Perioperative management - Appendectomy, laparoscopic

Appendectomy is the most common abdominal procedure worldwide. The lifetime risk of appendectomy is 7–8%.

Appendectomy is the treatment of choice for acute appendicitis in all age groups.

This paradigm in the treatment concept of acute appendicitis is currently under intense scrutiny and has been questioned since conservative therapeutic models have been published and become part of public opinion.

Since the evidence to date is too weak to suggest a benefit for non-surgical treatment, especially in uncomplicated appendicitis, conservative treatment of appendicitis cannot be recommended. Evidence based treatment recommendations in acute appendicitis have been published both in the German "Der Chirurg" (recommendations of a group of experts in light of the current literature: Andric et al. Chirurg 2020; 91:700-711) as well as in Deutsches Ärzteblatt (Téoule et al. Dtsch Arztebl Int 2020; 117: 764-74.

Depending on the degree of severity, acute appendicitis may be classified as uncomplicated or complicated. According to the EAES (European Association of Endoscopic Surgery), uncomplicated appendicitis refers to inflammation of the appendix without evidence of gangrene, adjacent phlegmon, free purulent fluid, and abscess.

In order to select the appropriate regimen, acute appendicitis should be classified as uncomplicated or complicated before treatment is initiated.

For decades, open access via a muscle-splitting incision in the right lower quadrant was regarded the gold standard.

In Germany today, the standard procedure in acute appendicitis is laparoscopic appendectomy. The benefits of laparoscopic surgery are evident and have prevailed over the open approach. Unlike open surgery, it excels with shorter length of stay and time to return to work, lower wound infection rates, and overall lower morbidity and mortality. This is offset by longer operating times and higher cost.

Open access continues to have its place as well. Both surgical approaches are legitimate worldwide.

Another benefit of laparoscopy is the opportunity of exploring the abdominal cavity to rule out differential diagnoses such as adnexitis / Meckel diverticulitis. Incidental appendectomy in the absence of contraindications is an option because although the gross appearance of the appendix may be unremarkable, histology may demonstrate appendicitis or other pathologies such as endometriosis, neoplasia, obstruction by appendicoliths, or parasites.

Under the right conditions, uncomplicated appendicitis may be managed conservatively. However, a meta-analysis published in 2019 (Prechal et al: Antibiotic therapy for acute uncomplicated appendicitis: a systematic review and meta-analysis. Int J Colorectal Dis 2019) showed that up to 37% of adult patients initially treated conservatively still had to undergo appendectomy within one year.

Risk factors for failure of conservative management and increased morbidity include evidence of appendicoliths, obesity, age > 65 years, immunosuppression, acquired immunodeficiency, and pregnancy.

If non-surgical management fails (persistent or progressive symptoms; about14%), an urgent operation is indicated. In most of these cases, the surgical situation will be complicated and technically challenging.

Complicated appendicitis is a serious clinical condition. In case of free perforation, emergent surgery is mandatory.

In case of periappendiceal phlegmon or abscess, the current data do not allow a definite recommendation regarding the timing of the operation. Prompt appendectomy tends to be recommended, especially in patients with risk factors, with gross abscess and inflammatory conglomerate tumor more likely to be treated with intervention and/or antibiotics.

If ultrasonography demonstrates a vermiform appendix/residual appendix 6-8 weeks later, interval appendectomy should be performed. According to the current literature (Li et al: Effect of delay to operation on outcomes in patients with acute appendicitis: a systematic review and meta-analysis. J Gastrointest Surg 2019; van Dijk et al.: Meta-analysis of in-hospital delay before surgery as a risk factor for complications in patients with acute appendicitis. Br J Surg 2018; Cameron et al.: Time to appendectomy for acute appendicitis: A systematic review. J Pediatr Surg 2018; 53: 396–405), if imaging suggests an uncomplicated course, appendectomy can be delayed for 12-24 hours from the time of diagnosis under antibiotics without increasing the risk of perforation. Exceptions apply to patients over 65 years of age and those with significant comorbidities, in particular immunosuppression and immunodeficiency; in these cases, surgery should be performed early, and a 12-hour time interval should not be exceeded. The same is true for children and adolescents.

In pregnant women, urgent appendectomy should be performed because of the risk of miscarriage. Appendectomy can be performed easily in any trimester, both as an open or laparoscopic procedure. Miscarriage can be prevented by short operating times and maintaining the pneumoperitoneum in the range of 10 to12 mmHg.

In justified cases (e.g., gynecologic differential diagnoses, suspected sigmoid diverticulitis), exploratory laparoscopy may be indicated if appendicitis is suspected.

If the gross appearance of the appendix is unremarkable intraoperatively and there is no differential diagnosis, appendectomy should be performed, since in 29% of these cases histology will confirm appendicitis after all. If during the operation another diagnosis is confirmed, appendectomy may not become necessary.

Tumors of the appendix as incidental findings on histopathology:

In the appendectomy specimens examined by the pathologist, the histopathologic workup reveals tumors as incidental findings in up to 2% of the specimens. According to the WHO classification, these tumors of the appendix can be differentiated into the two main groups of neuroendocrine tumors (NET) and mucinous neoplasms.

The neuroendocrine tumors of the appendix, the so-called appendiceal carcinoids, are rare incidental histologic findings almost always seen postoperatively after appendectomy. Most are located in the appendiceal apex, are smaller than 2 cm, and do not metastasize. Therefore, repeat surgery is rarely required. The following conditions necessitate secondary right hemicolectomy with mesenteric lymphadenectomy: Primary tumor >2 cm, mesoappendiceal infiltration, goblet cell carcinoid, intermediate or high-grade differentiation, R1 appendectomy. 

The mucinous neoplasms can be further classified into invasive mucinous adenocarcinoma and the low-grade appendiceal mucinous neoplasm masses (LAMN), which are regarded as precursors of pseudomyxoma peritonei (PMP).

These gelatinous tumors of the appendiceal lumen may rupture as they progress, thereby seeding the abdominal cavity.

There are no clear treatment regimens in the literature for the incidental finding of a LAMN. Treatment must weigh the risk of potential development of a PMP against the morbidity and mortality of the treatment.

Mc Donald et al. divide LAMN into 2 types, with evidence of mucin or mucin herniation in the appendiceal wall, perforation of the appendiceal wall, or evidence of mucin outside the appendix without evidence of perforation as the discriminating criteria.

Most HIPEC centers base their treatment decisions on this classification.

R0 appendectomy appears to be adequate only for LAMN type 1. In LAMN type 1 with R1 resection, as well as all in LAMN type 2 tumors, prophylactic HIPEC (Hyperthermic IntraPEritoneal Chemotherapy) with local peritonectomy is recommended, with re-excision of the margins in R1 situations. Lower quadrant peritonectomy and HIPEC may be performed laparoscopically.

Invasive mucinous appendiceal carcinoma requires oncologic hemicolectomy, while therapeutic (+ cytoreductive surgery (CRS)) or prophylactic HIPEC is recommended.

• Acute episode of Crohn disease with so-called "concomitant appendicitis". Initially medical treatment, and surgery only in further clinical deterioration.

Caution: Inflammatory changes at the cecum increase residual stump rupture rate and secondary fistula formation.

1->  McBurney point: Point of tenderness between the lateral and middle third of an imaginary line between the right anterior superior iliac spine and the umbilicus

2->  Lanz point: Point of tenderness on the right lateral third of an imaginary line between both anterior superior iliac spines

3-> Blumberg sign: Ipsi-/contralateral rebound tenderness

4-> Rovsing sign: Pain elicited in the right iliac fossa on deep palpation of the left iliac fossa 

Not shown -> Psoas sign: RLQ pain with extension of the right hip or with flexion of the right hip against resistance (suspecting retrocecal appendix)

• Although the diagnosis of acute appendicitis is a primarily clinical diagnosis, imaging studies play an important role in the differential diagnosis of RLQ abdominal pain.
• Clinical examination including the various signs of appendicitis (Mc Burney, Lanz, Blumberg, Rovsing, Psoas signs) and blood tests are mandatory. Leukocytosis/neutrophilia and elevated CRP levels are quite common. Patients often report pain migrating from the epigastrium to the RLQ.
• Although being nonspecific symptoms, elevated body temperature and fever correlate with advanced appendicitis.
• Localized RLQ guarding suggests irritation of the parietal peritoneum. Diffuse guarding suggests complicated severe appendicitis.
• For the assessment of differential diagnoses such as urolithiasis, urinary tract infection, adnexitis, extrauterine pregnancy, test strip or lab panel urinalysis, pregnancy testing in girls/women of childbearing age, and a gynecological consultation in case of inconclusive clinical findings are recommended.
• Appendicitis risk scores have not yet gained wide use in clinical practice.
• The modality of choice is abdominal ultrasonography. In expert hands, it is a reliable modality to confirm acute appendicitis, but is not reliable enough to rule it out.
• Although an abdominal CT study is superior to sonography and can reduce the negative appendectomy rate to less than 5%, it is not a routine modality because of radiation exposure, especially in young patients, children and pregnancy. In children and pregnancy, MRI is the preferred alternative to CT because it lacks radiation exposure and should be favored for this patient group and in equivocal sonographic findings.
• Inpatient monitoring with close clinical and laboratory re-evaluation is also an appropriate approach to reduce the number of negative explorations.
• Since the clinical signs in obesity (BMI >30 ) are less representative and sonographic assessment is usually limited, the rate of CT studies in this patient group is higher.

• Antibiotics should be instituted once the diagnosis is confirmed because this may reduce both the rate of wound infection and the incidence of postoperative abscess formation. In uncomplicated appendicitis, this should be continued only in justified cases.
• In complicated appendicitis, the antibiotic regimen should be continued postoperatively.
• A combination of cephalosporin with nitroimidazole or penicillin with beta-lactamase inhibitor is recommended.

• Secondary healing
• Intraabdominal abscess requiring revision or percutaneous drainage
• Postoperative ileus
• Adhesions
• Stump rupture
• Injury to other segments of the bowel, vessels, ureter
• Cutaneous emphysema
• Postlaparoscopic shoulder pain syndrome
• General surgical risks (bleeding, secondary bleeding, thrombosis, embolism, HIT)
• In case of complications convert to open technique, if necessary