Sonographic Differentiation of Complicated From Uncomplicated Appendicitis: Implications for Antibiotics-First Therapy

Update on acute appendicitis: Typical and untypical findings

Acute appendicitis is the most common indication for emergency abdominal surgery throughout the world and a common reason for consultation in emergency departments. In recent decades, diagnostic imaging has played a fundamental role in identifying acute appendicitis, helping to reduce the rate of blind laparotomies and hospital costs. Given the results of clinical trials supporting the use of antibiotic therapy over surgical treatment, radiologists need to know the diagnostic criteria for complicated acute appendicitis to be able to recommend the best treatment option. This review aims not only to define the diagnostic criteria for appendicitis in different imaging modalities (ultrasonography, computed tomography, and magnetic resonance imaging), but also to explain the diagnostic protocols, atypical presentations, and other conditions that can mimic appendicitis.

Evaluation of early sonographic predictors of gangrenous cholecystitis: mucosal discontinuity and echogenic pericholecystic fat

PURPOSE

To identify early sonographic features of gangrenous cholecystitis.

MATERIALS AND METHODS

101 patients with acute cholecystitis and a pre-operative sonogram were retrospectively reviewed by three radiologists in this IRB-approved and HIPAA-compliant study. Imaging data were correlated with histologic findings and compared using the Fisher's exact test or Student t test with p < 0.05 to determine statistical significance.

RESULTS

Forty-eight patients had gangrenous cholecystitis and 53 had non-gangrenous acute cholecystitis. Patients with gangrenous cholecystitis tended to be older (67 ± 17 vs 48 ± 18 years; p = 0.0001), male (ratio of male:female 2:1 vs 0.6:1; p = 0.005), tachycardic (60% vs 28%; p = 0.001), and diabetic (25% vs 8%; p = 0.001). Median time between pre-operative sonogram and surgery was 1 day. On imaging, patients with gangrenous cholecystitis were more likely to have echogenic pericholecystic fat (p = 0.001), mucosal discontinuity (p = 0.010), and frank perforation (p = 0.004), while no statistically significant differences were seen in the presence of sloughed mucosa (p = 0.104), pericholecystic fluid (p = 0.523) or wall striations (p = 0.839). In patients with gangrenous cholecystitis and echogenic pericholecystic fat, a smaller subset had concurrent mucosal discontinuity (57%), and a smaller subset of those had concurrent frank perforation (58%). The positive likelihood ratios for gangrenous cholecystitis with echogenic fat and mucosal discontinuity were 4.6 (95% confidence interval 1.9-11.3) and 14.4 (2.0-106), respectively.

CONCLUSION

Echogenic pericholecystic fat and mucosal discontinuity are early sonographic findings that may help identify gangrenous cholecystitis prior to late findings of frank perforation.

Predictive scoring systems to differentiate between simple and complex appendicitis in children (PRE-APP study)

BACKGROUND

Several clinical prediction rules have been developed for preoperative differentiation between simple and complex appendicitis in children, as potential treatment strategies differ. This study aimed to externally validate applicable clinical prediction rules that could be used to differentiate between simple and complex appendicitis in children.

METHODS

Potential clinical prediction rules were identified by a scoping review of the literature. Clinical prediction rules applicable in our daily practice were subsequently externally validated in a multicenter historical cohort consisting of 1 tertiary center and 1 large teaching hospital. All children (<18 years old) with histopathologically confirmed acute appendicitis between 2013 and 2020 were included. Test results of clinical prediction rules were compared to the gold standard of either simple or complex appendicitis consisting of predefined perioperative and histopathological criteria. Areas under the receiver operating characteristic curves were determined for the selected clinical prediction rules. Areas under the receiver operating characteristic curve >0.7 were considered acceptable and potentially useful.

RESULTS

In total, 31 clinical prediction rules were identified, of which 12 could be evaluated in our cohort consisting of 550 children. The main reason to exclude clinical prediction rules was the use of variables that were not routinely measured in our cohort. In our cohort, 208/550 (38%) were diagnosed with complex appendicitis according to the gold standard. Clinical prediction rules with areas under the receiver operating characteristic curve >0.7 were: Gorter (0.81), Bogaard (0.79), Bröker (0.79), Graham (0.77), Hansson (0.76), BADCF (0.76), and Eddama (0.75).

CONCLUSION

In this study, clinical prediction rules consisting of a combination of clinical and objective variables had the highest discriminative ability. External validation showed that 7 clinical prediction rules were potentially useful. Integration of these clinical prediction rules in daily practice is proposed to guide decision making regarding treatment strategies.

Diagnosis and Management of Acute Appendicitis in Adults: A Review

IMPORTANCE

Acute appendicitis is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults.

OBSERVATIONS

The clinical diagnosis of acute appendicitis is based on history and physical, laboratory evaluation, and imaging. Classic symptoms of appendicitis include vague periumbilical pain, anorexia/nausea/intermittent vomiting, migration of pain to the right lower quadrant, and low-grade fever. The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with these symptoms. Laparoscopic appendectomy remains the most common treatment. However, increasing evidence suggests that broad-spectrum antibiotics, such as piperacillin-tazobactam monotherapy or combination therapy with either cephalosporins or fluroquinolones with metronidazole, successfully treats uncomplicated acute appendicitis in approximately 70% of patients. Specific imaging findings on computed tomography (CT), such as appendiceal dilatation (appendiceal diameter ≥7 mm), or presence of appendicoliths, defined as the conglomeration of feces in the appendiceal lumen, identify patients for whom an antibiotics-first management strategy is more likely to fail. CT findings of appendicolith, mass effect, and a dilated appendix greater than 13 mm are associated with higher risk of treatment failure (≈40%) of an antibiotics-first approach. Therefore, surgical management should be recommended in patients with CT findings of appendicolith, mass effect, or a dilated appendix who are fit for surgery, defined as having relatively low risk of adverse outcomes or postoperative mortality and morbidity. In patients without high-risk CT findings, either appendectomy or antibiotics can be considered as first-line therapy. In unfit patients without these high-risk CT findings, the antibiotics-first approach is recommended, and surgery may be considered if antibiotic treatment fails. In unfit patients with high-risk CT findings, perioperative risk assessment as well as patient preferences should be considered.

CONCLUSIONS AND RELEVANCE

Acute appendicitis affects 96.5 to 100 people per 100 000 adults per year worldwide. Appendectomy remains first-line therapy for acute appendicitis, but treatment with antibiotics rather than surgery is appropriate in selected patients with uncomplicated appendicitis.

Sonographic diagnosis of appendicitis: A pictorial essay and a new diagnostic maneuver

While many cases of appendicitis are easy to diagnose clinically, a significant number need further workup in the form of imaging. Ultrasound and CT are both used extensively to diagnose or exclude appendicitis, or arrive at an alternate diagnosis. Ultrasound has many advantages but can be a difficult modality to use due to, among other reasons, the anatomical variations in appendicial location. The true retrocolic appendix is particularly difficult to diagnose with ultrasound. This pictorial essay examines the ultrasound features of normal and diseased appendix and proposes a new examining station, the prone view, for visualizing true retrocolic appendicitis.

Ultrasonographic features can predict outcome of conservative management of acute appendicitis in children

PURPOSE

To determine whether specific ultrasonographic features can predict failure of conservative treatment of acute appendicitis.

METHODS

A 2-year retrospective study was conducted on children admitted with acute appendicitis. Those with uncomplicated appendicitis diagnosed solely by ultrasound, and treated conservatively, were followed 18-24 m to assess treatment outcome. Management was considered successful if recurrent acute appendicitis was not observed during follow-up. Appendix diameter, wall thickness, presence of mucosal ulceration, hyperechogenic fat, free fluid, and lymph nodes were evaluated as potential discriminatory ultrasonographic predictors. T-tests, chi-square, sensitivity, specificity, and odds ratios were calculated.

RESULTS

Out of 556 consecutive patients that were admitted with acute appendicitis, 180 (32%) managed conservatively. One hundred eleven (62%) imaged by US only. Ninety-two out of 111 (83%) were followed 18-24 m to assess treatment outcome, and 19/111 (17%) were lost to follow-up. Conservative management was successful in 72/92 (78.2%), with treatment failure in 20/92 (21.8%) (5/92 (5.4%) with recurrent acute appendicitis and 15/92 (16.3%) underwent appendectomy). Of the ultrasonographic features studied, mucosal ulceration demonstrated statistically significant predictive value. Fifteen out of 20 (75%) treatment failures had mucosal ulceration, compared to 21/72 (29.2%) of the patients with successful treatment (p < 0.001). This yielded a positive odds ratio of 7.3 (2.3-22.6, 95% CI), 70.8% (58.9-80.9, 95% CI) specificity, and 75% (50.9-91.3, 95% CI) sensitivity. Positive predictive value was 41.6% (31.5-52.5, 95% CI) while intact mucosa had negative predictive value of 91% (82.4-95.6, 95% CI) for conservative management success.

CONCLUSION

The presence or absence of appendiceal mucosal ulceration at ultrasound can predict conservative management outcome in the setting of acute appendicitis, potentially improving pediatric patient selection for conservative management.

Efficacy of Preoperative Imaging Features and Blood Tests in Predicting the Increased Risk of Conversion in Laparoscopic Appendectomy Surgery

Background

In this study, we identified preoperative risk factors, including imaging features and blood tests, to predict conversion from laparoscopic appendectomy to open appendectomy. Thus, we aimed to prevent patients from being exposed to the risks of laparoscopy by choosing patients for whom proceeding directly to an open surgery as an initial approach was appropriate.

Patients and methods

The cohort of 632 patients who underwent laparoscopic appendectomy due to acute appendicitis in our center between January 2017 and March 2021 were analyzed, and 521 of these patients comprised the study population. Baseline characteristics, medical history, preoperative laboratory tests, imaging features, and postoperative pathologic findings of all patients according to groups who underwent laparoscopic appendectomy or conversion to open appendectomy were examined.

Results

Among 521 patients, the appendectomy procedure was completed laparoscopically in 498 (95.6%) patients, and conversion to open appendectomy was occurred in 23 (4.4%) patients. 223 (42.8%) patients were female, and 298 (57.2%) patients were male. The mean age of all patients was 35.17±12.61 years (range, 16-80 years). Preoperative ultrasonography feature associated with a higher rate of conversion was free fluid collection (p=0.001). The levels of C-reactive protein, neutrophil, and neutrophil/lymphocyte ratio on admission were found to be significantly higher in the conversion group compared to the laparoscopy group (p=0.001, p=0.027, p=0.02, respectively). 

Conclusions

Free fluid collection detected by ultrasonography, and elevation of C-reactive protein, neutrophil, and neutrophil/lymphocyte ratio may be useful in the prediction of a high risk of conversion appendectomy. Despite the unquestionable advantages of laparoscopic surgery, there are still substantial conversion rates. Within this framework, our study will help the surgeons to choose the most appropriate surgical methods for patients by evaluating them individually, and to inform them of the possibility of conversion to the open approach, and other risks before surgery. 

Accuracy of ultrasonography for differentiating between simple and complex appendicitis in children

PURPOSE

Accurate differentiation between simple and complex appendicitis is important since differences in treatment exist. This study aimed to assess the accuracy of ultrasonography in differentiating between simple and complex appendicitis.

METHODS

Data from children aged < 18 years who underwent appendectomy between the 1st of January 2013 and the 1st of January 2018 were analyzed retrospectively. Ultrasonography reports of eligible children were divided into simple (test negative) and complex appendicitis (test positive) based on predefined criteria and compared to a gold standard (a combination of predefined perioperative and histopathological criteria). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated to measure ultrasonographic accuracy in differentiating between simple and complex appendicitis.

RESULTS

176 children were eligible for inclusion. The mean age at the time of operation was 10.1 ± SD 4.6 years. 84 (47.7%) children had simple appendicitis and 92 (52.3%) had complex appendicitis. The use of ultrasonography yielded a sensitivity: 46%, specificity: 90%, PPV: 84%, and NPV: 60%.

CONCLUSION

Ultrasonography as standalone modality is not suitable for differentiating between simple and complex appendicitis in children. To improve preoperative differentiation, other variables such as clinical signs and laboratory data are necessary in conjunction with ultrasonography findings.

Hyperechoic Periappendiceal Fat: Evaluation of Criteria for Improving Specificity in the Sonographic Diagnosis of Appendicitis in Pediatric Patients

OBJECTIVES

To test the hypothesis that abutting and encasing types of hyperechoic periappendiceal fat are specific sonographic indicators of appendicitis in pediatric patients, including individuals with maximum outer diameters (MODs) of 6 to 8 mm in whom diagnosis by the MOD alone is known to be equivocal.

METHODS

Appendiceal sonograms of 271 consecutive pediatric patients were retrospectively evaluated for hyperechoic periappendiceal fat (globular, ≥1.0 cm; categorized as type 0, none; type 1, "abutting," encompassing <180° of the appendiceal circumference; or type 2, "encasing," encompassing 180° or more of the appendiceal circumference) and the MOD. Histopathologic and medical records constituted reference standards. Statistical methods included the binomial distribution, logistic regression, a receiver operating characteristic analysis, and the exact McNemar test.

RESULTS

All patients with hyperechoic fat and 105 of 107 patients with appendicitis had MODs of 6 mm or greater. The MOD and fat types 1 and 2 each were significantly associated with appendicitis in the univariable regression. The MOD and fat type 1 were independently associated with appendicitis in multivariable regression (odds ratio, 24.97; P = .034; and odds ratio, 5.35; P < .001, respectively). Specificities of an MOD of 6 to 8 mm and an MOD of 6 mm or greater alone were 89.0% (95% confidence interval, 83.2%-93.4%); these increased to 100.0% each (95% confidence interval, 97.8%-100.0%; P < .001) when combined with fat types 1, 2, and either 1 or 2 as diagnostic criteria, with positive predictive values of 100.0%.

CONCLUSIONS

Types 1 and 2 periappendiceal fat are specific indicators of appendicitis, and both improve specificity compared to the MOD. Importantly, they add specificity in diagnosing appendicitis in patients with diagnostically equivocal MODs of 6 to 8 mm.

Discriminating complicated from uncomplicated appendicitis by ultrasound imaging, computed tomography or magnetic resonance imaging: systematic review and meta-analysis of diagnostic accuracy

Background

Discriminating complicated from uncomplicated appendicitis is crucial. Patients with suspected complicated appendicitis are best treated by emergency surgery, whereas those with uncomplicated appendicitis may be treated with antibiotics alone. This study aimed to obtain summary estimates of the accuracy of ultrasound imaging, CT and MRI in discriminating complicated from uncomplicated appendicitis

Methods

A systematic literature review was conducted by an electronic search in PubMed, Embase and the Cochrane Library for studies describing the diagnostic accuracy of complicated versus uncomplicated appendicitis. Studies were included if the population comprised adults, and surgery or pathology was used as a reference standard. Risk of bias and applicability were assessed with QUADAS-2. Bivariable logitnormal random-effect models were used to estimate mean sensitivity and specificity.

Results

Two studies reporting on ultrasound imaging, 11 studies on CT, one on MRI, and one on ultrasonography with conditional CT were included. Summary estimates for sensitivity and specificity in detecting complicated appendicitis could be calculated only for CT, because of lack of data for the other imaging modalities. For CT, mean sensitivity was 78 (95 per cent c.i. 64 to 88) per cent, and mean specificity was 91 (85 to 99) per cent. At a median prevalence of 25 per cent, the positive predictive value of CT for complicated appendicitis would be 74 per cent and its negative predictive value 93 per cent.

Conclusion

Ultrasound imaging, CT and MRI have limitations in discriminating between complicated and uncomplicated appendicitis. Although CT has far from perfect sensitivity, its negative predictive value for complicated appendicitis is high.

A combined medical/surgical appendicitis pathway decreases pediatric CT utilization, perforation, and negative appendectomy rates

Background

We sought to improve the care of pediatric patients with possible appendicitis by decreasing unnecessary CT scanning. In an early QI initiative, we systematically emphasized the superiority of Ultrasonography (US) over CT, but did not find a decrease in CT utilization in practice. We therefore redoubled our initiative using a multimodal approach. We hypothesized a combined diagnostic and treatment pathway that allowed residual diagnostic uncertainty and used both surgery and antibiotic therapy for appendicitis that would decrease the need for diagnostic CT scanning.

Results

Prior to implementation of the protocol, 33% of ER patients with appendicitis typical abdominal pain were treated for appendicitis (with surgery); after implementation, the total number treated remained unchanged 32.5% (p = NS), but the appendectomy rate dropped from 33 (204/619) to 23% after implementation of the pathway (96/419, p < 0.0005) with 50 patients treated with antibiotics. There was a reduction in CT scanning (pre 39% vs. 11%, p < 0.0001) while the use of US increased (pre 30% vs. 53%, p < 0.0001). The perforation rate decreased from 12 to 5% (p < 0.002) and negative appendectomy decreased from 13 to 4% (p < 0.0001). Of the 50 patients treated with antibiotics, 10 eventually crossed over to surgery.

Conclusion

The use of a diagnostic and therapeutic pathway that offers antibiotic therapy for early probable appendicitis decreases the need for diagnostic CT scanning without increasing morbidity in pediatric appendicitis. Adherence to a medical/surgical treatment protocol that reserves surgery for clinically advanced appendicitis results in a reduction in CT scanning, perforation rates, negative appendectomy rates, and overall surgery for appendicitis.

Ultrasound features and the diagnostic strategy of subhepatic appendicitis

Background

This study aimed to compare the differences of ultrasound findings between subhepatic appendicitis and appendicitis at a normal position, then discuss the diagnostic strategies and improve the accuracy of diagnosis.

Methods

A retrospective analysis was performed in our hospital. One thousand five hundred ninety-one patients with appendicitis were diagnosed from January 2014 to January 2018. Eighteen patients with subhepatic appendicitis and 25 patients with appendicitis with regular positions were selected randomly as the control group. The difference in ultrasound features between the two groups was studied. Comparisons between the two groups showed statistically significant differences in the frequencies of the fishbone sign, enlarged appendix, appendicoliths, and hyperechoic omental cap (P<0.05).

Results

Statistical significance was not observed with the difference in the frequency of whether there was lymphadenectasis (P>0.05) in the abdominal cavity between the two groups. The Pareto chart was drawn to look for the main factors associated. The results of interpretation on the critical points of diagnosis for subhepatic appendicitis: (I) the fishbone sign of a dilated ileum in the right lower abdomen; and (II) the fishbone sign of a dilated ileum in the right lower abdomen + presence of an enlarged appendix in the right upper abdomen.

Conclusions

An abnormally dilated ileum in the right lower abdomen – the fishbone sign, is a vital sign leading to the diagnosis of subhepatic appendicitis. The fishbone sign of a dilated ileum in the right lower abdomen + whether there is a vermiform structure is an important diagnostic indicator for subhepatic appendicitis.

Combining Ultrasound with a Pediatric Appendicitis Score to Distinguish Complicated from Uncomplicated Appendicitis in a Pediatric Population

Background:

The accurate diagnosis of complicated appendicitis has been improved by using various diagnostic modalities. However, no preoperative diagnostic method could completely confirm the results. Therefore, preoperative diagnosis of complicated appendicitis to have the right management is still a huge challenge.

Objectives:

The aim of this study was to evaluate the diagnostic value of ultrasound combined with pediatric appendicitis score for differentiation between acute uncomplicated appendicitis and acute complicated appendicitis in a pediatric population.

Methods:

We prospectively evaluated 120 pediatric patients who underwent surgery for acute appendicitis from November 2017 to June 2019. Pediatric appendicitis score (PAS) was calculated and ultrasound (US) was performed before surgery. The histopathology of phlegmonous appendicitis corresponds to uncomplicated appendicitis (AUA), while gangrenous appendicitis and perforation are classified as complicated appendicitis (ACA).

Results:

Histopathologically, the results provided a diagnosis of acute appendicitis including 86 (71.7%) patients with AUA and 34 (28.3%) children with ACA. US findings showed a sensitivity of 23.5%, the specificity of 95.4%, PPV of 66.7%, NPV of 75.9%, and an accuracy of 75%. PAS of 8 was found to be the most appropriate cutoff point compatible with ACA; it resulted in a sensitivity of 76.5% and a specificity of 84.1%. Combining ultrasound with a pediatric appendicitis score resulted in a higher specificity to distinguish complicated from uncomplicated appendicitis when compared with ultrasound or PAS solely.

Conclusions:

the US is highly specific but nonsensitive for detecting complicated pediatric appendicitis. Combining ultrasound with pediatric appendicitis is a very good concept to distinguish complicated from uncomplicated appendicitis in a pediatric population.

Nongynecologic Causes of Pelvic Pain: Ultrasound First

Ultrasonography (US) is often the first-line imaging study used to evaluate women who present with acute or chronic pelvic pain. Detection of nongynecologic causes of pelvic pain is critical, because delay in diagnosis can cause significant morbidity and mortality. Evaluation of these entities requires a variety of transducers to achieve optimal imaging depth and changes in patient positioning. Specific imaging techniques (such as graded compression) may be required if bowel pathology is suspected. Contrast-enhanced ultrasonography is increasingly used to improve detection of certain entities. The US appearance of common gastrointestinal and urinary tract-related causes of pelvic pain is reviewed.

Hyperechoic Abdominal Fat: A Sentinel Sign of Inflammation

One of the most useful sonographic signs of acute abdominal inflammation is the identification of increased echogenicity of the surrounding fat. Hyperechoic fat results from vasodilation and edema extending from an adjacent source of infection or inflammation. These changes are mediated by such factors such as bradykinin, histamine, and various cytokines. The recognition of hyperechoic fat on sonography may be an important indicator of the primary source of pathology. In addition, it often reflects a more advanced degree of transmural pathology, such as "walled-off" perforation of a hollow viscus. This pictorial essay will present a variety of examples of hyperechoic inflamed fat involving different abdominal organs and will illustrate the diagnostic value of this finding.

Sonographic differentiation of complicated from uncomplicated appendicitis

OBJECTIVE

This study aims to differentiate acute uncomplicated and complicated appendicitis, by investigating the correlation between sonographic findings and histological results in different types of paediatric appendicitis.

METHODS

This is a retrospective study of 1017 paediatric patients (age < 18 years) who underwent ultrasound by paediatric radiologists before appendicectomy at our institution between 2006 and 2016. Histologically, uncomplicated appendicitis was primarily associated with transmural infiltration of neutrophil granulocytes, while complicated appendicitis was characterised by transmural myonecrosis. Logistic regression analyses were used to investigate the association between sonographic and histological findings.

RESULTS

Out of 566 (56%) male and 451 (44%) female patients with a mean age of 10.7 years, uncomplicated appendicitis was histologically diagnosed in 446 (44%) children and complicated appendicitis was diagnosed in 348 (34%) cases. The following ultrasound findings were significantly associated with complicated appendicitis in multivariate regression: an increased appendiceal diameter (OR = 1.3, p < .001), periappendiceal fat inflammation (OR = 1.5, p = 0.02), the presence of an appendicolith (OR = 1.7, p = 0.01) and a suspected perforation (OR = 6.0, p < .001) by the pediatric radiologist. For complicated appendicitis, an appendiceal diameter of more than 6 mm had the highest sensitivity (98%), while a sonographically suspected perforation showed the highest specificity (94%).

CONCLUSION

Abdominal sonography by paediatric radiologists can differentiate between uncomplicated and complicated appendicitis in paediatric patients by using an increased appendiceal diameter, periappendiceal fat inflammation, the presence of an appendicolith and a suspected perforation as discriminatory markers.

ADVANCES IN KNOWLEDGE

This paper demonstrates expanded information on ultrasound, which is not only an essential tool for diagnosing appendicitis, but also a key method for distinguishing between different forms of appendicitis when performed by paediatric radiologists. Compared with previous studies, the crucial distinction features in our analysis are 1) the definition of gangrene and not primarily perforation as an acute complicated appendicitis enabling early decision-making by sonography and 2) a large number of patients in a particularly affected age group.

High Ascending Retrocecal Appendicitis in a Pediatric Patient Detected by Point-of-care Ultrasound

A 10-year-old male presented to our pediatric emergency department with progressive, colicky abdominal pain for one day, associated with fever and non-bilious vomiting. He had a guarded abdomen with sluggish bowel sounds. He was noted to have poor perfusion with tachycardia, which resolved with fluid resuscitation. Abdominal radiograph demonstrated the presence of a circular radiopaque structure at the right hypochondrial region. Point-of-care ultrasound revealed an ascending appendicitis with signs of perforation, which was unusually located just at the inferior edge of the liver, over the right hypochondrium. The patient was immediately admitted to the surgical intermediate care unit. Urgent laparoscopic appendectomy was successfully performed, and the child was discharged well.

Luminal obstruction in uncomplicated appendicitis: Detection with sonography and potential clinical implications

PURPOSE

To determine the frequency of luminal obstruction on appendiceal graded compression sonography (US) in patients with uncomplicated appendicitis and test the hypothesis that this frequency is similar to the failure rates of primary antibiotic therapy for uncomplicated appendicitis when treatment selection is based on CT findings.

METHODS

Sonograms of 150 consecutive patients with appendicitis diagnosed on ultrasound (US) and proven histopathologically were retrospectively evaluated; 114 (76.0%) had uncomplicated appendicitis, that is, appendicitis without gangrene or perforation, and were evaluated for appendicolithiasis and lymphoid hyperplasia using previously published sonographic criteria, and for luminal obstruction.

RESULTS

Of the 114 patients with uncomplicated appendicitis, US demonstrated no luminal obstruction in 74 (64.9%) and luminal obstruction in 40 (35.1%, P = .018), the latter including 16 (40.0%) with lymphoid hyperplasia and 24 (60.0%, P = .074) with appendicolithiasis.

CONCLUSIONS

US demonstrated luminal obstruction in 35.1% of patients with uncomplicated appendicitis, similar to the published failure rates of antibiotic therapy when treatment selection is based on CT. This confirms the hypothesis, supporting the possibility that undiagnosed luminal obstruction may account for treatment failures when patients are selected by CT for primary antibiotic therapy, and suggests a role for US in selecting patients without luminal obstruction for antibiotic therapy.