Removal of the adnexal mass is one of the most commonly performed laparoscopic interventions.1,2 Laparoscopic adnexectomy is preferable to the open approach, resulting in reduced operative morbidity, decreased postoperative pain and analgesic requirements, and faster recovery.1,3,4 Because the robotic system (da Vinci surgical system, Intuitive Surgical, Inc., Sunnyvale, CA) affords technologic advancements over laparoscopy, we aimed to evaluate whether the application of robotic technology in the performance of adnexectomy resulted in benefits for the patient when compared with patients operated on by laparoscopy.
MATERIALS AND METHODS
All patients who underwent robotic and laparoscopic adnexectomy during the period of April 2003 to April 2008 at Mayo Clinic Arizona were evaluated retrospectively. Approval for the study was obtained from the Mayo Foundation Institutional Review Board. Data were abstracted from the robotic database and from patient records. Patients were stratified and compared by: age, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status classification, indications, unilateral compared with bilateral masses, tumor size and weight, and previous pelvic surgery.5 Body mass index was stratified as normal weight (less than 25), overweight (25–29) and obese (30 or more). Total operating time was defined from the beginning of skin incision to completion of skin closure. Adnexectomy is used to indicate salpingo-oophorectomy. In general, the laparoscopic approach was used when the robotic system was not available, although on occasion the patient or the surgeon indicated their preference for the robotic approach.
For the laparoscopic approach, four trocars were placed: a 12-mm umbilical trocar by the open technique, one bladeless Endopath Xcel 5-mm trocar (Ethicon Endo-Surgery, Guaynabo, PR) in each lower quadrant 10 cm lateral and 3 cm caudal to the umbilical trocar, and an Endopath Xcel 10-mm trocar (Ethicon Endo-Surgery) in the midline at the center of the pelvis.
For the robotic approach, four trocars were placed in the abdomen. A 12-mm umbilical trocar was introduced by the open technique, and two robotic trocars (8 mm each), inserted 10 cm to the right and left and at the same level of the umbilicus. A bladeless Endopath Xcel 10-mm trocar (Ethicon Endo-Surgery), used by the assistant, was placed 3 cm cranially and equidistant between the umbilical and the left robotic trocars. An EndoWrist PK Dissecting Forceps (Intuitive Surgical, Inc.) was used with the left robotic arm and, depending on the surgeon, an EndoWrist Permanent Cautery Spatula (Intuitive Surgical, Inc.) or EndoWrist Hot Shears Scissors (Intuitive Surgical, Inc.), but not both, with the right robotic arm.
The surgical technique for adnexectomy was similar for the robotic and laparoscopic approach. A peritoneal incision was initially performed at the level of the pelvic brim lateral and parallel to the infundibulopelvic ligament, to identify the ureter. Once identified, the infundibulopelvic ligament was isolated by creating a peritoneal window immediately below it and above the ureter. The infundibulopelvic ligament was sealed and transected with the Enseal tissue sealing device (SurgRx, Inc, Redwood City, CA) or the Valleylab LigaSure V vessel sealing instrument (Valleylab, Tyco Healthcare Group LP, Boulder, CO) (surgeon dependent) but not both. The lateral pelvic peritoneum was divided with monopolar current and the distal attachments transected with monopolar, Enseal or LigaSure. Endo Catch 10-mm bags (Tyco Healthcare, United States Surgical, Norwalk, CT) were used to remove the adnexa.
The umbilical fascia was closed in both techniques and subcuticular stitches were used to close the skin at all trocar sites. Blood loss was estimated by the difference in the total amounts of suctioned and irrigation fluids. Blood loss rate was defined as the milliliters of blood loss per minute of surgery. It was calculated by dividing the total amount of blood loss (in milliliters) by operating time (in minutes).
Univariate and multivariate analysis was used to determine factors favorable to each technique. For each continuously scaled measurement, comparisons between the groups were evaluated using the F test from a one-way analysis of variance model. Complication rates were compared between the groups using the Fisher exact test. All calculated P values were two-tailed, and P<.05 was considered significant.
A total of 176 consecutive patients underwent an adnexectomy, unilateral in 25 (14.2%) and bilateral in 151 (85.8%) at the Mayo Clinic Arizona. In 85 patients, it was performed with the da Vinci or da Vinci S system, whereas in 91 it was performed by laparoscopy. Indications for adnexectomy included the presence of an adnexal mass (97% and 90% for laparoscopy and robotics, respectively) and prophylactic oophorectomy (3% and 10% for laparoscopy and robotics, respectively).
Demographic data are depicted in Table 1. Statistically significant differences noted for the robotic group included a higher number of obese patients (BMI more than 30), ASA physical status classification of 2 or 3, and undergoing unilateral adnexectomy or concomitant appendectomy or both.
Perioperative data are shown in Table 2. The mean operating time was significantly longer, 12 minutes, for the robotic approach (P=.01). This difference also existed for patients with a BMI less than 30 (P=.04). However, among obese patients (BMI of 30 or more), there was no difference between the laparoscopic and robotic groups (P=.43). Upon removing the eight appendectomy patients of the robotic group, the mean±standard deviation total operating times for the robotic and laparoscopic groups were 81±29 minutes and 71±35 minutes, the difference still being statistically significant (P=.04). The mean blood loss was similar in the two groups. However, when correlated with BMI less than 30 or 30 or more, a significantly lower mean blood loss was noted only for robotic obese patients (BMI of 30 or more) (Table 2). No significant differences were noted between both groups relative to the number or type of intraoperative and postoperative complications (Table 3). Intraoperatively, one patient each in the laparoscopic and robotic groups experienced a recognized left ureteral injury corrected intraoperatively. Both had dense left adnexal adhesions to the lateral pelvic peritoneum and ureter. One patient experienced a rectotomy during a laparoscopic resection of an invasive endometriotic lesion of the anterior rectal wall and was included as a complication. No bladder, small bowel, or vascular complications were noted in either group. There were no conversions to laparotomy and no blood transfusions.
Postoperatively (6 weeks or less), no major complications occurred. Minor complications included umbilical infection, trocar site hematoma, urinary tract infection, and temporary paresthesias of the lower extremities (one patient in each group).
Laparoscopy remains the standard operative approach for adnexectomy in developed countries and offers patient advantages as compared with laparotomy.1–4,6–9 Laboratory drills comparing robotic compared with laparoscopic technology have shown faster performance times, increased accuracy, enhanced dexterity, faster suturing, and reduced number of errors with robotic technology.10 This study aimed to evaluate the differences in surgical outcomes between laparoscopic and robotic approaches in adnexectomy.
Shorter operating times have been reported for robotics as compared with laparoscopy for simple and radical hysterectomies.8,11 However, this advantage was not apparent in this retrospective review of robotic adnexectomy. Indeed, the mean operating time was 12 minutes longer for the robotic group, a statistically significant difference. This difference persisted for patients with BMI less than 30 but no difference was noted among obese patients (BMI of 30 or more) of the robotic and laparoscopic groups. In addition, because patient's BMI was found not to influence the operating time in our initial series of patients undergoing a robotic hysterectomy, it was likely not a major factor for the time difference.12 We have found that the lack of tactile feedback is a major advantage for the robotic surgeon operating on obese patients, because no resistance to the movement of the instruments against a thick abdominal wall is felt with robotics. Contributory factors to the longer operating time with robotics could be the additional time of docking and undocking the robotic arms, whether the operating surgeon was a staff member or trainee, and the longer laparoscopic experience of the surgeons as compared with robotics at the beginning of the series. We analyzed appendectomy as a potential factor, and the operating time difference remained after excluding the eight appendectomy patients in the analysis (P=.04). This is not unexpected considering the short operating time for robotic appendectomy.13 Although the robotic group had also a greater number of high risk (ASA physical status classification 2 and 3) and obese patients, no increased number of complications was observed among them.
In this study, the lack of availability of the robotic system resulted in a laparoscopic approach unless the patient or on occasion the surgeon indicated their preference for the robotic approach. We have learned that large adnexal masses are preferably approached by laparoscopy, because trocar placement is not restricted as in robotics, manipulation of large masses is easier, and intraoperative drainage of large benign cystic masses can be performed laparoscopically and not with robotic instruments.
In the presence of a malignant adnexal mass discovered at adnexectomy, a complete staging can be expeditiously performed with the addition of one to three trocars in laparoscopy. In robotics, five additional trocars, rotation of 180 degrees of the operating table, and undocking and redocking are necessary. In contrast to conventional laparoscopy, the present robotic system does not provide access to the upper abdomen without rotation of the operating table.
The limitations of this study include its retrospective nature with possible selection bias of the approach by patients or surgeons. Knowing its limitations, this study shows that there are no measurable differences between the two groups in terms of intraoperative or postoperative complications, blood loss, and hospital stay.
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