Br. J. Surg. Vol. 63 (1976)352-366
Subphrenic abscess: a study of 241 patients at the Royal Prince Edward Hospital, 1950-73 P. H A L L I D A Y A N D J . H. H A L L I D A Y * SUMMARY
A series of 241 patients with subphrenic abscess was anaiysed to seek reasons for the continuing mortality. Aspects of pathology, clinical presentation, special investigations and management were affectedby therapy with broad spectrum antibiotics to make diagnosis more dificult, particularly in relation to left subphrenic abscesses. When transperitoneal exploration and drainage were employed, high morbidity and mortality resulted. Satisfactory results followed extraserous drainage. The introduction of parenteral hyperalimentation promised control of fistulas associated with abscesses, a situation hitherto associated with a poor prognosis. THEclinical presentation and management of patients with subphrenic abscess continue to provide problems of considerable magnitude, with added difficulties in recent years owing to the masking effects of antibiotics (Halliday, 1975). A study of the clinical presentation of 104 patients treated at the Royal Prince Alfred Hospital, Sydney, between 1950 and 1961 (Halliday and Loewenthal, 1964) detailed aspects of these problems and discussed their significance. The aim of the present study is to record the patterns of presentation and treatment during 1962-73, and by a comparison of the two periods, to seek reasons for the continuing morbidity and mortality. Patients During the years 1962-73, 137 patients with subphrenic abscess were recorded at the Royal Prince Alfred Hospital. The age groups and the distribution of mortality were similar to those in the 104 patients treated during 1950-61 (Figs. 1, 2).
-
'950-6'>-
I
0 1
2
3
4
5
6
7
Fig. 1. Age distribution of patients through 1950-61 and 1962-73.6C
n
40
v)
L
Aetiology Surgical conditions complicated by the development of subphrenic abscess did not change significantly during the second decade (Table I ) . Surgery of the stomach, duodenum and biliary tract accounted for 56 per cent of the cases in the whole series. Among minor changes during the second decade, 13 patients developed subphrenic abscess as a complication of multiple abdominal and thoracic injuries sustained in a motor vehicle accident, as compared with 6 during 1950-61. Pathology The nomenclature of the subphrenic spaces (Fig. 3) used here follows the categories of Ariel and Kazarian (1971).
352
8
Decades
2 L
x 20
0 Age:
50 1962-73
Fig. 2. Mortality rates in the major age groups.
* Department of
Surgery, University of Sydney.
9
Subphrenic abscess Table I: AETIOLOGY OF SUBPHRENIC ABSCESS Primary condition or operation Surgery of stomach and Perforated peptic ulcer duodenum Peptic ulcer with haemorrhage Elective surgery for peptic ulcer Lower third of oesophagus
Surgery of diseases of the biliary tracts
Surgery of diseases of the liver other than trauma
Carcinoma of stomach and lower third of oesophagus Rupture of oesophagus Oesophageal varices with haemorrhage Oesophageal stricture
Other than trauma
Surgery of diseases of the pancreas
Miscellaneous causes
Primarv abscess
1
7 7 6
2
1 2
4 4
I1
3
3
6
-
1
1
1 1 1
1 2
3
3
6
8 3 1
8 6 2 1
1
1
4 3 2
4 2 8
10
11
3
14
3 2
4 7 1 4 3
-
3
8 5
I 9 1
4 6
-
1
3
4
1 1
1
1
6
I
104
137
24 1
1 1
-
Total
1
2 5
-
No cause discovered
1
-
2 3
3
Renal biopsy Pyonephrosis Cushing’s syndrome Trousseau’s syndrome/carcinoma of lung
15
2
-
Closed injury with : Ruptured spleen Lacerated liver Ruptured pancreas Ruptured hollow viscus Penetrating injury with involvement of hollow viscus*
7
29
11 11
-
Carcinoma Diverticulitis Various causes, e.g. ulcerative colitis, perforation Appendicitis
7 7
Total 47 13 14
1962-73
5
-
Hydatid disease Amoebic abscess Polycystic disease of liver and kidney Liver biopsy
Pancreatitis Carcinoma Zollinger-Ellison syndrome Islet cell hyperplasia
Surgery of abdominal trauma
8
-
Acute cholecystitis Elective cholecystectomy Elective cholecystectomywith exploration of common bile duct External biliary fistula Carcinoma of bile ducts
Surgery of splenic pathology
Surgery of diseases of large intestine and appendix
1950-61 18 6 7
1
* In 1950-61.
one case was due to gunshot wounds. In 1962-73 there were 3 cases due to gunshot wounds and 3 cases with multiple injuiies.
The left ‘perihepatic’ subphrenic space is the whole intraperitoneal space under the left dome of the diaphragm; the ‘left anterior space’ is only part of this space. The ‘left subhepatic space’ is the lesser sac; after a gastrectomy and various other procedures the lesser sac becomes potentially continuous with the left subphrenic space in the event of a large left subphrenic abscess developing. Because of the dorsal location of the bare area of the liver, the right subphrenic area is divided into right superior subphrenic and right subhepatic spaces. In the latter space an abscess may collect in the first instance either anteriorly or posteriorly. An anteriorly placed right subhepatic abscess may extend into the right superior subphrenic space or extend posteriorly, 35
but initially it is not in direct contact with the diaphragm. A posteriorly placed subhepatic abscess is from the outset more closely related to the diaphragm in the region of the 9th-12th ribs. Distribution of abscesses during 1950161 and 1962-73 (Table 11) During 1950-61 the pattern of distribution was similar to that of previous series (Harley, 1955; Halliday and Loewenthal, 1964), with abscesses on the right side predominating (67 right : 35 left). During 1962-73, however, left subphrenic abscesses predominated (73 left : 59 right). Table ZZalso gives the overall mortality rates for the various categories of abscess during the two periods.
353
P. Halliday and J. H. Halliday Table 11: SITE OF SUBPHRENIC ABSCESSES
1 2 1 +2 3 4 4+5 6 1+2+4
Site* Right superior subphrenic Right subhepatic Combined abscess, right superior and subhepatic Right extraperitoneal Left ‘perihepatic’ subphrenic Left perihepatic and left subhepatic (lesser sac) Left extraperitoneal and left perihepatic Bilateral abscesses, right and left subphrenic
1950-61 No.of No. of cases deaths 35 10 16 5 13 8 3 0 33 13 0 0 0 0 2 2
Total 1950-73 No. of No. of cases deaths 37 15 23 6 32 16 4 0 98 35 5 4 2 0 17 12
1962-73 No. of No.of cases deaths 22 5 7 1 19 8 1 0 65 22 5 4 2 0 15 10
* Abscesses numbered as in Fig. 3.
b
(1
Fig. 3. a, Subphrenic abscesses shown in relation to the dorsal aspect of the liver. Intraperitoneal abscesses: I , right superior subphrenic; 2, right subhepatic. 3, right extraperitoneal; 4, left ‘perihepatic’ subphrenic; 5 , left subhepatic (lesser sac); 6, left extraperitoneal (perinephric). b, The extent of the area involved by a right superior subphrenic abscess, and the dorsal location of the bare area.
Mortality%
601
i Right
Total patients
A. 1950-61 B, 1962-73
Left
Bilateral
Fig. 4. A comparison of the morbidity and mortality rates for right, left and bilateral subphrenic abscesses. The percentage distributions in the histograms of right and left abscesses refer to fractions of the total of such cases for the periods 1950-61 and 1962-73.
354
During the second period the mortality rate of right abscesses fell from 34 to 28.5 per cent, while that of left abscesses remained constant at 37 per cent. The improved results in treatment of right-sided abscesses were, however, offset by the increase in incidence of left-sided abscesses in which the prognosis was less satisfactory (Fig. 4). Bilateral abscesses have always been associated with a bad prognosis. Only 2 cases were recorded during the first period and both died. In the second period 15 cases were recorded, of whom 10 died.
Morbid anatomy Autopsies were performed on 32 patients between 1950-1961, and on 42 between 1962 and 1973. The reports on these autopsies were more detailed than operation reports, but taken in conjunction allow a more precise description to be established of abscesses in different regions. Peritonitis in some form was always present at the outset. In some patients the source of infection was an initial incident and not repeated; in the remainder
Subphrenic abscess the source was persistent, such as a fistula from a perforating viscus or a leaking gastro-intestinal anastomosis. The particular fashion in which an abscess developed was characteristic in each of the subphrenic spaces. The outcome, however, was closely related to the nature of the source of the infection in both the periods studied (Table ZZI). Continued contamination led to overall mortality rates of 80 per cent (1950-61) and 71 per cent (1962-73).
Table 111: MORTALITY RATES IN RELATION TO PATHOGENESIS 1950-61 1962-73 Source of No. of No. of No. of No. of infection acted as cases deaths cases deaths % Acute or single 76 20 26.3 77 9 11.7 incident Continued 28 22 19.6 60 46 76.6 contamination
Right subphrenic abscesses Superior abscesses (total recorded 1950-73, 86): When discovered at autopsy in patients who had not been submitted to surgery, these were usually described as ‘covering the whole superior aspect of the right lobe of the liver’, and loculi were seldom if ever mentioned (Fig. 36). This was consistent with operation reports of the drainage of a litre or more of pus from this area. Loculation was, however, the reason advanced for protracted patterns of recurrent right subphrenic abscess in 4 patients between 1950 and 1961 and in 8 patients between 1962 and 1973. At thoracotomy the right dome of the diaphragm was usually obscured by adherent lung. Removal of this in 2 patients disclosed a friable, boggy diaphragm, green in colour from bile staining. Such a forbidding appearance did not preclude successful incision and extraserous drainage in these patients, with debridement of underlying necrotic liver in one of them (Halliday et al., 1974). It is relevant to this observation that during 1960-1 drainage was frequently delayed until the necessity was certain-a longestablished practice-but under these circumstances, extraserous drainage was followed by pleural contamination and empyema in 4 patients. Intrathoracic spread of right subphrenic abscess followed the sequence of adherence of the right lobe of the lung to the diaphragm, penetration of the abscess process into the lower lobe and rupture into a bronchus. If the abscess was originally a hydatid, the resulting problem was often a major one; in one patient the hepatic cyst had extended to the apex of the lower lobe of the right lung. This process was slow; a common interval between an operation and the eventual development of a bronchial fistula was about 12 months. Variations in this time interval were seen in 4 patients between 1950 and 1961, and in 3 patients between 1962 and 1973. Right subhepatic abscesses (total recorded 1950-73, 55) : When situated anteriorly, these often communicated with a right superior subphrenic space, but this combination presented few additional problems. When located more posteriorly, lack of clinical features in some patients led to progressive extension of the pathology. In one patient a subhepatic abscess had been drained, but at autopsy there was a loculated small right superior abscess, a psoas abscess and a large subcutaneous abscess in the loin, all of which were clearly extensions of the initial abscess. In another patient, primarily suffering from infected hydatid cysts, a right superior abscess was drained, but thoracic involvement became evident. At thoracotomy
multiple abscesses were found in the right lower lobe of the lung. When lobectomy was performed, dissection of the adherent lobe from the diaphragm disclosed a fistula in the posterior costophrenic angle originating below the diaphragm, where there were two abscesses, one of which had been drained, but the other not (Halliday et al., 1974, Case 13). Right extraperitoneal abscesses (total recorded 195073, 4): All were hydatid cysts and all presented at a stage when extensive intrathoracic involvement had developed; in one case the cyst had reached as far as the apex of the lower lobe of the right lung. Left subphrenic abscesses Left ‘perihepatic’ subphrenic abscesses (total recorded 1950-73, 122): As previously noted, these abscesses were unusually frequent between 1962 and 1973, 87 being recorded. The range of pathology found was considerable. The only feature common to all abscesses in this category was that the part of the wall of the abscess in contact with the diaphragm consisted only of pyogenic membrane and diaphragm. The remainder of the ‘walls’ was a complex of friable and inflamed structures-the stomach and omentum, the small and large bowel, the spleen (if present)-all enmeshed in vascular inflammatory adhesions. If an abscess developed as an infection of a haemoserous collection after a splenectomy or a left colectomy, the abscess, at least initially, was relatively circumscribed. When a left subphrenic abscess developed in relation to a perforated peptic ulcer or a leaking anastomosis, the infected material produced initially a widespread peritonitis; the resultant subphrenic abscess reflected both the severity of the original peritonitis and the patient’s resistance. Many case and autopsy reports gave graphic descriptions of the resulting pathology. A characteristic feature was the presence of multiple smaller intraperitoneal collections in a diffuse chain of intensely vascular adhesions, extending at times as far as the right iliac fossa, with or without a pelvic abscess. If the main abscess had been drained but the patient died, at autopsy these smaller abscesses and vascular adhesions usually were replaced by dense fibrotic adhesions. The pathology of a left subphrenic abscess due to pancreatic disease was the most formidable, especially in the presence of acute haemorrhagic pancreatitis. This combination in 3 patients proved insuperable, with particularly gross pathology being evident at autopsy. The characteristic lethal end result in these 355
P. Halliday and J. H. Halliday Table IV: DELAY IN DIAGNOSIS Interval between primary incident and presentation Presentation Series < 1 mth 1-6 mth > 6 mth* Total 1950-61 16 5 3 With or as primary 1962-73 13 3 6 condition 1950-73 29 8 9 46 Asasubse195&61 67 10 2 quent com- 1962-73 96 14 6 plication 1950-73 163 24 8 195
* Chronic cases. Table V: CLINICAL COURSE BEFORE DIAGNOSIS 195&61 1962-73 Clinical course Insidious onset With toxaemia Without toxaemia Sudden onset or change of symptoms Sudden onset of toxaemia Spontaneous external rupture Spontaneous internal rupture Diagnosis established On admission At laparotomy Because of persistent toxaemia after primary treatment Because of abdominal or thoracic complications At autopsy
No.of cases
No.of No.of No.of deaths cases deaths
39 17
8 5
60 39
13 16
5
1
3 0
7 7
2 1
3
3
2
1
5 10 6
1 6 2
15 27 10
4 10 4
15
11
12 22
6 11
25
25
patients was uncontrollable secondary haemorrhage from the walls of the abscess. Even when the basic pathology was chronic pancreatitis or tumours of the organ, complicated by a subphrenic abscess, the tendency for aggressive extension of the pathology resulted in only 2 of 9 patients surviving. Two major complications of left subphrenic abscess deserve comment. Gastro-intestinal fistulas frequently caused the development of a subphrenic abscess and were a continuing problem, but in addition a number developed as a secondary complication after transperitoneal exploration. Haematemesis and melaena were related to direct involvement of the stomach in the wall of a left subphrenic abscess. This formed a major feature in the course of 12 patients during 1962-73, of whom 9 died. Spread of a left subphrenic abscess through the diaphragm leading to empyema thoracis was always related to some causal factor. These included needle aspiration and trauma to the diaphragm either as part of injuries in a motor vehicle accident or during operative procedures such as transpleural drainage or difficult extraserous drainage. The result was the development of a fistula from the abscess into the pleural cavity. When the diaphragmatic pleura was not adherent to the parietal pleura, transpleural 356
drainage of an empyema was ineffective, as all the patients so treated died. This experience is detailed because of the contrast between these results and those following combined transpleural exploration and extraserous drainage (Halliday et al., 1974). Left subhepatic or lesser sac abscesses (total recorded 1950-73, 5): Though the pathology of these abscesses is limited by the space they involve, lesser sac abscesses were fortunately rare, because of the major difficulties they present in diagnosis and management. None was recorded in the period 1950-61, and only 5 during 1962-73; in each case a left ‘perihepatic’ subphrenic abscess was also present. Three were associated with acute pancreatitis. One, due to a perforated gastric ulcer, was only found at autopsy after an extremely difficult and unsuccessful laparotomy at which a left ‘perihepatic’ abscess had been found and drained. In the remaining patient the abscess was located by a preliminary transpleural exploration and successfully drained by an appropriate extraserous route (Halliday et al., 1974). Left extraperitoneal abscesses: When a left perinephric abscess breaks through the renal fascia into the left subphrenic space, the pathology is usually confined to a restricted area. In one patient during the period 1962-73, however, the perinephric abscess and subphrenic abscess were initiated by a staghorn calculus; an empyema thoracis also developed. This pathology presented exceptional problems in surgical treatment. Chronic subphrenic abscesses (Table ZV) A subphrenic abscess was regarded as chronic when there was a latent period of 6 months or longer after the initial incident, such as an attack of acute cholecystitis, or when there was no obvious preceding related illness. The morbid anatomy in the majority of patients was characterized by the development of an epigastric mass with the slow rate of progress characteristic of a chronic process, relatively ‘simple’ walls and sterile contents. Five cases were collected during 1950-61, and 12 cases during 1962-73. The latent period could be established in 12 patients and in most ranged between 6 months and 3 years, though there was one clear instance of an 8-year interval and possibly another of an 11-year interval. Seven patients died; 2 directly due to metastatic abscesses, the others due to complications of the abscess itself becoming active without warning.
Clinical features and investigations In the series collected in the period 1950-61, changes were noted in the characteristic modes of presentation and standard methods of investigation (Halliday and Loewenthal, 1964). In the second period, patterns were on the whole similar, though some differences did appear (Tables ZV, V ) . Abdominal or hypochondria1 pain, hitherto regarded as a classic symptom, was prominent at the time of diagnosis in only 20 of the 137 patients of 1962-73. Absence of pain was thus of less significance.
Subphrenic abscess 60
40
60
n
1962-73
1
1950-61 1962-73
,p
f?1950-61
40
D ._ L
L
x
x
b
L
x 20
20
0 Severe
Moderate
Minor
Absent
0.
b
a Fig. 5. Changes in incidence of grades of
(a) pyrexia,
and (b) leucocytosis.
Similarly, pyrexia, leucocytosis and radiological abnormalities all retained their importance when present, but their absence in no way excluded the presence of an abscess. The changes in the incidence of grades of pyrexia and leucocytosis are shown in Fig. 5; the levels evaluated were those related to critical periods of diagnosis and management. These changes were significant (P< 0.05) in both series, using 2 x 4 and 2 x 3 contingency tables to calculate xa. These variations in the classic presentation of a subphrenic abscess made diagnosis more often difficult. Though, for instance, a diagnosis was reached in the majority of patients within 1 month (Table ZV, 80 per cent), the frequency of an insidious onset meant that diagnosis often appeared to be arrived at slowly. The clinical features in such patients were difficult to categorize, e.g. ‘failure to improve’, but may be summed up as prompting clinical suspicion which, in turn, led to essential radiological or isotope scanning investigations being made. Complications such as the development of a fistula or an empyema thoracis led to the diagnosis being established by exploratory laparotomy or thoracotomy in a group notable for a high overall mortality (Table V, 59 per cent). Throughout this group of patients delay was directly related to morbidity or mortality in only a small number of patients. The clinical presentation of patients with a chronic abscess was most frequently centred on an epigastric mass of uncertain origin or nature (8 of 17 patients). These abscesses were all successfully drained without complications, as were 2 others, one with an associated lung abscess and bronchial fistula, and the other with a chronic abscess discovered when periostitis at the site of a previous thoracotomy was drained (Halliday et al., 1974). As noted above, 7 patients in this group died as a result of insidious development of complications
or sudden development of activity in a chronic abscess. Radiological studies Radiological studies of at least one type were made in 135 patients during 1962-71. The 2 remaining patients were not investigated radiologically because of the increasing gravity of their condition. In view of the critical role played by radiological studies in the diagnosis of this condition, this represents an improvement on the period 1950-61 when radiological studies were less frequently employed (Halliday and Loewenthal, 1964). Three modes of investigation were employed: plain films of the chest or abdomen or both, screening of the diaphragm and studies using opaque contrast. As in the previous series, a report was accepted as diagnostic if it contained a direct statement that a subphrenic abscess was present. A descriptive report detailing the presence of a pleural effusion, basal collapse or consolidation, without inferences concerning the significance of the findings, was regarded as ‘nondiagnostic’. Normal findings or a direct negative were classed as ‘negative’. The incidence of abnormal findings during 1962-73 in examination by both plain films and screening showed similar changes to the alterations in clinical indices such as pain, pyrexia and leucocytosis. In particular, screening of the diaphragm was negative in 16 per cent, non-diagnostic in 66 per cent and positive in only 29 per cent of the studies undertaken. Results ofplain films of thechest and abdomen showed a similar shift away from data prompting a definite diagnosis (Fig. 6). Studies during 1962-73 using opaque contrast procedures fell into two groups. Sinograms (19 patients) were usually performed postoperatively, when their diagnostic value was limited to the identification of complications such as an intestinal fistula. The other 357
P. Halliday and J. H. Halliday I,
Positive
2. Not diagnostic
3, Negative
positive diagnosis on scanning was confirmed by drainage or at autopsy. In 4 patients a false negative report was followed by subsequent demonstration of the abscess. In 1 patient a false positive report led to a negative exploration, without further difficulty resulting. In the remaining 6 patients the results of scanning were inconclusive in that the diagnosis, management and course of the illness were uninfluenced. Bacteriology
3
I..
I..
..
;2-73 Fig. 6 . Changes in the value of radiological examination. Table VI: BACTERIOLOGY Oreanisrn Cultures from abscess Intestinal flora Escherichia coli Non-haemolytic streptococci Streptococcus faecalis Bacillus proteus Klebsiella Pseudomonas Bacteroides Clostridium welchii Candida Other flora Staphylococcus aureuslalbus Streptococcus pyogenes (A) Str.pyogenes, not group (A) Pneurnococcus Streptococcus viridans Diphtheroids No growth on culture Blood cultures E . coli Klebsiella B. proteus Pseudomonas Bacteroides Candida S. marcescens Staph. aureus N o growth on culture
1950-61
1962-73
Total
70 20 14 23 7 2 3
The results of bacterial cultures during the two periods show that the spectrum of bacteria did not change significantly (Table VZ). Intestinal flora made up 64 per cent of the cultures isolated during 1950-61, and 67 per cent during 1962-73, and staphylococci were found in 17 and 20 per cent of the cultures respectively. Blood cultures were attempted more often during 1962-73 because of the increased frequency of Gramnegative septicaemia during these years in general (Table VZ). The patient from whom Serratia marcescens was isolated was a diabetic with an appendiceal abscess and evidence of Gram-negative septicaemia. One of the patients with a positive culture of Staphylococcirs aureus died of staphylococcal pyaemia and acute ulcerative endocarditis.
Management and results In order to add detail to the conventional data of mortality rates, assessment of the results of treatment 4 was enlarged to include some objective measures of morbidity rates. Assessment of morbidity was based on the mode of 2 5 the patient’s course during convalescence or deteriora1 1 tion. An uninterrupted course leading to discharge 41 12 29 from hospital within 1 month was classed as ‘rapid’; 2 1 1 if longer than 1 month but still uncomplicated, as 3 2 ‘slow’. Complications such as fistulas almost inevit1 1 ably prolonged convalescence. Patients who developed 3 1 4 1 1 septicaemia or who needed intensive care for other 10 12 22 complications were usually described as having a ‘stormy convalescence’. The patterns of deterioration 1 to death, such as the state of gross wound infections 2 3 with fistulas (cf. Sherman et al., 1969), remained unfortunately characteristic throughout both the periods 1950-61 and 1962-73. To ensure consistency in classification, these aspects 1 3 of the management of the patients treated during 2 61 - 1950-61 were reviewed in the light of the experience of 1962-63. ‘Drainage through adhesions’ proved on group was made up of barium or Gastrografin meals review to have been transperitoneal drainage in most and enemas. If these were performed with the diagnosis cases. The few bilateral abscesses in the first period, of subphrenic abscess as a possibility, the studies not previously identified, have now been separated out. always provided information additional to that obTable VZZ summarizes the results of the various tained by screening the diaphragm alone. If the diag- methods of treatment as regards morbidity as well as nosis was not regarded as a possibility, few reports mortality in the 241 patients treated between 1950 were diagnostic. and 1973, and within each group the patients are separated according to age. There were insufficient Radio-isotope scanning numbers, however, to separate the results of treatTechniques using various isotopes became available ment of right- and left-sided abscesses. This obscures after 1962; their use was sporadic in the first 5 years, the effects on the morbidity and mortality, on the becoming progressively more frequent thereafter. one hand, of the considerable increase of left-sided Altogether 25 patients were studied thus. In 14, a subphrenic abscesses during 1962-73, and on the 358
32 8
38 12 14 19 7 2 3 3
Subphrenic abscess Table VII: MORBIDITY AND MORTALITY 1N.RELATION TO MANAGEMENT AND AGE GROUP Recoverv Method of management Extraserous drainage Transperitoneal drainage Transpleural drainage
Age t50
< 1 mth
> 1 mth
With complications
Stormy convalescence 3 (1.)
>50
8
5 2
8 3
(50 >50
4 9
6 3
8 6
50
21 (1*)
5 (It)
1
9 (2*, It) 2
3 3
-
-
Non-operative treatment
< 50 >50
6 2
5 7
3 1
1 1
50
7 (I$) 15 (3f)
8
> 50
3
2
1
No. of cases 43 16
5 2
1
Combined transpleural exploration and extraserous drainage
Subphrenic abscess: a study of 241 patients at the Royal Prince Edward Hospital, 1950-73 P. H A L L I D A Y A N D J . H. H A L L I D A Y * SUMMARY
A series of 241 patients with subphrenic abscess was anaiysed to seek reasons for the continuing mortality. Aspects of pathology, clinical presentation, special investigations and management were affectedby therapy with broad spectrum antibiotics to make diagnosis more dificult, particularly in relation to left subphrenic abscesses. When transperitoneal exploration and drainage were employed, high morbidity and mortality resulted. Satisfactory results followed extraserous drainage. The introduction of parenteral hyperalimentation promised control of fistulas associated with abscesses, a situation hitherto associated with a poor prognosis. THEclinical presentation and management of patients with subphrenic abscess continue to provide problems of considerable magnitude, with added difficulties in recent years owing to the masking effects of antibiotics (Halliday, 1975). A study of the clinical presentation of 104 patients treated at the Royal Prince Alfred Hospital, Sydney, between 1950 and 1961 (Halliday and Loewenthal, 1964) detailed aspects of these problems and discussed their significance. The aim of the present study is to record the patterns of presentation and treatment during 1962-73, and by a comparison of the two periods, to seek reasons for the continuing morbidity and mortality. Patients During the years 1962-73, 137 patients with subphrenic abscess were recorded at the Royal Prince Alfred Hospital. The age groups and the distribution of mortality were similar to those in the 104 patients treated during 1950-61 (Figs. 1, 2).
-
'950-6'>-
I
0 1
2
3
4
5
6
7
Fig. 1. Age distribution of patients through 1950-61 and 1962-73.6C
n
40
v)
L
Aetiology Surgical conditions complicated by the development of subphrenic abscess did not change significantly during the second decade (Table I ) . Surgery of the stomach, duodenum and biliary tract accounted for 56 per cent of the cases in the whole series. Among minor changes during the second decade, 13 patients developed subphrenic abscess as a complication of multiple abdominal and thoracic injuries sustained in a motor vehicle accident, as compared with 6 during 1950-61. Pathology The nomenclature of the subphrenic spaces (Fig. 3) used here follows the categories of Ariel and Kazarian (1971).
352
8
Decades
2 L
x 20
0 Age:
50 1962-73
Fig. 2. Mortality rates in the major age groups.
* Department of
Surgery, University of Sydney.
9
Subphrenic abscess Table I: AETIOLOGY OF SUBPHRENIC ABSCESS Primary condition or operation Surgery of stomach and Perforated peptic ulcer duodenum Peptic ulcer with haemorrhage Elective surgery for peptic ulcer Lower third of oesophagus
Surgery of diseases of the biliary tracts
Surgery of diseases of the liver other than trauma
Carcinoma of stomach and lower third of oesophagus Rupture of oesophagus Oesophageal varices with haemorrhage Oesophageal stricture
Other than trauma
Surgery of diseases of the pancreas
Miscellaneous causes
Primarv abscess
1
7 7 6
2
1 2
4 4
I1
3
3
6
-
1
1
1 1 1
1 2
3
3
6
8 3 1
8 6 2 1
1
1
4 3 2
4 2 8
10
11
3
14
3 2
4 7 1 4 3
-
3
8 5
I 9 1
4 6
-
1
3
4
1 1
1
1
6
I
104
137
24 1
1 1
-
Total
1
2 5
-
No cause discovered
1
-
2 3
3
Renal biopsy Pyonephrosis Cushing’s syndrome Trousseau’s syndrome/carcinoma of lung
15
2
-
Closed injury with : Ruptured spleen Lacerated liver Ruptured pancreas Ruptured hollow viscus Penetrating injury with involvement of hollow viscus*
7
29
11 11
-
Carcinoma Diverticulitis Various causes, e.g. ulcerative colitis, perforation Appendicitis
7 7
Total 47 13 14
1962-73
5
-
Hydatid disease Amoebic abscess Polycystic disease of liver and kidney Liver biopsy
Pancreatitis Carcinoma Zollinger-Ellison syndrome Islet cell hyperplasia
Surgery of abdominal trauma
8
-
Acute cholecystitis Elective cholecystectomy Elective cholecystectomywith exploration of common bile duct External biliary fistula Carcinoma of bile ducts
Surgery of splenic pathology
Surgery of diseases of large intestine and appendix
1950-61 18 6 7
1
* In 1950-61.
one case was due to gunshot wounds. In 1962-73 there were 3 cases due to gunshot wounds and 3 cases with multiple injuiies.
The left ‘perihepatic’ subphrenic space is the whole intraperitoneal space under the left dome of the diaphragm; the ‘left anterior space’ is only part of this space. The ‘left subhepatic space’ is the lesser sac; after a gastrectomy and various other procedures the lesser sac becomes potentially continuous with the left subphrenic space in the event of a large left subphrenic abscess developing. Because of the dorsal location of the bare area of the liver, the right subphrenic area is divided into right superior subphrenic and right subhepatic spaces. In the latter space an abscess may collect in the first instance either anteriorly or posteriorly. An anteriorly placed right subhepatic abscess may extend into the right superior subphrenic space or extend posteriorly, 35
but initially it is not in direct contact with the diaphragm. A posteriorly placed subhepatic abscess is from the outset more closely related to the diaphragm in the region of the 9th-12th ribs. Distribution of abscesses during 1950161 and 1962-73 (Table 11) During 1950-61 the pattern of distribution was similar to that of previous series (Harley, 1955; Halliday and Loewenthal, 1964), with abscesses on the right side predominating (67 right : 35 left). During 1962-73, however, left subphrenic abscesses predominated (73 left : 59 right). Table ZZalso gives the overall mortality rates for the various categories of abscess during the two periods.
353
P. Halliday and J. H. Halliday Table 11: SITE OF SUBPHRENIC ABSCESSES
1 2 1 +2 3 4 4+5 6 1+2+4
Site* Right superior subphrenic Right subhepatic Combined abscess, right superior and subhepatic Right extraperitoneal Left ‘perihepatic’ subphrenic Left perihepatic and left subhepatic (lesser sac) Left extraperitoneal and left perihepatic Bilateral abscesses, right and left subphrenic
1950-61 No.of No. of cases deaths 35 10 16 5 13 8 3 0 33 13 0 0 0 0 2 2
Total 1950-73 No. of No. of cases deaths 37 15 23 6 32 16 4 0 98 35 5 4 2 0 17 12
1962-73 No. of No.of cases deaths 22 5 7 1 19 8 1 0 65 22 5 4 2 0 15 10
* Abscesses numbered as in Fig. 3.
b
(1
Fig. 3. a, Subphrenic abscesses shown in relation to the dorsal aspect of the liver. Intraperitoneal abscesses: I , right superior subphrenic; 2, right subhepatic. 3, right extraperitoneal; 4, left ‘perihepatic’ subphrenic; 5 , left subhepatic (lesser sac); 6, left extraperitoneal (perinephric). b, The extent of the area involved by a right superior subphrenic abscess, and the dorsal location of the bare area.
Mortality%
601
i Right
Total patients
A. 1950-61 B, 1962-73
Left
Bilateral
Fig. 4. A comparison of the morbidity and mortality rates for right, left and bilateral subphrenic abscesses. The percentage distributions in the histograms of right and left abscesses refer to fractions of the total of such cases for the periods 1950-61 and 1962-73.
354
During the second period the mortality rate of right abscesses fell from 34 to 28.5 per cent, while that of left abscesses remained constant at 37 per cent. The improved results in treatment of right-sided abscesses were, however, offset by the increase in incidence of left-sided abscesses in which the prognosis was less satisfactory (Fig. 4). Bilateral abscesses have always been associated with a bad prognosis. Only 2 cases were recorded during the first period and both died. In the second period 15 cases were recorded, of whom 10 died.
Morbid anatomy Autopsies were performed on 32 patients between 1950-1961, and on 42 between 1962 and 1973. The reports on these autopsies were more detailed than operation reports, but taken in conjunction allow a more precise description to be established of abscesses in different regions. Peritonitis in some form was always present at the outset. In some patients the source of infection was an initial incident and not repeated; in the remainder
Subphrenic abscess the source was persistent, such as a fistula from a perforating viscus or a leaking gastro-intestinal anastomosis. The particular fashion in which an abscess developed was characteristic in each of the subphrenic spaces. The outcome, however, was closely related to the nature of the source of the infection in both the periods studied (Table ZZI). Continued contamination led to overall mortality rates of 80 per cent (1950-61) and 71 per cent (1962-73).
Table 111: MORTALITY RATES IN RELATION TO PATHOGENESIS 1950-61 1962-73 Source of No. of No. of No. of No. of infection acted as cases deaths cases deaths % Acute or single 76 20 26.3 77 9 11.7 incident Continued 28 22 19.6 60 46 76.6 contamination
Right subphrenic abscesses Superior abscesses (total recorded 1950-73, 86): When discovered at autopsy in patients who had not been submitted to surgery, these were usually described as ‘covering the whole superior aspect of the right lobe of the liver’, and loculi were seldom if ever mentioned (Fig. 36). This was consistent with operation reports of the drainage of a litre or more of pus from this area. Loculation was, however, the reason advanced for protracted patterns of recurrent right subphrenic abscess in 4 patients between 1950 and 1961 and in 8 patients between 1962 and 1973. At thoracotomy the right dome of the diaphragm was usually obscured by adherent lung. Removal of this in 2 patients disclosed a friable, boggy diaphragm, green in colour from bile staining. Such a forbidding appearance did not preclude successful incision and extraserous drainage in these patients, with debridement of underlying necrotic liver in one of them (Halliday et al., 1974). It is relevant to this observation that during 1960-1 drainage was frequently delayed until the necessity was certain-a longestablished practice-but under these circumstances, extraserous drainage was followed by pleural contamination and empyema in 4 patients. Intrathoracic spread of right subphrenic abscess followed the sequence of adherence of the right lobe of the lung to the diaphragm, penetration of the abscess process into the lower lobe and rupture into a bronchus. If the abscess was originally a hydatid, the resulting problem was often a major one; in one patient the hepatic cyst had extended to the apex of the lower lobe of the right lung. This process was slow; a common interval between an operation and the eventual development of a bronchial fistula was about 12 months. Variations in this time interval were seen in 4 patients between 1950 and 1961, and in 3 patients between 1962 and 1973. Right subhepatic abscesses (total recorded 1950-73, 55) : When situated anteriorly, these often communicated with a right superior subphrenic space, but this combination presented few additional problems. When located more posteriorly, lack of clinical features in some patients led to progressive extension of the pathology. In one patient a subhepatic abscess had been drained, but at autopsy there was a loculated small right superior abscess, a psoas abscess and a large subcutaneous abscess in the loin, all of which were clearly extensions of the initial abscess. In another patient, primarily suffering from infected hydatid cysts, a right superior abscess was drained, but thoracic involvement became evident. At thoracotomy
multiple abscesses were found in the right lower lobe of the lung. When lobectomy was performed, dissection of the adherent lobe from the diaphragm disclosed a fistula in the posterior costophrenic angle originating below the diaphragm, where there were two abscesses, one of which had been drained, but the other not (Halliday et al., 1974, Case 13). Right extraperitoneal abscesses (total recorded 195073, 4): All were hydatid cysts and all presented at a stage when extensive intrathoracic involvement had developed; in one case the cyst had reached as far as the apex of the lower lobe of the right lung. Left subphrenic abscesses Left ‘perihepatic’ subphrenic abscesses (total recorded 1950-73, 122): As previously noted, these abscesses were unusually frequent between 1962 and 1973, 87 being recorded. The range of pathology found was considerable. The only feature common to all abscesses in this category was that the part of the wall of the abscess in contact with the diaphragm consisted only of pyogenic membrane and diaphragm. The remainder of the ‘walls’ was a complex of friable and inflamed structures-the stomach and omentum, the small and large bowel, the spleen (if present)-all enmeshed in vascular inflammatory adhesions. If an abscess developed as an infection of a haemoserous collection after a splenectomy or a left colectomy, the abscess, at least initially, was relatively circumscribed. When a left subphrenic abscess developed in relation to a perforated peptic ulcer or a leaking anastomosis, the infected material produced initially a widespread peritonitis; the resultant subphrenic abscess reflected both the severity of the original peritonitis and the patient’s resistance. Many case and autopsy reports gave graphic descriptions of the resulting pathology. A characteristic feature was the presence of multiple smaller intraperitoneal collections in a diffuse chain of intensely vascular adhesions, extending at times as far as the right iliac fossa, with or without a pelvic abscess. If the main abscess had been drained but the patient died, at autopsy these smaller abscesses and vascular adhesions usually were replaced by dense fibrotic adhesions. The pathology of a left subphrenic abscess due to pancreatic disease was the most formidable, especially in the presence of acute haemorrhagic pancreatitis. This combination in 3 patients proved insuperable, with particularly gross pathology being evident at autopsy. The characteristic lethal end result in these 355
P. Halliday and J. H. Halliday Table IV: DELAY IN DIAGNOSIS Interval between primary incident and presentation Presentation Series < 1 mth 1-6 mth > 6 mth* Total 1950-61 16 5 3 With or as primary 1962-73 13 3 6 condition 1950-73 29 8 9 46 Asasubse195&61 67 10 2 quent com- 1962-73 96 14 6 plication 1950-73 163 24 8 195
* Chronic cases. Table V: CLINICAL COURSE BEFORE DIAGNOSIS 195&61 1962-73 Clinical course Insidious onset With toxaemia Without toxaemia Sudden onset or change of symptoms Sudden onset of toxaemia Spontaneous external rupture Spontaneous internal rupture Diagnosis established On admission At laparotomy Because of persistent toxaemia after primary treatment Because of abdominal or thoracic complications At autopsy
No.of cases
No.of No.of No.of deaths cases deaths
39 17
8 5
60 39
13 16
5
1
3 0
7 7
2 1
3
3
2
1
5 10 6
1 6 2
15 27 10
4 10 4
15
11
12 22
6 11
25
25
patients was uncontrollable secondary haemorrhage from the walls of the abscess. Even when the basic pathology was chronic pancreatitis or tumours of the organ, complicated by a subphrenic abscess, the tendency for aggressive extension of the pathology resulted in only 2 of 9 patients surviving. Two major complications of left subphrenic abscess deserve comment. Gastro-intestinal fistulas frequently caused the development of a subphrenic abscess and were a continuing problem, but in addition a number developed as a secondary complication after transperitoneal exploration. Haematemesis and melaena were related to direct involvement of the stomach in the wall of a left subphrenic abscess. This formed a major feature in the course of 12 patients during 1962-73, of whom 9 died. Spread of a left subphrenic abscess through the diaphragm leading to empyema thoracis was always related to some causal factor. These included needle aspiration and trauma to the diaphragm either as part of injuries in a motor vehicle accident or during operative procedures such as transpleural drainage or difficult extraserous drainage. The result was the development of a fistula from the abscess into the pleural cavity. When the diaphragmatic pleura was not adherent to the parietal pleura, transpleural 356
drainage of an empyema was ineffective, as all the patients so treated died. This experience is detailed because of the contrast between these results and those following combined transpleural exploration and extraserous drainage (Halliday et al., 1974). Left subhepatic or lesser sac abscesses (total recorded 1950-73, 5): Though the pathology of these abscesses is limited by the space they involve, lesser sac abscesses were fortunately rare, because of the major difficulties they present in diagnosis and management. None was recorded in the period 1950-61, and only 5 during 1962-73; in each case a left ‘perihepatic’ subphrenic abscess was also present. Three were associated with acute pancreatitis. One, due to a perforated gastric ulcer, was only found at autopsy after an extremely difficult and unsuccessful laparotomy at which a left ‘perihepatic’ abscess had been found and drained. In the remaining patient the abscess was located by a preliminary transpleural exploration and successfully drained by an appropriate extraserous route (Halliday et al., 1974). Left extraperitoneal abscesses: When a left perinephric abscess breaks through the renal fascia into the left subphrenic space, the pathology is usually confined to a restricted area. In one patient during the period 1962-73, however, the perinephric abscess and subphrenic abscess were initiated by a staghorn calculus; an empyema thoracis also developed. This pathology presented exceptional problems in surgical treatment. Chronic subphrenic abscesses (Table ZV) A subphrenic abscess was regarded as chronic when there was a latent period of 6 months or longer after the initial incident, such as an attack of acute cholecystitis, or when there was no obvious preceding related illness. The morbid anatomy in the majority of patients was characterized by the development of an epigastric mass with the slow rate of progress characteristic of a chronic process, relatively ‘simple’ walls and sterile contents. Five cases were collected during 1950-61, and 12 cases during 1962-73. The latent period could be established in 12 patients and in most ranged between 6 months and 3 years, though there was one clear instance of an 8-year interval and possibly another of an 11-year interval. Seven patients died; 2 directly due to metastatic abscesses, the others due to complications of the abscess itself becoming active without warning.
Clinical features and investigations In the series collected in the period 1950-61, changes were noted in the characteristic modes of presentation and standard methods of investigation (Halliday and Loewenthal, 1964). In the second period, patterns were on the whole similar, though some differences did appear (Tables ZV, V ) . Abdominal or hypochondria1 pain, hitherto regarded as a classic symptom, was prominent at the time of diagnosis in only 20 of the 137 patients of 1962-73. Absence of pain was thus of less significance.
Subphrenic abscess 60
40
60
n
1962-73
1
1950-61 1962-73
,p
f?1950-61
40
D ._ L
L
x
x
b
L
x 20
20
0 Severe
Moderate
Minor
Absent
0.
b
a Fig. 5. Changes in incidence of grades of
(a) pyrexia,
and (b) leucocytosis.
Similarly, pyrexia, leucocytosis and radiological abnormalities all retained their importance when present, but their absence in no way excluded the presence of an abscess. The changes in the incidence of grades of pyrexia and leucocytosis are shown in Fig. 5; the levels evaluated were those related to critical periods of diagnosis and management. These changes were significant (P< 0.05) in both series, using 2 x 4 and 2 x 3 contingency tables to calculate xa. These variations in the classic presentation of a subphrenic abscess made diagnosis more often difficult. Though, for instance, a diagnosis was reached in the majority of patients within 1 month (Table ZV, 80 per cent), the frequency of an insidious onset meant that diagnosis often appeared to be arrived at slowly. The clinical features in such patients were difficult to categorize, e.g. ‘failure to improve’, but may be summed up as prompting clinical suspicion which, in turn, led to essential radiological or isotope scanning investigations being made. Complications such as the development of a fistula or an empyema thoracis led to the diagnosis being established by exploratory laparotomy or thoracotomy in a group notable for a high overall mortality (Table V, 59 per cent). Throughout this group of patients delay was directly related to morbidity or mortality in only a small number of patients. The clinical presentation of patients with a chronic abscess was most frequently centred on an epigastric mass of uncertain origin or nature (8 of 17 patients). These abscesses were all successfully drained without complications, as were 2 others, one with an associated lung abscess and bronchial fistula, and the other with a chronic abscess discovered when periostitis at the site of a previous thoracotomy was drained (Halliday et al., 1974). As noted above, 7 patients in this group died as a result of insidious development of complications
or sudden development of activity in a chronic abscess. Radiological studies Radiological studies of at least one type were made in 135 patients during 1962-71. The 2 remaining patients were not investigated radiologically because of the increasing gravity of their condition. In view of the critical role played by radiological studies in the diagnosis of this condition, this represents an improvement on the period 1950-61 when radiological studies were less frequently employed (Halliday and Loewenthal, 1964). Three modes of investigation were employed: plain films of the chest or abdomen or both, screening of the diaphragm and studies using opaque contrast. As in the previous series, a report was accepted as diagnostic if it contained a direct statement that a subphrenic abscess was present. A descriptive report detailing the presence of a pleural effusion, basal collapse or consolidation, without inferences concerning the significance of the findings, was regarded as ‘nondiagnostic’. Normal findings or a direct negative were classed as ‘negative’. The incidence of abnormal findings during 1962-73 in examination by both plain films and screening showed similar changes to the alterations in clinical indices such as pain, pyrexia and leucocytosis. In particular, screening of the diaphragm was negative in 16 per cent, non-diagnostic in 66 per cent and positive in only 29 per cent of the studies undertaken. Results ofplain films of thechest and abdomen showed a similar shift away from data prompting a definite diagnosis (Fig. 6). Studies during 1962-73 using opaque contrast procedures fell into two groups. Sinograms (19 patients) were usually performed postoperatively, when their diagnostic value was limited to the identification of complications such as an intestinal fistula. The other 357
P. Halliday and J. H. Halliday I,
Positive
2. Not diagnostic
3, Negative
positive diagnosis on scanning was confirmed by drainage or at autopsy. In 4 patients a false negative report was followed by subsequent demonstration of the abscess. In 1 patient a false positive report led to a negative exploration, without further difficulty resulting. In the remaining 6 patients the results of scanning were inconclusive in that the diagnosis, management and course of the illness were uninfluenced. Bacteriology
3
I..
I..
..
;2-73 Fig. 6 . Changes in the value of radiological examination. Table VI: BACTERIOLOGY Oreanisrn Cultures from abscess Intestinal flora Escherichia coli Non-haemolytic streptococci Streptococcus faecalis Bacillus proteus Klebsiella Pseudomonas Bacteroides Clostridium welchii Candida Other flora Staphylococcus aureuslalbus Streptococcus pyogenes (A) Str.pyogenes, not group (A) Pneurnococcus Streptococcus viridans Diphtheroids No growth on culture Blood cultures E . coli Klebsiella B. proteus Pseudomonas Bacteroides Candida S. marcescens Staph. aureus N o growth on culture
1950-61
1962-73
Total
70 20 14 23 7 2 3
The results of bacterial cultures during the two periods show that the spectrum of bacteria did not change significantly (Table VZ). Intestinal flora made up 64 per cent of the cultures isolated during 1950-61, and 67 per cent during 1962-73, and staphylococci were found in 17 and 20 per cent of the cultures respectively. Blood cultures were attempted more often during 1962-73 because of the increased frequency of Gramnegative septicaemia during these years in general (Table VZ). The patient from whom Serratia marcescens was isolated was a diabetic with an appendiceal abscess and evidence of Gram-negative septicaemia. One of the patients with a positive culture of Staphylococcirs aureus died of staphylococcal pyaemia and acute ulcerative endocarditis.
Management and results In order to add detail to the conventional data of mortality rates, assessment of the results of treatment 4 was enlarged to include some objective measures of morbidity rates. Assessment of morbidity was based on the mode of 2 5 the patient’s course during convalescence or deteriora1 1 tion. An uninterrupted course leading to discharge 41 12 29 from hospital within 1 month was classed as ‘rapid’; 2 1 1 if longer than 1 month but still uncomplicated, as 3 2 ‘slow’. Complications such as fistulas almost inevit1 1 ably prolonged convalescence. Patients who developed 3 1 4 1 1 septicaemia or who needed intensive care for other 10 12 22 complications were usually described as having a ‘stormy convalescence’. The patterns of deterioration 1 to death, such as the state of gross wound infections 2 3 with fistulas (cf. Sherman et al., 1969), remained unfortunately characteristic throughout both the periods 1950-61 and 1962-73. To ensure consistency in classification, these aspects 1 3 of the management of the patients treated during 2 61 - 1950-61 were reviewed in the light of the experience of 1962-63. ‘Drainage through adhesions’ proved on group was made up of barium or Gastrografin meals review to have been transperitoneal drainage in most and enemas. If these were performed with the diagnosis cases. The few bilateral abscesses in the first period, of subphrenic abscess as a possibility, the studies not previously identified, have now been separated out. always provided information additional to that obTable VZZ summarizes the results of the various tained by screening the diaphragm alone. If the diag- methods of treatment as regards morbidity as well as nosis was not regarded as a possibility, few reports mortality in the 241 patients treated between 1950 were diagnostic. and 1973, and within each group the patients are separated according to age. There were insufficient Radio-isotope scanning numbers, however, to separate the results of treatTechniques using various isotopes became available ment of right- and left-sided abscesses. This obscures after 1962; their use was sporadic in the first 5 years, the effects on the morbidity and mortality, on the becoming progressively more frequent thereafter. one hand, of the considerable increase of left-sided Altogether 25 patients were studied thus. In 14, a subphrenic abscesses during 1962-73, and on the 358
32 8
38 12 14 19 7 2 3 3
Subphrenic abscess Table VII: MORBIDITY AND MORTALITY 1N.RELATION TO MANAGEMENT AND AGE GROUP Recoverv Method of management Extraserous drainage Transperitoneal drainage Transpleural drainage
Age t50
< 1 mth
> 1 mth
With complications
Stormy convalescence 3 (1.)
>50
8
5 2
8 3
(50 >50
4 9
6 3
8 6
50
21 (1*)
5 (It)
1
9 (2*, It) 2
3 3
-
-
Non-operative treatment
< 50 >50
6 2
5 7
3 1
1 1
50
7 (I$) 15 (3f)
8
> 50
3
2
1
No. of cases 43 16
5 2
1
Combined transpleural exploration and extraserous drainage
