A new approach to simplify surgical colpotomy in laparoscopic hysterectomy

Development and Validation of a Simulation Model for Laparoscopic Colpotomy

OBJECTIVE

To develop a realistic simulation model for performance of laparoscopic colpotomy and evaluate its construct and face validity.

METHODS

A simulation model was developed and constructed using polyvinyl chloride piping, a uterine manipulator, and synthetic vaginal tissue paired with a commercially available laparoscopic trainer. An observational study was conducted to validate the simulation model for use as a teaching tool. Construct validity was measured through performance evaluation of novice and expert surgeons using a standard and modified Global Operative Assessment of Laparoscopic Skills scale with possible score ranges of 5-25 and 5-40, respectively. Expert surgeons included attending surgeons across various gynecologic subspecialties who teach total laparoscopic hysterectomy to trainees and perform more than 50 total laparoscopic hysterectomies annually. Novice surgeons included residents who perform total laparoscopic hysterectomy as part of their training. Standards were set using a modified contrasting groups approach. Interrater reliability was calculated using Kendall's τ correlation coefficient. Participants were surveyed regarding the realism of the model and its utility as a teaching tool to assess face validity.

RESULTS

Five expert and 15 novice surgeons volunteered to participate. Expert surgeons scored higher than novice surgeons on the Global Operative Assessment of Laparoscopic Skills scale (22.8±1.52 vs 13.53±2.69, respectively) with a mean difference of 9.27 (95% CI 7.12-11.4, P<.01) and on a modified Global Operative Assessment of Laparoscopic Skills scale (36.9±2.19 vs 22.6±3.95, respectively) with a mean difference of 14.30 (95% CI 11.2-17.4, P<.01). Suggested passing range was set at 30.5-32.5 out of 40 total points. Kendall's τ interrater reliability was 0.86 (95% CI 0.798-0.923) and 0.87 (95% CI 0.818-0.922), respectively. All participants agreed that the training model was useful for teaching and learning laparoscopic colpotomy and for assessing the learner's ability to perform colpotomy before live surgery.

CONCLUSION

This validated simulation system offers novice surgeons an opportunity to practice the skill set necessary to perform laparoscopic colpotomy efficiently and may be used as an educational tool.

Human cadavers to evaluate prototypes of minimally invasive surgical instruments: A feasibility study

BACKGROUND

New technology should be extensively tested before it is tried on patients. Unfortunately representative models are lacking. In theory, fresh frozen human cadavers are excellent models.

OBJECTIVE

To identify strengths and weaknesses of fresh frozen human cadavers as research models for new technology prior to implementation in gynecological surgery.

METHODS

During pre-clinical validation studies regarding the MobiSep uterine manipulator, test procedures were performed on fresh frozen cadavers. Both the experimental setup as the performance of the prototype were assessed.

RESULTS

Five tests including six human cadavers were performed. Major changes were made to the MobiSep prototype design. The cadavers of two tests closely resembled surgical experiences as found in live patients. The anatomy of 4 of the 6 cadavers was not fully representative due to atrophy of the internal genitalia caused by age and due to the presence of pathology such extensive tumorous tissue.

CONCLUSION

The cadaver tests provided vital information regarding design and functionality, that failed to emerge during the in-vitro testing. However, experiments are subject to anatomical uncertainties or restrictions. Consequently, the suitability of a cadaver should be carefully assessed before it is used for testing new technology.

Comparing two Uterine Manipulators During Total Laparoscopic Hysterectomy: A Randomized Controlled Trial

STUDY OBJECTIVE

To compare 2 different types of uterine manipulators (i.e., tight fitting vs loose fitting) used for total laparoscopic hysterectomy (TLH).

DESIGN

A randomized controlled trial. The primary end points were time for colpotomy, time from skin incision to detachment of the uterus, and histologic assessment of thermal damage to the vagina (Canadian Task Force classification I).

SETTING

A university teaching hospital.

PATIENTS

All consecutive women scheduled for TLH from May 2014 to December 2015. Patients were excluded if pregnancy or malignancy was suspected or uterine size exceeded 20 weeks' gestation.

INTERVENTIONS

Patients were randomized to undergo TLH with 1 of the following uterine manipulators: (1) Colpo-Probe Vaginal Fornix Delineator (Cooper Surgical, Inc, Trumbull, CT) or (2) Hohl manipulator (KARL STORZ AG, Tuttlingen, Germany).

MEASUREMENTS AND MAIN RESULTS

A total of 91 patients, 49 in the Hohl manipulator group and 42 in the Colpo-Probe group, were included in the final analysis. There was no difference in patient characteristics, uterine weight, or estimated blood loss. The median time for insertion of the manipulator (2 minutes [interquartile range (IQR), 2-5 minutes] vs 6 minutes [IQR, 5-7], p < .001), the median time from skin incision to detachment of the uterus (55 minutes [IQR, 41-70] vs 65 minutes [IQR, 58-79], p = .004), and the median time for colpotomy (7 minutes [IQR, 5-10] vs 12 [IQR, 8-17], p < .001) were shorter with the Hohl manipulator. Thermal damage to the vagina varied greatly and ranged from 32 μm to 5232 μm but was not significantly different between groups (median maximum thermal damage = 1043 μm [IQR, 682-1934] vs 1522 μm [IQR, 884-2144], p = .211).

CONCLUSION

Use of the Hohl manipulator results in a shorter operative time from skin incision to detachment of the uterus during TLH. Although the colpotomy time is shorter using the Hohl manipulator, this did not translate to less thermal damage to the vaginal cuff. Further studies comparing uterine manipulators are warranted to find the optimal instrument for ease of surgery and decreased thermal spread.