The radiology of pulmonary change during the postoperative period

The

Radiology of Pulmonary Change the Postoperative Period JOHN

R. MITCHELL,

M.D.,

From tbe Department of Radiology, Yale University School of Medicine, New Haven, Connecticut, and tbe Radiologic Service of tbe Veterans Administration Hospital, West Haven, Connecticut.

In massive coIIapse of the Iung, the onset of symptoms is sudden. The collapse is accompanied by fever, pain, dyspnea and cyanosis. It is desirabIe to detect ateIectasis earIy to prevent superimposed infection. ROENTGEN MANIFESTATIONS With coIIapse of a whoIe Iobe the chest roentgenogram provided an accurate and characteristic appearance of the underIying process. The heart and mediastinum wiI1 shift to the side involved, the diaphragm eIevates and the ribs become cIoser together on the side affected; the uninvoIved Iobes become overexpanded, and the hiIar shadows shift in the direction of invoIvement. On the anteroposterior view the coIIapsing upper Ieft Iobe pivots on the hiIus so that the obIique fissure Ioses its contact with the IateraI chest waI1 and moves aIong the anterior chest wall and comes to lie Iike a cIosed fan in the anterior superior mediastinum obIiterating the aortic knob and upper Ieft cardiac border. During compIete coIIapse of the upper right Iobe the horizonta1 fissure moves to a vertica1 position with the lobe ffattened against and obliterating the outIine of the superior mediastinum. CoIIapse of the middIe right Iobe or IinguIa may cast onIy a faint shadow on the anteroposterior roentgenogram, but the heart border is obIiterated. AnguIation of the tube towards the head wiI1 demonstrate the coIIapse of the middIe right lobe better than a straight anteroposterior projection. In the Iower Iobes, as coIIapse becomes compIete, the cohapsed Iobes may be seen as a doubIe density behind the heart. The ateIec-

ATELECTASIS The frequency of postoperative ateIectasis depends upon: the type of surgery, the age and the heaIth of the patient. Brattstrom [2] has divided the agents contributing to ateIectasis into three groups: Those that cause a reduction in bronchia caIiber, those that contribute to stagnation of bronchia secretions, and those that inhibit the norma ventiIatory and expuIsive mechanisms. In practice it is impossibIe to separate one group from the other. Such conditions as preoperative infections of the respiratory tract, premeditations, irritating anesthesia, postoperative pain, surgica1 trauma, tight dressings and prolonged recumbency contribute to a11 groups. SmaII areas of Iinear or pIate ateIectasis may occur without any increase in symptoms or physica findings. In cases of moderate ateIectasis the appearance of symptoms may be 104. July

1961

findings somewhat

Iimited .

LTHOUGHpuImonarycomplications foIlowing surgery of the abdomen, peIvis, head and neck, or extremities may not be as dramatic as after chest surgery, they can cause serious difficulties. The purpose of this report is to review the roentgen manifestations of postoperative compIications observed on the chest roentgenogram. KIug and McPherson [I] found that puImonary and cardiovascuIar compIications accounted for about a third of a11 complications in the postoperative period in the eIderIy surgica1 patient: These are ateIectasis, pneumonia, thrombo-emboIism, puImonary edema and pIeura1 effusion.

Volume

Connecticut

insidious and the physica

A

American Journal of Surgery,

New Haven,

during

54

Radiology

of PuImonary

Change

during

Postoperative

Period

TABLE I CFIANGES OF

Lobe

OF THE

‘THE

OUTLINE

CHEST

BY

OF NONAERATED

SEGMENTAL

STRUCTURES

ATELECTASIS

OR

CONSOLIDATION

,

Structure

Segment

Affected

_ Lipper right

ipica

Br

Right superior mediastinal border is obscured Right ascending aorta and media1 portion of the horizonta1 &sure is blurred Lateral portion of the horizontal fissure is obliterated Lateral portion of the horizonta1 fissure is obscured Right border of heart is hidden Density of right hiIus increased Media1 third of right hemidiaphragm and Iower right heart border are conceaIed LateraI costophrenic angle and lateral part of the diaphragm are hidden LateraI costophrenic angle and IateraI part of the diaphragm are obscured The posterior lower right ribs and adjacent spine shadows are veiIed _ Obliteration of aortic knob

Anterior Bz

Posterior AI iddlc right

-atera

B3 B4

Medial B5 Lower right

Superior B6 Media1 basilar B7 Gnterior B8

basilar

Lateral

basiIar

B9 Posterior BIO Upper left

Lower left

basilar

ApicaI-posterior BI-3 Anterior Bz

FIG. I. Atclectasis of the Iower Ieft lobe. Chest roentgenogram taken six days after a herniorrhaphy rcveaIed a density behind the heart on the Ieft obscuring the descending aorta, Ieft hemidiaphragm and lower thoracic spine. The Ieft hiIus is depressed. There is a stight shift of the mediastinum, and there is emphyscma of the upper left lobe. These changes disappeared after remova of mucous plug from the lower left bronchus at bronchoscopy.

and it has been termed “plate” or “linear” [3] has expIained the atelectasis. Fleischner horizontal position of the collapsed part to be caused by media1 fixation of the part with peripheral emphysematous changes which occurred adjacent to the obstructed bronchiolar division.

BIurring of upper Ieft border of heart Lingula B4, B5 BIurring of Iower left border of heart Superior B6 Density of Ieft hilus increased Anteromedial Masking of anterior media1 basilar B7--8 portion of Ieft hemidiaphragm LateraI basiIar ObIiteration of costophrenic angIe B9 Posterior basilar r The oosterior lower Ieft ribs BIO and adjacent spine are masked

PNEUMONIA

The onset of fever and cough following a surgical procedure shouId raise the suspicion of pneumonia. Preoperative infections of the respiratory tract predispose to pneumonia in the postoperative period. AbnormaIities of the digestive tract and cIouded consciousness caused by trauma or medication are often associated with pneumonia from aspiration during and foIlowing surgery.

1

I

tatic Iobes become tIattened against the posterior mediastinum obhterating the shadow of the descending aorta on the Ieft but not affecting the cardiac outline. (Fig. I.) On the right the minor fissure moves downward with the hilus. Changes in the outline of atelectatic segments of the Iung are summarized in TabIe I. When smaI1 periphera1 bronchi or bronchioles become bIocked, a small area of ateIectasis occurs. It appears on the chest roentgenogram as horizonta1 streaks of increased density,

ROENTGEN

MANIFESTATIONS

As mentioned, ateIectasis and pneumonia may exist together, and one complicating the other. Lobar pneumonia is characterized roentgenoIogicaIIy by consolidation of Iarge bronchopulmonary segments, lobes or an entire Iung. 55

MitcheII emboIism to be 0.08 per cent in a world-wide survey. FowIer and BaIIinger [6] have reported ninety-seven patients who died from pulmonary emboIism. At postmortem exmaination 39 per cent of the emboIi arose from the heart, 26 per cent in the peIvis, 20 per cent from the veins of the thighs and Iegs, and no source couId be found in 13 per cent. HoIden et a1. [7] have shown in their experimenta1 studies with dogs that when more than 70 per cent of the puImonary arteria1 system is bIocked their dogs died. In patients with cardiorespiratory disease much smaIIer obstruction of the puImonary circuIation can cause death. Other mechanisms than obstruction may pIay a part. The Iack of reIiabIe diagnostic tests forces the physician to rely heaviIy on cIinica1 observations. The symptoms are those of a sudden onset of dyspnea, chest pain and bright red bIood in the sputum. ROENTGEN

MANIFESTATIONS

Hampton and CastIeman [8] found a predilection of puImonary infarction for the Iower Iobes, and particuIarIy on the Iobes of the right Iung. They cIassified puImonary infarction as compIete and incompIete, and they described the foIIowing underIying pathoIogic changes. In both types during the first twelve to twenty-four hours, the aIveoIi in the infarcted area fiI1 with bIood. The aIveoIar waIIs of the compIete infarct become necrotic, and then organization occurs during the next few weeks. This process may Iast severa months unti1 a fibrous scar forms. There is no necrosis of the aIveoIar waIIs in the incompIete infarct. The incompIete infarct heaIs by resoIution in two or more days. The shadow produced by the increased density of the compIete infarct aIways touches one or more pIeura1 surfaces. The media1 or cardiac margin is rounded and this appearance has been described by Hampton as “humpshaped” [S]. The shape of the infarct is determined by its Iocation and it may be trianguIar, round, rectanguIar or irreguIar. (Fig. 3.) The heaIed scar has been described by [9] as FIeischner, Hampton and CastIeman a dense Iine that may run in any direction to a pIeura1 surface. In about half of compIete infarcts some pIeura1 ffuid occurs. Westermark [IO] described a sharp cutoff of vascuIar markings with an area of increased radiabiIity in patients with puI-

FIG. 2. Pneumonia of Iower right Iobe. The demonstration of segmenta density of the Iower right Iung fieId was accompanied by fever and cough. Preservation of the outIine of the right heart border IocaIizes the pneumonia to the Iower right Iobe.

Bronchopneumonia has a patchy distribution. The invoIvement tends to be segmental and their segmenta nature is recognizabIe when several invoIved Iobules coalesce. Pneumonia foIIowing aspiration commonIy occurs biIateraIIy and in the dependent portions of the Iung. The right lung is affected more often than the Ieft. The invoIvement is aIways segmentaL (Fig. 2.) PuImonary edema and congestion are not segmenta in their distribution and may be distinguished from pneumonia on this basis. Changes in the outIine of consoIidated segments of the Iung are summarized in TabIe I. THROMBO-EMBOLISM

PuImonary emboIism continues to be a feared compIication of the postoperative period. Hermann et a1. [4] reported that 5.7 per cent of the postoperative mortaIity in their series was caused by puImonary emboIism. They aIso found that the greatest contributing factors to puImonary emboIism was heart disease, seniIity, dehydration, cachexia, tissue necrosis and Iimited activity. DeBakey [f] found the incidence of fata postoperative puImonary 56

RadioIogy

of PuImonary

Change

during

Postoperative

Period

,-a

”

FIG. 4. Pulmonary embolism without infarction. l~ollowing amputation of a Ieg because of arteriosclerotic gangrene, this eIderIy white man had a cIassic episode of pulmonary embobsm. Note the enlarged heart, deformed right hilus and decreased circulation to tht right lung. Infarction did not occur. The puticnt recovered with anticoagulant therapy.

FIG. 3. MultipIe pulmonary infarcts of right lung. An eIderIy patient egpericnced chest pain, dyspnea and bloody sputum foIIowing urologic surgery. Chest roentgcnograms demonstrated densities in both upper right and lower Iung heIds with the Iong axis of the densities against the pleura and with rounded media1 borders. The upper tlcnsity Iater cavitated then all arcas healed with irregular scars.

surgery, anesthesia, fusions, are prone postoperatively.

monary embohsm without infarction. In puImonary embolism a hiIus may be deformed or reduced in size or enIarged without pulmonary infarction. (Fig. 4.) Smith [II] has described transitory transverse and obIique I inear shadows with incompIete pulmonary infarction. CIinicaI evidence of puImonary embolism may never be accompanied by abnorma roentgen observations. Fat embolism may foIIow trauma, particularly fractures of the femur. The fat particIes first obstruct the puImonary vascular bed. The fat then undergoes hydrolysis to fatty acids with disruption of the waIIs of the puImonary capillaries. RoentgenographicaIIy small numerous patches of increased density occur throughout both Iungs. (Fig. 5.) PULMONARY

ROENTGEN

intravenous Auids or transto have puImonarv edema MANIFESTATIONS

In congestive Ieft ventricuIar heart failure the puImonary vessels are enlarged and fuzzy in outline. In pulmonary edema the lungs become opaque and the vessels traversing the consolidated areas cannot be distinguished from the fluid HIed alveoli. The air filled bronchi may appear as radiolucent streaks in the area of consolidation. Gould and Torrance [IZ] found the “butterfly” configuration to be the predominate x-ray appearance in pulmonary edema. Of IOO patients with puImonary edema, ninety had the “butterfly” type. Seven had a diffuse type of pulmonary edema, and three had focal edema. They expIained the formation of the wing-like configuration in most patients with pulmonary edema by the bellows-like effect of the cortical portions of the Iung forcing the edema ffuid to the more stationary centra1 portion of the lungs.

EDEMA

Acute puImonary edema may begin with terrifying suddenness or may deveIop gradually with sIight clinica manifestations. Patients with heart disease in whom Ieft ventricular heart faiIure deveIops because of 57

MitcheII

FIG. 5. Fat embokm of the Iungs. Four days folIowing a femora1 fracture, this young man had dyspnea, disorientation and petechia1 hemorrhages. The chest roentgenogram demonstrated muItipIe biIatera1 noduIar densities.

FIG. 6. BiIateraI puImonary edema. Note the “butterfly” configuration of the area of puImonary densities. The edema quickIy cleared with digitalis therapy.

Pulmonary edema is never segmental in appearance, and may be differentiated from ateIectasis and pneumonia on this basis in most patients. (Fig. 6.) PLEURAL

EFFUSION

Free fluid within the pIeura1 space may be blood, exudate, transudate, Iymph or a mixture of these. Passive congestion from heart faiIure is the most common cause of a transudate. BIood in the pIeura1 space usuahy accompanies trauma or neopIasm. An exudate is associated with inflammation either within the chest or abdomen. Aaron and Leahy [13] have stressed the importance of considering an abdomina1 disorder in cases of pIeurisy with effusion. FolIowing abdominal surgery varying amounts of fluid accumulate in the pleural spaces. ROENTGEN

MANIFESTATIONS

When the patient is erect, free fIuid accumulates in the costophrenic sinuses, as the fluid increases in amount it extends up the IateraI chest waI1 with a curved upper border. Hessen [r4] has described another pattern of free fIuid in which the lung is separated from the diaphragm by the fluid and the upper border is convex. The resuIting appearance is that resembIing an elevated diaphragm. (Fig. 7.) If the patient is too III to sit erect for the chest

FIG. 7. SubpuImonary effusion, Ieft. After a partia1 gastrectomy an erect chest roentgenogram demonstrated an area of increased density at the base of the Ieft Iung. The Ieft side of the heart is more dense than the right. The Ieft cardiophrenic and costophrenic angIes are obscured. The Ieft hemidiaphragm appears to be eIevated but at Auoroscopy it was found to be in norma position.

58

RadioIogy

of PuImonary

Change

POSITIONS

Postoperative

Period

the loss of detaiI because of the exposure time and to the unavoidabIe voluntary and involuntary movement resuIt in a film of poorer quality than those exposed under better circumstances. However, despite these technica disadvantages the portable chest roentgenogram is usually heIpfu1. If the examination is limited to a single anteroposterior roentgenogram of the chest, it is still possible to determine the position and nature of an abnormal density. The Iocalization of pulmonary; disease of segmental and Iobar extent, utilizmg onIy the posteroanterior view of the chest has been previously described [16-r 91. Robbins and Hale [20], Walker [21] and FeIson [r6] have described blurring and Ioss of outline of the heart, mediastinum, diaphragm and chest waI1 when adjacent lung becomes cohapsed or consolidated. Felson [16] has called this phenomenon the “siIhouette sign.” Collapsed or consohdated lung not adjacent to the normally denser structures such as the heart will not affect the definition of its border but will affect the density of its shadow. The appearance of the involved segments and lobes on an anteroposterior roentgenogram taken in a supine position in reIation to the surrounding structures does not differ a great deal from that described in the erect posteroanterior view. In the anteroposterior roentgenogram the posterior thoracic wall and posterior lung fields may be more clearIy outIined than in the more conventional posteroanterior view. Hobson [22] has pointed out that atelectasis or consolidation of the posterior basiIar segments which are commonly involved in the postoperative period will cause obhteration of the posterior ribs and outline of the spine. The changes of the outline of nonaerated structures of the chest by segmental atelectasis or consolidation on the anteroposterior chest roentgenogram is summarized in Table I.

roentgenogram a recumbent or decubitus projection shouId be taken. In the recumbent position the ffuid settles along the posterior pleural space and produces a homogeneous density over the involved side of the chest. In the decubitus fiIms, with the invoIved side down and the x-ray beam horizonta1, the free fluid will graviate to the dependent IateraI pleural space. The decubitus fiIms are recommended over the erect film because a smaller cohection of ffuid can be demonstrated and the iII postoperative patient can toIerate them better. When air is present within the pIeura1 space, fluid layering occurs. Thickened pIeura may resemble free fluid, but it does not change with changes in position of the patient. Fluid may become IocuIated within the pleura1 spaces. When this occurs its Iocahzation is not segmenta1, and the density usuaIIy has a rounded sharp border. Pleural fluid may accompany puImonary infarction, pneumonia and pulmonary edema. ROENTGENOGRAPHIC

during

AND

PROCEDURES

The roentgenographic Iocahzation of chest abnormalities can be accurately performed with the use of IateraI, oblique, stereoscopic and Iordotic views. FIuoroscopy and Iaminography are additiona procedures for better localization and detection of Iesions of the lungs. In the postoperative patient such additional procedures are often impractica1 and the surgeon may limit his request for postoperative x-ray examinations to fiIms with portabIe equipment. Robbins [IT] has recommended that the postoperative patient be taken to the hospita1 x-ray department, if thrombo-embohsm and puImonary infarction is suspected, so that, films of good quality and in different projections may be obtained for better visualization of smaII puImonary infarcts. If the patient is too III to be taken to the x-ray department, or too iII to sit up on the edge of the bed and hold a cassette in front of him, the cassette is sIid under the back in a reclining position and the exposure is made in the anteroposterior projection. The inability of the patient to roll the scapuIas IateraIly out of the Iung fields while Iying on his back, the distortion and emargement of the image because of the shorter target fiIm distance, and

SUMMARY I. Complications occurring during the postoperative period that are best demonstrated by roentgenographic means are those seen on examination of the chest roentgenogram. They are atelectasis, pneumonia, thrombo-embolism, pulmonary edema, and pIeural effusion. 2. Determination of the segmental nature of the shadow of the chest roentgenogram is of major importance in the differential diagnosis

59

MitcheII B. Linear shadows in the lung. Am. J. Roentgenol., 46: 610, 1941. IO. WESTERMARK, N. On the roentgen diagnosis of Iung embolism. Acta radiol., Ig: 357, 1938. I I. SMITH, M. J. Roentgenographic aspects of compIete and incompIete puImonary infarction. Dis. Chest,

during the postoperative period. Areas of ateIectasis and pneumonia are segmentaL Infarcts may be segmenta or of unusua1 shapes. PuImonary edema and pIeura1 effusion are never segmental. 3. The physiopathoIogic basis for the formation of the different shadows on the chest roentgenogram are reviewed. 4. Choice of projections are presented and discussed.

12. 13.

14.

REFERENCES I. KLUG, T. J. and MCPHERSON, R. C. Postoperative compIications in the eIderIy surgica1 patient. Am. J. Surg., 97: 713, rgfg. 2. BRATTSTROM, S. Postoperative puImonary ventiIations with reference to postoperative puImonary compIications. Acta c&r. scandinav., (supp. rg5) Vol. 108, 1954. 3. FLEISCHNER, F. PIattenformige AteIekIasen in den UnterIaypen der Lunge. Fortscbr. a. d. Geb. d. Riintgenstrablen, 54: 315, 1936. 4. HERMAN, R. E., DAVIS, J. H. and HOLDEN, W. D. PuImonary embohsm. Am. J. Surg., 102: rg. 1961. DEBAKEY, M. D. A critica evahration of the problem of thromboembobsm. Surg. Gynec. Ed Obst., 98: I, 1954. 6. FOWLER, E. F. and BOLLINGER, J. A. PuImonary emboIism. Surgery, 36: 650, 1954. 7. HOLDEN, W. D., SHAW, B. W., CAMERON, D. B., SHEA, P. J. and DAVIS, J. H. Experimenta puImonary emboIism. h-g. Gynec. Ed Obst., 88:

15. 16.

17.

18.

19.

20.

23: 532~ 1953. D. M. and TORRANCE, D. J. PuImonary edema. Am. J. Roentgenol., 73: 366, 1955. AARON, A. H. and LEAHY, L. J. The significance of pIeura1 effusions as indicating the presence of abdomina1 disease. Dis. Chest, ;5: 30,~ 1949. HESSEN, I. Roentgen examination of DIeuraI fluid. A study of the YocaIization of free &fusions, the potentiaIities of diagnosing minima1 quantities of Auid and its existence under physioIogica1 conditions. Acta radial., (supp. 86), I 95 I. ROBBINS, L. L. The technique of the roentgenoIogic demonstration of pulmonary infarcts. Am. J. Roentgenol., 56: 736, 1946. FELSON, B. and FELSON, H. LocaIization of introthoracic lesions by means of the posterioranterior roentgenogram. The siIhouette sign. Radiology, 55: 363, 1950. KANE, I. J. SegmentaI IocaIization of puImonary disease on the posterior-anterior roentgenogram. Radiology, 59: zzg, 1952. RIGLER, L. G. The density of the centra1 shadow in the diagnosis of intrathoracic Iesions. Radiology, 32: 316, 1939. PARKER, G. W., STURTEVANT, H. N., REED, J. E. and FLAHERTY, R. A. SegmentaI Iocalization of puImonary disease. Am. J. Roentgenol., 83: 217, 1960. ROBBINS, L. L. and HALE, C. H. The roentgen appearance of Iobar and segmenta coIlapse of the Iung. Radiology, 44: 107, 1945; 45: 120, 260, GOULD,

347, 1945. 21. WALKER, J. H. Significance and demonstration of Iobar and segmental coIIapse. No&west Med.,

23, ‘949. 8. HAMPTON, A. 0. and CASTLEMAN, B. CorreIation of post mortem chest teIeorentgenograms with autopsy findings. With specia1 reference to puImonary emboIism and infarction. Am. J. Roentgenol., 43: 305, 1940. 9. FLEISCHNER, F., HAMPTON, A. 0. and CASTLEMAN,

22.

48: 241, ‘949. HOBSON, C. J. The Iocalization of pulmonary collapse-consoIidation. J. Fat. Radiologist, 8: 41, ‘956.

60