Amyand hernia: a classification to improve management

We read with great interest the recent report by Milanchi and Allins [1] on history, imaging, and management of Amyand’s hernia. The authors recommend reduction of the appendix and mesh hernioplasty if there is no acute appendicitis, and appendectomy followed by endogenous repair if an inXamed vermiform appendix is found [1]. Although the recommendations of Milanchi and Allins are certainly acceptable, they do not fully reXect the potential variability of clinical scenarios resulting from the four basic types of Amyand’s hernias (Table 1). While the authors’ recommendations apply to Amyand Types I and II, the management of Types III and IV are more complex, and should also be considered. The absence of inXammatory changes in Type 1 approximates elective hernioplasty. Using a permanent prosthesis in such cases carries the expectation of an improved longevity of the repair because it avoids tension on the suture lines and circumvents the metabolic problems related to collagen deWciency known to exist in hernia patients [2]. Whether to remove or leave behind a normal appendix in this clinical scenario cannot be decided based on sound scientiWc data because no evidence-based information exists. The decision is rather based on common sense related to the age, life expectancy, and lifelong risk of developing acute appendicitis. Along these lines, pediatric or adolescent patients have a signiWcantly higher risk of suVering from acute appendicitis compared to middle-aged or elderly individuals in whom the appendix can probably more safely be left behind. However, consideration of appendectomy in young patients must be weighed against the size of the hernia, since prosthetic material is relatively contraindicated in the setting of even elective clean appendectomy, and larger hernias are more likely to recur if repaired using only endogenous tissue. Type 2 Amyand hernias are those in which the septic changes are conWned to the hernia sac [3]. Such hernias carry a higher risk of mesh infection. Thus, repairs using endogenous tissues or acellular collagen products (currently thought to be more resistant to infection than standard prosthetic materials [4, 5]) carry the expectation of a decreased morbidity, albeit at the risk of an increased recurrence rate. Type 3 represents a scenario where the sepsis has spread beyond the hernia sac and requires more extensive surgery [6]. Published examples in the setting of Amyand hernia include exploratory laparotomy for source control, orchiectomy, right hemicolectomy, or debridement of necrotizing fasciitis [6–9]. The advisability of performing hernia repair in such circumstances depends upon the magnitude of sepsis and condition of the patient, both reXecting the overall operative risk. It is common sense to defer the hernioplasty if the patient is critically ill or unstable. Type 4 of Amyand hernia includes all cases where a serious, complicating pathology exists outside of the hernia sac. Reported conditions in patients presenting with incarcerated Amyand hernias include appendiceal mucocele in the hernia sac associated with coexisting colon cancer [10], appendix with fecaliths and coexisting diverticulitis of the colon [11], adenocarcinoma of the vermiform appendix [12], and inguinal appendicocele with pseudomyxoma peritonei [13]. A high index of suspicion including CT scan, as suggested by Drs. Milanchi and Allins, can J. E. LosanoV (&) Department of Surgery (11S), John D. Dingell VA Medical Center, 4646 John R Street, Detroit, MI 48201, USA e-mail: jelosanoV@yahoo.com