Single-Port Laparoscopic Appendectomy: Comparison with Conventional Laparoscopic Appendectomy

Introduction

Laparoscopic surgery is now thought of as the “gold standard” for many operations performed by general surgeons such as appendectomy and cholecystectomy. Many studies have reported the advantages of laparoscopic surgery compared with open surgery such as less postoperative pain, faster recovery, fewer postoperative complications, better cosmetic results, and shorter hospital stay.^1,2 Laparoscopic surgery has significantly advanced the concept of minimally invasive surgery. As the popularity of minimally invasive surgery has increased, newer concepts to further enhance the minimally invasive nature of operations have arisen. The concept of natural orifice transluminal endoscopic surgery (NOTES) has been proposed as a new approach for common general surgical operations. ³ However, “pure” NOTES procedures have a relatively high risk of visceral injury as the risk for improving cosmetic results. ⁴ Another alternative concept to NOTES that is based on performing a less invasive procedure is the use of a single incision through the umbilicus for performing various common laparoscopic procedures. These techniques have been reported and are being used for procedures such as appendectomy, cholecystectomy, adrenalectomy, gastric wedge resection, and even colectomy. ⁵

Single-port laparoscopic appendectomy (SPLA) has been attempted in many surgical institutes. There are few comparison studies evaluating comparing surgical outcomes of SPLA with those of three-port conventional laparoscopic appendectomy (CLA),^6,7 and they are all retrospective studies.

The purpose of our study was to present our experience with SPLA and to evaluate the feasibility and safety of SPLA prospectively. We analyzed the postoperative outcomes of SPLA in comparison with those of CLA performed in our hospital during the same period.

Subjects and Methods

From November 2008 to July 2009, 121 patients were admitted to St. Paul's Hospital, The Catholic University of Korea, Seoul, Korea, for acute appendicitis. The preoperative diagnosis of appendicitis was based on results of computed tomography scan. Patients who were diagnosed with suppurative appendicitis without signs of perforation were included in this study. Patients who were diagnosed by computed tomography with perforated or complicated appendicitis with generalized peritonitis were operated on by CLA and excluded from the study. Other exclusion criteria included a history of previous abdominal surgery, a body mass index exceeding 30 kg/m², and refusal to participate in the study. Before operations, we illustrated the operative methods and differences between the two methods to the patients. The method of operation was determined by using randomly created numbers in sealed envelopes, which were not opened until the time of operation. All procedures were done after obtaining informed consent concerning the potential surgical procedures and risks. Our study was approved by the institutional review board of The Catholic Medical Center of The Catholic University of Korea. All operations were performed by two experienced laparoscopic surgeons (S.G.K. and J.P.) who had performed more than 500 cases of laparoscopic appendectomy. We evaluated demographic findings and surgical outcomes including duration of operation, postoperative pain score, hospital stay, pathology, and postoperative complications. The level of pain was measured on a visual analog scale (VAS) with grid points where 10 was the maximum and 0 indicated no pain; it was recorded 6 hours after surgery.

Surgical procedure

Patients were positioned supine and given general endotracheal anesthesia. A 15-mm vertical incision was made in the patient's umbilicus and carried down to the peritoneum. After a window was made to the peritoneum, an extra small–sized Alexis^® wound retractor (Applied Medical, Rancho Santa Maria, CA) was inserted through the window. The access port was prepared before the umbilical incision was made. After the first, third, and fifth fingertips of a 6½-sized surgical glove were cut off, three 5-mm short trocars were inserted into those sites (Fig. 1). After this homemade access port was applied on the wound retractor, CO₂ gas was used for insufflation. Abdominal gas pressure was maintained between 10 and 13 mm Hg and automatically regulated. After the pneumoperitoneum was established, a 5-mm 30° laparoscope was placed into the peritoneal cavity. Then one laparoscopic grasper and one dissector were inserted into the peritoneal cavity. After the location of the appendix was confirmed, the appendiceal artery was identified and coagulated by electrocoagulation. We did not use a metal clip or ultrasonic scalpel for ligation of appendiceal vessels. The appendiceal base was ligated with one Endoloop^® (Ethicon, Cincinnati, OH) and transected with an endoscissor. The specimen was extracted through the main incision and withdrawn into the fourth finger of the glove. After irrigation and inspection of the operative site, the surgical glove port and wound retractor were removed securely. The wound was closed in layers. The skin site was treated with Histoacryl^® (B. Braun, Melsungen, Germany).

OPEN IN VIEWER

FIG. 1.

Full setting of the glove port for single-port surgery.

Results

One hundred four patients were enrolled this study. Of those patients, 42 (40.4 %) underwent SPLA, and 62 (59.6%) underwent CLA. The CLA group of patients consisted of 41 men (66.1%) and 21 women (33.9%). The SPLA group consisted of 14 men (33.3%) and 28 women (66.7%). The mean age was 29.9 years in the CLA group and 23.9 years in the SPLA group. The average body mass index of patients was 23.0 kg/m² in the CLA group and 20.5 kg/m² in the SPLA group.

Mean operative time was defined as the time period between beginning with the skin incision and ending with wound closure. Mean operative time was 55.8 minutes in the CLA group and 51.7 minutes in the SPLA group. There was no conversion to open appendectomy in either group. Postoperative pain, indicated by VAS score, did not differ significantly between the two groups (Table 1).

The overall postoperative complication rate was 9.7% (n=6) for the CLA group and 14.3% (n=6) for the SPLA group (P=.390). Postoperative wound abscess developed in 3 patients in the SPLA group and 2 patients in the CLA group. There were 2 cases of umbilical cellulitis in the CLA group. They were treated with wound care and oral antibiotics on an outpatient basis. Postoperative ileus was seen in 2 patients of the CLA group and 3 patients of the SPLA group. All patients recovered after fasting for 2 days. There was no mortality in either group (Table 2).

Pathological reports for the CLA group showed 27 patients had suppurative appendicitis, 22 patients had gangrenous appendicitis, 5 patients had perforated appendicitis, and 8 patients had periappendiceal abscess. Reports for the SPLA group showed 22 patients had suppurative appendicitis, 13 patients had gangrenous appendicitis, 2 patients had perforated appendicitis, and 5 patients had periappendiceal abscess. There was no case of negative appendectomy.

The SPLA group was able to eat earlier than the CLA group (P=.011). The mean postoperative hospital stay was 2.9 days for the CLA group and 2.6 days for the SPLA group. There was no significant difference between the two groups (P=.215).

Discussion

Laparoscopic appendectomy has become the procedure of choice in Korea for the treatment of acute appendicitis. Its advantages over open appendectomy are the same as those of laparoscopic surgery over conventional open surgery. They include less postoperative pain, shorter hospital stay, and better cosmetic results. Another important advantage is the ability of wider exploration of the abdominal cavity.

For better outcomes in view of these points, several techniques have been proposed in minimally invasive surgery. Port sizes have been reduced to lessen pain, morbidity, and scarring; 2–3-mm ports have been used for this reason. ⁸ Most laparoscopic appendectomies are performed using three trocars. Surgeons have made an effort to reduce the number of ports for laparoscopic appendectomies. Valioulis et al. ⁹ reported a two-trocar technique for laparoscopic appendectomies in children. Panait et al. ¹⁰ reported the same technique for laparoscopic appendectomies in adults. Konstadoulakis et al. ¹¹ showed a two-trocar laparoscopic appendectomy technique had a relative advantage over CLAs.

Several single-port techniques have been developed for laparoscopic appendectomies. Ateş et al. ¹² described an intracorporeal single-port-assisted laparoscopic appendectomy with good clinical results. Roberts ¹³ introduced the “puppeteer technique” as a single-incision laparoscopic appendectomy. Other surgeons used a single transumbilical incision with a three-trocar techniques and reported feasible results with those techniques.^14–17

Our data show that SPLA took no more time than CLA. This may be due to surgeons who have performed many laparoscopic operations.

Patients in both groups experienced some postoperative complications. Postoperative wound abscesses were the most common complication in both groups. Postoperative ileus occurred in 2 cases of the SPLA group and 2 cases of the CLA group. Those 2 patients of the CLA group were observed to have cecal diverticulitis as well as acute appendicitis during surgery. All patient complications resolved with symptomatic therapy. There was no postoperative intraabdominal abscess in either group, and there were no reoperations.

Theoretically, SPLA has the possibility to lower the morbidity associated with laparoscopic surgery by reducing trocar number. In particular, it may reduce occurrence of hematoma, abscess, and postoperative wound pain. However, contrary to our expectations, we observed no difference for umbilical abscess formation after surgery between the two groups in our study. Studies have shown that postoperative pain is decreased when fewer and smaller trocars are used.^18,19 But, there was no significant difference in the postoperative pain scores between the two groups. It is presumed that compression around the umbilicus from the wound retractor that was used in the SPLA caused a component of the postoperative pain.

We experienced some technical difficulties in performing SPLA. The narrow opening in the peritoneum makes movement between the two laparoscopic instruments troublesome. Initially we used a cross technique like other authors. However, we found a conventional laparoscopic surgery technique could be applied in SPLA after some experience. It is true that SPLA is not an ergonomic technique, but we did not use angled instruments for SPLA because of cost-effectiveness. Some instruments have been designed for single-port surgery. They are more expensive than conventional laparoscopic instruments. Development of new instruments helps to facilitate the operation and find a solution to some of the technical problems of SPLA.

The average operation time of SPLA was 51.7 minutes, and there was no difference from CLA. This suggests this procedure has a very short learning curve for the experienced laparoscopic surgeon. There was also no difference between the two groups with respect to initiation of postoperative diet and postoperative hospital length of stay.

In our results, there is significant difference in gender between the two groups. This may be due to the small number of study cases.

In conclusion, despite the limitations of a non-randomized study and the small number of patients in the study, this study shows that SPLA is a safe and effective technique for appendectomy. All procedures were completed successfully without major complications. Our study population was restricted to patients with suppurative-type acute appendicitis diagnosed preoperatively. Further studies including multicenter prospective trials are required to ascertain the effectiveness of SPLA for all types of appendicitis.