Appendectomy outcomes in the modern era

Finally we have some data on the current rate of complications of appendectomy for uncomplicated appendicitis. But that’s not all. This new paper, published online in the journal Surgery, reveals much about the diagnosis, technique, and outcomes of appendectomy in the United States.

Using data from 115 hospitals participating in the National Surgical Quality Improvement Program, researchers at UCLA analyzed the results of 7778 adult patients undergoing appendectomy for simple appendicitis in 2016.

Here are the most important findings:

• 97.4% of appendectomies were performed laparoscopically with a rate of conversion to open appendectomy of only 0.5%. 
• 87.3% of patients having appendectomies were discharged on the day of  surgery or the day after. 
• 96.1% of appendectomy patients had preoperative diagnostic imaging. 
• Overall, 16.2% (1,256) of patients received of a pre-op ultrasound, but of these patients, 47% also had a CT scan and 4.2% also had an MRI. 
• Patients receiving an ultrasound had positive findings 53.6% of the time, equivocal findings 30.3% of the time, and negative findings 16.2% of the time. 
• Positive ultrasound findings were noted in 673 patients with 21.7% of them having at least one other study—either CT or MRI. 
• Equivocal and negative ultrasounds were followed by at least one other study 81.3% and 94.1% of the time, respectively. 
• Of the 7293 patients whose records included pathology results, 94.4% had appendicitis; 3.7% had a normal appendix; 1.1% had a tumor or malignancy; 0.8% had other pathology. 
• Tumors were found in 2.7% of geriatric (65 or older) patients which was much higher than the 1.0% among non-geriatric patients (p < .001). 
• When a patient had any positive imaging study, the negative appendectomy rate was 1.7%. 
• A positive CT scan was followed by negative appendectomy only 1.3% of the time. 
• Negative appendectomy after positive ultrasound occurred 3.5% of the time, higher than the rate in patients with positive CT scans (p < 0.001). 
• The 228 patients who had no imaging prior to surgery had a negative appendectomy rate of 19.4%. 
• Three (0.4%) patients died after appendectomy. Two were in the geriatric age group. 
• The 30 day complication rate overall was 3.0%. The most common complications were surgical site infections and unplanned reoperations. 

Laparoscopic appendectomy is clearly the operation of choice for appendicitis.

After laparoscopic appendectomy for simple appendicitis, the complication rate and hospital length of stay are much lower than figures quoted in previous studies.

From the discussion section of the paper: “It appears the days of a clinical diagnosis of appendicitis without imaging are almost gone, with only 4% of patients in this study undergoing appendectomy without preoperative imaging. Given the negative appendectomy rate of 19.4% in patients with no preoperative imaging, this trend may be justified.”

Compared to those 64 years old and less, geriatric patients had a significantly higher incidence of tumors at pathology and a significantly higher rate of complications.

All patients in this study underwent surgery for the presumed diagnosis of appendicitis. In this cohort, ultrasound was not very useful. Clinicians did not always trust a positive result because 21.7% of the time they followed a positive ultrasound with another imaging test. However, the study was not designed to address the accuracy of ultrasound in patients presenting with abdominal pain.

In an email, the study’s lead author Dr. Christopher Childers, a general surgery resident at UCLA, said, "If appendicitis is on the differential, CT is clearly the diagnostic image of choice, as has been endorsed by the American College of Radiology for some time."

Every surgeon and emergency physician should read this paper and use its findings to inform patients of the real risks and benefits of surgery during any consent discussion about the proposed treatment of simple appendicitis.