Single-incision Laparoscopic (SILS) Versus Conventional Laparoscopic Appendectomy for the Treatment of Acute Appendicitis

EXPERIMENTAL DESIGN AND METHODS Patient Enrollment: The study population will consist of patients who come to the emergency room with acute abdominal pain and are found to have acute appendicitis on the basis of clinical evaluation and CT of the abdomen/pelvis. At UCSF, such patients are first evaluated by a small group of general surgeons who provide emergency consultations. Once a decision to operate has been made on clinical grounds, the principal investigator (Dr. Carter) or his delegate will be contacted to approach the patient for enrollment and informed consent.

All patients will receive standard care which consists of preoperative broad-spectrum antibiotics consisting of Zosyn, Ertapenem, or Cipro/Flagyl and intravenous fluids.

Surgeon Enrollment: All surgeons at UCSF who take call in the Emergency Department routinely perform conventional laparoscopic appendectomy for acute appendicitis. Surgeons wishing to participate in the trial will perform 5 proctored SILS appendectomies outside of the trial before enrolling patients. We chose the number 5 because one study showed that SILS operative times (a surrogate for procedural mastery) leveled off by the 5th case for surgeons already proficient in laparoscopy.

Randomization: After enrollment, patients will be assigned to conventional laparoscopic appendectomy versus SILS appendectomy in a 1:1 ratio by a computerized random number generator (http://www.random.org). Even-numbered patients will receive conventional laparoscopic appendectomy, odd-numbered will receive SILS appendectomy.

Conventional laparoscopic appendectomy technique: Patients are placed in the supine position and given a general anesthetic. An orogastric tube is placed. Sequential compression devices are placed on the legs. Unless the patient has just voided, a Foley catheter is placed in the bladder. The left arm is tucked and the abdomen shaved as necessary. The umbilical skin is anesthetized with 5mL of 0.25% marcaine. A 1.5cm vertical or transverse skin incision is made within the umbilical stalk, the fascia is retracted, and a 1.5cm vertical fascial incision made with a scalpel. A 12mm Hasson port is placed through the fascia and the abdomen insufflated to 15mmHg with carbon dioxide gas. Alternatively, a small nick in the fascia can be made, a Veress needle used to achieve pneumoperitoneum, and a 12mm VersSTEP port placed through an introducer sheath. Diagnostic laparoscopy is then performed, with inspection of the stomach, liver, gallbladder, colon, small intestines, and pelvis. If a diagnosis other than acute appendicitis is made (such as pelvic inflammatory disease, sigmoid diverticulitis, cecal diverticulitis, Crohn's disease, perforated duodenal ulcer, etc.), the patient is excluded from the study and treated appropriately. If the appendix looks normal and no other pathology is found in the abdomen, the patient may stay enrolled in the study if the surgeon decides to remove the appendix.

Additional 5mm ports are placed in the left lower quadrant and suprapubic midline after the skin and peritoneum are anesthetized with 0.25% marcaine. A 5mm camera is transferred to the left lower quadrant port site and the appendix is exposed and retracted anteriorly. The mesoappendix may be divided with EndoGIA staplers, Ligasure, cautery and clips, or Harmonic Scalpel. The base of the appendix may be ligated with EndoGIA staplers or Endoloop. The appendix is removed through the umbilical incision after first placing it into an EndoCatch bag. Minimal irrigation is used; perforated cases are treated with suctioning of intra-abdominal pus and postoperative antibiotics. Blood loss is estimated. Umbilical fascia length is measured in millimeters, then closed with 0-Maxon absorbable suture. The umbilical skin is anesthetized with 0.25% marcaine, and all skin edges re-approximated with 4-0 biosyn. Indermil glue is the only dressing.

SILS Appendectomy Technique: Patients are placed in the supine position and given a general anesthetic. An orogastric tube is placed. Sequential compression devices are placed on the legs. Unless the patient has just voided, a Foley catheter is placed in the bladder. The left arm is tucked and the abdomen shaved as necessary. The base of the umbilical stalk is everted by two penetrating towel clamps placed either side of the midline. The skin is anesthetized with 5mL of 0.25% marcaine. A vertical skin incision is made within the umbilical stalk, the fascia is retracted, and a 3 cm vertical fascial incision made with a scalpel. The peritoneum is entered with either a gloved finger, Kelly clamp, or scissors. The incision is retracted anteriorly with an Army/Navy retractor, and the SILSPort inserted into the incision using a shoe-horn maneuver. 5mm trocars are placed in the SILSPort™, and the abdomen insufflated to 15mmHg with carbon dioxide gas, after which the trocars are repositioned into a staggered elevation. Diagnostic laparoscopy is then performed, with inspection of the stomach, liver, gallbladder, colon, small intestines, and pelvis. If a diagnosis other than acute appendicitis is made (such as pelvic inflammatory disease, sigmoid diverticulitis, cecal diverticulitis, Crohn's disease, perforated duodenal ulcer, etc.), the patient is excluded from the study and treated appropriately. If the appendix looks normal and no other pathology is found in the abdomen, the patient may stay enrolled in the study if the surgeon decides to remove the appendix.

The appendix is exposed and retracted anteriorly. The mesoappendix may be divided with EndoGIA staplers, Ligasure, cautery and clips, or Harmonic Scalpel. The base of the appendix may be ligated with EndoGIA staplers or Endoloop. When staplers are used, one of the 5mm trocars is replaced with a 12mm trocar. The appendix is removed through the umbilical incision after first placing it into an EndoCatch bag. Minimal irrigation is used; perforated cases are treated with suctioning of intra-abdominal pus and postoperative antibiotics. Blood loss is estimated. Umbilical fascia length is measured in millimeters, then closed with 0-Maxon absorbable simple interrupted sutures. Skin edges re-approximated with 4-0 biosyn. Indermil glue is the primary dressing.

Postoperative Care: Patients are given a full liquid diet immediately after surgery, and are advanced to an unrestricted diet as soon as the patient feels up to it. Pain is controlled by a hydromorphone PCA (patient-controlled analgesia) pump for at least 12 hours after surgery, after which oral pain medications are prescribed. If the patient is allergic to hydromorphone, morphine may be used. No supplemental pain medications (Motrin, Toradol, etc.) will be used for patients enrolled in the study. No steroids (e.g. Decadron) will be given. Antibiotics for appendicitis are given at the discretion of the attending surgeon. Patients are discharged at the discretion of the attending surgeon, generally when the patient can eat without vomiting, pain is controlled with oral medications, and the systemic inflammatory response to the appendicitis has subsided.

After 2-3 weeks, follow-up occurs in Dr. Carter's clinic. The wounds are assessed for infection, seroma, or hernia. Date of return-to-work and date of last opiate pain medication are recorded. At 6 months, patients return to clinic and complete a survey. The survey includes a Body Image Questionnaire, a Cosmetic Appearance Scale, and a Photo Series Questionnaire, all of which have been validated.8-12 The Body Image Questionnaire measures patients' perception of and satisfaction with their own body and explores attitudes toward their bodily appearance. Five questions are asked, with up to four points assigned per question, totaling 20 possible points. The Cosmetic Appearance Scale assesses the degree of patient satisfaction about the physical appearance of the abdomen (and its scars) using 100-mm visual analogue scale. The patient is asked to make a mark along the horizontal scale that indicates the overall aesthetic appearance of the abdomen as a whole, and incisions separately. Numeric scores are then obtained by measuring the horizontal distance from the low end of the scale to the marking, rounded to the nearest millimeter. Finally, the Photo Series Questionnaire assesses whether knowledge of the cosmetic results of the alternative approach (SILS or conventional laparoscopic) influences the evaluation of the scar. It also measures the strength of the preference. Patients who do not return for follow-up will be mailed a survey and/or called for a telephone interview. Data management and interviews will be managed by a research assistant hired for the study.

Definition of Study Variables and Outcome Measures Patient Characteristics: Age, height, weight, prior operations in the abdomen

Intraoperative Variables:

1. Operative time - defined as the amount of time to perform the operation from skin-incision to application of the dressing. This time is routinely charted by the circulating nurse in the operating room.
2. Conversion - defined by the use of incisions and/or trocars in addition to the ones described in the Methods section, or the need to perform an open procedure.
3. Visceral or vascular injury - defined as injury to the intestines, colon, omentum, vasculature, or pelvic organs during the dissection requiring intervention (suture or stapled repair, use of hemostatic agents).
4. Umbilical fascia incision length (in millimeters).

Postoperative Variables:

1. Mean pain score over 12 hours - Pain is assess by the ward nurse as needed, but at least every four hours, and documented in the patient's chart. Pain is scored on a scale of 0-10, 10 being the most severe pain imaginable. Average pain score for that patient is calculated over the first 12 hours (the time the patient is on a hydromorphone PCA)
2. Hydromorphone use over 12 hours - Total hydromorphone usage (in milligrams) is charted by the floor nurse. The amount used in the first 12 hours after surgery, starting from the time the patient is discharged from the recovery room, is recorded.
3. Length of stay - Number of calendar days the patient is hospitalized.
4. Wound infection - Defined as the need for additional antibiotics, prescribed beyond the perioperative antibiotics given for acute appendicitis, for the purpose or treating a wound cellulitis, or the need to open the wound to drain a wound abscess, within 6 months of surgery.
5. Deep space infection - Defined as the need for reoperation, readmission, or percutaneous drainage of a deep (organ space) infection within 6 months of surgery. All intra-abdominal abscesses are classified as deep space infections.
6. Wound seroma - Defined as an un-inflamed fluid collection under the skin incision > 1cm in diameter identified within 6 months of surgery.
7. Time to return to work - Defined as the number of calendar days between discharge from the hospital and the first day back at work.
8. Date of last opiate pain medication use.
9. Readmission with 30 days.
10. Body Image Score at 6 months
11. Cosmetic Appearance Scale at 6 months.
12. Photo Series Questionnaire at 6 months.