Symposium on Surgical Infections and Antibiotics
Etiology of Pneumatosis Cystoides Intestinalis
Charles E. Yale, M.D.*
Pneumatosis cystoides intestinalis (PCI) is an uncommon disorder characterized by the presence of gas-filled cysts within the wall of some part of the gastrointestinal tract. Similar cysts are frequently found in the mesentery adjacent to the involved intestine, and are occasionally found in other organs in the abdominal cavity, within the omentum or regional lymph nodes, or attached to any portion of the visceral or parietal peritoneum. PCI is also known as pneumatosis intestinalis, intestinal emphysema, cystic lymphopneumatosis, and abdominal or intestinal gas cysts. Ecker et al.4 state that PCI was first described in a human by DuVernoi in 1730 and was subsequently found in animals, especially swine. Other investigators have adequately reviewed the world literature.4. 7. 8 The condition occurs in both sexes and at all ages. Grossly, the intestinal gas-filled cyst may appear in several different forms. Sometimes they massively infiltrate the wall of the intestine and appear as innumerable coalescing cysts of 1 to 2 mm. diameter or less. This gives the bowel a spongy crepitant touch upon palpation. At other times only a few large (> 1 cm. diameter) cysts are attached to, or located just beneath, the serosa of an otherwise normal appearing segment of bowel. All gradations between these two appearances have been reported. Other gas-filled cysts found in the .abdominal cavity may resemble small grapes hanging from the omentum or a mass of soap bubbles adhering to a part of the peritoneal surface. Microscopically, the cysts may be found in the intestinal mucosa, submucosa and subserosa. Any combination of submucosal and subserosal PCI may be seen in a given patient. The cysts are usually lined by long flat cells (presumably histiocytes), and separated from one another by connective tissue containing a variable number of inflammatory cells. Bacteria are rarely seen in many of the subserosal cysts and infrequently in the inflammatory reaction that surrounds them. PCI has been found in association with any of a large number of ·Professor of Surgery, University of Wisconsin Medical School, Madison, Wisconsin Surgical Clinics of North America- Vol. 55, No.6, December 1975.
1297
1298 Table 1.
CHARLES
E.
YALE
Partial List of Conditions Associated with Pneumatosis Cystoides Intestinalis
Pulmonary Conditions Chronic lung disease Emphysema Pneumomediastinum Gastrointestinal Conditions Peptic ulceration Carcinoma of the gastrointestinal tract Pyloric stenosis and other forms of partial or complete intestinal obstruction Intestinal strangulation Chronic enterocolitis including tuberculosis, regional enteritis and ulcerative colitis Acute necrotizing enteritis Pseudomembranous enterocolitis Diarrhea of infancy Appendicitis Diverticulitis Peritonitis Intestinal injury due to blunt abdominal trauma, laparotomy or sigmoidoscopy Intestinal parasites Collagen diseases Whipple's disease
conditions3 (Table 1). It is seen more frequently in association with gastrointestinal conditions than with pulmonary conditions. The symptomatology and prognosis of PCI are generally those of the associated condition, although there have been cases where cystic infiltration of the intestine has caused partial intestinal obstruction. Some cases of PCI have been found incidentally in asymptomatic, usually adult, patients. This has led to the postulation that there are two types of PCI, an infant type which is symptomatic and an adult type which is not. The infant type is characterized by acute necrotizing enteritis, where the PCI is primarily submucosal and the course is rapidly fatal. It is postulated that the massive dissection of gas in the submucosa devascularizes the mucosa, which in turn sloughs and allows the highly toxic intraluminal material free access to the exposed blood vessels. A fulminating sepsis results. The adult type is found in the asymptomatic patient. Here the cysts are apt to be sub serosal. Gas in the subserosa does not jeopardize the vasculature of the bowel, and sepsis is infrequent. Some clinicians postulate that the two types of PCI, because they are so different, are caused by different mechanisms. A bacterial hypothesis has been used to explain the infant type and a pulmonary hypothesis has been postulated for the adult type. 9 , 10 This paper discusses some new evidence that supports the bacterial etiology of PCI, regardless of the type.
BACTERIAL HYPOTHESIS Several early investigators suggested that the gas in the cysts was formed by gas-producing bacteria within the lymphatics or within the
PNEUMATOSIS CYSTOIDES INTESTINALIS
1299
tissues of the gastrointestinal tract.!· 8 In the few cases where the gases within the cysts have been analyzed, there was a higher concentration of hydrogen and a lower concentration of oxygen in the cyst than in air.6 • 8 This suggests that the gas was produced by bacteria. However, the bacterial theory has been rejected by most investigators because, especially in the asymptomatic adult type of PCI, there is very little inflammation, very few bacteria are seen in or about the cysts on microscopic examination, and cultures of the cysts are frequently sterile. Perhaps a better reason was that until recently, PCI could not be consistently produced by injecting bacteria into experimental animals. In 1968 Stone et alP produced PCI in guinea pigs by injecting a culture of Escherichia coli, Enterobacter aerogenes or Clostridium perfringens into the intestinal submucosa. In 1971 we 12 reported the presence of PCI in rats after various strains of C. perfringens had been injected into an isolated segment of strangulated intestine in a germfree rat. This particular experimental animal model had been used over the previous 10 years to study the effect of a large variety of the common intestinal organisms in the monocontaminated animal with intestinal strangulation. We found PCI only in those animals contaminated with C. perfringens. A series of experiments were subsequently done and reported in which pure cultures of C. perfringens as well as nine other common intestinal bacteria, including E. coli and E. aerogenes, were injected into either the peritoneal cavity or into the wall of the terminal ileum and cecum of the germfree rat. 13 Only the C. perfringens contaminated animal developed PCI. There were instances in which multiple small submucosal cysts extensively involved the terminal ileum and all of the colon with its attached mesentery, and converted the bowel into a crepitant spongy mass of tissue. Large subserosal cysts, isolated grapelike clusters of omental cysts, and spoonfuls of peritoneal soap bubbles were also observed upon occasions. Almost any conceivable mixture of the various pathological pictures was seen in one animal or another. It was interesting to note that simple contamination of the peritoneal cavity through a small midline abdominal incision consistently resulted in the formation of PCI. Although trauma to the intestines and to the peritoneal cavity from the injection was minimal, PCI was consistently seen two to three weeks later. PCI was never seen before four days after operation and only infrequently at one week after operation. The PCI appeared to regress after 43 days, although this study was inconclusive. Recently, we have done some additional experimental work on the formation of PCI. To date, only clostridia have produced PCI in our experimental animals. Ten species of clostridia have now been studied, and among them are the species usually implicated in gas gangrene. These ten species are C. bifermentans, C. fallax, C. hemolyticum, C. histolyticum, C. perfringens, C. novyi, C. ramosum, C. septicum, C. sporogenes, and C, tertium. In addition to C. perfringens, we have found that a pure culture of C. tertium will produce PCI in a germfree rat under our experimental conditions. We are presently working to clarify the natural course of PCI, partic-
1300
CHARLES
E.
YALE
ularly the regression of the cysts, and the bacteriology of the peritoneal cavity. Many clinicians have reported that, in some cases of well developed PCI, especially those of the asymptomatic adult type, the surfaces of the cysts and of the peritoneal cavities were sterile. We have now opened and cultured the peritoneal cavities of some of our C. perfringens monocontaminated rats with well developed PCI, using aseptic techniques. These cultures were immediately transferred into gassed out culture tubes and transferred to an anaerobic glove box for incubation. These cultures were sterile. This shows that the lack of a positive peritoneal culture in the presence of well developed PCI does not invalidate the bacterial hypothesis. At present we know that at least two species of gas-producing clostridia can produce PCl. The bacterial hypothesis for the formation of at least some cases of PCI appears to be proven conclusively. It seems unlikely that many of the common intestinal bacteria, including E. coli and E. aerogenes, which have previously been implicated, can, by themselves, cause the formation of PCl.
OTHER HYPOTHESES In addition to the bacterial hypothesis there are biochemical, mechanical, neoplastic and nutritional theories for the origin of PCl. The biochemical, nutritional and neoplastic theories, as summarized by KOSS,7 have had little support in recent years. Currently, the mechanical theory is the most popular. According to this theory, gas is forced into cysts along the intestine in one of two ways. In the first way, pulmonary alveoli rupture occurs in patients with chronic lung disease, and air escapes from the thorax by dissecting along the aorta and mesenteric blood vessels to the bowel. In the second way, intraluminal intestinal gas passes through a mucosal tear or ulcer to reach the submucosa. We think the mechanical process is probably invalid in all but the rarest cases of PCI, because, in the many hundreds of operations that we have done on germfree rats, involving all types of very stressful intestinal obstruction and strangulation experiments, we have never recognized a case of PCl. As previously stated, a simple injection of a pure culture of 10 6 viable cells per ml. of a C. perfringens suspension into the free peritoneal cavity of a germfree rat almost invariably results in PCI formation. There appear to be no mechanical factors at work to cause this. It is possible that the pressure of the intraluminal gas may speed the entry of bacteria into the lymphatics of the bowel wall in some ulcerating conditions. However, it is certainly not necessary to invoke this mechanical hypothesis in order to explain the pathological picture in these cases.
COMMENTS In our experimental work with intestinal strangulation and obstruction, C. perfringens proved to be lethal when injected into a closed loop
I
PNEUMATOSIS CYSTOIDES INTESTINALIS
1301
of either ischemically or hemorrhagically strangulated bowel in a germfree rat. After injection of C. perfringens, massive amounts of gas quickly formed. This caused the total dissolution of the bowel and death of the animal within 12 hours. We have now shown, in other animal experiments, that clostridia can cause an innocuous case of PCI. The difference in lethality in these two instances depended on the amount and site of contamination, and on the presence of an anaerobic environment and dead tissue. Bornside et al. 2 recovered clostridia in concentrations of about lOS viable organisms per ml. of aspirate from the small intestine in 20 to 30 per cent of a group of patients with normal gastrointestinal tracts. It is likely that clostridia can be recovered at one time or another from almost all humans. It seems reasonable to assume that clostridia can cause the same wide spectrum of disease in the human as is seen in the animal. The PCI found in association with the fulminating lethal necrotizing enteritis of infancy or the pseudomembranous enterocolitis of the adult represents one extreme of. the pathophysiologic process caused or augmented by the clostridial organisms or by some as yet undiscovered gasforming bacteria. At the other extreme is the PCI frequently reported in asymptomatic adults, which causes no adverse pathophysiologic conditions. Recognition of PCI in the seriously ill patient, or the appearance of a toxic illness frequently associated with PCI, suggests that vigorous steps should be taken to control the anaerobic, gram-positive clostridia. In the treatment of a disease as deadly as necrotizing enterocolitis of infancy, massive intravenous doses of antibiotics to which the clostridia are usually sensitive should probably be used. Although the clostridia may be the principal organisms causing gaseous disruption of the bowel, the tissue planes opened by the gas will allow the other common intestinal bacteria ready access to the disrupted tissues. Therefore, antibiotic coverage should be extensive enough to cover the broad range of the usual intestinal pathogens. Hollin and van der Linden5 recently reported on two patients with PCI who were successfully treated when given high concentrations of oxygen to breathe over a five day period. Hyperbaric oxygenation has been repeatedly used in treating patients with gas gangrene, with variable results. Perhaps oxygen therapy also has a place in treating fulminating infections associated with PCI. Extensive surgical debridement is often required to control clostridial myositis, but probably has little place in the treatment of the fulminating diseases associated with PCI, unless perforation and peritonitis are present or thought to be imminent.
SUMMARY Pneumatosis cystoides intestinalis is an uncommon condition of previously unknown etiology. Experimental work is discussed which proves that either one of at least two clostridial species can produce PCI
1302
CHARLES
E.
YALE
after relatively atraumatic contamination of the peritoneal cavity of germfree animals. This work strongly supports the bacterial etiology of PCI. It further suggests that vigorous and early treatment be directed toward control of the clostridial organisms in those cases where fulminating conditions associated with PCI are present.
REFERENCES 1. Berglund, S.: Roentgen diagnosis of pneumatosis cystoides intestinorum hominis. Acta. RadioL, 20:401, 1939. 2. Bornside, G. H., Welsh, J. S., and Cohn, I. Jr.: Bacterial flora of the human small intestine. J.A.M.A., 196:1125,1966. 3. Bryk, D.: Unusual causes of small bowel pneumatosis: perforated duodenal ulcer and perforated jejunal diverticula. RadioL, 106:299, 1973. 4. Ecker, J. A., Williams, R. G., and Clay, K. L.: Pneumatosis cystoides intestinalis- bullous emphysema of the intestine. Amer. J. GastroenteroL, 56:125,1971. 5. Hiiflin, F., and van der Linden, W.: Pneumatosis cystoides intestinalis treated by oxygen breathing. Scand. J. GastroenteroL, 9:427,1974. 6. Hughes, D. T. D., Gordon, K. C. D., Swann, J. C., and Bolt, G. L.: Pneumatosis cystoides intestinalis. Gut, 7 :553, 1966. 7. Koss, L. G.: Abdominal gas cysts (pneumatosis cystoides intestinorum hominis). Arch. PathoL, 53:523,1952. 8. Nitch, C. A. R: Cystic pneumatosis of the intestinal tract. Br. J. Surg., 11 :714, 1924. 9. Reyna, R, Soper, R T., and Condon, R E.: Pneumatosis intestinalis. Report of twelve cases. Amer. J. Surg., 125:667, 1973. 10. Stiennon, A.: Pneumatosis intestinalis in the newborn. Amer. J. Dis. Child., 81 :651, 1951. 11. Stone, H. H., Allen, W. B., Smith, R B. III, and Haynes, C. D.: Infantile pneumatosis intestinalis. J. Surg. Res., 8 :301, 1968. 12. Yale, C. E., and Balish, E.: Intestinal strangulation in Clostridium perfringens monocontaminated rats. Infect. Immun., 3:481,1971. 13. Yale, C. E., BaUsh, E., and Wu, J. P.: The bacterial etiology of pneumatosis cystoides intestinaUs. Arch. Surg., 109 :89, 1974. Department of Surgery University Hospitals 1300 University Avenue Madison, Wisconsin 53706
Etiology of Pneumatosis Cystoides Intestinalis
Charles E. Yale, M.D.*
Pneumatosis cystoides intestinalis (PCI) is an uncommon disorder characterized by the presence of gas-filled cysts within the wall of some part of the gastrointestinal tract. Similar cysts are frequently found in the mesentery adjacent to the involved intestine, and are occasionally found in other organs in the abdominal cavity, within the omentum or regional lymph nodes, or attached to any portion of the visceral or parietal peritoneum. PCI is also known as pneumatosis intestinalis, intestinal emphysema, cystic lymphopneumatosis, and abdominal or intestinal gas cysts. Ecker et al.4 state that PCI was first described in a human by DuVernoi in 1730 and was subsequently found in animals, especially swine. Other investigators have adequately reviewed the world literature.4. 7. 8 The condition occurs in both sexes and at all ages. Grossly, the intestinal gas-filled cyst may appear in several different forms. Sometimes they massively infiltrate the wall of the intestine and appear as innumerable coalescing cysts of 1 to 2 mm. diameter or less. This gives the bowel a spongy crepitant touch upon palpation. At other times only a few large (> 1 cm. diameter) cysts are attached to, or located just beneath, the serosa of an otherwise normal appearing segment of bowel. All gradations between these two appearances have been reported. Other gas-filled cysts found in the .abdominal cavity may resemble small grapes hanging from the omentum or a mass of soap bubbles adhering to a part of the peritoneal surface. Microscopically, the cysts may be found in the intestinal mucosa, submucosa and subserosa. Any combination of submucosal and subserosal PCI may be seen in a given patient. The cysts are usually lined by long flat cells (presumably histiocytes), and separated from one another by connective tissue containing a variable number of inflammatory cells. Bacteria are rarely seen in many of the subserosal cysts and infrequently in the inflammatory reaction that surrounds them. PCI has been found in association with any of a large number of ·Professor of Surgery, University of Wisconsin Medical School, Madison, Wisconsin Surgical Clinics of North America- Vol. 55, No.6, December 1975.
1297
1298 Table 1.
CHARLES
E.
YALE
Partial List of Conditions Associated with Pneumatosis Cystoides Intestinalis
Pulmonary Conditions Chronic lung disease Emphysema Pneumomediastinum Gastrointestinal Conditions Peptic ulceration Carcinoma of the gastrointestinal tract Pyloric stenosis and other forms of partial or complete intestinal obstruction Intestinal strangulation Chronic enterocolitis including tuberculosis, regional enteritis and ulcerative colitis Acute necrotizing enteritis Pseudomembranous enterocolitis Diarrhea of infancy Appendicitis Diverticulitis Peritonitis Intestinal injury due to blunt abdominal trauma, laparotomy or sigmoidoscopy Intestinal parasites Collagen diseases Whipple's disease
conditions3 (Table 1). It is seen more frequently in association with gastrointestinal conditions than with pulmonary conditions. The symptomatology and prognosis of PCI are generally those of the associated condition, although there have been cases where cystic infiltration of the intestine has caused partial intestinal obstruction. Some cases of PCI have been found incidentally in asymptomatic, usually adult, patients. This has led to the postulation that there are two types of PCI, an infant type which is symptomatic and an adult type which is not. The infant type is characterized by acute necrotizing enteritis, where the PCI is primarily submucosal and the course is rapidly fatal. It is postulated that the massive dissection of gas in the submucosa devascularizes the mucosa, which in turn sloughs and allows the highly toxic intraluminal material free access to the exposed blood vessels. A fulminating sepsis results. The adult type is found in the asymptomatic patient. Here the cysts are apt to be sub serosal. Gas in the subserosa does not jeopardize the vasculature of the bowel, and sepsis is infrequent. Some clinicians postulate that the two types of PCI, because they are so different, are caused by different mechanisms. A bacterial hypothesis has been used to explain the infant type and a pulmonary hypothesis has been postulated for the adult type. 9 , 10 This paper discusses some new evidence that supports the bacterial etiology of PCI, regardless of the type.
BACTERIAL HYPOTHESIS Several early investigators suggested that the gas in the cysts was formed by gas-producing bacteria within the lymphatics or within the
PNEUMATOSIS CYSTOIDES INTESTINALIS
1299
tissues of the gastrointestinal tract.!· 8 In the few cases where the gases within the cysts have been analyzed, there was a higher concentration of hydrogen and a lower concentration of oxygen in the cyst than in air.6 • 8 This suggests that the gas was produced by bacteria. However, the bacterial theory has been rejected by most investigators because, especially in the asymptomatic adult type of PCI, there is very little inflammation, very few bacteria are seen in or about the cysts on microscopic examination, and cultures of the cysts are frequently sterile. Perhaps a better reason was that until recently, PCI could not be consistently produced by injecting bacteria into experimental animals. In 1968 Stone et alP produced PCI in guinea pigs by injecting a culture of Escherichia coli, Enterobacter aerogenes or Clostridium perfringens into the intestinal submucosa. In 1971 we 12 reported the presence of PCI in rats after various strains of C. perfringens had been injected into an isolated segment of strangulated intestine in a germfree rat. This particular experimental animal model had been used over the previous 10 years to study the effect of a large variety of the common intestinal organisms in the monocontaminated animal with intestinal strangulation. We found PCI only in those animals contaminated with C. perfringens. A series of experiments were subsequently done and reported in which pure cultures of C. perfringens as well as nine other common intestinal bacteria, including E. coli and E. aerogenes, were injected into either the peritoneal cavity or into the wall of the terminal ileum and cecum of the germfree rat. 13 Only the C. perfringens contaminated animal developed PCI. There were instances in which multiple small submucosal cysts extensively involved the terminal ileum and all of the colon with its attached mesentery, and converted the bowel into a crepitant spongy mass of tissue. Large subserosal cysts, isolated grapelike clusters of omental cysts, and spoonfuls of peritoneal soap bubbles were also observed upon occasions. Almost any conceivable mixture of the various pathological pictures was seen in one animal or another. It was interesting to note that simple contamination of the peritoneal cavity through a small midline abdominal incision consistently resulted in the formation of PCI. Although trauma to the intestines and to the peritoneal cavity from the injection was minimal, PCI was consistently seen two to three weeks later. PCI was never seen before four days after operation and only infrequently at one week after operation. The PCI appeared to regress after 43 days, although this study was inconclusive. Recently, we have done some additional experimental work on the formation of PCI. To date, only clostridia have produced PCI in our experimental animals. Ten species of clostridia have now been studied, and among them are the species usually implicated in gas gangrene. These ten species are C. bifermentans, C. fallax, C. hemolyticum, C. histolyticum, C. perfringens, C. novyi, C. ramosum, C. septicum, C. sporogenes, and C, tertium. In addition to C. perfringens, we have found that a pure culture of C. tertium will produce PCI in a germfree rat under our experimental conditions. We are presently working to clarify the natural course of PCI, partic-
1300
CHARLES
E.
YALE
ularly the regression of the cysts, and the bacteriology of the peritoneal cavity. Many clinicians have reported that, in some cases of well developed PCI, especially those of the asymptomatic adult type, the surfaces of the cysts and of the peritoneal cavities were sterile. We have now opened and cultured the peritoneal cavities of some of our C. perfringens monocontaminated rats with well developed PCI, using aseptic techniques. These cultures were immediately transferred into gassed out culture tubes and transferred to an anaerobic glove box for incubation. These cultures were sterile. This shows that the lack of a positive peritoneal culture in the presence of well developed PCI does not invalidate the bacterial hypothesis. At present we know that at least two species of gas-producing clostridia can produce PCl. The bacterial hypothesis for the formation of at least some cases of PCI appears to be proven conclusively. It seems unlikely that many of the common intestinal bacteria, including E. coli and E. aerogenes, which have previously been implicated, can, by themselves, cause the formation of PCl.
OTHER HYPOTHESES In addition to the bacterial hypothesis there are biochemical, mechanical, neoplastic and nutritional theories for the origin of PCl. The biochemical, nutritional and neoplastic theories, as summarized by KOSS,7 have had little support in recent years. Currently, the mechanical theory is the most popular. According to this theory, gas is forced into cysts along the intestine in one of two ways. In the first way, pulmonary alveoli rupture occurs in patients with chronic lung disease, and air escapes from the thorax by dissecting along the aorta and mesenteric blood vessels to the bowel. In the second way, intraluminal intestinal gas passes through a mucosal tear or ulcer to reach the submucosa. We think the mechanical process is probably invalid in all but the rarest cases of PCI, because, in the many hundreds of operations that we have done on germfree rats, involving all types of very stressful intestinal obstruction and strangulation experiments, we have never recognized a case of PCl. As previously stated, a simple injection of a pure culture of 10 6 viable cells per ml. of a C. perfringens suspension into the free peritoneal cavity of a germfree rat almost invariably results in PCI formation. There appear to be no mechanical factors at work to cause this. It is possible that the pressure of the intraluminal gas may speed the entry of bacteria into the lymphatics of the bowel wall in some ulcerating conditions. However, it is certainly not necessary to invoke this mechanical hypothesis in order to explain the pathological picture in these cases.
COMMENTS In our experimental work with intestinal strangulation and obstruction, C. perfringens proved to be lethal when injected into a closed loop
I
PNEUMATOSIS CYSTOIDES INTESTINALIS
1301
of either ischemically or hemorrhagically strangulated bowel in a germfree rat. After injection of C. perfringens, massive amounts of gas quickly formed. This caused the total dissolution of the bowel and death of the animal within 12 hours. We have now shown, in other animal experiments, that clostridia can cause an innocuous case of PCI. The difference in lethality in these two instances depended on the amount and site of contamination, and on the presence of an anaerobic environment and dead tissue. Bornside et al. 2 recovered clostridia in concentrations of about lOS viable organisms per ml. of aspirate from the small intestine in 20 to 30 per cent of a group of patients with normal gastrointestinal tracts. It is likely that clostridia can be recovered at one time or another from almost all humans. It seems reasonable to assume that clostridia can cause the same wide spectrum of disease in the human as is seen in the animal. The PCI found in association with the fulminating lethal necrotizing enteritis of infancy or the pseudomembranous enterocolitis of the adult represents one extreme of. the pathophysiologic process caused or augmented by the clostridial organisms or by some as yet undiscovered gasforming bacteria. At the other extreme is the PCI frequently reported in asymptomatic adults, which causes no adverse pathophysiologic conditions. Recognition of PCI in the seriously ill patient, or the appearance of a toxic illness frequently associated with PCI, suggests that vigorous steps should be taken to control the anaerobic, gram-positive clostridia. In the treatment of a disease as deadly as necrotizing enterocolitis of infancy, massive intravenous doses of antibiotics to which the clostridia are usually sensitive should probably be used. Although the clostridia may be the principal organisms causing gaseous disruption of the bowel, the tissue planes opened by the gas will allow the other common intestinal bacteria ready access to the disrupted tissues. Therefore, antibiotic coverage should be extensive enough to cover the broad range of the usual intestinal pathogens. Hollin and van der Linden5 recently reported on two patients with PCI who were successfully treated when given high concentrations of oxygen to breathe over a five day period. Hyperbaric oxygenation has been repeatedly used in treating patients with gas gangrene, with variable results. Perhaps oxygen therapy also has a place in treating fulminating infections associated with PCI. Extensive surgical debridement is often required to control clostridial myositis, but probably has little place in the treatment of the fulminating diseases associated with PCI, unless perforation and peritonitis are present or thought to be imminent.
SUMMARY Pneumatosis cystoides intestinalis is an uncommon condition of previously unknown etiology. Experimental work is discussed which proves that either one of at least two clostridial species can produce PCI
1302
CHARLES
E.
YALE
after relatively atraumatic contamination of the peritoneal cavity of germfree animals. This work strongly supports the bacterial etiology of PCI. It further suggests that vigorous and early treatment be directed toward control of the clostridial organisms in those cases where fulminating conditions associated with PCI are present.
REFERENCES 1. Berglund, S.: Roentgen diagnosis of pneumatosis cystoides intestinorum hominis. Acta. RadioL, 20:401, 1939. 2. Bornside, G. H., Welsh, J. S., and Cohn, I. Jr.: Bacterial flora of the human small intestine. J.A.M.A., 196:1125,1966. 3. Bryk, D.: Unusual causes of small bowel pneumatosis: perforated duodenal ulcer and perforated jejunal diverticula. RadioL, 106:299, 1973. 4. Ecker, J. A., Williams, R. G., and Clay, K. L.: Pneumatosis cystoides intestinalis- bullous emphysema of the intestine. Amer. J. GastroenteroL, 56:125,1971. 5. Hiiflin, F., and van der Linden, W.: Pneumatosis cystoides intestinalis treated by oxygen breathing. Scand. J. GastroenteroL, 9:427,1974. 6. Hughes, D. T. D., Gordon, K. C. D., Swann, J. C., and Bolt, G. L.: Pneumatosis cystoides intestinalis. Gut, 7 :553, 1966. 7. Koss, L. G.: Abdominal gas cysts (pneumatosis cystoides intestinorum hominis). Arch. PathoL, 53:523,1952. 8. Nitch, C. A. R: Cystic pneumatosis of the intestinal tract. Br. J. Surg., 11 :714, 1924. 9. Reyna, R, Soper, R T., and Condon, R E.: Pneumatosis intestinalis. Report of twelve cases. Amer. J. Surg., 125:667, 1973. 10. Stiennon, A.: Pneumatosis intestinalis in the newborn. Amer. J. Dis. Child., 81 :651, 1951. 11. Stone, H. H., Allen, W. B., Smith, R B. III, and Haynes, C. D.: Infantile pneumatosis intestinalis. J. Surg. Res., 8 :301, 1968. 12. Yale, C. E., and Balish, E.: Intestinal strangulation in Clostridium perfringens monocontaminated rats. Infect. Immun., 3:481,1971. 13. Yale, C. E., BaUsh, E., and Wu, J. P.: The bacterial etiology of pneumatosis cystoides intestinaUs. Arch. Surg., 109 :89, 1974. Department of Surgery University Hospitals 1300 University Avenue Madison, Wisconsin 53706
