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Randomized Double-masked Comparison of Radially Expanding Access Device and Conventional Cutting Tip Trocar in Laparoscopy

From the Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China.

Address reprint requests to: So Fan Yim, MBChB, MRCOG, Department of Obstetrics and Gynecology, Prince of Wales Hospital, Hong Kong, SAR, China, E-mail: sfyim{at}cuhk.edu.hk

	Abstract

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Objective: To compare postoperative wound pain associated with the radially expanding access device and the conventional disposable cutting-tip trocar.

Methods: Our randomized, double-masked, self-controlled study involved 34 women scheduled for laparoscopic adnexal surgery. In each, a 10-mm radially expanding access device was inserted laterally on one side of the lower abdomen and a size-matched disposable cutting-tip trocar was placed on the other side, using random assignment. Postoperative pain for each studied wound and patient satisfaction toward the wounds were assessed using a visual analog scale. Any bleeding complication associated with insertion of the trocar was also recorded.

Results: The radially expanding access device was associated with significant reduction in severity (median 1.4 versus 5.0, P < .001) and duration (median 11 versus 21 days, P < .001) of postoperative wound pain, shorter wound scars (14 versus 17 mm, P < .001), a lower incidence of wound induration (0 versus 9, P < .01), and a higher patient satisfaction (median 9.7 versus 6.2, P < .001). There were four inferior epigastric artery injuries, all at the conventional trocar wound.

Conclusion: The radially expanding access device was associated with less postoperative wound pain and more patient satisfaction than the conventional cutting-tip trocar.

Laparoscopic surgery is associated with reduced postoperative pain, shorter hospital stays, and quicker return of patients to work compared with conventional open surgery. Those benefits are largely the result of the small abdominal wound size created by various sizes of trocars and cannulas. Most conventional cannulas rely on a sharp pyramidal blade to cut through layers of the abdominal wall, which can potentially cause bleeding from the anterior abdominal wall and increase the risk of postoperative incisional hernia. Modified blades, such as a tapered conical tip and a single linear blade, cannot prevent those complications.

A new radially expanding access device (STEP; Inner Dyne, Sunnyvale, CA) has been advocated to prevent trocar site injury, especially wound bleeding.^1,2 The device uses a Veress needle, 1.9 mm in diameter, mounted on a radially expandable sleeve that is dilated using a blunt dilator and cannula. The radially expanding access device was reported to be associated with less postoperative pain than a size-matched conventional trocar, but the degree of pain was not quantified.¹ We report a randomized, double-masked, self-controlled study to compare degree of postoperative wound pain and patient satisfaction associated with the radially expanding access device and conventional cutting-tip trocar.

	Materials and Methods

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Between September 1997 and March 1998, 34 women scheduled for laparoscopic surgery for adnexal masses in a university teaching hospital were recruited. Written consent was obtained from the women on the day before surgery, and the study was approved by the university Clinical Research Ethics Committee.

Procedures were done using general anesthesia and a standardized anesthetic regimen. Three portals of entry were used in all cases. The primary port was inserted subumbilically by a closed technique using a 10-mm reusable trocar. The radially expanding access device, which was dilated to accommodate a 10-mm cannula, was inserted on one side of the lower abdomen lateral to the inferior epigastric artery (expanding site). A size-matched disposable trocar with a linear cutting blade (Endopath; Ethicon Endosurgery, Cincinnati, OH) was inserted on the contralateral side (cutting site). The allocation of trocars was based on computer-generated random numbers that were put inside consecutively labeled, sealed, opaque envelopes. Numbers were disclosed at surgery.

Operative specimens were removed from the left-sided port where the principal surgeon stood, using a bag retrieval technique as described.³ At the end of the procedure, the fascia of the cutting site was closed using EndoClose (AutoSuture; United States Surgical Corporation, Norwalk, CT) and a no. O Vicryl suture (Ethicon, Somerville, NJ), whereas that of the expanding site was left unclosed. The skin was approximated using Steri-strips (3M HealthCare, St. Paul, MN). No local anesthetic agent was used to infiltrate the wound.

Standardized analgesia was prescribed on demand postoperatively. Any trocar site injury and postoperative wound complication was recorded. The degree of pain associated with each studied wound was assessed using a 10-cm visual analog scale 24 and 48 hours postoperatively by an assessor not involved in the surgery. Patients and assessors were masked to trocar assignments. Patients were followed up by a single author (PMY) 8 weeks postoperatively. Assessments were made without the author knowing which trocar was used on which side. The duration of pain in each wound after surgery was assessed, and if pain persisted, the degree of residual pain was assessed again using the visual analog scale. Length of wound scar, induration around the wound, and development of incisional hernia were noted. The patients’ satisfaction toward the healing of each wound and preference for the wound also were assessed using the visual analog scale. A telephone survey was conducted to assess evidence of symptomatic incisional hernia and wound satisfaction again 21–25 months after surgery.

In a preliminary study of ten cases, the pain score associated with the 10-mm conventional cutting tip trocar was 4.9 (standard deviation [SD] 2.0). Therefore, we based our study on 30 cases to detect a 30% difference in pain score with a power of 80% and type I error of 0.05. Statistical analysis was done with Wilcoxon signed-rank test for continuous variables and McNemar test for matched proprotions. Data were presented as median and interquartile range, and P < .05 was considered statistically significant.

	Results

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The median age of the women was 36 years (interquartile range 32–40 years), and body mass index (BMI) was 21.9 kg/m² (interquartile range 20.4–24.6 kg/m²). Allocation of trocars was equally distributed on both sides of the lower abdomen. Eighteen ovarian masses occurred on the right side, ten on the left side, and six were bilateral. The size of the adnexal masses ranged from 3–10 cm, with a median of 5 cm. Ovarian cystectomy was done in 23 women and oophorectomy or salpingo-oophorectomy in 11 women. Endometrioma was the most common disease (14 cases), followed by dermoid cyst (seven cases). Median anesthetic and operating times were 75 minutes (interquartile range 60–105 minutes) and 60 minutes (interquartile range 45–90 minutes), respectively. Inferior epigastric arteries were injured in four women, all on the conventional trocar side. The injuries were during trocar insertion in two cases and during insertion of EndoClose in the other two. Bleeding was controlled with diathermy alone in two cases, Foley catheter in one, and suture in the remaining one. There were no intra-abdominal visceral injuries.

In all cases, primary outcomes were consistently in favor of the radially expanding access device (Table 1). There were no wound infections or incisional hernias in any of the lower abdominal wounds. The median pain score was significantly lower in the expanding wound than the cutting wound at 24 hours (1.4, interquartile range 0.3–2.4, versus 5.0, interquartile range 4.5–6.8, P < .001) and 48 hours (0.5, interquartile range 0–1.0, versus 3.8, 1.8–5.1, P < .001) after the operation. The duration of pain associated with the expanding wound was also significantly shorter (11 days, interquartile range 3–14 days, versus 21 days, interquartile range 14–42 days, P < .001). At 8 weeks after surgery, wound pain was still present in 17 women in either wound (seven with pain in both wounds, and ten in the cutting wound only, P = .02). For those with residual wound pain, the median pain score was significantly lower in the expanding wound (0, interquartile range 0–0.5 versus 1.3, interquartile range 0.7–2.1, P < .01).

	Discussion

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This study found that there was significantly less postoperative wound pain with the radially expanding access device compared with conventional cutting-tip trocar. Wounds healed better with minimal scarring and better cosmetic results and were associated with higher patient satisfaction.

The device is inserted using a small needle that is expanded using a dilator. The specially designed sheath allows easy insertion of the expanding trocar. Resistance of insertion arises mainly from the skin wound, so the insertion can be facilitated by making the skin incision slightly larger than the tip of the dilator. Unlike with a conventional trocar, the wound is created by splitting the muscle fascia instead of cutting through the muscle layers, which reduces wound pain, risk of abdominal wall vessel injury, and wound bleeding. Hemorrhage from epigastric vessels is the most common complication of laparoscopy, and a third of them require laparotomies.⁴ The risk of inferior epigastric vessel injury during laparoscopy is reported to be 1.5%⁵ and is higher with lateral lower abdominal placement of the trocars and the use of cutting-tip trocars. During this study, we had an unusually high incidence of inferior epigastric artery injury. Over 5 years, involving more than 500 cases of laparoscopic ovarian surgery, our incidence of inferior epigastric artery injury was only 1%.⁶ Despite identifying the vessel laparoscopically, injury can still occur if the trocar is inserted obliquely rather than perpendicular to the abdominal wall. It is important to be aware that the vessel can also be lacerated during repair of the fascial defect, especially when a needling technique is used to close the defect, as in two of our cases.

The overall incidence of incisional hernia after laparoscopic surgery was reported to be 1%.⁷ The risk is estimated based on conventional trocars and is higher if the port is extraumbilical, when trocar size is greater than 10 mm, and if the fascia is left unclosed. It is generally recommended that the fascia be closed when a trocar larger than 10 mm is used.^8,9 However, whether that applies to the radially expanding access wound is not known. Tissue fibers in the fascia are arrayed in a criss-cross pattern, and because fascia defects of the expanding wound are created by stretching the fibers without cutting them, the fascia tends to close by itself and the actual defect is half that created by conventional trocars.² Therefore, we suggest that the fascia defect created by the radially expanding access device need not be closed.^1,2 In a recent observational report of 541 radially expanding access wounds in 212 women who had various laparoscopic procedures and were followed up for 44 months, there was no incisional hernia.¹⁰ Although the difference in postoperative wound pain and wound induration in our study might be attributed to the suture applied to the fascia of the conventional trocar wound, it indicates the true clinical scenario and what the patients actually experienced in day-to-day practice.

Unlike the conventional trocar, the radially expanding access device is held firmly in place by the stretched abdominal wall, and the cannula seldom slips.¹⁰ Although anchoring devices reduce the frequency of slippage of conventional trocars, they tend to enlarge the fascia defect further and increase the risk of subsequent incisional hernia.^7,8 Despite the smaller fascia defect, we did not encounter any problems removing specimens through the expanding wound.

	Footnotes

 
PII S0029-7844(00)01156-X

Received July 31, 2000. Received in revised form October 20, 2000. Accepted October 26, 2000.

	References

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1. Turner DJ. A new, radially expanding access system for laparoscopic procedures versus conventional cannulas. J Am Assoc Gynecol Laparosc 1996;3:609–15.[Medline]

2. Bhoyrul S, Mori T, Way LW. Radially expanding dilatation. A superior method of laparoscopic trocar access. Surg Endosc 1996; 10:775–8.[Medline]

3. Yuen PM, Rogers MS. Laparoscopic removal of ovarian cysts using a zipper storage bag. Acta Obstet Gynecol Scand 1994;73:829–31.[Medline]

4. Jansen FW, Kapiteyn K, Trimbos-Kemper T, Hermans J, Trimbos JB. Complications of laparoscopy: A prospective multicentre observational study. Br J Obstet Gynaecol 1997;104:595–600.[Medline]

5. Vasque JM, Demarque AM, Diamond MP. Vascular complications of laparoscopic surgery. J Am Assoc Gynecol Laparosc 1994;1: 163–7.[Medline]

6. Lok IH, Sahotoa DS, Rogers MS, Yuen PM. Complications of laparoscopic surgery for benign ovarian cysts: A review of 513 cases. J Am Assoc Gynecol Laparosc 2000;7:529–34.[Medline]

7. Lajer H, Widecrantz S, Heisterberg L. Hernias in trocar ports following abdominal laparoscopy. A review. Acta Obstet Gynecol Scand 1997;76:389–93.[Medline]

8. Kadar N, Reich H, Liu CY, Manko GF, Gimpelson R. Incisional hernias after major laparoscopic gynecologic procedures. Am J Obstet Gynecol 1993;168:1493–5.[Medline]

9. Boike GM, Miller CE, Spirtos NM, Mercer LJ, Fowler JM, Summitt R, et al. Incisional bowel herniations after operative laparoscopy: A series of nineteen cases and review of the literature. Am J Obstet Gynecol 1995;172:1726–33.[Medline]

10. Galen DI, Jacobson A, Weckstein LN, Kaplan RA, DeNevi KL. Reduction of cannula-related laparoscopic complications using a radially expanding access device. J Am Assoc Gynecol Laparosc 1999;6:79–84.[Medline]

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