A Prospective Analysis of Endoloops and Endostaples for Closing the Stump of the Appendix in Children

Introduction

During laparoscopic appendectomy (LA), surgeons can choose from a variety of techniques for dividing the appendix—namely, simple coagulation, endo-linear cutters, ultrasonic dissectors, or hem-o-lok^® clips.^1–3 However, for closing the stump of the appendix, only endoloops (Ethicon, Inc.) and endostaples (Tyco Health Care, Inc.) are commonly used.^4,5

To date, there has been no prospective study conducted comparing loops with staples for closing the base of the appendix in children. We assessed the efficiency of each technique by focusing on intra- and postoperative complications versus cost.

Materials and Methods

Institutional review board approval was obtained for this prospective study of all LA performed for appendicitis between July 2005 and August 2009 at Juntendo University Hospital and Juntendo University's Nerima Hospital. Patients with complicated appendicitis such as perforated appendicitis or intra-abdominal abscess were excluded, leaving 75 patients who had the stump of the appendix closed with loops and 81 patients who had the stump of the appendix closed with staples. All surgery was performed under the direct supervision of 4 board-certified pediatric surgeons who each chose their technique for closure (loops of staples) according to personal preference.

We perform LA using a 3-trocar technique with a combination of 5-mm and 10-mm trocars. When loops are used, the 10-mm trocar is placed in the umbilicus to allow a disposable specimen retrieval bag (Endocatch: Tyco Health Care, Inc.) to be used and each of the two 5-mm trocars is placed laterally in the lower abdomen. Two loops are placed at the base of the appendix and one loop distally, and the appendix is ligated and divided between the two sets of loops with ultrasonographic shears. When staples are used, the 10-mm trocar is placed in the left lower abdomen for the stapler and disposable specimen retrieval bag; one 5-mm trocar is placed in the umbilicus and the other 5-mm trocar in the right lower abdomen. One staple load is used to divide the appendix. In all cases, a 5-mm scope was used through the umbilical trocar, ultrasonographic shears (Ethicon, Inc.) were used for dissecting the mesoappendix, and each specimen was retrieved inside a disposable specimen retrieval bag through the 10-mm site.

All cases were managed according to the same pre-, intra-, and postoperative protocols; that is, a loading dose of piperacillin tazobactam (Tazocin^®; Taisyotoyama Pharmaceutical Co., Ltd.) was administered intravenously within 30 minutes of the induction of anesthesia and only continued postoperatively in cases of complicated appendicitis.

The two groups were compared according to demographics, incidence of intra- and postoperative complications, readmission rates, length of hospitalization, duration of surgery, and total cost; data were collected prospectively according to the spreadsheet. Postoperative blood tests were not taken if there was no perforation. We defined complications as follows: postoperative intra-abdominal abscess as a collection diagnosed using ultrasonography; transient ileus as abdominal distention that began in the immediate postoperative period that resolved within 48 hours with nasogastric tube decompression; and wound infection as any superficial redness that required antibiotics. In all cases, patients were discharged when afebrile, oral analgesia was adequate for pain control, and oral feeding was stable.

During any surgery, differences in technique and choice of devices and materials can greatly increase costs. Our LA is essentially a standardized procedure, and as a rule, we try not to use too many devices, such as ultrasonographic shears and Endocatch bags. Thus, to compare cost, we added the fee for anesthesia to the actual price of the closure technique used. Anesthesia was charged at a flat rate of U.S. $738 for a standard LA considered to take up to 2.5 hours, with each additional 30 minutes charged at U.S. $73. The price of an endostapler set was U.S. $550 (U.S. $242 for the hand piece and U.S. $308 for a cartridge of 30 [2.0–2.5] staples), and the price of one endoloop was U.S. $48.

Data were analyzed using standard statistical methods. Demographic data were compared using the Student's t-test. The chi-squared test or Fisher's exact test was used for analyzing the incidence of complications. For all statistics, .05 was used to determine significance.

Results

There were no significant differences for mean age at surgery (loops: 10.5 [range: 3–16] years; staples: 10.8 [range: 5–16] years), gender (M/F) ratio (loops: 49/26; staples: 48/33), preoperative mean white blood cell count (loops: 13500/mm³; staples: 12000/mm³), mean C-reactive protein (loops: 3.9 mg/dL; staples: 2.7 mg/dL), histopathologic findings (gangrenous/phlegmonous/catarrhal appendicitis; loops: 13/42/20; staples: 21/49/11), mean duration of surgery (loops: 60 [range: 35–210] minutes; staples: 53 [range: 27–124] minutes), and mean length of hospitalization (loops: 4.3 [range: 3–13] days; staples: 3.9 [range: 2–10] days) (Table 1). There were no intra-operative complications or ICU admissions in either group, but one loop case needed to be converted to open surgery (P = NS). There were no significant differences in the incidences of intra-abdominal abscess (loops: n = 2 or 2.7%; staples: n = 1 or 1.2%), transient ileus (loops: n = 1 or 1.3%; staples: n = 2 or 2.5%), small bowel obstruction (loops: n = 0 or 0%; staples: n = 1 or 1.2%), re-operation (loops: n = 0; staples: n = 0), and wound infection (loops: n = 2 or 2.7%; staples: n = 1 or 1.2%; all responded to intravenous antibiotics without requiring surgical drainage). All cases of intra-abdominal abscess responded to intravenous antibiotics without surgical drainage being required and all had resolved by the time of discharge without any recurrences to date. The rate of readmission to hospital was 4.0% for loop cases (n = 3; indications: intra-abdominal abscess [n = 1], colitis [n = 1], and fever of unknown origin [n = 1], and 2.5% for staple cases (n = 2; indications: small bowel obstruction [n = 1] and intra-abdominal abscess [n = 1]) (P = NS). Mean total anesthetic time was 6.4 minutes shorter when staples were used. Overall, the mean cost for stapling was U.S. $405 more expensive than for loops; specifically, loops cost a mean of U.S. $891 (anesthesia and 3 loops) versus a mean of U.S. $1296 (anesthesia and one stapling set) for stapling (Table 1).

Discussion

This is the first prospective study comparing endoloops with endostaples for closing the stump of the appendix during LA for uncomplicated appendicitis in children. Although there was no significant difference in overall morbidity according to technique, stapling was more expensive. From the literature, it would appear that there is a higher incidence of intra-abdominal infections when loops are used instead of staples, even in patients with acute nonperforated appendicitis. ⁶ Loops also appear to be associated with a higher rate of abscess formation, which might be related to insufficient closure of the stump, exposure of contaminated mucosa at the cut edges to the abdominal cavity, or mucosal necrosis if with loops loosen. ⁷ On the other hand, there is a report in which stump invagination and simple ligation were compared in open appendectomy, and they showed simple ligation facilitates and shortens appendectomy without an increase in complications, including postoperative intra-abdominal abscess formation. ⁸ We did not observe any tendency for loop cases to have a higher rate of stump insufficiency due to inefficient closure of the base of the appendix; in fact, our data showed that staples and loops were both safe for stump closure, and there was also no difference in the cosmetic appearance of the abdomen according to technique.

In our study, there was no case where the choice of technique was determined clinically, that is, based on the degree of inflammation or the severity of appendicitis. Choice of technique was left to the attending surgeon as a direct reflection of the surgeon's experience and confidence. For example, one of our attending surgeons (M.U.) changed from using loops to staples after experiencing one case of postoperative intra-abdominal abscess before this study was commenced. Stapling is also widely used in pediatric surgery and trainee surgeons should be familiar with it.

Surgeons today must be aware of a heightened need for effective and cost-efficient therapy as a result of healthcare financing issues. High patient expectations, advances in technology, as well as departmental politics contribute to create overwhelming pressure. ⁹ Our data support the general concept that loops are cheaper than staples. However, the use of a particular technique should be individualized to the specific circumstance of each patient and the skill and confidence of the attending surgeon, keeping in mind that the ultimate goal is to perform the safest LA with minimal intra- and postoperative complications.

This is the first study to compare the use of endoloops and endostaples prospectively in children who had LA for uncomplicated appendicitis. Although stapling is more expensive, a surgeon's decision to choose a particular technique should be respected. It will indeed be a sad day when cost alone dictates treatment, but should that day eventuate, then surgeons will need to retrain, accept that there is a learning curve for using unfamiliar techniques, and be comfortable to assign their patients to colleagues who can perform better under stricter financial constraints.