Appendicitis represents one of the most common causes of abdominal pain with roughly 300,000 cases reported annually totaling 1 million patient days of admission. Since McBurney first successfully completed an appendectomy in 1889 it has been the main stay of treatment for acute appendicitis worldwide. Upon presentation of abdominal symptoms medical providers categorize appendicitis’ as an inflamed intact appendix (uncomplicated), perforated or abscessed (complicated) via assistance from CT and US. Due to the advances in surgical outcomes and techniques, appendectomies continue to be the mainstay of treatment for uncomplicated acute appendicitis and well-formed abscesses despite not requiring urgent surgical care. Non-operative alternatives such as antibiotic therapy for uncomplicated acute appendicitis have been considered by many physicians for years without a systematic conclusion. While recurrence with non-operative alternatives remains an issue, complication rates, hospital stay and overall cost all decrease with use of antibiotic in uncomplicated acute appendicitis.
- The appendix is a tube-like pouch coming off of the cecum in the right lower abdomen where the small and large intestines join. The average length of the appendix is approximately 9-10 cm, but the length can vary as much as 2-20 cm. The appendicular artery supplies blood flow to the entire length of the pouch. 1
- Historically the appendix was thought to have no function but recently research has shown the role in intestinal immunity. Through the unique shape and position in the abdomen it houses specific microbiota that may serve protective factors against many inflammatory diseases.2
- Appendicitis’ are caused by luminal obstruction of the pouch with etiologies ranging from benign or malignant tumors (1%), foreign bodies (4%), hardened feces (fecalith) (35%), and hyperplasia of lymphoid cells (60%). There is additional evidence to support that genetic, environmental and infectious properties all playing a role in the various etiologies.1 Environmentally, appendicitis’ are more likely to occur during the summer months due to higher levels of air pollution. Further, anatomically, risk factors include appendiceal length of 4-10 cm.
- The pathophysiology of appendicitis begins with blockage of the lumen which precipitates inflammation and mucus production in the pouch. This inflammation causes an increase in pressure. Further pressure is added as infection develops and bacteria grow and pus forms. Circulation of blood flow is compromised leading to ischemia of the pouch which may progress to necrosis. Necrosis may precipitate perforation and peritonitis.1
- Uncomplicated acute appendicitis is defined as acute inflammation of the appendix in the absence of an abscess, phlegmon, free perforation or peritonitis. 3
- Acute appendicitis has a life-time risk of 8.6% in men and 6.7% in women and the risk for emergency appendectomy is 12% in men and 23% in women.4 Caucasians are at increased risk in comparison to other ethnicities.
- Peak in incidence of appendicitis in the 2nd decade of life.5
- The rate of diagnosis of appendicitis in females has increased with time possibly due to increased use of CT scans in the last 15 years. Abdominal pain from gynecology etiologies is ruled out via CT scans and females are receiving appropriate diagnosis.6
- Appendicitis’ are more common in urban and industrialized areas and less common in more rural areas. This may be in explained by the type of diet in these areas with agrarian rural communities consuming diets rich in high fiber in comparison to low-fiber urban diets.6
- Patient Presentation
- Classic Presentation
- Pain is the first symptom and is often gradual and poorly localizes to either the epigastric or periumbilical area. Initially the pain is vague, but it may be intense enough to awaken patients from slumber. Pain will migrate to the lower right quadrant while increasing in intensity. 7
- As pain migrates, frequently associated symptoms include: nausea, anorexia and unstained vomiting. 7
- Patients often feel constipated even after passing a bowel movement.7
- Other signs/ symptoms:
- Guarding: involuntary contraction of abdominal muscles in anticipation of pain elicited by palpation
- Rebound Tenderness: pain following cessation of prolonged deep palpation to tender area
- Positive Rovsing’s sign: pain in right lower quadrant when left lower quadrant is deeply palpated
- Positive psoas sign: pain in right lower quadrant with flexion of the thigh against counterpressure above the knee.
- Positive obturator sign: pain in right lower quadrant with passive flexion of the right hip and knee with external rotation.
- Moderate leukocytosis, low-grade fever, malaise, constipation or diarrhea.
- Patients under the age of 15 are more likely to present with vomiting as their initial symptom, complain of GI/GU symptoms, high-grade fever and URI symptoms. Due to the atypical presentation, these patients are more likely to be misdiagnosed and experience perforation. 7
- Elderly typically do not present with the classic presenting symptoms. However, appendicitis accounts for 14% of all acute abdominal complaints amongst the elderly.7
- Classic Presentation
- 70% of appendicitis are considered “typical” and can be diagnosed on history, physical exam and evaluation of blood chemistry tests alone. However, in 30% of appendicitis cases the clinical presentation mimics other abdominal or pelvic diseases and are defined as “atypical.” In these atypical cases, imaging modalities are especially important.8
- Ultrasound is historically first line examination for someone presenting with appendicitis symptoms, however, it only has an accuracy between 75% and 95% (sensitivity around 85% and specificity around 90%). With atypical anatomical variations such as pelvic or retrocaval positioning the US is unable to even identify the appendix.8
- Diagnosis via ultrasound is made via appendiceal changes or periappendiceal changes.
- Appendiceal changes include “the identification of the inflamed appendix, which appears as a tubular and a peristaltic structure with a diameter > 6 mm (sensitivity and specificity values of 98% have been reported), a concentric wall stratification and target aspect.” 8
- Periappendiceal changes include: thickening of periappendiceal fat tissue because of a marked mesenteric hypertrophy, the presence of periappendiceal fluid collections and peritoneal fluid material, mesenteric lymphadenopathies, phlegmons, abscesses and inflammatory thickening of cecal or ileal walls. 8
- The main limitations of US are “represented by the difficulty to recognize normal appendix, the poor experience of operator, obesity, bowel gas, atypical appendicitis and perforation and finally by the pain caused by compression during examination.”8
- Abdominal CT is the best noninvasive diagnostic tool available due to high levels of both sensitivity and specificity.4
- The diagnostic accuracy of CT scans in between 94-100% in determining the site and course of the inflamed appendix. The sensitivity is 82-94% and specificity 91-100%. 8
- Alvarado Score to Perform CT
- While CT is considered the gold standard for diagnosis of appendicitis, concerns for radiation in pediatric populations can be reduced by utilizing the Alvarado score prior to performing CT. 9
- Recommendations for CT imaging and patient disposition based on the Alvarado score included: conservative use of CT for scores of 3 or less, surgical consultation prior to CT for scores of 7 or greater, and consideration of CT for equivocal scores of 4 through 6.9
- Scoring Features with a total of 10
- Migration of pain 1 point
- Anorexia 1 point
- Nausea 1 point
- Tenderness in right lower quadrant 2 points
- Rebound pain 1 point
- Elevated temperature 1 point
- Leukocytosis 2 points
- Shift of white blood cell count to the left 1 point
- Appendicitis Inflammatory Response
- The score is constructed using eight variables: right-lower-quadrant pain, rebound tenderness, muscular defense, WBC count, proportion neutrophils, CRP, body temperature, and vomiting. 10
- The Appendicitis Inflammatory Response score improved upon the Alvarado score by including objective measures rather than the subjective synthesis of information from variables with ill-defined diagnostic valve. Further, the Alvarado score was developed using a retrospective study rather than confirming suspicion of the appendicitis which coincides with the utility of the test. 10
- In one study, the scoring system was able to successfully identify 73% of the non-appendicitis patients to the low probability group and 67% of the patients with advanced appendicitis to the high-probability group with high accuracy. Only 37% of the patients remained in the indeterminate group. The Appendicitis Inflammatory Response performed more favorably than the Alvarado score.10
- Emergency Department Care
- Patients suspected of appendicitis should be NPO in preparation of emergent surgery.
- Historically, patients with acute undifferentiated abdominal pain were not given analgesics due to concern that analgesics would mask the patient’s symptoms and prevent physical exam findings from being as reliable. However, this has not been proven to delay diagnosis or accuracy in diagnosis. Analgesia should be given to patients with clinical judgement.11
- Preoperative Antibiotics:
- A single dose of a second-generation cephalosporin has been shown to reduce the rate of superficial surgical site infections in nonperforated, gangrenous, and perforated appendicitis.12
- The timing of administration of antibiotics preoperative has not shown to make a difference in reduction of surgical site infections.12
- Postoperative Antibiotics:
- Perforated appendicitis’ are treated with postoperative antibiotics as a supplement to surgical source control. The length of time of antibiotics given is variable and produces inconsistent results in reduction of superficial surgical site infections. However, due to the operative would class IV status, antibiotics for a minimal length of time are indicated.13
- Antibiotic therapy postoperative and preoperative for non-perforated appendicitis did not reduce the rate of surgical site infections, while also increasing the cost of care.13
- Guidelines form the Society of American Gastrointestinal and Endoscopic Surgeons list the indications for laparoscopic appendectomy identical to those for open appendectomy. However, it is contraindicated in patients with significant intra-abdominal adhesions, radiation or immunosuppressive therapy, severe portal hypertension, coagulopathies, and first trimester pregnancy.14
- Disadvantages include increased time in OR, operations typically last 20 minutes longer than open surgeries and increased cost.15
- Advantages include cosmetic satisfaction, shortened hospital stay and decreased post-op wound infections.15
- Risk factors for complications following appendectomies include: increasing age, female sex, rural residence, perforation status, daytime surgery and open surgical technique and surgical time greater than 77 minutes. 16,17
- Complications following appendectomy occur in 7% of children.5
- Abscess: Intraabdominal abscess is the most common complication of appendectomies. 18 There is no difference in laparoscopic vs open appendectomies in incidence of occurrence.19
- Small bowel obstruction: In one retrospective study of 3,000+ patients, small bowel obstruction was seen in 1.24% and was surgically treated in 0.68% of all appendectomies. 20
- Superficial surgical site infection: Risk factors for superficial surgical site infection include diabetes, incisional length >7 cm, fecal contamination and operative time >75 minutes.21
- Mortality: In one retrospective study in Sweden examining case fatality rates in 9 years showed 2.44 deaths per 1,000 appendectomies. The study had an excess rate of death for patients with nonperforated appendicitis and nonsurgical abdominal pain suggesting that the deaths may partly be caused by the surgical trauma.22
- Negative Appendectomies: Currently 15-25% of all presumed appendicitis result in negative appendectomies. These unnecessary surgeries result in the same complications listed above and coincide with non-perforated complications of appendectomies.8 Further, there is evidence that there is a greater risk of abdominal adhesions in patients with healthy appendices compared to that of acute appendicitis. 8
- Preoperative Antibiotics:
- Antibiotic Alternatives
- Despite appendectomies being the mainstay of treatment since the introduction of the surgical procedure in the 1880’s, in 1959 Coldrey studied nearly 500 patients treated with just antibiotics for appendicitis and proved low morbidity and mortality rates.23
- Recurrence Rates:
- Readmission Rates:
- Cost Savings
- Short duration of therapy:
- Minimal sick leave:
- Health Care Dollar Savings:
- Special Patient Populations:
- Resource limited areas
- Contraindications to surgery
- Emergency Department Care
- Conclusions/ Recommendations
- Increased use of CT scan for confirmation of diagnosis.
- Antibiotic use for uncomplicated appendicitis
- Patient should be involved in the decision-making process of treatment
- Operation: potential complications, cost, time off work
- Antibiotics: fear of impending recurrence, antibiotic side effects
- Schreiber ML. Acute Appendicitis: Classic Considerations with Cautions.
- Girard-Madoux MJH, Gomez de Agüero M, Ganal-Vonarburg SC, et al. The immunological functions of the Appendix: An example of redundancy?
Seminars in Immunology
. 2018;36:31-44. doi:10.1016/j.smim.2018.02.005.
- Rocha LL, Rossi FMB, Pessoa CMS, Campos FND, Pires CEF, Steinman M. Antibiotics alone versus appendectomy to treat uncomplicated acute appendicitis in adults: What do meta-analyses say
? World J Emerg Surg
. 2015;10(1):1-7. doi:10.1186/s13017-015-0046-1
- Paajanen H, Grönroos JM, Rautio T, et al. A prospective randomized controlled multicenter trial comparing antibiotic therapy with appendectomy in the treatment of uncomplicated acute appendicitis ( APPAC trial ). 2013. doi:10.1186/1471-2482-13-3
- Georgiou R, Eaton S, Stanton MP, Pierro A, Hall NJ. Efficacy and Safety of Nonoperative Treatment for Acute Appendicitis: A Meta-analysis.
. 2017. doi:10.1542/peds.2016-3003
- Buckius MT, McGrath B, Monk J, Grim R, Bell T, Ahuja V. Changing epidemiology of acute appendicitis in the United States: Study period 1993-2008.
J Surg Res
. 2012;175(2):185-190. doi:10.1016/j.jss.2011.07.017
- Pisarra VH. Recognizing the various presentations of appendicitis.
Dimensions of Critical Care Nursing
- Ryan WL.
Appendicitis : Symptoms, Diagnosis, and Treatments.
New York: Nova Science Publishers, Inc; 2010.
- Ohle R, O’Reilly F, O’Brien KK, Fahey T, Dimitrov BD. The Alvarado score for predicting acute appendicitis: a systematic review.
. 2011;9:139. Published 2011 Dec 28. doi:10.1186/1741-7015-9-139
- Andersson M, Andersson RE. The appendicitis inflammatory response score: A tool for the diagnosis of acute appendicitis that outperforms the Alvarado score.
WORLD JOURNAL OF SURGERY
. 32(8):1843-1849. doi:10.1007/s00268-008-9649-y.
- Singer DD, Thode JHC, Singer AJ. Effects of pain severity and CT imaging on analgesia prescription in acute appendicitis.
American Journal of Emergency Medicine.
- Wu W-T, Tai F-C, Wang P-C, Tsai M-L. Surgical site infection and timing of prophylactic antibiotics for appendectomy.
. 2014;15(6):781-785. doi:10.1089/sur.2013.167.
- Le D, Rusin W, Hill B, Langell J. Post-operative antibiotic use in nonperforated appendicitis
. Am J Surg.
- [Guideline] Korndorffer JR Jr, Fellinger E, Reed W. SAGES guideline for laparoscopic appendectomy. Surg Endosc. 2010 Apr. 24(4):757-61
- Kouhia ST, Heiskanen JT, Huttunen R, Ahtola HI, Kiviniemi VV, Hakala T. Long-term follow-up of a randomized clinical trial of open versus laparoscopic appendicectomy. Br J Surg. 2010 Sep. 97(9):1395-400.
- Patel SV, Nanji S, Brogly SB, Lajkosz K, Groome PA, Merchant S. High complication rate among patients undergoing appendectomy in Ontario: a population-based retrospective cohort study.
Canadian Journal Of Surgery
Journal Canadien De Chirurgie.
- Moreira LF, Garbin HI, Da-Natividade GR, Silveira BV, Xavier TV. Predicting factors of postoperative complications in appendectomies.
Revista Do Colegio Brasileiro De Cirurgioes.
- Alharbi FM, Almutairi TS, Algayed HK, et al. Predictors of Length of Stay, Complications and Patient’s Satisfaction after Appendectomy.
Egyptian Journal of Hospital Medicine
. 2017;69(8):3050-3053. doi:10.12816/0042854.
- Asarias, J.R., Schlussel, A.T., Cafasso, D.E. et al. Surg Endosc (2011) 25: 2678. doi.org/10.1007/s00464-011-1628-y
- Tingstedt B, Johansson J, Nehez L, Andersson R. Late abdominal complaints after appendectomy—readmissions during long‐term follow‐up.
2004; 21: 23–27
- Noorit P, Siribumrungwong B, Thakkinstian A. Clinical prediction score for superficial surgical site infection after appendectomy in adults with complicated appendicitis.
WORLD JOURNAL OF EMERGENCY SURGERY.
- Blomqvist PG, Andersson RE, Granath F, Lambe MP, Ekbom AR. Mortality after appendectomy in Sweden, 1987–1996.
2001; 233: 455–460.
- Coldrey E. Five years of conservative treatment of acute appendicitis.
J Int Coll
Surg 1959; 32: 255–261.