The Fresh Frozen Cadaveric Study of Direct Pouch of Douglas Laparoscopic and Robotic Trocar Insertion for Vaginal Natural Orifice Transluminal Endoscopic Surgery

Abstract

Study objective: To determine the distances and angles that assure a safe entry into the pouch of Douglas (POD) during blind laparoscopic and robotic trocar entry.

Design: Trocars were inserted into the POD of 4 intact fresh frozen female pelves. Cadaveric dissection was performed, and the distance from the POD to the sacrum at rest and with maximal pressure to POD with the trocar was measured. In addition, the optimal angle for trocar insertion and entry was evaluated.

Setting: Inova Advanced Simulation and Technology Evaluation Center.

Patients: Fresh frozen cadavers with intact reproductive organs.

Interventions: Vaginal POD trocar insertion.

Measurements and main results: Measurements were recorded from the sacrum to the POD at rest and from the sacrum to the hymen with trocar pressure. The dissection demonstrated correct trocar placement in the POD of human cadaveric specimens. The mean distances from the sacrum to the hymen, the sacrum to the POD, and the sacrum to the POD with pressure were 18.75 cm, 9.75 cm, and 7.25 cm, respectively. After the deployment of the trocar, the tip was observed to be 2 cm below the cervix in the POD. The mean trocar angle to clear the sacral promontory and the neurovascular structures without injury to the uterus was 25° to 40° from the horizontal plane and 15° to 30° from the coronal plane.

Conclusion: A direct trocar entry into the POD has been found to be feasible in fresh frozen cadaveric specimens. This study provided valuable information for the angle of entry into the POD to facilitate vaginal and robotic trocar entry for minimally invasive gynecologic procedures.

Keywords: Pouch of Douglas; Robotic trocar; Trocar; vNOTES.