Originally published by our sister publication General Surgery News
CLEVELAND—Clinical and radiological advancements notwithstanding, the diagnosis of acute appendicitis remains a challenge in pregnant patients, a new study has concluded.
The investigation found that neither the four scoring systems commonly used to diagnose acute appendicitis nor MRI had a positive predictive value exceeding 40% in this patient population, to go along with negative predictive values ranging from 94% to 98%.
“Acute appendicitis is the most common indication for general surgery in pregnant patients,” said Eliahu Bekhor, MD, an attending surgeon at Rabin Medical Center, in Petah Tikva, Israel. “And while there are numerous scoring systems for its diagnosis, none have been thoroughly investigated in pregnant patients.
“Additionally, we know that MRI is very commonly used in pregnant patients, particularly in the setting of suspected acute appendicitis,” he continued. “Once again, however, we don’t have enough data to support use of this method in pregnant patients.”
To help assess the accuracy of these various approaches, the investigators enrolled 141 pregnant patients into the trial, all of whom underwent MRI for a suspected diagnosis of acute appendicitis at the institution between 2013 and 2021. Using the final pathologic report, the researchers then classified patients into those with acute appendicitis or controls. The groups were then compared using the Alvarado, Tzanakis, RIPASA, and AIR scoring systems, as well as MRI findings.
In a presentation at the 2024 annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons, Dr. Bekhor reported that 19 of the 141 patients had confirmed acute appendicitis. Among these, it was found that less than half had positive clinical scores, as follows: Alvarado, 21%; Tzanakis, 16%; RIPASA, 37%; and AIR, 50%. For its part, MRI yielded a positive diagnosis in 84% of acute appendicitis cases.
The positive predictive value of the clinical scoring systems was found to be 23% for Alvarado, 34% for Tzanakis, 12% for RIPASA and 11% for AIR; MRI had a positive predictive value of 37%. On the other hand, the negative predictive value was 94% for each of the four scoring systems, and 98% for MRI.
“In light of these results, we conclude that we surgeons should always rely on our experience and clinical judgment when to comes to diagnosing acute appendicitis,” Dr. Bekhor said. “Because if you look at the numbers, we obviously can’t take a patient to the operating room based on any of those scoring systems alone. At the same time, we can’t really discharge patients based on a negative score either,” he said.
Helmuth T. Billy, MD, thought the inclusion of imaging technology was a “fascinating” adjunct to the scoring systems commonly used to assess for acute appendicitis. “How useful was MRI for delineating between appendicolith and non-appendicolith appendicitis?” asked Dr. Billy, the medical director of bariatric surgery with Ventura Advanced Surgical Associates, in California.
“We actually compared the percentage of appendicolith appendicitis between MRI in this study with previous results from ultrasound and CT scan,” Dr. Bekhor replied. “And we found a much lower diagnosis rate with MRI. That said, we don’t know if the presence of appendicoliths just happened to be lower in this study or if the accuracy of appendicolith diagnosis was lower with MRI. But since we had only 19 cases of acute appendicitis, it’s difficult to draw any firm conclusions.”
“Given that some cases of appendicitis will improve on their own, how can you be certain of negative findings?” asked Dimitrios Stefanidis, PhD, MD, the Harris B. Shumacker Jr. MD Professor of Surgery at Indiana University School of Medicine, in Indianapolis. “In other words, do you follow these patients to make sure that they don’t have a recurrence and ensure the negative diagnosis was truly negative?”
“In our system, we are able to follow up on all our patients nationwide to see if there is any recurrence,” Dr. Bekhor replied. “Our minimum follow-up was one year, and only one patient came back, nine months later, with acute appendicitis and underwent surgery. So, we can say with some level of certainty that none of the patients had any relevant medical attention in the year after we saw them.”
Dr. Stefanidis reported financial relationships with Applied Medical, Becton, Dickinson and Co., Intuitive Surgical, and Johnson & Johnson.