Non-Operative Management of Appendicitis: Evolution, not Revolution.

The medical fascination with the appendix vermiformis dates from the clandestine prosectors of the fifteenth century. The surgical management of appendiceal inflammation dates from 1735, but acceptance that acute appendicitis (AA) should be treated primarily by resection with or without drainage would not follow for 150 years. Recent publication of several randomized clinical trials (RCTs) of non-operative management (NOM) of AA affords the opportunity to review the historical record, describe the evolution of AA management toward NOM, and assess what is in the best interest of the patient. Review and synthesis of historical and contemporary English, French, German, and Italian literature with expert opinion. Modern understanding of AA dates to the landmark 1886 clinico-pathologic correlative study by Reginald Fitz, which coined the term appendicitis and coincided with recognition by surgeons that AA could be diagnosed pre-operatively and managed surgically, with mortality rates of approximately 10%. Not until 1901 did Albert Ochsner advocate NOM, paradoxically for severe cases unlikely to survive operation. Markedly decreased mortality coincided with the introduction of sulfanilamide in 1935 and penicillin and curare in 1942. The first large series of patients with AA treated primarily with NOM was published in 1956 by Eric Coldrey. Modern management evolved rapidly in the late twentieth century, including effective anti-anaerobic antibiotic agents (1970s), laparoscopic appendectomy (LA; 1980), and pelvis computed tomography with rectal contrast (1998) all representing important contributions. Randomized controlled trials of NOM of AA date to 1995, with one large trial (2015) showing that open appendectomy was not non-inferior to NOM, and another (2020) demonstrating non-inferiority between (mostly) LA and NOM. However, one-year failure rates are high (∼30%) and appear to increase further with longer follow-up. Laparoscopic appendectomy is curative and cost-effective management for AA, with low morbidity. Results of recent RCTs of NOM of AA indicate that LA remains the treatment of choice, particularly if a fecalith is present. However, patient preferences must be taken into account; some may prefer NOM for the 60%-70% chance that surgery may be avoided, which should be considered when providing informed consent. Non-operative management should be undertaken in the outpatient setting if possible. Antibiotic management-whether or not for NOM-should adhere to the principles of stewardship.