Single-Port Appendectomy

This article describes a pure single-port laparoscopic appendectomy (SPLA). Appendectomy is one of the most frequently performed surgical procedures in the United States. The lifetime risk of appendicitis is 8.6% for males and 6.7% for females.[1]

From the first laparoscopic removal of an inflamed appendix by Kurt Semm in 1980 to today's standard laparoscopic technique, minimally invasive surgical approaches have been widely recognized as offering significant advantages, including reduced postoperative pain, a shorter recovery time, and better cosmesis.[2]

The traditional approach to laparoscopic appendectomy employs three ports. Over the past decade, successful attempts to perform the procedure with fewer ports have been reported. The medical literature has described two-port techniques,[3]  hybrid approaches,[4, 5]  and single-port assisted techniques.[6, 7, 8]

The two-port appendectomy technique is very similar to the standard three-port technique, except that one port provides access for a rigid endoscope with a working channel, whereas the second port provides access for a grasping instrument that is used to retract the appendix.[3]

In the hybrid technique, the appendix is pulled through the umbilicus, and a traditional open appendectomy is then performed extracorporeally.[9, 10, 11, 12]

The single-port assisted technique is intriguing in that a stitch is placed through the anterior abdominal wall to pull the appendix to the abdominal wall; this creates the tension necessary for performing the appendectomy intracorporeally.[6, 13]

The total single-port approach, as described in this article, employs a technique resembling that of a puppeteer.[14] A "pulley" is constructed in the form of a loop to the anterior abdominal wall. This loop is used as an axle over which the appendix is elevated with a string to the abdominal wall; in this way, it compensates for the absence of the additional port traditionally needed for retraction of the inflamed appendix.

Although SPLA or multiport laparoscopic appendectomy (MPLA) is the gold standard for management of acute appendicitis, the laparoscopic approach may not yet be cost-effective in the developing world. The surgical-glove port single-incision laparoscopic appendectomy (SGP-SILA) has been proposed as a viable option in low- and middle- income countries in place of the conventional techniques and has been found to be a good alternative.[15]

Indications for single-port appendectomy include acute appendicitis, recurrent appendicitis, and chronic appendicitis. Whenever a single-port appendectomy is performed, it is important to maintain a low threshold for conversion to a standard laparoscopic or open approach.[11]

Absolute contraindications for SPLA include signs of perforation, pregnancy, and an American Society of Anesthesiologists (ASA) classification of 3 or 4. Patients with these contraindications are not suitable candidates for SPLA, and a standard laparoscopic appendectomy or open appendectomy should be performed instead.

Relative contraindications for SPLA include a retrocecal-lying appendix (because of the difficulty of mobilizing the appendix adequately) and adhesions from previous surgical procedures.

Anatomy

Anatomic considerations are of substantial clinical importance in the context of acute appendicitis; the location of the appendix often determines the symptoms and the site of pain if the appendix becomes inflamed.

The vermiform appendix is a vestigial structure that can range from less than 1 cm in length to more than 30 cm; on average, it is 6-9 cm long. Embryonically, the appendix first appears in the eighth week of life as an outgrowth of the terminal portion of the cecum. Throughout development, the cecum grows faster than the appendix does; as a result, the appendix is generally displaced more medially toward the ileocecal valve.

The three taeniae coli converge at the junction of the cecum with the appendix; this junction can and should be used as a landmark to identify the appendix. Appendiceal absence, duplication, and diverticula have all been described.

The appendiceal base is always just at the base of the cecum distal to the ileocecal valve. The tip of the appendix, however, has a more variable location and can be found in several different positions, including retrocecal, pelvic, subcecal, preileal, and right pericolic.

Studies comparing single-port and conventional laparoscopic techniques have not shown consistent findings.

Liang et al concluded that SILA resulted in rapid recovery, no increase in pain or complications, and a better cosmetic outcome.[16]  Choi et al found that postoperative pain outcomes between SILA yielded reduced pain as compared with conventional laparoscopic appendectomy.[17]  Qiu et al concluded that SPLA had no benefits over conventional laparoscopic appendectomy.[18]  Antoniou et al concluded that the two methods showed similar postoperative morbidity and wound infection.[19]

With regard to the use of single-port appendectomy in pediatric populations, Zhang et al found that in children, single-port appendectomy, though safe and feasible, appeared to offer no significant advantages.[20]  A transumbilical approach has also been found to be beneficial.[21, 11, 12]

In a study of conventional single-port appendectomy in children with complicated appendicitis, Karakus et al found the procedure to be associated with a reasonable operating time, a shorter hospitalization period, reduced rates of postoperative wound infection and adhesive intestinal obstruction, and equivalent operative costs as compared with open appendectomy and MPLA.[22]  

A report evaluating patient-surveyed scar assessments with SPLA versus MPLA showed that the Patient Scar Assessment Questionnaire (PSAQ) administered to patients 6 weeks after surgery favored the SPLA approach.[23] There were significant differences in total score (48 vs 55), appearance (15 vs 18), and consciousness (8 vs 10); however, there were no significant differences with respect to satisfaction with appearance or symptoms scale.

Advances in surgical equipment and protocols for SPLA have led to improved care of patients with acute appendicitis in terms of hospital costs, number of surgical incisions, and postoperative hospital stay.[24] The issues that persist are longer single-incision length, higher complication rates, and longer operating time. Accordingly, to optimize outcomes, surgical instruments and techniques should be rationally chosen on the basis of individual disease status and specific patient needs. 

Equipment used in single-port appendectomy includes the following:

• Standard laparoscopic equipment (see  Laparoscopic Appendectomy)
• One port, 11-12 mm in diameter
• An operating laparoscope (eg, a 10-mm endoscope with a 5-mm working channel)

General anesthesia is required for single-port appendectomy because of the need for gaseous insufflation of the abdominal cavity to provide the necessary visualization.

The patient should be placed in the Trendelenburg position with the left side down.

In a single-port appendectomy, the retraction required to permit dissection of the base of the appendix is achieved not with a grasping instrument, as in two- and three-port techniques, but with a surgically created "pulley."[14] This pulley is used as an axle over which the appendix is pulled laterally, anteriorly, and cephalad (see the video below).

The steps of the procedure are as follows.

Placement of trocar

A single 11-mm trocar is placed transumbilically; alternatively, the trocar may be placed in a suprapubic position.[25, 26]  A 10-mm rigid endoscope with a 5-mm working channel is usually employed. If necessary, a 5-mm 30º angled laparoscope may be used for better visualization.

Creation of "pulley"

To achieve a fulcrum effect, a pulley of sorts is created from synthetic suture material (eg, 0 glycolide-lactide) by mounting a loop tied as an air knot to the anterior abdominal wall within the abdominal cavity, just cephalad and lateral to the base of the appendix.

Next, a string (eg, Surgitie; Covidien, North Haven, CT) is placed around the appendix (see the first image below). This string is threaded through the previously created loop (see the second image below) and pulled through the 11-mm port so that it rests extracorporeally (see the third image below).

Mobilization of appendix

Once the string around the appendix has been brought out extracorporeally, the surgeon pulls on it in much the same way as a puppeteer would, thereby drawing the appendix laterally and anteriorly to the abdominal wall. The change in the position of the appendix yields the intended exposure of the appendiceal base (see the image below).

The mesoappendix is then dissected from the base of the appendix (see the image below). Either a tie (eg, 0 glycolide-lactide) or a tissue fusion device (eg, LigaSure; Covidien, North Haven, CT) may be used for ligation of the mesoappendix. A tie is placed at the base of the appendix.

Excision and retrieval of appendix

Just 1 cm from the tie at the appendiceal base, another tie is placed around the appendix. The appendix is then divided between the two ties. The surgical specimen is placed in an endoscopic retrieval bag (eg, Endo Catch; Covidien, North Haven, CT) and retrieved from the patient's abdomen (see the image below).

Completion and closure

The loop (pulley) is cut and removed. The 11-mm fascial defect is closed with a figure-eight stitch (eg, 0 glycolide-lactide). The skin is approximated with 4-0 polyglytone, and tissue adhesive (eg, Indermil; Covidien, North Haven, CT) is applied.

Complications after single-port appendectomy seem to be comparable to those seen after laparoscopic appendectomy.[14, 27, 28, 29, 30, 31, 32]  Further study is warranted.