Laparoscopic appendectomy

In 1889, McBurney published his first results on appendectomy, while de Kok published a ''new technique for resecting the non-inflamed not-adhesive appendix through a mini-laparotomy with the aid of the laparoscope'' in 1977. Currently, appendectomy is the most frequent surgical procedure performed by general surgeons. This dynamic chapter presentation includes embryological and anatomical notions along with indications and contra-indications for the laparoscopic approach, even in particular cases such as pregnancy. All aspects of laparoscopic appendectomy are presented.

Browse the WORLD
Virtual University

Laparoscopic   appendectomy

In 1889, McBurney published his first results on appendectomy, while de Kok published a "new technique for resecting the non-inflamed not-adhesive appendix through a mini-laparotomy with the aid of the laparoscope" in 1977. Currently, appendectomy is the most frequent surgical procedure performed by general surgeons. This dynamic chapter presentation includes embryological and anatomical notions along with indications and contra-indications for the laparoscopic approach, even in particular cases such as pregnancy. All aspects of laparoscopic appendectomy are presented.
Media type
Favorites Media
en cn

E-publication, Nov 2010;10(11).

Laparoscopic   appendectomy

1. Introduction
Appendicitis is the most common acute surgical condition of the abdomen. Despite technological advances, the diagnosis of appendicitis is still based primarily on the patient's history and the physical examination. Prompt diagnosis and surgical referral may reduce the risk of perforation and prevent complications. The mortality in non-perforated appendicitis is a rare event, but it may be more significant in very young and elderly patients, in whom diagnosis may be delayed, thus making perforation more likely. Appendectomy may be performed by laparotomy or laparoscopy. Diagnostic laparoscopy may be helpful in equivocal cases or in women of childbearing age, while laparoscopic appendectomy is becoming the preferred approach for any kind of appendicitis. The laparoscopic intervention has the advantages of decreased postoperative pain, faster recovery, earlier return to normal activity and better cosmetic results. This benefit has been shown through all age groups, but elderly patients in particular experience an advantage with the minimally invasive approach (Wang et al., 2006).
2. Embryology
At 4 weeks of gestation, the alimentary tract is divided into 3 parts: foregut, midgut, and hindgut. Between the 8th and 12th weeks of gestation, the midgut gives rise to the duodenum distal to the ampulla, to the entire small bowel and to the caecum, appendix, ascending colon and the proximal two thirds of the transverse colon. Because the appendix develops during the descent of the colon, its final position frequently is retrocaecal or retrocolonic.
3. Anatomy
• Location
The appendix is situated in the right lower quadrant of the abdomen in a region commonly called the right iliac fossa.
• Topography
1. Caecum
2. Ileocaecal junction
3. Female genital organs
4. Bladder
• Right iliac region
The appendicular ostium is situated one-third of the distance from the anterior superior iliac spine to the umbilicus (McBurney’s point). It is the most common location of the base of the appendix, where it is attached to the caecum.
• Variation
• Generalities
The appendix and caecum have a varied position within the abdomen. Their positions depend on the degree of development of the pericaecal fossas, associated adhesions, body habitus of the individual (Beneventano et al., 1966).
Ectopic caecum location:
1. Right iliac fossa
2. Pelvis
3. Subhepatic position
4. Retroverted caecum
• Classic appendiceal position
Classic appendiceal position
1. Retrocaecal
2. Pelvic
3. Mesocolic/mesocoeliac
3a: pre-ileal
3b: post-ileal
4. Laterocaecal
4. Local anatomy
• Vermicular appendix
The vermicular appendix is part of the right colon. It is a blind-ended loop of bowel that arises from the caecum 3 to 4cm below the ileocaecal valve. Its length ranges from 2 to 20cm and its diameter from 0.5 to 1cm. Although the base of the appendix is relatively fixed, its tip usually is freely mobile.
Unlike the rest of the colon, the appendix has a complete longitudinal muscle layer. The ostium of the appendix is situated on the medial part of the base of the caecum at the confluence of the free taenia.
• Peritoneum
1. Mesentery
2. Superior ileocaecal recess
3. Inferior ileocaecal recess
4. Meso-appendix
The ileocaecal fold delimiting the anterior or superior ileocaecal recess as well as the ileo-appendicular peritoneal fold delimiting the posterior or inferior ileocaecal recess with the meso-appendix are identified.
• Arterial supply
The ileocolic artery is a branch of the superior mesenteric artery that divides into:
1. Ileocolic artery
2. Posterior caecal artery
3. Anterior caecal artery
4. Appendicular artery
The blood supply of the appendix is found in a separate mesentery, the meso-appendix, and consists of an appendicular branch of the ileocolic branch of the superior mesenteric artery (Sleisenger et al., 2006).
• Lymphatic drainage
The lymphatic drainage of the appendix occurs via the ileocolic lymph nodes and is shared with the terminal ileum and right colon (Sleisenger et al., 2006).
5. Pregnancy
Appendix position during pregnancy
The appendix varies its anatomical position during pregnancy. It migrates from the right iliac fossa to the right hypochondrium, and it might be located under the right costal margin on the 8th month.

Diagnostic imaging
The diagnosis of acute appendicitis in the pregnant woman is a difficult task with several challenges. First, the ionizing radiation is a potential hazard for the developing foetus, the avoidance of unnecessary exposure should be a standard practice. Another challenge is the anatomical and physiological displacements of the appendix during the pregnancy or the physiologic leukocytosis.
If the US result is normal (negative) or inconclusive, a MRI or a CT-scan should be obtained (Chen et al., 2008; Wallace et al., 2008). The reason for not going directly to a CT-scan is to avoid the exposure of the patient and of the developing foetus to potentially unnecessary radiation. If the MRI is not available and a CT-scan is to be performed, a low dose protocol should be considered (McCollough et al., 2007; Lowe, 2004).

Appendectomy is the most frequent non-obstetric surgery performed during pregnancy (Ueberrueck et al., 2004; Tracey and Fletcher, 2000). It is usually associated with an increased risk for rupture and peritonitis due to: altered location of the appendix, overlap of signs and symptoms, limited sensitivity of laboratory studies (Melnick et al., 2004), and the reluctance to perform unnecessary surgery in a pregnant woman. Due to these disadvantages, some authors agree that a correct diagnosis of appendicitis is made more often during the first trimester of pregnancy than the later periods (Mazze and Kallen, 1991). The earlier the diagnosis is made, the fewer the rate of associated complications, the recommended interval between the onset of symptoms and the operation should not exceed 20-24 hours (Guidelines Committee of the Society of American Gastrointestinal and Endoscopic Surgeons, Yumi H, 2008; Yilmaz et al., 2007).
The laparoscopic approach has proven to be a safety procedure during any trimester of pregnancy (Park et al., 2010; Kirshtein et al., 2009), without any increased risk to the mother or foetus (Oelsner et al., 2003; Rollins et al., 2004). The decision to operate through a laparoscopic approach should be determined based on the surgeon’s experience and the availability of the competent equipment.

- technical difficulty due to the gravid uterus;
- possible injury to the pregnant uterus (mainly in the third trimester);
- decrease in the uteroplacental blood flows due to the increased intra-abdominal pressure.
6. Diagnosis
Clinical work-up
The laparoscopic approach does not replace the preoperative examinations, which are conventionally performed when appendicitis is suspected (clinical examination, blood test, ultrasonography, CT-scan).
Despite advances in diagnosis, the clinical history and physical examination remain paramount to the diagnosis of appendicitis. Preoperative management includes:
Clinical history:
- pain in the peri-umbilical or epigastric regions that subsequently localizes to the right lower quadrant over several hours (localization differs based on the position of the appendix). Nausea and anorexia are present nearly always and typically occur after the onset of pain. Vomiting may accompany the nausea, but rarely happens before the onset of pain if appendicitis is present. A subtle increase in rectal temperature (37.5-38.5°C) with a moderate pulse rate is classic, but this hyperthermia is only found in 50% of the cases.
Physical examination (Sauerland et al., 2006):
- tenderness in the right lower quadrant (RLQ), direct rebound tenderness; Rovsing’s sign, involuntary guarding, psoas sign and obturator sign.

Laboratory work-up
- laboratory data: no single laboratory value is accurate by itself, but a combination of values may be promising. The combination of values based on WBC count, neutrophil differential and C-reactive also known as a “triple test”, when they are within normal reference ranges, have a negative predictive value of 100% (Dueholm et al., 1989).

Imaging work-up
Advances in the diagnostic accuracy of imaging have altered the approach to patients who have suspected appendicitis. Adjunctive diagnostic tests are useful to confirm the diagnosis and indication for surgery.

Differential diagnosis
The differential diagnosis of appendicitis is broad, but the patient’s history and physical exam may clarify the diagnosis. Many gynaecologic conditions mimic appendicitis; therefore, a pelvic examination should be performed on all women with abdominal pain.
The pulmonary and genitourinary examinations are equally important.
The most common pathologies are: Meckel’s diverticulum, mesenteric lymphadenitis, cholecystitis, Crohn’s disease, diverticulitis, duodenal ulcer, pancreatitis, ectopic pregnancy, ovarian torsion, pelvic inflammatory disease, ruptured ovarian cyst, tubo-ovarian abscess, pleuritis, pneumonia, kidney stone, prostatitis, pyelonephritis, testicular torsion, urinary tract infection, omental appendix torsion.
7. Indications/Contraindications
Nowadays, the majority of surgeons preferred the laparoscopic approach for performing appendectomy, however preferential indications remain:
- uncertain diagnosis in female patients of reproductive age;
- suspected ectopic appendix (retrocaecal, etc.);
- obese patient;
- suspected appendicular peritonitis: the laparoscopic approach enables the surgeon to better assess the extent of the peritoneal sepsis (subphrenic collection, generalized peritonitis).
The laparoscopic approach does not replace the preoperative examinations which are conventionally performed when appendicitis is suspected (clinical examination, blood test, ultrasonography, etc).
According to the EAES recommendations (Surg Endos 2006; Yilmaz et al., 2007): patients with symptoms and diagnostic findings suggestive of acute appendicitis should undergo diagnostic laparoscopy (Grade of Recommendation A) and if the diagnosis is confirmed laparoscopic appendectomy (Grade of Recommendation A).

The Société Nationale Française de Gastroentérologie (SNFGE) states that the diagnosis of severe appendicitis can be ruled out if none of these situations occur (
- peritoneal guarding at abdominal exploration;
- temperature > or = 38°C;
- leukocytosis > 10,000 WBC/mL.

Contraindications are the same for all laparoscopic procedures:
- hemodynamic unstable patient (absolute);
- multiple previous abdominal surgery (relative);
- extensive adhesions (relative);
- radiation or immunosuppressive therapy (relative);
- severe portal hypertension (relative);
- coagulopathies (relative).
8. Operating room set-up
• Patient
• Standard position
The patient is usually positioned as for an open appendectomy.
- supine position;
- legs together and stretched out;
- right arm at an angle;
- left arm alongside the body.
The operating table is slightly tilted to the left in a Trendelenburg position.
• Pregnant patient
After the second half of pregnancy, the gravid uterus exerts pressure on the inferior vena cava resulting in decreased venous return. For this reason, the supine position should be avoided and a left lateral recumbent position should be adopted (Clark et al., 1991).
An intra-abdominal pressure of less than 12mmHg is recommended due to the potential effects of CO2 insufflation on the pregnant patient and her foetus (Malangoni, 2003).
• Team
Surgeon (1) and assistant (2) to the left of the patient.
As in all laparoscopic procedure, the axis of vision, the surgery site and the monitor should follow the same line (Begin, 2006).
• Equipment
1. Laparoscopic unit: to the right of the patient (at hip level).
2. Anesthetic equipment
3. Electrosurgery
4. Operating table
9. Instrumentation
• Standard instrumentation
The standard instrumentation is common to all laparoscopic procedures:
1. 0° laparoscope
2. Fine dissection scissors
3. Peanut swab (iodine)
4. Fenestrated grasping forceps
5. Bipolar cauterizing grasper
6. Clip applicator
7. Electrocautery hook
8. Suction-irrigation device
9. 2 surgical loops
10. Extraction bag.
• Others
Other instruments can sometimes be used:
1. 30° laparoscope
2. Endoscopic linear stapler
3. Needle holder
10. Trocar placement
• Principles
Three trocars placed in triangular formation are needed: one optical trocar and two operating trocars.
All ports should be placed in such a manner that they have free movement and do not interfere with each other. A symmetric triangulation is recommended.
Special considerations that should be taken into account before inserting the ports include:
- anatomical landmarks;
- cosmetic expectations;
- presence of scars from previous abdominal operations.
• Triangulation
• Standard placement
Three trocars placed in triangular formation are needed: one optical trocar and two operating trocars.
Three trocars (for most procedures) are used in a triangular formation.
Optical: 10/11mm trocar (5mm for some authors, notably used in children), supra-umbilical position, but also sub-umbilical or latero-umbilical.
Operating: Two operating trocars at a minimum of 8 to 10cm from one another.
One operating trocar (5 or 10/11mm) is placed in median suprapubic position and another operating trocar (5 or 10/11mm) is placed in left iliac fossa position; for some authors, this trocar can also be placed in the right iliac fossa or the suprapubic position.
Another option is to use two 5mm operating ports placed similarly.
Optional retractor:
- is used specially in cases of difficult exposure (obese patients) and in peritonitis;
- the right subcostal position is the most common, but its position depends on each clinical case.
Cosmetic issues:
Occasionally, for purely cosmetic reasons; the left operating trocar can be placed in the left suprapubic region at the limit of the pubic hair. The second operating suprapubic trocar must be slightly pushed towards the right.
- one supraumbilical trocar,
- two suprapubic trocars (on the border of the pubic hair).
• In case of pregnancy
- Primary trocar (initial access):
An open approach is recommended for the first trocar insertion (Friedman et al., 2002). The height of the fundus of the uterus should be determined prior to its insertion. The trocar can be placed in the supra-umbilical, subxiphoid midline or the left upper quadrant.
Secondary trocar:
These trocars are also inserted higher than in non pregnant women. Their locations vary according to the uterus height. An open approach is also recommended.
- Previous abdominal surgery
• Danger
Trocar position: a basic safety rule is to always place the suprapubic trocar(s) in the triangular safety zone delimited posteriorly by the bladder and laterally by the 2 umbilical arteries.
Trocar 1: Aorta, inferior vena cava, iliac vessels, colon
Trocar 2: Epigastric arteries
Trocar 3: Bladder
11. Pneumoperitoneum
• Principles
The creation of pneumoperitoneum and the safe placement of the primary trocar are considered the most important steps in laparoscopic surgery. Considering that more than 50% of major laparoscopic complications occur during the initial entry into the abdomen (Sauerland et al., 2006), several techniques of insufflation have been developed.
It was demonstrated that there was no method superior to the others; in fact, they have to be selected based on the surgeon’s preferences, patient characteristics and experience.
• Open technique (Hasson’s)
The risk of injuring a vessel or an organ justifies the use of visual control for trocar placement.
A small incision is made on the superior border of the umbilicus. The subcutaneous tissue is dissected in order to reach the aponeurosis. The use of long retractors allows for adequate visualization (especially in obese patients), a 10mm incision is made on the aponeurosis and after confirming that there are no adhesions, an atraumatic trocar is introduced.
• Closed technique
• Umbilical area (trans-, infra-, supra-)
The insertion of the needle is done blindly, and the specific site for its placement varies from one author to another. In our institution, this technique is not used. The patient is placed in a Trendelenburg position. A 1.5cm incision is made just above the umbilicus; after blunt dissection, the linea alba is visualized. Under direct vision two towel clips are applied to lift the abdominal wall. The towel clips are pulled upwards and the Veress needle inserted downwards at 90 degrees. During its insertion, the surgeon should stay in the midline. A successful insertion is confirmed by a click sound after having trespassed the parietal peritoneum.
Needle aspiration should be performed to rule out blood or intestinal contents. An air test is also useful: 10cc of air are aspirated in a syringe and then introduced through a Veress needle. The impossibility to re-aspirate that air means that the needle is correctly positioned. Intra-abdominal pressure must be low when connected to the insufflator.
• Left hypochondrium (Palmer’s point)
A 2mm incision is made in the left subcostal region (3cm below the left costal margin in the mid-clavicular line). The Veress needle should be introduced perpendicular to the abdominal wall. As the needle is introduced, the resistance of three layers should be felt (anterior and posterior rectus sheath and the peritoneum) and sometimes three click sounds can be heard. An air test is also useful: 10cc of air are aspirated in a syringe and then introduced through a Veress needle. The impossibility to re-aspirate that air means that the needle is correctly positioned. The needle’s tip should be felt free. For this technique, the stomach should be decompressed by a nasogastric tube and the patient should be with a good muscle relaxation.
12. Exploration
1. Right colon
2. Terminal ileum
3. Female genital organs
Exploration of the abdominal cavity is the first step of the procedure that may need to change the table’s position.
In this way, the diagnosis is confirmed or another pathology is assessed (female organs, diverticulitis, inguinal hernias, liver disease, carcinomatosis).
When the diagnosis of appendicitis is established, further exploration of the abdominal cavity is completed to search for purulent collections (subphrenic, subhepatic, paracolic, pelvic, between the loops of the small bowel); if necessary, bacteriological sampling is performed.
The value of intraoperative abdominal cavity culture is controversial due to the fact that colonic flora is largely predictable and the fact that broad-spectrum antibiotic therapy is very effective (Gladman et al., 2004; Chen et al., 2008; Wallace et al., 2008). The clinical outcome seems not to be influenced by the results obtained and even the positive intraoperative cultures do not predict infective complications.
Some authors recommend microbiological sampling in high risk and in immuno-compromised patients in whom the mortality and morbidity may increase significantly if an inadequate empirical antibiotic coverage is started (Chen et al., 2008).
In female patients, an inspection of the gynaecologic sphere is routinely done.
13. Exposure
Exposure of the appendix and of its mesentery is the first step of the procedure. This step must be performed carefully as the wall of the appendix must not be ruptured nor even weakened during its manipulation.
If the appendix is in its usual paracaecal position, the surgeon retracts the caecum and subsequently exposes the appendix.
Grasping and exposure of appendix:
The appendix is grasped with an atraumatic grasper.
If the appendix is significantly inflamed and friable, it is advisable not to grasp the appendix itself but rather to place a Babcock forceps around it. It is also preferable to grasp the meso-appendix with an atraumatic grasper.
14. Control of the meso-appendix
• Control of meso-appendix
• Option 1
1. Appendix
2. Meso-appendix
3. Appendicular artery
The grasping and upward retraction of the distal part of the appendix with an atraumatic grasper exposes the meso-appendix. In some peri-appendicular inflammatory masses, the distal portions of the small bowel and the omentum form an adhesive phlegmon, which must be freed before exposing the appendix.
Inflammation-induced changes in the ileocaecal junction can make it difficult to identify the usual anatomical landmarks (free taenia, antimesenteric border of the terminal ileum, etc.).
The first option for the control of the meso-appendix is to electrocoagulate all dividing branches of the appendicular artery close to the appendicular wall from the apex towards the base. The meso-appendix is cauterized with the monopolar hook until the base of the appendix is identified and completely freed.
• Option 2
1. Appendix
2. Meso-appendix
3. Appendicular artery
The second option for the control of the meso-appendix is to control the trunk of the appendicular artery at the base of the appendix using either a ligature or clips after creation of a window, followed by the distal division of the meso.
• Danger
Hemorrhage management
Control of meso-appendix bleeding is achieved using a bipolar electrocautery device.
• Variation/retrograde appendectomy
When the tip of the appendix is not clearly visible or in cases of fixed ectopic appendix, a retrograde appendectomy can be performed.
15. Ligation and resection of appendix
• Principles
The third step of the procedure involves the ligation and resection of the appendicular base 5 to 10mm from the caecum (in healthy appearing tissue) while avoiding any faecal contamination.
• Techniques
• Loop technique
One or two ligatures are inserted and tied at the base, while a last loop can be placed on the distal part of the appendix leaving space enough to transect the appendix. Another option to avoid the last loop is to apply a fenestrated forceps to clamp the distal part of the appendix in order to avoid potential faecal contamination.
• Loop and clipping technique
After ligating the base of the appendix with a loop on the side of the appendix, a clip can be applied 0.5-1cm from the ligature after pushing the contents of the appendix to the distal portion of the appendix. This can be done either by moving the partially closed clipping device transversely or using an atraumatic grasper. This avoids a potential faecal contamination when the appendicular base is resected.
• Stapling technique
Indications for the stapling technique are as follows:
- gangrenous appendicitis;
- severe inflammation of the caecum;
- abscess, perforation or peritonitis;
- questionable viability of the base of the appendix.
A window is created at the base of the meso-appendix. A 30mm Endostapler is used to divide the appendix.
This technique initially saves time, but it is more expensive and it will require a 12mm port.
When the base of the appendix on the caecum is highly inflamed with thick walls, a ligature may cut it, then it is better to use a mechanical stapler or to suture the caecal wall in 1 or 2 layers.
• In case of necrosis
In case of necrosis of the proximal part of the appendix and/or the caecum, the stapling of the stump of the appendix can be associated to the stapling of the proximal part of the caecum, herein performing a partial caecectomy.
Care must be taken not to damage the ileocaecal valve.
16. Extraction
• Objective
Goal: to avoid any contact between the infected appendix and the parietal wall.
Various technical tips can be used depending on the size of the appendix.
Conventionally, the specimen is extracted through the 10/11mm port site located suprapubically or in the left iliac fossa.
• Extraction bag
This practical and efficient option is more costly.
Rupture of the retrieval bag within the abdominal wall due to an inadequate fascial gap should be avoided under any circumstances. If delivery of the Endobag is difficult, it is recommended to widen the fascial incision.
• Dexterity glove
The appendix is placed in a finger of a dexterity glove (inexpensive hands-on hint). The specimen is then extracted, after removing the 10/11mm trocar from the left iliac fossa or the suprapubic area.
• Variation
When using two 5mm operating trocars, the extraction of the appendix should be performed through a larger trocar (10/11mm), i.e., the optical trocar. The objective is to align the forceps holding the appendix’s extremity with the optical trocar along the same axis. This technique is only feasible when the appendix is not too voluminous. On the contrary, if the appendix is too big, the 10/11mm trocar introduction site should be enlarged. The specimen should be placed in an extraction bag.
• Danger
The abdominal wall can be contaminated:
- when the extraction is performed without wall protection;
- if the extraction bag tears.
17. Cleaning
The purpose is to remove all debris and purulent fluid collections and blood from the surgical area.

Lavage of the peritoneal cavity with a normal saline solution is meant to clear any pus or blood collections, which may lead to postoperative abscesses, but remains controversial.

The routine use of drains is no longer recommended in case of laparoscopic appendectomy, but in case of associated peritonitis, a drain may be left in place according to the surgeon’s preference.
18. Closure
The trocars are removed one by one under visual control to check hemostasis of the trocar openings.
The musculo-aponeurotic plane is closed only for 10/11mm openings. The skin is approximated in a conventional manner using clips or suture.
19. Complications
- visceral injury;
- vascular injury.

- parietal haematoma;
- intra-abdominal haematoma;
- scapular pain (diaphragmatic irritation);
- subcutaneous emphysema;
- abdominal wall abscess/intra-abdominal abscess;
- abdominal wall hernia;
- obstructive syndrome (Nottingham, 2002);
- persistent appendicitis due to a persistent appendicular stump.
- fistula.
20. Reference
Ates M, Coban S, Sevil S, Terzi A. The efficacy of laparoscopic surgery in patients with peritonitis. Surg Laparosc Endosc Percutan Tech 2008;18:453-6.

Begin GF. Appendicectomie laparoscopique. EMC, Techniques chirurgicales – Appareil digestif. 2006;40-505.

Beldi G, Vorburger SA, Bruegger LE, Kocher T, Inderbitzin D, Candinas D. Analysis of stapling versus endoloops in appendiceal stump closure. Br J Surg 2006;93:1390-3.

Beneventano TC, Schein CJ, Jacobson HG. The roentgen aspects of some appendiceal abnormalities. Am J Roentgenol Radium Ther Nucl Med 1966;96:344-60.

Brunicardi FC, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Pollock RE. Schwartz’s Principles of surgery 1994;6:1307-18.

Chen MM, Coakley FV, Kaimal A, Laros RK Jr. Guidelines for computed tomography and magnetic resonance imaging use during pregnancy and lactation. Obstet Gynecol 2008;112:333-40.

Clark SL, Cotton DB, Pivarnik JM, Lee W, Hankins GD, Benedetti TJ et al. Position change and central hemodynamic profile during normal third-trimester pregnancy and post partum. Am J Obstet Gynecol 1991;164:883-7.

Corneille MG, Steigelman MB, Myers JG, Jundt J, Dent DL, Lopez PP et al. Laparoscopic appendectomy is superior to open appendectomy in obese patients. Am J Surg 2007;194:877-80.

Dueholm S, Bagi P, Bud M. Laboratory aid in the diagnosis of acute appendicitis. A blinded, prospective trial concerning diagnostic value of leukocyte count, neutrophil differential count, and C-reactive protein. Dis Colon Rectum 1989;32:855-9.

Friedman JD, Ramsey PS, Ramin KD, Berry C. Pneumoamnion and pregnancy loss after second-trimester laparoscopic surgery. Obstet Gynecol 2002;99:512-3.

Gladman MA, Knowles CH, Gladman LJ, Payne JG. Intra-operative culture in appendicitis: traditional practice challenged. Ann R Coll Surg Engl 2004;86:196-201.

Goldacre MJ. Demography of aging and the epidemiology of gastrointestinal disorders in the elderly. Best Pract Res Clin Gastroenterol 2009;23:793-804.

Guidelines Committee of the Society of American Gastrointestinal and Endoscopic Surgeons, Yumi H. Guidelines for diagnosis, treatment, and use of laparoscopy for surgical problems during pregnancy: this statement was reviewed and approved by the Board of Governors of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), September 2007. It was prepared by the SAGES Guidelines Committee. Surg Endosc 2008;22:849-61.

Kirshtein B, Perry ZH, Avinoach E, Mizrahi S, Lantsberg L. Safety of laparoscopic appendectomy during pregnancy. World J Surg 2009;33:475-80.

Lowe SA. Diagnostic radiography in pregnancy: risks and reality. Aust N Z J Obstet Gynaecol 2004;44:191-6.

Lukish J, Powell D, Morrow S, Cruess D, Guzzetta P. Laparoscopic appendectomy in children: use of the endoloop vs the endostapler. Arch Surg 2007;142:58-61.

Malangoni MA. Gastrointestinal surgery and pregnancy. Gastroenterol Clin North Am 2003;32:181-200.

Mazze RI, Källén B. Appendectomy during pregnancy: a Swedish registry study of 778 cases. Obstet Gynecol 1991;77:835-40.

McCollough CH, Schueler BA, Atwell TD, Braun NN, Regner DM, Brown DL, LeRoy AJ.Radiation exposure and pregnancy: when should we be concerned? Radiographics 2007;27:909-17.

Melnick DM, Wahl WL, Dalton VK. Management of general surgical problems in the pregnant patient. Am J Surg 2004;187:170-80.

Nottingham JM. Mechanical small bowel obstruction from a loose linear cutter staple after laparoscopic appendectomy. Surg Laparosc Endosc Percutan Tech 2002;12:289-90.

Oelsner G, Stockheim D, Soriano D, Goldenberg M, Seidman DS, Cohen SB, et al. Pregnancy outcome after laparoscopy or laparotomy in pregnancy. J Am Assoc Gynecol Laparosc 2003;10:200-4.

Park SH, Park MI, Choi JS, Lee JH, Kim HO, Kim H. Laparoscopic appendectomy performed during pregnancy by gynecological laparoscopists. Eur J Obstet Gynecol Reprod Biol 2010;148:44-8.

Paulson EK, Kalady MF, Pappas TN. Clinical practice. Suspected appendicitis. N Engl J Med 2003;349:305-6.

Rollins MD, Chan KJ, Price RR. Laparoscopy for appendicitis and cholelithiasis during pregnancy: a new standard of care. Surg Endosc 2004;18:237-41.

Sauerland S, Agresta F, Bergamaschi R, Borzellino G, Budzynski A, Champault G, et al. Laparoscopy for abdominal emergencies: evidence-based guidelines of the European Association for Endoscopic Surgery. Surg Endosc 2006;20:14-29.

Sleisenger MH, Feldman M, Friedman LS. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. Saunders Book Company 2006;8.

Tracey M, Fletcher HS. Appendicitis in pregnancy. Am Surg 2000;66:555-60.

Ueberrueck T, Koch A, Meyer L, Hinkel M, Gastinger I. Ninety-four appendectomies for suspected acute appendicitis during pregnancy. World J Surg 2004;28:508-11.

Wallace CA, Petrov MS, Soybel DI, Ferzoco SJ, Ashley SW, Tavakkolizadeh A. Influence of imaging on the negative appendectomy rate in pregnancy. J Gastrointest Surg 2008;12:46-50.

Wang YC, Yang HR, Chung PK, Jeng LB, Chen RJ. Laparoscopic appendectomy in the elderly. Surg Endosc 2006;20:887-9.

Yilmaz HG, Akgun Y, Bac B, Celik Y. Acute appendicitis in pregnancy--risk factors associated with principal outcomes: a case control study. Int J Surg 2007;5:192-7.