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The myth of the fecalith
The Myth of the Fecalith RICHARD L. MAENZA, MD LINDA SMITH, MD ALLAN B. WOLFSON, MD A radiographically demonstrated fecalith is widely considered a virtually pathognomonic sign of acute appendicitis. This case report describes a patient with a clinical presentation suggestive of appendicitis and a well-defined right lower quadrant fecalith who was found to have a normal appendix at surgery. This case calls into question the venerable dogma surrounding the fecalith and highlights the necessity for the physician to continue to rely on clinical judgment in making the diagnosis of appendicitis. (Am J Emerg Med 1996;14:394-397. Copyright © 1996 by W.B. Saunders Company) The emergency department (ED) evaluation of suspected appendicitis requires the clinician to integrate and interpret clinical, laboratory, and radiographic data. The diagnostic accuracy of clinical findings and ancillary studies, however, has been reported to be as low as 25%, and generally no greater than 85%. 1-1° The presence of a calcified, lamellated, appendiceal mass (termed a fecalith or appendicolith) (Figure 1) is widely identified as a virtually pathognomonic sign of acute appendicitis. 11-13 We recently cared for a patient with suspected appendicitis in whom a fecalith was found on abdominal radiography.
tenderness, involuntary guarding, or organomegaly. The rectal examination yielded stool that was trace-positive for blood but otherwise unremarkable. An electrocardiogram and chest radiograph were unchanged from previous studies. An abdominal radiograph showed no free air and a gas pattern consistent with small bowel ileus. A 0.75-cm lamellated, calcified density was seen in the right lower quadrant. Laboratory studies showed normal electrolyte, blood urea nitrogen, and creatinine levels. The white blood cell count was 11,000, with 79% neutrophils, 6% lyphocytes, and 4% band forms. The hematocrit was 34% and the platelet count 335,000. Liver function test results and amylase level were normal. A fecal smear showed no leukocytes. The urinalysis was negative except for trace blood and protein by dipstick. The patient was admitted to the hospital and observed. The abdominal pain intensified over the next 12 hours, and a repeat complete blood count showed an increase in the white blood cell count to 15,800, with 79% neutrophils and 10% band forms. The patient was taken to the operating room for appendectomy. At surgery a massively distended cecum (19 cm in diameter) and multiple small bowel adhesions were discovered. The was no pus or intestinal contents within the peritoneal cavity. The appendix was grossly normal, and this was confirmed on pathological and histological examination. A calcified fecalith was found in the lumen of the appendix.
CASE REPORT A 66-year-old man presented to the ED with a 4-day history of worsening right lower quadrant abdominal pain, nausea, anorexia, diarrhea, and a subjective feeling of fever. During this time he also had upper respiratory symptoms consisting of a mild cough and coryza. His medical history was significant for adult-onset diabetes mellitus, coronary artery disease, myocardial infarction, and ventricular arrhythmia. He had previously undergone a triple-vessel coronary artery bypass graft, a right lower lobectomy for lung cancer, and repair of a suprarenal abdominal aortic aneurysm. Physical examination revealed a robust man who preferred to lie very still. The vital signs were as follows: temperature, 36.9°C; blood pressure, 130/80 mm Hg; pulse, 88 beats/rain; and respirations, 18 breaths/min and unlabored. Skin, head, and neck examination results were within normal limits. Cardiac examination revealed a normal S i, a widely split $2, and no murmurs, rubs, or gallops. The lungs were clear to auscultation bilaterally. On abdominal examination there was right lower quadrant fullness, with tenderness to palpation. Palpation of the left lower quadrant produced pain in the right lower quadrant. Positive right-sided obturator and psoas signs were noted. There was no rebound
DISCUSSION A radiopaque fecalith in the right lower quadrant has been identified as a virtually pathonogmonic sign of early acute appendicitis by respected surgical, medical, and pediatric textbooks. 1H4 None of these texts, however, cite published evidence for these statements. In the case presented here, the finding of a normal appendix at surgery despite the presence of a fecalith calls this venerable dogma into question. The association between the presence of a radiographically identified fecalith and appendicitis is well documented. Fecaliths have been identified by plain radiography, 6,15-19 ultrasound, 16,2°-25 and computed tomography (CT)] 5,26 and at laparotomy. 27 Associated appendicitis in these reports was demonstrated by surgical or histological examination. However, the imaging studies were performed because o f clinically suspected intra-abdominal pathology, which may have introduced a strong selection bias.
Plain Film Radiography From the University of Pittsburgh Affiliated Residency in Emergency Medicine and The Center for Emergency Medicine of Western Pennsylvania, Pittsburgh. Manuscript received June 6, 1995, accepted June 6, 1995. Address reprint requests to Dr Wolfson, Center for Emergency Medicine, 230 McKee Place, Suite 500, Pittsburgh, PA 15213. Key Words:Appendicitis, abdominal pain, abdominal radiography. Copyright © 1996 by W.B. Saunders Company 0735-6757/96/1404-001555.00/0 394
A limited number o f studies from the 1940s and 1960s identified fecaliths of the appendix in normal abdomens as well as in patients with an acute abdomen. 2s'3° These articles reported that about 13% of patients with acute appendicitis at surgery had fecaliths visible on abdominal X-rays, compared to 2% to 4% of normal controls. More recent literature reports a significant number of patients in whom a radiographically identifiable fecalith was
MAENZA ET AL • MYTH OF THE FECALITH
395
associated with appendicitis and is therefore a pathonogmonic sign of this disease.
CT Scanning In a study by Malone et a126 utilizing unenhanced CT in the diagnosis of acute appendicitis, 211 patients with right lower quadrant abdominal pain underwent CT without oral or intravenous contrast. A fight lower quadrant calcification was noted in 40 of the 211 patients. However, at the time of surgery only 29 of the 40 (73%) had pathologically proven appendicitis. The authors concluded that calcification in the fight lower quadrant must be associated with inflammation for the diagnosis of appendicitis to be made. This finding concurs with those of Balthazar et al, 1~ who examined 38 patients with histologically proven appendicitis who had undergone CT scanning. Nine patients had an appendicolith identified on CT, but all were accompanied by focal signs of inflammation or abscess. These authors caution that appendicoliths are seen in asymptomatic individuals on CT scan and that in the absence of associated inflammatory changes they have no immediate clinical implications. Of interest is that all 38 of these patients also had plain abdominal radiographs taken and that a calcified appendieolith was identified in only 5 cases with this modality. FIGURE 1. Abdominal radiograph showing typical fecalith (arrow).
present and, yet, acute appendicitis was absent. In the largest series, 6 570 of 1,000 patients undergoing surgery for suspected appendicitis had plain films obtained. A fecalith was identified in 14 of these 570 patients; of these, 13 had histologically proven appendicitis. Teicher et a117investigated the usefulness of the plain film in developing a scoring system for the diagnosis of acute appendicitis. In this case-control study, two groups of patients were examined: 100 patients with proven appendicitis and 100 patients with surgically proven normal appendices. A fecalith was found in 10.5% of patients with appendicitis versus 3.3% of those with a normal appendix. Another study 18 evaluated the utility of plain films in pediatric patients presenting to the ED with abdominal pain. A "diagnostic" radiograph was defined as one that was "pathonogmonic" for acute appendicitis: appendicolith with ileus. Of 18 patients, 2 had misleading "diagnostic" films that demonstrated an appendicolith and ileus, but these 2 patients did not have appendicitis at surgery. Conversely, of the 16 patients who proved to have acute appendicitis, only 2 had "diagnostic" films. Several other studies have also noted the presence of a fecalith on plain radiography in the absence of histologically or surgically proven appendicitis. 6,15-19 These studies and others support the correlation between appendicitis and the presence of a fecalith on abdominal radiography, but each of them also mentions patients who had a fecalith but did not have appendicitis. The identification of a fecalith in these patients, and others such as the one reported here, refutes the widely held notion that a detectable fecalith is invariably
Laparotomy Burkitt 27reported the incidence of fecalith in two separate patient populations. One group of patients underwent laparotomy for any of a number of indications (including trauma). In these 73 patients, 44 incidental fecaliths were found (60%) in patients who were not suspected of having acute appendicitis. The second patient population underwent surgery for suspected appendicitis. Here 33 of 63 patients (52%) had a fecalith palpated at the time of surgery. The incidental finding of fecaliths was remarkably high when compared to the number of fecaliths found in patients with suspected appendicitis. This study did not note whether the appendicoliths were identifiable on plain radiography or with other imaging modalities.
Ultrasonography In the past 5 years, ultrasound has been increasingly utilized as an aid in the diagnosis of appendicitis. 3~-3sAmong the ultrasonographic signs of appendiceal inflammation or abscess are a noncompressible enlarged appendix, inflammation of periappendiceal fat, and local fluid collection or mass. Fecaliths are also visualized by ultrasound, one article reporting that 50% of these fecaliths were not detected on abdominal plain films. 3I The incidence of fecalith detectable by ultrasound in patients with surgically confirmed appendicitis is reported to be 9.7% to 33.7%. 31,35 Although the presence of a fecalith on ultrasound examination was considered by all investigators to support the diagnosis of appendicitis, in no case was it the sole evidence for appendicitis. In other words, in these studies the ultrasonographic diagnosis of appendicitis was based on signs of
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AMERICAN JOURNAL OF EMERGENCY MEDICINE • Volume 14, Number 4 • July 1996
appendiceal inflammation or infection, independent of the presence of a fecalith.
Pathophysiology One reason the fecalith has been widely considered a specific indicator of appendicitis 11,12,36 may be that obstruction of the appendiceal lumen is believed to play a central pathophysiologic role in the development of acute appendicitis. 11,1z37Classically, u,12,38,39 appendicitis has been thought to begin with luminal obstruction of the appendix by a fecalith, local inflammation, lymphoid hyperplasia, foreign body, or tumor, leading to accumulation of secreted mucus behind the obstruction. Bacteria within the static mucus proliferate, increasing intraluminal pressure and leading to ischemia and perforation of the appendix. The radiographically visualized fecalith is held to represent objective evidence of appendiceal luminal obstruction and, therefore, appendicitis. Nevertheless, the mere presence of a fecalith within the appendix is not necessarily indicative of obstruction. A growing body of evidence suggests that luminal obstruction is not a necessary factor in the production of appendicitis and, indeed, that the majority of cases of appendicitis occur without any evidence of obstruction of the appendiceal lumen. Arnbjorusson and Bengmark4° measured intralumihal pressure in the appendices of 33 patients undergoing appendectomy for suspected appendicitis. A fine needle was inserted into the appendix at surgery, and measurements were made of the hydrostatic pressure required to inject saline into the lumen. Of 21 patients with phlegmonous appendicitis at operation, only 2 were found to have luminal obstruction as indicated by an increased intraluminal pressure. In contrast, all 6 cases of gangrenous appendicitis had an elevated intraluminal pressure, indicating obstruction. The authors concluded that obstruction is not a necessary factor in the causation of acute appendicitis, but that it may develop as a result of the inflammatory process. Recently, some authors have attempted to identify ultrasonographic findings that could distinguish perforated from nonperforated appendicitis. 33,34Patients with a fecalith were found to be no more likely to have perforation than those without a fecalith. This observation supports the notion that either fecaliths do not obstruct the appendiceal lumen or that luminal obstruction is not important in the progression of appendicitis. Similarly, based on the study of 71,000 appendices over a period of 40 years as a pathologist, Collins 41 reported that 65% of cases of appendicitis were not associated with appendiceal obstruction. Other investigators have echoed the conclusion that obstruction is not a necessary part of the pathogenesis of acute appendicitis. ~5,4~
CONCLUSIONS The case reported here highlights the fact that the presence of a fecalith on plain film, ultrasound, or CT scan cannot in itself be considered pathonogmonic of appendicitis. Physicians should continue to rely on their clinical judgment in making the diagnosis of appendicitis, even in the presence of a fecalith.
REFERENCES 1. Dueholm S, Bagi P, Bud M: Laboratory aid in the diagnosis of acute appendicitis. Dis Colon Rectum 1989;32:855-859 2. Jess P, Bierregaard B, Brynitz S, et al: Acute appendicitis: Prospective trial concerning diagnostic accuracy and complications. Am J Surg 1981 ;141:232-234 3. Van Way CW, Murphy JR, Dunn EL: A feasibility study of computer aided diagnosis in appendicitis. Surg Gynecol Obstet 1982; 155:685-688 4. Lichtner S, Pflantz M: Appendectomy in the Federal Republic of Germany. Med Care 1971 ;9:311-330 5. Chang FC, Hogel HH, Welling DR: The fate of the negative appendix. Am J Surg 1973;126:752-755 6. Lewis FR: Appendicitis: A critical review of diagnosis and treatment in 1000 cases. Arch Surg 1975;110:677-684 7. Mason LB, Deyden WE: Primary appendectomy. Am Surg 1976;42:239-243 8. Berry J, Malt RAI: Appendicitis near its centenary. Ann Surg 1984;200:567-575 9. Kniskern J, Eskin E, Fletcher HS: Increasing accuracy in the diagnosis of acute appendicitis with modern diagnostic techniques. Am Surg 1984;52:222-225 10. Puylaert JB, Rutgers PH, Lalisang RI, et al: A prospective study of ultrasonography in the diagnosis of appendicitis. N Engl J Med 1987;317:666-669 11. Schwartz Sl: Appendix. In Schwartz SI (ed): Principles of Surgery. New York, NY, McGraw-Hill, 1989, p 1318 12. Condon RE, Telford GL: Appendicitis. In Sabiston DC (ed): Textbook of Surgery. Philadelphia, PA, Saunders, 1991, pp 884-889 13. Reisdorff EJ, Roberts MR, Wiegenstein JG (eds): Pediatric Emergency Medicine. Philadelphia, PA, Saunders, 1993 14. Singer JI, Losek JD: Grunting respirations: Chest or abdominal pathology? Pediatr Emerg Care 1992;8:354-358 15. Balthazar EJ, Megibow AJ, Halnick D, et al: CT of appendicitis. AJ R Am J Roentgenol 1986; 147:705-710 16. Vignault F, Filitarault D, Brandt ML, et al: Acute appendicitis in children: Evaluation with US. Radiology 1990; 176:501-505 17. Teicher I, Landa B, Cohen M, et al: Scoring system to aid in the diagnosis of appendicitis. Ann Surg 1983;198:753-759 18. Rothrock SG, Green SM, Harding M, et al: Plain abdominal radiography in the detection of medical and surgical disease in children: a retrospective analysis. Pediatr Emerg Care 1991;7:281285 19. Beneventano TC, Schein CJ, Jacobson HG: The Roentgen aspects of some appendiceal abnormalities. AJR Am J Roentgenol 1966;96:334-360 20. Jeffrey RB, Laing FC, Townsend RR: Acute appendicitis: sonographic criteria based on 250 cases. Radiology 1988;167:327329 21. Rubin SZ, Martin DJ: Ultrasonography in the management of possible appendicitis in childhood. J Pediatr Surg 1990;25:737-740 22. Siegel MJ, Carel C, Surratt S: Ultrasonography of acute abdominal pain in children. JAMA 1991 ;226:1987-1989 23. Sivit C J, Newman KD, Boenning DA, et al: Appendicitis: Usefulness of ultrasound in diagnosis in a pediatric population. Pediatr Radiol 1992;185:549-559 24. Crady SK, Jones JS, Wyn T: Clinical validity of ultrasound in children with suspected appendicitis. Ann Emerg Med 1993;22:11251129 25. Quillin SP: Appendicitis in children: Color Doppler sonography. Radiology 1992; 184:745-747 26. Malone A, Wolf C, Maimed A, et al: Diagnosis of acute appendicitis: Value of unenhanced CT. AJR Am J Roentgenol 1993; 160:763-766 27. Burkitt DP: The aetiology of appendicitis. Br J Surg 1971;58: 695-699 28. Felson B, Bernhard CM: Roentgenologic diagnosis of appendiceal calculi. Radiology 1947;49:178-191 29. Graham AD, Johnson HF: The incidence of radiographic findings in acute appendicitis compared to 200 normal abdomens. Mil Med 1966;272-276 30. Faegenburg D: Fecaliths of the appendix: Incidence and significance. AJR Am J Roentgeno11963;89:752-759
MAENZA ET AL • MYTH OF THE FECALITH
31. Ceres L, Alonso I, Lopez P, et al: Ultrasound study of acute appendicitis in children with emphasis upon the diagnosis of retrocecal appendicitis. Pediatr Radio11990;20:258-261 32. Swerk WB, Wichtrup B, Ruschoff J, et al: Acute and perforated appendicitis: current experience with ultrasound-aided diagnosis. World J Surg 1990;14:271-276 33. Borushok KF, Jeffrey RB Jr, Laing FC, et al: Sonographic diagnosis of perforation in patients with acute appendicitis. AJR Am J Roentgenol 1990;154:275-278 34. Quillin SP, Siegel SP: Color doppler US of children with acute lower abdominal pain. Radiographics 1993;13:1281-1293 35. Vignault F, Filiatrault D, Brandt ML, et al: Acute appendicitis in children: evaluation with US. Radiology 1990; 176:501-504 36. Fee HJ Jr, Jones PC, Kadell B, et al: Radiologic diagnosis of appendicitis. Arch Surg 1977;112:742-744 37. Jones BA, Demetriades D, Segal i, et al: The prevalence of
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appendiceal fecaliths in patients with and without appendicitis. Ann Surg 1985;202:80-82 38. Wangensteen OH, Bowers WF: Significance of the obstructive factor in the genesis of acute appendicitis. An experimental study. Arch Surg 1939;34:496-526 39. Wangensteen OH: Experimental proof of the obstructive origin of appendicitis in man. Ann Surg 1939;110:629-647 40. Arnbjornsson E, Bengmark S: Obstruction of the appendix lumen in relation to pathogenesis of acute appendicitis. Acta Chir Scand 1983;149:789-791 41. Collins DC: 71,000 lumen appendix specimens: A final report summarizing 40 years' study. Am J Procto11963;14:365-381 42. Sisson RG, Ahlvin HC, Harlow MC: Superficial mucosal ulceration and the pathogenesis of acute appendicitis. Am J Surg 1971;122:378-380
tenderness, involuntary guarding, or organomegaly. The rectal examination yielded stool that was trace-positive for blood but otherwise unremarkable. An electrocardiogram and chest radiograph were unchanged from previous studies. An abdominal radiograph showed no free air and a gas pattern consistent with small bowel ileus. A 0.75-cm lamellated, calcified density was seen in the right lower quadrant. Laboratory studies showed normal electrolyte, blood urea nitrogen, and creatinine levels. The white blood cell count was 11,000, with 79% neutrophils, 6% lyphocytes, and 4% band forms. The hematocrit was 34% and the platelet count 335,000. Liver function test results and amylase level were normal. A fecal smear showed no leukocytes. The urinalysis was negative except for trace blood and protein by dipstick. The patient was admitted to the hospital and observed. The abdominal pain intensified over the next 12 hours, and a repeat complete blood count showed an increase in the white blood cell count to 15,800, with 79% neutrophils and 10% band forms. The patient was taken to the operating room for appendectomy. At surgery a massively distended cecum (19 cm in diameter) and multiple small bowel adhesions were discovered. The was no pus or intestinal contents within the peritoneal cavity. The appendix was grossly normal, and this was confirmed on pathological and histological examination. A calcified fecalith was found in the lumen of the appendix.
CASE REPORT A 66-year-old man presented to the ED with a 4-day history of worsening right lower quadrant abdominal pain, nausea, anorexia, diarrhea, and a subjective feeling of fever. During this time he also had upper respiratory symptoms consisting of a mild cough and coryza. His medical history was significant for adult-onset diabetes mellitus, coronary artery disease, myocardial infarction, and ventricular arrhythmia. He had previously undergone a triple-vessel coronary artery bypass graft, a right lower lobectomy for lung cancer, and repair of a suprarenal abdominal aortic aneurysm. Physical examination revealed a robust man who preferred to lie very still. The vital signs were as follows: temperature, 36.9°C; blood pressure, 130/80 mm Hg; pulse, 88 beats/rain; and respirations, 18 breaths/min and unlabored. Skin, head, and neck examination results were within normal limits. Cardiac examination revealed a normal S i, a widely split $2, and no murmurs, rubs, or gallops. The lungs were clear to auscultation bilaterally. On abdominal examination there was right lower quadrant fullness, with tenderness to palpation. Palpation of the left lower quadrant produced pain in the right lower quadrant. Positive right-sided obturator and psoas signs were noted. There was no rebound
DISCUSSION A radiopaque fecalith in the right lower quadrant has been identified as a virtually pathonogmonic sign of early acute appendicitis by respected surgical, medical, and pediatric textbooks. 1H4 None of these texts, however, cite published evidence for these statements. In the case presented here, the finding of a normal appendix at surgery despite the presence of a fecalith calls this venerable dogma into question. The association between the presence of a radiographically identified fecalith and appendicitis is well documented. Fecaliths have been identified by plain radiography, 6,15-19 ultrasound, 16,2°-25 and computed tomography (CT)] 5,26 and at laparotomy. 27 Associated appendicitis in these reports was demonstrated by surgical or histological examination. However, the imaging studies were performed because o f clinically suspected intra-abdominal pathology, which may have introduced a strong selection bias.
Plain Film Radiography From the University of Pittsburgh Affiliated Residency in Emergency Medicine and The Center for Emergency Medicine of Western Pennsylvania, Pittsburgh. Manuscript received June 6, 1995, accepted June 6, 1995. Address reprint requests to Dr Wolfson, Center for Emergency Medicine, 230 McKee Place, Suite 500, Pittsburgh, PA 15213. Key Words:Appendicitis, abdominal pain, abdominal radiography. Copyright © 1996 by W.B. Saunders Company 0735-6757/96/1404-001555.00/0 394
A limited number o f studies from the 1940s and 1960s identified fecaliths of the appendix in normal abdomens as well as in patients with an acute abdomen. 2s'3° These articles reported that about 13% of patients with acute appendicitis at surgery had fecaliths visible on abdominal X-rays, compared to 2% to 4% of normal controls. More recent literature reports a significant number of patients in whom a radiographically identifiable fecalith was
MAENZA ET AL • MYTH OF THE FECALITH
395
associated with appendicitis and is therefore a pathonogmonic sign of this disease.
CT Scanning In a study by Malone et a126 utilizing unenhanced CT in the diagnosis of acute appendicitis, 211 patients with right lower quadrant abdominal pain underwent CT without oral or intravenous contrast. A fight lower quadrant calcification was noted in 40 of the 211 patients. However, at the time of surgery only 29 of the 40 (73%) had pathologically proven appendicitis. The authors concluded that calcification in the fight lower quadrant must be associated with inflammation for the diagnosis of appendicitis to be made. This finding concurs with those of Balthazar et al, 1~ who examined 38 patients with histologically proven appendicitis who had undergone CT scanning. Nine patients had an appendicolith identified on CT, but all were accompanied by focal signs of inflammation or abscess. These authors caution that appendicoliths are seen in asymptomatic individuals on CT scan and that in the absence of associated inflammatory changes they have no immediate clinical implications. Of interest is that all 38 of these patients also had plain abdominal radiographs taken and that a calcified appendieolith was identified in only 5 cases with this modality. FIGURE 1. Abdominal radiograph showing typical fecalith (arrow).
present and, yet, acute appendicitis was absent. In the largest series, 6 570 of 1,000 patients undergoing surgery for suspected appendicitis had plain films obtained. A fecalith was identified in 14 of these 570 patients; of these, 13 had histologically proven appendicitis. Teicher et a117investigated the usefulness of the plain film in developing a scoring system for the diagnosis of acute appendicitis. In this case-control study, two groups of patients were examined: 100 patients with proven appendicitis and 100 patients with surgically proven normal appendices. A fecalith was found in 10.5% of patients with appendicitis versus 3.3% of those with a normal appendix. Another study 18 evaluated the utility of plain films in pediatric patients presenting to the ED with abdominal pain. A "diagnostic" radiograph was defined as one that was "pathonogmonic" for acute appendicitis: appendicolith with ileus. Of 18 patients, 2 had misleading "diagnostic" films that demonstrated an appendicolith and ileus, but these 2 patients did not have appendicitis at surgery. Conversely, of the 16 patients who proved to have acute appendicitis, only 2 had "diagnostic" films. Several other studies have also noted the presence of a fecalith on plain radiography in the absence of histologically or surgically proven appendicitis. 6,15-19 These studies and others support the correlation between appendicitis and the presence of a fecalith on abdominal radiography, but each of them also mentions patients who had a fecalith but did not have appendicitis. The identification of a fecalith in these patients, and others such as the one reported here, refutes the widely held notion that a detectable fecalith is invariably
Laparotomy Burkitt 27reported the incidence of fecalith in two separate patient populations. One group of patients underwent laparotomy for any of a number of indications (including trauma). In these 73 patients, 44 incidental fecaliths were found (60%) in patients who were not suspected of having acute appendicitis. The second patient population underwent surgery for suspected appendicitis. Here 33 of 63 patients (52%) had a fecalith palpated at the time of surgery. The incidental finding of fecaliths was remarkably high when compared to the number of fecaliths found in patients with suspected appendicitis. This study did not note whether the appendicoliths were identifiable on plain radiography or with other imaging modalities.
Ultrasonography In the past 5 years, ultrasound has been increasingly utilized as an aid in the diagnosis of appendicitis. 3~-3sAmong the ultrasonographic signs of appendiceal inflammation or abscess are a noncompressible enlarged appendix, inflammation of periappendiceal fat, and local fluid collection or mass. Fecaliths are also visualized by ultrasound, one article reporting that 50% of these fecaliths were not detected on abdominal plain films. 3I The incidence of fecalith detectable by ultrasound in patients with surgically confirmed appendicitis is reported to be 9.7% to 33.7%. 31,35 Although the presence of a fecalith on ultrasound examination was considered by all investigators to support the diagnosis of appendicitis, in no case was it the sole evidence for appendicitis. In other words, in these studies the ultrasonographic diagnosis of appendicitis was based on signs of
396
AMERICAN JOURNAL OF EMERGENCY MEDICINE • Volume 14, Number 4 • July 1996
appendiceal inflammation or infection, independent of the presence of a fecalith.
Pathophysiology One reason the fecalith has been widely considered a specific indicator of appendicitis 11,12,36 may be that obstruction of the appendiceal lumen is believed to play a central pathophysiologic role in the development of acute appendicitis. 11,1z37Classically, u,12,38,39 appendicitis has been thought to begin with luminal obstruction of the appendix by a fecalith, local inflammation, lymphoid hyperplasia, foreign body, or tumor, leading to accumulation of secreted mucus behind the obstruction. Bacteria within the static mucus proliferate, increasing intraluminal pressure and leading to ischemia and perforation of the appendix. The radiographically visualized fecalith is held to represent objective evidence of appendiceal luminal obstruction and, therefore, appendicitis. Nevertheless, the mere presence of a fecalith within the appendix is not necessarily indicative of obstruction. A growing body of evidence suggests that luminal obstruction is not a necessary factor in the production of appendicitis and, indeed, that the majority of cases of appendicitis occur without any evidence of obstruction of the appendiceal lumen. Arnbjorusson and Bengmark4° measured intralumihal pressure in the appendices of 33 patients undergoing appendectomy for suspected appendicitis. A fine needle was inserted into the appendix at surgery, and measurements were made of the hydrostatic pressure required to inject saline into the lumen. Of 21 patients with phlegmonous appendicitis at operation, only 2 were found to have luminal obstruction as indicated by an increased intraluminal pressure. In contrast, all 6 cases of gangrenous appendicitis had an elevated intraluminal pressure, indicating obstruction. The authors concluded that obstruction is not a necessary factor in the causation of acute appendicitis, but that it may develop as a result of the inflammatory process. Recently, some authors have attempted to identify ultrasonographic findings that could distinguish perforated from nonperforated appendicitis. 33,34Patients with a fecalith were found to be no more likely to have perforation than those without a fecalith. This observation supports the notion that either fecaliths do not obstruct the appendiceal lumen or that luminal obstruction is not important in the progression of appendicitis. Similarly, based on the study of 71,000 appendices over a period of 40 years as a pathologist, Collins 41 reported that 65% of cases of appendicitis were not associated with appendiceal obstruction. Other investigators have echoed the conclusion that obstruction is not a necessary part of the pathogenesis of acute appendicitis. ~5,4~
CONCLUSIONS The case reported here highlights the fact that the presence of a fecalith on plain film, ultrasound, or CT scan cannot in itself be considered pathonogmonic of appendicitis. Physicians should continue to rely on their clinical judgment in making the diagnosis of appendicitis, even in the presence of a fecalith.
REFERENCES 1. Dueholm S, Bagi P, Bud M: Laboratory aid in the diagnosis of acute appendicitis. Dis Colon Rectum 1989;32:855-859 2. Jess P, Bierregaard B, Brynitz S, et al: Acute appendicitis: Prospective trial concerning diagnostic accuracy and complications. Am J Surg 1981 ;141:232-234 3. Van Way CW, Murphy JR, Dunn EL: A feasibility study of computer aided diagnosis in appendicitis. Surg Gynecol Obstet 1982; 155:685-688 4. Lichtner S, Pflantz M: Appendectomy in the Federal Republic of Germany. Med Care 1971 ;9:311-330 5. Chang FC, Hogel HH, Welling DR: The fate of the negative appendix. Am J Surg 1973;126:752-755 6. Lewis FR: Appendicitis: A critical review of diagnosis and treatment in 1000 cases. Arch Surg 1975;110:677-684 7. Mason LB, Deyden WE: Primary appendectomy. Am Surg 1976;42:239-243 8. Berry J, Malt RAI: Appendicitis near its centenary. Ann Surg 1984;200:567-575 9. Kniskern J, Eskin E, Fletcher HS: Increasing accuracy in the diagnosis of acute appendicitis with modern diagnostic techniques. Am Surg 1984;52:222-225 10. Puylaert JB, Rutgers PH, Lalisang RI, et al: A prospective study of ultrasonography in the diagnosis of appendicitis. N Engl J Med 1987;317:666-669 11. Schwartz Sl: Appendix. In Schwartz SI (ed): Principles of Surgery. New York, NY, McGraw-Hill, 1989, p 1318 12. Condon RE, Telford GL: Appendicitis. In Sabiston DC (ed): Textbook of Surgery. Philadelphia, PA, Saunders, 1991, pp 884-889 13. Reisdorff EJ, Roberts MR, Wiegenstein JG (eds): Pediatric Emergency Medicine. Philadelphia, PA, Saunders, 1993 14. Singer JI, Losek JD: Grunting respirations: Chest or abdominal pathology? Pediatr Emerg Care 1992;8:354-358 15. Balthazar EJ, Megibow AJ, Halnick D, et al: CT of appendicitis. AJ R Am J Roentgenol 1986; 147:705-710 16. Vignault F, Filitarault D, Brandt ML, et al: Acute appendicitis in children: Evaluation with US. Radiology 1990; 176:501-505 17. Teicher I, Landa B, Cohen M, et al: Scoring system to aid in the diagnosis of appendicitis. Ann Surg 1983;198:753-759 18. Rothrock SG, Green SM, Harding M, et al: Plain abdominal radiography in the detection of medical and surgical disease in children: a retrospective analysis. Pediatr Emerg Care 1991;7:281285 19. Beneventano TC, Schein CJ, Jacobson HG: The Roentgen aspects of some appendiceal abnormalities. AJR Am J Roentgenol 1966;96:334-360 20. Jeffrey RB, Laing FC, Townsend RR: Acute appendicitis: sonographic criteria based on 250 cases. Radiology 1988;167:327329 21. Rubin SZ, Martin DJ: Ultrasonography in the management of possible appendicitis in childhood. J Pediatr Surg 1990;25:737-740 22. Siegel MJ, Carel C, Surratt S: Ultrasonography of acute abdominal pain in children. JAMA 1991 ;226:1987-1989 23. Sivit C J, Newman KD, Boenning DA, et al: Appendicitis: Usefulness of ultrasound in diagnosis in a pediatric population. Pediatr Radiol 1992;185:549-559 24. Crady SK, Jones JS, Wyn T: Clinical validity of ultrasound in children with suspected appendicitis. Ann Emerg Med 1993;22:11251129 25. Quillin SP: Appendicitis in children: Color Doppler sonography. Radiology 1992; 184:745-747 26. Malone A, Wolf C, Maimed A, et al: Diagnosis of acute appendicitis: Value of unenhanced CT. AJR Am J Roentgenol 1993; 160:763-766 27. Burkitt DP: The aetiology of appendicitis. Br J Surg 1971;58: 695-699 28. Felson B, Bernhard CM: Roentgenologic diagnosis of appendiceal calculi. Radiology 1947;49:178-191 29. Graham AD, Johnson HF: The incidence of radiographic findings in acute appendicitis compared to 200 normal abdomens. Mil Med 1966;272-276 30. Faegenburg D: Fecaliths of the appendix: Incidence and significance. AJR Am J Roentgeno11963;89:752-759
MAENZA ET AL • MYTH OF THE FECALITH
31. Ceres L, Alonso I, Lopez P, et al: Ultrasound study of acute appendicitis in children with emphasis upon the diagnosis of retrocecal appendicitis. Pediatr Radio11990;20:258-261 32. Swerk WB, Wichtrup B, Ruschoff J, et al: Acute and perforated appendicitis: current experience with ultrasound-aided diagnosis. World J Surg 1990;14:271-276 33. Borushok KF, Jeffrey RB Jr, Laing FC, et al: Sonographic diagnosis of perforation in patients with acute appendicitis. AJR Am J Roentgenol 1990;154:275-278 34. Quillin SP, Siegel SP: Color doppler US of children with acute lower abdominal pain. Radiographics 1993;13:1281-1293 35. Vignault F, Filiatrault D, Brandt ML, et al: Acute appendicitis in children: evaluation with US. Radiology 1990; 176:501-504 36. Fee HJ Jr, Jones PC, Kadell B, et al: Radiologic diagnosis of appendicitis. Arch Surg 1977;112:742-744 37. Jones BA, Demetriades D, Segal i, et al: The prevalence of
397
appendiceal fecaliths in patients with and without appendicitis. Ann Surg 1985;202:80-82 38. Wangensteen OH, Bowers WF: Significance of the obstructive factor in the genesis of acute appendicitis. An experimental study. Arch Surg 1939;34:496-526 39. Wangensteen OH: Experimental proof of the obstructive origin of appendicitis in man. Ann Surg 1939;110:629-647 40. Arnbjornsson E, Bengmark S: Obstruction of the appendix lumen in relation to pathogenesis of acute appendicitis. Acta Chir Scand 1983;149:789-791 41. Collins DC: 71,000 lumen appendix specimens: A final report summarizing 40 years' study. Am J Procto11963;14:365-381 42. Sisson RG, Ahlvin HC, Harlow MC: Superficial mucosal ulceration and the pathogenesis of acute appendicitis. Am J Surg 1971;122:378-380