Utility of ultrasound for evaluating the appendix during the second and third trimester of pregnancy

Abstract

This study aims to retrospectively evaluate the right lower quadrant ultrasounds in women presenting during the second or third trimester of pregnancy for the frequency of appendix visualization and accuracy in diagnosing appendicitis. Institutional Review Board approval was obtained for this Health Insurance Portability and Accountability Act-compliant study. We reviewed imaging records from 99 consecutive pregnant women from 2001 to 2011 who presented during the second (≥14 weeks gestation) or third trimester for right lower quadrant ultrasound to evaluate the appendix. Visualization of the appendix as well as the size and compressibility, if identified, were recorded. The medical records and labs related to the initial patient presentation, subsequent management, and follow-up were reviewed for surgical and clinical outcomes. Pathology records were reviewed to determine if appendicitis was present when appendectomy was performed. Patients who underwent appendectomy were considered to have appendicitis based on pathology results, and patients managed non-operatively with symptom improvement and those with a normal appendix at pathology were considered to not have appendicitis. During the study period, 99 women meeting inclusion criteria presented to our institution for right lower quadrant ultrasound to evaluate the appendix during the second or third trimester of pregnancy. The mean gestational age at presentation was 23 weeks (±7 weeks). The mean maternal age was 28 years (±6.6 years). The appendix was not visualized in 97% (96/99) of right lower quadrant ultrasound examinations. Of the three studies in which the appendix was visualized, two were considered positive for appendicitis and one was considered negative. Eight patients in this group ultimately underwent appendectomy, including the two patients with positive right lower quadrant ultrasounds, and appendicitis confirmed at pathology in seven of these cases (87.5%). Right lower quadrant ultrasound successfully demonstrated an abnormal appendix in 28.7% (two of seven) of surgically confirmed cases; however, this technique did not detect appendicitis in 71% (five of seven) of patients with surgically proven disease due to nonvisualization of the appendix. Retrospective review of right lower quadrant ultrasounds performed during the second and third trimester of pregnancy suggests that this modality has limited utility for diagnosing appendicitis due to infrequent visualization of the appendix.

Impact of appendicitis during pregnancy: No delay in accurate diagnosis and treatment

“…The reported diagnostic performance of US for detecting appendicitis in pregnancy varies widely in the literature [13]. Sensitivity of 20%e46.1% [5,13,15,16] and specificity of 95.4%e100% [5,15,16] is reported. However, US seems to be of limited utility during pregnancy due to the high rate of non-visualization of the appendix (88%e97%) [13,15].…”

Acute appendicitis in pregnancy: literature review

“…28 Several studies have reported non-visualization of the appendix in a large percentage of pregnant women with suspected appendicitis. [29][30][31][32][33] However, in a review of studies on the value of ultrasound diagnostics during appendicitis in pregnancy, sensitivity ranged from 67 to 100% and specificity of 83 to 96%, compared with the general population, in which sensitivity and specificity were 86 and 96%, respectively. 34 Several factors influence the performance of ultrasound diagnosis of appendicitis in pregnancy, including gestational age, body mass index (BMI), and most importantly, the training and experience of the examiner.…”

The diagnosis of acute appendicitis in pregnant versus non-pregnant women: A comparative study

“…It is reported that USG has a high rate of non-visualization of the appendix during pregnancy. 12 Similarly, Aggenbach et al reported, in a study that evaluated 21 pregnant patients who underwent appendectomy, 75% of non-visualized appendix on USG. 13 Our result was inconsistent with this study, since we found non-visualized appendix in only 45.7% of the pregnant patients, less than the previously reported data.…”