.Low-dose steroid therapy at an early phase of postoperativeacute respiratory distress syndrome. Ann Thorac Surg 2005;79:405–10.

15. Kutlu CA, Williams EA, Evans TW, Pastorino U, GoldstrawP. Acute lung injury and acute respiratory distress syndromeafter pulmonary resection. Ann Thorac Surg 2000;69:376–80.

16. British Thoracic Society; Society of Cardiothoracic Surgeonsof Great Britain, and Ireland Working Party. BTS guidelines:guidelines on the selection of patients with lung cancer for

surgery. Thorax 2001;56:89–108.

INVITED COMMENTARY

The prognosis for idiopathic pulmonary fibrosis (IPF) isvery poor, with a median survival of 2 to 4 years after the

highly variable. Predicting prognosis in individual pa-tients is challenging, but various clinical and radiologic

variables have been identified. Although postoperative

0003-4975/$36.00doi:10.1016/j.athoracsur.2010.11.054