Laparoscopic Appendectomy

Acute appendicitis (AA), a common intra-abdominal surgical pathology, requires a comprehensive understanding of its presentation, evaluation, diagnosis, and overall operative management.

In the United States, the overall incidence of AA is approximately 7%, with a mortality of 0.2-0.8%. ^[1] The morbidity and mortality are related to the presenting stage of disease and are higher in cases of perforation.

Briefly, the pathophysiology and progressive timeline of AA are attributed to luminal obstruction, causing distention, ineffective venous and lymphatic drainage, bacterial invasion, and, finally, perforation with associated leakage of contents into the peritoneal cavity.

The presentation, evaluation, and diagnosis of AA are notoriously inconsistent; many factors attribute to these discrepancies. The classic history consists of anorexia and periumbilical pain, followed by nausea, right-lower-quadrant (RLQ) pain, and vomiting, as well as leukocytosis. ^[2] History and physical examination should provide enough clinical information to diagnose AA, with the use of imaging modalities as adjuncts in the assessment.

Treatment consists of providing aggressive intravenous (IV) fluid resuscitation and antibiotics, placing the patient on nil per os (NPO) status and on pain control, and obtaining a general surgical consultation for definitive operative management (either open or laparoscopic).

The authors' institution, a residency training facility, primarily uses the laparoscopic approach to AA, as is described in this article. The corresponding open procedure is discussed elsewhere (see Open Appendectomy). Laparoscopic approaches that use only one port have been described ^{[3, 4]} (see Single-Port Appendectomy). ^{[5, 6]} Transvaginal approaches have been described as well (see Transvaginal Appendectomy). 

The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) has published a guideline for laparoscopic appendectomy. ^[7]

Ever since being described by McBurney, ^[8] open appendectomy has been a well-established and widely performed operation indicated for patients with AA. Whether and when to perform a laparoscopic appendectomy as opposed to an open procedure remains a pertinent question.

In 2016, the World Society of Emergency Surgery (WSES) published guidelines for acute appendicitis that included recommendations regarding indications for laparoscopic appendectomy and choice of approach. ^[9]  These guidelines were subsequently updated in 2020 ^[10] and included the following recommendations:

• Laparoscopic appendectomy is recommended as the preferred approach over open appendectomy for both uncomplicated and complicated acute appendicitis where laparoscopic equipment and expertise are available
• Laparoscopic appendectomy should be preferred to open appendectomy in children where laparoscopic equipment and expertise are available
• Conventional three-port laparoscopic appendectomy is recommended over single-incision laparoscopic appendectomy
• In pediatric patients with acute appendicitis and favorable anatomy, single-incision/transumbilical extracorporeal laparoscopic assisted appendectomy or traditional three-port laparoscopic appendectomy is suggested, based on local skills and expertise 
• The adoption of outpatient laparoscopic appendectomy for uncomplicated appendicitis is suggested, provided that an ambulatory pathway with well-defined enhanced recovery after surgery (ERAS) protocols and patient information/consent are locally established
• Laparoscopic appendectomy is suggested over open appendectomy in obese patients, older patients, and patients with high peri- and postoperative risk factors
• Laparoscopic appendectomy should be preferred to open appendectomy in pregnant patients when surgery is indicated and laparoscopic expertise is available

In considering the indications for laparoscopic appendectomy, it may be equally or even more appropriate to focus on the contraindications, with the notion that all else falls into the indications category. (See Contraindications.)

Absolute contraindications for laparoscopic appendectomy are as follows:

• Hemodynamic instability
• Lack of surgical expertise

Relative contraindications have included the following:

• Severe abdominal distention that causes operative view obstruction or complicates abdominal entry and bowel manipulation
• Generalized peritonitis
• Multiple previous surgical procedures
• Severe pulmonary disease
• Pregnancy
• Extreme obesity

That said, as laparoscopic technology has advanced and surgeons' expertise has increased, many surgeons have successfully performed a multitude of laparoscopic procedures in the presence of these relative contraindications. The 2020 WSES guidelines reflect the growing acceptance of laparoscopic appendectomy in older patients, pregnant women, obese individuals, and those with high perioperative and postoperative risk factors. ^[10]

If intraoperative complications that cannot be handled with laparoscopy arise during laparoscopic appendectomy, conversion to an open appendectomy is indicated. It is crucial to understand the circumstances in which such conversion is warranted. ^{[11, 12]} Relative indications for conversion include the following:

• Dense adhesions due to inflammation or prior surgical procedures
• Perforated or gangrenous appendicitis
• Gangrenous or necrotic base
• Generalized peritonitis
• Retrocecal appendix
• Inability to visualize the appendix
• Uncontrolled bleeding
• Tumor of the appendix extending into base
• Other pathology, including malrotation, carcinoma, diverticula of cecum, endometriosis, pelvic inflammatory diseases, torsion of tubo-ovarian cyst
• Unexpected diagnosis

In a high-volume prospective cohort study by Antonacci et al, multivariate analysis indicated that preoperative comorbidities, appendiceal perforation, a retrocecal appendix, appendicular abscess, and diffuse peritonitis were factors significantly related to conversion from laparoscopic to open appendectomy. ^[13]

A study from Japan found a high preoperative C-reactive protein (CRP) level to be associated with an increased likelihood of conversion from laparoscopic to open appendectomy. ^[14]

Anatomy

The appendix is an elongated outpouching of the cecum, found at its posteromedial aspect about 2.5 cm below the ileocecal valve. It is derived embryologically from the midgut and first noted between weeks 5 and 8 of gestation. ^[15] It subsequently becomes fixed in the RLQ of the abdomen as the gut rotates during development. ^[15]

Function

Histologically, the walls of the appendix contain not only mucus-secreting goblet cells but also lymphoid tissue (developing during weeks 14 and 15 of gestation), implying immune function in early development. ^[15] Nevertheless, no specific function in the adult has been determined.

Positions

The base of the appendix can be identified during surgery by following the convergence of the taeniae coli toward the inferior portion of the cecum, which forms a continuous muscular layer surrounding the appendix. The position of the appendicular tip is inconstant and can be in various locations, including retrocecal (65%); descending pelvic (31%); transverse and retrocecal (2.5%); ascending, paracecal, and preileal (1%); and ascending, paracecal, and postileal (0.4%). This varied location explains the vast array of presentations. ^[16]

Blood supply

The blood supply of the appendix is derived from the appendicular artery, originating from the iliac ramus in 35% of cases, the ileocolic artery in 31%, the anterior cecal artery in 20%, the posterior cecal artery in 12%, and the ascending colic ramus in 2%. ^[17] The venous drainage parallels that of the arterial supply.

Associated structures

The mesoappendix consists of the mesentery of the appendix, containing all of the appendicular nerves and vasculature, which is ligated during an appendectomy. The fold of Treves, another useful anatomic landmark in locating the appendix during surgery, not only represents an avascular structure but is the only epiploic appendage located at the antimesenteric border of the small intestine. ^[18] It also serves as a marker indicating the junction of the ileum and cecum.

Procedural planning

The operative technique for AA consists of appendectomy; however, the choice between an open and a laparoscopic operation continues to be discussed in the medical literature. ^{[19, 20, 21]} Historically, the RLQ incision of open appendectomy has persisted essentially unchanged since it was pioneered by McBurney in the 19th century. ^[8] The use of laparoscopy in the surgical management of AA was first described in 1983, with a continued increasing trend in its use. ^[22]

As with other laparoscopic procedures, the literature describes decreased pain, earlier resumption of diet, and decreased length of hospital stay for laparoscopic appendectomy. ^[21] However, this must be objectively contrasted to the open procedure, which already involves minimal risk, an extremely short hospital stay, and a low complication rate. Relative disadvantages of laparoscopy include increased cost and longer operating time.

In a study comparing laparoscopic and open appendectomy for complicated appendicitis in adult patients, Taguchi et al found that the minimally invasive approach was safe and feasible in this setting, though it did not significantly reduce complications. ^[23] Li et al found that laparoscopic appendectomy, as compared with open appendectomy, was feasible and effective in pediatric patients presenting an appendiceal abscess and that it had beneficial clinical effects (eg, in terms of postoperative recovery of gastrointestinal function) and a lower rate of postoperative complications. ^[24]