The new tissue containment system in our study had three unique advantages. First, a rigid pipe was used to reduce puncture leakage during penetration of the abdominal wall. Second, the trocar could be tightly connected to the pipe to form a sealed space for power morcellation. Third, hard pipes were more convenient than soft bags in regards to removal from the abdominal cavity without leakage.
The current investigation was a pilot study performed at an academic hospital laparoscopic skills laboratory. The study design used pork specimens and an enclosed laparoscopic trainer box to simulate laparoscopic power morcellation during hysterectomy or myomectomy. The trainer boxes were covered with a 2 cm thick silica gel to simulate the abdominal wall (Fig. 1). The pork specimens were cut to a weight of 400 g, placed in the tissue containment system, and dyed using 5 mL methylene blue solution (Fig. 1b). The dye was added to aid in the detection of leakage. Two different tissue containment systems were evaluated. The new tissue containment system included hard pipes that could be connected to detachable trocars and was considered the “experimental group” (Fig. 2). The second system was a poly urethane bag, 12 mm sheath for its introduction into the peritoneal cavity, and an 11 mm optic sleeve and was considered the “control group” (Fig. 3). Thirty trials were performed using each of the two tissue containment systems with a multi-port approach. All physicians who participated in the study were gynecologic surgeons experienced at performing minimally invasive surgeries. Individual surgeons were randomly assigned to the experimental or control groups and all trials were monitored by a senior surgeon.
When using the experimental device, the tissue containment system was inserted into the abdominal cavity of the training box via the right lateral access with the aid of a 15 mm introduction sheath. Once the specimen was positioned in the tissue containment system, the two hard pipes were passed out through the umbilical and the left accesses, respectively, and connected to the trocar. The trocar inlet hole was used to inflate the bag. To assist with morcellation, a monitoring mirror was placed through the umbilical trocar and a forceps was placed on the left trocar. The right opening of the bag was used for access of the morcellator. The specimen was entirety morcellated under monitoring (Fig. 2b). Upon completion of the morcellation, the monitoring mirror and forceps were removed after deflation of the bag and the two hard pipes were covered with caps. Finally, the tissue containment system was removed via the right lateral access of the trainer box.
In the control group, the bag was inserted into the abdominal cavity of the training box via the lateral access with the help of a 10 mm introduction sheath. The specimen was then positioned into the bag via its large opening. Once the specimen was positioned in the bag, both openings of the bag needed to be exteriorized for optic and morcellator access. The optical trocar was then removed and re-inserted into the bag via the tubular bag opening through the umbilical access. A pseudo-pneumoperitoneum was established by inflating the bag via the umbilical trocar. After completing the morcellation, the optics were withdrawn from the bag. The everted tubular portion of the bag at the umbilical site was closed with two knots. Finally, the entire bag was removed by manually pulling it through the lateral side.
After removal of the tissue containment systems, the trainer boxes were examined for the presence of any dye (Fig. 4). The systems were then filled with 1000 mL saline to confirm the absence of damage (Fig. 5). Finally, each sheath was washed with cell culture solution and the solution evaluated for cytologic evidence to identify whether there were any muscle fragments present. The cytologic findings were obtained using an Auto Cycle Prep 2002 instrument (Becton, Dickinson and Company). Any positive cytologic results were considered to have resulted from leakage during the laparoscopic procedure.
The primary outcomes were (i) leakage rates, (ii) bag introduction time (time from bag insertion to start of abdominal insufflation and morcellation), (iii) bag removal time (time to remove the bag from the body and resume intraperitoneal observation), and (iv) in-bag morcellation time. Statistical analyses were performed using GraphPad software and included descriptive calculations of the mean and standard deviation (SD), 95% confidence interval (CI), median, and minimum-to-maximum range. Unrelated continuous data from the two study groups were compared using an unpaired t-test at a significance level of p ≤ 0.05. Categorical data were compared in a contingency table and analyzed using Fisher’s exact test for significance at a level of p ≤ 0.05.