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Postpneumonectomy empyema
J
THoRAc CARDIOV ASC SURG
79:851-855, 1980
Postpneumonectomy empyema The cloud with a silver lining? / have reviewed the literature concerning the effect of postoperative sepsis on survival following resection for carcinoma of the bronchus and added to this my experience over a /2 year period. Surgeons agree that because of its morbidity and the morbidity of measures necessary for its treatment, postoperative empyema is to be avoided, but many still hope that some compensation might be afforded the unfortunate sufferer by improvement in long-term survival. / have not found this to be the case and / feel that statistical evidence favors this view.
P. Goldstraw, F.R.C.S., Glasgow, Scotland
Ipyema t has often been claimed that patients surviving emcomplicating pneumonectomy for carcinoma of the bronchus have an increased chance of long-term survival. The basis for this assertion is usually anecdotal, I but there is one well-constructed study" which also supports this impression. Comforting though this possibility may seem, it has not been unopposed, and severalpapers document contrasting experience (Table I). This paper reports the survival statistics on patients undergoing pneumonectomy for carcinoma of the bronchus and the influence of postoperative empyema. I will discuss possible mechanisms for the proposed benefit of postpneumonectomy empyema and put forward explanations for the conflicting statistical evidence.
Patients In a 12 year period, 1964 to 1975 inclusive, 225 patients underwent pneumonectomy in Mearnskirk Hospital, near Glasgow, Scotland. The records of six patients were lost, and 33 had undergone pneumonectomy for conditions other than carcinoma of the bronchus. Therefore, the records of 186 patients were taken as a basis for the study, and 30 cases of postpneumonectomy empyema were found. In no case did empyema exist preoperatively. Since an empyema may be present in a patient who is apyrexial and has a normal From the Department of Cardiothoracic Surgery, Mearnskirk Hospital, and the Royal Infirmary, Glasgow, Scotland. Received for publication Aug. I, 1979. Accepted for publication Oct. 17, 1979. Address for reprints: P. Goldstraw, F.R.C.S., Brompton Hospital, London, England.
white cell count, all patients whose space fluid showed pus cells, regardless of negative cultures, were included. In 20% of the patients cultures were persistently negative, even at the drainage procedure. Mostly, these were patients who had had several courses of antibiotics for coincident chest infection. The 156 patients whose recovery was not complicated by overt space infection (control group) were compared to the empyema group in respect to age, sex, lung removed, and tumor type and stage (Table 11). The mean age of the patients in the empyema group was 53.2 years (range 21 to 66 years), and that of the control group was 52.7 years (range 25 to 69 years). Eighty-three percent ofthe empyema patients and 88% of the control group were men. There was a slight preponderance of left pneumonectomies in both groups. The distribution of cell types in the two groups was similar and is in line with other series. Tumors histologically confined to the lung without lymphatic dissemination were classed as Stage I, those with hilar node metastases as Stage II, and those with mediastinal node metastases as Stage III. There was no statistically significant difference between these two groups, and I consider them comparable as regards their potential for survival after pneumonectomy.
Results The 30 day perioperative mortality rate of the empyema group was higher than that of the control group. Although this difference did not reach statistical significance, it remains reasonable to expect a difference in view of the debilitating nature of this complication
0022-5223/80/060851+05$00.50/0 © 1980 The C. V. Mosby Co.
851
The Journal of
852
Thoracic and Cardiovascular Surgery
Goldstraw
Table I. The influence of postoperative empyema on 5 year survival rate following resection for carcinoma of the bronchus Perioperative mortality rate (%) Authors
Control
Cady and Cliffton" Lawton and Keehn' Ruckdeschel et al 2 All stages Stages I and II Sensenig et al" Takita" Present study
14.7 16
I
11 17.4 18.6
Five-year survival rate (%)
Empyema
Control
15 18
35 (333)* 25.2 (899)
o
18 (34) 23 (22) 22 (283) 27 (147) 30.8 (127)
7 23.3
I
Empyema 13 (40) 17.6 (34) 50 73 43 54 23
(18) (II)
(7)
(13) (23)
Influence on 5 year survival rate
H
p
< 0.01
~
i it i i
p = 0.0073 p = 0.0083
~
'The figures in parentheses indicate the initial number in each study.
Table II
No. in study Mean age (yr) Male: female ratio Left: right pneumonectomy Cell type (%) Squamous Oat cell Adenocarcinoma Anaplastic Tumor stage (%) 1 II III
Control group
Empyema group
156 52.7 7.2: 1 1.14: 1
30 53.2 5: 1 1.14: I
70 6.5 6.0 17.5
75 3.6 7.1 14.3
52.6 22.7 24.7
42.9 17.8 39.3
Table III. Survival following pneumonectomy for carcinoma of bronchus Percent survival (excluding periop . mortality)
Thirty-day operative mortality (%)
3 mo
18.6 23.3
92.5 89
Control Empyema
I 6 mo I 75.8 83
J yr
56.7 67
I 3 yr I 5 yr 35.8 50
30.8 23
and the morbidity of the procedures necessary for its treatment. The survival statistics for the empyema and control groups are shown in Table III, and the survival curves, excluding perioperative mortality rates, are depicted in Fig. I. The two curves are parallel and the difference between them at no stage reaches statistical significance.
Discussion It has been claimed repeatedly that patients surviving postpneumonectomy empyema have an increased
chance of long-term survival. In 1906, Coley t reported his remarkable success in the treatment of advanced sarcomas using mixed toxins of erysipelas and prodigiosus. From this arose the hope that infective problems complicating operations for neoplasm might represent "the cloud with a silver lining. "8 It can be seen in Table I that in the published series some remarkable 5 year survival rates have been associated with postpneumonectomy empyema. The beneficial effects of postpneumonectomy empyema have been attributed to immunologic mechanisms.! Nonspecific immune response was cited by Cady and Clifton," who observed that successful take of transplanted tumors is reduced after bacille Calmetre-Guerin (BCG) inoculation and that homografted skin is rejected more quickly after sensitization with certain bacteria, including Staphylococcus aureus. They showed that among 5 year survivors of postpneumonectomy empyema, S. aureus had been the infecting organism more frequently than would have been expected by chance. As this organism is the one most commonly responsible for postpneumonectomy empyema, the observation assumes especial interest. Vaisrub" noted the increased incidence of tumors in states of depressed immunity, whether occurring naturally, such as hypogammaglobulinemia, or induced pharmacologically with immunosuppressive agents. The immunologic mechanisms leading to enhanced nonspecific immunity have been discussed by Ruckdeschel and associates.? (Fig. 2). They discussed the role of macrophage-lymphocyte interaction, the production of Iymphokines, which can be locally cytotoxic, and the stimulation of macro phages by macrophageactivating factor to make them "angry," and to confer increased phagocytic power. They also postulated some increase in specific immunity by the exposure of tumor-specific antigens during enzymatic activity and the production of unblocking antibodies.
Volume 79
Postpneumonectomy empyema
Number 6
853
June, 1980
100 80
x. Empyema cases e=Control
60 40
20 O - t - -......_ _."...._......_ _......._ .........-_......._ _.__---Length of Survival. lyr 3yr 5yr 6yr 30 ~2 ~2 o days
Fig. 1. Survival curves, excluding perioperative mortality rates, for patients undergoing pneumonectomy for carcinoma of the bronchus. Empyema and control groups.
Lymphokines Lymphocytes
Fig. 2. Possible mechanisms for enhanced nonspecific immunity if sepsis complicates operation for neoplasm (after Rucksdeschel and associates)." M.A.F., Macrophage activating factor.
These papers appeared at a time of increasing enthusiasm for nonspecific immunotherapy in malignancy. Several studies more recently have shown the relative weakness of this response as a therapeutic agent. 9-11 Bone." claimed that any beneficial influence empyema might have on survival after resection for carcinoma of the bronchus would be the result of hyperthermia. This is a valid comment on the original work of Coley, 7 but it is at variance with clinical experience in patients with postpneumonectomy empyema. In such cases pyrexia may be absent, but there usually is a low-grade fever with occasional spikes. Rarely does the fever sustain the 39° to 40° C level necessary in experimental tumor thermotherapy. Cady and Clifton" observed no relationship between survival and the severity of toxic reaction with postpneumonectomy empyema.
Coley's? work is a poor base from which to argue in favor of a possible beneficial effect of empyema. He injected the combined toxins of hemolytic Streptococcus and Serratia marcescens directly into tumors and observed their regression. This treatment was accompanied by a high fever which could last up to 10 days, and hyperthermia might well have been therapeutically important. Local bacterial toxins have been observed to cause necrosis of certain experimental tumors;" and any consequent immunologic onslaught would also be directed locally. Coley's 7 treatment fell into disrepute when others could not reproduce his results. Our results are included in Table I, with those of other studies. In all these studies, the empyema group is small, so that statistical analysis is difficult. Where probability is expressed in Table I, it is the opinion of the respective author; otherwise, only suggested influence is depicted.
The Journal of
854
Goldstraw
Perioperative mortality rate. The increase in perioperative mortality rate associated with postoperative empyema is greater in our series than in any of the other series in Table I, perhaps because our figures concern pneumonectomy alone, whereas others included lesser resections, following on which empyema is less of a problem. Cady and Clifton" and Lawton and Keehn" reported similar incidences in the two groups, and Ruckdeschel and associates" gave no figures for perioperative survival. The perioperative mortality figures of Sensenig's group" and Takita" are remarkable at first glance, since not only would postoperative empyema seem to increase the chances of survival in the long term, but it also apparently increases the chance of surviving the perioperative period. Empyema by no means protects the patient from the other postoperative complications which led to the deaths in the control group. Therefore, it seems possible that these authors are failing to detect many of the empyemas occurring in the perioperative period. Three quarters of all postoperative empyemas occurred in the first month postoperatively. 14 Five-year survival. Empyema notoriously masquerades as tumor progression, making the patient cachectic, often without clinical or hematologic evidence of infection. Such a death being wrongly classified increases the mortality rate of the control group and simultaneously reduces the rate for the empyema group. This error might well be made by medical practitioners and physicians away from the parent surgical unit. Few such errors of classification would be needed to erode the dubiously significant differences in 5 year survival reported by Sensenig's group," and by Takita. 6 Ruckdeschel and associates- gave no data on perioperative mortality rate, restricting their statistical analysis to patients surviving the operation. Any study of 5 year survival based solely on the patients surviving 30 days postoperatively must raise the possibility that within that period selection has occurred favoring one group, giving them a better chance of survival from 30 days to 5 years. In many respects local sepsis and tumor test similar immune mechanisms. It may be that patients who are capable of responding to the challenge of local sepsis and thus survive empyema are also more capable of controlling regional cancer spread. This is a restatement of the thoughts of Ruckdeschel and associates" on local immune mechanisms. Empyema is a grave complication and constitutes a serious debilitating illness for the patients whose postoperative course is thus complicated. No doubt some
Thoracic and Cardiovascular Surgery
patients with marginal respiratory and constitutional reserve, who would have survived an uncomplicated operation, will die of empyema. It should be remembered that not all patients dying in the first 5 years after operation do so because of tumor; many die of respiratory infection and failure. It may well be that empyema removes some of these patients from survival statistics covering only the 30 day to 5 year period. These proposed mechanisms must have an influence on all studies. However, depending on the accuracy of diagnosis of postoperative empyema, the interval from operation to treatment, and the morbidity and the mortality rates of the measures used to treat the empyema, this extent will vary from series to series. Conclusions I have found that the perioperative mortality rate after pneumonectomy for carcinoma of the bronchus is adversely affected by the occurrence of postoperative empyema, but there was no statistically significant difference between the 5 year survival rates of the empyema and control groups. Initial opinion suggesting that postoperative empyema improves the 5 year survival rate was anecdotal, and statistical support more recently is not without its faults. Therefore, efforts should continue toward the prevention of postpneumonectomy empyema and its eventual elimination. I am grateful to Mr. R. S. Barclay, Mr. T. Welsh, and Mr. N. McSwann, Consultant Cardiothoracic Surgeons, Mearnskirk Hospital, Glasgow, Scotland, for permission to review the patients under their care; and to Mrs. J. Lowe and her colleagues in the Medical Illustration Department of Glasgow Royal Infirmary. I am grateful to Mrs. J. Kennedy, University Department of Cardiac Surgery, for her typing skills.
REFERENCES
2
3
4 5
6
7
Postoperative empyema and survival in lung cancer. Br Med J 1:504-505, 1973 Ruckdeschel JC, Codish SO, Stranahan A, McKneally MF: Postoperative empyema improves survival in lung cancer. N Engl J Med 287:1013-1017, 1972 Cady B, Cliffton EE: Empyema and survival following surgery for bronchogenic carcinoma. J THORAC CARDIOVASC SURG 53:102-108, 1967 Lawton RL, Keehn RJ: Bronchogenic cancer, sepsis and survival. J Surg Oneol 4:466-471, 1972 Sensenig OM, Rossi NP, Ehrenhaft JL: Results of the surgical treatment of bronchogenic carcinoma. Surg Gynecol Obstet 116:279-284, 1963 Takita H: Effects of postoperative empyema on survival of patients with bronchogenic carcinoma. J THORAC CARDIOVASC SURG 59:642-644, 1970 Coley WB: Late results of the treatment of inoperable
Volume 79
Postpneumonectomy empyema
Number 6 June, 1980
sarcoma by the mixed toxins of erysipelas and Bacillus prodigiosus. Am J Med Sci 131:375-430, 1906 8 Vaisrub S: Empyema in lung cancer-the cloud with a silver lining. JAMA 224:1644, 1973 9 Edwards FR, Whitwell F: Use of BCG as an immunostimulant in the surgical treatment of carcinoma of the lung. Thorax 29:654-658, 1974 10 Israel L, Mawas C, Bouvrain A, Mannoni P, Sors C: Immunology of bronchial carcinoma. Thorax 31:493506, 1967
855
11 Woodruff MFA: Tumour inhibiting properties of anaerobic corynebacterium. Transplant Proc 7:229-234, 1975 12 Bone G: Postoperative empyema and survival in lung cancer. Br Med J 2:178, 1973 13 Mihich E, Neter E: Necrotising effects of Staph. aureus extract on mouse sarcoma. Proc Soc Exp Bioi Med 106:97-101, 1961 14 Goldstraw P: Postpneumonectomy empyema. Thorax 33:129-130, 1978
Information for authors Most of the provisions of the Copyright Act of 1976 became effective on January I, 1978. Therefore, all manuscripts must be accompanied by the following written statement, signed by one author: "The undersigned author transfers all copyright ownership of the manuscript (title of article) to The C. V. Mosby Company in the event the work is published. The undersigned author warrants that the article is original, is not under consideration by another journal, and has not been previously published. I sign for and accept responsibility for releasing this material on behalf of any and all co-authors." Authors will be consulted, when possible, regarding republication of their material.
THoRAc CARDIOV ASC SURG
79:851-855, 1980
Postpneumonectomy empyema The cloud with a silver lining? / have reviewed the literature concerning the effect of postoperative sepsis on survival following resection for carcinoma of the bronchus and added to this my experience over a /2 year period. Surgeons agree that because of its morbidity and the morbidity of measures necessary for its treatment, postoperative empyema is to be avoided, but many still hope that some compensation might be afforded the unfortunate sufferer by improvement in long-term survival. / have not found this to be the case and / feel that statistical evidence favors this view.
P. Goldstraw, F.R.C.S., Glasgow, Scotland
Ipyema t has often been claimed that patients surviving emcomplicating pneumonectomy for carcinoma of the bronchus have an increased chance of long-term survival. The basis for this assertion is usually anecdotal, I but there is one well-constructed study" which also supports this impression. Comforting though this possibility may seem, it has not been unopposed, and severalpapers document contrasting experience (Table I). This paper reports the survival statistics on patients undergoing pneumonectomy for carcinoma of the bronchus and the influence of postoperative empyema. I will discuss possible mechanisms for the proposed benefit of postpneumonectomy empyema and put forward explanations for the conflicting statistical evidence.
Patients In a 12 year period, 1964 to 1975 inclusive, 225 patients underwent pneumonectomy in Mearnskirk Hospital, near Glasgow, Scotland. The records of six patients were lost, and 33 had undergone pneumonectomy for conditions other than carcinoma of the bronchus. Therefore, the records of 186 patients were taken as a basis for the study, and 30 cases of postpneumonectomy empyema were found. In no case did empyema exist preoperatively. Since an empyema may be present in a patient who is apyrexial and has a normal From the Department of Cardiothoracic Surgery, Mearnskirk Hospital, and the Royal Infirmary, Glasgow, Scotland. Received for publication Aug. I, 1979. Accepted for publication Oct. 17, 1979. Address for reprints: P. Goldstraw, F.R.C.S., Brompton Hospital, London, England.
white cell count, all patients whose space fluid showed pus cells, regardless of negative cultures, were included. In 20% of the patients cultures were persistently negative, even at the drainage procedure. Mostly, these were patients who had had several courses of antibiotics for coincident chest infection. The 156 patients whose recovery was not complicated by overt space infection (control group) were compared to the empyema group in respect to age, sex, lung removed, and tumor type and stage (Table 11). The mean age of the patients in the empyema group was 53.2 years (range 21 to 66 years), and that of the control group was 52.7 years (range 25 to 69 years). Eighty-three percent ofthe empyema patients and 88% of the control group were men. There was a slight preponderance of left pneumonectomies in both groups. The distribution of cell types in the two groups was similar and is in line with other series. Tumors histologically confined to the lung without lymphatic dissemination were classed as Stage I, those with hilar node metastases as Stage II, and those with mediastinal node metastases as Stage III. There was no statistically significant difference between these two groups, and I consider them comparable as regards their potential for survival after pneumonectomy.
Results The 30 day perioperative mortality rate of the empyema group was higher than that of the control group. Although this difference did not reach statistical significance, it remains reasonable to expect a difference in view of the debilitating nature of this complication
0022-5223/80/060851+05$00.50/0 © 1980 The C. V. Mosby Co.
851
The Journal of
852
Thoracic and Cardiovascular Surgery
Goldstraw
Table I. The influence of postoperative empyema on 5 year survival rate following resection for carcinoma of the bronchus Perioperative mortality rate (%) Authors
Control
Cady and Cliffton" Lawton and Keehn' Ruckdeschel et al 2 All stages Stages I and II Sensenig et al" Takita" Present study
14.7 16
I
11 17.4 18.6
Five-year survival rate (%)
Empyema
Control
15 18
35 (333)* 25.2 (899)
o
18 (34) 23 (22) 22 (283) 27 (147) 30.8 (127)
7 23.3
I
Empyema 13 (40) 17.6 (34) 50 73 43 54 23
(18) (II)
(7)
(13) (23)
Influence on 5 year survival rate
H
p
< 0.01
~
i it i i
p = 0.0073 p = 0.0083
~
'The figures in parentheses indicate the initial number in each study.
Table II
No. in study Mean age (yr) Male: female ratio Left: right pneumonectomy Cell type (%) Squamous Oat cell Adenocarcinoma Anaplastic Tumor stage (%) 1 II III
Control group
Empyema group
156 52.7 7.2: 1 1.14: 1
30 53.2 5: 1 1.14: I
70 6.5 6.0 17.5
75 3.6 7.1 14.3
52.6 22.7 24.7
42.9 17.8 39.3
Table III. Survival following pneumonectomy for carcinoma of bronchus Percent survival (excluding periop . mortality)
Thirty-day operative mortality (%)
3 mo
18.6 23.3
92.5 89
Control Empyema
I 6 mo I 75.8 83
J yr
56.7 67
I 3 yr I 5 yr 35.8 50
30.8 23
and the morbidity of the procedures necessary for its treatment. The survival statistics for the empyema and control groups are shown in Table III, and the survival curves, excluding perioperative mortality rates, are depicted in Fig. I. The two curves are parallel and the difference between them at no stage reaches statistical significance.
Discussion It has been claimed repeatedly that patients surviving postpneumonectomy empyema have an increased
chance of long-term survival. In 1906, Coley t reported his remarkable success in the treatment of advanced sarcomas using mixed toxins of erysipelas and prodigiosus. From this arose the hope that infective problems complicating operations for neoplasm might represent "the cloud with a silver lining. "8 It can be seen in Table I that in the published series some remarkable 5 year survival rates have been associated with postpneumonectomy empyema. The beneficial effects of postpneumonectomy empyema have been attributed to immunologic mechanisms.! Nonspecific immune response was cited by Cady and Clifton," who observed that successful take of transplanted tumors is reduced after bacille Calmetre-Guerin (BCG) inoculation and that homografted skin is rejected more quickly after sensitization with certain bacteria, including Staphylococcus aureus. They showed that among 5 year survivors of postpneumonectomy empyema, S. aureus had been the infecting organism more frequently than would have been expected by chance. As this organism is the one most commonly responsible for postpneumonectomy empyema, the observation assumes especial interest. Vaisrub" noted the increased incidence of tumors in states of depressed immunity, whether occurring naturally, such as hypogammaglobulinemia, or induced pharmacologically with immunosuppressive agents. The immunologic mechanisms leading to enhanced nonspecific immunity have been discussed by Ruckdeschel and associates.? (Fig. 2). They discussed the role of macrophage-lymphocyte interaction, the production of Iymphokines, which can be locally cytotoxic, and the stimulation of macro phages by macrophageactivating factor to make them "angry," and to confer increased phagocytic power. They also postulated some increase in specific immunity by the exposure of tumor-specific antigens during enzymatic activity and the production of unblocking antibodies.
Volume 79
Postpneumonectomy empyema
Number 6
853
June, 1980
100 80
x. Empyema cases e=Control
60 40
20 O - t - -......_ _."...._......_ _......._ .........-_......._ _.__---Length of Survival. lyr 3yr 5yr 6yr 30 ~2 ~2 o days
Fig. 1. Survival curves, excluding perioperative mortality rates, for patients undergoing pneumonectomy for carcinoma of the bronchus. Empyema and control groups.
Lymphokines Lymphocytes
Fig. 2. Possible mechanisms for enhanced nonspecific immunity if sepsis complicates operation for neoplasm (after Rucksdeschel and associates)." M.A.F., Macrophage activating factor.
These papers appeared at a time of increasing enthusiasm for nonspecific immunotherapy in malignancy. Several studies more recently have shown the relative weakness of this response as a therapeutic agent. 9-11 Bone." claimed that any beneficial influence empyema might have on survival after resection for carcinoma of the bronchus would be the result of hyperthermia. This is a valid comment on the original work of Coley, 7 but it is at variance with clinical experience in patients with postpneumonectomy empyema. In such cases pyrexia may be absent, but there usually is a low-grade fever with occasional spikes. Rarely does the fever sustain the 39° to 40° C level necessary in experimental tumor thermotherapy. Cady and Clifton" observed no relationship between survival and the severity of toxic reaction with postpneumonectomy empyema.
Coley's? work is a poor base from which to argue in favor of a possible beneficial effect of empyema. He injected the combined toxins of hemolytic Streptococcus and Serratia marcescens directly into tumors and observed their regression. This treatment was accompanied by a high fever which could last up to 10 days, and hyperthermia might well have been therapeutically important. Local bacterial toxins have been observed to cause necrosis of certain experimental tumors;" and any consequent immunologic onslaught would also be directed locally. Coley's 7 treatment fell into disrepute when others could not reproduce his results. Our results are included in Table I, with those of other studies. In all these studies, the empyema group is small, so that statistical analysis is difficult. Where probability is expressed in Table I, it is the opinion of the respective author; otherwise, only suggested influence is depicted.
The Journal of
854
Goldstraw
Perioperative mortality rate. The increase in perioperative mortality rate associated with postoperative empyema is greater in our series than in any of the other series in Table I, perhaps because our figures concern pneumonectomy alone, whereas others included lesser resections, following on which empyema is less of a problem. Cady and Clifton" and Lawton and Keehn" reported similar incidences in the two groups, and Ruckdeschel and associates" gave no figures for perioperative survival. The perioperative mortality figures of Sensenig's group" and Takita" are remarkable at first glance, since not only would postoperative empyema seem to increase the chances of survival in the long term, but it also apparently increases the chance of surviving the perioperative period. Empyema by no means protects the patient from the other postoperative complications which led to the deaths in the control group. Therefore, it seems possible that these authors are failing to detect many of the empyemas occurring in the perioperative period. Three quarters of all postoperative empyemas occurred in the first month postoperatively. 14 Five-year survival. Empyema notoriously masquerades as tumor progression, making the patient cachectic, often without clinical or hematologic evidence of infection. Such a death being wrongly classified increases the mortality rate of the control group and simultaneously reduces the rate for the empyema group. This error might well be made by medical practitioners and physicians away from the parent surgical unit. Few such errors of classification would be needed to erode the dubiously significant differences in 5 year survival reported by Sensenig's group," and by Takita. 6 Ruckdeschel and associates- gave no data on perioperative mortality rate, restricting their statistical analysis to patients surviving the operation. Any study of 5 year survival based solely on the patients surviving 30 days postoperatively must raise the possibility that within that period selection has occurred favoring one group, giving them a better chance of survival from 30 days to 5 years. In many respects local sepsis and tumor test similar immune mechanisms. It may be that patients who are capable of responding to the challenge of local sepsis and thus survive empyema are also more capable of controlling regional cancer spread. This is a restatement of the thoughts of Ruckdeschel and associates" on local immune mechanisms. Empyema is a grave complication and constitutes a serious debilitating illness for the patients whose postoperative course is thus complicated. No doubt some
Thoracic and Cardiovascular Surgery
patients with marginal respiratory and constitutional reserve, who would have survived an uncomplicated operation, will die of empyema. It should be remembered that not all patients dying in the first 5 years after operation do so because of tumor; many die of respiratory infection and failure. It may well be that empyema removes some of these patients from survival statistics covering only the 30 day to 5 year period. These proposed mechanisms must have an influence on all studies. However, depending on the accuracy of diagnosis of postoperative empyema, the interval from operation to treatment, and the morbidity and the mortality rates of the measures used to treat the empyema, this extent will vary from series to series. Conclusions I have found that the perioperative mortality rate after pneumonectomy for carcinoma of the bronchus is adversely affected by the occurrence of postoperative empyema, but there was no statistically significant difference between the 5 year survival rates of the empyema and control groups. Initial opinion suggesting that postoperative empyema improves the 5 year survival rate was anecdotal, and statistical support more recently is not without its faults. Therefore, efforts should continue toward the prevention of postpneumonectomy empyema and its eventual elimination. I am grateful to Mr. R. S. Barclay, Mr. T. Welsh, and Mr. N. McSwann, Consultant Cardiothoracic Surgeons, Mearnskirk Hospital, Glasgow, Scotland, for permission to review the patients under their care; and to Mrs. J. Lowe and her colleagues in the Medical Illustration Department of Glasgow Royal Infirmary. I am grateful to Mrs. J. Kennedy, University Department of Cardiac Surgery, for her typing skills.
REFERENCES
2
3
4 5
6
7
Postoperative empyema and survival in lung cancer. Br Med J 1:504-505, 1973 Ruckdeschel JC, Codish SO, Stranahan A, McKneally MF: Postoperative empyema improves survival in lung cancer. N Engl J Med 287:1013-1017, 1972 Cady B, Cliffton EE: Empyema and survival following surgery for bronchogenic carcinoma. J THORAC CARDIOVASC SURG 53:102-108, 1967 Lawton RL, Keehn RJ: Bronchogenic cancer, sepsis and survival. J Surg Oneol 4:466-471, 1972 Sensenig OM, Rossi NP, Ehrenhaft JL: Results of the surgical treatment of bronchogenic carcinoma. Surg Gynecol Obstet 116:279-284, 1963 Takita H: Effects of postoperative empyema on survival of patients with bronchogenic carcinoma. J THORAC CARDIOVASC SURG 59:642-644, 1970 Coley WB: Late results of the treatment of inoperable
Volume 79
Postpneumonectomy empyema
Number 6 June, 1980
sarcoma by the mixed toxins of erysipelas and Bacillus prodigiosus. Am J Med Sci 131:375-430, 1906 8 Vaisrub S: Empyema in lung cancer-the cloud with a silver lining. JAMA 224:1644, 1973 9 Edwards FR, Whitwell F: Use of BCG as an immunostimulant in the surgical treatment of carcinoma of the lung. Thorax 29:654-658, 1974 10 Israel L, Mawas C, Bouvrain A, Mannoni P, Sors C: Immunology of bronchial carcinoma. Thorax 31:493506, 1967
855
11 Woodruff MFA: Tumour inhibiting properties of anaerobic corynebacterium. Transplant Proc 7:229-234, 1975 12 Bone G: Postoperative empyema and survival in lung cancer. Br Med J 2:178, 1973 13 Mihich E, Neter E: Necrotising effects of Staph. aureus extract on mouse sarcoma. Proc Soc Exp Bioi Med 106:97-101, 1961 14 Goldstraw P: Postpneumonectomy empyema. Thorax 33:129-130, 1978
Information for authors Most of the provisions of the Copyright Act of 1976 became effective on January I, 1978. Therefore, all manuscripts must be accompanied by the following written statement, signed by one author: "The undersigned author transfers all copyright ownership of the manuscript (title of article) to The C. V. Mosby Company in the event the work is published. The undersigned author warrants that the article is original, is not under consideration by another journal, and has not been previously published. I sign for and accept responsibility for releasing this material on behalf of any and all co-authors." Authors will be consulted, when possible, regarding republication of their material.