Evaluating conservative treatment for acute appendicitis with lump formation.

BACKGROUND: Interval appendectomy after acute appendicitis with lump formation (phlegmon) remains controversial. We conducted this study to determine the risk of recurrent appendicitis following initial non-operative treatment for appendicitis, and evaluate factors associated with recurrence. Secondarily, we evaluate the efficacy of interval appendectomy versus no appendectomy.
MATERIALS AND METHODS: Patients who received conservative treatment for appendicitis with lump formation were prospectively studied from June 2006 to June 2008. These patients were followed for recurrence of appendicitis.
RESULTS: Of 763 patients with acute appendicitis some 220 patients had lump formation (28.8%). Median age was 28 years. Conservative treatment was successful in 213 (96.8%) patients. The rate of recurrence was 13.1%, all occurring within six months after the index admission. Mean follow-up was 26±18 months.
CONCLUSION: Conservative treatment of appendicitis with lump formation is efficient and the recurrence rate is low. Routine interval appendectomy after initial conservative treatment for lump formation is not a cost-effective intervention and not recommended.

INTRODUCTION

Management of acute appendicitis is purely surgical. However, in the setting of appendicitis with abscess or phlegmon, initial non-operative management has been shown to be safe and effective.[1-3] The treatment of appendicitis with phlegmon has been debated for more than 100 years. Conservative treatment is an established practice, but the necessity of interval appendectomy remains controversial. Advocates of interval appendectomy propose that appendectomy prevents recurrence and gives definitive treatment.[4-6] Appendectomy can also provide a definitive diagnosis, and may sometimes reveal an unexpected malignancy. However, another group of surgeons who oppose this policy[7-9] point out that the rate of recurrent appendicitis is around 6–20%,[71011] and that the complication rate of interval appendectomy is not low (9–19%).[41112] Furthermore, routine appendectomy may increase the cost for both patients and institutions. The aim of this study was to determine the risk of recurrent appendicitis following initial non-operative treatment for appendicitis, and evaluate factors associated with recurrence. Our hypothesis was that the risk of recurrent appendicitis is low and that interval appendectomy is not routinely indicated.

MATERIALS AND METHODS

Patients who received conservative treatment for appendicitis with lump formation were prospectively studied from June 2006 to June 2008. Detailed history with clinical examination was done in every patient. Baseline investigations viz complete blood count, liver function and kidney function was done in every patient. Computed tomography (CT) was done in every patient for confirmation of diagnosis. CT guided aspiration was done in seventeen patients. These patients had CT evidence of abscess. Every patient was treated with intravenous fluids, antibiotics (Third generation Cephalosporin, Amikacin and Metronidazole). Patients were only allowed orals after their condition improved clinically and biochemically. Patients were discharged home after complete resolution of symptoms.

Patients were followed up in outpatient department monthly for three months, bimonthly for another six months, and six monthly thereafter. If signs of recurrent appendicitis appeared (such as right lower quadrant pain, or tenderness with or without fever), CT was repeated and appendectomy was performed if recurrent appendicitis was confirmed. Data was collected and analyzed statistically using SPSS software.

RESULTS

A total of 763 patients with acute appendicitis were treated from June 2006 to June 2008. Out of them 220 (28.8%) patients presented with lump formation. They were diagnosed clinically and confirmed by CT scan. High rate of lump formation was because of late referral and due to poor health care facilities available in our state. Seven patients in this group (3.2%) were operated in the index admission as they did not respond to conservative treatment.

The remaining 213 patients were followed up regularly in the outpatient department. Mean follow up was 32 months. Out of the total; 115 of them were men and 98 were women. Median age was 28years (range 15-63 years). All patients had history of pain in the right lower abdomen. Most of the patients had classical history of pain, starting at the umbilicus then radiating to the right iliac region. Most of the patients (79.8%) had history of anorexia but nausea and vomiting was found in only 23.4% of patients. There was history of fever in 53.0% of the patients. All the patients had a lump palpable in the right iliac region on clinical examination. Right iliac region was tender in 84.5% of the patients [Table 1]. There was no clinical difference in the primary clinical presentation between the cases that later developed recurrence and the patients who did not had recurrence [Table 2].

Table 1

Clinical presentation of patients of appendicitis with lump formation

Table 2

Clinical presentation of patients who later had recurrence

Among 213 patients, 28 (13.1%) had recurrent appendicitis on follow-up and they were operated for the same. All these patients had recurrences within six months of the primary treatment [Figure 1]. Most recurrences were detected as emergencies; n=22 (10.3%). Few patients were detected on follow up; n=6 (2.8%).

Figure 1

Kaplan-Meier plot of the recurrence-free survival of the patients

DISCUSSION

Lump formation after acute appendicitis is as a result of walled off perforation of appendix. Lump can be an inflammatory mass consisting of inflamed appendix, adjacent viscera, and greater omentum or a pus containing appendiceal mass. Although management of acute appendicitis is primarily surgical, management of appendicitis with lump is controversial for more than a century now. Ochsner[13] introduced the conservative treatment for fear of dissemination of infection with surgical intervention. McPherson and Kinmonth[14] reported that non-operative management of appendicitis with tumor formation achieved a 76% success rate and 0.8% mortality rate.

Currently, conservative treatment of appendicitis with lump formation is the preferred one.[781115] The success rate of conservative treatment of appendicitis with tumor formation ranges from 76% to 97%.[6141617] CT- or ultrasound-guided drainage of an appendix abscess has made surgical drainage less common.[121617] However, some surgeons still advocate early surgical intervention instead of conservative approach,[101618] although this approach has been criticized because of possibility of spread of previously localized infection, injury to surrounding structures, and overall higher complication rate.

After successful conservative treatment the question arises whether or not to perform interval appendectomy. The morbidity of interval appendectomy ranges from 3.4% to 19%[46111519-21] which can be compared to the reported incidence of recurrent appendicitis after conservative treatment of an appendix mass that ranges from 0% to 20%.[46-810-12] The danger of recurrence is reported to be greatest during the first 6 months after the initial episode and minimal after 2 years.[8]

Hoffmann et al.,[8] and Lai et al.,[22] also suggested that routine elective appendectomy can be safely omitted in more than80% of patients. Two systematic reviews Andersson, Petzold[23] and Simillis et al.,[24] in their studies also support the practice of nonsurgical treatment without interval appendectomy in patients with appendiceal abscess or phlegmon.

CONCLUSION

Conservative treatment is efficient in most patients with appendicitis with a phlegmone formation. The risk of recurrence is low, which does not motivate routine interval appendectomy after initial conservative treatment.