Is there a role for abdominal computed tomographic scans in appendicitis?

Implications of removing a normal appendix

BACKGROUND

The diagnosis of acute appendicitis remains difficult, and therefore 15-30% of the removed appendices appear to be normal. The aim of this study is to investigate the morbidity, mortality and costs of removing a normal appendix in patients with suspected appendicitis.

PATIENTS AND METHODS

A retrospective study was performed on patients who underwent a negative appendectomy for suspected appendicitis in the period 1991-1999 with a median follow-up of 4.4 years. Patients who underwent an elective appendectomy or appendectomy for other reasons were excluded.

RESULTS

In 285 patients (70% women, 30% men) a normal appendix was removed. In 192 (67%) patients a muscle-splitting incision was performed, in 6 (2%) a median laparotomy, and in 51 (18%) the normal appendix was removed by laparoscopy. In 36 patients (13%) a diagnostic laparoscopy was converted to a muscle-splitting incision. Complications occurred in 16 (6%) patients, in 5 (2%) a reoperation was needed. The mean hospital stay was 4.4 (SE 2.8) days, in case of complication 7.4 (SE 4.2) days. The mean extra hospital costs of a negative appendectomy were EUR 2,712.

CONCLUSION

The removal of a normal appendix has considerable complications and costs. In an attempt to prevent these costs, extra diagnostic tools should be considered. Expensive diagnostic tools as diagnostic laparoscopy should be used selectively in order to not further exceed costs.

Ultrasonography and computed tomography in suspected acute appendicitis

Patients with typical signs and symptoms of acute appendicitis should have a prompt surgical consultation for timely appendectomy. The use of diagnostic imaging tests such as CT scan or ultrasonography should be selective in those with atypical presentation or findings. The high accuracy of imaging tests can be achieved when they are utilized according to well thought out clinical pathways. The use of imaging modalities in suspected acute appendicitis should be complement to, but not replacing, clinical assessment and judgement. The skillful use of clinical assessment and imaging modalities will reduce the negative appendectomy rate yet assure low perforation and mortality rates.

Surgical evaluation of appendicitis in the new era of radiographic imaging

Appendicitis remains a common disease with over 250,000 cases in the United States per year. Surgical intervention has been the primary treatment for over a century, and clinical evaluation has been the mainstay for diagnosis of acute appendicitis for decades. Appendiceal imaging modalities have become increasingly popular to assist with the diagnosis of appendicitis, and the surgeon is no longer the sole diagnostician for this disease. Radiologists and emergency medical physicians have entered the arena. This review examines the surgical and radiological literature to evaluate the current atmosphere of how surgeons, radiologists, and emergency physicians interact in the diagnosis of appendicitis.

Liberal use of computed tomography scanning does not improve diagnostic accuracy in appendicitis

BACKGROUND

Based on a study at our hospital in 1994, we established a practice guideline for appendicitis patients. The practice guideline was followed well except for an increased number of preoperative computed tomography (CT) scans.

METHODS

Data collected from the previous study of 100 patients were compared with data from consecutive patients, 118 total, seen over a similar time period in the year 2000.

RESULTS

The percentage of CT scans ordered for the diagnosis of patients who underwent appendectomy markedly increased from 11% in 1994 to 48.3% in 2000. (P <0.001) The percentage of normal appendixes removed did not change significantly from 12% in 1994 to 17.8% in 2000 (P = 0.317). Patients who had a CT scan were no less likely to have a normal appendix at surgery (P = 0.386) and a significant increase in preoperative Emergency Department length of stay (P <0.001). CT was accurate 80% of the time in 2000 and 81% of the time in 1994. Only 14 of 57 CT scans were ordered by surgeons.

CONCLUSIONS

The use of preoperative abdominal CT scanning has not improved the accuracy of the diagnosis of appendicitis at our institution. It has resulted in a significant increase in Emergency Department preoperative length of stay and the finding of a normal appendix at surgery. As nonsurgeons ordered the majority of preoperative CT scans, earlier input by surgeons might increase the rate of accurate clinical diagnosis and decrease the number of CT scans ordered.

The Role of Selective Computed Tomography in the Diagnosis and Management of Suspected Acute Appendicitis

The negative appendectomy rate in patients with clinically diagnosed acute appendicitis is 20 to 40 per cent. Recently CT has emerged as a powerful diagnostic tool in the evaluation of suspected appendicitis and its routine use has been advocated. The objective of this study was to evaluate the impact of selective use of abdominal CT on the negative appendectomy rate. Three hundred eight patients were enrolled in this prospective study. Abdominal CT was performed in patients with uncertain clinical signs of appendicitis. CT was not performed in patients with either a very high or a very low index of suspicion. The results were compared with a retrospective analysis of 85 consecutive patients operated by clinical diagnosis alone. One hundred twenty-seven patients had a final diagnosis of acute appendicitis. CT was performed in 198 patients (64%). The sensitivity, specificity, and accuracy of CT scans were 91, 92, and 91 per cent, respectively. Surgical management plans were altered in 54 patients after obtaining the CT results; unnecessary delay in surgical treatment or unnecessary operations were prevented in 28 and 26 patients, respectively. In addition CT detected unrelated pathologies in 23 patients. CT was not performed in patients with low index of suspicion and none were found to suffer from acute appendicitis. The negative appendectomy rate was 17 per cent (7% men and 24% women) in patients selected for surgery on the basis of very high clinical suspicion alone. Overall the negative appendectomy rate with the selective use of CT was 16 per cent, which is significantly lower than the rate achieved by diagnosing patients on clinical grounds alone (24%). CT is highly accurate in diagnosing or ruling out acute appendicitis and may substantially decrease the negative appendectomy rate as well as unnecessary delayed observation. We believe that CT should be performed routinely in women with suspected appendicitis and selectively in men.

Frequency of visualization and thickness of normal appendix at nonenhanced helical CT

PURPOSE

To evaluate the frequency of visualization, thickness, and features of the normal appendix at nonenhanced helical computed tomography (CT).

MATERIALS AND METHODS

Three radiologists blinded to patient surgical history retrospectively reviewed CT scans obtained for renal colic assessment in 187 consecutive patients. No contrast material was administered. The frequency of visualization and the two-wall thickness of normal appendices were recorded. Interobserver agreement and effect of adequacy of intraperitoneal fat on identification of the appendix were assessed.

RESULTS

The prevalence of appendectomy was 10.7% (20 of 187 patients). The means for the three reviewers' sensitivity, specificity, positive and negative predictive values, and accuracy of visualization of normal appendix were 79% (CI: 73%, 84%), 90% (CI: 78%, 96%), 98% (CI: 97%, 99%), 34% (CI: 22%, 47%), and 80% (CI: 74%, 86%), respectively. There was no significant difference among the three reviewers (P >.05) according to conditional logistic regression and exact McNemar test results. For all reviewers, the frequency of appendix visualization was significantly lower in patients with less intraperitoneal fat (P =.01-.001, chi(2) test). The mean thickness of normal appendix if no intraluminal content was visualized was 6.6 mm +/- 1.0 (SD), and the mean thickness, excluding visualized intraluminal content, was 3.6 mm +/- 0.8. The nonweighted kappa value for interobserver agreement for normal appendix visualization was 0.69-0.75 among the three reviewers, which indicated good to excellent agreement.

CONCLUSION

Most normal appendices are seen at nonenhanced helical CT. The thickness of normal appendix, when the content is not recognizable, overlaps the values currently used to diagnose appendicitis at CT.

Imaging for suspected appendicitis: negative appendectomy and perforation rates

PURPOSE

To determine which patients suspected of having acute appendicitis benefit from preoperative imaging.

MATERIALS AND METHODS

The medical records of 462 consecutive patients who underwent appendectomy for clinically suspected acute appendicitis and underwent preoperative evaluation at our institution were retrospectively reviewed. Patients were divided into four groups: women (n = 166), girls (n = 46), men (n = 178), and boys (n = 72). Preoperative computed tomography (CT) or ultrasonography (US), requested by the referring clinician, was performed in 313 of the 462 patients. Unnecessary, or negative, appendectomy and perforation rates were calculated for each group for preoperative evaluation with CT, with US, and with neither CT nor US. In addition, the sensitivity and positive predictive value of CT and US were calculated for diagnosing appendicitis.

RESULTS

In women, the negative appendectomy rate was significantly lower for those who underwent preoperative CT (7% [six of 85 patients], P =.005) or US (8% [four of 49 patients], P =.019), as compared with 28% [nine of 32 patients] for those who underwent no preoperative imaging (P >.35 for all groups). The negative appendectomy rates for girls, men, and boys were not significantly affected by preoperative imaging. The sensitivity of CT and US for diagnosing acute appendicitis exceeded 93% and 77%, respectively, in all groups. The positive predictive values for both CT and US were greater than 92% in all groups.

CONCLUSION

Women suspected of having appendicitis benefit the most from preoperative CT or US, with a statistically significantly lower negative appendectomy rate than women who undergo no preoperative imaging. Therefore, we propose that preoperative imaging be considered part of the routine evaluation of women suspected of having acute appendicitis.

Can Appendiceal CT Scanning be Utilized Effectively in Widespread General Surgical Practice?

Appendiceal CT was first reported in the radiological literature, and has only recently begun to appear in the surgical literature. Much of the enthusiasm surrounding appendiceal CT has come from several publications by relatively few authors. We report the feasibility of implementing an appendiceal CT scanning technique and our initial results. The charts (940) of all patients evaluated for possible appendicitis during a 3-month period were reviewed. A new appendiceal CT scanning technique was performed when the indication was solely to exclude appendicitis. The accuracy of this new technique Was determined. Eighty-seven patients were evaluated. Twenty-nine underwent appendiceal CT scanning. The accuracy of interpretation was 85 per cent. In 58 patients who did not receive an appendiceal CT scan the accuracy of surgical decision-making was 82 per cent. These values were not statistically different We found appendiceal CT scanning to be relatively easy to implement; and its accuracy was better than expected. Our accuracy does not match that reported in the literature by the pioneers of appendiceal CT scanning. More experience with this technique will be required to achieve consistently successful accuracy; the technique can then be utilized in surgical practice and potentially change the diagnostic approach to acute appendicitis.

Diagnostic value of unenhanced helical CT in adult patients with suspected acute appendicitis

Clinical diagnosis of appendicitis is usually made on the basis of history, physical examination and laboratory studies. Approximately 30-45% of patients with suspected appendicitis present with atypical clinical and laboratory findings. Recently graded compression ultrasound and thin section unenhanced helical CT have been used to establish diagnosis for patients with suspected acute appendicitis. The purpose of this study was to determine the diagnostic accuracy of thin section unenhanced helical CT protocol in adult patients with suspected acute appendicitis. CT scans obtained when patients presented with right lower quadrant pain and the clinical impression was equivocal for appendicitis were evaluated. Of 296 patients referred for CT, 123 patients subsequently underwent surgery. Appendicitis had been correctly predicted in 104 of 108 patients surgically proven to have appendicitis. Unenhanced helical CT in the diagnosis of acute appendicitis had a sensitivity of 96%, specificity of 98%, positive predictive value of 97% and negative predictive value of 98%. If no definite inflammatory changes are detected, on the basis of our experience we recommend that the patient be monitored clinically, and that thin section unenhanced helical CT is the optimal technique to detect acute appendicitis in adult patients.

Impact of abdominal CT imaging on the management of appendicitis: an update

BACKGROUND

Abdominal computed tomographic scanning (ACTS) has recently been shown to be an accurate diagnostic tool for appendicitis and may improve the negative exploration rate in our patient population.

MATERIALS AND METHODS

We reviewed 224 patients evaluated for appendicitis during 1998. Forty-two patients underwent appendectomy on clinical grounds alone (Group I), 182 patients underwent ACTS (Group II), and 79 patients in Group II were explored for appendicitis. Diagnostic errors, alternative diagnoses, and perforation rates were noted.

RESULTS

There were five negative explorations in Group I (11.9%) and five in Group II (6.3%), resulting in a combined negative rate of 8.3%. The negative exploration rate in women was 23.5% in Group I and 5.3% in Group II (P = 0.07), producing a combined negative rate of 10.9%. Fifty-eight alternative diagnoses were made by ACTS. The ACTS made a critical difference in the management of 67% of patients over 50 years of age and in 79% of Group II patients.

CONCLUSIONS

The negative exploration rate for appendicitis at our institution fell from 13.6 to 8.3% with selective use of ACTS. The most striking benefit occurred in women and in patients over 50 years of age.

Unenhanced helical CT scanning of the abdomen and pelvis changes disposition of patients presenting to the emergency department with possible acute appendicitis

This study sought to determine if obtaining an unenhanced abdominopelvic computed tomography (UHCT) scan alters the disposition of patients presenting to the Emergency Department (ED) with signs and symptoms of acute appendicitis. A convenience sample of 101 patients presenting with a clinical picture suggestive of appendicitis were prospectively enrolled. Emergency physicians (EPs) and general surgeons independently recorded their anticipated disposition of each patient as: discharge, admit for observation, or admit for appendectomy. A UHCT scan was then obtained and the patient's ultimate disposition recorded. EPs altered their dispositions after UHCT scanning in 35 patients (34.7%, 95% CI 25.4% to 44.0%), and general surgeons altered their dispositions in 27 patients (26.7%, 95% CI 18.1% to 35.3%). More patients underwent operative intervention than were originally selected by EPs [14 additional patients, (13.9%, 95% CI 7.1% to 20.6%)] or by surgeons [20 additional patients, (19.8%, 95% CI 12.0% to 27.6%)]. CT scan revealed alternative diagnoses in 20 patients (19.8%). UHCT scanning significantly alters patient disposition, and significantly increases the number of operative interventions performed in patients with suspected appendicitis. UHCT scanning may also identify alternate pathology that clinically mimics appendicitis.

Effect of contrast-enhanced computed tomography on diagnosis and management of acute abdomen in adults

AIM

To determine the impact of computed tomography (CT) on the diagnosis and treatment plan in patients with acute abdominal pain.

MATERIALS AND METHODS

A prospective study was undertaken in 125 adult patients presenting with acute abdominal pain (74 men and 51 women; 40.2 +/- 19.3 years; range, 18-92). Changes in diagnosis, gain in percentage diagnostic certainty and changes of treatment plan of the surgeons in the emergency department before and after CT were evaluated. Pre- and post-CT diagnoses were compared with the final diagnoses.

RESULTS

CT findings changed the initial diagnosis in 40 (32.0%) patients. The diagnostic certainty was 58.3 +/- 22.9% before CT, and its gain after CT was 21.9 +/- 18.5 points (P < 0.0001). Post-CT diagnoses were consistent with the final diagnosis in 116 patients (92.8%), while pre-CT diagnoses were correct in 89 patients (71.2%; P < 0.0001). Initial treatment plans were changed in 31 (24.8%) patients after CT. In 57 (45.6%) patients, CT information changed diagnoses and/or treatment plans. No significant differences were observed in the diagnosis, diagnostic certainty and treatment plan among four surgeons.

CONCLUSION

Contrast-enhanced CT frequently changed the clinical diagnoses with increased diagnostic certainty and the initial treatment plans.

Acute appendicitis: comparison of helical CT diagnosis focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material

PURPOSE

To compare the diagnostic accuracy of focused helical computed tomography (CT) with orally administered contrast material with that of nonfocused helical CT with orally and intravenously administered contrast material.

MATERIALS AND METHODS

After receiving oral contrast material, 228 patients with clinically suspected appendicitis underwent focused appendiceal CT (5-mm section thickness, 15-cm coverage in the right lower quadrant). Immediately thereafter, helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material (abdomen, 7-mm section thickness; pelvis, 5-mm section thickness). Studies were separated and independently interpreted by three observers who were blinded to patient names. Diagnoses were established by means of surgical and/or clinical follow-up findings.

RESULTS

Fifty-one (22.4%) of 228 patients had acute appendicitis. Readers diagnosed appendicitis with 83.3%, 73.8%, and 71.4% sensitivity and 93.0%, 92.3%, and 97.9% specificity with focused nonenhanced appendiceal CT. Readers diagnosed appendicitis with 92.9%, 92.9%, and 88.1% sensitivity and 93.7%, 95.1%, and 96.5% specificity with nonfocused enhanced CT. Summary areas under the receiver operating characteristic curve estimates for focused nonenhanced and nonfocused enhanced CT were 0.916 and 0.964, respectively; the differences were statistically significant (P <.05) for two of three readers. All readers demonstrated higher sensitivities for detecting the inflamed appendix with nonfocused enhanced CT. Appendicitis was missed with focused CT in two patients whose inflamed appendix was not included in the imaging of the right lower quadrant. All readers were significantly more confident in diagnosing alternative conditions with nonfocused enhanced CT.

CONCLUSION

Diagnostic accuracy of helical CT for acute appendicitis improved significantly with use of intravenous contrast material.

[Suspected acute appendicitis. Role of enhanced helical computed tomography. Prospective study of 100 patients]

AIM OF STUDY

To assess the diagnosis accuracy of helical computed tomography (CT) in patients with suspected appendicitis.

PATIENTS AND METHODS

This prospective study included 100 consecutive patients hospitalized for suspected appendicitis. There were 57 men and 43 women with a median age of 30 years (range: 17-91). An enhanced helical CT was performed at admission, without digestive opacification. Four criteria were interpreted as positive signs for appendicitis: appendix enlarged > or = 7 mm, right lower quadrant inflammation, stercorolith, and peri-appendicular collection. The patient was managed by the surgeon without knowing the result of CT. The final diagnosis was made pathologically.

RESULTS

Eighty-one patients were operated on laparoscopically for suspected appendicitis. Intraoperative diagnosis was corrected in three cases and 78 appendectomies were performed (73 histological appendicitis, six normal appendix). Final diagnosis was a medical disease in 19 patients. The findings of 67 CT were interpreted as positive (63 true positive and four false positive) and the findings of 33 CT were interpreted as negative (24 true negative, nine false negative). Sensitivity was 87%, specificity was 86%, positive predictive value was 94%, and negative predictive value was 73%. If the nine false negative cases with minimal lesions at pathological examination were considered as true negative, the rates would be 100%, 89%, 94%, 100%, respectively.

CONCLUSION

Enhanced helical CT is a good imaging diagnostic tool for suspected appendicitis. It may reduce the number of patients admitted for observation and decrease the rate of negative appendectomy.

Is appendiceal CT scan overused for evaluating patients with right lower quadrant pain?

Reports citing excellent sensitivity, specificity, and predictive accuracy of focused appendiceal computed tomography (CT) and showing an overall reduction in resource use and nontherapeutic laparotomies have led to increasing use of that imaging modality. Diagnostic algorithms have begun to incorporate appendiceal CT for patients presenting to the emergency department with right lower quadrant pain. We present a series of 4 cases in which use of appendiceal CT ultimately led to increased cost, resource use, and complexity in patient care. The results of these cases support an argument against unbridled use of appendiceal CT scanning and reinforce the need for clinical evaluation by the operating surgeon before routine performance of appendiceal CT scan.

Pediatric observation medicine

Observing pediatric patients in an OU (whether a pediatric or combined or hybrid unit) has many advantages: better patient care, a decrease in missed diagnoses and acuity, better risk management, decreased malpractice liability, cost effectiveness, increased patient and family satisfaction, and psychosocial benefits. Key principles of observation medicine (purpose, time frame, general patient inclusion and exclusion criteria, administration, CQI, and so forth) are equivalent for pediatric and adult observation patients, but there are important differences. Unique characteristics of pediatric observation patients include specific diagnosis, decreased length of stay, less need for cardiac monitoring, a highly variable admission rate, and a decreased percentage or admission rate to the OU from the ED. Whereas the adult OU is primarily a cardiac-monitoring unit, the pediatric OU is a respiratory and infectious disease unit with a frequent need for an i.v. therapy and hydration. Types of pediatric patients commonly treated in an OU include respiratory illnesses (asthma, croup, bronchiolitis, pneumonia), gastrointestinal disorders (gastroenteritis, abdominal pain), dehydration, infections (fever, cellulitis, lymphangitis, pyelonephritis or UTI), overdoses or poisonings, and seizures.

A normal appendix found during diagnostic laparoscopy should not be removed

BACKGROUND

Diagnostic laparoscopy has been introduced as a new diagnostic tool for suspected appendicitis. While the normal appendix used to be removed routinely, laparoscopy allows us to leave a normal looking appendix in place. This latter strategy is, however, not generally accepted. The long-term results of not removing a normal looking appendix were evaluated.

METHODS

This was a prospective evaluation of 109 diagnostic laparoscopies for suspected appendicitis in which a normal looking appendix was left in place. After a median follow-up of 4.4 years a telephone questionnaire was performed.

RESULTS

There were no false-negative laparoscopies. In 65 patients (60 per cent) another diagnosis was obtained (group 1). In 44 patients (40 per cent) no diagnosis was obtained (group 2). After a median interval of 8 months, 15 patients presented to the emergency department for symptoms possibly involving the appendix, during the median follow-up of 4.4 years. This resulted in readmission of nine patients, of whom eight were reoperated. In only one patient (1 per cent) was a histologically proven appendicitis found and the appendix removed. Some 105 patients were eligible for follow-up. Of the 100 patients interviewed (95 per cent), nine patients (9 per cent) (six in group 1 and three in group 2) still had recurrent pain in the right lower abdominal quadrant. There were no differences between patients with or without another diagnosis obtained during preceding laparoscopy.

CONCLUSION

It is safe to leave a normal looking appendix in place when a diagnostic laparoscopy for suspected appendicitis is performed, even if another diagnosis cannot be found at laparoscopy.

Evaluation of suspected appendicitis in children using limited helical CT and colonic contrast material

OBJECTIVE

Colonic contrast material evaluation of suspected appendicitis in pediatric patients is technically more challenging than in adults because less intraabdominal fat is present. To determine the accuracy and feasibility of focused CT for pediatric patients, we carried out this retrospective investigation.

MATERIALS AND METHODS

Between November 1995 and July 1999, 199 pediatric patients (1-18 years old; mean age, 12 years) were examined with focused CT in the emergency division for suspected appendicitis. The findings on CT were compared with the findings at surgery, pathology, and clinical follow-up.

RESULTS

There were 64 true-positive CT scans, two false-negative, 128 true-negative, one false-positive, and four indeterminate. Seventy-four patients underwent appendectomy, with a negative appendectomy rate of 9%. One hundred twenty-five patients without appendicitis were treated nonoperatively. The true-positive rate was 32%, true-negative rate was 64%, sensitivity was 97%, specificity was 99%, positive predictive value was 98%, negative predictive value was 98%, and overall accuracy was 96%. Pediatric patients tolerated the procedure well. Colonic contrast material saved time and provided improved identification of the cecum and appendix. In 62 patients without appendicitis, focused CT provided alternative diagnoses.

CONCLUSION

Focused CT appears to be nearly as accurate in pediatric patients as in adults. Focused CT provided alternative diagnoses in 48% of the patients for whom CT findings were negative for appendicitis.

The value of limited computed tomography with rectal contrast in the diagnosis of acute appendicitis

BACKGROUND

Multiple nonrandomized studies demonstrate the accuracy of computed tomography (CT) scan in diagnosing appendicitis. This study compared CT scan with standard management in diagnosing appendicitis.

METHODS

This was a prospective randomized study of patients who received general surgery consultation for appendicitis. Patients were randomized to receive CT scan or standard management.

RESULTS

There were 65 patients in the CT scan group and 63 patients in the standard management group. The sensitivity, specificity, and accuracy of CT scan were 94%, 100%, and 96%, respectively. CT scan positively altered the management in 26% and made alternative diagnoses in 14%. The sensitivity, specificity, and accuracy of the standard management group were 100%, 79%, and 89%, respectively. The standard management group had a negative appendectomy rate of 19%.

CONCLUSION

CT scan with rectal contrast is an effective method for diagnosing appendicitis and should be performed in all patients suspected of having appendicitis.

Selective use of diagnostic laparoscopy in patients with suspected appendicitis

BACKGROUND

Diagnostic laparoscopy has been introduced as a new diagnostic tool for patients with acute appendicitis. We performed diagnostic laparoscopy when the clinical diagnosis of appendicitis was in doubt. The aims of this study were to evaluate this strategy and to analyze the efficacy of diagnostic laparoscopy in patients with suspected appendicitis.

PATIENTS AND METHODS

All patients referred to our hospital with suspected appendicitis during the period 1994-1997 were evaluated prospectively. The clinical diagnosis was determined by the surgeon or resident on call based on the patient's history, physical examination, and leukocyte count. The patients were divided into three groups: group 1: appendicitis not likely. These patients were observed for 24 h or discharged. When they showed signs of appendicitis in 24 h, they were transferred to either group 2 or 3; group 2: doubt concerning diagnosis. These patients underwent diagnostic laparoscopy, and appendectomy was performed if indicated; group 3: In these patients the diagnosis appendicitis was felt to be certain. They were treated by primary appendectomy by an open procedure. In this study, 1,050 patients, 531 women (51%), 389 men (37%), and 130 children (12%) <11 yrs, were evaluated.

RESULTS

Altogether, 377 diagnostic laparoscopies were performed, leaving 109 healthy-looking appendices in place. This reduced the negative appendectomy rate from 25% to 14% in all surgically managed patients. The negative appendectomy rate for the women in group 2 was reduced from 49% to 14%, and for the men from 22% to 11%, so it also seemed worthwhile to perform diagnostic laparoscopy in men. Because the appendix sana was left in place in only three children, the benefit from laparoscopy is relatively small for children. In 48% of these patients a second diagnosis was obtained, most of them gynecologic in nature. There were no false-negative laparoscopies and no complications resulting from the laparoscopic procedure.

CONCLUSIONS

Diagnostic laparoscopy is a safe procedure that reduced the appendix sana rate without increasing the total number of operations. It is a useful method for obtaining other, mostly gynecologic, diagnoses. To further reduce the appendix sana rate, better criteria for laparoscopic assessment of the appendix are needed.

The clinical role of noncontrast helical computed tomography in the diagnosis of acute appendicitis

BACKGROUND

The accuracy of noncontrast helical computed tomography (CT) for appendicitis has recently been demonstrated. What is its clinical utility?

METHODS

This was a retrospective review of 443 consecutive community hospital patients evaluated for acute appendicitis over an 18-month period using limited pelvic CT scan or clinical acumen alone.

RESULTS

Appendicitis was pathologically proven in 158 patients. The negative appendectomy rate was 5.4%. The best radiological indicators for a positive CT for appendicitis were pericecal inflammation (88%) and appendicolith(57%). Appendiceal CT was found to have a 92% sensitivity, 99.6% specificity, and a 97.5% accuracy. There were 260 patients who had a negative CT; 243 of these were sent home. Alternative diagnoses were identified in 22% of patients.

CONCLUSIONS

The liberal use of noncontrast helical CT results in a low negative appendectomy rate and a high degree of confidence that a negative CT will allow patients to be sent home safely.

Diagnosis of acute appendicitis: comparison of 5- and 10-mm CT sections in the same patient

PURPOSE

To compare 5- and 10-mm computed tomographic (CT) sections in the same patient to diagnose acute appendicitis.

MATERIALS AND METHODS

During an 11-month period, 100 consecutive patients clinically suspected to have acute appendicitis underwent abdominal and pelvic CT. Helical, 10-mm-collimated sections from the diaphragm to the pubic symphysis and 5-mm-collimated sections through the lower part of the abdomen and upper part of the pelvis were obtained. The 10- and 5-mm sections from each patient were separated into two groups and were interpreted independently by two abdominal imaging attending physicians who were blinded to the final results. The interpretations were correlated with the histopathologic or final clinical diagnoses.

RESULTS

Data analysis from blinded reader interpretations of the 5- and 10-mm sections, respectively, revealed sensitivities of 99% and 82% (P <.001), specificities of 98% and 95% (P =.426), and accuracies of 99% and 89% (P <.001). Among the 48 cases of acute appendicitis, abnormal appendices were identified in 94% (n = 45) and 69% (n = 33) (P <.05) on 5- and 10-mm-collimated sections, respectively. Right-lower-quadrant inflammatory changes were identified in 98% (n = 47) and 71% (n = 34) (P <.05) on 5- and 10-mm-collimated sections, respectively. Normal appendices were identified in 75% (n = 39) and 52% (n = 27) of the 52 negative cases on 5- and 10-mm sections (P =.025), respectively.

CONCLUSION

Use of thin-section CT significantly improves the diagnosis of acute appendicitis.

Appendicitis at the millennium

Acute appendicitis is a common clinical problem. Accurate and prompt diagnosis is essential to minimize morbidity. While the clinical diagnosis may be straightforward in patients who present with classic signs and symptoms, atypical presentations may result in diagnostic confusion and delay in treatment. Helical computed tomography (CT) and graded compression color Doppler ultrasonography (US) are highly accurate means of establishing the diagnosis. These imaging modalities have now assumed critical roles in the treatment of patients suspected to have appendicitis. The purpose of this article is threefold: to provide an update on new information regarding the pathophysiology, clinical diagnosis, and laparoscopic treatment of acute appendicitis; to describe the state-of-the art use of CT and US in diagnosing this disease entity; and to address the role of medical imaging in this patient population.

A prospective trial of computed tomography and ultrasonography for diagnosing appendicitis in the atypical patient

BACKGROUND

The surgical diagnosis of acute appendicitis is customarily made on clinical grounds alone using history, physical examination, and white blood cell count. In the atypical patient, ie, the patient with prolonged symptoms, inconsistent history, or misleading physical examination, diagnostic studies should be helpful in establishing the appropriate diagnosis. Computed tomography (CT) scan and ultrasonography (US) have demonstrated utility in diagnosing appendicitis but have not been studied in the atypical patient population.

METHODS

A retrospective review of 500 consecutive appendectomy patients, coupled with a review of the literature, resulted in the development of an algorithm to help the medical physician to differentiate the atypical patient requiring an imaging study from those requiring immediate surgical consultation. This patient population was entered into a prospective, randomized study of CT scan or US examination.

RESULTS

Between May 1997 and May 1999, 106 patients were enrolled in the study; 17 were later excluded from the study because of typical presentation and direct admission to surgery without diagnostic imaging. Forty-nine patients were randomly assigned to CT scan and 40 to US examination. CT scan was 100% specific and 97% sensitive (P = 0.018). US was 90% specific and 76% sensitive. Based on the results of these imaging studies, 70 of the study patients underwent exploration for suspected appendicitis or other acute inflammatory process.

CONCLUSION

A subset of patients presenting with possible acute appendicitis has been identified that should benefit from imaging of the appendix prior to surgical consultation. For this group, CT scan appears superior to abdominal and pelvic US in terms of diagnostic accuracy and reliability. With this approach, a low incidence of negative laparotomies was achieved.

Cecal necrosis: infrequent variant of ischemic colitis. Report of five cases

PURPOSE

Spontaneous nonocclusive ischemic colitis involving only the right colon is an infrequent occurrence. Because this problem is less recognized than its counterpart involving the left colon, the correct diagnosis may not be considered. The purpose of this article was to describe the presentation and management of this unusual clinical problem.

METHODS

Five cases of nonocclusive ischemic cecal necrosis are described. Four of the patients presented with right-sided abdominal pain, tenderness, and leukocytosis. The preoperative diagnosis was incorrect in all patients, although cecal necrosis was considered in one. Two patients were thought to have. appendicitis, two were thought to have carcinoma, and one was thought to have a perforated viscus. Each patient underwent a right hemicolectomy and four survived.

RESULTS

Each of the patients had ischemic cecal necrosis without evidence of emboli or vasculitis. Although cecal gangrene may occur after systemic hypotension, no such event preceded these patients' presentation. We believe that the patients we treated had a form of nonocclusive ischemic colitis, which occasionally affects only the right colon.

CONCLUSION

Ischemic necrosis of the cecum is an infrequent variant of ischemic colitis that should be considered in the differential diagnosis of the elderly patient presenting with right lower quadrant pain.

Diagnosing appendicitis across the life span

Arriving at a definitive diagnosis of acute appendicitis (AA) requires an understanding of the various presenting signs and symptoms of all ages and genders across the life span. Primary care providers must also be aware of the pertinent laboratory tests and imaging procedures that will assist in providing useful information toward making an accurate diagnosis of AA. Utilizing an in-depth review of the literature, this article delineates the presenting signs and symptoms of AA from children to adults to elders. It also delineates which laboratory and imaging techniques should be used for each age group as effective adjuncts in diagnosing AA.

Suspected acute appendicitis: is ultrasonography or computed tomography the preferred imaging technique?

OBJECTIVE

To compare the sensitivity and specificity of unenhanced spiral computed tomography (CT) and ultrasonography (US) in patients with suspected acute appendicitis.

DESIGN

Prospective study.

SETTING

University hospital, Germany.

SUBJECTS

120 consecutive patients with acute appendicitis as a differential diagnosis, whose clinical findings were not enough to make operation essential, but were too severe to send home.

INTERVENTIONS

CT and US of the appendix.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive value.

RESULTS

The results were correlated with surgical and histopathological findings at appendicectomy or clinical follow-up. 93 patients had acute appendicitis, 27 patients did not. The sensitivity of CT was 95% and of US 87%. The corresponding specificities were 89% and 74%, positive predictive values 97% and 92%, negative predictive values 83% and 63%. In the 27 patients who did not have acute appendicitis, the correct diagnosis was established with CT in 14 patients and with US in eight.

CONCLUSION

CT is more sensitive and specific than US in patients suspected of having acute appendicitis, but in whom the presentation is equivocal. The use of unenhanced spiral CT led to a significant improvement in the accuracy of preoperative diagnosis and a lower negative appendicectomy rate.

Historical changes in the postoperative treatment of appendicitis in children: impact on medical outcome

BACKGROUND/PURPOSE

The introduction of managed care in the 1980s caused increased pressure to reduce costs for hospitalized patients. The authors hypothesized that these market forces have resulted in a decreased hospital stay and utilization of sophisticated diagnostic testing in children treated for appendicitis. If true, the impact of this paradigm shift on patient outcome is unknown.

METHODS

Hospital records for 913 pediatric patients treated for appendicitis from 1974 to 1998 were reviewed retrospectively. Patients were stratified into those with perforated appendicitis (PA) and nonperforated appendicitis (NPA). Demographics, perioperative hospital course, diagnostic testing, complications, and long-term outcomes were analyzed after stratification into time intervals.

RESULTS

Over time, children with NPA were treated with shorter antibiotic courses (P<.05) and were placed on a regular diet earlier (P<.05). These changes in treatment resulted in an earlier discharge (P<.05). The amount of time to become afebrile with a normal white blood cell count (WBC) did not change over time. Children with PA exhibited similar results with shorter antibiotic courses (P<.05), earlier dietary intake (P<.05) and earlier hospital discharge (P<.05) over time. In all children with appendicitis there was no significant difference in the rate of wound infections, abscesses requiring drains, readmission, or reoperations overtime. The utilization of abdominal radiographs (83%) and ultrasonography (USN; 40%) was high and remained unchanged over time. Utilization of computed tomography (CT scan) was low (4.3%) in the early decades and was not used as a preoperative test from 1991 to 1994. Given the high diagnostic accuracy of a pediatric surgeon for this disease, Bayesian analysis indicates that USN utilization rates should be 15%.

CONCLUSIONS

The market pressures of managed care have resulted in a new treatment paradigm with an earlier discharge of all children with appendicitis. There has been no concomitant increase in the complication rate in either group as a result of this paradigm shift. Bayesian analysis indicates that USN and abdominal radiographs are overutilized in our institution.

The role of computed tomography in the diagnosis of acute appendicitis

BACKGROUND

Routine contrast-enhanced computed tomography (CECT) has been described as an accurate diagnostic imaging modality in patients with acute appendicitis. However, most patients with acute appendicitis can be diagnosed by clinical findings and physical exam alone. The role of CECT in patients suspected of having appendicitis but with equivocal clinical exams remains ill defined.

METHODS

One hundred and seven consecutive patients who were thought to have appendicitis but with equivocal clinical findings and/or physical exams were imaged by CECT over a 12-month period. Oral and intravenous contrast-enhanced, spiral abdominal and pelvic images were obtained using 7-mm cuts. CECT images were interpreted by a board-certified radiologist. Main outcome measures included CECT sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in the diagnosis of acute appendicitis, comparing CECT with ultrasound, and determining the impact of CECT on the clinical management of this patient population.

RESULTS

A group of 107 patients consisting of 44 males (41%) and 63 females (59%) with a median age of 33 years (range 13 to 89 years) were imaged with CECT to evaluate suspected appendicitis. Of the 107 CECTs performed, 11 false-positive and 3 false-negative readings were identified, resulting in a sensitivity of 92%, specificity of 85%, PPV of 75%, NPV of 95%, and an overall accuracy of 90%. Forty-three patients were imaged with ultrasound and CECT, and CECT had significantly better sensitivity and accuracy (30% versus 92% and 69% versus 88%, P<0.01). With regard to clinical management, 100% (36/36) of patients with appendicitis, and 4.2% (3/71) of patients without appendicitis underwent appendectomy. Therefore, the overall negative appendectomy rate was 7.6% (3/39).

CONCLUSIONS

CECT is a useful diagnostic imaging modality for patients suspected of having acute appendicitis but with equivocal clinical findings and/or physical exams. CECT is more sensitive and accurate than ultrasound and is particularly useful in excluding the diagnosis of appendicitis in those without disease.

Appendicitis in childhood

Ultrasonography, CT scanning, and prolonged observation may improve diagnostic accuracy of appendicitis in children with atypical presentations. This article describes diagnostic pitfalls, including early presentation and abnormal appendiceal location.

[Laparoscopy with a diagnostic aim in abdominal emergencies]

In acute abdominal syndromes when a surgical exploration is required by the presence of peritoneal symptoms, laparoscopy allows to recognize the lesions and to perform simultaneously the appropriate treatment in most cases. When the surgical indication is doubtful, mainly in case of acute appendicitis, sonography or scanography may confirm the diagnosis. In case of persisting doubt, diagnostic laparoscopy is justified and laparoscopic appendicectomy seems to be the best method when another pathology is not detected by laparoscopy. In abdominal wounds, laparoscopy is useful to confirm their intraperitoneal penetration, mainly in gunshot wounds, and to recognize a diaphragmatic wound which is often isolated and unknown. Laparoscopy often fails to detect all abdominal injuries. In blunt abdominal traumas, laparoscopy is not recommended at the first step. In conclusion, laparoscopy with diagnostic intent only is rarely indicated in abdominal emergencies and its use is not worth being extended. Diagnostic value of laparoscopy is closely linked to its therapeutic interest. Laparoscopy with both diagnostic and therapeutic intent has to be developed in most abdominal emergencies.

Unenhanced CT in the evaluation of the acute abdomen: the community hospital experience

The "Great Mimicker," acute appendicitis, has finally found its match with the advent of rapid unenhanced computed tomography (RUCT). With little, if any, operator dependence, RUCT can be performed easily at any facility that has CT capabilities. With only minimal interpreter dependence, the examination is highly accurate in determining which patients with acute abdominal pain require further treatment and expenditure of resources. In this article we describe our experience, since devising the technique in 1991, with over 7,000 RUCT scans done on patients with acute abdominal pain, predominantly in the right lower quadrant. We show how RUCT is extremely useful and accurate, not only in the diagnosis of acute appendicitis, but in many other disease entities that mimic the "Great Mimicker."