Abstract
Abstract
Purpose:
Although laparoscopic appendectomy is one of the most commonly performed operations, operation procedures vary widely according to the surgeon. In particular, various methods using different instruments have been used for mesoappendix dissection, such as endostapler, endoclip (EC), Harmonic® (Ethicon Endo-Surgery, Cincinnati, OH) scalpel (HS), electrocautery, and LigaSure™ (Covidien, Mansfield, MA). Here we compared the results of mesoappendix dissection by EC, HS, and monopolar electrocautery (ME).
Subjects and Methods:
The study was performed on 1178 patients who received laparoscopic appendectomy at the Armed Forces Capital Hospital, Seongnam, Korea, from January 2003 to April 2013. Patients receiving mesoappendix dissection involving EC, HS, or ME were enrolled. Patient demographics, pathology of appendix, and perioperative data including operation time, hospital stay, and complications were analyzed. A theoretical model of disposable cost was constructed for each method to compare cost-effectiveness.
Results:
The average operation time for the 1178 patients was 58.0±24.9 minutes for the EC group, 51.4±25.5 minutes for the HS group, and 57.7±25.7 minutes for the ME group. The time for the HS group was significantly shorter. Hospital stay and complication rates did not differ. Disposable costs were 620,350 South Korean won (KRW) (571 U.S. dollars) for the EC group, 1,041,230 KRW (959 U.S. dollars) for the HS group, and 491,230 KRW (452 U.S. dollars) for the ME group.
Conclusions:
The operation time of ME was similar to that of EC. Although HS had a significantly shorter operation time, the operation time of all three methods was under 60 minutes. All three methods had acceptable complication rates. ME was the most cost-effective method and, given the other similarities, can be recommended for mesoappendix dissection in laparoscopic appendectomy.
Introduction
A
Subjects and Methods
Patients
This study retrospectively analyzed patients who received LA at the Armed Forces Capital Hospital, Seongnam, Korea, from January 2003 to April 2013, in whom mesoappendix dissection was performed with EC, HS, or ME. Patients were excluded when the operation records did not describe, or incompletely described, the method of mesoappendix dissection. Also, patients for whom conversion to open surgery was decided before dissection of the mesoappendix were excluded. Medical records were used to analyze the method of mesoappendix dissection, patient demographics, pathology of appendix, and perioperative data. A theoretical model was constructed for each method to compare cost-effectiveness. The costs of the EC applier, the HS, and disposable surgical supplies such as surgical gowns, gloves, draping material, and trocars were used to calculate the theoretical models, using the utilization reports of our hospital. Surgeon's fees, anesthesia fees, and hospital room costs were not included in the models. All costs were calculated in South Korean won (KRW) and reported in both KRW and U.S. dollars (USD). As of this writing (September 2013), the exchange rate is 0.000921 USD for 1 KRW. The study was approved by the Institutional Review Board of the Ethical Committee of our hospital.
Surgical technique
After general anesthesia, a periumbilical or intraumbilical incision was made, and a 10-mm trocar was inserted into the abdomen. Under direct vision, two 5-mm trocars were inserted. After identification of the appendix, trocar retraction exposed the mesoappendix. When EC was used, one clip was applied at the base of the mesoappendix, and another was applied near the appendix. Although some surgeons preferred to apply the clips directly on the mesoappendix, other surgeons preferred to expose the appendiceal artery before clipping. Electrocautery and Endo Shears™ (Covidien) were used to divide the clipped tissue. When HS was used, the mesoappendix was divided near the appendix using sequential application of the instrument. None of the surgeons attempted to expose the appendiceal artery when using HS. ME was used in a similar fashion, but the dissection was performed closer to the appendix. Whereas HS was applied about 3–5 mm from the appendix, ME was generally applied at the very edge of the mesentery. When the remaining mesoappendix showed signs of bleeding, it was controlled with only electrocautery. No additional ligatures were applied. After dissection of the mesoappendix, a pretied surgical loop was placed around the appendiceal base, and the appendix was resected and removed using a vinyl bag. Wound closure was performed. In cases with appendix perforation or abscess formation, a closed suction drain (Jackson Pratt drain) was placed. In the absence of such findings, drains were not placed.
Results
In total, 1178 patients were analyzed. EC was used in 460 patients, HS in 372 patients, and ME in 346 patients. Patient demographics are shown in Table 1. There were no significant differences in age, gender, body mass index, or appendix pathology among the groups. The perioperative data are summarized in Table 2. The average operation time was 58.0±24.9 minutes for the EC group, 51.4±25.5 minutes for the HS group, and 57.7±25.7 minutes for the ME group. The time was significantly shorter in the HS group. Hospital stay and complication rates did not show any significant differences among the three groups. In the EC group, there were 5 cases of wound infection, 2 cases of intraabdominal abscess, and 1 case of paralytic ileus. One case of intraabdominal abscess required reoperation, and the other case was managed with percutaneous drainage. There were 5 cases of wound infection in the HS group and 4 cases in the ME group. In the EC group, there was 1 case of open conversion due to appendix perforation and difficulty in dissection. In the HS group, there was 1 case of conversion due to massive bleeding at the appendiceal artery. There were no conversions in the ME group. The total cost of each theoretical model was 620,350 KRW (571 USD) for the EC group, 1,041,230 KRW (959 USD) for the HS group, and 491,230 KRW (452 USD) for the ME group. According to these models, ME was the most cost-effective method, compared with the other two methods.
EC, endoclip; HS, Harmonic scalpel; ME, monpolar electrocautery.
Post hoc analysis (Tukey's test) for HS group and ME group.
Discussion
LA is one of the most commonly performed operations. For many surgeons, it is also one of the first laparoscopic operations performed in their surgical careers. The method varies widely according to surgeon, with no standardized method. Recent reports have described single-incision appendectomy,9–11 but even this advanced method differs from surgeon to surgeon.12,13
Dissection of the mesoappendix is one of the main stages of LA. The various instruments used for this stage include EC, HS, LigaSure, ME, and endostapler.3–7 Because instrument failure at this stage can cause massive bleeding and conversion to open surgery, instrument choice is an important issue. 14 Endostaplers are one of the instruments used to divide the mesoappendix. 15 Also, several authors have recently reported on the feasibility of the electrothermal vessel sealing system LigaSure.3,5 Using an endostapler or LigaSure can be expensive, especially because LA is performed often. 16 Considering the fact that these instruments are used only during the mesoappendix dissection stage of the operation, the cost-effectiveness of these instruments may be less than that of other, relatively inexpensive instruments.
This study compared EC, HS, and ME. An advantage of using EC is that the appendiceal artery can be ligated under direct vision. Also, unlike ME, smoke is not created. But, there is the disadvantage of leaving unabsorbable foreign material in the peritoneal cavity. Some surgeons prefer to apply the clip directly on the mesentery overlying the appendiceal artery, whereas others prefer to expose the artery by dissecting the mesentery. When the clips are applied directly on the mesentery, the procedure time can be very short. But in patients with abundant visceral fat, the appendiceal artery can be missed by the clips, resulting in subsequent bleeding. When mesenteric dissection and artery exposure are done, the vessel wall can be damaged during dissection, although most cases of bleeding can be controlled promptly.
The main advantage of the HS is rapid dissection with a minimum of lateral thermal spread. 6 Many authors have reported on the safety of HS. But, most studies have been limited to small-sized arteries. 14 Also, because dissection is performed regardless of the anatomic plane, when the instrument fails massive bleeding can occur. Additionally, in patients with questionable anatomy, vigorous dissection can result in bowel injury.
When ME is used, dissection is performed at the junction of the mesentery and the appendix. The terminal branches of the appendiceal artery are small, and there is very little risk of bleeding. ME is generally performed using the endo dissector, so there is no need for instrument change, minimizing the risk of bowel injury. Because the appendiceal artery does not need to be exposed, the learning period is very short, and it is an ideal procedure from a teaching point of view. 4 Compared with the other two methods, however, dissection can cause smoke, which can interfere with the surgeon's view. The assistant may have to periodically dissipate the smoke.
In our study, the EC and ME groups had similar operation times; the operation time of the HS group was significantly shorter. But, the operation time of all three methods ranged from 50 to 60 minutes. The variable operation time may prove to be clinically irrelevant. The complication rates and the conversion rates were not significantly different among the groups. It is important that the cost-effectiveness model showed ME to have the lowest disposable cost. Minor differences in cost may not be important in rarely performed operations, but LA is performed very often in most hospitals. Because it is such a high-volume operation, cost-effectiveness must be considered. The total disposable cost for the ME group was less than half of the cost for the HS group
In this study, the hospital stay period was not a meaningful parameter, with an average stay of approximately 11 days. This is because our hospital is a military hospital, mainly treating soldiers in service. When patients in military service are discharged, they often have to return immediately back to duty, involving strenuous physical activity. For this reason, our hospital institutes an in-hospital convalescence policy, with admission periods of about 2 weeks for simple operations such as LA, laparoscopic herniorrhaphy, and laparoscopic cholecystectomy.
It seems that all three methods are safe to perform, considering the complication rates and conversion rates. HS was the fastest method, by about 6 minutes. ME was the most cost-effective method. EC did not have any obvious advantages.
There were limitations in the study. This study was retrospective, and the dissection methods were not randomized. Also, the hospital stay period was not a meaningful parameter because our hospital is a military hospital mainly treating soldiers in service, and hospitalization is typically much longer than in civilian hospitals. Further prospective studies are needed to confirm our findings.
Conclusions
The operation time of ME was similar to that of EC. Although HS had a significantly shorter operation time, the operation time of all three methods was under 60 minutes, and the difference may be clinically irrelevant. All three methods gave acceptable complication rates. Because ME requires no additional instruments, it may be the most cost-effective method for mesoappendix dissection in LA.
Footnotes
Disclosure Statement
No competing financial interests exist.